1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ E L A B -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1997-2018, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Atree; use Atree; 27with Checks; use Checks; 28with Debug; use Debug; 29with Einfo; use Einfo; 30with Elists; use Elists; 31with Errout; use Errout; 32with Exp_Ch11; use Exp_Ch11; 33with Exp_Tss; use Exp_Tss; 34with Exp_Util; use Exp_Util; 35with Expander; use Expander; 36with Lib; use Lib; 37with Lib.Load; use Lib.Load; 38with Namet; use Namet; 39with Nlists; use Nlists; 40with Nmake; use Nmake; 41with Opt; use Opt; 42with Output; use Output; 43with Restrict; use Restrict; 44with Rident; use Rident; 45with Rtsfind; use Rtsfind; 46with Sem; use Sem; 47with Sem_Aux; use Sem_Aux; 48with Sem_Cat; use Sem_Cat; 49with Sem_Ch7; use Sem_Ch7; 50with Sem_Ch8; use Sem_Ch8; 51with Sem_Prag; use Sem_Prag; 52with Sem_Util; use Sem_Util; 53with Sinfo; use Sinfo; 54with Sinput; use Sinput; 55with Snames; use Snames; 56with Stand; use Stand; 57with Table; 58with Tbuild; use Tbuild; 59with Uintp; use Uintp; 60with Uname; use Uname; 61 62with GNAT.HTable; use GNAT.HTable; 63 64package body Sem_Elab is 65 66 ----------------------------------------- 67 -- Access-before-elaboration mechanism -- 68 ----------------------------------------- 69 70 -- The access-before-elaboration (ABE) mechanism implemented in this unit 71 -- has the following objectives: 72 -- 73 -- * Diagnose at compile-time or install run-time checks to prevent ABE 74 -- access to data and behaviour. 75 -- 76 -- The high-level idea is to accurately diagnose ABE issues within a 77 -- single unit because the ABE mechanism can inspect the whole unit. 78 -- As soon as the elaboration graph extends to an external unit, the 79 -- diagnostics stop because the body of the unit may not be available. 80 -- Due to control and data flow, the ABE mechanism cannot accurately 81 -- determine whether a particular scenario will be elaborated or not. 82 -- Conditional ABE checks are therefore used to verify the elaboration 83 -- status of a local and external target at run time. 84 -- 85 -- * Supply elaboration dependencies for a unit to binde 86 -- 87 -- The ABE mechanism registers each outgoing elaboration edge for the 88 -- main unit in its ALI file. GNATbind and binde can then reconstruct 89 -- the full elaboration graph and determine the proper elaboration 90 -- order for all units in the compilation. 91 -- 92 -- The ABE mechanism supports three models of elaboration: 93 -- 94 -- * Dynamic model - This is the most permissive of the three models. 95 -- When the dynamic model is in effect, the mechanism performs very 96 -- little diagnostics and generates run-time checks to detect ABE 97 -- issues. The behaviour of this model is identical to that specified 98 -- by the Ada RM. This model is enabled with switch -gnatE. 99 -- 100 -- * Static model - This is the middle ground of the three models. When 101 -- the static model is in effect, the mechanism diagnoses and installs 102 -- run-time checks to detect ABE issues in the main unit. In addition, 103 -- the mechanism generates implicit Elaborate or Elaborate_All pragmas 104 -- to ensure the prior elaboration of withed units. The model employs 105 -- textual order, with clause context, and elaboration-related source 106 -- pragmas. This is the default model. 107 -- 108 -- * SPARK model - This is the most conservative of the three models and 109 -- impelements the semantics defined in SPARK RM 7.7. The SPARK model 110 -- is in effect only when a context resides in a SPARK_Mode On region, 111 -- otherwise the mechanism falls back to one of the previous models. 112 -- 113 -- The ABE mechanism consists of a "recording" phase and a "processing" 114 -- phase. 115 116 ----------------- 117 -- Terminology -- 118 ----------------- 119 120 -- * ABE - An attempt to activate, call, or instantiate a scenario which 121 -- has not been fully elaborated. 122 -- 123 -- * Bridge target - A type of target. A bridge target is a link between 124 -- scenarios. It is usually a byproduct of expansion and does not have 125 -- any direct ABE ramifications. 126 -- 127 -- * Call marker - A special node used to indicate the presence of a call 128 -- in the tree in case expansion transforms or eliminates the original 129 -- call. N_Call_Marker nodes do not have static and run-time semantics. 130 -- 131 -- * Conditional ABE - A type of ABE. A conditional ABE occurs when the 132 -- elaboration or invocation of a target by a scenario within the main 133 -- unit causes an ABE, but does not cause an ABE for another scenarios 134 -- within the main unit. 135 -- 136 -- * Declaration level - A type of enclosing level. A scenario or target is 137 -- at the declaration level when it appears within the declarations of a 138 -- block statement, entry body, subprogram body, or task body, ignoring 139 -- enclosing packages. 140 -- 141 -- * Early call region - A section of code which ends at a subprogram body 142 -- and starts from the nearest non-preelaborable construct which precedes 143 -- the subprogram body. The early call region extends from a package body 144 -- to a package spec when the spec carries pragma Elaborate_Body. 145 -- 146 -- * Generic library level - A type of enclosing level. A scenario or 147 -- target is at the generic library level if it appears in a generic 148 -- package library unit, ignoring enclosing packages. 149 -- 150 -- * Guaranteed ABE - A type of ABE. A guaranteed ABE occurs when the 151 -- elaboration or invocation of a target by all scenarios within the 152 -- main unit causes an ABE. 153 -- 154 -- * Instantiation library level - A type of enclosing level. A scenario 155 -- or target is at the instantiation library level if it appears in an 156 -- instantiation library unit, ignoring enclosing packages. 157 -- 158 -- * Library level - A type of enclosing level. A scenario or target is at 159 -- the library level if it appears in a package library unit, ignoring 160 -- enclosng packages. 161 -- 162 -- * Non-library-level encapsulator - A construct that cannot be elaborated 163 -- on its own and requires elaboration by a top-level scenario. 164 -- 165 -- * Scenario - A construct or context which may be elaborated or executed 166 -- by elaboration code. The scenarios recognized by the ABE mechanism are 167 -- as follows: 168 -- 169 -- - '[Unrestricted_]Access of entries, operators, and subprograms 170 -- 171 -- - Assignments to variables 172 -- 173 -- - Calls to entries, operators, and subprograms 174 -- 175 -- - Derived type declarations 176 -- 177 -- - Instantiations 178 -- 179 -- - Pragma Refined_State 180 -- 181 -- - Reads of variables 182 -- 183 -- - Task activation 184 -- 185 -- * Target - A construct referenced by a scenario. The targets recognized 186 -- by the ABE mechanism are as follows: 187 -- 188 -- - For '[Unrestricted_]Access of entries, operators, and subprograms, 189 -- the target is the entry, operator, or subprogram. 190 -- 191 -- - For assignments to variables, the target is the variable 192 -- 193 -- - For calls, the target is the entry, operator, or subprogram 194 -- 195 -- - For derived type declarations, the target is the derived type 196 -- 197 -- - For instantiations, the target is the generic template 198 -- 199 -- - For pragma Refined_State, the targets are the constituents 200 -- 201 -- - For reads of variables, the target is the variable 202 -- 203 -- - For task activation, the target is the task body 204 -- 205 -- * Top-level scenario - A scenario which appears in a non-generic main 206 -- unit. Depending on the elaboration model is in effect, the following 207 -- addotional restrictions apply: 208 -- 209 -- - Dynamic model - No restrictions 210 -- 211 -- - SPARK model - Falls back to either the dynamic or static model 212 -- 213 -- - Static model - The scenario must be at the library level 214 215 --------------------- 216 -- Recording phase -- 217 --------------------- 218 219 -- The Recording phase coincides with the analysis/resolution phase of the 220 -- compiler. It has the following objectives: 221 -- 222 -- * Record all top-level scenarios for examination by the Processing 223 -- phase. 224 -- 225 -- Saving only a certain number of nodes improves the performance of 226 -- the ABE mechanism. This eliminates the need to examine the whole 227 -- tree in a separate pass. 228 -- 229 -- * Record certain SPARK scenarios which are not necessarily executable 230 -- during elaboration, but still require elaboration-related checks. 231 -- 232 -- Saving only a certain number of nodes improves the performance of 233 -- the ABE mechanism. This eliminates the need to examine the whole 234 -- tree in a separate pass. 235 -- 236 -- * Detect and diagnose calls in preelaborable or pure units, including 237 -- generic bodies. 238 -- 239 -- This diagnostic is carried out during the Recording phase because it 240 -- does not need the heavy recursive traversal done by the Processing 241 -- phase. 242 -- 243 -- * Detect and diagnose guaranteed ABEs caused by instantiations, 244 -- calls, and task activation. 245 -- 246 -- The issues detected by the ABE mechanism are reported as warnings 247 -- because they do not violate Ada semantics. Forward instantiations 248 -- may thus reach gigi, however gigi cannot handle certain kinds of 249 -- premature instantiations and may crash. To avoid this limitation, 250 -- the ABE mechanism must identify forward instantiations as early as 251 -- possible and suppress their bodies. Calls and task activations are 252 -- included in this category for completeness. 253 254 ---------------------- 255 -- Processing phase -- 256 ---------------------- 257 258 -- The Processing phase is a separate pass which starts after instantiating 259 -- and/or inlining of bodies, but before the removal of Ghost code. It has 260 -- the following objectives: 261 -- 262 -- * Examine all top-level scenarios saved during the Recording phase 263 -- 264 -- The top-level scenarios act as roots for depth-first traversal of 265 -- the call/instantiation/task activation graph. The traversal stops 266 -- when an outgoing edge leaves the main unit. 267 -- 268 -- * Examine all SPARK scenarios saved during the Recording phase 269 -- 270 -- * Depending on the elaboration model in effect, perform the following 271 -- actions: 272 -- 273 -- - Dynamic model - Install run-time conditional ABE checks. 274 -- 275 -- - SPARK model - Enforce the SPARK elaboration rules 276 -- 277 -- - Static model - Diagnose conditional ABEs, install run-time 278 -- conditional ABE checks, and guarantee the elaboration of 279 -- external units. 280 -- 281 -- * Examine nested scenarios 282 -- 283 -- Nested scenarios discovered during the depth-first traversal are 284 -- in turn subjected to the same actions outlined above and examined 285 -- for the next level of nested scenarios. 286 287 ------------------ 288 -- Architecture -- 289 ------------------ 290 291 -- Analysis/Resolution 292 -- | 293 -- +- Build_Call_Marker 294 -- | 295 -- +- Build_Variable_Reference_Marker 296 -- | 297 -- +- | -------------------- Recording phase ---------------------------+ 298 -- | v | 299 -- | Record_Elaboration_Scenario | 300 -- | | | 301 -- | +--> Check_Preelaborated_Call | 302 -- | | | 303 -- | +--> Process_Guaranteed_ABE | 304 -- | | | | 305 -- | | +--> Process_Guaranteed_ABE_Activation | 306 -- | | | | 307 -- | | +--> Process_Guaranteed_ABE_Call | 308 -- | | | | 309 -- | | +--> Process_Guaranteed_ABE_Instantiation | 310 -- | | | 311 -- +- | ----------------------------------------------------------------+ 312 -- | 313 -- | 314 -- +--> SPARK_Scenarios 315 -- | +-----------+-----------+ .. +-----------+ 316 -- | | Scenario1 | Scenario2 | .. | ScenarioN | 317 -- | +-----------+-----------+ .. +-----------+ 318 -- | 319 -- +--> Top_Level_Scenarios 320 -- | +-----------+-----------+ .. +-----------+ 321 -- | | Scenario1 | Scenario2 | .. | ScenarioN | 322 -- | +-----------+-----------+ .. +-----------+ 323 -- | 324 -- End of Compilation 325 -- | 326 -- +- | --------------------- Processing phase -------------------------+ 327 -- | v | 328 -- | Check_Elaboration_Scenarios | 329 -- | | | 330 -- | +--> Check_SPARK_Scenario | 331 -- | | | | 332 -- | | +--> Check_SPARK_Derived_Type | 333 -- | | | | 334 -- | | +--> Check_SPARK_Instantiation | 335 -- | | | | 336 -- | | +--> Check_SPARK_Refined_State_Pragma | 337 -- | | | 338 -- | +--> Process_Conditional_ABE <---------------------------+ | 339 -- | | | | 340 -- | +--> Process_Conditional_ABE_Access Is_Suitable_Scenario | 341 -- | | ^ | 342 -- | +--> Process_Conditional_ABE_Activation | | 343 -- | | | | | 344 -- | | +-----------------------------+ | | 345 -- | | | | | 346 -- | +--> Process_Conditional_ABE_Call +--------> Traverse_Body | 347 -- | | | | | 348 -- | | +-----------------------------+ | 349 -- | | | 350 -- | +--> Process_Conditional_ABE_Instantiation | 351 -- | | | 352 -- | +--> Process_Conditional_ABE_Variable_Assignment | 353 -- | | | 354 -- | +--> Process_Conditional_ABE_Variable_Reference | 355 -- | | 356 -- +--------------------------------------------------------------------+ 357 358 ---------------------- 359 -- Important points -- 360 ---------------------- 361 362 -- The Processing phase starts after the analysis, resolution, expansion 363 -- phase has completed. As a result, no current semantic information is 364 -- available. The scope stack is empty, global flags such as In_Instance 365 -- or Inside_A_Generic become useless. To remedy this, the ABE mechanism 366 -- must either save or recompute semantic information. 367 368 -- Expansion heavily transforms calls and to some extent instantiations. To 369 -- remedy this, the ABE mechanism generates N_Call_Marker nodes in order to 370 -- capture the target and relevant attributes of the original call. 371 372 -- The diagnostics of the ABE mechanism depend on accurate source locations 373 -- to determine the spacial relation of nodes. 374 375 -------------- 376 -- Switches -- 377 -------------- 378 379 -- The following switches may be used to control the behavior of the ABE 380 -- mechanism. 381 -- 382 -- -gnatd_a stop elaboration checks on accept or select statement 383 -- 384 -- The ABE mechanism stops the traversal of a task body when it 385 -- encounters an accept or a select statement. This behavior is 386 -- equivalent to restriction No_Entry_Calls_In_Elaboration_Code, 387 -- but without penalizing actual entry calls during elaboration. 388 -- 389 -- -gnatd_e ignore entry calls and requeue statements for elaboration 390 -- 391 -- The ABE mechanism does not generate N_Call_Marker nodes for 392 -- protected or task entry calls as well as requeue statements. 393 -- As a result, the calls and requeues are not recorded or 394 -- processed. 395 -- 396 -- -gnatdE elaboration checks on predefined units 397 -- 398 -- The ABE mechanism considers scenarios which appear in internal 399 -- units (Ada, GNAT, Interfaces, System). 400 -- 401 -- -gnatd.G ignore calls through generic formal parameters for elaboration 402 -- 403 -- The ABE mechanism does not generate N_Call_Marker nodes for 404 -- calls which occur in expanded instances, and invoke generic 405 -- actual subprograms through generic formal subprograms. As a 406 -- result, the calls are not recorded or processed. 407 -- 408 -- -gnatd_i ignore activations and calls to instances for elaboration 409 -- 410 -- The ABE mechanism ignores calls and task activations when they 411 -- target a subprogram or task type defined an external instance. 412 -- As a result, the calls and task activations are not processed. 413 -- 414 -- -gnatdL ignore external calls from instances for elaboration 415 -- 416 -- The ABE mechanism does not generate N_Call_Marker nodes for 417 -- calls which occur in expanded instances, do not invoke generic 418 -- actual subprograms through formal subprograms, and the target 419 -- is external to the instance. As a result, the calls are not 420 -- recorded or processed. 421 -- 422 -- -gnatd.o conservative elaboration order for indirect calls 423 -- 424 -- The ABE mechanism treats '[Unrestricted_]Access of an entry, 425 -- operator, or subprogram as an immediate invocation of the 426 -- target. As a result, it performs ABE checks and diagnostics on 427 -- the immediate call. 428 -- 429 -- -gnatd_p ignore assertion pragmas for elaboration 430 -- 431 -- The ABE mechanism does not generate N_Call_Marker nodes for 432 -- calls to subprograms which verify the run-time semantics of 433 -- the following assertion pragmas: 434 -- 435 -- Default_Initial_Condition 436 -- Initial_Condition 437 -- Invariant 438 -- Invariant'Class 439 -- Post 440 -- Post'Class 441 -- Postcondition 442 -- Type_Invariant 443 -- Type_Invariant_Class 444 -- 445 -- As a result, the assertion expressions of the pragmas are not 446 -- processed. 447 -- 448 -- -gnatd.U ignore indirect calls for static elaboration 449 -- 450 -- The ABE mechanism does not consider '[Unrestricted_]Access of 451 -- entries, operators, and subprograms. As a result, the scenarios 452 -- are not recorder or processed. 453 -- 454 -- -gnatd.v enforce SPARK elaboration rules in SPARK code 455 -- 456 -- The ABE mechanism applies some of the SPARK elaboration rules 457 -- defined in the SPARK reference manual, chapter 7.7. Note that 458 -- certain rules are always enforced, regardless of whether the 459 -- switch is active. 460 -- 461 -- -gnatd.y disable implicit pragma Elaborate_All on task bodies 462 -- 463 -- The ABE mechanism does not generate implicit Elaborate_All when 464 -- the need for the pragma came from a task body. 465 -- 466 -- -gnatE dynamic elaboration checking mode enabled 467 -- 468 -- The ABE mechanism assumes that any scenario is elaborated or 469 -- invoked by elaboration code. The ABE mechanism performs very 470 -- little diagnostics and generates condintional ABE checks to 471 -- detect ABE issues at run-time. 472 -- 473 -- -gnatel turn on info messages on generated Elaborate[_All] pragmas 474 -- 475 -- The ABE mechanism produces information messages on generated 476 -- implicit Elabote[_All] pragmas along with traceback showing 477 -- why the pragma was generated. In addition, the ABE mechanism 478 -- produces information messages for each scenario elaborated or 479 -- invoked by elaboration code. 480 -- 481 -- -gnateL turn off info messages on generated Elaborate[_All] pragmas 482 -- 483 -- The complementary switch for -gnatel. 484 -- 485 -- -gnatH legacy elaboration checking mode enabled 486 -- 487 -- When this switch is in effect, the pre-18.x ABE model becomes 488 -- the defacto ABE model. This ammounts to cutting off all entry 489 -- points into the new ABE mechanism, and giving full control to 490 -- the old ABE mechanism. 491 -- 492 -- -gnatJ permissive elaboration checking mode enabled 493 -- 494 -- This switch activates the following switches: 495 -- 496 -- -gnatd_a 497 -- -gnatd_e 498 -- -gnatd.G 499 -- -gnatd_i 500 -- -gnatdL 501 -- -gnatd_p 502 -- -gnatd.U 503 -- -gnatd.y 504 -- 505 -- IMPORTANT: The behavior of the ABE mechanism becomes more 506 -- permissive at the cost of accurate diagnostics and runtime 507 -- ABE checks. 508 -- 509 -- -gnatw.f turn on warnings for suspicious Subp'Access 510 -- 511 -- The ABE mechanism treats '[Unrestricted_]Access of an entry, 512 -- operator, or subprogram as a pseudo invocation of the target. 513 -- As a result, it performs ABE diagnostics on the pseudo call. 514 -- 515 -- -gnatw.F turn off warnings for suspicious Subp'Access 516 -- 517 -- The complementary switch for -gnatw.f. 518 -- 519 -- -gnatwl turn on warnings for elaboration problems 520 -- 521 -- The ABE mechanism produces warnings on detected ABEs along with 522 -- a traceback showing the graph of the ABE. 523 -- 524 -- -gnatwL turn off warnings for elaboration problems 525 -- 526 -- The complementary switch for -gnatwl. 527 528 --------------------------- 529 -- Adding a new scenario -- 530 --------------------------- 531 532 -- The following steps describe how to add a new elaboration scenario and 533 -- preserve the existing architecture. Note that not all of the steps may 534 -- need to be carried out. 535 -- 536 -- 1) Update predicate Is_Scenario 537 -- 538 -- 2) Add predicate Is_Suitable_xxx. Include a call to it in predicate 539 -- Is_Suitable_Scenario. 540 -- 541 -- 3) Update routine Record_Elaboration_Scenario 542 -- 543 -- 4) Add routine Process_Conditional_ABE_xxx. Include a call to it in 544 -- routine Process_Conditional_ABE. 545 -- 546 -- 5) Add routine Process_Guaranteed_ABE_xxx. Include a call to it in 547 -- routine Process_Guaranteed_ABE. 548 -- 549 -- 6) Add routine Check_SPARK_xxx. Include a call to it in routine 550 -- Check_SPARK_Scenario. 551 -- 552 -- 7) Add routine Info_xxx. Include a call to it in routine 553 -- Process_Conditional_ABE_xxx. 554 -- 555 -- 8) Add routine Output_xxx. Include a call to it in routine 556 -- Output_Active_Scenarios. 557 -- 558 -- 9) Add routine Extract_xxx_Attributes 559 -- 560 -- 10) Update routine Is_Potential_Scenario 561 562 ------------------------- 563 -- Adding a new target -- 564 ------------------------- 565 566 -- The following steps describe how to add a new elaboration target and 567 -- preserve the existing architecture. Note that not all of the steps may 568 -- need to be carried out. 569 -- 570 -- 1) Add predicate Is_xxx. 571 -- 572 -- 2) Update the following predicates 573 -- 574 -- Is_Ada_Semantic_Target 575 -- Is_Assertion_Pragma_Target 576 -- Is_Bridge_Target 577 -- Is_SPARK_Semantic_Target 578 -- 579 -- If necessary, create a new category. 580 -- 581 -- 3) Update the appropriate Info_xxx routine. 582 -- 583 -- 4) Update the appropriate Output_xxx routine. 584 -- 585 -- 5) Update routine Extract_Target_Attributes. If necessary, create a 586 -- new Extract_xxx routine. 587 588 -------------------------- 589 -- Debugging ABE issues -- 590 -------------------------- 591 592 -- * If the issue involves a call, ensure that the call is eligible for ABE 593 -- processing and receives a corresponding call marker. The routines of 594 -- interest are 595 -- 596 -- Build_Call_Marker 597 -- Record_Elaboration_Scenario 598 599 -- * If the issue involves an arbitrary scenario, ensure that the scenario 600 -- is either recorded, or is successfully recognized while traversing a 601 -- body. The routines of interest are 602 -- 603 -- Record_Elaboration_Scenario 604 -- Process_Conditional_ABE 605 -- Process_Guaranteed_ABE 606 -- Traverse_Body 607 608 -- * If the issue involves a circularity in the elaboration order, examine 609 -- the ALI files and look for the following encodings next to units: 610 -- 611 -- E indicates a source Elaborate 612 -- 613 -- EA indicates a source Elaborate_All 614 -- 615 -- AD indicates an implicit Elaborate_All 616 -- 617 -- ED indicates an implicit Elaborate 618 -- 619 -- If possible, compare these encodings with those generated by the old 620 -- ABE mechanism. The routines of interest are 621 -- 622 -- Ensure_Prior_Elaboration 623 624 ---------------- 625 -- Attributes -- 626 ---------------- 627 628 -- To minimize the amount of code within routines, the ABE mechanism relies 629 -- on "attribute" records to capture relevant information for a scenario or 630 -- a target. 631 632 -- The following type captures relevant attributes which pertain to a call 633 634 type Call_Attributes is record 635 Elab_Checks_OK : Boolean; 636 -- This flag is set when the call has elaboration checks enabled 637 638 Elab_Warnings_OK : Boolean; 639 -- This flag is set when the call has elaboration warnings elabled 640 641 From_Source : Boolean; 642 -- This flag is set when the call comes from source 643 644 Ghost_Mode_Ignore : Boolean; 645 -- This flag is set when the call appears in a region subject to pragma 646 -- Ghost with policy Ignore. 647 648 In_Declarations : Boolean; 649 -- This flag is set when the call appears at the declaration level 650 651 Is_Dispatching : Boolean; 652 -- This flag is set when the call is dispatching 653 654 SPARK_Mode_On : Boolean; 655 -- This flag is set when the call appears in a region subject to pragma 656 -- SPARK_Mode with value On. 657 end record; 658 659 -- The following type captures relevant attributes which pertain to the 660 -- prior elaboration of a unit. This type is coupled together with a unit 661 -- to form a key -> value relationship. 662 663 type Elaboration_Attributes is record 664 Source_Pragma : Node_Id; 665 -- This attribute denotes a source Elaborate or Elaborate_All pragma 666 -- which guarantees the prior elaboration of some unit with respect 667 -- to the main unit. The pragma may come from the following contexts: 668 669 -- * The main unit 670 -- * The spec of the main unit (if applicable) 671 -- * Any parent spec of the main unit (if applicable) 672 -- * Any parent subunit of the main unit (if applicable) 673 674 -- The attribute remains Empty if no such pragma is available. Source 675 -- pragmas play a role in satisfying SPARK elaboration requirements. 676 677 With_Clause : Node_Id; 678 -- This attribute denotes an internally generated or source with clause 679 -- for some unit withed by the main unit. With clauses carry flags which 680 -- represent implicit Elaborate or Elaborate_All pragmas. These clauses 681 -- play a role in supplying the elaboration dependencies to binde. 682 end record; 683 684 No_Elaboration_Attributes : constant Elaboration_Attributes := 685 (Source_Pragma => Empty, 686 With_Clause => Empty); 687 688 -- The following type captures relevant attributes which pertain to an 689 -- instantiation. 690 691 type Instantiation_Attributes is record 692 Elab_Checks_OK : Boolean; 693 -- This flag is set when the instantiation has elaboration checks 694 -- enabled. 695 696 Elab_Warnings_OK : Boolean; 697 -- This flag is set when the instantiation has elaboration warnings 698 -- enabled. 699 700 Ghost_Mode_Ignore : Boolean; 701 -- This flag is set when the instantiation appears in a region subject 702 -- to pragma Ghost with policy ignore, or starts one such region. 703 704 In_Declarations : Boolean; 705 -- This flag is set when the instantiation appears at the declaration 706 -- level. 707 708 SPARK_Mode_On : Boolean; 709 -- This flag is set when the instantiation appears in a region subject 710 -- to pragma SPARK_Mode with value On, or starts one such region. 711 end record; 712 713 -- The following type captures relevant attributes which pertain to the 714 -- state of the Processing phase. 715 716 type Processing_Attributes is record 717 Suppress_Implicit_Pragmas : Boolean; 718 -- This flag is set when the Processing phase must not generate any 719 -- implicit Elaborate[_All] pragmas. 720 721 Within_Initial_Condition : Boolean; 722 -- This flag is set when the Processing phase is currently examining a 723 -- scenario which was reached from an initial condition procedure. 724 725 Within_Instance : Boolean; 726 -- This flag is set when the Processing phase is currently examining a 727 -- scenario which was reached from a scenario defined in an instance. 728 729 Within_Partial_Finalization : Boolean; 730 -- This flag is set when the Processing phase is currently examining a 731 -- scenario which was reached from a partial finalization procedure. 732 733 Within_Task_Body : Boolean; 734 -- This flag is set when the Processing phase is currently examining a 735 -- scenario which was reached from a task body. 736 end record; 737 738 Initial_State : constant Processing_Attributes := 739 (Suppress_Implicit_Pragmas => False, 740 Within_Initial_Condition => False, 741 Within_Instance => False, 742 Within_Partial_Finalization => False, 743 Within_Task_Body => False); 744 745 -- The following type captures relevant attributes which pertain to a 746 -- target. 747 748 type Target_Attributes is record 749 Elab_Checks_OK : Boolean; 750 -- This flag is set when the target has elaboration checks enabled 751 752 From_Source : Boolean; 753 -- This flag is set when the target comes from source 754 755 Ghost_Mode_Ignore : Boolean; 756 -- This flag is set when the target appears in a region subject to 757 -- pragma Ghost with policy ignore, or starts one such region. 758 759 SPARK_Mode_On : Boolean; 760 -- This flag is set when the target appears in a region subject to 761 -- pragma SPARK_Mode with value On, or starts one such region. 762 763 Spec_Decl : Node_Id; 764 -- This attribute denotes the declaration of Spec_Id 765 766 Unit_Id : Entity_Id; 767 -- This attribute denotes the top unit where Spec_Id resides 768 769 -- The semantics of the following attributes depend on the target 770 771 Body_Barf : Node_Id; 772 Body_Decl : Node_Id; 773 Spec_Id : Entity_Id; 774 775 -- The target is a generic package or a subprogram 776 -- 777 -- * Body_Barf - Empty 778 -- 779 -- * Body_Decl - This attribute denotes the generic or subprogram 780 -- body. 781 -- 782 -- * Spec_Id - This attribute denotes the entity of the generic 783 -- package or subprogram. 784 785 -- The target is a protected entry 786 -- 787 -- * Body_Barf - This attribute denotes the body of the barrier 788 -- function if expansion took place, otherwise it is Empty. 789 -- 790 -- * Body_Decl - This attribute denotes the body of the procedure 791 -- which emulates the entry if expansion took place, otherwise it 792 -- denotes the body of the protected entry. 793 -- 794 -- * Spec_Id - This attribute denotes the entity of the procedure 795 -- which emulates the entry if expansion took place, otherwise it 796 -- denotes the protected entry. 797 798 -- The target is a protected subprogram 799 -- 800 -- * Body_Barf - Empty 801 -- 802 -- * Body_Decl - This attribute denotes the body of the protected or 803 -- unprotected version of the protected subprogram if expansion took 804 -- place, otherwise it denotes the body of the protected subprogram. 805 -- 806 -- * Spec_Id - This attribute denotes the entity of the protected or 807 -- unprotected version of the protected subprogram if expansion took 808 -- place, otherwise it is the entity of the protected subprogram. 809 810 -- The target is a task entry 811 -- 812 -- * Body_Barf - Empty 813 -- 814 -- * Body_Decl - This attribute denotes the body of the procedure 815 -- which emulates the task body if expansion took place, otherwise 816 -- it denotes the body of the task type. 817 -- 818 -- * Spec_Id - This attribute denotes the entity of the procedure 819 -- which emulates the task body if expansion took place, otherwise 820 -- it denotes the entity of the task type. 821 end record; 822 823 -- The following type captures relevant attributes which pertain to a task 824 -- type. 825 826 type Task_Attributes is record 827 Body_Decl : Node_Id; 828 -- This attribute denotes the declaration of the procedure body which 829 -- emulates the behaviour of the task body. 830 831 Elab_Checks_OK : Boolean; 832 -- This flag is set when the task type has elaboration checks enabled 833 834 Ghost_Mode_Ignore : Boolean; 835 -- This flag is set when the task type appears in a region subject to 836 -- pragma Ghost with policy ignore, or starts one such region. 837 838 SPARK_Mode_On : Boolean; 839 -- This flag is set when the task type appears in a region subject to 840 -- pragma SPARK_Mode with value On, or starts one such region. 841 842 Spec_Id : Entity_Id; 843 -- This attribute denotes the entity of the initial declaration of the 844 -- procedure body which emulates the behaviour of the task body. 845 846 Task_Decl : Node_Id; 847 -- This attribute denotes the declaration of the task type 848 849 Unit_Id : Entity_Id; 850 -- This attribute denotes the entity of the compilation unit where the 851 -- task type resides. 852 end record; 853 854 -- The following type captures relevant attributes which pertain to a 855 -- variable. 856 857 type Variable_Attributes is record 858 Unit_Id : Entity_Id; 859 -- This attribute denotes the entity of the compilation unit where the 860 -- variable resides. 861 end record; 862 863 --------------------- 864 -- Data structures -- 865 --------------------- 866 867 -- The ABE mechanism employs lists and hash tables to store information 868 -- pertaining to scenarios and targets, as well as the Processing phase. 869 -- The need for data structures comes partly from the size limitation of 870 -- nodes. Note that the use of hash tables is conservative and operations 871 -- are carried out only when a particular hash table has at least one key 872 -- value pair (see xxx_In_Use flags). 873 874 -- The following table stores the early call regions of subprogram bodies 875 876 Early_Call_Regions_Max : constant := 101; 877 878 type Early_Call_Regions_Index is range 0 .. Early_Call_Regions_Max - 1; 879 880 function Early_Call_Regions_Hash 881 (Key : Entity_Id) return Early_Call_Regions_Index; 882 -- Obtain the hash value of entity Key 883 884 Early_Call_Regions_In_Use : Boolean := False; 885 -- This flag determines whether table Early_Call_Regions contains at least 886 -- least one key/value pair. 887 888 Early_Call_Regions_No_Element : constant Node_Id := Empty; 889 890 package Early_Call_Regions is new Simple_HTable 891 (Header_Num => Early_Call_Regions_Index, 892 Element => Node_Id, 893 No_Element => Early_Call_Regions_No_Element, 894 Key => Entity_Id, 895 Hash => Early_Call_Regions_Hash, 896 Equal => "="); 897 898 -- The following table stores the elaboration status of all units withed by 899 -- the main unit. 900 901 Elaboration_Statuses_Max : constant := 1009; 902 903 type Elaboration_Statuses_Index is range 0 .. Elaboration_Statuses_Max - 1; 904 905 function Elaboration_Statuses_Hash 906 (Key : Entity_Id) return Elaboration_Statuses_Index; 907 -- Obtain the hash value of entity Key 908 909 Elaboration_Statuses_In_Use : Boolean := False; 910 -- This flag flag determines whether table Elaboration_Statuses contains at 911 -- least one key/value pair. 912 913 Elaboration_Statuses_No_Element : constant Elaboration_Attributes := 914 No_Elaboration_Attributes; 915 916 package Elaboration_Statuses is new Simple_HTable 917 (Header_Num => Elaboration_Statuses_Index, 918 Element => Elaboration_Attributes, 919 No_Element => Elaboration_Statuses_No_Element, 920 Key => Entity_Id, 921 Hash => Elaboration_Statuses_Hash, 922 Equal => "="); 923 924 -- The following table stores a status flag for each SPARK scenario saved 925 -- in table SPARK_Scenarios. 926 927 Recorded_SPARK_Scenarios_Max : constant := 127; 928 929 type Recorded_SPARK_Scenarios_Index is 930 range 0 .. Recorded_SPARK_Scenarios_Max - 1; 931 932 function Recorded_SPARK_Scenarios_Hash 933 (Key : Node_Id) return Recorded_SPARK_Scenarios_Index; 934 -- Obtain the hash value of Key 935 936 Recorded_SPARK_Scenarios_In_Use : Boolean := False; 937 -- This flag flag determines whether table Recorded_SPARK_Scenarios 938 -- contains at least one key/value pair. 939 940 Recorded_SPARK_Scenarios_No_Element : constant Boolean := False; 941 942 package Recorded_SPARK_Scenarios is new Simple_HTable 943 (Header_Num => Recorded_SPARK_Scenarios_Index, 944 Element => Boolean, 945 No_Element => Recorded_SPARK_Scenarios_No_Element, 946 Key => Node_Id, 947 Hash => Recorded_SPARK_Scenarios_Hash, 948 Equal => "="); 949 950 -- The following table stores a status flag for each top-level scenario 951 -- recorded in table Top_Level_Scenarios. 952 953 Recorded_Top_Level_Scenarios_Max : constant := 503; 954 955 type Recorded_Top_Level_Scenarios_Index is 956 range 0 .. Recorded_Top_Level_Scenarios_Max - 1; 957 958 function Recorded_Top_Level_Scenarios_Hash 959 (Key : Node_Id) return Recorded_Top_Level_Scenarios_Index; 960 -- Obtain the hash value of entity Key 961 962 Recorded_Top_Level_Scenarios_In_Use : Boolean := False; 963 -- This flag flag determines whether table Recorded_Top_Level_Scenarios 964 -- contains at least one key/value pair. 965 966 Recorded_Top_Level_Scenarios_No_Element : constant Boolean := False; 967 968 package Recorded_Top_Level_Scenarios is new Simple_HTable 969 (Header_Num => Recorded_Top_Level_Scenarios_Index, 970 Element => Boolean, 971 No_Element => Recorded_Top_Level_Scenarios_No_Element, 972 Key => Node_Id, 973 Hash => Recorded_Top_Level_Scenarios_Hash, 974 Equal => "="); 975 976 -- The following table stores all active scenarios in a recursive traversal 977 -- starting from a top-level scenario. This table must be maintained in a 978 -- FIFO fashion. 979 980 package Scenario_Stack is new Table.Table 981 (Table_Component_Type => Node_Id, 982 Table_Index_Type => Int, 983 Table_Low_Bound => 1, 984 Table_Initial => 50, 985 Table_Increment => 100, 986 Table_Name => "Scenario_Stack"); 987 988 -- The following table stores SPARK scenarios which are not necessarily 989 -- executable during elaboration, but still require elaboration-related 990 -- checks. 991 992 package SPARK_Scenarios is new Table.Table 993 (Table_Component_Type => Node_Id, 994 Table_Index_Type => Int, 995 Table_Low_Bound => 1, 996 Table_Initial => 50, 997 Table_Increment => 100, 998 Table_Name => "SPARK_Scenarios"); 999 1000 -- The following table stores all top-level scenario saved during the 1001 -- Recording phase. The contents of this table act as traversal roots 1002 -- later in the Processing phase. This table must be maintained in a 1003 -- LIFO fashion. 1004 1005 package Top_Level_Scenarios is new Table.Table 1006 (Table_Component_Type => Node_Id, 1007 Table_Index_Type => Int, 1008 Table_Low_Bound => 1, 1009 Table_Initial => 1000, 1010 Table_Increment => 100, 1011 Table_Name => "Top_Level_Scenarios"); 1012 1013 -- The following table stores the bodies of all eligible scenarios visited 1014 -- during a traversal starting from a top-level scenario. The contents of 1015 -- this table must be reset upon each new traversal. 1016 1017 Visited_Bodies_Max : constant := 511; 1018 1019 type Visited_Bodies_Index is range 0 .. Visited_Bodies_Max - 1; 1020 1021 function Visited_Bodies_Hash (Key : Node_Id) return Visited_Bodies_Index; 1022 -- Obtain the hash value of node Key 1023 1024 Visited_Bodies_In_Use : Boolean := False; 1025 -- This flag determines whether table Visited_Bodies contains at least one 1026 -- key/value pair. 1027 1028 Visited_Bodies_No_Element : constant Boolean := False; 1029 1030 package Visited_Bodies is new Simple_HTable 1031 (Header_Num => Visited_Bodies_Index, 1032 Element => Boolean, 1033 No_Element => Visited_Bodies_No_Element, 1034 Key => Node_Id, 1035 Hash => Visited_Bodies_Hash, 1036 Equal => "="); 1037 1038 ----------------------- 1039 -- Local subprograms -- 1040 ----------------------- 1041 1042 -- Multiple local subprograms are utilized to lower the semantic complexity 1043 -- of the Recording and Processing phase. 1044 1045 procedure Check_Preelaborated_Call (Call : Node_Id); 1046 pragma Inline (Check_Preelaborated_Call); 1047 -- Verify that entry, operator, or subprogram call Call does not appear at 1048 -- the library level of a preelaborated unit. 1049 1050 procedure Check_SPARK_Derived_Type (Typ_Decl : Node_Id); 1051 pragma Inline (Check_SPARK_Derived_Type); 1052 -- Verify that the freeze node of a derived type denoted by declaration 1053 -- Typ_Decl is within the early call region of each overriding primitive 1054 -- body that belongs to the derived type (SPARK RM 7.7(8)). 1055 1056 procedure Check_SPARK_Instantiation (Exp_Inst : Node_Id); 1057 pragma Inline (Check_SPARK_Instantiation); 1058 -- Verify that expanded instance Exp_Inst does not precede the generic body 1059 -- it instantiates (SPARK RM 7.7(6)). 1060 1061 procedure Check_SPARK_Model_In_Effect (N : Node_Id); 1062 pragma Inline (Check_SPARK_Model_In_Effect); 1063 -- Determine whether a suitable elaboration model is currently in effect 1064 -- for verifying the SPARK rules of scenario N. Emit a warning if this is 1065 -- not the case. 1066 1067 procedure Check_SPARK_Scenario (N : Node_Id); 1068 pragma Inline (Check_SPARK_Scenario); 1069 -- Top-level dispatcher for verifying SPARK scenarios which are not always 1070 -- executable during elaboration but still need elaboration-related checks. 1071 1072 procedure Check_SPARK_Refined_State_Pragma (N : Node_Id); 1073 pragma Inline (Check_SPARK_Refined_State_Pragma); 1074 -- Verify that each constituent of Refined_State pragma N which belongs to 1075 -- an abstract state mentioned in pragma Initializes has prior elaboration 1076 -- with respect to the main unit (SPARK RM 7.7.1(7)). 1077 1078 function Compilation_Unit (Unit_Id : Entity_Id) return Node_Id; 1079 pragma Inline (Compilation_Unit); 1080 -- Return the N_Compilation_Unit node of unit Unit_Id 1081 1082 function Early_Call_Region (Body_Id : Entity_Id) return Node_Id; 1083 pragma Inline (Early_Call_Region); 1084 -- Return the early call region associated with entry or subprogram body 1085 -- Body_Id. IMPORTANT: This routine does not find the early call region. 1086 -- To compute it, use routine Find_Early_Call_Region. 1087 1088 procedure Elab_Msg_NE 1089 (Msg : String; 1090 N : Node_Id; 1091 Id : Entity_Id; 1092 Info_Msg : Boolean; 1093 In_SPARK : Boolean); 1094 pragma Inline (Elab_Msg_NE); 1095 -- Wrapper around Error_Msg_NE. Emit message Msg concerning arbitrary node 1096 -- N and entity. If flag Info_Msg is set, the routine emits an information 1097 -- message, otherwise it emits an error. If flag In_SPARK is set, then 1098 -- string " in SPARK" is added to the end of the message. 1099 1100 function Elaboration_Status 1101 (Unit_Id : Entity_Id) return Elaboration_Attributes; 1102 pragma Inline (Elaboration_Status); 1103 -- Return the set of elaboration attributes associated with unit Unit_Id 1104 1105 procedure Ensure_Prior_Elaboration 1106 (N : Node_Id; 1107 Unit_Id : Entity_Id; 1108 Prag_Nam : Name_Id; 1109 State : Processing_Attributes); 1110 -- Guarantee the elaboration of unit Unit_Id with respect to the main unit 1111 -- by installing pragma Elaborate or Elaborate_All denoted by Prag_Nam. N 1112 -- denotes the related scenario. State denotes the current state of the 1113 -- Processing phase. 1114 1115 procedure Ensure_Prior_Elaboration_Dynamic 1116 (N : Node_Id; 1117 Unit_Id : Entity_Id; 1118 Prag_Nam : Name_Id); 1119 -- Guarantee the elaboration of unit Unit_Id with respect to the main unit 1120 -- by suggesting the use of Elaborate[_All] with name Prag_Nam. N denotes 1121 -- the related scenario. 1122 1123 procedure Ensure_Prior_Elaboration_Static 1124 (N : Node_Id; 1125 Unit_Id : Entity_Id; 1126 Prag_Nam : Name_Id); 1127 -- Guarantee the elaboration of unit Unit_Id with respect to the main unit 1128 -- by installing an implicit Elaborate[_All] pragma with name Prag_Nam. N 1129 -- denotes the related scenario. 1130 1131 function Extract_Assignment_Name (Asmt : Node_Id) return Node_Id; 1132 pragma Inline (Extract_Assignment_Name); 1133 -- Obtain the Name attribute of assignment statement Asmt 1134 1135 procedure Extract_Call_Attributes 1136 (Call : Node_Id; 1137 Target_Id : out Entity_Id; 1138 Attrs : out Call_Attributes); 1139 pragma Inline (Extract_Call_Attributes); 1140 -- Obtain attributes Attrs associated with call Call. Target_Id is the 1141 -- entity of the call target. 1142 1143 function Extract_Call_Name (Call : Node_Id) return Node_Id; 1144 pragma Inline (Extract_Call_Name); 1145 -- Obtain the Name attribute of entry or subprogram call Call 1146 1147 procedure Extract_Instance_Attributes 1148 (Exp_Inst : Node_Id; 1149 Inst_Body : out Node_Id; 1150 Inst_Decl : out Node_Id); 1151 pragma Inline (Extract_Instance_Attributes); 1152 -- Obtain body Inst_Body and spec Inst_Decl of expanded instance Exp_Inst 1153 1154 procedure Extract_Instantiation_Attributes 1155 (Exp_Inst : Node_Id; 1156 Inst : out Node_Id; 1157 Inst_Id : out Entity_Id; 1158 Gen_Id : out Entity_Id; 1159 Attrs : out Instantiation_Attributes); 1160 pragma Inline (Extract_Instantiation_Attributes); 1161 -- Obtain attributes Attrs associated with expanded instantiation Exp_Inst. 1162 -- Inst is the instantiation. Inst_Id is the entity of the instance. Gen_Id 1163 -- is the entity of the generic unit being instantiated. 1164 1165 procedure Extract_Target_Attributes 1166 (Target_Id : Entity_Id; 1167 Attrs : out Target_Attributes); 1168 -- Obtain attributes Attrs associated with an entry, package, or subprogram 1169 -- denoted by Target_Id. 1170 1171 procedure Extract_Task_Attributes 1172 (Typ : Entity_Id; 1173 Attrs : out Task_Attributes); 1174 pragma Inline (Extract_Task_Attributes); 1175 -- Obtain attributes Attrs associated with task type Typ 1176 1177 procedure Extract_Variable_Reference_Attributes 1178 (Ref : Node_Id; 1179 Var_Id : out Entity_Id; 1180 Attrs : out Variable_Attributes); 1181 pragma Inline (Extract_Variable_Reference_Attributes); 1182 -- Obtain attributes Attrs associated with reference Ref that mentions 1183 -- variable Var_Id. 1184 1185 function Find_Code_Unit (N : Node_Or_Entity_Id) return Entity_Id; 1186 pragma Inline (Find_Code_Unit); 1187 -- Return the code unit which contains arbitrary node or entity N. This 1188 -- is the unit of the file which physically contains the related construct 1189 -- denoted by N except when N is within an instantiation. In that case the 1190 -- unit is that of the top-level instantiation. 1191 1192 function Find_Early_Call_Region 1193 (Body_Decl : Node_Id; 1194 Assume_Elab_Body : Boolean := False; 1195 Skip_Memoization : Boolean := False) return Node_Id; 1196 -- Find the start of the early call region which belongs to subprogram body 1197 -- Body_Decl as defined in SPARK RM 7.7. The behavior of the routine is to 1198 -- find the early call region, memoize it, and return it, but this behavior 1199 -- can be altered. Flag Assume_Elab_Body should be set when a package spec 1200 -- may lack pragma Elaborate_Body, but the routine must still examine that 1201 -- spec. Flag Skip_Memoization should be set when the routine must avoid 1202 -- memoizing the region. 1203 1204 procedure Find_Elaborated_Units; 1205 -- Populate table Elaboration_Statuses with all units which have prior 1206 -- elaboration with respect to the main unit. 1207 1208 function Find_Enclosing_Instance (N : Node_Id) return Node_Id; 1209 pragma Inline (Find_Enclosing_Instance); 1210 -- Find the declaration or body of the nearest expanded instance which 1211 -- encloses arbitrary node N. Return Empty if no such instance exists. 1212 1213 function Find_Top_Unit (N : Node_Or_Entity_Id) return Entity_Id; 1214 pragma Inline (Find_Top_Unit); 1215 -- Return the top unit which contains arbitrary node or entity N. The unit 1216 -- is obtained by logically unwinding instantiations and subunits when N 1217 -- resides within one. 1218 1219 function Find_Unit_Entity (N : Node_Id) return Entity_Id; 1220 pragma Inline (Find_Unit_Entity); 1221 -- Return the entity of unit N 1222 1223 function First_Formal_Type (Subp_Id : Entity_Id) return Entity_Id; 1224 pragma Inline (First_Formal_Type); 1225 -- Return the type of subprogram Subp_Id's first formal parameter. If the 1226 -- subprogram lacks formal parameters, return Empty. 1227 1228 function Has_Body (Pack_Decl : Node_Id) return Boolean; 1229 -- Determine whether package declaration Pack_Decl has a corresponding body 1230 -- or would eventually have one. 1231 1232 function Has_Prior_Elaboration 1233 (Unit_Id : Entity_Id; 1234 Context_OK : Boolean := False; 1235 Elab_Body_OK : Boolean := False; 1236 Same_Unit_OK : Boolean := False) return Boolean; 1237 pragma Inline (Has_Prior_Elaboration); 1238 -- Determine whether unit Unit_Id is elaborated prior to the main unit. 1239 -- If flag Context_OK is set, the routine considers the following case 1240 -- as valid prior elaboration: 1241 -- 1242 -- * Unit_Id is in the elaboration context of the main unit 1243 -- 1244 -- If flag Elab_Body_OK is set, the routine considers the following case 1245 -- as valid prior elaboration: 1246 -- 1247 -- * Unit_Id has pragma Elaborate_Body and is not the main unit 1248 -- 1249 -- If flag Same_Unit_OK is set, the routine considers the following cases 1250 -- as valid prior elaboration: 1251 -- 1252 -- * Unit_Id is the main unit 1253 -- 1254 -- * Unit_Id denotes the spec of the main unit body 1255 1256 function In_External_Instance 1257 (N : Node_Id; 1258 Target_Decl : Node_Id) return Boolean; 1259 pragma Inline (In_External_Instance); 1260 -- Determine whether a target desctibed by its declaration Target_Decl 1261 -- resides in a package instance which is external to scenario N. 1262 1263 function In_Main_Context (N : Node_Id) return Boolean; 1264 pragma Inline (In_Main_Context); 1265 -- Determine whether arbitrary node N appears within the main compilation 1266 -- unit. 1267 1268 function In_Same_Context 1269 (N1 : Node_Id; 1270 N2 : Node_Id; 1271 Nested_OK : Boolean := False) return Boolean; 1272 -- Determine whether two arbitrary nodes N1 and N2 appear within the same 1273 -- context ignoring enclosing library levels. Nested_OK should be set when 1274 -- the context of N1 can enclose that of N2. 1275 1276 procedure Info_Call 1277 (Call : Node_Id; 1278 Target_Id : Entity_Id; 1279 Info_Msg : Boolean; 1280 In_SPARK : Boolean); 1281 -- Output information concerning call Call which invokes target Target_Id. 1282 -- If flag Info_Msg is set, the routine emits an information message, 1283 -- otherwise it emits an error. If flag In_SPARK is set, then the string 1284 -- " in SPARK" is added to the end of the message. 1285 1286 procedure Info_Instantiation 1287 (Inst : Node_Id; 1288 Gen_Id : Entity_Id; 1289 Info_Msg : Boolean; 1290 In_SPARK : Boolean); 1291 pragma Inline (Info_Instantiation); 1292 -- Output information concerning instantiation Inst which instantiates 1293 -- generic unit Gen_Id. If flag Info_Msg is set, the routine emits an 1294 -- information message, otherwise it emits an error. If flag In_SPARK 1295 -- is set, then string " in SPARK" is added to the end of the message. 1296 1297 procedure Info_Variable_Reference 1298 (Ref : Node_Id; 1299 Var_Id : Entity_Id; 1300 Info_Msg : Boolean; 1301 In_SPARK : Boolean); 1302 pragma Inline (Info_Variable_Reference); 1303 -- Output information concerning reference Ref which mentions variable 1304 -- Var_Id. If flag Info_Msg is set, the routine emits an information 1305 -- message, otherwise it emits an error. If flag In_SPARK is set, then 1306 -- string " in SPARK" is added to the end of the message. 1307 1308 function Insertion_Node (N : Node_Id; Ins_Nod : Node_Id) return Node_Id; 1309 pragma Inline (Insertion_Node); 1310 -- Obtain the proper insertion node of an ABE check or failure for scenario 1311 -- N and candidate insertion node Ins_Nod. 1312 1313 procedure Install_ABE_Check 1314 (N : Node_Id; 1315 Id : Entity_Id; 1316 Ins_Nod : Node_Id); 1317 -- Insert a run-time ABE check for elaboration scenario N which verifies 1318 -- whether arbitrary entity Id is elaborated. The check in inserted prior 1319 -- to node Ins_Nod. 1320 1321 procedure Install_ABE_Check 1322 (N : Node_Id; 1323 Target_Id : Entity_Id; 1324 Target_Decl : Node_Id; 1325 Target_Body : Node_Id; 1326 Ins_Nod : Node_Id); 1327 -- Insert a run-time ABE check for elaboration scenario N which verifies 1328 -- whether target Target_Id with initial declaration Target_Decl and body 1329 -- Target_Body is elaborated. The check is inserted prior to node Ins_Nod. 1330 1331 procedure Install_ABE_Failure (N : Node_Id; Ins_Nod : Node_Id); 1332 -- Insert a Program_Error concerning a guaranteed ABE for elaboration 1333 -- scenario N. The failure is inserted prior to node Node_Id. 1334 1335 function Is_Accept_Alternative_Proc (Id : Entity_Id) return Boolean; 1336 pragma Inline (Is_Accept_Alternative_Proc); 1337 -- Determine whether arbitrary entity Id denotes an internally generated 1338 -- procedure which encapsulates the statements of an accept alternative. 1339 1340 function Is_Activation_Proc (Id : Entity_Id) return Boolean; 1341 pragma Inline (Is_Activation_Proc); 1342 -- Determine whether arbitrary entity Id denotes a runtime procedure in 1343 -- charge with activating tasks. 1344 1345 function Is_Ada_Semantic_Target (Id : Entity_Id) return Boolean; 1346 pragma Inline (Is_Ada_Semantic_Target); 1347 -- Determine whether arbitrary entity Id denodes a source or internally 1348 -- generated subprogram which emulates Ada semantics. 1349 1350 function Is_Assertion_Pragma_Target (Id : Entity_Id) return Boolean; 1351 pragma Inline (Is_Assertion_Pragma_Target); 1352 -- Determine whether arbitrary entity Id denotes a procedure which varifies 1353 -- the run-time semantics of an assertion pragma. 1354 1355 function Is_Bodiless_Subprogram (Subp_Id : Entity_Id) return Boolean; 1356 pragma Inline (Is_Bodiless_Subprogram); 1357 -- Determine whether subprogram Subp_Id will never have a body 1358 1359 function Is_Controlled_Proc 1360 (Subp_Id : Entity_Id; 1361 Subp_Nam : Name_Id) return Boolean; 1362 pragma Inline (Is_Controlled_Proc); 1363 -- Determine whether subprogram Subp_Id denotes controlled type primitives 1364 -- Adjust, Finalize, or Initialize as denoted by name Subp_Nam. 1365 1366 function Is_Default_Initial_Condition_Proc (Id : Entity_Id) return Boolean; 1367 pragma Inline (Is_Default_Initial_Condition_Proc); 1368 -- Determine whether arbitrary entity Id denotes internally generated 1369 -- routine Default_Initial_Condition. 1370 1371 function Is_Finalizer_Proc (Id : Entity_Id) return Boolean; 1372 pragma Inline (Is_Finalizer_Proc); 1373 -- Determine whether arbitrary entity Id denotes internally generated 1374 -- routine _Finalizer. 1375 1376 function Is_Guaranteed_ABE 1377 (N : Node_Id; 1378 Target_Decl : Node_Id; 1379 Target_Body : Node_Id) return Boolean; 1380 pragma Inline (Is_Guaranteed_ABE); 1381 -- Determine whether scenario N with a target described by its initial 1382 -- declaration Target_Decl and body Target_Decl results in a guaranteed 1383 -- ABE. 1384 1385 function Is_Initial_Condition_Proc (Id : Entity_Id) return Boolean; 1386 pragma Inline (Is_Initial_Condition_Proc); 1387 -- Determine whether arbitrary entity Id denotes internally generated 1388 -- routine Initial_Condition. 1389 1390 function Is_Initialized (Obj_Decl : Node_Id) return Boolean; 1391 pragma Inline (Is_Initialized); 1392 -- Determine whether object declaration Obj_Decl is initialized 1393 1394 function Is_Invariant_Proc (Id : Entity_Id) return Boolean; 1395 pragma Inline (Is_Invariant_Proc); 1396 -- Determine whether arbitrary entity Id denotes an invariant procedure 1397 1398 function Is_Non_Library_Level_Encapsulator (N : Node_Id) return Boolean; 1399 pragma Inline (Is_Non_Library_Level_Encapsulator); 1400 -- Determine whether arbitrary node N is a non-library encapsulator 1401 1402 function Is_Partial_Invariant_Proc (Id : Entity_Id) return Boolean; 1403 pragma Inline (Is_Partial_Invariant_Proc); 1404 -- Determine whether arbitrary entity Id denotes a partial invariant 1405 -- procedure. 1406 1407 function Is_Postconditions_Proc (Id : Entity_Id) return Boolean; 1408 pragma Inline (Is_Postconditions_Proc); 1409 -- Determine whether arbitrary entity Id denotes internally generated 1410 -- routine _Postconditions. 1411 1412 function Is_Preelaborated_Unit (Id : Entity_Id) return Boolean; 1413 pragma Inline (Is_Preelaborated_Unit); 1414 -- Determine whether arbitrary entity Id denotes a unit which is subject to 1415 -- one of the following pragmas: 1416 -- 1417 -- * Preelaborable 1418 -- * Pure 1419 -- * Remote_Call_Interface 1420 -- * Remote_Types 1421 -- * Shared_Passive 1422 1423 function Is_Protected_Entry (Id : Entity_Id) return Boolean; 1424 pragma Inline (Is_Protected_Entry); 1425 -- Determine whether arbitrary entity Id denotes a protected entry 1426 1427 function Is_Protected_Subp (Id : Entity_Id) return Boolean; 1428 pragma Inline (Is_Protected_Subp); 1429 -- Determine whether entity Id denotes a protected subprogram 1430 1431 function Is_Protected_Body_Subp (Id : Entity_Id) return Boolean; 1432 pragma Inline (Is_Protected_Body_Subp); 1433 -- Determine whether entity Id denotes the protected or unprotected version 1434 -- of a protected subprogram. 1435 1436 function Is_Recorded_SPARK_Scenario (N : Node_Id) return Boolean; 1437 pragma Inline (Is_Recorded_SPARK_Scenario); 1438 -- Determine whether arbitrary node N is a recorded SPARK scenario which 1439 -- appears in table SPARK_Scenarios. 1440 1441 function Is_Recorded_Top_Level_Scenario (N : Node_Id) return Boolean; 1442 pragma Inline (Is_Recorded_Top_Level_Scenario); 1443 -- Determine whether arbitrary node N is a recorded top-level scenario 1444 -- which appears in table Top_Level_Scenarios. 1445 1446 function Is_Safe_Activation 1447 (Call : Node_Id; 1448 Task_Decl : Node_Id) return Boolean; 1449 pragma Inline (Is_Safe_Activation); 1450 -- Determine whether call Call which activates a task object described by 1451 -- declaration Task_Decl is always ABE-safe. 1452 1453 function Is_Safe_Call 1454 (Call : Node_Id; 1455 Target_Attrs : Target_Attributes) return Boolean; 1456 pragma Inline (Is_Safe_Call); 1457 -- Determine whether call Call which invokes a target described by 1458 -- attributes Target_Attrs is always ABE-safe. 1459 1460 function Is_Safe_Instantiation 1461 (Inst : Node_Id; 1462 Gen_Attrs : Target_Attributes) return Boolean; 1463 pragma Inline (Is_Safe_Instantiation); 1464 -- Determine whether instance Inst which instantiates a generic unit 1465 -- described by attributes Gen_Attrs is always ABE-safe. 1466 1467 function Is_Same_Unit 1468 (Unit_1 : Entity_Id; 1469 Unit_2 : Entity_Id) return Boolean; 1470 pragma Inline (Is_Same_Unit); 1471 -- Determine whether entities Unit_1 and Unit_2 denote the same unit 1472 1473 function Is_Scenario (N : Node_Id) return Boolean; 1474 pragma Inline (Is_Scenario); 1475 -- Determine whether attribute node N denotes a scenario. The scenario may 1476 -- not necessarily be eligible for ABE processing. 1477 1478 function Is_SPARK_Semantic_Target (Id : Entity_Id) return Boolean; 1479 pragma Inline (Is_SPARK_Semantic_Target); 1480 -- Determine whether arbitrary entity Id nodes a source or internally 1481 -- generated subprogram which emulates SPARK semantics. 1482 1483 function Is_Suitable_Access (N : Node_Id) return Boolean; 1484 pragma Inline (Is_Suitable_Access); 1485 -- Determine whether arbitrary node N denotes a suitable attribute for ABE 1486 -- processing. 1487 1488 function Is_Suitable_Call (N : Node_Id) return Boolean; 1489 pragma Inline (Is_Suitable_Call); 1490 -- Determine whether arbitrary node N denotes a suitable call for ABE 1491 -- processing. 1492 1493 function Is_Suitable_Instantiation (N : Node_Id) return Boolean; 1494 pragma Inline (Is_Suitable_Instantiation); 1495 -- Determine whether arbitrary node N is a suitable instantiation for ABE 1496 -- processing. 1497 1498 function Is_Suitable_Scenario (N : Node_Id) return Boolean; 1499 pragma Inline (Is_Suitable_Scenario); 1500 -- Determine whether arbitrary node N is a suitable scenario for ABE 1501 -- processing. 1502 1503 function Is_Suitable_SPARK_Derived_Type (N : Node_Id) return Boolean; 1504 pragma Inline (Is_Suitable_SPARK_Derived_Type); 1505 -- Determine whether arbitrary node N denotes a suitable derived type 1506 -- declaration for ABE processing using the SPARK rules. 1507 1508 function Is_Suitable_SPARK_Instantiation (N : Node_Id) return Boolean; 1509 pragma Inline (Is_Suitable_SPARK_Instantiation); 1510 -- Determine whether arbitrary node N denotes a suitable instantiation for 1511 -- ABE processing using the SPARK rules. 1512 1513 function Is_Suitable_SPARK_Refined_State_Pragma 1514 (N : Node_Id) return Boolean; 1515 pragma Inline (Is_Suitable_SPARK_Refined_State_Pragma); 1516 -- Determine whether arbitrary node N denotes a suitable Refined_State 1517 -- pragma for ABE processing using the SPARK rules. 1518 1519 function Is_Suitable_Variable_Assignment (N : Node_Id) return Boolean; 1520 pragma Inline (Is_Suitable_Variable_Assignment); 1521 -- Determine whether arbitrary node N denotes a suitable assignment for ABE 1522 -- processing. 1523 1524 function Is_Suitable_Variable_Reference (N : Node_Id) return Boolean; 1525 pragma Inline (Is_Suitable_Variable_Reference); 1526 -- Determine whether arbitrary node N is a suitable variable reference for 1527 -- ABE processing. 1528 1529 function Is_Task_Entry (Id : Entity_Id) return Boolean; 1530 pragma Inline (Is_Task_Entry); 1531 -- Determine whether arbitrary entity Id denotes a task entry 1532 1533 function Is_Up_Level_Target (Target_Decl : Node_Id) return Boolean; 1534 pragma Inline (Is_Up_Level_Target); 1535 -- Determine whether the current root resides at the declaration level. If 1536 -- this is the case, determine whether a target described by declaration 1537 -- Target_Decl is within a context which encloses the current root or is in 1538 -- a different unit. 1539 1540 function Is_Visited_Body (Body_Decl : Node_Id) return Boolean; 1541 pragma Inline (Is_Visited_Body); 1542 -- Determine whether subprogram body Body_Decl is already visited during a 1543 -- recursive traversal started from a top-level scenario. 