1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 6 -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2015, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Aspects; use Aspects; 27with Atree; use Atree; 28with Checks; use Checks; 29with Contracts; use Contracts; 30with Debug; use Debug; 31with Einfo; use Einfo; 32with Elists; use Elists; 33with Errout; use Errout; 34with Expander; use Expander; 35with Exp_Ch6; use Exp_Ch6; 36with Exp_Ch7; use Exp_Ch7; 37with Exp_Ch9; use Exp_Ch9; 38with Exp_Dbug; use Exp_Dbug; 39with Exp_Disp; use Exp_Disp; 40with Exp_Tss; use Exp_Tss; 41with Exp_Util; use Exp_Util; 42with Fname; use Fname; 43with Freeze; use Freeze; 44with Ghost; use Ghost; 45with Inline; use Inline; 46with Itypes; use Itypes; 47with Lib.Xref; use Lib.Xref; 48with Layout; use Layout; 49with Namet; use Namet; 50with Lib; use Lib; 51with Nlists; use Nlists; 52with Nmake; use Nmake; 53with Opt; use Opt; 54with Output; use Output; 55with Restrict; use Restrict; 56with Rident; use Rident; 57with Rtsfind; use Rtsfind; 58with Sem; use Sem; 59with Sem_Aux; use Sem_Aux; 60with Sem_Cat; use Sem_Cat; 61with Sem_Ch3; use Sem_Ch3; 62with Sem_Ch4; use Sem_Ch4; 63with Sem_Ch5; use Sem_Ch5; 64with Sem_Ch8; use Sem_Ch8; 65with Sem_Ch10; use Sem_Ch10; 66with Sem_Ch12; use Sem_Ch12; 67with Sem_Ch13; use Sem_Ch13; 68with Sem_Dim; use Sem_Dim; 69with Sem_Disp; use Sem_Disp; 70with Sem_Dist; use Sem_Dist; 71with Sem_Elim; use Sem_Elim; 72with Sem_Eval; use Sem_Eval; 73with Sem_Mech; use Sem_Mech; 74with Sem_Prag; use Sem_Prag; 75with Sem_Res; use Sem_Res; 76with Sem_Util; use Sem_Util; 77with Sem_Type; use Sem_Type; 78with Sem_Warn; use Sem_Warn; 79with Sinput; use Sinput; 80with Stand; use Stand; 81with Sinfo; use Sinfo; 82with Sinfo.CN; use Sinfo.CN; 83with Snames; use Snames; 84with Stringt; use Stringt; 85with Style; 86with Stylesw; use Stylesw; 87with Tbuild; use Tbuild; 88with Uintp; use Uintp; 89with Urealp; use Urealp; 90with Validsw; use Validsw; 91 92package body Sem_Ch6 is 93 94 May_Hide_Profile : Boolean := False; 95 -- This flag is used to indicate that two formals in two subprograms being 96 -- checked for conformance differ only in that one is an access parameter 97 -- while the other is of a general access type with the same designated 98 -- type. In this case, if the rest of the signatures match, a call to 99 -- either subprogram may be ambiguous, which is worth a warning. The flag 100 -- is set in Compatible_Types, and the warning emitted in 101 -- New_Overloaded_Entity. 102 103 ----------------------- 104 -- Local Subprograms -- 105 ----------------------- 106 107 procedure Analyze_Function_Return (N : Node_Id); 108 -- Subsidiary to Analyze_Return_Statement. Called when the return statement 109 -- applies to a [generic] function. 110 111 procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id); 112 -- Analyze a generic subprogram body. N is the body to be analyzed, and 113 -- Gen_Id is the defining entity Id for the corresponding spec. 114 115 procedure Analyze_Null_Procedure 116 (N : Node_Id; 117 Is_Completion : out Boolean); 118 -- A null procedure can be a declaration or (Ada 2012) a completion 119 120 procedure Analyze_Return_Statement (N : Node_Id); 121 -- Common processing for simple and extended return statements 122 123 procedure Analyze_Return_Type (N : Node_Id); 124 -- Subsidiary to Process_Formals: analyze subtype mark in function 125 -- specification in a context where the formals are visible and hide 126 -- outer homographs. 127 128 procedure Analyze_Subprogram_Body_Helper (N : Node_Id); 129 -- Does all the real work of Analyze_Subprogram_Body. This is split out so 130 -- that we can use RETURN but not skip the debug output at the end. 131 132 function Can_Override_Operator (Subp : Entity_Id) return Boolean; 133 -- Returns true if Subp can override a predefined operator. 134 135 procedure Check_Conformance 136 (New_Id : Entity_Id; 137 Old_Id : Entity_Id; 138 Ctype : Conformance_Type; 139 Errmsg : Boolean; 140 Conforms : out Boolean; 141 Err_Loc : Node_Id := Empty; 142 Get_Inst : Boolean := False; 143 Skip_Controlling_Formals : Boolean := False); 144 -- Given two entities, this procedure checks that the profiles associated 145 -- with these entities meet the conformance criterion given by the third 146 -- parameter. If they conform, Conforms is set True and control returns 147 -- to the caller. If they do not conform, Conforms is set to False, and 148 -- in addition, if Errmsg is True on the call, proper messages are output 149 -- to complain about the conformance failure. If Err_Loc is non_Empty 150 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then 151 -- error messages are placed on the appropriate part of the construct 152 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance 153 -- against a formal access-to-subprogram type so Get_Instance_Of must 154 -- be called. 155 156 procedure Check_Limited_Return 157 (N : Node_Id; 158 Expr : Node_Id; 159 R_Type : Entity_Id); 160 -- Check the appropriate (Ada 95 or Ada 2005) rules for returning limited 161 -- types. Used only for simple return statements. Expr is the expression 162 -- returned. 163 164 procedure Check_Subprogram_Order (N : Node_Id); 165 -- N is the N_Subprogram_Body node for a subprogram. This routine applies 166 -- the alpha ordering rule for N if this ordering requirement applicable. 167 168 procedure Check_Returns 169 (HSS : Node_Id; 170 Mode : Character; 171 Err : out Boolean; 172 Proc : Entity_Id := Empty); 173 -- Called to check for missing return statements in a function body, or for 174 -- returns present in a procedure body which has No_Return set. HSS is the 175 -- handled statement sequence for the subprogram body. This procedure 176 -- checks all flow paths to make sure they either have return (Mode = 'F', 177 -- used for functions) or do not have a return (Mode = 'P', used for 178 -- No_Return procedures). The flag Err is set if there are any control 179 -- paths not explicitly terminated by a return in the function case, and is 180 -- True otherwise. Proc is the entity for the procedure case and is used 181 -- in posting the warning message. 182 183 procedure Check_Untagged_Equality (Eq_Op : Entity_Id); 184 -- In Ada 2012, a primitive equality operator on an untagged record type 185 -- must appear before the type is frozen, and have the same visibility as 186 -- that of the type. This procedure checks that this rule is met, and 187 -- otherwise emits an error on the subprogram declaration and a warning 188 -- on the earlier freeze point if it is easy to locate. In Ada 2012 mode, 189 -- this routine outputs errors (or warnings if -gnatd.E is set). In earlier 190 -- versions of Ada, warnings are output if Warn_On_Ada_2012_Incompatibility 191 -- is set, otherwise the call has no effect. 192 193 procedure Enter_Overloaded_Entity (S : Entity_Id); 194 -- This procedure makes S, a new overloaded entity, into the first visible 195 -- entity with that name. 196 197 function Is_Non_Overriding_Operation 198 (Prev_E : Entity_Id; 199 New_E : Entity_Id) return Boolean; 200 -- Enforce the rule given in 12.3(18): a private operation in an instance 201 -- overrides an inherited operation only if the corresponding operation 202 -- was overriding in the generic. This needs to be checked for primitive 203 -- operations of types derived (in the generic unit) from formal private 204 -- or formal derived types. 205 206 procedure Make_Inequality_Operator (S : Entity_Id); 207 -- Create the declaration for an inequality operator that is implicitly 208 -- created by a user-defined equality operator that yields a boolean. 209 210 procedure Set_Formal_Validity (Formal_Id : Entity_Id); 211 -- Formal_Id is an formal parameter entity. This procedure deals with 212 -- setting the proper validity status for this entity, which depends on 213 -- the kind of parameter and the validity checking mode. 214 215 --------------------------------------------- 216 -- Analyze_Abstract_Subprogram_Declaration -- 217 --------------------------------------------- 218 219 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is 220 Scop : constant Entity_Id := Current_Scope; 221 Subp_Id : constant Entity_Id := 222 Analyze_Subprogram_Specification (Specification (N)); 223 224 begin 225 Check_SPARK_05_Restriction ("abstract subprogram is not allowed", N); 226 227 Generate_Definition (Subp_Id); 228 229 Set_Is_Abstract_Subprogram (Subp_Id); 230 New_Overloaded_Entity (Subp_Id); 231 Check_Delayed_Subprogram (Subp_Id); 232 233 Set_Categorization_From_Scope (Subp_Id, Scop); 234 235 -- An abstract subprogram declared within a Ghost region is rendered 236 -- Ghost (SPARK RM 6.9(2)). 237 238 if Ghost_Mode > None then 239 Set_Is_Ghost_Entity (Subp_Id); 240 end if; 241 242 if Ekind (Scope (Subp_Id)) = E_Protected_Type then 243 Error_Msg_N ("abstract subprogram not allowed in protected type", N); 244 245 -- Issue a warning if the abstract subprogram is neither a dispatching 246 -- operation nor an operation that overrides an inherited subprogram or 247 -- predefined operator, since this most likely indicates a mistake. 248 249 elsif Warn_On_Redundant_Constructs 250 and then not Is_Dispatching_Operation (Subp_Id) 251 and then not Present (Overridden_Operation (Subp_Id)) 252 and then (not Is_Operator_Symbol_Name (Chars (Subp_Id)) 253 or else Scop /= Scope (Etype (First_Formal (Subp_Id)))) 254 then 255 Error_Msg_N 256 ("abstract subprogram is not dispatching or overriding?r?", N); 257 end if; 258 259 Generate_Reference_To_Formals (Subp_Id); 260 Check_Eliminated (Subp_Id); 261 262 if Has_Aspects (N) then 263 Analyze_Aspect_Specifications (N, Subp_Id); 264 end if; 265 end Analyze_Abstract_Subprogram_Declaration; 266 267 --------------------------------- 268 -- Analyze_Expression_Function -- 269 --------------------------------- 270 271 procedure Analyze_Expression_Function (N : Node_Id) is 272 Expr : constant Node_Id := Expression (N); 273 Loc : constant Source_Ptr := Sloc (N); 274 LocX : constant Source_Ptr := Sloc (Expr); 275 Spec : constant Node_Id := Specification (N); 276 277 Def_Id : Entity_Id; 278 279 Prev : Entity_Id; 280 -- If the expression is a completion, Prev is the entity whose 281 -- declaration is completed. Def_Id is needed to analyze the spec. 282 283 New_Body : Node_Id; 284 New_Spec : Node_Id; 285 Ret : Node_Id; 286 Asp : Node_Id; 287 288 begin 289 -- This is one of the occasions on which we transform the tree during 290 -- semantic analysis. If this is a completion, transform the expression 291 -- function into an equivalent subprogram body, and analyze it. 292 293 -- Expression functions are inlined unconditionally. The back-end will 294 -- determine whether this is possible. 295 296 Inline_Processing_Required := True; 297 298 -- Create a specification for the generated body. This must be done 299 -- prior to the analysis of the initial declaration. 300 301 New_Spec := Copy_Subprogram_Spec (Spec); 302 Prev := Current_Entity_In_Scope (Defining_Entity (Spec)); 303 304 -- If there are previous overloadable entities with the same name, 305 -- check whether any of them is completed by the expression function. 306 -- In a generic context a formal subprogram has no completion. 307 308 if Present (Prev) 309 and then Is_Overloadable (Prev) 310 and then not Is_Formal_Subprogram (Prev) 311 then 312 Def_Id := Analyze_Subprogram_Specification (Spec); 313 Prev := Find_Corresponding_Spec (N); 314 315 -- The previous entity may be an expression function as well, in 316 -- which case the redeclaration is illegal. 317 318 if Present (Prev) 319 and then Nkind (Original_Node (Unit_Declaration_Node (Prev))) = 320 N_Expression_Function 321 then 322 Error_Msg_Sloc := Sloc (Prev); 323 Error_Msg_N ("& conflicts with declaration#", Def_Id); 324 return; 325 end if; 326 end if; 327 328 Ret := Make_Simple_Return_Statement (LocX, Expression (N)); 329 330 New_Body := 331 Make_Subprogram_Body (Loc, 332 Specification => New_Spec, 333 Declarations => Empty_List, 334 Handled_Statement_Sequence => 335 Make_Handled_Sequence_Of_Statements (LocX, 336 Statements => New_List (Ret))); 337 Set_Was_Expression_Function (New_Body); 338 339 -- If the expression completes a generic subprogram, we must create a 340 -- separate node for the body, because at instantiation the original 341 -- node of the generic copy must be a generic subprogram body, and 342 -- cannot be a expression function. Otherwise we just rewrite the 343 -- expression with the non-generic body. 344 345 if Present (Prev) and then Ekind (Prev) = E_Generic_Function then 346 Insert_After (N, New_Body); 347 348 -- Propagate any aspects or pragmas that apply to the expression 349 -- function to the proper body when the expression function acts 350 -- as a completion. 351 352 if Has_Aspects (N) then 353 Move_Aspects (N, To => New_Body); 354 end if; 355 356 Relocate_Pragmas_To_Body (New_Body); 357 358 Rewrite (N, Make_Null_Statement (Loc)); 359 Set_Has_Completion (Prev, False); 360 Analyze (N); 361 Analyze (New_Body); 362 Set_Is_Inlined (Prev); 363 364 -- If the expression function is a completion, the previous declaration 365 -- must come from source. We know already that appears in the current 366 -- scope. The entity itself may be internally created if within a body 367 -- to be inlined. 368 369 elsif Present (Prev) 370 and then Comes_From_Source (Parent (Prev)) 371 and then not Is_Formal_Subprogram (Prev) 372 then 373 Set_Has_Completion (Prev, False); 374 375 -- An expression function that is a completion freezes the 376 -- expression. This means freezing the return type, and if it is 377 -- an access type, freezing its designated type as well. 378 379 -- Note that we cannot defer this freezing to the analysis of the 380 -- expression itself, because a freeze node might appear in a nested 381 -- scope, leading to an elaboration order issue in gigi. 382 383 Freeze_Before (N, Etype (Prev)); 384 385 if Is_Access_Type (Etype (Prev)) then 386 Freeze_Before (N, Designated_Type (Etype (Prev))); 387 end if; 388 389 -- For navigation purposes, indicate that the function is a body 390 391 Generate_Reference (Prev, Defining_Entity (N), 'b', Force => True); 392 Rewrite (N, New_Body); 393 394 -- Correct the parent pointer of the aspect specification list to 395 -- reference the rewritten node. 396 397 if Has_Aspects (N) then 398 Set_Parent (Aspect_Specifications (N), N); 399 end if; 400 401 -- Propagate any pragmas that apply to the expression function to the 402 -- proper body when the expression function acts as a completion. 403 -- Aspects are automatically transfered because of node rewriting. 404 405 Relocate_Pragmas_To_Body (N); 406 Analyze (N); 407 408 -- Prev is the previous entity with the same name, but it is can 409 -- be an unrelated spec that is not completed by the expression 410 -- function. In that case the relevant entity is the one in the body. 411 -- Not clear that the backend can inline it in this case ??? 412 413 if Has_Completion (Prev) then 414 Set_Is_Inlined (Prev); 415 416 -- The formals of the expression function are body formals, 417 -- and do not appear in the ali file, which will only contain 418 -- references to the formals of the original subprogram spec. 419 420 declare 421 F1 : Entity_Id; 422 F2 : Entity_Id; 423 424 begin 425 F1 := First_Formal (Def_Id); 426 F2 := First_Formal (Prev); 427 428 while Present (F1) loop 429 Set_Spec_Entity (F1, F2); 430 Next_Formal (F1); 431 Next_Formal (F2); 432 end loop; 433 end; 434 435 else 436 Set_Is_Inlined (Defining_Entity (New_Body)); 437 end if; 438 439 -- If this is not a completion, create both a declaration and a body, so 440 -- that the expression can be inlined whenever possible. 441 442 else 443 -- An expression function that is not a completion is not a 444 -- subprogram declaration, and thus cannot appear in a protected 445 -- definition. 446 447 if Nkind (Parent (N)) = N_Protected_Definition then 448 Error_Msg_N 449 ("an expression function is not a legal protected operation", N); 450 end if; 451 452 Rewrite (N, Make_Subprogram_Declaration (Loc, Specification => Spec)); 453 454 -- Correct the parent pointer of the aspect specification list to 455 -- reference the rewritten node. 456 457 if Has_Aspects (N) then 458 Set_Parent (Aspect_Specifications (N), N); 459 end if; 460 461 Analyze (N); 462 Def_Id := Defining_Entity (N); 463 464 -- If aspect SPARK_Mode was specified on the body, it needs to be 465 -- repeated both on the generated spec and the body. 466 467 Asp := Find_Aspect (Defining_Unit_Name (Spec), Aspect_SPARK_Mode); 468 469 if Present (Asp) then 470 Asp := New_Copy_Tree (Asp); 471 Set_Analyzed (Asp, False); 472 Set_Aspect_Specifications (New_Body, New_List (Asp)); 473 end if; 474 475 -- Within a generic pre-analyze the original expression for name 476 -- capture. The body is also generated but plays no role in 477 -- this because it is not part of the original source. 478 479 if Inside_A_Generic then 480 Set_Has_Completion (Def_Id); 481 Push_Scope (Def_Id); 482 Install_Formals (Def_Id); 483 Preanalyze_Spec_Expression (Expr, Etype (Def_Id)); 484 End_Scope; 485 end if; 486 487 Set_Is_Inlined (Defining_Entity (N)); 488 489 -- Establish the linkages between the spec and the body. These are 490 -- used when the expression function acts as the prefix of attribute 491 -- 'Access in order to freeze the original expression which has been 492 -- moved to the generated body. 493 494 Set_Corresponding_Body (N, Defining_Entity (New_Body)); 495 Set_Corresponding_Spec (New_Body, Defining_Entity (N)); 496 497 -- To prevent premature freeze action, insert the new body at the end 498 -- of the current declarations, or at the end of the package spec. 499 -- However, resolve usage names now, to prevent spurious visibility 500 -- on later entities. Note that the function can now be called in 501 -- the current declarative part, which will appear to be prior to 502 -- the presence of the body in the code. There are nevertheless no 503 -- order of elaboration issues because all name resolution has taken 504 -- place at the point of declaration. 505 506 declare 507 Decls : List_Id := List_Containing (N); 508 Expr : constant Node_Id := Expression (Ret); 509 Par : constant Node_Id := Parent (Decls); 510 Typ : constant Entity_Id := Etype (Def_Id); 511 512 begin 513 -- If this is a wrapper created for in an instance for a formal 514 -- subprogram, insert body after declaration, to be analyzed when 515 -- the enclosing instance is analyzed. 516 517 if GNATprove_Mode 518 and then Is_Generic_Actual_Subprogram (Defining_Entity (N)) 519 then 520 Insert_After (N, New_Body); 521 522 else 523 if Nkind (Par) = N_Package_Specification 524 and then Decls = Visible_Declarations (Par) 525 and then Present (Private_Declarations (Par)) 526 and then not Is_Empty_List (Private_Declarations (Par)) 527 then 528 Decls := Private_Declarations (Par); 529 end if; 530 531 Insert_After (Last (Decls), New_Body); 532 533 -- Preanalyze the expression for name capture, except in an 534 -- instance, where this has been done during generic analysis, 535 -- and will be redone when analyzing the body. 536 537 Set_Parent (Expr, Ret); 538 Push_Scope (Def_Id); 539 Install_Formals (Def_Id); 540 541 if not In_Instance then 542 Preanalyze_Spec_Expression (Expr, Typ); 543 Check_Limited_Return (Original_Node (N), Expr, Typ); 544 end if; 545 546 End_Scope; 547 end if; 548 end; 549 end if; 550 551 -- If the return expression is a static constant, we suppress warning 552 -- messages on unused formals, which in most cases will be noise. 553 554 Set_Is_Trivial_Subprogram 555 (Defining_Entity (New_Body), Is_OK_Static_Expression (Expr)); 556 end Analyze_Expression_Function; 557 558 ---------------------------------------- 559 -- Analyze_Extended_Return_Statement -- 560 ---------------------------------------- 561 562 procedure Analyze_Extended_Return_Statement (N : Node_Id) is 563 begin 564 Check_Compiler_Unit ("extended return statement", N); 565 Analyze_Return_Statement (N); 566 end Analyze_Extended_Return_Statement; 567 568 ---------------------------- 569 -- Analyze_Function_Call -- 570 ---------------------------- 571 572 procedure Analyze_Function_Call (N : Node_Id) is 573 Actuals : constant List_Id := Parameter_Associations (N); 574 Func_Nam : constant Node_Id := Name (N); 575 Actual : Node_Id; 576 577 begin 578 Analyze (Func_Nam); 579 580 -- A call of the form A.B (X) may be an Ada 2005 call, which is 581 -- rewritten as B (A, X). If the rewriting is successful, the call 582 -- has been analyzed and we just return. 583 584 if Nkind (Func_Nam) = N_Selected_Component 585 and then Name (N) /= Func_Nam 586 and then Is_Rewrite_Substitution (N) 587 and then Present (Etype (N)) 588 then 589 return; 590 end if; 591 592 -- If error analyzing name, then set Any_Type as result type and return 593 594 if Etype (Func_Nam) = Any_Type then 595 Set_Etype (N, Any_Type); 596 return; 597 end if; 598 599 -- Otherwise analyze the parameters 600 601 if Present (Actuals) then 602 Actual := First (Actuals); 603 while Present (Actual) loop 604 Analyze (Actual); 605 Check_Parameterless_Call (Actual); 606 Next (Actual); 607 end loop; 608 end if; 609 610 Analyze_Call (N); 611 end Analyze_Function_Call; 612 613 ----------------------------- 614 -- Analyze_Function_Return -- 615 ----------------------------- 616 617 procedure Analyze_Function_Return (N : Node_Id) is 618 Loc : constant Source_Ptr := Sloc (N); 619 Stm_Entity : constant Entity_Id := Return_Statement_Entity (N); 620 Scope_Id : constant Entity_Id := Return_Applies_To (Stm_Entity); 621 622 R_Type : constant Entity_Id := Etype (Scope_Id); 623 -- Function result subtype 624 625 procedure Check_Aggregate_Accessibility (Aggr : Node_Id); 626 -- Apply legality rule of 6.5 (8.2) to the access discriminants of an 627 -- aggregate in a return statement. 628 629 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id); 630 -- Check that the return_subtype_indication properly matches the result 631 -- subtype of the function, as required by RM-6.5(5.1/2-5.3/2). 632 633 ----------------------------------- 634 -- Check_Aggregate_Accessibility -- 635 ----------------------------------- 636 637 procedure Check_Aggregate_Accessibility (Aggr : Node_Id) is 638 Typ : constant Entity_Id := Etype (Aggr); 639 Assoc : Node_Id; 640 Discr : Entity_Id; 641 Expr : Node_Id; 642 Obj : Node_Id; 643 644 begin 645 if Is_Record_Type (Typ) and then Has_Discriminants (Typ) then 646 Discr := First_Discriminant (Typ); 647 Assoc := First (Component_Associations (Aggr)); 648 while Present (Discr) loop 649 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then 650 Expr := Expression (Assoc); 651 if Nkind (Expr) = N_Attribute_Reference 652 and then Attribute_Name (Expr) /= Name_Unrestricted_Access 653 then 654 Obj := Prefix (Expr); 655 while Nkind_In (Obj, N_Indexed_Component, 656 N_Selected_Component) 657 loop 658 Obj := Prefix (Obj); 659 end loop; 660 661 -- No check needed for an aliased formal. 662 -- A run-time check may still be needed ??? 663 664 if Is_Entity_Name (Obj) 665 and then Is_Formal (Entity (Obj)) 666 and then Is_Aliased (Entity (Obj)) 667 then 668 null; 669 670 elsif Object_Access_Level (Obj) > 671 Scope_Depth (Scope (Scope_Id)) 672 then 673 Error_Msg_N 674 ("access discriminant in return aggregate would be " 675 & "a dangling reference", Obj); 676 end if; 677 end if; 678 end if; 679 680 Next_Discriminant (Discr); 681 end loop; 682 end if; 683 end Check_Aggregate_Accessibility; 684 685 ------------------------------------- 686 -- Check_Return_Subtype_Indication -- 687 ------------------------------------- 688 689 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is 690 Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl); 691 692 R_Stm_Type : constant Entity_Id := Etype (Return_Obj); 693 -- Subtype given in the extended return statement (must match R_Type) 694 695 Subtype_Ind : constant Node_Id := 696 Object_Definition (Original_Node (Obj_Decl)); 697 698 R_Type_Is_Anon_Access : constant Boolean := 699 Ekind_In (R_Type, 700 E_Anonymous_Access_Subprogram_Type, 701 E_Anonymous_Access_Protected_Subprogram_Type, 702 E_Anonymous_Access_Type); 703 -- True if return type of the function is an anonymous access type 704 -- Can't we make Is_Anonymous_Access_Type in einfo ??? 705 706 R_Stm_Type_Is_Anon_Access : constant Boolean := 707 Ekind_In (R_Stm_Type, 708 E_Anonymous_Access_Subprogram_Type, 709 E_Anonymous_Access_Protected_Subprogram_Type, 710 E_Anonymous_Access_Type); 711 -- True if type of the return object is an anonymous access type 712 713 procedure Error_No_Match (N : Node_Id); 714 -- Output error messages for case where types do not statically 715 -- match. N is the location for the messages. 716 717 -------------------- 718 -- Error_No_Match -- 719 -------------------- 720 721 procedure Error_No_Match (N : Node_Id) is 722 begin 723 Error_Msg_N 724 ("subtype must statically match function result subtype", N); 725 726 if not Predicates_Match (R_Stm_Type, R_Type) then 727 Error_Msg_Node_2 := R_Type; 728 Error_Msg_NE 729 ("\predicate of& does not match predicate of&", 730 N, R_Stm_Type); 731 end if; 732 end Error_No_Match; 733 734 -- Start of processing for Check_Return_Subtype_Indication 735 736 begin 737 -- First, avoid cascaded errors 738 739 if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then 740 return; 741 end if; 742 743 -- "return access T" case; check that the return statement also has 744 -- "access T", and that the subtypes statically match: 745 -- if this is an access to subprogram the signatures must match. 746 747 if R_Type_Is_Anon_Access then 748 if R_Stm_Type_Is_Anon_Access then 749 if 750 Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type 751 then 752 if Base_Type (Designated_Type (R_Stm_Type)) /= 753 Base_Type (Designated_Type (R_Type)) 754 or else not Subtypes_Statically_Match (R_Stm_Type, R_Type) 755 then 756 Error_No_Match (Subtype_Mark (Subtype_Ind)); 757 end if; 758 759 else 760 -- For two anonymous access to subprogram types, the 761 -- types themselves must be type conformant. 762 763 if not Conforming_Types 764 (R_Stm_Type, R_Type, Fully_Conformant) 765 then 766 Error_No_Match (Subtype_Ind); 767 end if; 768 end if; 769 770 else 771 Error_Msg_N ("must use anonymous access type", Subtype_Ind); 772 end if; 773 774 -- If the return object is of an anonymous access type, then report 775 -- an error if the function's result type is not also anonymous. 776 777 elsif R_Stm_Type_Is_Anon_Access 778 and then not R_Type_Is_Anon_Access 779 then 780 Error_Msg_N ("anonymous access not allowed for function with " 781 & "named access result", Subtype_Ind); 782 783 -- Subtype indication case: check that the return object's type is 784 -- covered by the result type, and that the subtypes statically match 785 -- when the result subtype is constrained. Also handle record types 786 -- with unknown discriminants for which we have built the underlying 787 -- record view. Coverage is needed to allow specific-type return 788 -- objects when the result type is class-wide (see AI05-32). 789 790 elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type)) 791 or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type)) 792 and then 793 Covers 794 (Base_Type (R_Type), 795 Underlying_Record_View (Base_Type (R_Stm_Type)))) 796 then 797 -- A null exclusion may be present on the return type, on the 798 -- function specification, on the object declaration or on the 799 -- subtype itself. 800 801 if Is_Access_Type (R_Type) 802 and then 803 (Can_Never_Be_Null (R_Type) 804 or else Null_Exclusion_Present (Parent (Scope_Id))) /= 805 Can_Never_Be_Null (R_Stm_Type) 806 then 807 Error_No_Match (Subtype_Ind); 808 end if; 809 810 -- AI05-103: for elementary types, subtypes must statically match 811 812 if Is_Constrained (R_Type) 813 or else Is_Access_Type (R_Type) 814 then 815 if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then 816 Error_No_Match (Subtype_Ind); 817 end if; 818 end if; 819 820 -- All remaining cases are illegal 821 822 -- Note: previous versions of this subprogram allowed the return 823 -- value to be the ancestor of the return type if the return type 824 -- was a null extension. This was plainly incorrect. 825 826 else 827 Error_Msg_N 828 ("wrong type for return_subtype_indication", Subtype_Ind); 829 end if; 830 end Check_Return_Subtype_Indication; 831 832 --------------------- 833 -- Local Variables -- 834 --------------------- 835 836 Expr : Node_Id; 837 Obj_Decl : Node_Id; 838 839 -- Start of processing for Analyze_Function_Return 840 841 begin 842 Set_Return_Present (Scope_Id); 843 844 if Nkind (N) = N_Simple_Return_Statement then 845 Expr := Expression (N); 846 847 -- Guard against a malformed expression. The parser may have tried to 848 -- recover but the node is not analyzable. 849 850 if Nkind (Expr) = N_Error then 851 Set_Etype (Expr, Any_Type); 852 Expander_Mode_Save_And_Set (False); 853 return; 854 855 else 856 -- The resolution of a controlled [extension] aggregate associated 857 -- with a return statement creates a temporary which needs to be 858 -- finalized on function exit. Wrap the return statement inside a 859 -- block so that the finalization machinery can detect this case. 860 -- This early expansion is done only when the return statement is 861 -- not part of a handled sequence of statements. 862 863 if Nkind_In (Expr, N_Aggregate, 864 N_Extension_Aggregate) 865 and then Needs_Finalization (R_Type) 866 and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements 867 then 868 Rewrite (N, 869 Make_Block_Statement (Loc, 870 Handled_Statement_Sequence => 871 Make_Handled_Sequence_Of_Statements (Loc, 872 Statements => New_List (Relocate_Node (N))))); 873 874 Analyze (N); 875 return; 876 end if; 877 878 Analyze (Expr); 879 880 -- Ada 2005 (AI-251): If the type of the returned object is 881 -- an access to an interface type then we add an implicit type 882 -- conversion to force the displacement of the "this" pointer to 883 -- reference the secondary dispatch table. We cannot delay the 884 -- generation of this implicit conversion until the expansion 885 -- because in this case the type resolution changes the decoration 886 -- of the expression node to match R_Type; by contrast, if the 887 -- returned object is a class-wide interface type then it is too 888 -- early to generate here the implicit conversion since the return 889 -- statement may be rewritten by the expander into an extended 890 -- return statement whose expansion takes care of adding the 891 -- implicit type conversion to displace the pointer to the object. 892 893 if Expander_Active 894 and then Serious_Errors_Detected = 0 895 and then Is_Access_Type (R_Type) 896 and then Nkind (Expr) /= N_Null 897 and then Is_Interface (Designated_Type (R_Type)) 898 and then Is_Progenitor (Designated_Type (R_Type), 899 Designated_Type (Etype (Expr))) 900 then 901 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); 902 Analyze (Expr); 903 end if; 904 905 Resolve (Expr, R_Type); 906 Check_Limited_Return (N, Expr, R_Type); 907 908 if Present (Expr) and then Nkind (Expr) = N_Aggregate then 909 Check_Aggregate_Accessibility (Expr); 910 end if; 911 end if; 912 913 -- RETURN only allowed in SPARK as the last statement in function 914 915 if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements 916 and then 917 (Nkind (Parent (Parent (N))) /= N_Subprogram_Body 918 or else Present (Next (N))) 919 then 920 Check_SPARK_05_Restriction 921 ("RETURN should be the last statement in function", N); 922 end if; 923 924 else 925 Check_SPARK_05_Restriction ("extended RETURN is not allowed", N); 926 Obj_Decl := Last (Return_Object_Declarations (N)); 927 928 -- Analyze parts specific to extended_return_statement: 929 930 declare 931 Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl); 932 HSS : constant Node_Id := Handled_Statement_Sequence (N); 933 934 begin 935 Expr := Expression (Obj_Decl); 936 937 -- Note: The check for OK_For_Limited_Init will happen in 938 -- Analyze_Object_Declaration; we treat it as a normal 939 -- object declaration. 940 941 Set_Is_Return_Object (Defining_Identifier (Obj_Decl)); 942 Analyze (Obj_Decl); 943 944 Check_Return_Subtype_Indication (Obj_Decl); 945 946 if Present (HSS) then 947 Analyze (HSS); 948 949 if Present (Exception_Handlers (HSS)) then 950 951 -- ???Has_Nested_Block_With_Handler needs to be set. 952 -- Probably by creating an actual N_Block_Statement. 953 -- Probably in Expand. 954 955 null; 956 end if; 957 end if; 958 959 -- Mark the return object as referenced, since the return is an 960 -- implicit reference of the object. 961 962 Set_Referenced (Defining_Identifier (Obj_Decl)); 963 964 Check_References (Stm_Entity); 965 966 -- Check RM 6.5 (5.9/3) 967 968 if Has_Aliased then 969 if Ada_Version < Ada_2012 then 970 971 -- Shouldn't this test Warn_On_Ada_2012_Compatibility ??? 972 -- Can it really happen (extended return???) 973 974 Error_Msg_N 975 ("aliased only allowed for limited return objects " 976 & "in Ada 2012??", N); 977 978 elsif not Is_Limited_View (R_Type) then 979 Error_Msg_N 980 ("aliased only allowed for limited return objects", N); 981 end if; 982 end if; 983 end; 984 end if; 985 986 -- Case of Expr present 987 988 if Present (Expr) 989 990 -- Defend against previous errors 991 992 and then Nkind (Expr) /= N_Empty 993 and then Present (Etype (Expr)) 994 then 995 -- Apply constraint check. Note that this is done before the implicit 996 -- conversion of the expression done for anonymous access types to 997 -- ensure correct generation of the null-excluding check associated 998 -- with null-excluding expressions found in return statements. 999 1000 Apply_Constraint_Check (Expr, R_Type); 1001 1002 -- Ada 2005 (AI-318-02): When the result type is an anonymous access 1003 -- type, apply an implicit conversion of the expression to that type 1004 -- to force appropriate static and run-time accessibility checks. 1005 1006 if Ada_Version >= Ada_2005 1007 and then Ekind (R_Type) = E_Anonymous_Access_Type 1008 then 1009 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); 1010 Analyze_And_Resolve (Expr, R_Type); 1011 1012 -- If this is a local anonymous access to subprogram, the 1013 -- accessibility check can be applied statically. The return is 1014 -- illegal if the access type of the return expression is declared 1015 -- inside of the subprogram (except if it is the subtype indication 1016 -- of an extended return statement). 1017 1018 elsif Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type then 1019 if not Comes_From_Source (Current_Scope) 1020 or else Ekind (Current_Scope) = E_Return_Statement 1021 then 1022 null; 1023 1024 elsif 1025 Scope_Depth (Scope (Etype (Expr))) >= Scope_Depth (Scope_Id) 1026 then 1027 Error_Msg_N ("cannot return local access to subprogram", N); 1028 end if; 1029 1030 -- The expression cannot be of a formal incomplete type 1031 1032 elsif Ekind (Etype (Expr)) = E_Incomplete_Type 1033 and then Is_Generic_Type (Etype (Expr)) 1034 then 1035 Error_Msg_N 1036 ("cannot return expression of a formal incomplete type", N); 1037 end if; 1038 1039 -- If the result type is class-wide, then check that the return 1040 -- expression's type is not declared at a deeper level than the 1041 -- function (RM05-6.5(5.6/2)). 1042 1043 if Ada_Version >= Ada_2005 1044 and then Is_Class_Wide_Type (R_Type) 1045 then 1046 if Type_Access_Level (Etype (Expr)) > 1047 Subprogram_Access_Level (Scope_Id) 1048 then 1049 Error_Msg_N 1050 ("level of return expression type is deeper than " 1051 & "class-wide function!", Expr); 1052 end if; 1053 end if; 1054 1055 -- Check incorrect use of dynamically tagged expression 1056 1057 if Is_Tagged_Type (R_Type) then 1058 Check_Dynamically_Tagged_Expression 1059 (Expr => Expr, 1060 Typ => R_Type, 1061 Related_Nod => N); 1062 end if; 1063 1064 -- ??? A real run-time accessibility check is needed in cases 1065 -- involving dereferences of access parameters. For now we just 1066 -- check the static cases. 1067 1068 if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L) 1069 and then Is_Limited_View (Etype (Scope_Id)) 1070 and then Object_Access_Level (Expr) > 1071 Subprogram_Access_Level (Scope_Id) 1072 then 1073 -- Suppress the message in a generic, where the rewriting 1074 -- is irrelevant. 1075 1076 if Inside_A_Generic then 1077 null; 1078 1079 else 1080 Rewrite (N, 1081 Make_Raise_Program_Error (Loc, 1082 Reason => PE_Accessibility_Check_Failed)); 1083 Analyze (N); 1084 1085 Error_Msg_Warn := SPARK_Mode /= On; 1086 Error_Msg_N ("cannot return a local value by reference<<", N); 1087 Error_Msg_NE ("\& [<<", N, Standard_Program_Error); 1088 end if; 1089 end if; 1090 1091 if Known_Null (Expr) 1092 and then Nkind (Parent (Scope_Id)) = N_Function_Specification 1093 and then Null_Exclusion_Present (Parent (Scope_Id)) 1094 then 1095 Apply_Compile_Time_Constraint_Error 1096 (N => Expr, 1097 Msg => "(Ada 2005) null not allowed for " 1098 & "null-excluding return??", 1099 Reason => CE_Null_Not_Allowed); 1100 end if; 1101 1102 -- RM 6.5 (5.4/3): accessibility checks also apply if the return object 1103 -- has no initializing expression. 1104 1105 elsif Ada_Version > Ada_2005 and then Is_Class_Wide_Type (R_Type) then 1106 if Type_Access_Level (Etype (Defining_Identifier (Obj_Decl))) > 1107 Subprogram_Access_Level (Scope_Id) 1108 then 1109 Error_Msg_N 1110 ("level of return expression type is deeper than " 1111 & "class-wide function!", Obj_Decl); 1112 end if; 1113 end if; 1114 end Analyze_Function_Return; 1115 1116 ------------------------------------- 1117 -- Analyze_Generic_Subprogram_Body -- 1118 ------------------------------------- 1119 1120 procedure Analyze_Generic_Subprogram_Body 1121 (N : Node_Id; 1122 Gen_Id : Entity_Id) 1123 is 1124 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id); 1125 Kind : constant Entity_Kind := Ekind (Gen_Id); 1126 Body_Id : Entity_Id; 1127 New_N : Node_Id; 1128 Spec : Node_Id; 1129 1130 begin 1131 -- Copy body and disable expansion while analyzing the generic For a 1132 -- stub, do not copy the stub (which would load the proper body), this 1133 -- will be done when the proper body is analyzed. 1134 1135 if Nkind (N) /= N_Subprogram_Body_Stub then 1136 New_N := Copy_Generic_Node (N, Empty, Instantiating => False); 1137 Rewrite (N, New_N); 1138 1139 -- Once the contents of the generic copy and the template are 1140 -- swapped, do the same for their respective aspect specifications. 1141 1142 Exchange_Aspects (N, New_N); 1143 1144 -- Collect all contract-related source pragmas found within the 1145 -- template and attach them to the contract of the subprogram body. 1146 -- This contract is used in the capture of global references within 1147 -- annotations. 1148 1149 Create_Generic_Contract (N); 1150 1151 Start_Generic; 1152 end if; 1153 1154 Spec := Specification (N); 1155 1156 -- Within the body of the generic, the subprogram is callable, and 1157 -- behaves like the corresponding non-generic unit. 1158 1159 Body_Id := Defining_Entity (Spec); 1160 1161 if Kind = E_Generic_Procedure 1162 and then Nkind (Spec) /= N_Procedure_Specification 1163 then 1164 Error_Msg_N ("invalid body for generic procedure ", Body_Id); 1165 return; 1166 1167 elsif Kind = E_Generic_Function 1168 and then Nkind (Spec) /= N_Function_Specification 1169 then 1170 Error_Msg_N ("invalid body for generic function ", Body_Id); 1171 return; 1172 end if; 1173 1174 Set_Corresponding_Body (Gen_Decl, Body_Id); 1175 1176 if Has_Completion (Gen_Id) 1177 and then Nkind (Parent (N)) /= N_Subunit 1178 then 1179 Error_Msg_N ("duplicate generic body", N); 1180 return; 1181 else 1182 Set_Has_Completion (Gen_Id); 1183 end if; 1184 1185 if Nkind (N) = N_Subprogram_Body_Stub then 1186 Set_Ekind (Defining_Entity (Specification (N)), Kind); 1187 else 1188 Set_Corresponding_Spec (N, Gen_Id); 1189 end if; 1190 1191 if Nkind (Parent (N)) = N_Compilation_Unit then 1192 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N)); 1193 end if; 1194 1195 -- Make generic parameters immediately visible in the body. They are 1196 -- needed to process the formals declarations. Then make the formals 1197 -- visible in a separate step. 1198 1199 Push_Scope (Gen_Id); 1200 1201 declare 1202 E : Entity_Id; 1203 First_Ent : Entity_Id; 1204 1205 begin 1206 First_Ent := First_Entity (Gen_Id); 1207 1208 E := First_Ent; 1209 while Present (E) and then not Is_Formal (E) loop 1210 Install_Entity (E); 1211 Next_Entity (E); 1212 end loop; 1213 1214 Set_Use (Generic_Formal_Declarations (Gen_Decl)); 1215 1216 -- Now generic formals are visible, and the specification can be 1217 -- analyzed, for subsequent conformance check. 1218 1219 Body_Id := Analyze_Subprogram_Specification (Spec); 1220 1221 -- Make formal parameters visible 1222 1223 if Present (E) then 1224 1225 -- E is the first formal parameter, we loop through the formals 1226 -- installing them so that they will be visible. 1227 1228 Set_First_Entity (Gen_Id, E); 1229 while Present (E) loop 1230 Install_Entity (E); 1231 Next_Formal (E); 1232 end loop; 1233 end if; 1234 1235 -- Visible generic entity is callable within its own body 1236 1237 Set_Ekind (Gen_Id, Ekind (Body_Id)); 1238 Set_Ekind (Body_Id, E_Subprogram_Body); 1239 Set_Convention (Body_Id, Convention (Gen_Id)); 1240 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id)); 1241 Set_Scope (Body_Id, Scope (Gen_Id)); 1242 1243 -- Inherit the "ghostness" of the generic spec. Note that this 1244 -- property is not directly inherited as the body may be subject 1245 -- to a different Ghost assertion policy. 1246 1247 if Ghost_Mode > None or else Is_Ghost_Entity (Gen_Id) then 1248 Set_Is_Ghost_Entity (Body_Id); 1249 1250 -- The Ghost policy in effect at the point of declaration and at 1251 -- the point of completion must match (SPARK RM 6.9(14)). 1252 1253 Check_Ghost_Completion (Gen_Id, Body_Id); 1254 end if; 1255 1256 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id); 1257 1258 if Nkind (N) = N_Subprogram_Body_Stub then 1259 1260 -- No body to analyze, so restore state of generic unit 1261 1262 Set_Ekind (Gen_Id, Kind); 1263 Set_Ekind (Body_Id, Kind); 1264 1265 if Present (First_Ent) then 1266 Set_First_Entity (Gen_Id, First_Ent); 1267 end if; 1268 1269 End_Scope; 1270 return; 1271 end if; 1272 1273 -- If this is a compilation unit, it must be made visible explicitly, 1274 -- because the compilation of the declaration, unlike other library 1275 -- unit declarations, does not. If it is not a unit, the following 1276 -- is redundant but harmless. 1277 1278 Set_Is_Immediately_Visible (Gen_Id); 1279 Reference_Body_Formals (Gen_Id, Body_Id); 1280 1281 if Is_Child_Unit (Gen_Id) then 1282 Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False); 1283 end if; 1284 1285 Set_Actual_Subtypes (N, Current_Scope); 1286 1287 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 1288 Set_SPARK_Pragma_Inherited (Body_Id); 1289 1290 -- Analyze any aspect specifications that appear on the generic 1291 -- subprogram body. 1292 1293 if Has_Aspects (N) then 1294 Analyze_Aspect_Specifications_On_Body_Or_Stub (N); 1295 end if; 1296 1297 Analyze_Declarations (Declarations (N)); 1298 Check_Completion; 1299 1300 -- Process the contract of the subprogram body after all declarations 1301 -- have been analyzed. This ensures that any contract-related pragmas 1302 -- are available through the N_Contract node of the body. 1303 1304 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id); 1305 1306 Analyze (Handled_Statement_Sequence (N)); 1307 Save_Global_References (Original_Node (N)); 1308 1309 -- Prior to exiting the scope, include generic formals again (if any 1310 -- are present) in the set of local entities. 