1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C A T -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2019, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Atree; use Atree; 27with Debug; use Debug; 28with Einfo; use Einfo; 29with Elists; use Elists; 30with Errout; use Errout; 31with Lib; use Lib; 32with Namet; use Namet; 33with Nlists; use Nlists; 34with Opt; use Opt; 35with Sem; use Sem; 36with Sem_Attr; use Sem_Attr; 37with Sem_Aux; use Sem_Aux; 38with Sem_Dist; use Sem_Dist; 39with Sem_Eval; use Sem_Eval; 40with Sem_Util; use Sem_Util; 41with Sinfo; use Sinfo; 42with Snames; use Snames; 43with Stand; use Stand; 44 45package body Sem_Cat is 46 47 ----------------------- 48 -- Local Subprograms -- 49 ----------------------- 50 51 procedure Check_Categorization_Dependencies 52 (Unit_Entity : Entity_Id; 53 Depended_Entity : Entity_Id; 54 Info_Node : Node_Id; 55 Is_Subunit : Boolean); 56 -- This procedure checks that the categorization of a lib unit and that 57 -- of the depended unit satisfy dependency restrictions. 58 -- The depended_entity can be the entity in a with_clause item, in which 59 -- case Info_Node denotes that item. The depended_entity can also be the 60 -- parent unit of a child unit, in which case Info_Node is the declaration 61 -- of the child unit. The error message is posted on Info_Node, and is 62 -- specialized if Is_Subunit is true. 63 64 procedure Check_Non_Static_Default_Expr 65 (Type_Def : Node_Id; 66 Obj_Decl : Node_Id); 67 -- Iterate through the component list of a record definition, check 68 -- that no component is declared with a nonstatic default value. 69 -- If a nonstatic default exists, report an error on Obj_Decl. 70 71 function Has_Read_Write_Attributes (E : Entity_Id) return Boolean; 72 -- Return True if entity has attribute definition clauses for Read and 73 -- Write attributes that are visible at some place. 74 75 function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean; 76 -- Returns true if the entity is a type whose full view is a non-remote 77 -- access type, for the purpose of enforcing E.2.2(8) rules. 78 79 function Has_Non_Remote_Access (Typ : Entity_Id) return Boolean; 80 -- Return true if Typ or the type of any of its subcomponents is a non 81 -- remote access type and doesn't have user-defined stream attributes. 82 83 function No_External_Streaming (E : Entity_Id) return Boolean; 84 -- Return True if the entity or one of its subcomponents does not support 85 -- external streaming. 86 87 function In_RCI_Declaration return Boolean; 88 function In_RT_Declaration return Boolean; 89 -- Determine if current scope is within the declaration of a Remote Call 90 -- Interface or Remote Types unit, for semantic checking purposes. 91 92 function In_Package_Declaration return Boolean; 93 -- Shared supporting routine for In_RCI_Declaration and In_RT_Declaration 94 95 function In_Shared_Passive_Unit return Boolean; 96 -- Determines if current scope is within a Shared Passive compilation unit 97 98 function Static_Discriminant_Expr (L : List_Id) return Boolean; 99 -- Iterate through the list of discriminants to check if any of them 100 -- contains non-static default expression, which is a violation in 101 -- a preelaborated library unit. 102 103 procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id); 104 -- Check validity of declaration if RCI or RT unit. It should not contain 105 -- the declaration of an access-to-object type unless it is a general 106 -- access type that designates a class-wide limited private type. There are 107 -- also constraints about the primitive subprograms of the class-wide type. 108 -- RM E.2 (9, 13, 14) 109 110 procedure Validate_RACW_Primitive 111 (Subp : Entity_Id; 112 RACW : Entity_Id); 113 -- Check legality of the declaration of primitive Subp of the designated 114 -- type of the given RACW type. 115 116 --------------------------------------- 117 -- Check_Categorization_Dependencies -- 118 --------------------------------------- 119 120 procedure Check_Categorization_Dependencies 121 (Unit_Entity : Entity_Id; 122 Depended_Entity : Entity_Id; 123 Info_Node : Node_Id; 124 Is_Subunit : Boolean) 125 is 126 N : constant Node_Id := Info_Node; 127 Err : Boolean; 128 129 -- Here we define an enumeration type to represent categorization types, 130 -- ordered so that a unit with a given categorization can only WITH 131 -- units with lower or equal categorization type. 132 133 type Categorization is 134 (Pure, 135 Shared_Passive, 136 Remote_Types, 137 Remote_Call_Interface, 138 Normal); 139 140 function Get_Categorization (E : Entity_Id) return Categorization; 141 -- Check categorization flags from entity, and return in the form 142 -- of the lowest value of the Categorization type that applies to E. 143 144 ------------------------ 145 -- Get_Categorization -- 146 ------------------------ 147 148 function Get_Categorization (E : Entity_Id) return Categorization is 149 begin 150 -- Get the lowest categorization that corresponds to E. Note that 151 -- nothing prevents several (different) categorization pragmas 152 -- to apply to the same library unit, in which case the unit has 153 -- all associated categories, so we need to be careful here to 154 -- check pragmas in proper Categorization order in order to 155 -- return the lowest applicable value. 156 157 -- Ignore Pure specification if set by pragma Pure_Function 158 159 if Is_Pure (E) 160 and then not 161 (Has_Pragma_Pure_Function (E) and not Has_Pragma_Pure (E)) 162 then 163 return Pure; 164 165 elsif Is_Shared_Passive (E) then 166 return Shared_Passive; 167 168 elsif Is_Remote_Types (E) then 169 return Remote_Types; 170 171 elsif Is_Remote_Call_Interface (E) then 172 return Remote_Call_Interface; 173 174 else 175 return Normal; 176 end if; 177 end Get_Categorization; 178 179 Unit_Category : Categorization; 180 With_Category : Categorization; 181 182 -- Start of processing for Check_Categorization_Dependencies 183 184 begin 185 -- Intrinsic subprograms are preelaborated, so do not impose any 186 -- categorization dependencies. Also, ignore categorization 187 -- dependencies when compilation switch -gnatdu is used. 188 189 if Is_Intrinsic_Subprogram (Depended_Entity) or else Debug_Flag_U then 190 return; 191 end if; 192 193 -- First check 10.2.1 (11/1) rules on preelaborate packages 194 195 if Is_Preelaborated (Unit_Entity) 196 and then not Is_Preelaborated (Depended_Entity) 197 and then not Is_Pure (Depended_Entity) 198 then 199 Err := True; 200 else 201 Err := False; 202 end if; 203 204 -- Check categorization rules of RM E.2(5) 205 206 Unit_Category := Get_Categorization (Unit_Entity); 207 With_Category := Get_Categorization (Depended_Entity); 208 209 if With_Category > Unit_Category then 210 211 -- Special case: Remote_Types and Remote_Call_Interface are allowed 212 -- to WITH anything in the package body, per (RM E.2(5)). 213 214 if (Unit_Category = Remote_Types 215 or else Unit_Category = Remote_Call_Interface) 216 and then In_Package_Body (Unit_Entity) 217 then 218 null; 219 220 -- Special case: Remote_Types and Remote_Call_Interface declarations 221 -- can depend on a preelaborated unit via a private with_clause, per 222 -- AI05-0206. 223 224 elsif (Unit_Category = Remote_Types 225 or else 226 Unit_Category = Remote_Call_Interface) 227 and then Nkind (N) = N_With_Clause 228 and then Private_Present (N) 229 and then Is_Preelaborated (Depended_Entity) 230 then 231 null; 232 233 -- All other cases, we do have an error 234 235 else 236 Err := True; 237 end if; 238 end if; 239 240 -- Here if we have an error 241 242 if Err then 243 244 -- These messages are warnings in GNAT mode or if the -gnateP switch 245 -- was set. Otherwise these are real errors for real illegalities. 246 247 -- The reason we suppress these errors in GNAT mode is that the run- 248 -- time has several instances of violations of the categorization 249 -- errors (e.g. Pure units withing Preelaborate units. All these 250 -- violations are harmless in the cases where we intend them, and 251 -- we suppress the warnings with Warnings (Off). In cases where we 252 -- do not intend the violation, warnings are errors in GNAT mode 253 -- anyway, so we will still get an error. 254 255 Error_Msg_Warn := 256 Treat_Categorization_Errors_As_Warnings or GNAT_Mode; 257 258 -- Don't give error if main unit is not an internal unit, and the 259 -- unit generating the message is an internal unit. This is the 260 -- situation in which such messages would be ignored in any case, 261 -- so it is convenient not to generate them (since it causes 262 -- annoying interference with debugging). 263 264 if Is_Internal_Unit (Current_Sem_Unit) 265 and then not Is_Internal_Unit (Main_Unit) 266 then 267 return; 268 269 -- Dependence of Remote_Types or Remote_Call_Interface declaration 270 -- on a preelaborated unit with a normal with_clause. 