1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 6 -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2019, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with 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_Tss; use Exp_Tss; 40with Exp_Util; use Exp_Util; 41with Freeze; use Freeze; 42with Ghost; use Ghost; 43with Inline; use Inline; 44with Itypes; use Itypes; 45with Lib.Xref; use Lib.Xref; 46with Layout; use Layout; 47with Namet; use Namet; 48with Lib; use Lib; 49with Nlists; use Nlists; 50with Nmake; use Nmake; 51with Opt; use Opt; 52with Output; use Output; 53with Restrict; use Restrict; 54with Rident; use Rident; 55with Rtsfind; use Rtsfind; 56with Sem; use Sem; 57with Sem_Aux; use Sem_Aux; 58with Sem_Cat; use Sem_Cat; 59with Sem_Ch3; use Sem_Ch3; 60with Sem_Ch4; use Sem_Ch4; 61with Sem_Ch5; use Sem_Ch5; 62with Sem_Ch8; use Sem_Ch8; 63with Sem_Ch9; use Sem_Ch9; 64with Sem_Ch10; use Sem_Ch10; 65with Sem_Ch12; use Sem_Ch12; 66with Sem_Ch13; use Sem_Ch13; 67with Sem_Dim; use Sem_Dim; 68with Sem_Disp; use Sem_Disp; 69with Sem_Dist; use Sem_Dist; 70with Sem_Elim; use Sem_Elim; 71with Sem_Eval; use Sem_Eval; 72with Sem_Mech; use Sem_Mech; 73with Sem_Prag; use Sem_Prag; 74with Sem_Res; use Sem_Res; 75with Sem_Util; use Sem_Util; 76with Sem_Type; use Sem_Type; 77with Sem_Warn; use Sem_Warn; 78with Sinput; use Sinput; 79with Stand; use Stand; 80with Sinfo; use Sinfo; 81with Sinfo.CN; use Sinfo.CN; 82with Snames; use Snames; 83with Stringt; use Stringt; 84with Style; 85with Stylesw; use Stylesw; 86with Tbuild; use Tbuild; 87with Uintp; use Uintp; 88with Urealp; use Urealp; 89with Validsw; use Validsw; 90 91package body Sem_Ch6 is 92 93 May_Hide_Profile : Boolean := False; 94 -- This flag is used to indicate that two formals in two subprograms being 95 -- checked for conformance differ only in that one is an access parameter 96 -- while the other is of a general access type with the same designated 97 -- type. In this case, if the rest of the signatures match, a call to 98 -- either subprogram may be ambiguous, which is worth a warning. The flag 99 -- is set in Compatible_Types, and the warning emitted in 100 -- New_Overloaded_Entity. 101 102 ----------------------- 103 -- Local Subprograms -- 104 ----------------------- 105 106 procedure Analyze_Function_Return (N : Node_Id); 107 -- Subsidiary to Analyze_Return_Statement. Called when the return statement 108 -- applies to a [generic] function. 109 110 procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id); 111 -- Analyze a generic subprogram body. N is the body to be analyzed, and 112 -- Gen_Id is the defining entity Id for the corresponding spec. 113 114 procedure Analyze_Null_Procedure 115 (N : Node_Id; 116 Is_Completion : out Boolean); 117 -- A null procedure can be a declaration or (Ada 2012) a completion 118 119 procedure Analyze_Return_Statement (N : Node_Id); 120 -- Common processing for simple and extended return statements 121 122 procedure Analyze_Return_Type (N : Node_Id); 123 -- Subsidiary to Process_Formals: analyze subtype mark in function 124 -- specification in a context where the formals are visible and hide 125 -- outer homographs. 126 127 procedure Analyze_Subprogram_Body_Helper (N : Node_Id); 128 -- Does all the real work of Analyze_Subprogram_Body. This is split out so 129 -- that we can use RETURN but not skip the debug output at the end. 130 131 function Can_Override_Operator (Subp : Entity_Id) return Boolean; 132 -- Returns true if Subp can override a predefined operator. 133 134 procedure Check_Conformance 135 (New_Id : Entity_Id; 136 Old_Id : Entity_Id; 137 Ctype : Conformance_Type; 138 Errmsg : Boolean; 139 Conforms : out Boolean; 140 Err_Loc : Node_Id := Empty; 141 Get_Inst : Boolean := False; 142 Skip_Controlling_Formals : Boolean := False); 143 -- Given two entities, this procedure checks that the profiles associated 144 -- with these entities meet the conformance criterion given by the third 145 -- parameter. If they conform, Conforms is set True and control returns 146 -- to the caller. If they do not conform, Conforms is set to False, and 147 -- in addition, if Errmsg is True on the call, proper messages are output 148 -- to complain about the conformance failure. If Err_Loc is non_Empty 149 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then 150 -- error messages are placed on the appropriate part of the construct 151 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance 152 -- against a formal access-to-subprogram type so Get_Instance_Of must 153 -- be called. 154 155 procedure Check_Limited_Return 156 (N : Node_Id; 157 Expr : Node_Id; 158 R_Type : Entity_Id); 159 -- Check the appropriate (Ada 95 or Ada 2005) rules for returning limited 160 -- types. Used only for simple return statements. Expr is the expression 161 -- returned. 162 163 procedure Check_Subprogram_Order (N : Node_Id); 164 -- N is the N_Subprogram_Body node for a subprogram. This routine applies 165 -- the alpha ordering rule for N if this ordering requirement applicable. 166 167 procedure Check_Returns 168 (HSS : Node_Id; 169 Mode : Character; 170 Err : out Boolean; 171 Proc : Entity_Id := Empty); 172 -- Called to check for missing return statements in a function body, or for 173 -- returns present in a procedure body which has No_Return set. HSS is the 174 -- handled statement sequence for the subprogram body. This procedure 175 -- checks all flow paths to make sure they either have return (Mode = 'F', 176 -- used for functions) or do not have a return (Mode = 'P', used for 177 -- No_Return procedures). The flag Err is set if there are any control 178 -- paths not explicitly terminated by a return in the function case, and is 179 -- True otherwise. Proc is the entity for the procedure case and is used 180 -- in posting the warning message. 181 182 procedure Check_Untagged_Equality (Eq_Op : Entity_Id); 183 -- In Ada 2012, a primitive equality operator on an untagged record type 184 -- must appear before the type is frozen, and have the same visibility as 185 -- that of the type. This procedure checks that this rule is met, and 186 -- otherwise emits an error on the subprogram declaration and a warning 187 -- on the earlier freeze point if it is easy to locate. In Ada 2012 mode, 188 -- this routine outputs errors (or warnings if -gnatd.E is set). In earlier 189 -- versions of Ada, warnings are output if Warn_On_Ada_2012_Incompatibility 190 -- is set, otherwise the call has no effect. 191 192 procedure Enter_Overloaded_Entity (S : Entity_Id); 193 -- This procedure makes S, a new overloaded entity, into the first visible 194 -- entity with that name. 195 196 function Is_Non_Overriding_Operation 197 (Prev_E : Entity_Id; 198 New_E : Entity_Id) return Boolean; 199 -- Enforce the rule given in 12.3(18): a private operation in an instance 200 -- overrides an inherited operation only if the corresponding operation 201 -- was overriding in the generic. This needs to be checked for primitive 202 -- operations of types derived (in the generic unit) from formal private 203 -- or formal derived types. 204 205 procedure Make_Inequality_Operator (S : Entity_Id); 206 -- Create the declaration for an inequality operator that is implicitly 207 -- created by a user-defined equality operator that yields a boolean. 208 209 procedure Preanalyze_Formal_Expression (N : Node_Id; T : Entity_Id); 210 -- Preanalysis of default expressions of subprogram formals. N is the 211 -- expression to be analyzed and T is the expected type. 212 213 procedure Set_Formal_Validity (Formal_Id : Entity_Id); 214 -- Formal_Id is an formal parameter entity. This procedure deals with 215 -- setting the proper validity status for this entity, which depends on 216 -- the kind of parameter and the validity checking mode. 217 218 --------------------------------------------- 219 -- Analyze_Abstract_Subprogram_Declaration -- 220 --------------------------------------------- 221 222 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is 223 Scop : constant Entity_Id := Current_Scope; 224 Subp_Id : constant Entity_Id := 225 Analyze_Subprogram_Specification (Specification (N)); 226 227 begin 228 Check_SPARK_05_Restriction ("abstract subprogram is not allowed", N); 229 230 Generate_Definition (Subp_Id); 231 232 -- Set the SPARK mode from the current context (may be overwritten later 233 -- with explicit pragma). 234 235 Set_SPARK_Pragma (Subp_Id, SPARK_Mode_Pragma); 236 Set_SPARK_Pragma_Inherited (Subp_Id); 237 238 -- Preserve relevant elaboration-related attributes of the context which 239 -- are no longer available or very expensive to recompute once analysis, 240 -- resolution, and expansion are over. 241 242 Mark_Elaboration_Attributes 243 (N_Id => Subp_Id, 244 Checks => True, 245 Warnings => True); 246 247 Set_Is_Abstract_Subprogram (Subp_Id); 248 New_Overloaded_Entity (Subp_Id); 249 Check_Delayed_Subprogram (Subp_Id); 250 251 Set_Categorization_From_Scope (Subp_Id, Scop); 252 253 if Ekind (Scope (Subp_Id)) = E_Protected_Type then 254 Error_Msg_N ("abstract subprogram not allowed in protected type", N); 255 256 -- Issue a warning if the abstract subprogram is neither a dispatching 257 -- operation nor an operation that overrides an inherited subprogram or 258 -- predefined operator, since this most likely indicates a mistake. 259 260 elsif Warn_On_Redundant_Constructs 261 and then not Is_Dispatching_Operation (Subp_Id) 262 and then not Present (Overridden_Operation (Subp_Id)) 263 and then (not Is_Operator_Symbol_Name (Chars (Subp_Id)) 264 or else Scop /= Scope (Etype (First_Formal (Subp_Id)))) 265 then 266 Error_Msg_N 267 ("abstract subprogram is not dispatching or overriding?r?", N); 268 end if; 269 270 Generate_Reference_To_Formals (Subp_Id); 271 Check_Eliminated (Subp_Id); 272 273 if Has_Aspects (N) then 274 Analyze_Aspect_Specifications (N, Subp_Id); 275 end if; 276 end Analyze_Abstract_Subprogram_Declaration; 277 278 --------------------------------- 279 -- Analyze_Expression_Function -- 280 --------------------------------- 281 282 procedure Analyze_Expression_Function (N : Node_Id) is 283 Expr : constant Node_Id := Expression (N); 284 Loc : constant Source_Ptr := Sloc (N); 285 LocX : constant Source_Ptr := Sloc (Expr); 286 Spec : constant Node_Id := Specification (N); 287 288 -- Local variables 289 290 Asp : Node_Id; 291 New_Body : Node_Id; 292 New_Spec : Node_Id; 293 Orig_N : Node_Id; 294 Ret : Node_Id; 295 296 Def_Id : Entity_Id := Empty; 297 Prev : Entity_Id; 298 -- If the expression is a completion, Prev is the entity whose 299 -- declaration is completed. Def_Id is needed to analyze the spec. 300 301 -- Start of processing for Analyze_Expression_Function 302 303 begin 304 -- This is one of the occasions on which we transform the tree during 305 -- semantic analysis. If this is a completion, transform the expression 306 -- function into an equivalent subprogram body, and analyze it. 307 308 -- Expression functions are inlined unconditionally. The back-end will 309 -- determine whether this is possible. 310 311 Inline_Processing_Required := True; 312 313 -- Create a specification for the generated body. This must be done 314 -- prior to the analysis of the initial declaration. 315 316 New_Spec := Copy_Subprogram_Spec (Spec); 317 Prev := Current_Entity_In_Scope (Defining_Entity (Spec)); 318 319 -- If there are previous overloadable entities with the same name, 320 -- check whether any of them is completed by the expression function. 321 -- In a generic context a formal subprogram has no completion. 322 323 if Present (Prev) 324 and then Is_Overloadable (Prev) 325 and then not Is_Formal_Subprogram (Prev) 326 then 327 Def_Id := Analyze_Subprogram_Specification (Spec); 328 Prev := Find_Corresponding_Spec (N); 329 330 -- The previous entity may be an expression function as well, in 331 -- which case the redeclaration is illegal. 332 333 if Present (Prev) 334 and then Nkind (Original_Node (Unit_Declaration_Node (Prev))) = 335 N_Expression_Function 336 then 337 Error_Msg_Sloc := Sloc (Prev); 338 Error_Msg_N ("& conflicts with declaration#", Def_Id); 339 return; 340 end if; 341 end if; 342 343 Ret := Make_Simple_Return_Statement (LocX, Expr); 344 345 New_Body := 346 Make_Subprogram_Body (Loc, 347 Specification => New_Spec, 348 Declarations => Empty_List, 349 Handled_Statement_Sequence => 350 Make_Handled_Sequence_Of_Statements (LocX, 351 Statements => New_List (Ret))); 352 Set_Was_Expression_Function (New_Body); 353 354 -- If the expression completes a generic subprogram, we must create a 355 -- separate node for the body, because at instantiation the original 356 -- node of the generic copy must be a generic subprogram body, and 357 -- cannot be a expression function. Otherwise we just rewrite the 358 -- expression with the non-generic body. 359 360 if Present (Prev) and then Ekind (Prev) = E_Generic_Function then 361 Insert_After (N, New_Body); 362 363 -- Propagate any aspects or pragmas that apply to the expression 364 -- function to the proper body when the expression function acts 365 -- as a completion. 366 367 if Has_Aspects (N) then 368 Move_Aspects (N, To => New_Body); 369 end if; 370 371 Relocate_Pragmas_To_Body (New_Body); 372 373 Rewrite (N, Make_Null_Statement (Loc)); 374 Set_Has_Completion (Prev, False); 375 Analyze (N); 376 Analyze (New_Body); 377 Set_Is_Inlined (Prev); 378 379 -- If the expression function is a completion, the previous declaration 380 -- must come from source. We know already that it appears in the current 381 -- scope. The entity itself may be internally created if within a body 382 -- to be inlined. 383 384 elsif Present (Prev) 385 and then Is_Overloadable (Prev) 386 and then not Is_Formal_Subprogram (Prev) 387 and then Comes_From_Source (Parent (Prev)) 388 then 389 Set_Has_Completion (Prev, False); 390 Set_Is_Inlined (Prev); 391 392 -- AI12-0103: Expression functions that are a completion freeze their 393 -- expression but don't freeze anything else (unlike regular bodies). 394 395 -- Note that we cannot defer this freezing to the analysis of the 396 -- expression itself, because a freeze node might appear in a nested 397 -- scope, leading to an elaboration order issue in gigi. 398 -- As elsewhere, we do not emit freeze nodes within a generic unit. 399 400 if not Inside_A_Generic then 401 Freeze_Expr_Types 402 (Def_Id => Def_Id, 403 Typ => Etype (Def_Id), 404 Expr => Expr, 405 N => N); 406 end if; 407 408 -- For navigation purposes, indicate that the function is a body 409 410 Generate_Reference (Prev, Defining_Entity (N), 'b', Force => True); 411 Rewrite (N, New_Body); 412 413 -- Remove any existing aspects from the original node because the act 414 -- of rewriting causes the list to be shared between the two nodes. 415 416 Orig_N := Original_Node (N); 417 Remove_Aspects (Orig_N); 418 419 -- Propagate any pragmas that apply to expression function to the 420 -- proper body when the expression function acts as a completion. 421 -- Aspects are automatically transfered because of node rewriting. 422 423 Relocate_Pragmas_To_Body (N); 424 Analyze (N); 425 426 -- Once the aspects of the generated body have been analyzed, create 427 -- a copy for ASIS purposes and associate it with the original node. 428 429 if Has_Aspects (N) then 430 Set_Aspect_Specifications (Orig_N, 431 New_Copy_List_Tree (Aspect_Specifications (N))); 432 end if; 433 434 -- Prev is the previous entity with the same name, but it is can 435 -- be an unrelated spec that is not completed by the expression 436 -- function. In that case the relevant entity is the one in the body. 437 -- Not clear that the backend can inline it in this case ??? 438 439 if Has_Completion (Prev) then 440 441 -- The formals of the expression function are body formals, 442 -- and do not appear in the ali file, which will only contain 443 -- references to the formals of the original subprogram spec. 444 445 declare 446 F1 : Entity_Id; 447 F2 : Entity_Id; 448 449 begin 450 F1 := First_Formal (Def_Id); 451 F2 := First_Formal (Prev); 452 453 while Present (F1) loop 454 Set_Spec_Entity (F1, F2); 455 Next_Formal (F1); 456 Next_Formal (F2); 457 end loop; 458 end; 459 460 else 461 Set_Is_Inlined (Defining_Entity (New_Body)); 462 end if; 463 464 -- If this is not a completion, create both a declaration and a body, so 465 -- that the expression can be inlined whenever possible. 466 467 else 468 -- An expression function that is not a completion is not a 469 -- subprogram declaration, and thus cannot appear in a protected 470 -- definition. 471 472 if Nkind (Parent (N)) = N_Protected_Definition then 473 Error_Msg_N 474 ("an expression function is not a legal protected operation", N); 475 end if; 476 477 Rewrite (N, Make_Subprogram_Declaration (Loc, Specification => Spec)); 478 479 -- Remove any existing aspects from the original node because the act 480 -- of rewriting causes the list to be shared between the two nodes. 481 482 Orig_N := Original_Node (N); 483 Remove_Aspects (Orig_N); 484 485 Analyze (N); 486 487 -- Once the aspects of the generated spec have been analyzed, create 488 -- a copy for ASIS purposes and associate it with the original node. 489 490 if Has_Aspects (N) then 491 Set_Aspect_Specifications (Orig_N, 492 New_Copy_List_Tree (Aspect_Specifications (N))); 493 end if; 494 495 -- If aspect SPARK_Mode was specified on the body, it needs to be 496 -- repeated both on the generated spec and the body. 497 498 Asp := Find_Aspect (Defining_Unit_Name (Spec), Aspect_SPARK_Mode); 499 500 if Present (Asp) then 501 Asp := New_Copy_Tree (Asp); 502 Set_Analyzed (Asp, False); 503 Set_Aspect_Specifications (New_Body, New_List (Asp)); 504 end if; 505 506 Def_Id := Defining_Entity (N); 507 Set_Is_Inlined (Def_Id); 508 509 -- Establish the linkages between the spec and the body. These are 510 -- used when the expression function acts as the prefix of attribute 511 -- 'Access in order to freeze the original expression which has been 512 -- moved to the generated body. 513 514 Set_Corresponding_Body (N, Defining_Entity (New_Body)); 515 Set_Corresponding_Spec (New_Body, Def_Id); 516 517 -- Within a generic preanalyze the original expression for name 518 -- capture. The body is also generated but plays no role in 519 -- this because it is not part of the original source. 520 521 if Inside_A_Generic then 522 Set_Has_Completion (Def_Id); 523 Push_Scope (Def_Id); 524 Install_Formals (Def_Id); 525 Preanalyze_Spec_Expression (Expr, Etype (Def_Id)); 526 End_Scope; 527 end if; 528 529 -- To prevent premature freeze action, insert the new body at the end 530 -- of the current declarations, or at the end of the package spec. 531 -- However, resolve usage names now, to prevent spurious visibility 532 -- on later entities. Note that the function can now be called in 533 -- the current declarative part, which will appear to be prior to 534 -- the presence of the body in the code. There are nevertheless no 535 -- order of elaboration issues because all name resolution has taken 536 -- place at the point of declaration. 537 538 declare 539 Decls : List_Id := List_Containing (N); 540 Expr : constant Node_Id := Expression (Ret); 541 Par : constant Node_Id := Parent (Decls); 542 Typ : constant Entity_Id := Etype (Def_Id); 543 544 begin 545 -- If this is a wrapper created for in an instance for a formal 546 -- subprogram, insert body after declaration, to be analyzed when 547 -- the enclosing instance is analyzed. 548 549 if GNATprove_Mode 550 and then Is_Generic_Actual_Subprogram (Def_Id) 551 then 552 Insert_After (N, New_Body); 553 554 else 555 if Nkind (Par) = N_Package_Specification 556 and then Decls = Visible_Declarations (Par) 557 and then Present (Private_Declarations (Par)) 558 and then not Is_Empty_List (Private_Declarations (Par)) 559 then 560 Decls := Private_Declarations (Par); 561 end if; 562 563 Insert_After (Last (Decls), New_Body); 564 565 -- Preanalyze the expression if not already done above 566 567 if not Inside_A_Generic then 568 Push_Scope (Def_Id); 569 Install_Formals (Def_Id); 570 Preanalyze_Formal_Expression (Expr, Typ); 571 Check_Limited_Return (Original_Node (N), Expr, Typ); 572 End_Scope; 573 end if; 574 end if; 575 end; 576 end if; 577 578 -- Check incorrect use of dynamically tagged expression. This doesn't 579 -- fall out automatically when analyzing the generated function body, 580 -- because Check_Dynamically_Tagged_Expression deliberately ignores 581 -- nodes that don't come from source. 582 583 if Present (Def_Id) 584 and then Nkind (Def_Id) in N_Has_Etype 585 and then Is_Tagged_Type (Etype (Def_Id)) 586 then 587 Check_Dynamically_Tagged_Expression 588 (Expr => Expr, 589 Typ => Etype (Def_Id), 590 Related_Nod => Original_Node (N)); 591 end if; 592 593 -- We must enforce checks for unreferenced formals in our newly 594 -- generated function, so we propagate the referenced flag from the 595 -- original spec to the new spec as well as setting Comes_From_Source. 596 597 if Present (Parameter_Specifications (New_Spec)) then 598 declare 599 Form_New_Def : Entity_Id; 600 Form_New_Spec : Entity_Id; 601 Form_Old_Def : Entity_Id; 602 Form_Old_Spec : Entity_Id; 603 604 begin 605 Form_New_Spec := First (Parameter_Specifications (New_Spec)); 606 Form_Old_Spec := First (Parameter_Specifications (Spec)); 607 608 while Present (Form_New_Spec) and then Present (Form_Old_Spec) loop 609 Form_New_Def := Defining_Identifier (Form_New_Spec); 610 Form_Old_Def := Defining_Identifier (Form_Old_Spec); 611 612 Set_Comes_From_Source (Form_New_Def, True); 613 614 -- Because of the usefulness of unreferenced controlling 615 -- formals we exempt them from unreferenced warnings by marking 616 -- them as always referenced. 617 618 Set_Referenced (Form_Old_Def, 619 (Is_Formal (Form_Old_Def) 620 and then Is_Controlling_Formal (Form_Old_Def)) 621 or else Referenced (Form_Old_Def)); 622 623 Next (Form_New_Spec); 624 Next (Form_Old_Spec); 625 end loop; 626 end; 627 end if; 628 end Analyze_Expression_Function; 629 630 ---------------------------------------- 631 -- Analyze_Extended_Return_Statement -- 632 ---------------------------------------- 633 634 procedure Analyze_Extended_Return_Statement (N : Node_Id) is 635 begin 636 Check_Compiler_Unit ("extended return statement", N); 637 Analyze_Return_Statement (N); 638 end Analyze_Extended_Return_Statement; 639 640 ---------------------------- 641 -- Analyze_Function_Call -- 642 ---------------------------- 643 644 procedure Analyze_Function_Call (N : Node_Id) is 645 Actuals : constant List_Id := Parameter_Associations (N); 646 Func_Nam : constant Node_Id := Name (N); 647 Actual : Node_Id; 648 649 begin 650 Analyze (Func_Nam); 651 652 -- A call of the form A.B (X) may be an Ada 2005 call, which is 653 -- rewritten as B (A, X). If the rewriting is successful, the call 654 -- has been analyzed and we just return. 