1544 1545 procedure Meet_Elaboration_Requirement 1546 (N : Node_Id; 1547 Target_Id : Entity_Id; 1548 Req_Nam : Name_Id); 1549 -- Determine whether elaboration requirement Req_Nam for scenario N with 1550 -- target Target_Id is met by the context of the main unit using the SPARK 1551 -- rules. Req_Nam must denote either Elaborate or Elaborate_All. Emit an 1552 -- error if this is not the case. 1553 1554 function Non_Private_View (Typ : Entity_Id) return Entity_Id; 1555 pragma Inline (Non_Private_View); 1556 -- Return the full view of private type Typ if available, otherwise return 1557 -- type Typ. 1558 1559 procedure Output_Active_Scenarios (Error_Nod : Node_Id); 1560 -- Output the contents of the active scenario stack from earliest to latest 1561 -- to supplement an earlier error emitted for node Error_Nod. 1562 1563 procedure Pop_Active_Scenario (N : Node_Id); 1564 pragma Inline (Pop_Active_Scenario); 1565 -- Pop the top of the scenario stack. A check is made to ensure that the 1566 -- scenario being removed is the same as N. 1567 1568 generic 1569 with procedure Process_Single_Activation 1570 (Call : Node_Id; 1571 Call_Attrs : Call_Attributes; 1572 Obj_Id : Entity_Id; 1573 Task_Attrs : Task_Attributes; 1574 State : Processing_Attributes); 1575 -- Perform ABE checks and diagnostics for task activation call Call 1576 -- which activates task Obj_Id. Call_Attrs are the attributes of the 1577 -- activation call. Task_Attrs are the attributes of the task type. 1578 -- State is the current state of the Processing phase. 1579 1580 procedure Process_Activation_Generic 1581 (Call : Node_Id; 1582 Call_Attrs : Call_Attributes; 1583 State : Processing_Attributes); 1584 -- Perform ABE checks and diagnostics for activation call Call by invoking 1585 -- routine Process_Single_Activation on each task object being activated. 1586 -- Call_Attrs are the attributes of the activation call. State is the 1587 -- current state of the Processing phase. 1588 1589 procedure Process_Conditional_ABE 1590 (N : Node_Id; 1591 State : Processing_Attributes := Initial_State); 1592 -- Top-level dispatcher for processing of various elaboration scenarios. 1593 -- Perform conditional ABE checks and diagnostics for scenario N. State 1594 -- is the current state of the Processing phase. 1595 1596 procedure Process_Conditional_ABE_Access 1597 (Attr : Node_Id; 1598 State : Processing_Attributes); 1599 -- Perform ABE checks and diagnostics for 'Access to entry, operator, or 1600 -- subprogram denoted by Attr. State is the current state of the Processing 1601 -- phase. 1602 1603 procedure Process_Conditional_ABE_Activation_Impl 1604 (Call : Node_Id; 1605 Call_Attrs : Call_Attributes; 1606 Obj_Id : Entity_Id; 1607 Task_Attrs : Task_Attributes; 1608 State : Processing_Attributes); 1609 -- Perform common conditional ABE checks and diagnostics for call Call 1610 -- which activates task Obj_Id ignoring the Ada or SPARK rules. Call_Attrs 1611 -- are the attributes of the activation call. Task_Attrs are the attributes 1612 -- of the task type. State is the current state of the Processing phase. 1613 1614 procedure Process_Conditional_ABE_Call 1615 (Call : Node_Id; 1616 Call_Attrs : Call_Attributes; 1617 Target_Id : Entity_Id; 1618 State : Processing_Attributes); 1619 -- Top-level dispatcher for processing of calls. Perform ABE checks and 1620 -- diagnostics for call Call which invokes target Target_Id. Call_Attrs 1621 -- are the attributes of the call. State is the current state of the 1622 -- Processing phase. 1623 1624 procedure Process_Conditional_ABE_Call_Ada 1625 (Call : Node_Id; 1626 Call_Attrs : Call_Attributes; 1627 Target_Id : Entity_Id; 1628 Target_Attrs : Target_Attributes; 1629 State : Processing_Attributes); 1630 -- Perform ABE checks and diagnostics for call Call which invokes target 1631 -- Target_Id using the Ada rules. Call_Attrs are the attributes of the 1632 -- call. Target_Attrs are attributes of the target. State is the current 1633 -- state of the Processing phase. 1634 1635 procedure Process_Conditional_ABE_Call_SPARK 1636 (Call : Node_Id; 1637 Target_Id : Entity_Id; 1638 Target_Attrs : Target_Attributes; 1639 State : Processing_Attributes); 1640 -- Perform ABE checks and diagnostics for call Call which invokes target 1641 -- Target_Id using the SPARK rules. Target_Attrs denotes the attributes of 1642 -- the target. State is the current state of the Processing phase. 1643 1644 procedure Process_Conditional_ABE_Instantiation 1645 (Exp_Inst : Node_Id; 1646 State : Processing_Attributes); 1647 -- Top-level dispatcher for processing of instantiations. Perform ABE 1648 -- checks and diagnostics for expanded instantiation Exp_Inst. State is 1649 -- the current state of the Processing phase. 1650 1651 procedure Process_Conditional_ABE_Instantiation_Ada 1652 (Exp_Inst : Node_Id; 1653 Inst : Node_Id; 1654 Inst_Attrs : Instantiation_Attributes; 1655 Gen_Id : Entity_Id; 1656 Gen_Attrs : Target_Attributes; 1657 State : Processing_Attributes); 1658 -- Perform ABE checks and diagnostics for expanded instantiation Exp_Inst 1659 -- of generic Gen_Id using the Ada rules. Inst is the instantiation node. 1660 -- Inst_Attrs are the attributes of the instance. Gen_Attrs denotes the 1661 -- attributes of the generic. State is the current state of the Processing 1662 -- phase. 1663 1664 procedure Process_Conditional_ABE_Instantiation_SPARK 1665 (Inst : Node_Id; 1666 Gen_Id : Entity_Id; 1667 Gen_Attrs : Target_Attributes; 1668 State : Processing_Attributes); 1669 -- Perform ABE checks and diagnostics for instantiation Inst of generic 1670 -- Gen_Id using the SPARK rules. Gen_Attrs denotes the attributes of the 1671 -- generic. State is the current state of the Processing phase. 1672 1673 procedure Process_Conditional_ABE_Variable_Assignment (Asmt : Node_Id); 1674 -- Top-level dispatcher for processing of variable assignments. Perform ABE 1675 -- checks and diagnostics for assignment statement Asmt. 1676 1677 procedure Process_Conditional_ABE_Variable_Assignment_Ada 1678 (Asmt : Node_Id; 1679 Var_Id : Entity_Id); 1680 -- Perform ABE checks and diagnostics for assignment statement Asmt that 1681 -- updates the value of variable Var_Id using the Ada rules. 1682 1683 procedure Process_Conditional_ABE_Variable_Assignment_SPARK 1684 (Asmt : Node_Id; 1685 Var_Id : Entity_Id); 1686 -- Perform ABE checks and diagnostics for assignment statement Asmt that 1687 -- updates the value of variable Var_Id using the SPARK rules. 1688 1689 procedure Process_Conditional_ABE_Variable_Reference (Ref : Node_Id); 1690 -- Top-level dispatcher for processing of variable references. Perform ABE 1691 -- checks and diagnostics for variable reference Ref. 1692 1693 procedure Process_Conditional_ABE_Variable_Reference_Read 1694 (Ref : Node_Id; 1695 Var_Id : Entity_Id; 1696 Attrs : Variable_Attributes); 1697 -- Perform ABE checks and diagnostics for reference Ref described by its 1698 -- attributes Attrs, that reads variable Var_Id. 1699 1700 procedure Process_Guaranteed_ABE (N : Node_Id); 1701 -- Top-level dispatcher for processing of scenarios which result in a 1702 -- guaranteed ABE. 1703 1704 procedure Process_Guaranteed_ABE_Activation_Impl 1705 (Call : Node_Id; 1706 Call_Attrs : Call_Attributes; 1707 Obj_Id : Entity_Id; 1708 Task_Attrs : Task_Attributes; 1709 State : Processing_Attributes); 1710 -- Perform common guaranteed ABE checks and diagnostics for call Call which 1711 -- activates task Obj_Id ignoring the Ada or SPARK rules. Call_Attrs are 1712 -- the attributes of the activation call. Task_Attrs are the attributes of 1713 -- the task type. State is provided for compatibility and is not used. 1714 1715 procedure Process_Guaranteed_ABE_Call 1716 (Call : Node_Id; 1717 Call_Attrs : Call_Attributes; 1718 Target_Id : Entity_Id); 1719 -- Perform common guaranteed ABE checks and diagnostics for call Call which 1720 -- invokes target Target_Id ignoring the Ada or SPARK rules. Call_Attrs are 1721 -- the attributes of the call. 1722 1723 procedure Process_Guaranteed_ABE_Instantiation (Exp_Inst : Node_Id); 1724 -- Perform common guaranteed ABE checks and diagnostics for expanded 1725 -- instantiation Exp_Inst of generic Gen_Id ignoring the Ada or SPARK 1726 -- rules. 1727 1728 procedure Push_Active_Scenario (N : Node_Id); 1729 pragma Inline (Push_Active_Scenario); 1730 -- Push scenario N on top of the scenario stack 1731 1732 procedure Record_SPARK_Elaboration_Scenario (N : Node_Id); 1733 pragma Inline (Record_SPARK_Elaboration_Scenario); 1734 -- Save SPARK scenario N in table SPARK_Scenarios for later processing 1735 1736 procedure Reset_Visited_Bodies; 1737 pragma Inline (Reset_Visited_Bodies); 1738 -- Clear the contents of table Visited_Bodies 1739 1740 function Root_Scenario return Node_Id; 1741 pragma Inline (Root_Scenario); 1742 -- Return the top-level scenario which started a recursive search for other 1743 -- scenarios. It is assumed that there is a valid top-level scenario on the 1744 -- active scenario stack. 1745 1746 procedure Set_Early_Call_Region (Body_Id : Entity_Id; Start : Node_Id); 1747 pragma Inline (Set_Early_Call_Region); 1748 -- Associate an early call region with begins at construct Start with entry 1749 -- or subprogram body Body_Id. 1750 1751 procedure Set_Elaboration_Status 1752 (Unit_Id : Entity_Id; 1753 Val : Elaboration_Attributes); 1754 pragma Inline (Set_Elaboration_Status); 1755 -- Associate an set of elaboration attributes with unit Unit_Id 1756 1757 procedure Set_Is_Recorded_SPARK_Scenario 1758 (N : Node_Id; 1759 Val : Boolean := True); 1760 pragma Inline (Set_Is_Recorded_SPARK_Scenario); 1761 -- Mark scenario N as being recorded in table SPARK_Scenarios 1762 1763 procedure Set_Is_Recorded_Top_Level_Scenario 1764 (N : Node_Id; 1765 Val : Boolean := True); 1766 pragma Inline (Set_Is_Recorded_Top_Level_Scenario); 1767 -- Mark scenario N as being recorded in table Top_Level_Scenarios 1768 1769 procedure Set_Is_Visited_Body (Subp_Body : Node_Id); 1770 pragma Inline (Set_Is_Visited_Body); 1771 -- Mark subprogram body Subp_Body as being visited during a recursive 1772 -- traversal started from a top-level scenario. 1773 1774 function Static_Elaboration_Checks return Boolean; 1775 pragma Inline (Static_Elaboration_Checks); 1776 -- Determine whether the static model is in effect 1777 1778 procedure Traverse_Body (N : Node_Id; State : Processing_Attributes); 1779 -- Inspect the declarative and statement lists of subprogram body N for 1780 -- suitable elaboration scenarios and process them. State is the current 1781 -- state of the Processing phase. 1782 1783 procedure Update_Elaboration_Scenario (New_N : Node_Id; Old_N : Node_Id); 1784 pragma Inline (Update_Elaboration_Scenario); 1785 -- Update all relevant internal data structures when scenario Old_N is 1786 -- transformed into scenario New_N by Atree.Rewrite. 1787 1788 ----------------------- 1789 -- Build_Call_Marker -- 1790 ----------------------- 1791 1792 procedure Build_Call_Marker (N : Node_Id) is 1793 function In_External_Context 1794 (Call : Node_Id; 1795 Target_Attrs : Target_Attributes) return Boolean; 1796 pragma Inline (In_External_Context); 1797 -- Determine whether a target described by attributes Target_Attrs is 1798 -- external to call Call which must reside within an instance. 1799 1800 function In_Premature_Context (Call : Node_Id) return Boolean; 1801 -- Determine whether call Call appears within a premature context 1802 1803 function Is_Bridge_Target (Id : Entity_Id) return Boolean; 1804 pragma Inline (Is_Bridge_Target); 1805 -- Determine whether arbitrary entity Id denotes a bridge target 1806 1807 function Is_Default_Expression (Call : Node_Id) return Boolean; 1808 pragma Inline (Is_Default_Expression); 1809 -- Determine whether call Call acts as the expression of a defaulted 1810 -- parameter within a source call. 1811 1812 function Is_Generic_Formal_Subp (Subp_Id : Entity_Id) return Boolean; 1813 pragma Inline (Is_Generic_Formal_Subp); 1814 -- Determine whether subprogram Subp_Id denotes a generic formal 1815 -- subprogram which appears in the "prologue" of an instantiation. 1816 1817 ------------------------- 1818 -- In_External_Context -- 1819 ------------------------- 1820 1821 function In_External_Context 1822 (Call : Node_Id; 1823 Target_Attrs : Target_Attributes) return Boolean 1824 is 1825 Inst : Node_Id; 1826 Inst_Body : Node_Id; 1827 Inst_Decl : Node_Id; 1828 1829 begin 1830 -- Performance note: parent traversal 1831 1832 Inst := Find_Enclosing_Instance (Call); 1833 1834 -- The call appears within an instance 1835 1836 if Present (Inst) then 1837 1838 -- The call comes from the main unit and the target does not 1839 1840 if In_Extended_Main_Code_Unit (Call) 1841 and then not In_Extended_Main_Code_Unit (Target_Attrs.Spec_Decl) 1842 then 1843 return True; 1844 1845 -- Otherwise the target declaration must not appear within the 1846 -- instance spec or body. 1847 1848 else 1849 Extract_Instance_Attributes 1850 (Exp_Inst => Inst, 1851 Inst_Decl => Inst_Decl, 1852 Inst_Body => Inst_Body); 1853 1854 -- Performance note: parent traversal 1855 1856 return not In_Subtree 1857 (N => Target_Attrs.Spec_Decl, 1858 Root1 => Inst_Decl, 1859 Root2 => Inst_Body); 1860 end if; 1861 end if; 1862 1863 return False; 1864 end In_External_Context; 1865 1866 -------------------------- 1867 -- In_Premature_Context -- 1868 -------------------------- 1869 1870 function In_Premature_Context (Call : Node_Id) return Boolean is 1871 Par : Node_Id; 1872 1873 begin 1874 -- Climb the parent chain looking for premature contexts 1875 1876 Par := Parent (Call); 1877 while Present (Par) loop 1878 1879 -- Aspect specifications and generic associations are premature 1880 -- contexts because nested calls has not been relocated to their 1881 -- final context. 1882 1883 if Nkind_In (Par, N_Aspect_Specification, 1884 N_Generic_Association) 1885 then 1886 return True; 1887 1888 -- Prevent the search from going too far 1889 1890 elsif Is_Body_Or_Package_Declaration (Par) then 1891 exit; 1892 end if; 1893 1894 Par := Parent (Par); 1895 end loop; 1896 1897 return False; 1898 end In_Premature_Context; 1899 1900 ---------------------- 1901 -- Is_Bridge_Target -- 1902 ---------------------- 1903 1904 function Is_Bridge_Target (Id : Entity_Id) return Boolean is 1905 begin 1906 return 1907 Is_Accept_Alternative_Proc (Id) 1908 or else Is_Finalizer_Proc (Id) 1909 or else Is_Partial_Invariant_Proc (Id) 1910 or else Is_Postconditions_Proc (Id) 1911 or else Is_TSS (Id, TSS_Deep_Adjust) 1912 or else Is_TSS (Id, TSS_Deep_Finalize) 1913 or else Is_TSS (Id, TSS_Deep_Initialize); 1914 end Is_Bridge_Target; 1915 1916 --------------------------- 1917 -- Is_Default_Expression -- 1918 --------------------------- 1919 1920 function Is_Default_Expression (Call : Node_Id) return Boolean is 1921 Outer_Call : constant Node_Id := Parent (Call); 1922 Outer_Nam : Node_Id; 1923 1924 begin 1925 -- To qualify, the node must appear immediately within a source call 1926 -- which invokes a source target. 1927 1928 if Nkind_In (Outer_Call, N_Entry_Call_Statement, 1929 N_Function_Call, 1930 N_Procedure_Call_Statement) 1931 and then Comes_From_Source (Outer_Call) 1932 then 1933 Outer_Nam := Extract_Call_Name (Outer_Call); 1934 1935 return 1936 Is_Entity_Name (Outer_Nam) 1937 and then Present (Entity (Outer_Nam)) 1938 and then Is_Subprogram_Or_Entry (Entity (Outer_Nam)) 1939 and then Comes_From_Source (Entity (Outer_Nam)); 1940 end if; 1941 1942 return False; 1943 end Is_Default_Expression; 1944 1945 ---------------------------- 1946 -- Is_Generic_Formal_Subp -- 1947 ---------------------------- 1948 1949 function Is_Generic_Formal_Subp (Subp_Id : Entity_Id) return Boolean is 1950 Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id); 1951 Context : constant Node_Id := Parent (Subp_Decl); 1952 1953 begin 1954 -- To qualify, the subprogram must rename a generic actual subprogram 1955 -- where the enclosing context is an instantiation. 1956 1957 return 1958 Nkind (Subp_Decl) = N_Subprogram_Renaming_Declaration 1959 and then not Comes_From_Source (Subp_Decl) 1960 and then Nkind_In (Context, N_Function_Specification, 1961 N_Package_Specification, 1962 N_Procedure_Specification) 1963 and then Present (Generic_Parent (Context)); 1964 end Is_Generic_Formal_Subp; 1965 1966 -- Local variables 1967 1968 Call_Attrs : Call_Attributes; 1969 Call_Nam : Node_Id; 1970 Marker : Node_Id; 1971 Target_Attrs : Target_Attributes; 1972 Target_Id : Entity_Id; 1973 1974 -- Start of processing for Build_Call_Marker 1975 1976 begin 1977 -- Nothing to do when switch -gnatH (legacy elaboration checking mode 1978 -- enabled) is in effect because the legacy ABE mechanism does not need 1979 -- to carry out this action. 1980 1981 if Legacy_Elaboration_Checks then 1982 return; 1983 1984 -- Nothing to do for ASIS. As a result, ABE checks and diagnostics are 1985 -- not performed in this mode. 1986 1987 elsif ASIS_Mode then 1988 return; 1989 1990 -- Nothing to do when the call is being preanalyzed as the marker will 1991 -- be inserted in the wrong place. 1992 1993 elsif Preanalysis_Active then 1994 return; 1995 1996 -- Nothing to do when the input does not denote a call or a requeue 1997 1998 elsif not Nkind_In (N, N_Entry_Call_Statement, 1999 N_Function_Call, 2000 N_Procedure_Call_Statement, 2001 N_Requeue_Statement) 2002 then 2003 return; 2004 2005 -- Nothing to do when the input denotes entry call or requeue statement, 2006 -- and switch -gnatd_e (ignore entry calls and requeue statements for 2007 -- elaboration) is in effect. 2008 2009 elsif Debug_Flag_Underscore_E 2010 and then Nkind_In (N, N_Entry_Call_Statement, N_Requeue_Statement) 2011 then 2012 return; 2013 end if; 2014 2015 Call_Nam := Extract_Call_Name (N); 2016 2017 -- Nothing to do when the call is erroneous or left in a bad state 2018 2019 if not (Is_Entity_Name (Call_Nam) 2020 and then Present (Entity (Call_Nam)) 2021 and then Is_Subprogram_Or_Entry (Entity (Call_Nam))) 2022 then 2023 return; 2024 2025 -- Nothing to do when the call invokes a generic formal subprogram and 2026 -- switch -gnatd.G (ignore calls through generic formal parameters for 2027 -- elaboration) is in effect. This check must be performed with the 2028 -- direct target of the call to avoid the side effects of mapping 2029 -- actuals to formals using renamings. 2030 2031 elsif Debug_Flag_Dot_GG 2032 and then Is_Generic_Formal_Subp (Entity (Call_Nam)) 2033 then 2034 return; 2035 2036 -- Nothing to do when the call is analyzed/resolved too early within an 2037 -- intermediate context. This check is saved for last because it incurs 2038 -- a performance penalty. 2039 2040 -- Performance note: parent traversal 2041 2042 elsif In_Premature_Context (N) then 2043 return; 2044 end if; 2045 2046 Extract_Call_Attributes 2047 (Call => N, 2048 Target_Id => Target_Id, 2049 Attrs => Call_Attrs); 2050 2051 Extract_Target_Attributes 2052 (Target_Id => Target_Id, 2053 Attrs => Target_Attrs); 2054 2055 -- Nothing to do when the call appears within the expanded spec or 2056 -- body of an instantiated generic, the call does not invoke a generic 2057 -- formal subprogram, the target is external to the instance, and switch 2058 -- -gnatdL (ignore external calls from instances for elaboration) is in 2059 -- effect. 2060 2061 if Debug_Flag_LL 2062 and then not Is_Generic_Formal_Subp (Entity (Call_Nam)) 2063 2064 -- Performance note: parent traversal 2065 2066 and then In_External_Context 2067 (Call => N, 2068 Target_Attrs => Target_Attrs) 2069 then 2070 return; 2071 2072 -- Nothing to do when the call invokes an assertion pragma procedure 2073 -- and switch -gnatd_p (ignore assertion pragmas for elaboration) is 2074 -- in effect. 2075 2076 elsif Debug_Flag_Underscore_P 2077 and then Is_Assertion_Pragma_Target (Target_Id) 2078 then 2079 return; 2080 2081 -- Source calls to source targets are always considered because they 2082 -- reflect the original call graph. 2083 2084 elsif Target_Attrs.From_Source and then Call_Attrs.From_Source then 2085 null; 2086 2087 -- A call to a source function which acts as the default expression in 2088 -- another call requires special detection. 2089 2090 elsif Target_Attrs.From_Source 2091 and then Nkind (N) = N_Function_Call 2092 and then Is_Default_Expression (N) 2093 then 2094 null; 2095 2096 -- The target emulates Ada semantics 2097 2098 elsif Is_Ada_Semantic_Target (Target_Id) then 2099 null; 2100 2101 -- The target acts as a link between scenarios 2102 2103 elsif Is_Bridge_Target (Target_Id) then 2104 null; 2105 2106 -- The target emulates SPARK semantics 2107 2108 elsif Is_SPARK_Semantic_Target (Target_Id) then 2109 null; 2110 2111 -- Otherwise the call is not suitable for ABE processing. This prevents 2112 -- the generation of call markers which will never play a role in ABE 2113 -- diagnostics. 2114 2115 else 2116 return; 2117 end if; 2118 2119 -- At this point it is known that the call will play some role in ABE 2120 -- checks and diagnostics. Create a corresponding call marker in case 2121 -- the original call is heavily transformed by expansion later on. 2122 2123 Marker := Make_Call_Marker (Sloc (N)); 2124 2125 -- Inherit the attributes of the original call 2126 2127 Set_Target (Marker, Target_Id); 2128 Set_Is_Declaration_Level_Node (Marker, Call_Attrs.In_Declarations); 2129 Set_Is_Dispatching_Call (Marker, Call_Attrs.Is_Dispatching); 2130 Set_Is_Elaboration_Checks_OK_Node 2131 (Marker, Call_Attrs.Elab_Checks_OK); 2132 Set_Is_Elaboration_Warnings_OK_Node 2133 (Marker, Call_Attrs.Elab_Warnings_OK); 2134 Set_Is_Ignored_Ghost_Node (Marker, Call_Attrs.Ghost_Mode_Ignore); 2135 Set_Is_Source_Call (Marker, Call_Attrs.From_Source); 2136 Set_Is_SPARK_Mode_On_Node (Marker, Call_Attrs.SPARK_Mode_On); 2137 2138 -- The marker is inserted prior to the original call. This placement has 2139 -- several desirable effects: 2140 2141 -- 1) The marker appears in the same context, in close proximity to 2142 -- the call. 2143 2144 -- <marker> 2145 -- <call> 2146 2147 -- 2) Inserting the marker prior to the call ensures that an ABE check 2148 -- will take effect prior to the call. 2149 2150 -- <ABE check> 2151 -- <marker> 2152 -- <call> 2153 2154 -- 3) The above two properties are preserved even when the call is a 2155 -- function which is subsequently relocated in order to capture its 2156 -- result. Note that if the call is relocated to a new context, the 2157 -- relocated call will receive a marker of its own. 2158 2159 -- <ABE check> 2160 -- <maker> 2161 -- Temp : ... := Func_Call ...; 2162 -- ... Temp ... 2163 2164 -- The insertion must take place even when the call does not occur in 2165 -- the main unit to keep the tree symmetric. This ensures that internal 2166 -- name serialization is consistent in case the call marker causes the 2167 -- tree to transform in some way. 2168 2169 Insert_Action (N, Marker); 2170 2171 -- The marker becomes the "corresponding" scenario for the call. Save 2172 -- the marker for later processing by the ABE phase. 2173 2174 Record_Elaboration_Scenario (Marker); 2175 end Build_Call_Marker; 2176 2177 ------------------------------------- 2178 -- Build_Variable_Reference_Marker -- 2179 ------------------------------------- 2180 2181 procedure Build_Variable_Reference_Marker 2182 (N : Node_Id; 2183 Read : Boolean; 2184 Write : Boolean) 2185 is 2186 function In_Pragma (Nod : Node_Id) return Boolean; 2187 -- Determine whether arbitrary node Nod appears within a pragma 2188 2189 --------------- 2190 -- In_Pragma -- 2191 --------------- 2192 2193 function In_Pragma (Nod : Node_Id) return Boolean is 2194 Par : Node_Id; 2195 2196 begin 2197 Par := Nod; 2198 while Present (Par) loop 2199 if Nkind (Par) = N_Pragma then 2200 return True; 2201 2202 -- Prevent the search from going too far 2203 2204 elsif Is_Body_Or_Package_Declaration (Par) then 2205 exit; 2206 end if; 2207 2208 Par := Parent (Par); 2209 end loop; 2210 2211 return False; 2212 end In_Pragma; 2213 2214 -- Local variables 2215 2216 Marker : Node_Id; 2217 Prag : Node_Id; 2218 Var_Attrs : Variable_Attributes; 2219 Var_Id : Entity_Id; 2220 2221 -- Start of processing for Build_Variable_Reference_Marker 2222 2223 begin 2224 -- Nothing to do when switch -gnatH (legacy elaboration checking mode 2225 -- enabled) is in effect because the legacy ABE mechanism does not need 2226 -- to carry out this action. 2227 2228 if Legacy_Elaboration_Checks then 2229 return; 2230 2231 -- Nothing to do for ASIS. As a result, ABE checks and diagnostics are 2232 -- not performed in this mode. 2233 2234 elsif ASIS_Mode then 2235 return; 2236 2237 -- Nothing to do when the reference is being preanalyzed as the marker 2238 -- will be inserted in the wrong place. 2239 2240 elsif Preanalysis_Active then 2241 return; 2242 2243 -- Nothing to do when the input does not denote a reference 2244 2245 elsif not Nkind_In (N, N_Expanded_Name, N_Identifier) then 2246 return; 2247 2248 -- Nothing to do for internally-generated references 2249 2250 elsif not Comes_From_Source (N) then 2251 return; 2252 2253 -- Nothing to do when the reference is erroneous, left in a bad state, 2254 -- or does not denote a variable. 2255 2256 elsif not (Present (Entity (N)) 2257 and then Ekind (Entity (N)) = E_Variable 2258 and then Entity (N) /= Any_Id) 2259 then 2260 return; 2261 end if; 2262 2263 Extract_Variable_Reference_Attributes 2264 (Ref => N, 2265 Var_Id => Var_Id, 2266 Attrs => Var_Attrs); 2267 2268 Prag := SPARK_Pragma (Var_Id); 2269 2270 if Comes_From_Source (Var_Id) 2271 2272 -- Both the variable and the reference must appear in SPARK_Mode On 2273 -- regions because this scenario falls under the SPARK rules. 2274 2275 and then Present (Prag) 2276 and then Get_SPARK_Mode_From_Annotation (Prag) = On 2277 and then Is_SPARK_Mode_On_Node (N) 2278 2279 -- The reference must not be considered when it appears in a pragma. 2280 -- If the pragma has run-time semantics, then the reference will be 2281 -- reconsidered once the pragma is expanded. 2282 2283 -- Performance note: parent traversal 2284 2285 and then not In_Pragma (N) 2286 then 2287 null; 2288 2289 -- Otherwise the reference is not suitable for ABE processing. This 2290 -- prevents the generation of variable markers which will never play 2291 -- a role in ABE diagnostics. 2292 2293 else 2294 return; 2295 end if; 2296 2297 -- At this point it is known that the variable reference will play some 2298 -- role in ABE checks and diagnostics. Create a corresponding variable 2299 -- marker in case the original variable reference is folded or optimized 2300 -- away. 2301 2302 Marker := Make_Variable_Reference_Marker (Sloc (N)); 2303 2304 -- Inherit the attributes of the original variable reference 2305 2306 Set_Target (Marker, Var_Id); 2307 Set_Is_Read (Marker, Read); 2308 Set_Is_Write (Marker, Write); 2309 2310 -- The marker is inserted prior to the original variable reference. The 2311 -- insertion must take place even when the reference does not occur in 2312 -- the main unit to keep the tree symmetric. This ensures that internal 2313 -- name serialization is consistent in case the variable marker causes 2314 -- the tree to transform in some way. 2315 2316 Insert_Action (N, Marker); 2317 2318 -- The marker becomes the "corresponding" scenario for the reference. 2319 -- Save the marker for later processing for the ABE phase. 2320 2321 Record_Elaboration_Scenario (Marker); 2322 end Build_Variable_Reference_Marker; 2323 2324 --------------------------------- 2325 -- Check_Elaboration_Scenarios -- 2326 --------------------------------- 2327 2328 procedure Check_Elaboration_Scenarios is 2329 begin 2330 -- Nothing to do when switch -gnatH (legacy elaboration checking mode 2331 -- enabled) is in effect because the legacy ABE mechanism does not need 2332 -- to carry out this action. 2333 2334 if Legacy_Elaboration_Checks then 2335 return; 2336 2337 -- Nothing to do for ASIS. As a result, no ABE checks and diagnostics 2338 -- are performed in this mode. 2339 2340 elsif ASIS_Mode then 2341 return; 2342 end if; 2343 2344 -- Examine the context of the main unit and record all units with prior 2345 -- elaboration with respect to it. 2346 2347 Find_Elaborated_Units; 2348 2349 -- Examine each top-level scenario saved during the Recording phase for 2350 -- conditional ABEs and perform various actions depending on the model 2351 -- in effect. The table of visited bodies is created for each new top- 2352 -- level scenario. 2353 2354 for Index in Top_Level_Scenarios.First .. Top_Level_Scenarios.Last loop 2355 Reset_Visited_Bodies; 2356 2357 Process_Conditional_ABE (Top_Level_Scenarios.Table (Index)); 2358 end loop; 2359 2360 -- Examine each SPARK scenario saved during the Recording phase which 2361 -- is not necessarily executable during elaboration, but still requires 2362 -- elaboration-related checks. 2363 2364 for Index in SPARK_Scenarios.First .. SPARK_Scenarios.Last loop 2365 Check_SPARK_Scenario (SPARK_Scenarios.Table (Index)); 2366 end loop; 2367 end Check_Elaboration_Scenarios; 2368 2369 ------------------------------ 2370 -- Check_Preelaborated_Call -- 2371 ------------------------------ 2372 2373 procedure Check_Preelaborated_Call (Call : Node_Id) is 2374 function In_Preelaborated_Context (N : Node_Id) return Boolean; 2375 -- Determine whether arbitrary node appears in a preelaborated context 2376 2377 ------------------------------ 2378 -- In_Preelaborated_Context -- 2379 ------------------------------ 2380 2381 function In_Preelaborated_Context (N : Node_Id) return Boolean is 2382 Body_Id : constant Entity_Id := Find_Code_Unit (N); 2383 Spec_Id : constant Entity_Id := Unique_Entity (Body_Id); 2384 2385 begin 2386 -- The node appears within a package body whose corresponding spec is 2387 -- subject to pragma Remote_Call_Interface or Remote_Types. This does 2388 -- not result in a preelaborated context because the package body may 2389 -- be on another machine. 2390 2391 if Ekind (Body_Id) = E_Package_Body 2392 and then Ekind_In (Spec_Id, E_Generic_Package, E_Package) 2393 and then (Is_Remote_Call_Interface (Spec_Id) 2394 or else Is_Remote_Types (Spec_Id)) 2395 then 2396 return False; 2397 2398 -- Otherwise the node appears within a preelaborated context when the 2399 -- associated unit is preelaborated. 2400 2401 else 2402 return Is_Preelaborated_Unit (Spec_Id); 2403 end if; 2404 end In_Preelaborated_Context; 2405 2406 -- Local variables 2407 2408 Call_Attrs : Call_Attributes; 2409 Level : Enclosing_Level_Kind; 2410 Target_Id : Entity_Id; 2411 2412 -- Start of processing for Check_Preelaborated_Call 2413 2414 begin 2415 Extract_Call_Attributes 2416 (Call => Call, 2417 Target_Id => Target_Id, 2418 Attrs => Call_Attrs); 2419 2420 -- Nothing to do when the call is internally generated because it is 2421 -- assumed that it will never violate preelaboration. 2422 2423 if not Call_Attrs.From_Source then 2424 return; 2425 end if; 2426 2427 -- Performance note: parent traversal 2428 2429 Level := Find_Enclosing_Level (Call); 2430 2431 -- Library-level calls are always considered because they are part of 2432 -- the associated unit's elaboration actions. 2433 2434 if Level in Library_Level then 2435 null; 2436 2437 -- Calls at the library level of a generic package body must be checked 2438 -- because they would render an instantiation illegal if the template is 2439 -- marked as preelaborated. Note that this does not apply to calls at 2440 -- the library level of a generic package spec. 2441 2442 elsif Level = Generic_Package_Body then 2443 null; 2444 2445 -- Otherwise the call does not appear at the proper level and must not 2446 -- be considered for this check. 2447 2448 else 2449 return; 2450 end if; 2451 2452 -- The call appears within a preelaborated unit. Emit a warning only for 2453 -- internal uses, otherwise this is an error. 2454 2455 if In_Preelaborated_Context (Call) then 2456 Error_Msg_Warn := GNAT_Mode; 2457 Error_Msg_N 2458 ("<<non-static call not allowed in preelaborated unit", Call); 2459 end if; 2460 end Check_Preelaborated_Call; 2461 2462 ------------------------------ 2463 -- Check_SPARK_Derived_Type -- 2464 ------------------------------ 2465 2466 procedure Check_SPARK_Derived_Type (Typ_Decl : Node_Id) is 2467 Typ : constant Entity_Id := Defining_Entity (Typ_Decl); 2468 2469 -- NOTE: The routines within Check_SPARK_Derived_Type are intentionally 2470 -- unnested to avoid deep indentation of code. 2471 2472 Stop_Check : exception; 2473 -- This exception is raised when the freeze node violates the placement 2474 -- rules. 2475 2476 procedure Check_Overriding_Primitive 2477 (Prim : Entity_Id; 2478 FNode : Node_Id); 2479 pragma Inline (Check_Overriding_Primitive); 2480 -- Verify that freeze node FNode is within the early call region of 2481 -- overriding primitive Prim's body. 2482 2483 function Freeze_Node_Location (FNode : Node_Id) return Source_Ptr; 2484 pragma Inline (Freeze_Node_Location); 2485 -- Return a more accurate source location associated with freeze node 2486 -- FNode. 2487 2488 function Precedes_Source_Construct (N : Node_Id) return Boolean; 2489 pragma Inline (Precedes_Source_Construct); 2490 -- Determine whether arbitrary node N appears prior to some source 2491 -- construct. 2492 2493 procedure Suggest_Elaborate_Body 2494 (N : Node_Id; 2495 Body_Decl : Node_Id; 2496 Error_Nod : Node_Id); 2497 pragma Inline (Suggest_Elaborate_Body); 2498 -- Suggest the use of pragma Elaborate_Body when the pragma will allow 2499 -- for node N to appear within the early call region of subprogram body 2500 -- Body_Decl. The suggestion is attached to Error_Nod as a continuation 2501 -- error. 2502 2503 -------------------------------- 2504 -- Check_Overriding_Primitive -- 2505 -------------------------------- 2506 2507 procedure Check_Overriding_Primitive 2508 (Prim : Entity_Id; 2509 FNode : Node_Id) 2510 is 2511 Prim_Decl : constant Node_Id := Unit_Declaration_Node (Prim); 2512 Body_Decl : Node_Id; 2513 Body_Id : Entity_Id; 2514 Region : Node_Id; 2515 2516 begin 2517 Body_Id := Corresponding_Body (Prim_Decl); 2518 2519 -- Nothing to do when the primitive does not have a corresponding 2520 -- body. This can happen when the unit with the bodies is not the 2521 -- main unit subjected to ABE checks. 2522 2523 if No (Body_Id) then 2524 return; 2525 2526 -- The primitive overrides a parent or progenitor primitive 2527 2528 elsif Present (Overridden_Operation (Prim)) then 2529 2530 -- Nothing to do when overriding an interface primitive happens by 2531 -- inheriting a non-interface primitive as the check would be done 2532 -- on the parent primitive. 2533 2534 if Present (Alias (Prim)) then 2535 return; 2536 end if; 2537 2538 -- Nothing to do when the primitive is not overriding. The body of 2539 -- such a primitive cannot be targeted by a dispatching call which 2540 -- is executable during elaboration, and cannot cause an ABE. 2541 2542 else 2543 return; 2544 end if; 2545 2546 Body_Decl := Unit_Declaration_Node (Body_Id); 2547 Region := Find_Early_Call_Region (Body_Decl); 2548 2549 -- The freeze node appears prior to the early call region of the 2550 -- primitive body. 2551 2552 -- IMPORTANT: This check must always be performed even when -gnatd.v 2553 -- (enforce SPARK elaboration rules in SPARK code) is not specified 2554 -- because the static model cannot guarantee the absence of ABEs in 2555 -- in the presence of dispatching calls. 2556 2557 if Earlier_In_Extended_Unit (FNode, Region) then 2558 Error_Msg_Node_2 := Prim; 2559 Error_Msg_NE 2560 ("first freezing point of type & must appear within early call " 2561 & "region of primitive body & (SPARK RM 7.7(8))", 2562 Typ_Decl, Typ); 2563 2564 Error_Msg_Sloc := Sloc (Region); 2565 Error_Msg_N ("\region starts #", Typ_Decl); 2566 2567 Error_Msg_Sloc := Sloc (Body_Decl); 2568 Error_Msg_N ("\region ends #", Typ_Decl); 2569 2570 Error_Msg_Sloc := Freeze_Node_Location (FNode); 2571 Error_Msg_N ("\first freezing point #", Typ_Decl); 2572 2573 -- If applicable, suggest the use of pragma Elaborate_Body in the 2574 -- associated package spec. 2575 2576 Suggest_Elaborate_Body 2577 (N => FNode, 2578 Body_Decl => Body_Decl, 2579 Error_Nod => Typ_Decl); 2580 2581 raise Stop_Check; 2582 end if; 2583 end Check_Overriding_Primitive; 2584 2585 -------------------------- 2586 -- Freeze_Node_Location -- 2587 -------------------------- 2588 2589 function Freeze_Node_Location (FNode : Node_Id) return Source_Ptr is 2590 Context : constant Node_Id := Parent (FNode); 2591 Loc : constant Source_Ptr := Sloc (FNode); 2592 2593 Prv_Decls : List_Id; 2594 Vis_Decls : List_Id; 2595 2596 begin 2597 -- In general, the source location of the freeze node is as close as 2598 -- possible to the real freeze point, except when the freeze node is 2599 -- at the "bottom" of a package spec. 2600 2601 if Nkind (Context) = N_Package_Specification then 2602 Prv_Decls := Private_Declarations (Context); 2603 Vis_Decls := Visible_Declarations (Context); 2604 2605 -- The freeze node appears in the private declarations of the 2606 -- package. 2607 2608 if Present (Prv_Decls) 2609 and then List_Containing (FNode) = Prv_Decls 2610 then 2611 null; 2612 2613 -- The freeze node appears in the visible declarations of the 2614 -- package and there are no private declarations. 2615 2616 elsif Present (Vis_Decls) 2617 and then List_Containing (FNode) = Vis_Decls 2618 and then (No (Prv_Decls) or else Is_Empty_List (Prv_Decls)) 2619 then 2620 null; 2621 2622 -- Otherwise the freeze node is not in the "last" declarative list 2623 -- of the package. Use the existing source location of the freeze 2624 -- node. 2625 2626 else 2627 return Loc; 2628 end if; 2629 2630 -- The freeze node appears at the "bottom" of the package when it 2631 -- is in the "last" declarative list and is either the last in the 2632 -- list or is followed by internal constructs only. In that case 2633 -- the more appropriate source location is that of the package end 2634 -- label. 2635 2636 if not Precedes_Source_Construct (FNode) then 2637 return Sloc (End_Label (Context)); 2638 end if; 2639 end if; 2640 2641 return Loc; 2642 end Freeze_Node_Location; 2643 2644 ------------------------------- 2645 -- Precedes_Source_Construct -- 2646 ------------------------------- 2647 2648 function Precedes_Source_Construct (N : Node_Id) return Boolean is 2649 Decl : Node_Id; 2650 2651 begin 2652 Decl := Next (N); 2653 while Present (Decl) loop 2654 if Comes_From_Source (Decl) then 2655 return True; 2656 2657 -- A generated body for a source expression function is treated as 2658 -- a source construct. 2659 2660 elsif Nkind (Decl) = N_Subprogram_Body 2661 and then Was_Expression_Function (Decl) 2662 and then Comes_From_Source (Original_Node (Decl)) 2663 then 2664 return True; 2665 end if; 2666 2667 Next (Decl); 2668 end loop; 2669 2670 return False; 2671 end Precedes_Source_Construct; 2672 2673 ---------------------------- 2674 -- Suggest_Elaborate_Body -- 2675 ---------------------------- 2676 2677 procedure Suggest_Elaborate_Body 2678 (N : Node_Id; 2679 Body_Decl : Node_Id; 2680 Error_Nod : Node_Id) 2681 is 2682 Unt : constant Node_Id := Unit (Cunit (Main_Unit)); 2683 Region : Node_Id; 2684 2685 begin 2686 -- The suggestion applies only when the subprogram body resides in a 2687 -- compilation package body, and a pragma Elaborate_Body would allow 2688 -- for the node to appear in the early call region of the subprogram 2689 -- body. This implies that all code from the subprogram body up to 2690 -- the node is preelaborable. 2691 2692 if Nkind (Unt) = N_Package_Body then 2693 2694 -- Find the start of the early call region again assuming that the 2695 -- package spec has pragma Elaborate_Body. Note that the internal 2696 -- data structures are intentionally not updated because this is a 2697 -- speculative search. 2698 2699 Region := 2700 Find_Early_Call_Region 2701 (Body_Decl => Body_Decl, 2702 Assume_Elab_Body => True, 2703 Skip_Memoization => True); 2704 2705 -- If the node appears within the early call region, assuming that 2706 -- the package spec carries pragma Elaborate_Body, then it is safe 2707 -- to suggest the pragma. 2708 2709 if Earlier_In_Extended_Unit (Region, N) then 2710 Error_Msg_Name_1 := Name_Elaborate_Body; 2711 Error_Msg_NE 2712 ("\consider adding pragma % in spec of unit &", 2713 Error_Nod, Defining_Entity (Unt)); 2714 end if; 2715 end if; 2716 end Suggest_Elaborate_Body; 2717 2718 -- Local variables 2719 2720 FNode : constant Node_Id := Freeze_Node (Typ); 2721 Prims : constant Elist_Id := Direct_Primitive_Operations (Typ); 2722 2723 Prim_Elmt : Elmt_Id; 2724 2725 -- Start of processing for Check_SPARK_Derived_Type 2726 2727 begin 2728 -- A type should have its freeze node set by the time SPARK scenarios 2729 -- are being verified. 2730 2731 pragma Assert (Present (FNode)); 2732 2733 -- Verify that the freeze node of the derived type is within the early 2734 -- call region of each overriding primitive body (SPARK RM 7.7(8)). 2735 2736 if Present (Prims) then 2737 Prim_Elmt := First_Elmt (Prims); 2738 while Present (Prim_Elmt) loop 2739 Check_Overriding_Primitive 2740 (Prim => Node (Prim_Elmt), 2741 FNode => FNode); 2742 2743 Next_Elmt (Prim_Elmt); 2744 end loop; 2745 end if; 2746 2747 exception 2748 when Stop_Check => 2749 null; 2750 end Check_SPARK_Derived_Type; 2751 2752 ------------------------------- 2753 -- Check_SPARK_Instantiation -- 2754 ------------------------------- 2755 2756 procedure Check_SPARK_Instantiation (Exp_Inst : Node_Id) is 2757 Gen_Attrs : Target_Attributes; 2758 Gen_Id : Entity_Id; 2759 Inst : Node_Id; 2760 Inst_Attrs : Instantiation_Attributes; 2761 Inst_Id : Entity_Id; 2762 2763 begin 2764 Extract_Instantiation_Attributes 2765 (Exp_Inst => Exp_Inst, 2766 Inst => Inst, 2767 Inst_Id => Inst_Id, 2768 Gen_Id => Gen_Id, 2769 Attrs => Inst_Attrs); 2770 2771 Extract_Target_Attributes (Gen_Id, Gen_Attrs); 2772 2773 -- The instantiation and the generic body are both in the main unit 2774 2775 if Present (Gen_Attrs.Body_Decl) 2776 and then In_Extended_Main_Code_Unit (Gen_Attrs.Body_Decl) 2777 2778 -- If the instantiation appears prior to the generic body, then the 2779 -- instantiation is illegal (SPARK RM 7.7(6)). 2780 2781 -- IMPORTANT: This check must always be performed even when -gnatd.v 2782 -- (enforce SPARK elaboration rules in SPARK code) is not specified 2783 -- because the rule prevents use-before-declaration of objects that 2784 -- may precede the generic body. 2785 2786 and then Earlier_In_Extended_Unit (Inst, Gen_Attrs.Body_Decl) 2787 then 2788 Error_Msg_NE ("cannot instantiate & before body seen", Inst, Gen_Id); 2789 end if; 2790 end Check_SPARK_Instantiation; 2791 2792 --------------------------------- 2793 -- Check_SPARK_Model_In_Effect -- 2794 --------------------------------- 2795 2796 SPARK_Model_Warning_Posted : Boolean := False; 2797 -- This flag prevents the same SPARK model-related warning from being 2798 -- emitted multiple times. 2799 2800 procedure Check_SPARK_Model_In_Effect (N : Node_Id) is 2801 begin 2802 -- Do not emit the warning multiple times as this creates useless noise 2803 2804 if SPARK_Model_Warning_Posted then 2805 null; 2806 2807 -- SPARK rule verification requires the "strict" static model 2808 2809 elsif Static_Elaboration_Checks and not Relaxed_Elaboration_Checks then 2810 null; 2811 2812 -- Any other combination of models does not guarantee the absence of ABE 2813 -- problems for SPARK rule verification purposes. Note that there is no 2814 -- need to check for the legacy ABE mechanism because the legacy code 2815 -- has its own orthogonal processing for SPARK rules. 2816 2817 else 2818 SPARK_Model_Warning_Posted := True; 2819 2820 Error_Msg_N 2821 ("??SPARK elaboration checks require static elaboration model", N); 2822 2823 if Dynamic_Elaboration_Checks then 2824 Error_Msg_N ("\dynamic elaboration model is in effect", N); 2825 else 2826 pragma Assert (Relaxed_Elaboration_Checks); 2827 Error_Msg_N ("\relaxed elaboration model is in effect", N); 2828 end if; 2829 end if; 2830 end Check_SPARK_Model_In_Effect; 2831 2832 -------------------------- 2833 -- Check_SPARK_Scenario -- 2834 -------------------------- 2835 2836 procedure Check_SPARK_Scenario (N : Node_Id) is 2837 begin 2838 -- Ensure that a suitable elaboration model is in effect for SPARK rule 2839 -- verification. 2840 2841 Check_SPARK_Model_In_Effect (N); 2842 2843 -- Add the current scenario to the stack of active scenarios 2844 2845 Push_Active_Scenario (N); 2846 2847 if Is_Suitable_SPARK_Derived_Type (N) then 2848 Check_SPARK_Derived_Type (N); 2849 2850 elsif Is_Suitable_SPARK_Instantiation (N) then 2851 Check_SPARK_Instantiation (N); 2852 2853 elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then 2854 Check_SPARK_Refined_State_Pragma (N); 2855 end if; 2856 2857 -- Remove the current scenario from the stack of active scenarios once 2858 -- all ABE diagnostics and checks have been performed. 2859 2860 Pop_Active_Scenario (N); 2861 end Check_SPARK_Scenario; 2862 2863 -------------------------------------- 2864 -- Check_SPARK_Refined_State_Pragma -- 2865 -------------------------------------- 2866 2867 procedure Check_SPARK_Refined_State_Pragma (N : Node_Id) is 2868 2869 -- NOTE: The routines within Check_SPARK_Refined_State_Pragma are 2870 -- intentionally unnested to avoid deep indentation of code. 2871 2872 procedure Check_SPARK_Constituent (Constit_Id : Entity_Id); 2873 pragma Inline (Check_SPARK_Constituent); 2874 -- Ensure that a single constituent Constit_Id is elaborated prior to 2875 -- the main unit. 2876 2877 procedure Check_SPARK_Constituents (Constits : Elist_Id); 2878 pragma Inline (Check_SPARK_Constituents); 2879 -- Ensure that all constituents found in list Constits are elaborated 2880 -- prior to the main unit. 2881 2882 procedure Check_SPARK_Initialized_State (State : Node_Id); 2883 pragma Inline (Check_SPARK_Initialized_State); 2884 -- Ensure that the constituents of single abstract state State are 2885 -- elaborated prior to the main unit. 2886 2887 procedure Check_SPARK_Initialized_States (Pack_Id : Entity_Id); 2888 pragma Inline (Check_SPARK_Initialized_States); 2889 -- Ensure that the constituents of all abstract states which appear in 2890 -- the Initializes pragma of package Pack_Id are elaborated prior to the 2891 -- main unit. 2892 2893 ----------------------------- 2894 -- Check_SPARK_Constituent -- 2895 ----------------------------- 2896 2897 procedure Check_SPARK_Constituent (Constit_Id : Entity_Id) is 2898 Prag : Node_Id; 2899 2900 begin 2901 -- Nothing to do for "null" constituents 2902 2903 if Nkind (Constit_Id) = N_Null then 2904 return; 2905 2906 -- Nothing to do for illegal constituents 2907 2908 elsif Error_Posted (Constit_Id) then 2909 return; 2910 end if; 2911 2912 Prag := SPARK_Pragma (Constit_Id); 2913 2914 -- The check applies only when the constituent is subject to pragma 2915 -- SPARK_Mode On. 2916 2917 if Present (Prag) 2918 and then Get_SPARK_Mode_From_Annotation (Prag) = On 2919 then 2920 -- An external constituent of an abstract state which appears in 2921 -- the Initializes pragma of a package spec imposes an Elaborate 2922 -- requirement on the context of the main unit. Determine whether 2923 -- the context has a pragma strong enough to meet the requirement. 2924 2925 -- IMPORTANT: This check is performed only when -gnatd.v (enforce 2926 -- SPARK elaboration rules in SPARK code) is in effect because the 2927 -- static model can ensure the prior elaboration of the unit which 2928 -- contains a constituent by installing implicit Elaborate pragma. 2929 2930 if Debug_Flag_Dot_V then 2931 Meet_Elaboration_Requirement 2932 (N => N, 2933 Target_Id => Constit_Id, 2934 Req_Nam => Name_Elaborate); 2935 2936 -- Otherwise ensure that the unit with the external constituent is 2937 -- elaborated prior to the main unit. 2938 2939 else 2940 Ensure_Prior_Elaboration 2941 (N => N, 2942 Unit_Id => Find_Top_Unit (Constit_Id), 2943 Prag_Nam => Name_Elaborate, 2944 State => Initial_State); 2945 end if; 2946 end if; 2947 end Check_SPARK_Constituent; 2948 2949 ------------------------------ 2950 -- Check_SPARK_Constituents -- 2951 ------------------------------ 2952 2953 procedure Check_SPARK_Constituents (Constits : Elist_Id) is 2954 Constit_Elmt : Elmt_Id; 2955 2956 begin 2957 if Present (Constits) then 2958 Constit_Elmt := First_Elmt (Constits); 2959 while Present (Constit_Elmt) loop 2960 Check_SPARK_Constituent (Node (Constit_Elmt)); 2961 Next_Elmt (Constit_Elmt); 2962 end loop; 2963 end if; 2964 end Check_SPARK_Constituents; 2965 2966 ----------------------------------- 2967 -- Check_SPARK_Initialized_State -- 2968 ----------------------------------- 2969 2970 procedure Check_SPARK_Initialized_State (State : Node_Id) is 2971 Prag : Node_Id; 2972 State_Id : Entity_Id; 2973 2974 begin 2975 -- Nothing to do for "null" initialization items 2976 2977 if Nkind (State) = N_Null then 2978 return; 2979 2980 -- Nothing to do for illegal states 2981 2982 elsif Error_Posted (State) then 2983 return; 2984 end if; 2985 2986 State_Id := Entity_Of (State); 2987 2988 -- Sanitize the state 2989 2990 if No (State_Id) then 2991 return; 2992 2993 elsif Error_Posted (State_Id) then 2994 return; 2995 2996 elsif Ekind (State_Id) /= E_Abstract_State then 2997 return; 2998 end if; 2999 3000 -- The check is performed only when the abstract state is subject to 3001 -- SPARK_Mode On. 3002 3003 Prag := SPARK_Pragma (State_Id); 3004 3005 if Present (Prag) 3006 and then Get_SPARK_Mode_From_Annotation (Prag) = On 3007 then 3008 Check_SPARK_Constituents (Refinement_Constituents (State_Id)); 3009 end if; 3010 end Check_SPARK_Initialized_State; 3011 3012 ------------------------------------ 3013 -- Check_SPARK_Initialized_States -- 3014 ------------------------------------ 3015 3016 procedure Check_SPARK_Initialized_States (Pack_Id : Entity_Id) is 3017 Prag : constant Node_Id := Get_Pragma (Pack_Id, Pragma_Initializes); 3018 Init : Node_Id; 3019 Inits : Node_Id; 3020 3021 begin 3022 if Present (Prag) then 3023 Inits := Expression (Get_Argument (Prag, Pack_Id)); 3024 3025 -- Avoid processing a "null" initialization list. The only other 3026 -- alternative is an aggregate. 3027 3028 if Nkind (Inits) = N_Aggregate then 3029 3030 -- The initialization items appear in list form: 3031 -- 3032 -- (state1, state2) 3033 3034 if Present (Expressions (Inits)) then 3035 Init := First (Expressions (Inits)); 3036 while Present (Init) loop 3037 Check_SPARK_Initialized_State (Init); 3038 Next (Init); 3039 end loop; 3040 end if; 3041 3042 -- The initialization items appear in associated form: 3043 -- 3044 -- (state1 => item1, 3045 -- state2 => (item2, item3)) 3046 3047 if Present (Component_Associations (Inits)) then 3048 Init := First (Component_Associations (Inits)); 3049 while Present (Init) loop 3050 Check_SPARK_Initialized_State (Init); 3051 Next (Init); 3052 end loop; 3053 end if; 3054 end if; 3055 end if; 3056 end Check_SPARK_Initialized_States; 3057 3058 -- Local variables 3059 3060 Pack_Body : constant Node_Id := Find_Related_Package_Or_Body (N); 3061 3062 -- Start of processing for Check_SPARK_Refined_State_Pragma 3063 3064 begin 3065 -- Pragma Refined_State must be associated with a package body 3066 3067 pragma Assert 3068 (Present (Pack_Body) and then Nkind (Pack_Body) = N_Package_Body); 3069 3070 -- Verify that each external contitunent of an abstract state mentioned 3071 -- in pragma Initializes is properly elaborated. 3072 3073 Check_SPARK_Initialized_States (Unique_Defining_Entity (Pack_Body)); 3074 end Check_SPARK_Refined_State_Pragma; 3075 3076 ---------------------- 3077 -- Compilation_Unit -- 3078 ---------------------- 3079 3080 function Compilation_Unit (Unit_Id : Entity_Id) return Node_Id is 3081 Comp_Unit : Node_Id; 3082 3083 begin 3084 Comp_Unit := Parent (Unit_Id); 3085 3086 -- Handle the case where a concurrent subunit is rewritten as a null 3087 -- statement due to expansion activities. 3088 3089 if Nkind (Comp_Unit) = N_Null_Statement 3090 and then Nkind_In (Original_Node (Comp_Unit), N_Protected_Body, 3091 N_Task_Body) 3092 then 3093 Comp_Unit := Parent (Comp_Unit); 3094 pragma Assert (Nkind (Comp_Unit) = N_Subunit); 3095 3096 -- Otherwise use the declaration node of the unit 3097 3098 else 3099 Comp_Unit := Parent (Unit_Declaration_Node (Unit_Id)); 3100 end if; 3101 3102 -- Handle the case where a subprogram instantiation which acts as a 3103 -- compilation unit is expanded into an anonymous package that wraps 3104 -- the instantiated subprogram. 3105 3106 if Nkind (Comp_Unit) = N_Package_Specification 3107 and then Nkind_In (Original_Node (Parent (Comp_Unit)), 3108 N_Function_Instantiation, 3109 N_Procedure_Instantiation) 3110 then 3111 Comp_Unit := Parent (Parent (Comp_Unit)); 3112 3113 -- Handle the case where the compilation unit is a subunit 3114 3115 elsif Nkind (Comp_Unit) = N_Subunit then 3116 Comp_Unit := Parent (Comp_Unit); 3117 end if; 3118 3119 pragma Assert (Nkind (Comp_Unit) = N_Compilation_Unit); 3120 3121 return Comp_Unit; 3122 end Compilation_Unit; 3123 3124 ----------------------- 3125 -- Early_Call_Region -- 3126 ----------------------- 3127 3128 function Early_Call_Region (Body_Id : Entity_Id) return Node_Id is 3129 begin 3130 pragma Assert (Ekind_In (Body_Id, E_Entry, 3131 E_Entry_Family, 3132 E_Function, 3133 E_Procedure, 3134 E_Subprogram_Body)); 3135 3136 if Early_Call_Regions_In_Use then 3137 return Early_Call_Regions.Get (Body_Id); 3138 end if; 3139 3140 return Early_Call_Regions_No_Element; 3141 end Early_Call_Region; 3142 3143 ----------------------------- 3144 -- Early_Call_Regions_Hash -- 3145 ----------------------------- 3146 3147 function Early_Call_Regions_Hash 3148 (Key : Entity_Id) return Early_Call_Regions_Index 3149 is 3150 begin 3151 return Early_Call_Regions_Index (Key mod Early_Call_Regions_Max); 3152 end Early_Call_Regions_Hash; 3153 3154 ----------------- 3155 -- Elab_Msg_NE -- 3156 ----------------- 3157 3158 procedure Elab_Msg_NE 3159 (Msg : String; 3160 N : Node_Id; 3161 Id : Entity_Id; 3162 Info_Msg : Boolean; 3163 In_SPARK : Boolean) 3164 is 3165 function Prefix return String; 3166 -- Obtain the prefix of the message 3167 3168 function Suffix return String; 3169 -- Obtain the suffix of the message 3170 3171 ------------ 3172 -- Prefix -- 3173 ------------ 3174 3175 function Prefix return String is 3176 begin 3177 if Info_Msg then 3178 return "info: "; 3179 else 3180 return ""; 3181 end if; 3182 end Prefix; 3183 3184 ------------ 3185 -- Suffix -- 3186 ------------ 3187 3188 function Suffix return String is 3189 begin 3190 if In_SPARK then 3191 return " in SPARK"; 3192 else 3193 return ""; 3194 end if; 3195 end Suffix; 3196 3197 -- Start of processing for Elab_Msg_NE 3198 3199 begin 3200 Error_Msg_NE (Prefix & Msg & Suffix, N, Id); 3201 end Elab_Msg_NE; 3202 3203 ------------------------ 3204 -- Elaboration_Status -- 3205 ------------------------ 3206 3207 function Elaboration_Status 3208 (Unit_Id : Entity_Id) return Elaboration_Attributes 3209 is 3210 begin 3211 if Elaboration_Statuses_In_Use then 3212 return Elaboration_Statuses.Get (Unit_Id); 3213 end if; 3214 3215 return Elaboration_Statuses_No_Element; 3216 end Elaboration_Status; 3217 3218 ------------------------------- 3219 -- Elaboration_Statuses_Hash -- 3220 ------------------------------- 3221 3222 function Elaboration_Statuses_Hash 3223 (Key : Entity_Id) return Elaboration_Statuses_Index 3224 is 3225 begin 3226 return Elaboration_Statuses_Index (Key mod Elaboration_Statuses_Max); 3227 end Elaboration_Statuses_Hash; 3228 3229 ------------------------------ 3230 -- Ensure_Prior_Elaboration -- 3231 ------------------------------ 3232 3233 procedure Ensure_Prior_Elaboration 3234 (N : Node_Id; 3235 Unit_Id : Entity_Id; 3236 Prag_Nam : Name_Id; 3237 State : Processing_Attributes) 3238 is 3239 begin 3240 pragma Assert (Nam_In (Prag_Nam, Name_Elaborate, Name_Elaborate_All)); 3241 3242 -- Nothing to do when the caller has suppressed the generation of 3243 -- implicit Elaborate[_All] pragmas. 3244 3245 if State.Suppress_Implicit_Pragmas then 3246 return; 3247 3248 -- Nothing to do when the need for prior elaboration came from a partial 3249 -- finalization routine which occurs in an initialization context. This 3250 -- behaviour parallels that of the old ABE mechanism. 3251 3252 elsif State.Within_Partial_Finalization then 3253 return; 3254 3255 -- Nothing to do when the need for prior elaboration came from a task 3256 -- body and switch -gnatd.y (disable implicit pragma Elaborate_All on 3257 -- task bodies) is in effect. 3258 3259 elsif Debug_Flag_Dot_Y and then State.Within_Task_Body then 3260 return; 3261 3262 -- Nothing to do when the unit is elaborated prior to the main unit. 3263 -- This check must also consider the following cases: 3264 3265 -- * No check is made against the context of the main unit because this 3266 -- is specific to the elaboration model in effect and requires custom 3267 -- handling (see Ensure_xxx_Prior_Elaboration). 3268 3269 -- * Unit_Id is subject to pragma Elaborate_Body. An implicit pragma 3270 -- Elaborate[_All] MUST be generated even though Unit_Id is always 3271 -- elaborated prior to the main unit. This is a conservative strategy 3272 -- which ensures that other units withed by Unit_Id will not lead to 3273 -- an ABE. 3274 3275 -- package A is package body A is 3276 -- procedure ABE; procedure ABE is ... end ABE; 3277 -- end A; end A; 3278 3279 -- with A; 3280 -- package B is package body B is 3281 -- pragma Elaborate_Body; procedure Proc is 3282 -- begin 3283 -- procedure Proc; A.ABE; 3284 -- package B; end Proc; 3285 -- end B; 3286 3287 -- with B; 3288 -- package C is package body C is 3289 -- ... ... 3290 -- end C; begin 3291 -- B.Proc; 3292 -- end C; 3293 3294 -- In the example above, the elaboration of C invokes B.Proc. B is 3295 -- subject to pragma Elaborate_Body. If no pragma Elaborate[_All] is 3296 -- generated for B in C, then the following elaboratio order will lead 3297 -- to an ABE: 3298 3299 -- spec of A elaborated 3300 -- spec of B elaborated 3301 -- body of B elaborated 3302 -- spec of C elaborated 3303 -- body of C elaborated <-- calls B.Proc which calls A.ABE 3304 -- body of A elaborated <-- problem 3305 3306 -- The generation of an implicit pragma Elaborate_All (B) ensures that 3307 -- the elaboration order mechanism will not pick the above order. 3308 3309 -- An implicit Elaborate is NOT generated when the unit is subject to 3310 -- Elaborate_Body because both pragmas have the exact same effect. 3311 3312 -- * Unit_Id is the main unit. An implicit pragma Elaborate[_All] MUST 3313 -- NOT be generated in this case because a unit cannot depend on its 3314 -- own elaboration. This case is therefore treated as valid prior 3315 -- elaboration. 3316 3317 elsif Has_Prior_Elaboration 3318 (Unit_Id => Unit_Id, 3319 Same_Unit_OK => True, 3320 Elab_Body_OK => Prag_Nam = Name_Elaborate) 3321 then 3322 return; 3323 3324 -- Suggest the use of pragma Prag_Nam when the dynamic model is in 3325 -- effect. 3326 3327 elsif Dynamic_Elaboration_Checks then 3328 Ensure_Prior_Elaboration_Dynamic 3329 (N => N, 3330 Unit_Id => Unit_Id, 3331 Prag_Nam => Prag_Nam); 3332 3333 -- Install an implicit pragma Prag_Nam when the static model is in 3334 -- effect. 3335 3336 else 3337 pragma Assert (Static_Elaboration_Checks); 3338 3339 Ensure_Prior_Elaboration_Static 3340 (N => N, 3341 Unit_Id => Unit_Id, 3342 Prag_Nam => Prag_Nam); 3343 end if; 3344 end Ensure_Prior_Elaboration; 3345 3346 -------------------------------------- 3347 -- Ensure_Prior_Elaboration_Dynamic -- 3348 -------------------------------------- 3349 3350 procedure Ensure_Prior_Elaboration_Dynamic 3351 (N : Node_Id; 3352 Unit_Id : Entity_Id; 3353 Prag_Nam : Name_Id) 3354 is 3355 procedure Info_Missing_Pragma; 3356 pragma Inline (Info_Missing_Pragma); 3357 -- Output information concerning missing Elaborate or Elaborate_All 3358 -- pragma with name Prag_Nam for scenario N, which would ensure the 3359 -- prior elaboration of Unit_Id. 3360 3361 ------------------------- 3362 -- Info_Missing_Pragma -- 3363 ------------------------- 3364 3365 procedure Info_Missing_Pragma is 3366 begin 3367 -- Internal units are ignored as they cause unnecessary noise 3368 3369 if not In_Internal_Unit (Unit_Id) then 3370 3371 -- The name of the unit subjected to the elaboration pragma is 3372 -- fully qualified to improve the clarity of the info message. 3373 3374 Error_Msg_Name_1 := Prag_Nam; 3375 Error_Msg_Qual_Level := Nat'Last; 3376 3377 Error_Msg_NE ("info: missing pragma % for unit &", N, Unit_Id); 3378 Error_Msg_Qual_Level := 0; 3379 end if; 3380 end Info_Missing_Pragma; 3381 3382 -- Local variables 3383 3384 Elab_Attrs : Elaboration_Attributes; 3385 Level : Enclosing_Level_Kind; 3386 3387 -- Start of processing for Ensure_Prior_Elaboration_Dynamic 3388 3389 begin 3390 Elab_Attrs := Elaboration_Status (Unit_Id); 3391 3392 -- Nothing to do when the unit is guaranteed prior elaboration by means 3393 -- of a source Elaborate[_All] pragma. 3394 3395 if Present (Elab_Attrs.Source_Pragma) then 3396 return; 3397 end if; 3398 3399 -- Output extra information on a missing Elaborate[_All] pragma when 3400 -- switch -gnatel (info messages on implicit Elaborate[_All] pragmas 3401 -- is in effect. 3402 3403 if Elab_Info_Messages then 3404 3405 -- Performance note: parent traversal 3406 3407 Level := Find_Enclosing_Level (N); 3408 3409 -- Declaration-level scenario 3410 3411 if (Is_Suitable_Call (N) or else Is_Suitable_Instantiation (N)) 3412 and then Level = Declaration_Level 3413 then 3414 null; 3415 3416 -- Library-level scenario 3417 3418 elsif Level in Library_Level then 3419 null; 3420 3421 -- Instantiation library-level scenario 3422 3423 elsif Level = Instantiation then 3424 null; 3425 3426 -- Otherwise the scenario does not appear at the proper level and 3427 -- cannot possibly act as a top-level scenario. 