271 272 elsif (Unit_Category = Remote_Types 273 or else 274 Unit_Category = Remote_Call_Interface) 275 and then Is_Preelaborated (Depended_Entity) 276 then 277 Error_Msg_NE 278 ("<<must use private with clause for preelaborated unit& ", 279 N, Depended_Entity); 280 281 -- Subunit case 282 283 elsif Is_Subunit then 284 Error_Msg_NE 285 ("<subunit cannot depend on& " & 286 "(parent has wrong categorization)", N, Depended_Entity); 287 288 -- Normal unit, not subunit 289 290 else 291 Error_Msg_NE 292 ("<<cannot depend on& " & 293 "(wrong categorization)", N, Depended_Entity); 294 end if; 295 296 -- Add further explanation for Pure/Preelaborate common cases 297 298 if Unit_Category = Pure then 299 Error_Msg_NE 300 ("\<<pure unit cannot depend on non-pure unit", 301 N, Depended_Entity); 302 303 elsif Is_Preelaborated (Unit_Entity) 304 and then not Is_Preelaborated (Depended_Entity) 305 and then not Is_Pure (Depended_Entity) 306 then 307 Error_Msg_NE 308 ("\<<preelaborated unit cannot depend on " 309 & "non-preelaborated unit", 310 N, Depended_Entity); 311 end if; 312 end if; 313 end Check_Categorization_Dependencies; 314 315 ----------------------------------- 316 -- Check_Non_Static_Default_Expr -- 317 ----------------------------------- 318 319 procedure Check_Non_Static_Default_Expr 320 (Type_Def : Node_Id; 321 Obj_Decl : Node_Id) 322 is 323 Recdef : Node_Id; 324 Component_Decl : Node_Id; 325 326 begin 327 if Nkind (Type_Def) = N_Derived_Type_Definition then 328 Recdef := Record_Extension_Part (Type_Def); 329 330 if No (Recdef) then 331 return; 332 end if; 333 334 else 335 Recdef := Type_Def; 336 end if; 337 338 -- Check that component declarations do not involve: 339 340 -- a. a non-static default expression, where the object is 341 -- declared to be default initialized. 342 343 -- b. a dynamic Itype (discriminants and constraints) 344 345 if Null_Present (Recdef) then 346 return; 347 else 348 Component_Decl := First (Component_Items (Component_List (Recdef))); 349 end if; 350 351 while Present (Component_Decl) 352 and then Nkind (Component_Decl) = N_Component_Declaration 353 loop 354 if Present (Expression (Component_Decl)) 355 and then Nkind (Expression (Component_Decl)) /= N_Null 356 and then not Is_OK_Static_Expression (Expression (Component_Decl)) 357 then 358 Error_Msg_Sloc := Sloc (Component_Decl); 359 Error_Msg_F 360 ("object in preelaborated unit has non-static default#", 361 Obj_Decl); 362 363 -- Fix this later ??? 364 365 -- elsif Has_Dynamic_Itype (Component_Decl) then 366 -- Error_Msg_N 367 -- ("dynamic type discriminant," & 368 -- " constraint in preelaborated unit", 369 -- Component_Decl); 370 end if; 371 372 Next (Component_Decl); 373 end loop; 374 end Check_Non_Static_Default_Expr; 375 376 --------------------------- 377 -- Has_Non_Remote_Access -- 378 --------------------------- 379 380 function Has_Non_Remote_Access (Typ : Entity_Id) return Boolean is 381 Component : Entity_Id; 382 Comp_Type : Entity_Id; 383 U_Typ : constant Entity_Id := Underlying_Type (Typ); 384 385 begin 386 if No (U_Typ) then 387 return False; 388 389 elsif Has_Read_Write_Attributes (Typ) 390 or else Has_Read_Write_Attributes (U_Typ) 391 then 392 return False; 393 394 elsif Is_Non_Remote_Access_Type (U_Typ) then 395 return True; 396 end if; 397 398 if Is_Record_Type (U_Typ) then 399 Component := First_Entity (U_Typ); 400 while Present (Component) loop 401 if not Is_Tag (Component) then 402 Comp_Type := Etype (Component); 403 404 if Has_Non_Remote_Access (Comp_Type) then 405 return True; 406 end if; 407 end if; 408 409 Next_Entity (Component); 410 end loop; 411 412 elsif Is_Array_Type (U_Typ) then 413 return Has_Non_Remote_Access (Component_Type (U_Typ)); 414 415 end if; 416 417 return False; 418 end Has_Non_Remote_Access; 419 420 ------------------------------- 421 -- Has_Read_Write_Attributes -- 422 ------------------------------- 423 424 function Has_Read_Write_Attributes (E : Entity_Id) return Boolean is 425 begin 426 return True 427 and then Has_Stream_Attribute_Definition 428 (E, TSS_Stream_Read, At_Any_Place => True) 429 and then Has_Stream_Attribute_Definition 430 (E, TSS_Stream_Write, At_Any_Place => True); 431 end Has_Read_Write_Attributes; 432 433 ------------------------------------- 434 -- Has_Stream_Attribute_Definition -- 435 ------------------------------------- 436 437 function Has_Stream_Attribute_Definition 438 (Typ : Entity_Id; 439 Nam : TSS_Name_Type; 440 At_Any_Place : Boolean := False) return Boolean 441 is 442 Rep_Item : Node_Id; 443 444 Real_Rep : Node_Id; 445 -- The stream operation may be specified by an attribute definition 446 -- clause in the source, or by an aspect that generates such an 447 -- attribute definition. For an aspect, the generated attribute 448 -- definition may be placed at the freeze point of the full view of 449 -- the type, but the aspect specification makes the operation visible 450 -- to a client wherever the partial view is visible. 451 452 begin 453 -- We start from the declaration node and then loop until the end of 454 -- the list until we find the requested attribute definition clause. 455 -- In Ada 2005 mode, clauses are ignored if they are not currently 456 -- visible (this is tested using the corresponding Entity, which is 457 -- inserted by the expander at the point where the clause occurs), 458 -- unless At_Any_Place is true. 459 460 Rep_Item := First_Rep_Item (Typ); 461 while Present (Rep_Item) loop 462 Real_Rep := Rep_Item; 463 464 -- If the representation item is an aspect specification, retrieve 465 -- the corresponding pragma or attribute definition. 466 467 if Nkind (Rep_Item) = N_Aspect_Specification then 468 Real_Rep := Aspect_Rep_Item (Rep_Item); 469 end if; 470 471 if Nkind (Real_Rep) = N_Attribute_Definition_Clause then 472 case Chars (Real_Rep) is 473 when Name_Read => 474 exit when Nam = TSS_Stream_Read; 475 476 when Name_Write => 477 exit when Nam = TSS_Stream_Write; 478 479 when Name_Input => 480 exit when Nam = TSS_Stream_Input; 481 482 when Name_Output => 483 exit when Nam = TSS_Stream_Output; 484 485 when others => 486 null; 487 end case; 488 end if; 489 490 Next_Rep_Item (Rep_Item); 491 end loop; 492 493 -- If not found, and the type is derived from a private view, check 494 -- for a stream attribute inherited from parent. Any specified stream 495 -- attributes will be attached to the derived type's underlying type 496 -- rather the derived type entity itself (which is itself private). 497 498 if No (Rep_Item) 499 and then Is_Private_Type (Typ) 500 and then Is_Derived_Type (Typ) 501 and then Present (Full_View (Typ)) 502 then 503 return Has_Stream_Attribute_Definition 504 (Underlying_Type (Typ), Nam, At_Any_Place); 505 506 -- Otherwise, if At_Any_Place is true, return True if the attribute is 507 -- available at any place; if it is false, return True only if the 508 -- attribute is currently visible. 509 510 else 511 return Present (Rep_Item) 512 and then (Ada_Version < Ada_2005 513 or else At_Any_Place 514 or else not Is_Hidden (Entity (Rep_Item))); 515 end if; 516 end Has_Stream_Attribute_Definition; 517 518 ---------------------------- 519 -- In_Package_Declaration -- 520 ---------------------------- 521 522 function In_Package_Declaration return Boolean is 523 Unit_Kind : constant Node_Kind := 524 Nkind (Unit (Cunit (Current_Sem_Unit))); 525 526 begin 527 -- There are no restrictions on the body of an RCI or RT unit 528 529 return Is_Package_Or_Generic_Package (Current_Scope) 530 and then Unit_Kind /= N_Package_Body 531 and then not In_Package_Body (Current_Scope) 532 and then not In_Instance; 533 end In_Package_Declaration; 534 535 --------------------------- 536 -- In_Preelaborated_Unit -- 537 --------------------------- 538 539 function In_Preelaborated_Unit return Boolean is 540 Unit_Entity : Entity_Id := Current_Scope; 541 Unit_Kind : constant Node_Kind := 542 Nkind (Unit (Cunit (Current_Sem_Unit))); 543 544 begin 545 -- If evaluating actuals for a child unit instantiation, then ignore 546 -- the preelaboration status of the parent; use the child instead. 547 548 if Is_Compilation_Unit (Unit_Entity) 549 and then Unit_Kind in N_Generic_Instantiation 550 and then not In_Same_Source_Unit (Unit_Entity, 551 Cunit (Current_Sem_Unit)) 552 then 553 Unit_Entity := Cunit_Entity (Current_Sem_Unit); 554 end if; 555 556 -- There are no constraints on the body of Remote_Call_Interface or 557 -- Remote_Types packages. 