1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 7 -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2020, 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 26-- This package contains the routines to process package specifications and 27-- bodies. The most important semantic aspects of package processing are the 28-- handling of private and full declarations, and the construction of dispatch 29-- tables for tagged types. 30 31with Aspects; use Aspects; 32with Atree; use Atree; 33with Contracts; use Contracts; 34with Debug; use Debug; 35with Einfo; use Einfo; 36with Elists; use Elists; 37with Errout; use Errout; 38with Exp_Disp; use Exp_Disp; 39with Exp_Dist; use Exp_Dist; 40with Exp_Dbug; use Exp_Dbug; 41with Freeze; use Freeze; 42with Ghost; use Ghost; 43with GNAT_CUDA; use GNAT_CUDA; 44with Lib; use Lib; 45with Lib.Xref; use Lib.Xref; 46with Namet; use Namet; 47with Nmake; use Nmake; 48with Nlists; use Nlists; 49with Opt; use Opt; 50with Output; use Output; 51with Rtsfind; use Rtsfind; 52with Sem; use Sem; 53with Sem_Aux; use Sem_Aux; 54with Sem_Cat; use Sem_Cat; 55with Sem_Ch3; use Sem_Ch3; 56with Sem_Ch6; use Sem_Ch6; 57with Sem_Ch8; use Sem_Ch8; 58with Sem_Ch10; use Sem_Ch10; 59with Sem_Ch12; use Sem_Ch12; 60with Sem_Ch13; use Sem_Ch13; 61with Sem_Disp; use Sem_Disp; 62with Sem_Eval; use Sem_Eval; 63with Sem_Prag; use Sem_Prag; 64with Sem_Util; use Sem_Util; 65with Sem_Warn; use Sem_Warn; 66with Snames; use Snames; 67with Stand; use Stand; 68with Sinfo; use Sinfo; 69with Sinput; use Sinput; 70with Style; 71with Uintp; use Uintp; 72 73with GNAT.HTable; 74 75package body Sem_Ch7 is 76 77 ----------------------------------- 78 -- Handling private declarations -- 79 ----------------------------------- 80 81 -- The principle that each entity has a single defining occurrence clashes 82 -- with the presence of two separate definitions for private types: the 83 -- first is the private type declaration, and the second is the full type 84 -- declaration. It is important that all references to the type point to 85 -- the same defining occurrence, namely the first one. To enforce the two 86 -- separate views of the entity, the corresponding information is swapped 87 -- between the two declarations. Outside of the package, the defining 88 -- occurrence only contains the private declaration information, while in 89 -- the private part and the body of the package the defining occurrence 90 -- contains the full declaration. To simplify the swap, the defining 91 -- occurrence that currently holds the private declaration points to the 92 -- full declaration. During semantic processing the defining occurrence 93 -- also points to a list of private dependents, that is to say access types 94 -- or composite types whose designated types or component types are 95 -- subtypes or derived types of the private type in question. After the 96 -- full declaration has been seen, the private dependents are updated to 97 -- indicate that they have full definitions. 98 99 ----------------------- 100 -- Local Subprograms -- 101 ----------------------- 102 103 procedure Analyze_Package_Body_Helper (N : Node_Id); 104 -- Does all the real work of Analyze_Package_Body 105 106 procedure Check_Anonymous_Access_Types 107 (Spec_Id : Entity_Id; 108 P_Body : Node_Id); 109 -- If the spec of a package has a limited_with_clause, it may declare 110 -- anonymous access types whose designated type is a limited view, such an 111 -- anonymous access return type for a function. This access type cannot be 112 -- elaborated in the spec itself, but it may need an itype reference if it 113 -- is used within a nested scope. In that case the itype reference is 114 -- created at the beginning of the corresponding package body and inserted 115 -- before other body declarations. 116 117 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id); 118 -- Called upon entering the private part of a public child package and the 119 -- body of a nested package, to potentially declare certain inherited 120 -- subprograms that were inherited by types in the visible part, but whose 121 -- declaration was deferred because the parent operation was private and 122 -- not visible at that point. These subprograms are located by traversing 123 -- the visible part declarations looking for non-private type extensions 124 -- and then examining each of the primitive operations of such types to 125 -- find those that were inherited but declared with a special internal 126 -- name. Each such operation is now declared as an operation with a normal 127 -- name (using the name of the parent operation) and replaces the previous 128 -- implicit operation in the primitive operations list of the type. If the 129 -- inherited private operation has been overridden, then it's replaced by 130 -- the overriding operation. 131 132 procedure Install_Package_Entity (Id : Entity_Id); 133 -- Supporting procedure for Install_{Visible,Private}_Declarations. Places 134 -- one entity on its visibility chain, and recurses on the visible part if 135 -- the entity is an inner package. 136 137 function Is_Private_Base_Type (E : Entity_Id) return Boolean; 138 -- True for a private type that is not a subtype 139 140 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean; 141 -- If the private dependent is a private type whose full view is derived 142 -- from the parent type, its full properties are revealed only if we are in 143 -- the immediate scope of the private dependent. Should this predicate be 144 -- tightened further??? 145 146 function Requires_Completion_In_Body 147 (Id : Entity_Id; 148 Pack_Id : Entity_Id; 149 Do_Abstract_States : Boolean := False) return Boolean; 150 -- Subsidiary to routines Unit_Requires_Body and Unit_Requires_Body_Info. 151 -- Determine whether entity Id declared in package spec Pack_Id requires 152 -- completion in a package body. Flag Do_Abstract_Stats should be set when 153 -- abstract states are to be considered in the completion test. 154 155 procedure Unit_Requires_Body_Info (Pack_Id : Entity_Id); 156 -- Outputs info messages showing why package Pack_Id requires a body. The 157 -- caller has checked that the switch requesting this information is set, 158 -- and that the package does indeed require a body. 159 160 -------------------------- 161 -- Analyze_Package_Body -- 162 -------------------------- 163 164 procedure Analyze_Package_Body (N : Node_Id) is 165 Loc : constant Source_Ptr := Sloc (N); 166 167 begin 168 if Debug_Flag_C then 169 Write_Str ("==> package body "); 170 Write_Name (Chars (Defining_Entity (N))); 171 Write_Str (" from "); 172 Write_Location (Loc); 173 Write_Eol; 174 Indent; 175 end if; 176 177 -- The real work is split out into the helper, so it can do "return;" 178 -- without skipping the debug output. 179 180 Analyze_Package_Body_Helper (N); 181 182 if Debug_Flag_C then 183 Outdent; 184 Write_Str ("<== package body "); 185 Write_Name (Chars (Defining_Entity (N))); 186 Write_Str (" from "); 187 Write_Location (Loc); 188 Write_Eol; 189 end if; 190 end Analyze_Package_Body; 191 192 ------------------------------------------------------ 193 -- Analyze_Package_Body_Helper Data and Subprograms -- 194 ------------------------------------------------------ 195 196 Entity_Table_Size : constant := 4093; 197 -- Number of headers in hash table 198 199 subtype Entity_Header_Num is Integer range 0 .. Entity_Table_Size - 1; 200 -- Range of headers in hash table 201 202 function Node_Hash (Id : Entity_Id) return Entity_Header_Num; 203 -- Simple hash function for Entity_Ids 204 205 package Subprogram_Table is new GNAT.Htable.Simple_HTable 206 (Header_Num => Entity_Header_Num, 207 Element => Boolean, 208 No_Element => False, 209 Key => Entity_Id, 210 Hash => Node_Hash, 211 Equal => "="); 212 -- Hash table to record which subprograms are referenced. It is declared 213 -- at library level to avoid elaborating it for every call to Analyze. 214 215 package Traversed_Table is new GNAT.Htable.Simple_HTable 216 (Header_Num => Entity_Header_Num, 217 Element => Boolean, 218 No_Element => False, 219 Key => Node_Id, 220 Hash => Node_Hash, 221 Equal => "="); 222 -- Hash table to record which nodes we have traversed, so we can avoid 223 -- traversing the same nodes repeatedly. 224 225 ----------------- 226 -- Node_Hash -- 227 ----------------- 228 229 function Node_Hash (Id : Entity_Id) return Entity_Header_Num is 230 begin 231 return Entity_Header_Num (Id mod Entity_Table_Size); 232 end Node_Hash; 233 234 --------------------------------- 235 -- Analyze_Package_Body_Helper -- 236 --------------------------------- 237 238 -- WARNING: This routine manages Ghost regions. Return statements must be 239 -- replaced by gotos which jump to the end of the routine and restore the 240 -- Ghost mode. 241 242 procedure Analyze_Package_Body_Helper (N : Node_Id) is 243 procedure Hide_Public_Entities (Decls : List_Id); 244 -- Attempt to hide all public entities found in declarative list Decls 245 -- by resetting their Is_Public flag to False depending on whether the 246 -- entities are not referenced by inlined or generic bodies. This kind 247 -- of processing is a conservative approximation and will still leave 248 -- entities externally visible if the package is not simple enough. 249 250 procedure Install_Composite_Operations (P : Entity_Id); 251 -- Composite types declared in the current scope may depend on types 252 -- that were private at the point of declaration, and whose full view 253 -- is now in scope. Indicate that the corresponding operations on the 254 -- composite type are available. 255 256 -------------------------- 257 -- Hide_Public_Entities -- 258 -------------------------- 259 260 procedure Hide_Public_Entities (Decls : List_Id) is 261 function Has_Referencer 262 (Decls : List_Id; 263 In_Nested_Instance : Boolean; 264 Has_Outer_Referencer_Of_Non_Subprograms : Boolean) return Boolean; 265 -- A "referencer" is a construct which may reference a previous 266 -- declaration. Examine all declarations in list Decls in reverse 267 -- and determine whether one such referencer exists. All entities 268 -- in the range Last (Decls) .. Referencer are hidden from external 269 -- visibility. 270 271 function Scan_Subprogram_Ref (N : Node_Id) return Traverse_Result; 272 -- Determine whether a node denotes a reference to a subprogram 273 274 procedure Traverse_And_Scan_Subprogram_Refs is 275 new Traverse_Proc (Scan_Subprogram_Ref); 276 -- Subsidiary to routine Has_Referencer. Determine whether a node 277 -- contains references to a subprogram and record them. 278 -- WARNING: this is a very expensive routine as it performs a full 279 -- tree traversal. 280 281 procedure Scan_Subprogram_Refs (Node : Node_Id); 282 -- If we haven't already traversed Node, then mark it and traverse 283 -- it. 284 285 -------------------- 286 -- Has_Referencer -- 287 -------------------- 288 289 function Has_Referencer 290 (Decls : List_Id; 291 In_Nested_Instance : Boolean; 292 Has_Outer_Referencer_Of_Non_Subprograms : Boolean) return Boolean 293 is 294 Decl : Node_Id; 295 Decl_Id : Entity_Id; 296 Spec : Node_Id; 297 298 Has_Referencer_Of_Non_Subprograms : Boolean := 299 Has_Outer_Referencer_Of_Non_Subprograms; 300 -- Set if an inlined subprogram body was detected as a referencer. 301 -- In this case, we do not return True immediately but keep hiding 302 -- subprograms from external visibility. 303 304 begin 305 if No (Decls) then 306 return False; 307 end if; 308 309 -- Examine all declarations in reverse order, hiding all entities 310 -- from external visibility until a referencer has been found. The 311 -- algorithm recurses into nested packages. 312 313 Decl := Last (Decls); 314 while Present (Decl) loop 315 316 -- A stub is always considered a referencer 317 318 if Nkind (Decl) in N_Body_Stub then 319 return True; 320 321 -- Package declaration 322 323 elsif Nkind (Decl) = N_Package_Declaration then 324 Spec := Specification (Decl); 325 Decl_Id := Defining_Entity (Spec); 326 327 -- Inspect the declarations of a non-generic package to try 328 -- and hide more entities from external visibility. 329 330 if not Is_Generic_Unit (Decl_Id) then 331 if Has_Referencer (Private_Declarations (Spec), 332 In_Nested_Instance 333 or else 334 Is_Generic_Instance (Decl_Id), 335 Has_Referencer_Of_Non_Subprograms) 336 or else 337 Has_Referencer (Visible_Declarations (Spec), 338 In_Nested_Instance 339 or else 340 Is_Generic_Instance (Decl_Id), 341 Has_Referencer_Of_Non_Subprograms) 342 then 343 return True; 344 end if; 345 end if; 346 347 -- Package body 348 349 elsif Nkind (Decl) = N_Package_Body 350 and then Present (Corresponding_Spec (Decl)) 351 then 352 Decl_Id := Corresponding_Spec (Decl); 353 354 -- A generic package body is a referencer. It would seem 355 -- that we only have to consider generics that can be 356 -- exported, i.e. where the corresponding spec is the 357 -- spec of the current package, but because of nested 358 -- instantiations, a fully private generic body may export 359 -- other private body entities. Furthermore, regardless of 360 -- whether there was a previous inlined subprogram, (an 361 -- instantiation of) the generic package may reference any 362 -- entity declared before it. 363 364 if Is_Generic_Unit (Decl_Id) then 365 return True; 366 367 -- Inspect the declarations of a non-generic package body to 368 -- try and hide more entities from external visibility. 369 370 elsif Has_Referencer (Declarations (Decl), 371 In_Nested_Instance 372 or else 373 Is_Generic_Instance (Decl_Id), 374 Has_Referencer_Of_Non_Subprograms) 375 then 376 return True; 377 end if; 378 379 -- Subprogram body 380 381 elsif Nkind (Decl) = N_Subprogram_Body then 382 if Present (Corresponding_Spec (Decl)) then 383 Decl_Id := Corresponding_Spec (Decl); 384 385 -- A generic subprogram body acts as a referencer 386 387 if Is_Generic_Unit (Decl_Id) then 388 return True; 389 end if; 390 391 -- An inlined subprogram body acts as a referencer 392 -- unless we generate C code since inlining is then 393 -- handled by the C compiler. 394 395 -- Note that we test Has_Pragma_Inline here in addition 396 -- to Is_Inlined. We are doing this for a client, since 397 -- we are computing which entities should be public, and 398 -- it is the client who will decide if actual inlining 399 -- should occur, so we need to catch all cases where the 400 -- subprogram may be inlined by the client. 