3428 3429 else 3430 return; 3431 end if; 3432 3433 Info_Missing_Pragma; 3434 end if; 3435 end Ensure_Prior_Elaboration_Dynamic; 3436 3437 ------------------------------------- 3438 -- Ensure_Prior_Elaboration_Static -- 3439 ------------------------------------- 3440 3441 procedure Ensure_Prior_Elaboration_Static 3442 (N : Node_Id; 3443 Unit_Id : Entity_Id; 3444 Prag_Nam : Name_Id) 3445 is 3446 function Find_With_Clause 3447 (Items : List_Id; 3448 Withed_Id : Entity_Id) return Node_Id; 3449 pragma Inline (Find_With_Clause); 3450 -- Find a nonlimited with clause in the list of context items Items 3451 -- that withs unit Withed_Id. Return Empty if no such clause is found. 3452 3453 procedure Info_Implicit_Pragma; 3454 pragma Inline (Info_Implicit_Pragma); 3455 -- Output information concerning an implicitly generated Elaborate or 3456 -- Elaborate_All pragma with name Prag_Nam for scenario N which ensures 3457 -- the prior elaboration of unit Unit_Id. 3458 3459 ---------------------- 3460 -- Find_With_Clause -- 3461 ---------------------- 3462 3463 function Find_With_Clause 3464 (Items : List_Id; 3465 Withed_Id : Entity_Id) return Node_Id 3466 is 3467 Item : Node_Id; 3468 3469 begin 3470 -- Examine the context clauses looking for a suitable with. Note that 3471 -- limited clauses do not affect the elaboration order. 3472 3473 Item := First (Items); 3474 while Present (Item) loop 3475 if Nkind (Item) = N_With_Clause 3476 and then not Error_Posted (Item) 3477 and then not Limited_Present (Item) 3478 and then Entity (Name (Item)) = Withed_Id 3479 then 3480 return Item; 3481 end if; 3482 3483 Next (Item); 3484 end loop; 3485 3486 return Empty; 3487 end Find_With_Clause; 3488 3489 -------------------------- 3490 -- Info_Implicit_Pragma -- 3491 -------------------------- 3492 3493 procedure Info_Implicit_Pragma is 3494 begin 3495 -- Internal units are ignored as they cause unnecessary noise 3496 3497 if not In_Internal_Unit (Unit_Id) then 3498 3499 -- The name of the unit subjected to the elaboration pragma is 3500 -- fully qualified to improve the clarity of the info message. 3501 3502 Error_Msg_Name_1 := Prag_Nam; 3503 Error_Msg_Qual_Level := Nat'Last; 3504 3505 Error_Msg_NE 3506 ("info: implicit pragma % generated for unit &", N, Unit_Id); 3507 3508 Error_Msg_Qual_Level := 0; 3509 Output_Active_Scenarios (N); 3510 end if; 3511 end Info_Implicit_Pragma; 3512 3513 -- Local variables 3514 3515 Main_Cunit : constant Node_Id := Cunit (Main_Unit); 3516 Loc : constant Source_Ptr := Sloc (Main_Cunit); 3517 Unit_Cunit : constant Node_Id := Compilation_Unit (Unit_Id); 3518 3519 Clause : Node_Id; 3520 Elab_Attrs : Elaboration_Attributes; 3521 Items : List_Id; 3522 3523 -- Start of processing for Ensure_Prior_Elaboration_Static 3524 3525 begin 3526 Elab_Attrs := Elaboration_Status (Unit_Id); 3527 3528 -- Nothing to do when the unit is guaranteed prior elaboration by means 3529 -- of a source Elaborate[_All] pragma. 3530 3531 if Present (Elab_Attrs.Source_Pragma) then 3532 return; 3533 3534 -- Nothing to do when the unit has an existing implicit Elaborate[_All] 3535 -- pragma installed by a previous scenario. 3536 3537 elsif Present (Elab_Attrs.With_Clause) then 3538 3539 -- The unit is already guaranteed prior elaboration by means of an 3540 -- implicit Elaborate pragma, however the current scenario imposes 3541 -- a stronger requirement of Elaborate_All. "Upgrade" the existing 3542 -- pragma to match this new requirement. 3543 3544 if Elaborate_Desirable (Elab_Attrs.With_Clause) 3545 and then Prag_Nam = Name_Elaborate_All 3546 then 3547 Set_Elaborate_All_Desirable (Elab_Attrs.With_Clause); 3548 Set_Elaborate_Desirable (Elab_Attrs.With_Clause, False); 3549 end if; 3550 3551 return; 3552 end if; 3553 3554 -- At this point it is known that the unit has no prior elaboration 3555 -- according to pragmas and hierarchical relationships. 3556 3557 Items := Context_Items (Main_Cunit); 3558 3559 if No (Items) then 3560 Items := New_List; 3561 Set_Context_Items (Main_Cunit, Items); 3562 end if; 3563 3564 -- Locate the with clause for the unit. Note that there may not be a 3565 -- clause if the unit is visible through a subunit-body, body-spec, or 3566 -- spec-parent relationship. 3567 3568 Clause := 3569 Find_With_Clause 3570 (Items => Items, 3571 Withed_Id => Unit_Id); 3572 3573 -- Generate: 3574 -- with Id; 3575 3576 -- Note that adding implicit with clauses is safe because analysis, 3577 -- resolution, and expansion have already taken place and it is not 3578 -- possible to interfere with visibility. 3579 3580 if No (Clause) then 3581 Clause := 3582 Make_With_Clause (Loc, 3583 Name => New_Occurrence_Of (Unit_Id, Loc)); 3584 3585 Set_Implicit_With (Clause); 3586 Set_Library_Unit (Clause, Unit_Cunit); 3587 3588 Append_To (Items, Clause); 3589 end if; 3590 3591 -- Mark the with clause depending on the pragma required 3592 3593 if Prag_Nam = Name_Elaborate then 3594 Set_Elaborate_Desirable (Clause); 3595 else 3596 Set_Elaborate_All_Desirable (Clause); 3597 end if; 3598 3599 -- The implicit Elaborate[_All] ensures the prior elaboration of the 3600 -- unit. Include the unit in the elaboration context of the main unit. 3601 3602 Set_Elaboration_Status 3603 (Unit_Id => Unit_Id, 3604 Val => Elaboration_Attributes'(Source_Pragma => Empty, 3605 With_Clause => Clause)); 3606 3607 -- Output extra information on an implicit Elaborate[_All] pragma when 3608 -- switch -gnatel (info messages on implicit Elaborate[_All] pragmas is 3609 -- in effect. 3610 3611 if Elab_Info_Messages then 3612 Info_Implicit_Pragma; 3613 end if; 3614 end Ensure_Prior_Elaboration_Static; 3615 3616 ----------------------------- 3617 -- Extract_Assignment_Name -- 3618 ----------------------------- 3619 3620 function Extract_Assignment_Name (Asmt : Node_Id) return Node_Id is 3621 Nam : Node_Id; 3622 3623 begin 3624 Nam := Name (Asmt); 3625 3626 -- When the name denotes an array or record component, find the whole 3627 -- object. 3628 3629 while Nkind_In (Nam, N_Explicit_Dereference, 3630 N_Indexed_Component, 3631 N_Selected_Component, 3632 N_Slice) 3633 loop 3634 Nam := Prefix (Nam); 3635 end loop; 3636 3637 return Nam; 3638 end Extract_Assignment_Name; 3639 3640 ----------------------------- 3641 -- Extract_Call_Attributes -- 3642 ----------------------------- 3643 3644 procedure Extract_Call_Attributes 3645 (Call : Node_Id; 3646 Target_Id : out Entity_Id; 3647 Attrs : out Call_Attributes) 3648 is 3649 From_Source : Boolean; 3650 In_Declarations : Boolean; 3651 Is_Dispatching : Boolean; 3652 3653 begin 3654 -- Extraction for call markers 3655 3656 if Nkind (Call) = N_Call_Marker then 3657 Target_Id := Target (Call); 3658 From_Source := Is_Source_Call (Call); 3659 In_Declarations := Is_Declaration_Level_Node (Call); 3660 Is_Dispatching := Is_Dispatching_Call (Call); 3661 3662 -- Extraction for entry calls, requeue, and subprogram calls 3663 3664 else 3665 pragma Assert (Nkind_In (Call, N_Entry_Call_Statement, 3666 N_Function_Call, 3667 N_Procedure_Call_Statement, 3668 N_Requeue_Statement)); 3669 3670 Target_Id := Entity (Extract_Call_Name (Call)); 3671 From_Source := Comes_From_Source (Call); 3672 3673 -- Performance note: parent traversal 3674 3675 In_Declarations := Find_Enclosing_Level (Call) = Declaration_Level; 3676 Is_Dispatching := 3677 Nkind_In (Call, N_Function_Call, N_Procedure_Call_Statement) 3678 and then Present (Controlling_Argument (Call)); 3679 end if; 3680 3681 -- Obtain the original entry or subprogram which the target may rename 3682 -- except when the target is an instantiation. In this case the alias 3683 -- is the internally generated subprogram which appears within the the 3684 -- anonymous package created for the instantiation. Such an alias is not 3685 -- a suitable target. 3686 3687 if not (Is_Subprogram (Target_Id) 3688 and then Is_Generic_Instance (Target_Id)) 3689 then 3690 Target_Id := Get_Renamed_Entity (Target_Id); 3691 end if; 3692 3693 -- Set all attributes 3694 3695 Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Node (Call); 3696 Attrs.Elab_Warnings_OK := Is_Elaboration_Warnings_OK_Node (Call); 3697 Attrs.From_Source := From_Source; 3698 Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Node (Call); 3699 Attrs.In_Declarations := In_Declarations; 3700 Attrs.Is_Dispatching := Is_Dispatching; 3701 Attrs.SPARK_Mode_On := Is_SPARK_Mode_On_Node (Call); 3702 end Extract_Call_Attributes; 3703 3704 ----------------------- 3705 -- Extract_Call_Name -- 3706 ----------------------- 3707 3708 function Extract_Call_Name (Call : Node_Id) return Node_Id is 3709 Nam : Node_Id; 3710 3711 begin 3712 Nam := Name (Call); 3713 3714 -- When the call invokes an entry family, the name appears as an indexed 3715 -- component. 3716 3717 if Nkind (Nam) = N_Indexed_Component then 3718 Nam := Prefix (Nam); 3719 end if; 3720 3721 -- When the call employs the object.operation form, the name appears as 3722 -- a selected component. 3723 3724 if Nkind (Nam) = N_Selected_Component then 3725 Nam := Selector_Name (Nam); 3726 end if; 3727 3728 return Nam; 3729 end Extract_Call_Name; 3730 3731 --------------------------------- 3732 -- Extract_Instance_Attributes -- 3733 --------------------------------- 3734 3735 procedure Extract_Instance_Attributes 3736 (Exp_Inst : Node_Id; 3737 Inst_Body : out Node_Id; 3738 Inst_Decl : out Node_Id) 3739 is 3740 Body_Id : Entity_Id; 3741 3742 begin 3743 -- Assume that the attributes are unavailable 3744 3745 Inst_Body := Empty; 3746 Inst_Decl := Empty; 3747 3748 -- Generic package or subprogram spec 3749 3750 if Nkind_In (Exp_Inst, N_Package_Declaration, 3751 N_Subprogram_Declaration) 3752 then 3753 Inst_Decl := Exp_Inst; 3754 Body_Id := Corresponding_Body (Inst_Decl); 3755 3756 if Present (Body_Id) then 3757 Inst_Body := Unit_Declaration_Node (Body_Id); 3758 end if; 3759 3760 -- Generic package or subprogram body 3761 3762 else 3763 pragma Assert 3764 (Nkind_In (Exp_Inst, N_Package_Body, N_Subprogram_Body)); 3765 3766 Inst_Body := Exp_Inst; 3767 Inst_Decl := Unit_Declaration_Node (Corresponding_Spec (Inst_Body)); 3768 end if; 3769 end Extract_Instance_Attributes; 3770 3771 -------------------------------------- 3772 -- Extract_Instantiation_Attributes -- 3773 -------------------------------------- 3774 3775 procedure Extract_Instantiation_Attributes 3776 (Exp_Inst : Node_Id; 3777 Inst : out Node_Id; 3778 Inst_Id : out Entity_Id; 3779 Gen_Id : out Entity_Id; 3780 Attrs : out Instantiation_Attributes) 3781 is 3782 begin 3783 Inst := Original_Node (Exp_Inst); 3784 Inst_Id := Defining_Entity (Inst); 3785 3786 -- Traverse a possible chain of renamings to obtain the original generic 3787 -- being instantiatied. 3788 3789 Gen_Id := Get_Renamed_Entity (Entity (Name (Inst))); 3790 3791 -- Set all attributes 3792 3793 Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Node (Inst); 3794 Attrs.Elab_Warnings_OK := Is_Elaboration_Warnings_OK_Node (Inst); 3795 Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Node (Inst); 3796 Attrs.In_Declarations := Is_Declaration_Level_Node (Inst); 3797 Attrs.SPARK_Mode_On := Is_SPARK_Mode_On_Node (Inst); 3798 end Extract_Instantiation_Attributes; 3799 3800 ------------------------------- 3801 -- Extract_Target_Attributes -- 3802 ------------------------------- 3803 3804 procedure Extract_Target_Attributes 3805 (Target_Id : Entity_Id; 3806 Attrs : out Target_Attributes) 3807 is 3808 procedure Extract_Package_Or_Subprogram_Attributes 3809 (Spec_Id : out Entity_Id; 3810 Body_Decl : out Node_Id); 3811 -- Obtain the attributes associated with a package or a subprogram. 3812 -- Spec_Id is the package or subprogram. Body_Decl is the declaration 3813 -- of the corresponding package or subprogram body. 3814 3815 procedure Extract_Protected_Entry_Attributes 3816 (Spec_Id : out Entity_Id; 3817 Body_Decl : out Node_Id; 3818 Body_Barf : out Node_Id); 3819 -- Obtain the attributes associated with a protected entry [family]. 3820 -- Spec_Id is the entity of the protected body subprogram. Body_Decl 3821 -- is the declaration of Spec_Id's corresponding body. Body_Barf is 3822 -- the declaration of the barrier function body. 3823 3824 procedure Extract_Protected_Subprogram_Attributes 3825 (Spec_Id : out Entity_Id; 3826 Body_Decl : out Node_Id); 3827 -- Obtain the attributes associated with a protected subprogram. Formal 3828 -- Spec_Id is the entity of the protected body subprogram. Body_Decl is 3829 -- the declaration of Spec_Id's corresponding body. 3830 3831 procedure Extract_Task_Entry_Attributes 3832 (Spec_Id : out Entity_Id; 3833 Body_Decl : out Node_Id); 3834 -- Obtain the attributes associated with a task entry [family]. Formal 3835 -- Spec_Id is the entity of the task body procedure. Body_Decl is the 3836 -- declaration of Spec_Id's corresponding body. 3837 3838 ---------------------------------------------- 3839 -- Extract_Package_Or_Subprogram_Attributes -- 3840 ---------------------------------------------- 3841 3842 procedure Extract_Package_Or_Subprogram_Attributes 3843 (Spec_Id : out Entity_Id; 3844 Body_Decl : out Node_Id) 3845 is 3846 Body_Id : Entity_Id; 3847 Init_Id : Entity_Id; 3848 Spec_Decl : Node_Id; 3849 3850 begin 3851 -- Assume that the body is not available 3852 3853 Body_Decl := Empty; 3854 Spec_Id := Target_Id; 3855 3856 -- For body retrieval purposes, the entity of the initial declaration 3857 -- is that of the spec. 3858 3859 Init_Id := Spec_Id; 3860 3861 -- The only exception to the above is a function which returns a 3862 -- constrained array type in a SPARK-to-C compilation. In this case 3863 -- the function receives a corresponding procedure which has an out 3864 -- parameter. The proper body for ABE checks and diagnostics is that 3865 -- of the procedure. 3866 3867 if Ekind (Init_Id) = E_Function 3868 and then Rewritten_For_C (Init_Id) 3869 then 3870 Init_Id := Corresponding_Procedure (Init_Id); 3871 end if; 3872 3873 -- Extract the attributes of the body 3874 3875 Spec_Decl := Unit_Declaration_Node (Init_Id); 3876 3877 -- The initial declaration is a stand alone subprogram body 3878 3879 if Nkind (Spec_Decl) = N_Subprogram_Body then 3880 Body_Decl := Spec_Decl; 3881 3882 -- Otherwise the package or subprogram has a spec and a completing 3883 -- body. 3884 3885 elsif Nkind_In (Spec_Decl, N_Generic_Package_Declaration, 3886 N_Generic_Subprogram_Declaration, 3887 N_Package_Declaration, 3888 N_Subprogram_Body_Stub, 3889 N_Subprogram_Declaration) 3890 then 3891 Body_Id := Corresponding_Body (Spec_Decl); 3892 3893 if Present (Body_Id) then 3894 Body_Decl := Unit_Declaration_Node (Body_Id); 3895 end if; 3896 end if; 3897 end Extract_Package_Or_Subprogram_Attributes; 3898 3899 ---------------------------------------- 3900 -- Extract_Protected_Entry_Attributes -- 3901 ---------------------------------------- 3902 3903 procedure Extract_Protected_Entry_Attributes 3904 (Spec_Id : out Entity_Id; 3905 Body_Decl : out Node_Id; 3906 Body_Barf : out Node_Id) 3907 is 3908 Barf_Id : Entity_Id; 3909 Body_Id : Entity_Id; 3910 3911 begin 3912 -- Assume that the bodies are not available 3913 3914 Body_Barf := Empty; 3915 Body_Decl := Empty; 3916 3917 -- When the entry [family] has already been expanded, it carries both 3918 -- the procedure which emulates the behavior of the entry [family] as 3919 -- well as the barrier function. 3920 3921 if Present (Protected_Body_Subprogram (Target_Id)) then 3922 Spec_Id := Protected_Body_Subprogram (Target_Id); 3923 3924 -- Extract the attributes of the barrier function 3925 3926 Barf_Id := 3927 Corresponding_Body 3928 (Unit_Declaration_Node (Barrier_Function (Target_Id))); 3929 3930 if Present (Barf_Id) then 3931 Body_Barf := Unit_Declaration_Node (Barf_Id); 3932 end if; 3933 3934 -- Otherwise no expansion took place 3935 3936 else 3937 Spec_Id := Target_Id; 3938 end if; 3939 3940 -- Extract the attributes of the entry body 3941 3942 Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); 3943 3944 if Present (Body_Id) then 3945 Body_Decl := Unit_Declaration_Node (Body_Id); 3946 end if; 3947 end Extract_Protected_Entry_Attributes; 3948 3949 --------------------------------------------- 3950 -- Extract_Protected_Subprogram_Attributes -- 3951 --------------------------------------------- 3952 3953 procedure Extract_Protected_Subprogram_Attributes 3954 (Spec_Id : out Entity_Id; 3955 Body_Decl : out Node_Id) 3956 is 3957 Body_Id : Entity_Id; 3958 3959 begin 3960 -- Assume that the body is not available 3961 3962 Body_Decl := Empty; 3963 3964 -- When the protected subprogram has already been expanded, it 3965 -- carries the subprogram which seizes the lock and invokes the 3966 -- original statements. 3967 3968 if Present (Protected_Subprogram (Target_Id)) then 3969 Spec_Id := 3970 Protected_Body_Subprogram (Protected_Subprogram (Target_Id)); 3971 3972 -- Otherwise no expansion took place 3973 3974 else 3975 Spec_Id := Target_Id; 3976 end if; 3977 3978 -- Extract the attributes of the body 3979 3980 Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); 3981 3982 if Present (Body_Id) then 3983 Body_Decl := Unit_Declaration_Node (Body_Id); 3984 end if; 3985 end Extract_Protected_Subprogram_Attributes; 3986 3987 ----------------------------------- 3988 -- Extract_Task_Entry_Attributes -- 3989 ----------------------------------- 3990 3991 procedure Extract_Task_Entry_Attributes 3992 (Spec_Id : out Entity_Id; 3993 Body_Decl : out Node_Id) 3994 is 3995 Task_Typ : constant Entity_Id := Non_Private_View (Scope (Target_Id)); 3996 Body_Id : Entity_Id; 3997 3998 begin 3999 -- Assume that the body is not available 4000 4001 Body_Decl := Empty; 4002 4003 -- The the task type has already been expanded, it carries the 4004 -- procedure which emulates the behavior of the task body. 4005 4006 if Present (Task_Body_Procedure (Task_Typ)) then 4007 Spec_Id := Task_Body_Procedure (Task_Typ); 4008 4009 -- Otherwise no expansion took place 4010 4011 else 4012 Spec_Id := Task_Typ; 4013 end if; 4014 4015 -- Extract the attributes of the body 4016 4017 Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); 4018 4019 if Present (Body_Id) then 4020 Body_Decl := Unit_Declaration_Node (Body_Id); 4021 end if; 4022 end Extract_Task_Entry_Attributes; 4023 4024 -- Local variables 4025 4026 Prag : constant Node_Id := SPARK_Pragma (Target_Id); 4027 Body_Barf : Node_Id; 4028 Body_Decl : Node_Id; 4029 Spec_Id : Entity_Id; 4030 4031 -- Start of processing for Extract_Target_Attributes 4032 4033 begin 4034 -- Assume that the body of the barrier function is not available 4035 4036 Body_Barf := Empty; 4037 4038 -- The target is a protected entry [family] 4039 4040 if Is_Protected_Entry (Target_Id) then 4041 Extract_Protected_Entry_Attributes 4042 (Spec_Id => Spec_Id, 4043 Body_Decl => Body_Decl, 4044 Body_Barf => Body_Barf); 4045 4046 -- The target is a protected subprogram 4047 4048 elsif Is_Protected_Subp (Target_Id) 4049 or else Is_Protected_Body_Subp (Target_Id) 4050 then 4051 Extract_Protected_Subprogram_Attributes 4052 (Spec_Id => Spec_Id, 4053 Body_Decl => Body_Decl); 4054 4055 -- The target is a task entry [family] 4056 4057 elsif Is_Task_Entry (Target_Id) then 4058 Extract_Task_Entry_Attributes 4059 (Spec_Id => Spec_Id, 4060 Body_Decl => Body_Decl); 4061 4062 -- Otherwise the target is a package or a subprogram 4063 4064 else 4065 Extract_Package_Or_Subprogram_Attributes 4066 (Spec_Id => Spec_Id, 4067 Body_Decl => Body_Decl); 4068 end if; 4069 4070 -- Set all attributes 4071 4072 Attrs.Body_Barf := Body_Barf; 4073 Attrs.Body_Decl := Body_Decl; 4074 Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Id (Target_Id); 4075 Attrs.From_Source := Comes_From_Source (Target_Id); 4076 Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Entity (Target_Id); 4077 Attrs.SPARK_Mode_On := 4078 Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On; 4079 Attrs.Spec_Decl := Unit_Declaration_Node (Spec_Id); 4080 Attrs.Spec_Id := Spec_Id; 4081 Attrs.Unit_Id := Find_Top_Unit (Target_Id); 4082 4083 -- At this point certain attributes should always be available 4084 4085 pragma Assert (Present (Attrs.Spec_Decl)); 4086 pragma Assert (Present (Attrs.Spec_Id)); 4087 pragma Assert (Present (Attrs.Unit_Id)); 4088 end Extract_Target_Attributes; 4089 4090 ----------------------------- 4091 -- Extract_Task_Attributes -- 4092 ----------------------------- 4093 4094 procedure Extract_Task_Attributes 4095 (Typ : Entity_Id; 4096 Attrs : out Task_Attributes) 4097 is 4098 Task_Typ : constant Entity_Id := Non_Private_View (Typ); 4099 4100 Body_Decl : Node_Id; 4101 Body_Id : Entity_Id; 4102 Prag : Node_Id; 4103 Spec_Id : Entity_Id; 4104 4105 begin 4106 -- Assume that the body of the task procedure is not available 4107 4108 Body_Decl := Empty; 4109 4110 -- The initial declaration is that of the task body procedure 4111 4112 Spec_Id := Get_Task_Body_Procedure (Task_Typ); 4113 Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); 4114 4115 if Present (Body_Id) then 4116 Body_Decl := Unit_Declaration_Node (Body_Id); 4117 end if; 4118 4119 Prag := SPARK_Pragma (Task_Typ); 4120 4121 -- Set all attributes 4122 4123 Attrs.Body_Decl := Body_Decl; 4124 Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Id (Task_Typ); 4125 Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Entity (Task_Typ); 4126 Attrs.SPARK_Mode_On := 4127 Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On; 4128 Attrs.Spec_Id := Spec_Id; 4129 Attrs.Task_Decl := Declaration_Node (Task_Typ); 4130 Attrs.Unit_Id := Find_Top_Unit (Task_Typ); 4131 4132 -- At this point certain attributes should always be available 4133 4134 pragma Assert (Present (Attrs.Spec_Id)); 4135 pragma Assert (Present (Attrs.Task_Decl)); 4136 pragma Assert (Present (Attrs.Unit_Id)); 4137 end Extract_Task_Attributes; 4138 4139 ------------------------------------------- 4140 -- Extract_Variable_Reference_Attributes -- 4141 ------------------------------------------- 4142 4143 procedure Extract_Variable_Reference_Attributes 4144 (Ref : Node_Id; 4145 Var_Id : out Entity_Id; 4146 Attrs : out Variable_Attributes) 4147 is 4148 function Get_Renamed_Variable (Id : Entity_Id) return Entity_Id; 4149 -- Obtain the ultimate renamed variable of variable Id 4150 4151 -------------------------- 4152 -- Get_Renamed_Variable -- 4153 -------------------------- 4154 4155 function Get_Renamed_Variable (Id : Entity_Id) return Entity_Id is 4156 Ren_Id : Entity_Id; 4157 4158 begin 4159 Ren_Id := Id; 4160 while Present (Renamed_Entity (Ren_Id)) 4161 and then Nkind (Renamed_Entity (Ren_Id)) in N_Entity 4162 loop 4163 Ren_Id := Renamed_Entity (Ren_Id); 4164 end loop; 4165 4166 return Ren_Id; 4167 end Get_Renamed_Variable; 4168 4169 -- Start of processing for Extract_Variable_Reference_Attributes 4170 4171 begin 4172 -- Extraction for variable reference markers 4173 4174 if Nkind (Ref) = N_Variable_Reference_Marker then 4175 Var_Id := Target (Ref); 4176 4177 -- Extraction for expanded names and identifiers 4178 4179 else 4180 Var_Id := Entity (Ref); 4181 end if; 4182 4183 -- Obtain the original variable which the reference mentions 4184 4185 Var_Id := Get_Renamed_Variable (Var_Id); 4186 Attrs.Unit_Id := Find_Top_Unit (Var_Id); 4187 4188 -- At this point certain attributes should always be available 4189 4190 pragma Assert (Present (Attrs.Unit_Id)); 4191 end Extract_Variable_Reference_Attributes; 4192 4193 -------------------- 4194 -- Find_Code_Unit -- 4195 -------------------- 4196 4197 function Find_Code_Unit (N : Node_Or_Entity_Id) return Entity_Id is 4198 begin 4199 return Find_Unit_Entity (Unit (Cunit (Get_Code_Unit (N)))); 4200 end Find_Code_Unit; 4201 4202 ---------------------------- 4203 -- Find_Early_Call_Region -- 4204 ---------------------------- 4205 4206 function Find_Early_Call_Region 4207 (Body_Decl : Node_Id; 4208 Assume_Elab_Body : Boolean := False; 4209 Skip_Memoization : Boolean := False) return Node_Id 4210 is 4211 -- NOTE: The routines within Find_Early_Call_Region are intentionally 4212 -- unnested to avoid deep indentation of code. 4213 4214 ECR_Found : exception; 4215 -- This exception is raised when the early call region has been found 4216 4217 Start : Node_Id := Empty; 4218 -- The start of the early call region. This variable is updated by the 4219 -- various nested routines. Due to the use of exceptions, the variable 4220 -- must be global to the nested routines. 4221 4222 -- The algorithm implemented in this routine attempts to find the early 4223 -- call region of a subprogram body by inspecting constructs in reverse 4224 -- declarative order, while navigating the tree. The algorithm consists 4225 -- of an Inspection phase and an Advancement phase. The pseudocode is as 4226 -- follows: 4227 -- 4228 -- loop 4229 -- inspection phase 4230 -- advancement phase 4231 -- end loop 4232 -- 4233 -- The infinite loop is terminated by raising exception ECR_Found. The 4234 -- algorithm utilizes two pointers, Curr and Start, to represent the 4235 -- current construct to inspect and the start of the early call region. 4236 -- 4237 -- IMPORTANT: The algorithm must maintain the following invariant at all 4238 -- time for it to function properly - a nested construct is entered only 4239 -- when it contains suitable constructs. This guarantees that leaving a 4240 -- nested or encapsulating construct functions properly. 4241 -- 4242 -- The Inspection phase determines whether the current construct is non- 4243 -- preelaborable, and if it is, the algorithm terminates. 4244 -- 4245 -- The Advancement phase walks the tree in reverse declarative order, 4246 -- while entering and leaving nested and encapsulating constructs. It 4247 -- may also terminate the elaborithm. There are several special cases 4248 -- of advancement. 4249 -- 4250 -- 1) General case: 4251 -- 4252 -- <construct 1> 4253 -- ... 4254 -- <construct N-1> <- Curr 4255 -- <construct N> <- Start 4256 -- <subprogram body> 4257 -- 4258 -- In the general case, a declarative or statement list is traversed in 4259 -- reverse order where Curr is the lead pointer, and Start indicates the 4260 -- last preelaborable construct. 4261 -- 4262 -- 2) Entering handled bodies 4263 -- 4264 -- package body Nested is <- Curr (2.3) 4265 -- <declarations> <- Curr (2.2) 4266 -- begin 4267 -- <statements> <- Curr (2.1) 4268 -- end Nested; 4269 -- <construct> <- Start 4270 -- 4271 -- In this case, the algorithm enters a handled body by starting from 4272 -- the last statement (2.1), or the last declaration (2.2), or the body 4273 -- is consumed (2.3) because it is empty and thus preelaborable. 4274 -- 4275 -- 3) Entering package declarations 4276 -- 4277 -- package Nested is <- Curr (2.3) 4278 -- <visible declarations> <- Curr (2.2) 4279 -- private 4280 -- <private declarations> <- Curr (2.1) 4281 -- end Nested; 4282 -- <construct> <- Start 4283 -- 4284 -- In this case, the algorithm enters a package declaration by starting 4285 -- from the last private declaration (2.1), the last visible declaration 4286 -- (2.2), or the package is consumed (2.3) because it is empty and thus 4287 -- preelaborable. 4288 -- 4289 -- 4) Transitioning from list to list of the same construct 4290 -- 4291 -- Certain constructs have two eligible lists. The algorithm must thus 4292 -- transition from the second to the first list when the second list is 4293 -- exhausted. 4294 -- 4295 -- declare <- Curr (4.2) 4296 -- <declarations> <- Curr (4.1) 4297 -- begin 4298 -- <statements> <- Start 4299 -- end; 4300 -- 4301 -- In this case, the algorithm has exhausted the second list (statements 4302 -- in the example), and continues with the last declaration (4.1) or the 4303 -- construct is consumed (4.2) because it contains only preelaborable 4304 -- code. 4305 -- 4306 -- 5) Transitioning from list to construct 4307 -- 4308 -- tack body Task is <- Curr (5.1) 4309 -- <- Curr (Empty) 4310 -- <construct 1> <- Start 4311 -- 4312 -- In this case, the algorithm has exhausted a list, Curr is Empty, and 4313 -- the owner of the list is consumed (5.1). 4314 -- 4315 -- 6) Transitioning from unit to unit 4316 -- 4317 -- A package body with a spec subject to pragma Elaborate_Body extends 4318 -- the possible range of the early call region to the package spec. 4319 -- 4320 -- package Pack is <- Curr (6.3) 4321 -- pragma Elaborate_Body; <- Curr (6.2) 4322 -- <visible declarations> <- Curr (6.2) 4323 -- private 4324 -- <private declarations> <- Curr (6.1) 4325 -- end Pack; 4326 -- 4327 -- package body Pack is <- Curr, Start 4328 -- 4329 -- In this case, the algorithm has reached a package body compilation 4330 -- unit whose spec is subject to pragma Elaborate_Body, or the caller 4331 -- of the algorithm has specified this behavior. This transition is 4332 -- equivalent to 3). 4333 -- 4334 -- 7) Transitioning from unit to termination 4335 -- 4336 -- Reaching a compilation unit always terminates the algorithm as there 4337 -- are no more lists to examine. This must take 6) into account. 4338 -- 4339 -- 8) Transitioning from subunit to stub 4340 -- 4341 -- package body Pack is separate; <- Curr (8.1) 4342 -- 4343 -- separate (...) 4344 -- package body Pack is <- Curr, Start 4345 -- 4346 -- Reaching a subunit continues the search from the corresponding stub 4347 -- (8.1). 4348 4349 procedure Advance (Curr : in out Node_Id); 4350 pragma Inline (Advance); 4351 -- Update the Curr and Start pointers depending on their location in the 4352 -- tree to the next eligible construct. This routine raises ECR_Found. 4353 4354 procedure Enter_Handled_Body (Curr : in out Node_Id); 4355 pragma Inline (Enter_Handled_Body); 4356 -- Update the Curr and Start pointers to enter a nested handled body if 4357 -- applicable. This routine raises ECR_Found. 4358 4359 procedure Enter_Package_Declaration (Curr : in out Node_Id); 4360 pragma Inline (Enter_Package_Declaration); 4361 -- Update the Curr and Start pointers to enter a nested package spec if 4362 -- applicable. This routine raises ECR_Found. 4363 4364 function Find_ECR (N : Node_Id) return Node_Id; 4365 pragma Inline (Find_ECR); 4366 -- Find an early call region starting from arbitrary node N 4367 4368 function Has_Suitable_Construct (List : List_Id) return Boolean; 4369 pragma Inline (Has_Suitable_Construct); 4370 -- Determine whether list List contains at least one suitable construct 4371 -- for inclusion into an early call region. 4372 4373 procedure Include (N : Node_Id; Curr : out Node_Id); 4374 pragma Inline (Include); 4375 -- Update the Curr and Start pointers to include arbitrary construct N 4376 -- in the early call region. This routine raises ECR_Found. 4377 4378 function Is_OK_Preelaborable_Construct (N : Node_Id) return Boolean; 4379 pragma Inline (Is_OK_Preelaborable_Construct); 4380 -- Determine whether arbitrary node N denotes a preelaboration-safe 4381 -- construct. 4382 4383 function Is_Suitable_Construct (N : Node_Id) return Boolean; 4384 pragma Inline (Is_Suitable_Construct); 4385 -- Determine whether arbitrary node N denotes a suitable construct for 4386 -- inclusion into the early call region. 4387 4388 procedure Transition_Body_Declarations 4389 (Bod : Node_Id; 4390 Curr : in out Node_Id); 4391 pragma Inline (Transition_Body_Declarations); 4392 -- Update the Curr and Start pointers when construct Bod denotes a block 4393 -- statement or a suitable body. This routine raises ECR_Found. 4394 4395 procedure Transition_Handled_Statements 4396 (HSS : Node_Id; 4397 Curr : in out Node_Id); 4398 pragma Inline (Transition_Handled_Statements); 4399 -- Update the Curr and Start pointers when node HSS denotes a handled 4400 -- sequence of statements. This routine raises ECR_Found. 4401 4402 procedure Transition_Spec_Declarations 4403 (Spec : Node_Id; 4404 Curr : in out Node_Id); 4405 pragma Inline (Transition_Spec_Declarations); 4406 -- Update the Curr and Start pointers when construct Spec denotes 4407 -- a concurrent definition or a package spec. This routine raises 4408 -- ECR_Found. 4409 4410 procedure Transition_Unit (Unit : Node_Id; Curr : in out Node_Id); 4411 pragma Inline (Transition_Unit); 4412 -- Update the Curr and Start pointers when node Unit denotes a potential 4413 -- compilation unit. This routine raises ECR_Found. 4414 4415 ------------- 4416 -- Advance -- 4417 ------------- 4418 4419 procedure Advance (Curr : in out Node_Id) is 4420 Context : Node_Id; 4421 4422 begin 4423 -- Curr denotes one of the following cases upon entry into this 4424 -- routine: 4425 -- 4426 -- * Empty - There is no current construct when a declarative or a 4427 -- statement list has been exhausted. This does not necessarily 4428 -- indicate that the early call region has been computed as it 4429 -- may still be possible to transition to another list. 4430 -- 4431 -- * Encapsulator - The current construct encapsulates declarations 4432 -- and/or statements. This indicates that the early call region 4433 -- may extend within the nested construct. 4434 -- 4435 -- * Preelaborable - The current construct is always preelaborable 4436 -- because Find_ECR would not invoke Advance if this was not the 4437 -- case. 4438 4439 -- The current construct is an encapsulator or is preelaborable 4440 4441 if Present (Curr) then 4442 4443 -- Enter encapsulators by inspecting their declarations and/or 4444 -- statements. 4445 4446 if Nkind_In (Curr, N_Block_Statement, N_Package_Body) then 4447 Enter_Handled_Body (Curr); 4448 4449 elsif Nkind (Curr) = N_Package_Declaration then 4450 Enter_Package_Declaration (Curr); 4451 4452 -- Early call regions have a property which can be exploited to 4453 -- optimize the algorithm. 4454 -- 4455 -- <preceding subprogram body> 4456 -- <preelaborable construct 1> 4457 -- ... 4458 -- <preelaborable construct N> 4459 -- <initiating subprogram body> 4460 -- 4461 -- If a traversal initiated from a subprogram body reaches a 4462 -- preceding subprogram body, then both bodies share the same 4463 -- early call region. 4464 -- 4465 -- The property results in the following desirable effects: 4466 -- 4467 -- * If the preceding body already has an early call region, then 4468 -- the initiating body can reuse it. This minimizes the amount 4469 -- of processing performed by the algorithm. 4470 -- 4471 -- * If the preceding body lack an early call region, then the 4472 -- algorithm can compute the early call region, and reuse it 4473 -- for the initiating body. This processing performs the same 4474 -- amount of work, but has the beneficial effect of computing 4475 -- the early call regions of all preceding bodies. 4476 4477 elsif Nkind_In (Curr, N_Entry_Body, N_Subprogram_Body) then 4478 Start := 4479 Find_Early_Call_Region 4480 (Body_Decl => Curr, 4481 Assume_Elab_Body => Assume_Elab_Body, 4482 Skip_Memoization => Skip_Memoization); 4483 4484 raise ECR_Found; 4485 4486 -- Otherwise current construct is preelaborable. Unpdate the early 4487 -- call region to include it. 4488 4489 else 4490 Include (Curr, Curr); 4491 end if; 4492 4493 -- Otherwise the current construct is missing, indicating that the 4494 -- current list has been exhausted. Depending on the context of the 4495 -- list, several transitions are possible. 4496 4497 else 4498 -- The invariant of the algorithm ensures that Curr and Start are 4499 -- at the same level of nesting at the point of a transition. The 4500 -- algorithm can determine which list the traversal came from by 4501 -- examining Start. 4502 4503 Context := Parent (Start); 4504 4505 -- Attempt the following transitions: 4506 -- 4507 -- private declarations -> visible declarations 4508 -- private declarations -> upper level 4509 -- private declarations -> terminate 4510 -- visible declarations -> upper level 4511 -- visible declarations -> terminate 4512 4513 if Nkind_In (Context, N_Package_Specification, 4514 N_Protected_Definition, 4515 N_Task_Definition) 4516 then 4517 Transition_Spec_Declarations (Context, Curr); 4518 4519 -- Attempt the following transitions: 4520 -- 4521 -- statements -> declarations 4522 -- statements -> upper level 4523 -- statements -> corresponding package spec (Elab_Body) 4524 -- statements -> terminate 4525 4526 elsif Nkind (Context) = N_Handled_Sequence_Of_Statements then 4527 Transition_Handled_Statements (Context, Curr); 4528 4529 -- Attempt the following transitions: 4530 -- 4531 -- declarations -> upper level 4532 -- declarations -> corresponding package spec (Elab_Body) 4533 -- declarations -> terminate 4534 4535 elsif Nkind_In (Context, N_Block_Statement, 4536 N_Entry_Body, 4537 N_Package_Body, 4538 N_Protected_Body, 4539 N_Subprogram_Body, 4540 N_Task_Body) 4541 then 4542 Transition_Body_Declarations (Context, Curr); 4543 4544 -- Otherwise it is not possible to transition. Stop the search 4545 -- because there are no more declarations or statements to check. 4546 4547 else 4548 raise ECR_Found; 4549 end if; 4550 end if; 4551 end Advance; 4552 4553 -------------------------- 4554 -- Enter_Handled_Body -- 4555 -------------------------- 4556 4557 procedure Enter_Handled_Body (Curr : in out Node_Id) is 4558 Decls : constant List_Id := Declarations (Curr); 4559 HSS : constant Node_Id := Handled_Statement_Sequence (Curr); 4560 Stmts : List_Id := No_List; 4561 4562 begin 4563 if Present (HSS) then 4564 Stmts := Statements (HSS); 4565 end if; 4566 4567 -- The handled body has a non-empty statement sequence. The construct 4568 -- to inspect is the last statement. 4569 4570 if Has_Suitable_Construct (Stmts) then 4571 Curr := Last (Stmts); 4572 4573 -- The handled body lacks statements, but has non-empty declarations. 4574 -- The construct to inspect is the last declaration. 4575 4576 elsif Has_Suitable_Construct (Decls) then 4577 Curr := Last (Decls); 4578 4579 -- Otherwise the handled body lacks both declarations and statements. 4580 -- The construct to inspect is the node which precedes the handled 4581 -- body. Update the early call region to include the handled body. 4582 4583 else 4584 Include (Curr, Curr); 4585 end if; 4586 end Enter_Handled_Body; 4587 4588 ------------------------------- 4589 -- Enter_Package_Declaration -- 4590 ------------------------------- 4591 4592 procedure Enter_Package_Declaration (Curr : in out Node_Id) is 4593 Pack_Spec : constant Node_Id := Specification (Curr); 4594 Prv_Decls : constant List_Id := Private_Declarations (Pack_Spec); 4595 Vis_Decls : constant List_Id := Visible_Declarations (Pack_Spec); 4596 4597 begin 4598 -- The package has a non-empty private declarations. The construct to 4599 -- inspect is the last private declaration. 4600 4601 if Has_Suitable_Construct (Prv_Decls) then 4602 Curr := Last (Prv_Decls); 4603 4604 -- The package lacks private declarations, but has non-empty visible 4605 -- declarations. In this case the construct to inspect is the last 4606 -- visible declaration. 4607 4608 elsif Has_Suitable_Construct (Vis_Decls) then 4609 Curr := Last (Vis_Decls); 4610 4611 -- Otherwise the package lacks any declarations. The construct to 4612 -- inspect is the node which precedes the package. Update the early 4613 -- call region to include the package declaration. 4614 4615 else 4616 Include (Curr, Curr); 4617 end if; 4618 end Enter_Package_Declaration; 4619 4620 -------------- 4621 -- Find_ECR -- 4622 -------------- 4623 4624 function Find_ECR (N : Node_Id) return Node_Id is 4625 Curr : Node_Id; 4626 4627 begin 4628 -- The early call region starts at N 4629 4630 Curr := Prev (N); 4631 Start := N; 4632 4633 -- Inspect each node in reverse declarative order while going in and 4634 -- out of nested and enclosing constructs. Note that the only way to 4635 -- terminate this infinite loop is to raise exception ECR_Found. 4636 4637 loop 4638 -- The current construct is not preelaboration-safe. Terminate the 4639 -- traversal. 4640 4641 if Present (Curr) 4642 and then not Is_OK_Preelaborable_Construct (Curr) 4643 then 4644 raise ECR_Found; 4645 end if; 4646 4647 -- Advance to the next suitable construct. This may terminate the 4648 -- traversal by raising ECR_Found. 4649 4650 Advance (Curr); 4651 end loop; 4652 4653 exception 4654 when ECR_Found => 4655 return Start; 4656 end Find_ECR; 4657 4658 ---------------------------- 4659 -- Has_Suitable_Construct -- 4660 ---------------------------- 4661 4662 function Has_Suitable_Construct (List : List_Id) return Boolean is 4663 Item : Node_Id; 4664 4665 begin 4666 -- Examine the list in reverse declarative order, looking for a 4667 -- suitable construct. 4668 4669 if Present (List) then 4670 Item := Last (List); 4671 while Present (Item) loop 4672 if Is_Suitable_Construct (Item) then 4673 return True; 4674 end if; 4675 4676 Prev (Item); 4677 end loop; 4678 end if; 4679 4680 return False; 4681 end Has_Suitable_Construct; 4682 4683 ------------- 4684 -- Include -- 4685 ------------- 4686 4687 procedure Include (N : Node_Id; Curr : out Node_Id) is 4688 begin 4689 Start := N; 4690 4691 -- The input node is a compilation unit. This terminates the search 4692 -- because there are no more lists to inspect and there are no more 4693 -- enclosing constructs to climb up to. The transitions are: 4694 -- 4695 -- private declarations -> terminate 4696 -- visible declarations -> terminate 4697 -- statements -> terminate 4698 -- declarations -> terminate 4699 4700 if Nkind (Parent (Start)) = N_Compilation_Unit then 4701 raise ECR_Found; 4702 4703 -- Otherwise the input node is still within some list 4704 4705 else 4706 Curr := Prev (Start); 4707 end if; 4708 end Include; 4709 4710 ----------------------------------- 4711 -- Is_OK_Preelaborable_Construct -- 4712 ----------------------------------- 4713 4714 function Is_OK_Preelaborable_Construct (N : Node_Id) return Boolean is 4715 begin 4716 -- Assignment statements are acceptable as long as they were produced 4717 -- by the ABE mechanism to update elaboration flags. 4718 4719 if Nkind (N) = N_Assignment_Statement then 4720 return Is_Elaboration_Code (N); 4721 4722 -- Block statements are acceptable even though they directly violate 4723 -- preelaborability. The intention is not to penalize the early call 4724 -- region when a block contains only preelaborable constructs. 4725 -- 4726 -- declare 4727 -- Val : constant Integer := 1; 4728 -- begin 4729 -- pragma Assert (Val = 1); 4730 -- null; 4731 -- end; 4732 -- 4733 -- Note that the Advancement phase does enter blocks, and will detect 4734 -- any non-preelaborable declarations or statements within. 4735 4736 elsif Nkind (N) = N_Block_Statement then 4737 return True; 4738 end if; 4739 4740 -- Otherwise the construct must be preelaborable. The check must take 4741 -- the syntactic and semantic structure of the construct. DO NOT use 4742 -- Is_Preelaborable_Construct here. 4743 4744 return not Is_Non_Preelaborable_Construct (N); 4745 end Is_OK_Preelaborable_Construct; 4746 4747 --------------------------- 4748 -- Is_Suitable_Construct -- 4749 --------------------------- 4750 4751 function Is_Suitable_Construct (N : Node_Id) return Boolean is 4752 Context : constant Node_Id := Parent (N); 4753 4754 begin 4755 -- An internally-generated statement sequence which contains only a 4756 -- single null statement is not a suitable construct because it is a 4757 -- byproduct of the parser. Such a null statement should be excluded 4758 -- from the early call region because it carries the source location 4759 -- of the "end" keyword, and may lead to confusing diagnistics. 4760 4761 if Nkind (N) = N_Null_Statement 4762 and then not Comes_From_Source (N) 4763 and then Present (Context) 4764 and then Nkind (Context) = N_Handled_Sequence_Of_Statements 4765 and then not Comes_From_Source (N) 4766 then 4767 return False; 4768 end if; 4769 4770 -- Otherwise only constructs which correspond to pure Ada constructs 4771 -- are considered suitable. 4772 4773 case Nkind (N) is 4774 when N_Call_Marker 4775 | N_Freeze_Entity 4776 | N_Freeze_Generic_Entity 4777 | N_Implicit_Label_Declaration 4778 | N_Itype_Reference 4779 | N_Pop_Constraint_Error_Label 4780 | N_Pop_Program_Error_Label 4781 | N_Pop_Storage_Error_Label 4782 | N_Push_Constraint_Error_Label 4783 | N_Push_Program_Error_Label 4784 | N_Push_Storage_Error_Label 4785 | N_SCIL_Dispatch_Table_Tag_Init 4786 | N_SCIL_Dispatching_Call 4787 | N_SCIL_Membership_Test 4788 | N_Variable_Reference_Marker 4789 => 4790 return False; 4791 4792 when others => 4793 return True; 4794 end case; 4795 end Is_Suitable_Construct; 4796 4797 ---------------------------------- 4798 -- Transition_Body_Declarations -- 4799 ---------------------------------- 4800 4801 procedure Transition_Body_Declarations 4802 (Bod : Node_Id; 4803 Curr : in out Node_Id) 4804 is 4805 Decls : constant List_Id := Declarations (Bod); 4806 4807 begin 4808 -- The search must come from the declarations of the body 4809 4810 pragma Assert 4811 (Is_Non_Empty_List (Decls) 4812 and then List_Containing (Start) = Decls); 4813 4814 -- The search finished inspecting the declarations. The construct 4815 -- to inspect is the node which precedes the handled body, unless 4816 -- the body is a compilation unit. The transitions are: 4817 -- 4818 -- declarations -> upper level 4819 -- declarations -> corresponding package spec (Elab_Body) 4820 -- declarations -> terminate 4821 4822 Transition_Unit (Bod, Curr); 4823 end Transition_Body_Declarations; 4824 4825 ----------------------------------- 4826 -- Transition_Handled_Statements -- 4827 ----------------------------------- 4828 4829 procedure Transition_Handled_Statements 4830 (HSS : Node_Id; 4831 Curr : in out Node_Id) 4832 is 4833 Bod : constant Node_Id := Parent (HSS); 4834 Decls : constant List_Id := Declarations (Bod); 4835 Stmts : constant List_Id := Statements (HSS); 4836 4837 begin 4838 -- The search must come from the statements of certain bodies or 4839 -- statements. 4840 4841 pragma Assert (Nkind_In (Bod, N_Block_Statement, 4842 N_Entry_Body, 4843 N_Package_Body, 4844 N_Protected_Body, 4845 N_Subprogram_Body, 4846 N_Task_Body)); 4847 4848 -- The search must come from the statements of the handled sequence 4849 4850 pragma Assert 4851 (Is_Non_Empty_List (Stmts) 4852 and then List_Containing (Start) = Stmts); 4853 4854 -- The search finished inspecting the statements. The handled body 4855 -- has non-empty declarations. The construct to inspect is the last 4856 -- declaration. The transitions are: 4857 -- 4858 -- statements -> declarations 4859 4860 if Has_Suitable_Construct (Decls) then 4861 Curr := Last (Decls); 4862 4863 -- Otherwise the handled body lacks declarations. The construct to 4864 -- inspect is the node which precedes the handled body, unless the 4865 -- body is a compilation unit. The transitions are: 4866 -- 4867 -- statements -> upper level 4868 -- statements -> corresponding package spec (Elab_Body) 4869 -- statements -> terminate 4870 4871 else 4872 Transition_Unit (Bod, Curr); 4873 end if; 4874 end Transition_Handled_Statements; 4875 4876 ---------------------------------- 4877 -- Transition_Spec_Declarations -- 4878 ---------------------------------- 4879 4880 procedure Transition_Spec_Declarations 4881 (Spec : Node_Id; 4882 Curr : in out Node_Id) 4883 is 4884 Prv_Decls : constant List_Id := Private_Declarations (Spec); 4885 Vis_Decls : constant List_Id := Visible_Declarations (Spec); 4886 4887 begin 4888 pragma Assert (Present (Start) and then Is_List_Member (Start)); 4889 4890 -- The search came from the private declarations and finished their 4891 -- inspection. 4892 4893 if Has_Suitable_Construct (Prv_Decls) 4894 and then List_Containing (Start) = Prv_Decls 4895 then 4896 -- The context has non-empty visible declarations. The node to 4897 -- inspect is the last visible declaration. The transitions are: 4898 -- 4899 -- private declarations -> visible declarations 4900 4901 if Has_Suitable_Construct (Vis_Decls) then 4902 Curr := Last (Vis_Decls); 4903 4904 -- Otherwise the context lacks visible declarations. The construct 4905 -- to inspect is the node which precedes the context unless the 4906 -- context is a compilation unit. The transitions are: 4907 -- 4908 -- private declarations -> upper level 4909 -- private declarations -> terminate 4910 4911 else 4912 Transition_Unit (Parent (Spec), Curr); 4913 end if; 4914 4915 -- The search came from the visible declarations and finished their 4916 -- inspections. The construct to inspect is the node which precedes 4917 -- the context, unless the context is a compilaton unit. The 4918 -- transitions are: 4919 -- 4920 -- visible declarations -> upper level 4921 -- visible declarations -> terminate 4922 4923 elsif Has_Suitable_Construct (Vis_Decls) 4924 and then List_Containing (Start) = Vis_Decls 4925 then 4926 Transition_Unit (Parent (Spec), Curr); 4927 4928 -- At this point both declarative lists are empty, but the traversal 4929 -- still came from within the spec. This indicates that the invariant 4930 -- of the algorithm has been violated. 4931 4932 else 4933 pragma Assert (False); 4934 raise ECR_Found; 4935 end if; 4936 end Transition_Spec_Declarations; 4937 4938 --------------------- 4939 -- Transition_Unit -- 4940 --------------------- 4941 4942 procedure Transition_Unit 4943 (Unit : Node_Id; 4944 Curr : in out Node_Id) 4945 is 4946 Context : constant Node_Id := Parent (Unit); 4947 4948 begin 4949 -- The unit is a compilation unit. This terminates the search because 4950 -- there are no more lists to inspect and there are no more enclosing 4951 -- constructs to climb up to. 4952 4953 if Nkind (Context) = N_Compilation_Unit then 4954 4955 -- A package body with a corresponding spec subject to pragma 4956 -- Elaborate_Body is an exception to the above. The annotation 4957 -- allows the search to continue into the package declaration. 4958 -- The transitions are: 4959 -- 4960 -- statements -> corresponding package spec (Elab_Body) 4961 -- declarations -> corresponding package spec (Elab_Body) 4962 4963 if Nkind (Unit) = N_Package_Body 4964 and then (Assume_Elab_Body 4965 or else Has_Pragma_Elaborate_Body 4966 (Corresponding_Spec (Unit))) 4967 then 4968 Curr := Unit_Declaration_Node (Corresponding_Spec (Unit)); 4969 Enter_Package_Declaration (Curr); 4970 4971 -- Otherwise terminate the search. The transitions are: 4972 -- 4973 -- private declarations -> terminate 4974 -- visible declarations -> terminate 4975 -- statements -> terminate 4976 -- declarations -> terminate 4977 4978 else 4979 raise ECR_Found; 4980 end if; 4981 4982 -- The unit is a subunit. The construct to inspect is the node which 4983 -- precedes the corresponding stub. Update the early call region to 4984 -- include the unit. 4985 4986 elsif Nkind (Context) = N_Subunit then 4987 Start := Unit; 4988 Curr := Corresponding_Stub (Context); 4989 4990 -- Otherwise the unit is nested. The construct to inspect is the node 4991 -- which precedes the unit. Update the early call region to include 4992 -- the unit. 4993 4994 else 4995 Include (Unit, Curr); 4996 end if; 4997 end Transition_Unit; 4998 4999 -- Local variables 5000 5001 Body_Id : constant Entity_Id := Defining_Entity (Body_Decl); 5002 Region : Node_Id; 5003 5004 -- Start of processing for Find_Early_Call_Region 5005 5006 begin 5007 -- The caller demands the start of the early call region without saving 5008 -- or retrieving it to/from internal data structures. 5009 5010 if Skip_Memoization then 5011 Region := Find_ECR (Body_Decl); 5012 5013 -- Default behavior 5014 5015 else 5016 -- Check whether the early call region of the subprogram body is 5017 -- available. 5018 5019 Region := Early_Call_Region (Body_Id); 5020 5021 if No (Region) then 5022 5023 -- Traverse the declarations in reverse order, starting from the 5024 -- subprogram body, searching for the nearest non-preelaborable 5025 -- construct. The early call region starts after this construct 5026 -- and ends at the subprogram body. 5027 5028 Region := Find_ECR (Body_Decl); 5029 5030 -- Associate the early call region with the subprogram body in 5031 -- case other scenarios need it. 5032 5033 Set_Early_Call_Region (Body_Id, Region); 5034 end if; 5035 end if; 5036 5037 -- A subprogram body must always have an early call region 5038 5039 pragma Assert (Present (Region)); 5040 5041 return Region; 5042 end Find_Early_Call_Region; 5043 5044 --------------------------- 5045 -- Find_Elaborated_Units -- 5046 --------------------------- 5047 5048 procedure Find_Elaborated_Units is 5049 procedure Add_Pragma (Prag : Node_Id); 5050 -- Determine whether pragma Prag denotes a legal Elaborate[_All] pragma. 5051 -- If this is the case, add the related unit to the elaboration context. 5052 -- For pragma Elaborate_All, include recursively all units withed by the 5053 -- related unit. 5054 5055 procedure Add_Unit 5056 (Unit_Id : Entity_Id; 5057 Prag : Node_Id; 5058 Full_Context : Boolean); 5059 -- Add unit Unit_Id to the elaboration context. Prag denotes the pragma 5060 -- which prompted the inclusion of the unit to the elaboration context. 5061 -- If flag Full_Context is set, examine the nonlimited clauses of unit 5062 -- Unit_Id and add each withed unit to the context. 5063 5064 procedure Find_Elaboration_Context (Comp_Unit : Node_Id); 5065 -- Examine the context items of compilation unit Comp_Unit for suitable 5066 -- elaboration-related pragmas and add all related units to the context. 5067 5068 ---------------- 5069 -- Add_Pragma -- 5070 ---------------- 5071 5072 procedure Add_Pragma (Prag : Node_Id) is 5073 Prag_Args : constant List_Id := Pragma_Argument_Associations (Prag); 5074 Prag_Nam : constant Name_Id := Pragma_Name (Prag); 5075 Unit_Arg : Node_Id; 5076 5077 begin 5078 -- Nothing to do if the pragma is not related to elaboration 5079 5080 if not Nam_In (Prag_Nam, Name_Elaborate, Name_Elaborate_All) then 5081 return; 5082 5083 -- Nothing to do when the pragma is illegal 5084 5085 elsif Error_Posted (Prag) then 5086 return; 5087 end if; 5088 5089 Unit_Arg := Get_Pragma_Arg (First (Prag_Args)); 5090 5091 -- The argument of the pragma may appear in package.package form 5092 5093 if Nkind (Unit_Arg) = N_Selected_Component then 5094 Unit_Arg := Selector_Name (Unit_Arg); 5095 end if; 5096 5097 Add_Unit 5098 (Unit_Id => Entity (Unit_Arg), 5099 Prag => Prag, 5100 Full_Context => Prag_Nam = Name_Elaborate_All); 5101 end Add_Pragma; 5102 5103 -------------- 5104 -- Add_Unit -- 5105 -------------- 5106 5107 procedure Add_Unit 5108 (Unit_Id : Entity_Id; 5109 Prag : Node_Id; 5110 Full_Context : Boolean) 5111 is 5112 Clause : Node_Id; 5113 Elab_Attrs : Elaboration_Attributes; 5114 5115 begin 5116 -- Nothing to do when some previous error left a with clause or a 5117 -- pragma in a bad state. 5118 5119 if No (Unit_Id) then 5120 return; 5121 end if; 5122 5123 Elab_Attrs := Elaboration_Status (Unit_Id); 5124 5125 -- The unit is already included in the context by means of pragma 5126 -- Elaborate[_All]. 5127 5128 if Present (Elab_Attrs.Source_Pragma) then 5129 5130 -- Upgrade an existing pragma Elaborate when the unit is subject 5131 -- to Elaborate_All because the new pragma covers a larger set of 5132 -- units. 5133 5134 if Pragma_Name (Elab_Attrs.Source_Pragma) = Name_Elaborate 5135 and then Pragma_Name (Prag) = Name_Elaborate_All 5136 then 5137 Elab_Attrs.Source_Pragma := Prag; 5138 5139 -- Otherwise the unit retains its existing pragma and does not 5140 -- need to be included in the context again. 5141 5142 else 5143 return; 5144 end if; 5145 5146 -- The current unit is not part of the context. Prepare a new set of 5147 -- attributes. 5148 5149 else 5150 Elab_Attrs := 5151 Elaboration_Attributes'(Source_Pragma => Prag, 5152 With_Clause => Empty); 5153 end if; 5154 5155 -- Add or update the attributes of the unit 5156 5157 Set_Elaboration_Status (Unit_Id, Elab_Attrs); 5158 5159 -- Includes all units withed by the current one when computing the 5160 -- full context. 5161 5162 if Full_Context then 5163 5164 -- Process all nonlimited with clauses found in the context of 5165 -- the current unit. Note that limited clauses do not impose an 5166 -- elaboration order. 5167 5168 Clause := First (Context_Items (Compilation_Unit (Unit_Id))); 5169 while Present (Clause) loop 5170 if Nkind (Clause) = N_With_Clause 5171 and then not Error_Posted (Clause) 5172 and then not Limited_Present (Clause) 5173 then 5174 Add_Unit 5175 (Unit_Id => Entity (Name (Clause)), 5176 Prag => Prag, 5177 Full_Context => Full_Context); 5178 end if; 5179 5180 Next (Clause); 5181 end loop; 5182 end if; 5183 end Add_Unit; 5184 5185 ------------------------------ 5186 -- Find_Elaboration_Context -- 5187 ------------------------------ 5188 5189 procedure Find_Elaboration_Context (Comp_Unit : Node_Id) is 5190 Prag : Node_Id; 5191 5192 begin 5193 pragma Assert (Nkind (Comp_Unit) = N_Compilation_Unit); 5194 5195 -- Process all elaboration-related pragmas found in the context of 5196 -- the compilation unit. 5197 5198 Prag := First (Context_Items (Comp_Unit)); 5199 while Present (Prag) loop 5200 if Nkind (Prag) = N_Pragma then 5201 Add_Pragma (Prag); 5202 end if; 5203 5204 Next (Prag); 5205 end loop; 5206 end Find_Elaboration_Context; 5207 5208 -- Local variables 5209 5210 Par_Id : Entity_Id; 5211 Unt : Node_Id; 5212 5213 -- Start of processing for Find_Elaborated_Units 5214 5215 begin 5216 -- Perform a traversal which examines the context of the main unit and 5217 -- populates the Elaboration_Context table with all units elaborated 5218 -- prior to the main unit. The traversal performs the following jumps: 5219 5220 -- subunit -> parent subunit 5221 -- parent subunit -> body 5222 -- body -> spec 5223 -- spec -> parent spec 5224 -- parent spec -> grandparent spec and so on 5225 5226 -- The traversal relies on units rather than scopes because the scope of 5227 -- a subunit is some spec, while this traversal must process the body as 5228 -- well. Given that protected and task bodies can also be subunits, this 5229 -- complicates the scope approach even further. 5230 5231 Unt := Unit (Cunit (Main_Unit)); 5232 5233 -- Perform the following traversals when the main unit is a subunit 5234 5235 -- subunit -> parent subunit 5236 -- parent subunit -> body 5237 5238 while Present (Unt) and then Nkind (Unt) = N_Subunit loop 5239 Find_Elaboration_Context (Parent (Unt)); 5240 5241 -- Continue the traversal by going to the unit which contains the 5242 -- corresponding stub. 5243 5244 if Present (Corresponding_Stub (Unt)) then 5245 Unt := Unit (Cunit (Get_Source_Unit (Corresponding_Stub (Unt)))); 5246 5247 -- Otherwise the subunit may be erroneous or left in a bad state 5248 5249 else 5250 exit; 5251 end if; 5252 end loop; 5253 5254 -- Perform the following traversal now that subunits have been taken 5255 -- care of, or the main unit is a body. 5256 5257 -- body -> spec 5258 5259 if Present (Unt) 5260 and then Nkind_In (Unt, N_Package_Body, N_Subprogram_Body) 5261 then 5262 Find_Elaboration_Context (Parent (Unt)); 5263 5264 -- Continue the traversal by going to the unit which contains the 5265 -- corresponding spec. 5266 5267 if Present (Corresponding_Spec (Unt)) then 5268 Unt := Unit (Cunit (Get_Source_Unit (Corresponding_Spec (Unt)))); 5269 end if; 5270 end if; 5271 5272 -- Perform the following traversals now that the body has been taken 5273 -- care of, or the main unit is a spec. 5274 5275 -- spec -> parent spec 5276 -- parent spec -> grandparent spec and so on 5277 5278 if Present (Unt) 5279 and then Nkind_In (Unt, N_Generic_Package_Declaration, 5280 N_Generic_Subprogram_Declaration, 5281 N_Package_Declaration, 5282 N_Subprogram_Declaration) 5283 then 5284 Find_Elaboration_Context (Parent (Unt)); 5285 5286 -- Process a potential chain of parent units which ends with the 5287 -- main unit spec. The traversal can now safely rely on the scope 5288 -- chain. 5289 5290 Par_Id := Scope (Defining_Entity (Unt)); 5291 while Present (Par_Id) and then Par_Id /= Standard_Standard loop 5292 Find_Elaboration_Context (Compilation_Unit (Par_Id)); 5293 5294 Par_Id := Scope (Par_Id); 5295 end loop; 5296 end if; 5297 end Find_Elaborated_Units; 5298 5299 ----------------------------- 5300 -- Find_Enclosing_Instance -- 5301 ----------------------------- 5302 5303 function Find_Enclosing_Instance (N : Node_Id) return Node_Id is 5304 Par : Node_Id; 5305 Spec_Id : Entity_Id; 5306 5307 begin 5308 -- Climb the parent chain looking for an enclosing instance spec or body 5309 5310 Par := N; 5311 while Present (Par) loop 5312 5313 -- Generic package or subprogram spec 5314 5315 if Nkind_In (Par, N_Package_Declaration, 5316 N_Subprogram_Declaration) 5317 and then Is_Generic_Instance (Defining_Entity (Par)) 5318 then 5319 return Par; 5320 5321 -- Generic package or subprogram body 5322 5323 elsif Nkind_In (Par, N_Package_Body, N_Subprogram_Body) then 5324 Spec_Id := Corresponding_Spec (Par); 5325 5326 if Present (Spec_Id) and then Is_Generic_Instance (Spec_Id) then 5327 return Par; 5328 end if; 5329 end if; 5330 5331 Par := Parent (Par); 5332 end loop; 5333 5334 return Empty; 5335 end Find_Enclosing_Instance; 5336 5337 -------------------------- 5338 -- Find_Enclosing_Level -- 5339 -------------------------- 5340 5341 function Find_Enclosing_Level (N : Node_Id) return Enclosing_Level_Kind is 5342 function Level_Of (Unit : Node_Id) return Enclosing_Level_Kind; 5343 -- Obtain the corresponding level of unit Unit 5344 5345 -------------- 5346 -- Level_Of -- 5347 -------------- 5348 5349 function Level_Of (Unit : Node_Id) return Enclosing_Level_Kind is 5350 Spec_Id : Entity_Id; 5351 5352 begin 5353 if Nkind (Unit) in N_Generic_Instantiation then 5354 return Instantiation; 5355 5356 elsif Nkind (Unit) = N_Generic_Package_Declaration then 5357 return Generic_Package_Spec; 5358 5359 elsif Nkind (Unit) = N_Package_Declaration then 5360 return Package_Spec; 5361 5362 elsif Nkind (Unit) = N_Package_Body then 5363 Spec_Id := Corresponding_Spec (Unit); 5364 5365 -- The body belongs to a generic package 5366 5367 if Present (Spec_Id) 5368 and then Ekind (Spec_Id) = E_Generic_Package 5369 then 5370 return Generic_Package_Body; 5371 5372 -- Otherwise the body belongs to a non-generic package. This also 5373 -- treats an illegal package body without a corresponding spec as 5374 -- a non-generic package body. 5375 5376 else 5377 return Package_Body; 5378 end if; 5379 end if; 5380 5381 return No_Level; 5382 end Level_Of; 5383 5384 -- Local variables 5385 5386 Context : Node_Id; 5387 Curr : Node_Id; 5388 Prev : Node_Id; 5389 5390 -- Start of processing for Find_Enclosing_Level 5391 5392 begin 5393 -- Call markers and instantiations which appear at the declaration level 5394 -- but are later relocated in a different context retain their original 5395 -- declaration level. 