558 559 return (Unit_Entity /= Standard_Standard) 560 and then (Is_Preelaborated (Unit_Entity) 561 or else Is_Pure (Unit_Entity) 562 or else Is_Shared_Passive (Unit_Entity) 563 or else 564 ((Is_Remote_Types (Unit_Entity) 565 or else Is_Remote_Call_Interface (Unit_Entity)) 566 and then Ekind (Unit_Entity) = E_Package 567 and then Unit_Kind /= N_Package_Body 568 and then not In_Package_Body (Unit_Entity) 569 and then not In_Instance)); 570 end In_Preelaborated_Unit; 571 572 ------------------ 573 -- In_Pure_Unit -- 574 ------------------ 575 576 function In_Pure_Unit return Boolean is 577 begin 578 return Is_Pure (Current_Scope); 579 end In_Pure_Unit; 580 581 ------------------------ 582 -- In_RCI_Declaration -- 583 ------------------------ 584 585 function In_RCI_Declaration return Boolean is 586 begin 587 return Is_Remote_Call_Interface (Current_Scope) 588 and then In_Package_Declaration; 589 end In_RCI_Declaration; 590 591 ----------------------- 592 -- In_RT_Declaration -- 593 ----------------------- 594 595 function In_RT_Declaration return Boolean is 596 begin 597 return Is_Remote_Types (Current_Scope) and then In_Package_Declaration; 598 end In_RT_Declaration; 599 600 ---------------------------- 601 -- In_Shared_Passive_Unit -- 602 ---------------------------- 603 604 function In_Shared_Passive_Unit return Boolean is 605 Unit_Entity : constant Entity_Id := Current_Scope; 606 607 begin 608 return Is_Shared_Passive (Unit_Entity); 609 end In_Shared_Passive_Unit; 610 611 --------------------------------------- 612 -- In_Subprogram_Task_Protected_Unit -- 613 --------------------------------------- 614 615 function In_Subprogram_Task_Protected_Unit return Boolean is 616 E : Entity_Id; 617 618 begin 619 -- The following is to verify that a declaration is inside 620 -- subprogram, generic subprogram, task unit, protected unit. 621 -- Used to validate if a lib. unit is Pure. RM 10.2.1(16). 622 623 -- Use scope chain to check successively outer scopes 624 625 E := Current_Scope; 626 loop 627 if Is_Subprogram_Or_Generic_Subprogram (E) 628 or else 629 Is_Concurrent_Type (E) 630 then 631 return True; 632 633 elsif E = Standard_Standard then 634 return False; 635 end if; 636 637 E := Scope (E); 638 end loop; 639 end In_Subprogram_Task_Protected_Unit; 640 641 ------------------------------- 642 -- Is_Non_Remote_Access_Type -- 643 ------------------------------- 644 645 function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean is 646 U_E : constant Entity_Id := Underlying_Type (Base_Type (E)); 647 -- Use full view of base type to handle subtypes properly. 648 649 begin 650 if No (U_E) then 651 652 -- This case arises for the case of a generic formal type, in which 653 -- case E.2.2(8) rules will be enforced at instantiation time. 654 655 return False; 656 end if; 657 658 return Is_Access_Type (U_E) 659 and then not Is_Remote_Access_To_Class_Wide_Type (U_E) 660 and then not Is_Remote_Access_To_Subprogram_Type (U_E); 661 end Is_Non_Remote_Access_Type; 662 663 --------------------------- 664 -- No_External_Streaming -- 665 --------------------------- 666 667 function No_External_Streaming (E : Entity_Id) return Boolean is 668 U_E : constant Entity_Id := Underlying_Type (E); 669 670 begin 671 if No (U_E) then 672 return False; 673 674 elsif Has_Read_Write_Attributes (E) then 675 676 -- Note: availability of stream attributes is tested on E, not U_E. 677 -- There may be stream attributes defined on U_E that are not visible 678 -- at the place where support of external streaming is tested. 679 680 return False; 681 682 elsif Has_Non_Remote_Access (U_E) then 683 return True; 684 end if; 685 686 return Is_Limited_Type (E); 687 end No_External_Streaming; 688 689 ------------------------------------- 690 -- Set_Categorization_From_Pragmas -- 691 ------------------------------------- 692 693 procedure Set_Categorization_From_Pragmas (N : Node_Id) is 694 P : constant Node_Id := Parent (N); 695 S : constant Entity_Id := Current_Scope; 696 697 procedure Set_Parents (Visibility : Boolean); 698 -- If this is a child instance, the parents are not immediately 699 -- visible during analysis. Make them momentarily visible so that 700 -- the argument of the pragma can be resolved properly, and reset 701 -- afterwards. 702 703 ----------------- 704 -- Set_Parents -- 705 ----------------- 706 707 procedure Set_Parents (Visibility : Boolean) is 708 Par : Entity_Id; 709 begin 710 Par := Scope (S); 711 while Present (Par) and then Par /= Standard_Standard loop 712 Set_Is_Immediately_Visible (Par, Visibility); 713 Par := Scope (Par); 714 end loop; 715 end Set_Parents; 716 717 -- Start of processing for Set_Categorization_From_Pragmas 718 719 begin 720 -- Deal with categorization pragmas in Pragmas of Compilation_Unit. 721 -- The purpose is to set categorization flags before analyzing the 722 -- unit itself, so as to diagnose violations of categorization as 723 -- we process each declaration, even though the pragma appears after 724 -- the unit. This processing is only needed if compilation unit pragmas 725 -- are present. 726 -- Note: This code may be incorrect in the unlikely case a child generic 727 -- unit is instantiated as a child of its (nongeneric) parent, so that 728 -- generic and instance are siblings. 729 730 if Nkind (P) /= N_Compilation_Unit 731 or else No (First (Pragmas_After (Aux_Decls_Node (P)))) 732 then 733 return; 734 end if; 735 736 declare 737 PN : Node_Id; 738 739 begin 740 if Is_Child_Unit (S) and then Is_Generic_Instance (S) then 741 Set_Parents (True); 742 end if; 743 744 PN := First (Pragmas_After (Aux_Decls_Node (P))); 745 while Present (PN) loop 746 747 -- Skip implicit types that may have been introduced by 748 -- previous analysis. 749 750 if Nkind (PN) = N_Pragma then 751 case Get_Pragma_Id (PN) is 752 when Pragma_All_Calls_Remote 753 | Pragma_Preelaborate 754 | Pragma_Pure 755 | Pragma_Remote_Call_Interface 756 | Pragma_Remote_Types 757 | Pragma_Shared_Passive 758 => 759 Analyze (PN); 760 761 when others => 762 null; 763 end case; 764 end if; 765 766 Next (PN); 767 end loop; 768 769 if Is_Child_Unit (S) and then Is_Generic_Instance (S) then 770 Set_Parents (False); 771 end if; 772 end; 773 end Set_Categorization_From_Pragmas; 774 775 ----------------------------------- 776 -- Set_Categorization_From_Scope -- 777 ----------------------------------- 778 779 procedure Set_Categorization_From_Scope (E : Entity_Id; Scop : Entity_Id) is 780 Declaration : Node_Id := Empty; 781 Specification : Node_Id := Empty; 782 783 begin 784 -- Do not modify the purity of an internally generated entity if it has 785 -- been explicitly marked as pure for optimization purposes. 786 787 if not Has_Pragma_Pure_Function (E) then 788 Set_Is_Pure 789 (E, Is_Pure (Scop) and then Is_Library_Level_Entity (E)); 790 end if; 791 792 if not Is_Remote_Call_Interface (E) then 793 if Ekind (E) in Subprogram_Kind then 794 Declaration := Unit_Declaration_Node (E); 795 796 if Nkind_In (Declaration, N_Subprogram_Body, 797 N_Subprogram_Renaming_Declaration) 798 then 799 Specification := Corresponding_Spec (Declaration); 800 end if; 801 end if; 802 803 -- A subprogram body or renaming-as-body is a remote call interface 804 -- if it serves as the completion of a subprogram declaration that 805 -- is a remote call interface. 806 807 if Nkind (Specification) in N_Entity then 808 Set_Is_Remote_Call_Interface 809 (E, Is_Remote_Call_Interface (Specification)); 810 811 -- A subprogram declaration is a remote call interface when it is 812 -- declared within the visible part of, or declared by, a library 813 -- unit declaration that is a remote call interface. 814 815 else 816 Set_Is_Remote_Call_Interface 817 (E, Is_Remote_Call_Interface (Scop) 818 and then not (In_Private_Part (Scop) 819 or else In_Package_Body (Scop))); 820 end if; 821 end if; 822 823 Set_Is_Remote_Types 824 (E, Is_Remote_Types (Scop) 825 and then not (In_Private_Part (Scop) 826 or else In_Package_Body (Scop))); 827 end Set_Categorization_From_Scope; 828 829 ------------------------------ 830 -- Static_Discriminant_Expr -- 831 ------------------------------ 832 833 -- We need to accommodate a Why_Not_Static call somehow here ??? 834 835 function Static_Discriminant_Expr (L : List_Id) return Boolean is 836 Discriminant_Spec : Node_Id; 837 838 begin 839 Discriminant_Spec := First (L); 840 while Present (Discriminant_Spec) loop 841 if Present (Expression (Discriminant_Spec)) 842 and then 843 not Is_OK_Static_Expression (Expression (Discriminant_Spec)) 844 then 845 return False; 846 end if; 847 848 Next (Discriminant_Spec); 849 end loop; 850 851 return True; 852 end Static_Discriminant_Expr; 853 854 -------------------------------------- 855 -- Validate_Access_Type_Declaration -- 856 -------------------------------------- 857 858 procedure Validate_Access_Type_Declaration (T : Entity_Id; N : Node_Id) is 859 Def : constant Node_Id := Type_Definition (N); 860 861 begin 862 case Nkind (Def) is 863 864 -- Access to subprogram case 865 866 when N_Access_To_Subprogram_Definition => 867 868 -- A pure library_item must not contain the declaration of a 869 -- named access type, except within a subprogram, generic 870 -- subprogram, task unit, or protected unit (RM 10.2.1(16)). 