401 402 if not Generate_C_Code 403 and then (Is_Inlined (Decl_Id) 404 or else Has_Pragma_Inline (Decl_Id)) 405 then 406 Has_Referencer_Of_Non_Subprograms := True; 407 408 -- Inspect the statements of the subprogram body 409 -- to determine whether the body references other 410 -- subprograms. 411 412 Scan_Subprogram_Refs (Decl); 413 end if; 414 415 -- Otherwise this is a stand alone subprogram body 416 417 else 418 Decl_Id := Defining_Entity (Decl); 419 420 -- An inlined subprogram body acts as a referencer 421 -- unless we generate C code since inlining is then 422 -- handled by the C compiler. 423 424 if not Generate_C_Code 425 and then (Is_Inlined (Decl_Id) 426 or else Has_Pragma_Inline (Decl_Id)) 427 then 428 Has_Referencer_Of_Non_Subprograms := True; 429 430 -- Inspect the statements of the subprogram body 431 -- to determine whether the body references other 432 -- subprograms. 433 434 Scan_Subprogram_Refs (Decl); 435 436 -- Otherwise we can reset Is_Public right away 437 438 elsif not Subprogram_Table.Get (Decl_Id) then 439 Set_Is_Public (Decl_Id, False); 440 end if; 441 end if; 442 443 -- Freeze node 444 445 elsif Nkind (Decl) = N_Freeze_Entity then 446 declare 447 Discard : Boolean; 448 pragma Unreferenced (Discard); 449 begin 450 -- Inspect the actions to find references to subprograms. 451 -- We assume that the actions do not contain other kinds 452 -- of references and, therefore, we do not stop the scan 453 -- or set Has_Referencer_Of_Non_Subprograms here. Doing 454 -- it would pessimize common cases for which the actions 455 -- contain the declaration of an init procedure, since 456 -- such a procedure is automatically marked inline. 457 458 Discard := 459 Has_Referencer (Actions (Decl), 460 In_Nested_Instance, 461 Has_Referencer_Of_Non_Subprograms); 462 end; 463 464 -- Exceptions, objects and renamings do not need to be public 465 -- if they are not followed by a construct which can reference 466 -- and export them. 467 468 elsif Nkind (Decl) in N_Exception_Declaration 469 | N_Object_Declaration 470 | N_Object_Renaming_Declaration 471 then 472 Decl_Id := Defining_Entity (Decl); 473 474 if not In_Nested_Instance 475 and then not Is_Imported (Decl_Id) 476 and then not Is_Exported (Decl_Id) 477 and then No (Interface_Name (Decl_Id)) 478 and then not Has_Referencer_Of_Non_Subprograms 479 then 480 Set_Is_Public (Decl_Id, False); 481 end if; 482 483 -- Likewise for subprograms and renamings, but we work harder 484 -- for them to see whether they are referenced on an individual 485 -- basis by looking into the table of referenced subprograms. 486 487 elsif Nkind (Decl) in N_Subprogram_Declaration 488 | N_Subprogram_Renaming_Declaration 489 then 490 Decl_Id := Defining_Entity (Decl); 491 492 -- We cannot say anything for subprograms declared in nested 493 -- instances because instantiations are not done yet so the 494 -- bodies are not visible and could contain references to 495 -- them, except if we still have no subprograms at all which 496 -- are referenced by an inlined body. 497 498 if (not In_Nested_Instance 499 or else not Subprogram_Table.Get_First) 500 and then not Is_Imported (Decl_Id) 501 and then not Is_Exported (Decl_Id) 502 and then No (Interface_Name (Decl_Id)) 503 and then not Subprogram_Table.Get (Decl_Id) 504 then 505 Set_Is_Public (Decl_Id, False); 506 end if; 507 508 -- For a subprogram renaming, if the entity is referenced, 509 -- then so is the renamed subprogram. But there is an issue 510 -- with generic bodies because instantiations are not done 511 -- yet and, therefore, cannot be scanned for referencers. 512 -- That's why we use an approximation and test that we have 513 -- at least one subprogram referenced by an inlined body 514 -- instead of precisely the entity of this renaming. 515 516 if Nkind (Decl) = N_Subprogram_Renaming_Declaration 517 and then Subprogram_Table.Get_First 518 and then Is_Entity_Name (Name (Decl)) 519 and then Present (Entity (Name (Decl))) 520 and then Is_Subprogram (Entity (Name (Decl))) 521 then 522 Subprogram_Table.Set (Entity (Name (Decl)), True); 523 end if; 524 end if; 525 526 Prev (Decl); 527 end loop; 528 529 return Has_Referencer_Of_Non_Subprograms; 530 end Has_Referencer; 531 532 ------------------------- 533 -- Scan_Subprogram_Ref -- 534 ------------------------- 535 536 function Scan_Subprogram_Ref (N : Node_Id) return Traverse_Result is 537 begin 538 -- Detect a reference of the form 539 -- Subp_Call 540 541 if Nkind (N) in N_Subprogram_Call 542 and then Is_Entity_Name (Name (N)) 543 and then Present (Entity (Name (N))) 544 and then Is_Subprogram (Entity (Name (N))) 545 then 546 Subprogram_Table.Set (Entity (Name (N)), True); 547 548 -- Detect a reference of the form 549 -- Subp'Some_Attribute 550 551 elsif Nkind (N) = N_Attribute_Reference 552 and then Is_Entity_Name (Prefix (N)) 553 and then Present (Entity (Prefix (N))) 554 and then Is_Subprogram (Entity (Prefix (N))) 555 then 556 Subprogram_Table.Set (Entity (Prefix (N)), True); 557 558 -- Constants can be substituted by their value in gigi, which may 559 -- contain a reference, so scan the value recursively. 560 561 elsif Is_Entity_Name (N) 562 and then Present (Entity (N)) 563 and then Ekind (Entity (N)) = E_Constant 564 then 565 declare 566 Val : constant Node_Id := Constant_Value (Entity (N)); 567 begin 568 if Present (Val) 569 and then not Compile_Time_Known_Value (Val) 570 then 571 Scan_Subprogram_Refs (Val); 572 end if; 573 end; 574 end if; 575 576 return OK; 577 end Scan_Subprogram_Ref; 578 579 -------------------------- 580 -- Scan_Subprogram_Refs -- 581 -------------------------- 582 583 procedure Scan_Subprogram_Refs (Node : Node_Id) is 584 begin 585 if not Traversed_Table.Get (Node) then 586 Traversed_Table.Set (Node, True); 587 Traverse_And_Scan_Subprogram_Refs (Node); 588 end if; 589 end Scan_Subprogram_Refs; 590 591 -- Local variables 592 593 Discard : Boolean; 594 pragma Unreferenced (Discard); 595 596 -- Start of processing for Hide_Public_Entities 597 598 begin 599 -- The algorithm examines the top level declarations of a package 600 -- body in reverse looking for a construct that may export entities 601 -- declared prior to it. If such a scenario is encountered, then all 602 -- entities in the range Last (Decls) .. construct are hidden from 603 -- external visibility. Consider: 604 605 -- package Pack is 606 -- generic 607 -- package Gen is 608 -- end Gen; 609 -- end Pack; 610 611 -- package body Pack is 612 -- External_Obj : ...; -- (1) 613 614 -- package body Gen is -- (2) 615 -- ... External_Obj ... -- (3) 616 -- end Gen; 617 618 -- Local_Obj : ...; -- (4) 619 -- end Pack; 620 621 -- In this example Local_Obj (4) must not be externally visible as 622 -- it cannot be exported by anything in Pack. The body of generic 623 -- package Gen (2) on the other hand acts as a "referencer" and may 624 -- export anything declared before it. Since the compiler does not 625 -- perform flow analysis, it is not possible to determine precisely 626 -- which entities will be exported when Gen is instantiated. In the 627 -- example above External_Obj (1) is exported at (3), but this may 628 -- not always be the case. The algorithm takes a conservative stance 629 -- and leaves entity External_Obj public. 630 631 -- This very conservative algorithm is supplemented by a more precise 632 -- processing for inlined bodies. For them, we traverse the syntactic 633 -- tree and record which subprograms are actually referenced from it. 634 -- This makes it possible to compute a much smaller set of externally 635 -- visible subprograms in the absence of generic bodies, which can 636 -- have a significant impact on the inlining decisions made in the 637 -- back end and the removal of out-of-line bodies from the object 638 -- code. We do it only for inlined bodies because they are supposed 639 -- to be reasonably small and tree traversal is very expensive. 640 641 -- Note that even this special processing is not optimal for inlined 642 -- bodies, because we treat all inlined subprograms alike. An optimal 643 -- algorithm would require computing the transitive closure of the 644 -- inlined subprograms that can really be referenced from other units 645 -- in the source code. 646 647 -- We could extend this processing for inlined bodies and record all 648 -- entities, not just subprograms, referenced from them, which would 649 -- make it possible to compute a much smaller set of all externally 650 -- visible entities in the absence of generic bodies. But this would 651 -- mean implementing a more thorough tree traversal of the bodies, 652 -- i.e. not just syntactic, and the gain would very likely be worth 653 -- neither the hassle nor the slowdown of the compiler. 654 655 -- Finally, an important thing to be aware of is that, at this point, 656 -- instantiations are not done yet so we cannot directly see inlined 657 -- bodies coming from them. That's not catastrophic because only the 658 -- actual parameters of the instantiations matter here, and they are 659 -- present in the declarations list of the instantiated packages. 660 661 Traversed_Table.Reset; 662 Subprogram_Table.Reset; 663 Discard := Has_Referencer (Decls, False, False); 664 end Hide_Public_Entities; 665 666 ---------------------------------- 667 -- Install_Composite_Operations -- 668 ---------------------------------- 669 670 procedure Install_Composite_Operations (P : Entity_Id) is 671 Id : Entity_Id; 672 673 begin 674 Id := First_Entity (P); 675 while Present (Id) loop 676 if Is_Type (Id) 677 and then (Is_Limited_Composite (Id) 678 or else Is_Private_Composite (Id)) 679 and then No (Private_Component (Id)) 680 then 681 Set_Is_Limited_Composite (Id, False); 682 Set_Is_Private_Composite (Id, False); 683 end if; 684 685 Next_Entity (Id); 686 end loop; 687 end Install_Composite_Operations; 688 689 -- Local variables 690 691 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 692 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 693 Saved_EA : constant Boolean := Expander_Active; 694 Saved_ISMP : constant Boolean := 695 Ignore_SPARK_Mode_Pragmas_In_Instance; 696 -- Save the Ghost and SPARK mode-related data to restore on exit 697 698 Body_Id : Entity_Id; 699 HSS : Node_Id; 700 Last_Spec_Entity : Entity_Id; 701 New_N : Node_Id; 702 Pack_Decl : Node_Id; 703 Spec_Id : Entity_Id; 704 705 -- Start of processing for Analyze_Package_Body_Helper 706 707 begin 708 -- Find corresponding package specification, and establish the current 709 -- scope. The visible defining entity for the package is the defining 710 -- occurrence in the spec. On exit from the package body, all body 711 -- declarations are attached to the defining entity for the body, but 712 -- the later is never used for name resolution. In this fashion there 713 -- is only one visible entity that denotes the package. 714 715 -- Set Body_Id. Note that this will be reset to point to the generic 716 -- copy later on in the generic case. 717 718 Body_Id := Defining_Entity (N); 719 720 -- Body is body of package instantiation. Corresponding spec has already 721 -- been set. 722 723 if Present (Corresponding_Spec (N)) then 724 Spec_Id := Corresponding_Spec (N); 725 Pack_Decl := Unit_Declaration_Node (Spec_Id); 726 727 else 728 Spec_Id := Current_Entity_In_Scope (Defining_Entity (N)); 729 730 if Present (Spec_Id) 731 and then Is_Package_Or_Generic_Package (Spec_Id) 732 then 733 Pack_Decl := Unit_Declaration_Node (Spec_Id); 734 735 if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then 736 Error_Msg_N ("cannot supply body for package renaming", N); 737 return; 738 739 elsif Present (Corresponding_Body (Pack_Decl)) then 740 Error_Msg_N ("redefinition of package body", N); 741 return; 742 end if; 743 744 else 745 Error_Msg_N ("missing specification for package body", N); 746 return; 747 end if; 748 749 if Is_Package_Or_Generic_Package (Spec_Id) 750 and then (Scope (Spec_Id) = Standard_Standard 751 or else Is_Child_Unit (Spec_Id)) 752 and then not Unit_Requires_Body (Spec_Id) 753 then 754 if Ada_Version = Ada_83 then 755 Error_Msg_N 756 ("optional package body (not allowed in Ada 95)??", N); 757 else 758 Error_Msg_N ("spec of this package does not allow a body", N); 759 end if; 760 end if; 761 end if; 762 763 -- A [generic] package body freezes the contract of the nearest 764 -- enclosing package body and all other contracts encountered in 765 -- the same declarative part up to and excluding the package body: 766 767 -- package body Nearest_Enclosing_Package 768 -- with Refined_State => (State => Constit) 769 -- is 770 -- Constit : ...; 771 772 -- package body Freezes_Enclosing_Package_Body 773 -- with Refined_State => (State_2 => Constit_2) 774 -- is 775 -- Constit_2 : ...; 776 777 -- procedure Proc 778 -- with Refined_Depends => (Input => (Constit, Constit_2)) ... 779 780 -- This ensures that any annotations referenced by the contract of a 781 -- [generic] subprogram body declared within the current package body 782 -- are available. This form of freezing is decoupled from the usual 783 -- Freeze_xxx mechanism because it must also work in the context of 784 -- generics where normal freezing is disabled. 785 786 -- Only bodies coming from source should cause this type of freezing. 787 -- Instantiated generic bodies are excluded because their processing is 788 -- performed in a separate compilation pass which lacks enough semantic 789 -- information with respect to contract analysis. It is safe to suppress 790 -- the freezing of contracts in this case because this action already 791 -- took place at the end of the enclosing declarative part. 792 793 if Comes_From_Source (N) 794 and then not Is_Generic_Instance (Spec_Id) 795 then 796 Freeze_Previous_Contracts (N); 797 end if; 798 799 -- A package body is Ghost when the corresponding spec is Ghost. Set 800 -- the mode now to ensure that any nodes generated during analysis and 801 -- expansion are properly flagged as ignored Ghost. 802 803 Mark_And_Set_Ghost_Body (N, Spec_Id); 804 805 -- Deactivate expansion inside the body of ignored Ghost entities, 806 -- as this code will ultimately be ignored. This avoids requiring the 807 -- presence of run-time units which are not needed. Only do this for 808 -- user entities, as internally generated entities might still need 809 -- to be expanded (e.g. those generated for types). 