5396 5397 if Nkind_In (N, N_Call_Marker, 5398 N_Function_Instantiation, 5399 N_Package_Instantiation, 5400 N_Procedure_Instantiation) 5401 and then Is_Declaration_Level_Node (N) 5402 then 5403 return Declaration_Level; 5404 end if; 5405 5406 -- Climb the parent chain looking at the enclosing levels 5407 5408 Prev := N; 5409 Curr := Parent (Prev); 5410 while Present (Curr) loop 5411 5412 -- A traversal from a subunit continues via the corresponding stub 5413 5414 if Nkind (Curr) = N_Subunit then 5415 Curr := Corresponding_Stub (Curr); 5416 5417 -- The current construct is a package. Packages are ignored because 5418 -- they are always elaborated when the enclosing context is invoked 5419 -- or elaborated. 5420 5421 elsif Nkind_In (Curr, N_Package_Body, N_Package_Declaration) then 5422 null; 5423 5424 -- The current construct is a block statement 5425 5426 elsif Nkind (Curr) = N_Block_Statement then 5427 5428 -- Ignore internally generated blocks created by the expander for 5429 -- various purposes such as abort defer/undefer. 5430 5431 if not Comes_From_Source (Curr) then 5432 null; 5433 5434 -- If the traversal came from the handled sequence of statments, 5435 -- then the node appears at the level of the enclosing construct. 5436 -- This is a more reliable test because transients scopes within 5437 -- the declarative region of the encapsulator are hard to detect. 5438 5439 elsif Nkind (Prev) = N_Handled_Sequence_Of_Statements 5440 and then Handled_Statement_Sequence (Curr) = Prev 5441 then 5442 return Find_Enclosing_Level (Parent (Curr)); 5443 5444 -- Otherwise the traversal came from the declarations, the node is 5445 -- at the declaration level. 5446 5447 else 5448 return Declaration_Level; 5449 end if; 5450 5451 -- The current construct is a declaration-level encapsulator 5452 5453 elsif Nkind_In (Curr, N_Entry_Body, 5454 N_Subprogram_Body, 5455 N_Task_Body) 5456 then 5457 -- If the traversal came from the handled sequence of statments, 5458 -- then the node cannot possibly appear at any level. This is 5459 -- a more reliable test because transients scopes within the 5460 -- declarative region of the encapsulator are hard to detect. 5461 5462 if Nkind (Prev) = N_Handled_Sequence_Of_Statements 5463 and then Handled_Statement_Sequence (Curr) = Prev 5464 then 5465 return No_Level; 5466 5467 -- Otherwise the traversal came from the declarations, the node is 5468 -- at the declaration level. 5469 5470 else 5471 return Declaration_Level; 5472 end if; 5473 5474 -- The current construct is a non-library-level encapsulator which 5475 -- indicates that the node cannot possibly appear at any level. 5476 -- Note that this check must come after the declaration-level check 5477 -- because both predicates share certain nodes. 5478 5479 elsif Is_Non_Library_Level_Encapsulator (Curr) then 5480 Context := Parent (Curr); 5481 5482 -- The sole exception is when the encapsulator is the compilation 5483 -- utit itself because the compilation unit node requires special 5484 -- processing (see below). 5485 5486 if Present (Context) 5487 and then Nkind (Context) = N_Compilation_Unit 5488 then 5489 null; 5490 5491 -- Otherwise the node is not at any level 5492 5493 else 5494 return No_Level; 5495 end if; 5496 5497 -- The current construct is a compilation unit. The node appears at 5498 -- the [generic] library level when the unit is a [generic] package. 5499 5500 elsif Nkind (Curr) = N_Compilation_Unit then 5501 return Level_Of (Unit (Curr)); 5502 end if; 5503 5504 Prev := Curr; 5505 Curr := Parent (Prev); 5506 end loop; 5507 5508 return No_Level; 5509 end Find_Enclosing_Level; 5510 5511 ------------------- 5512 -- Find_Top_Unit -- 5513 ------------------- 5514 5515 function Find_Top_Unit (N : Node_Or_Entity_Id) return Entity_Id is 5516 begin 5517 return Find_Unit_Entity (Unit (Cunit (Get_Top_Level_Code_Unit (N)))); 5518 end Find_Top_Unit; 5519 5520 ---------------------- 5521 -- Find_Unit_Entity -- 5522 ---------------------- 5523 5524 function Find_Unit_Entity (N : Node_Id) return Entity_Id is 5525 Context : constant Node_Id := Parent (N); 5526 Orig_N : constant Node_Id := Original_Node (N); 5527 5528 begin 5529 -- The unit denotes a package body of an instantiation which acts as 5530 -- a compilation unit. The proper entity is that of the package spec. 5531 5532 if Nkind (N) = N_Package_Body 5533 and then Nkind (Orig_N) = N_Package_Instantiation 5534 and then Nkind (Context) = N_Compilation_Unit 5535 then 5536 return Corresponding_Spec (N); 5537 5538 -- The unit denotes an anonymous package created to wrap a subprogram 5539 -- instantiation which acts as a compilation unit. The proper entity is 5540 -- that of the "related instance". 5541 5542 elsif Nkind (N) = N_Package_Declaration 5543 and then Nkind_In (Orig_N, N_Function_Instantiation, 5544 N_Procedure_Instantiation) 5545 and then Nkind (Context) = N_Compilation_Unit 5546 then 5547 return 5548 Related_Instance (Defining_Entity (N, Concurrent_Subunit => True)); 5549 5550 -- Otherwise the proper entity is the defining entity 5551 5552 else 5553 return Defining_Entity (N, Concurrent_Subunit => True); 5554 end if; 5555 end Find_Unit_Entity; 5556 5557 ----------------------- 5558 -- First_Formal_Type -- 5559 ----------------------- 5560 5561 function First_Formal_Type (Subp_Id : Entity_Id) return Entity_Id is 5562 Formal_Id : constant Entity_Id := First_Formal (Subp_Id); 5563 Typ : Entity_Id; 5564 5565 begin 5566 if Present (Formal_Id) then 5567 Typ := Etype (Formal_Id); 5568 5569 -- Handle various combinations of concurrent and private types 5570 5571 loop 5572 if Ekind_In (Typ, E_Protected_Type, E_Task_Type) 5573 and then Present (Anonymous_Object (Typ)) 5574 then 5575 Typ := Anonymous_Object (Typ); 5576 5577 elsif Is_Concurrent_Record_Type (Typ) then 5578 Typ := Corresponding_Concurrent_Type (Typ); 5579 5580 elsif Is_Private_Type (Typ) and then Present (Full_View (Typ)) then 5581 Typ := Full_View (Typ); 5582 5583 else 5584 exit; 5585 end if; 5586 end loop; 5587 5588 return Typ; 5589 end if; 5590 5591 return Empty; 5592 end First_Formal_Type; 5593 5594 -------------- 5595 -- Has_Body -- 5596 -------------- 5597 5598 function Has_Body (Pack_Decl : Node_Id) return Boolean is 5599 function Find_Corresponding_Body (Spec_Id : Entity_Id) return Node_Id; 5600 -- Try to locate the corresponding body of spec Spec_Id. If no body is 5601 -- found, return Empty. 5602 5603 function Find_Body 5604 (Spec_Id : Entity_Id; 5605 From : Node_Id) return Node_Id; 5606 -- Try to locate the corresponding body of spec Spec_Id in the node list 5607 -- which follows arbitrary node From. If no body is found, return Empty. 5608 5609 function Load_Package_Body (Unit_Nam : Unit_Name_Type) return Node_Id; 5610 -- Attempt to load the body of unit Unit_Nam. If the load failed, return 5611 -- Empty. If the compilation will not generate code, return Empty. 5612 5613 ----------------------------- 5614 -- Find_Corresponding_Body -- 5615 ----------------------------- 5616 5617 function Find_Corresponding_Body (Spec_Id : Entity_Id) return Node_Id is 5618 Context : constant Entity_Id := Scope (Spec_Id); 5619 Spec_Decl : constant Node_Id := Unit_Declaration_Node (Spec_Id); 5620 Body_Decl : Node_Id; 5621 Body_Id : Entity_Id; 5622 5623 begin 5624 if Is_Compilation_Unit (Spec_Id) then 5625 Body_Id := Corresponding_Body (Spec_Decl); 5626 5627 if Present (Body_Id) then 5628 return Unit_Declaration_Node (Body_Id); 5629 5630 -- The package is at the library and requires a body. Load the 5631 -- corresponding body because the optional body may be declared 5632 -- there. 5633 5634 elsif Unit_Requires_Body (Spec_Id) then 5635 return 5636 Load_Package_Body 5637 (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec_Decl)))); 5638 5639 -- Otherwise there is no optional body 5640 5641 else 5642 return Empty; 5643 end if; 5644 5645 -- The immediate context is a package. The optional body may be 5646 -- within the body of that package. 5647 5648 -- procedure Proc is 5649 -- package Nested_1 is 5650 -- package Nested_2 is 5651 -- generic 5652 -- package Pack is 5653 -- end Pack; 5654 -- end Nested_2; 5655 -- end Nested_1; 5656 5657 -- package body Nested_1 is 5658 -- package body Nested_2 is separate; 5659 -- end Nested_1; 5660 5661 -- separate (Proc.Nested_1.Nested_2) 5662 -- package body Nested_2 is 5663 -- package body Pack is -- optional body 5664 -- ... 5665 -- end Pack; 5666 -- end Nested_2; 5667 5668 elsif Is_Package_Or_Generic_Package (Context) then 5669 Body_Decl := Find_Corresponding_Body (Context); 5670 5671 -- The optional body is within the body of the enclosing package 5672 5673 if Present (Body_Decl) then 5674 return 5675 Find_Body 5676 (Spec_Id => Spec_Id, 5677 From => First (Declarations (Body_Decl))); 5678 5679 -- Otherwise the enclosing package does not have a body. This may 5680 -- be the result of an error or a genuine lack of a body. 5681 5682 else 5683 return Empty; 5684 end if; 5685 5686 -- Otherwise the immediate context is a body. The optional body may 5687 -- be within the same list as the spec. 5688 5689 -- procedure Proc is 5690 -- generic 5691 -- package Pack is 5692 -- end Pack; 5693 5694 -- package body Pack is -- optional body 5695 -- ... 5696 -- end Pack; 5697 5698 else 5699 return 5700 Find_Body 5701 (Spec_Id => Spec_Id, 5702 From => Next (Spec_Decl)); 5703 end if; 5704 end Find_Corresponding_Body; 5705 5706 --------------- 5707 -- Find_Body -- 5708 --------------- 5709 5710 function Find_Body 5711 (Spec_Id : Entity_Id; 5712 From : Node_Id) return Node_Id 5713 is 5714 Spec_Nam : constant Name_Id := Chars (Spec_Id); 5715 Item : Node_Id; 5716 Lib_Unit : Node_Id; 5717 5718 begin 5719 Item := From; 5720 while Present (Item) loop 5721 5722 -- The current item denotes the optional body 5723 5724 if Nkind (Item) = N_Package_Body 5725 and then Chars (Defining_Entity (Item)) = Spec_Nam 5726 then 5727 return Item; 5728 5729 -- The current item denotes a stub, the optional body may be in 5730 -- the subunit. 5731 5732 elsif Nkind (Item) = N_Package_Body_Stub 5733 and then Chars (Defining_Entity (Item)) = Spec_Nam 5734 then 5735 Lib_Unit := Library_Unit (Item); 5736 5737 -- The corresponding subunit was previously loaded 5738 5739 if Present (Lib_Unit) then 5740 return Lib_Unit; 5741 5742 -- Otherwise attempt to load the corresponding subunit 5743 5744 else 5745 return Load_Package_Body (Get_Unit_Name (Item)); 5746 end if; 5747 end if; 5748 5749 Next (Item); 5750 end loop; 5751 5752 return Empty; 5753 end Find_Body; 5754 5755 ----------------------- 5756 -- Load_Package_Body -- 5757 ----------------------- 5758 5759 function Load_Package_Body (Unit_Nam : Unit_Name_Type) return Node_Id is 5760 Body_Decl : Node_Id; 5761 Unit_Num : Unit_Number_Type; 5762 5763 begin 5764 -- The load is performed only when the compilation will generate code 5765 5766 if Operating_Mode = Generate_Code then 5767 Unit_Num := 5768 Load_Unit 5769 (Load_Name => Unit_Nam, 5770 Required => False, 5771 Subunit => False, 5772 Error_Node => Pack_Decl); 5773 5774 -- The load failed most likely because the physical file is 5775 -- missing. 5776 5777 if Unit_Num = No_Unit then 5778 return Empty; 5779 5780 -- Otherwise the load was successful, return the body of the unit 5781 5782 else 5783 Body_Decl := Unit (Cunit (Unit_Num)); 5784 5785 -- If the unit is a subunit with an available proper body, 5786 -- return the proper body. 5787 5788 if Nkind (Body_Decl) = N_Subunit 5789 and then Present (Proper_Body (Body_Decl)) 5790 then 5791 Body_Decl := Proper_Body (Body_Decl); 5792 end if; 5793 5794 return Body_Decl; 5795 end if; 5796 end if; 5797 5798 return Empty; 5799 end Load_Package_Body; 5800 5801 -- Local variables 5802 5803 Pack_Id : constant Entity_Id := Defining_Entity (Pack_Decl); 5804 5805 -- Start of processing for Has_Body 5806 5807 begin 5808 -- The body is available 5809 5810 if Present (Corresponding_Body (Pack_Decl)) then 5811 return True; 5812 5813 -- The body is required if the package spec contains a construct which 5814 -- requires a completion in a body. 5815 5816 elsif Unit_Requires_Body (Pack_Id) then 5817 return True; 5818 5819 -- The body may be optional 5820 5821 else 5822 return Present (Find_Corresponding_Body (Pack_Id)); 5823 end if; 5824 end Has_Body; 5825 5826 --------------------------- 5827 -- Has_Prior_Elaboration -- 5828 --------------------------- 5829 5830 function Has_Prior_Elaboration 5831 (Unit_Id : Entity_Id; 5832 Context_OK : Boolean := False; 5833 Elab_Body_OK : Boolean := False; 5834 Same_Unit_OK : Boolean := False) return Boolean 5835 is 5836 Main_Id : constant Entity_Id := Cunit_Entity (Main_Unit); 5837 5838 begin 5839 -- A preelaborated unit is always elaborated prior to the main unit 5840 5841 if Is_Preelaborated_Unit (Unit_Id) then 5842 return True; 5843 5844 -- An internal unit is always elaborated prior to a non-internal main 5845 -- unit. 5846 5847 elsif In_Internal_Unit (Unit_Id) 5848 and then not In_Internal_Unit (Main_Id) 5849 then 5850 return True; 5851 5852 -- A unit has prior elaboration if it appears within the context of the 5853 -- main unit. Consider this case only when requested by the caller. 5854 5855 elsif Context_OK 5856 and then Elaboration_Status (Unit_Id) /= No_Elaboration_Attributes 5857 then 5858 return True; 5859 5860 -- A unit whose body is elaborated together with its spec has prior 5861 -- elaboration except with respect to itself. Consider this case only 5862 -- when requested by the caller. 5863 5864 elsif Elab_Body_OK 5865 and then Has_Pragma_Elaborate_Body (Unit_Id) 5866 and then not Is_Same_Unit (Unit_Id, Main_Id) 5867 then 5868 return True; 5869 5870 -- A unit has no prior elaboration with respect to itself, but does not 5871 -- require any means of ensuring its own elaboration either. Treat this 5872 -- case as valid prior elaboration only when requested by the caller. 5873 5874 elsif Same_Unit_OK and then Is_Same_Unit (Unit_Id, Main_Id) then 5875 return True; 5876 end if; 5877 5878 return False; 5879 end Has_Prior_Elaboration; 5880 5881 -------------------------- 5882 -- In_External_Instance -- 5883 -------------------------- 5884 5885 function In_External_Instance 5886 (N : Node_Id; 5887 Target_Decl : Node_Id) return Boolean 5888 is 5889 Dummy : Node_Id; 5890 Inst_Body : Node_Id; 5891 Inst_Decl : Node_Id; 5892 5893 begin 5894 -- Performance note: parent traversal 5895 5896 Inst_Decl := Find_Enclosing_Instance (Target_Decl); 5897 5898 -- The target declaration appears within an instance spec. Visibility is 5899 -- ignored because internally generated primitives for private types may 5900 -- reside in the private declarations and still be invoked from outside. 5901 5902 if Present (Inst_Decl) 5903 and then Nkind (Inst_Decl) = N_Package_Declaration 5904 then 5905 -- The scenario comes from the main unit and the instance does not 5906 5907 if In_Extended_Main_Code_Unit (N) 5908 and then not In_Extended_Main_Code_Unit (Inst_Decl) 5909 then 5910 return True; 5911 5912 -- Otherwise the scenario must not appear within the instance spec or 5913 -- body. 5914 5915 else 5916 Extract_Instance_Attributes 5917 (Exp_Inst => Inst_Decl, 5918 Inst_Body => Inst_Body, 5919 Inst_Decl => Dummy); 5920 5921 -- Performance note: parent traversal 5922 5923 return not In_Subtree 5924 (N => N, 5925 Root1 => Inst_Decl, 5926 Root2 => Inst_Body); 5927 end if; 5928 end if; 5929 5930 return False; 5931 end In_External_Instance; 5932 5933 --------------------- 5934 -- In_Main_Context -- 5935 --------------------- 5936 5937 function In_Main_Context (N : Node_Id) return Boolean is 5938 begin 5939 -- Scenarios outside the main unit are not considered because the ALI 5940 -- information supplied to binde is for the main unit only. 5941 5942 if not In_Extended_Main_Code_Unit (N) then 5943 return False; 5944 5945 -- Scenarios within internal units are not considered unless switch 5946 -- -gnatdE (elaboration checks on predefined units) is in effect. 5947 5948 elsif not Debug_Flag_EE and then In_Internal_Unit (N) then 5949 return False; 5950 end if; 5951 5952 return True; 5953 end In_Main_Context; 5954 5955 --------------------- 5956 -- In_Same_Context -- 5957 --------------------- 5958 5959 function In_Same_Context 5960 (N1 : Node_Id; 5961 N2 : Node_Id; 5962 Nested_OK : Boolean := False) return Boolean 5963 is 5964 function Find_Enclosing_Context (N : Node_Id) return Node_Id; 5965 -- Return the nearest enclosing non-library-level or compilation unit 5966 -- node which which encapsulates arbitrary node N. Return Empty is no 5967 -- such context is available. 5968 5969 function In_Nested_Context 5970 (Outer : Node_Id; 5971 Inner : Node_Id) return Boolean; 5972 -- Determine whether arbitrary node Outer encapsulates arbitrary node 5973 -- Inner. 5974 5975 ---------------------------- 5976 -- Find_Enclosing_Context -- 5977 ---------------------------- 5978 5979 function Find_Enclosing_Context (N : Node_Id) return Node_Id is 5980 Context : Node_Id; 5981 Par : Node_Id; 5982 5983 begin 5984 Par := Parent (N); 5985 while Present (Par) loop 5986 5987 -- A traversal from a subunit continues via the corresponding stub 5988 5989 if Nkind (Par) = N_Subunit then 5990 Par := Corresponding_Stub (Par); 5991 5992 -- Stop the traversal when the nearest enclosing non-library-level 5993 -- encapsulator has been reached. 5994 5995 elsif Is_Non_Library_Level_Encapsulator (Par) then 5996 Context := Parent (Par); 5997 5998 -- The sole exception is when the encapsulator is the unit of 5999 -- compilation because this case requires special processing 6000 -- (see below). 6001 6002 if Present (Context) 6003 and then Nkind (Context) = N_Compilation_Unit 6004 then 6005 null; 6006 6007 else 6008 return Par; 6009 end if; 6010 6011 -- Reaching a compilation unit node without hitting a non-library- 6012 -- level encapsulator indicates that N is at the library level in 6013 -- which case the compilation unit is the context. 6014 6015 elsif Nkind (Par) = N_Compilation_Unit then 6016 return Par; 6017 end if; 6018 6019 Par := Parent (Par); 6020 end loop; 6021 6022 return Empty; 6023 end Find_Enclosing_Context; 6024 6025 ----------------------- 6026 -- In_Nested_Context -- 6027 ----------------------- 6028 6029 function In_Nested_Context 6030 (Outer : Node_Id; 6031 Inner : Node_Id) return Boolean 6032 is 6033 Par : Node_Id; 6034 6035 begin 6036 Par := Inner; 6037 while Present (Par) loop 6038 6039 -- A traversal from a subunit continues via the corresponding stub 6040 6041 if Nkind (Par) = N_Subunit then 6042 Par := Corresponding_Stub (Par); 6043 6044 elsif Par = Outer then 6045 return True; 6046 end if; 6047 6048 Par := Parent (Par); 6049 end loop; 6050 6051 return False; 6052 end In_Nested_Context; 6053 6054 -- Local variables 6055 6056 Context_1 : constant Node_Id := Find_Enclosing_Context (N1); 6057 Context_2 : constant Node_Id := Find_Enclosing_Context (N2); 6058 6059 -- Start of processing for In_Same_Context 6060 6061 begin 6062 -- Both nodes appear within the same context 6063 6064 if Context_1 = Context_2 then 6065 return True; 6066 6067 -- Both nodes appear in compilation units. Determine whether one unit 6068 -- is the body of the other. 6069 6070 elsif Nkind (Context_1) = N_Compilation_Unit 6071 and then Nkind (Context_2) = N_Compilation_Unit 6072 then 6073 return 6074 Is_Same_Unit 6075 (Unit_1 => Defining_Entity (Unit (Context_1)), 6076 Unit_2 => Defining_Entity (Unit (Context_2))); 6077 6078 -- The context of N1 encloses the context of N2 6079 6080 elsif Nested_OK and then In_Nested_Context (Context_1, Context_2) then 6081 return True; 6082 end if; 6083 6084 return False; 6085 end In_Same_Context; 6086 6087 ---------------- 6088 -- Initialize -- 6089 ---------------- 6090 6091 procedure Initialize is 6092 begin 6093 -- Set the soft link which enables Atree.Rewrite to update a top-level 6094 -- scenario each time it is transformed into another node. 6095 6096 Set_Rewriting_Proc (Update_Elaboration_Scenario'Access); 6097 end Initialize; 6098 6099 --------------- 6100 -- Info_Call -- 6101 --------------- 6102 6103 procedure Info_Call 6104 (Call : Node_Id; 6105 Target_Id : Entity_Id; 6106 Info_Msg : Boolean; 6107 In_SPARK : Boolean) 6108 is 6109 procedure Info_Accept_Alternative; 6110 pragma Inline (Info_Accept_Alternative); 6111 -- Output information concerning an accept alternative 6112 6113 procedure Info_Simple_Call; 6114 pragma Inline (Info_Simple_Call); 6115 -- Output information concerning the call 6116 6117 procedure Info_Type_Actions (Action : String); 6118 pragma Inline (Info_Type_Actions); 6119 -- Output information concerning action Action of a type 6120 6121 procedure Info_Verification_Call 6122 (Pred : String; 6123 Id : Entity_Id; 6124 Id_Kind : String); 6125 pragma Inline (Info_Verification_Call); 6126 -- Output information concerning the verification of predicate Pred 6127 -- applied to related entity Id with kind Id_Kind. 6128 6129 ----------------------------- 6130 -- Info_Accept_Alternative -- 6131 ----------------------------- 6132 6133 procedure Info_Accept_Alternative is 6134 Entry_Id : constant Entity_Id := Receiving_Entry (Target_Id); 6135 6136 begin 6137 pragma Assert (Present (Entry_Id)); 6138 6139 Elab_Msg_NE 6140 (Msg => "accept for entry & during elaboration", 6141 N => Call, 6142 Id => Entry_Id, 6143 Info_Msg => Info_Msg, 6144 In_SPARK => In_SPARK); 6145 end Info_Accept_Alternative; 6146 6147 ---------------------- 6148 -- Info_Simple_Call -- 6149 ---------------------- 6150 6151 procedure Info_Simple_Call is 6152 begin 6153 Elab_Msg_NE 6154 (Msg => "call to & during elaboration", 6155 N => Call, 6156 Id => Target_Id, 6157 Info_Msg => Info_Msg, 6158 In_SPARK => In_SPARK); 6159 end Info_Simple_Call; 6160 6161 ----------------------- 6162 -- Info_Type_Actions -- 6163 ----------------------- 6164 6165 procedure Info_Type_Actions (Action : String) is 6166 Typ : constant Entity_Id := First_Formal_Type (Target_Id); 6167 6168 begin 6169 pragma Assert (Present (Typ)); 6170 6171 Elab_Msg_NE 6172 (Msg => Action & " actions for type & during elaboration", 6173 N => Call, 6174 Id => Typ, 6175 Info_Msg => Info_Msg, 6176 In_SPARK => In_SPARK); 6177 end Info_Type_Actions; 6178 6179 ---------------------------- 6180 -- Info_Verification_Call -- 6181 ---------------------------- 6182 6183 procedure Info_Verification_Call 6184 (Pred : String; 6185 Id : Entity_Id; 6186 Id_Kind : String) 6187 is 6188 begin 6189 pragma Assert (Present (Id)); 6190 6191 Elab_Msg_NE 6192 (Msg => 6193 "verification of " & Pred & " of " & Id_Kind & " & during " 6194 & "elaboration", 6195 N => Call, 6196 Id => Id, 6197 Info_Msg => Info_Msg, 6198 In_SPARK => In_SPARK); 6199 end Info_Verification_Call; 6200 6201 -- Start of processing for Info_Call 6202 6203 begin 6204 -- Do not output anything for targets defined in internal units because 6205 -- this creates noise. 6206 6207 if not In_Internal_Unit (Target_Id) then 6208 6209 -- Accept alternative 6210 6211 if Is_Accept_Alternative_Proc (Target_Id) then 6212 Info_Accept_Alternative; 6213 6214 -- Adjustment 6215 6216 elsif Is_TSS (Target_Id, TSS_Deep_Adjust) then 6217 Info_Type_Actions ("adjustment"); 6218 6219 -- Default_Initial_Condition 6220 6221 elsif Is_Default_Initial_Condition_Proc (Target_Id) then 6222 Info_Verification_Call 6223 (Pred => "Default_Initial_Condition", 6224 Id => First_Formal_Type (Target_Id), 6225 Id_Kind => "type"); 6226 6227 -- Entries 6228 6229 elsif Is_Protected_Entry (Target_Id) then 6230 Info_Simple_Call; 6231 6232 -- Task entry calls are never processed because the entry being 6233 -- invoked does not have a corresponding "body", it has a select. 6234 6235 elsif Is_Task_Entry (Target_Id) then 6236 null; 6237 6238 -- Finalization 6239 6240 elsif Is_TSS (Target_Id, TSS_Deep_Finalize) then 6241 Info_Type_Actions ("finalization"); 6242 6243 -- Calls to _Finalizer procedures must not appear in the output 6244 -- because this creates confusing noise. 6245 6246 elsif Is_Finalizer_Proc (Target_Id) then 6247 null; 6248 6249 -- Initial_Condition 6250 6251 elsif Is_Initial_Condition_Proc (Target_Id) then 6252 Info_Verification_Call 6253 (Pred => "Initial_Condition", 6254 Id => Find_Enclosing_Scope (Call), 6255 Id_Kind => "package"); 6256 6257 -- Initialization 6258 6259 elsif Is_Init_Proc (Target_Id) 6260 or else Is_TSS (Target_Id, TSS_Deep_Initialize) 6261 then 6262 Info_Type_Actions ("initialization"); 6263 6264 -- Invariant 6265 6266 elsif Is_Invariant_Proc (Target_Id) then 6267 Info_Verification_Call 6268 (Pred => "invariants", 6269 Id => First_Formal_Type (Target_Id), 6270 Id_Kind => "type"); 6271 6272 -- Partial invariant calls must not appear in the output because this 6273 -- creates confusing noise. 6274 6275 elsif Is_Partial_Invariant_Proc (Target_Id) then 6276 null; 6277 6278 -- _Postconditions 6279 6280 elsif Is_Postconditions_Proc (Target_Id) then 6281 Info_Verification_Call 6282 (Pred => "postconditions", 6283 Id => Find_Enclosing_Scope (Call), 6284 Id_Kind => "subprogram"); 6285 6286 -- Subprograms must come last because some of the previous cases fall 6287 -- under this category. 6288 6289 elsif Ekind (Target_Id) = E_Function then 6290 Info_Simple_Call; 6291 6292 elsif Ekind (Target_Id) = E_Procedure then 6293 Info_Simple_Call; 6294 6295 else 6296 pragma Assert (False); 6297 null; 6298 end if; 6299 end if; 6300 end Info_Call; 6301 6302 ------------------------ 6303 -- Info_Instantiation -- 6304 ------------------------ 6305 6306 procedure Info_Instantiation 6307 (Inst : Node_Id; 6308 Gen_Id : Entity_Id; 6309 Info_Msg : Boolean; 6310 In_SPARK : Boolean) 6311 is 6312 begin 6313 Elab_Msg_NE 6314 (Msg => "instantiation of & during elaboration", 6315 N => Inst, 6316 Id => Gen_Id, 6317 Info_Msg => Info_Msg, 6318 In_SPARK => In_SPARK); 6319 end Info_Instantiation; 6320 6321 ----------------------------- 6322 -- Info_Variable_Reference -- 6323 ----------------------------- 6324 6325 procedure Info_Variable_Reference 6326 (Ref : Node_Id; 6327 Var_Id : Entity_Id; 6328 Info_Msg : Boolean; 6329 In_SPARK : Boolean) 6330 is 6331 begin 6332 if Is_Read (Ref) then 6333 Elab_Msg_NE 6334 (Msg => "read of variable & during elaboration", 6335 N => Ref, 6336 Id => Var_Id, 6337 Info_Msg => Info_Msg, 6338 In_SPARK => In_SPARK); 6339 end if; 6340 end Info_Variable_Reference; 6341 6342 -------------------- 6343 -- Insertion_Node -- 6344 -------------------- 6345 6346 function Insertion_Node (N : Node_Id; Ins_Nod : Node_Id) return Node_Id is 6347 begin 6348 -- When the scenario denotes an instantiation, the proper insertion node 6349 -- is the instance spec. This ensures that the generic actuals will not 6350 -- be evaluated prior to a potential ABE. 6351 6352 if Nkind (N) in N_Generic_Instantiation 6353 and then Present (Instance_Spec (N)) 6354 then 6355 return Instance_Spec (N); 6356 6357 -- Otherwise the proper insertion node is the candidate insertion node 6358 6359 else 6360 return Ins_Nod; 6361 end if; 6362 end Insertion_Node; 6363 6364 ----------------------- 6365 -- Install_ABE_Check -- 6366 ----------------------- 6367 6368 procedure Install_ABE_Check 6369 (N : Node_Id; 6370 Id : Entity_Id; 6371 Ins_Nod : Node_Id) 6372 is 6373 Check_Ins_Nod : constant Node_Id := Insertion_Node (N, Ins_Nod); 6374 -- Insert the check prior to this node 6375 6376 Loc : constant Source_Ptr := Sloc (N); 6377 Spec_Id : constant Entity_Id := Unique_Entity (Id); 6378 Unit_Id : constant Entity_Id := Find_Top_Unit (Id); 6379 Scop_Id : Entity_Id; 6380 6381 begin 6382 -- Nothing to do when compiling for GNATprove because raise statements 6383 -- are not supported. 6384 6385 if GNATprove_Mode then 6386 return; 6387 6388 -- Nothing to do when the compilation will not produce an executable 6389 6390 elsif Serious_Errors_Detected > 0 then 6391 return; 6392 6393 -- Nothing to do for a compilation unit because there is no executable 6394 -- environment at that level. 6395 6396 elsif Nkind (Parent (Check_Ins_Nod)) = N_Compilation_Unit then 6397 return; 6398 6399 -- Nothing to do when the unit is elaborated prior to the main unit. 6400 -- This check must also consider the following cases: 6401 6402 -- * Id's unit appears in the context of the main unit 6403 6404 -- * Id's unit is subject to pragma Elaborate_Body. An ABE check MUST 6405 -- NOT be generated because Id's unit is always elaborated prior to 6406 -- the main unit. 6407 6408 -- * Id's unit is the main unit. An ABE check MUST be generated in this 6409 -- case because a conditional ABE may be raised depending on the flow 6410 -- of execution within the main unit (flag Same_Unit_OK is False). 6411 6412 elsif Has_Prior_Elaboration 6413 (Unit_Id => Unit_Id, 6414 Context_OK => True, 6415 Elab_Body_OK => True) 6416 then 6417 return; 6418 end if; 6419 6420 -- Prevent multiple scenarios from installing the same ABE check 6421 6422 Set_Is_Elaboration_Checks_OK_Node (N, False); 6423 6424 -- Install the nearest enclosing scope of the scenario as there must be 6425 -- something on the scope stack. 6426 6427 -- Performance note: parent traversal 6428 6429 Scop_Id := Find_Enclosing_Scope (Check_Ins_Nod); 6430 pragma Assert (Present (Scop_Id)); 6431 6432 Push_Scope (Scop_Id); 6433 6434 -- Generate: 6435 -- if not Spec_Id'Elaborated then 6436 -- raise Program_Error with "access before elaboration"; 6437 -- end if; 6438 6439 Insert_Action (Check_Ins_Nod, 6440 Make_Raise_Program_Error (Loc, 6441 Condition => 6442 Make_Op_Not (Loc, 6443 Right_Opnd => 6444 Make_Attribute_Reference (Loc, 6445 Prefix => New_Occurrence_Of (Spec_Id, Loc), 6446 Attribute_Name => Name_Elaborated)), 6447 Reason => PE_Access_Before_Elaboration)); 6448 6449 Pop_Scope; 6450 end Install_ABE_Check; 6451 6452 ----------------------- 6453 -- Install_ABE_Check -- 6454 ----------------------- 6455 6456 procedure Install_ABE_Check 6457 (N : Node_Id; 6458 Target_Id : Entity_Id; 6459 Target_Decl : Node_Id; 6460 Target_Body : Node_Id; 6461 Ins_Nod : Node_Id) 6462 is 6463 procedure Build_Elaboration_Entity; 6464 pragma Inline (Build_Elaboration_Entity); 6465 -- Create a new elaboration flag for Target_Id, insert it prior to 6466 -- Target_Decl, and set it after Body_Decl. 6467 6468 ------------------------------ 6469 -- Build_Elaboration_Entity -- 6470 ------------------------------ 6471 6472 procedure Build_Elaboration_Entity is 6473 Loc : constant Source_Ptr := Sloc (Target_Id); 6474 Flag_Id : Entity_Id; 6475 6476 begin 6477 -- Create the declaration of the elaboration flag. The name carries a 6478 -- unique counter in case of name overloading. 6479 6480 Flag_Id := 6481 Make_Defining_Identifier (Loc, 6482 Chars => New_External_Name (Chars (Target_Id), 'E', -1)); 6483 6484 Set_Elaboration_Entity (Target_Id, Flag_Id); 6485 Set_Elaboration_Entity_Required (Target_Id); 6486 6487 Push_Scope (Scope (Target_Id)); 6488 6489 -- Generate: 6490 -- Enn : Short_Integer := 0; 6491 6492 Insert_Action (Target_Decl, 6493 Make_Object_Declaration (Loc, 6494 Defining_Identifier => Flag_Id, 6495 Object_Definition => 6496 New_Occurrence_Of (Standard_Short_Integer, Loc), 6497 Expression => Make_Integer_Literal (Loc, Uint_0))); 6498 6499 -- Generate: 6500 -- Enn := 1; 6501 6502 Set_Elaboration_Flag (Target_Body, Target_Id); 6503 6504 Pop_Scope; 6505 end Build_Elaboration_Entity; 6506 6507 -- Local variables 6508 6509 Target_Unit_Id : constant Entity_Id := Find_Top_Unit (Target_Id); 6510 6511 -- Start for processing for Install_ABE_Check 6512 6513 begin 6514 -- Nothing to do when compiling for GNATprove because raise statements 6515 -- are not supported. 6516 6517 if GNATprove_Mode then 6518 return; 6519 6520 -- Nothing to do when the compilation will not produce an executable 6521 6522 elsif Serious_Errors_Detected > 0 then 6523 return; 6524 6525 -- Nothing to do when the target is a protected subprogram because the 6526 -- check is associated with the protected body subprogram. 6527 6528 elsif Is_Protected_Subp (Target_Id) then 6529 return; 6530 6531 -- Nothing to do when the target is elaborated prior to the main unit. 6532 -- This check must also consider the following cases: 6533 6534 -- * The unit of the target appears in the context of the main unit 6535 6536 -- * The unit of the target is subject to pragma Elaborate_Body. An ABE 6537 -- check MUST NOT be generated because the unit is always elaborated 6538 -- prior to the main unit. 6539 6540 -- * The unit of the target is the main unit. An ABE check MUST be added 6541 -- in this case because a conditional ABE may be raised depending on 6542 -- the flow of execution within the main unit (flag Same_Unit_OK is 6543 -- False). 6544 6545 elsif Has_Prior_Elaboration 6546 (Unit_Id => Target_Unit_Id, 6547 Context_OK => True, 6548 Elab_Body_OK => True) 6549 then 6550 return; 6551 6552 -- Create an elaboration flag for the target when it does not have one 6553 6554 elsif No (Elaboration_Entity (Target_Id)) then 6555 Build_Elaboration_Entity; 6556 end if; 6557 6558 Install_ABE_Check 6559 (N => N, 6560 Ins_Nod => Ins_Nod, 6561 Id => Target_Id); 6562 end Install_ABE_Check; 6563 6564 ------------------------- 6565 -- Install_ABE_Failure -- 6566 ------------------------- 6567 6568 procedure Install_ABE_Failure (N : Node_Id; Ins_Nod : Node_Id) is 6569 Fail_Ins_Nod : constant Node_Id := Insertion_Node (N, Ins_Nod); 6570 -- Insert the failure prior to this node 6571 6572 Loc : constant Source_Ptr := Sloc (N); 6573 Scop_Id : Entity_Id; 6574 6575 begin 6576 -- Nothing to do when compiling for GNATprove because raise statements 6577 -- are not supported. 6578 6579 if GNATprove_Mode then 6580 return; 6581 6582 -- Nothing to do when the compilation will not produce an executable 6583 6584 elsif Serious_Errors_Detected > 0 then 6585 return; 6586 6587 -- Do not install an ABE check for a compilation unit because there is 6588 -- no executable environment at that level. 6589 6590 elsif Nkind (Parent (Fail_Ins_Nod)) = N_Compilation_Unit then 6591 return; 6592 end if; 6593 6594 -- Prevent multiple scenarios from installing the same ABE failure 6595 6596 Set_Is_Elaboration_Checks_OK_Node (N, False); 6597 6598 -- Install the nearest enclosing scope of the scenario as there must be 6599 -- something on the scope stack. 6600 6601 -- Performance note: parent traversal 6602 6603 Scop_Id := Find_Enclosing_Scope (Fail_Ins_Nod); 6604 pragma Assert (Present (Scop_Id)); 6605 6606 Push_Scope (Scop_Id); 6607 6608 -- Generate: 6609 -- raise Program_Error with "access before elaboration"; 6610 6611 Insert_Action (Fail_Ins_Nod, 6612 Make_Raise_Program_Error (Loc, 6613 Reason => PE_Access_Before_Elaboration)); 6614 6615 Pop_Scope; 6616 end Install_ABE_Failure; 6617 6618 -------------------------------- 6619 -- Is_Accept_Alternative_Proc -- 6620 -------------------------------- 6621 6622 function Is_Accept_Alternative_Proc (Id : Entity_Id) return Boolean is 6623 begin 6624 -- To qualify, the entity must denote a procedure with a receiving entry 6625 6626 return Ekind (Id) = E_Procedure and then Present (Receiving_Entry (Id)); 6627 end Is_Accept_Alternative_Proc; 6628 6629 ------------------------ 6630 -- Is_Activation_Proc -- 6631 ------------------------ 6632 6633 function Is_Activation_Proc (Id : Entity_Id) return Boolean is 6634 begin 6635 -- To qualify, the entity must denote one of the runtime procedures in 6636 -- charge of task activation. 6637 6638 if Ekind (Id) = E_Procedure then 6639 if Restricted_Profile then 6640 return Is_RTE (Id, RE_Activate_Restricted_Tasks); 6641 else 6642 return Is_RTE (Id, RE_Activate_Tasks); 6643 end if; 6644 end if; 6645 6646 return False; 6647 end Is_Activation_Proc; 6648 6649 ---------------------------- 6650 -- Is_Ada_Semantic_Target -- 6651 ---------------------------- 6652 6653 function Is_Ada_Semantic_Target (Id : Entity_Id) return Boolean is 6654 begin 6655 return 6656 Is_Activation_Proc (Id) 6657 or else Is_Controlled_Proc (Id, Name_Adjust) 6658 or else Is_Controlled_Proc (Id, Name_Finalize) 6659 or else Is_Controlled_Proc (Id, Name_Initialize) 6660 or else Is_Init_Proc (Id) 6661 or else Is_Invariant_Proc (Id) 6662 or else Is_Protected_Entry (Id) 6663 or else Is_Protected_Subp (Id) 6664 or else Is_Protected_Body_Subp (Id) 6665 or else Is_Task_Entry (Id); 6666 end Is_Ada_Semantic_Target; 6667 6668 -------------------------------- 6669 -- Is_Assertion_Pragma_Target -- 6670 -------------------------------- 6671 6672 function Is_Assertion_Pragma_Target (Id : Entity_Id) return Boolean is 6673 begin 6674 return 6675 Is_Default_Initial_Condition_Proc (Id) 6676 or else Is_Initial_Condition_Proc (Id) 6677 or else Is_Invariant_Proc (Id) 6678 or else Is_Partial_Invariant_Proc (Id) 6679 or else Is_Postconditions_Proc (Id); 6680 end Is_Assertion_Pragma_Target; 6681 6682 ---------------------------- 6683 -- Is_Bodiless_Subprogram -- 6684 ---------------------------- 6685 6686 function Is_Bodiless_Subprogram (Subp_Id : Entity_Id) return Boolean is 6687 begin 6688 -- An abstract subprogram does not have a body 6689 6690 if Ekind_In (Subp_Id, E_Function, 6691 E_Operator, 6692 E_Procedure) 6693 and then Is_Abstract_Subprogram (Subp_Id) 6694 then 6695 return True; 6696 6697 -- A formal subprogram does not have a body 6698 6699 elsif Is_Formal_Subprogram (Subp_Id) then 6700 return True; 6701 6702 -- An imported subprogram may have a body, however it is not known at 6703 -- compile or bind time where the body resides and whether it will be 6704 -- elaborated on time. 6705 6706 elsif Is_Imported (Subp_Id) then 6707 return True; 6708 end if; 6709 6710 return False; 6711 end Is_Bodiless_Subprogram; 6712 6713 ------------------------ 6714 -- Is_Controlled_Proc -- 6715 ------------------------ 6716 6717 function Is_Controlled_Proc 6718 (Subp_Id : Entity_Id; 6719 Subp_Nam : Name_Id) return Boolean 6720 is 6721 Formal_Id : Entity_Id; 6722 6723 begin 6724 pragma Assert (Nam_In (Subp_Nam, Name_Adjust, 6725 Name_Finalize, 6726 Name_Initialize)); 6727 6728 -- To qualify, the subprogram must denote a source procedure with name 6729 -- Adjust, Finalize, or Initialize where the sole formal is controlled. 6730 6731 if Comes_From_Source (Subp_Id) 6732 and then Ekind (Subp_Id) = E_Procedure 6733 and then Chars (Subp_Id) = Subp_Nam 6734 then 6735 Formal_Id := First_Formal (Subp_Id); 6736 6737 return 6738 Present (Formal_Id) 6739 and then Is_Controlled (Etype (Formal_Id)) 6740 and then No (Next_Formal (Formal_Id)); 6741 end if; 6742 6743 return False; 6744 end Is_Controlled_Proc; 6745 6746 --------------------------------------- 6747 -- Is_Default_Initial_Condition_Proc -- 6748 --------------------------------------- 6749 6750 function Is_Default_Initial_Condition_Proc 6751 (Id : Entity_Id) return Boolean 6752 is 6753 begin 6754 -- To qualify, the entity must denote a Default_Initial_Condition 6755 -- procedure. 6756 6757 return Ekind (Id) = E_Procedure and then Is_DIC_Procedure (Id); 6758 end Is_Default_Initial_Condition_Proc; 6759 6760 ----------------------- 6761 -- Is_Finalizer_Proc -- 6762 ----------------------- 6763 6764 function Is_Finalizer_Proc (Id : Entity_Id) return Boolean is 6765 begin 6766 -- To qualify, the entity must denote a _Finalizer procedure 6767 6768 return Ekind (Id) = E_Procedure and then Chars (Id) = Name_uFinalizer; 6769 end Is_Finalizer_Proc; 6770 6771 ----------------------- 6772 -- Is_Guaranteed_ABE -- 6773 ----------------------- 6774 6775 function Is_Guaranteed_ABE 6776 (N : Node_Id; 6777 Target_Decl : Node_Id; 6778 Target_Body : Node_Id) return Boolean 6779 is 6780 begin 6781 -- Avoid cascaded errors if there were previous serious infractions. 6782 -- As a result the scenario will not be treated as a guaranteed ABE. 6783 -- This behaviour parallels that of the old ABE mechanism. 6784 6785 if Serious_Errors_Detected > 0 then 6786 return False; 6787 6788 -- The scenario and the target appear within the same context ignoring 6789 -- enclosing library levels. 6790 6791 -- Performance note: parent traversal 6792 6793 elsif In_Same_Context (N, Target_Decl) then 6794 6795 -- The target body has already been encountered. The scenario results 6796 -- in a guaranteed ABE if it appears prior to the body. 6797 6798 if Present (Target_Body) then 6799 return Earlier_In_Extended_Unit (N, Target_Body); 6800 6801 -- Otherwise the body has not been encountered yet. The scenario is 6802 -- a guaranteed ABE since the body will appear later. It is assumed 6803 -- that the caller has already checked whether the scenario is ABE- 6804 -- safe as optional bodies are not considered here. 6805 6806 else 6807 return True; 6808 end if; 6809 end if; 6810 6811 return False; 6812 end Is_Guaranteed_ABE; 6813 6814 ------------------------------- 6815 -- Is_Initial_Condition_Proc -- 6816 ------------------------------- 6817 6818 function Is_Initial_Condition_Proc (Id : Entity_Id) return Boolean is 6819 begin 6820 -- To qualify, the entity must denote an Initial_Condition procedure 6821 6822 return 6823 Ekind (Id) = E_Procedure and then Is_Initial_Condition_Procedure (Id); 6824 end Is_Initial_Condition_Proc; 6825 6826 -------------------- 6827 -- Is_Initialized -- 6828 -------------------- 6829 6830 function Is_Initialized (Obj_Decl : Node_Id) return Boolean is 6831 begin 6832 -- To qualify, the object declaration must have an expression 6833 6834 return 6835 Present (Expression (Obj_Decl)) or else Has_Init_Expression (Obj_Decl); 6836 end Is_Initialized; 6837 6838 ----------------------- 6839 -- Is_Invariant_Proc -- 6840 ----------------------- 6841 6842 function Is_Invariant_Proc (Id : Entity_Id) return Boolean is 6843 begin 6844 -- To qualify, the entity must denote the "full" invariant procedure 6845 6846 return Ekind (Id) = E_Procedure and then Is_Invariant_Procedure (Id); 6847 end Is_Invariant_Proc; 6848 6849 --------------------------------------- 6850 -- Is_Non_Library_Level_Encapsulator -- 6851 --------------------------------------- 6852 6853 function Is_Non_Library_Level_Encapsulator (N : Node_Id) return Boolean is 6854 begin 6855 case Nkind (N) is 6856 when N_Abstract_Subprogram_Declaration 6857 | N_Aspect_Specification 6858 | N_Component_Declaration 6859 | N_Entry_Body 6860 | N_Entry_Declaration 6861 | N_Expression_Function 6862 | N_Formal_Abstract_Subprogram_Declaration 6863 | N_Formal_Concrete_Subprogram_Declaration 6864 | N_Formal_Object_Declaration 6865 | N_Formal_Package_Declaration 6866 | N_Formal_Type_Declaration 6867 | N_Generic_Association 6868 | N_Implicit_Label_Declaration 6869 | N_Incomplete_Type_Declaration 6870 | N_Private_Extension_Declaration 6871 | N_Private_Type_Declaration 6872 | N_Protected_Body 6873 | N_Protected_Type_Declaration 6874 | N_Single_Protected_Declaration 6875 | N_Single_Task_Declaration 6876 | N_Subprogram_Body 6877 | N_Subprogram_Declaration 6878 | N_Task_Body 6879 | N_Task_Type_Declaration 6880 => 6881 return True; 6882 6883 when others => 6884 return Is_Generic_Declaration_Or_Body (N); 6885 end case; 6886 end Is_Non_Library_Level_Encapsulator; 6887 6888 ------------------------------- 6889 -- Is_Partial_Invariant_Proc -- 6890 ------------------------------- 6891 6892 function Is_Partial_Invariant_Proc (Id : Entity_Id) return Boolean is 6893 begin 6894 -- To qualify, the entity must denote the "partial" invariant procedure 6895 6896 return 6897 Ekind (Id) = E_Procedure and then Is_Partial_Invariant_Procedure (Id); 6898 end Is_Partial_Invariant_Proc; 6899 6900 ---------------------------- 6901 -- Is_Postconditions_Proc -- 6902 ---------------------------- 6903 6904 function Is_Postconditions_Proc (Id : Entity_Id) return Boolean is 6905 begin 6906 -- To qualify, the entity must denote a _Postconditions procedure 6907 6908 return 6909 Ekind (Id) = E_Procedure and then Chars (Id) = Name_uPostconditions; 6910 end Is_Postconditions_Proc; 6911 6912 --------------------------- 6913 -- Is_Preelaborated_Unit -- 6914 --------------------------- 6915 6916 function Is_Preelaborated_Unit (Id : Entity_Id) return Boolean is 6917 begin 6918 return 6919 Is_Preelaborated (Id) 6920 or else Is_Pure (Id) 6921 or else Is_Remote_Call_Interface (Id) 6922 or else Is_Remote_Types (Id) 6923 or else Is_Shared_Passive (Id); 6924 end Is_Preelaborated_Unit; 6925 6926 ------------------------ 6927 -- Is_Protected_Entry -- 6928 ------------------------ 6929 6930 function Is_Protected_Entry (Id : Entity_Id) return Boolean is 6931 begin 6932 -- To qualify, the entity must denote an entry defined in a protected 6933 -- type. 6934 6935 return 6936 Is_Entry (Id) 6937 and then Is_Protected_Type (Non_Private_View (Scope (Id))); 6938 end Is_Protected_Entry; 6939 6940 ----------------------- 6941 -- Is_Protected_Subp -- 6942 ----------------------- 6943 6944 function Is_Protected_Subp (Id : Entity_Id) return Boolean is 6945 begin 6946 -- To qualify, the entity must denote a subprogram defined within a 6947 -- protected type. 6948 6949 return 6950 Ekind_In (Id, E_Function, E_Procedure) 6951 and then Is_Protected_Type (Non_Private_View (Scope (Id))); 6952 end Is_Protected_Subp; 6953 6954 ---------------------------- 6955 -- Is_Protected_Body_Subp -- 6956 ---------------------------- 6957 6958 function Is_Protected_Body_Subp (Id : Entity_Id) return Boolean is 6959 begin 6960 -- To qualify, the entity must denote a subprogram with attribute 6961 -- Protected_Subprogram set. 6962 6963 return 6964 Ekind_In (Id, E_Function, E_Procedure) 6965 and then Present (Protected_Subprogram (Id)); 6966 end Is_Protected_Body_Subp; 6967 6968 -------------------------------- 6969 -- Is_Recorded_SPARK_Scenario -- 6970 -------------------------------- 6971 6972 function Is_Recorded_SPARK_Scenario (N : Node_Id) return Boolean is 6973 begin 6974 if Recorded_SPARK_Scenarios_In_Use then 6975 return Recorded_SPARK_Scenarios.Get (N); 6976 end if; 6977 6978 return Recorded_SPARK_Scenarios_No_Element; 6979 end Is_Recorded_SPARK_Scenario; 6980 6981 ------------------------------------ 6982 -- Is_Recorded_Top_Level_Scenario -- 6983 ------------------------------------ 6984 6985 function Is_Recorded_Top_Level_Scenario (N : Node_Id) return Boolean is 6986 begin 6987 if Recorded_Top_Level_Scenarios_In_Use then 6988 return Recorded_Top_Level_Scenarios.Get (N); 6989 end if; 6990 6991 return Recorded_Top_Level_Scenarios_No_Element; 6992 end Is_Recorded_Top_Level_Scenario; 6993 6994 ------------------------ 6995 -- Is_Safe_Activation -- 6996 ------------------------ 6997 6998 function Is_Safe_Activation 6999 (Call : Node_Id; 7000 Task_Decl : Node_Id) return Boolean 7001 is 7002 begin 7003 -- The activation of a task coming from an external instance cannot 7004 -- cause an ABE because the generic was already instantiated. Note 7005 -- that the instantiation itself may lead to an ABE. 7006 7007 return 7008 In_External_Instance 7009 (N => Call, 7010 Target_Decl => Task_Decl); 7011 end Is_Safe_Activation; 7012 7013 ------------------ 7014 -- Is_Safe_Call -- 7015 ------------------ 7016 7017 function Is_Safe_Call 7018 (Call : Node_Id; 7019 Target_Attrs : Target_Attributes) return Boolean 7020 is 7021 begin 7022 -- The target is either an abstract subprogram, formal subprogram, or 7023 -- imported, in which case it does not have a body at compile or bind 7024 -- time. Assume that the call is ABE-safe. 7025 7026 if Is_Bodiless_Subprogram (Target_Attrs.Spec_Id) then 7027 return True; 7028 7029 -- The target is an instantiation of a generic subprogram. The call 7030 -- cannot cause an ABE because the generic was already instantiated. 7031 -- Note that the instantiation itself may lead to an ABE. 7032 7033 elsif Is_Generic_Instance (Target_Attrs.Spec_Id) then 7034 return True; 7035 7036 -- The invocation of a target coming from an external instance cannot 7037 -- cause an ABE because the generic was already instantiated. Note that 7038 -- the instantiation itself may lead to an ABE. 7039 7040 elsif In_External_Instance 7041 (N => Call, 7042 Target_Decl => Target_Attrs.Spec_Decl) 7043 then 7044 return True; 7045 7046 -- The target is a subprogram body without a previous declaration. The 7047 -- call cannot cause an ABE because the body has already been seen. 7048 7049 elsif Nkind (Target_Attrs.Spec_Decl) = N_Subprogram_Body 7050 and then No (Corresponding_Spec (Target_Attrs.Spec_Decl)) 7051 then 7052 return True; 7053 7054 -- The target is a subprogram body stub without a prior declaration. 7055 -- The call cannot cause an ABE because the proper body substitutes 7056 -- the stub. 7057 7058 elsif Nkind (Target_Attrs.Spec_Decl) = N_Subprogram_Body_Stub 7059 and then No (Corresponding_Spec_Of_Stub (Target_Attrs.Spec_Decl)) 7060 then 7061 return True; 7062 7063 -- Subprogram bodies which wrap attribute references used as actuals 7064 -- in instantiations are always ABE-safe. These bodies are artifacts 7065 -- of expansion. 7066 7067 elsif Present (Target_Attrs.Body_Decl) 7068 and then Nkind (Target_Attrs.Body_Decl) = N_Subprogram_Body 7069 and then Was_Attribute_Reference (Target_Attrs.Body_Decl) 7070 then 7071 return True; 7072 end if; 7073 7074 return False; 7075 end Is_Safe_Call; 7076 7077 --------------------------- 7078 -- Is_Safe_Instantiation -- 7079 --------------------------- 7080 7081 function Is_Safe_Instantiation 7082 (Inst : Node_Id; 7083 Gen_Attrs : Target_Attributes) return Boolean 7084 is 7085 begin 7086 -- The generic is an intrinsic subprogram in which case it does not 7087 -- have a body at compile or bind time. Assume that the instantiation 7088 -- is ABE-safe. 7089 7090 if Is_Bodiless_Subprogram (Gen_Attrs.Spec_Id) then 7091 return True; 7092 7093 -- The instantiation of an external nested generic cannot cause an ABE 7094 -- if the outer generic was already instantiated. Note that the instance 7095 -- of the outer generic may lead to an ABE. 7096 7097 elsif In_External_Instance 7098 (N => Inst, 7099 Target_Decl => Gen_Attrs.Spec_Decl) 7100 then 7101 return True; 7102 7103 -- The generic is a package. The instantiation cannot cause an ABE when 7104 -- the package has no body. 7105 7106 elsif Ekind (Gen_Attrs.Spec_Id) = E_Generic_Package 7107 and then not Has_Body (Gen_Attrs.Spec_Decl) 7108 then 7109 return True; 7110 end if; 7111 7112 return False; 7113 end Is_Safe_Instantiation; 7114 7115 ------------------ 7116 -- Is_Same_Unit -- 7117 ------------------ 7118 7119 function Is_Same_Unit 7120 (Unit_1 : Entity_Id; 7121 Unit_2 : Entity_Id) return Boolean 7122 is 7123 function Is_Subunit (Unit_Id : Entity_Id) return Boolean; 7124 pragma Inline (Is_Subunit); 7125 -- Determine whether unit Unit_Id is a subunit 7126 7127 function Normalize_Unit (Unit_Id : Entity_Id) return Entity_Id; 7128 -- Strip a potential subunit chain ending with unit Unit_Id and return 7129 -- the corresponding spec. 7130 7131 ---------------- 7132 -- Is_Subunit -- 7133 ---------------- 7134 7135 function Is_Subunit (Unit_Id : Entity_Id) return Boolean is 7136 begin 7137 return Nkind (Parent (Unit_Declaration_Node (Unit_Id))) = N_Subunit; 7138 end Is_Subunit; 7139 7140 -------------------- 7141 -- Normalize_Unit -- 7142 -------------------- 7143 7144 function Normalize_Unit (Unit_Id : Entity_Id) return Entity_Id is 7145 Result : Entity_Id; 7146 7147 begin 7148 -- Eliminate a potential chain of subunits to reach to proper body 7149 7150 Result := Unit_Id; 7151 while Present (Result) 7152 and then Result /= Standard_Standard 7153 and then Is_Subunit (Result) 7154 loop 7155 Result := Scope (Result); 7156 end loop; 7157 7158 -- Obtain the entity of the corresponding spec (if any) 7159 7160 return Unique_Entity (Result); 7161 end Normalize_Unit; 7162 7163 -- Start of processing for Is_Same_Unit 7164 7165 begin 7166 return Normalize_Unit (Unit_1) = Normalize_Unit (Unit_2); 7167 end Is_Same_Unit; 7168 7169 ----------------- 7170 -- Is_Scenario -- 7171 ----------------- 7172 7173 function Is_Scenario (N : Node_Id) return Boolean is 7174 begin 7175 case Nkind (N) is 7176 when N_Assignment_Statement 7177 | N_Attribute_Reference 7178 | N_Call_Marker 7179 | N_Entry_Call_Statement 7180 | N_Expanded_Name 7181 | N_Function_Call 7182 | N_Function_Instantiation 7183 | N_Identifier 7184 | N_Package_Instantiation 7185 | N_Procedure_Call_Statement 7186 | N_Procedure_Instantiation 7187 | N_Requeue_Statement 7188 => 7189 return True; 7190 7191 when others => 7192 return False; 7193 end case; 7194 end Is_Scenario; 7195 7196 ------------------------------ 7197 -- Is_SPARK_Semantic_Target -- 7198 ------------------------------ 7199 7200 function Is_SPARK_Semantic_Target (Id : Entity_Id) return Boolean is 7201 begin 7202 return 7203 Is_Default_Initial_Condition_Proc (Id) 7204 or else Is_Initial_Condition_Proc (Id); 7205 end Is_SPARK_Semantic_Target; 7206 7207 ------------------------ 7208 -- Is_Suitable_Access -- 7209 ------------------------ 7210 7211 function Is_Suitable_Access (N : Node_Id) return Boolean is 7212 Nam : Name_Id; 7213 Pref : Node_Id; 7214 Subp_Id : Entity_Id; 7215 7216 begin 7217 -- This scenario is relevant only when the static model is in effect 7218 -- because it is graph-dependent and does not involve any run-time 7219 -- checks. Allowing it in the dynamic model would create confusing 7220 -- noise. 7221 7222 if not Static_Elaboration_Checks then 7223 return False; 7224 7225 -- Nothing to do when switch -gnatd.U (ignore 'Access) is in effect 7226 7227 elsif Debug_Flag_Dot_UU then 7228 return False; 7229 7230 -- Nothing to do when the scenario is not an attribute reference 7231 7232 elsif Nkind (N) /= N_Attribute_Reference then 7233 return False; 7234 7235 -- Nothing to do for internally-generated attributes because they are 7236 -- assumed to be ABE safe. 7237 7238 elsif not Comes_From_Source (N) then 7239 return False; 7240 end if; 7241 7242 Nam := Attribute_Name (N); 7243 Pref := Prefix (N); 7244 7245 -- Sanitize the prefix of the attribute 7246 7247 if not Is_Entity_Name (Pref) then 7248 return False; 7249 7250 elsif No (Entity (Pref)) then 7251 return False; 7252 end if; 7253 7254 Subp_Id := Entity (Pref); 7255 7256 if not Is_Subprogram_Or_Entry (Subp_Id) then 7257 return False; 7258 end if; 7259 7260 -- Traverse a possible chain of renamings to obtain the original entry 7261 -- or subprogram which the prefix may rename. 7262 7263 Subp_Id := Get_Renamed_Entity (Subp_Id); 7264 7265 -- To qualify, the attribute must meet the following prerequisites: 7266 7267 return 7268 7269 -- The prefix must denote a source entry, operator, or subprogram 7270 -- which is not imported. 7271 7272 Comes_From_Source (Subp_Id) 7273 and then Is_Subprogram_Or_Entry (Subp_Id) 7274 and then not Is_Bodiless_Subprogram (Subp_Id) 7275 7276 -- The attribute name must be one of the 'Access forms. Note that 7277 -- 'Unchecked_Access cannot apply to a subprogram. 7278 7279 and then Nam_In (Nam, Name_Access, Name_Unrestricted_Access); 7280 end Is_Suitable_Access; 7281 7282 ---------------------- 7283 -- Is_Suitable_Call -- 7284 ---------------------- 7285 7286 function Is_Suitable_Call (N : Node_Id) return Boolean is 7287 begin 7288 -- Entry and subprogram calls are intentionally ignored because they 7289 -- may undergo expansion depending on the compilation mode, previous 7290 -- errors, generic context, etc. Call markers play the role of calls 7291 -- and provide a uniform foundation for ABE processing. 7292 7293 return Nkind (N) = N_Call_Marker; 7294 end Is_Suitable_Call; 7295 7296 ------------------------------- 7297 -- Is_Suitable_Instantiation -- 7298 ------------------------------- 7299 7300 function Is_Suitable_Instantiation (N : Node_Id) return Boolean is 7301 Orig_N : constant Node_Id := Original_Node (N); 7302 -- Use the original node in case an instantiation library unit is 7303 -- rewritten as a package or subprogram. 7304 7305 begin 7306 -- To qualify, the instantiation must come from source 7307 7308 return 7309 Comes_From_Source (Orig_N) 7310 and then Nkind (Orig_N) in N_Generic_Instantiation; 7311 end Is_Suitable_Instantiation; 7312 7313 -------------------------- 7314 -- Is_Suitable_Scenario -- 7315 -------------------------- 7316 7317 function Is_Suitable_Scenario (N : Node_Id) return Boolean is 7318 begin 7319 -- NOTE: Derived types and pragma Refined_State are intentionally left 7320 -- out because they are not executable during elaboration. 7321 7322 return 7323 Is_Suitable_Access (N) 7324 or else Is_Suitable_Call (N) 7325 or else Is_Suitable_Instantiation (N) 7326 or else Is_Suitable_Variable_Assignment (N) 7327 or else Is_Suitable_Variable_Reference (N); 7328 end Is_Suitable_Scenario; 7329 7330 ------------------------------------ 7331 -- Is_Suitable_SPARK_Derived_Type -- 7332 ------------------------------------ 7333 7334 function Is_Suitable_SPARK_Derived_Type (N : Node_Id) return Boolean is 7335 Prag : Node_Id; 7336 Typ : Entity_Id; 7337 7338 begin 7339 -- To qualify, the type declaration must denote a derived tagged type 7340 -- with primitive operations, subject to pragma SPARK_Mode On. 7341 7342 if Nkind (N) = N_Full_Type_Declaration 7343 and then Nkind (Type_Definition (N)) = N_Derived_Type_Definition 7344 then 7345 Typ := Defining_Entity (N); 7346 Prag := SPARK_Pragma (Typ); 7347 7348 return 7349 Is_Tagged_Type (Typ) 7350 and then Has_Primitive_Operations (Typ) 7351 and then Present (Prag) 7352 and then Get_SPARK_Mode_From_Annotation (Prag) = On; 7353 end if; 7354 7355 return False; 7356 end Is_Suitable_SPARK_Derived_Type; 7357 7358 ------------------------------------- 7359 -- Is_Suitable_SPARK_Instantiation -- 7360 ------------------------------------- 7361 7362 function Is_Suitable_SPARK_Instantiation (N : Node_Id) return Boolean is 7363 Gen_Attrs : Target_Attributes; 7364 Gen_Id : Entity_Id; 7365 Inst : Node_Id; 7366 Inst_Attrs : Instantiation_Attributes; 7367 Inst_Id : Entity_Id; 7368 7369 begin 7370 -- To qualify, both the instantiation and the generic must be subject to 7371 -- SPARK_Mode On. 7372 7373 if Is_Suitable_Instantiation (N) then 7374 Extract_Instantiation_Attributes 7375 (Exp_Inst => N, 7376 Inst => Inst, 7377 Inst_Id => Inst_Id, 7378 Gen_Id => Gen_Id, 7379 Attrs => Inst_Attrs); 7380 7381 Extract_Target_Attributes (Gen_Id, Gen_Attrs); 7382 7383 return Inst_Attrs.SPARK_Mode_On and Gen_Attrs.SPARK_Mode_On; 7384 end if; 7385 7386 return False; 7387 end Is_Suitable_SPARK_Instantiation; 7388 7389 -------------------------------------------- 7390 -- Is_Suitable_SPARK_Refined_State_Pragma -- 7391 -------------------------------------------- 7392 7393 function Is_Suitable_SPARK_Refined_State_Pragma 7394 (N : Node_Id) return Boolean 7395 is 7396 begin 7397 -- To qualfy, the pragma must denote Refined_State 7398 7399 return 7400 Nkind (N) = N_Pragma 7401 and then Pragma_Name (N) = Name_Refined_State; 7402 end Is_Suitable_SPARK_Refined_State_Pragma; 7403 7404 ------------------------------------- 7405 -- Is_Suitable_Variable_Assignment -- 7406 ------------------------------------- 7407 7408 function Is_Suitable_Variable_Assignment (N : Node_Id) return Boolean is 7409 N_Unit : Node_Id; 7410 N_Unit_Id : Entity_Id; 7411 Nam : Node_Id; 7412 Var_Decl : Node_Id; 7413 Var_Id : Entity_Id; 7414 Var_Unit : Node_Id; 7415 Var_Unit_Id : Entity_Id; 7416 7417 begin 7418 -- This scenario is relevant only when the static model is in effect 7419 -- because it is graph-dependent and does not involve any run-time 7420 -- checks. Allowing it in the dynamic model would create confusing 7421 -- noise. 7422 7423 if not Static_Elaboration_Checks then 7424 return False; 7425 7426 -- Nothing to do when the scenario is not an assignment 7427 7428 elsif Nkind (N) /= N_Assignment_Statement then 7429 return False; 7430 7431 -- Nothing to do for internally-generated assignments because they are 7432 -- assumed to be ABE safe. 7433 7434 elsif not Comes_From_Source (N) then 7435 return False; 7436 7437 -- Assignments are ignored in GNAT mode on the assumption that they are 7438 -- ABE-safe. This behaviour parallels that of the old ABE mechanism. 