1311 1312 if Present (First_Ent) then 1313 Set_First_Entity (Gen_Id, First_Ent); 1314 end if; 1315 1316 Check_References (Gen_Id); 1317 end; 1318 1319 Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope); 1320 End_Scope; 1321 Check_Subprogram_Order (N); 1322 1323 -- Outside of its body, unit is generic again 1324 1325 Set_Ekind (Gen_Id, Kind); 1326 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False); 1327 1328 if Style_Check then 1329 Style.Check_Identifier (Body_Id, Gen_Id); 1330 end if; 1331 1332 End_Generic; 1333 end Analyze_Generic_Subprogram_Body; 1334 1335 ---------------------------- 1336 -- Analyze_Null_Procedure -- 1337 ---------------------------- 1338 1339 procedure Analyze_Null_Procedure 1340 (N : Node_Id; 1341 Is_Completion : out Boolean) 1342 is 1343 Loc : constant Source_Ptr := Sloc (N); 1344 Spec : constant Node_Id := Specification (N); 1345 Designator : Entity_Id; 1346 Form : Node_Id; 1347 Null_Body : Node_Id := Empty; 1348 Prev : Entity_Id; 1349 1350 begin 1351 -- Capture the profile of the null procedure before analysis, for 1352 -- expansion at the freeze point and at each point of call. The body is 1353 -- used if the procedure has preconditions, or if it is a completion. In 1354 -- the first case the body is analyzed at the freeze point, in the other 1355 -- it replaces the null procedure declaration. 1356 1357 Null_Body := 1358 Make_Subprogram_Body (Loc, 1359 Specification => New_Copy_Tree (Spec), 1360 Declarations => New_List, 1361 Handled_Statement_Sequence => 1362 Make_Handled_Sequence_Of_Statements (Loc, 1363 Statements => New_List (Make_Null_Statement (Loc)))); 1364 1365 -- Create new entities for body and formals 1366 1367 Set_Defining_Unit_Name (Specification (Null_Body), 1368 Make_Defining_Identifier 1369 (Sloc (Defining_Entity (N)), 1370 Chars (Defining_Entity (N)))); 1371 1372 Form := First (Parameter_Specifications (Specification (Null_Body))); 1373 while Present (Form) loop 1374 Set_Defining_Identifier (Form, 1375 Make_Defining_Identifier 1376 (Sloc (Defining_Identifier (Form)), 1377 Chars (Defining_Identifier (Form)))); 1378 Next (Form); 1379 end loop; 1380 1381 -- Determine whether the null procedure may be a completion of a generic 1382 -- suprogram, in which case we use the new null body as the completion 1383 -- and set minimal semantic information on the original declaration, 1384 -- which is rewritten as a null statement. 1385 1386 Prev := Current_Entity_In_Scope (Defining_Entity (Spec)); 1387 1388 if Present (Prev) and then Is_Generic_Subprogram (Prev) then 1389 Insert_Before (N, Null_Body); 1390 Set_Ekind (Defining_Entity (N), Ekind (Prev)); 1391 1392 Rewrite (N, Make_Null_Statement (Loc)); 1393 Analyze_Generic_Subprogram_Body (Null_Body, Prev); 1394 Is_Completion := True; 1395 return; 1396 1397 else 1398 -- Resolve the types of the formals now, because the freeze point 1399 -- may appear in a different context, e.g. an instantiation. 1400 1401 Form := First (Parameter_Specifications (Specification (Null_Body))); 1402 while Present (Form) loop 1403 if Nkind (Parameter_Type (Form)) /= N_Access_Definition then 1404 Find_Type (Parameter_Type (Form)); 1405 1406 elsif 1407 No (Access_To_Subprogram_Definition (Parameter_Type (Form))) 1408 then 1409 Find_Type (Subtype_Mark (Parameter_Type (Form))); 1410 1411 else 1412 -- The case of a null procedure with a formal that is an 1413 -- access_to_subprogram type, and that is used as an actual 1414 -- in an instantiation is left to the enthusiastic reader. 1415 1416 null; 1417 end if; 1418 1419 Next (Form); 1420 end loop; 1421 end if; 1422 1423 -- If there are previous overloadable entities with the same name, 1424 -- check whether any of them is completed by the null procedure. 1425 1426 if Present (Prev) and then Is_Overloadable (Prev) then 1427 Designator := Analyze_Subprogram_Specification (Spec); 1428 Prev := Find_Corresponding_Spec (N); 1429 end if; 1430 1431 if No (Prev) or else not Comes_From_Source (Prev) then 1432 Designator := Analyze_Subprogram_Specification (Spec); 1433 Set_Has_Completion (Designator); 1434 1435 -- Signal to caller that this is a procedure declaration 1436 1437 Is_Completion := False; 1438 1439 -- Null procedures are always inlined, but generic formal subprograms 1440 -- which appear as such in the internal instance of formal packages, 1441 -- need no completion and are not marked Inline. 1442 1443 if Expander_Active 1444 and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration 1445 then 1446 Set_Corresponding_Body (N, Defining_Entity (Null_Body)); 1447 Set_Body_To_Inline (N, Null_Body); 1448 Set_Is_Inlined (Designator); 1449 end if; 1450 1451 else 1452 -- The null procedure is a completion. We unconditionally rewrite 1453 -- this as a null body (even if expansion is not active), because 1454 -- there are various error checks that are applied on this body 1455 -- when it is analyzed (e.g. correct aspect placement). 1456 1457 if Has_Completion (Prev) then 1458 Error_Msg_Sloc := Sloc (Prev); 1459 Error_Msg_NE ("duplicate body for & declared#", N, Prev); 1460 end if; 1461 1462 Is_Completion := True; 1463 Rewrite (N, Null_Body); 1464 Analyze (N); 1465 end if; 1466 end Analyze_Null_Procedure; 1467 1468 ----------------------------- 1469 -- Analyze_Operator_Symbol -- 1470 ----------------------------- 1471 1472 -- An operator symbol such as "+" or "and" may appear in context where the 1473 -- literal denotes an entity name, such as "+"(x, y) or in context when it 1474 -- is just a string, as in (conjunction = "or"). In these cases the parser 1475 -- generates this node, and the semantics does the disambiguation. Other 1476 -- such case are actuals in an instantiation, the generic unit in an 1477 -- instantiation, and pragma arguments. 1478 1479 procedure Analyze_Operator_Symbol (N : Node_Id) is 1480 Par : constant Node_Id := Parent (N); 1481 1482 begin 1483 if (Nkind (Par) = N_Function_Call and then N = Name (Par)) 1484 or else Nkind (Par) = N_Function_Instantiation 1485 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par)) 1486 or else (Nkind (Par) = N_Pragma_Argument_Association 1487 and then not Is_Pragma_String_Literal (Par)) 1488 or else Nkind (Par) = N_Subprogram_Renaming_Declaration 1489 or else (Nkind (Par) = N_Attribute_Reference 1490 and then Attribute_Name (Par) /= Name_Value) 1491 then 1492 Find_Direct_Name (N); 1493 1494 else 1495 Change_Operator_Symbol_To_String_Literal (N); 1496 Analyze (N); 1497 end if; 1498 end Analyze_Operator_Symbol; 1499 1500 ----------------------------------- 1501 -- Analyze_Parameter_Association -- 1502 ----------------------------------- 1503 1504 procedure Analyze_Parameter_Association (N : Node_Id) is 1505 begin 1506 Analyze (Explicit_Actual_Parameter (N)); 1507 end Analyze_Parameter_Association; 1508 1509 ---------------------------- 1510 -- Analyze_Procedure_Call -- 1511 ---------------------------- 1512 1513 procedure Analyze_Procedure_Call (N : Node_Id) is 1514 procedure Analyze_Call_And_Resolve; 1515 -- Do Analyze and Resolve calls for procedure call 1516 -- At end, check illegal order dependence. 1517 1518 ------------------------------ 1519 -- Analyze_Call_And_Resolve -- 1520 ------------------------------ 1521 1522 procedure Analyze_Call_And_Resolve is 1523 begin 1524 if Nkind (N) = N_Procedure_Call_Statement then 1525 Analyze_Call (N); 1526 Resolve (N, Standard_Void_Type); 1527 else 1528 Analyze (N); 1529 end if; 1530 end Analyze_Call_And_Resolve; 1531 1532 -- Local variables 1533 1534 Actuals : constant List_Id := Parameter_Associations (N); 1535 Loc : constant Source_Ptr := Sloc (N); 1536 P : constant Node_Id := Name (N); 1537 Actual : Node_Id; 1538 New_N : Node_Id; 1539 1540 Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode; 1541 1542 -- Start of processing for Analyze_Procedure_Call 1543 1544 begin 1545 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote 1546 -- a procedure call or an entry call. The prefix may denote an access 1547 -- to subprogram type, in which case an implicit dereference applies. 1548 -- If the prefix is an indexed component (without implicit dereference) 1549 -- then the construct denotes a call to a member of an entire family. 1550 -- If the prefix is a simple name, it may still denote a call to a 1551 -- parameterless member of an entry family. Resolution of these various 1552 -- interpretations is delicate. 1553 1554 -- Do not analyze machine code statements to avoid rejecting them in 1555 -- CodePeer mode. 1556 1557 if CodePeer_Mode and then Nkind (P) = N_Qualified_Expression then 1558 Set_Etype (P, Standard_Void_Type); 1559 else 1560 Analyze (P); 1561 end if; 1562 1563 -- If this is a call of the form Obj.Op, the call may have been analyzed 1564 -- and possibly rewritten into a block, in which case we are done. 1565 1566 if Analyzed (N) then 1567 return; 1568 end if; 1569 1570 -- If there is an error analyzing the name (which may have been 1571 -- rewritten if the original call was in prefix notation) then error 1572 -- has been emitted already, mark node and return. 1573 1574 if Error_Posted (N) or else Etype (Name (N)) = Any_Type then 1575 Set_Etype (N, Any_Type); 1576 return; 1577 end if; 1578 1579 -- A procedure call is Ghost when its name denotes a Ghost procedure. 1580 -- Set the mode now to ensure that any nodes generated during analysis 1581 -- and expansion are properly marked as Ghost. 1582 1583 Set_Ghost_Mode (N); 1584 1585 -- Otherwise analyze the parameters 1586 1587 if Present (Actuals) then 1588 Actual := First (Actuals); 1589 1590 while Present (Actual) loop 1591 Analyze (Actual); 1592 Check_Parameterless_Call (Actual); 1593 Next (Actual); 1594 end loop; 1595 end if; 1596 1597 -- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls 1598 1599 if Nkind (P) = N_Attribute_Reference 1600 and then Nam_In (Attribute_Name (P), Name_Elab_Spec, 1601 Name_Elab_Body, 1602 Name_Elab_Subp_Body) 1603 then 1604 if Present (Actuals) then 1605 Error_Msg_N 1606 ("no parameters allowed for this call", First (Actuals)); 1607 return; 1608 end if; 1609 1610 Set_Etype (N, Standard_Void_Type); 1611 Set_Analyzed (N); 1612 1613 elsif Is_Entity_Name (P) 1614 and then Is_Record_Type (Etype (Entity (P))) 1615 and then Remote_AST_I_Dereference (P) 1616 then 1617 Ghost_Mode := Save_Ghost_Mode; 1618 return; 1619 1620 elsif Is_Entity_Name (P) 1621 and then Ekind (Entity (P)) /= E_Entry_Family 1622 then 1623 if Is_Access_Type (Etype (P)) 1624 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type 1625 and then No (Actuals) 1626 and then Comes_From_Source (N) 1627 then 1628 Error_Msg_N ("missing explicit dereference in call", N); 1629 end if; 1630 1631 Analyze_Call_And_Resolve; 1632 1633 -- If the prefix is the simple name of an entry family, this is a 1634 -- parameterless call from within the task body itself. 1635 1636 elsif Is_Entity_Name (P) 1637 and then Nkind (P) = N_Identifier 1638 and then Ekind (Entity (P)) = E_Entry_Family 1639 and then Present (Actuals) 1640 and then No (Next (First (Actuals))) 1641 then 1642 -- Can be call to parameterless entry family. What appears to be the 1643 -- sole argument is in fact the entry index. Rewrite prefix of node 1644 -- accordingly. Source representation is unchanged by this 1645 -- transformation. 1646 1647 New_N := 1648 Make_Indexed_Component (Loc, 1649 Prefix => 1650 Make_Selected_Component (Loc, 1651 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc), 1652 Selector_Name => New_Occurrence_Of (Entity (P), Loc)), 1653 Expressions => Actuals); 1654 Set_Name (N, New_N); 1655 Set_Etype (New_N, Standard_Void_Type); 1656 Set_Parameter_Associations (N, No_List); 1657 Analyze_Call_And_Resolve; 1658 1659 elsif Nkind (P) = N_Explicit_Dereference then 1660 if Ekind (Etype (P)) = E_Subprogram_Type then 1661 Analyze_Call_And_Resolve; 1662 else 1663 Error_Msg_N ("expect access to procedure in call", P); 1664 end if; 1665 1666 -- The name can be a selected component or an indexed component that 1667 -- yields an access to subprogram. Such a prefix is legal if the call 1668 -- has parameter associations. 1669 1670 elsif Is_Access_Type (Etype (P)) 1671 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type 1672 then 1673 if Present (Actuals) then 1674 Analyze_Call_And_Resolve; 1675 else 1676 Error_Msg_N ("missing explicit dereference in call ", N); 1677 end if; 1678 1679 -- If not an access to subprogram, then the prefix must resolve to the 1680 -- name of an entry, entry family, or protected operation. 1681 1682 -- For the case of a simple entry call, P is a selected component where 1683 -- the prefix is the task and the selector name is the entry. A call to 1684 -- a protected procedure will have the same syntax. If the protected 1685 -- object contains overloaded operations, the entity may appear as a 1686 -- function, the context will select the operation whose type is Void. 1687 1688 elsif Nkind (P) = N_Selected_Component 1689 and then Ekind_In (Entity (Selector_Name (P)), E_Entry, 1690 E_Procedure, 1691 E_Function) 1692 then 1693 Analyze_Call_And_Resolve; 1694 1695 elsif Nkind (P) = N_Selected_Component 1696 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family 1697 and then Present (Actuals) 1698 and then No (Next (First (Actuals))) 1699 then 1700 -- Can be call to parameterless entry family. What appears to be the 1701 -- sole argument is in fact the entry index. Rewrite prefix of node 1702 -- accordingly. Source representation is unchanged by this 1703 -- transformation. 1704 1705 New_N := 1706 Make_Indexed_Component (Loc, 1707 Prefix => New_Copy (P), 1708 Expressions => Actuals); 1709 Set_Name (N, New_N); 1710 Set_Etype (New_N, Standard_Void_Type); 1711 Set_Parameter_Associations (N, No_List); 1712 Analyze_Call_And_Resolve; 1713 1714 -- For the case of a reference to an element of an entry family, P is 1715 -- an indexed component whose prefix is a selected component (task and 1716 -- entry family), and whose index is the entry family index. 1717 1718 elsif Nkind (P) = N_Indexed_Component 1719 and then Nkind (Prefix (P)) = N_Selected_Component 1720 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family 1721 then 1722 Analyze_Call_And_Resolve; 1723 1724 -- If the prefix is the name of an entry family, it is a call from 1725 -- within the task body itself. 1726 1727 elsif Nkind (P) = N_Indexed_Component 1728 and then Nkind (Prefix (P)) = N_Identifier 1729 and then Ekind (Entity (Prefix (P))) = E_Entry_Family 1730 then 1731 New_N := 1732 Make_Selected_Component (Loc, 1733 Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc), 1734 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc)); 1735 Rewrite (Prefix (P), New_N); 1736 Analyze (P); 1737 Analyze_Call_And_Resolve; 1738 1739 -- In Ada 2012. a qualified expression is a name, but it cannot be a 1740 -- procedure name, so the construct can only be a qualified expression. 1741 1742 elsif Nkind (P) = N_Qualified_Expression 1743 and then Ada_Version >= Ada_2012 1744 then 1745 Rewrite (N, Make_Code_Statement (Loc, Expression => P)); 1746 Analyze (N); 1747 1748 -- Anything else is an error 1749 1750 else 1751 Error_Msg_N ("invalid procedure or entry call", N); 1752 end if; 1753 1754 Ghost_Mode := Save_Ghost_Mode; 1755 end Analyze_Procedure_Call; 1756 1757 ------------------------------ 1758 -- Analyze_Return_Statement -- 1759 ------------------------------ 1760 1761 procedure Analyze_Return_Statement (N : Node_Id) is 1762 1763 pragma Assert (Nkind_In (N, N_Simple_Return_Statement, 1764 N_Extended_Return_Statement)); 1765 1766 Returns_Object : constant Boolean := 1767 Nkind (N) = N_Extended_Return_Statement 1768 or else 1769 (Nkind (N) = N_Simple_Return_Statement 1770 and then Present (Expression (N))); 1771 -- True if we're returning something; that is, "return <expression>;" 1772 -- or "return Result : T [:= ...]". False for "return;". Used for error 1773 -- checking: If Returns_Object is True, N should apply to a function 1774 -- body; otherwise N should apply to a procedure body, entry body, 1775 -- accept statement, or extended return statement. 1776 1777 function Find_What_It_Applies_To return Entity_Id; 1778 -- Find the entity representing the innermost enclosing body, accept 1779 -- statement, or extended return statement. If the result is a callable 1780 -- construct or extended return statement, then this will be the value 1781 -- of the Return_Applies_To attribute. Otherwise, the program is 1782 -- illegal. See RM-6.5(4/2). 1783 1784 ----------------------------- 1785 -- Find_What_It_Applies_To -- 1786 ----------------------------- 1787 1788 function Find_What_It_Applies_To return Entity_Id is 1789 Result : Entity_Id := Empty; 1790 1791 begin 1792 -- Loop outward through the Scope_Stack, skipping blocks, loops, 1793 -- and postconditions. 1794 1795 for J in reverse 0 .. Scope_Stack.Last loop 1796 Result := Scope_Stack.Table (J).Entity; 1797 exit when not Ekind_In (Result, E_Block, E_Loop) 1798 and then Chars (Result) /= Name_uPostconditions; 1799 end loop; 1800 1801 pragma Assert (Present (Result)); 1802 return Result; 1803 end Find_What_It_Applies_To; 1804 1805 -- Local declarations 1806 1807 Scope_Id : constant Entity_Id := Find_What_It_Applies_To; 1808 Kind : constant Entity_Kind := Ekind (Scope_Id); 1809 Loc : constant Source_Ptr := Sloc (N); 1810 Stm_Entity : constant Entity_Id := 1811 New_Internal_Entity 1812 (E_Return_Statement, Current_Scope, Loc, 'R'); 1813 1814 -- Start of processing for Analyze_Return_Statement 1815 1816 begin 1817 Set_Return_Statement_Entity (N, Stm_Entity); 1818 1819 Set_Etype (Stm_Entity, Standard_Void_Type); 1820 Set_Return_Applies_To (Stm_Entity, Scope_Id); 1821 1822 -- Place Return entity on scope stack, to simplify enforcement of 6.5 1823 -- (4/2): an inner return statement will apply to this extended return. 1824 1825 if Nkind (N) = N_Extended_Return_Statement then 1826 Push_Scope (Stm_Entity); 1827 end if; 1828 1829 -- Check that pragma No_Return is obeyed. Don't complain about the 1830 -- implicitly-generated return that is placed at the end. 1831 1832 if No_Return (Scope_Id) and then Comes_From_Source (N) then 1833 Error_Msg_N ("RETURN statement not allowed (No_Return)", N); 1834 end if; 1835 1836 -- Warn on any unassigned OUT parameters if in procedure 1837 1838 if Ekind (Scope_Id) = E_Procedure then 1839 Warn_On_Unassigned_Out_Parameter (N, Scope_Id); 1840 end if; 1841 1842 -- Check that functions return objects, and other things do not 1843 1844 if Kind = E_Function or else Kind = E_Generic_Function then 1845 if not Returns_Object then 1846 Error_Msg_N ("missing expression in return from function", N); 1847 end if; 1848 1849 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then 1850 if Returns_Object then 1851 Error_Msg_N ("procedure cannot return value (use function)", N); 1852 end if; 1853 1854 elsif Kind = E_Entry or else Kind = E_Entry_Family then 1855 if Returns_Object then 1856 if Is_Protected_Type (Scope (Scope_Id)) then 1857 Error_Msg_N ("entry body cannot return value", N); 1858 else 1859 Error_Msg_N ("accept statement cannot return value", N); 1860 end if; 1861 end if; 1862 1863 elsif Kind = E_Return_Statement then 1864 1865 -- We are nested within another return statement, which must be an 1866 -- extended_return_statement. 1867 1868 if Returns_Object then 1869 if Nkind (N) = N_Extended_Return_Statement then 1870 Error_Msg_N 1871 ("extended return statement cannot be nested (use `RETURN;`)", 1872 N); 1873 1874 -- Case of a simple return statement with a value inside extended 1875 -- return statement. 1876 1877 else 1878 Error_Msg_N 1879 ("return nested in extended return statement cannot return " 1880 & "value (use `RETURN;`)", N); 1881 end if; 1882 end if; 1883 1884 else 1885 Error_Msg_N ("illegal context for return statement", N); 1886 end if; 1887 1888 if Ekind_In (Kind, E_Function, E_Generic_Function) then 1889 Analyze_Function_Return (N); 1890 1891 elsif Ekind_In (Kind, E_Procedure, E_Generic_Procedure) then 1892 Set_Return_Present (Scope_Id); 1893 end if; 1894 1895 if Nkind (N) = N_Extended_Return_Statement then 1896 End_Scope; 1897 end if; 1898 1899 Kill_Current_Values (Last_Assignment_Only => True); 1900 Check_Unreachable_Code (N); 1901 1902 Analyze_Dimension (N); 1903 end Analyze_Return_Statement; 1904 1905 ------------------------------------- 1906 -- Analyze_Simple_Return_Statement -- 1907 ------------------------------------- 1908 1909 procedure Analyze_Simple_Return_Statement (N : Node_Id) is 1910 begin 1911 if Present (Expression (N)) then 1912 Mark_Coextensions (N, Expression (N)); 1913 end if; 1914 1915 Analyze_Return_Statement (N); 1916 end Analyze_Simple_Return_Statement; 1917 1918 ------------------------- 1919 -- Analyze_Return_Type -- 1920 ------------------------- 1921 1922 procedure Analyze_Return_Type (N : Node_Id) is 1923 Designator : constant Entity_Id := Defining_Entity (N); 1924 Typ : Entity_Id := Empty; 1925 1926 begin 1927 -- Normal case where result definition does not indicate an error 1928 1929 if Result_Definition (N) /= Error then 1930 if Nkind (Result_Definition (N)) = N_Access_Definition then 1931 Check_SPARK_05_Restriction 1932 ("access result is not allowed", Result_Definition (N)); 1933 1934 -- Ada 2005 (AI-254): Handle anonymous access to subprograms 1935 1936 declare 1937 AD : constant Node_Id := 1938 Access_To_Subprogram_Definition (Result_Definition (N)); 1939 begin 1940 if Present (AD) and then Protected_Present (AD) then 1941 Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N); 1942 else 1943 Typ := Access_Definition (N, Result_Definition (N)); 1944 end if; 1945 end; 1946 1947 Set_Parent (Typ, Result_Definition (N)); 1948 Set_Is_Local_Anonymous_Access (Typ); 1949 Set_Etype (Designator, Typ); 1950 1951 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion 1952 1953 Null_Exclusion_Static_Checks (N); 1954 1955 -- Subtype_Mark case 1956 1957 else 1958 Find_Type (Result_Definition (N)); 1959 Typ := Entity (Result_Definition (N)); 1960 Set_Etype (Designator, Typ); 1961 1962 -- Unconstrained array as result is not allowed in SPARK 1963 1964 if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then 1965 Check_SPARK_05_Restriction 1966 ("returning an unconstrained array is not allowed", 1967 Result_Definition (N)); 1968 end if; 1969 1970 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion 1971 1972 Null_Exclusion_Static_Checks (N); 1973 1974 -- If a null exclusion is imposed on the result type, then create 1975 -- a null-excluding itype (an access subtype) and use it as the 1976 -- function's Etype. Note that the null exclusion checks are done 1977 -- right before this, because they don't get applied to types that 1978 -- do not come from source. 1979 1980 if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then 1981 Set_Etype (Designator, 1982 Create_Null_Excluding_Itype 1983 (T => Typ, 1984 Related_Nod => N, 1985 Scope_Id => Scope (Current_Scope))); 1986 1987 -- The new subtype must be elaborated before use because 1988 -- it is visible outside of the function. However its base 1989 -- type may not be frozen yet, so the reference that will 1990 -- force elaboration must be attached to the freezing of 1991 -- the base type. 1992 1993 -- If the return specification appears on a proper body, 1994 -- the subtype will have been created already on the spec. 1995 1996 if Is_Frozen (Typ) then 1997 if Nkind (Parent (N)) = N_Subprogram_Body 1998 and then Nkind (Parent (Parent (N))) = N_Subunit 1999 then 2000 null; 2001 else 2002 Build_Itype_Reference (Etype (Designator), Parent (N)); 2003 end if; 2004 2005 else 2006 Ensure_Freeze_Node (Typ); 2007 2008 declare 2009 IR : constant Node_Id := Make_Itype_Reference (Sloc (N)); 2010 begin 2011 Set_Itype (IR, Etype (Designator)); 2012 Append_Freeze_Actions (Typ, New_List (IR)); 2013 end; 2014 end if; 2015 2016 else 2017 Set_Etype (Designator, Typ); 2018 end if; 2019 2020 if Ekind (Typ) = E_Incomplete_Type 2021 or else (Is_Class_Wide_Type (Typ) 2022 and then Ekind (Root_Type (Typ)) = E_Incomplete_Type) 2023 then 2024 -- AI05-0151: Tagged incomplete types are allowed in all formal 2025 -- parts. Untagged incomplete types are not allowed in bodies. 2026 -- As a consequence, limited views cannot appear in a basic 2027 -- declaration that is itself within a body, because there is 2028 -- no point at which the non-limited view will become visible. 2029 2030 if Ada_Version >= Ada_2012 then 2031 if From_Limited_With (Typ) and then In_Package_Body then 2032 Error_Msg_NE 2033 ("invalid use of incomplete type&", 2034 Result_Definition (N), Typ); 2035 2036 -- The return type of a subprogram body cannot be of a 2037 -- formal incomplete type. 2038 2039 elsif Is_Generic_Type (Typ) 2040 and then Nkind (Parent (N)) = N_Subprogram_Body 2041 then 2042 Error_Msg_N 2043 ("return type cannot be a formal incomplete type", 2044 Result_Definition (N)); 2045 2046 elsif Is_Class_Wide_Type (Typ) 2047 and then Is_Generic_Type (Root_Type (Typ)) 2048 and then Nkind (Parent (N)) = N_Subprogram_Body 2049 then 2050 Error_Msg_N 2051 ("return type cannot be a formal incomplete type", 2052 Result_Definition (N)); 2053 2054 elsif Is_Tagged_Type (Typ) then 2055 null; 2056 2057 -- Use is legal in a thunk generated for an operation 2058 -- inherited from a progenitor. 2059 2060 elsif Is_Thunk (Designator) 2061 and then Present (Non_Limited_View (Typ)) 2062 then 2063 null; 2064 2065 elsif Nkind (Parent (N)) = N_Subprogram_Body 2066 or else Nkind_In (Parent (Parent (N)), N_Accept_Statement, 2067 N_Entry_Body) 2068 then 2069 Error_Msg_NE 2070 ("invalid use of untagged incomplete type&", 2071 Designator, Typ); 2072 end if; 2073 2074 -- The type must be completed in the current package. This 2075 -- is checked at the end of the package declaration when 2076 -- Taft-amendment types are identified. If the return type 2077 -- is class-wide, there is no required check, the type can 2078 -- be a bona fide TAT. 2079 2080 if Ekind (Scope (Current_Scope)) = E_Package 2081 and then In_Private_Part (Scope (Current_Scope)) 2082 and then not Is_Class_Wide_Type (Typ) 2083 then 2084 Append_Elmt (Designator, Private_Dependents (Typ)); 2085 end if; 2086 2087 else 2088 Error_Msg_NE 2089 ("invalid use of incomplete type&", Designator, Typ); 2090 end if; 2091 end if; 2092 end if; 2093 2094 -- Case where result definition does indicate an error 2095 2096 else 2097 Set_Etype (Designator, Any_Type); 2098 end if; 2099 end Analyze_Return_Type; 2100 2101 ----------------------------- 2102 -- Analyze_Subprogram_Body -- 2103 ----------------------------- 2104 2105 procedure Analyze_Subprogram_Body (N : Node_Id) is 2106 Loc : constant Source_Ptr := Sloc (N); 2107 Body_Spec : constant Node_Id := Specification (N); 2108 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec); 2109 2110 begin 2111 if Debug_Flag_C then 2112 Write_Str ("==> subprogram body "); 2113 Write_Name (Chars (Body_Id)); 2114 Write_Str (" from "); 2115 Write_Location (Loc); 2116 Write_Eol; 2117 Indent; 2118 end if; 2119 2120 Trace_Scope (N, Body_Id, " Analyze subprogram: "); 2121 2122 -- The real work is split out into the helper, so it can do "return;" 2123 -- without skipping the debug output: 2124 2125 Analyze_Subprogram_Body_Helper (N); 2126 2127 if Debug_Flag_C then 2128 Outdent; 2129 Write_Str ("<== subprogram body "); 2130 Write_Name (Chars (Body_Id)); 2131 Write_Str (" from "); 2132 Write_Location (Loc); 2133 Write_Eol; 2134 end if; 2135 end Analyze_Subprogram_Body; 2136 2137 ------------------------------------ 2138 -- Analyze_Subprogram_Body_Helper -- 2139 ------------------------------------ 2140 2141 -- This procedure is called for regular subprogram bodies, generic bodies, 2142 -- and for subprogram stubs of both kinds. In the case of stubs, only the 2143 -- specification matters, and is used to create a proper declaration for 2144 -- the subprogram, or to perform conformance checks. 2145 2146 procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is 2147 Loc : constant Source_Ptr := Sloc (N); 2148 Body_Spec : Node_Id := Specification (N); 2149 Body_Id : Entity_Id := Defining_Entity (Body_Spec); 2150 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id); 2151 Conformant : Boolean; 2152 HSS : Node_Id; 2153 Prot_Typ : Entity_Id := Empty; 2154 Spec_Id : Entity_Id; 2155 Spec_Decl : Node_Id := Empty; 2156 2157 Last_Real_Spec_Entity : Entity_Id := Empty; 2158 -- When we analyze a separate spec, the entity chain ends up containing 2159 -- the formals, as well as any itypes generated during analysis of the 2160 -- default expressions for parameters, or the arguments of associated 2161 -- precondition/postcondition pragmas (which are analyzed in the context 2162 -- of the spec since they have visibility on formals). 2163 -- 2164 -- These entities belong with the spec and not the body. However we do 2165 -- the analysis of the body in the context of the spec (again to obtain 2166 -- visibility to the formals), and all the entities generated during 2167 -- this analysis end up also chained to the entity chain of the spec. 2168 -- But they really belong to the body, and there is circuitry to move 2169 -- them from the spec to the body. 2170 -- 2171 -- However, when we do this move, we don't want to move the real spec 2172 -- entities (first para above) to the body. The Last_Real_Spec_Entity 2173 -- variable points to the last real spec entity, so we only move those 2174 -- chained beyond that point. It is initialized to Empty to deal with 2175 -- the case where there is no separate spec. 2176 2177 function Body_Has_Contract return Boolean; 2178 -- Check whether unanalyzed body has an aspect or pragma that may 2179 -- generate a SPARK contract. 2180 2181 procedure Build_Subprogram_Declaration; 2182 -- Create a matching subprogram declaration for subprogram body N 2183 2184 procedure Check_Anonymous_Return; 2185 -- Ada 2005: if a function returns an access type that denotes a task, 2186 -- or a type that contains tasks, we must create a master entity for 2187 -- the anonymous type, which typically will be used in an allocator 2188 -- in the body of the function. 2189 2190 procedure Check_Inline_Pragma (Spec : in out Node_Id); 2191 -- Look ahead to recognize a pragma that may appear after the body. 2192 -- If there is a previous spec, check that it appears in the same 2193 -- declarative part. If the pragma is Inline_Always, perform inlining 2194 -- unconditionally, otherwise only if Front_End_Inlining is requested. 2195 -- If the body acts as a spec, and inlining is required, we create a 2196 -- subprogram declaration for it, in order to attach the body to inline. 2197 -- If pragma does not appear after the body, check whether there is 2198 -- an inline pragma before any local declarations. 2199 2200 procedure Check_Missing_Return; 2201 -- Checks for a function with a no return statements, and also performs 2202 -- the warning checks implemented by Check_Returns. In formal mode, also 2203 -- verify that a function ends with a RETURN and that a procedure does 2204 -- not contain any RETURN. 2205 2206 function Disambiguate_Spec return Entity_Id; 2207 -- When a primitive is declared between the private view and the full 2208 -- view of a concurrent type which implements an interface, a special 2209 -- mechanism is used to find the corresponding spec of the primitive 2210 -- body. 2211 2212 procedure Exchange_Limited_Views (Subp_Id : Entity_Id); 2213 -- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains 2214 -- incomplete types coming from a limited context and swap their limited 2215 -- views with the non-limited ones. 2216 2217 function Is_Private_Concurrent_Primitive 2218 (Subp_Id : Entity_Id) return Boolean; 2219 -- Determine whether subprogram Subp_Id is a primitive of a concurrent 2220 -- type that implements an interface and has a private view. 2221 2222 procedure Set_Trivial_Subprogram (N : Node_Id); 2223 -- Sets the Is_Trivial_Subprogram flag in both spec and body of the 2224 -- subprogram whose body is being analyzed. N is the statement node 2225 -- causing the flag to be set, if the following statement is a return 2226 -- of an entity, we mark the entity as set in source to suppress any 2227 -- warning on the stylized use of function stubs with a dummy return. 2228 2229 procedure Verify_Overriding_Indicator; 2230 -- If there was a previous spec, the entity has been entered in the 2231 -- current scope previously. If the body itself carries an overriding 2232 -- indicator, check that it is consistent with the known status of the 2233 -- entity. 2234 2235 ----------------------- 2236 -- Body_Has_Contract -- 2237 ----------------------- 2238 2239 function Body_Has_Contract return Boolean is 2240 Decls : constant List_Id := Declarations (N); 2241 Item : Node_Id; 2242 2243 begin 2244 -- Check for aspects that may generate a contract 2245 2246 if Present (Aspect_Specifications (N)) then 2247 Item := First (Aspect_Specifications (N)); 2248 while Present (Item) loop 2249 if Is_Subprogram_Contract_Annotation (Item) then 2250 return True; 2251 end if; 2252 2253 Next (Item); 2254 end loop; 2255 end if; 2256 2257 -- Check for pragmas that may generate a contract 2258 2259 if Present (Decls) then 2260 Item := First (Decls); 2261 while Present (Item) loop 2262 if Nkind (Item) = N_Pragma 2263 and then Is_Subprogram_Contract_Annotation (Item) 2264 then 2265 return True; 2266 end if; 2267 2268 Next (Item); 2269 end loop; 2270 end if; 2271 2272 return False; 2273 end Body_Has_Contract; 2274 2275 ---------------------------------- 2276 -- Build_Subprogram_Declaration -- 2277 ---------------------------------- 2278 2279 procedure Build_Subprogram_Declaration is 2280 procedure Move_Pragmas (From : Node_Id; To : Node_Id); 2281 -- Relocate certain categorization pragmas from the declarative list 2282 -- of subprogram body From and insert them after node To. The pragmas 2283 -- in question are: 2284 -- Ghost 2285 -- SPARK_Mode 2286 -- Volatile_Function 2287 2288 ------------------ 2289 -- Move_Pragmas -- 2290 ------------------ 2291 2292 procedure Move_Pragmas (From : Node_Id; To : Node_Id) is 2293 Decl : Node_Id; 2294 Next_Decl : Node_Id; 2295 2296 begin 2297 pragma Assert (Nkind (From) = N_Subprogram_Body); 2298 2299 -- The destination node must be part of a list, as the pragmas are 2300 -- inserted after it. 2301 2302 pragma Assert (Is_List_Member (To)); 2303 2304 -- Inspect the declarations of the subprogram body looking for 2305 -- specific pragmas. 2306 2307 Decl := First (Declarations (N)); 2308 while Present (Decl) loop 2309 Next_Decl := Next (Decl); 2310 2311 if Nkind (Decl) = N_Pragma 2312 and then Nam_In (Pragma_Name (Decl), Name_Ghost, 2313 Name_SPARK_Mode, 2314 Name_Volatile_Function) 2315 then 2316 Remove (Decl); 2317 Insert_After (To, Decl); 2318 end if; 2319 2320 Decl := Next_Decl; 2321 end loop; 2322 end Move_Pragmas; 2323 2324 -- Local variables 2325 2326 Decl : Node_Id; 2327 Subp_Decl : Node_Id; 2328 2329 -- Start of processing for Build_Subprogram_Declaration 2330 2331 begin 2332 -- Create a matching subprogram spec using the profile of the body. 2333 -- The structure of the tree is identical, but has new entities for 2334 -- the defining unit name and formal parameters. 2335 2336 Subp_Decl := 2337 Make_Subprogram_Declaration (Loc, 2338 Specification => Copy_Subprogram_Spec (Body_Spec)); 2339 Set_Comes_From_Source (Subp_Decl, True); 2340 2341 -- Relocate the aspects and relevant pragmas from the subprogram body 2342 -- to the generated spec because it acts as the initial declaration. 2343 2344 Insert_Before (N, Subp_Decl); 2345 Move_Aspects (N, To => Subp_Decl); 2346 Move_Pragmas (N, To => Subp_Decl); 2347 2348 Analyze (Subp_Decl); 2349 2350 -- Analyze any relocated source pragmas or pragmas created for aspect 2351 -- specifications. 2352 2353 Decl := Next (Subp_Decl); 2354 while Present (Decl) loop 2355 2356 -- Stop the search for pragmas once the body has been reached as 2357 -- this terminates the region where pragmas may appear. 2358 2359 if Decl = N then 2360 exit; 2361 2362 elsif Nkind (Decl) = N_Pragma then 2363 Analyze (Decl); 2364 end if; 2365 2366 Next (Decl); 2367 end loop; 2368 2369 Spec_Id := Defining_Entity (Subp_Decl); 2370 Set_Corresponding_Spec (N, Spec_Id); 2371 2372 -- Mark the generated spec as a source construct to ensure that all 2373 -- calls to it are properly registered in ALI files for GNATprove. 2374 2375 Set_Comes_From_Source (Spec_Id, True); 2376 2377 -- Ensure that the specs of the subprogram declaration and its body 2378 -- are identical, otherwise they will appear non-conformant due to 2379 -- rewritings in the default values of formal parameters. 2380 2381 Body_Spec := Copy_Subprogram_Spec (Body_Spec); 2382 Set_Specification (N, Body_Spec); 2383 Body_Id := Analyze_Subprogram_Specification (Body_Spec); 2384 2385 -- Ensure that the generated corresponding spec and original body 2386 -- share the same Ghost and SPARK_Mode attributes. 2387 2388 Set_Is_Checked_Ghost_Entity 2389 (Body_Id, Is_Checked_Ghost_Entity (Spec_Id)); 2390 Set_Is_Ignored_Ghost_Entity 2391 (Body_Id, Is_Ignored_Ghost_Entity (Spec_Id)); 2392 2393 Set_SPARK_Pragma (Body_Id, SPARK_Pragma (Spec_Id)); 2394 Set_SPARK_Pragma_Inherited 2395 (Body_Id, SPARK_Pragma_Inherited (Spec_Id)); 2396 end Build_Subprogram_Declaration; 2397 2398 ---------------------------- 2399 -- Check_Anonymous_Return -- 2400 ---------------------------- 2401 2402 procedure Check_Anonymous_Return is 2403 Decl : Node_Id; 2404 Par : Node_Id; 2405 Scop : Entity_Id; 2406 2407 begin 2408 if Present (Spec_Id) then 2409 Scop := Spec_Id; 2410 else 2411 Scop := Body_Id; 2412 end if; 2413 2414 if Ekind (Scop) = E_Function 2415 and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type 2416 and then not Is_Thunk (Scop) 2417 2418 -- Skip internally built functions which handle the case of 2419 -- a null access (see Expand_Interface_Conversion) 2420 2421 and then not (Is_Interface (Designated_Type (Etype (Scop))) 2422 and then not Comes_From_Source (Parent (Scop))) 2423 2424 and then (Has_Task (Designated_Type (Etype (Scop))) 2425 or else 2426 (Is_Class_Wide_Type (Designated_Type (Etype (Scop))) 2427 and then 2428 Is_Limited_Record (Designated_Type (Etype (Scop))))) 2429 and then Expander_Active 2430 2431 -- Avoid cases with no tasking support 2432 2433 and then RTE_Available (RE_Current_Master) 2434 and then not Restriction_Active (No_Task_Hierarchy) 2435 then 2436 Decl := 2437 Make_Object_Declaration (Loc, 2438 Defining_Identifier => 2439 Make_Defining_Identifier (Loc, Name_uMaster), 2440 Constant_Present => True, 2441 Object_Definition => 2442 New_Occurrence_Of (RTE (RE_Master_Id), Loc), 2443 Expression => 2444 Make_Explicit_Dereference (Loc, 2445 New_Occurrence_Of (RTE (RE_Current_Master), Loc))); 2446 2447 if Present (Declarations (N)) then 2448 Prepend (Decl, Declarations (N)); 2449 else 2450 Set_Declarations (N, New_List (Decl)); 2451 end if; 2452 2453 Set_Master_Id (Etype (Scop), Defining_Identifier (Decl)); 2454 Set_Has_Master_Entity (Scop); 2455 2456 -- Now mark the containing scope as a task master 2457 2458 Par := N; 2459 while Nkind (Par) /= N_Compilation_Unit loop 2460 Par := Parent (Par); 2461 pragma Assert (Present (Par)); 2462 2463 -- If we fall off the top, we are at the outer level, and 2464 -- the environment task is our effective master, so nothing 2465 -- to mark. 2466 2467 if Nkind_In 2468 (Par, N_Task_Body, N_Block_Statement, N_Subprogram_Body) 2469 then 2470 Set_Is_Task_Master (Par, True); 2471 exit; 2472 end if; 2473 end loop; 2474 end if; 2475 end Check_Anonymous_Return; 2476 2477 ------------------------- 2478 -- Check_Inline_Pragma -- 2479 ------------------------- 2480 2481 procedure Check_Inline_Pragma (Spec : in out Node_Id) is 2482 Prag : Node_Id; 2483 Plist : List_Id; 2484 2485 function Is_Inline_Pragma (N : Node_Id) return Boolean; 2486 -- True when N is a pragma Inline or Inline_Always that applies 2487 -- to this subprogram. 2488 2489 ----------------------- 2490 -- Is_Inline_Pragma -- 2491 ----------------------- 2492 2493 function Is_Inline_Pragma (N : Node_Id) return Boolean is 2494 begin 2495 return 2496 Nkind (N) = N_Pragma 2497 and then 2498 (Pragma_Name (N) = Name_Inline_Always 2499 or else (Front_End_Inlining 2500 and then Pragma_Name (N) = Name_Inline)) 2501 and then 2502 Chars 2503 (Expression (First (Pragma_Argument_Associations (N)))) = 2504 Chars (Body_Id); 2505 end Is_Inline_Pragma; 2506 2507 -- Start of processing for Check_Inline_Pragma 2508 2509 begin 2510 if not Expander_Active then 2511 return; 2512 end if; 2513 2514 if Is_List_Member (N) 2515 and then Present (Next (N)) 2516 and then Is_Inline_Pragma (Next (N)) 2517 then 2518 Prag := Next (N); 2519 2520 elsif Nkind (N) /= N_Subprogram_Body_Stub 2521 and then Present (Declarations (N)) 2522 and then Is_Inline_Pragma (First (Declarations (N))) 2523 then 2524 Prag := First (Declarations (N)); 2525 2526 else 2527 Prag := Empty; 2528 end if; 2529 2530 if Present (Prag) then 2531 if Present (Spec_Id) then 2532 if In_Same_List (N, Unit_Declaration_Node (Spec_Id)) then 2533 Analyze (Prag); 2534 end if; 2535 2536 else 2537 -- Create a subprogram declaration, to make treatment uniform 2538 2539 declare 2540 Subp : constant Entity_Id := 2541 Make_Defining_Identifier (Loc, Chars (Body_Id)); 2542 Decl : constant Node_Id := 2543 Make_Subprogram_Declaration (Loc, 2544 Specification => 2545 New_Copy_Tree (Specification (N))); 2546 2547 begin 2548 Set_Defining_Unit_Name (Specification (Decl), Subp); 2549 2550 if Present (First_Formal (Body_Id)) then 2551 Plist := Copy_Parameter_List (Body_Id); 2552 Set_Parameter_Specifications 2553 (Specification (Decl), Plist); 2554 end if; 2555 2556 Insert_Before (N, Decl); 2557 Analyze (Decl); 2558 Analyze (Prag); 2559 Set_Has_Pragma_Inline (Subp); 2560 2561 if Pragma_Name (Prag) = Name_Inline_Always then 2562 Set_Is_Inlined (Subp); 2563 Set_Has_Pragma_Inline_Always (Subp); 2564 end if; 2565 2566 -- Prior to copying the subprogram body to create a template 2567 -- for it for subsequent inlining, remove the pragma from 2568 -- the current body so that the copy that will produce the 2569 -- new body will start from a completely unanalyzed tree. 2570 2571 if Nkind (Parent (Prag)) = N_Subprogram_Body then 2572 Rewrite (Prag, Make_Null_Statement (Sloc (Prag))); 2573 end if; 2574 2575 Spec := Subp; 2576 end; 2577 end if; 2578 end if; 2579 end Check_Inline_Pragma; 2580 2581 -------------------------- 2582 -- Check_Missing_Return -- 2583 -------------------------- 2584 2585 procedure Check_Missing_Return is 2586 Id : Entity_Id; 2587 Missing_Ret : Boolean; 2588 2589 begin 2590 if Nkind (Body_Spec) = N_Function_Specification then 2591 if Present (Spec_Id) then 2592 Id := Spec_Id; 2593 else 2594 Id := Body_Id; 2595 end if; 2596 2597 if Return_Present (Id) then 2598 Check_Returns (HSS, 'F', Missing_Ret); 2599 2600 if Missing_Ret then 2601 Set_Has_Missing_Return (Id); 2602 end if; 2603 2604 -- Within a premature instantiation of a package with no body, we 2605 -- build completions of the functions therein, with a Raise 2606 -- statement. No point in complaining about a missing return in 2607 -- this case. 2608 2609 elsif Ekind (Id) = E_Function 2610 and then In_Instance 2611 and then Present (Statements (HSS)) 2612 and then Nkind (First (Statements (HSS))) = N_Raise_Program_Error 2613 then 2614 null; 2615 2616 elsif Is_Generic_Subprogram (Id) 2617 or else not Is_Machine_Code_Subprogram (Id) 2618 then 2619 Error_Msg_N ("missing RETURN statement in function body", N); 2620 end if; 2621 2622 -- If procedure with No_Return, check returns 2623 2624 elsif Nkind (Body_Spec) = N_Procedure_Specification 2625 and then Present (Spec_Id) 2626 and then No_Return (Spec_Id) 2627 then 2628 Check_Returns (HSS, 'P', Missing_Ret, Spec_Id); 2629 end if; 2630 2631 -- Special checks in SPARK mode 2632 2633 if Nkind (Body_Spec) = N_Function_Specification then 2634 2635 -- In SPARK mode, last statement of a function should be a return 2636 2637 declare 2638 Stat : constant Node_Id := Last_Source_Statement (HSS); 2639 begin 2640 if Present (Stat) 2641 and then not Nkind_In (Stat, N_Simple_Return_Statement, 2642 N_Extended_Return_Statement) 2643 then 2644 Check_SPARK_05_Restriction 2645 ("last statement in function should be RETURN", Stat); 2646 end if; 2647 end; 2648 2649 -- In SPARK mode, verify that a procedure has no return 2650 2651 elsif Nkind (Body_Spec) = N_Procedure_Specification then 2652 if Present (Spec_Id) then 2653 Id := Spec_Id; 2654 else 2655 Id := Body_Id; 2656 end if; 2657 2658 -- Would be nice to point to return statement here, can we 2659 -- borrow the Check_Returns procedure here ??? 