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) 1997-2015, 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_Tss; use Exp_Tss; 33with Exp_Util; use Exp_Util; 34with Expander; use Expander; 35with Fname; use Fname; 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 Sem; use Sem; 46with Sem_Aux; use Sem_Aux; 47with Sem_Cat; use Sem_Cat; 48with Sem_Ch7; use Sem_Ch7; 49with Sem_Ch8; use Sem_Ch8; 50with Sem_Util; use Sem_Util; 51with Sinfo; use Sinfo; 52with Sinput; use Sinput; 53with Snames; use Snames; 54with Stand; use Stand; 55with Table; 56with Tbuild; use Tbuild; 57with Uintp; use Uintp; 58with Uname; use Uname; 59 60package body Sem_Elab is 61 62 -- The following table records the recursive call chain for output in the 63 -- Output routine. Each entry records the call node and the entity of the 64 -- called routine. The number of entries in the table (i.e. the value of 65 -- Elab_Call.Last) indicates the current depth of recursion and is used to 66 -- identify the outer level. 67 68 type Elab_Call_Entry is record 69 Cloc : Source_Ptr; 70 Ent : Entity_Id; 71 end record; 72 73 package Elab_Call is new Table.Table ( 74 Table_Component_Type => Elab_Call_Entry, 75 Table_Index_Type => Int, 76 Table_Low_Bound => 1, 77 Table_Initial => 50, 78 Table_Increment => 100, 79 Table_Name => "Elab_Call"); 80 81 -- This table is initialized at the start of each outer level call. It 82 -- holds the entities for all subprograms that have been examined for this 83 -- particular outer level call, and is used to prevent both infinite 84 -- recursion, and useless reanalysis of bodies already seen 85 86 package Elab_Visited is new Table.Table ( 87 Table_Component_Type => Entity_Id, 88 Table_Index_Type => Int, 89 Table_Low_Bound => 1, 90 Table_Initial => 200, 91 Table_Increment => 100, 92 Table_Name => "Elab_Visited"); 93 94 -- This table stores calls to Check_Internal_Call that are delayed 95 -- until all generics are instantiated, and in particular that all 96 -- generic bodies have been inserted. We need to delay, because we 97 -- need to be able to look through the inserted bodies. 98 99 type Delay_Element is record 100 N : Node_Id; 101 -- The parameter N from the call to Check_Internal_Call. Note that 102 -- this node may get rewritten over the delay period by expansion 103 -- in the call case (but not in the instantiation case). 104 105 E : Entity_Id; 106 -- The parameter E from the call to Check_Internal_Call 107 108 Orig_Ent : Entity_Id; 109 -- The parameter Orig_Ent from the call to Check_Internal_Call 110 111 Curscop : Entity_Id; 112 -- The current scope of the call. This is restored when we complete 113 -- the delayed call, so that we do this in the right scope. 114 115 From_Elab_Code : Boolean; 116 -- Save indication of whether this call is from elaboration code 117 118 Outer_Scope : Entity_Id; 119 -- Save scope of outer level call 120 end record; 121 122 package Delay_Check is new Table.Table ( 123 Table_Component_Type => Delay_Element, 124 Table_Index_Type => Int, 125 Table_Low_Bound => 1, 126 Table_Initial => 1000, 127 Table_Increment => 100, 128 Table_Name => "Delay_Check"); 129 130 C_Scope : Entity_Id; 131 -- Top level scope of current scope. Compute this only once at the outer 132 -- level, i.e. for a call to Check_Elab_Call from outside this unit. 133 134 Outer_Level_Sloc : Source_Ptr; 135 -- Save Sloc value for outer level call node for comparisons of source 136 -- locations. A body is too late if it appears after the *outer* level 137 -- call, not the particular call that is being analyzed. 138 139 From_Elab_Code : Boolean; 140 -- This flag shows whether the outer level call currently being examined 141 -- is or is not in elaboration code. We are only interested in calls to 142 -- routines in other units if this flag is True. 143 144 In_Task_Activation : Boolean := False; 145 -- This flag indicates whether we are performing elaboration checks on 146 -- task procedures, at the point of activation. If true, we do not trace 147 -- internal calls in these procedures, because all local bodies are known 148 -- to be elaborated. 149 150 Delaying_Elab_Checks : Boolean := True; 151 -- This is set True till the compilation is complete, including the 152 -- insertion of all instance bodies. Then when Check_Elab_Calls is called, 153 -- the delay table is used to make the delayed calls and this flag is reset 154 -- to False, so that the calls are processed. 155 156 ----------------------- 157 -- Local Subprograms -- 158 ----------------------- 159 160 -- Note: Outer_Scope in all following specs represents the scope of 161 -- interest of the outer level call. If it is set to Standard_Standard, 162 -- then it means the outer level call was at elaboration level, and that 163 -- thus all calls are of interest. If it was set to some other scope, 164 -- then the original call was an inner call, and we are not interested 165 -- in calls that go outside this scope. 166 167 procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id); 168 -- Analysis of construct N shows that we should set Elaborate_All_Desirable 169 -- for the WITH clause for unit U (which will always be present). A special 170 -- case is when N is a function or procedure instantiation, in which case 171 -- it is sufficient to set Elaborate_Desirable, since in this case there is 172 -- no possibility of transitive elaboration issues. 173 174 procedure Check_A_Call 175 (N : Node_Id; 176 E : Entity_Id; 177 Outer_Scope : Entity_Id; 178 Inter_Unit_Only : Boolean; 179 Generate_Warnings : Boolean := True; 180 In_Init_Proc : Boolean := False); 181 -- This is the internal recursive routine that is called to check for 182 -- possible elaboration error. The argument N is a subprogram call or 183 -- generic instantiation, or 'Access attribute reference to be checked, and 184 -- E is the entity of the called subprogram, or instantiated generic unit, 185 -- or subprogram referenced by 'Access. 186 -- 187 -- In SPARK mode, N can also be a variable reference, since in SPARK this 188 -- also triggers a requirement for Elaborate_All, and in this case E is the 189 -- entity being referenced. 190 -- 191 -- Outer_Scope is the outer level scope for the original reference. 192 -- Inter_Unit_Only is set if the call is only to be checked in the 193 -- case where it is to another unit (and skipped if within a unit). 194 -- Generate_Warnings is set to False to suppress warning messages about 195 -- missing pragma Elaborate_All's. These messages are not wanted for 196 -- inner calls in the dynamic model. Note that an instance of the Access 197 -- attribute applied to a subprogram also generates a call to this 198 -- procedure (since the referenced subprogram may be called later 199 -- indirectly). Flag In_Init_Proc should be set whenever the current 200 -- context is a type init proc. 201 -- 202 -- Note: this might better be called Check_A_Reference to recognize the 203 -- variable case for SPARK, but we prefer to retain the historical name 204 -- since in practice this is mostly about checking calls for the possible 205 -- occurrence of an access-before-elaboration exception. 206 207 procedure Check_Bad_Instantiation (N : Node_Id); 208 -- N is a node for an instantiation (if called with any other node kind, 209 -- Check_Bad_Instantiation ignores the call). This subprogram checks for 210 -- the special case of a generic instantiation of a generic spec in the 211 -- same declarative part as the instantiation where a body is present and 212 -- has not yet been seen. This is an obvious error, but needs to be checked 213 -- specially at the time of the instantiation, since it is a case where we 214 -- cannot insert the body anywhere. If this case is detected, warnings are 215 -- generated, and a raise of Program_Error is inserted. In addition any 216 -- subprograms in the generic spec are stubbed, and the Bad_Instantiation 217 -- flag is set on the instantiation node. The caller in Sem_Ch12 uses this 218 -- flag as an indication that no attempt should be made to insert an 219 -- instance body. 220 221 procedure Check_Internal_Call 222 (N : Node_Id; 223 E : Entity_Id; 224 Outer_Scope : Entity_Id; 225 Orig_Ent : Entity_Id); 226 -- N is a function call or procedure statement call node and E is the 227 -- entity of the called function, which is within the current compilation 228 -- unit (where subunits count as part of the parent). This call checks if 229 -- this call, or any call within any accessed body could cause an ABE, and 230 -- if so, outputs a warning. Orig_Ent differs from E only in the case of 231 -- renamings, and points to the original name of the entity. This is used 232 -- for error messages. Outer_Scope is the outer level scope for the 233 -- original call. 234 235 procedure Check_Internal_Call_Continue 236 (N : Node_Id; 237 E : Entity_Id; 238 Outer_Scope : Entity_Id; 239 Orig_Ent : Entity_Id); 240 -- The processing for Check_Internal_Call is divided up into two phases, 241 -- and this represents the second phase. The second phase is delayed if 242 -- Delaying_Elab_Calls is set to True. In this delayed case, the first 243 -- phase makes an entry in the Delay_Check table, which is processed when 244 -- Check_Elab_Calls is called. N, E and Orig_Ent are as for the call to 245 -- Check_Internal_Call. Outer_Scope is the outer level scope for the 246 -- original call. 247 248 function Has_Generic_Body (N : Node_Id) return Boolean; 249 -- N is a generic package instantiation node, and this routine determines 250 -- if this package spec does in fact have a generic body. If so, then 251 -- True is returned, otherwise False. Note that this is not at all the 252 -- same as checking if the unit requires a body, since it deals with 253 -- the case of optional bodies accurately (i.e. if a body is optional, 254 -- then it looks to see if a body is actually present). Note: this 255 -- function can only do a fully correct job if in generating code mode 256 -- where all bodies have to be present. If we are operating in semantics 257 -- check only mode, then in some cases of optional bodies, a result of 258 -- False may incorrectly be given. In practice this simply means that 259 -- some cases of warnings for incorrect order of elaboration will only 260 -- be given when generating code, which is not a big problem (and is 261 -- inevitable, given the optional body semantics of Ada). 262 263 procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty); 264 -- Given code for an elaboration check (or unconditional raise if the check 265 -- is not needed), inserts the code in the appropriate place. N is the call 266 -- or instantiation node for which the check code is required. C is the 267 -- test whose failure triggers the raise. 268 269 function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean; 270 -- Returns True if node N is a call to a generic formal subprogram 271 272 function Is_Finalization_Procedure (Id : Entity_Id) return Boolean; 273 -- Determine whether entity Id denotes a [Deep_]Finalize procedure 274 275 procedure Output_Calls 276 (N : Node_Id; 277 Check_Elab_Flag : Boolean); 278 -- Outputs chain of calls stored in the Elab_Call table. The caller has 279 -- already generated the main warning message, so the warnings generated 280 -- are all continuation messages. The argument is the call node at which 281 -- the messages are to be placed. When Check_Elab_Flag is set, calls are 282 -- enumerated only when flag Elab_Warning is set for the dynamic case or 283 -- when flag Elab_Info_Messages is set for the static case. 284 285 function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean; 286 -- Given two scopes, determine whether they are the same scope from an 287 -- elaboration point of view, i.e. packages and blocks are ignored. 288 289 procedure Set_C_Scope; 290 -- On entry C_Scope is set to some scope. On return, C_Scope is reset 291 -- to be the enclosing compilation unit of this scope. 292 293 function Get_Referenced_Ent (N : Node_Id) return Entity_Id; 294 -- N is either a function or procedure call or an access attribute that 295 -- references a subprogram. This call retrieves the relevant entity. If 296 -- this is a call to a protected subprogram, the entity is a selected 297 -- component. The callable entity may be absent, in which case Empty is 298 -- returned. This happens with non-analyzed calls in nested generics. 299 -- 300 -- If SPARK_Mode is On, then N can also be a reference to an E_Variable 301 -- entity, in which case, the value returned is simply this entity. 302 303 procedure Set_Elaboration_Constraint 304 (Call : Node_Id; 305 Subp : Entity_Id; 306 Scop : Entity_Id); 307 -- The current unit U may depend semantically on some unit P which is not 308 -- in the current context. If there is an elaboration call that reaches P, 309 -- we need to indicate that P requires an Elaborate_All, but this is not 310 -- effective in U's ali file, if there is no with_clause for P. In this 311 -- case we add the Elaborate_All on the unit Q that directly or indirectly 312 -- makes P available. This can happen in two cases: 313 -- 314 -- a) Q declares a subtype of a type declared in P, and the call is an 315 -- initialization call for an object of that subtype. 316 -- 317 -- b) Q declares an object of some tagged type whose root type is 318 -- declared in P, and the initialization call uses object notation on 319 -- that object to reach a primitive operation or a classwide operation 320 -- declared in P. 321 -- 322 -- If P appears in the context of U, the current processing is correct. 323 -- Otherwise we must identify these two cases to retrieve Q and place the 324 -- Elaborate_All_Desirable on it. 325 326 function Spec_Entity (E : Entity_Id) return Entity_Id; 327 -- Given a compilation unit entity, if it is a spec entity, it is returned 328 -- unchanged. If it is a body entity, then the spec for the corresponding 329 -- spec is returned 330 331 procedure Supply_Bodies (N : Node_Id); 332 -- Given a node, N, that is either a subprogram declaration or a package 333 -- declaration, this procedure supplies dummy bodies for the subprogram 334 -- or for all subprograms in the package. If the given node is not one of 335 -- these two possibilities, then Supply_Bodies does nothing. The dummy body 336 -- contains a single Raise statement. 