810 811 if Present (Ignored_Ghost_Region) 812 and then Comes_From_Source (Body_Id) 813 then 814 Expander_Active := False; 815 end if; 816 817 -- If the body completes the initial declaration of a compilation unit 818 -- which is subject to pragma Elaboration_Checks, set the model of the 819 -- pragma because it applies to all parts of the unit. 820 821 Install_Elaboration_Model (Spec_Id); 822 823 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 824 Style.Check_Identifier (Body_Id, Spec_Id); 825 826 if Is_Child_Unit (Spec_Id) then 827 if Nkind (Parent (N)) /= N_Compilation_Unit then 828 Error_Msg_NE 829 ("body of child unit& cannot be an inner package", N, Spec_Id); 830 end if; 831 832 Set_Is_Child_Unit (Body_Id); 833 end if; 834 835 -- Generic package case 836 837 if Ekind (Spec_Id) = E_Generic_Package then 838 839 -- Disable expansion and perform semantic analysis on copy. The 840 -- unannotated body will be used in all instantiations. 841 842 Body_Id := Defining_Entity (N); 843 Set_Ekind (Body_Id, E_Package_Body); 844 Set_Scope (Body_Id, Scope (Spec_Id)); 845 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id)); 846 Set_Body_Entity (Spec_Id, Body_Id); 847 Set_Spec_Entity (Body_Id, Spec_Id); 848 849 New_N := Copy_Generic_Node (N, Empty, Instantiating => False); 850 Rewrite (N, New_N); 851 852 -- Once the contents of the generic copy and the template are 853 -- swapped, do the same for their respective aspect specifications. 854 855 Exchange_Aspects (N, New_N); 856 857 -- Collect all contract-related source pragmas found within the 858 -- template and attach them to the contract of the package body. 859 -- This contract is used in the capture of global references within 860 -- annotations. 861 862 Create_Generic_Contract (N); 863 864 -- Update Body_Id to point to the copied node for the remainder of 865 -- the processing. 866 867 Body_Id := Defining_Entity (N); 868 Start_Generic; 869 end if; 870 871 -- The Body_Id is that of the copied node in the generic case, the 872 -- current node otherwise. Note that N was rewritten above, so we must 873 -- be sure to get the latest Body_Id value. 874 875 Set_Ekind (Body_Id, E_Package_Body); 876 Set_Body_Entity (Spec_Id, Body_Id); 877 Set_Spec_Entity (Body_Id, Spec_Id); 878 879 -- Defining name for the package body is not a visible entity: Only the 880 -- defining name for the declaration is visible. 881 882 Set_Etype (Body_Id, Standard_Void_Type); 883 Set_Scope (Body_Id, Scope (Spec_Id)); 884 Set_Corresponding_Spec (N, Spec_Id); 885 Set_Corresponding_Body (Pack_Decl, Body_Id); 886 887 -- The body entity is not used for semantics or code generation, but 888 -- it is attached to the entity list of the enclosing scope to simplify 889 -- the listing of back-annotations for the types it main contain. 890 891 if Scope (Spec_Id) /= Standard_Standard then 892 Append_Entity (Body_Id, Scope (Spec_Id)); 893 end if; 894 895 -- Indicate that we are currently compiling the body of the package 896 897 Set_In_Package_Body (Spec_Id); 898 Set_Has_Completion (Spec_Id); 899 Last_Spec_Entity := Last_Entity (Spec_Id); 900 901 if Has_Aspects (N) then 902 Analyze_Aspect_Specifications (N, Body_Id); 903 end if; 904 905 Push_Scope (Spec_Id); 906 907 -- Set SPARK_Mode only for non-generic package 908 909 if Ekind (Spec_Id) = E_Package then 910 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 911 Set_SPARK_Aux_Pragma (Body_Id, SPARK_Mode_Pragma); 912 Set_SPARK_Pragma_Inherited (Body_Id); 913 Set_SPARK_Aux_Pragma_Inherited (Body_Id); 914 915 -- A package body may be instantiated or inlined at a later pass. 916 -- Restore the state of Ignore_SPARK_Mode_Pragmas_In_Instance when 917 -- it applied to the package spec. 918 919 if Ignore_SPARK_Mode_Pragmas (Spec_Id) then 920 Ignore_SPARK_Mode_Pragmas_In_Instance := True; 921 end if; 922 end if; 923 924 Set_Categorization_From_Pragmas (N); 925 926 Install_Visible_Declarations (Spec_Id); 927 Install_Private_Declarations (Spec_Id); 928 Install_Private_With_Clauses (Spec_Id); 929 Install_Composite_Operations (Spec_Id); 930 931 Check_Anonymous_Access_Types (Spec_Id, N); 932 933 if Ekind (Spec_Id) = E_Generic_Package then 934 Set_Use (Generic_Formal_Declarations (Pack_Decl)); 935 end if; 936 937 Set_Use (Visible_Declarations (Specification (Pack_Decl))); 938 Set_Use (Private_Declarations (Specification (Pack_Decl))); 939 940 -- This is a nested package, so it may be necessary to declare certain 941 -- inherited subprograms that are not yet visible because the parent 942 -- type's subprograms are now visible. 943 -- Note that for child units these operations were generated when 944 -- analyzing the package specification. 945 946 if Ekind (Scope (Spec_Id)) = E_Package 947 and then Scope (Spec_Id) /= Standard_Standard 948 and then not Is_Child_Unit (Spec_Id) 949 then 950 Declare_Inherited_Private_Subprograms (Spec_Id); 951 end if; 952 953 if Present (Declarations (N)) then 954 Analyze_Declarations (Declarations (N)); 955 Inspect_Deferred_Constant_Completion (Declarations (N)); 956 end if; 957 958 -- Verify that the SPARK_Mode of the body agrees with that of its spec 959 960 if Present (SPARK_Pragma (Body_Id)) then 961 if Present (SPARK_Aux_Pragma (Spec_Id)) then 962 if Get_SPARK_Mode_From_Annotation (SPARK_Aux_Pragma (Spec_Id)) = 963 Off 964 and then 965 Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = On 966 then 967 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 968 Error_Msg_N ("incorrect application of SPARK_Mode#", N); 969 Error_Msg_Sloc := Sloc (SPARK_Aux_Pragma (Spec_Id)); 970 Error_Msg_NE 971 ("\value Off was set for SPARK_Mode on & #", N, Spec_Id); 972 end if; 973 974 -- SPARK_Mode Off could complete no SPARK_Mode in a generic, either 975 -- as specified in source code, or because SPARK_Mode On is ignored 976 -- in an instance where the context is SPARK_Mode Off/Auto. 977 978 elsif Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = Off 979 and then (Is_Generic_Unit (Spec_Id) or else In_Instance) 980 then 981 null; 982 983 else 984 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 985 Error_Msg_N ("incorrect application of SPARK_Mode#", N); 986 Error_Msg_Sloc := Sloc (Spec_Id); 987 Error_Msg_NE 988 ("\no value was set for SPARK_Mode on & #", N, Spec_Id); 989 end if; 990 end if; 991 992 -- Analyze_Declarations has caused freezing of all types. Now generate 993 -- bodies for RACW primitives and stream attributes, if any. 994 995 if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then 996 997 -- Attach subprogram bodies to support RACWs declared in spec 998 999 Append_RACW_Bodies (Declarations (N), Spec_Id); 1000 Analyze_List (Declarations (N)); 1001 end if; 1002 1003 -- If procedures marked with CUDA_Global have been defined within N, we 1004 -- need to register them with the CUDA runtime at program startup. This 1005 -- requires multiple declarations and function calls which need to be 1006 -- appended to N's declarations. 1007 1008 Build_And_Insert_CUDA_Initialization (N); 1009 1010 HSS := Handled_Statement_Sequence (N); 1011 1012 if Present (HSS) then 1013 Process_End_Label (HSS, 't', Spec_Id); 1014 Analyze (HSS); 1015 1016 -- Check that elaboration code in a preelaborable package body is 1017 -- empty other than null statements and labels (RM 10.2.1(6)). 1018 1019 Validate_Null_Statement_Sequence (N); 1020 end if; 1021 1022 Validate_Categorization_Dependency (N, Spec_Id); 1023 Check_Completion (Body_Id); 1024 1025 -- Generate start of body reference. Note that we do this fairly late, 1026 -- because the call will use In_Extended_Main_Source_Unit as a check, 1027 -- and we want to make sure that Corresponding_Stub links are set 1028 1029 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False); 1030 1031 -- For a generic package, collect global references and mark them on 1032 -- the original body so that they are not resolved again at the point 1033 -- of instantiation. 1034 1035 if Ekind (Spec_Id) /= E_Package then 1036 Save_Global_References (Original_Node (N)); 1037 End_Generic; 1038 end if; 1039 1040 -- The entities of the package body have so far been chained onto the 1041 -- declaration chain for the spec. That's been fine while we were in the 1042 -- body, since we wanted them to be visible, but now that we are leaving 1043 -- the package body, they are no longer visible, so we remove them from 1044 -- the entity chain of the package spec entity, and copy them to the 1045 -- entity chain of the package body entity, where they will never again 1046 -- be visible. 1047 1048 if Present (Last_Spec_Entity) then 1049 Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity)); 1050 Set_Next_Entity (Last_Spec_Entity, Empty); 1051 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 1052 Set_Last_Entity (Spec_Id, Last_Spec_Entity); 1053 1054 else 1055 Set_First_Entity (Body_Id, First_Entity (Spec_Id)); 1056 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 1057 Set_First_Entity (Spec_Id, Empty); 1058 Set_Last_Entity (Spec_Id, Empty); 1059 end if; 1060 1061 Update_Use_Clause_Chain; 1062 End_Package_Scope (Spec_Id); 1063 1064 -- All entities declared in body are not visible 1065 1066 declare 1067 E : Entity_Id; 1068 1069 begin 1070 E := First_Entity (Body_Id); 1071 while Present (E) loop 1072 Set_Is_Immediately_Visible (E, False); 1073 Set_Is_Potentially_Use_Visible (E, False); 1074 Set_Is_Hidden (E); 1075 1076 -- Child units may appear on the entity list (e.g. if they appear 1077 -- in the context of a subunit) but they are not body entities. 1078 1079 if not Is_Child_Unit (E) then 1080 Set_Is_Package_Body_Entity (E); 1081 end if; 1082 1083 Next_Entity (E); 1084 end loop; 1085 end; 1086 1087 Check_References (Body_Id); 1088 1089 -- For a generic unit, check that the formal parameters are referenced, 1090 -- and that local variables are used, as for regular packages. 1091 1092 if Ekind (Spec_Id) = E_Generic_Package then 1093 Check_References (Spec_Id); 1094 end if; 1095 1096 -- At this point all entities of the package body are externally visible 1097 -- to the linker as their Is_Public flag is set to True. This proactive 1098 -- approach is necessary because an inlined or a generic body for which 1099 -- code is generated in other units may need to see these entities. Cut 1100 -- down the number of global symbols that do not need public visibility 1101 -- as this has two beneficial effects: 1102 -- (1) It makes the compilation process more efficient. 1103 -- (2) It gives the code generator more leeway to optimize within each 1104 -- unit, especially subprograms. 1105 1106 -- This is done only for top-level library packages or child units as 1107 -- the algorithm does a top-down traversal of the package body. This is 1108 -- also done for instances because instantiations are still pending by 1109 -- the time the enclosing package body is analyzed. 1110 1111 if (Scope (Spec_Id) = Standard_Standard 1112 or else Is_Child_Unit (Spec_Id) 1113 or else Is_Generic_Instance (Spec_Id)) 1114 and then not Is_Generic_Unit (Spec_Id) 1115 then 1116 Hide_Public_Entities (Declarations (N)); 1117 end if; 1118 1119 -- If expander is not active, then here is where we turn off the 1120 -- In_Package_Body flag, otherwise it is turned off at the end of the 1121 -- corresponding expansion routine. If this is an instance body, we need 1122 -- to qualify names of local entities, because the body may have been 1123 -- compiled as a preliminary to another instantiation. 1124 1125 if not Expander_Active then 1126 Set_In_Package_Body (Spec_Id, False); 1127 1128 if Is_Generic_Instance (Spec_Id) 1129 and then Operating_Mode = Generate_Code 1130 then 1131 Qualify_Entity_Names (N); 1132 end if; 1133 end if; 1134 1135 if Present (Ignored_Ghost_Region) then 1136 Expander_Active := Saved_EA; 1137 end if; 1138 1139 Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP; 1140 Restore_Ghost_Region (Saved_GM, Saved_IGR); 1141 end Analyze_Package_Body_Helper; 1142 1143 --------------------------------- 1144 -- Analyze_Package_Declaration -- 1145 --------------------------------- 1146 1147 procedure Analyze_Package_Declaration (N : Node_Id) is 1148 Id : constant Node_Id := Defining_Entity (N); 1149 1150 Is_Comp_Unit : constant Boolean := 1151 Nkind (Parent (N)) = N_Compilation_Unit; 1152 1153 Body_Required : Boolean; 1154 -- True when this package declaration requires a corresponding body 1155 1156 begin 1157 if Debug_Flag_C then 1158 Write_Str ("==> package spec "); 1159 Write_Name (Chars (Id)); 1160 Write_Str (" from "); 1161 Write_Location (Sloc (N)); 1162 Write_Eol; 1163 Indent; 1164 end if; 1165 1166 Generate_Definition (Id); 1167 Enter_Name (Id); 1168 Set_Ekind (Id, E_Package); 1169 Set_Etype (Id, Standard_Void_Type); 1170 1171 -- Set SPARK_Mode from context 1172 1173 Set_SPARK_Pragma (Id, SPARK_Mode_Pragma); 1174 Set_SPARK_Aux_Pragma (Id, SPARK_Mode_Pragma); 1175 Set_SPARK_Pragma_Inherited (Id); 1176 Set_SPARK_Aux_Pragma_Inherited (Id); 1177 1178 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in case 1179 -- the body of this package is instantiated or inlined later and out of 1180 -- context. The body uses this attribute to restore the value of the 1181 -- global flag. 1182 1183 if Ignore_SPARK_Mode_Pragmas_In_Instance then 1184 Set_Ignore_SPARK_Mode_Pragmas (Id); 1185 end if; 1186 1187 -- Analyze aspect specifications immediately, since we need to recognize 1188 -- things like Pure early enough to diagnose violations during analysis. 1189 1190 if Has_Aspects (N) then 1191 Analyze_Aspect_Specifications (N, Id); 1192 end if; 1193 1194 -- Ada 2005 (AI-217): Check if the package has been illegally named in 1195 -- a limited-with clause of its own context. In this case the error has 1196 -- been previously notified by Analyze_Context. 1197 1198 -- limited with Pkg; -- ERROR 1199 -- package Pkg is ... 1200 1201 if From_Limited_With (Id) then 1202 return; 1203 end if; 1204 1205 Push_Scope (Id); 1206 1207 Set_Is_Pure (Id, Is_Pure (Enclosing_Lib_Unit_Entity)); 1208 Set_Categorization_From_Pragmas (N); 1209 1210 Analyze (Specification (N)); 1211 Validate_Categorization_Dependency (N, Id); 1212 1213 -- Determine whether the package requires a body. Abstract states are 1214 -- intentionally ignored because they do require refinement which can 1215 -- only come in a body, but at the same time they do not force the need 1216 -- for a body on their own (SPARK RM 7.1.4(4) and 7.2.2(3)). 