2660 2661 if Return_Present (Id) then 2662 Check_SPARK_05_Restriction 2663 ("procedure should not have RETURN", N); 2664 end if; 2665 end if; 2666 end Check_Missing_Return; 2667 2668 ----------------------- 2669 -- Disambiguate_Spec -- 2670 ----------------------- 2671 2672 function Disambiguate_Spec return Entity_Id is 2673 Priv_Spec : Entity_Id; 2674 Spec_N : Entity_Id; 2675 2676 procedure Replace_Types (To_Corresponding : Boolean); 2677 -- Depending on the flag, replace the type of formal parameters of 2678 -- Body_Id if it is a concurrent type implementing interfaces with 2679 -- the corresponding record type or the other way around. 2680 2681 procedure Replace_Types (To_Corresponding : Boolean) is 2682 Formal : Entity_Id; 2683 Formal_Typ : Entity_Id; 2684 2685 begin 2686 Formal := First_Formal (Body_Id); 2687 while Present (Formal) loop 2688 Formal_Typ := Etype (Formal); 2689 2690 if Is_Class_Wide_Type (Formal_Typ) then 2691 Formal_Typ := Root_Type (Formal_Typ); 2692 end if; 2693 2694 -- From concurrent type to corresponding record 2695 2696 if To_Corresponding then 2697 if Is_Concurrent_Type (Formal_Typ) 2698 and then Present (Corresponding_Record_Type (Formal_Typ)) 2699 and then 2700 Present (Interfaces 2701 (Corresponding_Record_Type (Formal_Typ))) 2702 then 2703 Set_Etype (Formal, 2704 Corresponding_Record_Type (Formal_Typ)); 2705 end if; 2706 2707 -- From corresponding record to concurrent type 2708 2709 else 2710 if Is_Concurrent_Record_Type (Formal_Typ) 2711 and then Present (Interfaces (Formal_Typ)) 2712 then 2713 Set_Etype (Formal, 2714 Corresponding_Concurrent_Type (Formal_Typ)); 2715 end if; 2716 end if; 2717 2718 Next_Formal (Formal); 2719 end loop; 2720 end Replace_Types; 2721 2722 -- Start of processing for Disambiguate_Spec 2723 2724 begin 2725 -- Try to retrieve the specification of the body as is. All error 2726 -- messages are suppressed because the body may not have a spec in 2727 -- its current state. 2728 2729 Spec_N := Find_Corresponding_Spec (N, False); 2730 2731 -- It is possible that this is the body of a primitive declared 2732 -- between a private and a full view of a concurrent type. The 2733 -- controlling parameter of the spec carries the concurrent type, 2734 -- not the corresponding record type as transformed by Analyze_ 2735 -- Subprogram_Specification. In such cases, we undo the change 2736 -- made by the analysis of the specification and try to find the 2737 -- spec again. 2738 2739 -- Note that wrappers already have their corresponding specs and 2740 -- bodies set during their creation, so if the candidate spec is 2741 -- a wrapper, then we definitely need to swap all types to their 2742 -- original concurrent status. 2743 2744 if No (Spec_N) 2745 or else Is_Primitive_Wrapper (Spec_N) 2746 then 2747 -- Restore all references of corresponding record types to the 2748 -- original concurrent types. 2749 2750 Replace_Types (To_Corresponding => False); 2751 Priv_Spec := Find_Corresponding_Spec (N, False); 2752 2753 -- The current body truly belongs to a primitive declared between 2754 -- a private and a full view. We leave the modified body as is, 2755 -- and return the true spec. 2756 2757 if Present (Priv_Spec) 2758 and then Is_Private_Primitive (Priv_Spec) 2759 then 2760 return Priv_Spec; 2761 end if; 2762 2763 -- In case that this is some sort of error, restore the original 2764 -- state of the body. 2765 2766 Replace_Types (To_Corresponding => True); 2767 end if; 2768 2769 return Spec_N; 2770 end Disambiguate_Spec; 2771 2772 ---------------------------- 2773 -- Exchange_Limited_Views -- 2774 ---------------------------- 2775 2776 procedure Exchange_Limited_Views (Subp_Id : Entity_Id) is 2777 procedure Detect_And_Exchange (Id : Entity_Id); 2778 -- Determine whether Id's type denotes an incomplete type associated 2779 -- with a limited with clause and exchange the limited view with the 2780 -- non-limited one when available. Note that the non-limited view 2781 -- may exist because of a with_clause in another unit in the context, 2782 -- but cannot be used because the current view of the enclosing unit 2783 -- is still a limited view. 2784 2785 ------------------------- 2786 -- Detect_And_Exchange -- 2787 ------------------------- 2788 2789 procedure Detect_And_Exchange (Id : Entity_Id) is 2790 Typ : constant Entity_Id := Etype (Id); 2791 begin 2792 if From_Limited_With (Typ) 2793 and then Has_Non_Limited_View (Typ) 2794 and then not From_Limited_With (Scope (Typ)) 2795 then 2796 Set_Etype (Id, Non_Limited_View (Typ)); 2797 end if; 2798 end Detect_And_Exchange; 2799 2800 -- Local variables 2801 2802 Formal : Entity_Id; 2803 2804 -- Start of processing for Exchange_Limited_Views 2805 2806 begin 2807 if No (Subp_Id) then 2808 return; 2809 2810 -- Do not process subprogram bodies as they already use the non- 2811 -- limited view of types. 2812 2813 elsif not Ekind_In (Subp_Id, E_Function, E_Procedure) then 2814 return; 2815 end if; 2816 2817 -- Examine all formals and swap views when applicable 2818 2819 Formal := First_Formal (Subp_Id); 2820 while Present (Formal) loop 2821 Detect_And_Exchange (Formal); 2822 2823 Next_Formal (Formal); 2824 end loop; 2825 2826 -- Process the return type of a function 2827 2828 if Ekind (Subp_Id) = E_Function then 2829 Detect_And_Exchange (Subp_Id); 2830 end if; 2831 end Exchange_Limited_Views; 2832 2833 ------------------------------------- 2834 -- Is_Private_Concurrent_Primitive -- 2835 ------------------------------------- 2836 2837 function Is_Private_Concurrent_Primitive 2838 (Subp_Id : Entity_Id) return Boolean 2839 is 2840 Formal_Typ : Entity_Id; 2841 2842 begin 2843 if Present (First_Formal (Subp_Id)) then 2844 Formal_Typ := Etype (First_Formal (Subp_Id)); 2845 2846 if Is_Concurrent_Record_Type (Formal_Typ) then 2847 if Is_Class_Wide_Type (Formal_Typ) then 2848 Formal_Typ := Root_Type (Formal_Typ); 2849 end if; 2850 2851 Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ); 2852 end if; 2853 2854 -- The type of the first formal is a concurrent tagged type with 2855 -- a private view. 2856 2857 return 2858 Is_Concurrent_Type (Formal_Typ) 2859 and then Is_Tagged_Type (Formal_Typ) 2860 and then Has_Private_Declaration (Formal_Typ); 2861 end if; 2862 2863 return False; 2864 end Is_Private_Concurrent_Primitive; 2865 2866 ---------------------------- 2867 -- Set_Trivial_Subprogram -- 2868 ---------------------------- 2869 2870 procedure Set_Trivial_Subprogram (N : Node_Id) is 2871 Nxt : constant Node_Id := Next (N); 2872 2873 begin 2874 Set_Is_Trivial_Subprogram (Body_Id); 2875 2876 if Present (Spec_Id) then 2877 Set_Is_Trivial_Subprogram (Spec_Id); 2878 end if; 2879 2880 if Present (Nxt) 2881 and then Nkind (Nxt) = N_Simple_Return_Statement 2882 and then No (Next (Nxt)) 2883 and then Present (Expression (Nxt)) 2884 and then Is_Entity_Name (Expression (Nxt)) 2885 then 2886 Set_Never_Set_In_Source (Entity (Expression (Nxt)), False); 2887 end if; 2888 end Set_Trivial_Subprogram; 2889 2890 --------------------------------- 2891 -- Verify_Overriding_Indicator -- 2892 --------------------------------- 2893 2894 procedure Verify_Overriding_Indicator is 2895 begin 2896 if Must_Override (Body_Spec) then 2897 if Nkind (Spec_Id) = N_Defining_Operator_Symbol 2898 and then Operator_Matches_Spec (Spec_Id, Spec_Id) 2899 then 2900 null; 2901 2902 elsif not Present (Overridden_Operation (Spec_Id)) then 2903 Error_Msg_NE 2904 ("subprogram& is not overriding", Body_Spec, Spec_Id); 2905 2906 -- Overriding indicators aren't allowed for protected subprogram 2907 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change 2908 -- this to a warning if -gnatd.E is enabled. 2909 2910 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then 2911 Error_Msg_Warn := Error_To_Warning; 2912 Error_Msg_N 2913 ("<<overriding indicator not allowed for protected " 2914 & "subprogram body", Body_Spec); 2915 end if; 2916 2917 elsif Must_Not_Override (Body_Spec) then 2918 if Present (Overridden_Operation (Spec_Id)) then 2919 Error_Msg_NE 2920 ("subprogram& overrides inherited operation", 2921 Body_Spec, Spec_Id); 2922 2923 elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol 2924 and then Operator_Matches_Spec (Spec_Id, Spec_Id) 2925 then 2926 Error_Msg_NE 2927 ("subprogram& overrides predefined operator ", 2928 Body_Spec, Spec_Id); 2929 2930 -- Overriding indicators aren't allowed for protected subprogram 2931 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change 2932 -- this to a warning if -gnatd.E is enabled. 2933 2934 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then 2935 Error_Msg_Warn := Error_To_Warning; 2936 2937 Error_Msg_N 2938 ("<<overriding indicator not allowed " 2939 & "for protected subprogram body", Body_Spec); 2940 2941 -- If this is not a primitive operation, then the overriding 2942 -- indicator is altogether illegal. 2943 2944 elsif not Is_Primitive (Spec_Id) then 2945 Error_Msg_N 2946 ("overriding indicator only allowed " 2947 & "if subprogram is primitive", Body_Spec); 2948 end if; 2949 2950 -- If checking the style rule and the operation overrides, then 2951 -- issue a warning about a missing overriding_indicator. Protected 2952 -- subprogram bodies are excluded from this style checking, since 2953 -- they aren't primitives (even though their declarations can 2954 -- override) and aren't allowed to have an overriding_indicator. 2955 2956 elsif Style_Check 2957 and then Present (Overridden_Operation (Spec_Id)) 2958 and then Ekind (Scope (Spec_Id)) /= E_Protected_Type 2959 then 2960 pragma Assert (Unit_Declaration_Node (Body_Id) = N); 2961 Style.Missing_Overriding (N, Body_Id); 2962 2963 elsif Style_Check 2964 and then Can_Override_Operator (Spec_Id) 2965 and then not Is_Predefined_File_Name 2966 (Unit_File_Name (Get_Source_Unit (Spec_Id))) 2967 then 2968 pragma Assert (Unit_Declaration_Node (Body_Id) = N); 2969 Style.Missing_Overriding (N, Body_Id); 2970 end if; 2971 end Verify_Overriding_Indicator; 2972 2973 -- Local variables 2974 2975 Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode; 2976 Cloned_Body_For_C : Node_Id := Empty; 2977 2978 -- Start of processing for Analyze_Subprogram_Body_Helper 2979 2980 begin 2981 -- A [generic] subprogram body "freezes" the contract of the nearest 2982 -- enclosing package body and all other contracts encountered in the 2983 -- same declarative part up to and excluding the subprogram body: 2984 2985 -- package body Nearest_Enclosing_Package 2986 -- with Refined_State => (State => Constit) 2987 -- is 2988 -- Constit : ...; 2989 2990 -- procedure Freezes_Enclosing_Package_Body 2991 -- with Refined_Depends => (Input => Constit) ... 2992 2993 -- This ensures that any annotations referenced by the contract of the 2994 -- [generic] subprogram body are available. This form of "freezing" is 2995 -- decoupled from the usual Freeze_xxx mechanism because it must also 2996 -- work in the context of generics where normal freezing is disabled. 2997 2998 -- Only bodies coming from source should cause this type of "freezing". 2999 -- Expression functions that act as bodies and complete an initial 3000 -- declaration must be included in this category, hence the use of 3001 -- Original_Node. 3002 3003 if Comes_From_Source (Original_Node (N)) then 3004 Analyze_Previous_Contracts (N); 3005 end if; 3006 3007 -- Generic subprograms are handled separately. They always have a 3008 -- generic specification. Determine whether current scope has a 3009 -- previous declaration. 3010 3011 -- If the subprogram body is defined within an instance of the same 3012 -- name, the instance appears as a package renaming, and will be hidden 3013 -- within the subprogram. 3014 3015 if Present (Prev_Id) 3016 and then not Is_Overloadable (Prev_Id) 3017 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration 3018 or else Comes_From_Source (Prev_Id)) 3019 then 3020 if Is_Generic_Subprogram (Prev_Id) then 3021 Spec_Id := Prev_Id; 3022 3023 -- A subprogram body is Ghost when it is stand alone and subject 3024 -- to pragma Ghost or when the corresponding spec is Ghost. Set 3025 -- the mode now to ensure that any nodes generated during analysis 3026 -- and expansion are properly marked as Ghost. 3027 3028 Set_Ghost_Mode (N, Spec_Id); 3029 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 3030 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); 3031 3032 Analyze_Generic_Subprogram_Body (N, Spec_Id); 3033 3034 if Nkind (N) = N_Subprogram_Body then 3035 HSS := Handled_Statement_Sequence (N); 3036 Check_Missing_Return; 3037 end if; 3038 3039 Ghost_Mode := Save_Ghost_Mode; 3040 return; 3041 3042 else 3043 -- Previous entity conflicts with subprogram name. Attempting to 3044 -- enter name will post error. 3045 3046 Enter_Name (Body_Id); 3047 Ghost_Mode := Save_Ghost_Mode; 3048 return; 3049 end if; 3050 3051 -- Non-generic case, find the subprogram declaration, if one was seen, 3052 -- or enter new overloaded entity in the current scope. If the 3053 -- Current_Entity is the Body_Id itself, the unit is being analyzed as 3054 -- part of the context of one of its subunits. No need to redo the 3055 -- analysis. 3056 3057 elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then 3058 Ghost_Mode := Save_Ghost_Mode; 3059 return; 3060 3061 else 3062 Body_Id := Analyze_Subprogram_Specification (Body_Spec); 3063 3064 if Nkind (N) = N_Subprogram_Body_Stub 3065 or else No (Corresponding_Spec (N)) 3066 then 3067 if Is_Private_Concurrent_Primitive (Body_Id) then 3068 Spec_Id := Disambiguate_Spec; 3069 3070 -- A subprogram body is Ghost when it is stand alone and 3071 -- subject to pragma Ghost or when the corresponding spec is 3072 -- Ghost. Set the mode now to ensure that any nodes generated 3073 -- during analysis and expansion are properly marked as Ghost. 3074 3075 Set_Ghost_Mode (N, Spec_Id); 3076 3077 else 3078 Spec_Id := Find_Corresponding_Spec (N); 3079 3080 -- A subprogram body is Ghost when it is stand alone and 3081 -- subject to pragma Ghost or when the corresponding spec is 3082 -- Ghost. Set the mode now to ensure that any nodes generated 3083 -- during analysis and expansion are properly marked as Ghost. 3084 3085 Set_Ghost_Mode (N, Spec_Id); 3086 3087 -- In GNATprove mode, if the body has no previous spec, create 3088 -- one so that the inlining machinery can operate properly. 3089 -- Transfer aspects, if any, to the new spec, so that they 3090 -- are legal and can be processed ahead of the body. 3091 -- We make two copies of the given spec, one for the new 3092 -- declaration, and one for the body. 3093 3094 if No (Spec_Id) and then GNATprove_Mode 3095 3096 -- Inlining does not apply during pre-analysis of code 3097 3098 and then Full_Analysis 3099 3100 -- Inlining only applies to full bodies, not stubs 3101 3102 and then Nkind (N) /= N_Subprogram_Body_Stub 3103 3104 -- Inlining only applies to bodies in the source code, not to 3105 -- those generated by the compiler. In particular, expression 3106 -- functions, whose body is generated by the compiler, are 3107 -- treated specially by GNATprove. 3108 3109 and then Comes_From_Source (Body_Id) 3110 3111 -- This cannot be done for a compilation unit, which is not 3112 -- in a context where we can insert a new spec. 3113 3114 and then Is_List_Member (N) 3115 3116 -- Inlining only applies to subprograms without contracts, 3117 -- as a contract is a sign that GNATprove should perform a 3118 -- modular analysis of the subprogram instead of a contextual 3119 -- analysis at each call site. The same test is performed in 3120 -- Inline.Can_Be_Inlined_In_GNATprove_Mode. It is repeated 3121 -- here in another form (because the contract has not 3122 -- been attached to the body) to avoid frontend errors in 3123 -- case pragmas are used instead of aspects, because the 3124 -- corresponding pragmas in the body would not be transferred 3125 -- to the spec, leading to legality errors. 3126 3127 and then not Body_Has_Contract 3128 and then not Inside_A_Generic 3129 then 3130 Build_Subprogram_Declaration; 3131 3132 -- If this is a function that returns a constrained array, and 3133 -- we are generating SPARK_For_C, create subprogram declaration 3134 -- to simplify subsequent C generation. 3135 3136 elsif No (Spec_Id) 3137 and then Modify_Tree_For_C 3138 and then Nkind (Body_Spec) = N_Function_Specification 3139 and then Is_Array_Type (Etype (Body_Id)) 3140 and then Is_Constrained (Etype (Body_Id)) 3141 then 3142 Build_Subprogram_Declaration; 3143 end if; 3144 end if; 3145 3146 -- If this is a duplicate body, no point in analyzing it 3147 3148 if Error_Posted (N) then 3149 Ghost_Mode := Save_Ghost_Mode; 3150 return; 3151 end if; 3152 3153 -- A subprogram body should cause freezing of its own declaration, 3154 -- but if there was no previous explicit declaration, then the 3155 -- subprogram will get frozen too late (there may be code within 3156 -- the body that depends on the subprogram having been frozen, 3157 -- such as uses of extra formals), so we force it to be frozen 3158 -- here. Same holds if the body and spec are compilation units. 3159 -- Finally, if the return type is an anonymous access to protected 3160 -- subprogram, it must be frozen before the body because its 3161 -- expansion has generated an equivalent type that is used when 3162 -- elaborating the body. 3163 3164 -- An exception in the case of Ada 2012, AI05-177: The bodies 3165 -- created for expression functions do not freeze. 3166 3167 if No (Spec_Id) 3168 and then Nkind (Original_Node (N)) /= N_Expression_Function 3169 then 3170 Freeze_Before (N, Body_Id); 3171 3172 elsif Nkind (Parent (N)) = N_Compilation_Unit then 3173 Freeze_Before (N, Spec_Id); 3174 3175 elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then 3176 Freeze_Before (N, Etype (Body_Id)); 3177 end if; 3178 3179 else 3180 Spec_Id := Corresponding_Spec (N); 3181 3182 -- A subprogram body is Ghost when it is stand alone and subject 3183 -- to pragma Ghost or when the corresponding spec is Ghost. Set 3184 -- the mode now to ensure that any nodes generated during analysis 3185 -- and expansion are properly marked as Ghost. 3186 3187 Set_Ghost_Mode (N, Spec_Id); 3188 end if; 3189 end if; 3190 3191 -- Previously we scanned the body to look for nested subprograms, and 3192 -- rejected an inline directive if nested subprograms were present, 3193 -- because the back-end would generate conflicting symbols for the 3194 -- nested bodies. This is now unnecessary. 3195 3196 -- Look ahead to recognize a pragma Inline that appears after the body 3197 3198 Check_Inline_Pragma (Spec_Id); 3199 3200 -- Deal with special case of a fully private operation in the body of 3201 -- the protected type. We must create a declaration for the subprogram, 3202 -- in order to attach the protected subprogram that will be used in 3203 -- internal calls. We exclude compiler generated bodies from the 3204 -- expander since the issue does not arise for those cases. 3205 3206 if No (Spec_Id) 3207 and then Comes_From_Source (N) 3208 and then Is_Protected_Type (Current_Scope) 3209 then 3210 Spec_Id := Build_Private_Protected_Declaration (N); 3211 end if; 3212 3213 -- If a separate spec is present, then deal with freezing issues 3214 3215 if Present (Spec_Id) then 3216 Spec_Decl := Unit_Declaration_Node (Spec_Id); 3217 Verify_Overriding_Indicator; 3218 3219 -- In general, the spec will be frozen when we start analyzing the 3220 -- body. However, for internally generated operations, such as 3221 -- wrapper functions for inherited operations with controlling 3222 -- results, the spec may not have been frozen by the time we expand 3223 -- the freeze actions that include the bodies. In particular, extra 3224 -- formals for accessibility or for return-in-place may need to be 3225 -- generated. Freeze nodes, if any, are inserted before the current 3226 -- body. These freeze actions are also needed in ASIS mode and in 3227 -- Compile_Only mode to enable the proper back-end type annotations. 3228 -- They are necessary in any case to insure order of elaboration 3229 -- in gigi. 3230 3231 if not Is_Frozen (Spec_Id) 3232 and then (Expander_Active 3233 or else ASIS_Mode 3234 or else (Operating_Mode = Check_Semantics 3235 and then Serious_Errors_Detected = 0)) 3236 then 3237 Set_Has_Delayed_Freeze (Spec_Id); 3238 Freeze_Before (N, Spec_Id); 3239 end if; 3240 end if; 3241 3242 -- Place subprogram on scope stack, and make formals visible. If there 3243 -- is a spec, the visible entity remains that of the spec. 3244 3245 if Present (Spec_Id) then 3246 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False); 3247 3248 if Is_Child_Unit (Spec_Id) then 3249 Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False); 3250 end if; 3251 3252 if Style_Check then 3253 Style.Check_Identifier (Body_Id, Spec_Id); 3254 end if; 3255 3256 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 3257 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); 3258 3259 if Is_Abstract_Subprogram (Spec_Id) then 3260 Error_Msg_N ("an abstract subprogram cannot have a body", N); 3261 Ghost_Mode := Save_Ghost_Mode; 3262 return; 3263 3264 else 3265 Set_Convention (Body_Id, Convention (Spec_Id)); 3266 Set_Has_Completion (Spec_Id); 3267 3268 -- Inherit the "ghostness" of the subprogram spec. Note that this 3269 -- property is not directly inherited as the body may be subject 3270 -- to a different Ghost assertion policy. 3271 3272 if Ghost_Mode > None or else Is_Ghost_Entity (Spec_Id) then 3273 Set_Is_Ghost_Entity (Body_Id); 3274 3275 -- The Ghost policy in effect at the point of declaration and 3276 -- at the point of completion must match (SPARK RM 6.9(14)). 3277 3278 Check_Ghost_Completion (Spec_Id, Body_Id); 3279 end if; 3280 3281 if Is_Protected_Type (Scope (Spec_Id)) then 3282 Prot_Typ := Scope (Spec_Id); 3283 end if; 3284 3285 -- If this is a body generated for a renaming, do not check for 3286 -- full conformance. The check is redundant, because the spec of 3287 -- the body is a copy of the spec in the renaming declaration, 3288 -- and the test can lead to spurious errors on nested defaults. 3289 3290 if Present (Spec_Decl) 3291 and then not Comes_From_Source (N) 3292 and then 3293 (Nkind (Original_Node (Spec_Decl)) = 3294 N_Subprogram_Renaming_Declaration 3295 or else (Present (Corresponding_Body (Spec_Decl)) 3296 and then 3297 Nkind (Unit_Declaration_Node 3298 (Corresponding_Body (Spec_Decl))) = 3299 N_Subprogram_Renaming_Declaration)) 3300 then 3301 Conformant := True; 3302 3303 -- Conversely, the spec may have been generated for specless body 3304 -- with an inline pragma. 3305 3306 elsif Comes_From_Source (N) 3307 and then not Comes_From_Source (Spec_Id) 3308 and then Has_Pragma_Inline (Spec_Id) 3309 then 3310 Conformant := True; 3311 3312 else 3313 Check_Conformance 3314 (Body_Id, Spec_Id, 3315 Fully_Conformant, True, Conformant, Body_Id); 3316 end if; 3317 3318 -- If the body is not fully conformant, we have to decide if we 3319 -- should analyze it or not. If it has a really messed up profile 3320 -- then we probably should not analyze it, since we will get too 3321 -- many bogus messages. 3322 3323 -- Our decision is to go ahead in the non-fully conformant case 3324 -- only if it is at least mode conformant with the spec. Note 3325 -- that the call to Check_Fully_Conformant has issued the proper 3326 -- error messages to complain about the lack of conformance. 3327 3328 if not Conformant 3329 and then not Mode_Conformant (Body_Id, Spec_Id) 3330 then 3331 Ghost_Mode := Save_Ghost_Mode; 3332 return; 3333 end if; 3334 end if; 3335 3336 if Spec_Id /= Body_Id then 3337 Reference_Body_Formals (Spec_Id, Body_Id); 3338 end if; 3339 3340 Set_Ekind (Body_Id, E_Subprogram_Body); 3341 3342 if Nkind (N) = N_Subprogram_Body_Stub then 3343 Set_Corresponding_Spec_Of_Stub (N, Spec_Id); 3344 3345 -- Regular body 3346 3347 else 3348 Set_Corresponding_Spec (N, Spec_Id); 3349 3350 -- Ada 2005 (AI-345): If the operation is a primitive operation 3351 -- of a concurrent type, the type of the first parameter has been 3352 -- replaced with the corresponding record, which is the proper 3353 -- run-time structure to use. However, within the body there may 3354 -- be uses of the formals that depend on primitive operations 3355 -- of the type (in particular calls in prefixed form) for which 3356 -- we need the original concurrent type. The operation may have 3357 -- several controlling formals, so the replacement must be done 3358 -- for all of them. 3359 3360 if Comes_From_Source (Spec_Id) 3361 and then Present (First_Entity (Spec_Id)) 3362 and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type 3363 and then Is_Tagged_Type (Etype (First_Entity (Spec_Id))) 3364 and then Present (Interfaces (Etype (First_Entity (Spec_Id)))) 3365 and then Present (Corresponding_Concurrent_Type 3366 (Etype (First_Entity (Spec_Id)))) 3367 then 3368 declare 3369 Typ : constant Entity_Id := Etype (First_Entity (Spec_Id)); 3370 Form : Entity_Id; 3371 3372 begin 3373 Form := First_Formal (Spec_Id); 3374 while Present (Form) loop 3375 if Etype (Form) = Typ then 3376 Set_Etype (Form, Corresponding_Concurrent_Type (Typ)); 3377 end if; 3378 3379 Next_Formal (Form); 3380 end loop; 3381 end; 3382 end if; 3383 3384 -- Make the formals visible, and place subprogram on scope stack. 3385 -- This is also the point at which we set Last_Real_Spec_Entity 3386 -- to mark the entities which will not be moved to the body. 3387 3388 Install_Formals (Spec_Id); 3389 Last_Real_Spec_Entity := Last_Entity (Spec_Id); 3390 3391 -- Within an instance, add local renaming declarations so that 3392 -- gdb can retrieve the values of actuals more easily. This is 3393 -- only relevant if generating code (and indeed we definitely 3394 -- do not want these definitions -gnatc mode, because that would 3395 -- confuse ASIS). 3396 3397 if Is_Generic_Instance (Spec_Id) 3398 and then Is_Wrapper_Package (Current_Scope) 3399 and then Expander_Active 3400 then 3401 Build_Subprogram_Instance_Renamings (N, Current_Scope); 3402 end if; 3403 3404 Push_Scope (Spec_Id); 3405 3406 -- Make sure that the subprogram is immediately visible. For 3407 -- child units that have no separate spec this is indispensable. 3408 -- Otherwise it is safe albeit redundant. 3409 3410 Set_Is_Immediately_Visible (Spec_Id); 3411 end if; 3412 3413 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id); 3414 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id)); 3415 Set_Scope (Body_Id, Scope (Spec_Id)); 3416 3417 -- Case of subprogram body with no previous spec 3418 3419 else 3420 -- Check for style warning required 3421 3422 if Style_Check 3423 3424 -- Only apply check for source level subprograms for which checks 3425 -- have not been suppressed. 3426 3427 and then Comes_From_Source (Body_Id) 3428 and then not Suppress_Style_Checks (Body_Id) 3429 3430 -- No warnings within an instance 3431 3432 and then not In_Instance 3433 3434 -- No warnings for expression functions 3435 3436 and then Nkind (Original_Node (N)) /= N_Expression_Function 3437 then 3438 Style.Body_With_No_Spec (N); 3439 end if; 3440 3441 New_Overloaded_Entity (Body_Id); 3442 3443 -- A subprogram body declared within a Ghost region is automatically 3444 -- Ghost (SPARK RM 6.9(2)). 3445 3446 if Ghost_Mode > None then 3447 Set_Is_Ghost_Entity (Body_Id); 3448 end if; 3449 3450 if Nkind (N) /= N_Subprogram_Body_Stub then 3451 Set_Acts_As_Spec (N); 3452 Generate_Definition (Body_Id); 3453 Generate_Reference 3454 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True); 3455 Install_Formals (Body_Id); 3456 3457 Push_Scope (Body_Id); 3458 end if; 3459 3460 -- For stubs and bodies with no previous spec, generate references to 3461 -- formals. 3462 3463 Generate_Reference_To_Formals (Body_Id); 3464 end if; 3465 3466 -- Entry barrier functions are generated outside the protected type and 3467 -- should not carry the SPARK_Mode of the enclosing context. 3468 3469 if Nkind (N) = N_Subprogram_Body 3470 and then Is_Entry_Barrier_Function (N) 3471 then 3472 null; 3473 3474 -- The body is generated as part of expression function expansion. When 3475 -- the expression function appears in the visible declarations of a 3476 -- package, the body is added to the private declarations. Since both 3477 -- declarative lists may be subject to a different SPARK_Mode, inherit 3478 -- the mode of the spec. 3479 3480 -- package P with SPARK_Mode is 3481 -- function Expr_Func ... is (...); -- original 3482 -- [function Expr_Func ...;] -- generated spec 3483 -- -- mode is ON 3484 -- private 3485 -- pragma SPARK_Mode (Off); 3486 -- [function Expr_Func ... is return ...;] -- generated body 3487 -- end P; -- mode is ON 3488 3489 elsif not Comes_From_Source (N) 3490 and then Present (Prev_Id) 3491 and then Is_Expression_Function (Prev_Id) 3492 then 3493 Set_SPARK_Pragma (Body_Id, SPARK_Pragma (Prev_Id)); 3494 Set_SPARK_Pragma_Inherited 3495 (Body_Id, SPARK_Pragma_Inherited (Prev_Id)); 3496 3497 -- Set the SPARK_Mode from the current context (may be overwritten later 3498 -- with explicit pragma). Exclude the case where the SPARK_Mode appears 3499 -- initially on a stand-alone subprogram body, but is then relocated to 3500 -- a generated corresponding spec. In this scenario the mode is shared 3501 -- between the spec and body. 3502 3503 elsif No (SPARK_Pragma (Body_Id)) then 3504 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 3505 Set_SPARK_Pragma_Inherited (Body_Id); 3506 end if; 3507 3508 -- If the return type is an anonymous access type whose designated type 3509 -- is the limited view of a class-wide type and the non-limited view is 3510 -- available, update the return type accordingly. 3511 3512 if Ada_Version >= Ada_2005 and then Comes_From_Source (N) then 3513 declare 3514 Etyp : Entity_Id; 3515 Rtyp : Entity_Id; 3516 3517 begin 3518 Rtyp := Etype (Current_Scope); 3519 3520 if Ekind (Rtyp) = E_Anonymous_Access_Type then 3521 Etyp := Directly_Designated_Type (Rtyp); 3522 3523 if Is_Class_Wide_Type (Etyp) 3524 and then From_Limited_With (Etyp) 3525 then 3526 Set_Directly_Designated_Type 3527 (Etype (Current_Scope), Available_View (Etyp)); 3528 end if; 3529 end if; 3530 end; 3531 end if; 3532 3533 -- If this is the proper body of a stub, we must verify that the stub 3534 -- conforms to the body, and to the previous spec if one was present. 3535 -- We know already that the body conforms to that spec. This test is 3536 -- only required for subprograms that come from source. 3537 3538 if Nkind (Parent (N)) = N_Subunit 3539 and then Comes_From_Source (N) 3540 and then not Error_Posted (Body_Id) 3541 and then Nkind (Corresponding_Stub (Parent (N))) = 3542 N_Subprogram_Body_Stub 3543 then 3544 declare 3545 Old_Id : constant Entity_Id := 3546 Defining_Entity 3547 (Specification (Corresponding_Stub (Parent (N)))); 3548 3549 Conformant : Boolean := False; 3550 3551 begin 3552 if No (Spec_Id) then 3553 Check_Fully_Conformant (Body_Id, Old_Id); 3554 3555 else 3556 Check_Conformance 3557 (Body_Id, Old_Id, Fully_Conformant, False, Conformant); 3558 3559 if not Conformant then 3560 3561 -- The stub was taken to be a new declaration. Indicate that 3562 -- it lacks a body. 3563 3564 Set_Has_Completion (Old_Id, False); 3565 end if; 3566 end if; 3567 end; 3568 end if; 3569 3570 Set_Has_Completion (Body_Id); 3571 Check_Eliminated (Body_Id); 3572 3573 -- Analyze any aspect specifications that appear on the subprogram body 3574 -- stub. Stop the analysis now as the stub does not have a declarative 3575 -- or a statement part, and it cannot be inlined. 3576 3577 if Nkind (N) = N_Subprogram_Body_Stub then 3578 if Has_Aspects (N) then 3579 Analyze_Aspect_Specifications_On_Body_Or_Stub (N); 3580 end if; 3581 3582 Ghost_Mode := Save_Ghost_Mode; 3583 return; 3584 end if; 3585 3586 -- If we are generating C and this is a function returning a constrained 3587 -- array type for which we must create a procedure with an extra out 3588 -- parameter then clone the body before it is analyzed. Needed to ensure 3589 -- that the body of the built procedure does not have any reference to 3590 -- the body of the function. 3591 3592 if Expander_Active 3593 and then Modify_Tree_For_C 3594 and then Present (Spec_Id) 3595 and then Ekind (Spec_Id) = E_Function 3596 and then Rewritten_For_C (Spec_Id) 3597 then 3598 Cloned_Body_For_C := Copy_Separate_Tree (N); 3599 end if; 3600 3601 -- Handle frontend inlining 3602 3603 -- Note: Normally we don't do any inlining if expansion is off, since 3604 -- we won't generate code in any case. An exception arises in GNATprove 3605 -- mode where we want to expand some calls in place, even with expansion 3606 -- disabled, since the inlining eases formal verification. 3607 3608 if not GNATprove_Mode 3609 and then Expander_Active 3610 and then Serious_Errors_Detected = 0 3611 and then Present (Spec_Id) 3612 and then Has_Pragma_Inline (Spec_Id) 3613 then 3614 -- Legacy implementation (relying on frontend inlining) 3615 3616 if not Back_End_Inlining then 3617 if (Has_Pragma_Inline_Always (Spec_Id) 3618 and then not Opt.Disable_FE_Inline_Always) 3619 or else 3620 (Has_Pragma_Inline (Spec_Id) and then Front_End_Inlining 3621 and then not Opt.Disable_FE_Inline) 3622 then 3623 Build_Body_To_Inline (N, Spec_Id); 3624 end if; 3625 3626 -- New implementation (relying on backend inlining) 3627 3628 else 3629 if Has_Pragma_Inline_Always (Spec_Id) 3630 or else Optimization_Level > 0 3631 then 3632 -- Handle function returning an unconstrained type 3633 3634 if Comes_From_Source (Body_Id) 3635 and then Ekind (Spec_Id) = E_Function 3636 and then Returns_Unconstrained_Type (Spec_Id) 3637 3638 -- If function builds in place, i.e. returns a limited type, 3639 -- inlining cannot be done. 3640 3641 and then not Is_Limited_Type (Etype (Spec_Id)) 3642 then 3643 Check_And_Split_Unconstrained_Function (N, Spec_Id, Body_Id); 3644 3645 else 3646 declare 3647 Subp_Body : constant Node_Id := 3648 Unit_Declaration_Node (Body_Id); 3649 Subp_Decl : constant List_Id := Declarations (Subp_Body); 3650 3651 begin 3652 -- Do not pass inlining to the backend if the subprogram 3653 -- has declarations or statements which cannot be inlined 3654 -- by the backend. This check is done here to emit an 3655 -- error instead of the generic warning message reported 3656 -- by the GCC backend (ie. "function might not be 3657 -- inlinable"). 3658 3659 if Present (Subp_Decl) 3660 and then Has_Excluded_Declaration (Spec_Id, Subp_Decl) 3661 then 3662 null; 3663 3664 elsif Has_Excluded_Statement 3665 (Spec_Id, 3666 Statements 3667 (Handled_Statement_Sequence (Subp_Body))) 3668 then 3669 null; 3670 3671 -- If the backend inlining is available then at this 3672 -- stage we only have to mark the subprogram as inlined. 3673 -- The expander will take care of registering it in the 3674 -- table of subprograms inlined by the backend a part of 3675 -- processing calls to it (cf. Expand_Call) 3676 3677 else 3678 Set_Is_Inlined (Spec_Id); 3679 end if; 3680 end; 3681 end if; 3682 end if; 3683 end if; 3684 3685 -- In GNATprove mode, inline only when there is a separate subprogram 3686 -- declaration for now, as inlining of subprogram bodies acting as 3687 -- declarations, or subprogram stubs, are not supported by frontend 3688 -- inlining. This inlining should occur after analysis of the body, so 3689 -- that it is known whether the value of SPARK_Mode, which can be 3690 -- defined by a pragma inside the body, is applicable to the body. 3691 3692 elsif GNATprove_Mode 3693 and then Full_Analysis 3694 and then not Inside_A_Generic 3695 and then Present (Spec_Id) 3696 and then 3697 Nkind (Unit_Declaration_Node (Spec_Id)) = N_Subprogram_Declaration 3698 and then Can_Be_Inlined_In_GNATprove_Mode (Spec_Id, Body_Id) 3699 and then not Body_Has_Contract 3700 then 3701 Build_Body_To_Inline (N, Spec_Id); 3702 end if; 3703 3704 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis 3705 -- of the specification we have to install the private withed units. 3706 -- This holds for child units as well. 3707 3708 if Is_Compilation_Unit (Body_Id) 3709 or else Nkind (Parent (N)) = N_Compilation_Unit 3710 then 3711 Install_Private_With_Clauses (Body_Id); 3712 end if; 3713 3714 Check_Anonymous_Return; 3715 3716 -- Set the Protected_Formal field of each extra formal of the protected 3717 -- subprogram to reference the corresponding extra formal of the 3718 -- subprogram that implements it. For regular formals this occurs when 3719 -- the protected subprogram's declaration is expanded, but the extra 3720 -- formals don't get created until the subprogram is frozen. We need to 3721 -- do this before analyzing the protected subprogram's body so that any 3722 -- references to the original subprogram's extra formals will be changed 3723 -- refer to the implementing subprogram's formals (see Expand_Formal). 3724 3725 if Present (Spec_Id) 3726 and then Is_Protected_Type (Scope (Spec_Id)) 3727 and then Present (Protected_Body_Subprogram (Spec_Id)) 3728 then 3729 declare 3730 Impl_Subp : constant Entity_Id := 3731 Protected_Body_Subprogram (Spec_Id); 3732 Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id); 3733 Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp); 3734 begin 3735 while Present (Prot_Ext_Formal) loop 3736 pragma Assert (Present (Impl_Ext_Formal)); 3737 Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal); 3738 Next_Formal_With_Extras (Prot_Ext_Formal); 3739 Next_Formal_With_Extras (Impl_Ext_Formal); 3740 end loop; 3741 end; 3742 end if; 3743 3744 -- Now we can go on to analyze the body 3745 3746 HSS := Handled_Statement_Sequence (N); 3747 Set_Actual_Subtypes (N, Current_Scope); 3748 3749 -- Add a declaration for the Protection object, renaming declarations 3750 -- for discriminals and privals and finally a declaration for the entry 3751 -- family index (if applicable). This form of early expansion is done 3752 -- when the Expander is active because Install_Private_Data_Declarations 3753 -- references entities which were created during regular expansion. The 3754 -- subprogram entity must come from source, and not be an internally 3755 -- generated subprogram. 3756 3757 if Expander_Active 3758 and then Present (Prot_Typ) 3759 and then Present (Spec_Id) 3760 and then Comes_From_Source (Spec_Id) 3761 and then not Is_Eliminated (Spec_Id) 3762 then 3763 Install_Private_Data_Declarations 3764 (Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N)); 3765 end if; 3766 3767 -- Ada 2012 (AI05-0151): Incomplete types coming from a limited context 3768 -- may now appear in parameter and result profiles. Since the analysis 3769 -- of a subprogram body may use the parameter and result profile of the 3770 -- spec, swap any limited views with their non-limited counterpart. 3771 3772 if Ada_Version >= Ada_2012 then 3773 Exchange_Limited_Views (Spec_Id); 3774 end if; 3775 3776 -- Analyze any aspect specifications that appear on the subprogram body 3777 3778 if Has_Aspects (N) then 3779 Analyze_Aspect_Specifications_On_Body_Or_Stub (N); 3780 end if; 3781 3782 Analyze_Declarations (Declarations (N)); 3783 3784 -- Verify that the SPARK_Mode of the body agrees with that of its spec 3785 3786 if Present (Spec_Id) and then Present (SPARK_Pragma (Body_Id)) then 3787 if Present (SPARK_Pragma (Spec_Id)) then 3788 if Get_SPARK_Mode_From_Pragma (SPARK_Pragma (Spec_Id)) = Off 3789 and then 3790 Get_SPARK_Mode_From_Pragma (SPARK_Pragma (Body_Id)) = On 3791 then 3792 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 3793 Error_Msg_N ("incorrect application of SPARK_Mode#", N); 3794 Error_Msg_Sloc := Sloc (SPARK_Pragma (Spec_Id)); 3795 Error_Msg_NE 3796 ("\value Off was set for SPARK_Mode on & #", N, Spec_Id); 3797 end if; 3798 3799 elsif Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Body_Stub then 3800 null; 3801 3802 else 3803 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 3804 Error_Msg_N ("incorrect application of SPARK_Mode #", N); 3805 Error_Msg_Sloc := Sloc (Spec_Id); 3806 Error_Msg_NE 3807 ("\no value was set for SPARK_Mode on & #", N, Spec_Id); 3808 end if; 3809 end if; 3810 3811 -- A subprogram body "freezes" its own contract. Analyze the contract 3812 -- after the declarations of the body have been processed as pragmas 3813 -- are now chained on the contract of the subprogram body. 3814 3815 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id); 3816 3817 -- If SPARK_Mode for body is not On, disable frontend inlining for this 3818 -- subprogram in GNATprove mode, as its body should not be analyzed. 3819 3820 if SPARK_Mode /= On 3821 and then GNATprove_Mode 3822 and then Present (Spec_Id) 3823 and then Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Declaration 3824 then 3825 Set_Body_To_Inline (Parent (Parent (Spec_Id)), Empty); 3826 Set_Is_Inlined_Always (Spec_Id, False); 3827 end if; 3828 3829 -- Check completion, and analyze the statements 3830 3831 Check_Completion; 3832 Inspect_Deferred_Constant_Completion (Declarations (N)); 3833 Analyze (HSS); 3834 3835 -- Deal with end of scope processing for the body 3836 3837 Process_End_Label (HSS, 't', Current_Scope); 3838 End_Scope; 3839 Check_Subprogram_Order (N); 3840 Set_Analyzed (Body_Id); 3841 3842 -- If we have a separate spec, then the analysis of the declarations 3843 -- caused the entities in the body to be chained to the spec id, but 3844 -- we want them chained to the body id. Only the formal parameters 3845 -- end up chained to the spec id in this case. 3846 3847 if Present (Spec_Id) then 3848 3849 -- We must conform to the categorization of our spec 3850 3851 Validate_Categorization_Dependency (N, Spec_Id); 3852 3853 -- And if this is a child unit, the parent units must conform 3854 3855 if Is_Child_Unit (Spec_Id) then 3856 Validate_Categorization_Dependency 3857 (Unit_Declaration_Node (Spec_Id), Spec_Id); 3858 end if; 3859 3860 -- Here is where we move entities from the spec to the body 3861 3862 -- Case where there are entities that stay with the spec 3863 3864 if Present (Last_Real_Spec_Entity) then 3865 3866 -- No body entities (happens when the only real spec entities come 3867 -- from precondition and postcondition pragmas). 3868 3869 if No (Last_Entity (Body_Id)) then 3870 Set_First_Entity (Body_Id, Next_Entity (Last_Real_Spec_Entity)); 3871 3872 -- Body entities present (formals), so chain stuff past them 3873 3874 else 3875 Set_Next_Entity 3876 (Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity)); 3877 end if; 3878 3879 Set_Next_Entity (Last_Real_Spec_Entity, Empty); 3880 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 3881 Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity); 3882 3883 -- Case where there are no spec entities, in this case there can be 3884 -- no body entities either, so just move everything. 3885 3886 -- If the body is generated for an expression function, it may have 3887 -- been preanalyzed already, if 'access was applied to it. 3888 3889 else 3890 if Nkind (Original_Node (Unit_Declaration_Node (Spec_Id))) /= 3891 N_Expression_Function 3892 then 3893 pragma Assert (No (Last_Entity (Body_Id))); 3894 null; 3895 end if; 3896 3897 Set_First_Entity (Body_Id, First_Entity (Spec_Id)); 3898 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 3899 Set_First_Entity (Spec_Id, Empty); 3900 Set_Last_Entity (Spec_Id, Empty); 3901 end if; 3902 end if; 3903 3904 Check_Missing_Return; 3905 3906 -- Now we are going to check for variables that are never modified in 3907 -- the body of the procedure. But first we deal with a special case 3908 -- where we want to modify this check. If the body of the subprogram 3909 -- starts with a raise statement or its equivalent, or if the body 3910 -- consists entirely of a null statement, then it is pretty obvious that 3911 -- it is OK to not reference the parameters. For example, this might be 3912 -- the following common idiom for a stubbed function: statement of the 3913 -- procedure raises an exception. In particular this deals with the 3914 -- common idiom of a stubbed function, which appears something like: 3915 3916 -- function F (A : Integer) return Some_Type; 3917 -- X : Some_Type; 3918 -- begin 3919 -- raise Program_Error; 3920 -- return X; 3921 -- end F; 3922 3923 -- Here the purpose of X is simply to satisfy the annoying requirement 3924 -- in Ada that there be at least one return, and we certainly do not 3925 -- want to go posting warnings on X that it is not initialized. On 3926 -- the other hand, if X is entirely unreferenced that should still 3927 -- get a warning. 