337 338 procedure Supply_Bodies (L : List_Id); 339 -- Calls Supply_Bodies for all elements of the given list L 340 341 function Within (E1, E2 : Entity_Id) return Boolean; 342 -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or is one 343 -- of its contained scopes, False otherwise. 344 345 function Within_Elaborate_All 346 (Unit : Unit_Number_Type; 347 E : Entity_Id) return Boolean; 348 -- Return True if we are within the scope of an Elaborate_All for E, or if 349 -- we are within the scope of an Elaborate_All for some other unit U, and U 350 -- with's E. This prevents spurious warnings when the called entity is 351 -- renamed within U, or in case of generic instances. 352 353 -------------------------------------- 354 -- Activate_Elaborate_All_Desirable -- 355 -------------------------------------- 356 357 procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id) is 358 UN : constant Unit_Number_Type := Get_Code_Unit (N); 359 CU : constant Node_Id := Cunit (UN); 360 UE : constant Entity_Id := Cunit_Entity (UN); 361 Unm : constant Unit_Name_Type := Unit_Name (UN); 362 CI : constant List_Id := Context_Items (CU); 363 Itm : Node_Id; 364 Ent : Entity_Id; 365 366 procedure Add_To_Context_And_Mark (Itm : Node_Id); 367 -- This procedure is called when the elaborate indication must be 368 -- applied to a unit not in the context of the referencing unit. The 369 -- unit gets added to the context as an implicit with. 370 371 function In_Withs_Of (UEs : Entity_Id) return Boolean; 372 -- UEs is the spec entity of a unit. If the unit to be marked is 373 -- in the context item list of this unit spec, then the call returns 374 -- True and Itm is left set to point to the relevant N_With_Clause node. 375 376 procedure Set_Elab_Flag (Itm : Node_Id); 377 -- Sets Elaborate_[All_]Desirable as appropriate on Itm 378 379 ----------------------------- 380 -- Add_To_Context_And_Mark -- 381 ----------------------------- 382 383 procedure Add_To_Context_And_Mark (Itm : Node_Id) is 384 CW : constant Node_Id := 385 Make_With_Clause (Sloc (Itm), 386 Name => Name (Itm)); 387 388 begin 389 Set_Library_Unit (CW, Library_Unit (Itm)); 390 Set_Implicit_With (CW, True); 391 392 -- Set elaborate all desirable on copy and then append the copy to 393 -- the list of body with's and we are done. 394 395 Set_Elab_Flag (CW); 396 Append_To (CI, CW); 397 end Add_To_Context_And_Mark; 398 399 ----------------- 400 -- In_Withs_Of -- 401 ----------------- 402 403 function In_Withs_Of (UEs : Entity_Id) return Boolean is 404 UNs : constant Unit_Number_Type := Get_Source_Unit (UEs); 405 CUs : constant Node_Id := Cunit (UNs); 406 CIs : constant List_Id := Context_Items (CUs); 407 408 begin 409 Itm := First (CIs); 410 while Present (Itm) loop 411 if Nkind (Itm) = N_With_Clause then 412 Ent := 413 Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); 414 415 if U = Ent then 416 return True; 417 end if; 418 end if; 419 420 Next (Itm); 421 end loop; 422 423 return False; 424 end In_Withs_Of; 425 426 ------------------- 427 -- Set_Elab_Flag -- 428 ------------------- 429 430 procedure Set_Elab_Flag (Itm : Node_Id) is 431 begin 432 if Nkind (N) in N_Subprogram_Instantiation then 433 Set_Elaborate_Desirable (Itm); 434 else 435 Set_Elaborate_All_Desirable (Itm); 436 end if; 437 end Set_Elab_Flag; 438 439 -- Start of processing for Activate_Elaborate_All_Desirable 440 441 begin 442 -- Do not set binder indication if expansion is disabled, as when 443 -- compiling a generic unit. 444 445 if not Expander_Active then 446 return; 447 end if; 448 449 Itm := First (CI); 450 while Present (Itm) loop 451 if Nkind (Itm) = N_With_Clause then 452 Ent := Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); 453 454 -- If we find it, then mark elaborate all desirable and return 455 456 if U = Ent then 457 Set_Elab_Flag (Itm); 458 return; 459 end if; 460 end if; 461 462 Next (Itm); 463 end loop; 464 465 -- If we fall through then the with clause is not present in the 466 -- current unit. One legitimate possibility is that the with clause 467 -- is present in the spec when we are a body. 468 469 if Is_Body_Name (Unm) 470 and then In_Withs_Of (Spec_Entity (UE)) 471 then 472 Add_To_Context_And_Mark (Itm); 473 return; 474 end if; 475 476 -- Similarly, we may be in the spec or body of a child unit, where 477 -- the unit in question is with'ed by some ancestor of the child unit. 478 479 if Is_Child_Name (Unm) then 480 declare 481 Pkg : Entity_Id; 482 483 begin 484 Pkg := UE; 485 loop 486 Pkg := Scope (Pkg); 487 exit when Pkg = Standard_Standard; 488 489 if In_Withs_Of (Pkg) then 490 Add_To_Context_And_Mark (Itm); 491 return; 492 end if; 493 end loop; 494 end; 495 end if; 496 497 -- Here if we do not find with clause on spec or body. We just ignore 498 -- this case, it means that the elaboration involves some other unit 499 -- than the unit being compiled, and will be caught elsewhere. 500 501 null; 502 end Activate_Elaborate_All_Desirable; 503 504 ------------------ 505 -- Check_A_Call -- 506 ------------------ 507 508 procedure Check_A_Call 509 (N : Node_Id; 510 E : Entity_Id; 511 Outer_Scope : Entity_Id; 512 Inter_Unit_Only : Boolean; 513 Generate_Warnings : Boolean := True; 514 In_Init_Proc : Boolean := False) 515 is 516 Access_Case : constant Boolean := Nkind (N) = N_Attribute_Reference; 517 -- Indicates if we have Access attribute case 518 519 Variable_Case : constant Boolean := 520 Nkind (N) in N_Has_Entity 521 and then Present (Entity (N)) 522 and then Ekind (Entity (N)) = E_Variable; 523 -- Indicates if we have variable reference case 524 525 procedure Elab_Warning 526 (Msg_D : String; 527 Msg_S : String; 528 Ent : Node_Or_Entity_Id); 529 -- Generate a call to Error_Msg_NE with parameters Msg_D or Msg_S (for 530 -- dynamic or static elaboration model), N and Ent. Msg_D is a real 531 -- warning (output if Msg_D is non-null and Elab_Warnings is set), 532 -- Msg_S is an info message (output if Elab_Info_Messages is set. 533 534 ------------------ 535 -- Elab_Warning -- 536 ------------------ 537 538 procedure Elab_Warning 539 (Msg_D : String; 540 Msg_S : String; 541 Ent : Node_Or_Entity_Id) 542 is 543 begin 544 -- Dynamic elaboration checks, real warning 545 546 if Dynamic_Elaboration_Checks then 547 if not Access_Case then 548 if Msg_D /= "" and then Elab_Warnings then 549 Error_Msg_NE (Msg_D, N, Ent); 550 end if; 551 552 -- In the access case emit first warning message as well, 553 -- otherwise list of calls will appear as errors. 554 555 elsif Elab_Warnings then 556 Error_Msg_NE (Msg_S, N, Ent); 557 end if; 558 559 -- Static elaboration checks, info message 560 561 else 562 if Elab_Info_Messages then 563 Error_Msg_NE (Msg_S, N, Ent); 564 end if; 565 end if; 566 end Elab_Warning; 567 568 -- Local variables 569 570 Loc : constant Source_Ptr := Sloc (N); 571 572 Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation; 573 -- Indicates if we have instantiation case 574 575 Ent : Entity_Id; 576 Callee_Unit_Internal : Boolean; 577 Caller_Unit_Internal : Boolean; 578 Decl : Node_Id; 579 Inst_Callee : Source_Ptr; 580 Inst_Caller : Source_Ptr; 581 Unit_Callee : Unit_Number_Type; 582 Unit_Caller : Unit_Number_Type; 583 584 Body_Acts_As_Spec : Boolean; 585 -- Set to true if call is to body acting as spec (no separate spec) 586 587 Cunit_SC : Boolean := False; 588 -- Set to suppress dynamic elaboration checks where one of the 589 -- enclosing scopes has Elaboration_Checks_Suppressed set, or else 590 -- if a pragma Elaborate[_All] applies to that scope, in which case 591 -- warnings on the scope are also suppressed. For the internal case, 592 -- we ignore this flag. 593 594 E_Scope : Entity_Id; 595 -- Top level scope of entity for called subprogram. This value includes 596 -- following renamings and derivations, so this scope can be in a 597 -- non-visible unit. This is the scope that is to be investigated to 598 -- see whether an elaboration check is required. 599 600 Is_DIC_Proc : Boolean := False; 601 -- Flag set when the call denotes the Default_Initial_Condition 602 -- procedure of a private type that wraps a nontrivial assertion 603 -- expression. 604 605 Issue_In_SPARK : Boolean; 606 -- Flag set when a source entity is called during elaboration in SPARK 607 608 W_Scope : Entity_Id; 609 -- Top level scope of directly called entity for subprogram. This 610 -- differs from E_Scope in the case where renamings or derivations 611 -- are involved, since it does not follow these links. W_Scope is 612 -- generally in a visible unit, and it is this scope that may require 613 -- an Elaborate_All. However, there are some cases (initialization 614 -- calls and calls involving object notation) where W_Scope might not 615 -- be in the context of the current unit, and there is an intermediate 616 -- package that is, in which case the Elaborate_All has to be placed 617 -- on this intermediate package. These special cases are handled in 618 -- Set_Elaboration_Constraint. 619 620 -- Start of processing for Check_A_Call 621 622 begin 623 -- If the call is known to be within a local Suppress Elaboration 624 -- pragma, nothing to check. This can happen in task bodies. But 625 -- we ignore this for a call to a generic formal. 626 627 if Nkind (N) in N_Subprogram_Call 628 and then No_Elaboration_Check (N) 629 and then not Is_Call_Of_Generic_Formal (N) 630 then 631 return; 632 end if; 633 634 -- If this is a rewrite of a Valid_Scalars attribute, then nothing to 635 -- check, we don't mind in this case if the call occurs before the body 636 -- since this is all generated code. 637 638 if Nkind (Original_Node (N)) = N_Attribute_Reference 639 and then Attribute_Name (Original_Node (N)) = Name_Valid_Scalars 640 then 641 return; 642 end if; 643 644 -- Proceed with check 645 646 Ent := E; 647 648 -- For a variable reference, just set Body_Acts_As_Spec to False 649 650 if Variable_Case then 651 Body_Acts_As_Spec := False; 652 653 -- Additional checks for all other cases 654 655 else 656 -- Go to parent for derived subprogram, or to original subprogram in 657 -- the case of a renaming (Alias covers both these cases). 658 659 loop 660 if (Suppress_Elaboration_Warnings (Ent) 661 or else Elaboration_Checks_Suppressed (Ent)) 662 and then (Inst_Case or else No (Alias (Ent))) 663 then 664 return; 665 end if; 666 667 -- Nothing to do for imported entities 668 669 if Is_Imported (Ent) then 670 return; 671 end if; 672 673 exit when Inst_Case or else No (Alias (Ent)); 674 Ent := Alias (Ent); 675 end loop; 676 677 Decl := Unit_Declaration_Node (Ent); 678 679 if Nkind (Decl) = N_Subprogram_Body then 680 Body_Acts_As_Spec := True; 681 682 elsif Nkind_In (Decl, N_Subprogram_Declaration, 683 N_Subprogram_Body_Stub) 684 or else Inst_Case 685 then 686 Body_Acts_As_Spec := False; 687 688 -- If we have none of an instantiation, subprogram body or subprogram 689 -- declaration, or in the SPARK case, a variable reference, then 690 -- it is not a case that we want to check. (One case is a call to a 691 -- generic formal subprogram, where we do not want the check in the 692 -- template). 693 694 else 695 return; 696 end if; 697 end if; 698 699 E_Scope := Ent; 700 loop 701 if Elaboration_Checks_Suppressed (E_Scope) 702 or else Suppress_Elaboration_Warnings (E_Scope) 703 then 704 Cunit_SC := True; 705 end if; 706 707 -- Exit when we get to compilation unit, not counting subunits 708 709 exit when Is_Compilation_Unit (E_Scope) 710 and then (Is_Child_Unit (E_Scope) 711 or else Scope (E_Scope) = Standard_Standard); 712 713 -- If we did not find a compilation unit, other than standard, 714 -- then nothing to check (happens in some instantiation cases) 715 716 if E_Scope = Standard_Standard then 717 return; 718 719 -- Otherwise move up a scope looking for compilation unit 720 721 else 722 E_Scope := Scope (E_Scope); 723 end if; 724 end loop; 725 726 -- No checks needed for pure or preelaborated compilation units 727 728 if Is_Pure (E_Scope) or else Is_Preelaborated (E_Scope) then 729 return; 730 end if; 731 732 -- If the generic entity is within a deeper instance than we are, then 733 -- either the instantiation to which we refer itself caused an ABE, in 734 -- which case that will be handled separately, or else we know that the 735 -- body we need appears as needed at the point of the instantiation. 736 -- However, this assumption is only valid if we are in static mode. 737 738 if not Dynamic_Elaboration_Checks 739 and then 740 Instantiation_Depth (Sloc (Ent)) > Instantiation_Depth (Sloc (N)) 741 then 742 return; 743 end if; 744 745 -- Do not give a warning for a package with no body 746 747 if Ekind (Ent) = E_Generic_Package and then not Has_Generic_Body (N) then 748 return; 749 end if; 750 751 -- Find top level scope for called entity (not following renamings 752 -- or derivations). This is where the Elaborate_All will go if it is 753 -- needed. We start with the called entity, except in the case of an 754 -- initialization procedure outside the current package, where the init 755 -- proc is in the root package, and we start from the entity of the name 756 -- in the call. 757 758 declare 759 Ent : constant Entity_Id := Get_Referenced_Ent (N); 760 begin 761 if Is_Init_Proc (Ent) and then not In_Same_Extended_Unit (N, Ent) then 762 W_Scope := Scope (Ent); 763 else 764 W_Scope := E; 765 end if; 766 end; 767 768 -- Now loop through scopes to get to the enclosing compilation unit 769 770 while not Is_Compilation_Unit (W_Scope) loop 771 W_Scope := Scope (W_Scope); 772 end loop; 773 774 -- Case of entity is in same unit as call or instantiation. In the 775 -- instantiation case, W_Scope may be different from E_Scope; we want 776 -- the unit in which the instantiation occurs, since we're analyzing 777 -- based on the expansion. 