655 656 if Nkind (Func_Nam) = N_Selected_Component 657 and then Name (N) /= Func_Nam 658 and then Is_Rewrite_Substitution (N) 659 and then Present (Etype (N)) 660 then 661 return; 662 end if; 663 664 -- If error analyzing name, then set Any_Type as result type and return 665 666 if Etype (Func_Nam) = Any_Type then 667 Set_Etype (N, Any_Type); 668 return; 669 end if; 670 671 -- Otherwise analyze the parameters 672 673 if Present (Actuals) then 674 Actual := First (Actuals); 675 while Present (Actual) loop 676 Analyze (Actual); 677 Check_Parameterless_Call (Actual); 678 Next (Actual); 679 end loop; 680 end if; 681 682 Analyze_Call (N); 683 end Analyze_Function_Call; 684 685 ----------------------------- 686 -- Analyze_Function_Return -- 687 ----------------------------- 688 689 procedure Analyze_Function_Return (N : Node_Id) is 690 Loc : constant Source_Ptr := Sloc (N); 691 Stm_Entity : constant Entity_Id := Return_Statement_Entity (N); 692 Scope_Id : constant Entity_Id := Return_Applies_To (Stm_Entity); 693 694 R_Type : constant Entity_Id := Etype (Scope_Id); 695 -- Function result subtype 696 697 procedure Check_Return_Obj_Accessibility (Return_Stmt : Node_Id); 698 -- Apply legality rule of 6.5 (5.9) to the access discriminants of an 699 -- aggregate in a return statement. 700 701 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id); 702 -- Check that the return_subtype_indication properly matches the result 703 -- subtype of the function, as required by RM-6.5(5.1/2-5.3/2). 704 705 ------------------------------------ 706 -- Check_Return_Obj_Accessibility -- 707 ------------------------------------ 708 709 procedure Check_Return_Obj_Accessibility (Return_Stmt : Node_Id) is 710 Assoc : Node_Id; 711 Agg : Node_Id := Empty; 712 Discr : Entity_Id; 713 Expr : Node_Id; 714 Obj : Node_Id; 715 Process_Exprs : Boolean := False; 716 Return_Obj : Node_Id; 717 718 begin 719 -- Only perform checks on record types with access discriminants 720 721 if not Is_Record_Type (R_Type) 722 or else not Has_Discriminants (R_Type) 723 then 724 return; 725 end if; 726 727 -- We are only interested in return statements 728 729 if not Nkind_In (Return_Stmt, N_Extended_Return_Statement, 730 N_Simple_Return_Statement) 731 then 732 return; 733 end if; 734 735 -- Fetch the object from the return statement, in the case of a 736 -- simple return statement the expression is part of the node. 737 738 if Nkind (Return_Stmt) = N_Extended_Return_Statement then 739 Return_Obj := Last (Return_Object_Declarations (Return_Stmt)); 740 741 -- We could be looking at something that's been expanded with 742 -- an initialzation procedure which we can safely ignore. 743 744 if Nkind (Return_Obj) /= N_Object_Declaration then 745 return; 746 end if; 747 else 748 Return_Obj := Return_Stmt; 749 end if; 750 751 -- We may need to check an aggregate or a subtype indication 752 -- depending on how the discriminants were specified and whether 753 -- we are looking at an extended return statement. 754 755 if Nkind (Return_Obj) = N_Object_Declaration 756 and then Nkind (Object_Definition (Return_Obj)) 757 = N_Subtype_Indication 758 then 759 Assoc := First (Constraints 760 (Constraint (Object_Definition (Return_Obj)))); 761 else 762 -- Qualified expressions may be nested 763 764 Agg := Original_Node (Expression (Return_Obj)); 765 while Nkind (Agg) = N_Qualified_Expression loop 766 Agg := Original_Node (Expression (Agg)); 767 end loop; 768 769 -- If we are looking at an aggregate instead of a function call we 770 -- can continue checking accessibility for the supplied 771 -- discriminant associations. 772 773 if Nkind (Agg) = N_Aggregate then 774 if Present (Expressions (Agg)) then 775 Assoc := First (Expressions (Agg)); 776 Process_Exprs := True; 777 else 778 Assoc := First (Component_Associations (Agg)); 779 end if; 780 781 -- Otherwise the expression is not of interest ??? 782 783 else 784 return; 785 end if; 786 end if; 787 788 -- Move through the discriminants checking the accessibility level 789 -- of each co-extension's associated expression. 790 791 Discr := First_Discriminant (R_Type); 792 while Present (Discr) loop 793 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then 794 795 if Nkind (Assoc) = N_Attribute_Reference then 796 Expr := Assoc; 797 elsif Nkind_In (Assoc, N_Component_Association, 798 N_Discriminant_Association) 799 then 800 Expr := Expression (Assoc); 801 end if; 802 803 -- This anonymous access discriminant has an associated 804 -- expression which needs checking. 805 806 if Nkind (Expr) = N_Attribute_Reference 807 and then Attribute_Name (Expr) /= Name_Unrestricted_Access 808 then 809 -- Obtain the object to perform static checks on by moving 810 -- up the prefixes in the expression taking into account 811 -- named access types. 812 813 Obj := Prefix (Expr); 814 while Nkind_In (Obj, N_Indexed_Component, 815 N_Selected_Component) 816 loop 817 -- When we encounter a named access type then we can 818 -- ignore accessibility checks on the dereference. 819 820 if Ekind (Etype (Prefix (Obj))) 821 in E_Access_Type .. 822 E_Access_Protected_Subprogram_Type 823 then 824 if Nkind (Obj) = N_Selected_Component then 825 Obj := Selector_Name (Obj); 826 end if; 827 exit; 828 end if; 829 830 -- Skip over the explicit dereference 831 832 if Nkind (Prefix (Obj)) = N_Explicit_Dereference then 833 Obj := Prefix (Prefix (Obj)); 834 835 -- Otherwise move up to the next prefix 836 837 else 838 Obj := Prefix (Obj); 839 end if; 840 end loop; 841 842 -- Do not check aliased formals or function calls. A 843 -- run-time check may still be needed ??? 844 845 if Is_Entity_Name (Obj) 846 and then Comes_From_Source (Obj) 847 then 848 -- Explicitly aliased formals are allowed 849 850 if Is_Formal (Entity (Obj)) 851 and then Is_Aliased (Entity (Obj)) 852 then 853 null; 854 855 elsif Object_Access_Level (Obj) > 856 Scope_Depth (Scope (Scope_Id)) 857 then 858 Error_Msg_N 859 ("access discriminant in return aggregate would " 860 & "be a dangling reference", Obj); 861 end if; 862 end if; 863 end if; 864 end if; 865 866 Next_Discriminant (Discr); 867 868 if not Is_List_Member (Assoc) then 869 Assoc := Empty; 870 else 871 Nlists.Next (Assoc); 872 end if; 873 874 -- After aggregate expressions, examine component associations if 875 -- present. 876 877 if No (Assoc) then 878 if Present (Agg) 879 and then Process_Exprs 880 and then Present (Component_Associations (Agg)) 881 then 882 Assoc := First (Component_Associations (Agg)); 883 Process_Exprs := False; 884 else 885 exit; 886 end if; 887 end if; 888 end loop; 889 end Check_Return_Obj_Accessibility; 890 891 ------------------------------------- 892 -- Check_Return_Subtype_Indication -- 893 ------------------------------------- 894 895 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is 896 Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl); 897 898 R_Stm_Type : constant Entity_Id := Etype (Return_Obj); 899 -- Subtype given in the extended return statement (must match R_Type) 900 901 Subtype_Ind : constant Node_Id := 902 Object_Definition (Original_Node (Obj_Decl)); 903 904 procedure Error_No_Match (N : Node_Id); 905 -- Output error messages for case where types do not statically 906 -- match. N is the location for the messages. 907 908 -------------------- 909 -- Error_No_Match -- 910 -------------------- 911 912 procedure Error_No_Match (N : Node_Id) is 913 begin 914 Error_Msg_N 915 ("subtype must statically match function result subtype", N); 916 917 if not Predicates_Match (R_Stm_Type, R_Type) then 918 Error_Msg_Node_2 := R_Type; 919 Error_Msg_NE 920 ("\predicate of& does not match predicate of&", 921 N, R_Stm_Type); 922 end if; 923 end Error_No_Match; 924 925 -- Start of processing for Check_Return_Subtype_Indication 926 927 begin 928 -- First, avoid cascaded errors 929 930 if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then 931 return; 932 end if; 933 934 -- "return access T" case; check that the return statement also has 935 -- "access T", and that the subtypes statically match: 936 -- if this is an access to subprogram the signatures must match. 937 938 if Is_Anonymous_Access_Type (R_Type) then 939 if Is_Anonymous_Access_Type (R_Stm_Type) then 940 if Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type 941 then 942 if Base_Type (Designated_Type (R_Stm_Type)) /= 943 Base_Type (Designated_Type (R_Type)) 944 or else not Subtypes_Statically_Match (R_Stm_Type, R_Type) 945 then 946 Error_No_Match (Subtype_Mark (Subtype_Ind)); 947 end if; 948 949 else 950 -- For two anonymous access to subprogram types, the types 951 -- themselves must be type conformant. 952 953 if not Conforming_Types 954 (R_Stm_Type, R_Type, Fully_Conformant) 955 then 956 Error_No_Match (Subtype_Ind); 957 end if; 958 end if; 959 960 else 961 Error_Msg_N ("must use anonymous access type", Subtype_Ind); 962 end if; 963 964 -- If the return object is of an anonymous access type, then report 965 -- an error if the function's result type is not also anonymous. 966 967 elsif Is_Anonymous_Access_Type (R_Stm_Type) then 968 pragma Assert (not Is_Anonymous_Access_Type (R_Type)); 969 Error_Msg_N 970 ("anonymous access not allowed for function with named access " 971 & "result", Subtype_Ind); 972 973 -- Subtype indication case: check that the return object's type is 974 -- covered by the result type, and that the subtypes statically match 975 -- when the result subtype is constrained. Also handle record types 976 -- with unknown discriminants for which we have built the underlying 977 -- record view. Coverage is needed to allow specific-type return 978 -- objects when the result type is class-wide (see AI05-32). 979 980 elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type)) 981 or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type)) 982 and then 983 Covers 984 (Base_Type (R_Type), 985 Underlying_Record_View (Base_Type (R_Stm_Type)))) 986 then 987 -- A null exclusion may be present on the return type, on the 988 -- function specification, on the object declaration or on the 989 -- subtype itself. 990 991 if Is_Access_Type (R_Type) 992 and then 993 (Can_Never_Be_Null (R_Type) 994 or else Null_Exclusion_Present (Parent (Scope_Id))) /= 995 Can_Never_Be_Null (R_Stm_Type) 996 then 997 Error_No_Match (Subtype_Ind); 998 end if; 999 1000 -- AI05-103: for elementary types, subtypes must statically match 1001 1002 if Is_Constrained (R_Type) or else Is_Access_Type (R_Type) then 1003 if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then 1004 Error_No_Match (Subtype_Ind); 1005 end if; 1006 end if; 1007 1008 -- All remaining cases are illegal 1009 1010 -- Note: previous versions of this subprogram allowed the return 1011 -- value to be the ancestor of the return type if the return type 1012 -- was a null extension. This was plainly incorrect. 1013 1014 else 1015 Error_Msg_N 1016 ("wrong type for return_subtype_indication", Subtype_Ind); 1017 end if; 1018 end Check_Return_Subtype_Indication; 1019 1020 --------------------- 1021 -- Local Variables -- 1022 --------------------- 1023 1024 Expr : Node_Id; 1025 Obj_Decl : Node_Id := Empty; 1026 1027 -- Start of processing for Analyze_Function_Return 1028 1029 begin 1030 Set_Return_Present (Scope_Id); 1031 1032 if Nkind (N) = N_Simple_Return_Statement then 1033 Expr := Expression (N); 1034 1035 -- Guard against a malformed expression. The parser may have tried to 1036 -- recover but the node is not analyzable. 1037 1038 if Nkind (Expr) = N_Error then 1039 Set_Etype (Expr, Any_Type); 1040 Expander_Mode_Save_And_Set (False); 1041 return; 1042 1043 else 1044 -- The resolution of a controlled [extension] aggregate associated 1045 -- with a return statement creates a temporary which needs to be 1046 -- finalized on function exit. Wrap the return statement inside a 1047 -- block so that the finalization machinery can detect this case. 1048 -- This early expansion is done only when the return statement is 1049 -- not part of a handled sequence of statements. 1050 1051 if Nkind_In (Expr, N_Aggregate, 1052 N_Extension_Aggregate) 1053 and then Needs_Finalization (R_Type) 1054 and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements 1055 then 1056 Rewrite (N, 1057 Make_Block_Statement (Loc, 1058 Handled_Statement_Sequence => 1059 Make_Handled_Sequence_Of_Statements (Loc, 1060 Statements => New_List (Relocate_Node (N))))); 1061 1062 Analyze (N); 1063 return; 1064 end if; 1065 1066 Analyze (Expr); 1067 1068 -- Ada 2005 (AI-251): If the type of the returned object is 1069 -- an access to an interface type then we add an implicit type 1070 -- conversion to force the displacement of the "this" pointer to 1071 -- reference the secondary dispatch table. We cannot delay the 1072 -- generation of this implicit conversion until the expansion 1073 -- because in this case the type resolution changes the decoration 1074 -- of the expression node to match R_Type; by contrast, if the 1075 -- returned object is a class-wide interface type then it is too 1076 -- early to generate here the implicit conversion since the return 1077 -- statement may be rewritten by the expander into an extended 1078 -- return statement whose expansion takes care of adding the 1079 -- implicit type conversion to displace the pointer to the object. 1080 1081 if Expander_Active 1082 and then Serious_Errors_Detected = 0 1083 and then Is_Access_Type (R_Type) 1084 and then not Nkind_In (Expr, N_Null, N_Raise_Expression) 1085 and then Is_Interface (Designated_Type (R_Type)) 1086 and then Is_Progenitor (Designated_Type (R_Type), 1087 Designated_Type (Etype (Expr))) 1088 then 1089 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); 1090 Analyze (Expr); 1091 end if; 1092 1093 Resolve (Expr, R_Type); 1094 Check_Limited_Return (N, Expr, R_Type); 1095 1096 Check_Return_Obj_Accessibility (N); 1097 end if; 1098 1099 -- RETURN only allowed in SPARK as the last statement in function 1100 1101 if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements 1102 and then 1103 (Nkind (Parent (Parent (N))) /= N_Subprogram_Body 1104 or else Present (Next (N))) 1105 then 1106 Check_SPARK_05_Restriction 1107 ("RETURN should be the last statement in function", N); 1108 end if; 1109 1110 else 1111 Check_SPARK_05_Restriction ("extended RETURN is not allowed", N); 1112 Obj_Decl := Last (Return_Object_Declarations (N)); 1113 1114 -- Analyze parts specific to extended_return_statement: 1115 1116 declare 1117 Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl); 1118 HSS : constant Node_Id := Handled_Statement_Sequence (N); 1119 1120 begin 1121 Expr := Expression (Obj_Decl); 1122 1123 -- Note: The check for OK_For_Limited_Init will happen in 1124 -- Analyze_Object_Declaration; we treat it as a normal 1125 -- object declaration. 1126 1127 Set_Is_Return_Object (Defining_Identifier (Obj_Decl)); 1128 Analyze (Obj_Decl); 1129 1130 Check_Return_Subtype_Indication (Obj_Decl); 1131 1132 if Present (HSS) then 1133 Analyze (HSS); 1134 1135 if Present (Exception_Handlers (HSS)) then 1136 1137 -- ???Has_Nested_Block_With_Handler needs to be set. 1138 -- Probably by creating an actual N_Block_Statement. 1139 -- Probably in Expand. 1140 1141 null; 1142 end if; 1143 end if; 1144 1145 -- Mark the return object as referenced, since the return is an 1146 -- implicit reference of the object. 1147 1148 Set_Referenced (Defining_Identifier (Obj_Decl)); 1149 1150 Check_References (Stm_Entity); 1151 1152 Check_Return_Obj_Accessibility (N); 1153 1154 -- Check RM 6.5 (5.9/3) 1155 1156 if Has_Aliased then 1157 if Ada_Version < Ada_2012 then 1158 1159 -- Shouldn't this test Warn_On_Ada_2012_Compatibility ??? 1160 -- Can it really happen (extended return???) 1161 1162 Error_Msg_N 1163 ("aliased only allowed for limited return objects " 1164 & "in Ada 2012??", N); 1165 1166 elsif not Is_Limited_View (R_Type) then 1167 Error_Msg_N 1168 ("aliased only allowed for limited return objects", N); 1169 end if; 1170 end if; 1171 end; 1172 end if; 1173 1174 -- Case of Expr present 1175 1176 if Present (Expr) then 1177 1178 -- Defend against previous errors 1179 1180 if Nkind (Expr) = N_Empty 1181 or else No (Etype (Expr)) 1182 then 1183 return; 1184 end if; 1185 1186 -- Apply constraint check. Note that this is done before the implicit 1187 -- conversion of the expression done for anonymous access types to 1188 -- ensure correct generation of the null-excluding check associated 1189 -- with null-excluding expressions found in return statements. We 1190 -- don't need a check if the subtype of the return object is the 1191 -- same as the result subtype of the function. 1192 1193 if Nkind (N) /= N_Extended_Return_Statement 1194 or else Nkind (Obj_Decl) /= N_Object_Declaration 1195 or else Nkind (Object_Definition (Obj_Decl)) not in N_Has_Entity 1196 or else Entity (Object_Definition (Obj_Decl)) /= R_Type 1197 then 1198 Apply_Constraint_Check (Expr, R_Type); 1199 end if; 1200 1201 -- The return value is converted to the return type of the function, 1202 -- which implies a predicate check if the return type is predicated. 1203 -- We do not apply the check to a case expression because it will 1204 -- be expanded into a series of return statements, each of which 1205 -- will receive a predicate check. 1206 1207 if Nkind (Expr) /= N_Case_Expression then 1208 Apply_Predicate_Check (Expr, R_Type); 1209 end if; 1210 1211 -- Ada 2005 (AI-318-02): When the result type is an anonymous access 1212 -- type, apply an implicit conversion of the expression to that type 1213 -- to force appropriate static and run-time accessibility checks. 1214 1215 if Ada_Version >= Ada_2005 1216 and then Ekind (R_Type) = E_Anonymous_Access_Type 1217 then 1218 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); 1219 Analyze_And_Resolve (Expr, R_Type); 1220 1221 -- If this is a local anonymous access to subprogram, the 1222 -- accessibility check can be applied statically. The return is 1223 -- illegal if the access type of the return expression is declared 1224 -- inside of the subprogram (except if it is the subtype indication 1225 -- of an extended return statement). 1226 1227 elsif Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type then 1228 if not Comes_From_Source (Current_Scope) 1229 or else Ekind (Current_Scope) = E_Return_Statement 1230 then 1231 null; 1232 1233 elsif 1234 Scope_Depth (Scope (Etype (Expr))) >= Scope_Depth (Scope_Id) 1235 then 1236 Error_Msg_N ("cannot return local access to subprogram", N); 1237 end if; 1238 1239 -- The expression cannot be of a formal incomplete type 1240 1241 elsif Ekind (Etype (Expr)) = E_Incomplete_Type 1242 and then Is_Generic_Type (Etype (Expr)) 1243 then 1244 Error_Msg_N 1245 ("cannot return expression of a formal incomplete type", N); 1246 end if; 1247 1248 -- If the result type is class-wide, then check that the return 1249 -- expression's type is not declared at a deeper level than the 1250 -- function (RM05-6.5(5.6/2)). 1251 1252 if Ada_Version >= Ada_2005 1253 and then Is_Class_Wide_Type (R_Type) 1254 then 1255 if Type_Access_Level (Etype (Expr)) > 1256 Subprogram_Access_Level (Scope_Id) 1257 then 1258 Error_Msg_N 1259 ("level of return expression type is deeper than " 1260 & "class-wide function!", Expr); 1261 end if; 1262 end if; 1263 1264 -- Check incorrect use of dynamically tagged expression 1265 1266 if Is_Tagged_Type (R_Type) then 1267 Check_Dynamically_Tagged_Expression 1268 (Expr => Expr, 1269 Typ => R_Type, 1270 Related_Nod => N); 1271 end if; 1272 1273 -- ??? A real run-time accessibility check is needed in cases 1274 -- involving dereferences of access parameters. For now we just 1275 -- check the static cases. 1276 1277 if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L) 1278 and then Is_Limited_View (Etype (Scope_Id)) 1279 and then Object_Access_Level (Expr) > 1280 Subprogram_Access_Level (Scope_Id) 1281 then 1282 -- Suppress the message in a generic, where the rewriting 1283 -- is irrelevant. 1284 1285 if Inside_A_Generic then 1286 null; 1287 1288 else 1289 Rewrite (N, 1290 Make_Raise_Program_Error (Loc, 1291 Reason => PE_Accessibility_Check_Failed)); 1292 Analyze (N); 1293 1294 Error_Msg_Warn := SPARK_Mode /= On; 1295 Error_Msg_N ("cannot return a local value by reference<<", N); 1296 Error_Msg_NE ("\& [<<", N, Standard_Program_Error); 1297 end if; 1298 end if; 1299 1300 if Known_Null (Expr) 1301 and then Nkind (Parent (Scope_Id)) = N_Function_Specification 1302 and then Null_Exclusion_Present (Parent (Scope_Id)) 1303 then 1304 Apply_Compile_Time_Constraint_Error 1305 (N => Expr, 1306 Msg => "(Ada 2005) null not allowed for " 1307 & "null-excluding return??", 1308 Reason => CE_Null_Not_Allowed); 1309 end if; 1310 1311 -- RM 6.5 (5.4/3): accessibility checks also apply if the return object 1312 -- has no initializing expression. 1313 1314 elsif Ada_Version > Ada_2005 and then Is_Class_Wide_Type (R_Type) then 1315 if Type_Access_Level (Etype (Defining_Identifier (Obj_Decl))) > 1316 Subprogram_Access_Level (Scope_Id) 1317 then 1318 Error_Msg_N 1319 ("level of return expression type is deeper than " 1320 & "class-wide function!", Obj_Decl); 1321 end if; 1322 end if; 1323 end Analyze_Function_Return; 1324 1325 ------------------------------------- 1326 -- Analyze_Generic_Subprogram_Body -- 1327 ------------------------------------- 1328 1329 procedure Analyze_Generic_Subprogram_Body 1330 (N : Node_Id; 1331 Gen_Id : Entity_Id) 1332 is 1333 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id); 1334 Kind : constant Entity_Kind := Ekind (Gen_Id); 1335 Body_Id : Entity_Id; 1336 New_N : Node_Id; 1337 Spec : Node_Id; 1338 1339 begin 1340 -- Copy body and disable expansion while analyzing the generic For a 1341 -- stub, do not copy the stub (which would load the proper body), this 1342 -- will be done when the proper body is analyzed. 1343 1344 if Nkind (N) /= N_Subprogram_Body_Stub then 1345 New_N := Copy_Generic_Node (N, Empty, Instantiating => False); 1346 Rewrite (N, New_N); 1347 1348 -- Once the contents of the generic copy and the template are 1349 -- swapped, do the same for their respective aspect specifications. 1350 1351 Exchange_Aspects (N, New_N); 1352 1353 -- Collect all contract-related source pragmas found within the 1354 -- template and attach them to the contract of the subprogram body. 1355 -- This contract is used in the capture of global references within 1356 -- annotations. 