871 872 -- This test is skipped in Ada 2005 (see AI-366) 873 874 if Ada_Version < Ada_2005 875 and then Comes_From_Source (T) 876 and then In_Pure_Unit 877 and then not In_Subprogram_Task_Protected_Unit 878 then 879 Error_Msg_N ("named access type not allowed in pure unit", T); 880 end if; 881 882 -- Access to object case 883 884 when N_Access_To_Object_Definition => 885 if Comes_From_Source (T) 886 and then In_Pure_Unit 887 and then not In_Subprogram_Task_Protected_Unit 888 then 889 -- We can't give the message yet, since the type is not frozen 890 -- and in Ada 2005 mode, access types are allowed in pure units 891 -- if the type has no storage pool (see AI-366). So we set a 892 -- flag which will be checked at freeze time. 893 894 Set_Is_Pure_Unit_Access_Type (T); 895 end if; 896 897 -- Check for RCI or RT unit type declaration: declaration of an 898 -- access-to-object type is illegal unless it is a general access 899 -- type that designates a class-wide limited private type. 900 -- Note that constraints on the primitive subprograms of the 901 -- designated tagged type are not enforced here but in 902 -- Validate_RACW_Primitives, which is done separately because the 903 -- designated type might not be frozen (and therefore its 904 -- primitive operations might not be completely known) at the 905 -- point of the RACW declaration. 906 907 Validate_Remote_Access_Object_Type_Declaration (T); 908 909 -- Check for shared passive unit type declaration. It should 910 -- not contain the declaration of access to class wide type, 911 -- access to task type and access to protected type with entry. 912 913 Validate_SP_Access_Object_Type_Decl (T); 914 915 when others => 916 null; 917 end case; 918 919 -- Set categorization flag from package on entity as well, to allow 920 -- easy checks later on for required validations of RCI or RT units. 921 -- This is only done for entities that are in the original source. 922 923 if Comes_From_Source (T) 924 and then not (In_Package_Body (Scope (T)) 925 or else In_Private_Part (Scope (T))) 926 then 927 Set_Is_Remote_Call_Interface 928 (T, Is_Remote_Call_Interface (Scope (T))); 929 Set_Is_Remote_Types 930 (T, Is_Remote_Types (Scope (T))); 931 end if; 932 end Validate_Access_Type_Declaration; 933 934 ---------------------------- 935 -- Validate_Ancestor_Part -- 936 ---------------------------- 937 938 procedure Validate_Ancestor_Part (N : Node_Id) is 939 A : constant Node_Id := Ancestor_Part (N); 940 T : constant Entity_Id := Entity (A); 941 942 begin 943 if In_Preelaborated_Unit 944 and then not In_Subprogram_Or_Concurrent_Unit 945 and then (not Inside_A_Generic 946 or else Present (Enclosing_Generic_Body (N))) 947 then 948 -- If the type is private, it must have the Ada 2005 pragma 949 -- Has_Preelaborable_Initialization. 950 951 -- The check is omitted within predefined units. This is probably 952 -- obsolete code to fix the Ada 95 weakness in this area ??? 953 954 if Is_Private_Type (T) 955 and then not Has_Pragma_Preelab_Init (T) 956 and then not In_Internal_Unit (N) 957 then 958 Error_Msg_N 959 ("private ancestor type not allowed in preelaborated unit", A); 960 961 elsif Is_Record_Type (T) then 962 if Nkind (Parent (T)) = N_Full_Type_Declaration then 963 Check_Non_Static_Default_Expr 964 (Type_Definition (Parent (T)), A); 965 end if; 966 end if; 967 end if; 968 end Validate_Ancestor_Part; 969 970 ---------------------------------------- 971 -- Validate_Categorization_Dependency -- 972 ---------------------------------------- 973 974 procedure Validate_Categorization_Dependency 975 (N : Node_Id; 976 E : Entity_Id) 977 is 978 K : constant Node_Kind := Nkind (N); 979 P : Node_Id := Parent (N); 980 U : Entity_Id := E; 981 Is_Subunit : constant Boolean := Nkind (P) = N_Subunit; 982 983 begin 984 -- Only validate library units and subunits. For subunits, checks 985 -- concerning withed units apply to the parent compilation unit. 986 987 if Is_Subunit then 988 P := Parent (P); 989 U := Scope (E); 990 991 while Present (U) 992 and then not Is_Compilation_Unit (U) 993 and then not Is_Child_Unit (U) 994 loop 995 U := Scope (U); 996 end loop; 997 end if; 998 999 if Nkind (P) /= N_Compilation_Unit then 1000 return; 1001 end if; 1002 1003 -- Body of RCI unit does not need validation 1004 1005 if Is_Remote_Call_Interface (E) 1006 and then Nkind_In (N, N_Package_Body, N_Subprogram_Body) 1007 then 1008 return; 1009 end if; 1010 1011 -- Ada 2005 (AI-50217): Process explicit non-limited with_clauses 1012 1013 declare 1014 Item : Node_Id; 1015 Entity_Of_Withed : Entity_Id; 1016 1017 begin 1018 Item := First (Context_Items (P)); 1019 while Present (Item) loop 1020 if Nkind (Item) = N_With_Clause 1021 and then 1022 not (Implicit_With (Item) 1023 or else Limited_Present (Item) 1024 1025 -- Skip if error already posted on the WITH clause (in 1026 -- which case the Name attribute may be invalid). In 1027 -- particular, this fixes the problem of hanging in the 1028 -- presence of a WITH clause on a child that is an 1029 -- illegal generic instantiation. 1030 1031 or else Error_Posted (Item)) 1032 and then 1033 not (Try_Semantics 1034 1035 -- Skip processing malformed trees 1036 1037 and then Nkind (Name (Item)) not in N_Has_Entity) 1038 then 1039 Entity_Of_Withed := Entity (Name (Item)); 1040 Check_Categorization_Dependencies 1041 (U, Entity_Of_Withed, Item, Is_Subunit); 1042 end if; 1043 1044 Next (Item); 1045 end loop; 1046 end; 1047 1048 -- Child depends on parent; therefore parent should also be categorized 1049 -- and satisfy the dependency hierarchy. 1050 1051 -- Check if N is a child spec 1052 1053 if (K in N_Generic_Declaration or else 1054 K in N_Generic_Instantiation or else 1055 K in N_Generic_Renaming_Declaration or else 1056 K = N_Package_Declaration or else 1057 K = N_Package_Renaming_Declaration or else 1058 K = N_Subprogram_Declaration or else 1059 K = N_Subprogram_Renaming_Declaration) 1060 and then Present (Parent_Spec (N)) 1061 then 1062 Check_Categorization_Dependencies (E, Scope (E), N, False); 1063 1064 -- Verify that public child of an RCI library unit must also be an 1065 -- RCI library unit (RM E.2.3(15)). 1066 1067 if Is_Remote_Call_Interface (Scope (E)) 1068 and then not Private_Present (P) 1069 and then not Is_Remote_Call_Interface (E) 1070 then 1071 Error_Msg_N ("public child of rci unit must also be rci unit", N); 1072 end if; 1073 end if; 1074 end Validate_Categorization_Dependency; 1075 1076 -------------------------------- 1077 -- Validate_Controlled_Object -- 1078 -------------------------------- 1079 1080 procedure Validate_Controlled_Object (E : Entity_Id) is 1081 begin 1082 -- Don't need this check in Ada 2005 mode, where this is all taken 1083 -- care of by the mechanism for Preelaborable Initialization. 1084 1085 if Ada_Version >= Ada_2005 then 1086 return; 1087 end if; 1088 1089 -- For now, never apply this check for internal GNAT units, since we 1090 -- have a number of cases in the library where we are stuck with objects 1091 -- of this type, and the RM requires Preelaborate. 1092 1093 -- For similar reasons, we only do this check for source entities, since 1094 -- we generate entities of this type in some situations. 1095 1096 -- Note that the 10.2.1(9) restrictions are not relevant to us anyway. 1097 -- We have to enforce them for RM compatibility, but we have no trouble 1098 -- accepting these objects and doing the right thing. Note that there is 1099 -- no requirement that Preelaborate not actually generate any code. 1100 1101 if In_Preelaborated_Unit 1102 and then not Debug_Flag_PP 1103 and then Comes_From_Source (E) 1104 and then not In_Internal_Unit (E) 1105 and then (not Inside_A_Generic 1106 or else Present (Enclosing_Generic_Body (E))) 1107 and then not Is_Protected_Type (Etype (E)) 1108 then 1109 Error_Msg_N 1110 ("library level controlled object not allowed in " & 1111 "preelaborated unit", E); 1112 end if; 1113 end Validate_Controlled_Object; 1114 1115 -------------------------------------- 1116 -- Validate_Null_Statement_Sequence -- 1117 -------------------------------------- 1118 1119 procedure Validate_Null_Statement_Sequence (N : Node_Id) is 1120 Item : Node_Id; 1121 1122 begin 1123 if In_Preelaborated_Unit then 1124 Item := First (Statements (Handled_Statement_Sequence (N))); 1125 while Present (Item) loop 1126 if Nkind (Item) /= N_Label 1127 and then Nkind (Item) /= N_Null_Statement 1128 then 1129 -- In GNAT mode, this is a warning, allowing the run-time 1130 -- to judiciously bypass this error condition. 