778 779 if W_Scope = C_Scope then 780 if not Inter_Unit_Only then 781 Check_Internal_Call (N, Ent, Outer_Scope, E); 782 end if; 783 784 return; 785 end if; 786 787 -- Case of entity is not in current unit (i.e. with'ed unit case) 788 789 -- We are only interested in such calls if the outer call was from 790 -- elaboration code, or if we are in Dynamic_Elaboration_Checks mode. 791 792 if not From_Elab_Code and then not Dynamic_Elaboration_Checks then 793 return; 794 end if; 795 796 -- Nothing to do if some scope said that no checks were required 797 798 if Cunit_SC then 799 return; 800 end if; 801 802 -- Nothing to do for a generic instance, because in this case the 803 -- checking was at the point of instantiation of the generic However, 804 -- this shortcut is only applicable in static mode. 805 806 if Is_Generic_Instance (Ent) and not Dynamic_Elaboration_Checks then 807 return; 808 end if; 809 810 -- Nothing to do if subprogram with no separate spec. However, a call 811 -- to Deep_Initialize may result in a call to a user-defined Initialize 812 -- procedure, which imposes a body dependency. This happens only if the 813 -- type is controlled and the Initialize procedure is not inherited. 814 815 if Body_Acts_As_Spec then 816 if Is_TSS (Ent, TSS_Deep_Initialize) then 817 declare 818 Typ : constant Entity_Id := Etype (First_Formal (Ent)); 819 Init : Entity_Id; 820 821 begin 822 if not Is_Controlled (Typ) then 823 return; 824 else 825 Init := Find_Prim_Op (Typ, Name_Initialize); 826 827 if Comes_From_Source (Init) then 828 Ent := Init; 829 else 830 return; 831 end if; 832 end if; 833 end; 834 835 else 836 return; 837 end if; 838 end if; 839 840 -- Check cases of internal units 841 842 Callee_Unit_Internal := 843 Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (E_Scope))); 844 845 -- Do not give a warning if the with'ed unit is internal and this is 846 -- the generic instantiation case (this saves a lot of hassle dealing 847 -- with the Text_IO special child units) 848 849 if Callee_Unit_Internal and Inst_Case then 850 return; 851 end if; 852 853 if C_Scope = Standard_Standard then 854 Caller_Unit_Internal := False; 855 else 856 Caller_Unit_Internal := 857 Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (C_Scope))); 858 end if; 859 860 -- Do not give a warning if the with'ed unit is internal and the 861 -- caller is not internal (since the binder always elaborates 862 -- internal units first). 863 864 if Callee_Unit_Internal and (not Caller_Unit_Internal) then 865 return; 866 end if; 867 868 -- For now, if debug flag -gnatdE is not set, do no checking for 869 -- one internal unit withing another. This fixes the problem with 870 -- the sgi build and storage errors. To be resolved later ??? 871 872 if (Callee_Unit_Internal and Caller_Unit_Internal) 873 and not Debug_Flag_EE 874 then 875 return; 876 end if; 877 878 if Is_TSS (E, TSS_Deep_Initialize) then 879 Ent := E; 880 end if; 881 882 -- If the call is in an instance, and the called entity is not 883 -- defined in the same instance, then the elaboration issue focuses 884 -- around the unit containing the template, it is this unit which 885 -- requires an Elaborate_All. 886 887 -- However, if we are doing dynamic elaboration, we need to chase the 888 -- call in the usual manner. 889 890 -- We also need to chase the call in the usual manner if it is a call 891 -- to a generic formal parameter, since that case was not handled as 892 -- part of the processing of the template. 893 894 Inst_Caller := Instantiation (Get_Source_File_Index (Sloc (N))); 895 Inst_Callee := Instantiation (Get_Source_File_Index (Sloc (Ent))); 896 897 if Inst_Caller = No_Location then 898 Unit_Caller := No_Unit; 899 else 900 Unit_Caller := Get_Source_Unit (N); 901 end if; 902 903 if Inst_Callee = No_Location then 904 Unit_Callee := No_Unit; 905 else 906 Unit_Callee := Get_Source_Unit (Ent); 907 end if; 908 909 if Unit_Caller /= No_Unit 910 and then Unit_Callee /= Unit_Caller 911 and then not Dynamic_Elaboration_Checks 912 and then not Is_Call_Of_Generic_Formal (N) 913 then 914 E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller)); 915 916 -- If we don't get a spec entity, just ignore call. Not quite 917 -- clear why this check is necessary. ??? 918 919 if No (E_Scope) then 920 return; 921 end if; 922 923 -- Otherwise step to enclosing compilation unit 924 925 while not Is_Compilation_Unit (E_Scope) loop 926 E_Scope := Scope (E_Scope); 927 end loop; 928 929 -- For the case where N is not an instance, and is not a call within 930 -- instance to other than a generic formal, we recompute E_Scope 931 -- for the error message, since we do NOT want to go to the unit 932 -- which has the ultimate declaration in the case of renaming and 933 -- derivation and we also want to go to the generic unit in the 934 -- case of an instance, and no further. 935 936 else 937 -- Loop to carefully follow renamings and derivations one step 938 -- outside the current unit, but not further. 939 940 if not (Inst_Case or Variable_Case) 941 and then Present (Alias (Ent)) 942 then 943 E_Scope := Alias (Ent); 944 else 945 E_Scope := Ent; 946 end if; 947 948 loop 949 while not Is_Compilation_Unit (E_Scope) loop 950 E_Scope := Scope (E_Scope); 951 end loop; 952 953 -- If E_Scope is the same as C_Scope, it means that there 954 -- definitely was a local renaming or derivation, and we 955 -- are not yet out of the current unit. 956 957 exit when E_Scope /= C_Scope; 958 Ent := Alias (Ent); 959 E_Scope := Ent; 960 961 -- If no alias, there is a previous error 962 963 if No (Ent) then 964 Check_Error_Detected; 965 return; 966 end if; 967 end loop; 968 end if; 969 970 if Within_Elaborate_All (Current_Sem_Unit, E_Scope) then 971 return; 972 end if; 973 974 Is_DIC_Proc := Is_Nontrivial_Default_Init_Cond_Procedure (Ent); 975 976 -- Elaboration issues in SPARK are reported only for source constructs 977 -- and for nontrivial Default_Initial_Condition procedures. The latter 978 -- must be checked because the default initialization of an object of a 979 -- private type triggers the evaluation of the Default_Initial_Condition 980 -- expression, which in turn may have side effects. 981 982 Issue_In_SPARK := 983 SPARK_Mode = On and (Comes_From_Source (Ent) or Is_DIC_Proc); 984 985 -- Now check if an Elaborate_All (or dynamic check) is needed 986 987 if not Suppress_Elaboration_Warnings (Ent) 988 and then not Elaboration_Checks_Suppressed (Ent) 989 and then not Suppress_Elaboration_Warnings (E_Scope) 990 and then not Elaboration_Checks_Suppressed (E_Scope) 991 and then ((Elab_Warnings or Elab_Info_Messages) 992 or else SPARK_Mode = On) 993 and then Generate_Warnings 994 then 995 -- Instantiation case 996 997 if Inst_Case then 998 if Issue_In_SPARK then 999 Error_Msg_NE 1000 ("instantiation of & during elaboration in SPARK", N, Ent); 1001 else 1002 Elab_Warning 1003 ("instantiation of & may raise Program_Error?l?", 1004 "info: instantiation of & during elaboration?$?", Ent); 1005 end if; 1006 1007 -- Indirect call case, info message only in static elaboration 1008 -- case, because the attribute reference itself cannot raise an 1009 -- exception. Note that SPARK does not permit indirect calls. 1010 1011 elsif Access_Case then 1012 Elab_Warning ("", "info: access to & during elaboration?$?", Ent); 1013 1014 -- Variable reference in SPARK mode 1015 1016 elsif Variable_Case and Issue_In_SPARK then 1017 Error_Msg_NE 1018 ("reference to & during elaboration in SPARK", N, Ent); 1019 1020 -- Subprogram call case 1021 1022 else 1023 if Nkind (Name (N)) in N_Has_Entity 1024 and then Is_Init_Proc (Entity (Name (N))) 1025 and then Comes_From_Source (Ent) 1026 then 1027 Elab_Warning 1028 ("implicit call to & may raise Program_Error?l?", 1029 "info: implicit call to & during elaboration?$?", 1030 Ent); 1031 1032 elsif Issue_In_SPARK then 1033 1034 -- Emit a specialized error message when the elaboration of an 1035 -- object of a private type evaluates the expression of pragma 1036 -- Default_Initial_Condition. This prevents the internal name 1037 -- of the procedure from appearing in the error message. 1038 1039 if Is_DIC_Proc then 1040 Error_Msg_N 1041 ("call to Default_Initial_Condition during elaboration in " 1042 & "SPARK", N); 1043 else 1044 Error_Msg_NE 1045 ("call to & during elaboration in SPARK", N, Ent); 1046 end if; 1047 1048 else 1049 Elab_Warning 1050 ("call to & may raise Program_Error?l?", 1051 "info: call to & during elaboration?$?", 1052 Ent); 1053 end if; 1054 end if; 1055 1056 Error_Msg_Qual_Level := Nat'Last; 1057 1058 -- Case of Elaborate_All not present and required, for SPARK this 1059 -- is an error, so give an error message. 1060 1061 if Issue_In_SPARK then 1062 Error_Msg_NE ("\Elaborate_All pragma required for&", N, W_Scope); 1063 1064 -- Otherwise we generate an implicit pragma. For a subprogram 1065 -- instantiation, Elaborate is good enough, since no transitive 1066 -- call is possible at elaboration time in this case. 1067 1068 elsif Nkind (N) in N_Subprogram_Instantiation then 1069 Elab_Warning 1070 ("\missing pragma Elaborate for&?l?", 1071 "\implicit pragma Elaborate for& generated?$?", 1072 W_Scope); 1073 1074 -- For all other cases, we need an implicit Elaborate_All 1075 1076 else 1077 Elab_Warning 1078 ("\missing pragma Elaborate_All for&?l?", 1079 "\implicit pragma Elaborate_All for & generated?$?", 1080 W_Scope); 1081 end if; 1082 1083 Error_Msg_Qual_Level := 0; 1084 1085 -- Take into account the flags related to elaboration warning 1086 -- messages when enumerating the various calls involved. This 1087 -- ensures the proper pairing of the main warning and the 1088 -- clarification messages generated by Output_Calls. 1089 1090 Output_Calls (N, Check_Elab_Flag => True); 1091 1092 -- Set flag to prevent further warnings for same unit unless in 1093 -- All_Errors_Mode. 1094 1095 if not All_Errors_Mode and not Dynamic_Elaboration_Checks then 1096 Set_Suppress_Elaboration_Warnings (W_Scope, True); 1097 end if; 1098 end if; 1099 1100 -- Check for runtime elaboration check required 1101 1102 if Dynamic_Elaboration_Checks then 1103 if not Elaboration_Checks_Suppressed (Ent) 1104 and then not Elaboration_Checks_Suppressed (W_Scope) 1105 and then not Elaboration_Checks_Suppressed (E_Scope) 1106 and then not Cunit_SC 1107 then 1108 -- Runtime elaboration check required. Generate check of the 1109 -- elaboration Boolean for the unit containing the entity. 1110 1111 -- Note that for this case, we do check the real unit (the one 1112 -- from following renamings, since that is the issue). 1113 1114 -- Could this possibly miss a useless but required PE??? 1115 1116 Insert_Elab_Check (N, 1117 Make_Attribute_Reference (Loc, 1118 Attribute_Name => Name_Elaborated, 1119 Prefix => 1120 New_Occurrence_Of (Spec_Entity (E_Scope), Loc))); 1121 1122 -- Prevent duplicate elaboration checks on the same call, 1123 -- which can happen if the body enclosing the call appears 1124 -- itself in a call whose elaboration check is delayed. 1125 1126 if Nkind (N) in N_Subprogram_Call then 1127 Set_No_Elaboration_Check (N); 1128 end if; 1129 end if; 1130 1131 -- Case of static elaboration model 1132 1133 else 1134 -- Do not do anything if elaboration checks suppressed. Note that 1135 -- we check Ent here, not E, since we want the real entity for the 1136 -- body to see if checks are suppressed for it, not the dummy 1137 -- entry for renamings or derivations. 1138 1139 if Elaboration_Checks_Suppressed (Ent) 1140 or else Elaboration_Checks_Suppressed (E_Scope) 1141 or else Elaboration_Checks_Suppressed (W_Scope) 1142 then 1143 null; 1144 1145 -- Do not generate an Elaborate_All for finalization routines 1146 -- which perform partial clean up as part of initialization. 1147 1148 elsif In_Init_Proc and then Is_Finalization_Procedure (Ent) then 1149 null; 1150 1151 -- Here we need to generate an implicit elaborate all 1152 1153 else 1154 -- Generate Elaborate_All warning unless suppressed 1155 1156 if (Elab_Info_Messages and Generate_Warnings and not Inst_Case) 1157 and then not Suppress_Elaboration_Warnings (Ent) 1158 and then not Suppress_Elaboration_Warnings (E_Scope) 1159 and then not Suppress_Elaboration_Warnings (W_Scope) 1160 then 1161 Error_Msg_Node_2 := W_Scope; 1162 Error_Msg_NE 1163 ("info: call to& in elaboration code " & 1164 "requires pragma Elaborate_All on&?$?", N, E); 1165 end if; 1166 1167 -- Set indication for binder to generate Elaborate_All 1168 1169 Set_Elaboration_Constraint (N, E, W_Scope); 1170 end if; 1171 end if; 1172 end Check_A_Call; 1173 1174 ----------------------------- 1175 -- Check_Bad_Instantiation -- 1176 ----------------------------- 1177 1178 procedure Check_Bad_Instantiation (N : Node_Id) is 1179 Ent : Entity_Id; 1180 1181 begin 1182 -- Nothing to do if we do not have an instantiation (happens in some 1183 -- error cases, and also in the formal package declaration case) 1184 1185 if Nkind (N) not in N_Generic_Instantiation then 1186 return; 1187 1188 -- Nothing to do if serious errors detected (avoid cascaded errors) 1189 1190 elsif Serious_Errors_Detected /= 0 then 1191 return; 1192 1193 -- Nothing to do if not in full analysis mode 1194 1195 elsif not Full_Analysis then 1196 return; 1197 1198 -- Nothing to do if inside a generic template 1199 1200 elsif Inside_A_Generic then 1201 return; 1202 1203 -- Nothing to do if a library level instantiation 1204 1205 elsif Nkind (Parent (N)) = N_Compilation_Unit then 1206 return; 1207 1208 -- Nothing to do if we are compiling a proper body for semantic 1209 -- purposes only. The generic body may be in another proper body. 1210 1211 elsif 1212 Nkind (Parent (Unit_Declaration_Node (Main_Unit_Entity))) = N_Subunit 1213 then 1214 return; 1215 end if; 1216 1217 Ent := Get_Generic_Entity (N); 1218 1219 -- The case we are interested in is when the generic spec is in the 1220 -- current declarative part 1221 1222 if not Same_Elaboration_Scope (Current_Scope, Scope (Ent)) 1223 or else not In_Same_Extended_Unit (N, Ent) 1224 then 1225 return; 1226 end if; 1227 1228 -- If the generic entity is within a deeper instance than we are, then 1229 -- either the instantiation to which we refer itself caused an ABE, in 1230 -- which case that will be handled separately. Otherwise, we know that 1231 -- the body we need appears as needed at the point of the instantiation. 1232 -- If they are both at the same level but not within the same instance 1233 -- then the body of the generic will be in the earlier instance. 