1357 1358 Create_Generic_Contract (N); 1359 1360 Start_Generic; 1361 end if; 1362 1363 Spec := Specification (N); 1364 1365 -- Within the body of the generic, the subprogram is callable, and 1366 -- behaves like the corresponding non-generic unit. 1367 1368 Body_Id := Defining_Entity (Spec); 1369 1370 if Kind = E_Generic_Procedure 1371 and then Nkind (Spec) /= N_Procedure_Specification 1372 then 1373 Error_Msg_N ("invalid body for generic procedure ", Body_Id); 1374 return; 1375 1376 elsif Kind = E_Generic_Function 1377 and then Nkind (Spec) /= N_Function_Specification 1378 then 1379 Error_Msg_N ("invalid body for generic function ", Body_Id); 1380 return; 1381 end if; 1382 1383 Set_Corresponding_Body (Gen_Decl, Body_Id); 1384 1385 if Has_Completion (Gen_Id) 1386 and then Nkind (Parent (N)) /= N_Subunit 1387 then 1388 Error_Msg_N ("duplicate generic body", N); 1389 return; 1390 else 1391 Set_Has_Completion (Gen_Id); 1392 end if; 1393 1394 if Nkind (N) = N_Subprogram_Body_Stub then 1395 Set_Ekind (Defining_Entity (Specification (N)), Kind); 1396 else 1397 Set_Corresponding_Spec (N, Gen_Id); 1398 end if; 1399 1400 if Nkind (Parent (N)) = N_Compilation_Unit then 1401 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N)); 1402 end if; 1403 1404 -- Make generic parameters immediately visible in the body. They are 1405 -- needed to process the formals declarations. Then make the formals 1406 -- visible in a separate step. 1407 1408 Push_Scope (Gen_Id); 1409 1410 declare 1411 E : Entity_Id; 1412 First_Ent : Entity_Id; 1413 1414 begin 1415 First_Ent := First_Entity (Gen_Id); 1416 1417 E := First_Ent; 1418 while Present (E) and then not Is_Formal (E) loop 1419 Install_Entity (E); 1420 Next_Entity (E); 1421 end loop; 1422 1423 Set_Use (Generic_Formal_Declarations (Gen_Decl)); 1424 1425 -- Now generic formals are visible, and the specification can be 1426 -- analyzed, for subsequent conformance check. 1427 1428 Body_Id := Analyze_Subprogram_Specification (Spec); 1429 1430 -- Make formal parameters visible 1431 1432 if Present (E) then 1433 1434 -- E is the first formal parameter, we loop through the formals 1435 -- installing them so that they will be visible. 1436 1437 Set_First_Entity (Gen_Id, E); 1438 while Present (E) loop 1439 Install_Entity (E); 1440 Next_Formal (E); 1441 end loop; 1442 end if; 1443 1444 -- Visible generic entity is callable within its own body 1445 1446 Set_Ekind (Gen_Id, Ekind (Body_Id)); 1447 Set_Ekind (Body_Id, E_Subprogram_Body); 1448 Set_Convention (Body_Id, Convention (Gen_Id)); 1449 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id)); 1450 Set_Scope (Body_Id, Scope (Gen_Id)); 1451 1452 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id); 1453 1454 if Nkind (N) = N_Subprogram_Body_Stub then 1455 1456 -- No body to analyze, so restore state of generic unit 1457 1458 Set_Ekind (Gen_Id, Kind); 1459 Set_Ekind (Body_Id, Kind); 1460 1461 if Present (First_Ent) then 1462 Set_First_Entity (Gen_Id, First_Ent); 1463 end if; 1464 1465 End_Scope; 1466 return; 1467 end if; 1468 1469 -- If this is a compilation unit, it must be made visible explicitly, 1470 -- because the compilation of the declaration, unlike other library 1471 -- unit declarations, does not. If it is not a unit, the following 1472 -- is redundant but harmless. 1473 1474 Set_Is_Immediately_Visible (Gen_Id); 1475 Reference_Body_Formals (Gen_Id, Body_Id); 1476 1477 if Is_Child_Unit (Gen_Id) then 1478 Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False); 1479 end if; 1480 1481 Set_Actual_Subtypes (N, Current_Scope); 1482 1483 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 1484 Set_SPARK_Pragma_Inherited (Body_Id); 1485 1486 -- Analyze any aspect specifications that appear on the generic 1487 -- subprogram body. 1488 1489 if Has_Aspects (N) then 1490 Analyze_Aspects_On_Subprogram_Body_Or_Stub (N); 1491 end if; 1492 1493 Analyze_Declarations (Declarations (N)); 1494 Check_Completion; 1495 1496 -- Process the contract of the subprogram body after all declarations 1497 -- have been analyzed. This ensures that any contract-related pragmas 1498 -- are available through the N_Contract node of the body. 1499 1500 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id); 1501 1502 Analyze (Handled_Statement_Sequence (N)); 1503 Save_Global_References (Original_Node (N)); 1504 1505 -- Prior to exiting the scope, include generic formals again (if any 1506 -- are present) in the set of local entities. 1507 1508 if Present (First_Ent) then 1509 Set_First_Entity (Gen_Id, First_Ent); 1510 end if; 1511 1512 Check_References (Gen_Id); 1513 end; 1514 1515 Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope); 1516 Update_Use_Clause_Chain; 1517 Validate_Categorization_Dependency (N, Gen_Id); 1518 End_Scope; 1519 Check_Subprogram_Order (N); 1520 1521 -- Outside of its body, unit is generic again 1522 1523 Set_Ekind (Gen_Id, Kind); 1524 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False); 1525 1526 if Style_Check then 1527 Style.Check_Identifier (Body_Id, Gen_Id); 1528 end if; 1529 1530 End_Generic; 1531 end Analyze_Generic_Subprogram_Body; 1532 1533 ---------------------------- 1534 -- Analyze_Null_Procedure -- 1535 ---------------------------- 1536 1537 -- WARNING: This routine manages Ghost regions. Return statements must be 1538 -- replaced by gotos that jump to the end of the routine and restore the 1539 -- Ghost mode. 1540 1541 procedure Analyze_Null_Procedure 1542 (N : Node_Id; 1543 Is_Completion : out Boolean) 1544 is 1545 Loc : constant Source_Ptr := Sloc (N); 1546 Spec : constant Node_Id := Specification (N); 1547 1548 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 1549 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 1550 Saved_ISMP : constant Boolean := 1551 Ignore_SPARK_Mode_Pragmas_In_Instance; 1552 -- Save the Ghost and SPARK mode-related data to restore on exit 1553 1554 Designator : Entity_Id; 1555 Form : Node_Id; 1556 Null_Body : Node_Id := Empty; 1557 Null_Stmt : Node_Id := Null_Statement (Spec); 1558 Prev : Entity_Id; 1559 1560 begin 1561 Prev := Current_Entity_In_Scope (Defining_Entity (Spec)); 1562 1563 -- A null procedure is Ghost when it is stand-alone and is subject to 1564 -- pragma Ghost, or when the corresponding spec is Ghost. Set the mode 1565 -- now, to ensure that any nodes generated during analysis and expansion 1566 -- are properly marked as Ghost. 1567 1568 if Present (Prev) then 1569 Mark_And_Set_Ghost_Body (N, Prev); 1570 end if; 1571 1572 -- Capture the profile of the null procedure before analysis, for 1573 -- expansion at the freeze point and at each point of call. The body is 1574 -- used if the procedure has preconditions, or if it is a completion. In 1575 -- the first case the body is analyzed at the freeze point, in the other 1576 -- it replaces the null procedure declaration. 1577 1578 -- For a null procedure that comes from source, a NULL statement is 1579 -- provided by the parser, which carries the source location of the 1580 -- NULL keyword, and has Comes_From_Source set. For a null procedure 1581 -- from expansion, create one now. 1582 1583 if No (Null_Stmt) then 1584 Null_Stmt := Make_Null_Statement (Loc); 1585 end if; 1586 1587 Null_Body := 1588 Make_Subprogram_Body (Loc, 1589 Specification => New_Copy_Tree (Spec), 1590 Declarations => New_List, 1591 Handled_Statement_Sequence => 1592 Make_Handled_Sequence_Of_Statements (Loc, 1593 Statements => New_List (Null_Stmt))); 1594 1595 -- Create new entities for body and formals 1596 1597 Set_Defining_Unit_Name (Specification (Null_Body), 1598 Make_Defining_Identifier 1599 (Sloc (Defining_Entity (N)), 1600 Chars (Defining_Entity (N)))); 1601 1602 Form := First (Parameter_Specifications (Specification (Null_Body))); 1603 while Present (Form) loop 1604 Set_Defining_Identifier (Form, 1605 Make_Defining_Identifier 1606 (Sloc (Defining_Identifier (Form)), 1607 Chars (Defining_Identifier (Form)))); 1608 Next (Form); 1609 end loop; 1610 1611 -- Determine whether the null procedure may be a completion of a generic 1612 -- suprogram, in which case we use the new null body as the completion 1613 -- and set minimal semantic information on the original declaration, 1614 -- which is rewritten as a null statement. 1615 1616 if Present (Prev) and then Is_Generic_Subprogram (Prev) then 1617 Insert_Before (N, Null_Body); 1618 Set_Ekind (Defining_Entity (N), Ekind (Prev)); 1619 1620 Rewrite (N, Make_Null_Statement (Loc)); 1621 Analyze_Generic_Subprogram_Body (Null_Body, Prev); 1622 Is_Completion := True; 1623 1624 goto Leave; 1625 1626 else 1627 -- Resolve the types of the formals now, because the freeze point may 1628 -- appear in a different context, e.g. an instantiation. 1629 1630 Form := First (Parameter_Specifications (Specification (Null_Body))); 1631 while Present (Form) loop 1632 if Nkind (Parameter_Type (Form)) /= N_Access_Definition then 1633 Find_Type (Parameter_Type (Form)); 1634 1635 elsif No (Access_To_Subprogram_Definition 1636 (Parameter_Type (Form))) 1637 then 1638 Find_Type (Subtype_Mark (Parameter_Type (Form))); 1639 1640 -- The case of a null procedure with a formal that is an 1641 -- access-to-subprogram type, and that is used as an actual 1642 -- in an instantiation is left to the enthusiastic reader. 1643 1644 else 1645 null; 1646 end if; 1647 1648 Next (Form); 1649 end loop; 1650 end if; 1651 1652 -- If there are previous overloadable entities with the same name, check 1653 -- whether any of them is completed by the null procedure. 1654 1655 if Present (Prev) and then Is_Overloadable (Prev) then 1656 Designator := Analyze_Subprogram_Specification (Spec); 1657 Prev := Find_Corresponding_Spec (N); 1658 end if; 1659 1660 if No (Prev) or else not Comes_From_Source (Prev) then 1661 Designator := Analyze_Subprogram_Specification (Spec); 1662 Set_Has_Completion (Designator); 1663 1664 -- Signal to caller that this is a procedure declaration 1665 1666 Is_Completion := False; 1667 1668 -- Null procedures are always inlined, but generic formal subprograms 1669 -- which appear as such in the internal instance of formal packages, 1670 -- need no completion and are not marked Inline. 1671 1672 if Expander_Active 1673 and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration 1674 then 1675 Set_Corresponding_Body (N, Defining_Entity (Null_Body)); 1676 Set_Body_To_Inline (N, Null_Body); 1677 Set_Is_Inlined (Designator); 1678 end if; 1679 1680 else 1681 -- The null procedure is a completion. We unconditionally rewrite 1682 -- this as a null body (even if expansion is not active), because 1683 -- there are various error checks that are applied on this body 1684 -- when it is analyzed (e.g. correct aspect placement). 1685 1686 if Has_Completion (Prev) then 1687 Error_Msg_Sloc := Sloc (Prev); 1688 Error_Msg_NE ("duplicate body for & declared#", N, Prev); 1689 end if; 1690 1691 Check_Previous_Null_Procedure (N, Prev); 1692 1693 Is_Completion := True; 1694 Rewrite (N, Null_Body); 1695 Analyze (N); 1696 end if; 1697 1698 <<Leave>> 1699 Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP; 1700 Restore_Ghost_Region (Saved_GM, Saved_IGR); 1701 end Analyze_Null_Procedure; 1702 1703 ----------------------------- 1704 -- Analyze_Operator_Symbol -- 1705 ----------------------------- 1706 1707 -- An operator symbol such as "+" or "and" may appear in context where the 1708 -- literal denotes an entity name, such as "+"(x, y) or in context when it 1709 -- is just a string, as in (conjunction = "or"). In these cases the parser 1710 -- generates this node, and the semantics does the disambiguation. Other 1711 -- such case are actuals in an instantiation, the generic unit in an 1712 -- instantiation, and pragma arguments. 1713 1714 procedure Analyze_Operator_Symbol (N : Node_Id) is 1715 Par : constant Node_Id := Parent (N); 1716 1717 begin 1718 if (Nkind (Par) = N_Function_Call and then N = Name (Par)) 1719 or else Nkind (Par) = N_Function_Instantiation 1720 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par)) 1721 or else (Nkind (Par) = N_Pragma_Argument_Association 1722 and then not Is_Pragma_String_Literal (Par)) 1723 or else Nkind (Par) = N_Subprogram_Renaming_Declaration 1724 or else (Nkind (Par) = N_Attribute_Reference 1725 and then Attribute_Name (Par) /= Name_Value) 1726 then 1727 Find_Direct_Name (N); 1728 1729 else 1730 Change_Operator_Symbol_To_String_Literal (N); 1731 Analyze (N); 1732 end if; 1733 end Analyze_Operator_Symbol; 1734 1735 ----------------------------------- 1736 -- Analyze_Parameter_Association -- 1737 ----------------------------------- 1738 1739 procedure Analyze_Parameter_Association (N : Node_Id) is 1740 begin 1741 Analyze (Explicit_Actual_Parameter (N)); 1742 end Analyze_Parameter_Association; 1743 1744 ---------------------------- 1745 -- Analyze_Procedure_Call -- 1746 ---------------------------- 1747 1748 -- WARNING: This routine manages Ghost regions. Return statements must be 1749 -- replaced by gotos that jump to the end of the routine and restore the 1750 -- Ghost mode. 1751 1752 procedure Analyze_Procedure_Call (N : Node_Id) is 1753 procedure Analyze_Call_And_Resolve; 1754 -- Do Analyze and Resolve calls for procedure call. At the end, check 1755 -- for illegal order dependence. 1756 -- ??? where is the check for illegal order dependencies? 1757 1758 ------------------------------ 1759 -- Analyze_Call_And_Resolve -- 1760 ------------------------------ 1761 1762 procedure Analyze_Call_And_Resolve is 1763 begin 1764 if Nkind (N) = N_Procedure_Call_Statement then 1765 Analyze_Call (N); 1766 Resolve (N, Standard_Void_Type); 1767 else 1768 Analyze (N); 1769 end if; 1770 end Analyze_Call_And_Resolve; 1771 1772 -- Local variables 1773 1774 Actuals : constant List_Id := Parameter_Associations (N); 1775 Loc : constant Source_Ptr := Sloc (N); 1776 P : constant Node_Id := Name (N); 1777 1778 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 1779 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 1780 -- Save the Ghost-related attributes to restore on exit 1781 1782 Actual : Node_Id; 1783 New_N : Node_Id; 1784 1785 -- Start of processing for Analyze_Procedure_Call 1786 1787 begin 1788 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote 1789 -- a procedure call or an entry call. The prefix may denote an access 1790 -- to subprogram type, in which case an implicit dereference applies. 1791 -- If the prefix is an indexed component (without implicit dereference) 1792 -- then the construct denotes a call to a member of an entire family. 1793 -- If the prefix is a simple name, it may still denote a call to a 1794 -- parameterless member of an entry family. Resolution of these various 1795 -- interpretations is delicate. 1796 1797 -- Do not analyze machine code statements to avoid rejecting them in 1798 -- CodePeer mode. 1799 1800 if CodePeer_Mode and then Nkind (P) = N_Qualified_Expression then 1801 Set_Etype (P, Standard_Void_Type); 1802 else 1803 Analyze (P); 1804 end if; 1805 1806 -- If this is a call of the form Obj.Op, the call may have been analyzed 1807 -- and possibly rewritten into a block, in which case we are done. 1808 1809 if Analyzed (N) then 1810 return; 1811 1812 -- If there is an error analyzing the name (which may have been 1813 -- rewritten if the original call was in prefix notation) then error 1814 -- has been emitted already, mark node and return. 1815 1816 elsif Error_Posted (N) or else Etype (Name (N)) = Any_Type then 1817 Set_Etype (N, Any_Type); 1818 return; 1819 end if; 1820 1821 -- A procedure call is Ghost when its name denotes a Ghost procedure. 1822 -- Set the mode now to ensure that any nodes generated during analysis 1823 -- and expansion are properly marked as Ghost. 1824 1825 Mark_And_Set_Ghost_Procedure_Call (N); 1826 1827 -- Otherwise analyze the parameters 1828 1829 if Present (Actuals) then 1830 Actual := First (Actuals); 1831 1832 while Present (Actual) loop 1833 Analyze (Actual); 1834 Check_Parameterless_Call (Actual); 1835 Next (Actual); 1836 end loop; 1837 end if; 1838 1839 -- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls 1840 1841 if Nkind (P) = N_Attribute_Reference 1842 and then Nam_In (Attribute_Name (P), Name_Elab_Spec, 1843 Name_Elab_Body, 1844 Name_Elab_Subp_Body) 1845 then 1846 if Present (Actuals) then 1847 Error_Msg_N 1848 ("no parameters allowed for this call", First (Actuals)); 1849 goto Leave; 1850 end if; 1851 1852 Set_Etype (N, Standard_Void_Type); 1853 Set_Analyzed (N); 1854 1855 elsif Is_Entity_Name (P) 1856 and then Is_Record_Type (Etype (Entity (P))) 1857 and then Remote_AST_I_Dereference (P) 1858 then 1859 goto Leave; 1860 1861 elsif Is_Entity_Name (P) 1862 and then Ekind (Entity (P)) /= E_Entry_Family 1863 then 1864 if Is_Access_Type (Etype (P)) 1865 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type 1866 and then No (Actuals) 1867 and then Comes_From_Source (N) 1868 then 1869 Error_Msg_N ("missing explicit dereference in call", N); 1870 end if; 1871 1872 Analyze_Call_And_Resolve; 1873 1874 -- If the prefix is the simple name of an entry family, this is a 1875 -- parameterless call from within the task body itself. 1876 1877 elsif Is_Entity_Name (P) 1878 and then Nkind (P) = N_Identifier 1879 and then Ekind (Entity (P)) = E_Entry_Family 1880 and then Present (Actuals) 1881 and then No (Next (First (Actuals))) 1882 then 1883 -- Can be call to parameterless entry family. What appears to be the 1884 -- sole argument is in fact the entry index. Rewrite prefix of node 1885 -- accordingly. Source representation is unchanged by this 1886 -- transformation. 1887 1888 New_N := 1889 Make_Indexed_Component (Loc, 1890 Prefix => 1891 Make_Selected_Component (Loc, 1892 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc), 1893 Selector_Name => New_Occurrence_Of (Entity (P), Loc)), 1894 Expressions => Actuals); 1895 Set_Name (N, New_N); 1896 Set_Etype (New_N, Standard_Void_Type); 1897 Set_Parameter_Associations (N, No_List); 1898 Analyze_Call_And_Resolve; 1899 1900 elsif Nkind (P) = N_Explicit_Dereference then 1901 if Ekind (Etype (P)) = E_Subprogram_Type then 1902 Analyze_Call_And_Resolve; 1903 else 1904 Error_Msg_N ("expect access to procedure in call", P); 1905 end if; 1906 1907 -- The name can be a selected component or an indexed component that 1908 -- yields an access to subprogram. Such a prefix is legal if the call 1909 -- has parameter associations. 1910 1911 elsif Is_Access_Type (Etype (P)) 1912 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type 1913 then 1914 if Present (Actuals) then 1915 Analyze_Call_And_Resolve; 1916 else 1917 Error_Msg_N ("missing explicit dereference in call ", N); 1918 end if; 1919 1920 -- If not an access to subprogram, then the prefix must resolve to the 1921 -- name of an entry, entry family, or protected operation. 1922 1923 -- For the case of a simple entry call, P is a selected component where 1924 -- the prefix is the task and the selector name is the entry. A call to 1925 -- a protected procedure will have the same syntax. If the protected 1926 -- object contains overloaded operations, the entity may appear as a 1927 -- function, the context will select the operation whose type is Void. 1928 1929 elsif Nkind (P) = N_Selected_Component 1930 and then Ekind_In (Entity (Selector_Name (P)), E_Entry, 1931 E_Function, 1932 E_Procedure) 1933 then 1934 -- When front-end inlining is enabled, as with SPARK_Mode, a call 1935 -- in prefix notation may still be missing its controlling argument, 1936 -- so perform the transformation now. 1937 1938 if SPARK_Mode = On and then In_Inlined_Body then 1939 declare 1940 Subp : constant Entity_Id := Entity (Selector_Name (P)); 1941 Typ : constant Entity_Id := Etype (Prefix (P)); 1942 1943 begin 1944 if Is_Tagged_Type (Typ) 1945 and then Present (First_Formal (Subp)) 1946 and then (Etype (First_Formal (Subp)) = Typ 1947 or else 1948 Class_Wide_Type (Etype (First_Formal (Subp))) = Typ) 1949 and then Try_Object_Operation (P) 1950 then 1951 return; 1952 1953 else 1954 Analyze_Call_And_Resolve; 1955 end if; 1956 end; 1957 1958 else 1959 Analyze_Call_And_Resolve; 1960 end if; 1961 1962 elsif Nkind (P) = N_Selected_Component 1963 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family 1964 and then Present (Actuals) 1965 and then No (Next (First (Actuals))) 1966 then 1967 -- Can be call to parameterless entry family. What appears to be the 1968 -- sole argument is in fact the entry index. Rewrite prefix of node 1969 -- accordingly. Source representation is unchanged by this 1970 -- transformation. 1971 1972 New_N := 1973 Make_Indexed_Component (Loc, 1974 Prefix => New_Copy (P), 1975 Expressions => Actuals); 1976 Set_Name (N, New_N); 1977 Set_Etype (New_N, Standard_Void_Type); 1978 Set_Parameter_Associations (N, No_List); 1979 Analyze_Call_And_Resolve; 1980 1981 -- For the case of a reference to an element of an entry family, P is 1982 -- an indexed component whose prefix is a selected component (task and 1983 -- entry family), and whose index is the entry family index. 1984 1985 elsif Nkind (P) = N_Indexed_Component 1986 and then Nkind (Prefix (P)) = N_Selected_Component 1987 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family 1988 then 1989 Analyze_Call_And_Resolve; 1990 1991 -- If the prefix is the name of an entry family, it is a call from 1992 -- within the task body itself. 1993 1994 elsif Nkind (P) = N_Indexed_Component 1995 and then Nkind (Prefix (P)) = N_Identifier 1996 and then Ekind (Entity (Prefix (P))) = E_Entry_Family 1997 then 1998 New_N := 1999 Make_Selected_Component (Loc, 2000 Prefix => 2001 New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc), 2002 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc)); 2003 Rewrite (Prefix (P), New_N); 2004 Analyze (P); 2005 Analyze_Call_And_Resolve; 2006 2007 -- In Ada 2012. a qualified expression is a name, but it cannot be a 2008 -- procedure name, so the construct can only be a qualified expression. 2009 2010 elsif Nkind (P) = N_Qualified_Expression 2011 and then Ada_Version >= Ada_2012 2012 then 2013 Rewrite (N, Make_Code_Statement (Loc, Expression => P)); 2014 Analyze (N); 2015 2016 -- Anything else is an error 2017 2018 else 2019 Error_Msg_N ("invalid procedure or entry call", N); 2020 end if; 2021 2022 <<Leave>> 2023 Restore_Ghost_Region (Saved_GM, Saved_IGR); 2024 end Analyze_Procedure_Call; 2025 2026 ------------------------------ 2027 -- Analyze_Return_Statement -- 2028 ------------------------------ 2029 2030 procedure Analyze_Return_Statement (N : Node_Id) is 2031 pragma Assert (Nkind_In (N, N_Extended_Return_Statement, 2032 N_Simple_Return_Statement)); 2033 2034 Returns_Object : constant Boolean := 2035 Nkind (N) = N_Extended_Return_Statement 2036 or else 2037 (Nkind (N) = N_Simple_Return_Statement 2038 and then Present (Expression (N))); 2039 -- True if we're returning something; that is, "return <expression>;" 2040 -- or "return Result : T [:= ...]". False for "return;". Used for error 2041 -- checking: If Returns_Object is True, N should apply to a function 2042 -- body; otherwise N should apply to a procedure body, entry body, 2043 -- accept statement, or extended return statement. 2044 2045 function Find_What_It_Applies_To return Entity_Id; 2046 -- Find the entity representing the innermost enclosing body, accept 2047 -- statement, or extended return statement. If the result is a callable 2048 -- construct or extended return statement, then this will be the value 2049 -- of the Return_Applies_To attribute. Otherwise, the program is 2050 -- illegal. See RM-6.5(4/2). 