3928 3929 -- What we do is to detect these cases, and if we find them, flag the 3930 -- subprogram as being Is_Trivial_Subprogram and then use that flag to 3931 -- suppress unwanted warnings. For the case of the function stub above 3932 -- we have a special test to set X as apparently assigned to suppress 3933 -- the warning. 3934 3935 declare 3936 Stm : Node_Id; 3937 3938 begin 3939 -- Skip initial labels (for one thing this occurs when we are in 3940 -- front end ZCX mode, but in any case it is irrelevant), and also 3941 -- initial Push_xxx_Error_Label nodes, which are also irrelevant. 3942 3943 Stm := First (Statements (HSS)); 3944 while Nkind (Stm) = N_Label 3945 or else Nkind (Stm) in N_Push_xxx_Label 3946 loop 3947 Next (Stm); 3948 end loop; 3949 3950 -- Do the test on the original statement before expansion 3951 3952 declare 3953 Ostm : constant Node_Id := Original_Node (Stm); 3954 3955 begin 3956 -- If explicit raise statement, turn on flag 3957 3958 if Nkind (Ostm) = N_Raise_Statement then 3959 Set_Trivial_Subprogram (Stm); 3960 3961 -- If null statement, and no following statements, turn on flag 3962 3963 elsif Nkind (Stm) = N_Null_Statement 3964 and then Comes_From_Source (Stm) 3965 and then No (Next (Stm)) 3966 then 3967 Set_Trivial_Subprogram (Stm); 3968 3969 -- Check for explicit call cases which likely raise an exception 3970 3971 elsif Nkind (Ostm) = N_Procedure_Call_Statement then 3972 if Is_Entity_Name (Name (Ostm)) then 3973 declare 3974 Ent : constant Entity_Id := Entity (Name (Ostm)); 3975 3976 begin 3977 -- If the procedure is marked No_Return, then likely it 3978 -- raises an exception, but in any case it is not coming 3979 -- back here, so turn on the flag. 3980 3981 if Present (Ent) 3982 and then Ekind (Ent) = E_Procedure 3983 and then No_Return (Ent) 3984 then 3985 Set_Trivial_Subprogram (Stm); 3986 end if; 3987 end; 3988 end if; 3989 end if; 3990 end; 3991 end; 3992 3993 -- Check for variables that are never modified 3994 3995 declare 3996 E1, E2 : Entity_Id; 3997 3998 begin 3999 -- If there is a separate spec, then transfer Never_Set_In_Source 4000 -- flags from out parameters to the corresponding entities in the 4001 -- body. The reason we do that is we want to post error flags on 4002 -- the body entities, not the spec entities. 4003 4004 if Present (Spec_Id) then 4005 E1 := First_Entity (Spec_Id); 4006 while Present (E1) loop 4007 if Ekind (E1) = E_Out_Parameter then 4008 E2 := First_Entity (Body_Id); 4009 while Present (E2) loop 4010 exit when Chars (E1) = Chars (E2); 4011 Next_Entity (E2); 4012 end loop; 4013 4014 if Present (E2) then 4015 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1)); 4016 end if; 4017 end if; 4018 4019 Next_Entity (E1); 4020 end loop; 4021 end if; 4022 4023 -- Check references in body 4024 4025 Check_References (Body_Id); 4026 end; 4027 4028 -- Check for nested subprogram, and mark outer level subprogram if so 4029 4030 declare 4031 Ent : Entity_Id; 4032 4033 begin 4034 if Present (Spec_Id) then 4035 Ent := Spec_Id; 4036 else 4037 Ent := Body_Id; 4038 end if; 4039 4040 loop 4041 Ent := Enclosing_Subprogram (Ent); 4042 exit when No (Ent) or else Is_Subprogram (Ent); 4043 end loop; 4044 4045 if Present (Ent) then 4046 Set_Has_Nested_Subprogram (Ent); 4047 end if; 4048 end; 4049 4050 -- When generating C code, transform a function that returns a 4051 -- constrained array type into a procedure with an out parameter 4052 -- that carries the return value. 4053 4054 if Present (Cloned_Body_For_C) then 4055 Rewrite (N, 4056 Build_Procedure_Body_Form (Spec_Id, Cloned_Body_For_C)); 4057 Analyze (N); 4058 end if; 4059 4060 Ghost_Mode := Save_Ghost_Mode; 4061 end Analyze_Subprogram_Body_Helper; 4062 4063 ------------------------------------ 4064 -- Analyze_Subprogram_Declaration -- 4065 ------------------------------------ 4066 4067 procedure Analyze_Subprogram_Declaration (N : Node_Id) is 4068 Scop : constant Entity_Id := Current_Scope; 4069 Designator : Entity_Id; 4070 4071 Is_Completion : Boolean; 4072 -- Indicates whether a null procedure declaration is a completion 4073 4074 begin 4075 -- Null procedures are not allowed in SPARK 4076 4077 if Nkind (Specification (N)) = N_Procedure_Specification 4078 and then Null_Present (Specification (N)) 4079 then 4080 Check_SPARK_05_Restriction ("null procedure is not allowed", N); 4081 4082 -- Null procedures are allowed in protected types, following the 4083 -- recent AI12-0147. 4084 4085 if Is_Protected_Type (Current_Scope) 4086 and then Ada_Version < Ada_2012 4087 then 4088 Error_Msg_N ("protected operation cannot be a null procedure", N); 4089 end if; 4090 4091 Analyze_Null_Procedure (N, Is_Completion); 4092 4093 -- The null procedure acts as a body, nothing further is needed 4094 4095 if Is_Completion then 4096 return; 4097 end if; 4098 end if; 4099 4100 Designator := Analyze_Subprogram_Specification (Specification (N)); 4101 4102 -- A reference may already have been generated for the unit name, in 4103 -- which case the following call is redundant. However it is needed for 4104 -- declarations that are the rewriting of an expression function. 4105 4106 Generate_Definition (Designator); 4107 4108 -- Set the SPARK mode from the current context (may be overwritten later 4109 -- with explicit pragma). This is not done for entry barrier functions 4110 -- because they are generated outside the protected type and should not 4111 -- carry the mode of the enclosing context. 4112 4113 if Nkind (N) = N_Subprogram_Declaration 4114 and then Is_Entry_Barrier_Function (N) 4115 then 4116 null; 4117 else 4118 Set_SPARK_Pragma (Designator, SPARK_Mode_Pragma); 4119 Set_SPARK_Pragma_Inherited (Designator); 4120 end if; 4121 4122 -- A subprogram declared within a Ghost region is automatically Ghost 4123 -- (SPARK RM 6.9(2)). 4124 4125 if Ghost_Mode > None then 4126 Set_Is_Ghost_Entity (Designator); 4127 end if; 4128 4129 if Debug_Flag_C then 4130 Write_Str ("==> subprogram spec "); 4131 Write_Name (Chars (Designator)); 4132 Write_Str (" from "); 4133 Write_Location (Sloc (N)); 4134 Write_Eol; 4135 Indent; 4136 end if; 4137 4138 Validate_RCI_Subprogram_Declaration (N); 4139 New_Overloaded_Entity (Designator); 4140 Check_Delayed_Subprogram (Designator); 4141 4142 -- If the type of the first formal of the current subprogram is a non- 4143 -- generic tagged private type, mark the subprogram as being a private 4144 -- primitive. Ditto if this is a function with controlling result, and 4145 -- the return type is currently private. In both cases, the type of the 4146 -- controlling argument or result must be in the current scope for the 4147 -- operation to be primitive. 4148 4149 if Has_Controlling_Result (Designator) 4150 and then Is_Private_Type (Etype (Designator)) 4151 and then Scope (Etype (Designator)) = Current_Scope 4152 and then not Is_Generic_Actual_Type (Etype (Designator)) 4153 then 4154 Set_Is_Private_Primitive (Designator); 4155 4156 elsif Present (First_Formal (Designator)) then 4157 declare 4158 Formal_Typ : constant Entity_Id := 4159 Etype (First_Formal (Designator)); 4160 begin 4161 Set_Is_Private_Primitive (Designator, 4162 Is_Tagged_Type (Formal_Typ) 4163 and then Scope (Formal_Typ) = Current_Scope 4164 and then Is_Private_Type (Formal_Typ) 4165 and then not Is_Generic_Actual_Type (Formal_Typ)); 4166 end; 4167 end if; 4168 4169 -- Ada 2005 (AI-251): Abstract interface primitives must be abstract 4170 -- or null. 4171 4172 if Ada_Version >= Ada_2005 4173 and then Comes_From_Source (N) 4174 and then Is_Dispatching_Operation (Designator) 4175 then 4176 declare 4177 E : Entity_Id; 4178 Etyp : Entity_Id; 4179 4180 begin 4181 if Has_Controlling_Result (Designator) then 4182 Etyp := Etype (Designator); 4183 4184 else 4185 E := First_Entity (Designator); 4186 while Present (E) 4187 and then Is_Formal (E) 4188 and then not Is_Controlling_Formal (E) 4189 loop 4190 Next_Entity (E); 4191 end loop; 4192 4193 Etyp := Etype (E); 4194 end if; 4195 4196 if Is_Access_Type (Etyp) then 4197 Etyp := Directly_Designated_Type (Etyp); 4198 end if; 4199 4200 if Is_Interface (Etyp) 4201 and then not Is_Abstract_Subprogram (Designator) 4202 and then not (Ekind (Designator) = E_Procedure 4203 and then Null_Present (Specification (N))) 4204 then 4205 Error_Msg_Name_1 := Chars (Defining_Entity (N)); 4206 4207 -- Specialize error message based on procedures vs. functions, 4208 -- since functions can't be null subprograms. 4209 4210 if Ekind (Designator) = E_Procedure then 4211 Error_Msg_N 4212 ("interface procedure % must be abstract or null", N); 4213 else 4214 Error_Msg_N 4215 ("interface function % must be abstract", N); 4216 end if; 4217 end if; 4218 end; 4219 end if; 4220 4221 -- What is the following code for, it used to be 4222 4223 -- ??? Set_Suppress_Elaboration_Checks 4224 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator)); 4225 4226 -- The following seems equivalent, but a bit dubious 4227 4228 if Elaboration_Checks_Suppressed (Designator) then 4229 Set_Kill_Elaboration_Checks (Designator); 4230 end if; 4231 4232 if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then 4233 Set_Categorization_From_Scope (Designator, Scop); 4234 4235 else 4236 -- For a compilation unit, check for library-unit pragmas 4237 4238 Push_Scope (Designator); 4239 Set_Categorization_From_Pragmas (N); 4240 Validate_Categorization_Dependency (N, Designator); 4241 Pop_Scope; 4242 end if; 4243 4244 -- For a compilation unit, set body required. This flag will only be 4245 -- reset if a valid Import or Interface pragma is processed later on. 4246 4247 if Nkind (Parent (N)) = N_Compilation_Unit then 4248 Set_Body_Required (Parent (N), True); 4249 4250 if Ada_Version >= Ada_2005 4251 and then Nkind (Specification (N)) = N_Procedure_Specification 4252 and then Null_Present (Specification (N)) 4253 then 4254 Error_Msg_N 4255 ("null procedure cannot be declared at library level", N); 4256 end if; 4257 end if; 4258 4259 Generate_Reference_To_Formals (Designator); 4260 Check_Eliminated (Designator); 4261 4262 if Debug_Flag_C then 4263 Outdent; 4264 Write_Str ("<== subprogram spec "); 4265 Write_Name (Chars (Designator)); 4266 Write_Str (" from "); 4267 Write_Location (Sloc (N)); 4268 Write_Eol; 4269 end if; 4270 4271 if Is_Protected_Type (Current_Scope) then 4272 4273 -- Indicate that this is a protected operation, because it may be 4274 -- used in subsequent declarations within the protected type. 4275 4276 Set_Convention (Designator, Convention_Protected); 4277 end if; 4278 4279 List_Inherited_Pre_Post_Aspects (Designator); 4280 4281 if Has_Aspects (N) then 4282 Analyze_Aspect_Specifications (N, Designator); 4283 end if; 4284 end Analyze_Subprogram_Declaration; 4285 4286 -------------------------------------- 4287 -- Analyze_Subprogram_Specification -- 4288 -------------------------------------- 4289 4290 -- Reminder: N here really is a subprogram specification (not a subprogram 4291 -- declaration). This procedure is called to analyze the specification in 4292 -- both subprogram bodies and subprogram declarations (specs). 4293 4294 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is 4295 Designator : constant Entity_Id := Defining_Entity (N); 4296 Formals : constant List_Id := Parameter_Specifications (N); 4297 4298 -- Start of processing for Analyze_Subprogram_Specification 4299 4300 begin 4301 -- User-defined operator is not allowed in SPARK, except as a renaming 4302 4303 if Nkind (Defining_Unit_Name (N)) = N_Defining_Operator_Symbol 4304 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration 4305 then 4306 Check_SPARK_05_Restriction 4307 ("user-defined operator is not allowed", N); 4308 end if; 4309 4310 -- Proceed with analysis. Do not emit a cross-reference entry if the 4311 -- specification comes from an expression function, because it may be 4312 -- the completion of a previous declaration. It is not, the cross- 4313 -- reference entry will be emitted for the new subprogram declaration. 4314 4315 if Nkind (Parent (N)) /= N_Expression_Function then 4316 Generate_Definition (Designator); 4317 end if; 4318 4319 if Nkind (N) = N_Function_Specification then 4320 Set_Ekind (Designator, E_Function); 4321 Set_Mechanism (Designator, Default_Mechanism); 4322 else 4323 Set_Ekind (Designator, E_Procedure); 4324 Set_Etype (Designator, Standard_Void_Type); 4325 end if; 4326 4327 -- Flag Is_Inlined_Always is True by default, and reversed to False for 4328 -- those subprograms which could be inlined in GNATprove mode (because 4329 -- Body_To_Inline is non-Empty) but should not be inlined. 4330 4331 if GNATprove_Mode then 4332 Set_Is_Inlined_Always (Designator); 4333 end if; 4334 4335 -- Introduce new scope for analysis of the formals and the return type 4336 4337 Set_Scope (Designator, Current_Scope); 4338 4339 if Present (Formals) then 4340 Push_Scope (Designator); 4341 Process_Formals (Formals, N); 4342 4343 -- Check dimensions in N for formals with default expression 4344 4345 Analyze_Dimension_Formals (N, Formals); 4346 4347 -- Ada 2005 (AI-345): If this is an overriding operation of an 4348 -- inherited interface operation, and the controlling type is 4349 -- a synchronized type, replace the type with its corresponding 4350 -- record, to match the proper signature of an overriding operation. 4351 -- Same processing for an access parameter whose designated type is 4352 -- derived from a synchronized interface. 4353 4354 if Ada_Version >= Ada_2005 then 4355 declare 4356 Formal : Entity_Id; 4357 Formal_Typ : Entity_Id; 4358 Rec_Typ : Entity_Id; 4359 Desig_Typ : Entity_Id; 4360 4361 begin 4362 Formal := First_Formal (Designator); 4363 while Present (Formal) loop 4364 Formal_Typ := Etype (Formal); 4365 4366 if Is_Concurrent_Type (Formal_Typ) 4367 and then Present (Corresponding_Record_Type (Formal_Typ)) 4368 then 4369 Rec_Typ := Corresponding_Record_Type (Formal_Typ); 4370 4371 if Present (Interfaces (Rec_Typ)) then 4372 Set_Etype (Formal, Rec_Typ); 4373 end if; 4374 4375 elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then 4376 Desig_Typ := Designated_Type (Formal_Typ); 4377 4378 if Is_Concurrent_Type (Desig_Typ) 4379 and then Present (Corresponding_Record_Type (Desig_Typ)) 4380 then 4381 Rec_Typ := Corresponding_Record_Type (Desig_Typ); 4382 4383 if Present (Interfaces (Rec_Typ)) then 4384 Set_Directly_Designated_Type (Formal_Typ, Rec_Typ); 4385 end if; 4386 end if; 4387 end if; 4388 4389 Next_Formal (Formal); 4390 end loop; 4391 end; 4392 end if; 4393 4394 End_Scope; 4395 4396 -- The subprogram scope is pushed and popped around the processing of 4397 -- the return type for consistency with call above to Process_Formals 4398 -- (which itself can call Analyze_Return_Type), and to ensure that any 4399 -- itype created for the return type will be associated with the proper 4400 -- scope. 4401 4402 elsif Nkind (N) = N_Function_Specification then 4403 Push_Scope (Designator); 4404 Analyze_Return_Type (N); 4405 End_Scope; 4406 end if; 4407 4408 -- Function case 4409 4410 if Nkind (N) = N_Function_Specification then 4411 4412 -- Deal with operator symbol case 4413 4414 if Nkind (Designator) = N_Defining_Operator_Symbol then 4415 Valid_Operator_Definition (Designator); 4416 end if; 4417 4418 May_Need_Actuals (Designator); 4419 4420 -- Ada 2005 (AI-251): If the return type is abstract, verify that 4421 -- the subprogram is abstract also. This does not apply to renaming 4422 -- declarations, where abstractness is inherited, and to subprogram 4423 -- bodies generated for stream operations, which become renamings as 4424 -- bodies. 4425 4426 -- In case of primitives associated with abstract interface types 4427 -- the check is applied later (see Analyze_Subprogram_Declaration). 4428 4429 if not Nkind_In (Original_Node (Parent (N)), 4430 N_Abstract_Subprogram_Declaration, 4431 N_Formal_Abstract_Subprogram_Declaration, 4432 N_Subprogram_Renaming_Declaration) 4433 then 4434 if Is_Abstract_Type (Etype (Designator)) 4435 and then not Is_Interface (Etype (Designator)) 4436 then 4437 Error_Msg_N 4438 ("function that returns abstract type must be abstract", N); 4439 4440 -- Ada 2012 (AI-0073): Extend this test to subprograms with an 4441 -- access result whose designated type is abstract. 4442 4443 elsif Ada_Version >= Ada_2012 4444 and then Nkind (Result_Definition (N)) = N_Access_Definition 4445 and then 4446 not Is_Class_Wide_Type (Designated_Type (Etype (Designator))) 4447 and then Is_Abstract_Type (Designated_Type (Etype (Designator))) 4448 then 4449 Error_Msg_N 4450 ("function whose access result designates abstract type " 4451 & "must be abstract", N); 4452 end if; 4453 end if; 4454 end if; 4455 4456 return Designator; 4457 end Analyze_Subprogram_Specification; 4458 4459 ----------------------- 4460 -- Check_Conformance -- 4461 ----------------------- 4462 4463 procedure Check_Conformance 4464 (New_Id : Entity_Id; 4465 Old_Id : Entity_Id; 4466 Ctype : Conformance_Type; 4467 Errmsg : Boolean; 4468 Conforms : out Boolean; 4469 Err_Loc : Node_Id := Empty; 4470 Get_Inst : Boolean := False; 4471 Skip_Controlling_Formals : Boolean := False) 4472 is 4473 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id); 4474 -- Sets Conforms to False. If Errmsg is False, then that's all it does. 4475 -- If Errmsg is True, then processing continues to post an error message 4476 -- for conformance error on given node. Two messages are output. The 4477 -- first message points to the previous declaration with a general "no 4478 -- conformance" message. The second is the detailed reason, supplied as 4479 -- Msg. The parameter N provide information for a possible & insertion 4480 -- in the message, and also provides the location for posting the 4481 -- message in the absence of a specified Err_Loc location. 4482 4483 ----------------------- 4484 -- Conformance_Error -- 4485 ----------------------- 4486 4487 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is 4488 Enode : Node_Id; 4489 4490 begin 4491 Conforms := False; 4492 4493 if Errmsg then 4494 if No (Err_Loc) then 4495 Enode := N; 4496 else 4497 Enode := Err_Loc; 4498 end if; 4499 4500 Error_Msg_Sloc := Sloc (Old_Id); 4501 4502 case Ctype is 4503 when Type_Conformant => 4504 Error_Msg_N -- CODEFIX 4505 ("not type conformant with declaration#!", Enode); 4506 4507 when Mode_Conformant => 4508 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 4509 Error_Msg_N 4510 ("not mode conformant with operation inherited#!", 4511 Enode); 4512 else 4513 Error_Msg_N 4514 ("not mode conformant with declaration#!", Enode); 4515 end if; 4516 4517 when Subtype_Conformant => 4518 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 4519 Error_Msg_N 4520 ("not subtype conformant with operation inherited#!", 4521 Enode); 4522 else 4523 Error_Msg_N 4524 ("not subtype conformant with declaration#!", Enode); 4525 end if; 4526 4527 when Fully_Conformant => 4528 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 4529 Error_Msg_N -- CODEFIX 4530 ("not fully conformant with operation inherited#!", 4531 Enode); 4532 else 4533 Error_Msg_N -- CODEFIX 4534 ("not fully conformant with declaration#!", Enode); 4535 end if; 4536 end case; 4537 4538 Error_Msg_NE (Msg, Enode, N); 4539 end if; 4540 end Conformance_Error; 4541 4542 -- Local Variables 4543 4544 Old_Type : constant Entity_Id := Etype (Old_Id); 4545 New_Type : constant Entity_Id := Etype (New_Id); 4546 Old_Formal : Entity_Id; 4547 New_Formal : Entity_Id; 4548 Access_Types_Match : Boolean; 4549 Old_Formal_Base : Entity_Id; 4550 New_Formal_Base : Entity_Id; 4551 4552 -- Start of processing for Check_Conformance 4553 4554 begin 4555 Conforms := True; 4556 4557 -- We need a special case for operators, since they don't appear 4558 -- explicitly. 4559 4560 if Ctype = Type_Conformant then 4561 if Ekind (New_Id) = E_Operator 4562 and then Operator_Matches_Spec (New_Id, Old_Id) 4563 then 4564 return; 4565 end if; 4566 end if; 4567 4568 -- If both are functions/operators, check return types conform 4569 4570 if Old_Type /= Standard_Void_Type 4571 and then 4572 New_Type /= Standard_Void_Type 4573 then 4574 -- If we are checking interface conformance we omit controlling 4575 -- arguments and result, because we are only checking the conformance 4576 -- of the remaining parameters. 4577 4578 if Has_Controlling_Result (Old_Id) 4579 and then Has_Controlling_Result (New_Id) 4580 and then Skip_Controlling_Formals 4581 then 4582 null; 4583 4584 elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then 4585 if Ctype >= Subtype_Conformant 4586 and then not Predicates_Match (Old_Type, New_Type) 4587 then 4588 Conformance_Error 4589 ("\predicate of return type does not match!", New_Id); 4590 else 4591 Conformance_Error 4592 ("\return type does not match!", New_Id); 4593 end if; 4594 4595 return; 4596 end if; 4597 4598 -- Ada 2005 (AI-231): In case of anonymous access types check the 4599 -- null-exclusion and access-to-constant attributes match. 4600 4601 if Ada_Version >= Ada_2005 4602 and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type 4603 and then 4604 (Can_Never_Be_Null (Old_Type) /= Can_Never_Be_Null (New_Type) 4605 or else Is_Access_Constant (Etype (Old_Type)) /= 4606 Is_Access_Constant (Etype (New_Type))) 4607 then 4608 Conformance_Error ("\return type does not match!", New_Id); 4609 return; 4610 end if; 4611 4612 -- If either is a function/operator and the other isn't, error 4613 4614 elsif Old_Type /= Standard_Void_Type 4615 or else New_Type /= Standard_Void_Type 4616 then 4617 Conformance_Error ("\functions can only match functions!", New_Id); 4618 return; 4619 end if; 4620 4621 -- In subtype conformant case, conventions must match (RM 6.3.1(16)). 4622 -- If this is a renaming as body, refine error message to indicate that 4623 -- the conflict is with the original declaration. If the entity is not 4624 -- frozen, the conventions don't have to match, the one of the renamed 4625 -- entity is inherited. 4626 4627 if Ctype >= Subtype_Conformant then 4628 if Convention (Old_Id) /= Convention (New_Id) then 4629 if not Is_Frozen (New_Id) then 4630 null; 4631 4632 elsif Present (Err_Loc) 4633 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration 4634 and then Present (Corresponding_Spec (Err_Loc)) 4635 then 4636 Error_Msg_Name_1 := Chars (New_Id); 4637 Error_Msg_Name_2 := 4638 Name_Ada + Convention_Id'Pos (Convention (New_Id)); 4639 Conformance_Error ("\prior declaration for% has convention %!"); 4640 4641 else 4642 Conformance_Error ("\calling conventions do not match!"); 4643 end if; 4644 4645 return; 4646 4647 elsif Is_Formal_Subprogram (Old_Id) 4648 or else Is_Formal_Subprogram (New_Id) 4649 then 4650 Conformance_Error ("\formal subprograms not allowed!"); 4651 return; 4652 4653 -- Pragma Ghost behaves as a convention in the context of subtype 4654 -- conformance (SPARK RM 6.9(5)). Do not check internally generated 4655 -- subprograms as their spec may reside in a Ghost region and their 4656 -- body not, or vice versa. 4657 4658 elsif Comes_From_Source (Old_Id) 4659 and then Comes_From_Source (New_Id) 4660 and then Is_Ghost_Entity (Old_Id) /= Is_Ghost_Entity (New_Id) 4661 then 4662 Conformance_Error ("\ghost modes do not match!"); 4663 return; 4664 end if; 4665 end if; 4666 4667 -- Deal with parameters 4668 4669 -- Note: we use the entity information, rather than going directly 4670 -- to the specification in the tree. This is not only simpler, but 4671 -- absolutely necessary for some cases of conformance tests between 4672 -- operators, where the declaration tree simply does not exist. 4673 4674 Old_Formal := First_Formal (Old_Id); 4675 New_Formal := First_Formal (New_Id); 4676 while Present (Old_Formal) and then Present (New_Formal) loop 4677 if Is_Controlling_Formal (Old_Formal) 4678 and then Is_Controlling_Formal (New_Formal) 4679 and then Skip_Controlling_Formals 4680 then 4681 -- The controlling formals will have different types when 4682 -- comparing an interface operation with its match, but both 4683 -- or neither must be access parameters. 4684 4685 if Is_Access_Type (Etype (Old_Formal)) 4686 = 4687 Is_Access_Type (Etype (New_Formal)) 4688 then 4689 goto Skip_Controlling_Formal; 4690 else 4691 Conformance_Error 4692 ("\access parameter does not match!", New_Formal); 4693 end if; 4694 end if; 4695 4696 -- Ada 2012: Mode conformance also requires that formal parameters 4697 -- be both aliased, or neither. 4698 4699 if Ctype >= Mode_Conformant and then Ada_Version >= Ada_2012 then 4700 if Is_Aliased (Old_Formal) /= Is_Aliased (New_Formal) then 4701 Conformance_Error 4702 ("\aliased parameter mismatch!", New_Formal); 4703 end if; 4704 end if; 4705 4706 if Ctype = Fully_Conformant then 4707 4708 -- Names must match. Error message is more accurate if we do 4709 -- this before checking that the types of the formals match. 4710 4711 if Chars (Old_Formal) /= Chars (New_Formal) then 4712 Conformance_Error ("\name& does not match!", New_Formal); 4713 4714 -- Set error posted flag on new formal as well to stop 4715 -- junk cascaded messages in some cases. 4716 4717 Set_Error_Posted (New_Formal); 4718 return; 4719 end if; 4720 4721 -- Null exclusion must match 4722 4723 if Null_Exclusion_Present (Parent (Old_Formal)) 4724 /= 4725 Null_Exclusion_Present (Parent (New_Formal)) 4726 then 4727 -- Only give error if both come from source. This should be 4728 -- investigated some time, since it should not be needed ??? 4729 4730 if Comes_From_Source (Old_Formal) 4731 and then 4732 Comes_From_Source (New_Formal) 4733 then 4734 Conformance_Error 4735 ("\null exclusion for& does not match", New_Formal); 4736 4737 -- Mark error posted on the new formal to avoid duplicated 4738 -- complaint about types not matching. 4739 4740 Set_Error_Posted (New_Formal); 4741 end if; 4742 end if; 4743 end if; 4744 4745 -- Ada 2005 (AI-423): Possible access [sub]type and itype match. This 4746 -- case occurs whenever a subprogram is being renamed and one of its 4747 -- parameters imposes a null exclusion. For example: 4748 4749 -- type T is null record; 4750 -- type Acc_T is access T; 4751 -- subtype Acc_T_Sub is Acc_T; 4752 4753 -- procedure P (Obj : not null Acc_T_Sub); -- itype 4754 -- procedure Ren_P (Obj : Acc_T_Sub) -- subtype 4755 -- renames P; 4756 4757 Old_Formal_Base := Etype (Old_Formal); 4758 New_Formal_Base := Etype (New_Formal); 4759 4760 if Get_Inst then 4761 Old_Formal_Base := Get_Instance_Of (Old_Formal_Base); 4762 New_Formal_Base := Get_Instance_Of (New_Formal_Base); 4763 end if; 4764 4765 Access_Types_Match := Ada_Version >= Ada_2005 4766 4767 -- Ensure that this rule is only applied when New_Id is a 4768 -- renaming of Old_Id. 4769 4770 and then Nkind (Parent (Parent (New_Id))) = 4771 N_Subprogram_Renaming_Declaration 4772 and then Nkind (Name (Parent (Parent (New_Id)))) in N_Has_Entity 4773 and then Present (Entity (Name (Parent (Parent (New_Id))))) 4774 and then Entity (Name (Parent (Parent (New_Id)))) = Old_Id 4775 4776 -- Now handle the allowed access-type case 4777 4778 and then Is_Access_Type (Old_Formal_Base) 4779 and then Is_Access_Type (New_Formal_Base) 4780 4781 -- The type kinds must match. The only exception occurs with 4782 -- multiple generics of the form: 4783 4784 -- generic generic 4785 -- type F is private; type A is private; 4786 -- type F_Ptr is access F; type A_Ptr is access A; 4787 -- with proc F_P (X : F_Ptr); with proc A_P (X : A_Ptr); 4788 -- package F_Pack is ... package A_Pack is 4789 -- package F_Inst is 4790 -- new F_Pack (A, A_Ptr, A_P); 4791 4792 -- When checking for conformance between the parameters of A_P 4793 -- and F_P, the type kinds of F_Ptr and A_Ptr will not match 4794 -- because the compiler has transformed A_Ptr into a subtype of 4795 -- F_Ptr. We catch this case in the code below. 4796 4797 and then (Ekind (Old_Formal_Base) = Ekind (New_Formal_Base) 4798 or else 4799 (Is_Generic_Type (Old_Formal_Base) 4800 and then Is_Generic_Type (New_Formal_Base) 4801 and then Is_Internal (New_Formal_Base) 4802 and then Etype (Etype (New_Formal_Base)) = 4803 Old_Formal_Base)) 4804 and then Directly_Designated_Type (Old_Formal_Base) = 4805 Directly_Designated_Type (New_Formal_Base) 4806 and then ((Is_Itype (Old_Formal_Base) 4807 and then Can_Never_Be_Null (Old_Formal_Base)) 4808 or else 4809 (Is_Itype (New_Formal_Base) 4810 and then Can_Never_Be_Null (New_Formal_Base))); 4811 4812 -- Types must always match. In the visible part of an instance, 4813 -- usual overloading rules for dispatching operations apply, and 4814 -- we check base types (not the actual subtypes). 4815 4816 if In_Instance_Visible_Part 4817 and then Is_Dispatching_Operation (New_Id) 4818 then 4819 if not Conforming_Types 4820 (T1 => Base_Type (Etype (Old_Formal)), 4821 T2 => Base_Type (Etype (New_Formal)), 4822 Ctype => Ctype, 4823 Get_Inst => Get_Inst) 4824 and then not Access_Types_Match 4825 then 4826 Conformance_Error ("\type of & does not match!", New_Formal); 4827 return; 4828 end if; 4829 4830 elsif not Conforming_Types 4831 (T1 => Old_Formal_Base, 4832 T2 => New_Formal_Base, 4833 Ctype => Ctype, 4834 Get_Inst => Get_Inst) 4835 and then not Access_Types_Match 4836 then 4837 -- Don't give error message if old type is Any_Type. This test 4838 -- avoids some cascaded errors, e.g. in case of a bad spec. 4839 4840 if Errmsg and then Old_Formal_Base = Any_Type then 4841 Conforms := False; 4842 else 4843 if Ctype >= Subtype_Conformant 4844 and then 4845 not Predicates_Match (Old_Formal_Base, New_Formal_Base) 4846 then 4847 Conformance_Error 4848 ("\predicate of & does not match!", New_Formal); 4849 else 4850 Conformance_Error 4851 ("\type of & does not match!", New_Formal); 4852 end if; 4853 end if; 4854 4855 return; 4856 end if; 4857 4858 -- For mode conformance, mode must match 4859 4860 if Ctype >= Mode_Conformant then 4861 if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then 4862 if not Ekind_In (New_Id, E_Function, E_Procedure) 4863 or else not Is_Primitive_Wrapper (New_Id) 4864 then 4865 Conformance_Error ("\mode of & does not match!", New_Formal); 4866 4867 else 4868 declare 4869 T : constant Entity_Id := Find_Dispatching_Type (New_Id); 4870 begin 4871 if Is_Protected_Type (Corresponding_Concurrent_Type (T)) 4872 then 4873 Error_Msg_PT (New_Id, Ultimate_Alias (Old_Id)); 4874 else 4875 Conformance_Error 4876 ("\mode of & does not match!", New_Formal); 4877 end if; 4878 end; 4879 end if; 4880 4881 return; 4882 4883 -- Part of mode conformance for access types is having the same 4884 -- constant modifier. 4885 4886 elsif Access_Types_Match 4887 and then Is_Access_Constant (Old_Formal_Base) /= 4888 Is_Access_Constant (New_Formal_Base) 4889 then 4890 Conformance_Error 4891 ("\constant modifier does not match!", New_Formal); 4892 return; 4893 end if; 4894 end if; 4895 4896 if Ctype >= Subtype_Conformant then 4897 4898 -- Ada 2005 (AI-231): In case of anonymous access types check 4899 -- the null-exclusion and access-to-constant attributes must 4900 -- match. For null exclusion, we test the types rather than the 4901 -- formals themselves, since the attribute is only set reliably 4902 -- on the formals in the Ada 95 case, and we exclude the case 4903 -- where Old_Formal is marked as controlling, to avoid errors 4904 -- when matching completing bodies with dispatching declarations 4905 -- (access formals in the bodies aren't marked Can_Never_Be_Null). 4906 4907 if Ada_Version >= Ada_2005 4908 and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type 4909 and then Ekind (Etype (New_Formal)) = E_Anonymous_Access_Type 4910 and then 4911 ((Can_Never_Be_Null (Etype (Old_Formal)) /= 4912 Can_Never_Be_Null (Etype (New_Formal)) 4913 and then 4914 not Is_Controlling_Formal (Old_Formal)) 4915 or else 4916 Is_Access_Constant (Etype (Old_Formal)) /= 4917 Is_Access_Constant (Etype (New_Formal))) 4918 4919 -- Do not complain if error already posted on New_Formal. This 4920 -- avoids some redundant error messages. 4921 4922 and then not Error_Posted (New_Formal) 4923 then 4924 -- It is allowed to omit the null-exclusion in case of stream 4925 -- attribute subprograms. We recognize stream subprograms 4926 -- through their TSS-generated suffix. 4927 4928 declare 4929 TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id); 4930 4931 begin 4932 if TSS_Name /= TSS_Stream_Read 4933 and then TSS_Name /= TSS_Stream_Write 4934 and then TSS_Name /= TSS_Stream_Input 4935 and then TSS_Name /= TSS_Stream_Output 4936 then 4937 -- Here we have a definite conformance error. It is worth 4938 -- special casing the error message for the case of a 4939 -- controlling formal (which excludes null). 4940 4941 if Is_Controlling_Formal (New_Formal) then 4942 Error_Msg_Node_2 := Scope (New_Formal); 4943 Conformance_Error 4944 ("\controlling formal & of & excludes null, " 4945 & "declaration must exclude null as well", 4946 New_Formal); 4947 4948 -- Normal case (couldn't we give more detail here???) 4949 4950 else 4951 Conformance_Error 4952 ("\type of & does not match!", New_Formal); 4953 end if; 4954 4955 return; 4956 end if; 4957 end; 4958 end if; 4959 end if; 4960 4961 -- Full conformance checks 4962 4963 if Ctype = Fully_Conformant then 4964 4965 -- We have checked already that names match 4966 4967 if Parameter_Mode (Old_Formal) = E_In_Parameter then 4968 4969 -- Check default expressions for in parameters 4970 4971 declare 4972 NewD : constant Boolean := 4973 Present (Default_Value (New_Formal)); 4974 OldD : constant Boolean := 4975 Present (Default_Value (Old_Formal)); 4976 begin 4977 if NewD or OldD then 4978 4979 -- The old default value has been analyzed because the 4980 -- current full declaration will have frozen everything 4981 -- before. The new default value has not been analyzed, 4982 -- so analyze it now before we check for conformance. 4983 4984 if NewD then 4985 Push_Scope (New_Id); 4986 Preanalyze_Spec_Expression 4987 (Default_Value (New_Formal), Etype (New_Formal)); 4988 End_Scope; 4989 end if; 4990 4991 if not (NewD and OldD) 4992 or else not Fully_Conformant_Expressions 4993 (Default_Value (Old_Formal), 4994 Default_Value (New_Formal)) 4995 then 4996 Conformance_Error 4997 ("\default expression for & does not match!", 4998 New_Formal); 4999 return; 5000 end if; 5001 end if; 5002 end; 5003 end if; 5004 end if; 5005 5006 -- A couple of special checks for Ada 83 mode. These checks are 5007 -- skipped if either entity is an operator in package Standard, 5008 -- or if either old or new instance is not from the source program. 5009 5010 if Ada_Version = Ada_83 5011 and then Sloc (Old_Id) > Standard_Location 5012 and then Sloc (New_Id) > Standard_Location 5013 and then Comes_From_Source (Old_Id) 5014 and then Comes_From_Source (New_Id) 5015 then 5016 declare 5017 Old_Param : constant Node_Id := Declaration_Node (Old_Formal); 5018 New_Param : constant Node_Id := Declaration_Node (New_Formal); 5019 5020 begin 5021 -- Explicit IN must be present or absent in both cases. This 5022 -- test is required only in the full conformance case. 5023 5024 if In_Present (Old_Param) /= In_Present (New_Param) 5025 and then Ctype = Fully_Conformant 5026 then 5027 Conformance_Error 5028 ("\(Ada 83) IN must appear in both declarations", 5029 New_Formal); 5030 return; 5031 end if; 5032 5033 -- Grouping (use of comma in param lists) must be the same 5034 -- This is where we catch a misconformance like: 5035 5036 -- A, B : Integer 5037 -- A : Integer; B : Integer 5038 5039 -- which are represented identically in the tree except 5040 -- for the setting of the flags More_Ids and Prev_Ids. 5041 5042 if More_Ids (Old_Param) /= More_Ids (New_Param) 5043 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param) 5044 then 5045 Conformance_Error 5046 ("\grouping of & does not match!", New_Formal); 5047 return; 5048 end if; 5049 end; 5050 end if; 5051 5052 -- This label is required when skipping controlling formals 5053 5054 <<Skip_Controlling_Formal>> 5055 5056 Next_Formal (Old_Formal); 5057 Next_Formal (New_Formal); 5058 end loop; 5059 5060 if Present (Old_Formal) then 5061 Conformance_Error ("\too few parameters!"); 5062 return; 5063 5064 elsif Present (New_Formal) then 5065 Conformance_Error ("\too many parameters!", New_Formal); 5066 return; 5067 end if; 5068 end Check_Conformance; 5069 5070 ----------------------- 5071 -- Check_Conventions -- 5072 ----------------------- 5073 5074 procedure Check_Conventions (Typ : Entity_Id) is 5075 Ifaces_List : Elist_Id; 5076 5077 procedure Check_Convention (Op : Entity_Id); 5078 -- Verify that the convention of inherited dispatching operation Op is 5079 -- consistent among all subprograms it overrides. In order to minimize 5080 -- the search, Search_From is utilized to designate a specific point in 5081 -- the list rather than iterating over the whole list once more. 5082 5083 ---------------------- 5084 -- Check_Convention -- 5085 ---------------------- 5086 5087 procedure Check_Convention (Op : Entity_Id) is 5088 Op_Conv : constant Convention_Id := Convention (Op); 5089 Iface_Conv : Convention_Id; 5090 Iface_Elmt : Elmt_Id; 5091 Iface_Prim_Elmt : Elmt_Id; 5092 Iface_Prim : Entity_Id; 5093 5094 begin 5095 Iface_Elmt := First_Elmt (Ifaces_List); 5096 while Present (Iface_Elmt) loop 5097 Iface_Prim_Elmt := 5098 First_Elmt (Primitive_Operations (Node (Iface_Elmt))); 5099 while Present (Iface_Prim_Elmt) loop 5100 Iface_Prim := Node (Iface_Prim_Elmt); 5101 Iface_Conv := Convention (Iface_Prim); 5102 5103 if Is_Interface_Conformant (Typ, Iface_Prim, Op) 5104 and then Iface_Conv /= Op_Conv 5105 then 5106 Error_Msg_N 5107 ("inconsistent conventions in primitive operations", Typ); 5108 5109 Error_Msg_Name_1 := Chars (Op); 5110 Error_Msg_Name_2 := Get_Convention_Name (Op_Conv); 5111 Error_Msg_Sloc := Sloc (Op); 5112 5113 if Comes_From_Source (Op) or else No (Alias (Op)) then 5114 if not Present (Overridden_Operation (Op)) then 5115 Error_Msg_N ("\\primitive % defined #", Typ); 5116 else 5117 Error_Msg_N 5118 ("\\overriding operation % with " 5119 & "convention % defined #", Typ); 5120 end if; 5121 5122 else pragma Assert (Present (Alias (Op))); 5123 Error_Msg_Sloc := Sloc (Alias (Op)); 5124 Error_Msg_N ("\\inherited operation % with " 5125 & "convention % defined #", Typ); 5126 end if; 5127 5128 Error_Msg_Name_1 := Chars (Op); 5129 Error_Msg_Name_2 := Get_Convention_Name (Iface_Conv); 5130 Error_Msg_Sloc := Sloc (Iface_Prim); 5131 Error_Msg_N ("\\overridden operation % with " 5132 & "convention % defined #", Typ); 5133 5134 -- Avoid cascading errors 5135 5136 return; 5137 end if; 5138 5139 Next_Elmt (Iface_Prim_Elmt); 5140 end loop; 5141 5142 Next_Elmt (Iface_Elmt); 5143 end loop; 5144 end Check_Convention; 5145 5146 -- Local variables 5147 5148 Prim_Op : Entity_Id; 5149 Prim_Op_Elmt : Elmt_Id; 5150 5151 -- Start of processing for Check_Conventions 5152 5153 begin 5154 if not Has_Interfaces (Typ) then 5155 return; 5156 end if; 5157 5158 Collect_Interfaces (Typ, Ifaces_List); 5159 5160 -- The algorithm checks every overriding dispatching operation against 5161 -- all the corresponding overridden dispatching operations, detecting 5162 -- differences in conventions. 5163 5164 Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ)); 5165 while Present (Prim_Op_Elmt) loop 5166 Prim_Op := Node (Prim_Op_Elmt); 5167 5168 -- A small optimization: skip the predefined dispatching operations 5169 -- since they always have the same convention. 5170 5171 if not Is_Predefined_Dispatching_Operation (Prim_Op) then 5172 Check_Convention (Prim_Op); 5173 end if; 5174 5175 Next_Elmt (Prim_Op_Elmt); 5176 end loop; 5177 end Check_Conventions; 5178 5179 ------------------------------ 5180 -- Check_Delayed_Subprogram -- 5181 ------------------------------ 5182 5183 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is 5184 F : Entity_Id; 5185 5186 procedure Possible_Freeze (T : Entity_Id); 5187 -- T is the type of either a formal parameter or of the return type. 5188 -- If T is not yet frozen and needs a delayed freeze, then the 5189 -- subprogram itself must be delayed. If T is the limited view of an 5190 -- incomplete type the subprogram must be frozen as well, because 5191 -- T may depend on local types that have not been frozen yet. 5192 5193 --------------------- 5194 -- Possible_Freeze -- 5195 --------------------- 5196 5197 procedure Possible_Freeze (T : Entity_Id) is 5198 begin 5199 if Has_Delayed_Freeze (T) and then not Is_Frozen (T) then 5200 Set_Has_Delayed_Freeze (Designator); 5201 5202 elsif Is_Access_Type (T) 5203 and then Has_Delayed_Freeze (Designated_Type (T)) 5204 and then not Is_Frozen (Designated_Type (T)) 5205 then 5206 Set_Has_Delayed_Freeze (Designator); 5207 5208 elsif Ekind (T) = E_Incomplete_Type 5209 and then From_Limited_With (T) 5210 then 5211 Set_Has_Delayed_Freeze (Designator); 5212 5213 -- AI05-0151: In Ada 2012, Incomplete types can appear in the profile 5214 -- of a subprogram or entry declaration. 5215 5216 elsif Ekind (T) = E_Incomplete_Type 5217 and then Ada_Version >= Ada_2012 5218 then 5219 Set_Has_Delayed_Freeze (Designator); 5220 end if; 5221 5222 end Possible_Freeze; 5223 5224 -- Start of processing for Check_Delayed_Subprogram 5225 5226 begin 5227 -- All subprograms, including abstract subprograms, may need a freeze 5228 -- node if some formal type or the return type needs one. 5229 5230 Possible_Freeze (Etype (Designator)); 5231 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ??? 5232 5233 -- Need delayed freeze if any of the formal types themselves need 5234 -- a delayed freeze and are not yet frozen. 5235 5236 F := First_Formal (Designator); 5237 while Present (F) loop 5238 Possible_Freeze (Etype (F)); 5239 Possible_Freeze (Base_Type (Etype (F))); -- needed ??? 5240 Next_Formal (F); 5241 end loop; 5242 5243 -- Mark functions that return by reference. Note that it cannot be 5244 -- done for delayed_freeze subprograms because the underlying 5245 -- returned type may not be known yet (for private types) 5246 5247 if not Has_Delayed_Freeze (Designator) and then Expander_Active then 5248 declare 5249 Typ : constant Entity_Id := Etype (Designator); 5250 Utyp : constant Entity_Id := Underlying_Type (Typ); 5251 begin 5252 if Is_Limited_View (Typ) then 5253 Set_Returns_By_Ref (Designator); 5254 elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then 5255 Set_Returns_By_Ref (Designator); 5256 end if; 5257 end; 5258 end if; 5259 end Check_Delayed_Subprogram; 5260 5261 ------------------------------------ 5262 -- Check_Discriminant_Conformance -- 5263 ------------------------------------ 5264 5265 procedure Check_Discriminant_Conformance 5266 (N : Node_Id; 5267 Prev : Entity_Id; 5268 Prev_Loc : Node_Id) 5269 is 5270 Old_Discr : Entity_Id := First_Discriminant (Prev); 5271 New_Discr : Node_Id := First (Discriminant_Specifications (N)); 5272 New_Discr_Id : Entity_Id; 5273 New_Discr_Type : Entity_Id; 5274 5275 procedure Conformance_Error (Msg : String; N : Node_Id); 5276 -- Post error message for conformance error on given node. Two messages 5277 -- are output. The first points to the previous declaration with a 5278 -- general "no conformance" message. The second is the detailed reason, 5279 -- supplied as Msg. The parameter N provide information for a possible 5280 -- & insertion in the message. 5281 5282 ----------------------- 5283 -- Conformance_Error -- 5284 ----------------------- 5285 5286 procedure Conformance_Error (Msg : String; N : Node_Id) is 5287 begin 5288 Error_Msg_Sloc := Sloc (Prev_Loc); 5289 Error_Msg_N -- CODEFIX 5290 ("not fully conformant with declaration#!", N); 5291 Error_Msg_NE (Msg, N, N); 5292 end Conformance_Error; 5293 5294 -- Start of processing for Check_Discriminant_Conformance 5295 5296 begin 5297 while Present (Old_Discr) and then Present (New_Discr) loop 5298 New_Discr_Id := Defining_Identifier (New_Discr); 5299 5300 -- The subtype mark of the discriminant on the full type has not 5301 -- been analyzed so we do it here. For an access discriminant a new 5302 -- type is created. 5303 5304 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then 5305 New_Discr_Type := 5306 Access_Definition (N, Discriminant_Type (New_Discr)); 5307 5308 else 5309 Analyze (Discriminant_Type (New_Discr)); 5310 New_Discr_Type := Etype (Discriminant_Type (New_Discr)); 5311 5312 -- Ada 2005: if the discriminant definition carries a null 5313 -- exclusion, create an itype to check properly for consistency 5314 -- with partial declaration. 