1234 1235 declare 1236 D1 : constant Int := Instantiation_Depth (Sloc (Ent)); 1237 D2 : constant Int := Instantiation_Depth (Sloc (N)); 1238 1239 begin 1240 if D1 > D2 then 1241 return; 1242 1243 elsif D1 = D2 1244 and then Is_Generic_Instance (Scope (Ent)) 1245 and then not In_Open_Scopes (Scope (Ent)) 1246 then 1247 return; 1248 end if; 1249 end; 1250 1251 -- Now we can proceed, if the entity being called has a completion, 1252 -- then we are definitely OK, since we have already seen the body. 1253 1254 if Has_Completion (Ent) then 1255 return; 1256 end if; 1257 1258 -- If there is no body, then nothing to do 1259 1260 if not Has_Generic_Body (N) then 1261 return; 1262 end if; 1263 1264 -- Here we definitely have a bad instantiation 1265 1266 Error_Msg_Warn := SPARK_Mode /= On; 1267 Error_Msg_NE ("cannot instantiate& before body seen<<", N, Ent); 1268 1269 if Present (Instance_Spec (N)) then 1270 Supply_Bodies (Instance_Spec (N)); 1271 end if; 1272 1273 Error_Msg_N ("\Program_Error [<<", N); 1274 Insert_Elab_Check (N); 1275 Set_ABE_Is_Certain (N); 1276 end Check_Bad_Instantiation; 1277 1278 --------------------- 1279 -- Check_Elab_Call -- 1280 --------------------- 1281 1282 procedure Check_Elab_Call 1283 (N : Node_Id; 1284 Outer_Scope : Entity_Id := Empty; 1285 In_Init_Proc : Boolean := False) 1286 is 1287 Ent : Entity_Id; 1288 P : Node_Id; 1289 1290 begin 1291 -- If the reference is not in the main unit, there is nothing to check. 1292 -- Elaboration call from units in the context of the main unit will lead 1293 -- to semantic dependencies when those units are compiled. 1294 1295 if not In_Extended_Main_Code_Unit (N) then 1296 return; 1297 end if; 1298 1299 -- For an entry call, check relevant restriction 1300 1301 if Nkind (N) = N_Entry_Call_Statement 1302 and then not In_Subprogram_Or_Concurrent_Unit 1303 then 1304 Check_Restriction (No_Entry_Calls_In_Elaboration_Code, N); 1305 1306 -- Nothing to do if this is not an expected type of reference (happens 1307 -- in some error conditions, and in some cases where rewriting occurs). 1308 1309 elsif Nkind (N) not in N_Subprogram_Call 1310 and then Nkind (N) /= N_Attribute_Reference 1311 and then (SPARK_Mode /= On 1312 or else Nkind (N) not in N_Has_Entity 1313 or else No (Entity (N)) 1314 or else Ekind (Entity (N)) /= E_Variable) 1315 then 1316 return; 1317 1318 -- Nothing to do if this is a call already rewritten for elab checking. 1319 -- Such calls appear as the targets of If_Expressions. 1320 1321 -- This check MUST be wrong, it catches far too much 1322 1323 elsif Nkind (Parent (N)) = N_If_Expression then 1324 return; 1325 1326 -- Nothing to do if inside a generic template 1327 1328 elsif Inside_A_Generic 1329 and then No (Enclosing_Generic_Body (N)) 1330 then 1331 return; 1332 1333 -- Nothing to do if call is being pre-analyzed, as when within a 1334 -- pre/postcondition, a predicate, or an invariant. 1335 1336 elsif In_Spec_Expression then 1337 return; 1338 end if; 1339 1340 -- Nothing to do if this is a call to a postcondition, which is always 1341 -- within a subprogram body, even though the current scope may be the 1342 -- enclosing scope of the subprogram. 1343 1344 if Nkind (N) = N_Procedure_Call_Statement 1345 and then Is_Entity_Name (Name (N)) 1346 and then Chars (Entity (Name (N))) = Name_uPostconditions 1347 then 1348 return; 1349 end if; 1350 1351 -- Here we have a reference at elaboration time which must be checked 1352 1353 if Debug_Flag_LL then 1354 Write_Str (" Check_Elab_Ref: "); 1355 1356 if Nkind (N) = N_Attribute_Reference then 1357 if not Is_Entity_Name (Prefix (N)) then 1358 Write_Str ("<<not entity name>>"); 1359 else 1360 Write_Name (Chars (Entity (Prefix (N)))); 1361 end if; 1362 1363 Write_Str ("'Access"); 1364 1365 elsif No (Name (N)) or else not Is_Entity_Name (Name (N)) then 1366 Write_Str ("<<not entity name>> "); 1367 1368 else 1369 Write_Name (Chars (Entity (Name (N)))); 1370 end if; 1371 1372 Write_Str (" reference at "); 1373 Write_Location (Sloc (N)); 1374 Write_Eol; 1375 end if; 1376 1377 -- Climb up the tree to make sure we are not inside default expression 1378 -- of a parameter specification or a record component, since in both 1379 -- these cases, we will be doing the actual reference later, not now, 1380 -- and it is at the time of the actual reference (statically speaking) 1381 -- that we must do our static check, not at the time of its initial 1382 -- analysis). 1383 1384 -- However, we have to check references within component definitions 1385 -- (e.g. a function call that determines an array component bound), 1386 -- so we terminate the loop in that case. 1387 1388 P := Parent (N); 1389 while Present (P) loop 1390 if Nkind_In (P, N_Parameter_Specification, 1391 N_Component_Declaration) 1392 then 1393 return; 1394 1395 -- The reference occurs within the constraint of a component, 1396 -- so it must be checked. 1397 1398 elsif Nkind (P) = N_Component_Definition then 1399 exit; 1400 1401 else 1402 P := Parent (P); 1403 end if; 1404 end loop; 1405 1406 -- Stuff that happens only at the outer level 1407 1408 if No (Outer_Scope) then 1409 Elab_Visited.Set_Last (0); 1410 1411 -- Nothing to do if current scope is Standard (this is a bit odd, but 1412 -- it happens in the case of generic instantiations). 1413 1414 C_Scope := Current_Scope; 1415 1416 if C_Scope = Standard_Standard then 1417 return; 1418 end if; 1419 1420 -- First case, we are in elaboration code 1421 1422 From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; 1423 1424 if From_Elab_Code then 1425 1426 -- Complain if ref that comes from source in preelaborated unit 1427 -- and we are not inside a subprogram (i.e. we are in elab code). 1428 1429 if Comes_From_Source (N) 1430 and then In_Preelaborated_Unit 1431 and then not In_Inlined_Body 1432 and then Nkind (N) /= N_Attribute_Reference 1433 then 1434 -- This is a warning in GNAT mode allowing such calls to be 1435 -- used in the predefined library with appropriate care. 1436 1437 Error_Msg_Warn := GNAT_Mode; 1438 Error_Msg_N 1439 ("<<non-static call not allowed in preelaborated unit", N); 1440 return; 1441 end if; 1442 1443 -- Second case, we are inside a subprogram or concurrent unit, which 1444 -- means we are not in elaboration code. 1445 1446 else 1447 -- In this case, the issue is whether we are inside the 1448 -- declarative part of the unit in which we live, or inside its 1449 -- statements. In the latter case, there is no issue of ABE calls 1450 -- at this level (a call from outside to the unit in which we live 1451 -- might cause an ABE, but that will be detected when we analyze 1452 -- that outer level call, as it recurses into the called unit). 1453 1454 -- Climb up the tree, doing this test, and also testing for being 1455 -- inside a default expression, which, as discussed above, is not 1456 -- checked at this stage. 1457 1458 declare 1459 P : Node_Id; 1460 L : List_Id; 1461 1462 begin 1463 P := N; 1464 loop 1465 -- If we find a parentless subtree, it seems safe to assume 1466 -- that we are not in a declarative part and that no 1467 -- checking is required. 1468 1469 if No (P) then 1470 return; 1471 end if; 1472 1473 if Is_List_Member (P) then 1474 L := List_Containing (P); 1475 P := Parent (L); 1476 else 1477 L := No_List; 1478 P := Parent (P); 1479 end if; 1480 1481 exit when Nkind (P) = N_Subunit; 1482 1483 -- Filter out case of default expressions, where we do not 1484 -- do the check at this stage. 1485 1486 if Nkind_In (P, N_Parameter_Specification, 1487 N_Component_Declaration) 1488 then 1489 return; 1490 end if; 1491 1492 -- A protected body has no elaboration code and contains 1493 -- only other bodies. 1494 1495 if Nkind (P) = N_Protected_Body then 1496 return; 1497 1498 elsif Nkind_In (P, N_Subprogram_Body, 1499 N_Task_Body, 1500 N_Block_Statement, 1501 N_Entry_Body) 1502 then 1503 if L = Declarations (P) then 1504 exit; 1505 1506 -- We are not in elaboration code, but we are doing 1507 -- dynamic elaboration checks, in this case, we still 1508 -- need to do the reference, since the subprogram we are 1509 -- in could be called from another unit, also in dynamic 1510 -- elaboration check mode, at elaboration time. 1511 1512 elsif Dynamic_Elaboration_Checks then 1513 1514 -- We provide a debug flag to disable this check. That 1515 -- way we have an easy work around for regressions 1516 -- that are caused by this new check. This debug flag 1517 -- can be removed later. 1518 1519 if Debug_Flag_DD then 1520 return; 1521 end if; 1522 1523 -- Do the check in this case 1524 1525 exit; 1526 1527 elsif Nkind (P) = N_Task_Body then 1528 1529 -- The check is deferred until Check_Task_Activation 1530 -- but we need to capture local suppress pragmas 1531 -- that may inhibit checks on this call. 1532 1533 Ent := Get_Referenced_Ent (N); 1534 1535 if No (Ent) then 1536 return; 1537 1538 elsif Elaboration_Checks_Suppressed (Current_Scope) 1539 or else Elaboration_Checks_Suppressed (Ent) 1540 or else Elaboration_Checks_Suppressed (Scope (Ent)) 1541 then 1542 if Nkind (N) in N_Subprogram_Call then 1543 Set_No_Elaboration_Check (N); 1544 end if; 1545 end if; 1546 1547 return; 1548 1549 -- Static model, call is not in elaboration code, we 1550 -- never need to worry, because in the static model the 1551 -- top level caller always takes care of things. 1552 1553 else 1554 return; 1555 end if; 1556 end if; 1557 end loop; 1558 end; 1559 end if; 1560 end if; 1561 1562 Ent := Get_Referenced_Ent (N); 1563 1564 if No (Ent) then 1565 return; 1566 end if; 1567 1568 -- Nothing to do if this is a recursive call (i.e. a call to 1569 -- an entity that is already in the Elab_Call stack) 1570 1571 for J in 1 .. Elab_Visited.Last loop 1572 if Ent = Elab_Visited.Table (J) then 1573 return; 1574 end if; 1575 end loop; 1576 1577 -- See if we need to analyze this reference. We analyze it if either of 1578 -- the following conditions is met: 1579 1580 -- It is an inner level call (since in this case it was triggered 1581 -- by an outer level call from elaboration code), but only if the 1582 -- call is within the scope of the original outer level call. 1583 1584 -- It is an outer level reference from elaboration code, or a call to 1585 -- an entity is in the same elaboration scope. 1586 1587 -- And in these cases, we will check both inter-unit calls and 1588 -- intra-unit (within a single unit) calls. 1589 1590 C_Scope := Current_Scope; 1591 1592 -- If not outer level reference, then we follow it if it is within the 1593 -- original scope of the outer reference. 1594 1595 if Present (Outer_Scope) 1596 and then Within (Scope (Ent), Outer_Scope) 1597 then 1598 Set_C_Scope; 1599 Check_A_Call 1600 (N => N, 1601 E => Ent, 1602 Outer_Scope => Outer_Scope, 1603 Inter_Unit_Only => False, 1604 In_Init_Proc => In_Init_Proc); 1605 1606 -- Nothing to do if elaboration checks suppressed for this scope. 1607 -- However, an interesting exception, the fact that elaboration checks 1608 -- are suppressed within an instance (because we can trace the body when 1609 -- we process the template) does not extend to calls to generic formal 1610 -- subprograms. 1611 1612 elsif Elaboration_Checks_Suppressed (Current_Scope) 1613 and then not Is_Call_Of_Generic_Formal (N) 1614 then 1615 null; 1616 1617 elsif From_Elab_Code then 1618 Set_C_Scope; 1619 Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False); 1620 1621 elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then 1622 Set_C_Scope; 1623 Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); 1624 1625 -- If none of those cases holds, but Dynamic_Elaboration_Checks mode 1626 -- is set, then we will do the check, but only in the inter-unit case 1627 -- (this is to accommodate unguarded elaboration calls from other units 1628 -- in which this same mode is set). We don't want warnings in this case, 1629 -- it would generate warnings having nothing to do with elaboration. 1630 1631 elsif Dynamic_Elaboration_Checks then 1632 Set_C_Scope; 1633 Check_A_Call 1634 (N, 1635 Ent, 1636 Standard_Standard, 1637 Inter_Unit_Only => True, 1638 Generate_Warnings => False); 1639 1640 -- Otherwise nothing to do 1641 1642 else 1643 return; 1644 end if; 1645 1646 -- A call to an Init_Proc in elaboration code may bring additional 1647 -- dependencies, if some of the record components thereof have 1648 -- initializations that are function calls that come from source. We 1649 -- treat the current node as a call to each of these functions, to check 1650 -- their elaboration impact. 1651 1652 if Is_Init_Proc (Ent) and then From_Elab_Code then 1653 Process_Init_Proc : declare 1654 Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent); 1655 1656 function Check_Init_Call (Nod : Node_Id) return Traverse_Result; 1657 -- Find subprogram calls within body of Init_Proc for Traverse 1658 -- instantiation below. 1659 1660 procedure Traverse_Body is new Traverse_Proc (Check_Init_Call); 1661 -- Traversal procedure to find all calls with body of Init_Proc 1662 1663 --------------------- 1664 -- Check_Init_Call -- 1665 --------------------- 1666 1667 function Check_Init_Call (Nod : Node_Id) return Traverse_Result is 1668 Func : Entity_Id; 1669 1670 begin 1671 if Nkind (Nod) in N_Subprogram_Call 1672 and then Is_Entity_Name (Name (Nod)) 1673 then 1674 Func := Entity (Name (Nod)); 1675 1676 if Comes_From_Source (Func) then 1677 Check_A_Call 1678 (N, Func, Standard_Standard, Inter_Unit_Only => True); 1679 end if; 1680 1681 return OK; 1682 1683 else 1684 return OK; 1685 end if; 1686 end Check_Init_Call; 1687 1688 -- Start of processing for Process_Init_Proc 1689 1690 begin 1691 if Nkind (Unit_Decl) = N_Subprogram_Body then 1692 Traverse_Body (Handled_Statement_Sequence (Unit_Decl)); 1693 end if; 1694 end Process_Init_Proc; 1695 end if; 1696 end Check_Elab_Call; 1697 1698 ----------------------- 1699 -- Check_Elab_Assign -- 1700 ----------------------- 1701 1702 procedure Check_Elab_Assign (N : Node_Id) is 1703 Ent : Entity_Id; 1704 Scop : Entity_Id; 1705 1706 Pkg_Spec : Entity_Id; 1707 Pkg_Body : Entity_Id; 1708 1709 begin 1710 -- For record or array component, check prefix. If it is an access type, 1711 -- then there is nothing to do (we do not know what is being assigned), 1712 -- but otherwise this is an assignment to the prefix. 