1131 1132 Error_Msg_Warn := GNAT_Mode; 1133 Error_Msg_N 1134 ("<<statements not allowed in preelaborated unit", Item); 1135 1136 exit; 1137 end if; 1138 1139 Next (Item); 1140 end loop; 1141 end if; 1142 end Validate_Null_Statement_Sequence; 1143 1144 --------------------------------- 1145 -- Validate_Object_Declaration -- 1146 --------------------------------- 1147 1148 procedure Validate_Object_Declaration (N : Node_Id) is 1149 Id : constant Entity_Id := Defining_Identifier (N); 1150 E : constant Node_Id := Expression (N); 1151 Odf : constant Node_Id := Object_Definition (N); 1152 T : constant Entity_Id := Etype (Id); 1153 1154 begin 1155 -- Verify that any access to subprogram object does not have in its 1156 -- subprogram profile access type parameters or limited parameters 1157 -- without Read and Write attributes (E.2.3(13)). 1158 1159 Validate_RCI_Subprogram_Declaration (N); 1160 1161 -- Check that if we are in preelaborated elaboration code, then we 1162 -- do not have an instance of a default initialized private, task or 1163 -- protected object declaration which would violate (RM 10.2.1(9)). 1164 -- Note that constants are never default initialized (and the test 1165 -- below also filters out deferred constants). A variable is default 1166 -- initialized if it does *not* have an initialization expression. 1167 1168 -- Filter out cases that are not declaration of a variable from source 1169 1170 if Nkind (N) /= N_Object_Declaration 1171 or else Constant_Present (N) 1172 or else not Comes_From_Source (Id) 1173 then 1174 return; 1175 end if; 1176 1177 -- Exclude generic specs from the checks (this will get rechecked 1178 -- on instantiations). 1179 1180 if Inside_A_Generic and then No (Enclosing_Generic_Body (Id)) then 1181 return; 1182 end if; 1183 1184 -- Required checks for declaration that is in a preelaborated package 1185 -- and is not within some subprogram. 1186 1187 if In_Preelaborated_Unit 1188 and then not In_Subprogram_Or_Concurrent_Unit 1189 then 1190 -- Check for default initialized variable case. Note that in 1191 -- accordance with (RM B.1(24)) imported objects are not subject to 1192 -- default initialization. 1193 -- If the initialization does not come from source and is an 1194 -- aggregate, it is a static initialization that replaces an 1195 -- implicit call, and must be treated as such. 1196 1197 if Present (E) 1198 and then (Comes_From_Source (E) or else Nkind (E) /= N_Aggregate) 1199 then 1200 null; 1201 1202 elsif Is_Imported (Id) then 1203 null; 1204 1205 else 1206 declare 1207 Ent : Entity_Id := T; 1208 1209 begin 1210 -- An array whose component type is a record with nonstatic 1211 -- default expressions is a violation, so we get the array's 1212 -- component type. 1213 1214 if Is_Array_Type (Ent) then 1215 declare 1216 Comp_Type : Entity_Id; 1217 1218 begin 1219 Comp_Type := Component_Type (Ent); 1220 while Is_Array_Type (Comp_Type) loop 1221 Comp_Type := Component_Type (Comp_Type); 1222 end loop; 1223 1224 Ent := Comp_Type; 1225 end; 1226 end if; 1227 1228 -- Object decl. that is of record type and has no default expr. 1229 -- should check if there is any non-static default expression 1230 -- in component decl. of the record type decl. 1231 1232 if Is_Record_Type (Ent) then 1233 if Nkind (Parent (Ent)) = N_Full_Type_Declaration then 1234 Check_Non_Static_Default_Expr 1235 (Type_Definition (Parent (Ent)), N); 1236 1237 elsif Nkind (Odf) = N_Subtype_Indication 1238 and then not Is_Array_Type (T) 1239 and then not Is_Private_Type (T) 1240 then 1241 Check_Non_Static_Default_Expr (Type_Definition 1242 (Parent (Entity (Subtype_Mark (Odf)))), N); 1243 end if; 1244 end if; 1245 1246 -- Check for invalid use of private object. Note that Ada 2005 1247 -- AI-161 modifies the rules for Ada 2005, including the use of 1248 -- the new pragma Preelaborable_Initialization. 1249 1250 if Is_Private_Type (Ent) 1251 or else Depends_On_Private (Ent) 1252 then 1253 -- Case where type has preelaborable initialization which 1254 -- means that a pragma Preelaborable_Initialization was 1255 -- given for the private type. 1256 1257 if Relaxed_RM_Semantics then 1258 1259 -- In relaxed mode, do not issue these messages, this 1260 -- is basically similar to the GNAT_Mode test below. 1261 1262 null; 1263 1264 elsif Has_Preelaborable_Initialization (Ent) then 1265 1266 -- But for the predefined units, we will ignore this 1267 -- status unless we are in Ada 2005 mode since we want 1268 -- Ada 95 compatible behavior, in which the entities 1269 -- marked with this pragma in the predefined library are 1270 -- not treated specially. 1271 1272 if Ada_Version < Ada_2005 then 1273 Error_Msg_N 1274 ("private object not allowed in preelaborated unit", 1275 N); 1276 Error_Msg_N ("\(would be legal in Ada 2005 mode)", N); 1277 end if; 1278 1279 -- Type does not have preelaborable initialization 1280 1281 else 1282 -- We allow this when compiling in GNAT mode to make life 1283 -- easier for some cases where it would otherwise be hard 1284 -- to be exactly valid Ada. 1285 1286 if not GNAT_Mode then 1287 Error_Msg_N 1288 ("private object not allowed in preelaborated unit", 1289 N); 1290 1291 -- Add a message if it would help to provide a pragma 1292 -- Preelaborable_Initialization on the type of the 1293 -- object (which would make it legal in Ada 2005). 1294 1295 -- If the type has no full view (generic type, or 1296 -- previous error), the warning does not apply. 1297 1298 if Is_Private_Type (Ent) 1299 and then Present (Full_View (Ent)) 1300 and then 1301 Has_Preelaborable_Initialization (Full_View (Ent)) 1302 then 1303 Error_Msg_Sloc := Sloc (Ent); 1304 1305 if Ada_Version >= Ada_2005 then 1306 Error_Msg_NE 1307 ("\would be legal if pragma Preelaborable_" & 1308 "Initialization given for & #", N, Ent); 1309 else 1310 Error_Msg_NE 1311 ("\would be legal in Ada 2005 if pragma " & 1312 "Preelaborable_Initialization given for & #", 1313 N, Ent); 1314 end if; 1315 end if; 1316 end if; 1317 end if; 1318 1319 -- Access to Task or Protected type 1320 1321 elsif Is_Entity_Name (Odf) 1322 and then Present (Etype (Odf)) 1323 and then Is_Access_Type (Etype (Odf)) 1324 then 1325 Ent := Designated_Type (Etype (Odf)); 1326 1327 elsif Is_Entity_Name (Odf) then 1328 Ent := Entity (Odf); 1329 1330 elsif Nkind (Odf) = N_Subtype_Indication then 1331 Ent := Etype (Subtype_Mark (Odf)); 1332 1333 elsif Nkind (Odf) = N_Constrained_Array_Definition then 1334 Ent := Component_Type (T); 1335 end if; 1336 1337 if Is_Task_Type (Ent) 1338 or else (Is_Protected_Type (Ent) and then Has_Entries (Ent)) 1339 then 1340 Error_Msg_N 1341 ("concurrent object not allowed in preelaborated unit", 1342 N); 1343 return; 1344 end if; 1345 end; 1346 end if; 1347 1348 -- Non-static discriminants not allowed in preelaborated unit. 1349 -- Objects of a controlled type with a user-defined Initialize 1350 -- are forbidden as well. 1351 1352 if Is_Record_Type (Etype (Id)) then 1353 declare 1354 ET : constant Entity_Id := Etype (Id); 1355 EE : constant Entity_Id := Etype (Etype (Id)); 1356 PEE : Node_Id; 1357 1358 begin 1359 if Has_Discriminants (ET) and then Present (EE) then 1360 PEE := Parent (EE); 1361 1362 if Nkind (PEE) = N_Full_Type_Declaration 1363 and then not Static_Discriminant_Expr 1364 (Discriminant_Specifications (PEE)) 1365 then 1366 Error_Msg_N 1367 ("non-static discriminant in preelaborated unit", 1368 PEE); 1369 end if; 1370 end if; 1371 1372 -- For controlled type or type with controlled component, check 1373 -- preelaboration flag, as there may be a non-null Initialize 1374 -- primitive. For language versions earlier than Ada 2005, 1375 -- there is no notion of preelaborable initialization, and 1376 -- Validate_Controlled_Object is used to enforce rules for 1377 -- controlled objects. 1378 1379 if (Is_Controlled (ET) or else Has_Controlled_Component (ET)) 1380 and then Ada_Version >= Ada_2005 1381 and then not Has_Preelaborable_Initialization (ET) 1382 then 1383 Error_Msg_NE 1384 ("controlled type& does not have" 1385 & " preelaborable initialization", N, ET); 1386 end if; 1387 end; 1388 1389 end if; 1390 end if; 1391 1392 -- A pure library_item must not contain the declaration of any variable 1393 -- except within a subprogram, generic subprogram, task unit, or 1394 -- protected unit (RM 10.2.1(16)). 1395 1396 if In_Pure_Unit and then not In_Subprogram_Task_Protected_Unit then 1397 Error_Msg_N ("declaration of variable not allowed in pure unit", N); 1398 1399 elsif not In_Private_Part (Id) then 1400 1401 -- The visible part of an RCI library unit must not contain the 1402 -- declaration of a variable (RM E.1.3(9)). 1403 1404 if In_RCI_Declaration then 1405 Error_Msg_N ("visible variable not allowed in 'R'C'I unit", N); 1406 1407 -- The visible part of a Shared Passive library unit must not contain 1408 -- the declaration of a variable (RM E.2.2(7)). 