5315 5316 if Is_Access_Type (New_Discr_Type) 5317 and then Null_Exclusion_Present (New_Discr) 5318 then 5319 New_Discr_Type := 5320 Create_Null_Excluding_Itype 5321 (T => New_Discr_Type, 5322 Related_Nod => New_Discr, 5323 Scope_Id => Current_Scope); 5324 end if; 5325 end if; 5326 5327 if not Conforming_Types 5328 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant) 5329 then 5330 Conformance_Error ("type of & does not match!", New_Discr_Id); 5331 return; 5332 else 5333 -- Treat the new discriminant as an occurrence of the old one, 5334 -- for navigation purposes, and fill in some semantic 5335 -- information, for completeness. 5336 5337 Generate_Reference (Old_Discr, New_Discr_Id, 'r'); 5338 Set_Etype (New_Discr_Id, Etype (Old_Discr)); 5339 Set_Scope (New_Discr_Id, Scope (Old_Discr)); 5340 end if; 5341 5342 -- Names must match 5343 5344 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then 5345 Conformance_Error ("name & does not match!", New_Discr_Id); 5346 return; 5347 end if; 5348 5349 -- Default expressions must match 5350 5351 declare 5352 NewD : constant Boolean := 5353 Present (Expression (New_Discr)); 5354 OldD : constant Boolean := 5355 Present (Expression (Parent (Old_Discr))); 5356 5357 begin 5358 if NewD or OldD then 5359 5360 -- The old default value has been analyzed and expanded, 5361 -- because the current full declaration will have frozen 5362 -- everything before. The new default values have not been 5363 -- expanded, so expand now to check conformance. 5364 5365 if NewD then 5366 Preanalyze_Spec_Expression 5367 (Expression (New_Discr), New_Discr_Type); 5368 end if; 5369 5370 if not (NewD and OldD) 5371 or else not Fully_Conformant_Expressions 5372 (Expression (Parent (Old_Discr)), 5373 Expression (New_Discr)) 5374 5375 then 5376 Conformance_Error 5377 ("default expression for & does not match!", 5378 New_Discr_Id); 5379 return; 5380 end if; 5381 end if; 5382 end; 5383 5384 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X) 5385 5386 if Ada_Version = Ada_83 then 5387 declare 5388 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr); 5389 5390 begin 5391 -- Grouping (use of comma in param lists) must be the same 5392 -- This is where we catch a misconformance like: 5393 5394 -- A, B : Integer 5395 -- A : Integer; B : Integer 5396 5397 -- which are represented identically in the tree except 5398 -- for the setting of the flags More_Ids and Prev_Ids. 5399 5400 if More_Ids (Old_Disc) /= More_Ids (New_Discr) 5401 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr) 5402 then 5403 Conformance_Error 5404 ("grouping of & does not match!", New_Discr_Id); 5405 return; 5406 end if; 5407 end; 5408 end if; 5409 5410 Next_Discriminant (Old_Discr); 5411 Next (New_Discr); 5412 end loop; 5413 5414 if Present (Old_Discr) then 5415 Conformance_Error ("too few discriminants!", Defining_Identifier (N)); 5416 return; 5417 5418 elsif Present (New_Discr) then 5419 Conformance_Error 5420 ("too many discriminants!", Defining_Identifier (New_Discr)); 5421 return; 5422 end if; 5423 end Check_Discriminant_Conformance; 5424 5425 ---------------------------- 5426 -- Check_Fully_Conformant -- 5427 ---------------------------- 5428 5429 procedure Check_Fully_Conformant 5430 (New_Id : Entity_Id; 5431 Old_Id : Entity_Id; 5432 Err_Loc : Node_Id := Empty) 5433 is 5434 Result : Boolean; 5435 pragma Warnings (Off, Result); 5436 begin 5437 Check_Conformance 5438 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc); 5439 end Check_Fully_Conformant; 5440 5441 -------------------------- 5442 -- Check_Limited_Return -- 5443 -------------------------- 5444 5445 procedure Check_Limited_Return 5446 (N : Node_Id; 5447 Expr : Node_Id; 5448 R_Type : Entity_Id) 5449 is 5450 begin 5451 -- Ada 2005 (AI-318-02): Return-by-reference types have been removed and 5452 -- replaced by anonymous access results. This is an incompatibility with 5453 -- Ada 95. Not clear whether this should be enforced yet or perhaps 5454 -- controllable with special switch. ??? 5455 5456 -- A limited interface that is not immutably limited is OK 5457 5458 if Is_Limited_Interface (R_Type) 5459 and then 5460 not (Is_Task_Interface (R_Type) 5461 or else Is_Protected_Interface (R_Type) 5462 or else Is_Synchronized_Interface (R_Type)) 5463 then 5464 null; 5465 5466 elsif Is_Limited_Type (R_Type) 5467 and then not Is_Interface (R_Type) 5468 and then Comes_From_Source (N) 5469 and then not In_Instance_Body 5470 and then not OK_For_Limited_Init_In_05 (R_Type, Expr) 5471 then 5472 -- Error in Ada 2005 5473 5474 if Ada_Version >= Ada_2005 5475 and then not Debug_Flag_Dot_L 5476 and then not GNAT_Mode 5477 then 5478 Error_Msg_N 5479 ("(Ada 2005) cannot copy object of a limited type " 5480 & "(RM-2005 6.5(5.5/2))", Expr); 5481 5482 if Is_Limited_View (R_Type) then 5483 Error_Msg_N 5484 ("\return by reference not permitted in Ada 2005", Expr); 5485 end if; 5486 5487 -- Warn in Ada 95 mode, to give folks a heads up about this 5488 -- incompatibility. 5489 5490 -- In GNAT mode, this is just a warning, to allow it to be evilly 5491 -- turned off. Otherwise it is a real error. 5492 5493 -- In a generic context, simplify the warning because it makes no 5494 -- sense to discuss pass-by-reference or copy. 5495 5496 elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then 5497 if Inside_A_Generic then 5498 Error_Msg_N 5499 ("return of limited object not permitted in Ada 2005 " 5500 & "(RM-2005 6.5(5.5/2))?y?", Expr); 5501 5502 elsif Is_Limited_View (R_Type) then 5503 Error_Msg_N 5504 ("return by reference not permitted in Ada 2005 " 5505 & "(RM-2005 6.5(5.5/2))?y?", Expr); 5506 else 5507 Error_Msg_N 5508 ("cannot copy object of a limited type in Ada 2005 " 5509 & "(RM-2005 6.5(5.5/2))?y?", Expr); 5510 end if; 5511 5512 -- Ada 95 mode, compatibility warnings disabled 5513 5514 else 5515 return; -- skip continuation messages below 5516 end if; 5517 5518 if not Inside_A_Generic then 5519 Error_Msg_N 5520 ("\consider switching to return of access type", Expr); 5521 Explain_Limited_Type (R_Type, Expr); 5522 end if; 5523 end if; 5524 end Check_Limited_Return; 5525 5526 --------------------------- 5527 -- Check_Mode_Conformant -- 5528 --------------------------- 5529 5530 procedure Check_Mode_Conformant 5531 (New_Id : Entity_Id; 5532 Old_Id : Entity_Id; 5533 Err_Loc : Node_Id := Empty; 5534 Get_Inst : Boolean := False) 5535 is 5536 Result : Boolean; 5537 pragma Warnings (Off, Result); 5538 begin 5539 Check_Conformance 5540 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst); 5541 end Check_Mode_Conformant; 5542 5543 -------------------------------- 5544 -- Check_Overriding_Indicator -- 5545 -------------------------------- 5546 5547 procedure Check_Overriding_Indicator 5548 (Subp : Entity_Id; 5549 Overridden_Subp : Entity_Id; 5550 Is_Primitive : Boolean) 5551 is 5552 Decl : Node_Id; 5553 Spec : Node_Id; 5554 5555 begin 5556 -- No overriding indicator for literals 5557 5558 if Ekind (Subp) = E_Enumeration_Literal then 5559 return; 5560 5561 elsif Ekind (Subp) = E_Entry then 5562 Decl := Parent (Subp); 5563 5564 -- No point in analyzing a malformed operator 5565 5566 elsif Nkind (Subp) = N_Defining_Operator_Symbol 5567 and then Error_Posted (Subp) 5568 then 5569 return; 5570 5571 else 5572 Decl := Unit_Declaration_Node (Subp); 5573 end if; 5574 5575 if Nkind_In (Decl, N_Subprogram_Body, 5576 N_Subprogram_Body_Stub, 5577 N_Subprogram_Declaration, 5578 N_Abstract_Subprogram_Declaration, 5579 N_Subprogram_Renaming_Declaration) 5580 then 5581 Spec := Specification (Decl); 5582 5583 elsif Nkind (Decl) = N_Entry_Declaration then 5584 Spec := Decl; 5585 5586 else 5587 return; 5588 end if; 5589 5590 -- The overriding operation is type conformant with the overridden one, 5591 -- but the names of the formals are not required to match. If the names 5592 -- appear permuted in the overriding operation, this is a possible 5593 -- source of confusion that is worth diagnosing. Controlling formals 5594 -- often carry names that reflect the type, and it is not worthwhile 5595 -- requiring that their names match. 5596 5597 if Present (Overridden_Subp) 5598 and then Nkind (Subp) /= N_Defining_Operator_Symbol 5599 then 5600 declare 5601 Form1 : Entity_Id; 5602 Form2 : Entity_Id; 5603 5604 begin 5605 Form1 := First_Formal (Subp); 5606 Form2 := First_Formal (Overridden_Subp); 5607 5608 -- If the overriding operation is a synchronized operation, skip 5609 -- the first parameter of the overridden operation, which is 5610 -- implicit in the new one. If the operation is declared in the 5611 -- body it is not primitive and all formals must match. 5612 5613 if Is_Concurrent_Type (Scope (Subp)) 5614 and then Is_Tagged_Type (Scope (Subp)) 5615 and then not Has_Completion (Scope (Subp)) 5616 then 5617 Form2 := Next_Formal (Form2); 5618 end if; 5619 5620 if Present (Form1) then 5621 Form1 := Next_Formal (Form1); 5622 Form2 := Next_Formal (Form2); 5623 end if; 5624 5625 while Present (Form1) loop 5626 if not Is_Controlling_Formal (Form1) 5627 and then Present (Next_Formal (Form2)) 5628 and then Chars (Form1) = Chars (Next_Formal (Form2)) 5629 then 5630 Error_Msg_Node_2 := Alias (Overridden_Subp); 5631 Error_Msg_Sloc := Sloc (Error_Msg_Node_2); 5632 Error_Msg_NE 5633 ("& does not match corresponding formal of&#", 5634 Form1, Form1); 5635 exit; 5636 end if; 5637 5638 Next_Formal (Form1); 5639 Next_Formal (Form2); 5640 end loop; 5641 end; 5642 end if; 5643 5644 -- If there is an overridden subprogram, then check that there is no 5645 -- "not overriding" indicator, and mark the subprogram as overriding. 5646 -- This is not done if the overridden subprogram is marked as hidden, 5647 -- which can occur for the case of inherited controlled operations 5648 -- (see Derive_Subprogram), unless the inherited subprogram's parent 5649 -- subprogram is not itself hidden. (Note: This condition could probably 5650 -- be simplified, leaving out the testing for the specific controlled 5651 -- cases, but it seems safer and clearer this way, and echoes similar 5652 -- special-case tests of this kind in other places.) 5653 5654 if Present (Overridden_Subp) 5655 and then (not Is_Hidden (Overridden_Subp) 5656 or else 5657 (Nam_In (Chars (Overridden_Subp), Name_Initialize, 5658 Name_Adjust, 5659 Name_Finalize) 5660 and then Present (Alias (Overridden_Subp)) 5661 and then not Is_Hidden (Alias (Overridden_Subp)))) 5662 then 5663 if Must_Not_Override (Spec) then 5664 Error_Msg_Sloc := Sloc (Overridden_Subp); 5665 5666 if Ekind (Subp) = E_Entry then 5667 Error_Msg_NE 5668 ("entry & overrides inherited operation #", Spec, Subp); 5669 else 5670 Error_Msg_NE 5671 ("subprogram & overrides inherited operation #", Spec, Subp); 5672 end if; 5673 5674 -- Special-case to fix a GNAT oddity: Limited_Controlled is declared 5675 -- as an extension of Root_Controlled, and thus has a useless Adjust 5676 -- operation. This operation should not be inherited by other limited 5677 -- controlled types. An explicit Adjust for them is not overriding. 5678 5679 elsif Must_Override (Spec) 5680 and then Chars (Overridden_Subp) = Name_Adjust 5681 and then Is_Limited_Type (Etype (First_Formal (Subp))) 5682 and then Present (Alias (Overridden_Subp)) 5683 and then 5684 Is_Predefined_File_Name 5685 (Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp)))) 5686 then 5687 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 5688 5689 elsif Is_Subprogram (Subp) then 5690 if Is_Init_Proc (Subp) then 5691 null; 5692 5693 elsif No (Overridden_Operation (Subp)) then 5694 5695 -- For entities generated by Derive_Subprograms the overridden 5696 -- operation is the inherited primitive (which is available 5697 -- through the attribute alias) 5698 5699 if (Is_Dispatching_Operation (Subp) 5700 or else Is_Dispatching_Operation (Overridden_Subp)) 5701 and then not Comes_From_Source (Overridden_Subp) 5702 and then Find_Dispatching_Type (Overridden_Subp) = 5703 Find_Dispatching_Type (Subp) 5704 and then Present (Alias (Overridden_Subp)) 5705 and then Comes_From_Source (Alias (Overridden_Subp)) 5706 then 5707 Set_Overridden_Operation (Subp, Alias (Overridden_Subp)); 5708 Inherit_Subprogram_Contract (Subp, Alias (Overridden_Subp)); 5709 5710 else 5711 Set_Overridden_Operation (Subp, Overridden_Subp); 5712 Inherit_Subprogram_Contract (Subp, Overridden_Subp); 5713 end if; 5714 end if; 5715 end if; 5716 5717 -- If primitive flag is set or this is a protected operation, then 5718 -- the operation is overriding at the point of its declaration, so 5719 -- warn if necessary. Otherwise it may have been declared before the 5720 -- operation it overrides and no check is required. 5721 5722 if Style_Check 5723 and then not Must_Override (Spec) 5724 and then (Is_Primitive 5725 or else Ekind (Scope (Subp)) = E_Protected_Type) 5726 then 5727 Style.Missing_Overriding (Decl, Subp); 5728 end if; 5729 5730 -- If Subp is an operator, it may override a predefined operation, if 5731 -- it is defined in the same scope as the type to which it applies. 5732 -- In that case Overridden_Subp is empty because of our implicit 5733 -- representation for predefined operators. We have to check whether the 5734 -- signature of Subp matches that of a predefined operator. Note that 5735 -- first argument provides the name of the operator, and the second 5736 -- argument the signature that may match that of a standard operation. 5737 -- If the indicator is overriding, then the operator must match a 5738 -- predefined signature, because we know already that there is no 5739 -- explicit overridden operation. 5740 5741 elsif Nkind (Subp) = N_Defining_Operator_Symbol then 5742 if Must_Not_Override (Spec) then 5743 5744 -- If this is not a primitive or a protected subprogram, then 5745 -- "not overriding" is illegal. 5746 5747 if not Is_Primitive 5748 and then Ekind (Scope (Subp)) /= E_Protected_Type 5749 then 5750 Error_Msg_N ("overriding indicator only allowed " 5751 & "if subprogram is primitive", Subp); 5752 5753 elsif Can_Override_Operator (Subp) then 5754 Error_Msg_NE 5755 ("subprogram& overrides predefined operator ", Spec, Subp); 5756 end if; 5757 5758 elsif Must_Override (Spec) then 5759 if No (Overridden_Operation (Subp)) 5760 and then not Can_Override_Operator (Subp) 5761 then 5762 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 5763 end if; 5764 5765 elsif not Error_Posted (Subp) 5766 and then Style_Check 5767 and then Can_Override_Operator (Subp) 5768 and then 5769 not Is_Predefined_File_Name 5770 (Unit_File_Name (Get_Source_Unit (Subp))) 5771 then 5772 -- If style checks are enabled, indicate that the indicator is 5773 -- missing. However, at the point of declaration, the type of 5774 -- which this is a primitive operation may be private, in which 5775 -- case the indicator would be premature. 5776 5777 if Has_Private_Declaration (Etype (Subp)) 5778 or else Has_Private_Declaration (Etype (First_Formal (Subp))) 5779 then 5780 null; 5781 else 5782 Style.Missing_Overriding (Decl, Subp); 5783 end if; 5784 end if; 5785 5786 elsif Must_Override (Spec) then 5787 if Ekind (Subp) = E_Entry then 5788 Error_Msg_NE ("entry & is not overriding", Spec, Subp); 5789 else 5790 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 5791 end if; 5792 5793 -- If the operation is marked "not overriding" and it's not primitive 5794 -- then an error is issued, unless this is an operation of a task or 5795 -- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding" 5796 -- has been specified have already been checked above. 5797 5798 elsif Must_Not_Override (Spec) 5799 and then not Is_Primitive 5800 and then Ekind (Subp) /= E_Entry 5801 and then Ekind (Scope (Subp)) /= E_Protected_Type 5802 then 5803 Error_Msg_N 5804 ("overriding indicator only allowed if subprogram is primitive", 5805 Subp); 5806 return; 5807 end if; 5808 end Check_Overriding_Indicator; 5809 5810 ------------------- 5811 -- Check_Returns -- 5812 ------------------- 5813 5814 -- Note: this procedure needs to know far too much about how the expander 5815 -- messes with exceptions. The use of the flag Exception_Junk and the 5816 -- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers 5817 -- works, but is not very clean. It would be better if the expansion 5818 -- routines would leave Original_Node working nicely, and we could use 5819 -- Original_Node here to ignore all the peculiar expander messing ??? 5820 5821 procedure Check_Returns 5822 (HSS : Node_Id; 5823 Mode : Character; 5824 Err : out Boolean; 5825 Proc : Entity_Id := Empty) 5826 is 5827 Handler : Node_Id; 5828 5829 procedure Check_Statement_Sequence (L : List_Id); 5830 -- Internal recursive procedure to check a list of statements for proper 5831 -- termination by a return statement (or a transfer of control or a 5832 -- compound statement that is itself internally properly terminated). 5833 5834 ------------------------------ 5835 -- Check_Statement_Sequence -- 5836 ------------------------------ 5837 5838 procedure Check_Statement_Sequence (L : List_Id) is 5839 Last_Stm : Node_Id; 5840 Stm : Node_Id; 5841 Kind : Node_Kind; 5842 5843 function Assert_False return Boolean; 5844 -- Returns True if Last_Stm is a pragma Assert (False) that has been 5845 -- rewritten as a null statement when assertions are off. The assert 5846 -- is not active, but it is still enough to kill the warning. 5847 5848 ------------------ 5849 -- Assert_False -- 5850 ------------------ 5851 5852 function Assert_False return Boolean is 5853 Orig : constant Node_Id := Original_Node (Last_Stm); 5854 5855 begin 5856 if Nkind (Orig) = N_Pragma 5857 and then Pragma_Name (Orig) = Name_Assert 5858 and then not Error_Posted (Orig) 5859 then 5860 declare 5861 Arg : constant Node_Id := 5862 First (Pragma_Argument_Associations (Orig)); 5863 Exp : constant Node_Id := Expression (Arg); 5864 begin 5865 return Nkind (Exp) = N_Identifier 5866 and then Chars (Exp) = Name_False; 5867 end; 5868 5869 else 5870 return False; 5871 end if; 5872 end Assert_False; 5873 5874 -- Local variables 5875 5876 Raise_Exception_Call : Boolean; 5877 -- Set True if statement sequence terminated by Raise_Exception call 5878 -- or a Reraise_Occurrence call. 5879 5880 -- Start of processing for Check_Statement_Sequence 5881 5882 begin 5883 Raise_Exception_Call := False; 5884 5885 -- Get last real statement 5886 5887 Last_Stm := Last (L); 5888 5889 -- Deal with digging out exception handler statement sequences that 5890 -- have been transformed by the local raise to goto optimization. 5891 -- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this 5892 -- optimization has occurred, we are looking at something like: 5893 5894 -- begin 5895 -- original stmts in block 5896 5897 -- exception \ 5898 -- when excep1 => | 5899 -- goto L1; | omitted if No_Exception_Propagation 5900 -- when excep2 => | 5901 -- goto L2; / 5902 -- end; 5903 5904 -- goto L3; -- skip handler when exception not raised 5905 5906 -- <<L1>> -- target label for local exception 5907 -- begin 5908 -- estmts1 5909 -- end; 5910 5911 -- goto L3; 5912 5913 -- <<L2>> 5914 -- begin 5915 -- estmts2 5916 -- end; 5917 5918 -- <<L3>> 5919 5920 -- and what we have to do is to dig out the estmts1 and estmts2 5921 -- sequences (which were the original sequences of statements in 5922 -- the exception handlers) and check them. 5923 5924 if Nkind (Last_Stm) = N_Label and then Exception_Junk (Last_Stm) then 5925 Stm := Last_Stm; 5926 loop 5927 Prev (Stm); 5928 exit when No (Stm); 5929 exit when Nkind (Stm) /= N_Block_Statement; 5930 exit when not Exception_Junk (Stm); 5931 Prev (Stm); 5932 exit when No (Stm); 5933 exit when Nkind (Stm) /= N_Label; 5934 exit when not Exception_Junk (Stm); 5935 Check_Statement_Sequence 5936 (Statements (Handled_Statement_Sequence (Next (Stm)))); 5937 5938 Prev (Stm); 5939 Last_Stm := Stm; 5940 exit when No (Stm); 5941 exit when Nkind (Stm) /= N_Goto_Statement; 5942 exit when not Exception_Junk (Stm); 5943 end loop; 5944 end if; 5945 5946 -- Don't count pragmas 5947 5948 while Nkind (Last_Stm) = N_Pragma 5949 5950 -- Don't count call to SS_Release (can happen after Raise_Exception) 5951 5952 or else 5953 (Nkind (Last_Stm) = N_Procedure_Call_Statement 5954 and then 5955 Nkind (Name (Last_Stm)) = N_Identifier 5956 and then 5957 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release)) 5958 5959 -- Don't count exception junk 5960 5961 or else 5962 (Nkind_In (Last_Stm, N_Goto_Statement, 5963 N_Label, 5964 N_Object_Declaration) 5965 and then Exception_Junk (Last_Stm)) 5966 or else Nkind (Last_Stm) in N_Push_xxx_Label 5967 or else Nkind (Last_Stm) in N_Pop_xxx_Label 5968 5969 -- Inserted code, such as finalization calls, is irrelevant: we only 5970 -- need to check original source. 5971 5972 or else Is_Rewrite_Insertion (Last_Stm) 5973 loop 5974 Prev (Last_Stm); 5975 end loop; 5976 5977 -- Here we have the "real" last statement 5978 5979 Kind := Nkind (Last_Stm); 5980 5981 -- Transfer of control, OK. Note that in the No_Return procedure 5982 -- case, we already diagnosed any explicit return statements, so 5983 -- we can treat them as OK in this context. 5984 5985 if Is_Transfer (Last_Stm) then 5986 return; 5987 5988 -- Check cases of explicit non-indirect procedure calls 5989 5990 elsif Kind = N_Procedure_Call_Statement 5991 and then Is_Entity_Name (Name (Last_Stm)) 5992 then 5993 -- Check call to Raise_Exception procedure which is treated 5994 -- specially, as is a call to Reraise_Occurrence. 5995 5996 -- We suppress the warning in these cases since it is likely that 5997 -- the programmer really does not expect to deal with the case 5998 -- of Null_Occurrence, and thus would find a warning about a 5999 -- missing return curious, and raising Program_Error does not 6000 -- seem such a bad behavior if this does occur. 6001 6002 -- Note that in the Ada 2005 case for Raise_Exception, the actual 6003 -- behavior will be to raise Constraint_Error (see AI-329). 6004 6005 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception) 6006 or else 6007 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence) 6008 then 6009 Raise_Exception_Call := True; 6010 6011 -- For Raise_Exception call, test first argument, if it is 6012 -- an attribute reference for a 'Identity call, then we know 6013 -- that the call cannot possibly return. 6014 6015 declare 6016 Arg : constant Node_Id := 6017 Original_Node (First_Actual (Last_Stm)); 6018 begin 6019 if Nkind (Arg) = N_Attribute_Reference 6020 and then Attribute_Name (Arg) = Name_Identity 6021 then 6022 return; 6023 end if; 6024 end; 6025 end if; 6026 6027 -- If statement, need to look inside if there is an else and check 6028 -- each constituent statement sequence for proper termination. 6029 6030 elsif Kind = N_If_Statement 6031 and then Present (Else_Statements (Last_Stm)) 6032 then 6033 Check_Statement_Sequence (Then_Statements (Last_Stm)); 6034 Check_Statement_Sequence (Else_Statements (Last_Stm)); 6035 6036 if Present (Elsif_Parts (Last_Stm)) then 6037 declare 6038 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm)); 6039 6040 begin 6041 while Present (Elsif_Part) loop 6042 Check_Statement_Sequence (Then_Statements (Elsif_Part)); 6043 Next (Elsif_Part); 6044 end loop; 6045 end; 6046 end if; 6047 6048 return; 6049 6050 -- Case statement, check each case for proper termination 6051 6052 elsif Kind = N_Case_Statement then 6053 declare 6054 Case_Alt : Node_Id; 6055 begin 6056 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm)); 6057 while Present (Case_Alt) loop 6058 Check_Statement_Sequence (Statements (Case_Alt)); 6059 Next_Non_Pragma (Case_Alt); 6060 end loop; 6061 end; 6062 6063 return; 6064 6065 -- Block statement, check its handled sequence of statements 6066 6067 elsif Kind = N_Block_Statement then 6068 declare 6069 Err1 : Boolean; 6070 6071 begin 6072 Check_Returns 6073 (Handled_Statement_Sequence (Last_Stm), Mode, Err1); 6074 6075 if Err1 then 6076 Err := True; 6077 end if; 6078 6079 return; 6080 end; 6081 6082 -- Loop statement. If there is an iteration scheme, we can definitely 6083 -- fall out of the loop. Similarly if there is an exit statement, we 6084 -- can fall out. In either case we need a following return. 6085 6086 elsif Kind = N_Loop_Statement then 6087 if Present (Iteration_Scheme (Last_Stm)) 6088 or else Has_Exit (Entity (Identifier (Last_Stm))) 6089 then 6090 null; 6091 6092 -- A loop with no exit statement or iteration scheme is either 6093 -- an infinite loop, or it has some other exit (raise/return). 6094 -- In either case, no warning is required. 6095 6096 else 6097 return; 6098 end if; 6099 6100 -- Timed entry call, check entry call and delay alternatives 6101 6102 -- Note: in expanded code, the timed entry call has been converted 6103 -- to a set of expanded statements on which the check will work 6104 -- correctly in any case. 6105 6106 elsif Kind = N_Timed_Entry_Call then 6107 declare 6108 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); 6109 DCA : constant Node_Id := Delay_Alternative (Last_Stm); 6110 6111 begin 6112 -- If statement sequence of entry call alternative is missing, 6113 -- then we can definitely fall through, and we post the error 6114 -- message on the entry call alternative itself. 6115 6116 if No (Statements (ECA)) then 6117 Last_Stm := ECA; 6118 6119 -- If statement sequence of delay alternative is missing, then 6120 -- we can definitely fall through, and we post the error 6121 -- message on the delay alternative itself. 6122 6123 -- Note: if both ECA and DCA are missing the return, then we 6124 -- post only one message, should be enough to fix the bugs. 6125 -- If not we will get a message next time on the DCA when the 6126 -- ECA is fixed. 6127 6128 elsif No (Statements (DCA)) then 6129 Last_Stm := DCA; 6130 6131 -- Else check both statement sequences 6132 6133 else 6134 Check_Statement_Sequence (Statements (ECA)); 6135 Check_Statement_Sequence (Statements (DCA)); 6136 return; 6137 end if; 6138 end; 6139 6140 -- Conditional entry call, check entry call and else part 6141 6142 -- Note: in expanded code, the conditional entry call has been 6143 -- converted to a set of expanded statements on which the check 6144 -- will work correctly in any case. 6145 6146 elsif Kind = N_Conditional_Entry_Call then 6147 declare 6148 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); 6149 6150 begin 6151 -- If statement sequence of entry call alternative is missing, 6152 -- then we can definitely fall through, and we post the error 6153 -- message on the entry call alternative itself. 6154 6155 if No (Statements (ECA)) then 6156 Last_Stm := ECA; 6157 6158 -- Else check statement sequence and else part 6159 6160 else 6161 Check_Statement_Sequence (Statements (ECA)); 6162 Check_Statement_Sequence (Else_Statements (Last_Stm)); 6163 return; 6164 end if; 6165 end; 6166 end if; 6167 6168 -- If we fall through, issue appropriate message 6169 6170 if Mode = 'F' then 6171 6172 -- Kill warning if last statement is a raise exception call, 6173 -- or a pragma Assert (False). Note that with assertions enabled, 6174 -- such a pragma has been converted into a raise exception call 6175 -- already, so the Assert_False is for the assertions off case. 6176 6177 if not Raise_Exception_Call and then not Assert_False then 6178 6179 -- In GNATprove mode, it is an error to have a missing return 6180 6181 Error_Msg_Warn := SPARK_Mode /= On; 6182 6183 -- Issue error message or warning 6184 6185 Error_Msg_N 6186 ("RETURN statement missing following this statement<<!", 6187 Last_Stm); 6188 Error_Msg_N 6189 ("\Program_Error ]<<!", Last_Stm); 6190 end if; 6191 6192 -- Note: we set Err even though we have not issued a warning 6193 -- because we still have a case of a missing return. This is 6194 -- an extremely marginal case, probably will never be noticed 6195 -- but we might as well get it right. 6196 6197 Err := True; 6198 6199 -- Otherwise we have the case of a procedure marked No_Return 6200 6201 else 6202 if not Raise_Exception_Call then 6203 if GNATprove_Mode then 6204 Error_Msg_N 6205 ("implied return after this statement " 6206 & "would have raised Program_Error", Last_Stm); 6207 else 6208 Error_Msg_N 6209 ("implied return after this statement " 6210 & "will raise Program_Error??", Last_Stm); 6211 end if; 6212 6213 Error_Msg_Warn := SPARK_Mode /= On; 6214 Error_Msg_NE 6215 ("\procedure & is marked as No_Return<<!", Last_Stm, Proc); 6216 end if; 6217 6218 declare 6219 RE : constant Node_Id := 6220 Make_Raise_Program_Error (Sloc (Last_Stm), 6221 Reason => PE_Implicit_Return); 6222 begin 6223 Insert_After (Last_Stm, RE); 6224 Analyze (RE); 6225 end; 6226 end if; 6227 end Check_Statement_Sequence; 6228 6229 -- Start of processing for Check_Returns 6230 6231 begin 6232 Err := False; 6233 Check_Statement_Sequence (Statements (HSS)); 6234 6235 if Present (Exception_Handlers (HSS)) then 6236 Handler := First_Non_Pragma (Exception_Handlers (HSS)); 6237 while Present (Handler) loop 6238 Check_Statement_Sequence (Statements (Handler)); 6239 Next_Non_Pragma (Handler); 6240 end loop; 6241 end if; 6242 end Check_Returns; 6243 6244 ---------------------------- 6245 -- Check_Subprogram_Order -- 6246 ---------------------------- 6247 6248 procedure Check_Subprogram_Order (N : Node_Id) is 6249 6250 function Subprogram_Name_Greater (S1, S2 : String) return Boolean; 6251 -- This is used to check if S1 > S2 in the sense required by this test, 6252 -- for example nameab < namec, but name2 < name10. 6253 6254 ----------------------------- 6255 -- Subprogram_Name_Greater -- 6256 ----------------------------- 6257 6258 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is 6259 L1, L2 : Positive; 6260 N1, N2 : Natural; 6261 6262 begin 6263 -- Deal with special case where names are identical except for a 6264 -- numerical suffix. These are handled specially, taking the numeric 6265 -- ordering from the suffix into account. 6266 6267 L1 := S1'Last; 6268 while S1 (L1) in '0' .. '9' loop 6269 L1 := L1 - 1; 6270 end loop; 6271 6272 L2 := S2'Last; 6273 while S2 (L2) in '0' .. '9' loop 6274 L2 := L2 - 1; 6275 end loop; 6276 6277 -- If non-numeric parts non-equal, do straight compare 6278 6279 if S1 (S1'First .. L1) /= S2 (S2'First .. L2) then 6280 return S1 > S2; 6281 6282 -- If non-numeric parts equal, compare suffixed numeric parts. Note 6283 -- that a missing suffix is treated as numeric zero in this test. 6284 6285 else 6286 N1 := 0; 6287 while L1 < S1'Last loop 6288 L1 := L1 + 1; 6289 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0'); 6290 end loop; 6291 6292 N2 := 0; 6293 while L2 < S2'Last loop 6294 L2 := L2 + 1; 6295 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0'); 6296 end loop; 6297 6298 return N1 > N2; 6299 end if; 6300 end Subprogram_Name_Greater; 6301 6302 -- Start of processing for Check_Subprogram_Order 6303 6304 begin 6305 -- Check body in alpha order if this is option 6306 6307 if Style_Check 6308 and then Style_Check_Order_Subprograms 6309 and then Nkind (N) = N_Subprogram_Body 6310 and then Comes_From_Source (N) 6311 and then In_Extended_Main_Source_Unit (N) 6312 then 6313 declare 6314 LSN : String_Ptr 6315 renames Scope_Stack.Table 6316 (Scope_Stack.Last).Last_Subprogram_Name; 6317 6318 Body_Id : constant Entity_Id := 6319 Defining_Entity (Specification (N)); 6320 6321 begin 6322 Get_Decoded_Name_String (Chars (Body_Id)); 6323 6324 if LSN /= null then 6325 if Subprogram_Name_Greater 6326 (LSN.all, Name_Buffer (1 .. Name_Len)) 6327 then 6328 Style.Subprogram_Not_In_Alpha_Order (Body_Id); 6329 end if; 6330 6331 Free (LSN); 6332 end if; 6333 6334 LSN := new String'(Name_Buffer (1 .. Name_Len)); 6335 end; 6336 end if; 6337 end Check_Subprogram_Order; 6338 6339 ------------------------------ 6340 -- Check_Subtype_Conformant -- 6341 ------------------------------ 6342 6343 procedure Check_Subtype_Conformant 6344 (New_Id : Entity_Id; 6345 Old_Id : Entity_Id; 6346 Err_Loc : Node_Id := Empty; 6347 Skip_Controlling_Formals : Boolean := False; 6348 Get_Inst : Boolean := False) 6349 is 6350 Result : Boolean; 6351 pragma Warnings (Off, Result); 6352 begin 6353 Check_Conformance 6354 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc, 6355 Skip_Controlling_Formals => Skip_Controlling_Formals, 6356 Get_Inst => Get_Inst); 6357 end Check_Subtype_Conformant; 6358 6359 --------------------------- 6360 -- Check_Type_Conformant -- 6361 --------------------------- 6362 6363 procedure Check_Type_Conformant 6364 (New_Id : Entity_Id; 6365 Old_Id : Entity_Id; 6366 Err_Loc : Node_Id := Empty) 6367 is 6368 Result : Boolean; 6369 pragma Warnings (Off, Result); 6370 begin 6371 Check_Conformance 6372 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc); 6373 end Check_Type_Conformant; 6374 6375 --------------------------- 6376 -- Can_Override_Operator -- 6377 --------------------------- 6378 6379 function Can_Override_Operator (Subp : Entity_Id) return Boolean is 6380 Typ : Entity_Id; 6381 6382 begin 6383 if Nkind (Subp) /= N_Defining_Operator_Symbol then 6384 return False; 6385 6386 else 6387 Typ := Base_Type (Etype (First_Formal (Subp))); 6388 6389 -- Check explicitly that the operation is a primitive of the type 6390 6391 return Operator_Matches_Spec (Subp, Subp) 6392 and then not Is_Generic_Type (Typ) 6393 and then Scope (Subp) = Scope (Typ) 6394 and then not Is_Class_Wide_Type (Typ); 6395 end if; 6396 end Can_Override_Operator; 6397 6398 ---------------------- 6399 -- Conforming_Types -- 6400 ---------------------- 6401 6402 function Conforming_Types 6403 (T1 : Entity_Id; 6404 T2 : Entity_Id; 6405 Ctype : Conformance_Type; 6406 Get_Inst : Boolean := False) return Boolean 6407 is 6408 Type_1 : Entity_Id := T1; 6409 Type_2 : Entity_Id := T2; 6410 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False; 6411 6412 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean; 6413 -- If neither T1 nor T2 are generic actual types, or if they are in 6414 -- different scopes (e.g. parent and child instances), then verify that 6415 -- the base types are equal. Otherwise T1 and T2 must be on the same 6416 -- subtype chain. The whole purpose of this procedure is to prevent 6417 -- spurious ambiguities in an instantiation that may arise if two 6418 -- distinct generic types are instantiated with the same actual. 6419 6420 function Find_Designated_Type (T : Entity_Id) return Entity_Id; 6421 -- An access parameter can designate an incomplete type. If the 6422 -- incomplete type is the limited view of a type from a limited_ 6423 -- with_clause, check whether the non-limited view is available. If 6424 -- it is a (non-limited) incomplete type, get the full view. 6425 6426 function Matches_Limited_With_View (T1, T2 : Entity_Id) return Boolean; 6427 -- Returns True if and only if either T1 denotes a limited view of T2 6428 -- or T2 denotes a limited view of T1. This can arise when the limited 6429 -- with view of a type is used in a subprogram declaration and the 6430 -- subprogram body is in the scope of a regular with clause for the 6431 -- same unit. In such a case, the two type entities can be considered 6432 -- identical for purposes of conformance checking. 6433 6434 ---------------------- 6435 -- Base_Types_Match -- 6436 ---------------------- 6437 6438 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is 6439 BT1 : constant Entity_Id := Base_Type (T1); 6440 BT2 : constant Entity_Id := Base_Type (T2); 6441 6442 begin 6443 if T1 = T2 then 6444 return True; 6445 6446 elsif BT1 = BT2 then 6447 6448 -- The following is too permissive. A more precise test should 6449 -- check that the generic actual is an ancestor subtype of the 6450 -- other ???. 6451 6452 -- See code in Find_Corresponding_Spec that applies an additional 6453 -- filter to handle accidental amiguities in instances. 6454 6455 return not Is_Generic_Actual_Type (T1) 6456 or else not Is_Generic_Actual_Type (T2) 6457 or else Scope (T1) /= Scope (T2); 6458 6459 -- If T2 is a generic actual type it is declared as the subtype of 6460 -- the actual. If that actual is itself a subtype we need to use its 6461 -- own base type to check for compatibility. 6462 6463 elsif Ekind (BT2) = Ekind (T2) and then BT1 = Base_Type (BT2) then 6464 return True; 6465 6466 elsif Ekind (BT1) = Ekind (T1) and then BT2 = Base_Type (BT1) then 6467 return True; 6468 6469 else 6470 return False; 6471 end if; 6472 end Base_Types_Match; 6473 6474 -------------------------- 6475 -- Find_Designated_Type -- 6476 -------------------------- 6477 6478 function Find_Designated_Type (T : Entity_Id) return Entity_Id is 6479 Desig : Entity_Id; 6480 6481 begin 6482 Desig := Directly_Designated_Type (T); 6483 6484 if Ekind (Desig) = E_Incomplete_Type then 6485 6486 -- If regular incomplete type, get full view if available 6487 6488 if Present (Full_View (Desig)) then 6489 Desig := Full_View (Desig); 6490 6491 -- If limited view of a type, get non-limited view if available, 6492 -- and check again for a regular incomplete type. 6493 6494 elsif Present (Non_Limited_View (Desig)) then 6495 Desig := Get_Full_View (Non_Limited_View (Desig)); 6496 end if; 6497 end if; 6498 6499 return Desig; 6500 end Find_Designated_Type; 6501 6502 ------------------------------- 6503 -- Matches_Limited_With_View -- 6504 ------------------------------- 6505 6506 function Matches_Limited_With_View (T1, T2 : Entity_Id) return Boolean is 6507 begin 6508 -- In some cases a type imported through a limited_with clause, and 6509 -- its nonlimited view are both visible, for example in an anonymous 6510 -- access-to-class-wide type in a formal, or when building the body 6511 -- for a subprogram renaming after the subprogram has been frozen. 6512 -- In these cases Both entities designate the same type. In addition, 6513 -- if one of them is an actual in an instance, it may be a subtype of 6514 -- the non-limited view of the other. 6515 6516 if From_Limited_With (T1) 6517 and then (T2 = Available_View (T1) 6518 or else Is_Subtype_Of (T2, Available_View (T1))) 6519 then 6520 return True; 6521 6522 elsif From_Limited_With (T2) 6523 and then (T1 = Available_View (T2) 6524 or else Is_Subtype_Of (T1, Available_View (T2))) 6525 then 6526 return True; 6527 6528 elsif From_Limited_With (T1) 6529 and then From_Limited_With (T2) 6530 and then Available_View (T1) = Available_View (T2) 6531 then 6532 return True; 6533 6534 else 6535 return False; 6536 end if; 6537 end Matches_Limited_With_View; 6538 6539 -- Start of processing for Conforming_Types 6540 6541 begin 6542 -- The context is an instance association for a formal access-to- 6543 -- subprogram type; the formal parameter types require mapping because 6544 -- they may denote other formal parameters of the generic unit. 6545 6546 if Get_Inst then 6547 Type_1 := Get_Instance_Of (T1); 6548 Type_2 := Get_Instance_Of (T2); 6549 end if; 6550 6551 -- If one of the types is a view of the other introduced by a limited 6552 -- with clause, treat these as conforming for all purposes. 6553 6554 if Matches_Limited_With_View (T1, T2) then 6555 return True; 6556 6557 elsif Base_Types_Match (Type_1, Type_2) then 6558 return Ctype <= Mode_Conformant 6559 or else Subtypes_Statically_Match (Type_1, Type_2); 6560 6561 elsif Is_Incomplete_Or_Private_Type (Type_1) 6562 and then Present (Full_View (Type_1)) 6563 and then Base_Types_Match (Full_View (Type_1), Type_2) 6564 then 6565 return Ctype <= Mode_Conformant 6566 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2); 6567 6568 elsif Ekind (Type_2) = E_Incomplete_Type 6569 and then Present (Full_View (Type_2)) 6570 and then Base_Types_Match (Type_1, Full_View (Type_2)) 6571 then 6572 return Ctype <= Mode_Conformant 6573 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); 6574 6575 elsif Is_Private_Type (Type_2) 6576 and then In_Instance 6577 and then Present (Full_View (Type_2)) 6578 and then Base_Types_Match (Type_1, Full_View (Type_2)) 6579 then 6580 return Ctype <= Mode_Conformant 6581 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); 6582 6583 -- In Ada 2012, incomplete types (including limited views) can appear 6584 -- as actuals in instantiations. 6585 6586 elsif Is_Incomplete_Type (Type_1) 6587 and then Is_Incomplete_Type (Type_2) 6588 and then (Used_As_Generic_Actual (Type_1) 6589 or else Used_As_Generic_Actual (Type_2)) 6590 then 6591 return True; 6592 end if; 6593 6594 -- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be 6595 -- treated recursively because they carry a signature. As far as 6596 -- conformance is concerned, convention plays no role, and either 6597 -- or both could be access to protected subprograms. 6598 6599 Are_Anonymous_Access_To_Subprogram_Types := 6600 Ekind_In (Type_1, E_Anonymous_Access_Subprogram_Type, 6601 E_Anonymous_Access_Protected_Subprogram_Type) 6602 and then 6603 Ekind_In (Type_2, E_Anonymous_Access_Subprogram_Type, 6604 E_Anonymous_Access_Protected_Subprogram_Type); 6605 6606 -- Test anonymous access type case. For this case, static subtype 6607 -- matching is required for mode conformance (RM 6.3.1(15)). We check 6608 -- the base types because we may have built internal subtype entities 6609 -- to handle null-excluding types (see Process_Formals). 6610 6611 if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type 6612 and then 6613 Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type) 6614 6615 -- Ada 2005 (AI-254) 6616 6617 or else Are_Anonymous_Access_To_Subprogram_Types 6618 then 6619 declare 6620 Desig_1 : Entity_Id; 6621 Desig_2 : Entity_Id; 6622 6623 begin 6624 -- In Ada 2005, access constant indicators must match for 6625 -- subtype conformance. 6626 6627 if Ada_Version >= Ada_2005 6628 and then Ctype >= Subtype_Conformant 6629 and then 6630 Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2) 6631 then 6632 return False; 6633 end if; 6634 6635 Desig_1 := Find_Designated_Type (Type_1); 6636 Desig_2 := Find_Designated_Type (Type_2); 6637 6638 -- If the context is an instance association for a formal 6639 -- access-to-subprogram type; formal access parameter designated 6640 -- types require mapping because they may denote other formal 6641 -- parameters of the generic unit. 6642 6643 if Get_Inst then 6644 Desig_1 := Get_Instance_Of (Desig_1); 6645 Desig_2 := Get_Instance_Of (Desig_2); 6646 end if; 6647 6648 -- It is possible for a Class_Wide_Type to be introduced for an 6649 -- incomplete type, in which case there is a separate class_ wide 6650 -- type for the full view. The types conform if their Etypes 6651 -- conform, i.e. one may be the full view of the other. This can 6652 -- only happen in the context of an access parameter, other uses 6653 -- of an incomplete Class_Wide_Type are illegal. 6654 6655 if Is_Class_Wide_Type (Desig_1) 6656 and then 6657 Is_Class_Wide_Type (Desig_2) 6658 then 6659 return 6660 Conforming_Types 6661 (Etype (Base_Type (Desig_1)), 6662 Etype (Base_Type (Desig_2)), Ctype); 6663 6664 elsif Are_Anonymous_Access_To_Subprogram_Types then 6665 if Ada_Version < Ada_2005 then 6666 return Ctype = Type_Conformant 6667 or else 6668 Subtypes_Statically_Match (Desig_1, Desig_2); 6669 6670 -- We must check the conformance of the signatures themselves 6671 6672 else 6673 declare 6674 Conformant : Boolean; 6675 begin 6676 Check_Conformance 6677 (Desig_1, Desig_2, Ctype, False, Conformant); 6678 return Conformant; 6679 end; 6680 end if; 6681 6682 -- A limited view of an actual matches the corresponding 6683 -- incomplete formal. 6684 6685 elsif Ekind (Desig_2) = E_Incomplete_Subtype 6686 and then From_Limited_With (Desig_2) 6687 and then Used_As_Generic_Actual (Etype (Desig_2)) 6688 then 6689 return True; 6690 6691 else 6692 return Base_Type (Desig_1) = Base_Type (Desig_2) 6693 and then (Ctype = Type_Conformant 6694 or else 6695 Subtypes_Statically_Match (Desig_1, Desig_2)); 6696 end if; 6697 end; 6698 6699 -- Otherwise definitely no match 6700 6701 else 6702 if ((Ekind (Type_1) = E_Anonymous_Access_Type 6703 and then Is_Access_Type (Type_2)) 6704 or else (Ekind (Type_2) = E_Anonymous_Access_Type 6705 and then Is_Access_Type (Type_1))) 6706 and then 6707 Conforming_Types 6708 (Designated_Type (Type_1), Designated_Type (Type_2), Ctype) 6709 then 6710 May_Hide_Profile := True; 6711 end if; 6712 6713 return False; 6714 end if; 6715 end Conforming_Types; 6716 6717 -------------------------- 6718 -- Create_Extra_Formals -- 6719 -------------------------- 6720 6721 procedure Create_Extra_Formals (E : Entity_Id) is 6722 Formal : Entity_Id; 6723 First_Extra : Entity_Id := Empty; 6724 Last_Extra : Entity_Id; 6725 Formal_Type : Entity_Id; 6726 P_Formal : Entity_Id := Empty; 6727 6728 function Add_Extra_Formal 6729 (Assoc_Entity : Entity_Id; 6730 Typ : Entity_Id; 6731 Scope : Entity_Id; 6732 Suffix : String) return Entity_Id; 6733 -- Add an extra formal to the current list of formals and extra formals. 