1713 1714 if Nkind_In (N, N_Indexed_Component, 1715 N_Selected_Component, 1716 N_Slice) 1717 then 1718 if not Is_Access_Type (Etype (Prefix (N))) then 1719 Check_Elab_Assign (Prefix (N)); 1720 end if; 1721 1722 return; 1723 end if; 1724 1725 -- For type conversion, check expression 1726 1727 if Nkind (N) = N_Type_Conversion then 1728 Check_Elab_Assign (Expression (N)); 1729 return; 1730 end if; 1731 1732 -- Nothing to do if this is not an entity reference otherwise get entity 1733 1734 if Is_Entity_Name (N) then 1735 Ent := Entity (N); 1736 else 1737 return; 1738 end if; 1739 1740 -- What we are looking for is a reference in the body of a package that 1741 -- modifies a variable declared in the visible part of the package spec. 1742 1743 if Present (Ent) 1744 and then Comes_From_Source (N) 1745 and then not Suppress_Elaboration_Warnings (Ent) 1746 and then Ekind (Ent) = E_Variable 1747 and then not In_Private_Part (Ent) 1748 and then Is_Library_Level_Entity (Ent) 1749 then 1750 Scop := Current_Scope; 1751 loop 1752 if No (Scop) or else Scop = Standard_Standard then 1753 return; 1754 elsif Ekind (Scop) = E_Package 1755 and then Is_Compilation_Unit (Scop) 1756 then 1757 exit; 1758 else 1759 Scop := Scope (Scop); 1760 end if; 1761 end loop; 1762 1763 -- Here Scop points to the containing library package 1764 1765 Pkg_Spec := Scop; 1766 Pkg_Body := Body_Entity (Pkg_Spec); 1767 1768 -- All OK if the package has an Elaborate_Body pragma 1769 1770 if Has_Pragma_Elaborate_Body (Scop) then 1771 return; 1772 end if; 1773 1774 -- OK if entity being modified is not in containing package spec 1775 1776 if not In_Same_Source_Unit (Scop, Ent) then 1777 return; 1778 end if; 1779 1780 -- All OK if entity appears in generic package or generic instance. 1781 -- We just get too messed up trying to give proper warnings in the 1782 -- presence of generics. Better no message than a junk one. 1783 1784 Scop := Scope (Ent); 1785 while Present (Scop) and then Scop /= Pkg_Spec loop 1786 if Ekind (Scop) = E_Generic_Package then 1787 return; 1788 elsif Ekind (Scop) = E_Package 1789 and then Is_Generic_Instance (Scop) 1790 then 1791 return; 1792 end if; 1793 1794 Scop := Scope (Scop); 1795 end loop; 1796 1797 -- All OK if in task, don't issue warnings there 1798 1799 if In_Task_Activation then 1800 return; 1801 end if; 1802 1803 -- OK if no package body 1804 1805 if No (Pkg_Body) then 1806 return; 1807 end if; 1808 1809 -- OK if reference is not in package body 1810 1811 if not In_Same_Source_Unit (Pkg_Body, N) then 1812 return; 1813 end if; 1814 1815 -- OK if package body has no handled statement sequence 1816 1817 declare 1818 HSS : constant Node_Id := 1819 Handled_Statement_Sequence (Declaration_Node (Pkg_Body)); 1820 begin 1821 if No (HSS) or else not Comes_From_Source (HSS) then 1822 return; 1823 end if; 1824 end; 1825 1826 -- We definitely have a case of a modification of an entity in 1827 -- the package spec from the elaboration code of the package body. 1828 -- We may not give the warning (because there are some additional 1829 -- checks to avoid too many false positives), but it would be a good 1830 -- idea for the binder to try to keep the body elaboration close to 1831 -- the spec elaboration. 1832 1833 Set_Elaborate_Body_Desirable (Pkg_Spec); 1834 1835 -- All OK in gnat mode (we know what we are doing) 1836 1837 if GNAT_Mode then 1838 return; 1839 end if; 1840 1841 -- All OK if all warnings suppressed 1842 1843 if Warning_Mode = Suppress then 1844 return; 1845 end if; 1846 1847 -- All OK if elaboration checks suppressed for entity 1848 1849 if Checks_May_Be_Suppressed (Ent) 1850 and then Is_Check_Suppressed (Ent, Elaboration_Check) 1851 then 1852 return; 1853 end if; 1854 1855 -- OK if the entity is initialized. Note that the No_Initialization 1856 -- flag usually means that the initialization has been rewritten into 1857 -- assignments, but that still counts for us. 1858 1859 declare 1860 Decl : constant Node_Id := Declaration_Node (Ent); 1861 begin 1862 if Nkind (Decl) = N_Object_Declaration 1863 and then (Present (Expression (Decl)) 1864 or else No_Initialization (Decl)) 1865 then 1866 return; 1867 end if; 1868 end; 1869 1870 -- Here is where we give the warning 1871 1872 -- All OK if warnings suppressed on the entity 1873 1874 if not Has_Warnings_Off (Ent) then 1875 Error_Msg_Sloc := Sloc (Ent); 1876 1877 Error_Msg_NE 1878 ("??& can be accessed by clients before this initialization", 1879 N, Ent); 1880 Error_Msg_NE 1881 ("\??add Elaborate_Body to spec to ensure & is initialized", 1882 N, Ent); 1883 end if; 1884 1885 if not All_Errors_Mode then 1886 Set_Suppress_Elaboration_Warnings (Ent); 1887 end if; 1888 end if; 1889 end Check_Elab_Assign; 1890 1891 ---------------------- 1892 -- Check_Elab_Calls -- 1893 ---------------------- 1894 1895 procedure Check_Elab_Calls is 1896 begin 1897 -- If expansion is disabled, do not generate any checks. Also skip 1898 -- checks if any subunits are missing because in either case we lack the 1899 -- full information that we need, and no object file will be created in 1900 -- any case. 1901 1902 if not Expander_Active 1903 or else Is_Generic_Unit (Cunit_Entity (Main_Unit)) 1904 or else Subunits_Missing 1905 then 1906 return; 1907 end if; 1908 1909 -- Skip delayed calls if we had any errors 1910 1911 if Serious_Errors_Detected = 0 then 1912 Delaying_Elab_Checks := False; 1913 Expander_Mode_Save_And_Set (True); 1914 1915 for J in Delay_Check.First .. Delay_Check.Last loop 1916 Push_Scope (Delay_Check.Table (J).Curscop); 1917 From_Elab_Code := Delay_Check.Table (J).From_Elab_Code; 1918 1919 Check_Internal_Call_Continue ( 1920 N => Delay_Check.Table (J).N, 1921 E => Delay_Check.Table (J).E, 1922 Outer_Scope => Delay_Check.Table (J).Outer_Scope, 1923 Orig_Ent => Delay_Check.Table (J).Orig_Ent); 1924 1925 Pop_Scope; 1926 end loop; 1927 1928 -- Set Delaying_Elab_Checks back on for next main compilation 1929 1930 Expander_Mode_Restore; 1931 Delaying_Elab_Checks := True; 1932 end if; 1933 end Check_Elab_Calls; 1934 1935 ------------------------------ 1936 -- Check_Elab_Instantiation -- 1937 ------------------------------ 1938 1939 procedure Check_Elab_Instantiation 1940 (N : Node_Id; 1941 Outer_Scope : Entity_Id := Empty) 1942 is 1943 Ent : Entity_Id; 1944 1945 begin 1946 -- Check for and deal with bad instantiation case. There is some 1947 -- duplicated code here, but we will worry about this later ??? 1948 1949 Check_Bad_Instantiation (N); 1950 1951 if ABE_Is_Certain (N) then 1952 return; 1953 end if; 1954 1955 -- Nothing to do if we do not have an instantiation (happens in some 1956 -- error cases, and also in the formal package declaration case) 1957 1958 if Nkind (N) not in N_Generic_Instantiation then 1959 return; 1960 end if; 1961 1962 -- Nothing to do if inside a generic template 1963 1964 if Inside_A_Generic then 1965 return; 1966 end if; 1967 1968 -- Nothing to do if the instantiation is not in the main unit 1969 1970 if not In_Extended_Main_Code_Unit (N) then 1971 return; 1972 end if; 1973 1974 Ent := Get_Generic_Entity (N); 1975 From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; 1976 1977 -- See if we need to analyze this instantiation. We analyze it if 1978 -- either of the following conditions is met: 1979 1980 -- It is an inner level instantiation (since in this case it was 1981 -- triggered by an outer level call from elaboration code), but 1982 -- only if the instantiation is within the scope of the original 1983 -- outer level call. 1984 1985 -- It is an outer level instantiation from elaboration code, or the 1986 -- instantiated entity is in the same elaboration scope. 1987 1988 -- And in these cases, we will check both the inter-unit case and 1989 -- the intra-unit (within a single unit) case. 1990 1991 C_Scope := Current_Scope; 1992 1993 if Present (Outer_Scope) and then Within (Scope (Ent), Outer_Scope) then 1994 Set_C_Scope; 1995 Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False); 1996 1997 elsif From_Elab_Code then 1998 Set_C_Scope; 1999 Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False); 2000 2001 elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then 2002 Set_C_Scope; 2003 Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); 2004 2005 -- If none of those cases holds, but Dynamic_Elaboration_Checks mode is 2006 -- set, then we will do the check, but only in the inter-unit case (this 2007 -- is to accommodate unguarded elaboration calls from other units in 2008 -- which this same mode is set). We inhibit warnings in this case, since 2009 -- this instantiation is not occurring in elaboration code. 2010 2011 elsif Dynamic_Elaboration_Checks then 2012 Set_C_Scope; 2013 Check_A_Call 2014 (N, 2015 Ent, 2016 Standard_Standard, 2017 Inter_Unit_Only => True, 2018 Generate_Warnings => False); 2019 2020 else 2021 return; 2022 end if; 2023 end Check_Elab_Instantiation; 2024 2025 ------------------------- 2026 -- Check_Internal_Call -- 2027 ------------------------- 2028 2029 procedure Check_Internal_Call 2030 (N : Node_Id; 2031 E : Entity_Id; 2032 Outer_Scope : Entity_Id; 2033 Orig_Ent : Entity_Id) 2034 is 2035 Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation; 2036 2037 begin 2038 -- For P'Access, we want to warn if the -gnatw.f switch is set, and the 2039 -- node comes from source. 2040 2041 if Nkind (N) = N_Attribute_Reference and then 2042 (not Warn_On_Elab_Access or else not Comes_From_Source (N)) 2043 then 2044 return; 2045 2046 -- If not function or procedure call, instantiation, or 'Access, then 2047 -- ignore call (this happens in some error cases and rewriting cases). 2048 2049 elsif not Nkind_In 2050 (N, N_Function_Call, 2051 N_Procedure_Call_Statement, 2052 N_Attribute_Reference) 2053 and then not Inst_Case 2054 then 2055 return; 2056 2057 -- Nothing to do if this is a call or instantiation that has already 2058 -- been found to be a sure ABE. 2059 2060 elsif Nkind (N) /= N_Attribute_Reference and then ABE_Is_Certain (N) then 2061 return; 2062 2063 -- Nothing to do if errors already detected (avoid cascaded errors) 2064 2065 elsif Serious_Errors_Detected /= 0 then 2066 return; 2067 2068 -- Nothing to do if not in full analysis mode 2069 2070 elsif not Full_Analysis then 2071 return; 2072 2073 -- Nothing to do if analyzing in special spec-expression mode, since the 2074 -- call is not actually being made at this time. 2075 2076 elsif In_Spec_Expression then 2077 return; 2078 2079 -- Nothing to do for call to intrinsic subprogram 2080 2081 elsif Is_Intrinsic_Subprogram (E) then 2082 return; 2083 2084 -- No need to trace local calls if checking task activation, because 2085 -- other local bodies are elaborated already. 2086 2087 elsif In_Task_Activation then 2088 return; 2089 2090 -- Nothing to do if call is within a generic unit 2091 2092 elsif Inside_A_Generic then 2093 return; 2094 end if; 2095 2096 -- Delay this call if we are still delaying calls 2097 2098 if Delaying_Elab_Checks then 2099 Delay_Check.Append ( 2100 (N => N, 2101 E => E, 2102 Orig_Ent => Orig_Ent, 2103 Curscop => Current_Scope, 2104 Outer_Scope => Outer_Scope, 2105 From_Elab_Code => From_Elab_Code)); 2106 return; 2107 2108 -- Otherwise, call phase 2 continuation right now 2109 2110 else 2111 Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent); 2112 end if; 2113 end Check_Internal_Call; 2114 2115 ---------------------------------- 2116 -- Check_Internal_Call_Continue -- 2117 ---------------------------------- 2118 2119 procedure Check_Internal_Call_Continue 2120 (N : Node_Id; 2121 E : Entity_Id; 2122 Outer_Scope : Entity_Id; 2123 Orig_Ent : Entity_Id) 2124 is 2125 function Find_Elab_Reference (N : Node_Id) return Traverse_Result; 2126 -- Function applied to each node as we traverse the body. Checks for 2127 -- call or entity reference that needs checking, and if so checks it. 2128 -- Always returns OK, so entire tree is traversed, except that as 2129 -- described below subprogram bodies are skipped for now. 2130 2131 procedure Traverse is new Atree.Traverse_Proc (Find_Elab_Reference); 2132 -- Traverse procedure using above Find_Elab_Reference function 2133 2134 ------------------------- 2135 -- Find_Elab_Reference -- 2136 ------------------------- 2137 2138 function Find_Elab_Reference (N : Node_Id) return Traverse_Result is 2139 Actual : Node_Id; 2140 2141 begin 2142 -- If user has specified that there are no entry calls in elaboration 2143 -- code, do not trace past an accept statement, because the rendez- 2144 -- vous will happen after elaboration. 2145 2146 if Nkind_In (Original_Node (N), N_Accept_Statement, 2147 N_Selective_Accept) 2148 and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code) 2149 then 2150 return Abandon; 2151 2152 -- If we have a function call, check it 2153 2154 elsif Nkind (N) = N_Function_Call then 2155 Check_Elab_Call (N, Outer_Scope); 2156 return OK; 2157 2158 -- If we have a procedure call, check the call, and also check 2159 -- arguments that are assignments (OUT or IN OUT mode formals). 2160 2161 elsif Nkind (N) = N_Procedure_Call_Statement then 2162 Check_Elab_Call (N, Outer_Scope, In_Init_Proc => Is_Init_Proc (E)); 2163 2164 Actual := First_Actual (N); 2165 while Present (Actual) loop 2166 if Known_To_Be_Assigned (Actual) then 2167 Check_Elab_Assign (Actual); 2168 end if; 2169 2170 Next_Actual (Actual); 2171 end loop; 2172 2173 return OK; 2174 2175 -- If we have an access attribute for a subprogram, check it. 2176 -- Suppress this behavior under debug flag. 2177 2178 elsif not Debug_Flag_Dot_UU 2179 and then Nkind (N) = N_Attribute_Reference 2180 and then Nam_In (Attribute_Name (N), Name_Access, 2181 Name_Unrestricted_Access) 2182 and then Is_Entity_Name (Prefix (N)) 2183 and then Is_Subprogram (Entity (Prefix (N))) 2184 then 2185 Check_Elab_Call (N, Outer_Scope); 2186 return OK; 2187 2188 -- In SPARK mode, if we have an entity reference to a variable, then 2189 -- check it. For now we consider any reference. 2190 2191 elsif SPARK_Mode = On 2192 and then Nkind (N) in N_Has_Entity 2193 and then Present (Entity (N)) 2194 and then Ekind (Entity (N)) = E_Variable 2195 then 2196 Check_Elab_Call (N, Outer_Scope); 2197 return OK; 2198 2199 -- If we have a generic instantiation, check it 2200 2201 elsif Nkind (N) in N_Generic_Instantiation then 2202 Check_Elab_Instantiation (N, Outer_Scope); 2203 return OK; 2204 2205 -- Skip subprogram bodies that come from source (wait for call to 2206 -- analyze these). The reason for the come from source test is to 2207 -- avoid catching task bodies. 2208 2209 -- For task bodies, we should really avoid these too, waiting for the 2210 -- task activation, but that's too much trouble to catch for now, so 2211 -- we go in unconditionally. This is not so terrible, it means the 2212 -- error backtrace is not quite complete, and we are too eager to 2213 -- scan bodies of tasks that are unused, but this is hardly very 2214 -- significant. 