7439 7440 elsif GNAT_Mode then 7441 return False; 7442 end if; 7443 7444 Nam := Extract_Assignment_Name (N); 7445 7446 -- Sanitize the left hand side of the assignment 7447 7448 if not Is_Entity_Name (Nam) then 7449 return False; 7450 7451 elsif No (Entity (Nam)) then 7452 return False; 7453 end if; 7454 7455 Var_Id := Entity (Nam); 7456 7457 -- Sanitize the variable 7458 7459 if Var_Id = Any_Id then 7460 return False; 7461 7462 elsif Ekind (Var_Id) /= E_Variable then 7463 return False; 7464 end if; 7465 7466 Var_Decl := Declaration_Node (Var_Id); 7467 7468 if Nkind (Var_Decl) /= N_Object_Declaration then 7469 return False; 7470 end if; 7471 7472 N_Unit_Id := Find_Top_Unit (N); 7473 N_Unit := Unit_Declaration_Node (N_Unit_Id); 7474 7475 Var_Unit_Id := Find_Top_Unit (Var_Decl); 7476 Var_Unit := Unit_Declaration_Node (Var_Unit_Id); 7477 7478 -- To qualify, the assignment must meet the following prerequisites: 7479 7480 return 7481 Comes_From_Source (Var_Id) 7482 7483 -- The variable must be declared in the spec of compilation unit U 7484 7485 and then Nkind (Var_Unit) = N_Package_Declaration 7486 7487 -- Performance note: parent traversal 7488 7489 and then Find_Enclosing_Level (Var_Decl) = Package_Spec 7490 7491 -- The assignment must occur in the body of compilation unit U 7492 7493 and then Nkind (N_Unit) = N_Package_Body 7494 and then Present (Corresponding_Body (Var_Unit)) 7495 and then Corresponding_Body (Var_Unit) = N_Unit_Id; 7496 end Is_Suitable_Variable_Assignment; 7497 7498 ------------------------------------ 7499 -- Is_Suitable_Variable_Reference -- 7500 ------------------------------------ 7501 7502 function Is_Suitable_Variable_Reference (N : Node_Id) return Boolean is 7503 begin 7504 -- Expanded names and identifiers are intentionally ignored because they 7505 -- be folded, optimized away, etc. Variable references markers play the 7506 -- role of variable references and provide a uniform foundation for ABE 7507 -- processing. 7508 7509 return Nkind (N) = N_Variable_Reference_Marker; 7510 end Is_Suitable_Variable_Reference; 7511 7512 ------------------- 7513 -- Is_Task_Entry -- 7514 ------------------- 7515 7516 function Is_Task_Entry (Id : Entity_Id) return Boolean is 7517 begin 7518 -- To qualify, the entity must denote an entry defined in a task type 7519 7520 return 7521 Is_Entry (Id) and then Is_Task_Type (Non_Private_View (Scope (Id))); 7522 end Is_Task_Entry; 7523 7524 ------------------------ 7525 -- Is_Up_Level_Target -- 7526 ------------------------ 7527 7528 function Is_Up_Level_Target (Target_Decl : Node_Id) return Boolean is 7529 Root : constant Node_Id := Root_Scenario; 7530 7531 begin 7532 -- The root appears within the declaratons of a block statement, entry 7533 -- body, subprogram body, or task body ignoring enclosing packages. The 7534 -- root is always within the main unit. An up-level target is a notion 7535 -- applicable only to the static model because scenarios are reached by 7536 -- means of graph traversal started from a fixed declarative or library 7537 -- level. 7538 7539 -- Performance note: parent traversal 7540 7541 if Static_Elaboration_Checks 7542 and then Find_Enclosing_Level (Root) = Declaration_Level 7543 then 7544 -- The target is within the main unit. It acts as an up-level target 7545 -- when it appears within a context which encloses the root. 7546 7547 -- package body Main_Unit is 7548 -- function Func ...; -- target 7549 7550 -- procedure Proc is 7551 -- X : ... := Func; -- root scenario 7552 7553 if In_Extended_Main_Code_Unit (Target_Decl) then 7554 7555 -- Performance note: parent traversal 7556 7557 return not In_Same_Context (Root, Target_Decl, Nested_OK => True); 7558 7559 -- Otherwise the target is external to the main unit which makes it 7560 -- an up-level target. 7561 7562 else 7563 return True; 7564 end if; 7565 end if; 7566 7567 return False; 7568 end Is_Up_Level_Target; 7569 7570 --------------------- 7571 -- Is_Visited_Body -- 7572 --------------------- 7573 7574 function Is_Visited_Body (Body_Decl : Node_Id) return Boolean is 7575 begin 7576 if Visited_Bodies_In_Use then 7577 return Visited_Bodies.Get (Body_Decl); 7578 end if; 7579 7580 return Visited_Bodies_No_Element; 7581 end Is_Visited_Body; 7582 7583 ------------------------------- 7584 -- Kill_Elaboration_Scenario -- 7585 ------------------------------- 7586 7587 procedure Kill_Elaboration_Scenario (N : Node_Id) is 7588 procedure Kill_SPARK_Scenario; 7589 pragma Inline (Kill_SPARK_Scenario); 7590 -- Eliminate scenario N from table SPARK_Scenarios if it is recorded 7591 -- there. 7592 7593 procedure Kill_Top_Level_Scenario; 7594 pragma Inline (Kill_Top_Level_Scenario); 7595 -- Eliminate scenario N from table Top_Level_Scenarios if it is recorded 7596 -- there. 7597 7598 ------------------------- 7599 -- Kill_SPARK_Scenario -- 7600 ------------------------- 7601 7602 procedure Kill_SPARK_Scenario is 7603 package Scenarios renames SPARK_Scenarios; 7604 7605 begin 7606 if Is_Recorded_SPARK_Scenario (N) then 7607 7608 -- Performance note: list traversal 7609 7610 for Index in Scenarios.First .. Scenarios.Last loop 7611 if Scenarios.Table (Index) = N then 7612 Scenarios.Table (Index) := Empty; 7613 7614 -- The SPARK scenario is no longer recorded 7615 7616 Set_Is_Recorded_SPARK_Scenario (N, False); 7617 return; 7618 end if; 7619 end loop; 7620 7621 -- A recorded SPARK scenario must be in the table of recorded 7622 -- SPARK scenarios. 7623 7624 pragma Assert (False); 7625 end if; 7626 end Kill_SPARK_Scenario; 7627 7628 ----------------------------- 7629 -- Kill_Top_Level_Scenario -- 7630 ----------------------------- 7631 7632 procedure Kill_Top_Level_Scenario is 7633 package Scenarios renames Top_Level_Scenarios; 7634 7635 begin 7636 if Is_Recorded_Top_Level_Scenario (N) then 7637 7638 -- Performance node: list traversal 7639 7640 for Index in Scenarios.First .. Scenarios.Last loop 7641 if Scenarios.Table (Index) = N then 7642 Scenarios.Table (Index) := Empty; 7643 7644 -- The top-level scenario is no longer recorded 7645 7646 Set_Is_Recorded_Top_Level_Scenario (N, False); 7647 return; 7648 end if; 7649 end loop; 7650 7651 -- A recorded top-level scenario must be in the table of recorded 7652 -- top-level scenarios. 7653 7654 pragma Assert (False); 7655 end if; 7656 end Kill_Top_Level_Scenario; 7657 7658 -- Start of processing for Kill_Elaboration_Scenario 7659 7660 begin 7661 -- Nothing to do when switch -gnatH (legacy elaboration checking mode 7662 -- enabled) is in effect because the legacy ABE lechanism does not need 7663 -- to carry out this action. 7664 7665 if Legacy_Elaboration_Checks then 7666 return; 7667 end if; 7668 7669 -- Eliminate a recorded scenario when it appears within dead code 7670 -- because it will not be executed at elaboration time. 7671 7672 if Is_Scenario (N) then 7673 Kill_SPARK_Scenario; 7674 Kill_Top_Level_Scenario; 7675 end if; 7676 end Kill_Elaboration_Scenario; 7677 7678 ---------------------------------- 7679 -- Meet_Elaboration_Requirement -- 7680 ---------------------------------- 7681 7682 procedure Meet_Elaboration_Requirement 7683 (N : Node_Id; 7684 Target_Id : Entity_Id; 7685 Req_Nam : Name_Id) 7686 is 7687 Main_Id : constant Entity_Id := Cunit_Entity (Main_Unit); 7688 Unit_Id : constant Entity_Id := Find_Top_Unit (Target_Id); 7689 7690 function Find_Preelaboration_Pragma 7691 (Prag_Nam : Name_Id) return Node_Id; 7692 pragma Inline (Find_Preelaboration_Pragma); 7693 -- Traverse the visible declarations of unit Unit_Id and locate a source 7694 -- preelaboration-related pragma with name Prag_Nam. 7695 7696 procedure Info_Requirement_Met (Prag : Node_Id); 7697 pragma Inline (Info_Requirement_Met); 7698 -- Output information concerning pragma Prag which meets requirement 7699 -- Req_Nam. 7700 7701 procedure Info_Scenario; 7702 pragma Inline (Info_Scenario); 7703 -- Output information concerning scenario N 7704 7705 -------------------------------- 7706 -- Find_Preelaboration_Pragma -- 7707 -------------------------------- 7708 7709 function Find_Preelaboration_Pragma 7710 (Prag_Nam : Name_Id) return Node_Id 7711 is 7712 Spec : constant Node_Id := Parent (Unit_Id); 7713 Decl : Node_Id; 7714 7715 begin 7716 -- A preelaboration-related pragma comes from source and appears at 7717 -- the top of the visible declarations of a package. 7718 7719 if Nkind (Spec) = N_Package_Specification then 7720 Decl := First (Visible_Declarations (Spec)); 7721 while Present (Decl) loop 7722 if Comes_From_Source (Decl) then 7723 if Nkind (Decl) = N_Pragma 7724 and then Pragma_Name (Decl) = Prag_Nam 7725 then 7726 return Decl; 7727 7728 -- Otherwise the construct terminates the region where the 7729 -- preelabortion-related pragma may appear. 7730 7731 else 7732 exit; 7733 end if; 7734 end if; 7735 7736 Next (Decl); 7737 end loop; 7738 end if; 7739 7740 return Empty; 7741 end Find_Preelaboration_Pragma; 7742 7743 -------------------------- 7744 -- Info_Requirement_Met -- 7745 -------------------------- 7746 7747 procedure Info_Requirement_Met (Prag : Node_Id) is 7748 begin 7749 pragma Assert (Present (Prag)); 7750 7751 Error_Msg_Name_1 := Req_Nam; 7752 Error_Msg_Sloc := Sloc (Prag); 7753 Error_Msg_NE 7754 ("\\% requirement for unit & met by pragma #", N, Unit_Id); 7755 end Info_Requirement_Met; 7756 7757 ------------------- 7758 -- Info_Scenario -- 7759 ------------------- 7760 7761 procedure Info_Scenario is 7762 begin 7763 if Is_Suitable_Call (N) then 7764 Info_Call 7765 (Call => N, 7766 Target_Id => Target_Id, 7767 Info_Msg => False, 7768 In_SPARK => True); 7769 7770 elsif Is_Suitable_Instantiation (N) then 7771 Info_Instantiation 7772 (Inst => N, 7773 Gen_Id => Target_Id, 7774 Info_Msg => False, 7775 In_SPARK => True); 7776 7777 elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then 7778 Error_Msg_N 7779 ("read of refinement constituents during elaboration in SPARK", 7780 N); 7781 7782 elsif Is_Suitable_Variable_Reference (N) then 7783 Info_Variable_Reference 7784 (Ref => N, 7785 Var_Id => Target_Id, 7786 Info_Msg => False, 7787 In_SPARK => True); 7788 7789 -- No other scenario may impose a requirement on the context of the 7790 -- main unit. 7791 7792 else 7793 pragma Assert (False); 7794 null; 7795 end if; 7796 end Info_Scenario; 7797 7798 -- Local variables 7799 7800 Elab_Attrs : Elaboration_Attributes; 7801 Elab_Nam : Name_Id; 7802 Req_Met : Boolean; 7803 7804 -- Start of processing for Meet_Elaboration_Requirement 7805 7806 begin 7807 pragma Assert (Nam_In (Req_Nam, Name_Elaborate, Name_Elaborate_All)); 7808 7809 -- Assume that the requirement has not been met 7810 7811 Req_Met := False; 7812 7813 -- Elaboration requirements are verified only when the static model is 7814 -- in effect because this diagnostic is graph-dependent. 7815 7816 if not Static_Elaboration_Checks then 7817 return; 7818 7819 -- If the target is within the main unit, either at the source level or 7820 -- through an instantiation, then there is no real requirement to meet 7821 -- because the main unit cannot force its own elaboration by means of an 7822 -- Elaborate[_All] pragma. Treat this case as valid coverage. 7823 7824 elsif In_Extended_Main_Code_Unit (Target_Id) then 7825 Req_Met := True; 7826 7827 -- Otherwise the target resides in an external unit 7828 7829 -- The requirement is met when the target comes from an internal unit 7830 -- because such a unit is elaborated prior to a non-internal unit. 7831 7832 elsif In_Internal_Unit (Unit_Id) 7833 and then not In_Internal_Unit (Main_Id) 7834 then 7835 Req_Met := True; 7836 7837 -- The requirement is met when the target comes from a preelaborated 7838 -- unit. This portion must parallel predicate Is_Preelaborated_Unit. 7839 7840 elsif Is_Preelaborated_Unit (Unit_Id) then 7841 Req_Met := True; 7842 7843 -- Output extra information when switch -gnatel (info messages on 7844 -- implicit Elaborate[_All] pragmas. 7845 7846 if Elab_Info_Messages then 7847 if Is_Preelaborated (Unit_Id) then 7848 Elab_Nam := Name_Preelaborate; 7849 7850 elsif Is_Pure (Unit_Id) then 7851 Elab_Nam := Name_Pure; 7852 7853 elsif Is_Remote_Call_Interface (Unit_Id) then 7854 Elab_Nam := Name_Remote_Call_Interface; 7855 7856 elsif Is_Remote_Types (Unit_Id) then 7857 Elab_Nam := Name_Remote_Types; 7858 7859 else 7860 pragma Assert (Is_Shared_Passive (Unit_Id)); 7861 Elab_Nam := Name_Shared_Passive; 7862 end if; 7863 7864 Info_Requirement_Met (Find_Preelaboration_Pragma (Elab_Nam)); 7865 end if; 7866 7867 -- Determine whether the context of the main unit has a pragma strong 7868 -- enough to meet the requirement. 7869 7870 else 7871 Elab_Attrs := Elaboration_Status (Unit_Id); 7872 7873 -- The pragma must be either Elaborate_All or be as strong as the 7874 -- requirement. 7875 7876 if Present (Elab_Attrs.Source_Pragma) 7877 and then Nam_In (Pragma_Name (Elab_Attrs.Source_Pragma), 7878 Name_Elaborate_All, 7879 Req_Nam) 7880 then 7881 Req_Met := True; 7882 7883 -- Output extra information when switch -gnatel (info messages on 7884 -- implicit Elaborate[_All] pragmas. 7885 7886 if Elab_Info_Messages then 7887 Info_Requirement_Met (Elab_Attrs.Source_Pragma); 7888 end if; 7889 end if; 7890 end if; 7891 7892 -- The requirement was not met by the context of the main unit, issue an 7893 -- error. 7894 7895 if not Req_Met then 7896 Info_Scenario; 7897 7898 Error_Msg_Name_1 := Req_Nam; 7899 Error_Msg_Node_2 := Unit_Id; 7900 Error_Msg_NE ("\\unit & requires pragma % for &", N, Main_Id); 7901 7902 Output_Active_Scenarios (N); 7903 end if; 7904 end Meet_Elaboration_Requirement; 7905 7906 ---------------------- 7907 -- Non_Private_View -- 7908 ---------------------- 7909 7910 function Non_Private_View (Typ : Entity_Id) return Entity_Id is 7911 Result : Entity_Id; 7912 7913 begin 7914 Result := Typ; 7915 7916 if Is_Private_Type (Result) and then Present (Full_View (Result)) then 7917 Result := Full_View (Result); 7918 end if; 7919 7920 return Result; 7921 end Non_Private_View; 7922 7923 ----------------------------- 7924 -- Output_Active_Scenarios -- 7925 ----------------------------- 7926 7927 procedure Output_Active_Scenarios (Error_Nod : Node_Id) is 7928 procedure Output_Access (N : Node_Id); 7929 -- Emit a specific diagnostic message for 'Access denote by N 7930 7931 procedure Output_Activation_Call (N : Node_Id); 7932 -- Emit a specific diagnostic message for task activation N 7933 7934 procedure Output_Call (N : Node_Id; Target_Id : Entity_Id); 7935 -- Emit a specific diagnostic message for call N which invokes target 7936 -- Target_Id. 7937 7938 procedure Output_Header; 7939 -- Emit a specific diagnostic message for the unit of the root scenario 7940 7941 procedure Output_Instantiation (N : Node_Id); 7942 -- Emit a specific diagnostic message for instantiation N 7943 7944 procedure Output_SPARK_Refined_State_Pragma (N : Node_Id); 7945 -- Emit a specific diagnostic message for Refined_State pragma N 7946 7947 procedure Output_Variable_Assignment (N : Node_Id); 7948 -- Emit a specific diagnostic message for assignment statement N 7949 7950 procedure Output_Variable_Reference (N : Node_Id); 7951 -- Emit a specific diagnostic message for reference N which mentions a 7952 -- variable. 7953 7954 ------------------- 7955 -- Output_Access -- 7956 ------------------- 7957 7958 procedure Output_Access (N : Node_Id) is 7959 Subp_Id : constant Entity_Id := Entity (Prefix (N)); 7960 7961 begin 7962 Error_Msg_Name_1 := Attribute_Name (N); 7963 Error_Msg_Sloc := Sloc (N); 7964 Error_Msg_NE ("\\ % of & taken #", Error_Nod, Subp_Id); 7965 end Output_Access; 7966 7967 ---------------------------- 7968 -- Output_Activation_Call -- 7969 ---------------------------- 7970 7971 procedure Output_Activation_Call (N : Node_Id) is 7972 function Find_Activator (Call : Node_Id) return Entity_Id; 7973 -- Find the nearest enclosing construct which houses call Call 7974 7975 -------------------- 7976 -- Find_Activator -- 7977 -------------------- 7978 7979 function Find_Activator (Call : Node_Id) return Entity_Id is 7980 Par : Node_Id; 7981 7982 begin 7983 -- Climb the parent chain looking for a package [body] or a 7984 -- construct with a statement sequence. 7985 7986 Par := Parent (Call); 7987 while Present (Par) loop 7988 if Nkind_In (Par, N_Package_Body, N_Package_Declaration) then 7989 return Defining_Entity (Par); 7990 7991 elsif Nkind (Par) = N_Handled_Sequence_Of_Statements then 7992 return Defining_Entity (Parent (Par)); 7993 end if; 7994 7995 Par := Parent (Par); 7996 end loop; 7997 7998 return Empty; 7999 end Find_Activator; 8000 8001 -- Local variables 8002 8003 Activator : constant Entity_Id := Find_Activator (N); 8004 8005 -- Start of processing for Output_Activation_Call 8006 8007 begin 8008 pragma Assert (Present (Activator)); 8009 8010 Error_Msg_NE ("\\ local tasks of & activated", Error_Nod, Activator); 8011 end Output_Activation_Call; 8012 8013 ----------------- 8014 -- Output_Call -- 8015 ----------------- 8016 8017 procedure Output_Call (N : Node_Id; Target_Id : Entity_Id) is 8018 procedure Output_Accept_Alternative; 8019 pragma Inline (Output_Accept_Alternative); 8020 -- Emit a specific diagnostic message concerning an accept 8021 -- alternative. 8022 8023 procedure Output_Call (Kind : String); 8024 pragma Inline (Output_Call); 8025 -- Emit a specific diagnostic message concerning a call of kind Kind 8026 8027 procedure Output_Type_Actions (Action : String); 8028 pragma Inline (Output_Type_Actions); 8029 -- Emit a specific diagnostic message concerning action Action of a 8030 -- type. 8031 8032 procedure Output_Verification_Call 8033 (Pred : String; 8034 Id : Entity_Id; 8035 Id_Kind : String); 8036 pragma Inline (Output_Verification_Call); 8037 -- Emit a specific diagnostic message concerning the verification of 8038 -- predicate Pred applied to related entity Id with kind Id_Kind. 8039 8040 ------------------------------- 8041 -- Output_Accept_Alternative -- 8042 ------------------------------- 8043 8044 procedure Output_Accept_Alternative is 8045 Entry_Id : constant Entity_Id := Receiving_Entry (Target_Id); 8046 8047 begin 8048 pragma Assert (Present (Entry_Id)); 8049 8050 Error_Msg_NE ("\\ entry & selected #", Error_Nod, Entry_Id); 8051 end Output_Accept_Alternative; 8052 8053 ----------------- 8054 -- Output_Call -- 8055 ----------------- 8056 8057 procedure Output_Call (Kind : String) is 8058 begin 8059 Error_Msg_NE ("\\ " & Kind & " & called #", Error_Nod, Target_Id); 8060 end Output_Call; 8061 8062 ------------------------- 8063 -- Output_Type_Actions -- 8064 ------------------------- 8065 8066 procedure Output_Type_Actions (Action : String) is 8067 Typ : constant Entity_Id := First_Formal_Type (Target_Id); 8068 8069 begin 8070 pragma Assert (Present (Typ)); 8071 8072 Error_Msg_NE 8073 ("\\ " & Action & " actions for type & #", Error_Nod, Typ); 8074 end Output_Type_Actions; 8075 8076 ------------------------------ 8077 -- Output_Verification_Call -- 8078 ------------------------------ 8079 8080 procedure Output_Verification_Call 8081 (Pred : String; 8082 Id : Entity_Id; 8083 Id_Kind : String) 8084 is 8085 begin 8086 pragma Assert (Present (Id)); 8087 8088 Error_Msg_NE 8089 ("\\ " & Pred & " of " & Id_Kind & " & verified #", 8090 Error_Nod, Id); 8091 end Output_Verification_Call; 8092 8093 -- Start of processing for Output_Call 8094 8095 begin 8096 Error_Msg_Sloc := Sloc (N); 8097 8098 -- Accept alternative 8099 8100 if Is_Accept_Alternative_Proc (Target_Id) then 8101 Output_Accept_Alternative; 8102 8103 -- Adjustment 8104 8105 elsif Is_TSS (Target_Id, TSS_Deep_Adjust) then 8106 Output_Type_Actions ("adjustment"); 8107 8108 -- Default_Initial_Condition 8109 8110 elsif Is_Default_Initial_Condition_Proc (Target_Id) then 8111 Output_Verification_Call 8112 (Pred => "Default_Initial_Condition", 8113 Id => First_Formal_Type (Target_Id), 8114 Id_Kind => "type"); 8115 8116 -- Entries 8117 8118 elsif Is_Protected_Entry (Target_Id) then 8119 Output_Call ("entry"); 8120 8121 -- Task entry calls are never processed because the entry being 8122 -- invoked does not have a corresponding "body", it has a select. A 8123 -- task entry call appears in the stack of active scenarios for the 8124 -- sole purpose of checking No_Entry_Calls_In_Elaboration_Code and 8125 -- nothing more. 8126 8127 elsif Is_Task_Entry (Target_Id) then 8128 null; 8129 8130 -- Finalization 8131 8132 elsif Is_TSS (Target_Id, TSS_Deep_Finalize) then 8133 Output_Type_Actions ("finalization"); 8134 8135 -- Calls to _Finalizer procedures must not appear in the output 8136 -- because this creates confusing noise. 8137 8138 elsif Is_Finalizer_Proc (Target_Id) then 8139 null; 8140 8141 -- Initial_Condition 8142 8143 elsif Is_Initial_Condition_Proc (Target_Id) then 8144 Output_Verification_Call 8145 (Pred => "Initial_Condition", 8146 Id => Find_Enclosing_Scope (N), 8147 Id_Kind => "package"); 8148 8149 -- Initialization 8150 8151 elsif Is_Init_Proc (Target_Id) 8152 or else Is_TSS (Target_Id, TSS_Deep_Initialize) 8153 then 8154 Output_Type_Actions ("initialization"); 8155 8156 -- Invariant 8157 8158 elsif Is_Invariant_Proc (Target_Id) then 8159 Output_Verification_Call 8160 (Pred => "invariants", 8161 Id => First_Formal_Type (Target_Id), 8162 Id_Kind => "type"); 8163 8164 -- Partial invariant calls must not appear in the output because this 8165 -- creates confusing noise. Note that a partial invariant is always 8166 -- invoked by the "full" invariant which is already placed on the 8167 -- stack. 8168 8169 elsif Is_Partial_Invariant_Proc (Target_Id) then 8170 null; 8171 8172 -- _Postconditions 8173 8174 elsif Is_Postconditions_Proc (Target_Id) then 8175 Output_Verification_Call 8176 (Pred => "postconditions", 8177 Id => Find_Enclosing_Scope (N), 8178 Id_Kind => "subprogram"); 8179 8180 -- Subprograms must come last because some of the previous cases fall 8181 -- under this category. 8182 8183 elsif Ekind (Target_Id) = E_Function then 8184 Output_Call ("function"); 8185 8186 elsif Ekind (Target_Id) = E_Procedure then 8187 Output_Call ("procedure"); 8188 8189 else 8190 pragma Assert (False); 8191 null; 8192 end if; 8193 end Output_Call; 8194 8195 ------------------- 8196 -- Output_Header -- 8197 ------------------- 8198 8199 procedure Output_Header is 8200 Unit_Id : constant Entity_Id := Find_Top_Unit (Root_Scenario); 8201 8202 begin 8203 if Ekind (Unit_Id) = E_Package then 8204 Error_Msg_NE ("\\ spec of unit & elaborated", Error_Nod, Unit_Id); 8205 8206 elsif Ekind (Unit_Id) = E_Package_Body then 8207 Error_Msg_NE ("\\ body of unit & elaborated", Error_Nod, Unit_Id); 8208 8209 else 8210 Error_Msg_NE ("\\ in body of unit &", Error_Nod, Unit_Id); 8211 end if; 8212 end Output_Header; 8213 8214 -------------------------- 8215 -- Output_Instantiation -- 8216 -------------------------- 8217 8218 procedure Output_Instantiation (N : Node_Id) is 8219 procedure Output_Instantiation (Gen_Id : Entity_Id; Kind : String); 8220 pragma Inline (Output_Instantiation); 8221 -- Emit a specific diagnostic message concerning an instantiation of 8222 -- generic unit Gen_Id. Kind denotes the kind of the instantiation. 8223 8224 -------------------------- 8225 -- Output_Instantiation -- 8226 -------------------------- 8227 8228 procedure Output_Instantiation (Gen_Id : Entity_Id; Kind : String) is 8229 begin 8230 Error_Msg_NE 8231 ("\\ " & Kind & " & instantiated as & #", Error_Nod, Gen_Id); 8232 end Output_Instantiation; 8233 8234 -- Local variables 8235 8236 Inst : Node_Id; 8237 Inst_Attrs : Instantiation_Attributes; 8238 Inst_Id : Entity_Id; 8239 Gen_Id : Entity_Id; 8240 8241 -- Start of processing for Output_Instantiation 8242 8243 begin 8244 Extract_Instantiation_Attributes 8245 (Exp_Inst => N, 8246 Inst => Inst, 8247 Inst_Id => Inst_Id, 8248 Gen_Id => Gen_Id, 8249 Attrs => Inst_Attrs); 8250 8251 Error_Msg_Node_2 := Inst_Id; 8252 Error_Msg_Sloc := Sloc (Inst); 8253 8254 if Nkind (Inst) = N_Function_Instantiation then 8255 Output_Instantiation (Gen_Id, "function"); 8256 8257 elsif Nkind (Inst) = N_Package_Instantiation then 8258 Output_Instantiation (Gen_Id, "package"); 8259 8260 elsif Nkind (Inst) = N_Procedure_Instantiation then 8261 Output_Instantiation (Gen_Id, "procedure"); 8262 8263 else 8264 pragma Assert (False); 8265 null; 8266 end if; 8267 end Output_Instantiation; 8268 8269 --------------------------------------- 8270 -- Output_SPARK_Refined_State_Pragma -- 8271 --------------------------------------- 8272 8273 procedure Output_SPARK_Refined_State_Pragma (N : Node_Id) is 8274 begin 8275 Error_Msg_Sloc := Sloc (N); 8276 Error_Msg_N ("\\ refinement constituents read #", Error_Nod); 8277 end Output_SPARK_Refined_State_Pragma; 8278 8279 -------------------------------- 8280 -- Output_Variable_Assignment -- 8281 -------------------------------- 8282 8283 procedure Output_Variable_Assignment (N : Node_Id) is 8284 Var_Id : constant Entity_Id := Entity (Extract_Assignment_Name (N)); 8285 8286 begin 8287 Error_Msg_Sloc := Sloc (N); 8288 Error_Msg_NE ("\\ variable & assigned #", Error_Nod, Var_Id); 8289 end Output_Variable_Assignment; 8290 8291 ------------------------------- 8292 -- Output_Variable_Reference -- 8293 ------------------------------- 8294 8295 procedure Output_Variable_Reference (N : Node_Id) is 8296 Dummy : Variable_Attributes; 8297 Var_Id : Entity_Id; 8298 8299 begin 8300 Extract_Variable_Reference_Attributes 8301 (Ref => N, 8302 Var_Id => Var_Id, 8303 Attrs => Dummy); 8304 8305 Error_Msg_Sloc := Sloc (N); 8306 8307 if Is_Read (N) then 8308 Error_Msg_NE ("\\ variable & read #", Error_Nod, Var_Id); 8309 8310 else 8311 pragma Assert (False); 8312 null; 8313 end if; 8314 end Output_Variable_Reference; 8315 8316 -- Local variables 8317 8318 package Stack renames Scenario_Stack; 8319 8320 Dummy : Call_Attributes; 8321 N : Node_Id; 8322 Posted : Boolean; 8323 Target_Id : Entity_Id; 8324 8325 -- Start of processing for Output_Active_Scenarios 8326 8327 begin 8328 -- Active scenarios are emitted only when the static model is in effect 8329 -- because there is an inherent order by which all these scenarios were 8330 -- reached from the declaration or library level. 8331 8332 if not Static_Elaboration_Checks then 8333 return; 8334 end if; 8335 8336 Posted := False; 8337 8338 for Index in Stack.First .. Stack.Last loop 8339 N := Stack.Table (Index); 8340 8341 if not Posted then 8342 Posted := True; 8343 Output_Header; 8344 end if; 8345 8346 -- 'Access 8347 8348 if Nkind (N) = N_Attribute_Reference then 8349 Output_Access (N); 8350 8351 -- Calls 8352 8353 elsif Is_Suitable_Call (N) then 8354 Extract_Call_Attributes 8355 (Call => N, 8356 Target_Id => Target_Id, 8357 Attrs => Dummy); 8358 8359 if Is_Activation_Proc (Target_Id) then 8360 Output_Activation_Call (N); 8361 else 8362 Output_Call (N, Target_Id); 8363 end if; 8364 8365 -- Instantiations 8366 8367 elsif Is_Suitable_Instantiation (N) then 8368 Output_Instantiation (N); 8369 8370 -- Pragma Refined_State 8371 8372 elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then 8373 Output_SPARK_Refined_State_Pragma (N); 8374 8375 -- Variable assignments 8376 8377 elsif Nkind (N) = N_Assignment_Statement then 8378 Output_Variable_Assignment (N); 8379 8380 -- Variable references 8381 8382 elsif Is_Suitable_Variable_Reference (N) then 8383 Output_Variable_Reference (N); 8384 8385 else 8386 pragma Assert (False); 8387 null; 8388 end if; 8389 end loop; 8390 end Output_Active_Scenarios; 8391 8392 ------------------------- 8393 -- Pop_Active_Scenario -- 8394 ------------------------- 8395 8396 procedure Pop_Active_Scenario (N : Node_Id) is 8397 Top : Node_Id renames Scenario_Stack.Table (Scenario_Stack.Last); 8398 8399 begin 8400 pragma Assert (Top = N); 8401 Scenario_Stack.Decrement_Last; 8402 end Pop_Active_Scenario; 8403 8404 -------------------------------- 8405 -- Process_Activation_Generic -- 8406 -------------------------------- 8407 8408 procedure Process_Activation_Generic 8409 (Call : Node_Id; 8410 Call_Attrs : Call_Attributes; 8411 State : Processing_Attributes) 8412 is 8413 procedure Process_Task_Object (Obj_Id : Entity_Id; Typ : Entity_Id); 8414 -- Perform ABE checks and diagnostics for object Obj_Id with type Typ. 8415 -- Typ may be a task type or a composite type with at least one task 8416 -- component. 8417 8418 procedure Process_Task_Objects (List : List_Id); 8419 -- Perform ABE checks and diagnostics for all task objects found in 8420 -- the list List. 8421 8422 ------------------------- 8423 -- Process_Task_Object -- 8424 ------------------------- 8425 8426 procedure Process_Task_Object (Obj_Id : Entity_Id; Typ : Entity_Id) is 8427 Base_Typ : constant Entity_Id := Base_Type (Typ); 8428 8429 Comp_Id : Entity_Id; 8430 Task_Attrs : Task_Attributes; 8431 8432 begin 8433 if Is_Task_Type (Typ) then 8434 Extract_Task_Attributes 8435 (Typ => Base_Typ, 8436 Attrs => Task_Attrs); 8437 8438 Process_Single_Activation 8439 (Call => Call, 8440 Call_Attrs => Call_Attrs, 8441 Obj_Id => Obj_Id, 8442 Task_Attrs => Task_Attrs, 8443 State => State); 8444 8445 -- Examine the component type when the object is an array 8446 8447 elsif Is_Array_Type (Typ) and then Has_Task (Base_Typ) then 8448 Process_Task_Object (Obj_Id, Component_Type (Typ)); 8449 8450 -- Examine individual component types when the object is a record 8451 8452 elsif Is_Record_Type (Typ) and then Has_Task (Base_Typ) then 8453 Comp_Id := First_Component (Typ); 8454 while Present (Comp_Id) loop 8455 Process_Task_Object (Obj_Id, Etype (Comp_Id)); 8456 Next_Component (Comp_Id); 8457 end loop; 8458 end if; 8459 end Process_Task_Object; 8460 8461 -------------------------- 8462 -- Process_Task_Objects -- 8463 -------------------------- 8464 8465 procedure Process_Task_Objects (List : List_Id) is 8466 Item : Node_Id; 8467 Item_Id : Entity_Id; 8468 Item_Typ : Entity_Id; 8469 8470 begin 8471 -- Examine the contents of the list looking for an object declaration 8472 -- of a task type or one that contains a task within. 8473 8474 Item := First (List); 8475 while Present (Item) loop 8476 if Nkind (Item) = N_Object_Declaration then 8477 Item_Id := Defining_Entity (Item); 8478 Item_Typ := Etype (Item_Id); 8479 8480 if Has_Task (Item_Typ) then 8481 Process_Task_Object (Item_Id, Item_Typ); 8482 end if; 8483 end if; 8484 8485 Next (Item); 8486 end loop; 8487 end Process_Task_Objects; 8488 8489 -- Local variables 8490 8491 Context : Node_Id; 8492 Spec : Node_Id; 8493 8494 -- Start of processing for Process_Activation_Generic 8495 8496 begin 8497 -- Nothing to do when the activation is a guaranteed ABE 8498 8499 if Is_Known_Guaranteed_ABE (Call) then 8500 return; 8501 end if; 8502 8503 -- Find the proper context of the activation call where all task objects 8504 -- being activated are declared. This is usually the immediate parent of 8505 -- the call. 8506 8507 Context := Parent (Call); 8508 8509 -- In the case of package bodies, the activation call is in the handled 8510 -- sequence of statements, but the task objects are in the declaration 8511 -- list of the body. 8512 8513 if Nkind (Context) = N_Handled_Sequence_Of_Statements 8514 and then Nkind (Parent (Context)) = N_Package_Body 8515 then 8516 Context := Parent (Context); 8517 end if; 8518 8519 -- Process all task objects defined in both the spec and body when the 8520 -- activation call precedes the "begin" of a package body. 8521 8522 if Nkind (Context) = N_Package_Body then 8523 Spec := 8524 Specification 8525 (Unit_Declaration_Node (Corresponding_Spec (Context))); 8526 8527 Process_Task_Objects (Visible_Declarations (Spec)); 8528 Process_Task_Objects (Private_Declarations (Spec)); 8529 Process_Task_Objects (Declarations (Context)); 8530 8531 -- Process all task objects defined in the spec when the activation call 8532 -- appears at the end of a package spec. 8533 8534 elsif Nkind (Context) = N_Package_Specification then 8535 Process_Task_Objects (Visible_Declarations (Context)); 8536 Process_Task_Objects (Private_Declarations (Context)); 8537 8538 -- Otherwise the context of the activation is some construct with a 8539 -- declarative part. Note that the corresponding record type of a task 8540 -- type is controlled. Because of this, the finalization machinery must 8541 -- relocate the task object to the handled statements of the construct 8542 -- to perform proper finalization in case of an exception. Examine the 8543 -- statements of the construct rather than the declarations. 8544 8545 else 8546 pragma Assert (Nkind (Context) = N_Handled_Sequence_Of_Statements); 8547 8548 Process_Task_Objects (Statements (Context)); 8549 end if; 8550 end Process_Activation_Generic; 8551 8552 ------------------------------------ 8553 -- Process_Conditional_ABE_Access -- 8554 ------------------------------------ 8555 8556 procedure Process_Conditional_ABE_Access 8557 (Attr : Node_Id; 8558 State : Processing_Attributes) 8559 is 8560 function Build_Access_Marker (Target_Id : Entity_Id) return Node_Id; 8561 pragma Inline (Build_Access_Marker); 8562 -- Create a suitable call marker which invokes target Target_Id 8563 8564 ------------------------- 8565 -- Build_Access_Marker -- 8566 ------------------------- 8567 8568 function Build_Access_Marker (Target_Id : Entity_Id) return Node_Id is 8569 Marker : Node_Id; 8570 8571 begin 8572 Marker := Make_Call_Marker (Sloc (Attr)); 8573 8574 -- Inherit relevant attributes from the attribute 8575 8576 -- Performance note: parent traversal 8577 8578 Set_Target (Marker, Target_Id); 8579 Set_Is_Declaration_Level_Node 8580 (Marker, Find_Enclosing_Level (Attr) = Declaration_Level); 8581 Set_Is_Dispatching_Call 8582 (Marker, False); 8583 Set_Is_Elaboration_Checks_OK_Node 8584 (Marker, Is_Elaboration_Checks_OK_Node (Attr)); 8585 Set_Is_Source_Call 8586 (Marker, Comes_From_Source (Attr)); 8587 Set_Is_SPARK_Mode_On_Node 8588 (Marker, Is_SPARK_Mode_On_Node (Attr)); 8589 8590 -- Partially insert the call marker into the tree by setting its 8591 -- parent pointer. 8592 8593 Set_Parent (Marker, Attr); 8594 8595 return Marker; 8596 end Build_Access_Marker; 8597 8598 -- Local variables 8599 8600 Root : constant Node_Id := Root_Scenario; 8601 Target_Id : constant Entity_Id := Entity (Prefix (Attr)); 8602 8603 Target_Attrs : Target_Attributes; 8604 8605 -- Start of processing for Process_Conditional_ABE_Access 8606 8607 begin 8608 -- Output relevant information when switch -gnatel (info messages on 8609 -- implicit Elaborate[_All] pragmas) is in effect. 8610 8611 if Elab_Info_Messages then 8612 Error_Msg_NE 8613 ("info: access to & during elaboration", Attr, Target_Id); 8614 end if; 8615 8616 Extract_Target_Attributes 8617 (Target_Id => Target_Id, 8618 Attrs => Target_Attrs); 8619 8620 -- Both the attribute and the corresponding body are in the same unit. 8621 -- The corresponding body must appear prior to the root scenario which 8622 -- started the recursive search. If this is not the case, then there is 8623 -- a potential ABE if the access value is used to call the subprogram. 8624 -- Emit a warning only when switch -gnatw.f (warnings on suspucious 8625 -- 'Access) is in effect. 8626 8627 if Warn_On_Elab_Access 8628 and then Present (Target_Attrs.Body_Decl) 8629 and then In_Extended_Main_Code_Unit (Target_Attrs.Body_Decl) 8630 and then Earlier_In_Extended_Unit (Root, Target_Attrs.Body_Decl) 8631 then 8632 Error_Msg_Name_1 := Attribute_Name (Attr); 8633 Error_Msg_NE ("??% attribute of & before body seen", Attr, Target_Id); 8634 Error_Msg_N ("\possible Program_Error on later references", Attr); 8635 8636 Output_Active_Scenarios (Attr); 8637 end if; 8638 8639 -- Treat the attribute as an immediate invocation of the target when 8640 -- switch -gnatd.o (conservative elaboration order for indirect calls) 8641 -- is in effect. Note that the prior elaboration of the unit containing 8642 -- the target is ensured processing the corresponding call marker. 8643 8644 if Debug_Flag_Dot_O then 8645 Process_Conditional_ABE 8646 (N => Build_Access_Marker (Target_Id), 8647 State => State); 8648 8649 -- Otherwise ensure that the unit with the corresponding body is 8650 -- elaborated prior to the main unit. 8651 8652 else 8653 Ensure_Prior_Elaboration 8654 (N => Attr, 8655 Unit_Id => Target_Attrs.Unit_Id, 8656 Prag_Nam => Name_Elaborate_All, 8657 State => State); 8658 end if; 8659 end Process_Conditional_ABE_Access; 8660 8661 --------------------------------------------- 8662 -- Process_Conditional_ABE_Activation_Impl -- 8663 --------------------------------------------- 8664 8665 procedure Process_Conditional_ABE_Activation_Impl 8666 (Call : Node_Id; 8667 Call_Attrs : Call_Attributes; 8668 Obj_Id : Entity_Id; 8669 Task_Attrs : Task_Attributes; 8670 State : Processing_Attributes) 8671 is 8672 Check_OK : constant Boolean := 8673 not Is_Ignored_Ghost_Entity (Obj_Id) 8674 and then not Task_Attrs.Ghost_Mode_Ignore 8675 and then Is_Elaboration_Checks_OK_Id (Obj_Id) 8676 and then Task_Attrs.Elab_Checks_OK; 8677 -- A run-time ABE check may be installed only when the object and the 8678 -- task type have active elaboration checks, and both are not ignored 8679 -- Ghost constructs. 8680 8681 Root : constant Node_Id := Root_Scenario; 8682 8683 New_State : Processing_Attributes := State; 8684 -- Each step of the Processing phase constitutes a new state 8685 8686 begin 8687 -- Output relevant information when switch -gnatel (info messages on 8688 -- implicit Elaborate[_All] pragmas) is in effect. 8689 8690 if Elab_Info_Messages then 8691 Error_Msg_NE 8692 ("info: activation of & during elaboration", Call, Obj_Id); 8693 end if; 8694 8695 -- Nothing to do when the call activates a task whose type is defined 8696 -- within an instance and switch -gnatd_i (ignore activations and calls 8697 -- to instances for elaboration) is in effect. 8698 8699 if Debug_Flag_Underscore_I 8700 and then In_External_Instance 8701 (N => Call, 8702 Target_Decl => Task_Attrs.Task_Decl) 8703 then 8704 return; 8705 8706 -- Nothing to do when the activation is a guaranteed ABE 8707 8708 elsif Is_Known_Guaranteed_ABE (Call) then 8709 return; 8710 8711 -- Nothing to do when the root scenario appears at the declaration 8712 -- level and the task is in the same unit, but outside this context. 8713 -- 8714 -- task type Task_Typ; -- task declaration 8715 -- 8716 -- procedure Proc is 8717 -- function A ... is 8718 -- begin 8719 -- if Some_Condition then 8720 -- declare 8721 -- T : Task_Typ; 8722 -- begin 8723 -- <activation call> -- activation site 8724 -- end; 8725 -- ... 8726 -- end A; 8727 -- 8728 -- X : ... := A; -- root scenario 8729 -- ... 8730 -- 8731 -- task body Task_Typ is 8732 -- ... 8733 -- end Task_Typ; 8734 -- 8735 -- In the example above, the context of X is the declarative list of 8736 -- Proc. The "elaboration" of X may reach the activation of T whose body 8737 -- is defined outside of X's context. The task body is relevant only 8738 -- when Proc is invoked, but this happens only in "normal" elaboration, 8739 -- therefore the task body must not be considered if this is not the 8740 -- case. 8741 8742 -- Performance note: parent traversal 8743 8744 elsif Is_Up_Level_Target (Task_Attrs.Task_Decl) then 8745 return; 8746 8747 -- Nothing to do when the activation is ABE-safe 8748 -- 8749 -- generic 8750 -- package Gen is 8751 -- task type Task_Typ; 8752 -- end Gen; 8753 -- 8754 -- package body Gen is 8755 -- task body Task_Typ is 8756 -- begin 8757 -- ... 8758 -- end Task_Typ; 8759 -- end Gen; 8760 -- 8761 -- with Gen; 8762 -- procedure Main is 8763 -- package Nested is 8764 -- package Inst is new Gen; 8765 -- T : Inst.Task_Typ; 8766 -- <activation call> -- safe activation 8767 -- end Nested; 8768 -- ... 8769 8770 elsif Is_Safe_Activation (Call, Task_Attrs.Task_Decl) then 8771 8772 -- Note that the task body must still be examined for any nested 8773 -- scenarios. 8774 8775 null; 8776 8777 -- The activation call and the task body are both in the main unit 8778 8779 elsif Present (Task_Attrs.Body_Decl) 8780 and then In_Extended_Main_Code_Unit (Task_Attrs.Body_Decl) 8781 then 8782 -- If the root scenario appears prior to the task body, then this is 8783 -- a possible ABE with respect to the root scenario. 8784 -- 8785 -- task type Task_Typ; 8786 -- 8787 -- function A ... is 8788 -- begin 8789 -- if Some_Condition then 8790 -- declare 8791 -- package Pack is 8792 -- T : Task_Typ; 8793 -- end Pack; -- activation of T 8794 -- ... 8795 -- end A; 8796 -- 8797 -- X : ... := A; -- root scenario 8798 -- 8799 -- task body Task_Typ is -- task body 8800 -- ... 8801 -- end Task_Typ; 8802 -- 8803 -- Y : ... := A; -- root scenario 8804 -- 8805 -- IMPORTANT: The activation of T is a possible ABE for X, but 8806 -- not for Y. Intalling an unconditional ABE raise prior to the 8807 -- activation call would be wrong as it will fail for Y as well 8808 -- but in Y's case the activation of T is never an ABE. 8809 8810 if Earlier_In_Extended_Unit (Root, Task_Attrs.Body_Decl) then 8811 8812 -- Do not emit any ABE diagnostics when the activation occurs in 8813 -- a partial finalization context because this leads to confusing 8814 -- noise. 8815 8816 if State.Within_Partial_Finalization then 8817 null; 8818 8819 -- ABE diagnostics are emitted only in the static model because 8820 -- there is a well-defined order to visiting scenarios. Without 8821 -- this order diagnostics appear jumbled and result in unwanted 8822 -- noise. 8823 8824 elsif Static_Elaboration_Checks 8825 and then Call_Attrs.Elab_Warnings_OK 8826 then 8827 Error_Msg_Sloc := Sloc (Call); 8828 Error_Msg_N 8829 ("??task & will be activated # before elaboration of its " 8830 & "body", Obj_Id); 8831 Error_Msg_N 8832 ("\Program_Error may be raised at run time", Obj_Id); 8833 8834 Output_Active_Scenarios (Obj_Id); 8835 end if; 8836 8837 -- Install a conditional run-time ABE check to verify that the 8838 -- task body has been elaborated prior to the activation call. 8839 8840 if Check_OK then 8841 Install_ABE_Check 8842 (N => Call, 8843 Ins_Nod => Call, 8844 Target_Id => Task_Attrs.Spec_Id, 8845 Target_Decl => Task_Attrs.Task_Decl, 8846 Target_Body => Task_Attrs.Body_Decl); 8847 8848 -- Update the state of the Processing phase to indicate that 8849 -- no implicit Elaborate[_All] pragmas must be generated from 8850 -- this point on. 8851 -- 8852 -- task type Task_Typ; 8853 -- 8854 -- function A ... is 8855 -- begin 8856 -- if Some_Condition then 8857 -- declare 8858 -- package Pack is 8859 -- <ABE check> 8860 -- T : Task_Typ; 8861 -- end Pack; -- activation of T 8862 -- ... 8863 -- end A; 8864 -- 8865 -- X : ... := A; 8866 -- 8867 -- task body Task_Typ is 8868 -- begin 8869 -- External.Subp; -- imparts Elaborate_All 8870 -- end Task_Typ; 8871 -- 8872 -- If Some_Condition is True, then the ABE check will fail at 8873 -- runtime and the call to External.Subp will never take place, 8874 -- rendering the implicit Elaborate_All useless. 8875 -- 8876 -- If Some_Condition is False, then the call to External.Subp 8877 -- will never take place, rendering the implicit Elaborate_All 8878 -- useless. 8879 8880 New_State.Suppress_Implicit_Pragmas := True; 8881 end if; 8882 end if; 8883 8884 -- Otherwise the task body is not available in this compilation or it 8885 -- resides in an external unit. Install a run-time ABE check to verify 8886 -- that the task body has been elaborated prior to the activation call 8887 -- when the dynamic model is in effect. 8888 8889 elsif Dynamic_Elaboration_Checks and then Check_OK then 8890 Install_ABE_Check 8891 (N => Call, 8892 Ins_Nod => Call, 8893 Id => Task_Attrs.Unit_Id); 8894 end if; 8895 8896 -- Update the state of the Processing phase to indicate that any further 8897 -- traversal is now within a task body. 8898 8899 New_State.Within_Task_Body := True; 8900 8901 -- Both the activation call and task type are subject to SPARK_Mode 8902 -- On, this triggers the SPARK rules for task activation. Compared to 8903 -- calls and instantiations, task activation in SPARK does not require 8904 -- the presence of Elaborate[_All] pragmas in case the task type is 8905 -- defined outside the main unit. This is because SPARK utilizes a 8906 -- special policy which activates all tasks after the main unit has 8907 -- finished its elaboration. 8908 8909 if Call_Attrs.SPARK_Mode_On and Task_Attrs.SPARK_Mode_On then 8910 null; 8911 8912 -- Otherwise the Ada rules are in effect. Ensure that the unit with the 8913 -- task body is elaborated prior to the main unit. 8914 8915 else 8916 Ensure_Prior_Elaboration 8917 (N => Call, 8918 Unit_Id => Task_Attrs.Unit_Id, 8919 Prag_Nam => Name_Elaborate_All, 8920 State => New_State); 8921 end if; 8922 8923 Traverse_Body 8924 (N => Task_Attrs.Body_Decl, 8925 State => New_State); 8926 end Process_Conditional_ABE_Activation_Impl; 8927 8928 procedure Process_Conditional_ABE_Activation is 8929 new Process_Activation_Generic (Process_Conditional_ABE_Activation_Impl); 8930 8931 ---------------------------------- 8932 -- Process_Conditional_ABE_Call -- 8933 ---------------------------------- 8934 8935 procedure Process_Conditional_ABE_Call 8936 (Call : Node_Id; 8937 Call_Attrs : Call_Attributes; 8938 Target_Id : Entity_Id; 8939 State : Processing_Attributes) 8940 is 8941 function In_Initialization_Context (N : Node_Id) return Boolean; 8942 -- Determine whether arbitrary node N appears within a type init proc, 8943 -- primitive [Deep_]Initialize, or a block created for initialization 8944 -- purposes. 8945 8946 function Is_Partial_Finalization_Proc return Boolean; 8947 pragma Inline (Is_Partial_Finalization_Proc); 8948 -- Determine whether call Call with target Target_Id invokes a partial 8949 -- finalization procedure. 8950 8951 ------------------------------- 8952 -- In_Initialization_Context -- 8953 ------------------------------- 8954 8955 function In_Initialization_Context (N : Node_Id) return Boolean is 8956 Par : Node_Id; 8957 Spec_Id : Entity_Id; 8958 8959 begin 8960 -- Climb the parent chain looking for initialization actions 8961 8962 Par := Parent (N); 8963 while Present (Par) loop 8964 8965 -- A block may be part of the initialization actions of a default 8966 -- initialized object. 8967 8968 if Nkind (Par) = N_Block_Statement 8969 and then Is_Initialization_Block (Par) 8970 then 8971 return True; 8972 8973 -- A subprogram body may denote an initialization routine 8974 8975 elsif Nkind (Par) = N_Subprogram_Body then 8976 Spec_Id := Unique_Defining_Entity (Par); 8977 8978 -- The current subprogram body denotes a type init proc or 8979 -- primitive [Deep_]Initialize. 8980 8981 if Is_Init_Proc (Spec_Id) 8982 or else Is_Controlled_Proc (Spec_Id, Name_Initialize) 8983 or else Is_TSS (Spec_Id, TSS_Deep_Initialize) 8984 then 8985 return True; 8986 end if; 8987 8988 -- Prevent the search from going too far 8989 8990 elsif Is_Body_Or_Package_Declaration (Par) then 8991 exit; 8992 end if; 8993 8994 Par := Parent (Par); 8995 end loop; 8996 8997 return False; 8998 end In_Initialization_Context; 8999 9000 ---------------------------------- 9001 -- Is_Partial_Finalization_Proc -- 9002 ---------------------------------- 9003 9004 function Is_Partial_Finalization_Proc return Boolean is 9005 begin 9006 -- To qualify, the target must denote primitive [Deep_]Finalize or a 9007 -- finalizer procedure, and the call must appear in an initialization 9008 -- context. 9009 9010 return 9011 (Is_Controlled_Proc (Target_Id, Name_Finalize) 9012 or else Is_Finalizer_Proc (Target_Id) 9013 or else Is_TSS (Target_Id, TSS_Deep_Finalize)) 9014 and then In_Initialization_Context (Call); 9015 end Is_Partial_Finalization_Proc; 9016 9017 -- Local variables 9018 9019 SPARK_Rules_On : Boolean; 9020 Target_Attrs : Target_Attributes; 9021 9022 New_State : Processing_Attributes := State; 9023 -- Each step of the Processing phase constitutes a new state 9024 9025 -- Start of processing for Process_Conditional_ABE_Call 9026 9027 begin 9028 Extract_Target_Attributes 9029 (Target_Id => Target_Id, 9030 Attrs => Target_Attrs); 9031 9032 -- The SPARK rules are in effect when both the call and target are 9033 -- subject to SPARK_Mode On. 9034 9035 SPARK_Rules_On := 9036 Call_Attrs.SPARK_Mode_On and Target_Attrs.SPARK_Mode_On; 9037 9038 -- Output relevant information when switch -gnatel (info messages on 9039 -- implicit Elaborate[_All] pragmas) is in effect. 9040 9041 if Elab_Info_Messages then 9042 Info_Call 9043 (Call => Call, 9044 Target_Id => Target_Id, 9045 Info_Msg => True, 9046 In_SPARK => SPARK_Rules_On); 9047 end if; 9048 9049 -- Check whether the invocation of an entry clashes with an existing 9050 -- restriction. 9051 9052 if Is_Protected_Entry (Target_Id) then 9053 Check_Restriction (No_Entry_Calls_In_Elaboration_Code, Call); 9054 9055 elsif Is_Task_Entry (Target_Id) then 9056 Check_Restriction (No_Entry_Calls_In_Elaboration_Code, Call); 9057 9058 -- Task entry calls are never processed because the entry being 9059 -- invoked does not have a corresponding "body", it has a select. 9060 9061 return; 9062 end if; 9063 9064 -- Nothing to do when the call invokes a target defined within an 9065 -- instance and switch -gnatd_i (ignore activations and calls to 9066 -- instances for elaboration) is in effect. 9067 9068 if Debug_Flag_Underscore_I 9069 and then In_External_Instance 9070 (N => Call, 9071 Target_Decl => Target_Attrs.Spec_Decl) 9072 then 9073 return; 9074 9075 -- Nothing to do when the call is a guaranteed ABE 9076 9077 elsif Is_Known_Guaranteed_ABE (Call) then 9078 return; 9079 9080 -- Nothing to do when the root scenario appears at the declaration level 9081 -- and the target is in the same unit, but outside this context. 9082 -- 9083 -- function B ...; -- target declaration 9084 -- 9085 -- procedure Proc is 9086 -- function A ... is 9087 -- begin 9088 -- if Some_Condition then 9089 -- return B; -- call site 9090 -- ... 9091 -- end A; 9092 -- 9093 -- X : ... := A; -- root scenario 9094 -- ... 9095 -- 9096 -- function B ... is 9097 -- ... 9098 -- end B; 9099 -- 9100 -- In the example above, the context of X is the declarative region of 9101 -- Proc. The "elaboration" of X may eventually reach B which is defined 9102 -- outside of X's context. B is relevant only when Proc is invoked, but 9103 -- this happens only by means of "normal" elaboration, therefore B must 9104 -- not be considered if this is not the case. 9105 9106 -- Performance note: parent traversal 9107 9108 elsif Is_Up_Level_Target (Target_Attrs.Spec_Decl) then 9109 return; 9110 end if; 9111 9112 -- The call occurs in an initial condition context when a prior scenario 9113 -- is already in that mode, or when the target is an Initial_Condition 9114 -- procedure. Update the state of the Processing phase to reflect this. 9115 9116 New_State.Within_Initial_Condition := 9117 New_State.Within_Initial_Condition 9118 or else Is_Initial_Condition_Proc (Target_Id); 9119 9120 -- The call occurs in a partial finalization context when a prior 9121 -- scenario is already in that mode, or when the target denotes a 9122 -- [Deep_]Finalize primitive or a finalizer within an initialization 9123 -- context. Update the state of the Processing phase to reflect this. 9124 9125 New_State.Within_Partial_Finalization := 9126 New_State.Within_Partial_Finalization 9127 or else Is_Partial_Finalization_Proc; 9128 9129 -- The SPARK rules are in effect. Note that -gnatd.v (enforce SPARK 9130 -- elaboration rules in SPARK code) is intentionally not taken into 9131 -- account here because Process_Conditional_ABE_Call_SPARK has two 9132 -- separate modes of operation. 9133 9134 if SPARK_Rules_On then 9135 Process_Conditional_ABE_Call_SPARK 9136 (Call => Call, 9137 Target_Id => Target_Id, 9138 Target_Attrs => Target_Attrs, 9139 State => New_State); 9140 9141 -- Otherwise the Ada rules are in effect 9142 9143 else 9144 Process_Conditional_ABE_Call_Ada 9145 (Call => Call, 9146 Call_Attrs => Call_Attrs, 9147 Target_Id => Target_Id, 9148 Target_Attrs => Target_Attrs, 9149 State => New_State); 9150 end if; 9151 9152 -- Inspect the target body (and barried function) for other suitable 9153 -- elaboration scenarios. 9154 9155 Traverse_Body 9156 (N => Target_Attrs.Body_Barf, 9157 State => New_State); 9158 9159 Traverse_Body 9160 (N => Target_Attrs.Body_Decl, 9161 State => New_State); 9162 end Process_Conditional_ABE_Call; 9163 9164 -------------------------------------- 9165 -- Process_Conditional_ABE_Call_Ada -- 9166 -------------------------------------- 9167 9168 procedure Process_Conditional_ABE_Call_Ada 9169 (Call : Node_Id; 9170 Call_Attrs : Call_Attributes; 9171 Target_Id : Entity_Id; 9172 Target_Attrs : Target_Attributes; 9173 State : Processing_Attributes) 9174 is 9175 Check_OK : constant Boolean := 9176 not Call_Attrs.Ghost_Mode_Ignore 9177 and then not Target_Attrs.Ghost_Mode_Ignore 9178 and then Call_Attrs.Elab_Checks_OK 9179 and then Target_Attrs.Elab_Checks_OK; 9180 -- A run-time ABE check may be installed only when both the call and the 9181 -- target have active elaboration checks, and both are not ignored Ghost 9182 -- constructs. 9183 9184 Root : constant Node_Id := Root_Scenario; 9185 9186 New_State : Processing_Attributes := State; 9187 -- Each step of the Processing phase constitutes a new state 9188 9189 begin 9190 -- Nothing to do for an Ada dispatching call because there are no ABE 9191 -- diagnostics for either models. ABE checks for the dynamic model are 9192 -- handled by Install_Primitive_Elaboration_Check. 9193 9194 if Call_Attrs.Is_Dispatching then 9195 return; 9196 9197 -- Nothing to do when the call is ABE-safe 9198 -- 9199 -- generic 9200 -- function Gen ...; 9201 -- 9202 -- function Gen ... is 9203 -- begin 9204 -- ... 9205 -- end Gen; 9206 -- 9207 -- with Gen; 9208 -- procedure Main is 9209 -- function Inst is new Gen; 9210 -- X : ... := Inst; -- safe call 9211 -- ... 9212 9213 elsif Is_Safe_Call (Call, Target_Attrs) then 9214 return; 9215 9216 -- The call and the target body are both in the main unit 9217 9218 elsif Present (Target_Attrs.Body_Decl) 9219 and then In_Extended_Main_Code_Unit (Target_Attrs.Body_Decl) 9220 then 9221 -- If the root scenario appears prior to the target body, then this 9222 -- is a possible ABE with respect to the root scenario. 9223 -- 9224 -- function B ...; 9225 -- 9226 -- function A ... is 9227 -- begin 9228 -- if Some_Condition then 9229 -- return B; -- call site 9230 -- ... 9231 -- end A; 9232 -- 9233 -- X : ... := A; -- root scenario 9234 -- 9235 -- function B ... is -- target body 9236 -- ... 9237 -- end B; 9238 -- 9239 -- Y : ... := A; -- root scenario 9240 -- 9241 -- IMPORTANT: The call to B from A is a possible ABE for X, but not 9242 -- for Y. Installing an unconditional ABE raise prior to the call to 9243 -- B would be wrong as it will fail for Y as well, but in Y's case 9244 -- the call to B is never an ABE. 9245 9246 if Earlier_In_Extended_Unit (Root, Target_Attrs.Body_Decl) then 9247 9248 -- Do not emit any ABE diagnostics when the call occurs in a 9249 -- partial finalization context because this leads to confusing 9250 -- noise. 9251 9252 if State.Within_Partial_Finalization then 9253 null; 9254 9255 -- ABE diagnostics are emitted only in the static model because 9256 -- there is a well-defined order to visiting scenarios. Without 9257 -- this order diagnostics appear jumbled and result in unwanted 9258 -- noise. 9259 9260 elsif Static_Elaboration_Checks 9261 and then Call_Attrs.Elab_Warnings_OK 9262 then 9263 Error_Msg_NE 9264 ("??cannot call & before body seen", Call, Target_Id); 9265 Error_Msg_N ("\Program_Error may be raised at run time", Call); 9266 9267 Output_Active_Scenarios (Call); 9268 end if; 9269 9270 -- Install a conditional run-time ABE check to verify that the 9271 -- target body has been elaborated prior to the call. 9272 9273 if Check_OK then 9274 Install_ABE_Check 9275 (N => Call, 9276 Ins_Nod => Call, 9277 Target_Id => Target_Attrs.Spec_Id, 9278 Target_Decl => Target_Attrs.Spec_Decl, 9279 Target_Body => Target_Attrs.Body_Decl); 9280 9281 -- Update the state of the Processing phase to indicate that 9282 -- no implicit Elaborate[_All] pragmas must be generated from 9283 -- this point on. 9284 -- 9285 -- function B ...; 9286 -- 9287 -- function A ... is 9288 -- begin 9289 -- if Some_Condition then 9290 -- <ABE check> 9291 -- return B; 9292 -- ... 9293 -- end A; 9294 -- 9295 -- X : ... := A; 9296 -- 9297 -- function B ... is 9298 -- External.Subp; -- imparts Elaborate_All 9299 -- end B; 9300 -- 9301 -- If Some_Condition is True, then the ABE check will fail at 9302 -- runtime and the call to External.Subp will never take place, 9303 -- rendering the implicit Elaborate_All useless. 9304 -- 9305 -- If Some_Condition is False, then the call to External.Subp 9306 -- will never take place, rendering the implicit Elaborate_All 9307 -- useless. 9308 9309 New_State.Suppress_Implicit_Pragmas := True; 9310 end if; 9311 end if; 9312 9313 -- Otherwise the target body is not available in this compilation or it 9314 -- resides in an external unit. Install a run-time ABE check to verify 9315 -- that the target body has been elaborated prior to the call site when 9316 -- the dynamic model is in effect. 9317 9318 elsif Dynamic_Elaboration_Checks and then Check_OK then 9319 Install_ABE_Check 9320 (N => Call, 9321 Ins_Nod => Call, 9322 Id => Target_Attrs.Unit_Id); 9323 end if; 9324 9325 -- Ensure that the unit with the target body is elaborated prior to the 9326 -- main unit. The implicit Elaborate[_All] is generated only when the 9327 -- call has elaboration checks enabled. This behaviour parallels that of 9328 -- the old ABE mechanism. 9329 9330 if Call_Attrs.Elab_Checks_OK then 9331 Ensure_Prior_Elaboration 9332 (N => Call, 9333 Unit_Id => Target_Attrs.Unit_Id, 9334 Prag_Nam => Name_Elaborate_All, 9335 State => New_State); 9336 end if; 9337 end Process_Conditional_ABE_Call_Ada; 9338 9339 ---------------------------------------- 9340 -- Process_Conditional_ABE_Call_SPARK -- 9341 ---------------------------------------- 9342 9343 procedure Process_Conditional_ABE_Call_SPARK 9344 (Call : Node_Id; 9345 Target_Id : Entity_Id; 9346 Target_Attrs : Target_Attributes; 9347 State : Processing_Attributes) 9348 is 9349 Region : Node_Id; 9350 9351 begin 9352 -- Ensure that a suitable elaboration model is in effect for SPARK rule 9353 -- verification. 9354 9355 Check_SPARK_Model_In_Effect (Call); 9356 9357 -- The call and the target body are both in the main unit 9358 9359 if Present (Target_Attrs.Body_Decl) 9360 and then In_Extended_Main_Code_Unit (Target_Attrs.Body_Decl) 9361 then 9362 -- If the call appears prior to the target body, then the call must 9363 -- appear within the early call region of the target body. 9364 -- 9365 -- function B ...; 9366 -- 9367 -- X : ... := B; -- call site 9368 -- 9369 -- <preelaborable construct 1> --+ 9370 -- ... | early call region 9371 -- <preelaborable construct N> --+ 9372 -- 9373 -- function B ... is -- target body 9374 -- ... 9375 -- end B; 9376 -- 9377 -- When the call to B is not nested within some other scenario, the 9378 -- call is automatically illegal because it can never appear in the 9379 -- early call region of B's body. This is equivalent to a guaranteed 9380 -- ABE. 9381 -- 9382 -- <preelaborable construct 1> --+ 9383 -- | 9384 -- function B ...; | 9385 -- | 9386 -- function A ... is | 9387 -- begin | early call region 9388 -- if Some_Condition then 9389 -- return B; -- call site 9390 -- ... 9391 -- end A; | 9392 -- | 9393 -- <preelaborable construct N> --+ 9394 -- 9395 -- function B ... is -- target body 9396 -- ... 9397 -- end B; 9398 -- 9399 -- When the call to B is nested within some other scenario, the call 9400 -- is always ABE-safe. It is not immediately obvious why this is the 9401 -- case. The elaboration safety follows from the early call region 9402 -- rule being applied to ALL calls preceding their associated bodies. 9403 -- 9404 -- In the example above, the call to B is safe as long as the call to 9405 -- A is safe. There are several cases to consider: 9406 -- 9407 -- <call 1 to A> 9408 -- function B ...; 9409 -- 9410 -- <call 2 to A> 9411 -- function A ... is 9412 -- begin 9413 -- if Some_Condition then 9414 -- return B; 9415 -- ... 9416 -- end A; 9417 -- 9418 -- <call 3 to A> 9419 -- function B ... is 9420 -- ... 9421 -- end B; 9422 -- 9423 -- * Call 1 - This call is either nested within some scenario or not, 9424 -- which falls under the two general cases outlined above. 9425 -- 9426 -- * Call 2 - This is the same case as Call 1. 9427 -- 9428 -- * Call 3 - The placement of this call limits the range of B's 9429 -- early call region unto call 3, therefore the call to B is no 9430 -- longer within the early call region of B's body, making it ABE- 9431 -- unsafe and therefore illegal. 9432 9433 if Earlier_In_Extended_Unit (Call, Target_Attrs.Body_Decl) then 9434 9435 -- Do not emit any ABE diagnostics when the call occurs in an 9436 -- initial condition context because this leads to incorrect 9437 -- diagnostics. 9438 9439 if State.Within_Initial_Condition then 9440 null; 9441 9442 -- Do not emit any ABE diagnostics when the call occurs in a 9443 -- partial finalization context because this leads to confusing 9444 -- noise. 9445 9446 elsif State.Within_Partial_Finalization then 9447 null; 9448 9449 -- ABE diagnostics are emitted only in the static model because 9450 -- there is a well-defined order to visiting scenarios. Without 9451 -- this order diagnostics appear jumbled and result in unwanted 9452 -- noise. 9453 9454 elsif Static_Elaboration_Checks then 9455 9456 -- Ensure that a call which textually precedes the subprogram 9457 -- body it invokes appears within the early call region of the 9458 -- subprogram body. 9459 9460 -- IMPORTANT: This check must always be performed even when 9461 -- -gnatd.v (enforce SPARK elaboration rules in SPARK code) is 9462 -- not specified because the static model cannot guarantee the 9463 -- absence of elaboration issues in the presence of dispatching 9464 -- calls. 