6734 -- The extra formal is added to the end of the list of extra formals, 6735 -- and also returned as the result. These formals are always of mode IN. 6736 -- The new formal has the type Typ, is declared in Scope, and its name 6737 -- is given by a concatenation of the name of Assoc_Entity and Suffix. 6738 -- The following suffixes are currently used. They should not be changed 6739 -- without coordinating with CodePeer, which makes use of these to 6740 -- provide better messages. 6741 6742 -- O denotes the Constrained bit. 6743 -- L denotes the accessibility level. 6744 -- BIP_xxx denotes an extra formal for a build-in-place function. See 6745 -- the full list in exp_ch6.BIP_Formal_Kind. 6746 6747 ---------------------- 6748 -- Add_Extra_Formal -- 6749 ---------------------- 6750 6751 function Add_Extra_Formal 6752 (Assoc_Entity : Entity_Id; 6753 Typ : Entity_Id; 6754 Scope : Entity_Id; 6755 Suffix : String) return Entity_Id 6756 is 6757 EF : constant Entity_Id := 6758 Make_Defining_Identifier (Sloc (Assoc_Entity), 6759 Chars => New_External_Name (Chars (Assoc_Entity), 6760 Suffix => Suffix)); 6761 6762 begin 6763 -- A little optimization. Never generate an extra formal for the 6764 -- _init operand of an initialization procedure, since it could 6765 -- never be used. 6766 6767 if Chars (Formal) = Name_uInit then 6768 return Empty; 6769 end if; 6770 6771 Set_Ekind (EF, E_In_Parameter); 6772 Set_Actual_Subtype (EF, Typ); 6773 Set_Etype (EF, Typ); 6774 Set_Scope (EF, Scope); 6775 Set_Mechanism (EF, Default_Mechanism); 6776 Set_Formal_Validity (EF); 6777 6778 if No (First_Extra) then 6779 First_Extra := EF; 6780 Set_Extra_Formals (Scope, First_Extra); 6781 end if; 6782 6783 if Present (Last_Extra) then 6784 Set_Extra_Formal (Last_Extra, EF); 6785 end if; 6786 6787 Last_Extra := EF; 6788 6789 return EF; 6790 end Add_Extra_Formal; 6791 6792 -- Start of processing for Create_Extra_Formals 6793 6794 begin 6795 -- We never generate extra formals if expansion is not active because we 6796 -- don't need them unless we are generating code. 6797 6798 if not Expander_Active then 6799 return; 6800 end if; 6801 6802 -- No need to generate extra formals in interface thunks whose target 6803 -- primitive has no extra formals. 6804 6805 if Is_Thunk (E) and then No (Extra_Formals (Thunk_Entity (E))) then 6806 return; 6807 end if; 6808 6809 -- If this is a derived subprogram then the subtypes of the parent 6810 -- subprogram's formal parameters will be used to determine the need 6811 -- for extra formals. 6812 6813 if Is_Overloadable (E) and then Present (Alias (E)) then 6814 P_Formal := First_Formal (Alias (E)); 6815 end if; 6816 6817 Last_Extra := Empty; 6818 Formal := First_Formal (E); 6819 while Present (Formal) loop 6820 Last_Extra := Formal; 6821 Next_Formal (Formal); 6822 end loop; 6823 6824 -- If Extra_Formals were already created, don't do it again. This 6825 -- situation may arise for subprogram types created as part of 6826 -- dispatching calls (see Expand_Dispatching_Call) 6827 6828 if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then 6829 return; 6830 end if; 6831 6832 -- If the subprogram is a predefined dispatching subprogram then don't 6833 -- generate any extra constrained or accessibility level formals. In 6834 -- general we suppress these for internal subprograms (by not calling 6835 -- Freeze_Subprogram and Create_Extra_Formals at all), but internally 6836 -- generated stream attributes do get passed through because extra 6837 -- build-in-place formals are needed in some cases (limited 'Input). 6838 6839 if Is_Predefined_Internal_Operation (E) then 6840 goto Test_For_Func_Result_Extras; 6841 end if; 6842 6843 Formal := First_Formal (E); 6844 while Present (Formal) loop 6845 6846 -- Create extra formal for supporting the attribute 'Constrained. 6847 -- The case of a private type view without discriminants also 6848 -- requires the extra formal if the underlying type has defaulted 6849 -- discriminants. 6850 6851 if Ekind (Formal) /= E_In_Parameter then 6852 if Present (P_Formal) then 6853 Formal_Type := Etype (P_Formal); 6854 else 6855 Formal_Type := Etype (Formal); 6856 end if; 6857 6858 -- Do not produce extra formals for Unchecked_Union parameters. 6859 -- Jump directly to the end of the loop. 6860 6861 if Is_Unchecked_Union (Base_Type (Formal_Type)) then 6862 goto Skip_Extra_Formal_Generation; 6863 end if; 6864 6865 if not Has_Discriminants (Formal_Type) 6866 and then Ekind (Formal_Type) in Private_Kind 6867 and then Present (Underlying_Type (Formal_Type)) 6868 then 6869 Formal_Type := Underlying_Type (Formal_Type); 6870 end if; 6871 6872 -- Suppress the extra formal if formal's subtype is constrained or 6873 -- indefinite, or we're compiling for Ada 2012 and the underlying 6874 -- type is tagged and limited. In Ada 2012, a limited tagged type 6875 -- can have defaulted discriminants, but 'Constrained is required 6876 -- to return True, so the formal is never needed (see AI05-0214). 6877 -- Note that this ensures consistency of calling sequences for 6878 -- dispatching operations when some types in a class have defaults 6879 -- on discriminants and others do not (and requiring the extra 6880 -- formal would introduce distributed overhead). 6881 6882 -- If the type does not have a completion yet, treat as prior to 6883 -- Ada 2012 for consistency. 6884 6885 if Has_Discriminants (Formal_Type) 6886 and then not Is_Constrained (Formal_Type) 6887 and then Is_Definite_Subtype (Formal_Type) 6888 and then (Ada_Version < Ada_2012 6889 or else No (Underlying_Type (Formal_Type)) 6890 or else not 6891 (Is_Limited_Type (Formal_Type) 6892 and then 6893 (Is_Tagged_Type 6894 (Underlying_Type (Formal_Type))))) 6895 then 6896 Set_Extra_Constrained 6897 (Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O")); 6898 end if; 6899 end if; 6900 6901 -- Create extra formal for supporting accessibility checking. This 6902 -- is done for both anonymous access formals and formals of named 6903 -- access types that are marked as controlling formals. The latter 6904 -- case can occur when Expand_Dispatching_Call creates a subprogram 6905 -- type and substitutes the types of access-to-class-wide actuals 6906 -- for the anonymous access-to-specific-type of controlling formals. 6907 -- Base_Type is applied because in cases where there is a null 6908 -- exclusion the formal may have an access subtype. 6909 6910 -- This is suppressed if we specifically suppress accessibility 6911 -- checks at the package level for either the subprogram, or the 6912 -- package in which it resides. However, we do not suppress it 6913 -- simply if the scope has accessibility checks suppressed, since 6914 -- this could cause trouble when clients are compiled with a 6915 -- different suppression setting. The explicit checks at the 6916 -- package level are safe from this point of view. 6917 6918 if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type 6919 or else (Is_Controlling_Formal (Formal) 6920 and then Is_Access_Type (Base_Type (Etype (Formal))))) 6921 and then not 6922 (Explicit_Suppress (E, Accessibility_Check) 6923 or else 6924 Explicit_Suppress (Scope (E), Accessibility_Check)) 6925 and then 6926 (No (P_Formal) 6927 or else Present (Extra_Accessibility (P_Formal))) 6928 then 6929 Set_Extra_Accessibility 6930 (Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L")); 6931 end if; 6932 6933 -- This label is required when skipping extra formal generation for 6934 -- Unchecked_Union parameters. 6935 6936 <<Skip_Extra_Formal_Generation>> 6937 6938 if Present (P_Formal) then 6939 Next_Formal (P_Formal); 6940 end if; 6941 6942 Next_Formal (Formal); 6943 end loop; 6944 6945 <<Test_For_Func_Result_Extras>> 6946 6947 -- Ada 2012 (AI05-234): "the accessibility level of the result of a 6948 -- function call is ... determined by the point of call ...". 6949 6950 if Needs_Result_Accessibility_Level (E) then 6951 Set_Extra_Accessibility_Of_Result 6952 (E, Add_Extra_Formal (E, Standard_Natural, E, "L")); 6953 end if; 6954 6955 -- Ada 2005 (AI-318-02): In the case of build-in-place functions, add 6956 -- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind. 6957 6958 if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function (E) then 6959 declare 6960 Result_Subt : constant Entity_Id := Etype (E); 6961 Full_Subt : constant Entity_Id := Available_View (Result_Subt); 6962 Formal_Typ : Entity_Id; 6963 6964 Discard : Entity_Id; 6965 pragma Warnings (Off, Discard); 6966 6967 begin 6968 -- In the case of functions with unconstrained result subtypes, 6969 -- add a 4-state formal indicating whether the return object is 6970 -- allocated by the caller (1), or should be allocated by the 6971 -- callee on the secondary stack (2), in the global heap (3), or 6972 -- in a user-defined storage pool (4). For the moment we just use 6973 -- Natural for the type of this formal. Note that this formal 6974 -- isn't usually needed in the case where the result subtype is 6975 -- constrained, but it is needed when the function has a tagged 6976 -- result, because generally such functions can be called in a 6977 -- dispatching context and such calls must be handled like calls 6978 -- to a class-wide function. 6979 6980 if Needs_BIP_Alloc_Form (E) then 6981 Discard := 6982 Add_Extra_Formal 6983 (E, Standard_Natural, 6984 E, BIP_Formal_Suffix (BIP_Alloc_Form)); 6985 6986 -- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to 6987 -- use a user-defined pool. This formal is not added on 6988 -- ZFP as those targets do not support pools. 6989 6990 if RTE_Available (RE_Root_Storage_Pool_Ptr) then 6991 Discard := 6992 Add_Extra_Formal 6993 (E, RTE (RE_Root_Storage_Pool_Ptr), 6994 E, BIP_Formal_Suffix (BIP_Storage_Pool)); 6995 end if; 6996 end if; 6997 6998 -- In the case of functions whose result type needs finalization, 6999 -- add an extra formal which represents the finalization master. 7000 7001 if Needs_BIP_Finalization_Master (E) then 7002 Discard := 7003 Add_Extra_Formal 7004 (E, RTE (RE_Finalization_Master_Ptr), 7005 E, BIP_Formal_Suffix (BIP_Finalization_Master)); 7006 end if; 7007 7008 -- When the result type contains tasks, add two extra formals: the 7009 -- master of the tasks to be created, and the caller's activation 7010 -- chain. 7011 7012 if Has_Task (Full_Subt) then 7013 Discard := 7014 Add_Extra_Formal 7015 (E, RTE (RE_Master_Id), 7016 E, BIP_Formal_Suffix (BIP_Task_Master)); 7017 Discard := 7018 Add_Extra_Formal 7019 (E, RTE (RE_Activation_Chain_Access), 7020 E, BIP_Formal_Suffix (BIP_Activation_Chain)); 7021 end if; 7022 7023 -- All build-in-place functions get an extra formal that will be 7024 -- passed the address of the return object within the caller. 7025 7026 Formal_Typ := 7027 Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E)); 7028 7029 Set_Directly_Designated_Type (Formal_Typ, Result_Subt); 7030 Set_Etype (Formal_Typ, Formal_Typ); 7031 Set_Depends_On_Private 7032 (Formal_Typ, Has_Private_Component (Formal_Typ)); 7033 Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ))); 7034 Set_Is_Access_Constant (Formal_Typ, False); 7035 7036 -- Ada 2005 (AI-50217): Propagate the attribute that indicates 7037 -- the designated type comes from the limited view (for back-end 7038 -- purposes). 7039 7040 Set_From_Limited_With 7041 (Formal_Typ, From_Limited_With (Result_Subt)); 7042 7043 Layout_Type (Formal_Typ); 7044 7045 Discard := 7046 Add_Extra_Formal 7047 (E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access)); 7048 end; 7049 end if; 7050 end Create_Extra_Formals; 7051 7052 ----------------------------- 7053 -- Enter_Overloaded_Entity -- 7054 ----------------------------- 7055 7056 procedure Enter_Overloaded_Entity (S : Entity_Id) is 7057 E : Entity_Id := Current_Entity_In_Scope (S); 7058 C_E : Entity_Id := Current_Entity (S); 7059 7060 begin 7061 if Present (E) then 7062 Set_Has_Homonym (E); 7063 Set_Has_Homonym (S); 7064 end if; 7065 7066 Set_Is_Immediately_Visible (S); 7067 Set_Scope (S, Current_Scope); 7068 7069 -- Chain new entity if front of homonym in current scope, so that 7070 -- homonyms are contiguous. 7071 7072 if Present (E) and then E /= C_E then 7073 while Homonym (C_E) /= E loop 7074 C_E := Homonym (C_E); 7075 end loop; 7076 7077 Set_Homonym (C_E, S); 7078 7079 else 7080 E := C_E; 7081 Set_Current_Entity (S); 7082 end if; 7083 7084 Set_Homonym (S, E); 7085 7086 if Is_Inherited_Operation (S) then 7087 Append_Inherited_Subprogram (S); 7088 else 7089 Append_Entity (S, Current_Scope); 7090 end if; 7091 7092 Set_Public_Status (S); 7093 7094 if Debug_Flag_E then 7095 Write_Str ("New overloaded entity chain: "); 7096 Write_Name (Chars (S)); 7097 7098 E := S; 7099 while Present (E) loop 7100 Write_Str (" "); Write_Int (Int (E)); 7101 E := Homonym (E); 7102 end loop; 7103 7104 Write_Eol; 7105 end if; 7106 7107 -- Generate warning for hiding 7108 7109 if Warn_On_Hiding 7110 and then Comes_From_Source (S) 7111 and then In_Extended_Main_Source_Unit (S) 7112 then 7113 E := S; 7114 loop 7115 E := Homonym (E); 7116 exit when No (E); 7117 7118 -- Warn unless genuine overloading. Do not emit warning on 7119 -- hiding predefined operators in Standard (these are either an 7120 -- (artifact of our implicit declarations, or simple noise) but 7121 -- keep warning on a operator defined on a local subtype, because 7122 -- of the real danger that different operators may be applied in 7123 -- various parts of the program. 7124 7125 -- Note that if E and S have the same scope, there is never any 7126 -- hiding. Either the two conflict, and the program is illegal, 7127 -- or S is overriding an implicit inherited subprogram. 7128 7129 if Scope (E) /= Scope (S) 7130 and then (not Is_Overloadable (E) 7131 or else Subtype_Conformant (E, S)) 7132 and then (Is_Immediately_Visible (E) 7133 or else 7134 Is_Potentially_Use_Visible (S)) 7135 then 7136 if Scope (E) /= Standard_Standard then 7137 Error_Msg_Sloc := Sloc (E); 7138 Error_Msg_N ("declaration of & hides one #?h?", S); 7139 7140 elsif Nkind (S) = N_Defining_Operator_Symbol 7141 and then 7142 Scope (Base_Type (Etype (First_Formal (S)))) /= Scope (S) 7143 then 7144 Error_Msg_N 7145 ("declaration of & hides predefined operator?h?", S); 7146 end if; 7147 end if; 7148 end loop; 7149 end if; 7150 end Enter_Overloaded_Entity; 7151 7152 ----------------------------- 7153 -- Check_Untagged_Equality -- 7154 ----------------------------- 7155 7156 procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is 7157 Typ : constant Entity_Id := Etype (First_Formal (Eq_Op)); 7158 Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op); 7159 Obj_Decl : Node_Id; 7160 7161 begin 7162 -- This check applies only if we have a subprogram declaration with an 7163 -- untagged record type. 7164 7165 if Nkind (Decl) /= N_Subprogram_Declaration 7166 or else not Is_Record_Type (Typ) 7167 or else Is_Tagged_Type (Typ) 7168 then 7169 return; 7170 end if; 7171 7172 -- In Ada 2012 case, we will output errors or warnings depending on 7173 -- the setting of debug flag -gnatd.E. 7174 7175 if Ada_Version >= Ada_2012 then 7176 Error_Msg_Warn := Debug_Flag_Dot_EE; 7177 7178 -- In earlier versions of Ada, nothing to do unless we are warning on 7179 -- Ada 2012 incompatibilities (Warn_On_Ada_2012_Incompatibility set). 7180 7181 else 7182 if not Warn_On_Ada_2012_Compatibility then 7183 return; 7184 end if; 7185 end if; 7186 7187 -- Cases where the type has already been frozen 7188 7189 if Is_Frozen (Typ) then 7190 7191 -- If the type is not declared in a package, or if we are in the body 7192 -- of the package or in some other scope, the new operation is not 7193 -- primitive, and therefore legal, though suspicious. Should we 7194 -- generate a warning in this case ??? 7195 7196 if Ekind (Scope (Typ)) /= E_Package 7197 or else Scope (Typ) /= Current_Scope 7198 then 7199 return; 7200 7201 -- If the type is a generic actual (sub)type, the operation is not 7202 -- primitive either because the base type is declared elsewhere. 7203 7204 elsif Is_Generic_Actual_Type (Typ) then 7205 return; 7206 7207 -- Here we have a definite error of declaration after freezing 7208 7209 else 7210 if Ada_Version >= Ada_2012 then 7211 Error_Msg_NE 7212 ("equality operator must be declared before type & is " 7213 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)<<", Eq_Op, Typ); 7214 7215 -- In Ada 2012 mode with error turned to warning, output one 7216 -- more warning to warn that the equality operation may not 7217 -- compose. This is the consequence of ignoring the error. 7218 7219 if Error_Msg_Warn then 7220 Error_Msg_N ("\equality operation may not compose??", Eq_Op); 7221 end if; 7222 7223 else 7224 Error_Msg_NE 7225 ("equality operator must be declared before type& is " 7226 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)?y?", Eq_Op, Typ); 7227 end if; 7228 7229 -- If we are in the package body, we could just move the 7230 -- declaration to the package spec, so add a message saying that. 7231 7232 if In_Package_Body (Scope (Typ)) then 7233 if Ada_Version >= Ada_2012 then 7234 Error_Msg_N 7235 ("\move declaration to package spec<<", Eq_Op); 7236 else 7237 Error_Msg_N 7238 ("\move declaration to package spec (Ada 2012)?y?", Eq_Op); 7239 end if; 7240 7241 -- Otherwise try to find the freezing point 7242 7243 else 7244 Obj_Decl := Next (Parent (Typ)); 7245 while Present (Obj_Decl) and then Obj_Decl /= Decl loop 7246 if Nkind (Obj_Decl) = N_Object_Declaration 7247 and then Etype (Defining_Identifier (Obj_Decl)) = Typ 7248 then 7249 -- Freezing point, output warnings 7250 7251 if Ada_Version >= Ada_2012 then 7252 Error_Msg_NE 7253 ("type& is frozen by declaration??", Obj_Decl, Typ); 7254 Error_Msg_N 7255 ("\an equality operator cannot be declared after " 7256 & "this point??", 7257 Obj_Decl); 7258 else 7259 Error_Msg_NE 7260 ("type& is frozen by declaration (Ada 2012)?y?", 7261 Obj_Decl, Typ); 7262 Error_Msg_N 7263 ("\an equality operator cannot be declared after " 7264 & "this point (Ada 2012)?y?", 7265 Obj_Decl); 7266 end if; 7267 7268 exit; 7269 end if; 7270 7271 Next (Obj_Decl); 7272 end loop; 7273 end if; 7274 end if; 7275 7276 -- Here if type is not frozen yet. It is illegal to have a primitive 7277 -- equality declared in the private part if the type is visible. 7278 7279 elsif not In_Same_List (Parent (Typ), Decl) 7280 and then not Is_Limited_Type (Typ) 7281 then 7282 -- Shouldn't we give an RM reference here??? 7283 7284 if Ada_Version >= Ada_2012 then 7285 Error_Msg_N 7286 ("equality operator appears too late<<", Eq_Op); 7287 else 7288 Error_Msg_N 7289 ("equality operator appears too late (Ada 2012)?y?", Eq_Op); 7290 end if; 7291 7292 -- No error detected 7293 7294 else 7295 return; 7296 end if; 7297 end Check_Untagged_Equality; 7298 7299 ----------------------------- 7300 -- Find_Corresponding_Spec -- 7301 ----------------------------- 7302 7303 function Find_Corresponding_Spec 7304 (N : Node_Id; 7305 Post_Error : Boolean := True) return Entity_Id 7306 is 7307 Spec : constant Node_Id := Specification (N); 7308 Designator : constant Entity_Id := Defining_Entity (Spec); 7309 7310 E : Entity_Id; 7311 7312 function Different_Generic_Profile (E : Entity_Id) return Boolean; 7313 -- Even if fully conformant, a body may depend on a generic actual when 7314 -- the spec does not, or vice versa, in which case they were distinct 7315 -- entities in the generic. 7316 7317 ------------------------------- 7318 -- Different_Generic_Profile -- 7319 ------------------------------- 7320 7321 function Different_Generic_Profile (E : Entity_Id) return Boolean is 7322 F1, F2 : Entity_Id; 7323 7324 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean; 7325 -- Check that the types of corresponding formals have the same 7326 -- generic actual if any. We have to account for subtypes of a 7327 -- generic formal, declared between a spec and a body, which may 7328 -- appear distinct in an instance but matched in the generic, and 7329 -- the subtype may be used either in the spec or the body of the 7330 -- subprogram being checked. 7331 7332 ------------------------- 7333 -- Same_Generic_Actual -- 7334 ------------------------- 7335 7336 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean is 7337 7338 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean; 7339 -- Predicate to check whether S1 is a subtype of S2 in the source 7340 -- of the instance. 7341 7342 ------------------------- 7343 -- Is_Declared_Subtype -- 7344 ------------------------- 7345 7346 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean is 7347 begin 7348 return Comes_From_Source (Parent (S1)) 7349 and then Nkind (Parent (S1)) = N_Subtype_Declaration 7350 and then Is_Entity_Name (Subtype_Indication (Parent (S1))) 7351 and then Entity (Subtype_Indication (Parent (S1))) = S2; 7352 end Is_Declared_Subtype; 7353 7354 -- Start of processing for Same_Generic_Actual 7355 7356 begin 7357 return Is_Generic_Actual_Type (T1) = Is_Generic_Actual_Type (T2) 7358 or else Is_Declared_Subtype (T1, T2) 7359 or else Is_Declared_Subtype (T2, T1); 7360 end Same_Generic_Actual; 7361 7362 -- Start of processing for Different_Generic_Profile 7363 7364 begin 7365 if not In_Instance then 7366 return False; 7367 7368 elsif Ekind (E) = E_Function 7369 and then not Same_Generic_Actual (Etype (E), Etype (Designator)) 7370 then 7371 return True; 7372 end if; 7373 7374 F1 := First_Formal (Designator); 7375 F2 := First_Formal (E); 7376 while Present (F1) loop 7377 if not Same_Generic_Actual (Etype (F1), Etype (F2)) then 7378 return True; 7379 end if; 7380 7381 Next_Formal (F1); 7382 Next_Formal (F2); 7383 end loop; 7384 7385 return False; 7386 end Different_Generic_Profile; 7387 7388 -- Start of processing for Find_Corresponding_Spec 7389 7390 begin 7391 E := Current_Entity (Designator); 7392 while Present (E) loop 7393 7394 -- We are looking for a matching spec. It must have the same scope, 7395 -- and the same name, and either be type conformant, or be the case 7396 -- of a library procedure spec and its body (which belong to one 7397 -- another regardless of whether they are type conformant or not). 7398 7399 if Scope (E) = Current_Scope then 7400 if Current_Scope = Standard_Standard 7401 or else (Ekind (E) = Ekind (Designator) 7402 and then Type_Conformant (E, Designator)) 7403 then 7404 -- Within an instantiation, we know that spec and body are 7405 -- subtype conformant, because they were subtype conformant in 7406 -- the generic. We choose the subtype-conformant entity here as 7407 -- well, to resolve spurious ambiguities in the instance that 7408 -- were not present in the generic (i.e. when two different 7409 -- types are given the same actual). If we are looking for a 7410 -- spec to match a body, full conformance is expected. 7411 7412 if In_Instance then 7413 7414 -- Inherit the convention and "ghostness" of the matching 7415 -- spec to ensure proper full and subtype conformance. 7416 7417 Set_Convention (Designator, Convention (E)); 7418 7419 if Is_Ghost_Entity (E) then 7420 Set_Is_Ghost_Entity (Designator); 7421 end if; 7422 7423 -- Skip past subprogram bodies and subprogram renamings that 7424 -- may appear to have a matching spec, but that aren't fully 7425 -- conformant with it. That can occur in cases where an 7426 -- actual type causes unrelated homographs in the instance. 7427 7428 if Nkind_In (N, N_Subprogram_Body, 7429 N_Subprogram_Renaming_Declaration) 7430 and then Present (Homonym (E)) 7431 and then not Fully_Conformant (Designator, E) 7432 then 7433 goto Next_Entity; 7434 7435 elsif not Subtype_Conformant (Designator, E) then 7436 goto Next_Entity; 7437 7438 elsif Different_Generic_Profile (E) then 7439 goto Next_Entity; 7440 end if; 7441 end if; 7442 7443 -- Ada 2012 (AI05-0165): For internally generated bodies of 7444 -- null procedures locate the internally generated spec. We 7445 -- enforce mode conformance since a tagged type may inherit 7446 -- from interfaces several null primitives which differ only 7447 -- in the mode of the formals. 7448 7449 if not (Comes_From_Source (E)) 7450 and then Is_Null_Procedure (E) 7451 and then not Mode_Conformant (Designator, E) 7452 then 7453 null; 7454 7455 -- For null procedures coming from source that are completions, 7456 -- analysis of the generated body will establish the link. 7457 7458 elsif Comes_From_Source (E) 7459 and then Nkind (Spec) = N_Procedure_Specification 7460 and then Null_Present (Spec) 7461 then 7462 return E; 7463 7464 -- Expression functions can be completions, but cannot be 7465 -- completed by an explicit body. 7466 7467 elsif Comes_From_Source (E) 7468 and then Comes_From_Source (N) 7469 and then Nkind (N) = N_Subprogram_Body 7470 and then Nkind (Original_Node (Unit_Declaration_Node (E))) = 7471 N_Expression_Function 7472 then 7473 Error_Msg_Sloc := Sloc (E); 7474 Error_Msg_N ("body conflicts with expression function#", N); 7475 return Empty; 7476 7477 elsif not Has_Completion (E) then 7478 if Nkind (N) /= N_Subprogram_Body_Stub then 7479 Set_Corresponding_Spec (N, E); 7480 end if; 7481 7482 Set_Has_Completion (E); 7483 return E; 7484 7485 elsif Nkind (Parent (N)) = N_Subunit then 7486 7487 -- If this is the proper body of a subunit, the completion 7488 -- flag is set when analyzing the stub. 7489 7490 return E; 7491 7492 -- If E is an internal function with a controlling result that 7493 -- was created for an operation inherited by a null extension, 7494 -- it may be overridden by a body without a previous spec (one 7495 -- more reason why these should be shunned). In that case we 7496 -- remove the generated body if present, because the current 7497 -- one is the explicit overriding. 7498 7499 elsif Ekind (E) = E_Function 7500 and then Ada_Version >= Ada_2005 7501 and then not Comes_From_Source (E) 7502 and then Has_Controlling_Result (E) 7503 and then Is_Null_Extension (Etype (E)) 7504 and then Comes_From_Source (Spec) 7505 then 7506 Set_Has_Completion (E, False); 7507 7508 if Expander_Active 7509 and then Nkind (Parent (E)) = N_Function_Specification 7510 then 7511 Remove 7512 (Unit_Declaration_Node 7513 (Corresponding_Body (Unit_Declaration_Node (E)))); 7514 7515 return E; 7516 7517 -- If expansion is disabled, or if the wrapper function has 7518 -- not been generated yet, this a late body overriding an 7519 -- inherited operation, or it is an overriding by some other 7520 -- declaration before the controlling result is frozen. In 7521 -- either case this is a declaration of a new entity. 7522 7523 else 7524 return Empty; 7525 end if; 7526 7527 -- If the body already exists, then this is an error unless 7528 -- the previous declaration is the implicit declaration of a 7529 -- derived subprogram. It is also legal for an instance to 7530 -- contain type conformant overloadable declarations (but the 7531 -- generic declaration may not), per 8.3(26/2). 7532 7533 elsif No (Alias (E)) 7534 and then not Is_Intrinsic_Subprogram (E) 7535 and then not In_Instance 7536 and then Post_Error 7537 then 7538 Error_Msg_Sloc := Sloc (E); 7539 7540 if Is_Imported (E) then 7541 Error_Msg_NE 7542 ("body not allowed for imported subprogram & declared#", 7543 N, E); 7544 else 7545 Error_Msg_NE ("duplicate body for & declared#", N, E); 7546 end if; 7547 end if; 7548 7549 -- Child units cannot be overloaded, so a conformance mismatch 7550 -- between body and a previous spec is an error. 7551 7552 elsif Is_Child_Unit (E) 7553 and then 7554 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body 7555 and then 7556 Nkind (Parent (Unit_Declaration_Node (Designator))) = 7557 N_Compilation_Unit 7558 and then Post_Error 7559 then 7560 Error_Msg_N 7561 ("body of child unit does not match previous declaration", N); 7562 end if; 7563 end if; 7564 7565 <<Next_Entity>> 7566 E := Homonym (E); 7567 end loop; 7568 7569 -- On exit, we know that no previous declaration of subprogram exists 7570 7571 return Empty; 7572 end Find_Corresponding_Spec; 7573 7574 ---------------------- 7575 -- Fully_Conformant -- 7576 ---------------------- 7577 7578 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is 7579 Result : Boolean; 7580 begin 7581 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result); 7582 return Result; 7583 end Fully_Conformant; 7584 7585 ---------------------------------- 7586 -- Fully_Conformant_Expressions -- 7587 ---------------------------------- 7588 7589 function Fully_Conformant_Expressions 7590 (Given_E1 : Node_Id; 7591 Given_E2 : Node_Id) return Boolean 7592 is 7593 E1 : constant Node_Id := Original_Node (Given_E1); 7594 E2 : constant Node_Id := Original_Node (Given_E2); 7595 -- We always test conformance on original nodes, since it is possible 7596 -- for analysis and/or expansion to make things look as though they 7597 -- conform when they do not, e.g. by converting 1+2 into 3. 7598 7599 function FCE (Given_E1, Given_E2 : Node_Id) return Boolean 7600 renames Fully_Conformant_Expressions; 7601 7602 function FCL (L1, L2 : List_Id) return Boolean; 7603 -- Compare elements of two lists for conformance. Elements have to be 7604 -- conformant, and actuals inserted as default parameters do not match 7605 -- explicit actuals with the same value. 7606 7607 function FCO (Op_Node, Call_Node : Node_Id) return Boolean; 7608 -- Compare an operator node with a function call 7609 7610 --------- 7611 -- FCL -- 7612 --------- 7613 7614 function FCL (L1, L2 : List_Id) return Boolean is 7615 N1, N2 : Node_Id; 7616 7617 begin 7618 if L1 = No_List then 7619 N1 := Empty; 7620 else 7621 N1 := First (L1); 7622 end if; 7623 7624 if L2 = No_List then 7625 N2 := Empty; 7626 else 7627 N2 := First (L2); 7628 end if; 7629 7630 -- Compare two lists, skipping rewrite insertions (we want to compare 7631 -- the original trees, not the expanded versions). 7632 7633 loop 7634 if Is_Rewrite_Insertion (N1) then 7635 Next (N1); 7636 elsif Is_Rewrite_Insertion (N2) then 7637 Next (N2); 7638 elsif No (N1) then 7639 return No (N2); 7640 elsif No (N2) then 7641 return False; 7642 elsif not FCE (N1, N2) then 7643 return False; 7644 else 7645 Next (N1); 7646 Next (N2); 7647 end if; 7648 end loop; 7649 end FCL; 7650 7651 --------- 7652 -- FCO -- 7653 --------- 7654 7655 function FCO (Op_Node, Call_Node : Node_Id) return Boolean is 7656 Actuals : constant List_Id := Parameter_Associations (Call_Node); 7657 Act : Node_Id; 7658 7659 begin 7660 if No (Actuals) 7661 or else Entity (Op_Node) /= Entity (Name (Call_Node)) 7662 then 7663 return False; 7664 7665 else 7666 Act := First (Actuals); 7667 7668 if Nkind (Op_Node) in N_Binary_Op then 7669 if not FCE (Left_Opnd (Op_Node), Act) then 7670 return False; 7671 end if; 7672 7673 Next (Act); 7674 end if; 7675 7676 return Present (Act) 7677 and then FCE (Right_Opnd (Op_Node), Act) 7678 and then No (Next (Act)); 7679 end if; 7680 end FCO; 7681 7682 -- Start of processing for Fully_Conformant_Expressions 7683 7684 begin 7685 -- Non-conformant if paren count does not match. Note: if some idiot 7686 -- complains that we don't do this right for more than 3 levels of 7687 -- parentheses, they will be treated with the respect they deserve. 7688 7689 if Paren_Count (E1) /= Paren_Count (E2) then 7690 return False; 7691 7692 -- If same entities are referenced, then they are conformant even if 7693 -- they have different forms (RM 8.3.1(19-20)). 7694 7695 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then 7696 if Present (Entity (E1)) then 7697 return Entity (E1) = Entity (E2) 7698 or else (Chars (Entity (E1)) = Chars (Entity (E2)) 7699 and then Ekind (Entity (E1)) = E_Discriminant 7700 and then Ekind (Entity (E2)) = E_In_Parameter); 7701 7702 elsif Nkind (E1) = N_Expanded_Name 7703 and then Nkind (E2) = N_Expanded_Name 7704 and then Nkind (Selector_Name (E1)) = N_Character_Literal 7705 and then Nkind (Selector_Name (E2)) = N_Character_Literal 7706 then 7707 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)); 7708 7709 else 7710 -- Identifiers in component associations don't always have 7711 -- entities, but their names must conform. 7712 7713 return Nkind (E1) = N_Identifier 7714 and then Nkind (E2) = N_Identifier 7715 and then Chars (E1) = Chars (E2); 7716 end if; 7717 7718 elsif Nkind (E1) = N_Character_Literal 7719 and then Nkind (E2) = N_Expanded_Name 7720 then 7721 return Nkind (Selector_Name (E2)) = N_Character_Literal 7722 and then Chars (E1) = Chars (Selector_Name (E2)); 7723 7724 elsif Nkind (E2) = N_Character_Literal 7725 and then Nkind (E1) = N_Expanded_Name 7726 then 7727 return Nkind (Selector_Name (E1)) = N_Character_Literal 7728 and then Chars (E2) = Chars (Selector_Name (E1)); 7729 7730 elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then 7731 return FCO (E1, E2); 7732 7733 elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then 7734 return FCO (E2, E1); 7735 7736 -- Otherwise we must have the same syntactic entity 7737 7738 elsif Nkind (E1) /= Nkind (E2) then 7739 return False; 7740 7741 -- At this point, we specialize by node type 7742 7743 else 7744 case Nkind (E1) is 7745 7746 when N_Aggregate => 7747 return 7748 FCL (Expressions (E1), Expressions (E2)) 7749 and then 7750 FCL (Component_Associations (E1), 7751 Component_Associations (E2)); 7752 7753 when N_Allocator => 7754 if Nkind (Expression (E1)) = N_Qualified_Expression 7755 or else 7756 Nkind (Expression (E2)) = N_Qualified_Expression 7757 then 7758 return FCE (Expression (E1), Expression (E2)); 7759 7760 -- Check that the subtype marks and any constraints 7761 -- are conformant 7762 7763 else 7764 declare 7765 Indic1 : constant Node_Id := Expression (E1); 7766 Indic2 : constant Node_Id := Expression (E2); 7767 Elt1 : Node_Id; 7768 Elt2 : Node_Id; 7769 7770 begin 7771 if Nkind (Indic1) /= N_Subtype_Indication then 7772 return 7773 Nkind (Indic2) /= N_Subtype_Indication 7774 and then Entity (Indic1) = Entity (Indic2); 7775 7776 elsif Nkind (Indic2) /= N_Subtype_Indication then 7777 return 7778 Nkind (Indic1) /= N_Subtype_Indication 7779 and then Entity (Indic1) = Entity (Indic2); 7780 7781 else 7782 if Entity (Subtype_Mark (Indic1)) /= 7783 Entity (Subtype_Mark (Indic2)) 7784 then 7785 return False; 7786 end if; 7787 7788 Elt1 := First (Constraints (Constraint (Indic1))); 7789 Elt2 := First (Constraints (Constraint (Indic2))); 7790 while Present (Elt1) and then Present (Elt2) loop 7791 if not FCE (Elt1, Elt2) then 7792 return False; 7793 end if; 7794 7795 Next (Elt1); 7796 Next (Elt2); 7797 end loop; 7798 7799 return True; 7800 end if; 7801 end; 7802 end if; 7803 7804 when N_Attribute_Reference => 7805 return 7806 Attribute_Name (E1) = Attribute_Name (E2) 7807 and then FCL (Expressions (E1), Expressions (E2)); 7808 7809 when N_Binary_Op => 7810 return 7811 Entity (E1) = Entity (E2) 7812 and then FCE (Left_Opnd (E1), Left_Opnd (E2)) 7813 and then FCE (Right_Opnd (E1), Right_Opnd (E2)); 7814 7815 when N_Short_Circuit | N_Membership_Test => 7816 return 7817 FCE (Left_Opnd (E1), Left_Opnd (E2)) 7818 and then 7819 FCE (Right_Opnd (E1), Right_Opnd (E2)); 7820 7821 when N_Case_Expression => 7822 declare 7823 Alt1 : Node_Id; 7824 Alt2 : Node_Id; 7825 7826 begin 7827 if not FCE (Expression (E1), Expression (E2)) then 7828 return False; 7829 7830 else 7831 Alt1 := First (Alternatives (E1)); 7832 Alt2 := First (Alternatives (E2)); 7833 loop 7834 if Present (Alt1) /= Present (Alt2) then 7835 return False; 7836 elsif No (Alt1) then 7837 return True; 7838 end if; 7839 7840 if not FCE (Expression (Alt1), Expression (Alt2)) 7841 or else not FCL (Discrete_Choices (Alt1), 7842 Discrete_Choices (Alt2)) 7843 then 7844 return False; 7845 end if; 7846 7847 Next (Alt1); 7848 Next (Alt2); 7849 end loop; 7850 end if; 7851 end; 7852 7853 when N_Character_Literal => 7854 return 7855 Char_Literal_Value (E1) = Char_Literal_Value (E2); 7856 7857 when N_Component_Association => 7858 return 7859 FCL (Choices (E1), Choices (E2)) 7860 and then 7861 FCE (Expression (E1), Expression (E2)); 7862 7863 when N_Explicit_Dereference => 7864 return 7865 FCE (Prefix (E1), Prefix (E2)); 7866 7867 when N_Extension_Aggregate => 7868 return 7869 FCL (Expressions (E1), Expressions (E2)) 7870 and then Null_Record_Present (E1) = 7871 Null_Record_Present (E2) 7872 and then FCL (Component_Associations (E1), 7873 Component_Associations (E2)); 7874 7875 when N_Function_Call => 7876 return 7877 FCE (Name (E1), Name (E2)) 7878 and then 7879 FCL (Parameter_Associations (E1), 7880 Parameter_Associations (E2)); 7881 7882 when N_If_Expression => 7883 return 7884 FCL (Expressions (E1), Expressions (E2)); 7885 7886 when N_Indexed_Component => 7887 return 7888 FCE (Prefix (E1), Prefix (E2)) 7889 and then 7890 FCL (Expressions (E1), Expressions (E2)); 7891 7892 when N_Integer_Literal => 7893 return (Intval (E1) = Intval (E2)); 7894 7895 when N_Null => 7896 return True; 7897 7898 when N_Operator_Symbol => 7899 return 7900 Chars (E1) = Chars (E2); 7901 7902 when N_Others_Choice => 7903 return True; 7904 7905 when N_Parameter_Association => 7906 return 7907 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)) 7908 and then FCE (Explicit_Actual_Parameter (E1), 7909 Explicit_Actual_Parameter (E2)); 7910 7911 when N_Qualified_Expression => 7912 return 7913 FCE (Subtype_Mark (E1), Subtype_Mark (E2)) 7914 and then 7915 FCE (Expression (E1), Expression (E2)); 7916 7917 when N_Quantified_Expression => 7918 if not FCE (Condition (E1), Condition (E2)) then 7919 return False; 7920 end if; 7921 7922 if Present (Loop_Parameter_Specification (E1)) 7923 and then Present (Loop_Parameter_Specification (E2)) 7924 then 7925 declare 7926 L1 : constant Node_Id := 7927 Loop_Parameter_Specification (E1); 7928 L2 : constant Node_Id := 7929 Loop_Parameter_Specification (E2); 7930 7931 begin 7932 return 7933 Reverse_Present (L1) = Reverse_Present (L2) 7934 and then 7935 FCE (Defining_Identifier (L1), 7936 Defining_Identifier (L2)) 7937 and then 7938 FCE (Discrete_Subtype_Definition (L1), 7939 Discrete_Subtype_Definition (L2)); 7940 end; 7941 7942 elsif Present (Iterator_Specification (E1)) 7943 and then Present (Iterator_Specification (E2)) 7944 then 7945 declare 7946 I1 : constant Node_Id := Iterator_Specification (E1); 7947 I2 : constant Node_Id := Iterator_Specification (E2); 7948 7949 begin 7950 return 7951 FCE (Defining_Identifier (I1), 7952 Defining_Identifier (I2)) 7953 and then 7954 Of_Present (I1) = Of_Present (I2) 7955 and then 7956 Reverse_Present (I1) = Reverse_Present (I2) 7957 and then FCE (Name (I1), Name (I2)) 7958 and then FCE (Subtype_Indication (I1), 7959 Subtype_Indication (I2)); 7960 end; 7961 7962 -- The quantified expressions used different specifications to 7963 -- walk their respective ranges. 7964 7965 else 7966 return False; 7967 end if; 7968 7969 when N_Range => 7970 return 7971 FCE (Low_Bound (E1), Low_Bound (E2)) 7972 and then 7973 FCE (High_Bound (E1), High_Bound (E2)); 7974 7975 when N_Real_Literal => 7976 return (Realval (E1) = Realval (E2)); 7977 7978 when N_Selected_Component => 7979 return 7980 FCE (Prefix (E1), Prefix (E2)) 7981 and then 7982 FCE (Selector_Name (E1), Selector_Name (E2)); 7983 7984 when N_Slice => 7985 return 7986 FCE (Prefix (E1), Prefix (E2)) 7987 and then 7988 FCE (Discrete_Range (E1), Discrete_Range (E2)); 7989 7990 when N_String_Literal => 7991 declare 7992 S1 : constant String_Id := Strval (E1); 7993 S2 : constant String_Id := Strval (E2); 7994 L1 : constant Nat := String_Length (S1); 7995 L2 : constant Nat := String_Length (S2); 7996 7997 begin 7998 if L1 /= L2 then 7999 return False; 8000 8001 else 8002 for J in 1 .. L1 loop 8003 if Get_String_Char (S1, J) /= 8004 Get_String_Char (S2, J) 8005 then 8006 return False; 8007 end if; 8008 end loop; 8009 8010 return True; 8011 end if; 8012 end; 8013 8014 when N_Type_Conversion => 8015 return 8016 FCE (Subtype_Mark (E1), Subtype_Mark (E2)) 8017 and then 8018 FCE (Expression (E1), Expression (E2)); 8019 8020 when N_Unary_Op => 8021 return 8022 Entity (E1) = Entity (E2) 8023 and then 8024 FCE (Right_Opnd (E1), Right_Opnd (E2)); 8025 8026 when N_Unchecked_Type_Conversion => 8027 return 8028 FCE (Subtype_Mark (E1), Subtype_Mark (E2)) 8029 and then 8030 FCE (Expression (E1), Expression (E2)); 8031 8032 -- All other node types cannot appear in this context. Strictly 8033 -- we should raise a fatal internal error. Instead we just ignore 8034 -- the nodes. This means that if anyone makes a mistake in the 8035 -- expander and mucks an expression tree irretrievably, the result 8036 -- will be a failure to detect a (probably very obscure) case 8037 -- of non-conformance, which is better than bombing on some 8038 -- case where two expressions do in fact conform. 8039 8040 when others => 8041 return True; 8042 8043 end case; 8044 end if; 8045 end Fully_Conformant_Expressions; 8046 8047 ---------------------------------------- 8048 -- Fully_Conformant_Discrete_Subtypes -- 8049 ---------------------------------------- 8050 8051 function Fully_Conformant_Discrete_Subtypes 8052 (Given_S1 : Node_Id; 8053 Given_S2 : Node_Id) return Boolean 8054 is 8055 S1 : constant Node_Id := Original_Node (Given_S1); 8056 S2 : constant Node_Id := Original_Node (Given_S2); 8057 8058 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean; 8059 -- Special-case for a bound given by a discriminant, which in the body 8060 -- is replaced with the discriminal of the enclosing type. 8061 8062 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean; 8063 -- Check both bounds 8064 8065 ----------------------- 8066 -- Conforming_Bounds -- 8067 ----------------------- 8068 8069 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is 8070 begin 8071 if Is_Entity_Name (B1) 8072 and then Is_Entity_Name (B2) 8073 and then Ekind (Entity (B1)) = E_Discriminant 8074 then 8075 return Chars (B1) = Chars (B2); 8076 8077 else 8078 return Fully_Conformant_Expressions (B1, B2); 8079 end if; 8080 end Conforming_Bounds; 8081 8082 ----------------------- 8083 -- Conforming_Ranges -- 8084 ----------------------- 8085 8086 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is 8087 begin 8088 return 8089 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2)) 8090 and then 8091 Conforming_Bounds (High_Bound (R1), High_Bound (R2)); 8092 end Conforming_Ranges; 8093 8094 -- Start of processing for Fully_Conformant_Discrete_Subtypes 8095 8096 begin 8097 if Nkind (S1) /= Nkind (S2) then 8098 return False; 8099 8100 elsif Is_Entity_Name (S1) then 8101 return Entity (S1) = Entity (S2); 8102 8103 elsif Nkind (S1) = N_Range then 8104 return Conforming_Ranges (S1, S2); 8105 8106 elsif Nkind (S1) = N_Subtype_Indication then 8107 return 8108 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2)) 8109 and then 8110 Conforming_Ranges 8111 (Range_Expression (Constraint (S1)), 8112 Range_Expression (Constraint (S2))); 8113 else 8114 return True; 8115 end if; 8116 end Fully_Conformant_Discrete_Subtypes; 8117 8118 -------------------- 8119 -- Install_Entity -- 8120 -------------------- 8121 8122 procedure Install_Entity (E : Entity_Id) is 8123 Prev : constant Entity_Id := Current_Entity (E); 8124 begin 8125 Set_Is_Immediately_Visible (E); 8126 Set_Current_Entity (E); 8127 Set_Homonym (E, Prev); 8128 end Install_Entity; 8129 8130 --------------------- 8131 -- Install_Formals -- 8132 --------------------- 8133 8134 procedure Install_Formals (Id : Entity_Id) is 8135 F : Entity_Id; 8136 begin 8137 F := First_Formal (Id); 8138 while Present (F) loop 8139 Install_Entity (F); 8140 Next_Formal (F); 8141 end loop; 8142 end Install_Formals; 8143 8144 ----------------------------- 8145 -- Is_Interface_Conformant -- 8146 ----------------------------- 8147 8148 function Is_Interface_Conformant 8149 (Tagged_Type : Entity_Id; 8150 Iface_Prim : Entity_Id; 8151 Prim : Entity_Id) return Boolean 8152 is 8153 -- The operation may in fact be an inherited (implicit) operation 8154 -- rather than the original interface primitive, so retrieve the 8155 -- ultimate ancestor. 