2215 2216 elsif Nkind (N) = N_Subprogram_Body 2217 and then Comes_From_Source (N) 2218 then 2219 return Skip; 2220 2221 elsif Nkind (N) = N_Assignment_Statement 2222 and then Comes_From_Source (N) 2223 then 2224 Check_Elab_Assign (Name (N)); 2225 return OK; 2226 2227 else 2228 return OK; 2229 end if; 2230 end Find_Elab_Reference; 2231 2232 Inst_Case : constant Boolean := Is_Generic_Unit (E); 2233 Loc : constant Source_Ptr := Sloc (N); 2234 2235 Ebody : Entity_Id; 2236 Sbody : Node_Id; 2237 2238 -- Start of processing for Check_Internal_Call_Continue 2239 2240 begin 2241 -- Save outer level call if at outer level 2242 2243 if Elab_Call.Last = 0 then 2244 Outer_Level_Sloc := Loc; 2245 end if; 2246 2247 Elab_Visited.Append (E); 2248 2249 -- If the call is to a function that renames a literal, no check needed 2250 2251 if Ekind (E) = E_Enumeration_Literal then 2252 return; 2253 end if; 2254 2255 Sbody := Unit_Declaration_Node (E); 2256 2257 if not Nkind_In (Sbody, N_Subprogram_Body, N_Package_Body) then 2258 Ebody := Corresponding_Body (Sbody); 2259 2260 if No (Ebody) then 2261 return; 2262 else 2263 Sbody := Unit_Declaration_Node (Ebody); 2264 end if; 2265 end if; 2266 2267 -- If the body appears after the outer level call or instantiation then 2268 -- we have an error case handled below. 2269 2270 if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody)) 2271 and then not In_Task_Activation 2272 then 2273 null; 2274 2275 -- If we have the instantiation case we are done, since we now 2276 -- know that the body of the generic appeared earlier. 2277 2278 elsif Inst_Case then 2279 return; 2280 2281 -- Otherwise we have a call, so we trace through the called body to see 2282 -- if it has any problems. 2283 2284 else 2285 pragma Assert (Nkind (Sbody) = N_Subprogram_Body); 2286 2287 Elab_Call.Append ((Cloc => Loc, Ent => E)); 2288 2289 if Debug_Flag_LL then 2290 Write_Str ("Elab_Call.Last = "); 2291 Write_Int (Int (Elab_Call.Last)); 2292 Write_Str (" Ent = "); 2293 Write_Name (Chars (E)); 2294 Write_Str (" at "); 2295 Write_Location (Sloc (N)); 2296 Write_Eol; 2297 end if; 2298 2299 -- Now traverse declarations and statements of subprogram body. Note 2300 -- that we cannot simply Traverse (Sbody), since traverse does not 2301 -- normally visit subprogram bodies. 2302 2303 declare 2304 Decl : Node_Id; 2305 begin 2306 Decl := First (Declarations (Sbody)); 2307 while Present (Decl) loop 2308 Traverse (Decl); 2309 Next (Decl); 2310 end loop; 2311 end; 2312 2313 Traverse (Handled_Statement_Sequence (Sbody)); 2314 2315 Elab_Call.Decrement_Last; 2316 return; 2317 end if; 2318 2319 -- Here is the case of calling a subprogram where the body has not yet 2320 -- been encountered. A warning message is needed, except if this is the 2321 -- case of appearing within an aspect specification that results in 2322 -- a check call, we do not really have such a situation, so no warning 2323 -- is needed (e.g. the case of a precondition, where the call appears 2324 -- textually before the body, but in actual fact is moved to the 2325 -- appropriate subprogram body and so does not need a check). 2326 2327 declare 2328 P : Node_Id; 2329 O : Node_Id; 2330 2331 begin 2332 P := Parent (N); 2333 loop 2334 -- Keep looking at parents if we are still in the subexpression 2335 2336 if Nkind (P) in N_Subexpr then 2337 P := Parent (P); 2338 2339 -- Here P is the parent of the expression, check for special case 2340 2341 else 2342 O := Original_Node (P); 2343 2344 -- Definitely not the special case if orig node is not a pragma 2345 2346 exit when Nkind (O) /= N_Pragma; 2347 2348 -- Check we have an If statement or a null statement (happens 2349 -- when the If has been expanded to be True). 2350 2351 exit when not Nkind_In (P, N_If_Statement, N_Null_Statement); 2352 2353 -- Our special case will be indicated either by the pragma 2354 -- coming from an aspect ... 2355 2356 if Present (Corresponding_Aspect (O)) then 2357 return; 2358 2359 -- Or, in the case of an initial condition, specifically by a 2360 -- Check pragma specifying an Initial_Condition check. 2361 2362 elsif Pragma_Name (O) = Name_Check 2363 and then 2364 Chars 2365 (Expression (First (Pragma_Argument_Associations (O)))) = 2366 Name_Initial_Condition 2367 then 2368 return; 2369 2370 -- For anything else, we have an error 2371 2372 else 2373 exit; 2374 end if; 2375 end if; 2376 end loop; 2377 end; 2378 2379 -- Not that special case, warning and dynamic check is required 2380 2381 -- If we have nothing in the call stack, then this is at the outer 2382 -- level, and the ABE is bound to occur, unless it's a 'Access, or 2383 -- it's a renaming. 2384 2385 if Elab_Call.Last = 0 then 2386 Error_Msg_Warn := SPARK_Mode /= On; 2387 2388 declare 2389 Insert_Check : Boolean := True; 2390 -- This flag is set to True if an elaboration check should be 2391 -- inserted. 2392 2393 begin 2394 if Inst_Case then 2395 Error_Msg_NE 2396 ("cannot instantiate& before body seen<<", N, Orig_Ent); 2397 2398 elsif Nkind (N) = N_Attribute_Reference then 2399 Error_Msg_NE 2400 ("Access attribute of & before body seen<<", N, Orig_Ent); 2401 Error_Msg_N ("\possible Program_Error on later references<", N); 2402 Insert_Check := False; 2403 2404 elsif Nkind (Unit_Declaration_Node (Orig_Ent)) /= 2405 N_Subprogram_Renaming_Declaration 2406 then 2407 Error_Msg_NE 2408 ("cannot call& before body seen<<", N, Orig_Ent); 2409 2410 elsif not Is_Generic_Actual_Subprogram (Orig_Ent) then 2411 Insert_Check := False; 2412 end if; 2413 2414 if Insert_Check then 2415 Error_Msg_N ("\Program_Error [<<", N); 2416 Insert_Elab_Check (N); 2417 end if; 2418 end; 2419 2420 -- Call is not at outer level 2421 2422 else 2423 -- Deal with dynamic elaboration check 2424 2425 if not Elaboration_Checks_Suppressed (E) then 2426 Set_Elaboration_Entity_Required (E); 2427 2428 -- Case of no elaboration entity allocated yet 2429 2430 if No (Elaboration_Entity (E)) then 2431 2432 -- Create object declaration for elaboration entity, and put it 2433 -- just in front of the spec of the subprogram or generic unit, 2434 -- in the same scope as this unit. The subprogram may be over- 2435 -- loaded, so make the name of elaboration entity unique by 2436 -- means of a numeric suffix. 2437 2438 declare 2439 Loce : constant Source_Ptr := Sloc (E); 2440 Ent : constant Entity_Id := 2441 Make_Defining_Identifier (Loc, 2442 Chars => New_External_Name (Chars (E), 'E', -1)); 2443 2444 begin 2445 Set_Elaboration_Entity (E, Ent); 2446 Push_Scope (Scope (E)); 2447 2448 Insert_Action (Declaration_Node (E), 2449 Make_Object_Declaration (Loce, 2450 Defining_Identifier => Ent, 2451 Object_Definition => 2452 New_Occurrence_Of (Standard_Short_Integer, Loce), 2453 Expression => 2454 Make_Integer_Literal (Loc, Uint_0))); 2455 2456 -- Set elaboration flag at the point of the body 2457 2458 Set_Elaboration_Flag (Sbody, E); 2459 2460 -- Kill current value indication. This is necessary because 2461 -- the tests of this flag are inserted out of sequence and 2462 -- must not pick up bogus indications of the wrong constant 2463 -- value. Also, this is never a true constant, since one way 2464 -- or another, it gets reset. 2465 2466 Set_Current_Value (Ent, Empty); 2467 Set_Last_Assignment (Ent, Empty); 2468 Set_Is_True_Constant (Ent, False); 2469 Pop_Scope; 2470 end; 2471 end if; 2472 2473 -- Generate check of the elaboration counter 2474 2475 Insert_Elab_Check (N, 2476 Make_Attribute_Reference (Loc, 2477 Attribute_Name => Name_Elaborated, 2478 Prefix => New_Occurrence_Of (E, Loc))); 2479 end if; 2480 2481 -- Generate the warning 2482 2483 if not Suppress_Elaboration_Warnings (E) 2484 and then not Elaboration_Checks_Suppressed (E) 2485 2486 -- Suppress this warning if we have a function call that occurred 2487 -- within an assertion expression, since we can get false warnings 2488 -- in this case, due to the out of order handling in this case. 2489 2490 and then 2491 (Nkind (Original_Node (N)) /= N_Function_Call 2492 or else not In_Assertion_Expression_Pragma (Original_Node (N))) 2493 then 2494 Error_Msg_Warn := SPARK_Mode /= On; 2495 2496 if Inst_Case then 2497 Error_Msg_NE 2498 ("instantiation of& may occur before body is seen<l<", 2499 N, Orig_Ent); 2500 else 2501 -- A rather specific check. For Finalize/Adjust/Initialize, 2502 -- if the type has Warnings_Off set, suppress the warning. 2503 2504 if Nam_In (Chars (E), Name_Adjust, 2505 Name_Finalize, 2506 Name_Initialize) 2507 and then Present (First_Formal (E)) 2508 then 2509 declare 2510 T : constant Entity_Id := Etype (First_Formal (E)); 2511 begin 2512 if Is_Controlled (T) then 2513 if Warnings_Off (T) 2514 or else (Ekind (T) = E_Private_Type 2515 and then Warnings_Off (Full_View (T))) 2516 then 2517 goto Output; 2518 end if; 2519 end if; 2520 end; 2521 end if; 2522 2523 -- Go ahead and give warning if not this special case 2524 2525 Error_Msg_NE 2526 ("call to& may occur before body is seen<l<", N, Orig_Ent); 2527 end if; 2528 2529 Error_Msg_N ("\Program_Error ]<l<", N); 2530 2531 -- There is no need to query the elaboration warning message flags 2532 -- because the main message is an error, not a warning, therefore 2533 -- all the clarification messages produces by Output_Calls must be 2534 -- emitted unconditionally. 2535 2536 <<Output>> 2537 2538 Output_Calls (N, Check_Elab_Flag => False); 2539 end if; 2540 end if; 2541 2542 -- Set flag to suppress further warnings on same subprogram 2543 -- unless in all errors mode 2544 2545 if not All_Errors_Mode then 2546 Set_Suppress_Elaboration_Warnings (E); 2547 end if; 2548 end Check_Internal_Call_Continue; 2549 2550 --------------------------- 2551 -- Check_Task_Activation -- 2552 --------------------------- 2553 2554 procedure Check_Task_Activation (N : Node_Id) is 2555 Loc : constant Source_Ptr := Sloc (N); 2556 Inter_Procs : constant Elist_Id := New_Elmt_List; 2557 Intra_Procs : constant Elist_Id := New_Elmt_List; 2558 Ent : Entity_Id; 2559 P : Entity_Id; 2560 Task_Scope : Entity_Id; 2561 Cunit_SC : Boolean := False; 2562 Decl : Node_Id; 2563 Elmt : Elmt_Id; 2564 Enclosing : Entity_Id; 2565 2566 procedure Add_Task_Proc (Typ : Entity_Id); 2567 -- Add to Task_Procs the task body procedure(s) of task types in Typ. 2568 -- For record types, this procedure recurses over component types. 2569 2570 procedure Collect_Tasks (Decls : List_Id); 2571 -- Collect the types of the tasks that are to be activated in the given 2572 -- list of declarations, in order to perform elaboration checks on the 2573 -- corresponding task procedures which are called implicitly here. 2574 2575 function Outer_Unit (E : Entity_Id) return Entity_Id; 2576 -- find enclosing compilation unit of Entity, ignoring subunits, or 2577 -- else enclosing subprogram. If E is not a package, there is no need 2578 -- for inter-unit elaboration checks. 2579 2580 ------------------- 2581 -- Add_Task_Proc -- 2582 ------------------- 2583 2584 procedure Add_Task_Proc (Typ : Entity_Id) is 2585 Comp : Entity_Id; 2586 Proc : Entity_Id := Empty; 2587 2588 begin 2589 if Is_Task_Type (Typ) then 2590 Proc := Get_Task_Body_Procedure (Typ); 2591 2592 elsif Is_Array_Type (Typ) 2593 and then Has_Task (Base_Type (Typ)) 2594 then 2595 Add_Task_Proc (Component_Type (Typ)); 2596 2597 elsif Is_Record_Type (Typ) 2598 and then Has_Task (Base_Type (Typ)) 2599 then 2600 Comp := First_Component (Typ); 2601 while Present (Comp) loop 2602 Add_Task_Proc (Etype (Comp)); 2603 Comp := Next_Component (Comp); 2604 end loop; 2605 end if; 2606 2607 -- If the task type is another unit, we will perform the usual 2608 -- elaboration check on its enclosing unit. If the type is in the 2609 -- same unit, we can trace the task body as for an internal call, 2610 -- but we only need to examine other external calls, because at 2611 -- the point the task is activated, internal subprogram bodies 2612 -- will have been elaborated already. We keep separate lists for 2613 -- each kind of task. 2614 2615 -- Skip this test if errors have occurred, since in this case 2616 -- we can get false indications. 2617 2618 if Serious_Errors_Detected /= 0 then 2619 return; 2620 end if; 2621 2622 if Present (Proc) then 2623 if Outer_Unit (Scope (Proc)) = Enclosing then 2624 2625 if No (Corresponding_Body (Unit_Declaration_Node (Proc))) 2626 and then 2627 (not Is_Generic_Instance (Scope (Proc)) 2628 or else Scope (Proc) = Scope (Defining_Identifier (Decl))) 2629 then 2630 Error_Msg_Warn := SPARK_Mode /= On; 2631 Error_Msg_N 2632 ("task will be activated before elaboration of its body<<", 2633 Decl); 2634 Error_Msg_N ("\Program_Error [<<", Decl); 2635 2636 elsif Present 2637 (Corresponding_Body (Unit_Declaration_Node (Proc))) 2638 then 2639 Append_Elmt (Proc, Intra_Procs); 2640 end if; 2641 2642 else 2643 -- No need for multiple entries of the same type 2644 2645 Elmt := First_Elmt (Inter_Procs); 2646 while Present (Elmt) loop 2647 if Node (Elmt) = Proc then 2648 return; 2649 end if; 2650 2651 Next_Elmt (Elmt); 2652 end loop; 2653 2654 Append_Elmt (Proc, Inter_Procs); 2655 end if; 2656 end if; 2657 end Add_Task_Proc; 2658 2659 ------------------- 2660 -- Collect_Tasks -- 2661 ------------------- 2662 2663 procedure Collect_Tasks (Decls : List_Id) is 2664 begin 2665 if Present (Decls) then 2666 Decl := First (Decls); 2667 while Present (Decl) loop 2668 if Nkind (Decl) = N_Object_Declaration 2669 and then Has_Task (Etype (Defining_Identifier (Decl))) 2670 then 2671 Add_Task_Proc (Etype (Defining_Identifier (Decl))); 2672 end if; 2673 2674 Next (Decl); 2675 end loop; 2676 end if; 2677 end Collect_Tasks; 2678 2679 ---------------- 2680 -- Outer_Unit -- 2681 ---------------- 2682 2683 function Outer_Unit (E : Entity_Id) return Entity_Id is 2684 Outer : Entity_Id; 2685 2686 begin 2687 Outer := E; 2688 while Present (Outer) loop 2689 if Elaboration_Checks_Suppressed (Outer) then 2690 Cunit_SC := True; 2691 end if; 2692 2693 exit when Is_Child_Unit (Outer) 2694 or else Scope (Outer) = Standard_Standard 2695 or else Ekind (Outer) /= E_Package; 2696 Outer := Scope (Outer); 2697 end loop; 2698 2699 return Outer; 2700 end Outer_Unit; 2701 2702 -- Start of processing for Check_Task_Activation 2703 2704 begin 2705 Enclosing := Outer_Unit (Current_Scope); 2706 2707 -- Find all tasks declared in the current unit 2708 2709 if Nkind (N) = N_Package_Body then 2710 P := Unit_Declaration_Node (Corresponding_Spec (N)); 2711 2712 Collect_Tasks (Declarations (N)); 2713 Collect_Tasks (Visible_Declarations (Specification (P))); 2714 Collect_Tasks (Private_Declarations (Specification (P))); 2715 2716 elsif Nkind (N) = N_Package_Declaration then 2717 Collect_Tasks (Visible_Declarations (Specification (N))); 2718 Collect_Tasks (Private_Declarations (Specification (N))); 2719 2720 else 2721 Collect_Tasks (Declarations (N)); 2722 end if; 2723 2724 -- We only perform detailed checks in all tasks that are library level 2725 -- entities. If the master is a subprogram or task, activation will 2726 -- depend on the activation of the master itself. 