9465 9466 Region := Find_Early_Call_Region (Target_Attrs.Body_Decl); 9467 9468 if Earlier_In_Extended_Unit (Call, Region) then 9469 Error_Msg_NE 9470 ("call must appear within early call region of subprogram " 9471 & "body & (SPARK RM 7.7(3))", Call, Target_Id); 9472 9473 Error_Msg_Sloc := Sloc (Region); 9474 Error_Msg_N ("\region starts #", Call); 9475 9476 Error_Msg_Sloc := Sloc (Target_Attrs.Body_Decl); 9477 Error_Msg_N ("\region ends #", Call); 9478 9479 Output_Active_Scenarios (Call); 9480 end if; 9481 end if; 9482 9483 -- Otherwise the call appears after the target body. The call is 9484 -- ABE-safe as a consequence of applying the early call region rule 9485 -- to ALL calls preceding their associated bodies. 9486 9487 else 9488 null; 9489 end if; 9490 end if; 9491 9492 -- A call to a source target or to a target which emulates Ada or SPARK 9493 -- semantics imposes an Elaborate_All requirement on the context of the 9494 -- main unit. Determine whether the context has a pragma strong enough 9495 -- to meet the requirement. 9496 9497 -- IMPORTANT: This check must be performed only when -gnatd.v (enforce 9498 -- SPARK elaboration rules in SPARK code) is active because the static 9499 -- model can ensure the prior elaboration of the unit which contains a 9500 -- body by installing an implicit Elaborate[_All] pragma. 9501 9502 if Debug_Flag_Dot_V then 9503 if Target_Attrs.From_Source 9504 or else Is_Ada_Semantic_Target (Target_Id) 9505 or else Is_SPARK_Semantic_Target (Target_Id) 9506 then 9507 Meet_Elaboration_Requirement 9508 (N => Call, 9509 Target_Id => Target_Id, 9510 Req_Nam => Name_Elaborate_All); 9511 end if; 9512 9513 -- Otherwise ensure that the unit with the target body is elaborated 9514 -- prior to the main unit. 9515 9516 else 9517 Ensure_Prior_Elaboration 9518 (N => Call, 9519 Unit_Id => Target_Attrs.Unit_Id, 9520 Prag_Nam => Name_Elaborate_All, 9521 State => State); 9522 end if; 9523 end Process_Conditional_ABE_Call_SPARK; 9524 9525 ------------------------------------------- 9526 -- Process_Conditional_ABE_Instantiation -- 9527 ------------------------------------------- 9528 9529 procedure Process_Conditional_ABE_Instantiation 9530 (Exp_Inst : Node_Id; 9531 State : Processing_Attributes) 9532 is 9533 Gen_Attrs : Target_Attributes; 9534 Gen_Id : Entity_Id; 9535 Inst : Node_Id; 9536 Inst_Attrs : Instantiation_Attributes; 9537 Inst_Id : Entity_Id; 9538 9539 SPARK_Rules_On : Boolean; 9540 -- This flag is set when the SPARK rules are in effect 9541 9542 begin 9543 Extract_Instantiation_Attributes 9544 (Exp_Inst => Exp_Inst, 9545 Inst => Inst, 9546 Inst_Id => Inst_Id, 9547 Gen_Id => Gen_Id, 9548 Attrs => Inst_Attrs); 9549 9550 Extract_Target_Attributes (Gen_Id, Gen_Attrs); 9551 9552 -- The SPARK rules are in effect when both the instantiation and generic 9553 -- are subject to SPARK_Mode On. 9554 9555 SPARK_Rules_On := Inst_Attrs.SPARK_Mode_On and Gen_Attrs.SPARK_Mode_On; 9556 9557 -- Output relevant information when switch -gnatel (info messages on 9558 -- implicit Elaborate[_All] pragmas) is in effect. 9559 9560 if Elab_Info_Messages then 9561 Info_Instantiation 9562 (Inst => Inst, 9563 Gen_Id => Gen_Id, 9564 Info_Msg => True, 9565 In_SPARK => SPARK_Rules_On); 9566 end if; 9567 9568 -- Nothing to do when the instantiation is a guaranteed ABE 9569 9570 if Is_Known_Guaranteed_ABE (Inst) then 9571 return; 9572 9573 -- Nothing to do when the root scenario appears at the declaration level 9574 -- and the generic is in the same unit, but outside this context. 9575 -- 9576 -- generic 9577 -- procedure Gen is ...; -- generic declaration 9578 -- 9579 -- procedure Proc is 9580 -- function A ... is 9581 -- begin 9582 -- if Some_Condition then 9583 -- declare 9584 -- procedure I is new Gen; -- instantiation site 9585 -- ... 9586 -- ... 9587 -- end A; 9588 -- 9589 -- X : ... := A; -- root scenario 9590 -- ... 9591 -- 9592 -- procedure Gen is 9593 -- ... 9594 -- end Gen; 9595 -- 9596 -- In the example above, the context of X is the declarative region of 9597 -- Proc. The "elaboration" of X may eventually reach Gen which appears 9598 -- outside of X's context. Gen is relevant only when Proc is invoked, 9599 -- but this happens only by means of "normal" elaboration, therefore 9600 -- Gen must not be considered if this is not the case. 9601 9602 -- Performance note: parent traversal 9603 9604 elsif Is_Up_Level_Target (Gen_Attrs.Spec_Decl) then 9605 return; 9606 9607 -- The SPARK rules are in effect 9608 9609 elsif SPARK_Rules_On then 9610 Process_Conditional_ABE_Instantiation_SPARK 9611 (Inst => Inst, 9612 Gen_Id => Gen_Id, 9613 Gen_Attrs => Gen_Attrs, 9614 State => State); 9615 9616 -- Otherwise the Ada rules are in effect, or SPARK code is allowed to 9617 -- violate the SPARK rules. 9618 9619 else 9620 Process_Conditional_ABE_Instantiation_Ada 9621 (Exp_Inst => Exp_Inst, 9622 Inst => Inst, 9623 Inst_Attrs => Inst_Attrs, 9624 Gen_Id => Gen_Id, 9625 Gen_Attrs => Gen_Attrs, 9626 State => State); 9627 end if; 9628 end Process_Conditional_ABE_Instantiation; 9629 9630 ----------------------------------------------- 9631 -- Process_Conditional_ABE_Instantiation_Ada -- 9632 ----------------------------------------------- 9633 9634 procedure Process_Conditional_ABE_Instantiation_Ada 9635 (Exp_Inst : Node_Id; 9636 Inst : Node_Id; 9637 Inst_Attrs : Instantiation_Attributes; 9638 Gen_Id : Entity_Id; 9639 Gen_Attrs : Target_Attributes; 9640 State : Processing_Attributes) 9641 is 9642 Check_OK : constant Boolean := 9643 not Inst_Attrs.Ghost_Mode_Ignore 9644 and then not Gen_Attrs.Ghost_Mode_Ignore 9645 and then Inst_Attrs.Elab_Checks_OK 9646 and then Gen_Attrs.Elab_Checks_OK; 9647 -- A run-time ABE check may be installed only when both the instance and 9648 -- the generic have active elaboration checks and both are not ignored 9649 -- Ghost constructs. 9650 9651 New_State : Processing_Attributes := State; 9652 -- Each step of the Processing phase constitutes a new state 9653 9654 Root : constant Node_Id := Root_Scenario; 9655 9656 begin 9657 -- Nothing to do when the instantiation is ABE-safe 9658 -- 9659 -- generic 9660 -- package Gen is 9661 -- ... 9662 -- end Gen; 9663 -- 9664 -- package body Gen is 9665 -- ... 9666 -- end Gen; 9667 -- 9668 -- with Gen; 9669 -- procedure Main is 9670 -- package Inst is new Gen (ABE); -- safe instantiation 9671 -- ... 9672 9673 if Is_Safe_Instantiation (Inst, Gen_Attrs) then 9674 return; 9675 9676 -- The instantiation and the generic body are both in the main unit 9677 9678 elsif Present (Gen_Attrs.Body_Decl) 9679 and then In_Extended_Main_Code_Unit (Gen_Attrs.Body_Decl) 9680 then 9681 -- If the root scenario appears prior to the generic body, then this 9682 -- is a possible ABE with respect to the root scenario. 9683 -- 9684 -- generic 9685 -- package Gen is 9686 -- ... 9687 -- end Gen; 9688 -- 9689 -- function A ... is 9690 -- begin 9691 -- if Some_Condition then 9692 -- declare 9693 -- package Inst is new Gen; -- instantiation site 9694 -- ... 9695 -- end A; 9696 -- 9697 -- X : ... := A; -- root scenario 9698 -- 9699 -- package body Gen is -- generic body 9700 -- ... 9701 -- end Gen; 9702 -- 9703 -- Y : ... := A; -- root scenario 9704 -- 9705 -- IMPORTANT: The instantiation of Gen is a possible ABE for X, but 9706 -- not for Y. Installing an unconditional ABE raise prior to the 9707 -- instance site would be wrong as it will fail for Y as well, but in 9708 -- Y's case the instantiation of Gen is never an ABE. 9709 9710 if Earlier_In_Extended_Unit (Root, Gen_Attrs.Body_Decl) then 9711 9712 -- Do not emit any ABE diagnostics when the instantiation occurs 9713 -- in partial finalization context because this leads to unwanted 9714 -- noise. 9715 9716 if State.Within_Partial_Finalization then 9717 null; 9718 9719 -- ABE diagnostics are emitted only in the static model because 9720 -- there is a well-defined order to visiting scenarios. Without 9721 -- this order diagnostics appear jumbled and result in unwanted 9722 -- noise. 9723 9724 elsif Static_Elaboration_Checks 9725 and then Inst_Attrs.Elab_Warnings_OK 9726 then 9727 Error_Msg_NE 9728 ("??cannot instantiate & before body seen", Inst, Gen_Id); 9729 Error_Msg_N ("\Program_Error may be raised at run time", Inst); 9730 9731 Output_Active_Scenarios (Inst); 9732 end if; 9733 9734 -- Install a conditional run-time ABE check to verify that the 9735 -- generic body has been elaborated prior to the instantiation. 9736 9737 if Check_OK then 9738 Install_ABE_Check 9739 (N => Inst, 9740 Ins_Nod => Exp_Inst, 9741 Target_Id => Gen_Attrs.Spec_Id, 9742 Target_Decl => Gen_Attrs.Spec_Decl, 9743 Target_Body => Gen_Attrs.Body_Decl); 9744 9745 -- Update the state of the Processing phase to indicate that 9746 -- no implicit Elaborate[_All] pragmas must be generated from 9747 -- this point on. 9748 -- 9749 -- generic 9750 -- package Gen is 9751 -- ... 9752 -- end Gen; 9753 -- 9754 -- function A ... is 9755 -- begin 9756 -- if Some_Condition then 9757 -- <ABE check> 9758 -- declare Inst is new Gen; 9759 -- ... 9760 -- end A; 9761 -- 9762 -- X : ... := A; 9763 -- 9764 -- package body Gen is 9765 -- begin 9766 -- External.Subp; -- imparts Elaborate_All 9767 -- end Gen; 9768 -- 9769 -- If Some_Condition is True, then the ABE check will fail at 9770 -- runtime and the call to External.Subp will never take place, 9771 -- rendering the implicit Elaborate_All useless. 9772 -- 9773 -- If Some_Condition is False, then the call to External.Subp 9774 -- will never take place, rendering the implicit Elaborate_All 9775 -- useless. 9776 9777 New_State.Suppress_Implicit_Pragmas := True; 9778 end if; 9779 end if; 9780 9781 -- Otherwise the generic body is not available in this compilation or it 9782 -- resides in an external unit. Install a run-time ABE check to verify 9783 -- that the generic body has been elaborated prior to the instantiation 9784 -- when the dynamic model is in effect. 9785 9786 elsif Dynamic_Elaboration_Checks and then Check_OK then 9787 Install_ABE_Check 9788 (N => Inst, 9789 Ins_Nod => Exp_Inst, 9790 Id => Gen_Attrs.Unit_Id); 9791 end if; 9792 9793 -- Ensure that the unit with the generic body is elaborated prior to 9794 -- the main unit. No implicit pragma is generated if the instantiation 9795 -- has elaboration checks suppressed. This behaviour parallels that of 9796 -- the old ABE mechanism. 9797 9798 if Inst_Attrs.Elab_Checks_OK then 9799 Ensure_Prior_Elaboration 9800 (N => Inst, 9801 Unit_Id => Gen_Attrs.Unit_Id, 9802 Prag_Nam => Name_Elaborate, 9803 State => New_State); 9804 end if; 9805 end Process_Conditional_ABE_Instantiation_Ada; 9806 9807 ------------------------------------------------- 9808 -- Process_Conditional_ABE_Instantiation_SPARK -- 9809 ------------------------------------------------- 9810 9811 procedure Process_Conditional_ABE_Instantiation_SPARK 9812 (Inst : Node_Id; 9813 Gen_Id : Entity_Id; 9814 Gen_Attrs : Target_Attributes; 9815 State : Processing_Attributes) 9816 is 9817 Req_Nam : Name_Id; 9818 9819 begin 9820 -- Ensure that a suitable elaboration model is in effect for SPARK rule 9821 -- verification. 9822 9823 Check_SPARK_Model_In_Effect (Inst); 9824 9825 -- A source instantiation imposes an Elaborate[_All] requirement on the 9826 -- context of the main unit. Determine whether the context has a pragma 9827 -- strong enough to meet the requirement. The check is orthogonal to the 9828 -- ABE ramifications of the instantiation. 9829 9830 -- IMPORTANT: This check must be performed only when -gnatd.v (enforce 9831 -- SPARK elaboration rules in SPARK code) is active because the static 9832 -- model can ensure the prior elaboration of the unit which contains a 9833 -- body by installing an implicit Elaborate[_All] pragma. 9834 9835 if Debug_Flag_Dot_V then 9836 if Nkind (Inst) = N_Package_Instantiation then 9837 Req_Nam := Name_Elaborate_All; 9838 else 9839 Req_Nam := Name_Elaborate; 9840 end if; 9841 9842 Meet_Elaboration_Requirement 9843 (N => Inst, 9844 Target_Id => Gen_Id, 9845 Req_Nam => Req_Nam); 9846 9847 -- Otherwise ensure that the unit with the target body is elaborated 9848 -- prior to the main unit. 9849 9850 else 9851 Ensure_Prior_Elaboration 9852 (N => Inst, 9853 Unit_Id => Gen_Attrs.Unit_Id, 9854 Prag_Nam => Name_Elaborate, 9855 State => State); 9856 end if; 9857 end Process_Conditional_ABE_Instantiation_SPARK; 9858 9859 ------------------------------------------------- 9860 -- Process_Conditional_ABE_Variable_Assignment -- 9861 ------------------------------------------------- 9862 9863 procedure Process_Conditional_ABE_Variable_Assignment (Asmt : Node_Id) is 9864 Var_Id : constant Entity_Id := Entity (Extract_Assignment_Name (Asmt)); 9865 Prag : constant Node_Id := SPARK_Pragma (Var_Id); 9866 9867 SPARK_Rules_On : Boolean; 9868 -- This flag is set when the SPARK rules are in effect 9869 9870 begin 9871 -- The SPARK rules are in effect when both the assignment and the 9872 -- variable are subject to SPARK_Mode On. 9873 9874 SPARK_Rules_On := 9875 Present (Prag) 9876 and then Get_SPARK_Mode_From_Annotation (Prag) = On 9877 and then Is_SPARK_Mode_On_Node (Asmt); 9878 9879 -- Output relevant information when switch -gnatel (info messages on 9880 -- implicit Elaborate[_All] pragmas) is in effect. 9881 9882 if Elab_Info_Messages then 9883 Elab_Msg_NE 9884 (Msg => "assignment to & during elaboration", 9885 N => Asmt, 9886 Id => Var_Id, 9887 Info_Msg => True, 9888 In_SPARK => SPARK_Rules_On); 9889 end if; 9890 9891 -- The SPARK rules are in effect. These rules are applied regardless of 9892 -- whether -gnatd.v (enforce SPARK elaboration rules in SPARK code) is 9893 -- in effect because the static model cannot ensure safe assignment of 9894 -- variables. 9895 9896 if SPARK_Rules_On then 9897 Process_Conditional_ABE_Variable_Assignment_SPARK 9898 (Asmt => Asmt, 9899 Var_Id => Var_Id); 9900 9901 -- Otherwise the Ada rules are in effect 9902 9903 else 9904 Process_Conditional_ABE_Variable_Assignment_Ada 9905 (Asmt => Asmt, 9906 Var_Id => Var_Id); 9907 end if; 9908 end Process_Conditional_ABE_Variable_Assignment; 9909 9910 ----------------------------------------------------- 9911 -- Process_Conditional_ABE_Variable_Assignment_Ada -- 9912 ----------------------------------------------------- 9913 9914 procedure Process_Conditional_ABE_Variable_Assignment_Ada 9915 (Asmt : Node_Id; 9916 Var_Id : Entity_Id) 9917 is 9918 Var_Decl : constant Node_Id := Declaration_Node (Var_Id); 9919 Spec_Id : constant Entity_Id := Find_Top_Unit (Var_Decl); 9920 9921 begin 9922 -- Emit a warning when an uninitialized variable declared in a package 9923 -- spec without a pragma Elaborate_Body is initialized by elaboration 9924 -- code within the corresponding body. 9925 9926 if not Warnings_Off (Var_Id) 9927 and then not Is_Initialized (Var_Decl) 9928 and then not Has_Pragma_Elaborate_Body (Spec_Id) 9929 then 9930 Error_Msg_NE 9931 ("??variable & can be accessed by clients before this " 9932 & "initialization", Asmt, Var_Id); 9933 9934 Error_Msg_NE 9935 ("\add pragma ""Elaborate_Body"" to spec & to ensure proper " 9936 & "initialization", Asmt, Spec_Id); 9937 9938 Output_Active_Scenarios (Asmt); 9939 9940 -- Generate an implicit Elaborate_Body in the spec 9941 9942 Set_Elaborate_Body_Desirable (Spec_Id); 9943 end if; 9944 end Process_Conditional_ABE_Variable_Assignment_Ada; 9945 9946 ------------------------------------------------------- 9947 -- Process_Conditional_ABE_Variable_Assignment_SPARK -- 9948 ------------------------------------------------------- 9949 9950 procedure Process_Conditional_ABE_Variable_Assignment_SPARK 9951 (Asmt : Node_Id; 9952 Var_Id : Entity_Id) 9953 is 9954 Var_Decl : constant Node_Id := Declaration_Node (Var_Id); 9955 Spec_Id : constant Entity_Id := Find_Top_Unit (Var_Decl); 9956 9957 begin 9958 -- Ensure that a suitable elaboration model is in effect for SPARK rule 9959 -- verification. 9960 9961 Check_SPARK_Model_In_Effect (Asmt); 9962 9963 -- Emit an error when an initialized variable declared in a package spec 9964 -- without pragma Elaborate_Body is further modified by elaboration code 9965 -- within the corresponding body. 9966 9967 if Is_Initialized (Var_Decl) 9968 and then not Has_Pragma_Elaborate_Body (Spec_Id) 9969 then 9970 Error_Msg_NE 9971 ("variable & modified by elaboration code in package body", 9972 Asmt, Var_Id); 9973 9974 Error_Msg_NE 9975 ("\add pragma ""Elaborate_Body"" to spec & to ensure full " 9976 & "initialization", Asmt, Spec_Id); 9977 9978 Output_Active_Scenarios (Asmt); 9979 end if; 9980 end Process_Conditional_ABE_Variable_Assignment_SPARK; 9981 9982 ------------------------------------------------ 9983 -- Process_Conditional_ABE_Variable_Reference -- 9984 ------------------------------------------------ 9985 9986 procedure Process_Conditional_ABE_Variable_Reference (Ref : Node_Id) is 9987 Var_Attrs : Variable_Attributes; 9988 Var_Id : Entity_Id; 9989 9990 begin 9991 Extract_Variable_Reference_Attributes 9992 (Ref => Ref, 9993 Var_Id => Var_Id, 9994 Attrs => Var_Attrs); 9995 9996 if Is_Read (Ref) then 9997 Process_Conditional_ABE_Variable_Reference_Read 9998 (Ref => Ref, 9999 Var_Id => Var_Id, 10000 Attrs => Var_Attrs); 10001 end if; 10002 end Process_Conditional_ABE_Variable_Reference; 10003 10004 ----------------------------------------------------- 10005 -- Process_Conditional_ABE_Variable_Reference_Read -- 10006 ----------------------------------------------------- 10007 10008 procedure Process_Conditional_ABE_Variable_Reference_Read 10009 (Ref : Node_Id; 10010 Var_Id : Entity_Id; 10011 Attrs : Variable_Attributes) 10012 is 10013 begin 10014 -- Output relevant information when switch -gnatel (info messages on 10015 -- implicit Elaborate[_All] pragmas) is in effect. 10016 10017 if Elab_Info_Messages then 10018 Elab_Msg_NE 10019 (Msg => "read of variable & during elaboration", 10020 N => Ref, 10021 Id => Var_Id, 10022 Info_Msg => True, 10023 In_SPARK => True); 10024 end if; 10025 10026 -- Nothing to do when the variable appears within the main unit because 10027 -- diagnostics on reads are relevant only for external variables. 10028 10029 if Is_Same_Unit (Attrs.Unit_Id, Cunit_Entity (Main_Unit)) then 10030 null; 10031 10032 -- Nothing to do when the variable is already initialized. Note that the 10033 -- variable may be further modified by the external unit. 10034 10035 elsif Is_Initialized (Declaration_Node (Var_Id)) then 10036 null; 10037 10038 -- Nothing to do when the external unit guarantees the initialization of 10039 -- the variable by means of pragma Elaborate_Body. 10040 10041 elsif Has_Pragma_Elaborate_Body (Attrs.Unit_Id) then 10042 null; 10043 10044 -- A variable read imposes an Elaborate requirement on the context of 10045 -- the main unit. Determine whether the context has a pragma strong 10046 -- enough to meet the requirement. 10047 10048 else 10049 Meet_Elaboration_Requirement 10050 (N => Ref, 10051 Target_Id => Var_Id, 10052 Req_Nam => Name_Elaborate); 10053 end if; 10054 end Process_Conditional_ABE_Variable_Reference_Read; 10055 10056 ----------------------------- 10057 -- Process_Conditional_ABE -- 10058 ----------------------------- 10059 10060 -- NOTE: The body of this routine is intentionally out of order because it 10061 -- invokes an instantiated subprogram (Process_Conditional_ABE_Activation). 10062 -- Placing the body in alphabetical order will result in a guaranteed ABE. 10063 10064 procedure Process_Conditional_ABE 10065 (N : Node_Id; 10066 State : Processing_Attributes := Initial_State) 10067 is 10068 Call_Attrs : Call_Attributes; 10069 Target_Id : Entity_Id; 10070 10071 begin 10072 -- Add the current scenario to the stack of active scenarios 10073 10074 Push_Active_Scenario (N); 10075 10076 -- 'Access 10077 10078 if Is_Suitable_Access (N) then 10079 Process_Conditional_ABE_Access 10080 (Attr => N, 10081 State => State); 10082 10083 -- Activations and calls 10084 10085 elsif Is_Suitable_Call (N) then 10086 10087 -- In general, only calls found within the main unit are processed 10088 -- because the ALI information supplied to binde is for the main 10089 -- unit only. However, to preserve the consistency of the tree and 10090 -- ensure proper serialization of internal names, external calls 10091 -- also receive corresponding call markers (see Build_Call_Marker). 10092 -- Regardless of the reason, external calls must not be processed. 10093 10094 if In_Main_Context (N) then 10095 Extract_Call_Attributes 10096 (Call => N, 10097 Target_Id => Target_Id, 10098 Attrs => Call_Attrs); 10099 10100 if Is_Activation_Proc (Target_Id) then 10101 Process_Conditional_ABE_Activation 10102 (Call => N, 10103 Call_Attrs => Call_Attrs, 10104 State => State); 10105 10106 else 10107 Process_Conditional_ABE_Call 10108 (Call => N, 10109 Call_Attrs => Call_Attrs, 10110 Target_Id => Target_Id, 10111 State => State); 10112 end if; 10113 end if; 10114 10115 -- Instantiations 10116 10117 elsif Is_Suitable_Instantiation (N) then 10118 Process_Conditional_ABE_Instantiation 10119 (Exp_Inst => N, 10120 State => State); 10121 10122 -- Variable assignments 10123 10124 elsif Is_Suitable_Variable_Assignment (N) then 10125 Process_Conditional_ABE_Variable_Assignment (N); 10126 10127 -- Variable references 10128 10129 elsif Is_Suitable_Variable_Reference (N) then 10130 10131 -- In general, only variable references found within the main unit 10132 -- are processed because the ALI information supplied to binde is for 10133 -- the main unit only. However, to preserve the consistency of the 10134 -- tree and ensure proper serialization of internal names, external 10135 -- variable references also receive corresponding variable reference 10136 -- markers (see Build_Varaible_Reference_Marker). Regardless of the 10137 -- reason, external variable references must not be processed. 10138 10139 if In_Main_Context (N) then 10140 Process_Conditional_ABE_Variable_Reference (N); 10141 end if; 10142 end if; 10143 10144 -- Remove the current scenario from the stack of active scenarios once 10145 -- all ABE diagnostics and checks have been performed. 10146 10147 Pop_Active_Scenario (N); 10148 end Process_Conditional_ABE; 10149 10150 -------------------------------------------- 10151 -- Process_Guaranteed_ABE_Activation_Impl -- 10152 -------------------------------------------- 10153 10154 procedure Process_Guaranteed_ABE_Activation_Impl 10155 (Call : Node_Id; 10156 Call_Attrs : Call_Attributes; 10157 Obj_Id : Entity_Id; 10158 Task_Attrs : Task_Attributes; 10159 State : Processing_Attributes) 10160 is 10161 pragma Unreferenced (State); 10162 10163 Check_OK : constant Boolean := 10164 not Is_Ignored_Ghost_Entity (Obj_Id) 10165 and then not Task_Attrs.Ghost_Mode_Ignore 10166 and then Is_Elaboration_Checks_OK_Id (Obj_Id) 10167 and then Task_Attrs.Elab_Checks_OK; 10168 -- A run-time ABE check may be installed only when the object and the 10169 -- task type have active elaboration checks, and both are not ignored 10170 -- Ghost constructs. 10171 10172 begin 10173 -- Nothing to do when the root scenario appears at the declaration 10174 -- level and the task is in the same unit, but outside this context. 10175 -- 10176 -- task type Task_Typ; -- task declaration 10177 -- 10178 -- procedure Proc is 10179 -- function A ... is 10180 -- begin 10181 -- if Some_Condition then 10182 -- declare 10183 -- T : Task_Typ; 10184 -- begin 10185 -- <activation call> -- activation site 10186 -- end; 10187 -- ... 10188 -- end A; 10189 -- 10190 -- X : ... := A; -- root scenario 10191 -- ... 10192 -- 10193 -- task body Task_Typ is 10194 -- ... 10195 -- end Task_Typ; 10196 -- 10197 -- In the example above, the context of X is the declarative list of 10198 -- Proc. The "elaboration" of X may reach the activation of T whose body 10199 -- is defined outside of X's context. The task body is relevant only 10200 -- when Proc is invoked, but this happens only in "normal" elaboration, 10201 -- therefore the task body must not be considered if this is not the 10202 -- case. 10203 10204 -- Performance note: parent traversal 10205 10206 if Is_Up_Level_Target (Task_Attrs.Task_Decl) then 10207 return; 10208 10209 -- Nothing to do when the activation is ABE-safe 10210 -- 10211 -- generic 10212 -- package Gen is 10213 -- task type Task_Typ; 10214 -- end Gen; 10215 -- 10216 -- package body Gen is 10217 -- task body Task_Typ is 10218 -- begin 10219 -- ... 10220 -- end Task_Typ; 10221 -- end Gen; 10222 -- 10223 -- with Gen; 10224 -- procedure Main is 10225 -- package Nested is 10226 -- package Inst is new Gen; 10227 -- T : Inst.Task_Typ; 10228 -- end Nested; -- safe activation 10229 -- ... 10230 10231 elsif Is_Safe_Activation (Call, Task_Attrs.Task_Decl) then 10232 return; 10233 10234 -- An activation call leads to a guaranteed ABE when the activation 10235 -- call and the task appear within the same context ignoring library 10236 -- levels, and the body of the task has not been seen yet or appears 10237 -- after the activation call. 10238 -- 10239 -- procedure Guaranteed_ABE is 10240 -- task type Task_Typ; 10241 -- 10242 -- package Nested is 10243 -- T : Task_Typ; 10244 -- <activation call> -- guaranteed ABE 10245 -- end Nested; 10246 -- 10247 -- task body Task_Typ is 10248 -- ... 10249 -- end Task_Typ; 10250 -- ... 10251 10252 -- Performance note: parent traversal 10253 10254 elsif Is_Guaranteed_ABE 10255 (N => Call, 10256 Target_Decl => Task_Attrs.Task_Decl, 10257 Target_Body => Task_Attrs.Body_Decl) 10258 then 10259 if Call_Attrs.Elab_Warnings_OK then 10260 Error_Msg_Sloc := Sloc (Call); 10261 Error_Msg_N 10262 ("??task & will be activated # before elaboration of its body", 10263 Obj_Id); 10264 Error_Msg_N ("\Program_Error will be raised at run time", Obj_Id); 10265 end if; 10266 10267 -- Mark the activation call as a guaranteed ABE 10268 10269 Set_Is_Known_Guaranteed_ABE (Call); 10270 10271 -- Install a run-time ABE failue because this activation call will 10272 -- always result in an ABE. 10273 10274 if Check_OK then 10275 Install_ABE_Failure 10276 (N => Call, 10277 Ins_Nod => Call); 10278 end if; 10279 end if; 10280 end Process_Guaranteed_ABE_Activation_Impl; 10281 10282 procedure Process_Guaranteed_ABE_Activation is 10283 new Process_Activation_Generic (Process_Guaranteed_ABE_Activation_Impl); 10284 10285 --------------------------------- 10286 -- Process_Guaranteed_ABE_Call -- 10287 --------------------------------- 10288 10289 procedure Process_Guaranteed_ABE_Call 10290 (Call : Node_Id; 10291 Call_Attrs : Call_Attributes; 10292 Target_Id : Entity_Id) 10293 is 10294 Target_Attrs : Target_Attributes; 10295 10296 begin 10297 Extract_Target_Attributes 10298 (Target_Id => Target_Id, 10299 Attrs => Target_Attrs); 10300 10301 -- Nothing to do when the root scenario appears at the declaration level 10302 -- and the target is in the same unit, but outside this context. 10303 -- 10304 -- function B ...; -- target declaration 10305 -- 10306 -- procedure Proc is 10307 -- function A ... is 10308 -- begin 10309 -- if Some_Condition then 10310 -- return B; -- call site 10311 -- ... 10312 -- end A; 10313 -- 10314 -- X : ... := A; -- root scenario 10315 -- ... 10316 -- 10317 -- function B ... is 10318 -- ... 10319 -- end B; 10320 -- 10321 -- In the example above, the context of X is the declarative region of 10322 -- Proc. The "elaboration" of X may eventually reach B which is defined 10323 -- outside of X's context. B is relevant only when Proc is invoked, but 10324 -- this happens only by means of "normal" elaboration, therefore B must 10325 -- not be considered if this is not the case. 10326 10327 -- Performance note: parent traversal 10328 10329 if Is_Up_Level_Target (Target_Attrs.Spec_Decl) then 10330 return; 10331 10332 -- Nothing to do when the call is ABE-safe 10333 -- 10334 -- generic 10335 -- function Gen ...; 10336 -- 10337 -- function Gen ... is 10338 -- begin 10339 -- ... 10340 -- end Gen; 10341 -- 10342 -- with Gen; 10343 -- procedure Main is 10344 -- function Inst is new Gen; 10345 -- X : ... := Inst; -- safe call 10346 -- ... 10347 10348 elsif Is_Safe_Call (Call, Target_Attrs) then 10349 return; 10350 10351 -- A call leads to a guaranteed ABE when the call and the target appear 10352 -- within the same context ignoring library levels, and the body of the 10353 -- target has not been seen yet or appears after the call. 10354 -- 10355 -- procedure Guaranteed_ABE is 10356 -- function Func ...; 10357 -- 10358 -- package Nested is 10359 -- Obj : ... := Func; -- guaranteed ABE 10360 -- end Nested; 10361 -- 10362 -- function Func ... is 10363 -- ... 10364 -- end Func; 10365 -- ... 10366 10367 -- Performance note: parent traversal 10368 10369 elsif Is_Guaranteed_ABE 10370 (N => Call, 10371 Target_Decl => Target_Attrs.Spec_Decl, 10372 Target_Body => Target_Attrs.Body_Decl) 10373 then 10374 if Call_Attrs.Elab_Warnings_OK then 10375 Error_Msg_NE ("??cannot call & before body seen", Call, Target_Id); 10376 Error_Msg_N ("\Program_Error will be raised at run time", Call); 10377 end if; 10378 10379 -- Mark the call as a guarnateed ABE 10380 10381 Set_Is_Known_Guaranteed_ABE (Call); 10382 10383 -- Install a run-time ABE failure because the call will always result 10384 -- in an ABE. The failure is installed when both the call and target 10385 -- have enabled elaboration checks, and both are not ignored Ghost 10386 -- constructs. 10387 10388 if Call_Attrs.Elab_Checks_OK 10389 and then Target_Attrs.Elab_Checks_OK 10390 and then not Call_Attrs.Ghost_Mode_Ignore 10391 and then not Target_Attrs.Ghost_Mode_Ignore 10392 then 10393 Install_ABE_Failure 10394 (N => Call, 10395 Ins_Nod => Call); 10396 end if; 10397 end if; 10398 end Process_Guaranteed_ABE_Call; 10399 10400 ------------------------------------------ 10401 -- Process_Guaranteed_ABE_Instantiation -- 10402 ------------------------------------------ 10403 10404 procedure Process_Guaranteed_ABE_Instantiation (Exp_Inst : Node_Id) is 10405 Gen_Attrs : Target_Attributes; 10406 Gen_Id : Entity_Id; 10407 Inst : Node_Id; 10408 Inst_Attrs : Instantiation_Attributes; 10409 Inst_Id : Entity_Id; 10410 10411 begin 10412 Extract_Instantiation_Attributes 10413 (Exp_Inst => Exp_Inst, 10414 Inst => Inst, 10415 Inst_Id => Inst_Id, 10416 Gen_Id => Gen_Id, 10417 Attrs => Inst_Attrs); 10418 10419 Extract_Target_Attributes (Gen_Id, Gen_Attrs); 10420 10421 -- Nothing to do when the root scenario appears at the declaration level 10422 -- and the generic is in the same unit, but outside this context. 10423 -- 10424 -- generic 10425 -- procedure Gen is ...; -- generic declaration 10426 -- 10427 -- procedure Proc is 10428 -- function A ... is 10429 -- begin 10430 -- if Some_Condition then 10431 -- declare 10432 -- procedure I is new Gen; -- instantiation site 10433 -- ... 10434 -- ... 10435 -- end A; 10436 -- 10437 -- X : ... := A; -- root scenario 10438 -- ... 10439 -- 10440 -- procedure Gen is 10441 -- ... 10442 -- end Gen; 10443 -- 10444 -- In the example above, the context of X is the declarative region of 10445 -- Proc. The "elaboration" of X may eventually reach Gen which appears 10446 -- outside of X's context. Gen is relevant only when Proc is invoked, 10447 -- but this happens only by means of "normal" elaboration, therefore 10448 -- Gen must not be considered if this is not the case. 10449 10450 -- Performance note: parent traversal 10451 10452 if Is_Up_Level_Target (Gen_Attrs.Spec_Decl) then 10453 return; 10454 10455 -- Nothing to do when the instantiation is ABE-safe 10456 -- 10457 -- generic 10458 -- package Gen is 10459 -- ... 10460 -- end Gen; 10461 -- 10462 -- package body Gen is 10463 -- ... 10464 -- end Gen; 10465 -- 10466 -- with Gen; 10467 -- procedure Main is 10468 -- package Inst is new Gen (ABE); -- safe instantiation 10469 -- ... 10470 10471 elsif Is_Safe_Instantiation (Inst, Gen_Attrs) then 10472 return; 10473 10474 -- An instantiation leads to a guaranteed ABE when the instantiation and 10475 -- the generic appear within the same context ignoring library levels, 10476 -- and the body of the generic has not been seen yet or appears after 10477 -- the instantiation. 10478 -- 10479 -- procedure Guaranteed_ABE is 10480 -- generic 10481 -- procedure Gen; 10482 -- 10483 -- package Nested is 10484 -- procedure Inst is new Gen; -- guaranteed ABE 10485 -- end Nested; 10486 -- 10487 -- procedure Gen is 10488 -- ... 10489 -- end Gen; 10490 -- ... 10491 10492 -- Performance note: parent traversal 10493 10494 elsif Is_Guaranteed_ABE 10495 (N => Inst, 10496 Target_Decl => Gen_Attrs.Spec_Decl, 10497 Target_Body => Gen_Attrs.Body_Decl) 10498 then 10499 if Inst_Attrs.Elab_Warnings_OK then 10500 Error_Msg_NE 10501 ("??cannot instantiate & before body seen", Inst, Gen_Id); 10502 Error_Msg_N ("\Program_Error will be raised at run time", Inst); 10503 end if; 10504 10505 -- Mark the instantiation as a guarantee ABE. This automatically 10506 -- suppresses the instantiation of the generic body. 10507 10508 Set_Is_Known_Guaranteed_ABE (Inst); 10509 10510 -- Install a run-time ABE failure because the instantiation will 10511 -- always result in an ABE. The failure is installed when both the 10512 -- instance and the generic have enabled elaboration checks, and both 10513 -- are not ignored Ghost constructs. 10514 10515 if Inst_Attrs.Elab_Checks_OK 10516 and then Gen_Attrs.Elab_Checks_OK 10517 and then not Inst_Attrs.Ghost_Mode_Ignore 10518 and then not Gen_Attrs.Ghost_Mode_Ignore 10519 then 10520 Install_ABE_Failure 10521 (N => Inst, 10522 Ins_Nod => Exp_Inst); 10523 end if; 10524 end if; 10525 end Process_Guaranteed_ABE_Instantiation; 10526 10527 ---------------------------- 10528 -- Process_Guaranteed_ABE -- 10529 ---------------------------- 10530 10531 -- NOTE: The body of this routine is intentionally out of order because it 10532 -- invokes an instantiated subprogram (Process_Guaranteed_ABE_Activation). 10533 -- Placing the body in alphabetical order will result in a guaranteed ABE. 10534 10535 procedure Process_Guaranteed_ABE (N : Node_Id) is 10536 Call_Attrs : Call_Attributes; 10537 Target_Id : Entity_Id; 10538 10539 begin 10540 -- Add the current scenario to the stack of active scenarios 10541 10542 Push_Active_Scenario (N); 10543 10544 -- Only calls, instantiations, and task activations may result in a 10545 -- guaranteed ABE. 10546 10547 if Is_Suitable_Call (N) then 10548 Extract_Call_Attributes 10549 (Call => N, 10550 Target_Id => Target_Id, 10551 Attrs => Call_Attrs); 10552 10553 if Is_Activation_Proc (Target_Id) then 10554 Process_Guaranteed_ABE_Activation 10555 (Call => N, 10556 Call_Attrs => Call_Attrs, 10557 State => Initial_State); 10558 10559 else 10560 Process_Guaranteed_ABE_Call 10561 (Call => N, 10562 Call_Attrs => Call_Attrs, 10563 Target_Id => Target_Id); 10564 end if; 10565 10566 elsif Is_Suitable_Instantiation (N) then 10567 Process_Guaranteed_ABE_Instantiation (N); 10568 end if; 10569 10570 -- Remove the current scenario from the stack of active scenarios once 10571 -- all ABE diagnostics and checks have been performed. 10572 10573 Pop_Active_Scenario (N); 10574 end Process_Guaranteed_ABE; 10575 10576 -------------------------- 10577 -- Push_Active_Scenario -- 10578 -------------------------- 10579 10580 procedure Push_Active_Scenario (N : Node_Id) is 10581 begin 10582 Scenario_Stack.Append (N); 10583 end Push_Active_Scenario; 10584 10585 --------------------------------- 10586 -- Record_Elaboration_Scenario -- 10587 --------------------------------- 10588 10589 procedure Record_Elaboration_Scenario (N : Node_Id) is 10590 Level : Enclosing_Level_Kind; 10591 10592 Any_Level_OK : Boolean; 10593 -- This flag is set when a particular scenario is allowed to appear at 10594 -- any level. 10595 10596 Declaration_Level_OK : Boolean; 10597 -- This flag is set when a particular scenario is allowed to appear at 10598 -- the declaration level. 10599 10600 Library_Level_OK : Boolean; 10601 -- This flag is set when a particular scenario is allowed to appear at 10602 -- the library level. 10603 10604 begin 10605 -- Assume that the scenario cannot appear on any level 10606 10607 Any_Level_OK := False; 10608 Declaration_Level_OK := False; 10609 Library_Level_OK := False; 10610 10611 -- Nothing to do when switch -gnatH (legacy elaboration checking mode 10612 -- enabled) is in effect because the legacy ABE mechanism does not need 10613 -- to carry out this action. 10614 10615 if Legacy_Elaboration_Checks then 10616 return; 10617 10618 -- Nothing to do for ASIS. As a result, no ABE checks and diagnostics 10619 -- are performed in this mode. 10620 10621 elsif ASIS_Mode then 10622 return; 10623 10624 -- Nothing to do when the scenario is being preanalyzed 10625 10626 elsif Preanalysis_Active then 10627 return; 10628 end if; 10629 10630 -- Ensure that a library-level call does not appear in a preelaborated 10631 -- unit. The check must come before ignoring scenarios within external 10632 -- units or inside generics because calls in those context must also be 10633 -- verified. 10634 10635 if Is_Suitable_Call (N) then 10636 Check_Preelaborated_Call (N); 10637 end if; 10638 10639 -- Nothing to do when the scenario does not appear within the main unit 10640 10641 if not In_Main_Context (N) then 10642 return; 10643 10644 -- Scenarios within a generic unit are never considered because generics 10645 -- cannot be elaborated. 10646 10647 elsif Inside_A_Generic then 10648 return; 10649 10650 -- Scenarios which do not fall in one of the elaboration categories 10651 -- listed below are not considered. The categories are: 10652 10653 -- 'Access for entries, operators, and subprograms 10654 -- Assignments to variables 10655 -- Calls (includes task activation) 10656 -- Derived types 10657 -- Instantiations 10658 -- Pragma Refined_State 10659 -- Reads of variables 10660 10661 elsif Is_Suitable_Access (N) then 10662 Library_Level_OK := True; 10663 10664 -- Signal any enclosing local exception handlers that the 'Access may 10665 -- raise Program_Error due to a failed ABE check when switch -gnatd.o 10666 -- (conservative elaboration order for indirect calls) is in effect. 10667 -- Marking the exception handlers ensures proper expansion by both 10668 -- the front and back end restriction when No_Exception_Propagation 10669 -- is in effect. 10670 10671 if Debug_Flag_Dot_O then 10672 Possible_Local_Raise (N, Standard_Program_Error); 10673 end if; 10674 10675 elsif Is_Suitable_Call (N) or else Is_Suitable_Instantiation (N) then 10676 Declaration_Level_OK := True; 10677 Library_Level_OK := True; 10678 10679 -- Signal any enclosing local exception handlers that the call or 10680 -- instantiation may raise Program_Error due to a failed ABE check. 10681 -- Marking the exception handlers ensures proper expansion by both 10682 -- the front and back end restriction when No_Exception_Propagation 10683 -- is in effect. 10684 10685 Possible_Local_Raise (N, Standard_Program_Error); 10686 10687 elsif Is_Suitable_SPARK_Derived_Type (N) then 10688 Any_Level_OK := True; 10689 10690 elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then 10691 Library_Level_OK := True; 10692 10693 elsif Is_Suitable_Variable_Assignment (N) 10694 or else Is_Suitable_Variable_Reference (N) 10695 then 10696 Library_Level_OK := True; 10697 10698 -- Otherwise the input does not denote a suitable scenario 10699 10700 else 10701 return; 10702 end if; 10703 10704 -- The static model imposes additional restrictions on the placement of 10705 -- scenarios. In contrast, the dynamic model assumes that every scenario 10706 -- will be elaborated or invoked at some point. 10707 10708 if Static_Elaboration_Checks then 10709 10710 -- Certain scenarios are allowed to appear at any level. This check 10711 -- is performed here in order to save on a parent traversal. 10712 10713 if Any_Level_OK then 10714 null; 10715 10716 -- Otherwise the scenario must appear at a specific level 10717 10718 else 10719 -- Performance note: parent traversal 10720 10721 Level := Find_Enclosing_Level (N); 10722 10723 -- Declaration-level scenario 10724 10725 if Declaration_Level_OK and then Level = Declaration_Level then 10726 null; 10727 10728 -- Library-level or instantiation scenario 10729 10730 elsif Library_Level_OK 10731 and then Level in Library_Or_Instantiation_Level 10732 then 10733 null; 10734 10735 -- Otherwise the scenario does not appear at the proper level and 10736 -- cannot possibly act as a top-level scenario. 10737 10738 else 10739 return; 10740 end if; 10741 end if; 10742 end if; 10743 10744 -- Derived types subject to SPARK_Mode On require elaboration-related 10745 -- checks even though the type may not be declared within elaboration 10746 -- code. The types are recorded in a separate table which is examined 10747 -- during the Processing phase. Note that the checks must be delayed 10748 -- because the bodies of overriding primitives are not available yet. 10749 10750 if Is_Suitable_SPARK_Derived_Type (N) then 10751 Record_SPARK_Elaboration_Scenario (N); 10752 10753 -- Nothing left to do for derived types 10754 10755 return; 10756 10757 -- Instantiations of generics both subject to SPARK_Mode On require 10758 -- elaboration-related checks even though the instantiations may not 10759 -- appear within elaboration code. The instantiations are recored in 10760 -- a separate table which is examined during the Procesing phase. Note 10761 -- that the checks must be delayed because it is not known yet whether 10762 -- the generic unit has a body or not. 10763 10764 -- IMPORTANT: A SPARK instantiation is also a normal instantiation which 10765 -- is subject to common conditional and guaranteed ABE checks. 10766 10767 elsif Is_Suitable_SPARK_Instantiation (N) then 10768 Record_SPARK_Elaboration_Scenario (N); 10769 10770 -- External constituents that refine abstract states which appear in 10771 -- pragma Initializes require elaboration-related checks even though 10772 -- a Refined_State pragma lacks any elaboration semantic. 10773 10774 elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then 10775 Record_SPARK_Elaboration_Scenario (N); 10776 10777 -- Nothing left to do for pragma Refined_State 10778 10779 return; 10780 end if; 10781 10782 -- Perform early detection of guaranteed ABEs in order to suppress the 10783 -- instantiation of generic bodies as gigi cannot handle certain types 10784 -- of premature instantiations. 10785 10786 Process_Guaranteed_ABE (N); 10787 10788 -- At this point all checks have been performed. Record the scenario for 10789 -- later processing by the ABE phase. 10790 10791 Top_Level_Scenarios.Append (N); 10792 Set_Is_Recorded_Top_Level_Scenario (N); 10793 end Record_Elaboration_Scenario; 10794 10795 --------------------------------------- 10796 -- Record_SPARK_Elaboration_Scenario -- 10797 --------------------------------------- 10798 10799 procedure Record_SPARK_Elaboration_Scenario (N : Node_Id) is 10800 begin 10801 SPARK_Scenarios.Append (N); 10802 Set_Is_Recorded_SPARK_Scenario (N); 10803 end Record_SPARK_Elaboration_Scenario; 10804 10805 ----------------------------------- 10806 -- Recorded_SPARK_Scenarios_Hash -- 10807 ----------------------------------- 10808 10809 function Recorded_SPARK_Scenarios_Hash 10810 (Key : Node_Id) return Recorded_SPARK_Scenarios_Index 10811 is 10812 begin 10813 return 10814 Recorded_SPARK_Scenarios_Index (Key mod Recorded_SPARK_Scenarios_Max); 10815 end Recorded_SPARK_Scenarios_Hash; 10816 10817 --------------------------------------- 10818 -- Recorded_Top_Level_Scenarios_Hash -- 10819 --------------------------------------- 10820 10821 function Recorded_Top_Level_Scenarios_Hash 10822 (Key : Node_Id) return Recorded_Top_Level_Scenarios_Index 10823 is 10824 begin 10825 return 10826 Recorded_Top_Level_Scenarios_Index 10827 (Key mod Recorded_Top_Level_Scenarios_Max); 10828 end Recorded_Top_Level_Scenarios_Hash; 10829 10830 -------------------------- 10831 -- Reset_Visited_Bodies -- 10832 -------------------------- 10833 10834 procedure Reset_Visited_Bodies is 10835 begin 10836 if Visited_Bodies_In_Use then 10837 Visited_Bodies_In_Use := False; 10838 Visited_Bodies.Reset; 10839 end if; 10840 end Reset_Visited_Bodies; 10841 10842 ------------------- 10843 -- Root_Scenario -- 10844 ------------------- 10845 10846 function Root_Scenario return Node_Id is 10847 package Stack renames Scenario_Stack; 10848 10849 begin 10850 -- Ensure that the scenario stack has at least one active scenario in 10851 -- it. The one at the bottom (index First) is the root scenario. 10852 10853 pragma Assert (Stack.Last >= Stack.First); 10854 return Stack.Table (Stack.First); 10855 end Root_Scenario; 10856 10857 --------------------------- 10858 -- Set_Early_Call_Region -- 10859 --------------------------- 10860 10861 procedure Set_Early_Call_Region (Body_Id : Entity_Id; Start : Node_Id) is 10862 begin 10863 pragma Assert (Ekind_In (Body_Id, E_Entry, 10864 E_Entry_Family, 10865 E_Function, 10866 E_Procedure, 10867 E_Subprogram_Body)); 10868 10869 Early_Call_Regions_In_Use := True; 10870 Early_Call_Regions.Set (Body_Id, Start); 10871 end Set_Early_Call_Region; 10872 10873 ---------------------------- 10874 -- Set_Elaboration_Status -- 10875 ---------------------------- 10876 10877 procedure Set_Elaboration_Status 10878 (Unit_Id : Entity_Id; 10879 Val : Elaboration_Attributes) 10880 is 10881 begin 10882 Elaboration_Statuses_In_Use := True; 10883 Elaboration_Statuses.Set (Unit_Id, Val); 10884 end Set_Elaboration_Status; 10885 10886 ------------------------------------ 10887 -- Set_Is_Recorded_SPARK_Scenario -- 10888 ------------------------------------ 10889 10890 procedure Set_Is_Recorded_SPARK_Scenario 10891 (N : Node_Id; 10892 Val : Boolean := True) 10893 is 10894 begin 10895 Recorded_SPARK_Scenarios_In_Use := True; 10896 Recorded_SPARK_Scenarios.Set (N, Val); 10897 end Set_Is_Recorded_SPARK_Scenario; 10898 10899 ---------------------------------------- 10900 -- Set_Is_Recorded_Top_Level_Scenario -- 10901 ---------------------------------------- 10902 10903 procedure Set_Is_Recorded_Top_Level_Scenario 10904 (N : Node_Id; 10905 Val : Boolean := True) 10906 is 10907 begin 10908 Recorded_Top_Level_Scenarios_In_Use := True; 10909 Recorded_Top_Level_Scenarios.Set (N, Val); 10910 end Set_Is_Recorded_Top_Level_Scenario; 10911 10912 ------------------------- 10913 -- Set_Is_Visited_Body -- 10914 ------------------------- 10915 10916 procedure Set_Is_Visited_Body (Subp_Body : Node_Id) is 10917 begin 10918 Visited_Bodies_In_Use := True; 10919 Visited_Bodies.Set (Subp_Body, True); 10920 end Set_Is_Visited_Body; 10921 10922 ------------------------------- 10923 -- Static_Elaboration_Checks -- 10924 ------------------------------- 10925 10926 function Static_Elaboration_Checks return Boolean is 10927 begin 10928 return not Dynamic_Elaboration_Checks; 10929 end Static_Elaboration_Checks; 10930 10931 ------------------- 10932 -- Traverse_Body -- 10933 ------------------- 10934 10935 procedure Traverse_Body (N : Node_Id; State : Processing_Attributes) is 10936 procedure Find_And_Process_Nested_Scenarios; 10937 pragma Inline (Find_And_Process_Nested_Scenarios); 10938 -- Examine the declarations and statements of subprogram body N for 10939 -- suitable scenarios. Save each discovered scenario and process it 10940 -- accordingly. 10941 10942 procedure Process_Nested_Scenarios (Nested : Elist_Id); 10943 pragma Inline (Process_Nested_Scenarios); 10944 -- Invoke Process_Conditional_ABE on each individual scenario found in 10945 -- list Nested. 10946 10947 --------------------------------------- 10948 -- Find_And_Process_Nested_Scenarios -- 10949 --------------------------------------- 10950 10951 procedure Find_And_Process_Nested_Scenarios is 10952 Body_Id : constant Entity_Id := Defining_Entity (N); 10953 10954 function Is_Potential_Scenario 10955 (Nod : Node_Id) return Traverse_Result; 10956 -- Determine whether arbitrary node Nod denotes a suitable scenario. 10957 -- If it does, save it in the Nested_Scenarios list of the subprogram 10958 -- body, and process it. 10959 10960 procedure Save_Scenario (Nod : Node_Id); 10961 pragma Inline (Save_Scenario); 10962 -- Save scenario Nod in the Nested_Scenarios list of the subprogram 10963 -- body. 10964 10965 procedure Traverse_List (List : List_Id); 10966 pragma Inline (Traverse_List); 10967 -- Invoke Traverse_Potential_Scenarios on each node in list List 10968 10969 procedure Traverse_Potential_Scenarios is 10970 new Traverse_Proc (Is_Potential_Scenario); 10971 10972 --------------------------- 10973 -- Is_Potential_Scenario -- 10974 --------------------------- 10975 10976 function Is_Potential_Scenario 10977 (Nod : Node_Id) return Traverse_Result 10978 is 10979 begin 10980 -- Special cases 10981 10982 -- Skip constructs which do not have elaboration of their own and 10983 -- need to be elaborated by other means such as invocation, task 10984 -- activation, etc. 10985 10986 if Is_Non_Library_Level_Encapsulator (Nod) then 10987 return Skip; 10988 10989 -- Terminate the traversal of a task body with an accept statement 10990 -- when no entry calls in elaboration are allowed because the task 10991 -- will block at run-time and the remaining statements will not be 10992 -- executed. 10993 10994 elsif Nkind_In (Original_Node (Nod), N_Accept_Statement, 10995 N_Selective_Accept) 10996 then 10997 if Restriction_Active (No_Entry_Calls_In_Elaboration_Code) then 10998 return Abandon; 10999 11000 -- The same behavior is achieved when switch -gnatd_a (stop 11001 -- elabortion checks on accept or select statement) is in 11002 -- effect. 11003 11004 elsif Debug_Flag_Underscore_A then 11005 return Abandon; 11006 end if; 11007 11008 -- Certain nodes carry semantic lists which act as repositories 11009 -- until expansion transforms the node and relocates the contents. 11010 -- Examine these lists in case expansion is disabled. 11011 11012 elsif Nkind_In (Nod, N_And_Then, N_Or_Else) then 11013 Traverse_List (Actions (Nod)); 11014 11015 elsif Nkind_In (Nod, N_Elsif_Part, N_Iteration_Scheme) then 11016 Traverse_List (Condition_Actions (Nod)); 11017 11018 elsif Nkind (Nod) = N_If_Expression then 11019 Traverse_List (Then_Actions (Nod)); 11020 Traverse_List (Else_Actions (Nod)); 11021 11022 elsif Nkind_In (Nod, N_Component_Association, 11023 N_Iterated_Component_Association) 11024 then 11025 Traverse_List (Loop_Actions (Nod)); 11026 11027 -- General case 11028 11029 -- Save a suitable scenario in the Nested_Scenarios list of the 11030 -- subprogram body. As a result any subsequent traversals of the 11031 -- subprogram body started from a different top-level scenario no 11032 -- longer need to reexamine the tree. 11033 11034 elsif Is_Suitable_Scenario (Nod) then 11035 Save_Scenario (Nod); 11036 11037 Process_Conditional_ABE 11038 (N => Nod, 11039 State => State); 11040 end if; 11041 11042 return OK; 11043 end Is_Potential_Scenario; 11044 11045 ------------------- 11046 -- Save_Scenario -- 11047 ------------------- 11048 11049 procedure Save_Scenario (Nod : Node_Id) is 11050 Nested : Elist_Id; 11051 11052 begin 11053 Nested := Nested_Scenarios (Body_Id); 11054 11055 if No (Nested) then 11056 Nested := New_Elmt_List; 11057 Set_Nested_Scenarios (Body_Id, Nested); 11058 end if; 11059 11060 Append_Elmt (Nod, Nested); 11061 end Save_Scenario; 11062 11063 ------------------- 11064 -- Traverse_List -- 11065 ------------------- 11066 11067 procedure Traverse_List (List : List_Id) is 11068 Item : Node_Id; 11069 11070 begin 11071 Item := First (List); 11072 while Present (Item) loop 11073 Traverse_Potential_Scenarios (Item); 11074 Next (Item); 11075 end loop; 11076 end Traverse_List; 11077 11078 -- Start of processing for Find_And_Process_Nested_Scenarios 11079 11080 begin 11081 -- Examine the declarations for suitable scenarios 11082 11083 Traverse_List (Declarations (N)); 11084 11085 -- Examine the handled sequence of statements. This also includes any 11086 -- exceptions handlers. 11087 11088 Traverse_Potential_Scenarios (Handled_Statement_Sequence (N)); 11089 end Find_And_Process_Nested_Scenarios; 11090 11091 ------------------------------ 11092 -- Process_Nested_Scenarios -- 11093 ------------------------------ 11094 11095 procedure Process_Nested_Scenarios (Nested : Elist_Id) is 11096 Nested_Elmt : Elmt_Id; 11097 11098 begin 11099 Nested_Elmt := First_Elmt (Nested); 11100 while Present (Nested_Elmt) loop 11101 Process_Conditional_ABE 11102 (N => Node (Nested_Elmt), 11103 State => State); 11104 11105 Next_Elmt (Nested_Elmt); 11106 end loop; 11107 end Process_Nested_Scenarios; 11108 11109 -- Local variables 11110 11111 Nested : Elist_Id; 11112 11113 -- Start of processing for Traverse_Body 11114 11115 begin 11116 -- Nothing to do when there is no body 11117 11118 if No (N) then 11119 return; 11120 11121 elsif Nkind (N) /= N_Subprogram_Body then 11122 return; 11123 end if; 11124 11125 -- Nothing to do if the body was already traversed during the processing 11126 -- of the same top-level scenario. 11127 11128 if Is_Visited_Body (N) then 11129 return; 11130 11131 -- Otherwise mark the body as traversed 11132 11133 else 11134 Set_Is_Visited_Body (N); 11135 end if; 11136 11137 Nested := Nested_Scenarios (Defining_Entity (N)); 11138 11139 -- The subprogram body was already examined as part of the elaboration 11140 -- graph starting from a different top-level scenario. There is no need 11141 -- to traverse the declarations and statements again because this will 11142 -- yield the exact same scenarios. Use the nested scenarios collected 11143 -- during the first inspection of the body. 11144 11145 if Present (Nested) then 11146 Process_Nested_Scenarios (Nested); 11147 11148 -- Otherwise examine the declarations and statements of the subprogram 11149 -- body for suitable scenarios, save and process them accordingly. 11150 11151 else 11152 Find_And_Process_Nested_Scenarios; 11153 end if; 11154 end Traverse_Body; 11155 11156 --------------------------------- 11157 -- Update_Elaboration_Scenario -- 11158 --------------------------------- 11159 11160 procedure Update_Elaboration_Scenario (New_N : Node_Id; Old_N : Node_Id) is 11161 procedure Update_SPARK_Scenario; 11162 pragma Inline (Update_SPARK_Scenario); 11163 -- Update the contents of table SPARK_Scenarios if Old_N is recorded 11164 -- there. 11165 11166 procedure Update_Top_Level_Scenario; 11167 pragma Inline (Update_Top_Level_Scenario); 11168 -- Update the contexts of table Top_Level_Scenarios if Old_N is recorded 11169 -- there. 11170 11171 --------------------------- 11172 -- Update_SPARK_Scenario -- 11173 --------------------------- 11174 11175 procedure Update_SPARK_Scenario is 11176 package Scenarios renames SPARK_Scenarios; 11177 11178 begin 11179 if Is_Recorded_SPARK_Scenario (Old_N) then 11180 11181 -- Performance note: list traversal 11182 11183 for Index in Scenarios.First .. Scenarios.Last loop 11184 if Scenarios.Table (Index) = Old_N then 11185 Scenarios.Table (Index) := New_N; 11186 11187 -- The old SPARK scenario is no longer recorded, but the new 11188 -- one is. 11189 11190 Set_Is_Recorded_Top_Level_Scenario (Old_N, False); 11191 Set_Is_Recorded_Top_Level_Scenario (New_N); 11192 return; 11193 end if; 11194 end loop; 11195 11196 -- A recorded SPARK scenario must be in the table of recorded 11197 -- SPARK scenarios. 11198 11199 pragma Assert (False); 11200 end if; 11201 end Update_SPARK_Scenario; 11202 11203 ------------------------------- 11204 -- Update_Top_Level_Scenario -- 11205 ------------------------------- 11206 11207 procedure Update_Top_Level_Scenario is 11208 package Scenarios renames Top_Level_Scenarios; 11209 11210 begin 11211 if Is_Recorded_Top_Level_Scenario (Old_N) then 11212 11213 -- Performance note: list traversal 11214 11215 for Index in Scenarios.First .. Scenarios.Last loop 11216 if Scenarios.Table (Index) = Old_N then 11217 Scenarios.Table (Index) := New_N; 11218 11219 -- The old top-level scenario is no longer recorded, but the 11220 -- new one is. 11221 11222 Set_Is_Recorded_Top_Level_Scenario (Old_N, False); 11223 Set_Is_Recorded_Top_Level_Scenario (New_N); 11224 return; 11225 end if; 11226 end loop; 11227 11228 -- A recorded top-level scenario must be in the table of recorded 11229 -- top-level scenarios. 11230 11231 pragma Assert (False); 11232 end if; 11233 end Update_Top_Level_Scenario; 11234 11235 -- Start of processing for Update_Elaboration_Requirement 11236 11237 begin 11238 -- Nothing to do when the old and new scenarios are one and the same 11239 11240 if Old_N = New_N then 11241 return; 11242 11243 -- A scenario is being transformed by Atree.Rewrite. Update all relevant 11244 -- internal data structures to reflect this change. This ensures that a 11245 -- potential run-time conditional ABE check or a guaranteed ABE failure 11246 -- is inserted at the proper place in the tree. 11247 11248 elsif Is_Scenario (Old_N) then 11249 Update_SPARK_Scenario; 11250 Update_Top_Level_Scenario; 11251 end if; 11252 end Update_Elaboration_Scenario; 11253 11254 ------------------------- 11255 -- Visited_Bodies_Hash -- 11256 ------------------------- 11257 11258 function Visited_Bodies_Hash (Key : Node_Id) return Visited_Bodies_Index is 11259 begin 11260 return Visited_Bodies_Index (Key mod Visited_Bodies_Max); 11261 end Visited_Bodies_Hash; 11262 11263 --------------------------------------------------------------------------- 11264 -- -- 11265 -- L E G A C Y A C C E S S B E F O R E E L A B O R A T I O N -- 11266 -- -- 11267 -- M E C H A N I S M -- 11268 -- -- 11269 --------------------------------------------------------------------------- 11270 11271 -- This section contains the implementation of the pre-18.x legacy ABE 11272 -- mechanism. The mechanism can be activated using switch -gnatH (legacy 11273 -- elaboration checking mode enabled). 11274 11275 ----------------------------- 11276 -- Description of Approach -- 11277 ----------------------------- 11278 11279 -- Every non-static call that is encountered by Sem_Res results in a call 11280 -- to Check_Elab_Call, with N being the call node, and Outer set to its 11281 -- default value of True. In addition X'Access is treated like a call 11282 -- for the access-to-procedure case, and in SPARK mode only we also 11283 -- check variable references. 11284 11285 -- The goal of Check_Elab_Call is to determine whether or not the reference 11286 -- in question can generate an access before elaboration error (raising 11287 -- Program_Error) either by directly calling a subprogram whose body 11288 -- has not yet been elaborated, or indirectly, by calling a subprogram 11289 -- whose body has been elaborated, but which contains a call to such a 11290 -- subprogram. 11291 11292 -- In addition, in SPARK mode, we are checking for a variable reference in 11293 -- another package, which requires an explicit Elaborate_All pragma. 11294 11295 -- The only references that we need to look at the outer level are 11296 -- references that occur in elaboration code. There are two cases. The 11297 -- reference can be at the outer level of elaboration code, or it can 11298 -- be within another unit, e.g. the elaboration code of a subprogram. 11299 11300 -- In the case of an elaboration call at the outer level, we must trace 11301 -- all calls to outer level routines either within the current unit or to 11302 -- other units that are with'ed. For calls within the current unit, we can 11303 -- determine if the body has been elaborated or not, and if it has not, 11304 -- then a warning is generated. 11305 11306 -- Note that there are two subcases. If the original call directly calls a 11307 -- subprogram whose body has not been elaborated, then we know that an ABE 11308 -- will take place, and we replace the call by a raise of Program_Error. 11309 -- If the call is indirect, then we don't know that the PE will be raised, 11310 -- since the call might be guarded by a conditional. In this case we set 11311 -- Do_Elab_Check on the call so that a dynamic check is generated, and 11312 -- output a warning. 11313 11314 -- For calls to a subprogram in a with'ed unit or a 'Access or variable 11315 -- reference (SPARK mode case), we require that a pragma Elaborate_All 11316 -- or pragma Elaborate be present, or that the referenced unit have a 11317 -- pragma Preelaborate, pragma Pure, or pragma Elaborate_Body. If none 11318 -- of these conditions is met, then a warning is generated that a pragma 11319 -- Elaborate_All may be needed (error in the SPARK case), or an implicit 11320 -- pragma is generated. 11321 11322 -- For the case of an elaboration call at some inner level, we are 11323 -- interested in tracing only calls to subprograms at the same level, i.e. 11324 -- those that can be called during elaboration. Any calls to outer level 11325 -- routines cannot cause ABE's as a result of the original call (there 11326 -- might be an outer level call to the subprogram from outside that causes 11327 -- the ABE, but that gets analyzed separately). 11328 11329 -- Note that we never trace calls to inner level subprograms, since these 11330 -- cannot result in ABE's unless there is an elaboration problem at a lower 11331 -- level, which will be separately detected. 11332 11333 -- Note on pragma Elaborate. The checking here assumes that a pragma 11334 -- Elaborate on a with'ed unit guarantees that subprograms within the unit 11335 -- can be called without causing an ABE. This is not in fact the case since 11336 -- pragma Elaborate does not guarantee the transitive coverage guaranteed 11337 -- by Elaborate_All. However, we decide to trust the user in this case. 11338 11339 -------------------------------------- 11340 -- Instantiation Elaboration Errors -- 11341 -------------------------------------- 11342 11343 -- A special case arises when an instantiation appears in a context that is 11344 -- known to be before the body is elaborated, e.g. 11345 11346 -- generic package x is ... 