2051 2052 ----------------------------- 2053 -- Find_What_It_Applies_To -- 2054 ----------------------------- 2055 2056 function Find_What_It_Applies_To return Entity_Id is 2057 Result : Entity_Id := Empty; 2058 2059 begin 2060 -- Loop outward through the Scope_Stack, skipping blocks, loops, 2061 -- and postconditions. 2062 2063 for J in reverse 0 .. Scope_Stack.Last loop 2064 Result := Scope_Stack.Table (J).Entity; 2065 exit when not Ekind_In (Result, E_Block, E_Loop) 2066 and then Chars (Result) /= Name_uPostconditions; 2067 end loop; 2068 2069 pragma Assert (Present (Result)); 2070 return Result; 2071 end Find_What_It_Applies_To; 2072 2073 -- Local declarations 2074 2075 Scope_Id : constant Entity_Id := Find_What_It_Applies_To; 2076 Kind : constant Entity_Kind := Ekind (Scope_Id); 2077 Loc : constant Source_Ptr := Sloc (N); 2078 Stm_Entity : constant Entity_Id := 2079 New_Internal_Entity 2080 (E_Return_Statement, Current_Scope, Loc, 'R'); 2081 2082 -- Start of processing for Analyze_Return_Statement 2083 2084 begin 2085 Set_Return_Statement_Entity (N, Stm_Entity); 2086 2087 Set_Etype (Stm_Entity, Standard_Void_Type); 2088 Set_Return_Applies_To (Stm_Entity, Scope_Id); 2089 2090 -- Place Return entity on scope stack, to simplify enforcement of 6.5 2091 -- (4/2): an inner return statement will apply to this extended return. 2092 2093 if Nkind (N) = N_Extended_Return_Statement then 2094 Push_Scope (Stm_Entity); 2095 end if; 2096 2097 -- Check that pragma No_Return is obeyed. Don't complain about the 2098 -- implicitly-generated return that is placed at the end. 2099 2100 if No_Return (Scope_Id) and then Comes_From_Source (N) then 2101 Error_Msg_N ("RETURN statement not allowed (No_Return)", N); 2102 end if; 2103 2104 -- Warn on any unassigned OUT parameters if in procedure 2105 2106 if Ekind (Scope_Id) = E_Procedure then 2107 Warn_On_Unassigned_Out_Parameter (N, Scope_Id); 2108 end if; 2109 2110 -- Check that functions return objects, and other things do not 2111 2112 if Kind = E_Function or else Kind = E_Generic_Function then 2113 if not Returns_Object then 2114 Error_Msg_N ("missing expression in return from function", N); 2115 end if; 2116 2117 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then 2118 if Returns_Object then 2119 Error_Msg_N ("procedure cannot return value (use function)", N); 2120 end if; 2121 2122 elsif Kind = E_Entry or else Kind = E_Entry_Family then 2123 if Returns_Object then 2124 if Is_Protected_Type (Scope (Scope_Id)) then 2125 Error_Msg_N ("entry body cannot return value", N); 2126 else 2127 Error_Msg_N ("accept statement cannot return value", N); 2128 end if; 2129 end if; 2130 2131 elsif Kind = E_Return_Statement then 2132 2133 -- We are nested within another return statement, which must be an 2134 -- extended_return_statement. 2135 2136 if Returns_Object then 2137 if Nkind (N) = N_Extended_Return_Statement then 2138 Error_Msg_N 2139 ("extended return statement cannot be nested (use `RETURN;`)", 2140 N); 2141 2142 -- Case of a simple return statement with a value inside extended 2143 -- return statement. 2144 2145 else 2146 Error_Msg_N 2147 ("return nested in extended return statement cannot return " 2148 & "value (use `RETURN;`)", N); 2149 end if; 2150 end if; 2151 2152 else 2153 Error_Msg_N ("illegal context for return statement", N); 2154 end if; 2155 2156 if Ekind_In (Kind, E_Function, E_Generic_Function) then 2157 Analyze_Function_Return (N); 2158 2159 elsif Ekind_In (Kind, E_Procedure, E_Generic_Procedure) then 2160 Set_Return_Present (Scope_Id); 2161 end if; 2162 2163 if Nkind (N) = N_Extended_Return_Statement then 2164 End_Scope; 2165 end if; 2166 2167 Kill_Current_Values (Last_Assignment_Only => True); 2168 Check_Unreachable_Code (N); 2169 2170 Analyze_Dimension (N); 2171 end Analyze_Return_Statement; 2172 2173 ------------------------------------- 2174 -- Analyze_Simple_Return_Statement -- 2175 ------------------------------------- 2176 2177 procedure Analyze_Simple_Return_Statement (N : Node_Id) is 2178 begin 2179 if Present (Expression (N)) then 2180 Mark_Coextensions (N, Expression (N)); 2181 end if; 2182 2183 Analyze_Return_Statement (N); 2184 end Analyze_Simple_Return_Statement; 2185 2186 ------------------------- 2187 -- Analyze_Return_Type -- 2188 ------------------------- 2189 2190 procedure Analyze_Return_Type (N : Node_Id) is 2191 Designator : constant Entity_Id := Defining_Entity (N); 2192 Typ : Entity_Id := Empty; 2193 2194 begin 2195 -- Normal case where result definition does not indicate an error 2196 2197 if Result_Definition (N) /= Error then 2198 if Nkind (Result_Definition (N)) = N_Access_Definition then 2199 Check_SPARK_05_Restriction 2200 ("access result is not allowed", Result_Definition (N)); 2201 2202 -- Ada 2005 (AI-254): Handle anonymous access to subprograms 2203 2204 declare 2205 AD : constant Node_Id := 2206 Access_To_Subprogram_Definition (Result_Definition (N)); 2207 begin 2208 if Present (AD) and then Protected_Present (AD) then 2209 Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N); 2210 else 2211 Typ := Access_Definition (N, Result_Definition (N)); 2212 end if; 2213 end; 2214 2215 Set_Parent (Typ, Result_Definition (N)); 2216 Set_Is_Local_Anonymous_Access (Typ); 2217 Set_Etype (Designator, Typ); 2218 2219 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion 2220 2221 Null_Exclusion_Static_Checks (N); 2222 2223 -- Subtype_Mark case 2224 2225 else 2226 Find_Type (Result_Definition (N)); 2227 Typ := Entity (Result_Definition (N)); 2228 Set_Etype (Designator, Typ); 2229 2230 -- Unconstrained array as result is not allowed in SPARK 2231 2232 if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then 2233 Check_SPARK_05_Restriction 2234 ("returning an unconstrained array is not allowed", 2235 Result_Definition (N)); 2236 end if; 2237 2238 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion 2239 2240 Null_Exclusion_Static_Checks (N); 2241 2242 -- If a null exclusion is imposed on the result type, then create 2243 -- a null-excluding itype (an access subtype) and use it as the 2244 -- function's Etype. Note that the null exclusion checks are done 2245 -- right before this, because they don't get applied to types that 2246 -- do not come from source. 2247 2248 if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then 2249 Set_Etype (Designator, 2250 Create_Null_Excluding_Itype 2251 (T => Typ, 2252 Related_Nod => N, 2253 Scope_Id => Scope (Current_Scope))); 2254 2255 -- The new subtype must be elaborated before use because 2256 -- it is visible outside of the function. However its base 2257 -- type may not be frozen yet, so the reference that will 2258 -- force elaboration must be attached to the freezing of 2259 -- the base type. 2260 2261 -- If the return specification appears on a proper body, 2262 -- the subtype will have been created already on the spec. 2263 2264 if Is_Frozen (Typ) then 2265 if Nkind (Parent (N)) = N_Subprogram_Body 2266 and then Nkind (Parent (Parent (N))) = N_Subunit 2267 then 2268 null; 2269 else 2270 Build_Itype_Reference (Etype (Designator), Parent (N)); 2271 end if; 2272 2273 else 2274 Ensure_Freeze_Node (Typ); 2275 2276 declare 2277 IR : constant Node_Id := Make_Itype_Reference (Sloc (N)); 2278 begin 2279 Set_Itype (IR, Etype (Designator)); 2280 Append_Freeze_Actions (Typ, New_List (IR)); 2281 end; 2282 end if; 2283 2284 else 2285 Set_Etype (Designator, Typ); 2286 end if; 2287 2288 if Ekind (Typ) = E_Incomplete_Type 2289 or else (Is_Class_Wide_Type (Typ) 2290 and then Ekind (Root_Type (Typ)) = E_Incomplete_Type) 2291 then 2292 -- AI05-0151: Tagged incomplete types are allowed in all formal 2293 -- parts. Untagged incomplete types are not allowed in bodies. 2294 -- As a consequence, limited views cannot appear in a basic 2295 -- declaration that is itself within a body, because there is 2296 -- no point at which the non-limited view will become visible. 2297 2298 if Ada_Version >= Ada_2012 then 2299 if From_Limited_With (Typ) and then In_Package_Body then 2300 Error_Msg_NE 2301 ("invalid use of incomplete type&", 2302 Result_Definition (N), Typ); 2303 2304 -- The return type of a subprogram body cannot be of a 2305 -- formal incomplete type. 2306 2307 elsif Is_Generic_Type (Typ) 2308 and then Nkind (Parent (N)) = N_Subprogram_Body 2309 then 2310 Error_Msg_N 2311 ("return type cannot be a formal incomplete type", 2312 Result_Definition (N)); 2313 2314 elsif Is_Class_Wide_Type (Typ) 2315 and then Is_Generic_Type (Root_Type (Typ)) 2316 and then Nkind (Parent (N)) = N_Subprogram_Body 2317 then 2318 Error_Msg_N 2319 ("return type cannot be a formal incomplete type", 2320 Result_Definition (N)); 2321 2322 elsif Is_Tagged_Type (Typ) then 2323 null; 2324 2325 -- Use is legal in a thunk generated for an operation 2326 -- inherited from a progenitor. 2327 2328 elsif Is_Thunk (Designator) 2329 and then Present (Non_Limited_View (Typ)) 2330 then 2331 null; 2332 2333 elsif Nkind (Parent (N)) = N_Subprogram_Body 2334 or else Nkind_In (Parent (Parent (N)), N_Accept_Statement, 2335 N_Entry_Body) 2336 then 2337 Error_Msg_NE 2338 ("invalid use of untagged incomplete type&", 2339 Designator, Typ); 2340 end if; 2341 2342 -- The type must be completed in the current package. This 2343 -- is checked at the end of the package declaration when 2344 -- Taft-amendment types are identified. If the return type 2345 -- is class-wide, there is no required check, the type can 2346 -- be a bona fide TAT. 2347 2348 if Ekind (Scope (Current_Scope)) = E_Package 2349 and then In_Private_Part (Scope (Current_Scope)) 2350 and then not Is_Class_Wide_Type (Typ) 2351 then 2352 Append_Elmt (Designator, Private_Dependents (Typ)); 2353 end if; 2354 2355 else 2356 Error_Msg_NE 2357 ("invalid use of incomplete type&", Designator, Typ); 2358 end if; 2359 end if; 2360 end if; 2361 2362 -- Case where result definition does indicate an error 2363 2364 else 2365 Set_Etype (Designator, Any_Type); 2366 end if; 2367 end Analyze_Return_Type; 2368 2369 ----------------------------- 2370 -- Analyze_Subprogram_Body -- 2371 ----------------------------- 2372 2373 procedure Analyze_Subprogram_Body (N : Node_Id) is 2374 Loc : constant Source_Ptr := Sloc (N); 2375 Body_Spec : constant Node_Id := Specification (N); 2376 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec); 2377 2378 begin 2379 if Debug_Flag_C then 2380 Write_Str ("==> subprogram body "); 2381 Write_Name (Chars (Body_Id)); 2382 Write_Str (" from "); 2383 Write_Location (Loc); 2384 Write_Eol; 2385 Indent; 2386 end if; 2387 2388 Trace_Scope (N, Body_Id, " Analyze subprogram: "); 2389 2390 -- The real work is split out into the helper, so it can do "return;" 2391 -- without skipping the debug output: 2392 2393 Analyze_Subprogram_Body_Helper (N); 2394 2395 if Debug_Flag_C then 2396 Outdent; 2397 Write_Str ("<== subprogram body "); 2398 Write_Name (Chars (Body_Id)); 2399 Write_Str (" from "); 2400 Write_Location (Loc); 2401 Write_Eol; 2402 end if; 2403 end Analyze_Subprogram_Body; 2404 2405 ------------------------------------ 2406 -- Analyze_Subprogram_Body_Helper -- 2407 ------------------------------------ 2408 2409 -- This procedure is called for regular subprogram bodies, generic bodies, 2410 -- and for subprogram stubs of both kinds. In the case of stubs, only the 2411 -- specification matters, and is used to create a proper declaration for 2412 -- the subprogram, or to perform conformance checks. 2413 2414 -- WARNING: This routine manages Ghost regions. Return statements must be 2415 -- replaced by gotos that jump to the end of the routine and restore the 2416 -- Ghost mode. 2417 2418 procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is 2419 Body_Spec : Node_Id := Specification (N); 2420 Body_Id : Entity_Id := Defining_Entity (Body_Spec); 2421 Loc : constant Source_Ptr := Sloc (N); 2422 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id); 2423 2424 Conformant : Boolean; 2425 Desig_View : Entity_Id := Empty; 2426 Exch_Views : Elist_Id := No_Elist; 2427 HSS : Node_Id; 2428 Mask_Types : Elist_Id := No_Elist; 2429 Prot_Typ : Entity_Id := Empty; 2430 Spec_Decl : Node_Id := Empty; 2431 Spec_Id : Entity_Id; 2432 2433 Last_Real_Spec_Entity : Entity_Id := Empty; 2434 -- When we analyze a separate spec, the entity chain ends up containing 2435 -- the formals, as well as any itypes generated during analysis of the 2436 -- default expressions for parameters, or the arguments of associated 2437 -- precondition/postcondition pragmas (which are analyzed in the context 2438 -- of the spec since they have visibility on formals). 2439 -- 2440 -- These entities belong with the spec and not the body. However we do 2441 -- the analysis of the body in the context of the spec (again to obtain 2442 -- visibility to the formals), and all the entities generated during 2443 -- this analysis end up also chained to the entity chain of the spec. 2444 -- But they really belong to the body, and there is circuitry to move 2445 -- them from the spec to the body. 2446 -- 2447 -- However, when we do this move, we don't want to move the real spec 2448 -- entities (first para above) to the body. The Last_Real_Spec_Entity 2449 -- variable points to the last real spec entity, so we only move those 2450 -- chained beyond that point. It is initialized to Empty to deal with 2451 -- the case where there is no separate spec. 2452 2453 function Body_Has_Contract return Boolean; 2454 -- Check whether unanalyzed body has an aspect or pragma that may 2455 -- generate a SPARK contract. 2456 2457 function Body_Has_SPARK_Mode_On return Boolean; 2458 -- Check whether SPARK_Mode On applies to the subprogram body, either 2459 -- because it is specified directly on the body, or because it is 2460 -- inherited from the enclosing subprogram or package. 2461 2462 procedure Build_Subprogram_Declaration; 2463 -- Create a matching subprogram declaration for subprogram body N 2464 2465 procedure Check_Anonymous_Return; 2466 -- Ada 2005: if a function returns an access type that denotes a task, 2467 -- or a type that contains tasks, we must create a master entity for 2468 -- the anonymous type, which typically will be used in an allocator 2469 -- in the body of the function. 2470 2471 procedure Check_Inline_Pragma (Spec : in out Node_Id); 2472 -- Look ahead to recognize a pragma that may appear after the body. 2473 -- If there is a previous spec, check that it appears in the same 2474 -- declarative part. If the pragma is Inline_Always, perform inlining 2475 -- unconditionally, otherwise only if Front_End_Inlining is requested. 2476 -- If the body acts as a spec, and inlining is required, we create a 2477 -- subprogram declaration for it, in order to attach the body to inline. 2478 -- If pragma does not appear after the body, check whether there is 2479 -- an inline pragma before any local declarations. 2480 2481 procedure Check_Missing_Return; 2482 -- Checks for a function with a no return statements, and also performs 2483 -- the warning checks implemented by Check_Returns. In formal mode, also 2484 -- verify that a function ends with a RETURN and that a procedure does 2485 -- not contain any RETURN. 2486 2487 function Disambiguate_Spec return Entity_Id; 2488 -- When a primitive is declared between the private view and the full 2489 -- view of a concurrent type which implements an interface, a special 2490 -- mechanism is used to find the corresponding spec of the primitive 2491 -- body. 2492 2493 function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id; 2494 -- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains 2495 -- incomplete types coming from a limited context and replace their 2496 -- limited views with the non-limited ones. Return the list of changes 2497 -- to be used to undo the transformation. 2498 2499 function Is_Private_Concurrent_Primitive 2500 (Subp_Id : Entity_Id) return Boolean; 2501 -- Determine whether subprogram Subp_Id is a primitive of a concurrent 2502 -- type that implements an interface and has a private view. 2503 2504 function Mask_Unfrozen_Types (Spec_Id : Entity_Id) return Elist_Id; 2505 -- N is the body generated for an expression function that is not a 2506 -- completion and Spec_Id the defining entity of its spec. Mark all 2507 -- the not-yet-frozen types referenced by the simple return statement 2508 -- of the function as formally frozen. 2509 2510 procedure Restore_Limited_Views (Restore_List : Elist_Id); 2511 -- Undo the transformation done by Exchange_Limited_Views. 2512 2513 procedure Set_Trivial_Subprogram (N : Node_Id); 2514 -- Sets the Is_Trivial_Subprogram flag in both spec and body of the 2515 -- subprogram whose body is being analyzed. N is the statement node 2516 -- causing the flag to be set, if the following statement is a return 2517 -- of an entity, we mark the entity as set in source to suppress any 2518 -- warning on the stylized use of function stubs with a dummy return. 2519 2520 procedure Unmask_Unfrozen_Types (Unmask_List : Elist_Id); 2521 -- Undo the transformation done by Mask_Unfrozen_Types 2522 2523 procedure Verify_Overriding_Indicator; 2524 -- If there was a previous spec, the entity has been entered in the 2525 -- current scope previously. If the body itself carries an overriding 2526 -- indicator, check that it is consistent with the known status of the 2527 -- entity. 2528 2529 ----------------------- 2530 -- Body_Has_Contract -- 2531 ----------------------- 2532 2533 function Body_Has_Contract return Boolean is 2534 Decls : constant List_Id := Declarations (N); 2535 Item : Node_Id; 2536 2537 begin 2538 -- Check for aspects that may generate a contract 2539 2540 if Present (Aspect_Specifications (N)) then 2541 Item := First (Aspect_Specifications (N)); 2542 while Present (Item) loop 2543 if Is_Subprogram_Contract_Annotation (Item) then 2544 return True; 2545 end if; 2546 2547 Next (Item); 2548 end loop; 2549 end if; 2550 2551 -- Check for pragmas that may generate a contract 2552 2553 if Present (Decls) then 2554 Item := First (Decls); 2555 while Present (Item) loop 2556 if Nkind (Item) = N_Pragma 2557 and then Is_Subprogram_Contract_Annotation (Item) 2558 then 2559 return True; 2560 end if; 2561 2562 Next (Item); 2563 end loop; 2564 end if; 2565 2566 return False; 2567 end Body_Has_Contract; 2568 2569 ---------------------------- 2570 -- Body_Has_SPARK_Mode_On -- 2571 ---------------------------- 2572 2573 function Body_Has_SPARK_Mode_On return Boolean is 2574 Decls : constant List_Id := Declarations (N); 2575 Item : Node_Id; 2576 2577 begin 2578 -- Check for SPARK_Mode aspect 2579 2580 if Present (Aspect_Specifications (N)) then 2581 Item := First (Aspect_Specifications (N)); 2582 while Present (Item) loop 2583 if Get_Aspect_Id (Item) = Aspect_SPARK_Mode then 2584 return Get_SPARK_Mode_From_Annotation (Item) = On; 2585 end if; 2586 2587 Next (Item); 2588 end loop; 2589 end if; 2590 2591 -- Check for SPARK_Mode pragma 2592 2593 if Present (Decls) then 2594 Item := First (Decls); 2595 while Present (Item) loop 2596 2597 -- Pragmas that apply to a subprogram body are usually grouped 2598 -- together. Look for a potential pragma SPARK_Mode among them. 2599 2600 if Nkind (Item) = N_Pragma then 2601 if Get_Pragma_Id (Item) = Pragma_SPARK_Mode then 2602 return Get_SPARK_Mode_From_Annotation (Item) = On; 2603 end if; 2604 2605 -- Otherwise the first non-pragma declarative item terminates 2606 -- the region where pragma SPARK_Mode may appear. 2607 2608 else 2609 exit; 2610 end if; 2611 2612 Next (Item); 2613 end loop; 2614 end if; 2615 2616 -- Otherwise, the applicable SPARK_Mode is inherited from the 2617 -- enclosing subprogram or package. 2618 2619 return SPARK_Mode = On; 2620 end Body_Has_SPARK_Mode_On; 2621 2622 ---------------------------------- 2623 -- Build_Subprogram_Declaration -- 2624 ---------------------------------- 2625 2626 procedure Build_Subprogram_Declaration is 2627 procedure Move_Pragmas (From : Node_Id; To : Node_Id); 2628 -- Relocate certain categorization pragmas from the declarative list 2629 -- of subprogram body From and insert them after node To. The pragmas 2630 -- in question are: 2631 -- Ghost 2632 -- Volatile_Function 2633 -- Also copy pragma SPARK_Mode if present in the declarative list 2634 -- of subprogram body From and insert it after node To. This pragma 2635 -- should not be moved, as it applies to the body too. 2636 2637 ------------------ 2638 -- Move_Pragmas -- 2639 ------------------ 2640 2641 procedure Move_Pragmas (From : Node_Id; To : Node_Id) is 2642 Decl : Node_Id; 2643 Next_Decl : Node_Id; 2644 2645 begin 2646 pragma Assert (Nkind (From) = N_Subprogram_Body); 2647 2648 -- The destination node must be part of a list, as the pragmas are 2649 -- inserted after it. 2650 2651 pragma Assert (Is_List_Member (To)); 2652 2653 -- Inspect the declarations of the subprogram body looking for 2654 -- specific pragmas. 2655 2656 Decl := First (Declarations (N)); 2657 while Present (Decl) loop 2658 Next_Decl := Next (Decl); 2659 2660 if Nkind (Decl) = N_Pragma then 2661 if Pragma_Name_Unmapped (Decl) = Name_SPARK_Mode then 2662 Insert_After (To, New_Copy_Tree (Decl)); 2663 2664 elsif Nam_In (Pragma_Name_Unmapped (Decl), 2665 Name_Ghost, 2666 Name_Volatile_Function) 2667 then 2668 Remove (Decl); 2669 Insert_After (To, Decl); 2670 end if; 2671 end if; 2672 2673 Decl := Next_Decl; 2674 end loop; 2675 end Move_Pragmas; 2676 2677 -- Local variables 2678 2679 Decl : Node_Id; 2680 Subp_Decl : Node_Id; 2681 2682 -- Start of processing for Build_Subprogram_Declaration 2683 2684 begin 2685 -- Create a matching subprogram spec using the profile of the body. 2686 -- The structure of the tree is identical, but has new entities for 2687 -- the defining unit name and formal parameters. 2688 2689 Subp_Decl := 2690 Make_Subprogram_Declaration (Loc, 2691 Specification => Copy_Subprogram_Spec (Body_Spec)); 2692 Set_Comes_From_Source (Subp_Decl, True); 2693 2694 -- Also mark parameters as coming from source 2695 2696 if Present (Parameter_Specifications (Specification (Subp_Decl))) then 2697 declare 2698 Form : Entity_Id; 2699 begin 2700 Form := 2701 First (Parameter_Specifications (Specification (Subp_Decl))); 2702 2703 while Present (Form) loop 2704 Set_Comes_From_Source (Defining_Identifier (Form), True); 2705 Next (Form); 2706 end loop; 2707 end; 2708 end if; 2709 2710 -- Relocate the aspects and relevant pragmas from the subprogram body 2711 -- to the generated spec because it acts as the initial declaration. 2712 2713 Insert_Before (N, Subp_Decl); 2714 Move_Aspects (N, To => Subp_Decl); 2715 Move_Pragmas (N, To => Subp_Decl); 2716 2717 -- Ensure that the generated corresponding spec and original body 2718 -- share the same SPARK_Mode pragma or aspect. As a result, both have 2719 -- the same SPARK_Mode attributes, and the global SPARK_Mode value is 2720 -- correctly set for local subprograms. 