1217 1218 Body_Required := Unit_Requires_Body (Id); 1219 1220 if not Body_Required then 1221 1222 -- If the package spec does not require an explicit body, then there 1223 -- are not entities requiring completion in the language sense. Call 1224 -- Check_Completion now to ensure that nested package declarations 1225 -- that require an implicit body get one. (In the case where a body 1226 -- is required, Check_Completion is called at the end of the body's 1227 -- declarative part.) 1228 1229 Check_Completion; 1230 1231 -- If the package spec does not require an explicit body, then all 1232 -- abstract states declared in nested packages cannot possibly get 1233 -- a proper refinement (SPARK RM 7.2.2(3)). This check is performed 1234 -- only when the compilation unit is the main unit to allow for 1235 -- modular SPARK analysis where packages do not necessarily have 1236 -- bodies. 1237 1238 if Is_Comp_Unit then 1239 Check_State_Refinements 1240 (Context => N, 1241 Is_Main_Unit => Parent (N) = Cunit (Main_Unit)); 1242 end if; 1243 end if; 1244 1245 -- Set Body_Required indication on the compilation unit node 1246 1247 if Is_Comp_Unit then 1248 Set_Body_Required (Parent (N), Body_Required); 1249 1250 if Legacy_Elaboration_Checks and not Body_Required then 1251 Set_Suppress_Elaboration_Warnings (Id); 1252 end if; 1253 end if; 1254 1255 End_Package_Scope (Id); 1256 1257 -- For the declaration of a library unit that is a remote types package, 1258 -- check legality rules regarding availability of stream attributes for 1259 -- types that contain non-remote access values. This subprogram performs 1260 -- visibility tests that rely on the fact that we have exited the scope 1261 -- of Id. 1262 1263 if Is_Comp_Unit then 1264 Validate_RT_RAT_Component (N); 1265 end if; 1266 1267 if Debug_Flag_C then 1268 Outdent; 1269 Write_Str ("<== package spec "); 1270 Write_Name (Chars (Id)); 1271 Write_Str (" from "); 1272 Write_Location (Sloc (N)); 1273 Write_Eol; 1274 end if; 1275 end Analyze_Package_Declaration; 1276 1277 ----------------------------------- 1278 -- Analyze_Package_Specification -- 1279 ----------------------------------- 1280 1281 -- Note that this code is shared for the analysis of generic package specs 1282 -- (see Sem_Ch12.Analyze_Generic_Package_Declaration for details). 1283 1284 procedure Analyze_Package_Specification (N : Node_Id) is 1285 Id : constant Entity_Id := Defining_Entity (N); 1286 Orig_Decl : constant Node_Id := Original_Node (Parent (N)); 1287 Vis_Decls : constant List_Id := Visible_Declarations (N); 1288 Priv_Decls : constant List_Id := Private_Declarations (N); 1289 E : Entity_Id; 1290 L : Entity_Id; 1291 Public_Child : Boolean; 1292 1293 Private_With_Clauses_Installed : Boolean := False; 1294 -- In Ada 2005, private with_clauses are visible in the private part 1295 -- of a nested package, even if it appears in the public part of the 1296 -- enclosing package. This requires a separate step to install these 1297 -- private_with_clauses, and remove them at the end of the nested 1298 -- package. 1299 1300 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id); 1301 -- Clears constant indications (Never_Set_In_Source, Constant_Value, and 1302 -- Is_True_Constant) on all variables that are entities of Id, and on 1303 -- the chain whose first element is FE. A recursive call is made for all 1304 -- packages and generic packages. 1305 1306 procedure Generate_Parent_References; 1307 -- For a child unit, generate references to parent units, for 1308 -- GNAT Studio navigation purposes. 1309 1310 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean; 1311 -- Child and Unit are entities of compilation units. True if Child 1312 -- is a public child of Parent as defined in 10.1.1 1313 1314 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id); 1315 -- Reject completion of an incomplete or private type declarations 1316 -- having a known discriminant part by an unchecked union. 1317 1318 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id); 1319 -- Given the package entity of a generic package instantiation or 1320 -- formal package whose corresponding generic is a child unit, installs 1321 -- the private declarations of each of the child unit's parents. 1322 -- This has to be done at the point of entering the instance package's 1323 -- private part rather than being done in Sem_Ch12.Install_Parent 1324 -- (which is where the parents' visible declarations are installed). 1325 1326 --------------------- 1327 -- Clear_Constants -- 1328 --------------------- 1329 1330 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is 1331 E : Entity_Id; 1332 1333 begin 1334 -- Ignore package renamings, not interesting and they can cause self 1335 -- referential loops in the code below. 1336 1337 if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then 1338 return; 1339 end if; 1340 1341 -- Note: in the loop below, the check for Next_Entity pointing back 1342 -- to the package entity may seem odd, but it is needed, because a 1343 -- package can contain a renaming declaration to itself, and such 1344 -- renamings are generated automatically within package instances. 1345 1346 E := FE; 1347 while Present (E) and then E /= Id loop 1348 if Is_Assignable (E) then 1349 Set_Never_Set_In_Source (E, False); 1350 Set_Is_True_Constant (E, False); 1351 Set_Current_Value (E, Empty); 1352 Set_Is_Known_Null (E, False); 1353 Set_Last_Assignment (E, Empty); 1354 1355 if not Can_Never_Be_Null (E) then 1356 Set_Is_Known_Non_Null (E, False); 1357 end if; 1358 1359 elsif Is_Package_Or_Generic_Package (E) then 1360 Clear_Constants (E, First_Entity (E)); 1361 Clear_Constants (E, First_Private_Entity (E)); 1362 end if; 1363 1364 Next_Entity (E); 1365 end loop; 1366 end Clear_Constants; 1367 1368 -------------------------------- 1369 -- Generate_Parent_References -- 1370 -------------------------------- 1371 1372 procedure Generate_Parent_References is 1373 Decl : constant Node_Id := Parent (N); 1374 1375 begin 1376 if Id = Cunit_Entity (Main_Unit) 1377 or else Parent (Decl) = Library_Unit (Cunit (Main_Unit)) 1378 then 1379 Generate_Reference (Id, Scope (Id), 'k', False); 1380 1381 elsif Nkind (Unit (Cunit (Main_Unit))) not in 1382 N_Subprogram_Body | N_Subunit 1383 then 1384 -- If current unit is an ancestor of main unit, generate a 1385 -- reference to its own parent. 1386 1387 declare 1388 U : Node_Id; 1389 Main_Spec : Node_Id := Unit (Cunit (Main_Unit)); 1390 1391 begin 1392 if Nkind (Main_Spec) = N_Package_Body then 1393 Main_Spec := Unit (Library_Unit (Cunit (Main_Unit))); 1394 end if; 1395 1396 U := Parent_Spec (Main_Spec); 1397 while Present (U) loop 1398 if U = Parent (Decl) then 1399 Generate_Reference (Id, Scope (Id), 'k', False); 1400 exit; 1401 1402 elsif Nkind (Unit (U)) = N_Package_Body then 1403 exit; 1404 1405 else 1406 U := Parent_Spec (Unit (U)); 1407 end if; 1408 end loop; 1409 end; 1410 end if; 1411 end Generate_Parent_References; 1412 1413 --------------------- 1414 -- Is_Public_Child -- 1415 --------------------- 1416 1417 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is 1418 begin 1419 if not Is_Private_Descendant (Child) then 1420 return True; 1421 else 1422 if Child = Unit then 1423 return not Private_Present ( 1424 Parent (Unit_Declaration_Node (Child))); 1425 else 1426 return Is_Public_Child (Scope (Child), Unit); 1427 end if; 1428 end if; 1429 end Is_Public_Child; 1430 1431 ---------------------------------------- 1432 -- Inspect_Unchecked_Union_Completion -- 1433 ---------------------------------------- 1434 1435 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is 1436 Decl : Node_Id; 1437 1438 begin 1439 Decl := First (Decls); 1440 while Present (Decl) loop 1441 1442 -- We are looking at an incomplete or private type declaration 1443 -- with a known_discriminant_part whose full view is an 1444 -- Unchecked_Union. The seemingly useless check with Is_Type 1445 -- prevents cascaded errors when routines defined only for type 1446 -- entities are called with non-type entities. 1447 1448 if Nkind (Decl) in N_Incomplete_Type_Declaration 1449 | N_Private_Type_Declaration 1450 and then Is_Type (Defining_Identifier (Decl)) 1451 and then Has_Discriminants (Defining_Identifier (Decl)) 1452 and then Present (Full_View (Defining_Identifier (Decl))) 1453 and then 1454 Is_Unchecked_Union (Full_View (Defining_Identifier (Decl))) 1455 then 1456 Error_Msg_N 1457 ("completion of discriminated partial view " 1458 & "cannot be an unchecked union", 1459 Full_View (Defining_Identifier (Decl))); 1460 end if; 1461 1462 Next (Decl); 1463 end loop; 1464 end Inspect_Unchecked_Union_Completion; 1465 1466 ----------------------------------------- 1467 -- Install_Parent_Private_Declarations -- 1468 ----------------------------------------- 1469 1470 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is 1471 Inst_Par : Entity_Id; 1472 Gen_Par : Entity_Id; 1473 Inst_Node : Node_Id; 1474 1475 begin 1476 Inst_Par := Inst_Id; 1477 1478 Gen_Par := 1479 Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par))); 1480 while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop 1481 Inst_Node := Get_Unit_Instantiation_Node (Inst_Par); 1482 1483 if Nkind (Inst_Node) in 1484 N_Package_Instantiation | N_Formal_Package_Declaration 1485 and then Nkind (Name (Inst_Node)) = N_Expanded_Name 1486 then 1487 Inst_Par := Entity (Prefix (Name (Inst_Node))); 1488 1489 if Present (Renamed_Entity (Inst_Par)) then 1490 Inst_Par := Renamed_Entity (Inst_Par); 1491 end if; 1492 1493 -- The instance may appear in a sibling generic unit, in 1494 -- which case the prefix must include the common (generic) 1495 -- ancestor, which is treated as a current instance. 1496 1497 if Inside_A_Generic 1498 and then Ekind (Inst_Par) = E_Generic_Package 1499 then 1500 Gen_Par := Inst_Par; 1501 pragma Assert (In_Open_Scopes (Gen_Par)); 1502 1503 else 1504 Gen_Par := 1505 Generic_Parent 1506 (Specification (Unit_Declaration_Node (Inst_Par))); 1507 end if; 1508 1509 -- Install the private declarations and private use clauses 1510 -- of a parent instance of the child instance, unless the 1511 -- parent instance private declarations have already been 1512 -- installed earlier in Analyze_Package_Specification, which 1513 -- happens when a generic child is instantiated, and the 1514 -- instance is a child of the parent instance. 1515 1516 -- Installing the use clauses of the parent instance twice 1517 -- is both unnecessary and wrong, because it would cause the 1518 -- clauses to be chained to themselves in the use clauses 1519 -- list of the scope stack entry. That in turn would cause 1520 -- an endless loop from End_Use_Clauses upon scope exit. 1521 1522 -- The parent is now fully visible. It may be a hidden open 1523 -- scope if we are currently compiling some child instance 1524 -- declared within it, but while the current instance is being 1525 -- compiled the parent is immediately visible. In particular 1526 -- its entities must remain visible if a stack save/restore 1527 -- takes place through a call to Rtsfind. 1528 1529 if Present (Gen_Par) then 1530 if not In_Private_Part (Inst_Par) then 1531 Install_Private_Declarations (Inst_Par); 1532 Set_Use (Private_Declarations 1533 (Specification 1534 (Unit_Declaration_Node (Inst_Par)))); 1535 Set_Is_Hidden_Open_Scope (Inst_Par, False); 1536 end if; 1537 1538 -- If we've reached the end of the generic instance parents, 1539 -- then finish off by looping through the nongeneric parents 1540 -- and installing their private declarations. 1541 1542 -- If one of the non-generic parents is itself on the scope 1543 -- stack, do not install its private declarations: they are 1544 -- installed in due time when the private part of that parent 1545 -- is analyzed. 1546 1547 else 1548 while Present (Inst_Par) 1549 and then Inst_Par /= Standard_Standard 1550 and then (not In_Open_Scopes (Inst_Par) 1551 or else not In_Private_Part (Inst_Par)) 1552 loop 1553 if Nkind (Inst_Node) = N_Formal_Package_Declaration 1554 or else 1555 not Is_Ancestor_Package 1556 (Inst_Par, Cunit_Entity (Current_Sem_Unit)) 1557 then 1558 Install_Private_Declarations (Inst_Par); 1559 Set_Use 1560 (Private_Declarations 1561 (Specification 1562 (Unit_Declaration_Node (Inst_Par)))); 1563 Inst_Par := Scope (Inst_Par); 1564 else 1565 exit; 1566 end if; 1567 end loop; 1568 1569 exit; 1570 end if; 1571 1572 else 1573 exit; 1574 end if; 1575 end loop; 1576 end Install_Parent_Private_Declarations; 1577 1578 -- Start of processing for Analyze_Package_Specification 1579 1580 begin 1581 if Present (Vis_Decls) then 1582 Analyze_Declarations (Vis_Decls); 1583 end if; 1584 1585 -- Inspect the entities defined in the package and ensure that all 1586 -- incomplete types have received full declarations. Build default 1587 -- initial condition and invariant procedures for all qualifying types. 1588 1589 E := First_Entity (Id); 1590 while Present (E) loop 1591 1592 -- Check on incomplete types 1593 1594 -- AI05-0213: A formal incomplete type has no completion, and neither 1595 -- does the corresponding subtype in an instance. 1596 1597 if Is_Incomplete_Type (E) 1598 and then No (Full_View (E)) 1599 and then not Is_Generic_Type (E) 1600 and then not From_Limited_With (E) 1601 and then not Is_Generic_Actual_Type (E) 1602 then 1603 Error_Msg_N ("no declaration in visible part for incomplete}", E); 1604 end if; 1605 1606 Next_Entity (E); 1607 end loop; 1608 1609 if Is_Remote_Call_Interface (Id) 1610 and then Nkind (Parent (Parent (N))) = N_Compilation_Unit 1611 then 1612 Validate_RCI_Declarations (Id); 1613 end if; 1614 1615 -- Save global references in the visible declarations, before installing 1616 -- private declarations of parent unit if there is one, because the 1617 -- privacy status of types defined in the parent will change. This is 1618 -- only relevant for generic child units, but is done in all cases for 1619 -- uniformity. 