1409 1410 elsif In_RT_Declaration then 1411 Error_Msg_N 1412 ("visible variable not allowed in remote types unit", N); 1413 end if; 1414 end if; 1415 end Validate_Object_Declaration; 1416 1417 ----------------------------- 1418 -- Validate_RACW_Primitive -- 1419 ----------------------------- 1420 1421 procedure Validate_RACW_Primitive 1422 (Subp : Entity_Id; 1423 RACW : Entity_Id) 1424 is 1425 procedure Illegal_Remote_Subp (Msg : String; N : Node_Id); 1426 -- Diagnose illegality on N. If RACW is present, report the error on it 1427 -- rather than on N. 1428 1429 ------------------------- 1430 -- Illegal_Remote_Subp -- 1431 ------------------------- 1432 1433 procedure Illegal_Remote_Subp (Msg : String; N : Node_Id) is 1434 begin 1435 if Present (RACW) then 1436 if not Error_Posted (RACW) then 1437 Error_Msg_N 1438 ("illegal remote access to class-wide type&", RACW); 1439 end if; 1440 1441 Error_Msg_Sloc := Sloc (N); 1442 Error_Msg_NE ("\\" & Msg & " in primitive& #", RACW, Subp); 1443 1444 else 1445 Error_Msg_NE (Msg & " in remote subprogram&", N, Subp); 1446 end if; 1447 end Illegal_Remote_Subp; 1448 1449 Rtyp : Entity_Id; 1450 Param : Node_Id; 1451 Param_Spec : Node_Id; 1452 Param_Type : Entity_Id; 1453 1454 -- Start of processing for Validate_RACW_Primitive 1455 1456 begin 1457 -- Check return type 1458 1459 if Ekind (Subp) = E_Function then 1460 Rtyp := Etype (Subp); 1461 1462 -- AI05-0101 (Binding Interpretation): The result type of a remote 1463 -- function must either support external streaming or be a 1464 -- controlling access result type. 1465 1466 if Has_Controlling_Result (Subp) then 1467 null; 1468 1469 elsif Ekind (Rtyp) = E_Anonymous_Access_Type then 1470 Illegal_Remote_Subp ("anonymous access result", Rtyp); 1471 1472 elsif Is_Limited_Type (Rtyp) then 1473 if No (TSS (Rtyp, TSS_Stream_Read)) 1474 or else 1475 No (TSS (Rtyp, TSS_Stream_Write)) 1476 then 1477 Illegal_Remote_Subp 1478 ("limited return type must have Read and Write attributes", 1479 Parent (Subp)); 1480 Explain_Limited_Type (Rtyp, Parent (Subp)); 1481 end if; 1482 1483 -- Check that the return type supports external streaming 1484 1485 elsif No_External_Streaming (Rtyp) 1486 and then not Error_Posted (Rtyp) 1487 then 1488 Illegal_Remote_Subp ("return type containing non-remote access " 1489 & "must have Read and Write attributes", 1490 Parent (Subp)); 1491 end if; 1492 end if; 1493 1494 Param := First_Formal (Subp); 1495 while Present (Param) loop 1496 1497 -- Now find out if this parameter is a controlling parameter 1498 1499 Param_Spec := Parent (Param); 1500 Param_Type := Etype (Param); 1501 1502 if Is_Controlling_Formal (Param) then 1503 1504 -- It is a controlling parameter, so specific checks below do not 1505 -- apply. 1506 1507 null; 1508 1509 elsif Ekind_In (Param_Type, E_Anonymous_Access_Type, 1510 E_Anonymous_Access_Subprogram_Type) 1511 then 1512 -- From RM E.2.2(14), no anonymous access parameter other than 1513 -- controlling ones may be used (because an anonymous access 1514 -- type never supports external streaming). 1515 1516 Illegal_Remote_Subp 1517 ("non-controlling access parameter", Param_Spec); 1518 1519 elsif No_External_Streaming (Param_Type) 1520 and then not Error_Posted (Param_Type) 1521 then 1522 Illegal_Remote_Subp ("formal parameter in remote subprogram must " 1523 & "support external streaming", Param_Spec); 1524 end if; 1525 1526 -- Check next parameter in this subprogram 1527 1528 Next_Formal (Param); 1529 end loop; 1530 end Validate_RACW_Primitive; 1531 1532 ------------------------------ 1533 -- Validate_RACW_Primitives -- 1534 ------------------------------ 1535 1536 procedure Validate_RACW_Primitives (T : Entity_Id) is 1537 Desig_Type : Entity_Id; 1538 Primitive_Subprograms : Elist_Id; 1539 Subprogram_Elmt : Elmt_Id; 1540 Subprogram : Entity_Id; 1541 1542 begin 1543 Desig_Type := Etype (Designated_Type (T)); 1544 1545 -- No action needed for concurrent types 1546 1547 if Is_Concurrent_Type (Desig_Type) then 1548 return; 1549 end if; 1550 1551 Primitive_Subprograms := Primitive_Operations (Desig_Type); 1552 1553 Subprogram_Elmt := First_Elmt (Primitive_Subprograms); 1554 while Subprogram_Elmt /= No_Elmt loop 1555 Subprogram := Node (Subprogram_Elmt); 1556 1557 if Is_Predefined_Dispatching_Operation (Subprogram) 1558 or else Is_Hidden (Subprogram) 1559 then 1560 goto Next_Subprogram; 1561 end if; 1562 1563 Validate_RACW_Primitive (Subp => Subprogram, RACW => T); 1564 1565 <<Next_Subprogram>> 1566 Next_Elmt (Subprogram_Elmt); 1567 end loop; 1568 end Validate_RACW_Primitives; 1569 1570 ------------------------------- 1571 -- Validate_RCI_Declarations -- 1572 ------------------------------- 1573 1574 procedure Validate_RCI_Declarations (P : Entity_Id) is 1575 E : Entity_Id; 1576 1577 begin 1578 E := First_Entity (P); 1579 while Present (E) loop 1580 if Comes_From_Source (E) then 1581 if Is_Limited_Type (E) then 1582 Error_Msg_N 1583 ("limited type not allowed in rci unit", Parent (E)); 1584 Explain_Limited_Type (E, Parent (E)); 1585 1586 elsif Ekind_In (E, E_Generic_Function, 1587 E_Generic_Package, 1588 E_Generic_Procedure) 1589 then 1590 Error_Msg_N ("generic declaration not allowed in rci unit", 1591 Parent (E)); 1592 1593 elsif (Ekind (E) = E_Function or else Ekind (E) = E_Procedure) 1594 and then Has_Pragma_Inline (E) 1595 then 1596 Error_Msg_N 1597 ("inlined subprogram not allowed in rci unit", Parent (E)); 1598 1599 -- Inner packages that are renamings need not be checked. Generic 1600 -- RCI packages are subject to the checks, but entities that come 1601 -- from formal packages are not part of the visible declarations 1602 -- of the package and are not checked. 1603 1604 elsif Ekind (E) = E_Package then 1605 if Present (Renamed_Entity (E)) then 1606 null; 1607 1608 elsif Ekind (P) /= E_Generic_Package 1609 or else List_Containing (Unit_Declaration_Node (E)) /= 1610 Generic_Formal_Declarations 1611 (Unit_Declaration_Node (P)) 1612 then 1613 Validate_RCI_Declarations (E); 1614 end if; 1615 end if; 1616 end if; 1617 1618 Next_Entity (E); 1619 end loop; 1620 end Validate_RCI_Declarations; 1621 1622 ----------------------------------------- 1623 -- Validate_RCI_Subprogram_Declaration -- 1624 ----------------------------------------- 1625 1626 procedure Validate_RCI_Subprogram_Declaration (N : Node_Id) is 1627 K : constant Node_Kind := Nkind (N); 1628 Profile : List_Id; 1629 Id : constant Entity_Id := Defining_Entity (N); 1630 Param_Spec : Node_Id; 1631 Param_Type : Entity_Id; 1632 Error_Node : Node_Id := N; 1633 1634 begin 1635 -- This procedure enforces rules on subprogram and access to subprogram 1636 -- declarations in RCI units. These rules do not apply to expander 1637 -- generated routines, which are not remote subprograms. It is called: 1638 1639 -- 1. from Analyze_Subprogram_Declaration. 1640 -- 2. from Validate_Object_Declaration (access to subprogram). 1641 1642 if not (Comes_From_Source (N) 1643 and then In_RCI_Declaration 1644 and then not In_Private_Part (Scope (Id))) 1645 then 1646 return; 1647 end if; 1648 1649 if K = N_Subprogram_Declaration then 1650 Profile := Parameter_Specifications (Specification (N)); 1651 1652 else 1653 pragma Assert (K = N_Object_Declaration); 1654 1655 -- The above assertion is dubious, the visible declarations of an 1656 -- RCI unit never contain an object declaration, this should be an 1657 -- ACCESS-to-object declaration??? 1658 1659 if Nkind (Id) = N_Defining_Identifier 1660 and then Nkind (Parent (Etype (Id))) = N_Full_Type_Declaration 1661 and then Ekind (Etype (Id)) = E_Access_Subprogram_Type 1662 then 1663 Profile := 1664 Parameter_Specifications (Type_Definition (Parent (Etype (Id)))); 1665 else 1666 return; 1667 end if; 1668 end if; 1669 1670 -- Iterate through the parameter specification list, checking that 1671 -- no access parameter and no limited type parameter in the list. 1672 -- RM E.2.3(14). 1673 1674 if Present (Profile) then 1675 Param_Spec := First (Profile); 1676 while Present (Param_Spec) loop 1677 Param_Type := Etype (Defining_Identifier (Param_Spec)); 1678 1679 if Ekind (Param_Type) = E_Anonymous_Access_Type then 1680 if K = N_Subprogram_Declaration then 1681 Error_Node := Param_Spec; 1682 end if; 1683 1684 -- Report error only if declaration is in source program 1685 1686 if Comes_From_Source (Id) then 1687 Error_Msg_N 1688 ("subprogram in 'R'C'I unit cannot have access parameter", 1689 Error_Node); 1690 end if; 1691 1692 -- For a limited private type parameter, we check only the private 1693 -- declaration and ignore full type declaration, unless this is 1694 -- the only declaration for the type, e.g., as a limited record. 