8156 8157 Iface : constant Entity_Id := 8158 Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)); 8159 Typ : constant Entity_Id := Find_Dispatching_Type (Prim); 8160 8161 function Controlling_Formal (Prim : Entity_Id) return Entity_Id; 8162 -- Return the controlling formal of Prim 8163 8164 ------------------------ 8165 -- Controlling_Formal -- 8166 ------------------------ 8167 8168 function Controlling_Formal (Prim : Entity_Id) return Entity_Id is 8169 E : Entity_Id; 8170 8171 begin 8172 E := First_Entity (Prim); 8173 while Present (E) loop 8174 if Is_Formal (E) and then Is_Controlling_Formal (E) then 8175 return E; 8176 end if; 8177 8178 Next_Entity (E); 8179 end loop; 8180 8181 return Empty; 8182 end Controlling_Formal; 8183 8184 -- Local variables 8185 8186 Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim); 8187 Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim); 8188 8189 -- Start of processing for Is_Interface_Conformant 8190 8191 begin 8192 pragma Assert (Is_Subprogram (Iface_Prim) 8193 and then Is_Subprogram (Prim) 8194 and then Is_Dispatching_Operation (Iface_Prim) 8195 and then Is_Dispatching_Operation (Prim)); 8196 8197 pragma Assert (Is_Interface (Iface) 8198 or else (Present (Alias (Iface_Prim)) 8199 and then 8200 Is_Interface 8201 (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim))))); 8202 8203 if Prim = Iface_Prim 8204 or else not Is_Subprogram (Prim) 8205 or else Ekind (Prim) /= Ekind (Iface_Prim) 8206 or else not Is_Dispatching_Operation (Prim) 8207 or else Scope (Prim) /= Scope (Tagged_Type) 8208 or else No (Typ) 8209 or else Base_Type (Typ) /= Base_Type (Tagged_Type) 8210 or else not Primitive_Names_Match (Iface_Prim, Prim) 8211 then 8212 return False; 8213 8214 -- The mode of the controlling formals must match 8215 8216 elsif Present (Iface_Ctrl_F) 8217 and then Present (Prim_Ctrl_F) 8218 and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F) 8219 then 8220 return False; 8221 8222 -- Case of a procedure, or a function whose result type matches the 8223 -- result type of the interface primitive, or a function that has no 8224 -- controlling result (I or access I). 8225 8226 elsif Ekind (Iface_Prim) = E_Procedure 8227 or else Etype (Prim) = Etype (Iface_Prim) 8228 or else not Has_Controlling_Result (Prim) 8229 then 8230 return Type_Conformant 8231 (Iface_Prim, Prim, Skip_Controlling_Formals => True); 8232 8233 -- Case of a function returning an interface, or an access to one. Check 8234 -- that the return types correspond. 8235 8236 elsif Implements_Interface (Typ, Iface) then 8237 if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type) 8238 /= 8239 (Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type) 8240 then 8241 return False; 8242 else 8243 return 8244 Type_Conformant (Prim, Ultimate_Alias (Iface_Prim), 8245 Skip_Controlling_Formals => True); 8246 end if; 8247 8248 else 8249 return False; 8250 end if; 8251 end Is_Interface_Conformant; 8252 8253 --------------------------------- 8254 -- Is_Non_Overriding_Operation -- 8255 --------------------------------- 8256 8257 function Is_Non_Overriding_Operation 8258 (Prev_E : Entity_Id; 8259 New_E : Entity_Id) return Boolean 8260 is 8261 Formal : Entity_Id; 8262 F_Typ : Entity_Id; 8263 G_Typ : Entity_Id := Empty; 8264 8265 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id; 8266 -- If F_Type is a derived type associated with a generic actual subtype, 8267 -- then return its Generic_Parent_Type attribute, else return Empty. 8268 8269 function Types_Correspond 8270 (P_Type : Entity_Id; 8271 N_Type : Entity_Id) return Boolean; 8272 -- Returns true if and only if the types (or designated types in the 8273 -- case of anonymous access types) are the same or N_Type is derived 8274 -- directly or indirectly from P_Type. 8275 8276 ----------------------------- 8277 -- Get_Generic_Parent_Type -- 8278 ----------------------------- 8279 8280 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is 8281 G_Typ : Entity_Id; 8282 Defn : Node_Id; 8283 Indic : Node_Id; 8284 8285 begin 8286 if Is_Derived_Type (F_Typ) 8287 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration 8288 then 8289 -- The tree must be traversed to determine the parent subtype in 8290 -- the generic unit, which unfortunately isn't always available 8291 -- via semantic attributes. ??? (Note: The use of Original_Node 8292 -- is needed for cases where a full derived type has been 8293 -- rewritten.) 8294 8295 -- If the parent type is a scalar type, the derivation creates 8296 -- an anonymous base type for it, and the source type is its 8297 -- first subtype. 8298 8299 if Is_Scalar_Type (F_Typ) 8300 and then not Comes_From_Source (F_Typ) 8301 then 8302 Defn := 8303 Type_Definition 8304 (Original_Node (Parent (First_Subtype (F_Typ)))); 8305 else 8306 Defn := Type_Definition (Original_Node (Parent (F_Typ))); 8307 end if; 8308 if Nkind (Defn) = N_Derived_Type_Definition then 8309 Indic := Subtype_Indication (Defn); 8310 8311 if Nkind (Indic) = N_Subtype_Indication then 8312 G_Typ := Entity (Subtype_Mark (Indic)); 8313 else 8314 G_Typ := Entity (Indic); 8315 end if; 8316 8317 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration 8318 and then Present (Generic_Parent_Type (Parent (G_Typ))) 8319 then 8320 return Generic_Parent_Type (Parent (G_Typ)); 8321 end if; 8322 end if; 8323 end if; 8324 8325 return Empty; 8326 end Get_Generic_Parent_Type; 8327 8328 ---------------------- 8329 -- Types_Correspond -- 8330 ---------------------- 8331 8332 function Types_Correspond 8333 (P_Type : Entity_Id; 8334 N_Type : Entity_Id) return Boolean 8335 is 8336 Prev_Type : Entity_Id := Base_Type (P_Type); 8337 New_Type : Entity_Id := Base_Type (N_Type); 8338 8339 begin 8340 if Ekind (Prev_Type) = E_Anonymous_Access_Type then 8341 Prev_Type := Designated_Type (Prev_Type); 8342 end if; 8343 8344 if Ekind (New_Type) = E_Anonymous_Access_Type then 8345 New_Type := Designated_Type (New_Type); 8346 end if; 8347 8348 if Prev_Type = New_Type then 8349 return True; 8350 8351 elsif not Is_Class_Wide_Type (New_Type) then 8352 while Etype (New_Type) /= New_Type loop 8353 New_Type := Etype (New_Type); 8354 8355 if New_Type = Prev_Type then 8356 return True; 8357 end if; 8358 end loop; 8359 end if; 8360 return False; 8361 end Types_Correspond; 8362 8363 -- Start of processing for Is_Non_Overriding_Operation 8364 8365 begin 8366 -- In the case where both operations are implicit derived subprograms 8367 -- then neither overrides the other. This can only occur in certain 8368 -- obscure cases (e.g., derivation from homographs created in a generic 8369 -- instantiation). 8370 8371 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then 8372 return True; 8373 8374 elsif Ekind (Current_Scope) = E_Package 8375 and then Is_Generic_Instance (Current_Scope) 8376 and then In_Private_Part (Current_Scope) 8377 and then Comes_From_Source (New_E) 8378 then 8379 -- We examine the formals and result type of the inherited operation, 8380 -- to determine whether their type is derived from (the instance of) 8381 -- a generic type. The first such formal or result type is the one 8382 -- tested. 8383 8384 Formal := First_Formal (Prev_E); 8385 while Present (Formal) loop 8386 F_Typ := Base_Type (Etype (Formal)); 8387 8388 if Ekind (F_Typ) = E_Anonymous_Access_Type then 8389 F_Typ := Designated_Type (F_Typ); 8390 end if; 8391 8392 G_Typ := Get_Generic_Parent_Type (F_Typ); 8393 exit when Present (G_Typ); 8394 8395 Next_Formal (Formal); 8396 end loop; 8397 8398 if No (G_Typ) and then Ekind (Prev_E) = E_Function then 8399 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E))); 8400 end if; 8401 8402 if No (G_Typ) then 8403 return False; 8404 end if; 8405 8406 -- If the generic type is a private type, then the original operation 8407 -- was not overriding in the generic, because there was no primitive 8408 -- operation to override. 8409 8410 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration 8411 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) = 8412 N_Formal_Private_Type_Definition 8413 then 8414 return True; 8415 8416 -- The generic parent type is the ancestor of a formal derived 8417 -- type declaration. We need to check whether it has a primitive 8418 -- operation that should be overridden by New_E in the generic. 8419 8420 else 8421 declare 8422 P_Formal : Entity_Id; 8423 N_Formal : Entity_Id; 8424 P_Typ : Entity_Id; 8425 N_Typ : Entity_Id; 8426 P_Prim : Entity_Id; 8427 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ)); 8428 8429 begin 8430 while Present (Prim_Elt) loop 8431 P_Prim := Node (Prim_Elt); 8432 8433 if Chars (P_Prim) = Chars (New_E) 8434 and then Ekind (P_Prim) = Ekind (New_E) 8435 then 8436 P_Formal := First_Formal (P_Prim); 8437 N_Formal := First_Formal (New_E); 8438 while Present (P_Formal) and then Present (N_Formal) loop 8439 P_Typ := Etype (P_Formal); 8440 N_Typ := Etype (N_Formal); 8441 8442 if not Types_Correspond (P_Typ, N_Typ) then 8443 exit; 8444 end if; 8445 8446 Next_Entity (P_Formal); 8447 Next_Entity (N_Formal); 8448 end loop; 8449 8450 -- Found a matching primitive operation belonging to the 8451 -- formal ancestor type, so the new subprogram is 8452 -- overriding. 8453 8454 if No (P_Formal) 8455 and then No (N_Formal) 8456 and then (Ekind (New_E) /= E_Function 8457 or else 8458 Types_Correspond 8459 (Etype (P_Prim), Etype (New_E))) 8460 then 8461 return False; 8462 end if; 8463 end if; 8464 8465 Next_Elmt (Prim_Elt); 8466 end loop; 8467 8468 -- If no match found, then the new subprogram does not override 8469 -- in the generic (nor in the instance). 8470 8471 -- If the type in question is not abstract, and the subprogram 8472 -- is, this will be an error if the new operation is in the 8473 -- private part of the instance. Emit a warning now, which will 8474 -- make the subsequent error message easier to understand. 8475 8476 if not Is_Abstract_Type (F_Typ) 8477 and then Is_Abstract_Subprogram (Prev_E) 8478 and then In_Private_Part (Current_Scope) 8479 then 8480 Error_Msg_Node_2 := F_Typ; 8481 Error_Msg_NE 8482 ("private operation& in generic unit does not override " 8483 & "any primitive operation of& (RM 12.3 (18))??", 8484 New_E, New_E); 8485 end if; 8486 8487 return True; 8488 end; 8489 end if; 8490 else 8491 return False; 8492 end if; 8493 end Is_Non_Overriding_Operation; 8494 8495 ------------------------------------- 8496 -- List_Inherited_Pre_Post_Aspects -- 8497 ------------------------------------- 8498 8499 procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is 8500 begin 8501 if Opt.List_Inherited_Aspects 8502 and then Is_Subprogram_Or_Generic_Subprogram (E) 8503 then 8504 declare 8505 Subps : constant Subprogram_List := Inherited_Subprograms (E); 8506 Items : Node_Id; 8507 Prag : Node_Id; 8508 8509 begin 8510 for Index in Subps'Range loop 8511 Items := Contract (Subps (Index)); 8512 8513 if Present (Items) then 8514 Prag := Pre_Post_Conditions (Items); 8515 while Present (Prag) loop 8516 Error_Msg_Sloc := Sloc (Prag); 8517 8518 if Class_Present (Prag) 8519 and then not Split_PPC (Prag) 8520 then 8521 if Pragma_Name (Prag) = Name_Precondition then 8522 Error_Msg_N 8523 ("info: & inherits `Pre''Class` aspect from " 8524 & "#?L?", E); 8525 else 8526 Error_Msg_N 8527 ("info: & inherits `Post''Class` aspect from " 8528 & "#?L?", E); 8529 end if; 8530 end if; 8531 8532 Prag := Next_Pragma (Prag); 8533 end loop; 8534 end if; 8535 end loop; 8536 end; 8537 end if; 8538 end List_Inherited_Pre_Post_Aspects; 8539 8540 ------------------------------ 8541 -- Make_Inequality_Operator -- 8542 ------------------------------ 8543 8544 -- S is the defining identifier of an equality operator. We build a 8545 -- subprogram declaration with the right signature. This operation is 8546 -- intrinsic, because it is always expanded as the negation of the 8547 -- call to the equality function. 8548 8549 procedure Make_Inequality_Operator (S : Entity_Id) is 8550 Loc : constant Source_Ptr := Sloc (S); 8551 Decl : Node_Id; 8552 Formals : List_Id; 8553 Op_Name : Entity_Id; 8554 8555 FF : constant Entity_Id := First_Formal (S); 8556 NF : constant Entity_Id := Next_Formal (FF); 8557 8558 begin 8559 -- Check that equality was properly defined, ignore call if not 8560 8561 if No (NF) then 8562 return; 8563 end if; 8564 8565 declare 8566 A : constant Entity_Id := 8567 Make_Defining_Identifier (Sloc (FF), 8568 Chars => Chars (FF)); 8569 8570 B : constant Entity_Id := 8571 Make_Defining_Identifier (Sloc (NF), 8572 Chars => Chars (NF)); 8573 8574 begin 8575 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne); 8576 8577 Formals := New_List ( 8578 Make_Parameter_Specification (Loc, 8579 Defining_Identifier => A, 8580 Parameter_Type => 8581 New_Occurrence_Of (Etype (First_Formal (S)), 8582 Sloc (Etype (First_Formal (S))))), 8583 8584 Make_Parameter_Specification (Loc, 8585 Defining_Identifier => B, 8586 Parameter_Type => 8587 New_Occurrence_Of (Etype (Next_Formal (First_Formal (S))), 8588 Sloc (Etype (Next_Formal (First_Formal (S))))))); 8589 8590 Decl := 8591 Make_Subprogram_Declaration (Loc, 8592 Specification => 8593 Make_Function_Specification (Loc, 8594 Defining_Unit_Name => Op_Name, 8595 Parameter_Specifications => Formals, 8596 Result_Definition => 8597 New_Occurrence_Of (Standard_Boolean, Loc))); 8598 8599 -- Insert inequality right after equality if it is explicit or after 8600 -- the derived type when implicit. These entities are created only 8601 -- for visibility purposes, and eventually replaced in the course 8602 -- of expansion, so they do not need to be attached to the tree and 8603 -- seen by the back-end. Keeping them internal also avoids spurious 8604 -- freezing problems. The declaration is inserted in the tree for 8605 -- analysis, and removed afterwards. If the equality operator comes 8606 -- from an explicit declaration, attach the inequality immediately 8607 -- after. Else the equality is inherited from a derived type 8608 -- declaration, so insert inequality after that declaration. 8609 8610 if No (Alias (S)) then 8611 Insert_After (Unit_Declaration_Node (S), Decl); 8612 elsif Is_List_Member (Parent (S)) then 8613 Insert_After (Parent (S), Decl); 8614 else 8615 Insert_After (Parent (Etype (First_Formal (S))), Decl); 8616 end if; 8617 8618 Mark_Rewrite_Insertion (Decl); 8619 Set_Is_Intrinsic_Subprogram (Op_Name); 8620 Analyze (Decl); 8621 Remove (Decl); 8622 Set_Has_Completion (Op_Name); 8623 Set_Corresponding_Equality (Op_Name, S); 8624 Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S)); 8625 end; 8626 end Make_Inequality_Operator; 8627 8628 ---------------------- 8629 -- May_Need_Actuals -- 8630 ---------------------- 8631 8632 procedure May_Need_Actuals (Fun : Entity_Id) is 8633 F : Entity_Id; 8634 B : Boolean; 8635 8636 begin 8637 F := First_Formal (Fun); 8638 B := True; 8639 while Present (F) loop 8640 if No (Default_Value (F)) then 8641 B := False; 8642 exit; 8643 end if; 8644 8645 Next_Formal (F); 8646 end loop; 8647 8648 Set_Needs_No_Actuals (Fun, B); 8649 end May_Need_Actuals; 8650 8651 --------------------- 8652 -- Mode_Conformant -- 8653 --------------------- 8654 8655 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is 8656 Result : Boolean; 8657 begin 8658 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result); 8659 return Result; 8660 end Mode_Conformant; 8661 8662 --------------------------- 8663 -- New_Overloaded_Entity -- 8664 --------------------------- 8665 8666 procedure New_Overloaded_Entity 8667 (S : Entity_Id; 8668 Derived_Type : Entity_Id := Empty) 8669 is 8670 Overridden_Subp : Entity_Id := Empty; 8671 -- Set if the current scope has an operation that is type-conformant 8672 -- with S, and becomes hidden by S. 8673 8674 Is_Primitive_Subp : Boolean; 8675 -- Set to True if the new subprogram is primitive 8676 8677 E : Entity_Id; 8678 -- Entity that S overrides 8679 8680 Prev_Vis : Entity_Id := Empty; 8681 -- Predecessor of E in Homonym chain 8682 8683 procedure Check_For_Primitive_Subprogram 8684 (Is_Primitive : out Boolean; 8685 Is_Overriding : Boolean := False); 8686 -- If the subprogram being analyzed is a primitive operation of the type 8687 -- of a formal or result, set the Has_Primitive_Operations flag on the 8688 -- type, and set Is_Primitive to True (otherwise set to False). Set the 8689 -- corresponding flag on the entity itself for later use. 8690 8691 procedure Check_Synchronized_Overriding 8692 (Def_Id : Entity_Id; 8693 Overridden_Subp : out Entity_Id); 8694 -- First determine if Def_Id is an entry or a subprogram either defined 8695 -- in the scope of a task or protected type, or is a primitive of such 8696 -- a type. Check whether Def_Id overrides a subprogram of an interface 8697 -- implemented by the synchronized type, return the overridden entity 8698 -- or Empty. 8699 8700 function Is_Private_Declaration (E : Entity_Id) return Boolean; 8701 -- Check that E is declared in the private part of the current package, 8702 -- or in the package body, where it may hide a previous declaration. 8703 -- We can't use In_Private_Part by itself because this flag is also 8704 -- set when freezing entities, so we must examine the place of the 8705 -- declaration in the tree, and recognize wrapper packages as well. 8706 8707 function Is_Overriding_Alias 8708 (Old_E : Entity_Id; 8709 New_E : Entity_Id) return Boolean; 8710 -- Check whether new subprogram and old subprogram are both inherited 8711 -- from subprograms that have distinct dispatch table entries. This can 8712 -- occur with derivations from instances with accidental homonyms. The 8713 -- function is conservative given that the converse is only true within 8714 -- instances that contain accidental overloadings. 8715 8716 ------------------------------------ 8717 -- Check_For_Primitive_Subprogram -- 8718 ------------------------------------ 8719 8720 procedure Check_For_Primitive_Subprogram 8721 (Is_Primitive : out Boolean; 8722 Is_Overriding : Boolean := False) 8723 is 8724 Formal : Entity_Id; 8725 F_Typ : Entity_Id; 8726 B_Typ : Entity_Id; 8727 8728 function Visible_Part_Type (T : Entity_Id) return Boolean; 8729 -- Returns true if T is declared in the visible part of the current 8730 -- package scope; otherwise returns false. Assumes that T is declared 8731 -- in a package. 8732 8733 procedure Check_Private_Overriding (T : Entity_Id); 8734 -- Checks that if a primitive abstract subprogram of a visible 8735 -- abstract type is declared in a private part, then it must override 8736 -- an abstract subprogram declared in the visible part. Also checks 8737 -- that if a primitive function with a controlling result is declared 8738 -- in a private part, then it must override a function declared in 8739 -- the visible part. 8740 8741 ------------------------------ 8742 -- Check_Private_Overriding -- 8743 ------------------------------ 8744 8745 procedure Check_Private_Overriding (T : Entity_Id) is 8746 function Overrides_Private_Part_Op return Boolean; 8747 -- This detects the special case where the overriding subprogram 8748 -- is overriding a subprogram that was declared in the same 8749 -- private part. That case is illegal by 3.9.3(10). 8750 8751 function Overrides_Visible_Function 8752 (Partial_View : Entity_Id) return Boolean; 8753 -- True if S overrides a function in the visible part. The 8754 -- overridden function could be explicitly or implicitly declared. 8755 8756 ------------------------------- 8757 -- Overrides_Private_Part_Op -- 8758 ------------------------------- 8759 8760 function Overrides_Private_Part_Op return Boolean is 8761 Over_Decl : constant Node_Id := 8762 Unit_Declaration_Node (Overridden_Operation (S)); 8763 Subp_Decl : constant Node_Id := Unit_Declaration_Node (S); 8764 8765 begin 8766 pragma Assert (Is_Overriding); 8767 pragma Assert 8768 (Nkind (Over_Decl) = N_Abstract_Subprogram_Declaration); 8769 pragma Assert 8770 (Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration); 8771 8772 return In_Same_List (Over_Decl, Subp_Decl); 8773 end Overrides_Private_Part_Op; 8774 8775 -------------------------------- 8776 -- Overrides_Visible_Function -- 8777 -------------------------------- 8778 8779 function Overrides_Visible_Function 8780 (Partial_View : Entity_Id) return Boolean 8781 is 8782 begin 8783 if not Is_Overriding or else not Has_Homonym (S) then 8784 return False; 8785 end if; 8786 8787 if not Present (Partial_View) then 8788 return True; 8789 end if; 8790 8791 -- Search through all the homonyms H of S in the current 8792 -- package spec, and return True if we find one that matches. 8793 -- Note that Parent (H) will be the declaration of the 8794 -- partial view of T for a match. 8795 8796 declare 8797 H : Entity_Id := S; 8798 begin 8799 loop 8800 H := Homonym (H); 8801 exit when not Present (H) or else Scope (H) /= Scope (S); 8802 8803 if Nkind_In 8804 (Parent (H), 8805 N_Private_Extension_Declaration, 8806 N_Private_Type_Declaration) 8807 and then Defining_Identifier (Parent (H)) = Partial_View 8808 then 8809 return True; 8810 end if; 8811 end loop; 8812 end; 8813 8814 return False; 8815 end Overrides_Visible_Function; 8816 8817 -- Start of processing for Check_Private_Overriding 8818 8819 begin 8820 if Is_Package_Or_Generic_Package (Current_Scope) 8821 and then In_Private_Part (Current_Scope) 8822 and then Visible_Part_Type (T) 8823 and then not In_Instance 8824 then 8825 if Is_Abstract_Type (T) 8826 and then Is_Abstract_Subprogram (S) 8827 and then (not Is_Overriding 8828 or else not Is_Abstract_Subprogram (E) 8829 or else Overrides_Private_Part_Op) 8830 then 8831 Error_Msg_N 8832 ("abstract subprograms must be visible (RM 3.9.3(10))!", 8833 S); 8834 8835 elsif Ekind (S) = E_Function then 8836 declare 8837 Partial_View : constant Entity_Id := 8838 Incomplete_Or_Partial_View (T); 8839 8840 begin 8841 if not Overrides_Visible_Function (Partial_View) then 8842 8843 -- Here, S is "function ... return T;" declared in 8844 -- the private part, not overriding some visible 8845 -- operation. That's illegal in the tagged case 8846 -- (but not if the private type is untagged). 8847 8848 if ((Present (Partial_View) 8849 and then Is_Tagged_Type (Partial_View)) 8850 or else (not Present (Partial_View) 8851 and then Is_Tagged_Type (T))) 8852 and then T = Base_Type (Etype (S)) 8853 then 8854 Error_Msg_N 8855 ("private function with tagged result must" 8856 & " override visible-part function", S); 8857 Error_Msg_N 8858 ("\move subprogram to the visible part" 8859 & " (RM 3.9.3(10))", S); 8860 8861 -- AI05-0073: extend this test to the case of a 8862 -- function with a controlling access result. 8863 8864 elsif Ekind (Etype (S)) = E_Anonymous_Access_Type 8865 and then Is_Tagged_Type (Designated_Type (Etype (S))) 8866 and then 8867 not Is_Class_Wide_Type 8868 (Designated_Type (Etype (S))) 8869 and then Ada_Version >= Ada_2012 8870 then 8871 Error_Msg_N 8872 ("private function with controlling access " 8873 & "result must override visible-part function", 8874 S); 8875 Error_Msg_N 8876 ("\move subprogram to the visible part" 8877 & " (RM 3.9.3(10))", S); 8878 end if; 8879 end if; 8880 end; 8881 end if; 8882 end if; 8883 end Check_Private_Overriding; 8884 8885 ----------------------- 8886 -- Visible_Part_Type -- 8887 ----------------------- 8888 8889 function Visible_Part_Type (T : Entity_Id) return Boolean is 8890 P : constant Node_Id := Unit_Declaration_Node (Scope (T)); 8891 N : Node_Id; 8892 8893 begin 8894 -- If the entity is a private type, then it must be declared in a 8895 -- visible part. 8896 8897 if Ekind (T) in Private_Kind then 8898 return True; 8899 end if; 8900 8901 -- Otherwise, we traverse the visible part looking for its 8902 -- corresponding declaration. We cannot use the declaration 8903 -- node directly because in the private part the entity of a 8904 -- private type is the one in the full view, which does not 8905 -- indicate that it is the completion of something visible. 8906 8907 N := First (Visible_Declarations (Specification (P))); 8908 while Present (N) loop 8909 if Nkind (N) = N_Full_Type_Declaration 8910 and then Present (Defining_Identifier (N)) 8911 and then T = Defining_Identifier (N) 8912 then 8913 return True; 8914 8915 elsif Nkind_In (N, N_Private_Type_Declaration, 8916 N_Private_Extension_Declaration) 8917 and then Present (Defining_Identifier (N)) 8918 and then T = Full_View (Defining_Identifier (N)) 8919 then 8920 return True; 8921 end if; 8922 8923 Next (N); 8924 end loop; 8925 8926 return False; 8927 end Visible_Part_Type; 8928 8929 -- Start of processing for Check_For_Primitive_Subprogram 8930 8931 begin 8932 Is_Primitive := False; 8933 8934 if not Comes_From_Source (S) then 8935 null; 8936 8937 -- If subprogram is at library level, it is not primitive operation 8938 8939 elsif Current_Scope = Standard_Standard then 8940 null; 8941 8942 elsif (Is_Package_Or_Generic_Package (Current_Scope) 8943 and then not In_Package_Body (Current_Scope)) 8944 or else Is_Overriding 8945 then 8946 -- For function, check return type 8947 8948 if Ekind (S) = E_Function then 8949 if Ekind (Etype (S)) = E_Anonymous_Access_Type then 8950 F_Typ := Designated_Type (Etype (S)); 8951 else 8952 F_Typ := Etype (S); 8953 end if; 8954 8955 B_Typ := Base_Type (F_Typ); 8956 8957 if Scope (B_Typ) = Current_Scope 8958 and then not Is_Class_Wide_Type (B_Typ) 8959 and then not Is_Generic_Type (B_Typ) 8960 then 8961 Is_Primitive := True; 8962 Set_Has_Primitive_Operations (B_Typ); 8963 Set_Is_Primitive (S); 8964 Check_Private_Overriding (B_Typ); 8965 end if; 8966 end if; 8967 8968 -- For all subprograms, check formals 8969 8970 Formal := First_Formal (S); 8971 while Present (Formal) loop 8972 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then 8973 F_Typ := Designated_Type (Etype (Formal)); 8974 else 8975 F_Typ := Etype (Formal); 8976 end if; 8977 8978 B_Typ := Base_Type (F_Typ); 8979 8980 if Ekind (B_Typ) = E_Access_Subtype then 8981 B_Typ := Base_Type (B_Typ); 8982 end if; 8983 8984 if Scope (B_Typ) = Current_Scope 8985 and then not Is_Class_Wide_Type (B_Typ) 8986 and then not Is_Generic_Type (B_Typ) 8987 then 8988 Is_Primitive := True; 8989 Set_Is_Primitive (S); 8990 Set_Has_Primitive_Operations (B_Typ); 8991 Check_Private_Overriding (B_Typ); 8992 end if; 8993 8994 Next_Formal (Formal); 8995 end loop; 8996 8997 -- Special case: An equality function can be redefined for a type 8998 -- occurring in a declarative part, and won't otherwise be treated as 8999 -- a primitive because it doesn't occur in a package spec and doesn't 9000 -- override an inherited subprogram. It's important that we mark it 9001 -- primitive so it can be returned by Collect_Primitive_Operations 9002 -- and be used in composing the equality operation of later types 9003 -- that have a component of the type. 9004 9005 elsif Chars (S) = Name_Op_Eq 9006 and then Etype (S) = Standard_Boolean 9007 then 9008 B_Typ := Base_Type (Etype (First_Formal (S))); 9009 9010 if Scope (B_Typ) = Current_Scope 9011 and then 9012 Base_Type (Etype (Next_Formal (First_Formal (S)))) = B_Typ 9013 and then not Is_Limited_Type (B_Typ) 9014 then 9015 Is_Primitive := True; 9016 Set_Is_Primitive (S); 9017 Set_Has_Primitive_Operations (B_Typ); 9018 Check_Private_Overriding (B_Typ); 9019 end if; 9020 end if; 9021 end Check_For_Primitive_Subprogram; 9022 9023 ----------------------------------- 9024 -- Check_Synchronized_Overriding -- 9025 ----------------------------------- 9026 9027 procedure Check_Synchronized_Overriding 9028 (Def_Id : Entity_Id; 9029 Overridden_Subp : out Entity_Id) 9030 is 9031 Ifaces_List : Elist_Id; 9032 In_Scope : Boolean; 9033 Typ : Entity_Id; 9034 9035 function Matches_Prefixed_View_Profile 9036 (Prim_Params : List_Id; 9037 Iface_Params : List_Id) return Boolean; 9038 -- Determine whether a subprogram's parameter profile Prim_Params 9039 -- matches that of a potentially overridden interface subprogram 9040 -- Iface_Params. Also determine if the type of first parameter of 9041 -- Iface_Params is an implemented interface. 9042 9043 ----------------------------------- 9044 -- Matches_Prefixed_View_Profile -- 9045 ----------------------------------- 9046 9047 function Matches_Prefixed_View_Profile 9048 (Prim_Params : List_Id; 9049 Iface_Params : List_Id) return Boolean 9050 is 9051 Iface_Id : Entity_Id; 9052 Iface_Param : Node_Id; 9053 Iface_Typ : Entity_Id; 9054 Prim_Id : Entity_Id; 9055 Prim_Param : Node_Id; 9056 Prim_Typ : Entity_Id; 9057 9058 function Is_Implemented 9059 (Ifaces_List : Elist_Id; 9060 Iface : Entity_Id) return Boolean; 9061 -- Determine if Iface is implemented by the current task or 9062 -- protected type. 9063 9064 -------------------- 9065 -- Is_Implemented -- 9066 -------------------- 9067 9068 function Is_Implemented 9069 (Ifaces_List : Elist_Id; 9070 Iface : Entity_Id) return Boolean 9071 is 9072 Iface_Elmt : Elmt_Id; 9073 9074 begin 9075 Iface_Elmt := First_Elmt (Ifaces_List); 9076 while Present (Iface_Elmt) loop 9077 if Node (Iface_Elmt) = Iface then 9078 return True; 9079 end if; 9080 9081 Next_Elmt (Iface_Elmt); 9082 end loop; 9083 9084 return False; 9085 end Is_Implemented; 9086 9087 -- Start of processing for Matches_Prefixed_View_Profile 9088 9089 begin 9090 Iface_Param := First (Iface_Params); 9091 Iface_Typ := Etype (Defining_Identifier (Iface_Param)); 9092 9093 if Is_Access_Type (Iface_Typ) then 9094 Iface_Typ := Designated_Type (Iface_Typ); 9095 end if; 9096 9097 Prim_Param := First (Prim_Params); 9098 9099 -- The first parameter of the potentially overridden subprogram 9100 -- must be an interface implemented by Prim. 9101 9102 if not Is_Interface (Iface_Typ) 9103 or else not Is_Implemented (Ifaces_List, Iface_Typ) 9104 then 9105 return False; 9106 end if; 9107 9108 -- The checks on the object parameters are done, move onto the 9109 -- rest of the parameters. 9110 9111 if not In_Scope then 9112 Prim_Param := Next (Prim_Param); 9113 end if; 9114 9115 Iface_Param := Next (Iface_Param); 9116 while Present (Iface_Param) and then Present (Prim_Param) loop 9117 Iface_Id := Defining_Identifier (Iface_Param); 9118 Iface_Typ := Find_Parameter_Type (Iface_Param); 9119 9120 Prim_Id := Defining_Identifier (Prim_Param); 9121 Prim_Typ := Find_Parameter_Type (Prim_Param); 9122 9123 if Ekind (Iface_Typ) = E_Anonymous_Access_Type 9124 and then Ekind (Prim_Typ) = E_Anonymous_Access_Type 9125 and then Is_Concurrent_Type (Designated_Type (Prim_Typ)) 9126 then 9127 Iface_Typ := Designated_Type (Iface_Typ); 9128 Prim_Typ := Designated_Type (Prim_Typ); 9129 end if; 9130 9131 -- Case of multiple interface types inside a parameter profile 9132 9133 -- (Obj_Param : in out Iface; ...; Param : Iface) 9134 9135 -- If the interface type is implemented, then the matching type 9136 -- in the primitive should be the implementing record type. 9137 9138 if Ekind (Iface_Typ) = E_Record_Type 9139 and then Is_Interface (Iface_Typ) 9140 and then Is_Implemented (Ifaces_List, Iface_Typ) 9141 then 9142 if Prim_Typ /= Typ then 9143 return False; 9144 end if; 9145 9146 -- The two parameters must be both mode and subtype conformant 9147 9148 elsif Ekind (Iface_Id) /= Ekind (Prim_Id) 9149 or else not 9150 Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant) 9151 then 9152 return False; 9153 end if; 9154 9155 Next (Iface_Param); 9156 Next (Prim_Param); 9157 end loop; 9158 9159 -- One of the two lists contains more parameters than the other 9160 9161 if Present (Iface_Param) or else Present (Prim_Param) then 9162 return False; 9163 end if; 9164 9165 return True; 9166 end Matches_Prefixed_View_Profile; 9167 9168 -- Start of processing for Check_Synchronized_Overriding 9169 9170 begin 9171 Overridden_Subp := Empty; 9172 9173 -- Def_Id must be an entry or a subprogram. We should skip predefined 9174 -- primitives internally generated by the frontend; however at this 9175 -- stage predefined primitives are still not fully decorated. As a 9176 -- minor optimization we skip here internally generated subprograms. 9177 9178 if (Ekind (Def_Id) /= E_Entry 9179 and then Ekind (Def_Id) /= E_Function 9180 and then Ekind (Def_Id) /= E_Procedure) 9181 or else not Comes_From_Source (Def_Id) 9182 then 9183 return; 9184 end if; 9185 9186 -- Search for the concurrent declaration since it contains the list 9187 -- of all implemented interfaces. In this case, the subprogram is 9188 -- declared within the scope of a protected or a task type. 9189 9190 if Present (Scope (Def_Id)) 9191 and then Is_Concurrent_Type (Scope (Def_Id)) 9192 and then not Is_Generic_Actual_Type (Scope (Def_Id)) 9193 then 9194 Typ := Scope (Def_Id); 9195 In_Scope := True; 9196 9197 -- The enclosing scope is not a synchronized type and the subprogram 9198 -- has no formals. 9199 9200 elsif No (First_Formal (Def_Id)) then 9201 return; 9202 9203 -- The subprogram has formals and hence it may be a primitive of a 9204 -- concurrent type. 9205 9206 else 9207 Typ := Etype (First_Formal (Def_Id)); 9208 9209 if Is_Access_Type (Typ) then 9210 Typ := Directly_Designated_Type (Typ); 9211 end if; 9212 9213 if Is_Concurrent_Type (Typ) 9214 and then not Is_Generic_Actual_Type (Typ) 9215 then 9216 In_Scope := False; 9217 9218 -- This case occurs when the concurrent type is declared within 9219 -- a generic unit. As a result the corresponding record has been 9220 -- built and used as the type of the first formal, we just have 9221 -- to retrieve the corresponding concurrent type. 9222 9223 elsif Is_Concurrent_Record_Type (Typ) 9224 and then not Is_Class_Wide_Type (Typ) 9225 and then Present (Corresponding_Concurrent_Type (Typ)) 9226 then 9227 Typ := Corresponding_Concurrent_Type (Typ); 9228 In_Scope := False; 9229 9230 else 9231 return; 9232 end if; 9233 end if; 9234 9235 -- There is no overriding to check if is an inherited operation in a 9236 -- type derivation on for a generic actual. 9237 9238 Collect_Interfaces (Typ, Ifaces_List); 9239 9240 if Is_Empty_Elmt_List (Ifaces_List) then 9241 return; 9242 end if; 9243 9244 -- Determine whether entry or subprogram Def_Id overrides a primitive 9245 -- operation that belongs to one of the interfaces in Ifaces_List. 9246 9247 declare 9248 Candidate : Entity_Id := Empty; 9249 Hom : Entity_Id := Empty; 9250 Subp : Entity_Id := Empty; 9251 9252 begin 9253 -- Traverse the homonym chain, looking for a potentially 9254 -- overridden subprogram that belongs to an implemented 9255 -- interface. 9256 9257 Hom := Current_Entity_In_Scope (Def_Id); 9258 while Present (Hom) loop 9259 Subp := Hom; 9260 9261 if Subp = Def_Id 9262 or else not Is_Overloadable (Subp) 9263 or else not Is_Primitive (Subp) 9264 or else not Is_Dispatching_Operation (Subp) 9265 or else not Present (Find_Dispatching_Type (Subp)) 9266 or else not Is_Interface (Find_Dispatching_Type (Subp)) 9267 then 9268 null; 9269 9270 -- Entries and procedures can override abstract or null 9271 -- interface procedures. 9272 9273 elsif (Ekind (Def_Id) = E_Procedure 9274 or else Ekind (Def_Id) = E_Entry) 9275 and then Ekind (Subp) = E_Procedure 9276 and then Matches_Prefixed_View_Profile 9277 (Parameter_Specifications (Parent (Def_Id)), 9278 Parameter_Specifications (Parent (Subp))) 9279 then 9280 Candidate := Subp; 9281 9282 -- For an overridden subprogram Subp, check whether the mode 9283 -- of its first parameter is correct depending on the kind 9284 -- of synchronized type. 9285 9286 declare 9287 Formal : constant Node_Id := First_Formal (Candidate); 9288 9289 begin 9290 -- In order for an entry or a protected procedure to 9291 -- override, the first parameter of the overridden 9292 -- routine must be of mode "out", "in out" or 9293 -- access-to-variable. 9294 9295 if Ekind_In (Candidate, E_Entry, E_Procedure) 9296 and then Is_Protected_Type (Typ) 9297 and then Ekind (Formal) /= E_In_Out_Parameter 9298 and then Ekind (Formal) /= E_Out_Parameter 9299 and then Nkind (Parameter_Type (Parent (Formal))) /= 9300 N_Access_Definition 9301 then 9302 null; 9303 9304 -- All other cases are OK since a task entry or routine 9305 -- does not have a restriction on the mode of the first 9306 -- parameter of the overridden interface routine. 9307 9308 else 9309 Overridden_Subp := Candidate; 9310 return; 9311 end if; 9312 end; 9313 9314 -- Functions can override abstract interface functions 9315 9316 elsif Ekind (Def_Id) = E_Function 9317 and then Ekind (Subp) = E_Function 9318 and then Matches_Prefixed_View_Profile 9319 (Parameter_Specifications (Parent (Def_Id)), 9320 Parameter_Specifications (Parent (Subp))) 9321 and then Etype (Result_Definition (Parent (Def_Id))) = 9322 Etype (Result_Definition (Parent (Subp))) 9323 then 9324 Candidate := Subp; 9325 9326 -- If an inherited subprogram is implemented by a protected 9327 -- function, then the first parameter of the inherited 9328 -- subprogram shall be of mode in, but not an 9329 -- access-to-variable parameter (RM 9.4(11/9) 9330 9331 if Present (First_Formal (Subp)) 9332 and then Ekind (First_Formal (Subp)) = E_In_Parameter 9333 and then 9334 (not Is_Access_Type (Etype (First_Formal (Subp))) 9335 or else 9336 Is_Access_Constant (Etype (First_Formal (Subp)))) 9337 then 9338 Overridden_Subp := Subp; 9339 return; 9340 end if; 9341 end if; 9342 9343 Hom := Homonym (Hom); 9344 end loop; 9345 9346 -- After examining all candidates for overriding, we are left with 9347 -- the best match which is a mode incompatible interface routine. 9348 9349 if In_Scope and then Present (Candidate) then 9350 Error_Msg_PT (Def_Id, Candidate); 9351 end if; 9352 9353 Overridden_Subp := Candidate; 9354 return; 9355 end; 9356 end Check_Synchronized_Overriding; 9357 9358 ---------------------------- 9359 -- Is_Private_Declaration -- 9360 ---------------------------- 9361 9362 function Is_Private_Declaration (E : Entity_Id) return Boolean is 9363 Priv_Decls : List_Id; 9364 Decl : constant Node_Id := Unit_Declaration_Node (E); 9365 9366 begin 9367 if Is_Package_Or_Generic_Package (Current_Scope) 9368 and then In_Private_Part (Current_Scope) 9369 then 9370 Priv_Decls := 9371 Private_Declarations (Package_Specification (Current_Scope)); 9372 9373 return In_Package_Body (Current_Scope) 9374 or else 9375 (Is_List_Member (Decl) 9376 and then List_Containing (Decl) = Priv_Decls) 9377 or else (Nkind (Parent (Decl)) = N_Package_Specification 9378 and then not 9379 Is_Compilation_Unit 9380 (Defining_Entity (Parent (Decl))) 9381 and then List_Containing (Parent (Parent (Decl))) = 9382 Priv_Decls); 9383 else 9384 return False; 9385 end if; 9386 end Is_Private_Declaration; 9387 9388 -------------------------- 9389 -- Is_Overriding_Alias -- 9390 -------------------------- 9391 9392 function Is_Overriding_Alias 9393 (Old_E : Entity_Id; 9394 New_E : Entity_Id) return Boolean 9395 is 9396 AO : constant Entity_Id := Alias (Old_E); 9397 AN : constant Entity_Id := Alias (New_E); 9398 begin 9399 return Scope (AO) /= Scope (AN) 9400 or else No (DTC_Entity (AO)) 9401 or else No (DTC_Entity (AN)) 9402 or else DT_Position (AO) = DT_Position (AN); 9403 end Is_Overriding_Alias; 9404 9405 -- Start of processing for New_Overloaded_Entity 9406 9407 begin 9408 -- We need to look for an entity that S may override. This must be a 9409 -- homonym in the current scope, so we look for the first homonym of 9410 -- S in the current scope as the starting point for the search. 9411 9412 E := Current_Entity_In_Scope (S); 9413 9414 -- Ada 2005 (AI-251): Derivation of abstract interface primitives. 9415 -- They are directly added to the list of primitive operations of 9416 -- Derived_Type, unless this is a rederivation in the private part 9417 -- of an operation that was already derived in the visible part of 9418 -- the current package. 9419 9420 if Ada_Version >= Ada_2005 9421 and then Present (Derived_Type) 9422 and then Present (Alias (S)) 9423 and then Is_Dispatching_Operation (Alias (S)) 9424 and then Present (Find_Dispatching_Type (Alias (S))) 9425 and then Is_Interface (Find_Dispatching_Type (Alias (S))) 9426 then 9427 -- For private types, when the full-view is processed we propagate to 9428 -- the full view the non-overridden entities whose attribute "alias" 9429 -- references an interface primitive. These entities were added by 9430 -- Derive_Subprograms to ensure that interface primitives are 9431 -- covered. 9432 9433 -- Inside_Freeze_Actions is non zero when S corresponds with an 9434 -- internal entity that links an interface primitive with its 9435 -- covering primitive through attribute Interface_Alias (see 9436 -- Add_Internal_Interface_Entities). 9437 9438 if Inside_Freezing_Actions = 0 9439 and then Is_Package_Or_Generic_Package (Current_Scope) 9440 and then In_Private_Part (Current_Scope) 9441 and then Nkind (Parent (E)) = N_Private_Extension_Declaration 9442 and then Nkind (Parent (S)) = N_Full_Type_Declaration 9443 and then Full_View (Defining_Identifier (Parent (E))) 9444 = Defining_Identifier (Parent (S)) 9445 and then Alias (E) = Alias (S) 9446 then 9447 Check_Operation_From_Private_View (S, E); 9448 Set_Is_Dispatching_Operation (S); 9449 9450 -- Common case 9451 9452 else 9453 Enter_Overloaded_Entity (S); 9454 Check_Dispatching_Operation (S, Empty); 9455 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 9456 end if; 9457 9458 return; 9459 end if; 9460 9461 -- If there is no homonym then this is definitely not overriding 9462 9463 if No (E) then 9464 Enter_Overloaded_Entity (S); 9465 Check_Dispatching_Operation (S, Empty); 9466 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 9467 9468 -- If subprogram has an explicit declaration, check whether it has an 9469 -- overriding indicator. 9470 9471 if Comes_From_Source (S) then 9472 Check_Synchronized_Overriding (S, Overridden_Subp); 9473 9474 -- (Ada 2012: AI05-0125-1): If S is a dispatching operation then 9475 -- it may have overridden some hidden inherited primitive. Update 9476 -- Overridden_Subp to avoid spurious errors when checking the 9477 -- overriding indicator. 9478 9479 if Ada_Version >= Ada_2012 9480 and then No (Overridden_Subp) 9481 and then Is_Dispatching_Operation (S) 9482 and then Present (Overridden_Operation (S)) 9483 then 9484 Overridden_Subp := Overridden_Operation (S); 9485 end if; 9486 9487 Check_Overriding_Indicator 9488 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); 9489 9490 -- The Ghost policy in effect at the point of declaration of a 9491 -- parent subprogram and an overriding subprogram must match 9492 -- (SPARK RM 6.9(17)). 9493 9494 Check_Ghost_Overriding (S, Overridden_Subp); 9495 end if; 9496 9497 -- If there is a homonym that is not overloadable, then we have an 9498 -- error, except for the special cases checked explicitly below. 9499 9500 elsif not Is_Overloadable (E) then 9501 9502 -- Check for spurious conflict produced by a subprogram that has the 9503 -- same name as that of the enclosing generic package. The conflict 9504 -- occurs within an instance, between the subprogram and the renaming 9505 -- declaration for the package. After the subprogram, the package 9506 -- renaming declaration becomes hidden. 9507 9508 if Ekind (E) = E_Package 9509 and then Present (Renamed_Object (E)) 9510 and then Renamed_Object (E) = Current_Scope 9511 and then Nkind (Parent (Renamed_Object (E))) = 9512 N_Package_Specification 9513 and then Present (Generic_Parent (Parent (Renamed_Object (E)))) 9514 then 9515 Set_Is_Hidden (E); 9516 Set_Is_Immediately_Visible (E, False); 9517 Enter_Overloaded_Entity (S); 9518 Set_Homonym (S, Homonym (E)); 9519 Check_Dispatching_Operation (S, Empty); 9520 Check_Overriding_Indicator (S, Empty, Is_Primitive => False); 9521 9522 -- If the subprogram is implicit it is hidden by the previous 9523 -- declaration. However if it is dispatching, it must appear in the 9524 -- dispatch table anyway, because it can be dispatched to even if it 9525 -- cannot be called directly. 9526 9527 elsif Present (Alias (S)) and then not Comes_From_Source (S) then 9528 Set_Scope (S, Current_Scope); 9529 9530 if Is_Dispatching_Operation (Alias (S)) then 9531 Check_Dispatching_Operation (S, Empty); 9532 end if; 9533 9534 return; 9535 9536 else 9537 Error_Msg_Sloc := Sloc (E); 9538 9539 -- Generate message, with useful additional warning if in generic 9540 9541 if Is_Generic_Unit (E) then 9542 Error_Msg_N ("previous generic unit cannot be overloaded", S); 9543 Error_Msg_N ("\& conflicts with declaration#", S); 9544 else 9545 Error_Msg_N ("& conflicts with declaration#", S); 9546 end if; 9547 9548 return; 9549 end if; 9550 9551 -- E exists and is overloadable 9552 9553 else 9554 Check_Synchronized_Overriding (S, Overridden_Subp); 9555 9556 -- Loop through E and its homonyms to determine if any of them is 9557 -- the candidate for overriding by S. 9558 9559 while Present (E) loop 9560 9561 -- Definitely not interesting if not in the current scope 9562 9563 if Scope (E) /= Current_Scope then 9564 null; 9565 9566 -- A function can overload the name of an abstract state. The 9567 -- state can be viewed as a function with a profile that cannot 9568 -- be matched by anything. 