1620 1621 if Ekind (Id) = E_Generic_Package 1622 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration 1623 then 1624 declare 1625 Orig_Spec : constant Node_Id := Specification (Orig_Decl); 1626 Save_Priv : constant List_Id := Private_Declarations (Orig_Spec); 1627 1628 begin 1629 -- Insert the freezing nodes after the visible declarations to 1630 -- ensure that we analyze its aspects; needed to ensure that 1631 -- global entities referenced in the aspects are properly handled. 1632 1633 if Ada_Version >= Ada_2012 1634 and then Is_Non_Empty_List (Vis_Decls) 1635 and then Is_Empty_List (Priv_Decls) 1636 then 1637 Insert_List_After_And_Analyze 1638 (Last (Vis_Decls), Freeze_Entity (Id, Last (Vis_Decls))); 1639 end if; 1640 1641 Set_Private_Declarations (Orig_Spec, Empty_List); 1642 Save_Global_References (Orig_Decl); 1643 Set_Private_Declarations (Orig_Spec, Save_Priv); 1644 end; 1645 end if; 1646 1647 -- If package is a public child unit, then make the private declarations 1648 -- of the parent visible. 1649 1650 Public_Child := False; 1651 1652 declare 1653 Par : Entity_Id; 1654 Pack_Decl : Node_Id; 1655 Par_Spec : Node_Id; 1656 1657 begin 1658 Par := Id; 1659 Par_Spec := Parent_Spec (Parent (N)); 1660 1661 -- If the package is formal package of an enclosing generic, it is 1662 -- transformed into a local generic declaration, and compiled to make 1663 -- its spec available. We need to retrieve the original generic to 1664 -- determine whether it is a child unit, and install its parents. 1665 1666 if No (Par_Spec) 1667 and then 1668 Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration 1669 then 1670 Par := Entity (Name (Original_Node (Parent (N)))); 1671 Par_Spec := Parent_Spec (Unit_Declaration_Node (Par)); 1672 end if; 1673 1674 if Present (Par_Spec) then 1675 Generate_Parent_References; 1676 1677 while Scope (Par) /= Standard_Standard 1678 and then Is_Public_Child (Id, Par) 1679 and then In_Open_Scopes (Par) 1680 loop 1681 Public_Child := True; 1682 Par := Scope (Par); 1683 Install_Private_Declarations (Par); 1684 Install_Private_With_Clauses (Par); 1685 Pack_Decl := Unit_Declaration_Node (Par); 1686 Set_Use (Private_Declarations (Specification (Pack_Decl))); 1687 end loop; 1688 end if; 1689 end; 1690 1691 if Is_Compilation_Unit (Id) then 1692 Install_Private_With_Clauses (Id); 1693 else 1694 -- The current compilation unit may include private with_clauses, 1695 -- which are visible in the private part of the current nested 1696 -- package, and have to be installed now. This is not done for 1697 -- nested instantiations, where the private with_clauses of the 1698 -- enclosing unit have no effect once the instantiation info is 1699 -- established and we start analyzing the package declaration. 1700 1701 declare 1702 Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); 1703 begin 1704 if Is_Package_Or_Generic_Package (Comp_Unit) 1705 and then not In_Private_Part (Comp_Unit) 1706 and then not In_Instance 1707 then 1708 Install_Private_With_Clauses (Comp_Unit); 1709 Private_With_Clauses_Installed := True; 1710 end if; 1711 end; 1712 end if; 1713 1714 -- If this is a package associated with a generic instance or formal 1715 -- package, then the private declarations of each of the generic's 1716 -- parents must be installed at this point. 1717 1718 if Is_Generic_Instance (Id) then 1719 Install_Parent_Private_Declarations (Id); 1720 end if; 1721 1722 -- Analyze private part if present. The flag In_Private_Part is reset 1723 -- in End_Package_Scope. 1724 1725 L := Last_Entity (Id); 1726 1727 if Present (Priv_Decls) then 1728 Set_In_Private_Part (Id); 1729 1730 -- Upon entering a public child's private part, it may be necessary 1731 -- to declare subprograms that were derived in the package's visible 1732 -- part but not yet made visible. 1733 1734 if Public_Child then 1735 Declare_Inherited_Private_Subprograms (Id); 1736 end if; 1737 1738 Analyze_Declarations (Priv_Decls); 1739 1740 -- Check the private declarations for incomplete deferred constants 1741 1742 Inspect_Deferred_Constant_Completion (Priv_Decls); 1743 1744 -- The first private entity is the immediate follower of the last 1745 -- visible entity, if there was one. 1746 1747 if Present (L) then 1748 Set_First_Private_Entity (Id, Next_Entity (L)); 1749 else 1750 Set_First_Private_Entity (Id, First_Entity (Id)); 1751 end if; 1752 1753 -- There may be inherited private subprograms that need to be declared, 1754 -- even in the absence of an explicit private part. If there are any 1755 -- public declarations in the package and the package is a public child 1756 -- unit, then an implicit private part is assumed. 1757 1758 elsif Present (L) and then Public_Child then 1759 Set_In_Private_Part (Id); 1760 Declare_Inherited_Private_Subprograms (Id); 1761 Set_First_Private_Entity (Id, Next_Entity (L)); 1762 end if; 1763 1764 E := First_Entity (Id); 1765 while Present (E) loop 1766 1767 -- Check rule of 3.6(11), which in general requires waiting till all 1768 -- full types have been seen. 1769 1770 if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then 1771 Check_Aliased_Component_Types (E); 1772 end if; 1773 1774 -- Check preelaborable initialization for full type completing a 1775 -- private type for which pragma Preelaborable_Initialization given. 1776 1777 if Is_Type (E) 1778 and then Must_Have_Preelab_Init (E) 1779 and then not Has_Preelaborable_Initialization (E) 1780 then 1781 Error_Msg_N 1782 ("full view of & does not have preelaborable initialization", E); 1783 end if; 1784 1785 Next_Entity (E); 1786 end loop; 1787 1788 -- Ada 2005 (AI-216): The completion of an incomplete or private type 1789 -- declaration having a known_discriminant_part shall not be an 1790 -- unchecked union type. 1791 1792 if Present (Vis_Decls) then 1793 Inspect_Unchecked_Union_Completion (Vis_Decls); 1794 end if; 1795 1796 if Present (Priv_Decls) then 1797 Inspect_Unchecked_Union_Completion (Priv_Decls); 1798 end if; 1799 1800 if Ekind (Id) = E_Generic_Package 1801 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration 1802 and then Present (Priv_Decls) 1803 then 1804 -- Save global references in private declarations, ignoring the 1805 -- visible declarations that were processed earlier. 1806 1807 declare 1808 Orig_Spec : constant Node_Id := Specification (Orig_Decl); 1809 Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec); 1810 Save_Form : constant List_Id := 1811 Generic_Formal_Declarations (Orig_Decl); 1812 1813 begin 1814 -- Insert the freezing nodes after the private declarations to 1815 -- ensure that we analyze its aspects; needed to ensure that 1816 -- global entities referenced in the aspects are properly handled. 1817 1818 if Ada_Version >= Ada_2012 1819 and then Is_Non_Empty_List (Priv_Decls) 1820 then 1821 Insert_List_After_And_Analyze 1822 (Last (Priv_Decls), Freeze_Entity (Id, Last (Priv_Decls))); 1823 end if; 1824 1825 Set_Visible_Declarations (Orig_Spec, Empty_List); 1826 Set_Generic_Formal_Declarations (Orig_Decl, Empty_List); 1827 Save_Global_References (Orig_Decl); 1828 Set_Generic_Formal_Declarations (Orig_Decl, Save_Form); 1829 Set_Visible_Declarations (Orig_Spec, Save_Vis); 1830 end; 1831 end if; 1832 1833 Process_End_Label (N, 'e', Id); 1834 1835 -- Remove private_with_clauses of enclosing compilation unit, if they 1836 -- were installed. 1837 1838 if Private_With_Clauses_Installed then 1839 Remove_Private_With_Clauses (Cunit (Current_Sem_Unit)); 1840 end if; 1841 1842 -- For the case of a library level package, we must go through all the 1843 -- entities clearing the indications that the value may be constant and 1844 -- not modified. Why? Because any client of this package may modify 1845 -- these values freely from anywhere. This also applies to any nested 1846 -- packages or generic packages. 1847 1848 -- For now we unconditionally clear constants for packages that are 1849 -- instances of generic packages. The reason is that we do not have the 1850 -- body yet, and we otherwise think things are unreferenced when they 1851 -- are not. This should be fixed sometime (the effect is not terrible, 1852 -- we just lose some warnings, and also some cases of value propagation) 1853 -- ??? 1854 1855 if Is_Library_Level_Entity (Id) 1856 or else Is_Generic_Instance (Id) 1857 then 1858 Clear_Constants (Id, First_Entity (Id)); 1859 Clear_Constants (Id, First_Private_Entity (Id)); 1860 end if; 1861 1862 -- Output relevant information as to why the package requires a body. 1863 -- Do not consider generated packages as this exposes internal symbols 1864 -- and leads to confusing messages. 1865 1866 if List_Body_Required_Info 1867 and then In_Extended_Main_Source_Unit (Id) 1868 and then Unit_Requires_Body (Id) 1869 and then Comes_From_Source (Id) 1870 then 1871 Unit_Requires_Body_Info (Id); 1872 end if; 1873 1874 -- Nested package specs that do not require bodies are not checked for 1875 -- ineffective use clauses due to the possibility of subunits. This is 1876 -- because at this stage it is impossible to tell whether there will be 1877 -- a separate body. 1878 1879 if not Unit_Requires_Body (Id) 1880 and then Is_Compilation_Unit (Id) 1881 and then not Is_Private_Descendant (Id) 1882 then 1883 Update_Use_Clause_Chain; 1884 end if; 1885 end Analyze_Package_Specification; 1886 1887 -------------------------------------- 1888 -- Analyze_Private_Type_Declaration -- 1889 -------------------------------------- 1890 1891 procedure Analyze_Private_Type_Declaration (N : Node_Id) is 1892 Id : constant Entity_Id := Defining_Identifier (N); 1893 PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity); 1894 1895 begin 1896 Generate_Definition (Id); 1897 Set_Is_Pure (Id, PF); 1898 Init_Size_Align (Id); 1899 1900 if not Is_Package_Or_Generic_Package (Current_Scope) 1901 or else In_Private_Part (Current_Scope) 1902 then 1903 Error_Msg_N ("invalid context for private declaration", N); 1904 end if; 1905 1906 New_Private_Type (N, Id, N); 1907 Set_Depends_On_Private (Id); 1908 1909 -- Set the SPARK mode from the current context 1910 1911 Set_SPARK_Pragma (Id, SPARK_Mode_Pragma); 1912 Set_SPARK_Pragma_Inherited (Id); 1913 1914 if Has_Aspects (N) then 1915 Analyze_Aspect_Specifications (N, Id); 1916 end if; 1917 end Analyze_Private_Type_Declaration; 1918 1919 ---------------------------------- 1920 -- Check_Anonymous_Access_Types -- 1921 ---------------------------------- 1922 1923 procedure Check_Anonymous_Access_Types 1924 (Spec_Id : Entity_Id; 1925 P_Body : Node_Id) 1926 is 1927 E : Entity_Id; 1928 IR : Node_Id; 1929 1930 begin 1931 -- Itype references are only needed by gigi, to force elaboration of 1932 -- itypes. In the absence of code generation, they are not needed. 1933 1934 if not Expander_Active then 1935 return; 1936 end if; 1937 1938 E := First_Entity (Spec_Id); 1939 while Present (E) loop 1940 if Ekind (E) = E_Anonymous_Access_Type 1941 and then From_Limited_With (E) 1942 then 1943 IR := Make_Itype_Reference (Sloc (P_Body)); 1944 Set_Itype (IR, E); 1945 1946 if No (Declarations (P_Body)) then 1947 Set_Declarations (P_Body, New_List (IR)); 1948 else 1949 Prepend (IR, Declarations (P_Body)); 1950 end if; 1951 end if; 1952 1953 Next_Entity (E); 1954 end loop; 1955 end Check_Anonymous_Access_Types; 1956 1957 ------------------------------------------- 1958 -- Declare_Inherited_Private_Subprograms -- 1959 ------------------------------------------- 1960 1961 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is 1962 1963 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean; 1964 -- Check whether an inherited subprogram S is an operation of an 1965 -- untagged derived type T. 1966 1967 --------------------- 1968 -- Is_Primitive_Of -- 1969 --------------------- 1970 1971 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is 1972 Formal : Entity_Id; 1973 1974 begin 1975 -- If the full view is a scalar type, the type is the anonymous base 1976 -- type, but the operation mentions the first subtype, so check the 1977 -- signature against the base type. 1978 1979 if Base_Type (Etype (S)) = Base_Type (T) then 1980 return True; 1981 1982 else 1983 Formal := First_Formal (S); 1984 while Present (Formal) loop 1985 if Base_Type (Etype (Formal)) = Base_Type (T) then 1986 return True; 1987 end if; 1988 1989 Next_Formal (Formal); 1990 end loop; 1991 1992 return False; 1993 end if; 1994 end Is_Primitive_Of; 1995 1996 -- Local variables 1997 1998 E : Entity_Id; 1999 Op_List : Elist_Id; 2000 Op_Elmt : Elmt_Id; 2001 Op_Elmt_2 : Elmt_Id; 2002 Prim_Op : Entity_Id; 2003 New_Op : Entity_Id := Empty; 2004 Parent_Subp : Entity_Id; 2005 Tag : Entity_Id; 2006 2007 -- Start of processing for Declare_Inherited_Private_Subprograms 2008 2009 begin 2010 E := First_Entity (Id); 2011 while Present (E) loop 2012 2013 -- If the entity is a nonprivate type extension whose parent type 2014 -- is declared in an open scope, then the type may have inherited 2015 -- operations that now need to be made visible. Ditto if the entity 2016 -- is a formal derived type in a child unit. 2017 2018 if ((Is_Derived_Type (E) and then not Is_Private_Type (E)) 2019 or else 2020 (Nkind (Parent (E)) = N_Private_Extension_Declaration 2021 and then Is_Generic_Type (E))) 2022 and then In_Open_Scopes (Scope (Etype (E))) 2023 and then Is_Base_Type (E) 2024 then 2025 if Is_Tagged_Type (E) then 2026 Op_List := Primitive_Operations (E); 2027 New_Op := Empty; 2028 Tag := First_Tag_Component (E); 2029 2030 Op_Elmt := First_Elmt (Op_List); 2031 while Present (Op_Elmt) loop 2032 Prim_Op := Node (Op_Elmt); 2033 2034 -- Search primitives that are implicit operations with an 2035 -- internal name whose parent operation has a normal name. 2036 2037 if Present (Alias (Prim_Op)) 2038 and then Find_Dispatching_Type (Alias (Prim_Op)) /= E 2039 and then not Comes_From_Source (Prim_Op) 2040 and then Is_Internal_Name (Chars (Prim_Op)) 2041 and then not Is_Internal_Name (Chars (Alias (Prim_Op))) 2042 then 2043 Parent_Subp := Alias (Prim_Op); 2044 2045 -- Case 1: Check if the type has also an explicit 2046 -- overriding for this primitive. 2047 2048 Op_Elmt_2 := Next_Elmt (Op_Elmt); 2049 while Present (Op_Elmt_2) loop 2050 2051 -- Skip entities with attribute Interface_Alias since 2052 -- they are not overriding primitives (these entities 2053 -- link an interface primitive with their covering 2054 -- primitive) 2055 2056 if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp) 2057 and then Type_Conformant (Prim_Op, Node (Op_Elmt_2)) 2058 and then No (Interface_Alias (Node (Op_Elmt_2))) 2059 then 2060 -- The private inherited operation has been 2061 -- overridden by an explicit subprogram: 2062 -- replace the former by the latter. 