2721 2722 Copy_SPARK_Mode_Aspect (Subp_Decl, To => N); 2723 2724 Analyze (Subp_Decl); 2725 2726 -- Propagate the attributes Rewritten_For_C and Corresponding_Proc to 2727 -- the body since the expander may generate calls using that entity. 2728 -- Required to ensure that Expand_Call rewrites calls to this 2729 -- function by calls to the built procedure. 2730 2731 if Modify_Tree_For_C 2732 and then Nkind (Body_Spec) = N_Function_Specification 2733 and then 2734 Rewritten_For_C (Defining_Entity (Specification (Subp_Decl))) 2735 then 2736 Set_Rewritten_For_C (Defining_Entity (Body_Spec)); 2737 Set_Corresponding_Procedure (Defining_Entity (Body_Spec), 2738 Corresponding_Procedure 2739 (Defining_Entity (Specification (Subp_Decl)))); 2740 end if; 2741 2742 -- Analyze any relocated source pragmas or pragmas created for aspect 2743 -- specifications. 2744 2745 Decl := Next (Subp_Decl); 2746 while Present (Decl) loop 2747 2748 -- Stop the search for pragmas once the body has been reached as 2749 -- this terminates the region where pragmas may appear. 2750 2751 if Decl = N then 2752 exit; 2753 2754 elsif Nkind (Decl) = N_Pragma then 2755 Analyze (Decl); 2756 end if; 2757 2758 Next (Decl); 2759 end loop; 2760 2761 Spec_Id := Defining_Entity (Subp_Decl); 2762 Set_Corresponding_Spec (N, Spec_Id); 2763 2764 -- Mark the generated spec as a source construct to ensure that all 2765 -- calls to it are properly registered in ALI files for GNATprove. 2766 2767 Set_Comes_From_Source (Spec_Id, True); 2768 2769 -- Ensure that the specs of the subprogram declaration and its body 2770 -- are identical, otherwise they will appear non-conformant due to 2771 -- rewritings in the default values of formal parameters. 2772 2773 Body_Spec := Copy_Subprogram_Spec (Body_Spec); 2774 Set_Specification (N, Body_Spec); 2775 Body_Id := Analyze_Subprogram_Specification (Body_Spec); 2776 end Build_Subprogram_Declaration; 2777 2778 ---------------------------- 2779 -- Check_Anonymous_Return -- 2780 ---------------------------- 2781 2782 procedure Check_Anonymous_Return is 2783 Decl : Node_Id; 2784 Par : Node_Id; 2785 Scop : Entity_Id; 2786 2787 begin 2788 if Present (Spec_Id) then 2789 Scop := Spec_Id; 2790 else 2791 Scop := Body_Id; 2792 end if; 2793 2794 if Ekind (Scop) = E_Function 2795 and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type 2796 and then not Is_Thunk (Scop) 2797 2798 -- Skip internally built functions which handle the case of 2799 -- a null access (see Expand_Interface_Conversion) 2800 2801 and then not (Is_Interface (Designated_Type (Etype (Scop))) 2802 and then not Comes_From_Source (Parent (Scop))) 2803 2804 and then (Has_Task (Designated_Type (Etype (Scop))) 2805 or else 2806 (Is_Class_Wide_Type (Designated_Type (Etype (Scop))) 2807 and then 2808 Is_Limited_Record (Designated_Type (Etype (Scop))))) 2809 and then Expander_Active 2810 2811 -- Avoid cases with no tasking support 2812 2813 and then RTE_Available (RE_Current_Master) 2814 and then not Restriction_Active (No_Task_Hierarchy) 2815 then 2816 Decl := 2817 Make_Object_Declaration (Loc, 2818 Defining_Identifier => 2819 Make_Defining_Identifier (Loc, Name_uMaster), 2820 Constant_Present => True, 2821 Object_Definition => 2822 New_Occurrence_Of (RTE (RE_Master_Id), Loc), 2823 Expression => 2824 Make_Explicit_Dereference (Loc, 2825 New_Occurrence_Of (RTE (RE_Current_Master), Loc))); 2826 2827 if Present (Declarations (N)) then 2828 Prepend (Decl, Declarations (N)); 2829 else 2830 Set_Declarations (N, New_List (Decl)); 2831 end if; 2832 2833 Set_Master_Id (Etype (Scop), Defining_Identifier (Decl)); 2834 Set_Has_Master_Entity (Scop); 2835 2836 -- Now mark the containing scope as a task master 2837 2838 Par := N; 2839 while Nkind (Par) /= N_Compilation_Unit loop 2840 Par := Parent (Par); 2841 pragma Assert (Present (Par)); 2842 2843 -- If we fall off the top, we are at the outer level, and 2844 -- the environment task is our effective master, so nothing 2845 -- to mark. 2846 2847 if Nkind_In 2848 (Par, N_Task_Body, N_Block_Statement, N_Subprogram_Body) 2849 then 2850 Set_Is_Task_Master (Par, True); 2851 exit; 2852 end if; 2853 end loop; 2854 end if; 2855 end Check_Anonymous_Return; 2856 2857 ------------------------- 2858 -- Check_Inline_Pragma -- 2859 ------------------------- 2860 2861 procedure Check_Inline_Pragma (Spec : in out Node_Id) is 2862 Prag : Node_Id; 2863 Plist : List_Id; 2864 2865 function Is_Inline_Pragma (N : Node_Id) return Boolean; 2866 -- True when N is a pragma Inline or Inline_Always that applies 2867 -- to this subprogram. 2868 2869 ----------------------- 2870 -- Is_Inline_Pragma -- 2871 ----------------------- 2872 2873 function Is_Inline_Pragma (N : Node_Id) return Boolean is 2874 begin 2875 if Nkind (N) = N_Pragma 2876 and then 2877 (Pragma_Name_Unmapped (N) = Name_Inline_Always 2878 or else (Pragma_Name_Unmapped (N) = Name_Inline 2879 and then 2880 (Front_End_Inlining or else Optimization_Level > 0))) 2881 and then Present (Pragma_Argument_Associations (N)) 2882 then 2883 declare 2884 Pragma_Arg : Node_Id := 2885 Expression (First (Pragma_Argument_Associations (N))); 2886 begin 2887 if Nkind (Pragma_Arg) = N_Selected_Component then 2888 Pragma_Arg := Selector_Name (Pragma_Arg); 2889 end if; 2890 2891 return Chars (Pragma_Arg) = Chars (Body_Id); 2892 end; 2893 2894 else 2895 return False; 2896 end if; 2897 end Is_Inline_Pragma; 2898 2899 -- Start of processing for Check_Inline_Pragma 2900 2901 begin 2902 if not Expander_Active then 2903 return; 2904 end if; 2905 2906 if Is_List_Member (N) 2907 and then Present (Next (N)) 2908 and then Is_Inline_Pragma (Next (N)) 2909 then 2910 Prag := Next (N); 2911 2912 elsif Nkind (N) /= N_Subprogram_Body_Stub 2913 and then Present (Declarations (N)) 2914 and then Is_Inline_Pragma (First (Declarations (N))) 2915 then 2916 Prag := First (Declarations (N)); 2917 2918 else 2919 Prag := Empty; 2920 end if; 2921 2922 if Present (Prag) then 2923 if Present (Spec_Id) then 2924 if Is_List_Member (N) 2925 and then Is_List_Member (Unit_Declaration_Node (Spec_Id)) 2926 and then In_Same_List (N, Unit_Declaration_Node (Spec_Id)) 2927 then 2928 Analyze (Prag); 2929 end if; 2930 2931 else 2932 -- Create a subprogram declaration, to make treatment uniform. 2933 -- Make the sloc of the subprogram name that of the entity in 2934 -- the body, so that style checks find identical strings. 2935 2936 declare 2937 Subp : constant Entity_Id := 2938 Make_Defining_Identifier 2939 (Sloc (Body_Id), Chars (Body_Id)); 2940 Decl : constant Node_Id := 2941 Make_Subprogram_Declaration (Loc, 2942 Specification => 2943 New_Copy_Tree (Specification (N))); 2944 2945 begin 2946 -- Link the body and the generated spec 2947 2948 Set_Corresponding_Body (Decl, Body_Id); 2949 Set_Corresponding_Spec (N, Subp); 2950 2951 Set_Defining_Unit_Name (Specification (Decl), Subp); 2952 2953 -- To ensure proper coverage when body is inlined, indicate 2954 -- whether the subprogram comes from source. 2955 2956 Set_Comes_From_Source (Subp, Comes_From_Source (N)); 2957 2958 if Present (First_Formal (Body_Id)) then 2959 Plist := Copy_Parameter_List (Body_Id); 2960 Set_Parameter_Specifications 2961 (Specification (Decl), Plist); 2962 end if; 2963 2964 -- Move aspects to the new spec 2965 2966 if Has_Aspects (N) then 2967 Move_Aspects (N, To => Decl); 2968 end if; 2969 2970 Insert_Before (N, Decl); 2971 Analyze (Decl); 2972 Analyze (Prag); 2973 Set_Has_Pragma_Inline (Subp); 2974 2975 if Pragma_Name (Prag) = Name_Inline_Always then 2976 Set_Is_Inlined (Subp); 2977 Set_Has_Pragma_Inline_Always (Subp); 2978 end if; 2979 2980 -- Prior to copying the subprogram body to create a template 2981 -- for it for subsequent inlining, remove the pragma from 2982 -- the current body so that the copy that will produce the 2983 -- new body will start from a completely unanalyzed tree. 2984 2985 if Nkind (Parent (Prag)) = N_Subprogram_Body then 2986 Rewrite (Prag, Make_Null_Statement (Sloc (Prag))); 2987 end if; 2988 2989 Spec := Subp; 2990 end; 2991 end if; 2992 end if; 2993 end Check_Inline_Pragma; 2994 2995 -------------------------- 2996 -- Check_Missing_Return -- 2997 -------------------------- 2998 2999 procedure Check_Missing_Return is 3000 Id : Entity_Id; 3001 Missing_Ret : Boolean; 3002 3003 begin 3004 if Nkind (Body_Spec) = N_Function_Specification then 3005 if Present (Spec_Id) then 3006 Id := Spec_Id; 3007 else 3008 Id := Body_Id; 3009 end if; 3010 3011 if Return_Present (Id) then 3012 Check_Returns (HSS, 'F', Missing_Ret); 3013 3014 if Missing_Ret then 3015 Set_Has_Missing_Return (Id); 3016 end if; 3017 3018 -- Within a premature instantiation of a package with no body, we 3019 -- build completions of the functions therein, with a Raise 3020 -- statement. No point in complaining about a missing return in 3021 -- this case. 3022 3023 elsif Ekind (Id) = E_Function 3024 and then In_Instance 3025 and then Present (Statements (HSS)) 3026 and then Nkind (First (Statements (HSS))) = N_Raise_Program_Error 3027 then 3028 null; 3029 3030 elsif Is_Generic_Subprogram (Id) 3031 or else not Is_Machine_Code_Subprogram (Id) 3032 then 3033 Error_Msg_N ("missing RETURN statement in function body", N); 3034 end if; 3035 3036 -- If procedure with No_Return, check returns 3037 3038 elsif Nkind (Body_Spec) = N_Procedure_Specification then 3039 if Present (Spec_Id) then 3040 Id := Spec_Id; 3041 else 3042 Id := Body_Id; 3043 end if; 3044 3045 if No_Return (Id) then 3046 Check_Returns (HSS, 'P', Missing_Ret, Id); 3047 end if; 3048 end if; 3049 3050 -- Special checks in SPARK mode 3051 3052 if Nkind (Body_Spec) = N_Function_Specification then 3053 3054 -- In SPARK mode, last statement of a function should be a return 3055 3056 declare 3057 Stat : constant Node_Id := Last_Source_Statement (HSS); 3058 begin 3059 if Present (Stat) 3060 and then not Nkind_In (Stat, N_Simple_Return_Statement, 3061 N_Extended_Return_Statement) 3062 then 3063 Check_SPARK_05_Restriction 3064 ("last statement in function should be RETURN", Stat); 3065 end if; 3066 end; 3067 3068 -- In SPARK mode, verify that a procedure has no return 3069 3070 elsif Nkind (Body_Spec) = N_Procedure_Specification then 3071 if Present (Spec_Id) then 3072 Id := Spec_Id; 3073 else 3074 Id := Body_Id; 3075 end if; 3076 3077 -- Would be nice to point to return statement here, can we 3078 -- borrow the Check_Returns procedure here ??? 3079 3080 if Return_Present (Id) then 3081 Check_SPARK_05_Restriction 3082 ("procedure should not have RETURN", N); 3083 end if; 3084 end if; 3085 end Check_Missing_Return; 3086 3087 ----------------------- 3088 -- Disambiguate_Spec -- 3089 ----------------------- 3090 3091 function Disambiguate_Spec return Entity_Id is 3092 Priv_Spec : Entity_Id; 3093 Spec_N : Entity_Id; 3094 3095 procedure Replace_Types (To_Corresponding : Boolean); 3096 -- Depending on the flag, replace the type of formal parameters of 3097 -- Body_Id if it is a concurrent type implementing interfaces with 3098 -- the corresponding record type or the other way around. 3099 3100 procedure Replace_Types (To_Corresponding : Boolean) is 3101 Formal : Entity_Id; 3102 Formal_Typ : Entity_Id; 3103 3104 begin 3105 Formal := First_Formal (Body_Id); 3106 while Present (Formal) loop 3107 Formal_Typ := Etype (Formal); 3108 3109 if Is_Class_Wide_Type (Formal_Typ) then 3110 Formal_Typ := Root_Type (Formal_Typ); 3111 end if; 3112 3113 -- From concurrent type to corresponding record 3114 3115 if To_Corresponding then 3116 if Is_Concurrent_Type (Formal_Typ) 3117 and then Present (Corresponding_Record_Type (Formal_Typ)) 3118 and then 3119 Present (Interfaces 3120 (Corresponding_Record_Type (Formal_Typ))) 3121 then 3122 Set_Etype (Formal, 3123 Corresponding_Record_Type (Formal_Typ)); 3124 end if; 3125 3126 -- From corresponding record to concurrent type 3127 3128 else 3129 if Is_Concurrent_Record_Type (Formal_Typ) 3130 and then Present (Interfaces (Formal_Typ)) 3131 then 3132 Set_Etype (Formal, 3133 Corresponding_Concurrent_Type (Formal_Typ)); 3134 end if; 3135 end if; 3136 3137 Next_Formal (Formal); 3138 end loop; 3139 end Replace_Types; 3140 3141 -- Start of processing for Disambiguate_Spec 3142 3143 begin 3144 -- Try to retrieve the specification of the body as is. All error 3145 -- messages are suppressed because the body may not have a spec in 3146 -- its current state. 3147 3148 Spec_N := Find_Corresponding_Spec (N, False); 3149 3150 -- It is possible that this is the body of a primitive declared 3151 -- between a private and a full view of a concurrent type. The 3152 -- controlling parameter of the spec carries the concurrent type, 3153 -- not the corresponding record type as transformed by Analyze_ 3154 -- Subprogram_Specification. In such cases, we undo the change 3155 -- made by the analysis of the specification and try to find the 3156 -- spec again. 3157 3158 -- Note that wrappers already have their corresponding specs and 3159 -- bodies set during their creation, so if the candidate spec is 3160 -- a wrapper, then we definitely need to swap all types to their 3161 -- original concurrent status. 3162 3163 if No (Spec_N) 3164 or else Is_Primitive_Wrapper (Spec_N) 3165 then 3166 -- Restore all references of corresponding record types to the 3167 -- original concurrent types. 3168 3169 Replace_Types (To_Corresponding => False); 3170 Priv_Spec := Find_Corresponding_Spec (N, False); 3171 3172 -- The current body truly belongs to a primitive declared between 3173 -- a private and a full view. We leave the modified body as is, 3174 -- and return the true spec. 3175 3176 if Present (Priv_Spec) 3177 and then Is_Private_Primitive (Priv_Spec) 3178 then 3179 return Priv_Spec; 3180 end if; 3181 3182 -- In case that this is some sort of error, restore the original 3183 -- state of the body. 3184 3185 Replace_Types (To_Corresponding => True); 3186 end if; 3187 3188 return Spec_N; 3189 end Disambiguate_Spec; 3190 3191 ---------------------------- 3192 -- Exchange_Limited_Views -- 3193 ---------------------------- 3194 3195 function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id is 3196 Result : Elist_Id := No_Elist; 3197 3198 procedure Detect_And_Exchange (Id : Entity_Id); 3199 -- Determine whether Id's type denotes an incomplete type associated 3200 -- with a limited with clause and exchange the limited view with the 3201 -- non-limited one when available. Note that the non-limited view 3202 -- may exist because of a with_clause in another unit in the context, 3203 -- but cannot be used because the current view of the enclosing unit 3204 -- is still a limited view. 3205 3206 ------------------------- 3207 -- Detect_And_Exchange -- 3208 ------------------------- 3209 3210 procedure Detect_And_Exchange (Id : Entity_Id) is 3211 Typ : constant Entity_Id := Etype (Id); 3212 begin 3213 if From_Limited_With (Typ) 3214 and then Has_Non_Limited_View (Typ) 3215 and then not From_Limited_With (Scope (Typ)) 3216 then 3217 if No (Result) then 3218 Result := New_Elmt_List; 3219 end if; 3220 3221 Prepend_Elmt (Typ, Result); 3222 Prepend_Elmt (Id, Result); 3223 Set_Etype (Id, Non_Limited_View (Typ)); 3224 end if; 3225 end Detect_And_Exchange; 3226 3227 -- Local variables 3228 3229 Formal : Entity_Id; 3230 3231 -- Start of processing for Exchange_Limited_Views 3232 3233 begin 3234 -- Do not process subprogram bodies as they already use the non- 3235 -- limited view of types. 3236 3237 if not Ekind_In (Subp_Id, E_Function, E_Procedure) then 3238 return No_Elist; 3239 end if; 3240 3241 -- Examine all formals and swap views when applicable 3242 3243 Formal := First_Formal (Subp_Id); 3244 while Present (Formal) loop 3245 Detect_And_Exchange (Formal); 3246 3247 Next_Formal (Formal); 3248 end loop; 3249 3250 -- Process the return type of a function 3251 3252 if Ekind (Subp_Id) = E_Function then 3253 Detect_And_Exchange (Subp_Id); 3254 end if; 3255 3256 return Result; 3257 end Exchange_Limited_Views; 3258 3259 ------------------------------------- 3260 -- Is_Private_Concurrent_Primitive -- 3261 ------------------------------------- 3262 3263 function Is_Private_Concurrent_Primitive 3264 (Subp_Id : Entity_Id) return Boolean 3265 is 3266 Formal_Typ : Entity_Id; 3267 3268 begin 3269 if Present (First_Formal (Subp_Id)) then 3270 Formal_Typ := Etype (First_Formal (Subp_Id)); 3271 3272 if Is_Concurrent_Record_Type (Formal_Typ) then 3273 if Is_Class_Wide_Type (Formal_Typ) then 3274 Formal_Typ := Root_Type (Formal_Typ); 3275 end if; 3276 3277 Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ); 3278 end if; 3279 3280 -- The type of the first formal is a concurrent tagged type with 3281 -- a private view. 3282 3283 return 3284 Is_Concurrent_Type (Formal_Typ) 3285 and then Is_Tagged_Type (Formal_Typ) 3286 and then Has_Private_Declaration (Formal_Typ); 3287 end if; 3288 3289 return False; 3290 end Is_Private_Concurrent_Primitive; 3291 3292 ------------------------- 3293 -- Mask_Unfrozen_Types -- 3294 ------------------------- 3295 3296 function Mask_Unfrozen_Types (Spec_Id : Entity_Id) return Elist_Id is 3297 Result : Elist_Id := No_Elist; 3298 3299 function Mask_Type_Refs (Node : Node_Id) return Traverse_Result; 3300 -- Mask all types referenced in the subtree rooted at Node 3301 3302 -------------------- 3303 -- Mask_Type_Refs -- 3304 -------------------- 3305 3306 function Mask_Type_Refs (Node : Node_Id) return Traverse_Result is 3307 procedure Mask_Type (Typ : Entity_Id); 3308 -- ??? what does this do? 3309 3310 --------------- 3311 -- Mask_Type -- 3312 --------------- 3313 3314 procedure Mask_Type (Typ : Entity_Id) is 3315 begin 3316 -- Skip Itypes created by the preanalysis 3317 3318 if Is_Itype (Typ) 3319 and then Scope_Within_Or_Same (Scope (Typ), Spec_Id) 3320 then 3321 return; 3322 end if; 3323 3324 if not Is_Frozen (Typ) then 3325 if Scope (Typ) /= Current_Scope then 3326 Set_Is_Frozen (Typ); 3327 Append_New_Elmt (Typ, Result); 3328 else 3329 Freeze_Before (N, Typ); 3330 end if; 3331 end if; 3332 end Mask_Type; 3333 3334 -- Start of processing for Mask_Type_Refs 3335 3336 begin 3337 if Is_Entity_Name (Node) and then Present (Entity (Node)) then 3338 Mask_Type (Etype (Entity (Node))); 3339 3340 if Ekind_In (Entity (Node), E_Component, E_Discriminant) then 3341 Mask_Type (Scope (Entity (Node))); 3342 end if; 3343 3344 elsif Nkind_In (Node, N_Aggregate, N_Null, N_Type_Conversion) 3345 and then Present (Etype (Node)) 3346 then 3347 Mask_Type (Etype (Node)); 3348 end if; 3349 3350 return OK; 3351 end Mask_Type_Refs; 3352 3353 procedure Mask_References is new Traverse_Proc (Mask_Type_Refs); 3354 3355 -- Local variables 3356 3357 Return_Stmt : constant Node_Id := 3358 First (Statements (Handled_Statement_Sequence (N))); 3359 3360 -- Start of processing for Mask_Unfrozen_Types 3361 3362 begin 3363 pragma Assert (Nkind (Return_Stmt) = N_Simple_Return_Statement); 3364 3365 Mask_References (Expression (Return_Stmt)); 3366 3367 return Result; 3368 end Mask_Unfrozen_Types; 3369 3370 --------------------------- 3371 -- Restore_Limited_Views -- 3372 --------------------------- 3373 3374 procedure Restore_Limited_Views (Restore_List : Elist_Id) is 3375 Elmt : Elmt_Id := First_Elmt (Restore_List); 3376 Id : Entity_Id; 3377 3378 begin 3379 while Present (Elmt) loop 3380 Id := Node (Elmt); 3381 Next_Elmt (Elmt); 3382 Set_Etype (Id, Node (Elmt)); 3383 Next_Elmt (Elmt); 3384 end loop; 3385 end Restore_Limited_Views; 3386 3387 ---------------------------- 3388 -- Set_Trivial_Subprogram -- 3389 ---------------------------- 3390 3391 procedure Set_Trivial_Subprogram (N : Node_Id) is 3392 Nxt : constant Node_Id := Next (N); 3393 3394 begin 3395 Set_Is_Trivial_Subprogram (Body_Id); 3396 3397 if Present (Spec_Id) then 3398 Set_Is_Trivial_Subprogram (Spec_Id); 3399 end if; 3400 3401 if Present (Nxt) 3402 and then Nkind (Nxt) = N_Simple_Return_Statement 3403 and then No (Next (Nxt)) 3404 and then Present (Expression (Nxt)) 3405 and then Is_Entity_Name (Expression (Nxt)) 3406 then 3407 Set_Never_Set_In_Source (Entity (Expression (Nxt)), False); 3408 end if; 3409 end Set_Trivial_Subprogram; 3410 3411 --------------------------- 3412 -- Unmask_Unfrozen_Types -- 3413 --------------------------- 3414 3415 procedure Unmask_Unfrozen_Types (Unmask_List : Elist_Id) is 3416 Elmt : Elmt_Id := First_Elmt (Unmask_List); 3417 3418 begin 3419 while Present (Elmt) loop 3420 Set_Is_Frozen (Node (Elmt), False); 3421 Next_Elmt (Elmt); 3422 end loop; 3423 end Unmask_Unfrozen_Types; 3424 3425 --------------------------------- 3426 -- Verify_Overriding_Indicator -- 3427 --------------------------------- 3428 3429 procedure Verify_Overriding_Indicator is 3430 begin 3431 if Must_Override (Body_Spec) then 3432 if Nkind (Spec_Id) = N_Defining_Operator_Symbol 3433 and then Operator_Matches_Spec (Spec_Id, Spec_Id) 3434 then 3435 null; 3436 3437 -- Overridden controlled primitives may have had their 3438 -- Overridden_Operation field cleared according to the setting of 3439 -- the Is_Hidden flag. An issue arises, however, when analyzing 3440 -- an instance that may have manipulated the flag during 3441 -- expansion. As a result, we add an exception for this case. 3442 3443 elsif not Present (Overridden_Operation (Spec_Id)) 3444 and then not (Nam_In (Chars (Spec_Id), Name_Adjust, 3445 Name_Finalize, 3446 Name_Initialize) 3447 and then In_Instance) 3448 then 3449 Error_Msg_NE 3450 ("subprogram& is not overriding", Body_Spec, Spec_Id); 3451 3452 -- Overriding indicators aren't allowed for protected subprogram 3453 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change 3454 -- this to a warning if -gnatd.E is enabled. 3455 3456 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then 3457 Error_Msg_Warn := Error_To_Warning; 3458 Error_Msg_N 3459 ("<<overriding indicator not allowed for protected " 3460 & "subprogram body", Body_Spec); 3461 end if; 3462 3463 elsif Must_Not_Override (Body_Spec) then 3464 if Present (Overridden_Operation (Spec_Id)) then 3465 Error_Msg_NE 3466 ("subprogram& overrides inherited operation", 3467 Body_Spec, Spec_Id); 3468 3469 elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol 3470 and then Operator_Matches_Spec (Spec_Id, Spec_Id) 3471 then 3472 Error_Msg_NE 3473 ("subprogram& overrides predefined operator ", 3474 Body_Spec, Spec_Id); 3475 3476 -- Overriding indicators aren't allowed for protected subprogram 3477 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change 3478 -- this to a warning if -gnatd.E is enabled. 3479 3480 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then 3481 Error_Msg_Warn := Error_To_Warning; 3482 3483 Error_Msg_N 3484 ("<<overriding indicator not allowed " 3485 & "for protected subprogram body", Body_Spec); 3486 3487 -- If this is not a primitive operation, then the overriding 3488 -- indicator is altogether illegal. 