1695 1696 elsif No_External_Streaming (Param_Type) then 1697 if K = N_Subprogram_Declaration then 1698 Error_Node := Param_Spec; 1699 end if; 1700 1701 Error_Msg_NE 1702 ("formal of remote subprogram& " 1703 & "must support external streaming", 1704 Error_Node, Id); 1705 if Is_Limited_Type (Param_Type) then 1706 Explain_Limited_Type (Param_Type, Error_Node); 1707 end if; 1708 end if; 1709 1710 Next (Param_Spec); 1711 end loop; 1712 end if; 1713 1714 if Ekind (Id) = E_Function 1715 and then Ekind (Etype (Id)) = E_Anonymous_Access_Type 1716 and then Comes_From_Source (Id) 1717 then 1718 Error_Msg_N 1719 ("function in 'R'C'I unit cannot have access result", 1720 Error_Node); 1721 end if; 1722 end Validate_RCI_Subprogram_Declaration; 1723 1724 ---------------------------------------------------- 1725 -- Validate_Remote_Access_Object_Type_Declaration -- 1726 ---------------------------------------------------- 1727 1728 procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id) is 1729 Direct_Designated_Type : Entity_Id; 1730 Desig_Type : Entity_Id; 1731 1732 begin 1733 -- We are called from Analyze_Full_Type_Declaration, and the Nkind of 1734 -- the given node is N_Access_To_Object_Definition. 1735 1736 if not Comes_From_Source (T) 1737 or else (not In_RCI_Declaration and then not In_RT_Declaration) 1738 then 1739 return; 1740 end if; 1741 1742 -- An access definition in the private part of a package is not a 1743 -- remote access type. Restrictions related to external streaming 1744 -- support for non-remote access types are enforced elsewhere. Note 1745 -- that In_Private_Part is never set on type entities: check flag 1746 -- on enclosing scope. 1747 1748 if In_Private_Part (Scope (T)) then 1749 return; 1750 end if; 1751 1752 -- Check RCI or RT unit type declaration. It may not contain the 1753 -- declaration of an access-to-object type unless it is a general access 1754 -- type that designates a class-wide limited private type or subtype. 1755 -- There are also constraints on the primitive subprograms of the 1756 -- class-wide type (RM E.2.2(14), see Validate_RACW_Primitives). 1757 1758 if Ekind (T) /= E_General_Access_Type 1759 or else not Is_Class_Wide_Type (Designated_Type (T)) 1760 then 1761 if In_RCI_Declaration then 1762 Error_Msg_N 1763 ("error in access type in Remote_Call_Interface unit", T); 1764 else 1765 Error_Msg_N 1766 ("error in access type in Remote_Types unit", T); 1767 end if; 1768 1769 Error_Msg_N ("\must be general access to class-wide type", T); 1770 return; 1771 end if; 1772 1773 Direct_Designated_Type := Designated_Type (T); 1774 Desig_Type := Etype (Direct_Designated_Type); 1775 1776 -- Why is this check not in Validate_Remote_Access_To_Class_Wide_Type??? 1777 1778 if not Is_Valid_Remote_Object_Type (Desig_Type) then 1779 Error_Msg_N 1780 ("error in designated type of remote access to class-wide type", T); 1781 Error_Msg_N 1782 ("\must be tagged limited private or private extension", T); 1783 return; 1784 end if; 1785 end Validate_Remote_Access_Object_Type_Declaration; 1786 1787 ----------------------------------------------- 1788 -- Validate_Remote_Access_To_Class_Wide_Type -- 1789 ----------------------------------------------- 1790 1791 procedure Validate_Remote_Access_To_Class_Wide_Type (N : Node_Id) is 1792 K : constant Node_Kind := Nkind (N); 1793 PK : constant Node_Kind := Nkind (Parent (N)); 1794 E : Entity_Id; 1795 1796 begin 1797 -- This subprogram enforces the checks in (RM E.2.2(8)) for certain uses 1798 -- of class-wide limited private types. 1799 1800 -- Storage_Pool and Storage_Size are not defined for such types 1801 -- 1802 -- The expected type of allocator must not be such a type. 1803 1804 -- The actual parameter of generic instantiation must not be such a 1805 -- type if the formal parameter is of an access type. 1806 1807 -- On entry, there are several cases: 1808 1809 -- 1. called from sem_attr Analyze_Attribute where attribute name is 1810 -- either Storage_Pool or Storage_Size. 1811 1812 -- 2. called from exp_ch4 Expand_N_Allocator 1813 1814 -- 3. called from sem_ch4 Analyze_Explicit_Dereference 1815 1816 -- 4. called from sem_res Resolve_Actuals 1817 1818 if K = N_Attribute_Reference then 1819 E := Etype (Prefix (N)); 1820 1821 if Is_Remote_Access_To_Class_Wide_Type (E) then 1822 Error_Msg_N ("incorrect attribute of remote operand", N); 1823 return; 1824 end if; 1825 1826 elsif K = N_Allocator then 1827 E := Etype (N); 1828 1829 if Is_Remote_Access_To_Class_Wide_Type (E) then 1830 Error_Msg_N ("incorrect expected remote type of allocator", N); 1831 return; 1832 end if; 1833 1834 -- This subprogram also enforces the checks in E.2.2(13). A value of 1835 -- such type must not be dereferenced unless as controlling operand of 1836 -- a dispatching call. Explicit dereferences not coming from source are 1837 -- exempted from this checking because the expander produces them in 1838 -- some cases (such as for tag checks on dispatching calls with multiple 1839 -- controlling operands). However we do check in the case of an implicit 1840 -- dereference that is expanded to an explicit dereference (hence the 1841 -- test of whether Original_Node (N) comes from source). 1842 1843 elsif K = N_Explicit_Dereference 1844 and then Comes_From_Source (Original_Node (N)) 1845 then 1846 E := Etype (Prefix (N)); 1847 1848 -- If the class-wide type is not a remote one, the restrictions 1849 -- do not apply. 1850 1851 if not Is_Remote_Access_To_Class_Wide_Type (E) then 1852 return; 1853 end if; 1854 1855 -- If we have a true dereference that comes from source and that 1856 -- is a controlling argument for a dispatching call, accept it. 1857 1858 if Is_Actual_Parameter (N) and then Is_Controlling_Actual (N) then 1859 return; 1860 end if; 1861 1862 -- If we are just within a procedure or function call and the 1863 -- dereference has not been analyzed, return because this procedure 1864 -- will be called again from sem_res Resolve_Actuals. The same can 1865 -- apply in the case of dereference that is the prefix of a selected 1866 -- component, which can be a call given in prefixed form. 1867 1868 if (Is_Actual_Parameter (N) or else PK = N_Selected_Component) 1869 and then not Analyzed (N) 1870 then 1871 return; 1872 end if; 1873 1874 -- We must allow expanded code to generate a reference to the tag of 1875 -- the designated object (may be either the actual tag, or the stub 1876 -- tag in the case of a remote object). 1877 1878 if PK = N_Selected_Component 1879 and then Is_Tag (Entity (Selector_Name (Parent (N)))) 1880 then 1881 return; 1882 end if; 1883 1884 Error_Msg_N 1885 ("invalid dereference of a remote access-to-class-wide value", N); 1886 end if; 1887 end Validate_Remote_Access_To_Class_Wide_Type; 1888 1889 ------------------------------------------ 1890 -- Validate_Remote_Type_Type_Conversion -- 1891 ------------------------------------------ 1892 1893 procedure Validate_Remote_Type_Type_Conversion (N : Node_Id) is 1894 S : constant Entity_Id := Etype (N); 1895 E : constant Entity_Id := Etype (Expression (N)); 1896 1897 begin 1898 -- This test is required in the case where a conversion appears inside a 1899 -- normal package, it does not necessarily have to be inside an RCI, 1900 -- Remote_Types unit (RM E.2.2(9,12)). 1901 1902 if Is_Remote_Access_To_Subprogram_Type (E) 1903 and then not Is_Remote_Access_To_Subprogram_Type (S) 1904 then 1905 Error_Msg_N 1906 ("incorrect conversion of remote operand to local type", N); 1907 return; 1908 1909 elsif not Is_Remote_Access_To_Subprogram_Type (E) 1910 and then Is_Remote_Access_To_Subprogram_Type (S) 1911 then 1912 Error_Msg_N 1913 ("incorrect conversion of local operand to remote type", N); 1914 return; 1915 1916 elsif Is_Remote_Access_To_Class_Wide_Type (E) 1917 and then not Is_Remote_Access_To_Class_Wide_Type (S) 1918 then 1919 Error_Msg_N 1920 ("incorrect conversion of remote operand to local type", N); 1921 return; 1922 end if; 1923 1924 -- If a local access type is converted into a RACW type, then the 1925 -- current unit has a pointer that may now be exported to another 1926 -- partition. 1927 1928 if Is_Remote_Access_To_Class_Wide_Type (S) 1929 and then not Is_Remote_Access_To_Class_Wide_Type (E) 1930 then 1931 Set_Has_RACW (Current_Sem_Unit); 1932 end if; 1933 end Validate_Remote_Type_Type_Conversion; 1934 1935 ------------------------------- 1936 -- Validate_RT_RAT_Component -- 1937 ------------------------------- 1938 1939 procedure Validate_RT_RAT_Component (N : Node_Id) is 1940 Spec : constant Node_Id := Specification (N); 1941 Name_U : constant Entity_Id := Defining_Entity (Spec); 1942 Typ : Entity_Id; 1943 U_Typ : Entity_Id; 1944 First_Priv_Ent : constant Entity_Id := First_Private_Entity (Name_U); 1945 1946 function Stream_Attributes_Available (Typ : Entity_Id) return Boolean; 1947 -- True if any stream attribute is available for Typ 1948 1949 --------------------------------- 1950 -- Stream_Attributes_Available -- 1951 --------------------------------- 1952 1953 function Stream_Attributes_Available (Typ : Entity_Id) return Boolean 1954 is 1955 begin 1956 return Stream_Attribute_Available (Typ, TSS_Stream_Read) 1957 or else 1958 Stream_Attribute_Available (Typ, TSS_Stream_Write) 1959 or else 1960 Stream_Attribute_Available (Typ, TSS_Stream_Input) 1961 or else 1962 Stream_Attribute_Available (Typ, TSS_Stream_Output); 1963 end Stream_Attributes_Available; 1964 1965 -- Start of processing for Validate_RT_RAT_Component 1966 1967 begin 1968 if not Is_Remote_Types (Name_U) then 1969 return; 1970 end if; 1971 1972 Typ := First_Entity (Name_U); 1973 while Present (Typ) and then Typ /= First_Priv_Ent loop 1974 U_Typ := Underlying_Type (Base_Type (Typ)); 1975 1976 if No (U_Typ) then 1977 U_Typ := Typ; 1978 end if; 1979 1980 if Comes_From_Source (Typ) and then Is_Type (Typ) 1981 and then Ekind (Typ) /= E_Incomplete_Type 1982 then 1983 -- Check that the type can be meaningfully transmitted to another 1984 -- partition (E.2.2(8)). 