2063 2064 New_Op := Node (Op_Elmt_2); 2065 Replace_Elmt (Op_Elmt, New_Op); 2066 Remove_Elmt (Op_List, Op_Elmt_2); 2067 Set_Overridden_Operation (New_Op, Parent_Subp); 2068 2069 -- We don't need to inherit its dispatching slot. 2070 -- Set_All_DT_Position has previously ensured that 2071 -- the same slot was assigned to the two primitives 2072 2073 if Present (Tag) 2074 and then Present (DTC_Entity (New_Op)) 2075 and then Present (DTC_Entity (Prim_Op)) 2076 then 2077 pragma Assert 2078 (DT_Position (New_Op) = DT_Position (Prim_Op)); 2079 null; 2080 end if; 2081 2082 goto Next_Primitive; 2083 end if; 2084 2085 Next_Elmt (Op_Elmt_2); 2086 end loop; 2087 2088 -- Case 2: We have not found any explicit overriding and 2089 -- hence we need to declare the operation (i.e., make it 2090 -- visible). 2091 2092 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E)); 2093 2094 -- Inherit the dispatching slot if E is already frozen 2095 2096 if Is_Frozen (E) 2097 and then Present (DTC_Entity (Alias (Prim_Op))) 2098 then 2099 Set_DTC_Entity_Value (E, New_Op); 2100 Set_DT_Position_Value (New_Op, 2101 DT_Position (Alias (Prim_Op))); 2102 end if; 2103 2104 pragma Assert 2105 (Is_Dispatching_Operation (New_Op) 2106 and then Node (Last_Elmt (Op_List)) = New_Op); 2107 2108 -- Substitute the new operation for the old one in the 2109 -- type's primitive operations list. Since the new 2110 -- operation was also just added to the end of list, 2111 -- the last element must be removed. 2112 2113 -- (Question: is there a simpler way of declaring the 2114 -- operation, say by just replacing the name of the 2115 -- earlier operation, reentering it in the in the symbol 2116 -- table (how?), and marking it as private???) 2117 2118 Replace_Elmt (Op_Elmt, New_Op); 2119 Remove_Last_Elmt (Op_List); 2120 end if; 2121 2122 <<Next_Primitive>> 2123 Next_Elmt (Op_Elmt); 2124 end loop; 2125 2126 -- Generate listing showing the contents of the dispatch table 2127 2128 if Debug_Flag_ZZ then 2129 Write_DT (E); 2130 end if; 2131 2132 else 2133 -- For untagged type, scan forward to locate inherited hidden 2134 -- operations. 2135 2136 Prim_Op := Next_Entity (E); 2137 while Present (Prim_Op) loop 2138 if Is_Subprogram (Prim_Op) 2139 and then Present (Alias (Prim_Op)) 2140 and then not Comes_From_Source (Prim_Op) 2141 and then Is_Internal_Name (Chars (Prim_Op)) 2142 and then not Is_Internal_Name (Chars (Alias (Prim_Op))) 2143 and then Is_Primitive_Of (E, Prim_Op) 2144 then 2145 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E)); 2146 end if; 2147 2148 Next_Entity (Prim_Op); 2149 2150 -- Derived operations appear immediately after the type 2151 -- declaration (or the following subtype indication for 2152 -- a derived scalar type). Further declarations cannot 2153 -- include inherited operations of the type. 2154 2155 if Present (Prim_Op) then 2156 exit when Ekind (Prim_Op) not in Overloadable_Kind; 2157 end if; 2158 end loop; 2159 end if; 2160 end if; 2161 2162 Next_Entity (E); 2163 end loop; 2164 end Declare_Inherited_Private_Subprograms; 2165 2166 ----------------------- 2167 -- End_Package_Scope -- 2168 ----------------------- 2169 2170 procedure End_Package_Scope (P : Entity_Id) is 2171 begin 2172 Uninstall_Declarations (P); 2173 Pop_Scope; 2174 end End_Package_Scope; 2175 2176 --------------------------- 2177 -- Exchange_Declarations -- 2178 --------------------------- 2179 2180 procedure Exchange_Declarations (Id : Entity_Id) is 2181 Full_Id : constant Entity_Id := Full_View (Id); 2182 H1 : constant Entity_Id := Homonym (Id); 2183 Next1 : constant Entity_Id := Next_Entity (Id); 2184 H2 : Entity_Id; 2185 Next2 : Entity_Id; 2186 2187 begin 2188 -- If missing full declaration for type, nothing to exchange 2189 2190 if No (Full_Id) then 2191 return; 2192 end if; 2193 2194 -- Otherwise complete the exchange, and preserve semantic links 2195 2196 Next2 := Next_Entity (Full_Id); 2197 H2 := Homonym (Full_Id); 2198 2199 -- Reset full declaration pointer to reflect the switched entities and 2200 -- readjust the next entity chains. 2201 2202 Exchange_Entities (Id, Full_Id); 2203 2204 Link_Entities (Id, Next1); 2205 Set_Homonym (Id, H1); 2206 2207 Set_Full_View (Full_Id, Id); 2208 Link_Entities (Full_Id, Next2); 2209 Set_Homonym (Full_Id, H2); 2210 end Exchange_Declarations; 2211 2212 ---------------------------- 2213 -- Install_Package_Entity -- 2214 ---------------------------- 2215 2216 procedure Install_Package_Entity (Id : Entity_Id) is 2217 begin 2218 if not Is_Internal (Id) then 2219 if Debug_Flag_E then 2220 Write_Str ("Install: "); 2221 Write_Name (Chars (Id)); 2222 Write_Eol; 2223 end if; 2224 2225 if Is_Child_Unit (Id) then 2226 null; 2227 2228 -- Do not enter implicitly inherited non-overridden subprograms of 2229 -- a tagged type back into visibility if they have non-conformant 2230 -- homographs (Ada RM 8.3 12.3/2). 2231 2232 elsif Is_Hidden_Non_Overridden_Subpgm (Id) then 2233 null; 2234 2235 else 2236 Set_Is_Immediately_Visible (Id); 2237 end if; 2238 end if; 2239 end Install_Package_Entity; 2240 2241 ---------------------------------- 2242 -- Install_Private_Declarations -- 2243 ---------------------------------- 2244 2245 procedure Install_Private_Declarations (P : Entity_Id) is 2246 Id : Entity_Id; 2247 Full : Entity_Id; 2248 Priv_Deps : Elist_Id; 2249 2250 procedure Swap_Private_Dependents (Priv_Deps : Elist_Id); 2251 -- When the full view of a private type is made available, we do the 2252 -- same for its private dependents under proper visibility conditions. 2253 -- When compiling a child unit this needs to be done recursively. 2254 2255 ----------------------------- 2256 -- Swap_Private_Dependents -- 2257 ----------------------------- 2258 2259 procedure Swap_Private_Dependents (Priv_Deps : Elist_Id) is 2260 Cunit : Entity_Id; 2261 Deps : Elist_Id; 2262 Priv : Entity_Id; 2263 Priv_Elmt : Elmt_Id; 2264 Is_Priv : Boolean; 2265 2266 begin 2267 Priv_Elmt := First_Elmt (Priv_Deps); 2268 while Present (Priv_Elmt) loop 2269 Priv := Node (Priv_Elmt); 2270 2271 -- Before the exchange, verify that the presence of the Full_View 2272 -- field. This field will be empty if the entity has already been 2273 -- installed due to a previous call. 2274 2275 if Present (Full_View (Priv)) and then Is_Visible_Dependent (Priv) 2276 then 2277 if Is_Private_Type (Priv) then 2278 Cunit := Cunit_Entity (Current_Sem_Unit); 2279 Deps := Private_Dependents (Priv); 2280 Is_Priv := True; 2281 else 2282 Is_Priv := False; 2283 end if; 2284 2285 -- For each subtype that is swapped, we also swap the reference 2286 -- to it in Private_Dependents, to allow access to it when we 2287 -- swap them out in End_Package_Scope. 2288 2289 Replace_Elmt (Priv_Elmt, Full_View (Priv)); 2290 2291 -- Ensure that both views of the dependent private subtype are 2292 -- immediately visible if within some open scope. Check full 2293 -- view before exchanging views. 2294 2295 if In_Open_Scopes (Scope (Full_View (Priv))) then 2296 Set_Is_Immediately_Visible (Priv); 2297 end if; 2298 2299 Exchange_Declarations (Priv); 2300 Set_Is_Immediately_Visible 2301 (Priv, In_Open_Scopes (Scope (Priv))); 2302 2303 Set_Is_Potentially_Use_Visible 2304 (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt))); 2305 2306 -- Recurse for child units, except in generic child units, 2307 -- which unfortunately handle private_dependents separately. 2308 -- Note that the current unit may not have been analyzed, 2309 -- for example a package body, so we cannot rely solely on 2310 -- the Is_Child_Unit flag, but that's only an optimization. 2311 2312 if Is_Priv 2313 and then (No (Etype (Cunit)) or else Is_Child_Unit (Cunit)) 2314 and then not Is_Empty_Elmt_List (Deps) 2315 and then not Inside_A_Generic 2316 then 2317 Swap_Private_Dependents (Deps); 2318 end if; 2319 end if; 2320 2321 Next_Elmt (Priv_Elmt); 2322 end loop; 2323 end Swap_Private_Dependents; 2324 2325 -- Start of processing for Install_Private_Declarations 2326 2327 begin 2328 -- First exchange declarations for private types, so that the full 2329 -- declaration is visible. For each private type, we check its 2330 -- Private_Dependents list and also exchange any subtypes of or derived 2331 -- types from it. Finally, if this is a Taft amendment type, the 2332 -- incomplete declaration is irrelevant, and we want to link the 2333 -- eventual full declaration with the original private one so we 2334 -- also skip the exchange. 2335 2336 Id := First_Entity (P); 2337 while Present (Id) and then Id /= First_Private_Entity (P) loop 2338 if Is_Private_Base_Type (Id) 2339 and then Present (Full_View (Id)) 2340 and then Comes_From_Source (Full_View (Id)) 2341 and then Scope (Full_View (Id)) = Scope (Id) 2342 and then Ekind (Full_View (Id)) /= E_Incomplete_Type 2343 then 2344 -- If there is a use-type clause on the private type, set the full 2345 -- view accordingly. 2346 2347 Set_In_Use (Full_View (Id), In_Use (Id)); 2348 Full := Full_View (Id); 2349 2350 if Is_Private_Base_Type (Full) 2351 and then Has_Private_Declaration (Full) 2352 and then Nkind (Parent (Full)) = N_Full_Type_Declaration 2353 and then In_Open_Scopes (Scope (Etype (Full))) 2354 and then In_Package_Body (Current_Scope) 2355 and then not Is_Private_Type (Etype (Full)) 2356 then 2357 -- This is the completion of a private type by a derivation 2358 -- from another private type which is not private anymore. This 2359 -- can only happen in a package nested within a child package, 2360 -- when the parent type is defined in the parent unit. At this 2361 -- point the current type is not private either, and we have 2362 -- to install the underlying full view, which is now visible. 2363 -- Save the current full view as well, so that all views can be 2364 -- restored on exit. It may seem that after compiling the child 2365 -- body there are not environments to restore, but the back-end 2366 -- expects those links to be valid, and freeze nodes depend on 2367 -- them. 2368 2369 if No (Full_View (Full)) 2370 and then Present (Underlying_Full_View (Full)) 2371 then 2372 Set_Full_View (Id, Underlying_Full_View (Full)); 2373 Set_Underlying_Full_View (Id, Full); 2374 Set_Is_Underlying_Full_View (Full); 2375 2376 Set_Underlying_Full_View (Full, Empty); 2377 Set_Is_Frozen (Full_View (Id)); 2378 end if; 2379 end if; 2380 2381 Priv_Deps := Private_Dependents (Id); 2382 Exchange_Declarations (Id); 2383 Set_Is_Immediately_Visible (Id); 2384 Swap_Private_Dependents (Priv_Deps); 2385 end if; 2386 2387 Next_Entity (Id); 2388 end loop; 2389 2390 -- Next make other declarations in the private part visible as well 2391 2392 Id := First_Private_Entity (P); 2393 while Present (Id) loop 2394 Install_Package_Entity (Id); 2395 Set_Is_Hidden (Id, False); 2396 Next_Entity (Id); 2397 end loop; 2398 2399 -- An abstract state is partially refined when it has at least one 2400 -- Part_Of constituent. Since these constituents are being installed 2401 -- into visibility, update the partial refinement status of any state 2402 -- defined in the associated package, subject to at least one Part_Of 2403 -- constituent. 2404 2405 if Is_Package_Or_Generic_Package (P) then 2406 declare 2407 States : constant Elist_Id := Abstract_States (P); 2408 State_Elmt : Elmt_Id; 2409 State_Id : Entity_Id; 2410 2411 begin 2412 if Present (States) then 2413 State_Elmt := First_Elmt (States); 2414 while Present (State_Elmt) loop 2415 State_Id := Node (State_Elmt); 2416 2417 if Present (Part_Of_Constituents (State_Id)) then 2418 Set_Has_Partial_Visible_Refinement (State_Id); 2419 end if; 2420 2421 Next_Elmt (State_Elmt); 2422 end loop; 2423 end if; 2424 end; 2425 end if; 2426 2427 -- Indicate that the private part is currently visible, so it can be 2428 -- properly reset on exit. 2429 2430 Set_In_Private_Part (P); 2431 end Install_Private_Declarations; 2432 2433 ---------------------------------- 2434 -- Install_Visible_Declarations -- 2435 ---------------------------------- 2436 2437 procedure Install_Visible_Declarations (P : Entity_Id) is 2438 Id : Entity_Id; 2439 Last_Entity : Entity_Id; 2440 2441 begin 2442 pragma Assert 2443 (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P)); 2444 2445 if Is_Package_Or_Generic_Package (P) then 2446 Last_Entity := First_Private_Entity (P); 2447 else 2448 Last_Entity := Empty; 2449 end if; 2450 2451 Id := First_Entity (P); 2452 while Present (Id) and then Id /= Last_Entity loop 2453 Install_Package_Entity (Id); 2454 Next_Entity (Id); 2455 end loop; 2456 end Install_Visible_Declarations; 2457 2458 -------------------------- 2459 -- Is_Private_Base_Type -- 2460 -------------------------- 2461 2462 function Is_Private_Base_Type (E : Entity_Id) return Boolean is 2463 begin 2464 return Ekind (E) = E_Private_Type 2465 or else Ekind (E) = E_Limited_Private_Type 2466 or else Ekind (E) = E_Record_Type_With_Private; 2467 end Is_Private_Base_Type; 2468 2469 -------------------------- 2470 -- Is_Visible_Dependent -- 2471 -------------------------- 2472 2473 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean 2474 is 2475 S : constant Entity_Id := Scope (Dep); 2476 2477 begin 2478 -- Renamings created for actual types have the visibility of the actual 2479 2480 if Ekind (S) = E_Package 2481 and then Is_Generic_Instance (S) 2482 and then (Is_Generic_Actual_Type (Dep) 2483 or else Is_Generic_Actual_Type (Full_View (Dep))) 2484 then 2485 return True; 2486 2487 elsif not (Is_Derived_Type (Dep)) 2488 and then Is_Derived_Type (Full_View (Dep)) 2489 then 2490 -- When instantiating a package body, the scope stack is empty, so 2491 -- check instead whether the dependent type is defined in the same 2492 -- scope as the instance itself. 