3489 3490 elsif not Is_Primitive (Spec_Id) then 3491 Error_Msg_N 3492 ("overriding indicator only allowed " 3493 & "if subprogram is primitive", Body_Spec); 3494 end if; 3495 3496 -- If checking the style rule and the operation overrides, then 3497 -- issue a warning about a missing overriding_indicator. Protected 3498 -- subprogram bodies are excluded from this style checking, since 3499 -- they aren't primitives (even though their declarations can 3500 -- override) and aren't allowed to have an overriding_indicator. 3501 3502 elsif Style_Check 3503 and then Present (Overridden_Operation (Spec_Id)) 3504 and then Ekind (Scope (Spec_Id)) /= E_Protected_Type 3505 then 3506 pragma Assert (Unit_Declaration_Node (Body_Id) = N); 3507 Style.Missing_Overriding (N, Body_Id); 3508 3509 elsif Style_Check 3510 and then Can_Override_Operator (Spec_Id) 3511 and then not In_Predefined_Unit (Spec_Id) 3512 then 3513 pragma Assert (Unit_Declaration_Node (Body_Id) = N); 3514 Style.Missing_Overriding (N, Body_Id); 3515 end if; 3516 end Verify_Overriding_Indicator; 3517 3518 -- Local variables 3519 3520 Body_Nod : Node_Id := Empty; 3521 Minimum_Acc_Objs : List_Id := No_List; 3522 3523 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 3524 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 3525 Saved_EA : constant Boolean := Expander_Active; 3526 Saved_ISMP : constant Boolean := 3527 Ignore_SPARK_Mode_Pragmas_In_Instance; 3528 -- Save the Ghost and SPARK mode-related data to restore on exit 3529 3530 -- Start of processing for Analyze_Subprogram_Body_Helper 3531 3532 begin 3533 -- A [generic] subprogram body freezes the contract of the nearest 3534 -- enclosing package body and all other contracts encountered in the 3535 -- same declarative part up to and excluding the subprogram body: 3536 3537 -- package body Nearest_Enclosing_Package 3538 -- with Refined_State => (State => Constit) 3539 -- is 3540 -- Constit : ...; 3541 3542 -- procedure Freezes_Enclosing_Package_Body 3543 -- with Refined_Depends => (Input => Constit) ... 3544 3545 -- This ensures that any annotations referenced by the contract of the 3546 -- [generic] subprogram body are available. This form of freezing is 3547 -- decoupled from the usual Freeze_xxx mechanism because it must also 3548 -- work in the context of generics where normal freezing is disabled. 3549 3550 -- Only bodies coming from source should cause this type of freezing. 3551 -- Expression functions that act as bodies and complete an initial 3552 -- declaration must be included in this category, hence the use of 3553 -- Original_Node. 3554 3555 if Comes_From_Source (Original_Node (N)) then 3556 Freeze_Previous_Contracts (N); 3557 end if; 3558 3559 -- Generic subprograms are handled separately. They always have a 3560 -- generic specification. Determine whether current scope has a 3561 -- previous declaration. 3562 3563 -- If the subprogram body is defined within an instance of the same 3564 -- name, the instance appears as a package renaming, and will be hidden 3565 -- within the subprogram. 3566 3567 if Present (Prev_Id) 3568 and then not Is_Overloadable (Prev_Id) 3569 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration 3570 or else Comes_From_Source (Prev_Id)) 3571 then 3572 if Is_Generic_Subprogram (Prev_Id) then 3573 Spec_Id := Prev_Id; 3574 3575 -- A subprogram body is Ghost when it is stand-alone and subject 3576 -- to pragma Ghost or when the corresponding spec is Ghost. Set 3577 -- the mode now to ensure that any nodes generated during analysis 3578 -- and expansion are properly marked as Ghost. 3579 3580 Mark_And_Set_Ghost_Body (N, Spec_Id); 3581 3582 -- If the body completes the initial declaration of a compilation 3583 -- unit which is subject to pragma Elaboration_Checks, set the 3584 -- model specified by the pragma because it applies to all parts 3585 -- of the unit. 3586 3587 Install_Elaboration_Model (Spec_Id); 3588 3589 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 3590 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); 3591 3592 Analyze_Generic_Subprogram_Body (N, Spec_Id); 3593 3594 if Nkind (N) = N_Subprogram_Body then 3595 HSS := Handled_Statement_Sequence (N); 3596 Check_Missing_Return; 3597 end if; 3598 3599 goto Leave; 3600 3601 -- Otherwise a previous entity conflicts with the subprogram name. 3602 -- Attempting to enter name will post error. 3603 3604 else 3605 Enter_Name (Body_Id); 3606 goto Leave; 3607 end if; 3608 3609 -- Non-generic case, find the subprogram declaration, if one was seen, 3610 -- or enter new overloaded entity in the current scope. If the 3611 -- Current_Entity is the Body_Id itself, the unit is being analyzed as 3612 -- part of the context of one of its subunits. No need to redo the 3613 -- analysis. 3614 3615 elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then 3616 goto Leave; 3617 3618 else 3619 Body_Id := Analyze_Subprogram_Specification (Body_Spec); 3620 3621 if Nkind (N) = N_Subprogram_Body_Stub 3622 or else No (Corresponding_Spec (N)) 3623 then 3624 if Is_Private_Concurrent_Primitive (Body_Id) then 3625 Spec_Id := Disambiguate_Spec; 3626 3627 -- A subprogram body is Ghost when it is stand-alone and 3628 -- subject to pragma Ghost or when the corresponding spec is 3629 -- Ghost. Set the mode now to ensure that any nodes generated 3630 -- during analysis and expansion are properly marked as Ghost. 3631 3632 Mark_And_Set_Ghost_Body (N, Spec_Id); 3633 3634 -- If the body completes a compilation unit which is subject 3635 -- to pragma Elaboration_Checks, set the model specified by 3636 -- the pragma because it applies to all parts of the unit. 3637 3638 Install_Elaboration_Model (Spec_Id); 3639 3640 else 3641 Spec_Id := Find_Corresponding_Spec (N); 3642 3643 -- A subprogram body is Ghost when it is stand-alone and 3644 -- subject to pragma Ghost or when the corresponding spec is 3645 -- Ghost. Set the mode now to ensure that any nodes generated 3646 -- during analysis and expansion are properly marked as Ghost. 3647 3648 Mark_And_Set_Ghost_Body (N, Spec_Id); 3649 3650 -- If the body completes a compilation unit which is subject 3651 -- to pragma Elaboration_Checks, set the model specified by 3652 -- the pragma because it applies to all parts of the unit. 3653 3654 Install_Elaboration_Model (Spec_Id); 3655 3656 -- In GNATprove mode, if the body has no previous spec, create 3657 -- one so that the inlining machinery can operate properly. 3658 -- Transfer aspects, if any, to the new spec, so that they 3659 -- are legal and can be processed ahead of the body. 3660 -- We make two copies of the given spec, one for the new 3661 -- declaration, and one for the body. 3662 3663 if No (Spec_Id) and then GNATprove_Mode 3664 3665 -- Inlining does not apply during preanalysis of code 3666 3667 and then Full_Analysis 3668 3669 -- Inlining only applies to full bodies, not stubs 3670 3671 and then Nkind (N) /= N_Subprogram_Body_Stub 3672 3673 -- Inlining only applies to bodies in the source code, not to 3674 -- those generated by the compiler. In particular, expression 3675 -- functions, whose body is generated by the compiler, are 3676 -- treated specially by GNATprove. 3677 3678 and then Comes_From_Source (Body_Id) 3679 3680 -- This cannot be done for a compilation unit, which is not 3681 -- in a context where we can insert a new spec. 3682 3683 and then Is_List_Member (N) 3684 3685 -- Inlining only applies to subprograms without contracts, 3686 -- as a contract is a sign that GNATprove should perform a 3687 -- modular analysis of the subprogram instead of a contextual 3688 -- analysis at each call site. The same test is performed in 3689 -- Inline.Can_Be_Inlined_In_GNATprove_Mode. It is repeated 3690 -- here in another form (because the contract has not been 3691 -- attached to the body) to avoid front-end errors in case 3692 -- pragmas are used instead of aspects, because the 3693 -- corresponding pragmas in the body would not be transferred 3694 -- to the spec, leading to legality errors. 3695 3696 and then not Body_Has_Contract 3697 and then not Inside_A_Generic 3698 then 3699 Build_Subprogram_Declaration; 3700 3701 -- If this is a function that returns a constrained array, and 3702 -- we are generating SPARK_For_C, create subprogram declaration 3703 -- to simplify subsequent C generation. 3704 3705 elsif No (Spec_Id) 3706 and then Modify_Tree_For_C 3707 and then Nkind (Body_Spec) = N_Function_Specification 3708 and then Is_Array_Type (Etype (Body_Id)) 3709 and then Is_Constrained (Etype (Body_Id)) 3710 then 3711 Build_Subprogram_Declaration; 3712 end if; 3713 end if; 3714 3715 -- If this is a duplicate body, no point in analyzing it 3716 3717 if Error_Posted (N) then 3718 goto Leave; 3719 end if; 3720 3721 -- A subprogram body should cause freezing of its own declaration, 3722 -- but if there was no previous explicit declaration, then the 3723 -- subprogram will get frozen too late (there may be code within 3724 -- the body that depends on the subprogram having been frozen, 3725 -- such as uses of extra formals), so we force it to be frozen 3726 -- here. Same holds if the body and spec are compilation units. 3727 -- Finally, if the return type is an anonymous access to protected 3728 -- subprogram, it must be frozen before the body because its 3729 -- expansion has generated an equivalent type that is used when 3730 -- elaborating the body. 3731 3732 -- An exception in the case of Ada 2012, AI05-177: The bodies 3733 -- created for expression functions do not freeze. 3734 3735 if No (Spec_Id) 3736 and then Nkind (Original_Node (N)) /= N_Expression_Function 3737 then 3738 Freeze_Before (N, Body_Id); 3739 3740 elsif Nkind (Parent (N)) = N_Compilation_Unit then 3741 Freeze_Before (N, Spec_Id); 3742 3743 elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then 3744 Freeze_Before (N, Etype (Body_Id)); 3745 end if; 3746 3747 else 3748 Spec_Id := Corresponding_Spec (N); 3749 3750 -- A subprogram body is Ghost when it is stand-alone and subject 3751 -- to pragma Ghost or when the corresponding spec is Ghost. Set 3752 -- the mode now to ensure that any nodes generated during analysis 3753 -- and expansion are properly marked as Ghost. 3754 3755 Mark_And_Set_Ghost_Body (N, Spec_Id); 3756 3757 -- If the body completes the initial declaration of a compilation 3758 -- unit which is subject to pragma Elaboration_Checks, set the 3759 -- model specified by the pragma because it applies to all parts 3760 -- of the unit. 3761 3762 Install_Elaboration_Model (Spec_Id); 3763 end if; 3764 end if; 3765 3766 -- Deactivate expansion inside the body of ignored Ghost entities, 3767 -- as this code will ultimately be ignored. This avoids requiring the 3768 -- presence of run-time units which are not needed. Only do this for 3769 -- user entities, as internally generated entitities might still need 3770 -- to be expanded (e.g. those generated for types). 3771 3772 if Present (Ignored_Ghost_Region) 3773 and then Comes_From_Source (Body_Id) 3774 then 3775 Expander_Active := False; 3776 end if; 3777 3778 -- Previously we scanned the body to look for nested subprograms, and 3779 -- rejected an inline directive if nested subprograms were present, 3780 -- because the back-end would generate conflicting symbols for the 3781 -- nested bodies. This is now unnecessary. 3782 3783 -- Look ahead to recognize a pragma Inline that appears after the body 3784 3785 Check_Inline_Pragma (Spec_Id); 3786 3787 -- Deal with special case of a fully private operation in the body of 3788 -- the protected type. We must create a declaration for the subprogram, 3789 -- in order to attach the protected subprogram that will be used in 3790 -- internal calls. We exclude compiler generated bodies from the 3791 -- expander since the issue does not arise for those cases. 3792 3793 if No (Spec_Id) 3794 and then Comes_From_Source (N) 3795 and then Is_Protected_Type (Current_Scope) 3796 then 3797 Spec_Id := Build_Private_Protected_Declaration (N); 3798 end if; 3799 3800 -- If we are generating C and this is a function returning a constrained 3801 -- array type for which we must create a procedure with an extra out 3802 -- parameter, build and analyze the body now. The procedure declaration 3803 -- has already been created. We reuse the source body of the function, 3804 -- because in an instance it may contain global references that cannot 3805 -- be reanalyzed. The source function itself is not used any further, 3806 -- so we mark it as having a completion. If the subprogram is a stub the 3807 -- transformation is done later, when the proper body is analyzed. 3808 3809 if Expander_Active 3810 and then Modify_Tree_For_C 3811 and then Present (Spec_Id) 3812 and then Ekind (Spec_Id) = E_Function 3813 and then Nkind (N) /= N_Subprogram_Body_Stub 3814 and then Rewritten_For_C (Spec_Id) 3815 then 3816 Set_Has_Completion (Spec_Id); 3817 3818 Rewrite (N, Build_Procedure_Body_Form (Spec_Id, N)); 3819 Analyze (N); 3820 3821 -- The entity for the created procedure must remain invisible, so it 3822 -- does not participate in resolution of subsequent references to the 3823 -- function. 3824 3825 Set_Is_Immediately_Visible (Corresponding_Spec (N), False); 3826 goto Leave; 3827 end if; 3828 3829 -- If a separate spec is present, then deal with freezing issues 3830 3831 if Present (Spec_Id) then 3832 Spec_Decl := Unit_Declaration_Node (Spec_Id); 3833 Verify_Overriding_Indicator; 3834 3835 -- In general, the spec will be frozen when we start analyzing the 3836 -- body. However, for internally generated operations, such as 3837 -- wrapper functions for inherited operations with controlling 3838 -- results, the spec may not have been frozen by the time we expand 3839 -- the freeze actions that include the bodies. In particular, extra 3840 -- formals for accessibility or for return-in-place may need to be 3841 -- generated. Freeze nodes, if any, are inserted before the current 3842 -- body. These freeze actions are also needed in ASIS mode and in 3843 -- Compile_Only mode to enable the proper back-end type annotations. 3844 -- They are necessary in any case to ensure proper elaboration order 3845 -- in gigi. 3846 3847 if Nkind (N) = N_Subprogram_Body 3848 and then Was_Expression_Function (N) 3849 and then not Has_Completion (Spec_Id) 3850 and then Serious_Errors_Detected = 0 3851 and then (Expander_Active 3852 or else ASIS_Mode 3853 or else Operating_Mode = Check_Semantics 3854 or else Is_Ignored_Ghost_Entity (Spec_Id)) 3855 then 3856 -- The body generated for an expression function that is not a 3857 -- completion is a freeze point neither for the profile nor for 3858 -- anything else. That's why, in order to prevent any freezing 3859 -- during analysis, we need to mask types declared outside the 3860 -- expression (and in an outer scope) that are not yet frozen. 3861 -- This also needs to be done in the case of an ignored Ghost 3862 -- expression function, where the expander isn't active. 3863 3864 Set_Is_Frozen (Spec_Id); 3865 Mask_Types := Mask_Unfrozen_Types (Spec_Id); 3866 3867 elsif not Is_Frozen (Spec_Id) 3868 and then Serious_Errors_Detected = 0 3869 then 3870 Set_Has_Delayed_Freeze (Spec_Id); 3871 Freeze_Before (N, Spec_Id); 3872 end if; 3873 end if; 3874 3875 -- If the subprogram has a class-wide clone, build its body as a copy 3876 -- of the original body, and rewrite body of original subprogram as a 3877 -- wrapper that calls the clone. If N is a stub, this construction will 3878 -- take place when the proper body is analyzed. No action needed if this 3879 -- subprogram has been eliminated. 3880 3881 if Present (Spec_Id) 3882 and then Present (Class_Wide_Clone (Spec_Id)) 3883 and then (Comes_From_Source (N) or else Was_Expression_Function (N)) 3884 and then Nkind (N) /= N_Subprogram_Body_Stub 3885 and then not (Expander_Active and then Is_Eliminated (Spec_Id)) 3886 then 3887 Build_Class_Wide_Clone_Body (Spec_Id, N); 3888 3889 -- This is the new body for the existing primitive operation 3890 3891 Rewrite (N, Build_Class_Wide_Clone_Call 3892 (Sloc (N), New_List, Spec_Id, Parent (Spec_Id))); 3893 Set_Has_Completion (Spec_Id, False); 3894 Analyze (N); 3895 return; 3896 end if; 3897 3898 -- Place subprogram on scope stack, and make formals visible. If there 3899 -- is a spec, the visible entity remains that of the spec. 3900 3901 if Present (Spec_Id) then 3902 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False); 3903 3904 if Is_Child_Unit (Spec_Id) then 3905 Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False); 3906 end if; 3907 3908 if Style_Check then 3909 Style.Check_Identifier (Body_Id, Spec_Id); 3910 end if; 3911 3912 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 3913 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); 3914 3915 if Is_Abstract_Subprogram (Spec_Id) then 3916 Error_Msg_N ("an abstract subprogram cannot have a body", N); 3917 goto Leave; 3918 3919 else 3920 Set_Convention (Body_Id, Convention (Spec_Id)); 3921 Set_Has_Completion (Spec_Id); 3922 3923 if Is_Protected_Type (Scope (Spec_Id)) then 3924 Prot_Typ := Scope (Spec_Id); 3925 end if; 3926 3927 -- If this is a body generated for a renaming, do not check for 3928 -- full conformance. The check is redundant, because the spec of 3929 -- the body is a copy of the spec in the renaming declaration, 3930 -- and the test can lead to spurious errors on nested defaults. 3931 3932 if Present (Spec_Decl) 3933 and then not Comes_From_Source (N) 3934 and then 3935 (Nkind (Original_Node (Spec_Decl)) = 3936 N_Subprogram_Renaming_Declaration 3937 or else (Present (Corresponding_Body (Spec_Decl)) 3938 and then 3939 Nkind (Unit_Declaration_Node 3940 (Corresponding_Body (Spec_Decl))) = 3941 N_Subprogram_Renaming_Declaration)) 3942 then 3943 Conformant := True; 3944 3945 -- Conversely, the spec may have been generated for specless body 3946 -- with an inline pragma. The entity comes from source, which is 3947 -- both semantically correct and necessary for proper inlining. 3948 -- The subprogram declaration itself is not in the source. 3949 3950 elsif Comes_From_Source (N) 3951 and then Present (Spec_Decl) 3952 and then not Comes_From_Source (Spec_Decl) 3953 and then Has_Pragma_Inline (Spec_Id) 3954 then 3955 Conformant := True; 3956 3957 else 3958 Check_Conformance 3959 (Body_Id, Spec_Id, 3960 Fully_Conformant, True, Conformant, Body_Id); 3961 end if; 3962 3963 -- If the body is not fully conformant, we have to decide if we 3964 -- should analyze it or not. If it has a really messed up profile 3965 -- then we probably should not analyze it, since we will get too 3966 -- many bogus messages. 3967 3968 -- Our decision is to go ahead in the non-fully conformant case 3969 -- only if it is at least mode conformant with the spec. Note 3970 -- that the call to Check_Fully_Conformant has issued the proper 3971 -- error messages to complain about the lack of conformance. 3972 3973 if not Conformant 3974 and then not Mode_Conformant (Body_Id, Spec_Id) 3975 then 3976 goto Leave; 3977 end if; 3978 end if; 3979 3980 -- In the case we are dealing with an expression function we check 3981 -- the formals attached to the spec instead of the body - so we don't 3982 -- reference body formals. 3983 3984 if Spec_Id /= Body_Id 3985 and then not Is_Expression_Function (Spec_Id) 3986 then 3987 Reference_Body_Formals (Spec_Id, Body_Id); 3988 end if; 3989 3990 Set_Ekind (Body_Id, E_Subprogram_Body); 3991 3992 if Nkind (N) = N_Subprogram_Body_Stub then 3993 Set_Corresponding_Spec_Of_Stub (N, Spec_Id); 3994 3995 -- Regular body 3996 3997 else 3998 Set_Corresponding_Spec (N, Spec_Id); 3999 4000 -- Ada 2005 (AI-345): If the operation is a primitive operation 4001 -- of a concurrent type, the type of the first parameter has been 4002 -- replaced with the corresponding record, which is the proper 4003 -- run-time structure to use. However, within the body there may 4004 -- be uses of the formals that depend on primitive operations 4005 -- of the type (in particular calls in prefixed form) for which 4006 -- we need the original concurrent type. The operation may have 4007 -- several controlling formals, so the replacement must be done 4008 -- for all of them. 4009 4010 if Comes_From_Source (Spec_Id) 4011 and then Present (First_Entity (Spec_Id)) 4012 and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type 4013 and then Is_Tagged_Type (Etype (First_Entity (Spec_Id))) 4014 and then Present (Interfaces (Etype (First_Entity (Spec_Id)))) 4015 and then Present (Corresponding_Concurrent_Type 4016 (Etype (First_Entity (Spec_Id)))) 4017 then 4018 declare 4019 Typ : constant Entity_Id := Etype (First_Entity (Spec_Id)); 4020 Form : Entity_Id; 4021 4022 begin 4023 Form := First_Formal (Spec_Id); 4024 while Present (Form) loop 4025 if Etype (Form) = Typ then 4026 Set_Etype (Form, Corresponding_Concurrent_Type (Typ)); 4027 end if; 4028 4029 Next_Formal (Form); 4030 end loop; 4031 end; 4032 end if; 4033 4034 -- Make the formals visible, and place subprogram on scope stack. 4035 -- This is also the point at which we set Last_Real_Spec_Entity 4036 -- to mark the entities which will not be moved to the body. 4037 4038 Install_Formals (Spec_Id); 4039 Last_Real_Spec_Entity := Last_Entity (Spec_Id); 4040 4041 -- Within an instance, add local renaming declarations so that 4042 -- gdb can retrieve the values of actuals more easily. This is 4043 -- only relevant if generating code (and indeed we definitely 4044 -- do not want these definitions -gnatc mode, because that would 4045 -- confuse ASIS). 4046 4047 if Is_Generic_Instance (Spec_Id) 4048 and then Is_Wrapper_Package (Current_Scope) 4049 and then Expander_Active 4050 then 4051 Build_Subprogram_Instance_Renamings (N, Current_Scope); 4052 end if; 4053 4054 Push_Scope (Spec_Id); 4055 4056 -- Make sure that the subprogram is immediately visible. For 4057 -- child units that have no separate spec this is indispensable. 4058 -- Otherwise it is safe albeit redundant. 4059 4060 Set_Is_Immediately_Visible (Spec_Id); 4061 end if; 4062 4063 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id); 4064 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id)); 4065 Set_Scope (Body_Id, Scope (Spec_Id)); 4066 4067 -- Case of subprogram body with no previous spec 4068 4069 else 4070 -- Check for style warning required 4071 4072 if Style_Check 4073 4074 -- Only apply check for source level subprograms for which checks 4075 -- have not been suppressed. 