9569 9570 elsif Ekind (S) = E_Function 9571 and then Ekind (E) = E_Abstract_State 9572 then 9573 Enter_Overloaded_Entity (S); 9574 return; 9575 9576 -- Ada 2012 (AI05-0165): For internally generated bodies of null 9577 -- procedures locate the internally generated spec. We enforce 9578 -- mode conformance since a tagged type may inherit from 9579 -- interfaces several null primitives which differ only in 9580 -- the mode of the formals. 9581 9582 elsif not Comes_From_Source (S) 9583 and then Is_Null_Procedure (S) 9584 and then not Mode_Conformant (E, S) 9585 then 9586 null; 9587 9588 -- Check if we have type conformance 9589 9590 elsif Type_Conformant (E, S) then 9591 9592 -- If the old and new entities have the same profile and one 9593 -- is not the body of the other, then this is an error, unless 9594 -- one of them is implicitly declared. 9595 9596 -- There are some cases when both can be implicit, for example 9597 -- when both a literal and a function that overrides it are 9598 -- inherited in a derivation, or when an inherited operation 9599 -- of a tagged full type overrides the inherited operation of 9600 -- a private extension. Ada 83 had a special rule for the 9601 -- literal case. In Ada 95, the later implicit operation hides 9602 -- the former, and the literal is always the former. In the 9603 -- odd case where both are derived operations declared at the 9604 -- same point, both operations should be declared, and in that 9605 -- case we bypass the following test and proceed to the next 9606 -- part. This can only occur for certain obscure cases in 9607 -- instances, when an operation on a type derived from a formal 9608 -- private type does not override a homograph inherited from 9609 -- the actual. In subsequent derivations of such a type, the 9610 -- DT positions of these operations remain distinct, if they 9611 -- have been set. 9612 9613 if Present (Alias (S)) 9614 and then (No (Alias (E)) 9615 or else Comes_From_Source (E) 9616 or else Is_Abstract_Subprogram (S) 9617 or else 9618 (Is_Dispatching_Operation (E) 9619 and then Is_Overriding_Alias (E, S))) 9620 and then Ekind (E) /= E_Enumeration_Literal 9621 then 9622 -- When an derived operation is overloaded it may be due to 9623 -- the fact that the full view of a private extension 9624 -- re-inherits. It has to be dealt with. 9625 9626 if Is_Package_Or_Generic_Package (Current_Scope) 9627 and then In_Private_Part (Current_Scope) 9628 then 9629 Check_Operation_From_Private_View (S, E); 9630 end if; 9631 9632 -- In any case the implicit operation remains hidden by the 9633 -- existing declaration, which is overriding. Indicate that 9634 -- E overrides the operation from which S is inherited. 9635 9636 if Present (Alias (S)) then 9637 Set_Overridden_Operation (E, Alias (S)); 9638 Inherit_Subprogram_Contract (E, Alias (S)); 9639 9640 else 9641 Set_Overridden_Operation (E, S); 9642 Inherit_Subprogram_Contract (E, S); 9643 end if; 9644 9645 if Comes_From_Source (E) then 9646 Check_Overriding_Indicator (E, S, Is_Primitive => False); 9647 9648 -- The Ghost policy in effect at the point of declaration 9649 -- of a parent subprogram and an overriding subprogram 9650 -- must match (SPARK RM 6.9(17)). 9651 9652 Check_Ghost_Overriding (E, S); 9653 end if; 9654 9655 return; 9656 9657 -- Within an instance, the renaming declarations for actual 9658 -- subprograms may become ambiguous, but they do not hide each 9659 -- other. 9660 9661 elsif Ekind (E) /= E_Entry 9662 and then not Comes_From_Source (E) 9663 and then not Is_Generic_Instance (E) 9664 and then (Present (Alias (E)) 9665 or else Is_Intrinsic_Subprogram (E)) 9666 and then (not In_Instance 9667 or else No (Parent (E)) 9668 or else Nkind (Unit_Declaration_Node (E)) /= 9669 N_Subprogram_Renaming_Declaration) 9670 then 9671 -- A subprogram child unit is not allowed to override an 9672 -- inherited subprogram (10.1.1(20)). 9673 9674 if Is_Child_Unit (S) then 9675 Error_Msg_N 9676 ("child unit overrides inherited subprogram in parent", 9677 S); 9678 return; 9679 end if; 9680 9681 if Is_Non_Overriding_Operation (E, S) then 9682 Enter_Overloaded_Entity (S); 9683 9684 if No (Derived_Type) 9685 or else Is_Tagged_Type (Derived_Type) 9686 then 9687 Check_Dispatching_Operation (S, Empty); 9688 end if; 9689 9690 return; 9691 end if; 9692 9693 -- E is a derived operation or an internal operator which 9694 -- is being overridden. Remove E from further visibility. 9695 -- Furthermore, if E is a dispatching operation, it must be 9696 -- replaced in the list of primitive operations of its type 9697 -- (see Override_Dispatching_Operation). 9698 9699 Overridden_Subp := E; 9700 9701 declare 9702 Prev : Entity_Id; 9703 9704 begin 9705 Prev := First_Entity (Current_Scope); 9706 while Present (Prev) and then Next_Entity (Prev) /= E loop 9707 Next_Entity (Prev); 9708 end loop; 9709 9710 -- It is possible for E to be in the current scope and 9711 -- yet not in the entity chain. This can only occur in a 9712 -- generic context where E is an implicit concatenation 9713 -- in the formal part, because in a generic body the 9714 -- entity chain starts with the formals. 9715 9716 -- In GNATprove mode, a wrapper for an operation with 9717 -- axiomatization may be a homonym of another declaration 9718 -- for an actual subprogram (needs refinement ???). 9719 9720 if No (Prev) then 9721 if In_Instance 9722 and then GNATprove_Mode 9723 and then 9724 Nkind (Original_Node (Unit_Declaration_Node (S))) = 9725 N_Subprogram_Renaming_Declaration 9726 then 9727 return; 9728 else 9729 pragma Assert (Chars (E) = Name_Op_Concat); 9730 null; 9731 end if; 9732 end if; 9733 9734 -- E must be removed both from the entity_list of the 9735 -- current scope, and from the visibility chain. 9736 9737 if Debug_Flag_E then 9738 Write_Str ("Override implicit operation "); 9739 Write_Int (Int (E)); 9740 Write_Eol; 9741 end if; 9742 9743 -- If E is a predefined concatenation, it stands for four 9744 -- different operations. As a result, a single explicit 9745 -- declaration does not hide it. In a possible ambiguous 9746 -- situation, Disambiguate chooses the user-defined op, 9747 -- so it is correct to retain the previous internal one. 9748 9749 if Chars (E) /= Name_Op_Concat 9750 or else Ekind (E) /= E_Operator 9751 then 9752 -- For nondispatching derived operations that are 9753 -- overridden by a subprogram declared in the private 9754 -- part of a package, we retain the derived subprogram 9755 -- but mark it as not immediately visible. If the 9756 -- derived operation was declared in the visible part 9757 -- then this ensures that it will still be visible 9758 -- outside the package with the proper signature 9759 -- (calls from outside must also be directed to this 9760 -- version rather than the overriding one, unlike the 9761 -- dispatching case). Calls from inside the package 9762 -- will still resolve to the overriding subprogram 9763 -- since the derived one is marked as not visible 9764 -- within the package. 9765 9766 -- If the private operation is dispatching, we achieve 9767 -- the overriding by keeping the implicit operation 9768 -- but setting its alias to be the overriding one. In 9769 -- this fashion the proper body is executed in all 9770 -- cases, but the original signature is used outside 9771 -- of the package. 9772 9773 -- If the overriding is not in the private part, we 9774 -- remove the implicit operation altogether. 9775 9776 if Is_Private_Declaration (S) then 9777 if not Is_Dispatching_Operation (E) then 9778 Set_Is_Immediately_Visible (E, False); 9779 else 9780 -- Work done in Override_Dispatching_Operation, 9781 -- so nothing else needs to be done here. 9782 9783 null; 9784 end if; 9785 9786 else 9787 -- Find predecessor of E in Homonym chain 9788 9789 if E = Current_Entity (E) then 9790 Prev_Vis := Empty; 9791 else 9792 Prev_Vis := Current_Entity (E); 9793 while Homonym (Prev_Vis) /= E loop 9794 Prev_Vis := Homonym (Prev_Vis); 9795 end loop; 9796 end if; 9797 9798 if Prev_Vis /= Empty then 9799 9800 -- Skip E in the visibility chain 9801 9802 Set_Homonym (Prev_Vis, Homonym (E)); 9803 9804 else 9805 Set_Name_Entity_Id (Chars (E), Homonym (E)); 9806 end if; 9807 9808 Set_Next_Entity (Prev, Next_Entity (E)); 9809 9810 if No (Next_Entity (Prev)) then 9811 Set_Last_Entity (Current_Scope, Prev); 9812 end if; 9813 end if; 9814 end if; 9815 9816 Enter_Overloaded_Entity (S); 9817 9818 -- For entities generated by Derive_Subprograms the 9819 -- overridden operation is the inherited primitive 9820 -- (which is available through the attribute alias). 9821 9822 if not (Comes_From_Source (E)) 9823 and then Is_Dispatching_Operation (E) 9824 and then Find_Dispatching_Type (E) = 9825 Find_Dispatching_Type (S) 9826 and then Present (Alias (E)) 9827 and then Comes_From_Source (Alias (E)) 9828 then 9829 Set_Overridden_Operation (S, Alias (E)); 9830 Inherit_Subprogram_Contract (S, Alias (E)); 9831 9832 -- Normal case of setting entity as overridden 9833 9834 -- Note: Static_Initialization and Overridden_Operation 9835 -- attributes use the same field in subprogram entities. 9836 -- Static_Initialization is only defined for internal 9837 -- initialization procedures, where Overridden_Operation 9838 -- is irrelevant. Therefore the setting of this attribute 9839 -- must check whether the target is an init_proc. 9840 9841 elsif not Is_Init_Proc (S) then 9842 Set_Overridden_Operation (S, E); 9843 Inherit_Subprogram_Contract (S, E); 9844 end if; 9845 9846 Check_Overriding_Indicator (S, E, Is_Primitive => True); 9847 9848 -- The Ghost policy in effect at the point of declaration 9849 -- of a parent subprogram and an overriding subprogram 9850 -- must match (SPARK RM 6.9(17)). 9851 9852 Check_Ghost_Overriding (S, E); 9853 9854 -- If S is a user-defined subprogram or a null procedure 9855 -- expanded to override an inherited null procedure, or a 9856 -- predefined dispatching primitive then indicate that E 9857 -- overrides the operation from which S is inherited. 9858 9859 if Comes_From_Source (S) 9860 or else 9861 (Present (Parent (S)) 9862 and then 9863 Nkind (Parent (S)) = N_Procedure_Specification 9864 and then 9865 Null_Present (Parent (S))) 9866 or else 9867 (Present (Alias (E)) 9868 and then 9869 Is_Predefined_Dispatching_Operation (Alias (E))) 9870 then 9871 if Present (Alias (E)) then 9872 Set_Overridden_Operation (S, Alias (E)); 9873 Inherit_Subprogram_Contract (S, Alias (E)); 9874 end if; 9875 end if; 9876 9877 if Is_Dispatching_Operation (E) then 9878 9879 -- An overriding dispatching subprogram inherits the 9880 -- convention of the overridden subprogram (AI-117). 9881 9882 Set_Convention (S, Convention (E)); 9883 Check_Dispatching_Operation (S, E); 9884 9885 else 9886 Check_Dispatching_Operation (S, Empty); 9887 end if; 9888 9889 Check_For_Primitive_Subprogram 9890 (Is_Primitive_Subp, Is_Overriding => True); 9891 goto Check_Inequality; 9892 end; 9893 9894 -- Apparent redeclarations in instances can occur when two 9895 -- formal types get the same actual type. The subprograms in 9896 -- in the instance are legal, even if not callable from the 9897 -- outside. Calls from within are disambiguated elsewhere. 9898 -- For dispatching operations in the visible part, the usual 9899 -- rules apply, and operations with the same profile are not 9900 -- legal (B830001). 9901 9902 elsif (In_Instance_Visible_Part 9903 and then not Is_Dispatching_Operation (E)) 9904 or else In_Instance_Not_Visible 9905 then 9906 null; 9907 9908 -- Here we have a real error (identical profile) 9909 9910 else 9911 Error_Msg_Sloc := Sloc (E); 9912 9913 -- Avoid cascaded errors if the entity appears in 9914 -- subsequent calls. 9915 9916 Set_Scope (S, Current_Scope); 9917 9918 -- Generate error, with extra useful warning for the case 9919 -- of a generic instance with no completion. 9920 9921 if Is_Generic_Instance (S) 9922 and then not Has_Completion (E) 9923 then 9924 Error_Msg_N 9925 ("instantiation cannot provide body for&", S); 9926 Error_Msg_N ("\& conflicts with declaration#", S); 9927 else 9928 Error_Msg_N ("& conflicts with declaration#", S); 9929 end if; 9930 9931 return; 9932 end if; 9933 9934 else 9935 -- If one subprogram has an access parameter and the other 9936 -- a parameter of an access type, calls to either might be 9937 -- ambiguous. Verify that parameters match except for the 9938 -- access parameter. 9939 9940 if May_Hide_Profile then 9941 declare 9942 F1 : Entity_Id; 9943 F2 : Entity_Id; 9944 9945 begin 9946 F1 := First_Formal (S); 9947 F2 := First_Formal (E); 9948 while Present (F1) and then Present (F2) loop 9949 if Is_Access_Type (Etype (F1)) then 9950 if not Is_Access_Type (Etype (F2)) 9951 or else not Conforming_Types 9952 (Designated_Type (Etype (F1)), 9953 Designated_Type (Etype (F2)), 9954 Type_Conformant) 9955 then 9956 May_Hide_Profile := False; 9957 end if; 9958 9959 elsif 9960 not Conforming_Types 9961 (Etype (F1), Etype (F2), Type_Conformant) 9962 then 9963 May_Hide_Profile := False; 9964 end if; 9965 9966 Next_Formal (F1); 9967 Next_Formal (F2); 9968 end loop; 9969 9970 if May_Hide_Profile 9971 and then No (F1) 9972 and then No (F2) 9973 then 9974 Error_Msg_NE ("calls to& may be ambiguous??", S, S); 9975 end if; 9976 end; 9977 end if; 9978 end if; 9979 9980 E := Homonym (E); 9981 end loop; 9982 9983 -- On exit, we know that S is a new entity 9984 9985 Enter_Overloaded_Entity (S); 9986 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 9987 Check_Overriding_Indicator 9988 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); 9989 9990 -- The Ghost policy in effect at the point of declaration of a parent 9991 -- subprogram and an overriding subprogram must match 9992 -- (SPARK RM 6.9(17)). 9993 9994 Check_Ghost_Overriding (S, Overridden_Subp); 9995 9996 -- Overloading is not allowed in SPARK, except for operators 9997 9998 if Nkind (S) /= N_Defining_Operator_Symbol then 9999 Error_Msg_Sloc := Sloc (Homonym (S)); 10000 Check_SPARK_05_Restriction 10001 ("overloading not allowed with entity#", S); 10002 end if; 10003 10004 -- If S is a derived operation for an untagged type then by 10005 -- definition it's not a dispatching operation (even if the parent 10006 -- operation was dispatching), so Check_Dispatching_Operation is not 10007 -- called in that case. 10008 10009 if No (Derived_Type) 10010 or else Is_Tagged_Type (Derived_Type) 10011 then 10012 Check_Dispatching_Operation (S, Empty); 10013 end if; 10014 end if; 10015 10016 -- If this is a user-defined equality operator that is not a derived 10017 -- subprogram, create the corresponding inequality. If the operation is 10018 -- dispatching, the expansion is done elsewhere, and we do not create 10019 -- an explicit inequality operation. 10020 10021 <<Check_Inequality>> 10022 if Chars (S) = Name_Op_Eq 10023 and then Etype (S) = Standard_Boolean 10024 and then Present (Parent (S)) 10025 and then not Is_Dispatching_Operation (S) 10026 then 10027 Make_Inequality_Operator (S); 10028 Check_Untagged_Equality (S); 10029 end if; 10030 end New_Overloaded_Entity; 10031 10032 --------------------- 10033 -- Process_Formals -- 10034 --------------------- 10035 10036 procedure Process_Formals 10037 (T : List_Id; 10038 Related_Nod : Node_Id) 10039 is 10040 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean; 10041 -- Determine whether an access type designates a type coming from a 10042 -- limited view. 10043 10044 function Is_Class_Wide_Default (D : Node_Id) return Boolean; 10045 -- Check whether the default has a class-wide type. After analysis the 10046 -- default has the type of the formal, so we must also check explicitly 10047 -- for an access attribute. 10048 10049 ---------------------------------- 10050 -- Designates_From_Limited_With -- 10051 ---------------------------------- 10052 10053 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean is 10054 Desig : Entity_Id := Typ; 10055 10056 begin 10057 if Is_Access_Type (Desig) then 10058 Desig := Directly_Designated_Type (Desig); 10059 end if; 10060 10061 if Is_Class_Wide_Type (Desig) then 10062 Desig := Root_Type (Desig); 10063 end if; 10064 10065 return 10066 Ekind (Desig) = E_Incomplete_Type 10067 and then From_Limited_With (Desig); 10068 end Designates_From_Limited_With; 10069 10070 --------------------------- 10071 -- Is_Class_Wide_Default -- 10072 --------------------------- 10073 10074 function Is_Class_Wide_Default (D : Node_Id) return Boolean is 10075 begin 10076 return Is_Class_Wide_Type (Designated_Type (Etype (D))) 10077 or else (Nkind (D) = N_Attribute_Reference 10078 and then Attribute_Name (D) = Name_Access 10079 and then Is_Class_Wide_Type (Etype (Prefix (D)))); 10080 end Is_Class_Wide_Default; 10081 10082 -- Local variables 10083 10084 Context : constant Node_Id := Parent (Parent (T)); 10085 Default : Node_Id; 10086 Formal : Entity_Id; 10087 Formal_Type : Entity_Id; 10088 Param_Spec : Node_Id; 10089 Ptype : Entity_Id; 10090 10091 Num_Out_Params : Nat := 0; 10092 First_Out_Param : Entity_Id := Empty; 10093 -- Used for setting Is_Only_Out_Parameter 10094 10095 -- Start of processing for Process_Formals 10096 10097 begin 10098 -- In order to prevent premature use of the formals in the same formal 10099 -- part, the Ekind is left undefined until all default expressions are 10100 -- analyzed. The Ekind is established in a separate loop at the end. 10101 10102 Param_Spec := First (T); 10103 while Present (Param_Spec) loop 10104 Formal := Defining_Identifier (Param_Spec); 10105 Set_Never_Set_In_Source (Formal, True); 10106 Enter_Name (Formal); 10107 10108 -- Case of ordinary parameters 10109 10110 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then 10111 Find_Type (Parameter_Type (Param_Spec)); 10112 Ptype := Parameter_Type (Param_Spec); 10113 10114 if Ptype = Error then 10115 goto Continue; 10116 end if; 10117 10118 Formal_Type := Entity (Ptype); 10119 10120 if Is_Incomplete_Type (Formal_Type) 10121 or else 10122 (Is_Class_Wide_Type (Formal_Type) 10123 and then Is_Incomplete_Type (Root_Type (Formal_Type))) 10124 then 10125 -- Ada 2005 (AI-326): Tagged incomplete types allowed in 10126 -- primitive operations, as long as their completion is 10127 -- in the same declarative part. If in the private part 10128 -- this means that the type cannot be a Taft-amendment type. 10129 -- Check is done on package exit. For access to subprograms, 10130 -- the use is legal for Taft-amendment types. 10131 10132 -- Ada 2012: tagged incomplete types are allowed as generic 10133 -- formal types. They do not introduce dependencies and the 10134 -- corresponding generic subprogram does not have a delayed 10135 -- freeze, because it does not need a freeze node. However, 10136 -- it is still the case that untagged incomplete types cannot 10137 -- be Taft-amendment types and must be completed in private 10138 -- part, so the subprogram must appear in the list of private 10139 -- dependents of the type. If the type is class-wide, it is 10140 -- not a primitive, but the freezing of the subprogram must 10141 -- also be delayed to force the creation of a freeze node. 10142 10143 if Is_Tagged_Type (Formal_Type) 10144 or else (Ada_Version >= Ada_2012 10145 and then not From_Limited_With (Formal_Type) 10146 and then not Is_Generic_Type (Formal_Type)) 10147 then 10148 if Ekind (Scope (Current_Scope)) = E_Package 10149 and then not Is_Generic_Type (Formal_Type) 10150 then 10151 if not Nkind_In 10152 (Parent (T), N_Access_Function_Definition, 10153 N_Access_Procedure_Definition) 10154 then 10155 -- A limited view has no private dependents 10156 10157 if not Is_Class_Wide_Type (Formal_Type) 10158 and then not From_Limited_With (Formal_Type) 10159 then 10160 Append_Elmt (Current_Scope, 10161 Private_Dependents (Base_Type (Formal_Type))); 10162 end if; 10163 10164 -- Freezing is delayed to ensure that Register_Prim 10165 -- will get called for this operation, which is needed 10166 -- in cases where static dispatch tables aren't built. 10167 -- (Note that the same is done for controlling access 10168 -- parameter cases in function Access_Definition.) 10169 10170 if not Is_Thunk (Current_Scope) then 10171 Set_Has_Delayed_Freeze (Current_Scope); 10172 end if; 10173 end if; 10174 end if; 10175 10176 elsif not Nkind_In (Parent (T), N_Access_Function_Definition, 10177 N_Access_Procedure_Definition) 10178 then 10179 -- AI05-0151: Tagged incomplete types are allowed in all 10180 -- formal parts. Untagged incomplete types are not allowed 10181 -- in bodies. Limited views of either kind are not allowed 10182 -- if there is no place at which the non-limited view can 10183 -- become available. 10184 10185 -- Incomplete formal untagged types are not allowed in 10186 -- subprogram bodies (but are legal in their declarations). 10187 -- This excludes bodies created for null procedures, which 10188 -- are basic declarations. 10189 10190 if Is_Generic_Type (Formal_Type) 10191 and then not Is_Tagged_Type (Formal_Type) 10192 and then Nkind (Parent (Related_Nod)) = N_Subprogram_Body 10193 then 10194 Error_Msg_N 10195 ("invalid use of formal incomplete type", Param_Spec); 10196 10197 elsif Ada_Version >= Ada_2012 then 10198 if Is_Tagged_Type (Formal_Type) 10199 and then (not From_Limited_With (Formal_Type) 10200 or else not In_Package_Body) 10201 then 10202 null; 10203 10204 elsif Nkind_In (Context, N_Accept_Statement, 10205 N_Accept_Alternative, 10206 N_Entry_Body) 10207 or else (Nkind (Context) = N_Subprogram_Body 10208 and then Comes_From_Source (Context)) 10209 then 10210 Error_Msg_NE 10211 ("invalid use of untagged incomplete type &", 10212 Ptype, Formal_Type); 10213 end if; 10214 10215 else 10216 Error_Msg_NE 10217 ("invalid use of incomplete type&", 10218 Param_Spec, Formal_Type); 10219 10220 -- Further checks on the legality of incomplete types 10221 -- in formal parts are delayed until the freeze point 10222 -- of the enclosing subprogram or access to subprogram. 10223 end if; 10224 end if; 10225 10226 elsif Ekind (Formal_Type) = E_Void then 10227 Error_Msg_NE 10228 ("premature use of&", 10229 Parameter_Type (Param_Spec), Formal_Type); 10230 end if; 10231 10232 -- Ada 2012 (AI-142): Handle aliased parameters 10233 10234 if Ada_Version >= Ada_2012 10235 and then Aliased_Present (Param_Spec) 10236 then 10237 Set_Is_Aliased (Formal); 10238 end if; 10239 10240 -- Ada 2005 (AI-231): Create and decorate an internal subtype 10241 -- declaration corresponding to the null-excluding type of the 10242 -- formal in the enclosing scope. Finally, replace the parameter 10243 -- type of the formal with the internal subtype. 10244 10245 if Ada_Version >= Ada_2005 10246 and then Null_Exclusion_Present (Param_Spec) 10247 then 10248 if not Is_Access_Type (Formal_Type) then 10249 Error_Msg_N 10250 ("`NOT NULL` allowed only for an access type", Param_Spec); 10251 10252 else 10253 if Can_Never_Be_Null (Formal_Type) 10254 and then Comes_From_Source (Related_Nod) 10255 then 10256 Error_Msg_NE 10257 ("`NOT NULL` not allowed (& already excludes null)", 10258 Param_Spec, Formal_Type); 10259 end if; 10260 10261 Formal_Type := 10262 Create_Null_Excluding_Itype 10263 (T => Formal_Type, 10264 Related_Nod => Related_Nod, 10265 Scope_Id => Scope (Current_Scope)); 10266 10267 -- If the designated type of the itype is an itype that is 10268 -- not frozen yet, we set the Has_Delayed_Freeze attribute 10269 -- on the access subtype, to prevent order-of-elaboration 10270 -- issues in the backend. 10271 10272 -- Example: 10273 -- type T is access procedure; 10274 -- procedure Op (O : not null T); 10275 10276 if Is_Itype (Directly_Designated_Type (Formal_Type)) 10277 and then 10278 not Is_Frozen (Directly_Designated_Type (Formal_Type)) 10279 then 10280 Set_Has_Delayed_Freeze (Formal_Type); 10281 end if; 10282 end if; 10283 end if; 10284 10285 -- An access formal type 10286 10287 else 10288 Formal_Type := 10289 Access_Definition (Related_Nod, Parameter_Type (Param_Spec)); 10290 10291 -- No need to continue if we already notified errors 10292 10293 if not Present (Formal_Type) then 10294 return; 10295 end if; 10296 10297 -- Ada 2005 (AI-254) 10298 10299 declare 10300 AD : constant Node_Id := 10301 Access_To_Subprogram_Definition 10302 (Parameter_Type (Param_Spec)); 10303 begin 10304 if Present (AD) and then Protected_Present (AD) then 10305 Formal_Type := 10306 Replace_Anonymous_Access_To_Protected_Subprogram 10307 (Param_Spec); 10308 end if; 10309 end; 10310 end if; 10311 10312 Set_Etype (Formal, Formal_Type); 10313 10314 -- Deal with default expression if present 10315 10316 Default := Expression (Param_Spec); 10317 10318 if Present (Default) then 10319 Check_SPARK_05_Restriction 10320 ("default expression is not allowed", Default); 10321 10322 if Out_Present (Param_Spec) then 10323 Error_Msg_N 10324 ("default initialization only allowed for IN parameters", 10325 Param_Spec); 10326 end if; 10327 10328 -- Do the special preanalysis of the expression (see section on 10329 -- "Handling of Default Expressions" in the spec of package Sem). 10330 10331 Preanalyze_Spec_Expression (Default, Formal_Type); 10332 10333 -- An access to constant cannot be the default for 10334 -- an access parameter that is an access to variable. 10335 10336 if Ekind (Formal_Type) = E_Anonymous_Access_Type 10337 and then not Is_Access_Constant (Formal_Type) 10338 and then Is_Access_Type (Etype (Default)) 10339 and then Is_Access_Constant (Etype (Default)) 10340 then 10341 Error_Msg_N 10342 ("formal that is access to variable cannot be initialized " 10343 & "with an access-to-constant expression", Default); 10344 end if; 10345 10346 -- Check that the designated type of an access parameter's default 10347 -- is not a class-wide type unless the parameter's designated type 10348 -- is also class-wide. 10349 10350 if Ekind (Formal_Type) = E_Anonymous_Access_Type 10351 and then not Designates_From_Limited_With (Formal_Type) 10352 and then Is_Class_Wide_Default (Default) 10353 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type)) 10354 then 10355 Error_Msg_N 10356 ("access to class-wide expression not allowed here", Default); 10357 end if; 10358 10359 -- Check incorrect use of dynamically tagged expressions 10360 10361 if Is_Tagged_Type (Formal_Type) then 10362 Check_Dynamically_Tagged_Expression 10363 (Expr => Default, 10364 Typ => Formal_Type, 10365 Related_Nod => Default); 10366 end if; 10367 end if; 10368 10369 -- Ada 2005 (AI-231): Static checks 10370 10371 if Ada_Version >= Ada_2005 10372 and then Is_Access_Type (Etype (Formal)) 10373 and then Can_Never_Be_Null (Etype (Formal)) 10374 then 10375 Null_Exclusion_Static_Checks (Param_Spec); 10376 end if; 10377 10378 -- The following checks are relevant only when SPARK_Mode is on as 10379 -- these are not standard Ada legality rules. 10380 10381 if SPARK_Mode = On then 10382 if Ekind_In (Scope (Formal), E_Function, E_Generic_Function) then 10383 10384 -- A function cannot have a parameter of mode IN OUT or OUT 10385 -- (SPARK RM 6.1). 10386 10387 if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then 10388 Error_Msg_N 10389 ("function cannot have parameter of mode `OUT` or " 10390 & "`IN OUT`", Formal); 10391 end if; 10392 10393 -- A procedure cannot have an effectively volatile formal 10394 -- parameter of mode IN because it behaves as a constant 10395 -- (SPARK RM 7.1.3(6)). 10396 10397 elsif Ekind (Scope (Formal)) = E_Procedure 10398 and then Ekind (Formal) = E_In_Parameter 10399 and then Is_Effectively_Volatile (Formal) 10400 then 10401 Error_Msg_N 10402 ("formal parameter of mode `IN` cannot be volatile", Formal); 10403 end if; 10404 end if; 10405 10406 <<Continue>> 10407 Next (Param_Spec); 10408 end loop; 10409 10410 -- If this is the formal part of a function specification, analyze the 10411 -- subtype mark in the context where the formals are visible but not 10412 -- yet usable, and may hide outer homographs. 10413 10414 if Nkind (Related_Nod) = N_Function_Specification then 10415 Analyze_Return_Type (Related_Nod); 10416 10417 -- If return type is class-wide, subprogram freezing may be 10418 -- delayed as well, unless the declaration is a compilation unit 10419 -- in which case the freeze node would appear too late. 10420 10421 if Is_Class_Wide_Type (Etype (Current_Scope)) 10422 and then not Is_Thunk (Current_Scope) 10423 and then not Is_Compilation_Unit (Current_Scope) 10424 and then Nkind (Unit_Declaration_Node (Current_Scope)) = 10425 N_Subprogram_Declaration 10426 then 10427 Set_Has_Delayed_Freeze (Current_Scope); 10428 end if; 10429 end if; 10430 10431 -- Now set the kind (mode) of each formal 10432 10433 Param_Spec := First (T); 10434 while Present (Param_Spec) loop 10435 Formal := Defining_Identifier (Param_Spec); 10436 Set_Formal_Mode (Formal); 10437 10438 if Ekind (Formal) = E_In_Parameter then 10439 Set_Default_Value (Formal, Expression (Param_Spec)); 10440 10441 if Present (Expression (Param_Spec)) then 10442 Default := Expression (Param_Spec); 10443 10444 if Is_Scalar_Type (Etype (Default)) then 10445 if Nkind (Parameter_Type (Param_Spec)) /= 10446 N_Access_Definition 10447 then 10448 Formal_Type := Entity (Parameter_Type (Param_Spec)); 10449 else 10450 Formal_Type := 10451 Access_Definition 10452 (Related_Nod, Parameter_Type (Param_Spec)); 10453 end if; 10454 10455 Apply_Scalar_Range_Check (Default, Formal_Type); 10456 end if; 10457 end if; 10458 10459 elsif Ekind (Formal) = E_Out_Parameter then 10460 Num_Out_Params := Num_Out_Params + 1; 10461 10462 if Num_Out_Params = 1 then 10463 First_Out_Param := Formal; 10464 end if; 10465 10466 elsif Ekind (Formal) = E_In_Out_Parameter then 10467 Num_Out_Params := Num_Out_Params + 1; 10468 end if; 10469 10470 -- Skip remaining processing if formal type was in error 10471 10472 if Etype (Formal) = Any_Type or else Error_Posted (Formal) then 10473 goto Next_Parameter; 10474 end if; 10475 10476 -- Force call by reference if aliased 10477 10478 if Is_Aliased (Formal) then 10479 Set_Mechanism (Formal, By_Reference); 10480 10481 -- Warn if user asked this to be passed by copy 10482 10483 if Convention (Formal_Type) = Convention_Ada_Pass_By_Copy then 10484 Error_Msg_N 10485 ("cannot pass aliased parameter & by copy??", Formal); 10486 end if; 10487 10488 -- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy 10489 10490 elsif Convention (Formal_Type) = Convention_Ada_Pass_By_Copy then 10491 Set_Mechanism (Formal, By_Copy); 10492 10493 elsif Convention (Formal_Type) = Convention_Ada_Pass_By_Reference then 10494 Set_Mechanism (Formal, By_Reference); 10495 end if; 10496 10497 <<Next_Parameter>> 10498 Next (Param_Spec); 10499 end loop; 10500 10501 if Present (First_Out_Param) and then Num_Out_Params = 1 then 10502 Set_Is_Only_Out_Parameter (First_Out_Param); 10503 end if; 10504 end Process_Formals; 10505 10506 ---------------------------- 10507 -- Reference_Body_Formals -- 10508 ---------------------------- 10509 10510 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is 10511 Fs : Entity_Id; 10512 Fb : Entity_Id; 10513 10514 begin 10515 if Error_Posted (Spec) then 10516 return; 10517 end if; 10518 10519 -- Iterate over both lists. They may be of different lengths if the two 10520 -- specs are not conformant. 10521 10522 Fs := First_Formal (Spec); 10523 Fb := First_Formal (Bod); 10524 while Present (Fs) and then Present (Fb) loop 10525 Generate_Reference (Fs, Fb, 'b'); 10526 10527 if Style_Check then 10528 Style.Check_Identifier (Fb, Fs); 10529 end if; 10530 10531 Set_Spec_Entity (Fb, Fs); 10532 Set_Referenced (Fs, False); 10533 Next_Formal (Fs); 10534 Next_Formal (Fb); 10535 end loop; 10536 end Reference_Body_Formals; 10537 10538 ------------------------- 10539 -- Set_Actual_Subtypes -- 10540 ------------------------- 10541 10542 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is 10543 Decl : Node_Id; 10544 Formal : Entity_Id; 10545 T : Entity_Id; 10546 First_Stmt : Node_Id := Empty; 10547 AS_Needed : Boolean; 10548 10549 begin 10550 -- If this is an empty initialization procedure, no need to create 10551 -- actual subtypes (small optimization). 10552 10553 if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then 10554 return; 10555 end if; 10556 10557 Formal := First_Formal (Subp); 10558 while Present (Formal) loop 10559 T := Etype (Formal); 10560 10561 -- We never need an actual subtype for a constrained formal 10562 10563 if Is_Constrained (T) then 10564 AS_Needed := False; 10565 10566 -- If we have unknown discriminants, then we do not need an actual 10567 -- subtype, or more accurately we cannot figure it out. Note that 10568 -- all class-wide types have unknown discriminants. 10569 10570 elsif Has_Unknown_Discriminants (T) then 10571 AS_Needed := False; 10572 10573 -- At this stage we have an unconstrained type that may need an 10574 -- actual subtype. For sure the actual subtype is needed if we have 10575 -- an unconstrained array type. 10576 10577 elsif Is_Array_Type (T) then 10578 AS_Needed := True; 10579 10580 -- The only other case needing an actual subtype is an unconstrained 10581 -- record type which is an IN parameter (we cannot generate actual 10582 -- subtypes for the OUT or IN OUT case, since an assignment can 10583 -- change the discriminant values. However we exclude the case of 10584 -- initialization procedures, since discriminants are handled very 10585 -- specially in this context, see the section entitled "Handling of 10586 -- Discriminants" in Einfo. 10587 10588 -- We also exclude the case of Discrim_SO_Functions (functions used 10589 -- in front end layout mode for size/offset values), since in such 10590 -- functions only discriminants are referenced, and not only are such 10591 -- subtypes not needed, but they cannot always be generated, because 10592 -- of order of elaboration issues. 10593 10594 elsif Is_Record_Type (T) 10595 and then Ekind (Formal) = E_In_Parameter 10596 and then Chars (Formal) /= Name_uInit 10597 and then not Is_Unchecked_Union (T) 10598 and then not Is_Discrim_SO_Function (Subp) 10599 then 10600 AS_Needed := True; 10601 10602 -- All other cases do not need an actual subtype 10603 10604 else 10605 AS_Needed := False; 10606 end if; 10607 10608 -- Generate actual subtypes for unconstrained arrays and 10609 -- unconstrained discriminated records. 10610 10611 if AS_Needed then 10612 if Nkind (N) = N_Accept_Statement then 10613 10614 -- If expansion is active, the formal is replaced by a local 10615 -- variable that renames the corresponding entry of the 10616 -- parameter block, and it is this local variable that may 10617 -- require an actual subtype. 10618 10619 if Expander_Active then 10620 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal)); 10621 else 10622 Decl := Build_Actual_Subtype (T, Formal); 10623 end if; 10624 10625 if Present (Handled_Statement_Sequence (N)) then 10626 First_Stmt := 10627 First (Statements (Handled_Statement_Sequence (N))); 10628 Prepend (Decl, Statements (Handled_Statement_Sequence (N))); 10629 Mark_Rewrite_Insertion (Decl); 10630 else 10631 -- If the accept statement has no body, there will be no 10632 -- reference to the actuals, so no need to compute actual 10633 -- subtypes. 10634 10635 return; 10636 end if; 10637 10638 else 10639 Decl := Build_Actual_Subtype (T, Formal); 10640 Prepend (Decl, Declarations (N)); 10641 Mark_Rewrite_Insertion (Decl); 10642 end if; 10643 10644 -- The declaration uses the bounds of an existing object, and 10645 -- therefore needs no constraint checks. 10646 10647 Analyze (Decl, Suppress => All_Checks); 10648 10649 -- We need to freeze manually the generated type when it is 10650 -- inserted anywhere else than in a declarative part. 10651 10652 if Present (First_Stmt) then 10653 Insert_List_Before_And_Analyze (First_Stmt, 10654 Freeze_Entity (Defining_Identifier (Decl), N)); 10655 10656 -- Ditto if the type has a dynamic predicate, because the 10657 -- generated function will mention the actual subtype. 10658 10659 elsif Has_Dynamic_Predicate_Aspect (T) then 10660 Insert_List_Before_And_Analyze (Decl, 10661 Freeze_Entity (Defining_Identifier (Decl), N)); 10662 end if; 10663 10664 if Nkind (N) = N_Accept_Statement 10665 and then Expander_Active 10666 then 10667 Set_Actual_Subtype (Renamed_Object (Formal), 10668 Defining_Identifier (Decl)); 10669 else 10670 Set_Actual_Subtype (Formal, Defining_Identifier (Decl)); 10671 end if; 10672 end if; 10673 10674 Next_Formal (Formal); 10675 end loop; 10676 end Set_Actual_Subtypes; 10677 10678 --------------------- 10679 -- Set_Formal_Mode -- 10680 --------------------- 10681 10682 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is 10683 Spec : constant Node_Id := Parent (Formal_Id); 10684 Id : constant Entity_Id := Scope (Formal_Id); 10685 10686 begin 10687 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters 10688 -- since we ensure that corresponding actuals are always valid at the 10689 -- point of the call. 10690 10691 if Out_Present (Spec) then 10692 if Ekind_In (Id, E_Entry, E_Entry_Family) 10693 or else Is_Subprogram_Or_Generic_Subprogram (Id) 10694 then 10695 Set_Has_Out_Or_In_Out_Parameter (Id, True); 10696 end if; 10697 10698 if Ekind_In (Id, E_Function, E_Generic_Function) then 10699 10700 -- [IN] OUT parameters allowed for functions in Ada 2012 10701 10702 if Ada_Version >= Ada_2012 then 10703 10704 -- Even in Ada 2012 operators can only have IN parameters 10705 10706 if Is_Operator_Symbol_Name (Chars (Scope (Formal_Id))) then 10707 Error_Msg_N ("operators can only have IN parameters", Spec); 10708 end if; 10709 10710 if In_Present (Spec) then 10711 Set_Ekind (Formal_Id, E_In_Out_Parameter); 10712 else 10713 Set_Ekind (Formal_Id, E_Out_Parameter); 10714 end if; 10715 10716 -- But not in earlier versions of Ada 10717 10718 else 10719 Error_Msg_N ("functions can only have IN parameters", Spec); 10720 Set_Ekind (Formal_Id, E_In_Parameter); 10721 end if; 10722 10723 elsif In_Present (Spec) then 10724 Set_Ekind (Formal_Id, E_In_Out_Parameter); 10725 10726 else 10727 Set_Ekind (Formal_Id, E_Out_Parameter); 10728 Set_Never_Set_In_Source (Formal_Id, True); 10729 Set_Is_True_Constant (Formal_Id, False); 10730 Set_Current_Value (Formal_Id, Empty); 10731 end if; 10732 10733 else 10734 Set_Ekind (Formal_Id, E_In_Parameter); 10735 end if; 10736 10737 -- Set Is_Known_Non_Null for access parameters since the language 10738 -- guarantees that access parameters are always non-null. We also set 10739 -- Can_Never_Be_Null, since there is no way to change the value. 10740 10741 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then 10742 10743 -- Ada 2005 (AI-231): In Ada 95, access parameters are always non- 10744 -- null; In Ada 2005, only if then null_exclusion is explicit. 10745 10746 if Ada_Version < Ada_2005 10747 or else Can_Never_Be_Null (Etype (Formal_Id)) 10748 then 10749 Set_Is_Known_Non_Null (Formal_Id); 10750 Set_Can_Never_Be_Null (Formal_Id); 10751 end if; 10752 10753 -- Ada 2005 (AI-231): Null-exclusion access subtype 10754 10755 elsif Is_Access_Type (Etype (Formal_Id)) 10756 and then Can_Never_Be_Null (Etype (Formal_Id)) 10757 then 10758 Set_Is_Known_Non_Null (Formal_Id); 10759 10760 -- We can also set Can_Never_Be_Null (thus preventing some junk 10761 -- access checks) for the case of an IN parameter, which cannot 10762 -- be changed, or for an IN OUT parameter, which can be changed but 10763 -- not to a null value. But for an OUT parameter, the initial value 10764 -- passed in can be null, so we can't set this flag in that case. 10765 10766 if Ekind (Formal_Id) /= E_Out_Parameter then 10767 Set_Can_Never_Be_Null (Formal_Id); 10768 end if; 10769 end if; 10770 10771 Set_Mechanism (Formal_Id, Default_Mechanism); 10772 Set_Formal_Validity (Formal_Id); 10773 end Set_Formal_Mode; 10774 10775 ------------------------- 10776 -- Set_Formal_Validity -- 10777 ------------------------- 10778 10779 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is 10780 begin 10781 -- If no validity checking, then we cannot assume anything about the 10782 -- validity of parameters, since we do not know there is any checking 10783 -- of the validity on the call side. 10784 10785 if not Validity_Checks_On then 10786 return; 10787 10788 -- If validity checking for parameters is enabled, this means we are 10789 -- not supposed to make any assumptions about argument values. 10790 10791 elsif Validity_Check_Parameters then 10792 return; 10793 10794 -- If we are checking in parameters, we will assume that the caller is 10795 -- also checking parameters, so we can assume the parameter is valid. 10796 10797 elsif Ekind (Formal_Id) = E_In_Parameter 10798 and then Validity_Check_In_Params 10799 then 10800 Set_Is_Known_Valid (Formal_Id, True); 10801 10802 -- Similar treatment for IN OUT parameters 10803 10804 elsif Ekind (Formal_Id) = E_In_Out_Parameter 10805 and then Validity_Check_In_Out_Params 10806 then 10807 Set_Is_Known_Valid (Formal_Id, True); 10808 end if; 10809 end Set_Formal_Validity; 10810 10811 ------------------------ 10812 -- Subtype_Conformant -- 10813 ------------------------ 10814 10815 function Subtype_Conformant 10816 (New_Id : Entity_Id; 10817 Old_Id : Entity_Id; 10818 Skip_Controlling_Formals : Boolean := False) return Boolean 10819 is 10820 Result : Boolean; 10821 begin 10822 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result, 10823 Skip_Controlling_Formals => Skip_Controlling_Formals); 10824 return Result; 10825 end Subtype_Conformant; 10826 10827 --------------------- 10828 -- Type_Conformant -- 10829 --------------------- 10830 10831 function Type_Conformant 10832 (New_Id : Entity_Id; 10833 Old_Id : Entity_Id; 10834 Skip_Controlling_Formals : Boolean := False) return Boolean 10835 is 10836 Result : Boolean; 10837 begin 10838 May_Hide_Profile := False; 10839 Check_Conformance 10840 (New_Id, Old_Id, Type_Conformant, False, Result, 10841 Skip_Controlling_Formals => Skip_Controlling_Formals); 10842 return Result; 10843 end Type_Conformant; 10844 10845 ------------------------------- 10846 -- Valid_Operator_Definition -- 10847 ------------------------------- 10848 10849 procedure Valid_Operator_Definition (Designator : Entity_Id) is 10850 N : Integer := 0; 10851 F : Entity_Id; 10852 Id : constant Name_Id := Chars (Designator); 10853 N_OK : Boolean; 10854 10855 begin 10856 F := First_Formal (Designator); 10857 while Present (F) loop 10858 N := N + 1; 10859 10860 if Present (Default_Value (F)) then 10861 Error_Msg_N 10862 ("default values not allowed for operator parameters", 10863 Parent (F)); 10864 10865 -- For function instantiations that are operators, we must check 10866 -- separately that the corresponding generic only has in-parameters. 10867 -- For subprogram declarations this is done in Set_Formal_Mode. Such 10868 -- an error could not arise in earlier versions of the language. 10869 10870 elsif Ekind (F) /= E_In_Parameter then 10871 Error_Msg_N ("operators can only have IN parameters", F); 10872 end if; 10873 10874 Next_Formal (F); 10875 end loop; 10876 10877 -- Verify that user-defined operators have proper number of arguments 10878 -- First case of operators which can only be unary 10879 10880 if Nam_In (Id, Name_Op_Not, Name_Op_Abs) then 10881 N_OK := (N = 1); 10882 10883 -- Case of operators which can be unary or binary 10884 10885 elsif Nam_In (Id, Name_Op_Add, Name_Op_Subtract) then 10886 N_OK := (N in 1 .. 2); 10887 10888 -- All other operators can only be binary 10889 10890 else 10891 N_OK := (N = 2); 10892 end if; 10893 10894 if not N_OK then 10895 Error_Msg_N 10896 ("incorrect number of arguments for operator", Designator); 10897 end if; 10898 10899 if Id = Name_Op_Ne 10900 and then Base_Type (Etype (Designator)) = Standard_Boolean 10901 and then not Is_Intrinsic_Subprogram (Designator) 10902 then 10903 Error_Msg_N 10904 ("explicit definition of inequality not allowed", Designator); 10905 end if; 10906 end Valid_Operator_Definition; 10907 10908end Sem_Ch6; 10909