2727 2728 -- Should dynamic checks be added in the more general case??? 2729 2730 if Ekind (Enclosing) /= E_Package then 2731 return; 2732 end if; 2733 2734 -- For task types defined in other units, we want the unit containing 2735 -- the task body to be elaborated before the current one. 2736 2737 Elmt := First_Elmt (Inter_Procs); 2738 while Present (Elmt) loop 2739 Ent := Node (Elmt); 2740 Task_Scope := Outer_Unit (Scope (Ent)); 2741 2742 if not Is_Compilation_Unit (Task_Scope) then 2743 null; 2744 2745 elsif Suppress_Elaboration_Warnings (Task_Scope) 2746 or else Elaboration_Checks_Suppressed (Task_Scope) 2747 then 2748 null; 2749 2750 elsif Dynamic_Elaboration_Checks then 2751 if not Elaboration_Checks_Suppressed (Ent) 2752 and then not Cunit_SC 2753 and then 2754 not Restriction_Active (No_Entry_Calls_In_Elaboration_Code) 2755 then 2756 -- Runtime elaboration check required. Generate check of the 2757 -- elaboration counter for the unit containing the entity. 2758 2759 Insert_Elab_Check (N, 2760 Make_Attribute_Reference (Loc, 2761 Attribute_Name => Name_Elaborated, 2762 Prefix => 2763 New_Occurrence_Of (Spec_Entity (Task_Scope), Loc))); 2764 end if; 2765 2766 else 2767 -- Force the binder to elaborate other unit first 2768 2769 if not Suppress_Elaboration_Warnings (Ent) 2770 and then not Elaboration_Checks_Suppressed (Ent) 2771 and then Elab_Info_Messages 2772 and then not Suppress_Elaboration_Warnings (Task_Scope) 2773 and then not Elaboration_Checks_Suppressed (Task_Scope) 2774 then 2775 Error_Msg_Node_2 := Task_Scope; 2776 Error_Msg_NE 2777 ("info: activation of an instance of task type&" & 2778 " requires pragma Elaborate_All on &?$?", N, Ent); 2779 end if; 2780 2781 Activate_Elaborate_All_Desirable (N, Task_Scope); 2782 Set_Suppress_Elaboration_Warnings (Task_Scope); 2783 end if; 2784 2785 Next_Elmt (Elmt); 2786 end loop; 2787 2788 -- For tasks declared in the current unit, trace other calls within 2789 -- the task procedure bodies, which are available. 2790 2791 In_Task_Activation := True; 2792 2793 Elmt := First_Elmt (Intra_Procs); 2794 while Present (Elmt) loop 2795 Ent := Node (Elmt); 2796 Check_Internal_Call_Continue (N, Ent, Enclosing, Ent); 2797 Next_Elmt (Elmt); 2798 end loop; 2799 2800 In_Task_Activation := False; 2801 end Check_Task_Activation; 2802 2803 ------------------------------- 2804 -- Is_Call_Of_Generic_Formal -- 2805 ------------------------------- 2806 2807 function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean is 2808 begin 2809 return Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) 2810 2811 -- Always return False if debug flag -gnatd.G is set 2812 2813 and then not Debug_Flag_Dot_GG 2814 2815 -- For now, we detect this by looking for the strange identifier 2816 -- node, whose Chars reflect the name of the generic formal, but 2817 -- the Chars of the Entity references the generic actual. 2818 2819 and then Nkind (Name (N)) = N_Identifier 2820 and then Chars (Name (N)) /= Chars (Entity (Name (N))); 2821 end Is_Call_Of_Generic_Formal; 2822 2823 -------------------------------- 2824 -- Set_Elaboration_Constraint -- 2825 -------------------------------- 2826 2827 procedure Set_Elaboration_Constraint 2828 (Call : Node_Id; 2829 Subp : Entity_Id; 2830 Scop : Entity_Id) 2831 is 2832 Elab_Unit : Entity_Id; 2833 2834 -- Check whether this is a call to an Initialize subprogram for a 2835 -- controlled type. Note that Call can also be a 'Access attribute 2836 -- reference, which now generates an elaboration check. 2837 2838 Init_Call : constant Boolean := 2839 Nkind (Call) = N_Procedure_Call_Statement 2840 and then Chars (Subp) = Name_Initialize 2841 and then Comes_From_Source (Subp) 2842 and then Present (Parameter_Associations (Call)) 2843 and then Is_Controlled (Etype (First_Actual (Call))); 2844 begin 2845 -- If the unit is mentioned in a with_clause of the current unit, it is 2846 -- visible, and we can set the elaboration flag. 2847 2848 if Is_Immediately_Visible (Scop) 2849 or else (Is_Child_Unit (Scop) and then Is_Visible_Lib_Unit (Scop)) 2850 then 2851 Activate_Elaborate_All_Desirable (Call, Scop); 2852 Set_Suppress_Elaboration_Warnings (Scop, True); 2853 return; 2854 end if; 2855 2856 -- If this is not an initialization call or a call using object notation 2857 -- we know that the unit of the called entity is in the context, and 2858 -- we can set the flag as well. The unit need not be visible if the call 2859 -- occurs within an instantiation. 2860 2861 if Is_Init_Proc (Subp) 2862 or else Init_Call 2863 or else Nkind (Original_Node (Call)) = N_Selected_Component 2864 then 2865 null; -- detailed processing follows. 2866 2867 else 2868 Activate_Elaborate_All_Desirable (Call, Scop); 2869 Set_Suppress_Elaboration_Warnings (Scop, True); 2870 return; 2871 end if; 2872 2873 -- If the unit is not in the context, there must be an intermediate unit 2874 -- that is, on which we need to place to elaboration flag. This happens 2875 -- with init proc calls. 2876 2877 if Is_Init_Proc (Subp) or else Init_Call then 2878 2879 -- The initialization call is on an object whose type is not declared 2880 -- in the same scope as the subprogram. The type of the object must 2881 -- be a subtype of the type of operation. This object is the first 2882 -- actual in the call. 2883 2884 declare 2885 Typ : constant Entity_Id := 2886 Etype (First (Parameter_Associations (Call))); 2887 begin 2888 Elab_Unit := Scope (Typ); 2889 while (Present (Elab_Unit)) 2890 and then not Is_Compilation_Unit (Elab_Unit) 2891 loop 2892 Elab_Unit := Scope (Elab_Unit); 2893 end loop; 2894 end; 2895 2896 -- If original node uses selected component notation, the prefix is 2897 -- visible and determines the scope that must be elaborated. After 2898 -- rewriting, the prefix is the first actual in the call. 2899 2900 elsif Nkind (Original_Node (Call)) = N_Selected_Component then 2901 Elab_Unit := Scope (Etype (First (Parameter_Associations (Call)))); 2902 2903 -- Not one of special cases above 2904 2905 else 2906 -- Using previously computed scope. If the elaboration check is 2907 -- done after analysis, the scope is not visible any longer, but 2908 -- must still be in the context. 2909 2910 Elab_Unit := Scop; 2911 end if; 2912 2913 Activate_Elaborate_All_Desirable (Call, Elab_Unit); 2914 Set_Suppress_Elaboration_Warnings (Elab_Unit, True); 2915 end Set_Elaboration_Constraint; 2916 2917 ------------------------ 2918 -- Get_Referenced_Ent -- 2919 ------------------------ 2920 2921 function Get_Referenced_Ent (N : Node_Id) return Entity_Id is 2922 Nam : Node_Id; 2923 2924 begin 2925 if Nkind (N) in N_Has_Entity 2926 and then Present (Entity (N)) 2927 and then Ekind (Entity (N)) = E_Variable 2928 then 2929 return Entity (N); 2930 end if; 2931 2932 if Nkind (N) = N_Attribute_Reference then 2933 Nam := Prefix (N); 2934 else 2935 Nam := Name (N); 2936 end if; 2937 2938 if No (Nam) then 2939 return Empty; 2940 elsif Nkind (Nam) = N_Selected_Component then 2941 return Entity (Selector_Name (Nam)); 2942 elsif not Is_Entity_Name (Nam) then 2943 return Empty; 2944 else 2945 return Entity (Nam); 2946 end if; 2947 end Get_Referenced_Ent; 2948 2949 ---------------------- 2950 -- Has_Generic_Body -- 2951 ---------------------- 2952 2953 function Has_Generic_Body (N : Node_Id) return Boolean is 2954 Ent : constant Entity_Id := Get_Generic_Entity (N); 2955 Decl : constant Node_Id := Unit_Declaration_Node (Ent); 2956 Scop : Entity_Id; 2957 2958 function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id; 2959 -- Determine if the list of nodes headed by N and linked by Next 2960 -- contains a package body for the package spec entity E, and if so 2961 -- return the package body. If not, then returns Empty. 2962 2963 function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id; 2964 -- This procedure is called load the unit whose name is given by Nam. 2965 -- This unit is being loaded to see whether it contains an optional 2966 -- generic body. The returned value is the loaded unit, which is always 2967 -- a package body (only package bodies can contain other entities in the 2968 -- sense in which Has_Generic_Body is interested). We only attempt to 2969 -- load bodies if we are generating code. If we are in semantics check 2970 -- only mode, then it would be wrong to load bodies that are not 2971 -- required from a semantic point of view, so in this case we return 2972 -- Empty. The result is that the caller may incorrectly decide that a 2973 -- generic spec does not have a body when in fact it does, but the only 2974 -- harm in this is that some warnings on elaboration problems may be 2975 -- lost in semantic checks only mode, which is not big loss. We also 2976 -- return Empty if we go for a body and it is not there. 2977 2978 function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id; 2979 -- PE is the entity for a package spec. This function locates the 2980 -- corresponding package body, returning Empty if none is found. The 2981 -- package body returned is fully parsed but may not yet be analyzed, 2982 -- so only syntactic fields should be referenced. 2983 2984 ------------------ 2985 -- Find_Body_In -- 2986 ------------------ 2987 2988 function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id is 2989 Nod : Node_Id; 2990 2991 begin 2992 Nod := N; 2993 while Present (Nod) loop 2994 2995 -- If we found the package body we are looking for, return it 2996 2997 if Nkind (Nod) = N_Package_Body 2998 and then Chars (Defining_Unit_Name (Nod)) = Chars (E) 2999 then 3000 return Nod; 3001 3002 -- If we found the stub for the body, go after the subunit, 3003 -- loading it if necessary. 3004 3005 elsif Nkind (Nod) = N_Package_Body_Stub 3006 and then Chars (Defining_Identifier (Nod)) = Chars (E) 3007 then 3008 if Present (Library_Unit (Nod)) then 3009 return Unit (Library_Unit (Nod)); 3010 3011 else 3012 return Load_Package_Body (Get_Unit_Name (Nod)); 3013 end if; 3014 3015 -- If neither package body nor stub, keep looking on chain 3016 3017 else 3018 Next (Nod); 3019 end if; 3020 end loop; 3021 3022 return Empty; 3023 end Find_Body_In; 3024 3025 ----------------------- 3026 -- Load_Package_Body -- 3027 ----------------------- 3028 3029 function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id is 3030 U : Unit_Number_Type; 3031 3032 begin 3033 if Operating_Mode /= Generate_Code then 3034 return Empty; 3035 else 3036 U := 3037 Load_Unit 3038 (Load_Name => Nam, 3039 Required => False, 3040 Subunit => False, 3041 Error_Node => N); 3042 3043 if U = No_Unit then 3044 return Empty; 3045 else 3046 return Unit (Cunit (U)); 3047 end if; 3048 end if; 3049 end Load_Package_Body; 3050 3051 ------------------------------- 3052 -- Locate_Corresponding_Body -- 3053 ------------------------------- 3054 3055 function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id is 3056 Spec : constant Node_Id := Declaration_Node (PE); 3057 Decl : constant Node_Id := Parent (Spec); 3058 Scop : constant Entity_Id := Scope (PE); 3059 PBody : Node_Id; 3060 3061 begin 3062 if Is_Library_Level_Entity (PE) then 3063 3064 -- If package is a library unit that requires a body, we have no 3065 -- choice but to go after that body because it might contain an 3066 -- optional body for the original generic package. 3067 3068 if Unit_Requires_Body (PE) then 3069 3070 -- Load the body. Note that we are a little careful here to use 3071 -- Spec to get the unit number, rather than PE or Decl, since 3072 -- in the case where the package is itself a library level 3073 -- instantiation, Spec will properly reference the generic 3074 -- template, which is what we really want. 3075 3076 return 3077 Load_Package_Body 3078 (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec)))); 3079 3080 -- But if the package is a library unit that does NOT require 3081 -- a body, then no body is permitted, so we are sure that there 3082 -- is no body for the original generic package. 3083 3084 else 3085 return Empty; 3086 end if; 3087 3088 -- Otherwise look and see if we are embedded in a further package 3089 3090 elsif Is_Package_Or_Generic_Package (Scop) then 3091 3092 -- If so, get the body of the enclosing package, and look in 3093 -- its package body for the package body we are looking for. 3094 3095 PBody := Locate_Corresponding_Body (Scop); 3096 3097 if No (PBody) then 3098 return Empty; 3099 else 3100 return Find_Body_In (PE, First (Declarations (PBody))); 3101 end if; 3102 3103 -- If we are not embedded in a further package, then the body 3104 -- must be in the same declarative part as we are. 3105 3106 else 3107 return Find_Body_In (PE, Next (Decl)); 3108 end if; 3109 end Locate_Corresponding_Body; 3110 3111 -- Start of processing for Has_Generic_Body 3112 3113 begin 3114 if Present (Corresponding_Body (Decl)) then 3115 return True; 3116 3117 elsif Unit_Requires_Body (Ent) then 3118 return True; 3119 3120 -- Compilation units cannot have optional bodies 3121 3122 elsif Is_Compilation_Unit (Ent) then 3123 return False; 3124 3125 -- Otherwise look at what scope we are in 3126 3127 else 3128 Scop := Scope (Ent); 3129 3130 -- Case of entity is in other than a package spec, in this case 3131 -- the body, if present, must be in the same declarative part. 3132 3133 if not Is_Package_Or_Generic_Package (Scop) then 3134 declare 3135 P : Node_Id; 3136 3137 begin 3138 -- Declaration node may get us a spec, so if so, go to 3139 -- the parent declaration. 