4076 4077 and then Comes_From_Source (Body_Id) 4078 and then not Suppress_Style_Checks (Body_Id) 4079 4080 -- No warnings within an instance 4081 4082 and then not In_Instance 4083 4084 -- No warnings for expression functions 4085 4086 and then Nkind (Original_Node (N)) /= N_Expression_Function 4087 then 4088 Style.Body_With_No_Spec (N); 4089 end if; 4090 4091 New_Overloaded_Entity (Body_Id); 4092 4093 if Nkind (N) /= N_Subprogram_Body_Stub then 4094 Set_Acts_As_Spec (N); 4095 Generate_Definition (Body_Id); 4096 Generate_Reference 4097 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True); 4098 4099 -- If the body is an entry wrapper created for an entry with 4100 -- preconditions, it must be compiled in the context of the 4101 -- enclosing synchronized object, because it may mention other 4102 -- operations of the type. 4103 4104 if Is_Entry_Wrapper (Body_Id) then 4105 declare 4106 Prot : constant Entity_Id := Etype (First_Entity (Body_Id)); 4107 begin 4108 Push_Scope (Prot); 4109 Install_Declarations (Prot); 4110 end; 4111 end if; 4112 4113 Install_Formals (Body_Id); 4114 4115 Push_Scope (Body_Id); 4116 end if; 4117 4118 -- For stubs and bodies with no previous spec, generate references to 4119 -- formals. 4120 4121 Generate_Reference_To_Formals (Body_Id); 4122 end if; 4123 4124 -- Entry barrier functions are generated outside the protected type and 4125 -- should not carry the SPARK_Mode of the enclosing context. 4126 4127 if Nkind (N) = N_Subprogram_Body 4128 and then Is_Entry_Barrier_Function (N) 4129 then 4130 null; 4131 4132 -- The body is generated as part of expression function expansion. When 4133 -- the expression function appears in the visible declarations of a 4134 -- package, the body is added to the private declarations. Since both 4135 -- declarative lists may be subject to a different SPARK_Mode, inherit 4136 -- the mode of the spec. 4137 4138 -- package P with SPARK_Mode is 4139 -- function Expr_Func ... is (...); -- original 4140 -- [function Expr_Func ...;] -- generated spec 4141 -- -- mode is ON 4142 -- private 4143 -- pragma SPARK_Mode (Off); 4144 -- [function Expr_Func ... is return ...;] -- generated body 4145 -- end P; -- mode is ON 4146 4147 elsif not Comes_From_Source (N) 4148 and then Present (Spec_Id) 4149 and then Is_Expression_Function (Spec_Id) 4150 then 4151 Set_SPARK_Pragma (Body_Id, SPARK_Pragma (Spec_Id)); 4152 Set_SPARK_Pragma_Inherited 4153 (Body_Id, SPARK_Pragma_Inherited (Spec_Id)); 4154 4155 -- Set the SPARK_Mode from the current context (may be overwritten later 4156 -- with explicit pragma). Exclude the case where the SPARK_Mode appears 4157 -- initially on a stand-alone subprogram body, but is then relocated to 4158 -- a generated corresponding spec. In this scenario the mode is shared 4159 -- between the spec and body. 4160 4161 elsif No (SPARK_Pragma (Body_Id)) then 4162 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 4163 Set_SPARK_Pragma_Inherited (Body_Id); 4164 end if; 4165 4166 -- A subprogram body may be instantiated or inlined at a later pass. 4167 -- Restore the state of Ignore_SPARK_Mode_Pragmas_In_Instance when it 4168 -- applied to the initial declaration of the body. 4169 4170 if Present (Spec_Id) then 4171 if Ignore_SPARK_Mode_Pragmas (Spec_Id) then 4172 Ignore_SPARK_Mode_Pragmas_In_Instance := True; 4173 end if; 4174 4175 else 4176 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in 4177 -- case the body is instantiated or inlined later and out of context. 4178 -- The body uses this attribute to restore the value of the global 4179 -- flag. 4180 4181 if Ignore_SPARK_Mode_Pragmas_In_Instance then 4182 Set_Ignore_SPARK_Mode_Pragmas (Body_Id); 4183 4184 elsif Ignore_SPARK_Mode_Pragmas (Body_Id) then 4185 Ignore_SPARK_Mode_Pragmas_In_Instance := True; 4186 end if; 4187 end if; 4188 4189 -- Preserve relevant elaboration-related attributes of the context which 4190 -- are no longer available or very expensive to recompute once analysis, 4191 -- resolution, and expansion are over. 4192 4193 if No (Spec_Id) then 4194 Mark_Elaboration_Attributes 4195 (N_Id => Body_Id, 4196 Checks => True, 4197 Warnings => True); 4198 end if; 4199 4200 -- If this is the proper body of a stub, we must verify that the stub 4201 -- conforms to the body, and to the previous spec if one was present. 4202 -- We know already that the body conforms to that spec. This test is 4203 -- only required for subprograms that come from source. 4204 4205 if Nkind (Parent (N)) = N_Subunit 4206 and then Comes_From_Source (N) 4207 and then not Error_Posted (Body_Id) 4208 and then Nkind (Corresponding_Stub (Parent (N))) = 4209 N_Subprogram_Body_Stub 4210 then 4211 declare 4212 Old_Id : constant Entity_Id := 4213 Defining_Entity 4214 (Specification (Corresponding_Stub (Parent (N)))); 4215 4216 Conformant : Boolean := False; 4217 4218 begin 4219 if No (Spec_Id) then 4220 Check_Fully_Conformant (Body_Id, Old_Id); 4221 4222 else 4223 Check_Conformance 4224 (Body_Id, Old_Id, Fully_Conformant, False, Conformant); 4225 4226 if not Conformant then 4227 4228 -- The stub was taken to be a new declaration. Indicate that 4229 -- it lacks a body. 4230 4231 Set_Has_Completion (Old_Id, False); 4232 end if; 4233 end if; 4234 end; 4235 end if; 4236 4237 Set_Has_Completion (Body_Id); 4238 Check_Eliminated (Body_Id); 4239 4240 -- Analyze any aspect specifications that appear on the subprogram body 4241 -- stub. Stop the analysis now as the stub does not have a declarative 4242 -- or a statement part, and it cannot be inlined. 4243 4244 if Nkind (N) = N_Subprogram_Body_Stub then 4245 if Has_Aspects (N) then 4246 Analyze_Aspects_On_Subprogram_Body_Or_Stub (N); 4247 end if; 4248 4249 goto Leave; 4250 end if; 4251 4252 -- Handle inlining 4253 4254 -- Note: Normally we don't do any inlining if expansion is off, since 4255 -- we won't generate code in any case. An exception arises in GNATprove 4256 -- mode where we want to expand some calls in place, even with expansion 4257 -- disabled, since the inlining eases formal verification. 4258 4259 if not GNATprove_Mode 4260 and then Expander_Active 4261 and then Serious_Errors_Detected = 0 4262 and then Present (Spec_Id) 4263 and then Has_Pragma_Inline (Spec_Id) 4264 then 4265 -- Legacy implementation (relying on front-end inlining) 4266 4267 if not Back_End_Inlining then 4268 if (Has_Pragma_Inline_Always (Spec_Id) 4269 and then not Opt.Disable_FE_Inline_Always) 4270 or else (Front_End_Inlining 4271 and then not Opt.Disable_FE_Inline) 4272 then 4273 Build_Body_To_Inline (N, Spec_Id); 4274 end if; 4275 4276 -- New implementation (relying on back-end inlining) 4277 4278 else 4279 if Has_Pragma_Inline_Always (Spec_Id) 4280 or else Optimization_Level > 0 4281 then 4282 -- Handle function returning an unconstrained type 4283 4284 if Comes_From_Source (Body_Id) 4285 and then Ekind (Spec_Id) = E_Function 4286 and then Returns_Unconstrained_Type (Spec_Id) 4287 4288 -- If function builds in place, i.e. returns a limited type, 4289 -- inlining cannot be done. 4290 4291 and then not Is_Limited_Type (Etype (Spec_Id)) 4292 then 4293 Check_And_Split_Unconstrained_Function (N, Spec_Id, Body_Id); 4294 4295 else 4296 declare 4297 Subp_Body : constant Node_Id := 4298 Unit_Declaration_Node (Body_Id); 4299 Subp_Decl : constant List_Id := Declarations (Subp_Body); 4300 4301 begin 4302 -- Do not pass inlining to the backend if the subprogram 4303 -- has declarations or statements which cannot be inlined 4304 -- by the backend. This check is done here to emit an 4305 -- error instead of the generic warning message reported 4306 -- by the GCC backend (ie. "function might not be 4307 -- inlinable"). 4308 4309 if Present (Subp_Decl) 4310 and then Has_Excluded_Declaration (Spec_Id, Subp_Decl) 4311 then 4312 null; 4313 4314 elsif Has_Excluded_Statement 4315 (Spec_Id, 4316 Statements 4317 (Handled_Statement_Sequence (Subp_Body))) 4318 then 4319 null; 4320 4321 -- If the backend inlining is available then at this 4322 -- stage we only have to mark the subprogram as inlined. 4323 -- The expander will take care of registering it in the 4324 -- table of subprograms inlined by the backend a part of 4325 -- processing calls to it (cf. Expand_Call) 4326 4327 else 4328 Set_Is_Inlined (Spec_Id); 4329 end if; 4330 end; 4331 end if; 4332 end if; 4333 end if; 4334 4335 -- In GNATprove mode, inline only when there is a separate subprogram 4336 -- declaration for now, as inlining of subprogram bodies acting as 4337 -- declarations, or subprogram stubs, are not supported by front-end 4338 -- inlining. This inlining should occur after analysis of the body, so 4339 -- that it is known whether the value of SPARK_Mode, which can be 4340 -- defined by a pragma inside the body, is applicable to the body. 4341 -- Inlining can be disabled with switch -gnatdm 4342 4343 elsif GNATprove_Mode 4344 and then Full_Analysis 4345 and then not Inside_A_Generic 4346 and then Present (Spec_Id) 4347 and then 4348 Nkind (Unit_Declaration_Node (Spec_Id)) = N_Subprogram_Declaration 4349 and then Body_Has_SPARK_Mode_On 4350 and then Can_Be_Inlined_In_GNATprove_Mode (Spec_Id, Body_Id) 4351 and then not Body_Has_Contract 4352 and then not Debug_Flag_M 4353 then 4354 Build_Body_To_Inline (N, Spec_Id); 4355 end if; 4356 4357 -- When generating code, inherited pre/postconditions are handled when 4358 -- expanding the corresponding contract. 4359 4360 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis 4361 -- of the specification we have to install the private withed units. 4362 -- This holds for child units as well. 4363 4364 if Is_Compilation_Unit (Body_Id) 4365 or else Nkind (Parent (N)) = N_Compilation_Unit 4366 then 4367 Install_Private_With_Clauses (Body_Id); 4368 end if; 4369 4370 Check_Anonymous_Return; 4371 4372 -- Set the Protected_Formal field of each extra formal of the protected 4373 -- subprogram to reference the corresponding extra formal of the 4374 -- subprogram that implements it. For regular formals this occurs when 4375 -- the protected subprogram's declaration is expanded, but the extra 4376 -- formals don't get created until the subprogram is frozen. We need to 4377 -- do this before analyzing the protected subprogram's body so that any 4378 -- references to the original subprogram's extra formals will be changed 4379 -- refer to the implementing subprogram's formals (see Expand_Formal). 4380 4381 if Present (Spec_Id) 4382 and then Is_Protected_Type (Scope (Spec_Id)) 4383 and then Present (Protected_Body_Subprogram (Spec_Id)) 4384 then 4385 declare 4386 Impl_Subp : constant Entity_Id := 4387 Protected_Body_Subprogram (Spec_Id); 4388 Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id); 4389 Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp); 4390 4391 begin 4392 while Present (Prot_Ext_Formal) loop 4393 pragma Assert (Present (Impl_Ext_Formal)); 4394 Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal); 4395 Next_Formal_With_Extras (Prot_Ext_Formal); 4396 Next_Formal_With_Extras (Impl_Ext_Formal); 4397 end loop; 4398 end; 4399 end if; 4400 4401 -- Generate minimum accessibility local objects to correspond with 4402 -- any extra formal added for anonymous access types. This new local 4403 -- object can then be used instead of the formal in case it is used 4404 -- in an actual to a call to a nested subprogram. 4405 4406 -- This method is used to supplement our "small integer model" for 4407 -- accessibility-check generation (for more information see 4408 -- Dynamic_Accessibility_Level). 4409 4410 -- Because we allow accessibility values greater than our expected value 4411 -- passing along the same extra accessibility formal as an actual 4412 -- to a nested subprogram becomes a problem because high values mean 4413 -- different things to the callee even though they are the same to the 4414 -- caller. So, as described in the first section, we create a local 4415 -- object representing the minimum of the accessibility level value that 4416 -- is passed in and the accessibility level of the callee's parameter 4417 -- and locals and use it in the case of a call to a nested subprogram. 4418 -- This generated object is refered to as a "minimum accessiblity 4419 -- level." 4420 4421 if Present (Spec_Id) or else Present (Body_Id) then 4422 Body_Nod := Unit_Declaration_Node (Body_Id); 4423 4424 declare 4425 Form : Entity_Id; 4426 begin 4427 -- Grab the appropriate formal depending on whether there exists 4428 -- an actual spec for the subprogram or whether we are dealing 4429 -- with a protected subprogram. 4430 4431 if Present (Spec_Id) then 4432 if Present (Protected_Body_Subprogram (Spec_Id)) then 4433 Form := First_Formal (Protected_Body_Subprogram (Spec_Id)); 4434 else 4435 Form := First_Formal (Spec_Id); 4436 end if; 4437 else 4438 Form := First_Formal (Body_Id); 4439 end if; 4440 4441 -- Loop through formals if the subprogram is capable of accepting 4442 -- a generated local object. If it is not then it is also not 4443 -- capable of having local subprograms meaning it would not need 4444 -- a minimum accessibility level object anyway. 4445 4446 if Present (Body_Nod) 4447 and then Has_Declarations (Body_Nod) 4448 and then Nkind (Body_Nod) /= N_Package_Specification 4449 then 4450 while Present (Form) loop 4451 4452 if Present (Extra_Accessibility (Form)) 4453 and then No (Minimum_Accessibility (Form)) 4454 then 4455 -- Generate the minimum accessibility level object 4456 4457 -- A60b : integer := integer'min(2, paramL); 4458 4459 declare 4460 Loc : constant Source_Ptr := Sloc (Body_Nod); 4461 Obj_Node : constant Node_Id := 4462 Make_Object_Declaration (Loc, 4463 Defining_Identifier => 4464 Make_Temporary 4465 (Loc, 'A', Extra_Accessibility (Form)), 4466 Object_Definition => New_Occurrence_Of 4467 (Standard_Integer, Loc), 4468 Expression => 4469 Make_Attribute_Reference (Loc, 4470 Prefix => New_Occurrence_Of 4471 (Standard_Integer, Loc), 4472 Attribute_Name => Name_Min, 4473 Expressions => New_List ( 4474 Make_Integer_Literal (Loc, 4475 Object_Access_Level (Form)), 4476 New_Occurrence_Of 4477 (Extra_Accessibility (Form), Loc)))); 4478 begin 4479 -- Add the new local object to the Minimum_Acc_Obj to 4480 -- be later prepended to the subprogram's list of 4481 -- declarations after we are sure all expansion is 4482 -- done. 4483 4484 if Present (Minimum_Acc_Objs) then 4485 Prepend (Obj_Node, Minimum_Acc_Objs); 4486 else 4487 Minimum_Acc_Objs := New_List (Obj_Node); 4488 end if; 4489 4490 -- Register the object and analyze it 4491 4492 Set_Minimum_Accessibility 4493 (Form, Defining_Identifier (Obj_Node)); 4494 4495 Analyze (Obj_Node); 4496 end; 4497 end if; 4498 4499 Next_Formal (Form); 4500 end loop; 4501 end if; 4502 end; 4503 end if; 4504 4505 -- Now we can go on to analyze the body 4506 4507 HSS := Handled_Statement_Sequence (N); 4508 Set_Actual_Subtypes (N, Current_Scope); 4509 4510 -- Add a declaration for the Protection object, renaming declarations 4511 -- for discriminals and privals and finally a declaration for the entry 4512 -- family index (if applicable). This form of early expansion is done 4513 -- when the Expander is active because Install_Private_Data_Declarations 4514 -- references entities which were created during regular expansion. The 4515 -- subprogram entity must come from source, and not be an internally 4516 -- generated subprogram. 4517 4518 if Expander_Active 4519 and then Present (Prot_Typ) 4520 and then Present (Spec_Id) 4521 and then Comes_From_Source (Spec_Id) 4522 and then not Is_Eliminated (Spec_Id) 4523 then 4524 Install_Private_Data_Declarations 4525 (Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N)); 4526 end if; 4527 4528 -- Ada 2012 (AI05-0151): Incomplete types coming from a limited context 4529 -- may now appear in parameter and result profiles. Since the analysis 4530 -- of a subprogram body may use the parameter and result profile of the 4531 -- spec, swap any limited views with their non-limited counterpart. 4532 4533 if Ada_Version >= Ada_2012 and then Present (Spec_Id) then 4534 Exch_Views := Exchange_Limited_Views (Spec_Id); 4535 end if; 4536 4537 -- If the return type is an anonymous access type whose designated type 4538 -- is the limited view of a class-wide type and the non-limited view is 4539 -- available, update the return type accordingly. 4540 4541 if Ada_Version >= Ada_2005 and then Present (Spec_Id) then 4542 declare 4543 Etyp : Entity_Id; 4544 Rtyp : Entity_Id; 4545 4546 begin 4547 Rtyp := Etype (Spec_Id); 4548 4549 if Ekind (Rtyp) = E_Anonymous_Access_Type then 4550 Etyp := Directly_Designated_Type (Rtyp); 4551 4552 if Is_Class_Wide_Type (Etyp) 4553 and then From_Limited_With (Etyp) 4554 then 4555 Desig_View := Etyp; 4556 Set_Directly_Designated_Type (Rtyp, Available_View (Etyp)); 4557 end if; 4558 end if; 4559 end; 4560 end if; 4561 4562 -- Analyze any aspect specifications that appear on the subprogram body 4563 4564 if Has_Aspects (N) then 4565 Analyze_Aspects_On_Subprogram_Body_Or_Stub (N); 4566 end if; 4567 4568 Analyze_Declarations (Declarations (N)); 4569 4570 -- Verify that the SPARK_Mode of the body agrees with that of its spec 4571 4572 if Present (Spec_Id) and then Present (SPARK_Pragma (Body_Id)) then 4573 if Present (SPARK_Pragma (Spec_Id)) then 4574 if Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Spec_Id)) = Off 4575 and then 4576 Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = On 4577 then 4578 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 4579 Error_Msg_N ("incorrect application of SPARK_Mode#", N); 4580 Error_Msg_Sloc := Sloc (SPARK_Pragma (Spec_Id)); 4581 Error_Msg_NE 4582 ("\value Off was set for SPARK_Mode on & #", N, Spec_Id); 4583 end if; 4584 4585 elsif Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Body_Stub then 4586 null; 4587 4588 else 4589 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 4590 Error_Msg_N ("incorrect application of SPARK_Mode #", N); 4591 Error_Msg_Sloc := Sloc (Spec_Id); 4592 Error_Msg_NE 4593 ("\no value was set for SPARK_Mode on & #", N, Spec_Id); 4594 end if; 4595 end if; 4596 4597 -- A subprogram body freezes its own contract. Analyze the contract 4598 -- after the declarations of the body have been processed as pragmas 4599 -- are now chained on the contract of the subprogram body. 4600 4601 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id); 4602 4603 -- Check completion, and analyze the statements 4604 4605 Check_Completion; 4606 Inspect_Deferred_Constant_Completion (Declarations (N)); 4607 Analyze (HSS); 4608 4609 -- Add the generated minimum accessibility objects to the subprogram 4610 -- body's list of declarations after analysis of the statements and 4611 -- contracts. 4612 4613 while Is_Non_Empty_List (Minimum_Acc_Objs) loop 4614 if Present (Declarations (Body_Nod)) then 4615 Prepend (Remove_Head (Minimum_Acc_Objs), Declarations (Body_Nod)); 4616 else 4617 Set_Declarations 4618 (Body_Nod, New_List (Remove_Head (Minimum_Acc_Objs))); 4619 end if; 4620 end loop; 4621 4622 -- Deal with end of scope processing for the body 4623 4624 Process_End_Label (HSS, 't', Current_Scope); 4625 Update_Use_Clause_Chain; 4626 End_Scope; 4627 4628 -- If we are compiling an entry wrapper, remove the enclosing 4629 -- synchronized object from the stack. 4630 4631 if Is_Entry_Wrapper (Body_Id) then 4632 End_Scope; 4633 end if; 4634 4635 Check_Subprogram_Order (N); 4636 Set_Analyzed (Body_Id); 4637 4638 -- If we have a separate spec, then the analysis of the declarations 4639 -- caused the entities in the body to be chained to the spec id, but 4640 -- we want them chained to the body id. Only the formal parameters 4641 -- end up chained to the spec id in this case. 4642 4643 if Present (Spec_Id) then 4644 4645 -- We must conform to the categorization of our spec 4646 4647 Validate_Categorization_Dependency (N, Spec_Id); 4648 4649 -- And if this is a child unit, the parent units must conform 4650 4651 if Is_Child_Unit (Spec_Id) then 4652 Validate_Categorization_Dependency 4653 (Unit_Declaration_Node (Spec_Id), Spec_Id); 4654 end if; 4655 4656 -- Here is where we move entities from the spec to the body 4657 4658 -- Case where there are entities that stay with the spec 4659 4660 if Present (Last_Real_Spec_Entity) then 4661 4662 -- No body entities (happens when the only real spec entities come 4663 -- from precondition and postcondition pragmas). 4664 4665 if No (Last_Entity (Body_Id)) then 4666 Set_First_Entity (Body_Id, Next_Entity (Last_Real_Spec_Entity)); 4667 4668 -- Body entities present (formals), so chain stuff past them 4669 4670 else 4671 Link_Entities 4672 (Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity)); 4673 end if; 4674 4675 Set_Next_Entity (Last_Real_Spec_Entity, Empty); 4676 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 4677 Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity); 4678 4679 -- Case where there are no spec entities, in this case there can be 4680 -- no body entities either, so just move everything. 4681 4682 -- If the body is generated for an expression function, it may have 4683 -- been preanalyzed already, if 'access was applied to it. 4684 4685 else 4686 if Nkind (Original_Node (Unit_Declaration_Node (Spec_Id))) /= 4687 N_Expression_Function 4688 then 4689 pragma Assert (No (Last_Entity (Body_Id))); 4690 null; 4691 end if; 4692 4693 Set_First_Entity (Body_Id, First_Entity (Spec_Id)); 4694 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 4695 Set_First_Entity (Spec_Id, Empty); 4696 Set_Last_Entity (Spec_Id, Empty); 4697 end if; 4698 4699 -- Otherwise the body does not complete a previous declaration. Check 4700 -- the categorization of the body against the units it withs. 4701 4702 else 4703 Validate_Categorization_Dependency (N, Body_Id); 4704 end if; 4705 4706 Check_Missing_Return; 4707 4708 -- Now we are going to check for variables that are never modified in 4709 -- the body of the procedure. But first we deal with a special case 4710 -- where we want to modify this check. If the body of the subprogram 4711 -- starts with a raise statement or its equivalent, or if the body 4712 -- consists entirely of a null statement, then it is pretty obvious that 4713 -- it is OK to not reference the parameters. For example, this might be 4714 -- the following common idiom for a stubbed function: statement of the 4715 -- procedure raises an exception. In particular this deals with the 4716 -- common idiom of a stubbed function, which appears something like: 4717 4718 -- function F (A : Integer) return Some_Type; 4719 -- X : Some_Type; 4720 -- begin 4721 -- raise Program_Error; 4722 -- return X; 4723 -- end F; 4724 4725 -- Here the purpose of X is simply to satisfy the annoying requirement 4726 -- in Ada that there be at least one return, and we certainly do not 4727 -- want to go posting warnings on X that it is not initialized. On 4728 -- the other hand, if X is entirely unreferenced that should still 4729 -- get a warning. 4730 4731 -- What we do is to detect these cases, and if we find them, flag the 4732 -- subprogram as being Is_Trivial_Subprogram and then use that flag to 4733 -- suppress unwanted warnings. For the case of the function stub above 4734 -- we have a special test to set X as apparently assigned to suppress 4735 -- the warning. 4736 4737 declare 4738 Stm : Node_Id; 4739 4740 begin 4741 -- Skip call markers installed by the ABE mechanism, labels, and 4742 -- Push_xxx_Error_Label to find the first real statement. 