11347 -- ... 11348 -- package xx is new x; 11349 -- ... 11350 -- package body x is ... 11351 11352 -- In this situation it is certain that an elaboration error will occur, 11353 -- and an unconditional raise Program_Error statement is inserted before 11354 -- the instantiation, and a warning generated. 11355 11356 -- The problem is that in this case we have no place to put the body of 11357 -- the instantiation. We can't put it in the normal place, because it is 11358 -- too early, and will cause errors to occur as a result of referencing 11359 -- entities before they are declared. 11360 11361 -- Our approach in this case is simply to avoid creating the body of the 11362 -- instantiation in such a case. The instantiation spec is modified to 11363 -- include dummy bodies for all subprograms, so that the resulting code 11364 -- does not contain subprogram specs with no corresponding bodies. 11365 11366 -- The following table records the recursive call chain for output in the 11367 -- Output routine. Each entry records the call node and the entity of the 11368 -- called routine. The number of entries in the table (i.e. the value of 11369 -- Elab_Call.Last) indicates the current depth of recursion and is used to 11370 -- identify the outer level. 11371 11372 type Elab_Call_Element is record 11373 Cloc : Source_Ptr; 11374 Ent : Entity_Id; 11375 end record; 11376 11377 package Elab_Call is new Table.Table 11378 (Table_Component_Type => Elab_Call_Element, 11379 Table_Index_Type => Int, 11380 Table_Low_Bound => 1, 11381 Table_Initial => 50, 11382 Table_Increment => 100, 11383 Table_Name => "Elab_Call"); 11384 11385 -- The following table records all calls that have been processed starting 11386 -- from an outer level call. The table prevents both infinite recursion and 11387 -- useless reanalysis of calls within the same context. The use of context 11388 -- is important because it allows for proper checks in more complex code: 11389 11390 -- if ... then 11391 -- Call; -- requires a check 11392 -- Call; -- does not need a check thanks to the table 11393 -- elsif ... then 11394 -- Call; -- requires a check, different context 11395 -- end if; 11396 11397 -- Call; -- requires a check, different context 11398 11399 type Visited_Element is record 11400 Subp_Id : Entity_Id; 11401 -- The entity of the subprogram being called 11402 11403 Context : Node_Id; 11404 -- The context where the call to the subprogram occurs 11405 end record; 11406 11407 package Elab_Visited is new Table.Table 11408 (Table_Component_Type => Visited_Element, 11409 Table_Index_Type => Int, 11410 Table_Low_Bound => 1, 11411 Table_Initial => 200, 11412 Table_Increment => 100, 11413 Table_Name => "Elab_Visited"); 11414 11415 -- The following table records delayed calls which must be examined after 11416 -- all generic bodies have been instantiated. 11417 11418 type Delay_Element is record 11419 N : Node_Id; 11420 -- The parameter N from the call to Check_Internal_Call. Note that this 11421 -- node may get rewritten over the delay period by expansion in the call 11422 -- case (but not in the instantiation case). 11423 11424 E : Entity_Id; 11425 -- The parameter E from the call to Check_Internal_Call 11426 11427 Orig_Ent : Entity_Id; 11428 -- The parameter Orig_Ent from the call to Check_Internal_Call 11429 11430 Curscop : Entity_Id; 11431 -- The current scope of the call. This is restored when we complete the 11432 -- delayed call, so that we do this in the right scope. 11433 11434 Outer_Scope : Entity_Id; 11435 -- Save scope of outer level call 11436 11437 From_Elab_Code : Boolean; 11438 -- Save indication of whether this call is from elaboration code 11439 11440 In_Task_Activation : Boolean; 11441 -- Save indication of whether this call is from a task body. Tasks are 11442 -- activated at the "begin", which is after all local procedure bodies, 11443 -- so calls to those procedures can't fail, even if they occur after the 11444 -- task body. 11445 11446 From_SPARK_Code : Boolean; 11447 -- Save indication of whether this call is under SPARK_Mode => On 11448 end record; 11449 11450 package Delay_Check is new Table.Table 11451 (Table_Component_Type => Delay_Element, 11452 Table_Index_Type => Int, 11453 Table_Low_Bound => 1, 11454 Table_Initial => 1000, 11455 Table_Increment => 100, 11456 Table_Name => "Delay_Check"); 11457 11458 C_Scope : Entity_Id; 11459 -- Top-level scope of current scope. Compute this only once at the outer 11460 -- level, i.e. for a call to Check_Elab_Call from outside this unit. 11461 11462 Outer_Level_Sloc : Source_Ptr; 11463 -- Save Sloc value for outer level call node for comparisons of source 11464 -- locations. A body is too late if it appears after the *outer* level 11465 -- call, not the particular call that is being analyzed. 11466 11467 From_Elab_Code : Boolean; 11468 -- This flag shows whether the outer level call currently being examined 11469 -- is or is not in elaboration code. We are only interested in calls to 11470 -- routines in other units if this flag is True. 11471 11472 In_Task_Activation : Boolean := False; 11473 -- This flag indicates whether we are performing elaboration checks on task 11474 -- bodies, at the point of activation. If true, we do not raise 11475 -- Program_Error for calls to local procedures, because all local bodies 11476 -- are known to be elaborated. However, we still need to trace such calls, 11477 -- because a local procedure could call a procedure in another package, 11478 -- so we might need an implicit Elaborate_All. 11479 11480 Delaying_Elab_Checks : Boolean := True; 11481 -- This is set True till the compilation is complete, including the 11482 -- insertion of all instance bodies. Then when Check_Elab_Calls is called, 11483 -- the delay table is used to make the delayed calls and this flag is reset 11484 -- to False, so that the calls are processed. 11485 11486 ----------------------- 11487 -- Local Subprograms -- 11488 ----------------------- 11489 11490 -- Note: Outer_Scope in all following specs represents the scope of 11491 -- interest of the outer level call. If it is set to Standard_Standard, 11492 -- then it means the outer level call was at elaboration level, and that 11493 -- thus all calls are of interest. If it was set to some other scope, 11494 -- then the original call was an inner call, and we are not interested 11495 -- in calls that go outside this scope. 11496 11497 procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id); 11498 -- Analysis of construct N shows that we should set Elaborate_All_Desirable 11499 -- for the WITH clause for unit U (which will always be present). A special 11500 -- case is when N is a function or procedure instantiation, in which case 11501 -- it is sufficient to set Elaborate_Desirable, since in this case there is 11502 -- no possibility of transitive elaboration issues. 11503 11504 procedure Check_A_Call 11505 (N : Node_Id; 11506 E : Entity_Id; 11507 Outer_Scope : Entity_Id; 11508 Inter_Unit_Only : Boolean; 11509 Generate_Warnings : Boolean := True; 11510 In_Init_Proc : Boolean := False); 11511 -- This is the internal recursive routine that is called to check for 11512 -- possible elaboration error. The argument N is a subprogram call or 11513 -- generic instantiation, or 'Access attribute reference to be checked, and 11514 -- E is the entity of the called subprogram, or instantiated generic unit, 11515 -- or subprogram referenced by 'Access. 11516 -- 11517 -- In SPARK mode, N can also be a variable reference, since in SPARK this 11518 -- also triggers a requirement for Elaborate_All, and in this case E is the 11519 -- entity being referenced. 11520 -- 11521 -- Outer_Scope is the outer level scope for the original reference. 11522 -- Inter_Unit_Only is set if the call is only to be checked in the 11523 -- case where it is to another unit (and skipped if within a unit). 11524 -- Generate_Warnings is set to False to suppress warning messages about 11525 -- missing pragma Elaborate_All's. These messages are not wanted for 11526 -- inner calls in the dynamic model. Note that an instance of the Access 11527 -- attribute applied to a subprogram also generates a call to this 11528 -- procedure (since the referenced subprogram may be called later 11529 -- indirectly). Flag In_Init_Proc should be set whenever the current 11530 -- context is a type init proc. 11531 -- 11532 -- Note: this might better be called Check_A_Reference to recognize the 11533 -- variable case for SPARK, but we prefer to retain the historical name 11534 -- since in practice this is mostly about checking calls for the possible 11535 -- occurrence of an access-before-elaboration exception. 11536 11537 procedure Check_Bad_Instantiation (N : Node_Id); 11538 -- N is a node for an instantiation (if called with any other node kind, 11539 -- Check_Bad_Instantiation ignores the call). This subprogram checks for 11540 -- the special case of a generic instantiation of a generic spec in the 11541 -- same declarative part as the instantiation where a body is present and 11542 -- has not yet been seen. This is an obvious error, but needs to be checked 11543 -- specially at the time of the instantiation, since it is a case where we 11544 -- cannot insert the body anywhere. If this case is detected, warnings are 11545 -- generated, and a raise of Program_Error is inserted. In addition any 11546 -- subprograms in the generic spec are stubbed, and the Bad_Instantiation 11547 -- flag is set on the instantiation node. The caller in Sem_Ch12 uses this 11548 -- flag as an indication that no attempt should be made to insert an 11549 -- instance body. 11550 11551 procedure Check_Internal_Call 11552 (N : Node_Id; 11553 E : Entity_Id; 11554 Outer_Scope : Entity_Id; 11555 Orig_Ent : Entity_Id); 11556 -- N is a function call or procedure statement call node and E is the 11557 -- entity of the called function, which is within the current compilation 11558 -- unit (where subunits count as part of the parent). This call checks if 11559 -- this call, or any call within any accessed body could cause an ABE, and 11560 -- if so, outputs a warning. Orig_Ent differs from E only in the case of 11561 -- renamings, and points to the original name of the entity. This is used 11562 -- for error messages. Outer_Scope is the outer level scope for the 11563 -- original call. 11564 11565 procedure Check_Internal_Call_Continue 11566 (N : Node_Id; 11567 E : Entity_Id; 11568 Outer_Scope : Entity_Id; 11569 Orig_Ent : Entity_Id); 11570 -- The processing for Check_Internal_Call is divided up into two phases, 11571 -- and this represents the second phase. The second phase is delayed if 11572 -- Delaying_Elab_Checks is set to True. In this delayed case, the first 11573 -- phase makes an entry in the Delay_Check table, which is processed when 11574 -- Check_Elab_Calls is called. N, E and Orig_Ent are as for the call to 11575 -- Check_Internal_Call. Outer_Scope is the outer level scope for the 11576 -- original call. 11577 11578 function Get_Referenced_Ent (N : Node_Id) return Entity_Id; 11579 -- N is either a function or procedure call or an access attribute that 11580 -- references a subprogram. This call retrieves the relevant entity. If 11581 -- this is a call to a protected subprogram, the entity is a selected 11582 -- component. The callable entity may be absent, in which case Empty is 11583 -- returned. This happens with non-analyzed calls in nested generics. 11584 -- 11585 -- If SPARK_Mode is On, then N can also be a reference to an E_Variable 11586 -- entity, in which case, the value returned is simply this entity. 11587 11588 function Has_Generic_Body (N : Node_Id) return Boolean; 11589 -- N is a generic package instantiation node, and this routine determines 11590 -- if this package spec does in fact have a generic body. If so, then 11591 -- True is returned, otherwise False. Note that this is not at all the 11592 -- same as checking if the unit requires a body, since it deals with 11593 -- the case of optional bodies accurately (i.e. if a body is optional, 11594 -- then it looks to see if a body is actually present). Note: this 11595 -- function can only do a fully correct job if in generating code mode 11596 -- where all bodies have to be present. If we are operating in semantics 11597 -- check only mode, then in some cases of optional bodies, a result of 11598 -- False may incorrectly be given. In practice this simply means that 11599 -- some cases of warnings for incorrect order of elaboration will only 11600 -- be given when generating code, which is not a big problem (and is 11601 -- inevitable, given the optional body semantics of Ada). 11602 11603 procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty); 11604 -- Given code for an elaboration check (or unconditional raise if the check 11605 -- is not needed), inserts the code in the appropriate place. N is the call 11606 -- or instantiation node for which the check code is required. C is the 11607 -- test whose failure triggers the raise. 11608 11609 function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean; 11610 -- Returns True if node N is a call to a generic formal subprogram 11611 11612 function Is_Finalization_Procedure (Id : Entity_Id) return Boolean; 11613 -- Determine whether entity Id denotes a [Deep_]Finalize procedure 11614 11615 procedure Output_Calls 11616 (N : Node_Id; 11617 Check_Elab_Flag : Boolean); 11618 -- Outputs chain of calls stored in the Elab_Call table. The caller has 11619 -- already generated the main warning message, so the warnings generated 11620 -- are all continuation messages. The argument is the call node at which 11621 -- the messages are to be placed. When Check_Elab_Flag is set, calls are 11622 -- enumerated only when flag Elab_Warning is set for the dynamic case or 11623 -- when flag Elab_Info_Messages is set for the static case. 11624 11625 function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean; 11626 -- Given two scopes, determine whether they are the same scope from an 11627 -- elaboration point of view, i.e. packages and blocks are ignored. 11628 11629 procedure Set_C_Scope; 11630 -- On entry C_Scope is set to some scope. On return, C_Scope is reset 11631 -- to be the enclosing compilation unit of this scope. 11632 11633 procedure Set_Elaboration_Constraint 11634 (Call : Node_Id; 11635 Subp : Entity_Id; 11636 Scop : Entity_Id); 11637 -- The current unit U may depend semantically on some unit P that is not 11638 -- in the current context. If there is an elaboration call that reaches P, 11639 -- we need to indicate that P requires an Elaborate_All, but this is not 11640 -- effective in U's ali file, if there is no with_clause for P. In this 11641 -- case we add the Elaborate_All on the unit Q that directly or indirectly 11642 -- makes P available. This can happen in two cases: 11643 -- 11644 -- a) Q declares a subtype of a type declared in P, and the call is an 11645 -- initialization call for an object of that subtype. 11646 -- 11647 -- b) Q declares an object of some tagged type whose root type is 11648 -- declared in P, and the initialization call uses object notation on 11649 -- that object to reach a primitive operation or a classwide operation 11650 -- declared in P. 11651 -- 11652 -- If P appears in the context of U, the current processing is correct. 11653 -- Otherwise we must identify these two cases to retrieve Q and place the 11654 -- Elaborate_All_Desirable on it. 11655 11656 function Spec_Entity (E : Entity_Id) return Entity_Id; 11657 -- Given a compilation unit entity, if it is a spec entity, it is returned 11658 -- unchanged. If it is a body entity, then the spec for the corresponding 11659 -- spec is returned 11660 11661 function Within (E1, E2 : Entity_Id) return Boolean; 11662 -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or is one 11663 -- of its contained scopes, False otherwise. 11664 11665 function Within_Elaborate_All 11666 (Unit : Unit_Number_Type; 11667 E : Entity_Id) return Boolean; 11668 -- Return True if we are within the scope of an Elaborate_All for E, or if 11669 -- we are within the scope of an Elaborate_All for some other unit U, and U 11670 -- with's E. This prevents spurious warnings when the called entity is 11671 -- renamed within U, or in case of generic instances. 11672 11673 -------------------------------------- 11674 -- Activate_Elaborate_All_Desirable -- 11675 -------------------------------------- 11676 11677 procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id) is 11678 UN : constant Unit_Number_Type := Get_Code_Unit (N); 11679 CU : constant Node_Id := Cunit (UN); 11680 UE : constant Entity_Id := Cunit_Entity (UN); 11681 Unm : constant Unit_Name_Type := Unit_Name (UN); 11682 CI : constant List_Id := Context_Items (CU); 11683 Itm : Node_Id; 11684 Ent : Entity_Id; 11685 11686 procedure Add_To_Context_And_Mark (Itm : Node_Id); 11687 -- This procedure is called when the elaborate indication must be 11688 -- applied to a unit not in the context of the referencing unit. The 11689 -- unit gets added to the context as an implicit with. 11690 11691 function In_Withs_Of (UEs : Entity_Id) return Boolean; 11692 -- UEs is the spec entity of a unit. If the unit to be marked is 11693 -- in the context item list of this unit spec, then the call returns 11694 -- True and Itm is left set to point to the relevant N_With_Clause node. 11695 11696 procedure Set_Elab_Flag (Itm : Node_Id); 11697 -- Sets Elaborate_[All_]Desirable as appropriate on Itm 11698 11699 ----------------------------- 11700 -- Add_To_Context_And_Mark -- 11701 ----------------------------- 11702 11703 procedure Add_To_Context_And_Mark (Itm : Node_Id) is 11704 CW : constant Node_Id := 11705 Make_With_Clause (Sloc (Itm), 11706 Name => Name (Itm)); 11707 11708 begin 11709 Set_Library_Unit (CW, Library_Unit (Itm)); 11710 Set_Implicit_With (CW); 11711 11712 -- Set elaborate all desirable on copy and then append the copy to 11713 -- the list of body with's and we are done. 11714 11715 Set_Elab_Flag (CW); 11716 Append_To (CI, CW); 11717 end Add_To_Context_And_Mark; 11718 11719 ----------------- 11720 -- In_Withs_Of -- 11721 ----------------- 11722 11723 function In_Withs_Of (UEs : Entity_Id) return Boolean is 11724 UNs : constant Unit_Number_Type := Get_Source_Unit (UEs); 11725 CUs : constant Node_Id := Cunit (UNs); 11726 CIs : constant List_Id := Context_Items (CUs); 11727 11728 begin 11729 Itm := First (CIs); 11730 while Present (Itm) loop 11731 if Nkind (Itm) = N_With_Clause then 11732 Ent := 11733 Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); 11734 11735 if U = Ent then 11736 return True; 11737 end if; 11738 end if; 11739 11740 Next (Itm); 11741 end loop; 11742 11743 return False; 11744 end In_Withs_Of; 11745 11746 ------------------- 11747 -- Set_Elab_Flag -- 11748 ------------------- 11749 11750 procedure Set_Elab_Flag (Itm : Node_Id) is 11751 begin 11752 if Nkind (N) in N_Subprogram_Instantiation then 11753 Set_Elaborate_Desirable (Itm); 11754 else 11755 Set_Elaborate_All_Desirable (Itm); 11756 end if; 11757 end Set_Elab_Flag; 11758 11759 -- Start of processing for Activate_Elaborate_All_Desirable 11760 11761 begin 11762 -- Do not set binder indication if expansion is disabled, as when 11763 -- compiling a generic unit. 11764 11765 if not Expander_Active then 11766 return; 11767 end if; 11768 11769 -- If an instance of a generic package contains a controlled object (so 11770 -- we're calling Initialize at elaboration time), and the instance is in 11771 -- a package body P that says "with P;", then we need to return without 11772 -- adding "pragma Elaborate_All (P);" to P. 11773 11774 if U = Main_Unit_Entity then 11775 return; 11776 end if; 11777 11778 Itm := First (CI); 11779 while Present (Itm) loop 11780 if Nkind (Itm) = N_With_Clause then 11781 Ent := Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); 11782 11783 -- If we find it, then mark elaborate all desirable and return 11784 11785 if U = Ent then 11786 Set_Elab_Flag (Itm); 11787 return; 11788 end if; 11789 end if; 11790 11791 Next (Itm); 11792 end loop; 11793 11794 -- If we fall through then the with clause is not present in the 11795 -- current unit. One legitimate possibility is that the with clause 11796 -- is present in the spec when we are a body. 11797 11798 if Is_Body_Name (Unm) 11799 and then In_Withs_Of (Spec_Entity (UE)) 11800 then 11801 Add_To_Context_And_Mark (Itm); 11802 return; 11803 end if; 11804 11805 -- Similarly, we may be in the spec or body of a child unit, where 11806 -- the unit in question is with'ed by some ancestor of the child unit. 11807 11808 if Is_Child_Name (Unm) then 11809 declare 11810 Pkg : Entity_Id; 11811 11812 begin 11813 Pkg := UE; 11814 loop 11815 Pkg := Scope (Pkg); 11816 exit when Pkg = Standard_Standard; 11817 11818 if In_Withs_Of (Pkg) then 11819 Add_To_Context_And_Mark (Itm); 11820 return; 11821 end if; 11822 end loop; 11823 end; 11824 end if; 11825 11826 -- Here if we do not find with clause on spec or body. We just ignore 11827 -- this case; it means that the elaboration involves some other unit 11828 -- than the unit being compiled, and will be caught elsewhere. 11829 end Activate_Elaborate_All_Desirable; 11830 11831 ------------------ 11832 -- Check_A_Call -- 11833 ------------------ 11834 11835 procedure Check_A_Call 11836 (N : Node_Id; 11837 E : Entity_Id; 11838 Outer_Scope : Entity_Id; 11839 Inter_Unit_Only : Boolean; 11840 Generate_Warnings : Boolean := True; 11841 In_Init_Proc : Boolean := False) 11842 is 11843 Access_Case : constant Boolean := Nkind (N) = N_Attribute_Reference; 11844 -- Indicates if we have Access attribute case 11845 11846 function Call_To_Instance_From_Outside (Id : Entity_Id) return Boolean; 11847 -- True if we're calling an instance of a generic subprogram, or a 11848 -- subprogram in an instance of a generic package, and the call is 11849 -- outside that instance. 11850 11851 procedure Elab_Warning 11852 (Msg_D : String; 11853 Msg_S : String; 11854 Ent : Node_Or_Entity_Id); 11855 -- Generate a call to Error_Msg_NE with parameters Msg_D or Msg_S (for 11856 -- dynamic or static elaboration model), N and Ent. Msg_D is a real 11857 -- warning (output if Msg_D is non-null and Elab_Warnings is set), 11858 -- Msg_S is an info message (output if Elab_Info_Messages is set). 11859 11860 function Find_W_Scope return Entity_Id; 11861 -- Find top-level scope for called entity (not following renamings 11862 -- or derivations). This is where the Elaborate_All will go if it is 11863 -- needed. We start with the called entity, except in the case of an 11864 -- initialization procedure outside the current package, where the init 11865 -- proc is in the root package, and we start from the entity of the name 11866 -- in the call. 11867 11868 ----------------------------------- 11869 -- Call_To_Instance_From_Outside -- 11870 ----------------------------------- 11871 11872 function Call_To_Instance_From_Outside (Id : Entity_Id) return Boolean is 11873 Scop : Entity_Id := Id; 11874 11875 begin 11876 loop 11877 if Scop = Standard_Standard then 11878 return False; 11879 end if; 11880 11881 if Is_Generic_Instance (Scop) then 11882 return not In_Open_Scopes (Scop); 11883 end if; 11884 11885 Scop := Scope (Scop); 11886 end loop; 11887 end Call_To_Instance_From_Outside; 11888 11889 ------------------ 11890 -- Elab_Warning -- 11891 ------------------ 11892 11893 procedure Elab_Warning 11894 (Msg_D : String; 11895 Msg_S : String; 11896 Ent : Node_Or_Entity_Id) 11897 is 11898 begin 11899 -- Dynamic elaboration checks, real warning 11900 11901 if Dynamic_Elaboration_Checks then 11902 if not Access_Case then 11903 if Msg_D /= "" and then Elab_Warnings then 11904 Error_Msg_NE (Msg_D, N, Ent); 11905 end if; 11906 11907 -- In the access case emit first warning message as well, 11908 -- otherwise list of calls will appear as errors. 11909 11910 elsif Elab_Warnings then 11911 Error_Msg_NE (Msg_S, N, Ent); 11912 end if; 11913 11914 -- Static elaboration checks, info message 11915 11916 else 11917 if Elab_Info_Messages then 11918 Error_Msg_NE (Msg_S, N, Ent); 11919 end if; 11920 end if; 11921 end Elab_Warning; 11922 11923 ------------------ 11924 -- Find_W_Scope -- 11925 ------------------ 11926 11927 function Find_W_Scope return Entity_Id is 11928 Refed_Ent : constant Entity_Id := Get_Referenced_Ent (N); 11929 W_Scope : Entity_Id; 11930 11931 begin 11932 if Is_Init_Proc (Refed_Ent) 11933 and then not In_Same_Extended_Unit (N, Refed_Ent) 11934 then 11935 W_Scope := Scope (Refed_Ent); 11936 else 11937 W_Scope := E; 11938 end if; 11939 11940 -- Now loop through scopes to get to the enclosing compilation unit 11941 11942 while not Is_Compilation_Unit (W_Scope) loop 11943 W_Scope := Scope (W_Scope); 11944 end loop; 11945 11946 return W_Scope; 11947 end Find_W_Scope; 11948 11949 -- Local variables 11950 11951 Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation; 11952 -- Indicates if we have instantiation case 11953 11954 Loc : constant Source_Ptr := Sloc (N); 11955 11956 Variable_Case : constant Boolean := 11957 Nkind (N) in N_Has_Entity 11958 and then Present (Entity (N)) 11959 and then Ekind (Entity (N)) = E_Variable; 11960 -- Indicates if we have variable reference case 11961 11962 W_Scope : constant Entity_Id := Find_W_Scope; 11963 -- Top-level scope of directly called entity for subprogram. This 11964 -- differs from E_Scope in the case where renamings or derivations 11965 -- are involved, since it does not follow these links. W_Scope is 11966 -- generally in a visible unit, and it is this scope that may require 11967 -- an Elaborate_All. However, there are some cases (initialization 11968 -- calls and calls involving object notation) where W_Scope might not 11969 -- be in the context of the current unit, and there is an intermediate 11970 -- package that is, in which case the Elaborate_All has to be placed 11971 -- on this intermediate package. These special cases are handled in 11972 -- Set_Elaboration_Constraint. 11973 11974 Ent : Entity_Id; 11975 Callee_Unit_Internal : Boolean; 11976 Caller_Unit_Internal : Boolean; 11977 Decl : Node_Id; 11978 Inst_Callee : Source_Ptr; 11979 Inst_Caller : Source_Ptr; 11980 Unit_Callee : Unit_Number_Type; 11981 Unit_Caller : Unit_Number_Type; 11982 11983 Body_Acts_As_Spec : Boolean; 11984 -- Set to true if call is to body acting as spec (no separate spec) 11985 11986 Cunit_SC : Boolean := False; 11987 -- Set to suppress dynamic elaboration checks where one of the 11988 -- enclosing scopes has Elaboration_Checks_Suppressed set, or else 11989 -- if a pragma Elaborate[_All] applies to that scope, in which case 11990 -- warnings on the scope are also suppressed. For the internal case, 11991 -- we ignore this flag. 11992 11993 E_Scope : Entity_Id; 11994 -- Top-level scope of entity for called subprogram. This value includes 11995 -- following renamings and derivations, so this scope can be in a 11996 -- non-visible unit. This is the scope that is to be investigated to 11997 -- see whether an elaboration check is required. 11998 11999 Is_DIC : Boolean; 12000 -- Flag set when the subprogram being invoked is the procedure generated 12001 -- for pragma Default_Initial_Condition. 12002 12003 SPARK_Elab_Errors : Boolean; 12004 -- Flag set when an entity is called or a variable is read during SPARK 12005 -- dynamic elaboration. 12006 12007 -- Start of processing for Check_A_Call 12008 12009 begin 12010 -- If the call is known to be within a local Suppress Elaboration 12011 -- pragma, nothing to check. This can happen in task bodies. But 12012 -- we ignore this for a call to a generic formal. 12013 12014 if Nkind (N) in N_Subprogram_Call 12015 and then No_Elaboration_Check (N) 12016 and then not Is_Call_Of_Generic_Formal (N) 12017 then 12018 return; 12019 12020 -- If this is a rewrite of a Valid_Scalars attribute, then nothing to 12021 -- check, we don't mind in this case if the call occurs before the body 12022 -- since this is all generated code. 12023 12024 elsif Nkind (Original_Node (N)) = N_Attribute_Reference 12025 and then Attribute_Name (Original_Node (N)) = Name_Valid_Scalars 12026 then 12027 return; 12028 12029 -- Intrinsics such as instances of Unchecked_Deallocation do not have 12030 -- any body, so elaboration checking is not needed, and would be wrong. 12031 12032 elsif Is_Intrinsic_Subprogram (E) then 12033 return; 12034 12035 -- Do not consider references to internal variables for SPARK semantics 12036 12037 elsif Variable_Case and then not Comes_From_Source (E) then 12038 return; 12039 end if; 12040 12041 -- Proceed with check 12042 12043 Ent := E; 12044 12045 -- For a variable reference, just set Body_Acts_As_Spec to False 12046 12047 if Variable_Case then 12048 Body_Acts_As_Spec := False; 12049 12050 -- Additional checks for all other cases 12051 12052 else 12053 -- Go to parent for derived subprogram, or to original subprogram in 12054 -- the case of a renaming (Alias covers both these cases). 12055 12056 loop 12057 if (Suppress_Elaboration_Warnings (Ent) 12058 or else Elaboration_Checks_Suppressed (Ent)) 12059 and then (Inst_Case or else No (Alias (Ent))) 12060 then 12061 return; 12062 end if; 12063 12064 -- Nothing to do for imported entities 12065 12066 if Is_Imported (Ent) then 12067 return; 12068 end if; 12069 12070 exit when Inst_Case or else No (Alias (Ent)); 12071 Ent := Alias (Ent); 12072 end loop; 12073 12074 Decl := Unit_Declaration_Node (Ent); 12075 12076 if Nkind (Decl) = N_Subprogram_Body then 12077 Body_Acts_As_Spec := True; 12078 12079 elsif Nkind_In (Decl, N_Subprogram_Declaration, 12080 N_Subprogram_Body_Stub) 12081 or else Inst_Case 12082 then 12083 Body_Acts_As_Spec := False; 12084 12085 -- If we have none of an instantiation, subprogram body or subprogram 12086 -- declaration, or in the SPARK case, a variable reference, then 12087 -- it is not a case that we want to check. (One case is a call to a 12088 -- generic formal subprogram, where we do not want the check in the 12089 -- template). 12090 12091 else 12092 return; 12093 end if; 12094 end if; 12095 12096 E_Scope := Ent; 12097 loop 12098 if Elaboration_Checks_Suppressed (E_Scope) 12099 or else Suppress_Elaboration_Warnings (E_Scope) 12100 then 12101 Cunit_SC := True; 12102 end if; 12103 12104 -- Exit when we get to compilation unit, not counting subunits 12105 12106 exit when Is_Compilation_Unit (E_Scope) 12107 and then (Is_Child_Unit (E_Scope) 12108 or else Scope (E_Scope) = Standard_Standard); 12109 12110 pragma Assert (E_Scope /= Standard_Standard); 12111 12112 -- Move up a scope looking for compilation unit 12113 12114 E_Scope := Scope (E_Scope); 12115 end loop; 12116 12117 -- No checks needed for pure or preelaborated compilation units 12118 12119 if Is_Pure (E_Scope) or else Is_Preelaborated (E_Scope) then 12120 return; 12121 end if; 12122 12123 -- If the generic entity is within a deeper instance than we are, then 12124 -- either the instantiation to which we refer itself caused an ABE, in 12125 -- which case that will be handled separately, or else we know that the 12126 -- body we need appears as needed at the point of the instantiation. 12127 -- However, this assumption is only valid if we are in static mode. 12128 12129 if not Dynamic_Elaboration_Checks 12130 and then 12131 Instantiation_Depth (Sloc (Ent)) > Instantiation_Depth (Sloc (N)) 12132 then 12133 return; 12134 end if; 12135 12136 -- Do not give a warning for a package with no body 12137 12138 if Ekind (Ent) = E_Generic_Package and then not Has_Generic_Body (N) then 12139 return; 12140 end if; 12141 12142 -- Case of entity is in same unit as call or instantiation. In the 12143 -- instantiation case, W_Scope may be different from E_Scope; we want 12144 -- the unit in which the instantiation occurs, since we're analyzing 12145 -- based on the expansion. 12146 12147 if W_Scope = C_Scope then 12148 if not Inter_Unit_Only then 12149 Check_Internal_Call (N, Ent, Outer_Scope, E); 12150 end if; 12151 12152 return; 12153 end if; 12154 12155 -- Case of entity is not in current unit (i.e. with'ed unit case) 12156 12157 -- We are only interested in such calls if the outer call was from 12158 -- elaboration code, or if we are in Dynamic_Elaboration_Checks mode. 12159 12160 if not From_Elab_Code and then not Dynamic_Elaboration_Checks then 12161 return; 12162 end if; 12163 12164 -- Nothing to do if some scope said that no checks were required 12165 12166 if Cunit_SC then 12167 return; 12168 end if; 12169 12170 -- Nothing to do for a generic instance, because a call to an instance 12171 -- cannot fail the elaboration check, because the body of the instance 12172 -- is always elaborated immediately after the spec. 12173 12174 if Call_To_Instance_From_Outside (Ent) then 12175 return; 12176 end if; 12177 12178 -- Nothing to do if subprogram with no separate spec. However, a call 12179 -- to Deep_Initialize may result in a call to a user-defined Initialize 12180 -- procedure, which imposes a body dependency. This happens only if the 12181 -- type is controlled and the Initialize procedure is not inherited. 12182 12183 if Body_Acts_As_Spec then 12184 if Is_TSS (Ent, TSS_Deep_Initialize) then 12185 declare 12186 Typ : constant Entity_Id := Etype (First_Formal (Ent)); 12187 Init : Entity_Id; 12188 12189 begin 12190 if not Is_Controlled (Typ) then 12191 return; 12192 else 12193 Init := Find_Prim_Op (Typ, Name_Initialize); 12194 12195 if Comes_From_Source (Init) then 12196 Ent := Init; 12197 else 12198 return; 12199 end if; 12200 end if; 12201 end; 12202 12203 else 12204 return; 12205 end if; 12206 end if; 12207 12208 -- Check cases of internal units 12209 12210 Callee_Unit_Internal := In_Internal_Unit (E_Scope); 12211 12212 -- Do not give a warning if the with'ed unit is internal and this is 12213 -- the generic instantiation case (this saves a lot of hassle dealing 12214 -- with the Text_IO special child units) 12215 12216 if Callee_Unit_Internal and Inst_Case then 12217 return; 12218 end if; 12219 12220 if C_Scope = Standard_Standard then 12221 Caller_Unit_Internal := False; 12222 else 12223 Caller_Unit_Internal := In_Internal_Unit (C_Scope); 12224 end if; 12225 12226 -- Do not give a warning if the with'ed unit is internal and the caller 12227 -- is not internal (since the binder always elaborates internal units 12228 -- first). 12229 12230 if Callee_Unit_Internal and not Caller_Unit_Internal then 12231 return; 12232 end if; 12233 12234 -- For now, if debug flag -gnatdE is not set, do no checking for one 12235 -- internal unit withing another. This fixes the problem with the sgi 12236 -- build and storage errors. To be resolved later ??? 12237 12238 if (Callee_Unit_Internal and Caller_Unit_Internal) 12239 and not Debug_Flag_EE 12240 then 12241 return; 12242 end if; 12243 12244 if Is_TSS (E, TSS_Deep_Initialize) then 12245 Ent := E; 12246 end if; 12247 12248 -- If the call is in an instance, and the called entity is not 12249 -- defined in the same instance, then the elaboration issue focuses 12250 -- around the unit containing the template, it is this unit that 12251 -- requires an Elaborate_All. 12252 12253 -- However, if we are doing dynamic elaboration, we need to chase the 12254 -- call in the usual manner. 12255 12256 -- We also need to chase the call in the usual manner if it is a call 12257 -- to a generic formal parameter, since that case was not handled as 12258 -- part of the processing of the template. 12259 12260 Inst_Caller := Instantiation (Get_Source_File_Index (Sloc (N))); 12261 Inst_Callee := Instantiation (Get_Source_File_Index (Sloc (Ent))); 12262 12263 if Inst_Caller = No_Location then 12264 Unit_Caller := No_Unit; 12265 else 12266 Unit_Caller := Get_Source_Unit (N); 12267 end if; 12268 12269 if Inst_Callee = No_Location then 12270 Unit_Callee := No_Unit; 12271 else 12272 Unit_Callee := Get_Source_Unit (Ent); 12273 end if; 12274 12275 if Unit_Caller /= No_Unit 12276 and then Unit_Callee /= Unit_Caller 12277 and then not Dynamic_Elaboration_Checks 12278 and then not Is_Call_Of_Generic_Formal (N) 12279 then 12280 E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller)); 12281 12282 -- If we don't get a spec entity, just ignore call. Not quite 12283 -- clear why this check is necessary. ??? 12284 12285 if No (E_Scope) then 12286 return; 12287 end if; 12288 12289 -- Otherwise step to enclosing compilation unit 12290 12291 while not Is_Compilation_Unit (E_Scope) loop 12292 E_Scope := Scope (E_Scope); 12293 end loop; 12294 12295 -- For the case where N is not an instance, and is not a call within 12296 -- instance to other than a generic formal, we recompute E_Scope 12297 -- for the error message, since we do NOT want to go to the unit 12298 -- that has the ultimate declaration in the case of renaming and 12299 -- derivation and we also want to go to the generic unit in the 12300 -- case of an instance, and no further. 12301 12302 else 12303 -- Loop to carefully follow renamings and derivations one step 12304 -- outside the current unit, but not further. 12305 12306 if not (Inst_Case or Variable_Case) 12307 and then Present (Alias (Ent)) 12308 then 12309 E_Scope := Alias (Ent); 12310 else 12311 E_Scope := Ent; 12312 end if; 12313 12314 loop 12315 while not Is_Compilation_Unit (E_Scope) loop 12316 E_Scope := Scope (E_Scope); 12317 end loop; 12318 12319 -- If E_Scope is the same as C_Scope, it means that there 12320 -- definitely was a local renaming or derivation, and we 12321 -- are not yet out of the current unit. 12322 12323 exit when E_Scope /= C_Scope; 12324 Ent := Alias (Ent); 12325 E_Scope := Ent; 12326 12327 -- If no alias, there could be a previous error, but not if we've 12328 -- already reached the outermost level (Standard). 12329 12330 if No (Ent) then 12331 return; 12332 end if; 12333 end loop; 12334 end if; 12335 12336 if Within_Elaborate_All (Current_Sem_Unit, E_Scope) then 12337 return; 12338 end if; 12339 12340 -- Determine whether the Default_Initial_Condition procedure of some 12341 -- type is being invoked. 12342 12343 Is_DIC := Ekind (Ent) = E_Procedure and then Is_DIC_Procedure (Ent); 12344 12345 -- Checks related to Default_Initial_Condition fall under the SPARK 12346 -- umbrella because this is a SPARK-specific annotation. 12347 12348 SPARK_Elab_Errors := 12349 SPARK_Mode = On and (Is_DIC or Dynamic_Elaboration_Checks); 12350 12351 -- Now check if an Elaborate_All (or dynamic check) is needed 12352 12353 if (Elab_Info_Messages or Elab_Warnings or SPARK_Elab_Errors) 12354 and then Generate_Warnings 12355 and then not Suppress_Elaboration_Warnings (Ent) 12356 and then not Elaboration_Checks_Suppressed (Ent) 12357 and then not Suppress_Elaboration_Warnings (E_Scope) 12358 and then not Elaboration_Checks_Suppressed (E_Scope) 12359 then 12360 -- Instantiation case 12361 12362 if Inst_Case then 12363 if Comes_From_Source (Ent) and then SPARK_Elab_Errors then 12364 Error_Msg_NE 12365 ("instantiation of & during elaboration in SPARK", N, Ent); 12366 else 12367 Elab_Warning 12368 ("instantiation of & may raise Program_Error?l?", 12369 "info: instantiation of & during elaboration?$?", Ent); 12370 end if; 12371 12372 -- Indirect call case, info message only in static elaboration 12373 -- case, because the attribute reference itself cannot raise an 12374 -- exception. Note that SPARK does not permit indirect calls. 12375 12376 elsif Access_Case then 12377 Elab_Warning ("", "info: access to & during elaboration?$?", Ent); 12378 12379 -- Variable reference in SPARK mode 12380 12381 elsif Variable_Case then 12382 if Comes_From_Source (Ent) and then SPARK_Elab_Errors then 12383 Error_Msg_NE 12384 ("reference to & during elaboration in SPARK", N, Ent); 12385 end if; 12386 12387 -- Subprogram call case 12388 12389 else 12390 if Nkind (Name (N)) in N_Has_Entity 12391 and then Is_Init_Proc (Entity (Name (N))) 12392 and then Comes_From_Source (Ent) 12393 then 12394 Elab_Warning 12395 ("implicit call to & may raise Program_Error?l?", 12396 "info: implicit call to & during elaboration?$?", 12397 Ent); 12398 12399 elsif SPARK_Elab_Errors then 12400 12401 -- Emit a specialized error message when the elaboration of an 12402 -- object of a private type evaluates the expression of pragma 12403 -- Default_Initial_Condition. This prevents the internal name 12404 -- of the procedure from appearing in the error message. 12405 12406 if Is_DIC then 12407 Error_Msg_N 12408 ("call to Default_Initial_Condition during elaboration in " 12409 & "SPARK", N); 12410 else 12411 Error_Msg_NE 12412 ("call to & during elaboration in SPARK", N, Ent); 12413 end if; 12414 12415 else 12416 Elab_Warning 12417 ("call to & may raise Program_Error?l?", 12418 "info: call to & during elaboration?$?", 12419 Ent); 12420 end if; 12421 end if; 12422 12423 Error_Msg_Qual_Level := Nat'Last; 12424 12425 -- Case of Elaborate_All not present and required, for SPARK this 12426 -- is an error, so give an error message. 12427 12428 if SPARK_Elab_Errors then 12429 Error_Msg_NE -- CODEFIX 12430 ("\Elaborate_All pragma required for&", N, W_Scope); 12431 12432 -- Otherwise we generate an implicit pragma. For a subprogram 12433 -- instantiation, Elaborate is good enough, since no transitive 12434 -- call is possible at elaboration time in this case. 12435 12436 elsif Nkind (N) in N_Subprogram_Instantiation then 12437 Elab_Warning 12438 ("\missing pragma Elaborate for&?l?", 12439 "\implicit pragma Elaborate for& generated?$?", 12440 W_Scope); 12441 12442 -- For all other cases, we need an implicit Elaborate_All 12443 12444 else 12445 Elab_Warning 12446 ("\missing pragma Elaborate_All for&?l?", 12447 "\implicit pragma Elaborate_All for & generated?$?", 12448 W_Scope); 12449 end if; 12450 12451 Error_Msg_Qual_Level := 0; 12452 12453 -- Take into account the flags related to elaboration warning 12454 -- messages when enumerating the various calls involved. This 12455 -- ensures the proper pairing of the main warning and the 12456 -- clarification messages generated by Output_Calls. 12457 12458 Output_Calls (N, Check_Elab_Flag => True); 12459 12460 -- Set flag to prevent further warnings for same unit unless in 12461 -- All_Errors_Mode. 12462 12463 if not All_Errors_Mode and not Dynamic_Elaboration_Checks then 12464 Set_Suppress_Elaboration_Warnings (W_Scope); 12465 end if; 12466 end if; 12467 12468 -- Check for runtime elaboration check required 12469 12470 if Dynamic_Elaboration_Checks then 12471 if not Elaboration_Checks_Suppressed (Ent) 12472 and then not Elaboration_Checks_Suppressed (W_Scope) 12473 and then not Elaboration_Checks_Suppressed (E_Scope) 12474 and then not Cunit_SC 12475 then 12476 -- Runtime elaboration check required. Generate check of the 12477 -- elaboration Boolean for the unit containing the entity. 12478 12479 -- Note that for this case, we do check the real unit (the one 12480 -- from following renamings, since that is the issue). 12481 12482 -- Could this possibly miss a useless but required PE??? 12483 12484 Insert_Elab_Check (N, 12485 Make_Attribute_Reference (Loc, 12486 Attribute_Name => Name_Elaborated, 12487 Prefix => 12488 New_Occurrence_Of (Spec_Entity (E_Scope), Loc))); 12489 12490 -- Prevent duplicate elaboration checks on the same call, which 12491 -- can happen if the body enclosing the call appears itself in a 12492 -- call whose elaboration check is delayed. 12493 12494 if Nkind (N) in N_Subprogram_Call then 12495 Set_No_Elaboration_Check (N); 12496 end if; 12497 end if; 12498 12499 -- Case of static elaboration model 12500 12501 else 12502 -- Do not do anything if elaboration checks suppressed. Note that 12503 -- we check Ent here, not E, since we want the real entity for the 12504 -- body to see if checks are suppressed for it, not the dummy 12505 -- entry for renamings or derivations. 12506 12507 if Elaboration_Checks_Suppressed (Ent) 12508 or else Elaboration_Checks_Suppressed (E_Scope) 12509 or else Elaboration_Checks_Suppressed (W_Scope) 12510 then 12511 null; 12512 12513 -- Do not generate an Elaborate_All for finalization routines 12514 -- that perform partial clean up as part of initialization. 12515 12516 elsif In_Init_Proc and then Is_Finalization_Procedure (Ent) then 12517 null; 12518 12519 -- Here we need to generate an implicit elaborate all 12520 12521 else 12522 -- Generate Elaborate_All warning unless suppressed 12523 12524 if (Elab_Info_Messages and Generate_Warnings and not Inst_Case) 12525 and then not Suppress_Elaboration_Warnings (Ent) 12526 and then not Suppress_Elaboration_Warnings (E_Scope) 12527 and then not Suppress_Elaboration_Warnings (W_Scope) 12528 then 12529 Error_Msg_Node_2 := W_Scope; 12530 Error_Msg_NE 12531 ("info: call to& in elaboration code requires pragma " 12532 & "Elaborate_All on&?$?", N, E); 12533 end if; 12534 12535 -- Set indication for binder to generate Elaborate_All 12536 12537 Set_Elaboration_Constraint (N, E, W_Scope); 12538 end if; 12539 end if; 12540 end Check_A_Call; 12541 12542 ----------------------------- 12543 -- Check_Bad_Instantiation -- 12544 ----------------------------- 12545 12546 procedure Check_Bad_Instantiation (N : Node_Id) is 12547 Ent : Entity_Id; 12548 12549 begin 12550 -- Nothing to do if we do not have an instantiation (happens in some 12551 -- error cases, and also in the formal package declaration case) 12552 12553 if Nkind (N) not in N_Generic_Instantiation then 12554 return; 12555 12556 -- Nothing to do if serious errors detected (avoid cascaded errors) 12557 12558 elsif Serious_Errors_Detected /= 0 then 12559 return; 12560 12561 -- Nothing to do if not in full analysis mode 12562 12563 elsif not Full_Analysis then 12564 return; 12565 12566 -- Nothing to do if inside a generic template 12567 12568 elsif Inside_A_Generic then 12569 return; 12570 12571 -- Nothing to do if a library level instantiation 12572 12573 elsif Nkind (Parent (N)) = N_Compilation_Unit then 12574 return; 12575 12576 -- Nothing to do if we are compiling a proper body for semantic 12577 -- purposes only. The generic body may be in another proper body. 12578 12579 elsif 12580 Nkind (Parent (Unit_Declaration_Node (Main_Unit_Entity))) = N_Subunit 12581 then 12582 return; 12583 end if; 12584 12585 Ent := Get_Generic_Entity (N); 12586 12587 -- The case we are interested in is when the generic spec is in the 12588 -- current declarative part 12589 12590 if not Same_Elaboration_Scope (Current_Scope, Scope (Ent)) 12591 or else not In_Same_Extended_Unit (N, Ent) 12592 then 12593 return; 12594 end if; 12595 12596 -- If the generic entity is within a deeper instance than we are, then 12597 -- either the instantiation to which we refer itself caused an ABE, in 12598 -- which case that will be handled separately. Otherwise, we know that 12599 -- the body we need appears as needed at the point of the instantiation. 12600 -- If they are both at the same level but not within the same instance 12601 -- then the body of the generic will be in the earlier instance. 12602 12603 declare 12604 D1 : constant Nat := Instantiation_Depth (Sloc (Ent)); 12605 D2 : constant Nat := Instantiation_Depth (Sloc (N)); 12606 12607 begin 12608 if D1 > D2 then 12609 return; 12610 12611 elsif D1 = D2 12612 and then Is_Generic_Instance (Scope (Ent)) 12613 and then not In_Open_Scopes (Scope (Ent)) 12614 then 12615 return; 12616 end if; 12617 end; 12618 12619 -- Now we can proceed, if the entity being called has a completion, 12620 -- then we are definitely OK, since we have already seen the body. 12621 12622 if Has_Completion (Ent) then 12623 return; 12624 end if; 12625 12626 -- If there is no body, then nothing to do 12627 12628 if not Has_Generic_Body (N) then 12629 return; 12630 end if; 12631 12632 -- Here we definitely have a bad instantiation 12633 12634 Error_Msg_Warn := SPARK_Mode /= On; 12635 Error_Msg_NE ("cannot instantiate& before body seen<<", N, Ent); 12636 Error_Msg_N ("\Program_Error [<<", N); 12637 12638 Insert_Elab_Check (N); 12639 Set_Is_Known_Guaranteed_ABE (N); 12640 end Check_Bad_Instantiation; 12641 12642 --------------------- 12643 -- Check_Elab_Call -- 12644 --------------------- 12645 12646 procedure Check_Elab_Call 12647 (N : Node_Id; 12648 Outer_Scope : Entity_Id := Empty; 12649 In_Init_Proc : Boolean := False) 12650 is 12651 Ent : Entity_Id; 12652 P : Node_Id; 12653 12654 begin 12655 pragma Assert (Legacy_Elaboration_Checks); 12656 12657 -- If the reference is not in the main unit, there is nothing to check. 12658 -- Elaboration call from units in the context of the main unit will lead 12659 -- to semantic dependencies when those units are compiled. 12660 12661 if not In_Extended_Main_Code_Unit (N) then 12662 return; 12663 end if; 12664 12665 -- For an entry call, check relevant restriction 12666 12667 if Nkind (N) = N_Entry_Call_Statement 12668 and then not In_Subprogram_Or_Concurrent_Unit 12669 then 12670 Check_Restriction (No_Entry_Calls_In_Elaboration_Code, N); 12671 12672 -- Nothing to do if this is not an expected type of reference (happens 12673 -- in some error conditions, and in some cases where rewriting occurs). 12674 12675 elsif Nkind (N) not in N_Subprogram_Call 12676 and then Nkind (N) /= N_Attribute_Reference 12677 and then (SPARK_Mode /= On 12678 or else Nkind (N) not in N_Has_Entity 12679 or else No (Entity (N)) 12680 or else Ekind (Entity (N)) /= E_Variable) 12681 then 12682 return; 12683 12684 -- Nothing to do if this is a call already rewritten for elab checking. 12685 -- Such calls appear as the targets of If_Expressions. 12686 12687 -- This check MUST be wrong, it catches far too much 12688 12689 elsif Nkind (Parent (N)) = N_If_Expression then 12690 return; 12691 12692 -- Nothing to do if inside a generic template 12693 12694 elsif Inside_A_Generic 12695 and then No (Enclosing_Generic_Body (N)) 12696 then 12697 return; 12698 12699 -- Nothing to do if call is being pre-analyzed, as when within a 12700 -- pre/postcondition, a predicate, or an invariant. 12701 12702 elsif In_Spec_Expression then 12703 return; 12704 end if; 12705 12706 -- Nothing to do if this is a call to a postcondition, which is always 12707 -- within a subprogram body, even though the current scope may be the 12708 -- enclosing scope of the subprogram. 12709 12710 if Nkind (N) = N_Procedure_Call_Statement 12711 and then Is_Entity_Name (Name (N)) 12712 and then Chars (Entity (Name (N))) = Name_uPostconditions 12713 then 12714 return; 12715 end if; 12716 12717 -- Here we have a reference at elaboration time that must be checked 12718 12719 if Debug_Flag_Underscore_LL then 12720 Write_Str (" Check_Elab_Ref: "); 12721 12722 if Nkind (N) = N_Attribute_Reference then 12723 if not Is_Entity_Name (Prefix (N)) then 12724 Write_Str ("<<not entity name>>"); 12725 else 12726 Write_Name (Chars (Entity (Prefix (N)))); 12727 end if; 12728 12729 Write_Str ("'Access"); 12730 12731 elsif No (Name (N)) or else not Is_Entity_Name (Name (N)) then 12732 Write_Str ("<<not entity name>> "); 12733 12734 else 12735 Write_Name (Chars (Entity (Name (N)))); 12736 end if; 12737 12738 Write_Str (" reference at "); 12739 Write_Location (Sloc (N)); 12740 Write_Eol; 12741 end if; 12742 12743 -- Climb up the tree to make sure we are not inside default expression 12744 -- of a parameter specification or a record component, since in both 12745 -- these cases, we will be doing the actual reference later, not now, 12746 -- and it is at the time of the actual reference (statically speaking) 12747 -- that we must do our static check, not at the time of its initial 12748 -- analysis). 12749 12750 -- However, we have to check references within component definitions 12751 -- (e.g. a function call that determines an array component bound), 12752 -- so we terminate the loop in that case. 12753 12754 P := Parent (N); 12755 while Present (P) loop 12756 if Nkind_In (P, N_Parameter_Specification, 12757 N_Component_Declaration) 12758 then 12759 return; 12760 12761 -- The reference occurs within the constraint of a component, 12762 -- so it must be checked. 12763 12764 elsif Nkind (P) = N_Component_Definition then 12765 exit; 12766 12767 else 12768 P := Parent (P); 12769 end if; 12770 end loop; 12771 12772 -- Stuff that happens only at the outer level 12773 12774 if No (Outer_Scope) then 12775 Elab_Visited.Set_Last (0); 12776 12777 -- Nothing to do if current scope is Standard (this is a bit odd, but 12778 -- it happens in the case of generic instantiations). 12779 12780 C_Scope := Current_Scope; 12781 12782 if C_Scope = Standard_Standard then 12783 return; 12784 end if; 12785 12786 -- First case, we are in elaboration code 12787 12788 From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; 12789 12790 if From_Elab_Code then 12791 12792 -- Complain if ref that comes from source in preelaborated unit 12793 -- and we are not inside a subprogram (i.e. we are in elab code). 12794 12795 if Comes_From_Source (N) 12796 and then In_Preelaborated_Unit 12797 and then not In_Inlined_Body 12798 and then Nkind (N) /= N_Attribute_Reference 12799 then 12800 -- This is a warning in GNAT mode allowing such calls to be 12801 -- used in the predefined library with appropriate care. 12802 12803 Error_Msg_Warn := GNAT_Mode; 12804 Error_Msg_N 12805 ("<<non-static call not allowed in preelaborated unit", N); 12806 return; 12807 end if; 12808 12809 -- Second case, we are inside a subprogram or concurrent unit, which 12810 -- means we are not in elaboration code. 12811 12812 else 12813 -- In this case, the issue is whether we are inside the 12814 -- declarative part of the unit in which we live, or inside its 12815 -- statements. In the latter case, there is no issue of ABE calls 12816 -- at this level (a call from outside to the unit in which we live 12817 -- might cause an ABE, but that will be detected when we analyze 12818 -- that outer level call, as it recurses into the called unit). 12819 12820 -- Climb up the tree, doing this test, and also testing for being 12821 -- inside a default expression, which, as discussed above, is not 12822 -- checked at this stage. 12823 12824 declare 12825 P : Node_Id; 12826 L : List_Id; 12827 12828 begin 12829 P := N; 12830 loop 12831 -- If we find a parentless subtree, it seems safe to assume 12832 -- that we are not in a declarative part and that no 12833 -- checking is required. 12834 12835 if No (P) then 12836 return; 12837 end if; 12838 12839 if Is_List_Member (P) then 12840 L := List_Containing (P); 12841 P := Parent (L); 12842 else 12843 L := No_List; 12844 P := Parent (P); 12845 end if; 12846 12847 exit when Nkind (P) = N_Subunit; 12848 12849 -- Filter out case of default expressions, where we do not 12850 -- do the check at this stage. 12851 12852 if Nkind_In (P, N_Parameter_Specification, 12853 N_Component_Declaration) 12854 then 12855 return; 12856 end if; 12857 12858 -- A protected body has no elaboration code and contains 12859 -- only other bodies. 12860 12861 if Nkind (P) = N_Protected_Body then 12862 return; 12863 12864 elsif Nkind_In (P, N_Subprogram_Body, 12865 N_Task_Body, 12866 N_Block_Statement, 12867 N_Entry_Body) 12868 then 12869 if L = Declarations (P) then 12870 exit; 12871 12872 -- We are not in elaboration code, but we are doing 12873 -- dynamic elaboration checks, in this case, we still 12874 -- need to do the reference, since the subprogram we are 12875 -- in could be called from another unit, also in dynamic 12876 -- elaboration check mode, at elaboration time. 12877 12878 elsif Dynamic_Elaboration_Checks then 12879 12880 -- We provide a debug flag to disable this check. That 12881 -- way we have an easy work around for regressions 12882 -- that are caused by this new check. This debug flag 12883 -- can be removed later. 12884 12885 if Debug_Flag_DD then 12886 return; 12887 end if; 12888 12889 -- Do the check in this case 12890 12891 exit; 12892 12893 elsif Nkind (P) = N_Task_Body then 12894 12895 -- The check is deferred until Check_Task_Activation 12896 -- but we need to capture local suppress pragmas 12897 -- that may inhibit checks on this call. 12898 12899 Ent := Get_Referenced_Ent (N); 12900 12901 if No (Ent) then 12902 return; 12903 12904 elsif Elaboration_Checks_Suppressed (Current_Scope) 12905 or else Elaboration_Checks_Suppressed (Ent) 12906 or else Elaboration_Checks_Suppressed (Scope (Ent)) 12907 then 12908 if Nkind (N) in N_Subprogram_Call then 12909 Set_No_Elaboration_Check (N); 12910 end if; 12911 end if; 12912 12913 return; 12914 12915 -- Static model, call is not in elaboration code, we 12916 -- never need to worry, because in the static model the 12917 -- top-level caller always takes care of things. 12918 12919 else 12920 return; 12921 end if; 12922 end if; 12923 end loop; 12924 end; 12925 end if; 12926 end if; 12927 12928 Ent := Get_Referenced_Ent (N); 12929 12930 if No (Ent) then 12931 return; 12932 end if; 12933 12934 -- Determine whether a prior call to the same subprogram was already 12935 -- examined within the same context. If this is the case, then there is 12936 -- no need to proceed with the various warnings and checks because the 12937 -- work was already done for the previous call. 12938 12939 declare 12940 Self : constant Visited_Element := 12941 (Subp_Id => Ent, Context => Parent (N)); 12942 12943 begin 12944 for Index in 1 .. Elab_Visited.Last loop 12945 if Self = Elab_Visited.Table (Index) then 12946 return; 12947 end if; 12948 end loop; 12949 end; 12950 12951 -- See if we need to analyze this reference. We analyze it if either of 12952 -- the following conditions is met: 12953 12954 -- It is an inner level call (since in this case it was triggered 12955 -- by an outer level call from elaboration code), but only if the 12956 -- call is within the scope of the original outer level call. 12957 12958 -- It is an outer level reference from elaboration code, or a call to 12959 -- an entity is in the same elaboration scope. 12960 12961 -- And in these cases, we will check both inter-unit calls and 12962 -- intra-unit (within a single unit) calls. 12963 12964 C_Scope := Current_Scope; 12965 12966 -- If not outer level reference, then we follow it if it is within the 12967 -- original scope of the outer reference. 12968 12969 if Present (Outer_Scope) 12970 and then Within (Scope (Ent), Outer_Scope) 12971 then 12972 Set_C_Scope; 12973 Check_A_Call 12974 (N => N, 12975 E => Ent, 12976 Outer_Scope => Outer_Scope, 12977 Inter_Unit_Only => False, 12978 In_Init_Proc => In_Init_Proc); 12979 12980 -- Nothing to do if elaboration checks suppressed for this scope. 12981 -- However, an interesting exception, the fact that elaboration checks 12982 -- are suppressed within an instance (because we can trace the body when 12983 -- we process the template) does not extend to calls to generic formal 12984 -- subprograms. 12985 12986 elsif Elaboration_Checks_Suppressed (Current_Scope) 12987 and then not Is_Call_Of_Generic_Formal (N) 12988 then 12989 null; 12990 12991 elsif From_Elab_Code then 12992 Set_C_Scope; 12993 Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False); 12994 12995 elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then 12996 Set_C_Scope; 12997 Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); 12998 12999 -- If none of those cases holds, but Dynamic_Elaboration_Checks mode 13000 -- is set, then we will do the check, but only in the inter-unit case 13001 -- (this is to accommodate unguarded elaboration calls from other units 13002 -- in which this same mode is set). We don't want warnings in this case, 13003 -- it would generate warnings having nothing to do with elaboration. 13004 13005 elsif Dynamic_Elaboration_Checks then 13006 Set_C_Scope; 13007 Check_A_Call 13008 (N, 13009 Ent, 13010 Standard_Standard, 13011 Inter_Unit_Only => True, 13012 Generate_Warnings => False); 13013 13014 -- Otherwise nothing to do 13015 13016 else 13017 return; 13018 end if; 13019 13020 -- A call to an Init_Proc in elaboration code may bring additional 13021 -- dependencies, if some of the record components thereof have 13022 -- initializations that are function calls that come from source. We 13023 -- treat the current node as a call to each of these functions, to check 13024 -- their elaboration impact. 13025 13026 if Is_Init_Proc (Ent) and then From_Elab_Code then 13027 Process_Init_Proc : declare 13028 Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent); 13029 13030 function Check_Init_Call (Nod : Node_Id) return Traverse_Result; 13031 -- Find subprogram calls within body of Init_Proc for Traverse 13032 -- instantiation below. 13033 13034 procedure Traverse_Body is new Traverse_Proc (Check_Init_Call); 13035 -- Traversal procedure to find all calls with body of Init_Proc 13036 13037 --------------------- 13038 -- Check_Init_Call -- 13039 --------------------- 13040 13041 function Check_Init_Call (Nod : Node_Id) return Traverse_Result is 13042 Func : Entity_Id; 13043 13044 begin 13045 if Nkind (Nod) in N_Subprogram_Call 13046 and then Is_Entity_Name (Name (Nod)) 13047 then 13048 Func := Entity (Name (Nod)); 13049 13050 if Comes_From_Source (Func) then 13051 Check_A_Call 13052 (N, Func, Standard_Standard, Inter_Unit_Only => True); 13053 end if; 13054 13055 return OK; 13056 13057 else 13058 return OK; 13059 end if; 13060 end Check_Init_Call; 13061 13062 -- Start of processing for Process_Init_Proc 13063 13064 begin 13065 if Nkind (Unit_Decl) = N_Subprogram_Body then 13066 Traverse_Body (Handled_Statement_Sequence (Unit_Decl)); 13067 end if; 13068 end Process_Init_Proc; 13069 end if; 13070 end Check_Elab_Call; 13071 13072 ----------------------- 13073 -- Check_Elab_Assign -- 13074 ----------------------- 13075 13076 procedure Check_Elab_Assign (N : Node_Id) is 13077 Ent : Entity_Id; 13078 Scop : Entity_Id; 13079 13080 Pkg_Spec : Entity_Id; 13081 Pkg_Body : Entity_Id; 13082 13083 begin 13084 pragma Assert (Legacy_Elaboration_Checks); 13085 13086 -- For record or array component, check prefix. If it is an access type, 13087 -- then there is nothing to do (we do not know what is being assigned), 13088 -- but otherwise this is an assignment to the prefix. 