2493 2494 return In_Open_Scopes (S) 2495 or else (Is_Generic_Instance (Current_Scope) 2496 and then Scope (Dep) = Scope (Current_Scope)); 2497 else 2498 return True; 2499 end if; 2500 end Is_Visible_Dependent; 2501 2502 ---------------------------- 2503 -- May_Need_Implicit_Body -- 2504 ---------------------------- 2505 2506 procedure May_Need_Implicit_Body (E : Entity_Id) is 2507 P : constant Node_Id := Unit_Declaration_Node (E); 2508 S : constant Node_Id := Parent (P); 2509 B : Node_Id; 2510 Decls : List_Id; 2511 2512 begin 2513 if not Has_Completion (E) 2514 and then Nkind (P) = N_Package_Declaration 2515 and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E)) 2516 then 2517 B := 2518 Make_Package_Body (Sloc (E), 2519 Defining_Unit_Name => Make_Defining_Identifier (Sloc (E), 2520 Chars => Chars (E)), 2521 Declarations => New_List); 2522 2523 if Nkind (S) = N_Package_Specification then 2524 if Present (Private_Declarations (S)) then 2525 Decls := Private_Declarations (S); 2526 else 2527 Decls := Visible_Declarations (S); 2528 end if; 2529 else 2530 Decls := Declarations (S); 2531 end if; 2532 2533 Append (B, Decls); 2534 Analyze (B); 2535 end if; 2536 end May_Need_Implicit_Body; 2537 2538 ---------------------- 2539 -- New_Private_Type -- 2540 ---------------------- 2541 2542 procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is 2543 begin 2544 -- For other than Ada 2012, enter the name in the current scope 2545 2546 if Ada_Version < Ada_2012 then 2547 Enter_Name (Id); 2548 2549 -- Ada 2012 (AI05-0162): Enter the name in the current scope. Note that 2550 -- there may be an incomplete previous view. 2551 2552 else 2553 declare 2554 Prev : Entity_Id; 2555 begin 2556 Prev := Find_Type_Name (N); 2557 pragma Assert (Prev = Id 2558 or else (Ekind (Prev) = E_Incomplete_Type 2559 and then Present (Full_View (Prev)) 2560 and then Full_View (Prev) = Id)); 2561 end; 2562 end if; 2563 2564 if Limited_Present (Def) then 2565 Set_Ekind (Id, E_Limited_Private_Type); 2566 else 2567 Set_Ekind (Id, E_Private_Type); 2568 end if; 2569 2570 Set_Etype (Id, Id); 2571 Set_Has_Delayed_Freeze (Id); 2572 Set_Is_First_Subtype (Id); 2573 Init_Size_Align (Id); 2574 2575 Set_Is_Constrained (Id, 2576 No (Discriminant_Specifications (N)) 2577 and then not Unknown_Discriminants_Present (N)); 2578 2579 -- Set tagged flag before processing discriminants, to catch illegal 2580 -- usage. 2581 2582 Set_Is_Tagged_Type (Id, Tagged_Present (Def)); 2583 2584 Set_Discriminant_Constraint (Id, No_Elist); 2585 Set_Stored_Constraint (Id, No_Elist); 2586 2587 if Present (Discriminant_Specifications (N)) then 2588 Push_Scope (Id); 2589 Process_Discriminants (N); 2590 End_Scope; 2591 2592 elsif Unknown_Discriminants_Present (N) then 2593 Set_Has_Unknown_Discriminants (Id); 2594 end if; 2595 2596 Set_Private_Dependents (Id, New_Elmt_List); 2597 2598 if Tagged_Present (Def) then 2599 Set_Ekind (Id, E_Record_Type_With_Private); 2600 Set_Direct_Primitive_Operations (Id, New_Elmt_List); 2601 Set_Is_Abstract_Type (Id, Abstract_Present (Def)); 2602 Set_Is_Limited_Record (Id, Limited_Present (Def)); 2603 Set_Has_Delayed_Freeze (Id, True); 2604 2605 -- Recognize Ada.Real_Time.Timing_Events.Timing_Events here 2606 2607 if Is_RTE (Id, RE_Timing_Event) then 2608 Set_Has_Timing_Event (Id); 2609 end if; 2610 2611 -- Create a class-wide type with the same attributes 2612 2613 Make_Class_Wide_Type (Id); 2614 2615 elsif Abstract_Present (Def) then 2616 Error_Msg_N ("only a tagged type can be abstract", N); 2617 end if; 2618 end New_Private_Type; 2619 2620 --------------------------------- 2621 -- Requires_Completion_In_Body -- 2622 --------------------------------- 2623 2624 function Requires_Completion_In_Body 2625 (Id : Entity_Id; 2626 Pack_Id : Entity_Id; 2627 Do_Abstract_States : Boolean := False) return Boolean 2628 is 2629 begin 2630 -- Always ignore child units. Child units get added to the entity list 2631 -- of a parent unit, but are not original entities of the parent, and 2632 -- so do not affect whether the parent needs a body. 2633 2634 if Is_Child_Unit (Id) then 2635 return False; 2636 2637 -- Ignore formal packages and their renamings 2638 2639 elsif Ekind (Id) = E_Package 2640 and then Nkind (Original_Node (Unit_Declaration_Node (Id))) = 2641 N_Formal_Package_Declaration 2642 then 2643 return False; 2644 2645 -- Otherwise test to see if entity requires a completion. Note that 2646 -- subprogram entities whose declaration does not come from source are 2647 -- ignored here on the basis that we assume the expander will provide an 2648 -- implicit completion at some point. 2649 2650 elsif (Is_Overloadable (Id) 2651 and then Ekind (Id) not in E_Enumeration_Literal | E_Operator 2652 and then not Is_Abstract_Subprogram (Id) 2653 and then not Has_Completion (Id) 2654 and then Comes_From_Source (Parent (Id))) 2655 2656 or else 2657 (Ekind (Id) = E_Package 2658 and then Id /= Pack_Id 2659 and then not Has_Completion (Id) 2660 and then Unit_Requires_Body (Id, Do_Abstract_States)) 2661 2662 or else 2663 (Ekind (Id) = E_Incomplete_Type 2664 and then No (Full_View (Id)) 2665 and then not Is_Generic_Type (Id)) 2666 2667 or else 2668 (Ekind (Id) in E_Task_Type | E_Protected_Type 2669 and then not Has_Completion (Id)) 2670 2671 or else 2672 (Ekind (Id) = E_Generic_Package 2673 and then Id /= Pack_Id 2674 and then not Has_Completion (Id) 2675 and then Unit_Requires_Body (Id, Do_Abstract_States)) 2676 2677 or else 2678 (Is_Generic_Subprogram (Id) 2679 and then not Has_Completion (Id)) 2680 then 2681 return True; 2682 2683 -- Otherwise the entity does not require completion in a package body 2684 2685 else 2686 return False; 2687 end if; 2688 end Requires_Completion_In_Body; 2689 2690 ---------------------------- 2691 -- Uninstall_Declarations -- 2692 ---------------------------- 2693 2694 procedure Uninstall_Declarations (P : Entity_Id) is 2695 Decl : constant Node_Id := Unit_Declaration_Node (P); 2696 Id : Entity_Id; 2697 Full : Entity_Id; 2698 2699 procedure Preserve_Full_Attributes (Priv : Entity_Id; Full : Entity_Id); 2700 -- Copy to the private declaration the attributes of the full view that 2701 -- need to be available for the partial view also. 2702 2703 procedure Swap_Private_Dependents (Priv_Deps : Elist_Id); 2704 -- When the full view of a private type is made unavailable, we do the 2705 -- same for its private dependents under proper visibility conditions. 2706 -- When compiling a child unit this needs to be done recursively. 2707 2708 function Type_In_Use (T : Entity_Id) return Boolean; 2709 -- Check whether type or base type appear in an active use_type clause 2710 2711 ------------------------------ 2712 -- Preserve_Full_Attributes -- 2713 ------------------------------ 2714 2715 procedure Preserve_Full_Attributes 2716 (Priv : Entity_Id; 2717 Full : Entity_Id) 2718 is 2719 Full_Base : constant Entity_Id := Base_Type (Full); 2720 Priv_Is_Base_Type : constant Boolean := Is_Base_Type (Priv); 2721 2722 begin 2723 Set_Size_Info (Priv, Full); 2724 Set_RM_Size (Priv, RM_Size (Full)); 2725 Set_Size_Known_At_Compile_Time 2726 (Priv, Size_Known_At_Compile_Time (Full)); 2727 Set_Is_Volatile (Priv, Is_Volatile (Full)); 2728 Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full)); 2729 Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full)); 2730 Set_Is_Ada_2012_Only (Priv, Is_Ada_2012_Only (Full)); 2731 Set_Has_Pragma_Unmodified (Priv, Has_Pragma_Unmodified (Full)); 2732 Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full)); 2733 Set_Has_Pragma_Unreferenced_Objects 2734 (Priv, Has_Pragma_Unreferenced_Objects 2735 (Full)); 2736 Set_Predicates_Ignored (Priv, Predicates_Ignored (Full)); 2737 if Is_Unchecked_Union (Full) then 2738 Set_Is_Unchecked_Union (Base_Type (Priv)); 2739 end if; 2740 -- Why is atomic not copied here ??? 2741 2742 if Referenced (Full) then 2743 Set_Referenced (Priv); 2744 end if; 2745 2746 if Priv_Is_Base_Type then 2747 Set_Is_Controlled_Active 2748 (Priv, Is_Controlled_Active (Full_Base)); 2749 Set_Finalize_Storage_Only 2750 (Priv, Finalize_Storage_Only (Full_Base)); 2751 Set_Has_Controlled_Component 2752 (Priv, Has_Controlled_Component (Full_Base)); 2753 2754 Propagate_Concurrent_Flags (Priv, Base_Type (Full)); 2755 end if; 2756 2757 -- As explained in Freeze_Entity, private types are required to point 2758 -- to the same freeze node as their corresponding full view, if any. 2759 -- But we ought not to overwrite a node already inserted in the tree. 2760 2761 pragma Assert 2762 (Serious_Errors_Detected /= 0 2763 or else No (Freeze_Node (Priv)) 2764 or else No (Parent (Freeze_Node (Priv))) 2765 or else Freeze_Node (Priv) = Freeze_Node (Full)); 2766 2767 Set_Freeze_Node (Priv, Freeze_Node (Full)); 2768 2769 -- Propagate Default_Initial_Condition-related attributes from the 2770 -- full view to the private view. 2771 2772 Propagate_DIC_Attributes (Priv, From_Typ => Full); 2773 2774 -- Propagate invariant-related attributes from the full view to the 2775 -- private view. 2776 2777 Propagate_Invariant_Attributes (Priv, From_Typ => Full); 2778 2779 -- Propagate predicate-related attributes from the full view to the 2780 -- private view. 2781 2782 Propagate_Predicate_Attributes (Priv, From_Typ => Full); 2783 2784 if Is_Tagged_Type (Priv) 2785 and then Is_Tagged_Type (Full) 2786 and then not Error_Posted (Full) 2787 then 2788 if Is_Tagged_Type (Priv) then 2789 2790 -- If the type is tagged, the tag itself must be available on 2791 -- the partial view, for expansion purposes. 2792 2793 Set_First_Entity (Priv, First_Entity (Full)); 2794 2795 -- If there are discriminants in the partial view, these remain 2796 -- visible. Otherwise only the tag itself is visible, and there 2797 -- are no nameable components in the partial view. 2798 2799 if No (Last_Entity (Priv)) then 2800 Set_Last_Entity (Priv, First_Entity (Priv)); 2801 end if; 2802 end if; 2803 2804 Set_Has_Discriminants (Priv, Has_Discriminants (Full)); 2805 2806 if Has_Discriminants (Full) then 2807 Set_Discriminant_Constraint (Priv, 2808 Discriminant_Constraint (Full)); 2809 end if; 2810 end if; 2811 end Preserve_Full_Attributes; 2812 2813 ----------------------------- 2814 -- Swap_Private_Dependents -- 2815 ----------------------------- 2816 2817 procedure Swap_Private_Dependents (Priv_Deps : Elist_Id) is 2818 Cunit : Entity_Id; 2819 Deps : Elist_Id; 2820 Priv : Entity_Id; 2821 Priv_Elmt : Elmt_Id; 2822 Is_Priv : Boolean; 2823 2824 begin 2825 Priv_Elmt := First_Elmt (Priv_Deps); 2826 while Present (Priv_Elmt) loop 2827 Priv := Node (Priv_Elmt); 2828 2829 -- Before we do the swap, we verify the presence of the Full_View 2830 -- field, which may be empty due to a swap by a previous call to 2831 -- End_Package_Scope (e.g. from the freezing mechanism). 2832 2833 if Present (Full_View (Priv)) then 2834 if Is_Private_Type (Priv) then 2835 Cunit := Cunit_Entity (Current_Sem_Unit); 2836 Deps := Private_Dependents (Priv); 2837 Is_Priv := True; 2838 else 2839 Is_Priv := False; 2840 end if; 2841 2842 if Scope (Priv) = P 2843 or else not In_Open_Scopes (Scope (Priv)) 2844 then 2845 Set_Is_Immediately_Visible (Priv, False); 2846 end if; 2847 2848 if Is_Visible_Dependent (Priv) then 2849 Preserve_Full_Attributes (Priv, Full_View (Priv)); 2850 Replace_Elmt (Priv_Elmt, Full_View (Priv)); 2851 Exchange_Declarations (Priv); 2852 2853 -- Recurse for child units, except in generic child units, 2854 -- which unfortunately handle private_dependents separately. 2855 -- Note that the current unit may not have been analyzed, 2856 -- for example a package body, so we cannot rely solely on 2857 -- the Is_Child_Unit flag, but that's only an optimization. 2858 2859 if Is_Priv 2860 and then (No (Etype (Cunit)) or else Is_Child_Unit (Cunit)) 2861 and then not Is_Empty_Elmt_List (Deps) 2862 and then not Inside_A_Generic 2863 then 2864 Swap_Private_Dependents (Deps); 2865 end if; 2866 end if; 2867 end if; 2868 2869 Next_Elmt (Priv_Elmt); 2870 end loop; 2871 end Swap_Private_Dependents; 2872 2873 ----------------- 2874 -- Type_In_Use -- 2875 ----------------- 2876 2877 function Type_In_Use (T : Entity_Id) return Boolean is 2878 begin 2879 return Scope (Base_Type (T)) = P 2880 and then (In_Use (T) or else In_Use (Base_Type (T))); 2881 end Type_In_Use; 2882 2883 -- Start of processing for Uninstall_Declarations 2884 2885 begin 2886 Id := First_Entity (P); 2887 while Present (Id) and then Id /= First_Private_Entity (P) loop 2888 if Debug_Flag_E then 2889 Write_Str ("unlinking visible entity "); 2890 Write_Int (Int (Id)); 2891 Write_Eol; 2892 end if; 2893 2894 -- On exit from the package scope, we must preserve the visibility 2895 -- established by use clauses in the current scope. Two cases: 2896 2897 -- a) If the entity is an operator, it may be a primitive operator of 2898 -- a type for which there is a visible use-type clause. 2899 2900 -- b) For other entities, their use-visibility is determined by a 2901 -- visible use clause for the package itself or a use-all-type clause 2902 -- applied directly to the entity's type. For a generic instance, 2903 -- the instantiation of the formals appears in the visible part, 2904 -- but the formals are private and remain so. 2905 2906 if Ekind (Id) = E_Function 2907 and then Is_Operator_Symbol_Name (Chars (Id)) 2908 and then not Is_Hidden (Id) 2909 and then not Error_Posted (Id) 2910 then 2911 Set_Is_Potentially_Use_Visible (Id, 2912 In_Use (P) 2913 or else Type_In_Use (Etype (Id)) 2914 or else Type_In_Use (Etype (First_Formal (Id))) 2915 or else (Present (Next_Formal (First_Formal (Id))) 2916 and then 2917 Type_In_Use 2918 (Etype (Next_Formal (First_Formal (Id)))))); 2919 else 2920 if In_Use (P) and then not Is_Hidden (Id) then 2921 2922 -- A child unit of a use-visible package remains use-visible 2923 -- only if it is itself a visible child unit. Otherwise it 2924 -- would remain visible in other contexts where P is use- 2925 -- visible, because once compiled it stays in the entity list 2926 -- of its parent unit. 2927 2928 if Is_Child_Unit (Id) then 2929 Set_Is_Potentially_Use_Visible 2930 (Id, Is_Visible_Lib_Unit (Id)); 2931 else 2932 Set_Is_Potentially_Use_Visible (Id); 2933 end if; 2934 2935 -- We need to avoid incorrectly marking enumeration literals as 2936 -- non-visible when a visible use-all-type clause is in effect. 