1985 1986 if (Ada_Version < Ada_2005 and then Has_Non_Remote_Access (U_Typ)) 1987 or else (Stream_Attributes_Available (Typ) 1988 and then No_External_Streaming (U_Typ)) 1989 then 1990 if Is_Non_Remote_Access_Type (Typ) then 1991 Error_Msg_N ("error in non-remote access type", U_Typ); 1992 else 1993 Error_Msg_N 1994 ("error in record type containing a component of a " & 1995 "non-remote access type", U_Typ); 1996 end if; 1997 1998 if Ada_Version >= Ada_2005 then 1999 Error_Msg_N 2000 ("\must have visible Read and Write attribute " & 2001 "definition clauses (RM E.2.2(8))", U_Typ); 2002 else 2003 Error_Msg_N 2004 ("\must have Read and Write attribute " & 2005 "definition clauses (RM E.2.2(8))", U_Typ); 2006 end if; 2007 end if; 2008 end if; 2009 2010 Next_Entity (Typ); 2011 end loop; 2012 end Validate_RT_RAT_Component; 2013 2014 ----------------------------------------- 2015 -- Validate_SP_Access_Object_Type_Decl -- 2016 ----------------------------------------- 2017 2018 procedure Validate_SP_Access_Object_Type_Decl (T : Entity_Id) is 2019 Direct_Designated_Type : Entity_Id; 2020 2021 function Has_Entry_Declarations (E : Entity_Id) return Boolean; 2022 -- Return true if the protected type designated by T has entry 2023 -- declarations. 2024 2025 ---------------------------- 2026 -- Has_Entry_Declarations -- 2027 ---------------------------- 2028 2029 function Has_Entry_Declarations (E : Entity_Id) return Boolean is 2030 Ety : Entity_Id; 2031 2032 begin 2033 if Nkind (Parent (E)) = N_Protected_Type_Declaration then 2034 Ety := First_Entity (E); 2035 while Present (Ety) loop 2036 if Ekind (Ety) = E_Entry then 2037 return True; 2038 end if; 2039 2040 Next_Entity (Ety); 2041 end loop; 2042 end if; 2043 2044 return False; 2045 end Has_Entry_Declarations; 2046 2047 -- Start of processing for Validate_SP_Access_Object_Type_Decl 2048 2049 begin 2050 -- We are called from Sem_Ch3.Analyze_Full_Type_Declaration, and the 2051 -- Nkind of the given entity is N_Access_To_Object_Definition. 2052 2053 if not Comes_From_Source (T) 2054 or else not In_Shared_Passive_Unit 2055 or else In_Subprogram_Task_Protected_Unit 2056 then 2057 return; 2058 end if; 2059 2060 -- Check Shared Passive unit. It should not contain the declaration 2061 -- of an access-to-object type whose designated type is a class-wide 2062 -- type, task type or protected type with entry (RM E.2.1(7)). 2063 2064 Direct_Designated_Type := Designated_Type (T); 2065 2066 if Ekind (Direct_Designated_Type) = E_Class_Wide_Type then 2067 Error_Msg_N 2068 ("invalid access-to-class-wide type in shared passive unit", T); 2069 return; 2070 2071 elsif Ekind (Direct_Designated_Type) in Task_Kind then 2072 Error_Msg_N 2073 ("invalid access-to-task type in shared passive unit", T); 2074 return; 2075 2076 elsif Ekind (Direct_Designated_Type) in Protected_Kind 2077 and then Has_Entry_Declarations (Direct_Designated_Type) 2078 then 2079 Error_Msg_N 2080 ("invalid access-to-protected type in shared passive unit", T); 2081 return; 2082 end if; 2083 end Validate_SP_Access_Object_Type_Decl; 2084 2085 --------------------------------- 2086 -- Validate_Static_Object_Name -- 2087 --------------------------------- 2088 2089 procedure Validate_Static_Object_Name (N : Node_Id) is 2090 E : Entity_Id; 2091 Val : Node_Id; 2092 2093 function Is_Primary (N : Node_Id) return Boolean; 2094 -- Determine whether node is syntactically a primary in an expression 2095 -- This function should probably be somewhere else ??? 2096 -- 2097 -- Also it does not do what it says, e.g if N is a binary operator 2098 -- whose parent is a binary operator, Is_Primary returns True ??? 2099 2100 ---------------- 2101 -- Is_Primary -- 2102 ---------------- 2103 2104 function Is_Primary (N : Node_Id) return Boolean is 2105 K : constant Node_Kind := Nkind (Parent (N)); 2106 2107 begin 2108 case K is 2109 when N_Aggregate 2110 | N_Component_Association 2111 | N_Index_Or_Discriminant_Constraint 2112 | N_Membership_Test 2113 | N_Op 2114 => 2115 return True; 2116 2117 when N_Attribute_Reference => 2118 declare 2119 Attr : constant Name_Id := Attribute_Name (Parent (N)); 2120 2121 begin 2122 return Attr /= Name_Address 2123 and then Attr /= Name_Access 2124 and then Attr /= Name_Unchecked_Access 2125 and then Attr /= Name_Unrestricted_Access; 2126 end; 2127 2128 when N_Indexed_Component => 2129 return N /= Prefix (Parent (N)) or else Is_Primary (Parent (N)); 2130 2131 when N_Qualified_Expression 2132 | N_Type_Conversion 2133 => 2134 return Is_Primary (Parent (N)); 2135 2136 when N_Assignment_Statement 2137 | N_Object_Declaration 2138 => 2139 return N = Expression (Parent (N)); 2140 2141 when N_Selected_Component => 2142 return Is_Primary (Parent (N)); 2143 2144 when others => 2145 return False; 2146 end case; 2147 end Is_Primary; 2148 2149 -- Start of processing for Validate_Static_Object_Name 2150 2151 begin 2152 if not In_Preelaborated_Unit 2153 or else not Comes_From_Source (N) 2154 or else In_Subprogram_Or_Concurrent_Unit 2155 or else Ekind (Current_Scope) = E_Block 2156 then 2157 return; 2158 2159 -- Filter out cases where primary is default in a component declaration, 2160 -- discriminant specification, or actual in a record type initialization 2161 -- call. 2162 2163 -- Initialization call of internal types 2164 2165 elsif Nkind (Parent (N)) = N_Procedure_Call_Statement then 2166 2167 if Present (Parent (Parent (N))) 2168 and then Nkind (Parent (Parent (N))) = N_Freeze_Entity 2169 then 2170 return; 2171 end if; 2172 2173 if Nkind (Name (Parent (N))) = N_Identifier 2174 and then not Comes_From_Source (Entity (Name (Parent (N)))) 2175 then 2176 return; 2177 end if; 2178 end if; 2179 2180 -- Error if the name is a primary in an expression. The parent must not 2181 -- be an operator, or a selected component or an indexed component that 2182 -- is itself a primary. Entities that are actuals do not need to be 2183 -- checked, because the call itself will be diagnosed. Entities in a 2184 -- generic unit or within a preanalyzed expression are not checked: 2185 -- only their use in executable code matters. 2186 2187 if Is_Primary (N) 2188 and then (not Inside_A_Generic 2189 or else Present (Enclosing_Generic_Body (N))) 2190 and then not In_Spec_Expression 2191 then 2192 if Ekind (Entity (N)) = E_Variable 2193 or else Ekind (Entity (N)) in Formal_Object_Kind 2194 then 2195 Flag_Non_Static_Expr 2196 ("non-static object name in preelaborated unit", N); 2197 2198 -- Give an error for a reference to a nonstatic constant, unless the 2199 -- constant is in another GNAT library unit that is preelaborable. 2200 2201 elsif Ekind (Entity (N)) = E_Constant 2202 and then not Is_Static_Expression (N) 2203 then 2204 E := Entity (N); 2205 Val := Constant_Value (E); 2206 2207 if In_Internal_Unit (N) 2208 and then 2209 Enclosing_Comp_Unit_Node (N) /= Enclosing_Comp_Unit_Node (E) 2210 and then (Is_Preelaborated (Scope (E)) 2211 or else Is_Pure (Scope (E)) 2212 or else (Present (Renamed_Object (E)) 2213 and then Is_Entity_Name (Renamed_Object (E)) 2214 and then 2215 (Is_Preelaborated 2216 (Scope (Renamed_Object (E))) 2217 or else 2218 Is_Pure 2219 (Scope (Renamed_Object (E)))))) 2220 then 2221 null; 2222 2223 -- If the value of the constant is a local variable that renames 2224 -- an aggregate, this is in itself legal. The aggregate may be 2225 -- expanded into a loop, but this does not affect preelaborability 2226 -- in itself. If some aggregate components are non-static, that is 2227 -- to say if they involve non static primaries, they will be 2228 -- flagged when analyzed. 2229 2230 elsif Present (Val) 2231 and then Is_Entity_Name (Val) 2232 and then Is_Array_Type (Etype (Val)) 2233 and then not Comes_From_Source (Val) 2234 and then Nkind (Original_Node (Val)) = N_Aggregate 2235 then 2236 null; 2237 2238 -- This is the error case 2239 2240 else 2241 -- In GNAT mode or Relaxed RM Semantic mode, this is just a 2242 -- warning, to allow it to be judiciously turned off. 2243 -- Otherwise it is a real error. 2244 2245 if GNAT_Mode or Relaxed_RM_Semantics then 2246 Error_Msg_N 2247 ("??non-static constant in preelaborated unit", N); 2248 else 2249 Flag_Non_Static_Expr 2250 ("non-static constant in preelaborated unit", N); 2251 end if; 2252 end if; 2253 end if; 2254 end if; 2255 end Validate_Static_Object_Name; 2256 2257end Sem_Cat; 2258