13089 13090 if Nkind_In (N, N_Indexed_Component, 13091 N_Selected_Component, 13092 N_Slice) 13093 then 13094 if not Is_Access_Type (Etype (Prefix (N))) then 13095 Check_Elab_Assign (Prefix (N)); 13096 end if; 13097 13098 return; 13099 end if; 13100 13101 -- For type conversion, check expression 13102 13103 if Nkind (N) = N_Type_Conversion then 13104 Check_Elab_Assign (Expression (N)); 13105 return; 13106 end if; 13107 13108 -- Nothing to do if this is not an entity reference otherwise get entity 13109 13110 if Is_Entity_Name (N) then 13111 Ent := Entity (N); 13112 else 13113 return; 13114 end if; 13115 13116 -- What we are looking for is a reference in the body of a package that 13117 -- modifies a variable declared in the visible part of the package spec. 13118 13119 if Present (Ent) 13120 and then Comes_From_Source (N) 13121 and then not Suppress_Elaboration_Warnings (Ent) 13122 and then Ekind (Ent) = E_Variable 13123 and then not In_Private_Part (Ent) 13124 and then Is_Library_Level_Entity (Ent) 13125 then 13126 Scop := Current_Scope; 13127 loop 13128 if No (Scop) or else Scop = Standard_Standard then 13129 return; 13130 elsif Ekind (Scop) = E_Package 13131 and then Is_Compilation_Unit (Scop) 13132 then 13133 exit; 13134 else 13135 Scop := Scope (Scop); 13136 end if; 13137 end loop; 13138 13139 -- Here Scop points to the containing library package 13140 13141 Pkg_Spec := Scop; 13142 Pkg_Body := Body_Entity (Pkg_Spec); 13143 13144 -- All OK if the package has an Elaborate_Body pragma 13145 13146 if Has_Pragma_Elaborate_Body (Scop) then 13147 return; 13148 end if; 13149 13150 -- OK if entity being modified is not in containing package spec 13151 13152 if not In_Same_Source_Unit (Scop, Ent) then 13153 return; 13154 end if; 13155 13156 -- All OK if entity appears in generic package or generic instance. 13157 -- We just get too messed up trying to give proper warnings in the 13158 -- presence of generics. Better no message than a junk one. 13159 13160 Scop := Scope (Ent); 13161 while Present (Scop) and then Scop /= Pkg_Spec loop 13162 if Ekind (Scop) = E_Generic_Package then 13163 return; 13164 elsif Ekind (Scop) = E_Package 13165 and then Is_Generic_Instance (Scop) 13166 then 13167 return; 13168 end if; 13169 13170 Scop := Scope (Scop); 13171 end loop; 13172 13173 -- All OK if in task, don't issue warnings there 13174 13175 if In_Task_Activation then 13176 return; 13177 end if; 13178 13179 -- OK if no package body 13180 13181 if No (Pkg_Body) then 13182 return; 13183 end if; 13184 13185 -- OK if reference is not in package body 13186 13187 if not In_Same_Source_Unit (Pkg_Body, N) then 13188 return; 13189 end if; 13190 13191 -- OK if package body has no handled statement sequence 13192 13193 declare 13194 HSS : constant Node_Id := 13195 Handled_Statement_Sequence (Declaration_Node (Pkg_Body)); 13196 begin 13197 if No (HSS) or else not Comes_From_Source (HSS) then 13198 return; 13199 end if; 13200 end; 13201 13202 -- We definitely have a case of a modification of an entity in 13203 -- the package spec from the elaboration code of the package body. 13204 -- We may not give the warning (because there are some additional 13205 -- checks to avoid too many false positives), but it would be a good 13206 -- idea for the binder to try to keep the body elaboration close to 13207 -- the spec elaboration. 13208 13209 Set_Elaborate_Body_Desirable (Pkg_Spec); 13210 13211 -- All OK in gnat mode (we know what we are doing) 13212 13213 if GNAT_Mode then 13214 return; 13215 end if; 13216 13217 -- All OK if all warnings suppressed 13218 13219 if Warning_Mode = Suppress then 13220 return; 13221 end if; 13222 13223 -- All OK if elaboration checks suppressed for entity 13224 13225 if Checks_May_Be_Suppressed (Ent) 13226 and then Is_Check_Suppressed (Ent, Elaboration_Check) 13227 then 13228 return; 13229 end if; 13230 13231 -- OK if the entity is initialized. Note that the No_Initialization 13232 -- flag usually means that the initialization has been rewritten into 13233 -- assignments, but that still counts for us. 13234 13235 declare 13236 Decl : constant Node_Id := Declaration_Node (Ent); 13237 begin 13238 if Nkind (Decl) = N_Object_Declaration 13239 and then (Present (Expression (Decl)) 13240 or else No_Initialization (Decl)) 13241 then 13242 return; 13243 end if; 13244 end; 13245 13246 -- Here is where we give the warning 13247 13248 -- All OK if warnings suppressed on the entity 13249 13250 if not Has_Warnings_Off (Ent) then 13251 Error_Msg_Sloc := Sloc (Ent); 13252 13253 Error_Msg_NE 13254 ("??& can be accessed by clients before this initialization", 13255 N, Ent); 13256 Error_Msg_NE 13257 ("\??add Elaborate_Body to spec to ensure & is initialized", 13258 N, Ent); 13259 end if; 13260 13261 if not All_Errors_Mode then 13262 Set_Suppress_Elaboration_Warnings (Ent); 13263 end if; 13264 end if; 13265 end Check_Elab_Assign; 13266 13267 ---------------------- 13268 -- Check_Elab_Calls -- 13269 ---------------------- 13270 13271 -- WARNING: This routine manages SPARK regions 13272 13273 procedure Check_Elab_Calls is 13274 Saved_SM : SPARK_Mode_Type; 13275 Saved_SMP : Node_Id; 13276 13277 begin 13278 pragma Assert (Legacy_Elaboration_Checks); 13279 13280 -- If expansion is disabled, do not generate any checks, unless we 13281 -- are in GNATprove mode, so that errors are issued in GNATprove for 13282 -- violations of static elaboration rules in SPARK code. Also skip 13283 -- checks if any subunits are missing because in either case we lack the 13284 -- full information that we need, and no object file will be created in 13285 -- any case. 13286 13287 if (not Expander_Active and not GNATprove_Mode) 13288 or else Is_Generic_Unit (Cunit_Entity (Main_Unit)) 13289 or else Subunits_Missing 13290 then 13291 return; 13292 end if; 13293 13294 -- Skip delayed calls if we had any errors 13295 13296 if Serious_Errors_Detected = 0 then 13297 Delaying_Elab_Checks := False; 13298 Expander_Mode_Save_And_Set (True); 13299 13300 for J in Delay_Check.First .. Delay_Check.Last loop 13301 Push_Scope (Delay_Check.Table (J).Curscop); 13302 From_Elab_Code := Delay_Check.Table (J).From_Elab_Code; 13303 In_Task_Activation := Delay_Check.Table (J).In_Task_Activation; 13304 13305 Saved_SM := SPARK_Mode; 13306 Saved_SMP := SPARK_Mode_Pragma; 13307 13308 -- Set appropriate value of SPARK_Mode 13309 13310 if Delay_Check.Table (J).From_SPARK_Code then 13311 SPARK_Mode := On; 13312 end if; 13313 13314 Check_Internal_Call_Continue 13315 (N => Delay_Check.Table (J).N, 13316 E => Delay_Check.Table (J).E, 13317 Outer_Scope => Delay_Check.Table (J).Outer_Scope, 13318 Orig_Ent => Delay_Check.Table (J).Orig_Ent); 13319 13320 Restore_SPARK_Mode (Saved_SM, Saved_SMP); 13321 Pop_Scope; 13322 end loop; 13323 13324 -- Set Delaying_Elab_Checks back on for next main compilation 13325 13326 Expander_Mode_Restore; 13327 Delaying_Elab_Checks := True; 13328 end if; 13329 end Check_Elab_Calls; 13330 13331 ------------------------------ 13332 -- Check_Elab_Instantiation -- 13333 ------------------------------ 13334 13335 procedure Check_Elab_Instantiation 13336 (N : Node_Id; 13337 Outer_Scope : Entity_Id := Empty) 13338 is 13339 Ent : Entity_Id; 13340 13341 begin 13342 pragma Assert (Legacy_Elaboration_Checks); 13343 13344 -- Check for and deal with bad instantiation case. There is some 13345 -- duplicated code here, but we will worry about this later ??? 13346 13347 Check_Bad_Instantiation (N); 13348 13349 if Is_Known_Guaranteed_ABE (N) then 13350 return; 13351 end if; 13352 13353 -- Nothing to do if we do not have an instantiation (happens in some 13354 -- error cases, and also in the formal package declaration case) 13355 13356 if Nkind (N) not in N_Generic_Instantiation then 13357 return; 13358 end if; 13359 13360 -- Nothing to do if inside a generic template 13361 13362 if Inside_A_Generic then 13363 return; 13364 end if; 13365 13366 -- Nothing to do if the instantiation is not in the main unit 13367 13368 if not In_Extended_Main_Code_Unit (N) then 13369 return; 13370 end if; 13371 13372 Ent := Get_Generic_Entity (N); 13373 From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; 13374 13375 -- See if we need to analyze this instantiation. We analyze it if 13376 -- either of the following conditions is met: 13377 13378 -- It is an inner level instantiation (since in this case it was 13379 -- triggered by an outer level call from elaboration code), but 13380 -- only if the instantiation is within the scope of the original 13381 -- outer level call. 13382 13383 -- It is an outer level instantiation from elaboration code, or the 13384 -- instantiated entity is in the same elaboration scope. 13385 13386 -- And in these cases, we will check both the inter-unit case and 13387 -- the intra-unit (within a single unit) case. 13388 13389 C_Scope := Current_Scope; 13390 13391 if Present (Outer_Scope) and then Within (Scope (Ent), Outer_Scope) then 13392 Set_C_Scope; 13393 Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False); 13394 13395 elsif From_Elab_Code then 13396 Set_C_Scope; 13397 Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False); 13398 13399 elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then 13400 Set_C_Scope; 13401 Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); 13402 13403 -- If none of those cases holds, but Dynamic_Elaboration_Checks mode is 13404 -- set, then we will do the check, but only in the inter-unit case (this 13405 -- is to accommodate unguarded elaboration calls from other units in 13406 -- which this same mode is set). We inhibit warnings in this case, since 13407 -- this instantiation is not occurring in elaboration code. 13408 13409 elsif Dynamic_Elaboration_Checks then 13410 Set_C_Scope; 13411 Check_A_Call 13412 (N, 13413 Ent, 13414 Standard_Standard, 13415 Inter_Unit_Only => True, 13416 Generate_Warnings => False); 13417 13418 else 13419 return; 13420 end if; 13421 end Check_Elab_Instantiation; 13422 13423 ------------------------- 13424 -- Check_Internal_Call -- 13425 ------------------------- 13426 13427 procedure Check_Internal_Call 13428 (N : Node_Id; 13429 E : Entity_Id; 13430 Outer_Scope : Entity_Id; 13431 Orig_Ent : Entity_Id) 13432 is 13433 function Within_Initial_Condition (Call : Node_Id) return Boolean; 13434 -- Determine whether call Call occurs within pragma Initial_Condition or 13435 -- pragma Check with check_kind set to Initial_Condition. 13436 13437 ------------------------------ 13438 -- Within_Initial_Condition -- 13439 ------------------------------ 13440 13441 function Within_Initial_Condition (Call : Node_Id) return Boolean is 13442 Args : List_Id; 13443 Nam : Name_Id; 13444 Par : Node_Id; 13445 13446 begin 13447 -- Traverse the parent chain looking for an enclosing pragma 13448 13449 Par := Call; 13450 while Present (Par) loop 13451 if Nkind (Par) = N_Pragma then 13452 Nam := Pragma_Name (Par); 13453 13454 -- Pragma Initial_Condition appears in its alternative from as 13455 -- Check (Initial_Condition, ...). 13456 13457 if Nam = Name_Check then 13458 Args := Pragma_Argument_Associations (Par); 13459 13460 -- Pragma Check should have at least two arguments 13461 13462 pragma Assert (Present (Args)); 13463 13464 return 13465 Chars (Expression (First (Args))) = Name_Initial_Condition; 13466 13467 -- Direct match 13468 13469 elsif Nam = Name_Initial_Condition then 13470 return True; 13471 13472 -- Since pragmas are never nested within other pragmas, stop 13473 -- the traversal. 13474 13475 else 13476 return False; 13477 end if; 13478 13479 -- Prevent the search from going too far 13480 13481 elsif Is_Body_Or_Package_Declaration (Par) then 13482 exit; 13483 end if; 13484 13485 Par := Parent (Par); 13486 13487 -- If assertions are not enabled, the check pragma is rewritten 13488 -- as an if_statement in sem_prag, to generate various warnings 13489 -- on boolean expressions. Retrieve the original pragma. 13490 13491 if Nkind (Original_Node (Par)) = N_Pragma then 13492 Par := Original_Node (Par); 13493 end if; 13494 end loop; 13495 13496 return False; 13497 end Within_Initial_Condition; 13498 13499 -- Local variables 13500 13501 Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation; 13502 13503 -- Start of processing for Check_Internal_Call 13504 13505 begin 13506 -- For P'Access, we want to warn if the -gnatw.f switch is set, and the 13507 -- node comes from source. 13508 13509 if Nkind (N) = N_Attribute_Reference 13510 and then ((not Warn_On_Elab_Access and then not Debug_Flag_Dot_O) 13511 or else not Comes_From_Source (N)) 13512 then 13513 return; 13514 13515 -- If not function or procedure call, instantiation, or 'Access, then 13516 -- ignore call (this happens in some error cases and rewriting cases). 13517 13518 elsif not Nkind_In (N, N_Attribute_Reference, 13519 N_Function_Call, 13520 N_Procedure_Call_Statement) 13521 and then not Inst_Case 13522 then 13523 return; 13524 13525 -- Nothing to do if this is a call or instantiation that has already 13526 -- been found to be a sure ABE. 13527 13528 elsif Nkind (N) /= N_Attribute_Reference 13529 and then Is_Known_Guaranteed_ABE (N) 13530 then 13531 return; 13532 13533 -- Nothing to do if errors already detected (avoid cascaded errors) 13534 13535 elsif Serious_Errors_Detected /= 0 then 13536 return; 13537 13538 -- Nothing to do if not in full analysis mode 13539 13540 elsif not Full_Analysis then 13541 return; 13542 13543 -- Nothing to do if analyzing in special spec-expression mode, since the 13544 -- call is not actually being made at this time. 13545 13546 elsif In_Spec_Expression then 13547 return; 13548 13549 -- Nothing to do for call to intrinsic subprogram 13550 13551 elsif Is_Intrinsic_Subprogram (E) then 13552 return; 13553 13554 -- Nothing to do if call is within a generic unit 13555 13556 elsif Inside_A_Generic then 13557 return; 13558 13559 -- Nothing to do when the call appears within pragma Initial_Condition. 13560 -- The pragma is part of the elaboration statements of a package body 13561 -- and may only call external subprograms or subprograms whose body is 13562 -- already available. 13563 13564 elsif Within_Initial_Condition (N) then 13565 return; 13566 end if; 13567 13568 -- Delay this call if we are still delaying calls 13569 13570 if Delaying_Elab_Checks then 13571 Delay_Check.Append 13572 ((N => N, 13573 E => E, 13574 Orig_Ent => Orig_Ent, 13575 Curscop => Current_Scope, 13576 Outer_Scope => Outer_Scope, 13577 From_Elab_Code => From_Elab_Code, 13578 In_Task_Activation => In_Task_Activation, 13579 From_SPARK_Code => SPARK_Mode = On)); 13580 return; 13581 13582 -- Otherwise, call phase 2 continuation right now 13583 13584 else 13585 Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent); 13586 end if; 13587 end Check_Internal_Call; 13588 13589 ---------------------------------- 13590 -- Check_Internal_Call_Continue -- 13591 ---------------------------------- 13592 13593 procedure Check_Internal_Call_Continue 13594 (N : Node_Id; 13595 E : Entity_Id; 13596 Outer_Scope : Entity_Id; 13597 Orig_Ent : Entity_Id) 13598 is 13599 function Find_Elab_Reference (N : Node_Id) return Traverse_Result; 13600 -- Function applied to each node as we traverse the body. Checks for 13601 -- call or entity reference that needs checking, and if so checks it. 13602 -- Always returns OK, so entire tree is traversed, except that as 13603 -- described below subprogram bodies are skipped for now. 13604 13605 procedure Traverse is new Atree.Traverse_Proc (Find_Elab_Reference); 13606 -- Traverse procedure using above Find_Elab_Reference function 13607 13608 ------------------------- 13609 -- Find_Elab_Reference -- 13610 ------------------------- 13611 13612 function Find_Elab_Reference (N : Node_Id) return Traverse_Result is 13613 Actual : Node_Id; 13614 13615 begin 13616 -- If user has specified that there are no entry calls in elaboration 13617 -- code, do not trace past an accept statement, because the rendez- 13618 -- vous will happen after elaboration. 13619 13620 if Nkind_In (Original_Node (N), N_Accept_Statement, 13621 N_Selective_Accept) 13622 and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code) 13623 then 13624 return Abandon; 13625 13626 -- If we have a function call, check it 13627 13628 elsif Nkind (N) = N_Function_Call then 13629 Check_Elab_Call (N, Outer_Scope); 13630 return OK; 13631 13632 -- If we have a procedure call, check the call, and also check 13633 -- arguments that are assignments (OUT or IN OUT mode formals). 13634 13635 elsif Nkind (N) = N_Procedure_Call_Statement then 13636 Check_Elab_Call (N, Outer_Scope, In_Init_Proc => Is_Init_Proc (E)); 13637 13638 Actual := First_Actual (N); 13639 while Present (Actual) loop 13640 if Known_To_Be_Assigned (Actual) then 13641 Check_Elab_Assign (Actual); 13642 end if; 13643 13644 Next_Actual (Actual); 13645 end loop; 13646 13647 return OK; 13648 13649 -- If we have an access attribute for a subprogram, check it. 13650 -- Suppress this behavior under debug flag. 13651 13652 elsif not Debug_Flag_Dot_UU 13653 and then Nkind (N) = N_Attribute_Reference 13654 and then Nam_In (Attribute_Name (N), Name_Access, 13655 Name_Unrestricted_Access) 13656 and then Is_Entity_Name (Prefix (N)) 13657 and then Is_Subprogram (Entity (Prefix (N))) 13658 then 13659 Check_Elab_Call (N, Outer_Scope); 13660 return OK; 13661 13662 -- In SPARK mode, if we have an entity reference to a variable, then 13663 -- check it. For now we consider any reference. 13664 13665 elsif SPARK_Mode = On 13666 and then Nkind (N) in N_Has_Entity 13667 and then Present (Entity (N)) 13668 and then Ekind (Entity (N)) = E_Variable 13669 then 13670 Check_Elab_Call (N, Outer_Scope); 13671 return OK; 13672 13673 -- If we have a generic instantiation, check it 13674 13675 elsif Nkind (N) in N_Generic_Instantiation then 13676 Check_Elab_Instantiation (N, Outer_Scope); 13677 return OK; 13678 13679 -- Skip subprogram bodies that come from source (wait for call to 13680 -- analyze these). The reason for the come from source test is to 13681 -- avoid catching task bodies. 13682 13683 -- For task bodies, we should really avoid these too, waiting for the 13684 -- task activation, but that's too much trouble to catch for now, so 13685 -- we go in unconditionally. This is not so terrible, it means the 13686 -- error backtrace is not quite complete, and we are too eager to 13687 -- scan bodies of tasks that are unused, but this is hardly very 13688 -- significant. 13689 13690 elsif Nkind (N) = N_Subprogram_Body 13691 and then Comes_From_Source (N) 13692 then 13693 return Skip; 13694 13695 elsif Nkind (N) = N_Assignment_Statement 13696 and then Comes_From_Source (N) 13697 then 13698 Check_Elab_Assign (Name (N)); 13699 return OK; 13700 13701 else 13702 return OK; 13703 end if; 13704 end Find_Elab_Reference; 13705 13706 Inst_Case : constant Boolean := Is_Generic_Unit (E); 13707 Loc : constant Source_Ptr := Sloc (N); 13708 13709 Ebody : Entity_Id; 13710 Sbody : Node_Id; 13711 13712 -- Start of processing for Check_Internal_Call_Continue 13713 13714 begin 13715 -- Save outer level call if at outer level 13716 13717 if Elab_Call.Last = 0 then 13718 Outer_Level_Sloc := Loc; 13719 end if; 13720 13721 -- If the call is to a function that renames a literal, no check needed 13722 13723 if Ekind (E) = E_Enumeration_Literal then 13724 return; 13725 end if; 13726 13727 -- Register the subprogram as examined within this particular context. 13728 -- This ensures that calls to the same subprogram but in different 13729 -- contexts receive warnings and checks of their own since the calls 13730 -- may be reached through different flow paths. 13731 13732 Elab_Visited.Append ((Subp_Id => E, Context => Parent (N))); 13733 13734 Sbody := Unit_Declaration_Node (E); 13735 13736 if not Nkind_In (Sbody, N_Subprogram_Body, N_Package_Body) then 13737 Ebody := Corresponding_Body (Sbody); 13738 13739 if No (Ebody) then 13740 return; 13741 else 13742 Sbody := Unit_Declaration_Node (Ebody); 13743 end if; 13744 end if; 13745 13746 -- If the body appears after the outer level call or instantiation then 13747 -- we have an error case handled below. 13748 13749 if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody)) 13750 and then not In_Task_Activation 13751 then 13752 null; 13753 13754 -- If we have the instantiation case we are done, since we now know that 13755 -- the body of the generic appeared earlier. 13756 13757 elsif Inst_Case then 13758 return; 13759 13760 -- Otherwise we have a call, so we trace through the called body to see 13761 -- if it has any problems. 13762 13763 else 13764 pragma Assert (Nkind (Sbody) = N_Subprogram_Body); 13765 13766 Elab_Call.Append ((Cloc => Loc, Ent => E)); 13767 13768 if Debug_Flag_Underscore_LL then 13769 Write_Str ("Elab_Call.Last = "); 13770 Write_Int (Int (Elab_Call.Last)); 13771 Write_Str (" Ent = "); 13772 Write_Name (Chars (E)); 13773 Write_Str (" at "); 13774 Write_Location (Sloc (N)); 13775 Write_Eol; 13776 end if; 13777 13778 -- Now traverse declarations and statements of subprogram body. Note 13779 -- that we cannot simply Traverse (Sbody), since traverse does not 13780 -- normally visit subprogram bodies. 13781 13782 declare 13783 Decl : Node_Id; 13784 begin 13785 Decl := First (Declarations (Sbody)); 13786 while Present (Decl) loop 13787 Traverse (Decl); 13788 Next (Decl); 13789 end loop; 13790 end; 13791 13792 Traverse (Handled_Statement_Sequence (Sbody)); 13793 13794 Elab_Call.Decrement_Last; 13795 return; 13796 end if; 13797 13798 -- Here is the case of calling a subprogram where the body has not yet 13799 -- been encountered. A warning message is needed, except if this is the 13800 -- case of appearing within an aspect specification that results in 13801 -- a check call, we do not really have such a situation, so no warning 13802 -- is needed (e.g. the case of a precondition, where the call appears 13803 -- textually before the body, but in actual fact is moved to the 13804 -- appropriate subprogram body and so does not need a check). 13805 13806 declare 13807 P : Node_Id; 13808 O : Node_Id; 13809 13810 begin 13811 P := Parent (N); 13812 loop 13813 -- Keep looking at parents if we are still in the subexpression 13814 13815 if Nkind (P) in N_Subexpr then 13816 P := Parent (P); 13817 13818 -- Here P is the parent of the expression, check for special case 13819 13820 else 13821 O := Original_Node (P); 13822 13823 -- Definitely not the special case if orig node is not a pragma 13824 13825 exit when Nkind (O) /= N_Pragma; 13826 13827 -- Check we have an If statement or a null statement (happens 13828 -- when the If has been expanded to be True). 13829 13830 exit when not Nkind_In (P, N_If_Statement, N_Null_Statement); 13831 13832 -- Our special case will be indicated either by the pragma 13833 -- coming from an aspect ... 13834 13835 if Present (Corresponding_Aspect (O)) then 13836 return; 13837 13838 -- Or, in the case of an initial condition, specifically by a 13839 -- Check pragma specifying an Initial_Condition check. 13840 13841 elsif Pragma_Name (O) = Name_Check 13842 and then 13843 Chars 13844 (Expression (First (Pragma_Argument_Associations (O)))) = 13845 Name_Initial_Condition 13846 then 13847 return; 13848 13849 -- For anything else, we have an error 13850 13851 else 13852 exit; 13853 end if; 13854 end if; 13855 end loop; 13856 end; 13857 13858 -- Not that special case, warning and dynamic check is required 13859 13860 -- If we have nothing in the call stack, then this is at the outer 13861 -- level, and the ABE is bound to occur, unless it's a 'Access, or 13862 -- it's a renaming. 13863 13864 if Elab_Call.Last = 0 then 13865 Error_Msg_Warn := SPARK_Mode /= On; 13866 13867 declare 13868 Insert_Check : Boolean := True; 13869 -- This flag is set to True if an elaboration check should be 13870 -- inserted. 13871 13872 begin 13873 if In_Task_Activation then 13874 Insert_Check := False; 13875 13876 elsif Inst_Case then 13877 Error_Msg_NE 13878 ("cannot instantiate& before body seen<<", N, Orig_Ent); 13879 13880 elsif Nkind (N) = N_Attribute_Reference then 13881 Error_Msg_NE 13882 ("Access attribute of & before body seen<<", N, Orig_Ent); 13883 Error_Msg_N ("\possible Program_Error on later references<", N); 13884 Insert_Check := False; 13885 13886 elsif Nkind (Unit_Declaration_Node (Orig_Ent)) /= 13887 N_Subprogram_Renaming_Declaration 13888 then 13889 Error_Msg_NE 13890 ("cannot call& before body seen<<", N, Orig_Ent); 13891 13892 elsif not Is_Generic_Actual_Subprogram (Orig_Ent) then 13893 Insert_Check := False; 13894 end if; 13895 13896 if Insert_Check then 13897 Error_Msg_N ("\Program_Error [<<", N); 13898 Insert_Elab_Check (N); 13899 end if; 13900 end; 13901 13902 -- Call is not at outer level 13903 13904 else 13905 -- Do not generate elaboration checks in GNATprove mode because the 13906 -- elaboration counter and the check are both forms of expansion. 13907 13908 if GNATprove_Mode then 13909 null; 13910 13911 -- Generate an elaboration check 13912 13913 elsif not Elaboration_Checks_Suppressed (E) then 13914 Set_Elaboration_Entity_Required (E); 13915 13916 -- Create a declaration of the elaboration entity, and insert it 13917 -- prior to the subprogram or the generic unit, within the same 13918 -- scope. Since the subprogram may be overloaded, create a unique 13919 -- entity. 13920 13921 if No (Elaboration_Entity (E)) then 13922 declare 13923 Loce : constant Source_Ptr := Sloc (E); 13924 Ent : constant Entity_Id := 13925 Make_Defining_Identifier (Loc, 13926 New_External_Name (Chars (E), 'E', -1)); 13927 13928 begin 13929 Set_Elaboration_Entity (E, Ent); 13930 Push_Scope (Scope (E)); 13931 13932 Insert_Action (Declaration_Node (E), 13933 Make_Object_Declaration (Loce, 13934 Defining_Identifier => Ent, 13935 Object_Definition => 13936 New_Occurrence_Of (Standard_Short_Integer, Loce), 13937 Expression => 13938 Make_Integer_Literal (Loc, Uint_0))); 13939 13940 -- Set elaboration flag at the point of the body 13941 13942 Set_Elaboration_Flag (Sbody, E); 13943 13944 -- Kill current value indication. This is necessary because 13945 -- the tests of this flag are inserted out of sequence and 13946 -- must not pick up bogus indications of the wrong constant 13947 -- value. Also, this is never a true constant, since one way 13948 -- or another, it gets reset. 13949 13950 Set_Current_Value (Ent, Empty); 13951 Set_Last_Assignment (Ent, Empty); 13952 Set_Is_True_Constant (Ent, False); 13953 Pop_Scope; 13954 end; 13955 end if; 13956 13957 -- Generate: 13958 -- if Enn = 0 then 13959 -- raise Program_Error with "access before elaboration"; 13960 -- end if; 13961 13962 Insert_Elab_Check (N, 13963 Make_Attribute_Reference (Loc, 13964 Attribute_Name => Name_Elaborated, 13965 Prefix => New_Occurrence_Of (E, Loc))); 13966 end if; 13967 13968 -- Generate the warning 13969 13970 if not Suppress_Elaboration_Warnings (E) 13971 and then not Elaboration_Checks_Suppressed (E) 13972 13973 -- Suppress this warning if we have a function call that occurred 13974 -- within an assertion expression, since we can get false warnings 13975 -- in this case, due to the out of order handling in this case. 13976 13977 and then 13978 (Nkind (Original_Node (N)) /= N_Function_Call 13979 or else not In_Assertion_Expression_Pragma (Original_Node (N))) 13980 then 13981 Error_Msg_Warn := SPARK_Mode /= On; 13982 13983 if Inst_Case then 13984 Error_Msg_NE 13985 ("instantiation of& may occur before body is seen<l<", 13986 N, Orig_Ent); 13987 else 13988 -- A rather specific check. For Finalize/Adjust/Initialize, if 13989 -- the type has Warnings_Off set, suppress the warning. 13990 13991 if Nam_In (Chars (E), Name_Adjust, 13992 Name_Finalize, 13993 Name_Initialize) 13994 and then Present (First_Formal (E)) 13995 then 13996 declare 13997 T : constant Entity_Id := Etype (First_Formal (E)); 13998 begin 13999 if Is_Controlled (T) then 14000 if Warnings_Off (T) 14001 or else (Ekind (T) = E_Private_Type 14002 and then Warnings_Off (Full_View (T))) 14003 then 14004 goto Output; 14005 end if; 14006 end if; 14007 end; 14008 end if; 14009 14010 -- Go ahead and give warning if not this special case 14011 14012 Error_Msg_NE 14013 ("call to& may occur before body is seen<l<", N, Orig_Ent); 14014 end if; 14015 14016 Error_Msg_N ("\Program_Error ]<l<", N); 14017 14018 -- There is no need to query the elaboration warning message flags 14019 -- because the main message is an error, not a warning, therefore 14020 -- all the clarification messages produces by Output_Calls must be 14021 -- emitted unconditionally. 14022 14023 <<Output>> 14024 14025 Output_Calls (N, Check_Elab_Flag => False); 14026 end if; 14027 end if; 14028 end Check_Internal_Call_Continue; 14029 14030 --------------------------- 14031 -- Check_Task_Activation -- 14032 --------------------------- 14033 14034 procedure Check_Task_Activation (N : Node_Id) is 14035 Loc : constant Source_Ptr := Sloc (N); 14036 Inter_Procs : constant Elist_Id := New_Elmt_List; 14037 Intra_Procs : constant Elist_Id := New_Elmt_List; 14038 Ent : Entity_Id; 14039 P : Entity_Id; 14040 Task_Scope : Entity_Id; 14041 Cunit_SC : Boolean := False; 14042 Decl : Node_Id; 14043 Elmt : Elmt_Id; 14044 Enclosing : Entity_Id; 14045 14046 procedure Add_Task_Proc (Typ : Entity_Id); 14047 -- Add to Task_Procs the task body procedure(s) of task types in Typ. 14048 -- For record types, this procedure recurses over component types. 14049 14050 procedure Collect_Tasks (Decls : List_Id); 14051 -- Collect the types of the tasks that are to be activated in the given 14052 -- list of declarations, in order to perform elaboration checks on the 14053 -- corresponding task procedures that are called implicitly here. 14054 14055 function Outer_Unit (E : Entity_Id) return Entity_Id; 14056 -- find enclosing compilation unit of Entity, ignoring subunits, or 14057 -- else enclosing subprogram. If E is not a package, there is no need 14058 -- for inter-unit elaboration checks. 14059 14060 ------------------- 14061 -- Add_Task_Proc -- 14062 ------------------- 14063 14064 procedure Add_Task_Proc (Typ : Entity_Id) is 14065 Comp : Entity_Id; 14066 Proc : Entity_Id := Empty; 14067 14068 begin 14069 if Is_Task_Type (Typ) then 14070 Proc := Get_Task_Body_Procedure (Typ); 14071 14072 elsif Is_Array_Type (Typ) 14073 and then Has_Task (Base_Type (Typ)) 14074 then 14075 Add_Task_Proc (Component_Type (Typ)); 14076 14077 elsif Is_Record_Type (Typ) 14078 and then Has_Task (Base_Type (Typ)) 14079 then 14080 Comp := First_Component (Typ); 14081 while Present (Comp) loop 14082 Add_Task_Proc (Etype (Comp)); 14083 Comp := Next_Component (Comp); 14084 end loop; 14085 end if; 14086 14087 -- If the task type is another unit, we will perform the usual 14088 -- elaboration check on its enclosing unit. If the type is in the 14089 -- same unit, we can trace the task body as for an internal call, 14090 -- but we only need to examine other external calls, because at 14091 -- the point the task is activated, internal subprogram bodies 14092 -- will have been elaborated already. We keep separate lists for 14093 -- each kind of task. 14094 14095 -- Skip this test if errors have occurred, since in this case 14096 -- we can get false indications. 14097 14098 if Serious_Errors_Detected /= 0 then 14099 return; 14100 end if; 14101 14102 if Present (Proc) then 14103 if Outer_Unit (Scope (Proc)) = Enclosing then 14104 14105 if No (Corresponding_Body (Unit_Declaration_Node (Proc))) 14106 and then 14107 (not Is_Generic_Instance (Scope (Proc)) 14108 or else Scope (Proc) = Scope (Defining_Identifier (Decl))) 14109 then 14110 Error_Msg_Warn := SPARK_Mode /= On; 14111 Error_Msg_N 14112 ("task will be activated before elaboration of its body<<", 14113 Decl); 14114 Error_Msg_N ("\Program_Error [<<", Decl); 14115 14116 elsif Present 14117 (Corresponding_Body (Unit_Declaration_Node (Proc))) 14118 then 14119 Append_Elmt (Proc, Intra_Procs); 14120 end if; 14121 14122 else 14123 -- No need for multiple entries of the same type 14124 14125 Elmt := First_Elmt (Inter_Procs); 14126 while Present (Elmt) loop 14127 if Node (Elmt) = Proc then 14128 return; 14129 end if; 14130 14131 Next_Elmt (Elmt); 14132 end loop; 14133 14134 Append_Elmt (Proc, Inter_Procs); 14135 end if; 14136 end if; 14137 end Add_Task_Proc; 14138 14139 ------------------- 14140 -- Collect_Tasks -- 14141 ------------------- 14142 14143 procedure Collect_Tasks (Decls : List_Id) is 14144 begin 14145 if Present (Decls) then 14146 Decl := First (Decls); 14147 while Present (Decl) loop 14148 if Nkind (Decl) = N_Object_Declaration 14149 and then Has_Task (Etype (Defining_Identifier (Decl))) 14150 then 14151 Add_Task_Proc (Etype (Defining_Identifier (Decl))); 14152 end if; 14153 14154 Next (Decl); 14155 end loop; 14156 end if; 14157 end Collect_Tasks; 14158 14159 ---------------- 14160 -- Outer_Unit -- 14161 ---------------- 14162 14163 function Outer_Unit (E : Entity_Id) return Entity_Id is 14164 Outer : Entity_Id; 14165 14166 begin 14167 Outer := E; 14168 while Present (Outer) loop 14169 if Elaboration_Checks_Suppressed (Outer) then 14170 Cunit_SC := True; 14171 end if; 14172 14173 exit when Is_Child_Unit (Outer) 14174 or else Scope (Outer) = Standard_Standard 14175 or else Ekind (Outer) /= E_Package; 14176 Outer := Scope (Outer); 14177 end loop; 14178 14179 return Outer; 14180 end Outer_Unit; 14181 14182 -- Start of processing for Check_Task_Activation 14183 14184 begin 14185 pragma Assert (Legacy_Elaboration_Checks); 14186 14187 Enclosing := Outer_Unit (Current_Scope); 14188 14189 -- Find all tasks declared in the current unit 14190 14191 if Nkind (N) = N_Package_Body then 14192 P := Unit_Declaration_Node (Corresponding_Spec (N)); 14193 14194 Collect_Tasks (Declarations (N)); 14195 Collect_Tasks (Visible_Declarations (Specification (P))); 14196 Collect_Tasks (Private_Declarations (Specification (P))); 14197 14198 elsif Nkind (N) = N_Package_Declaration then 14199 Collect_Tasks (Visible_Declarations (Specification (N))); 14200 Collect_Tasks (Private_Declarations (Specification (N))); 14201 14202 else 14203 Collect_Tasks (Declarations (N)); 14204 end if; 14205 14206 -- We only perform detailed checks in all tasks that are library level 14207 -- entities. If the master is a subprogram or task, activation will 14208 -- depend on the activation of the master itself. 14209 14210 -- Should dynamic checks be added in the more general case??? 14211 14212 if Ekind (Enclosing) /= E_Package then 14213 return; 14214 end if; 14215 14216 -- For task types defined in other units, we want the unit containing 14217 -- the task body to be elaborated before the current one. 14218 14219 Elmt := First_Elmt (Inter_Procs); 14220 while Present (Elmt) loop 14221 Ent := Node (Elmt); 14222 Task_Scope := Outer_Unit (Scope (Ent)); 14223 14224 if not Is_Compilation_Unit (Task_Scope) then 14225 null; 14226 14227 elsif Suppress_Elaboration_Warnings (Task_Scope) 14228 or else Elaboration_Checks_Suppressed (Task_Scope) 14229 then 14230 null; 14231 14232 elsif Dynamic_Elaboration_Checks then 14233 if not Elaboration_Checks_Suppressed (Ent) 14234 and then not Cunit_SC 14235 and then not Restriction_Active 14236 (No_Entry_Calls_In_Elaboration_Code) 14237 then 14238 -- Runtime elaboration check required. Generate check of the 14239 -- elaboration counter for the unit containing the entity. 14240 14241 Insert_Elab_Check (N, 14242 Make_Attribute_Reference (Loc, 14243 Prefix => 14244 New_Occurrence_Of (Spec_Entity (Task_Scope), Loc), 14245 Attribute_Name => Name_Elaborated)); 14246 end if; 14247 14248 else 14249 -- Force the binder to elaborate other unit first 14250 14251 if Elab_Info_Messages 14252 and then not Suppress_Elaboration_Warnings (Ent) 14253 and then not Elaboration_Checks_Suppressed (Ent) 14254 and then not Suppress_Elaboration_Warnings (Task_Scope) 14255 and then not Elaboration_Checks_Suppressed (Task_Scope) 14256 then 14257 Error_Msg_Node_2 := Task_Scope; 14258 Error_Msg_NE 14259 ("info: activation of an instance of task type & requires " 14260 & "pragma Elaborate_All on &?$?", N, Ent); 14261 end if; 14262 14263 Activate_Elaborate_All_Desirable (N, Task_Scope); 14264 Set_Suppress_Elaboration_Warnings (Task_Scope); 14265 end if; 14266 14267 Next_Elmt (Elmt); 14268 end loop; 14269 14270 -- For tasks declared in the current unit, trace other calls within the 14271 -- task procedure bodies, which are available. 14272 14273 if not Debug_Flag_Dot_Y then 14274 In_Task_Activation := True; 14275 14276 Elmt := First_Elmt (Intra_Procs); 14277 while Present (Elmt) loop 14278 Ent := Node (Elmt); 14279 Check_Internal_Call_Continue (N, Ent, Enclosing, Ent); 14280 Next_Elmt (Elmt); 14281 end loop; 14282 14283 In_Task_Activation := False; 14284 end if; 14285 end Check_Task_Activation; 14286 14287 ------------------------ 14288 -- Get_Referenced_Ent -- 14289 ------------------------ 14290 14291 function Get_Referenced_Ent (N : Node_Id) return Entity_Id is 14292 Nam : Node_Id; 14293 14294 begin 14295 if Nkind (N) in N_Has_Entity 14296 and then Present (Entity (N)) 14297 and then Ekind (Entity (N)) = E_Variable 14298 then 14299 return Entity (N); 14300 end if; 14301 14302 if Nkind (N) = N_Attribute_Reference then 14303 Nam := Prefix (N); 14304 else 14305 Nam := Name (N); 14306 end if; 14307 14308 if No (Nam) then 14309 return Empty; 14310 elsif Nkind (Nam) = N_Selected_Component then 14311 return Entity (Selector_Name (Nam)); 14312 elsif not Is_Entity_Name (Nam) then 14313 return Empty; 14314 else 14315 return Entity (Nam); 14316 end if; 14317 end Get_Referenced_Ent; 14318 14319 ---------------------- 14320 -- Has_Generic_Body -- 14321 ---------------------- 14322 14323 function Has_Generic_Body (N : Node_Id) return Boolean is 14324 Ent : constant Entity_Id := Get_Generic_Entity (N); 14325 Decl : constant Node_Id := Unit_Declaration_Node (Ent); 14326 Scop : Entity_Id; 14327 14328 function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id; 14329 -- Determine if the list of nodes headed by N and linked by Next 14330 -- contains a package body for the package spec entity E, and if so 14331 -- return the package body. If not, then returns Empty. 14332 14333 function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id; 14334 -- This procedure is called load the unit whose name is given by Nam. 14335 -- This unit is being loaded to see whether it contains an optional 14336 -- generic body. The returned value is the loaded unit, which is always 14337 -- a package body (only package bodies can contain other entities in the 14338 -- sense in which Has_Generic_Body is interested). We only attempt to 14339 -- load bodies if we are generating code. If we are in semantics check 14340 -- only mode, then it would be wrong to load bodies that are not 14341 -- required from a semantic point of view, so in this case we return 14342 -- Empty. The result is that the caller may incorrectly decide that a 14343 -- generic spec does not have a body when in fact it does, but the only 14344 -- harm in this is that some warnings on elaboration problems may be 14345 -- lost in semantic checks only mode, which is not big loss. We also 14346 -- return Empty if we go for a body and it is not there. 14347 14348 function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id; 14349 -- PE is the entity for a package spec. This function locates the 14350 -- corresponding package body, returning Empty if none is found. The 14351 -- package body returned is fully parsed but may not yet be analyzed, 14352 -- so only syntactic fields should be referenced. 14353 14354 ------------------ 14355 -- Find_Body_In -- 14356 ------------------ 14357 14358 function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id is 14359 Nod : Node_Id; 14360 14361 begin 14362 Nod := N; 14363 while Present (Nod) loop 14364 14365 -- If we found the package body we are looking for, return it 14366 14367 if Nkind (Nod) = N_Package_Body 14368 and then Chars (Defining_Unit_Name (Nod)) = Chars (E) 14369 then 14370 return Nod; 14371 14372 -- If we found the stub for the body, go after the subunit, 14373 -- loading it if necessary. 14374 14375 elsif Nkind (Nod) = N_Package_Body_Stub 14376 and then Chars (Defining_Identifier (Nod)) = Chars (E) 14377 then 14378 if Present (Library_Unit (Nod)) then 14379 return Unit (Library_Unit (Nod)); 14380 14381 else 14382 return Load_Package_Body (Get_Unit_Name (Nod)); 14383 end if; 14384 14385 -- If neither package body nor stub, keep looking on chain 14386 14387 else 14388 Next (Nod); 14389 end if; 14390 end loop; 14391 14392 return Empty; 14393 end Find_Body_In; 14394 14395 ----------------------- 14396 -- Load_Package_Body -- 14397 ----------------------- 14398 14399 function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id is 14400 U : Unit_Number_Type; 14401 14402 begin 14403 if Operating_Mode /= Generate_Code then 14404 return Empty; 14405 else 14406 U := 14407 Load_Unit 14408 (Load_Name => Nam, 14409 Required => False, 14410 Subunit => False, 14411 Error_Node => N); 14412 14413 if U = No_Unit then 14414 return Empty; 14415 else 14416 return Unit (Cunit (U)); 14417 end if; 14418 end if; 14419 end Load_Package_Body; 14420 14421 ------------------------------- 14422 -- Locate_Corresponding_Body -- 14423 ------------------------------- 14424 14425 function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id is 14426 Spec : constant Node_Id := Declaration_Node (PE); 14427 Decl : constant Node_Id := Parent (Spec); 14428 Scop : constant Entity_Id := Scope (PE); 14429 PBody : Node_Id; 14430 14431 begin 14432 if Is_Library_Level_Entity (PE) then 14433 14434 -- If package is a library unit that requires a body, we have no 14435 -- choice but to go after that body because it might contain an 14436 -- optional body for the original generic package. 14437 14438 if Unit_Requires_Body (PE) then 14439 14440 -- Load the body. Note that we are a little careful here to use 14441 -- Spec to get the unit number, rather than PE or Decl, since 14442 -- in the case where the package is itself a library level 14443 -- instantiation, Spec will properly reference the generic 14444 -- template, which is what we really want. 14445 14446 return 14447 Load_Package_Body 14448 (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec)))); 14449 14450 -- But if the package is a library unit that does NOT require 14451 -- a body, then no body is permitted, so we are sure that there 14452 -- is no body for the original generic package. 14453 14454 else 14455 return Empty; 14456 end if; 14457 14458 -- Otherwise look and see if we are embedded in a further package 14459 14460 elsif Is_Package_Or_Generic_Package (Scop) then 14461 14462 -- If so, get the body of the enclosing package, and look in 14463 -- its package body for the package body we are looking for. 14464 14465 PBody := Locate_Corresponding_Body (Scop); 14466 14467 if No (PBody) then 14468 return Empty; 14469 else 14470 return Find_Body_In (PE, First (Declarations (PBody))); 14471 end if; 14472 14473 -- If we are not embedded in a further package, then the body 14474 -- must be in the same declarative part as we are. 14475 14476 else 14477 return Find_Body_In (PE, Next (Decl)); 14478 end if; 14479 end Locate_Corresponding_Body; 14480 14481 -- Start of processing for Has_Generic_Body 14482 14483 begin 14484 if Present (Corresponding_Body (Decl)) then 14485 return True; 14486 14487 elsif Unit_Requires_Body (Ent) then 14488 return True; 14489 14490 -- Compilation units cannot have optional bodies 14491 14492 elsif Is_Compilation_Unit (Ent) then 14493 return False; 14494 14495 -- Otherwise look at what scope we are in 14496 14497 else 14498 Scop := Scope (Ent); 14499 14500 -- Case of entity is in other than a package spec, in this case 14501 -- the body, if present, must be in the same declarative part. 14502 14503 if not Is_Package_Or_Generic_Package (Scop) then 14504 declare 14505 P : Node_Id; 14506 14507 begin 14508 -- Declaration node may get us a spec, so if so, go to 14509 -- the parent declaration. 14510 14511 P := Declaration_Node (Ent); 14512 while not Is_List_Member (P) loop 14513 P := Parent (P); 14514 end loop; 14515 14516 return Present (Find_Body_In (Ent, Next (P))); 14517 end; 14518 14519 -- If the entity is in a package spec, then we have to locate 14520 -- the corresponding package body, and look there. 14521 14522 else 14523 declare 14524 PBody : constant Node_Id := Locate_Corresponding_Body (Scop); 14525 14526 begin 14527 if No (PBody) then 14528 return False; 14529 else 14530 return 14531 Present 14532 (Find_Body_In (Ent, (First (Declarations (PBody))))); 14533 end if; 14534 end; 14535 end if; 14536 end if; 14537 end Has_Generic_Body; 14538 14539 ----------------------- 14540 -- Insert_Elab_Check -- 14541 ----------------------- 14542 14543 procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty) is 14544 Nod : Node_Id; 14545 Loc : constant Source_Ptr := Sloc (N); 14546 14547 Chk : Node_Id; 14548 -- The check (N_Raise_Program_Error) node to be inserted 14549 14550 begin 14551 -- If expansion is disabled, do not generate any checks. Also 14552 -- skip checks if any subunits are missing because in either 14553 -- case we lack the full information that we need, and no object 14554 -- file will be created in any case. 14555 14556 if not Expander_Active or else Subunits_Missing then 14557 return; 14558 end if; 14559 14560 -- If we have a generic instantiation, where Instance_Spec is set, 14561 -- then this field points to a generic instance spec that has 14562 -- been inserted before the instantiation node itself, so that 14563 -- is where we want to insert a check. 14564 14565 if Nkind (N) in N_Generic_Instantiation 14566 and then Present (Instance_Spec (N)) 14567 then 14568 Nod := Instance_Spec (N); 14569 else 14570 Nod := N; 14571 end if; 14572 14573 -- Build check node, possibly with condition 14574 14575 Chk := 14576 Make_Raise_Program_Error (Loc, Reason => PE_Access_Before_Elaboration); 14577 14578 if Present (C) then 14579 Set_Condition (Chk, Make_Op_Not (Loc, Right_Opnd => C)); 14580 end if; 14581 14582 -- If we are inserting at the top level, insert in Aux_Decls 14583 14584 if Nkind (Parent (Nod)) = N_Compilation_Unit then 14585 declare 14586 ADN : constant Node_Id := Aux_Decls_Node (Parent (Nod)); 14587 14588 begin 14589 if No (Declarations (ADN)) then 14590 Set_Declarations (ADN, New_List (Chk)); 14591 else 14592 Append_To (Declarations (ADN), Chk); 14593 end if; 14594 14595 Analyze (Chk); 14596 end; 14597 14598 -- Otherwise just insert as an action on the node in question 14599 14600 else 14601 Insert_Action (Nod, Chk); 14602 end if; 14603 end Insert_Elab_Check; 14604 14605 ------------------------------- 14606 -- Is_Call_Of_Generic_Formal -- 14607 ------------------------------- 14608 14609 function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean is 14610 begin 14611 return Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) 14612 14613 -- Always return False if debug flag -gnatd.G is set 14614 14615 and then not Debug_Flag_Dot_GG 14616 14617 -- For now, we detect this by looking for the strange identifier 14618 -- node, whose Chars reflect the name of the generic formal, but 14619 -- the Chars of the Entity references the generic actual. 14620 14621 and then Nkind (Name (N)) = N_Identifier 14622 and then Chars (Name (N)) /= Chars (Entity (Name (N))); 14623 end Is_Call_Of_Generic_Formal; 14624 14625 ------------------------------- 14626 -- Is_Finalization_Procedure -- 14627 ------------------------------- 14628 14629 function Is_Finalization_Procedure (Id : Entity_Id) return Boolean is 14630 begin 14631 -- Check whether Id is a procedure with at least one parameter 14632 14633 if Ekind (Id) = E_Procedure and then Present (First_Formal (Id)) then 14634 declare 14635 Typ : constant Entity_Id := Etype (First_Formal (Id)); 14636 Deep_Fin : Entity_Id := Empty; 14637 Fin : Entity_Id := Empty; 14638 14639 begin 14640 -- If the type of the first formal does not require finalization 14641 -- actions, then this is definitely not [Deep_]Finalize. 14642 14643 if not Needs_Finalization (Typ) then 14644 return False; 14645 end if; 14646 14647 -- At this point we have the following scenario: 14648 14649 -- procedure Name (Param1 : [in] [out] Ctrl[; Param2 : ...]); 14650 14651 -- Recover the two possible versions of [Deep_]Finalize using the 14652 -- type of the first parameter and compare with the input. 14653 14654 Deep_Fin := TSS (Typ, TSS_Deep_Finalize); 14655 14656 if Is_Controlled (Typ) then 14657 Fin := Find_Prim_Op (Typ, Name_Finalize); 14658 end if; 14659 14660 return (Present (Deep_Fin) and then Id = Deep_Fin) 14661 or else (Present (Fin) and then Id = Fin); 14662 end; 14663 end if; 14664 14665 return False; 14666 end Is_Finalization_Procedure; 14667 14668 ------------------ 14669 -- Output_Calls -- 14670 ------------------ 14671 14672 procedure Output_Calls 14673 (N : Node_Id; 14674 Check_Elab_Flag : Boolean) 14675 is 14676 function Emit (Flag : Boolean) return Boolean; 14677 -- Determine whether to emit an error message based on the combination 14678 -- of flags Check_Elab_Flag and Flag. 14679 14680 function Is_Printable_Error_Name return Boolean; 14681 -- An internal function, used to determine if a name, stored in the 14682 -- Name_Buffer, is either a non-internal name, or is an internal name 14683 -- that is printable by the error message circuits (i.e. it has a single 14684 -- upper case letter at the end). 14685 14686 ---------- 14687 -- Emit -- 14688 ---------- 14689 14690 function Emit (Flag : Boolean) return Boolean is 14691 begin 14692 if Check_Elab_Flag then 14693 return Flag; 14694 else 14695 return True; 14696 end if; 14697 end Emit; 14698 14699 ----------------------------- 14700 -- Is_Printable_Error_Name -- 14701 ----------------------------- 14702 14703 function Is_Printable_Error_Name return Boolean is 14704 begin 14705 if not Is_Internal_Name then 14706 return True; 14707 14708 elsif Name_Len = 1 then 14709 return False; 14710 14711 else 14712 Name_Len := Name_Len - 1; 14713 return not Is_Internal_Name; 14714 end if; 14715 end Is_Printable_Error_Name; 14716 14717 -- Local variables 14718 14719 Ent : Entity_Id; 14720 14721 -- Start of processing for Output_Calls 14722 14723 begin 14724 for J in reverse 1 .. Elab_Call.Last loop 14725 Error_Msg_Sloc := Elab_Call.Table (J).Cloc; 14726 14727 Ent := Elab_Call.Table (J).Ent; 14728 Get_Name_String (Chars (Ent)); 14729 14730 -- Dynamic elaboration model, warnings controlled by -gnatwl 14731 14732 if Dynamic_Elaboration_Checks then 14733 if Emit (Elab_Warnings) then 14734 if Is_Generic_Unit (Ent) then 14735 Error_Msg_NE ("\\?l?& instantiated #", N, Ent); 14736 elsif Is_Init_Proc (Ent) then 14737 Error_Msg_N ("\\?l?initialization procedure called #", N); 14738 elsif Is_Printable_Error_Name then 14739 Error_Msg_NE ("\\?l?& called #", N, Ent); 14740 else 14741 Error_Msg_N ("\\?l?called #", N); 14742 end if; 14743 end if; 14744 14745 -- Static elaboration model, info messages controlled by -gnatel 14746 14747 else 14748 if Emit (Elab_Info_Messages) then 14749 if Is_Generic_Unit (Ent) then 14750 Error_Msg_NE ("\\?$?& instantiated #", N, Ent); 14751 elsif Is_Init_Proc (Ent) then 14752 Error_Msg_N ("\\?$?initialization procedure called #", N); 14753 elsif Is_Printable_Error_Name then 14754 Error_Msg_NE ("\\?$?& called #", N, Ent); 14755 else 14756 Error_Msg_N ("\\?$?called #", N); 14757 end if; 14758 end if; 14759 end if; 14760 end loop; 14761 end Output_Calls; 14762 14763 ---------------------------- 14764 -- Same_Elaboration_Scope -- 14765 ---------------------------- 14766 14767 function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is 14768 S1 : Entity_Id; 14769 S2 : Entity_Id; 14770 14771 begin 14772 -- Find elaboration scope for Scop1 14773 -- This is either a subprogram or a compilation unit. 14774 14775 S1 := Scop1; 14776 while S1 /= Standard_Standard 14777 and then not Is_Compilation_Unit (S1) 14778 and then Ekind_In (S1, E_Package, E_Protected_Type, E_Block) 14779 loop 14780 S1 := Scope (S1); 14781 end loop; 14782 14783 -- Find elaboration scope for Scop2 14784 14785 S2 := Scop2; 14786 while S2 /= Standard_Standard 14787 and then not Is_Compilation_Unit (S2) 14788 and then Ekind_In (S2, E_Package, E_Protected_Type, E_Block) 14789 loop 14790 S2 := Scope (S2); 14791 end loop; 14792 14793 return S1 = S2; 14794 end Same_Elaboration_Scope; 14795 14796 ----------------- 14797 -- Set_C_Scope -- 14798 ----------------- 14799 14800 procedure Set_C_Scope is 14801 begin 14802 while not Is_Compilation_Unit (C_Scope) loop 14803 C_Scope := Scope (C_Scope); 14804 end loop; 14805 end Set_C_Scope; 14806 14807 -------------------------------- 14808 -- Set_Elaboration_Constraint -- 14809 -------------------------------- 14810 14811 procedure Set_Elaboration_Constraint 14812 (Call : Node_Id; 14813 Subp : Entity_Id; 14814 Scop : Entity_Id) 14815 is 14816 Elab_Unit : Entity_Id; 14817 14818 -- Check whether this is a call to an Initialize subprogram for a 14819 -- controlled type. Note that Call can also be a 'Access attribute 14820 -- reference, which now generates an elaboration check. 14821 14822 Init_Call : constant Boolean := 14823 Nkind (Call) = N_Procedure_Call_Statement 14824 and then Chars (Subp) = Name_Initialize 14825 and then Comes_From_Source (Subp) 14826 and then Present (Parameter_Associations (Call)) 14827 and then Is_Controlled (Etype (First_Actual (Call))); 14828 14829 begin 14830 -- If the unit is mentioned in a with_clause of the current unit, it is 14831 -- visible, and we can set the elaboration flag. 14832 14833 if Is_Immediately_Visible (Scop) 14834 or else (Is_Child_Unit (Scop) and then Is_Visible_Lib_Unit (Scop)) 14835 then 14836 Activate_Elaborate_All_Desirable (Call, Scop); 14837 Set_Suppress_Elaboration_Warnings (Scop); 14838 return; 14839 end if; 14840 14841 -- If this is not an initialization call or a call using object notation 14842 -- we know that the unit of the called entity is in the context, and we 14843 -- can set the flag as well. The unit need not be visible if the call 14844 -- occurs within an instantiation. 14845 14846 if Is_Init_Proc (Subp) 14847 or else Init_Call 14848 or else Nkind (Original_Node (Call)) = N_Selected_Component 14849 then 14850 null; -- detailed processing follows. 14851 14852 else 14853 Activate_Elaborate_All_Desirable (Call, Scop); 14854 Set_Suppress_Elaboration_Warnings (Scop); 14855 return; 14856 end if; 14857 14858 -- If the unit is not in the context, there must be an intermediate unit 14859 -- that is, on which we need to place to elaboration flag. This happens 14860 -- with init proc calls. 14861 14862 if Is_Init_Proc (Subp) or else Init_Call then 14863 14864 -- The initialization call is on an object whose type is not declared 14865 -- in the same scope as the subprogram. The type of the object must 14866 -- be a subtype of the type of operation. This object is the first 14867 -- actual in the call. 14868 14869 declare 14870 Typ : constant Entity_Id := 14871 Etype (First (Parameter_Associations (Call))); 14872 begin 14873 Elab_Unit := Scope (Typ); 14874 while (Present (Elab_Unit)) 14875 and then not Is_Compilation_Unit (Elab_Unit) 14876 loop 14877 Elab_Unit := Scope (Elab_Unit); 14878 end loop; 14879 end; 14880 14881 -- If original node uses selected component notation, the prefix is 14882 -- visible and determines the scope that must be elaborated. After 14883 -- rewriting, the prefix is the first actual in the call. 14884 14885 elsif Nkind (Original_Node (Call)) = N_Selected_Component then 14886 Elab_Unit := Scope (Etype (First (Parameter_Associations (Call)))); 14887 14888 -- Not one of special cases above 14889 14890 else 14891 -- Using previously computed scope. If the elaboration check is 14892 -- done after analysis, the scope is not visible any longer, but 14893 -- must still be in the context. 14894 14895 Elab_Unit := Scop; 14896 end if; 14897 14898 Activate_Elaborate_All_Desirable (Call, Elab_Unit); 14899 Set_Suppress_Elaboration_Warnings (Elab_Unit); 14900 end Set_Elaboration_Constraint; 14901 14902 ----------------- 14903 -- Spec_Entity -- 14904 ----------------- 14905 14906 function Spec_Entity (E : Entity_Id) return Entity_Id is 14907 Decl : Node_Id; 14908 14909 begin 14910 -- Check for case of body entity 14911 -- Why is the check for E_Void needed??? 14912 14913 if Ekind_In (E, E_Void, E_Subprogram_Body, E_Package_Body) then 14914 Decl := E; 14915 14916 loop 14917 Decl := Parent (Decl); 14918 exit when Nkind (Decl) in N_Proper_Body; 14919 end loop; 14920 14921 return Corresponding_Spec (Decl); 14922 14923 else 14924 return E; 14925 end if; 14926 end Spec_Entity; 14927 14928 ------------ 14929 -- Within -- 14930 ------------ 14931 14932 function Within (E1, E2 : Entity_Id) return Boolean is 14933 Scop : Entity_Id; 14934 begin 14935 Scop := E1; 14936 loop 14937 if Scop = E2 then 14938 return True; 14939 elsif Scop = Standard_Standard then 14940 return False; 14941 else 14942 Scop := Scope (Scop); 14943 end if; 14944 end loop; 14945 end Within; 14946 14947 -------------------------- 14948 -- Within_Elaborate_All -- 14949 -------------------------- 14950 14951 function Within_Elaborate_All 14952 (Unit : Unit_Number_Type; 14953 E : Entity_Id) return Boolean 14954 is 14955 type Unit_Number_Set is array (Main_Unit .. Last_Unit) of Boolean; 14956 pragma Pack (Unit_Number_Set); 14957 14958 Seen : Unit_Number_Set := (others => False); 14959 -- Seen (X) is True after we have seen unit X in the walk. This is used 14960 -- to prevent processing the same unit more than once. 14961 14962 Result : Boolean := False; 14963 14964 procedure Helper (Unit : Unit_Number_Type); 14965 -- This helper procedure does all the work for Within_Elaborate_All. It 14966 -- walks the dependency graph, and sets Result to True if it finds an 14967 -- appropriate Elaborate_All. 14968 14969 ------------ 14970 -- Helper -- 14971 ------------ 14972 14973 procedure Helper (Unit : Unit_Number_Type) is 14974 CU : constant Node_Id := Cunit (Unit); 14975 14976 Item : Node_Id; 14977 Item2 : Node_Id; 14978 Elab_Id : Entity_Id; 14979 Par : Node_Id; 14980 14981 begin 14982 if Seen (Unit) then 14983 return; 14984 else 14985 Seen (Unit) := True; 14986 end if; 14987 14988 -- First, check for Elaborate_Alls on this unit 14989 14990 Item := First (Context_Items (CU)); 14991 while Present (Item) loop 14992 if Nkind (Item) = N_Pragma 14993 and then Pragma_Name (Item) = Name_Elaborate_All 14994 then 14995 -- Return if some previous error on the pragma itself. The 14996 -- pragma may be unanalyzed, because of a previous error, or 14997 -- if it is the context of a subunit, inherited by its parent. 14998 14999 if Error_Posted (Item) or else not Analyzed (Item) then 15000 return; 15001 end if; 15002 15003 Elab_Id := 15004 Entity 15005 (Expression (First (Pragma_Argument_Associations (Item)))); 15006 15007 if E = Elab_Id then 15008 Result := True; 15009 return; 15010 end if; 15011 15012 Par := Parent (Unit_Declaration_Node (Elab_Id)); 15013 15014 Item2 := First (Context_Items (Par)); 15015 while Present (Item2) loop 15016 if Nkind (Item2) = N_With_Clause 15017 and then Entity (Name (Item2)) = E 15018 and then not Limited_Present (Item2) 15019 then 15020 Result := True; 15021 return; 15022 end if; 15023 15024 Next (Item2); 15025 end loop; 15026 end if; 15027 15028 Next (Item); 15029 end loop; 15030 15031 -- Second, recurse on with's. We could do this as part of the above 15032 -- loop, but it's probably more efficient to have two loops, because 15033 -- the relevant Elaborate_All is likely to be on the initial unit. In 15034 -- other words, we're walking the with's breadth-first. This part is 15035 -- only necessary in the dynamic elaboration model. 15036 15037 if Dynamic_Elaboration_Checks then 15038 Item := First (Context_Items (CU)); 15039 while Present (Item) loop 15040 if Nkind (Item) = N_With_Clause 15041 and then not Limited_Present (Item) 15042 then 15043 -- Note: the following call to Get_Cunit_Unit_Number does a 15044 -- linear search, which could be slow, but it's OK because 15045 -- we're about to give a warning anyway. Also, there might 15046 -- be hundreds of units, but not millions. If it turns out 15047 -- to be a problem, we could store the Get_Cunit_Unit_Number 15048 -- in each N_Compilation_Unit node, but that would involve 15049 -- rearranging N_Compilation_Unit_Aux to make room. 15050 15051 Helper (Get_Cunit_Unit_Number (Library_Unit (Item))); 15052 15053 if Result then 15054 return; 15055 end if; 15056 end if; 15057 15058 Next (Item); 15059 end loop; 15060 end if; 15061 end Helper; 15062 15063 -- Start of processing for Within_Elaborate_All 15064 15065 begin 15066 Helper (Unit); 15067 return Result; 15068 end Within_Elaborate_All; 15069 15070end Sem_Elab; 15071