3140 3141 P := Declaration_Node (Ent); 3142 while not Is_List_Member (P) loop 3143 P := Parent (P); 3144 end loop; 3145 3146 return Present (Find_Body_In (Ent, Next (P))); 3147 end; 3148 3149 -- If the entity is in a package spec, then we have to locate 3150 -- the corresponding package body, and look there. 3151 3152 else 3153 declare 3154 PBody : constant Node_Id := Locate_Corresponding_Body (Scop); 3155 3156 begin 3157 if No (PBody) then 3158 return False; 3159 else 3160 return 3161 Present 3162 (Find_Body_In (Ent, (First (Declarations (PBody))))); 3163 end if; 3164 end; 3165 end if; 3166 end if; 3167 end Has_Generic_Body; 3168 3169 ----------------------- 3170 -- Insert_Elab_Check -- 3171 ----------------------- 3172 3173 procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty) is 3174 Nod : Node_Id; 3175 Loc : constant Source_Ptr := Sloc (N); 3176 3177 Chk : Node_Id; 3178 -- The check (N_Raise_Program_Error) node to be inserted 3179 3180 begin 3181 -- If expansion is disabled, do not generate any checks. Also 3182 -- skip checks if any subunits are missing because in either 3183 -- case we lack the full information that we need, and no object 3184 -- file will be created in any case. 3185 3186 if not Expander_Active or else Subunits_Missing then 3187 return; 3188 end if; 3189 3190 -- If we have a generic instantiation, where Instance_Spec is set, 3191 -- then this field points to a generic instance spec that has 3192 -- been inserted before the instantiation node itself, so that 3193 -- is where we want to insert a check. 3194 3195 if Nkind (N) in N_Generic_Instantiation 3196 and then Present (Instance_Spec (N)) 3197 then 3198 Nod := Instance_Spec (N); 3199 else 3200 Nod := N; 3201 end if; 3202 3203 -- Build check node, possibly with condition 3204 3205 Chk := 3206 Make_Raise_Program_Error (Loc, Reason => PE_Access_Before_Elaboration); 3207 3208 if Present (C) then 3209 Set_Condition (Chk, Make_Op_Not (Loc, Right_Opnd => C)); 3210 end if; 3211 3212 -- If we are inserting at the top level, insert in Aux_Decls 3213 3214 if Nkind (Parent (Nod)) = N_Compilation_Unit then 3215 declare 3216 ADN : constant Node_Id := Aux_Decls_Node (Parent (Nod)); 3217 3218 begin 3219 if No (Declarations (ADN)) then 3220 Set_Declarations (ADN, New_List (Chk)); 3221 else 3222 Append_To (Declarations (ADN), Chk); 3223 end if; 3224 3225 Analyze (Chk); 3226 end; 3227 3228 -- Otherwise just insert as an action on the node in question 3229 3230 else 3231 Insert_Action (Nod, Chk); 3232 end if; 3233 end Insert_Elab_Check; 3234 3235 ------------------------------- 3236 -- Is_Finalization_Procedure -- 3237 ------------------------------- 3238 3239 function Is_Finalization_Procedure (Id : Entity_Id) return Boolean is 3240 begin 3241 -- Check whether Id is a procedure with at least one parameter 3242 3243 if Ekind (Id) = E_Procedure and then Present (First_Formal (Id)) then 3244 declare 3245 Typ : constant Entity_Id := Etype (First_Formal (Id)); 3246 Deep_Fin : Entity_Id := Empty; 3247 Fin : Entity_Id := Empty; 3248 3249 begin 3250 -- If the type of the first formal does not require finalization 3251 -- actions, then this is definitely not [Deep_]Finalize. 3252 3253 if not Needs_Finalization (Typ) then 3254 return False; 3255 end if; 3256 3257 -- At this point we have the following scenario: 3258 3259 -- procedure Name (Param1 : [in] [out] Ctrl[; Param2 : ...]); 3260 3261 -- Recover the two possible versions of [Deep_]Finalize using the 3262 -- type of the first parameter and compare with the input. 3263 3264 Deep_Fin := TSS (Typ, TSS_Deep_Finalize); 3265 3266 if Is_Controlled (Typ) then 3267 Fin := Find_Prim_Op (Typ, Name_Finalize); 3268 end if; 3269 3270 return (Present (Deep_Fin) and then Id = Deep_Fin) 3271 or else (Present (Fin) and then Id = Fin); 3272 end; 3273 end if; 3274 3275 return False; 3276 end Is_Finalization_Procedure; 3277 3278 ------------------ 3279 -- Output_Calls -- 3280 ------------------ 3281 3282 procedure Output_Calls 3283 (N : Node_Id; 3284 Check_Elab_Flag : Boolean) 3285 is 3286 function Emit (Flag : Boolean) return Boolean; 3287 -- Determine whether to emit an error message based on the combination 3288 -- of flags Check_Elab_Flag and Flag. 3289 3290 function Is_Printable_Error_Name (Nm : Name_Id) return Boolean; 3291 -- An internal function, used to determine if a name, Nm, is either 3292 -- a non-internal name, or is an internal name that is printable 3293 -- by the error message circuits (i.e. it has a single upper 3294 -- case letter at the end). 3295 3296 ---------- 3297 -- Emit -- 3298 ---------- 3299 3300 function Emit (Flag : Boolean) return Boolean is 3301 begin 3302 if Check_Elab_Flag then 3303 return Flag; 3304 else 3305 return True; 3306 end if; 3307 end Emit; 3308 3309 ----------------------------- 3310 -- Is_Printable_Error_Name -- 3311 ----------------------------- 3312 3313 function Is_Printable_Error_Name (Nm : Name_Id) return Boolean is 3314 begin 3315 if not Is_Internal_Name (Nm) then 3316 return True; 3317 3318 elsif Name_Len = 1 then 3319 return False; 3320 3321 else 3322 Name_Len := Name_Len - 1; 3323 return not Is_Internal_Name; 3324 end if; 3325 end Is_Printable_Error_Name; 3326 3327 -- Local variables 3328 3329 Ent : Entity_Id; 3330 3331 -- Start of processing for Output_Calls 3332 3333 begin 3334 for J in reverse 1 .. Elab_Call.Last loop 3335 Error_Msg_Sloc := Elab_Call.Table (J).Cloc; 3336 3337 Ent := Elab_Call.Table (J).Ent; 3338 3339 -- Dynamic elaboration model, warnings controlled by -gnatwl 3340 3341 if Dynamic_Elaboration_Checks then 3342 if Emit (Elab_Warnings) then 3343 if Is_Generic_Unit (Ent) then 3344 Error_Msg_NE ("\\?l?& instantiated #", N, Ent); 3345 elsif Is_Init_Proc (Ent) then 3346 Error_Msg_N ("\\?l?initialization procedure called #", N); 3347 elsif Is_Printable_Error_Name (Chars (Ent)) then 3348 Error_Msg_NE ("\\?l?& called #", N, Ent); 3349 else 3350 Error_Msg_N ("\\?l?called #", N); 3351 end if; 3352 end if; 3353 3354 -- Static elaboration model, info messages controlled by -gnatel 3355 3356 else 3357 if Emit (Elab_Info_Messages) then 3358 if Is_Generic_Unit (Ent) then 3359 Error_Msg_NE ("\\?$?& instantiated #", N, Ent); 3360 elsif Is_Init_Proc (Ent) then 3361 Error_Msg_N ("\\?$?initialization procedure called #", N); 3362 elsif Is_Printable_Error_Name (Chars (Ent)) then 3363 Error_Msg_NE ("\\?$?& called #", N, Ent); 3364 else 3365 Error_Msg_N ("\\?$?called #", N); 3366 end if; 3367 end if; 3368 end if; 3369 end loop; 3370 end Output_Calls; 3371 3372 ---------------------------- 3373 -- Same_Elaboration_Scope -- 3374 ---------------------------- 3375 3376 function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is 3377 S1 : Entity_Id; 3378 S2 : Entity_Id; 3379 3380 begin 3381 -- Find elaboration scope for Scop1 3382 -- This is either a subprogram or a compilation unit. 3383 3384 S1 := Scop1; 3385 while S1 /= Standard_Standard 3386 and then not Is_Compilation_Unit (S1) 3387 and then Ekind_In (S1, E_Package, E_Protected_Type, E_Block) 3388 loop 3389 S1 := Scope (S1); 3390 end loop; 3391 3392 -- Find elaboration scope for Scop2 3393 3394 S2 := Scop2; 3395 while S2 /= Standard_Standard 3396 and then not Is_Compilation_Unit (S2) 3397 and then Ekind_In (S2, E_Package, E_Protected_Type, E_Block) 3398 loop 3399 S2 := Scope (S2); 3400 end loop; 3401 3402 return S1 = S2; 3403 end Same_Elaboration_Scope; 3404 3405 ----------------- 3406 -- Set_C_Scope -- 3407 ----------------- 3408 3409 procedure Set_C_Scope is 3410 begin 3411 while not Is_Compilation_Unit (C_Scope) loop 3412 C_Scope := Scope (C_Scope); 3413 end loop; 3414 end Set_C_Scope; 3415 3416 ----------------- 3417 -- Spec_Entity -- 3418 ----------------- 3419 3420 function Spec_Entity (E : Entity_Id) return Entity_Id is 3421 Decl : Node_Id; 3422 3423 begin 3424 -- Check for case of body entity 3425 -- Why is the check for E_Void needed??? 3426 3427 if Ekind_In (E, E_Void, E_Subprogram_Body, E_Package_Body) then 3428 Decl := E; 3429 3430 loop 3431 Decl := Parent (Decl); 3432 exit when Nkind (Decl) in N_Proper_Body; 3433 end loop; 3434 3435 return Corresponding_Spec (Decl); 3436 3437 else 3438 return E; 3439 end if; 3440 end Spec_Entity; 3441 3442 ------------------- 3443 -- Supply_Bodies -- 3444 ------------------- 3445 3446 procedure Supply_Bodies (N : Node_Id) is 3447 begin 3448 if Nkind (N) = N_Subprogram_Declaration then 3449 declare 3450 Ent : constant Entity_Id := Defining_Unit_Name (Specification (N)); 3451 3452 begin 3453 -- Internal subprograms will already have a generated body, so 3454 -- there is no need to provide a stub for them. 3455 3456 if No (Corresponding_Body (N)) then 3457 declare 3458 Loc : constant Source_Ptr := Sloc (N); 3459 B : Node_Id; 3460 Formals : constant List_Id := Copy_Parameter_List (Ent); 3461 Nam : constant Entity_Id := 3462 Make_Defining_Identifier (Loc, Chars (Ent)); 3463 Spec : Node_Id; 3464 Stats : constant List_Id := 3465 New_List 3466 (Make_Raise_Program_Error (Loc, 3467 Reason => PE_Access_Before_Elaboration)); 3468 3469 begin 3470 if Ekind (Ent) = E_Function then 3471 Spec := 3472 Make_Function_Specification (Loc, 3473 Defining_Unit_Name => Nam, 3474 Parameter_Specifications => Formals, 3475 Result_Definition => 3476 New_Copy_Tree 3477 (Result_Definition (Specification (N)))); 3478 3479 -- We cannot reliably make a return statement for this 3480 -- body, but none is needed because the call raises 3481 -- program error. 3482 3483 Set_Return_Present (Ent); 3484 3485 else 3486 Spec := 3487 Make_Procedure_Specification (Loc, 3488 Defining_Unit_Name => Nam, 3489 Parameter_Specifications => Formals); 3490 end if; 3491 3492 B := Make_Subprogram_Body (Loc, 3493 Specification => Spec, 3494 Declarations => New_List, 3495 Handled_Statement_Sequence => 3496 Make_Handled_Sequence_Of_Statements (Loc, Stats)); 3497 Insert_After (N, B); 3498 Analyze (B); 3499 end; 3500 end if; 3501 end; 3502 3503 elsif Nkind (N) = N_Package_Declaration then 3504 declare 3505 Spec : constant Node_Id := Specification (N); 3506 begin 3507 Push_Scope (Defining_Unit_Name (Spec)); 3508 Supply_Bodies (Visible_Declarations (Spec)); 3509 Supply_Bodies (Private_Declarations (Spec)); 3510 Pop_Scope; 3511 end; 3512 end if; 3513 end Supply_Bodies; 3514 3515 procedure Supply_Bodies (L : List_Id) is 3516 Elmt : Node_Id; 3517 begin 3518 if Present (L) then 3519 Elmt := First (L); 3520 while Present (Elmt) loop 3521 Supply_Bodies (Elmt); 3522 Next (Elmt); 3523 end loop; 3524 end if; 3525 end Supply_Bodies; 3526 3527 ------------ 3528 -- Within -- 3529 ------------ 3530 3531 function Within (E1, E2 : Entity_Id) return Boolean is 3532 Scop : Entity_Id; 3533 begin 3534 Scop := E1; 3535 loop 3536 if Scop = E2 then 3537 return True; 3538 elsif Scop = Standard_Standard then 3539 return False; 3540 else 3541 Scop := Scope (Scop); 3542 end if; 3543 end loop; 3544 end Within; 3545 3546 -------------------------- 3547 -- Within_Elaborate_All -- 3548 -------------------------- 3549 3550 function Within_Elaborate_All 3551 (Unit : Unit_Number_Type; 3552 E : Entity_Id) return Boolean 3553 is 3554 type Unit_Number_Set is array (Main_Unit .. Last_Unit) of Boolean; 3555 pragma Pack (Unit_Number_Set); 3556 3557 Seen : Unit_Number_Set := (others => False); 3558 -- Seen (X) is True after we have seen unit X in the walk. This is used 3559 -- to prevent processing the same unit more than once. 3560 3561 Result : Boolean := False; 3562 3563 procedure Helper (Unit : Unit_Number_Type); 3564 -- This helper procedure does all the work for Within_Elaborate_All. It 3565 -- walks the dependency graph, and sets Result to True if it finds an 3566 -- appropriate Elaborate_All. 3567 3568 ------------ 3569 -- Helper -- 3570 ------------ 3571 3572 procedure Helper (Unit : Unit_Number_Type) is 3573 CU : constant Node_Id := Cunit (Unit); 3574 3575 Item : Node_Id; 3576 Item2 : Node_Id; 3577 Elab_Id : Entity_Id; 3578 Par : Node_Id; 3579 3580 begin 3581 if Seen (Unit) then 3582 return; 3583 else 3584 Seen (Unit) := True; 3585 end if; 3586 3587 -- First, check for Elaborate_Alls on this unit 3588 3589 Item := First (Context_Items (CU)); 3590 while Present (Item) loop 3591 if Nkind (Item) = N_Pragma 3592 and then Pragma_Name (Item) = Name_Elaborate_All 3593 then 3594 -- Return if some previous error on the pragma itself. The 3595 -- pragma may be unanalyzed, because of a previous error, or 3596 -- if it is the context of a subunit, inherited by its parent. 3597 3598 if Error_Posted (Item) or else not Analyzed (Item) then 3599 return; 3600 end if; 3601 3602 Elab_Id := 3603 Entity 3604 (Expression (First (Pragma_Argument_Associations (Item)))); 3605 3606 if E = Elab_Id then 3607 Result := True; 3608 return; 3609 end if; 3610 3611 Par := Parent (Unit_Declaration_Node (Elab_Id)); 3612 3613 Item2 := First (Context_Items (Par)); 3614 while Present (Item2) loop 3615 if Nkind (Item2) = N_With_Clause 3616 and then Entity (Name (Item2)) = E 3617 and then not Limited_Present (Item2) 3618 then 3619 Result := True; 3620 return; 3621 end if; 3622 3623 Next (Item2); 3624 end loop; 3625 end if; 3626 3627 Next (Item); 3628 end loop; 3629 3630 -- Second, recurse on with's. We could do this as part of the above 3631 -- loop, but it's probably more efficient to have two loops, because 3632 -- the relevant Elaborate_All is likely to be on the initial unit. In 3633 -- other words, we're walking the with's breadth-first. This part is 3634 -- only necessary in the dynamic elaboration model. 3635 3636 if Dynamic_Elaboration_Checks then 3637 Item := First (Context_Items (CU)); 3638 while Present (Item) loop 3639 if Nkind (Item) = N_With_Clause 3640 and then not Limited_Present (Item) 3641 then 3642 -- Note: the following call to Get_Cunit_Unit_Number does a 3643 -- linear search, which could be slow, but it's OK because 3644 -- we're about to give a warning anyway. Also, there might 3645 -- be hundreds of units, but not millions. If it turns out 3646 -- to be a problem, we could store the Get_Cunit_Unit_Number 3647 -- in each N_Compilation_Unit node, but that would involve 3648 -- rearranging N_Compilation_Unit_Aux to make room. 3649 3650 Helper (Get_Cunit_Unit_Number (Library_Unit (Item))); 3651 3652 if Result then 3653 return; 3654 end if; 3655 end if; 3656 3657 Next (Item); 3658 end loop; 3659 end if; 3660 end Helper; 3661 3662 -- Start of processing for Within_Elaborate_All 3663 3664 begin 3665 Helper (Unit); 3666 return Result; 3667 end Within_Elaborate_All; 3668 3669end Sem_Elab; 3670