2937 2938 elsif Type_In_Use (Etype (Id)) 2939 and then Nkind (Current_Use_Clause (Etype (Id))) = 2940 N_Use_Type_Clause 2941 and then All_Present (Current_Use_Clause (Etype (Id))) 2942 then 2943 null; 2944 2945 else 2946 Set_Is_Potentially_Use_Visible (Id, False); 2947 end if; 2948 end if; 2949 2950 -- Local entities are not immediately visible outside of the package 2951 2952 Set_Is_Immediately_Visible (Id, False); 2953 2954 -- If this is a private type with a full view (for example a local 2955 -- subtype of a private type declared elsewhere), ensure that the 2956 -- full view is also removed from visibility: it may be exposed when 2957 -- swapping views in an instantiation. Similarly, ensure that the 2958 -- use-visibility is properly set on both views. 2959 2960 if Is_Type (Id) and then Present (Full_View (Id)) then 2961 Set_Is_Immediately_Visible (Full_View (Id), False); 2962 Set_Is_Potentially_Use_Visible (Full_View (Id), 2963 Is_Potentially_Use_Visible (Id)); 2964 end if; 2965 2966 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then 2967 Check_Abstract_Overriding (Id); 2968 Check_Conventions (Id); 2969 end if; 2970 2971 if Ekind (Id) in E_Private_Type | E_Limited_Private_Type 2972 and then No (Full_View (Id)) 2973 and then not Is_Generic_Type (Id) 2974 and then not Is_Derived_Type (Id) 2975 then 2976 Error_Msg_N ("missing full declaration for private type&", Id); 2977 2978 elsif Ekind (Id) = E_Record_Type_With_Private 2979 and then not Is_Generic_Type (Id) 2980 and then No (Full_View (Id)) 2981 then 2982 if Nkind (Parent (Id)) = N_Private_Type_Declaration then 2983 Error_Msg_N ("missing full declaration for private type&", Id); 2984 else 2985 Error_Msg_N 2986 ("missing full declaration for private extension", Id); 2987 end if; 2988 2989 -- Case of constant, check for deferred constant declaration with 2990 -- no full view. Likely just a matter of a missing expression, or 2991 -- accidental use of the keyword constant. 2992 2993 elsif Ekind (Id) = E_Constant 2994 2995 -- OK if constant value present 2996 2997 and then No (Constant_Value (Id)) 2998 2999 -- OK if full view present 3000 3001 and then No (Full_View (Id)) 3002 3003 -- OK if imported, since that provides the completion 3004 3005 and then not Is_Imported (Id) 3006 3007 -- OK if object declaration replaced by renaming declaration as 3008 -- a result of OK_To_Rename processing (e.g. for concatenation) 3009 3010 and then Nkind (Parent (Id)) /= N_Object_Renaming_Declaration 3011 3012 -- OK if object declaration with the No_Initialization flag set 3013 3014 and then not (Nkind (Parent (Id)) = N_Object_Declaration 3015 and then No_Initialization (Parent (Id))) 3016 then 3017 -- If no private declaration is present, we assume the user did 3018 -- not intend a deferred constant declaration and the problem 3019 -- is simply that the initializing expression is missing. 3020 3021 if not Has_Private_Declaration (Etype (Id)) then 3022 3023 -- We assume that the user did not intend a deferred constant 3024 -- declaration, and the expression is just missing. 3025 3026 Error_Msg_N 3027 ("constant declaration requires initialization expression", 3028 Parent (Id)); 3029 3030 if Is_Limited_Type (Etype (Id)) then 3031 Error_Msg_N 3032 ("\if variable intended, remove CONSTANT from declaration", 3033 Parent (Id)); 3034 end if; 3035 3036 -- Otherwise if a private declaration is present, then we are 3037 -- missing the full declaration for the deferred constant. 3038 3039 else 3040 Error_Msg_N 3041 ("missing full declaration for deferred constant (RM 7.4)", 3042 Id); 3043 3044 if Is_Limited_Type (Etype (Id)) then 3045 Error_Msg_N 3046 ("\if variable intended, remove CONSTANT from declaration", 3047 Parent (Id)); 3048 end if; 3049 end if; 3050 end if; 3051 3052 Next_Entity (Id); 3053 end loop; 3054 3055 -- If the specification was installed as the parent of a public child 3056 -- unit, the private declarations were not installed, and there is 3057 -- nothing to do. 3058 3059 if not In_Private_Part (P) then 3060 return; 3061 else 3062 Set_In_Private_Part (P, False); 3063 end if; 3064 3065 -- Make private entities invisible and exchange full and private 3066 -- declarations for private types. Id is now the first private entity 3067 -- in the package. 3068 3069 while Present (Id) loop 3070 if Debug_Flag_E then 3071 Write_Str ("unlinking private entity "); 3072 Write_Int (Int (Id)); 3073 Write_Eol; 3074 end if; 3075 3076 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then 3077 Check_Abstract_Overriding (Id); 3078 Check_Conventions (Id); 3079 end if; 3080 3081 Set_Is_Immediately_Visible (Id, False); 3082 3083 if Is_Private_Base_Type (Id) and then Present (Full_View (Id)) then 3084 Full := Full_View (Id); 3085 3086 -- If the partial view is not declared in the visible part of the 3087 -- package (as is the case when it is a type derived from some 3088 -- other private type in the private part of the current package), 3089 -- no exchange takes place. 3090 3091 if No (Parent (Id)) 3092 or else List_Containing (Parent (Id)) /= 3093 Visible_Declarations (Specification (Decl)) 3094 then 3095 goto Next_Id; 3096 end if; 3097 3098 -- The entry in the private part points to the full declaration, 3099 -- which is currently visible. Exchange them so only the private 3100 -- type declaration remains accessible, and link private and full 3101 -- declaration in the opposite direction. Before the actual 3102 -- exchange, we copy back attributes of the full view that must 3103 -- be available to the partial view too. 3104 3105 Preserve_Full_Attributes (Id, Full); 3106 3107 Set_Is_Potentially_Use_Visible (Id, In_Use (P)); 3108 3109 -- The following test may be redundant, as this is already 3110 -- diagnosed in sem_ch3. ??? 3111 3112 if not Is_Definite_Subtype (Full) 3113 and then Is_Definite_Subtype (Id) 3114 then 3115 Error_Msg_Sloc := Sloc (Parent (Id)); 3116 Error_Msg_NE 3117 ("full view of& not compatible with declaration#", Full, Id); 3118 end if; 3119 3120 -- Swap out the subtypes and derived types of Id that 3121 -- were compiled in this scope, or installed previously 3122 -- by Install_Private_Declarations. 3123 3124 Swap_Private_Dependents (Private_Dependents (Id)); 3125 3126 -- Now restore the type itself to its private view 3127 3128 Exchange_Declarations (Id); 3129 3130 -- If we have installed an underlying full view for a type derived 3131 -- from a private type in a child unit, restore the proper views 3132 -- of private and full view. See corresponding code in 3133 -- Install_Private_Declarations. 3134 3135 -- After the exchange, Full denotes the private type in the 3136 -- visible part of the package. 3137 3138 if Is_Private_Base_Type (Full) 3139 and then Present (Full_View (Full)) 3140 and then Present (Underlying_Full_View (Full)) 3141 and then In_Package_Body (Current_Scope) 3142 then 3143 Set_Full_View (Full, Underlying_Full_View (Full)); 3144 Set_Underlying_Full_View (Full, Empty); 3145 end if; 3146 3147 elsif Ekind (Id) = E_Incomplete_Type 3148 and then Comes_From_Source (Id) 3149 and then No (Full_View (Id)) 3150 then 3151 -- Mark Taft amendment types. Verify that there are no primitive 3152 -- operations declared for the type (3.10.1(9)). 3153 3154 Set_Has_Completion_In_Body (Id); 3155 3156 declare 3157 Elmt : Elmt_Id; 3158 Subp : Entity_Id; 3159 3160 begin 3161 Elmt := First_Elmt (Private_Dependents (Id)); 3162 while Present (Elmt) loop 3163 Subp := Node (Elmt); 3164 3165 -- Is_Primitive is tested because there can be cases where 3166 -- nonprimitive subprograms (in nested packages) are added 3167 -- to the Private_Dependents list. 3168 3169 if Is_Overloadable (Subp) and then Is_Primitive (Subp) then 3170 Error_Msg_NE 3171 ("type& must be completed in the private part", 3172 Parent (Subp), Id); 3173 3174 -- The result type of an access-to-function type cannot be a 3175 -- Taft-amendment type, unless the version is Ada 2012 or 3176 -- later (see AI05-151). 3177 3178 elsif Ada_Version < Ada_2012 3179 and then Ekind (Subp) = E_Subprogram_Type 3180 then 3181 if Etype (Subp) = Id 3182 or else 3183 (Is_Class_Wide_Type (Etype (Subp)) 3184 and then Etype (Etype (Subp)) = Id) 3185 then 3186 Error_Msg_NE 3187 ("type& must be completed in the private part", 3188 Associated_Node_For_Itype (Subp), Id); 3189 end if; 3190 end if; 3191 3192 Next_Elmt (Elmt); 3193 end loop; 3194 end; 3195 3196 -- For subtypes of private types the frontend generates two entities: 3197 -- one associated with the partial view and the other associated with 3198 -- the full view. When the subtype declaration is public the frontend 3199 -- places the former entity in the list of public entities of the 3200 -- package and the latter entity in the private part of the package. 3201 -- When the subtype declaration is private it generates these two 3202 -- entities but both are placed in the private part of the package 3203 -- (and the full view has the same source location as the partial 3204 -- view and no parent; see Prepare_Private_Subtype_Completion). 3205 3206 elsif Ekind (Id) in E_Private_Subtype 3207 | E_Limited_Private_Subtype 3208 and then Present (Full_View (Id)) 3209 and then Sloc (Id) = Sloc (Full_View (Id)) 3210 and then No (Parent (Full_View (Id))) 3211 then 3212 Set_Is_Hidden (Id); 3213 Set_Is_Potentially_Use_Visible (Id, False); 3214 3215 elsif not Is_Child_Unit (Id) 3216 and then (not Is_Private_Type (Id) or else No (Full_View (Id))) 3217 then 3218 Set_Is_Hidden (Id); 3219 Set_Is_Potentially_Use_Visible (Id, False); 3220 end if; 3221 3222 <<Next_Id>> 3223 Next_Entity (Id); 3224 end loop; 3225 end Uninstall_Declarations; 3226 3227 ------------------------ 3228 -- Unit_Requires_Body -- 3229 ------------------------ 3230 3231 function Unit_Requires_Body 3232 (Pack_Id : Entity_Id; 3233 Do_Abstract_States : Boolean := False) return Boolean 3234 is 3235 E : Entity_Id; 3236 3237 Requires_Body : Boolean := False; 3238 -- Flag set when the unit has at least one construct that requires 3239 -- completion in a body. 3240 3241 begin 3242 -- Imported entity never requires body. Right now, only subprograms can 3243 -- be imported, but perhaps in the future we will allow import of 3244 -- packages. 3245 3246 if Is_Imported (Pack_Id) then 3247 return False; 3248 3249 -- Body required if library package with pragma Elaborate_Body 3250 3251 elsif Has_Pragma_Elaborate_Body (Pack_Id) then 3252 return True; 3253 3254 -- Body required if subprogram 3255 3256 elsif Is_Subprogram_Or_Generic_Subprogram (Pack_Id) then 3257 return True; 3258 3259 -- Treat a block as requiring a body 3260 3261 elsif Ekind (Pack_Id) = E_Block then 3262 return True; 3263 3264 elsif Ekind (Pack_Id) = E_Package 3265 and then Nkind (Parent (Pack_Id)) = N_Package_Specification 3266 and then Present (Generic_Parent (Parent (Pack_Id))) 3267 then 3268 declare 3269 G_P : constant Entity_Id := Generic_Parent (Parent (Pack_Id)); 3270 begin 3271 if Has_Pragma_Elaborate_Body (G_P) then 3272 return True; 3273 end if; 3274 end; 3275 end if; 3276 3277 -- Traverse the entity chain of the package and look for constructs that 3278 -- require a completion in a body. 3279 3280 E := First_Entity (Pack_Id); 3281 while Present (E) loop 3282 3283 -- Skip abstract states because their completion depends on several 3284 -- criteria (see below). 3285 3286 if Ekind (E) = E_Abstract_State then 3287 null; 3288 3289 elsif Requires_Completion_In_Body 3290 (E, Pack_Id, Do_Abstract_States) 3291 then 3292 Requires_Body := True; 3293 exit; 3294 end if; 3295 3296 Next_Entity (E); 3297 end loop; 3298 3299 -- A [generic] package that defines at least one non-null abstract state 3300 -- requires a completion only when at least one other construct requires 3301 -- a completion in a body (SPARK RM 7.1.4(4) and (5)). This check is not 3302 -- performed if the caller requests this behavior. 3303 3304 if Do_Abstract_States 3305 and then Is_Package_Or_Generic_Package (Pack_Id) 3306 and then Has_Non_Null_Abstract_State (Pack_Id) 3307 and then Requires_Body 3308 then 3309 return True; 3310 end if; 3311 3312 return Requires_Body; 3313 end Unit_Requires_Body; 3314 3315 ----------------------------- 3316 -- Unit_Requires_Body_Info -- 3317 ----------------------------- 3318 3319 procedure Unit_Requires_Body_Info (Pack_Id : Entity_Id) is 3320 E : Entity_Id; 3321 3322 begin 3323 -- An imported entity never requires body. Right now, only subprograms 3324 -- can be imported, but perhaps in the future we will allow import of 3325 -- packages. 3326 3327 if Is_Imported (Pack_Id) then 3328 return; 3329 3330 -- Body required if library package with pragma Elaborate_Body 3331 3332 elsif Has_Pragma_Elaborate_Body (Pack_Id) then 3333 Error_Msg_N ("info: & requires body (Elaborate_Body)?Y?", Pack_Id); 3334 3335 -- Body required if subprogram 3336 3337 elsif Is_Subprogram_Or_Generic_Subprogram (Pack_Id) then 3338 Error_Msg_N ("info: & requires body (subprogram case)?Y?", Pack_Id); 3339 3340 -- Body required if generic parent has Elaborate_Body 3341 3342 elsif Ekind (Pack_Id) = E_Package 3343 and then Nkind (Parent (Pack_Id)) = N_Package_Specification 3344 and then Present (Generic_Parent (Parent (Pack_Id))) 3345 then 3346 declare 3347 G_P : constant Entity_Id := Generic_Parent (Parent (Pack_Id)); 3348 begin 3349 if Has_Pragma_Elaborate_Body (G_P) then 3350 Error_Msg_N 3351 ("info: & requires body (generic parent Elaborate_Body)?Y?", 3352 Pack_Id); 3353 end if; 3354 end; 3355 3356 -- A [generic] package that introduces at least one non-null abstract 3357 -- state requires completion. However, there is a separate rule that 3358 -- requires that such a package have a reason other than this for a 3359 -- body being required (if necessary a pragma Elaborate_Body must be 3360 -- provided). If Ignore_Abstract_State is True, we don't do this check 3361 -- (so we can use Unit_Requires_Body to check for some other reason). 3362 3363 elsif Is_Package_Or_Generic_Package (Pack_Id) 3364 and then Present (Abstract_States (Pack_Id)) 3365 and then not Is_Null_State 3366 (Node (First_Elmt (Abstract_States (Pack_Id)))) 3367 then 3368 Error_Msg_N 3369 ("info: & requires body (non-null abstract state aspect)?Y?", 3370 Pack_Id); 3371 end if; 3372 3373 -- Otherwise search entity chain for entity requiring completion 3374 3375 E := First_Entity (Pack_Id); 3376 while Present (E) loop 3377 if Requires_Completion_In_Body (E, Pack_Id) then 3378 Error_Msg_Node_2 := E; 3379 Error_Msg_NE 3380 ("info: & requires body (& requires completion)?Y?", E, Pack_Id); 3381 end if; 3382 3383 Next_Entity (E); 3384 end loop; 3385 end Unit_Requires_Body_Info; 3386 3387end Sem_Ch7; 3388