4743 4744 Stm := First (Statements (HSS)); 4745 while Nkind_In (Stm, N_Call_Marker, N_Label) 4746 or else Nkind (Stm) in N_Push_xxx_Label 4747 loop 4748 Next (Stm); 4749 end loop; 4750 4751 -- Do the test on the original statement before expansion 4752 4753 declare 4754 Ostm : constant Node_Id := Original_Node (Stm); 4755 4756 begin 4757 -- If explicit raise statement, turn on flag 4758 4759 if Nkind (Ostm) = N_Raise_Statement then 4760 Set_Trivial_Subprogram (Stm); 4761 4762 -- If null statement, and no following statements, turn on flag 4763 4764 elsif Nkind (Stm) = N_Null_Statement 4765 and then Comes_From_Source (Stm) 4766 and then No (Next (Stm)) 4767 then 4768 Set_Trivial_Subprogram (Stm); 4769 4770 -- Check for explicit call cases which likely raise an exception 4771 4772 elsif Nkind (Ostm) = N_Procedure_Call_Statement then 4773 if Is_Entity_Name (Name (Ostm)) then 4774 declare 4775 Ent : constant Entity_Id := Entity (Name (Ostm)); 4776 4777 begin 4778 -- If the procedure is marked No_Return, then likely it 4779 -- raises an exception, but in any case it is not coming 4780 -- back here, so turn on the flag. 4781 4782 if Present (Ent) 4783 and then Ekind (Ent) = E_Procedure 4784 and then No_Return (Ent) 4785 then 4786 Set_Trivial_Subprogram (Stm); 4787 end if; 4788 end; 4789 end if; 4790 end if; 4791 end; 4792 end; 4793 4794 -- Check for variables that are never modified 4795 4796 declare 4797 E1 : Entity_Id; 4798 E2 : Entity_Id; 4799 4800 begin 4801 -- If there is a separate spec, then transfer Never_Set_In_Source 4802 -- flags from out parameters to the corresponding entities in the 4803 -- body. The reason we do that is we want to post error flags on 4804 -- the body entities, not the spec entities. 4805 4806 if Present (Spec_Id) then 4807 E1 := First_Entity (Spec_Id); 4808 while Present (E1) loop 4809 if Ekind (E1) = E_Out_Parameter then 4810 E2 := First_Entity (Body_Id); 4811 while Present (E2) loop 4812 exit when Chars (E1) = Chars (E2); 4813 Next_Entity (E2); 4814 end loop; 4815 4816 if Present (E2) then 4817 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1)); 4818 end if; 4819 end if; 4820 4821 Next_Entity (E1); 4822 end loop; 4823 end if; 4824 4825 -- Check references of the subprogram spec when we are dealing with 4826 -- an expression function due to it having a generated body. 4827 -- Otherwise, we simply check the formals of the subprogram body. 4828 4829 if Present (Spec_Id) 4830 and then Is_Expression_Function (Spec_Id) 4831 then 4832 Check_References (Spec_Id); 4833 else 4834 Check_References (Body_Id); 4835 end if; 4836 end; 4837 4838 -- Check for nested subprogram, and mark outer level subprogram if so 4839 4840 declare 4841 Ent : Entity_Id; 4842 4843 begin 4844 if Present (Spec_Id) then 4845 Ent := Spec_Id; 4846 else 4847 Ent := Body_Id; 4848 end if; 4849 4850 loop 4851 Ent := Enclosing_Subprogram (Ent); 4852 exit when No (Ent) or else Is_Subprogram (Ent); 4853 end loop; 4854 4855 if Present (Ent) then 4856 Set_Has_Nested_Subprogram (Ent); 4857 end if; 4858 end; 4859 4860 -- Restore the limited views in the spec, if any, to let the back end 4861 -- process it without running into circularities. 4862 4863 if Exch_Views /= No_Elist then 4864 Restore_Limited_Views (Exch_Views); 4865 end if; 4866 4867 if Mask_Types /= No_Elist then 4868 Unmask_Unfrozen_Types (Mask_Types); 4869 end if; 4870 4871 if Present (Desig_View) then 4872 Set_Directly_Designated_Type (Etype (Spec_Id), Desig_View); 4873 end if; 4874 4875 <<Leave>> 4876 if Present (Ignored_Ghost_Region) then 4877 Expander_Active := Saved_EA; 4878 end if; 4879 4880 Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP; 4881 Restore_Ghost_Region (Saved_GM, Saved_IGR); 4882 end Analyze_Subprogram_Body_Helper; 4883 4884 ------------------------------------ 4885 -- Analyze_Subprogram_Declaration -- 4886 ------------------------------------ 4887 4888 procedure Analyze_Subprogram_Declaration (N : Node_Id) is 4889 Scop : constant Entity_Id := Current_Scope; 4890 Designator : Entity_Id; 4891 4892 Is_Completion : Boolean; 4893 -- Indicates whether a null procedure declaration is a completion 4894 4895 begin 4896 -- Null procedures are not allowed in SPARK 4897 4898 if Nkind (Specification (N)) = N_Procedure_Specification 4899 and then Null_Present (Specification (N)) 4900 then 4901 Check_SPARK_05_Restriction ("null procedure is not allowed", N); 4902 4903 -- Null procedures are allowed in protected types, following the 4904 -- recent AI12-0147. 4905 4906 if Is_Protected_Type (Current_Scope) 4907 and then Ada_Version < Ada_2012 4908 then 4909 Error_Msg_N ("protected operation cannot be a null procedure", N); 4910 end if; 4911 4912 Analyze_Null_Procedure (N, Is_Completion); 4913 4914 -- The null procedure acts as a body, nothing further is needed 4915 4916 if Is_Completion then 4917 return; 4918 end if; 4919 end if; 4920 4921 Designator := Analyze_Subprogram_Specification (Specification (N)); 4922 4923 -- A reference may already have been generated for the unit name, in 4924 -- which case the following call is redundant. However it is needed for 4925 -- declarations that are the rewriting of an expression function. 4926 4927 Generate_Definition (Designator); 4928 4929 -- Set the SPARK mode from the current context (may be overwritten later 4930 -- with explicit pragma). This is not done for entry barrier functions 4931 -- because they are generated outside the protected type and should not 4932 -- carry the mode of the enclosing context. 4933 4934 if Nkind (N) = N_Subprogram_Declaration 4935 and then Is_Entry_Barrier_Function (N) 4936 then 4937 null; 4938 4939 else 4940 Set_SPARK_Pragma (Designator, SPARK_Mode_Pragma); 4941 Set_SPARK_Pragma_Inherited (Designator); 4942 end if; 4943 4944 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in case 4945 -- the body of this subprogram is instantiated or inlined later and out 4946 -- of context. The body uses this attribute to restore the value of the 4947 -- global flag. 4948 4949 if Ignore_SPARK_Mode_Pragmas_In_Instance then 4950 Set_Ignore_SPARK_Mode_Pragmas (Designator); 4951 end if; 4952 4953 -- Preserve relevant elaboration-related attributes of the context which 4954 -- are no longer available or very expensive to recompute once analysis, 4955 -- resolution, and expansion are over. 4956 4957 Mark_Elaboration_Attributes 4958 (N_Id => Designator, 4959 Checks => True, 4960 Warnings => True); 4961 4962 if Debug_Flag_C then 4963 Write_Str ("==> subprogram spec "); 4964 Write_Name (Chars (Designator)); 4965 Write_Str (" from "); 4966 Write_Location (Sloc (N)); 4967 Write_Eol; 4968 Indent; 4969 end if; 4970 4971 Validate_RCI_Subprogram_Declaration (N); 4972 New_Overloaded_Entity (Designator); 4973 Check_Delayed_Subprogram (Designator); 4974 4975 -- If the type of the first formal of the current subprogram is a non- 4976 -- generic tagged private type, mark the subprogram as being a private 4977 -- primitive. Ditto if this is a function with controlling result, and 4978 -- the return type is currently private. In both cases, the type of the 4979 -- controlling argument or result must be in the current scope for the 4980 -- operation to be primitive. 4981 4982 if Has_Controlling_Result (Designator) 4983 and then Is_Private_Type (Etype (Designator)) 4984 and then Scope (Etype (Designator)) = Current_Scope 4985 and then not Is_Generic_Actual_Type (Etype (Designator)) 4986 then 4987 Set_Is_Private_Primitive (Designator); 4988 4989 elsif Present (First_Formal (Designator)) then 4990 declare 4991 Formal_Typ : constant Entity_Id := 4992 Etype (First_Formal (Designator)); 4993 begin 4994 Set_Is_Private_Primitive (Designator, 4995 Is_Tagged_Type (Formal_Typ) 4996 and then Scope (Formal_Typ) = Current_Scope 4997 and then Is_Private_Type (Formal_Typ) 4998 and then not Is_Generic_Actual_Type (Formal_Typ)); 4999 end; 5000 end if; 5001 5002 -- Ada 2005 (AI-251): Abstract interface primitives must be abstract 5003 -- or null. 5004 5005 if Ada_Version >= Ada_2005 5006 and then Comes_From_Source (N) 5007 and then Is_Dispatching_Operation (Designator) 5008 then 5009 declare 5010 E : Entity_Id; 5011 Etyp : Entity_Id; 5012 5013 begin 5014 if Has_Controlling_Result (Designator) then 5015 Etyp := Etype (Designator); 5016 5017 else 5018 E := First_Entity (Designator); 5019 while Present (E) 5020 and then Is_Formal (E) 5021 and then not Is_Controlling_Formal (E) 5022 loop 5023 Next_Entity (E); 5024 end loop; 5025 5026 Etyp := Etype (E); 5027 end if; 5028 5029 if Is_Access_Type (Etyp) then 5030 Etyp := Directly_Designated_Type (Etyp); 5031 end if; 5032 5033 if Is_Interface (Etyp) 5034 and then not Is_Abstract_Subprogram (Designator) 5035 and then not (Ekind (Designator) = E_Procedure 5036 and then Null_Present (Specification (N))) 5037 then 5038 Error_Msg_Name_1 := Chars (Defining_Entity (N)); 5039 5040 -- Specialize error message based on procedures vs. functions, 5041 -- since functions can't be null subprograms. 5042 5043 if Ekind (Designator) = E_Procedure then 5044 Error_Msg_N 5045 ("interface procedure % must be abstract or null", N); 5046 else 5047 Error_Msg_N 5048 ("interface function % must be abstract", N); 5049 end if; 5050 end if; 5051 end; 5052 end if; 5053 5054 -- What is the following code for, it used to be 5055 5056 -- ??? Set_Suppress_Elaboration_Checks 5057 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator)); 5058 5059 -- The following seems equivalent, but a bit dubious 5060 5061 if Elaboration_Checks_Suppressed (Designator) then 5062 Set_Kill_Elaboration_Checks (Designator); 5063 end if; 5064 5065 -- For a compilation unit, set body required. This flag will only be 5066 -- reset if a valid Import or Interface pragma is processed later on. 5067 5068 if Nkind (Parent (N)) = N_Compilation_Unit then 5069 Set_Body_Required (Parent (N), True); 5070 5071 if Ada_Version >= Ada_2005 5072 and then Nkind (Specification (N)) = N_Procedure_Specification 5073 and then Null_Present (Specification (N)) 5074 then 5075 Error_Msg_N 5076 ("null procedure cannot be declared at library level", N); 5077 end if; 5078 end if; 5079 5080 Generate_Reference_To_Formals (Designator); 5081 Check_Eliminated (Designator); 5082 5083 if Debug_Flag_C then 5084 Outdent; 5085 Write_Str ("<== subprogram spec "); 5086 Write_Name (Chars (Designator)); 5087 Write_Str (" from "); 5088 Write_Location (Sloc (N)); 5089 Write_Eol; 5090 end if; 5091 5092 -- Indicate that this is a protected operation, because it may be used 5093 -- in subsequent declarations within the protected type. 5094 5095 if Is_Protected_Type (Current_Scope) then 5096 Set_Convention (Designator, Convention_Protected); 5097 end if; 5098 5099 List_Inherited_Pre_Post_Aspects (Designator); 5100 5101 -- Process the aspects before establishing the proper categorization in 5102 -- case the subprogram is a compilation unit and one of its aspects is 5103 -- converted into a categorization pragma. 5104 5105 if Has_Aspects (N) then 5106 Analyze_Aspect_Specifications (N, Designator); 5107 end if; 5108 5109 if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then 5110 Set_Categorization_From_Scope (Designator, Scop); 5111 5112 -- Otherwise the unit is a compilation unit and/or a child unit. Set the 5113 -- proper categorization of the unit based on its pragmas. 5114 5115 else 5116 Push_Scope (Designator); 5117 Set_Categorization_From_Pragmas (N); 5118 Validate_Categorization_Dependency (N, Designator); 5119 Pop_Scope; 5120 end if; 5121 end Analyze_Subprogram_Declaration; 5122 5123 -------------------------------------- 5124 -- Analyze_Subprogram_Specification -- 5125 -------------------------------------- 5126 5127 -- Reminder: N here really is a subprogram specification (not a subprogram 5128 -- declaration). This procedure is called to analyze the specification in 5129 -- both subprogram bodies and subprogram declarations (specs). 5130 5131 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is 5132 function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean; 5133 -- Determine whether entity E denotes the spec or body of an invariant 5134 -- procedure. 5135 5136 ------------------------------------ 5137 -- Is_Invariant_Procedure_Or_Body -- 5138 ------------------------------------ 5139 5140 function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean is 5141 Decl : constant Node_Id := Unit_Declaration_Node (E); 5142 Spec : Entity_Id; 5143 5144 begin 5145 if Nkind (Decl) = N_Subprogram_Body then 5146 Spec := Corresponding_Spec (Decl); 5147 else 5148 Spec := E; 5149 end if; 5150 5151 return 5152 Present (Spec) 5153 and then Ekind (Spec) = E_Procedure 5154 and then (Is_Partial_Invariant_Procedure (Spec) 5155 or else Is_Invariant_Procedure (Spec)); 5156 end Is_Invariant_Procedure_Or_Body; 5157 5158 -- Local variables 5159 5160 Designator : constant Entity_Id := Defining_Entity (N); 5161 Formals : constant List_Id := Parameter_Specifications (N); 5162 5163 -- Start of processing for Analyze_Subprogram_Specification 5164 5165 begin 5166 -- User-defined operator is not allowed in SPARK, except as a renaming 5167 5168 if Nkind (Defining_Unit_Name (N)) = N_Defining_Operator_Symbol 5169 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration 5170 then 5171 Check_SPARK_05_Restriction 5172 ("user-defined operator is not allowed", N); 5173 end if; 5174 5175 -- Proceed with analysis. Do not emit a cross-reference entry if the 5176 -- specification comes from an expression function, because it may be 5177 -- the completion of a previous declaration. If it is not, the cross- 5178 -- reference entry will be emitted for the new subprogram declaration. 5179 5180 if Nkind (Parent (N)) /= N_Expression_Function then 5181 Generate_Definition (Designator); 5182 end if; 5183 5184 if Nkind (N) = N_Function_Specification then 5185 Set_Ekind (Designator, E_Function); 5186 Set_Mechanism (Designator, Default_Mechanism); 5187 else 5188 Set_Ekind (Designator, E_Procedure); 5189 Set_Etype (Designator, Standard_Void_Type); 5190 end if; 5191 5192 -- Flag Is_Inlined_Always is True by default, and reversed to False for 5193 -- those subprograms which could be inlined in GNATprove mode (because 5194 -- Body_To_Inline is non-Empty) but should not be inlined. 5195 5196 if GNATprove_Mode then 5197 Set_Is_Inlined_Always (Designator); 5198 end if; 5199 5200 -- Introduce new scope for analysis of the formals and the return type 5201 5202 Set_Scope (Designator, Current_Scope); 5203 5204 if Present (Formals) then 5205 Push_Scope (Designator); 5206 Process_Formals (Formals, N); 5207 5208 -- Check dimensions in N for formals with default expression 5209 5210 Analyze_Dimension_Formals (N, Formals); 5211 5212 -- Ada 2005 (AI-345): If this is an overriding operation of an 5213 -- inherited interface operation, and the controlling type is 5214 -- a synchronized type, replace the type with its corresponding 5215 -- record, to match the proper signature of an overriding operation. 5216 -- Same processing for an access parameter whose designated type is 5217 -- derived from a synchronized interface. 5218 5219 -- This modification is not done for invariant procedures because 5220 -- the corresponding record may not necessarely be visible when the 5221 -- concurrent type acts as the full view of a private type. 5222 5223 -- package Pack is 5224 -- type Prot is private with Type_Invariant => ...; 5225 -- procedure ConcInvariant (Obj : Prot); 5226 -- private 5227 -- protected type Prot is ...; 5228 -- type Concurrent_Record_Prot is record ...; 5229 -- procedure ConcInvariant (Obj : Prot) is 5230 -- ... 5231 -- end ConcInvariant; 5232 -- end Pack; 5233 5234 -- In the example above, both the spec and body of the invariant 5235 -- procedure must utilize the private type as the controlling type. 5236 5237 if Ada_Version >= Ada_2005 5238 and then not Is_Invariant_Procedure_Or_Body (Designator) 5239 then 5240 declare 5241 Formal : Entity_Id; 5242 Formal_Typ : Entity_Id; 5243 Rec_Typ : Entity_Id; 5244 Desig_Typ : Entity_Id; 5245 5246 begin 5247 Formal := First_Formal (Designator); 5248 while Present (Formal) loop 5249 Formal_Typ := Etype (Formal); 5250 5251 if Is_Concurrent_Type (Formal_Typ) 5252 and then Present (Corresponding_Record_Type (Formal_Typ)) 5253 then 5254 Rec_Typ := Corresponding_Record_Type (Formal_Typ); 5255 5256 if Present (Interfaces (Rec_Typ)) then 5257 Set_Etype (Formal, Rec_Typ); 5258 end if; 5259 5260 elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then 5261 Desig_Typ := Designated_Type (Formal_Typ); 5262 5263 if Is_Concurrent_Type (Desig_Typ) 5264 and then Present (Corresponding_Record_Type (Desig_Typ)) 5265 then 5266 Rec_Typ := Corresponding_Record_Type (Desig_Typ); 5267 5268 if Present (Interfaces (Rec_Typ)) then 5269 Set_Directly_Designated_Type (Formal_Typ, Rec_Typ); 5270 end if; 5271 end if; 5272 end if; 5273 5274 Next_Formal (Formal); 5275 end loop; 5276 end; 5277 end if; 5278 5279 End_Scope; 5280 5281 -- The subprogram scope is pushed and popped around the processing of 5282 -- the return type for consistency with call above to Process_Formals 5283 -- (which itself can call Analyze_Return_Type), and to ensure that any 5284 -- itype created for the return type will be associated with the proper 5285 -- scope. 5286 5287 elsif Nkind (N) = N_Function_Specification then 5288 Push_Scope (Designator); 5289 Analyze_Return_Type (N); 5290 End_Scope; 5291 end if; 5292 5293 -- Function case 5294 5295 if Nkind (N) = N_Function_Specification then 5296 5297 -- Deal with operator symbol case 5298 5299 if Nkind (Designator) = N_Defining_Operator_Symbol then 5300 Valid_Operator_Definition (Designator); 5301 end if; 5302 5303 May_Need_Actuals (Designator); 5304 5305 -- Ada 2005 (AI-251): If the return type is abstract, verify that 5306 -- the subprogram is abstract also. This does not apply to renaming 5307 -- declarations, where abstractness is inherited, and to subprogram 5308 -- bodies generated for stream operations, which become renamings as 5309 -- bodies. 5310 5311 -- In case of primitives associated with abstract interface types 5312 -- the check is applied later (see Analyze_Subprogram_Declaration). 5313 5314 if not Nkind_In (Original_Node (Parent (N)), 5315 N_Abstract_Subprogram_Declaration, 5316 N_Formal_Abstract_Subprogram_Declaration, 5317 N_Subprogram_Renaming_Declaration) 5318 then 5319 if Is_Abstract_Type (Etype (Designator)) 5320 and then not Is_Interface (Etype (Designator)) 5321 then 5322 Error_Msg_N 5323 ("function that returns abstract type must be abstract", N); 5324 5325 -- Ada 2012 (AI-0073): Extend this test to subprograms with an 5326 -- access result whose designated type is abstract. 5327 5328 elsif Ada_Version >= Ada_2012 5329 and then Nkind (Result_Definition (N)) = N_Access_Definition 5330 and then 5331 not Is_Class_Wide_Type (Designated_Type (Etype (Designator))) 5332 and then Is_Abstract_Type (Designated_Type (Etype (Designator))) 5333 then 5334 Error_Msg_N 5335 ("function whose access result designates abstract type " 5336 & "must be abstract", N); 5337 end if; 5338 end if; 5339 end if; 5340 5341 return Designator; 5342 end Analyze_Subprogram_Specification; 5343 5344 ----------------------- 5345 -- Check_Conformance -- 5346 ----------------------- 5347 5348 procedure Check_Conformance 5349 (New_Id : Entity_Id; 5350 Old_Id : Entity_Id; 5351 Ctype : Conformance_Type; 5352 Errmsg : Boolean; 5353 Conforms : out Boolean; 5354 Err_Loc : Node_Id := Empty; 5355 Get_Inst : Boolean := False; 5356 Skip_Controlling_Formals : Boolean := False) 5357 is 5358 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id); 5359 -- Sets Conforms to False. If Errmsg is False, then that's all it does. 5360 -- If Errmsg is True, then processing continues to post an error message 5361 -- for conformance error on given node. Two messages are output. The 5362 -- first message points to the previous declaration with a general "no 5363 -- conformance" message. The second is the detailed reason, supplied as 5364 -- Msg. The parameter N provide information for a possible & insertion 5365 -- in the message, and also provides the location for posting the 5366 -- message in the absence of a specified Err_Loc location. 5367 5368 function Conventions_Match 5369 (Id1 : Entity_Id; 5370 Id2 : Entity_Id) return Boolean; 5371 -- Determine whether the conventions of arbitrary entities Id1 and Id2 5372 -- match. 5373 5374 ----------------------- 5375 -- Conformance_Error -- 5376 ----------------------- 5377 5378 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is 5379 Enode : Node_Id; 5380 5381 begin 5382 Conforms := False; 5383 5384 if Errmsg then 5385 if No (Err_Loc) then 5386 Enode := N; 5387 else 5388 Enode := Err_Loc; 5389 end if; 5390 5391 Error_Msg_Sloc := Sloc (Old_Id); 5392 5393 case Ctype is 5394 when Type_Conformant => 5395 Error_Msg_N -- CODEFIX 5396 ("not type conformant with declaration#!", Enode); 5397 5398 when Mode_Conformant => 5399 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 5400 Error_Msg_N 5401 ("not mode conformant with operation inherited#!", 5402 Enode); 5403 else 5404 Error_Msg_N 5405 ("not mode conformant with declaration#!", Enode); 5406 end if; 5407 5408 when Subtype_Conformant => 5409 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 5410 Error_Msg_N 5411 ("not subtype conformant with operation inherited#!", 5412 Enode); 5413 else 5414 Error_Msg_N 5415 ("not subtype conformant with declaration#!", Enode); 5416 end if; 5417 5418 when Fully_Conformant => 5419 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 5420 Error_Msg_N -- CODEFIX 5421 ("not fully conformant with operation inherited#!", 5422 Enode); 5423 else 5424 Error_Msg_N -- CODEFIX 5425 ("not fully conformant with declaration#!", Enode); 5426 end if; 5427 end case; 5428 5429 Error_Msg_NE (Msg, Enode, N); 5430 end if; 5431 end Conformance_Error; 5432 5433 ----------------------- 5434 -- Conventions_Match -- 5435 ----------------------- 5436 5437 function Conventions_Match 5438 (Id1 : Entity_Id; 5439 Id2 : Entity_Id) return Boolean 5440 is 5441 begin 5442 -- Ignore the conventions of anonymous access-to-subprogram types 5443 -- and subprogram types because these are internally generated and 5444 -- the only way these may receive a convention is if they inherit 5445 -- the convention of a related subprogram. 5446 5447 if Ekind_In (Id1, E_Anonymous_Access_Subprogram_Type, 5448 E_Subprogram_Type) 5449 or else 5450 Ekind_In (Id2, E_Anonymous_Access_Subprogram_Type, 5451 E_Subprogram_Type) 5452 then 5453 return True; 5454 5455 -- Otherwise compare the conventions directly 5456 5457 else 5458 return Convention (Id1) = Convention (Id2); 5459 end if; 5460 end Conventions_Match; 5461 5462 -- Local Variables 5463 5464 Old_Type : constant Entity_Id := Etype (Old_Id); 5465 New_Type : constant Entity_Id := Etype (New_Id); 5466 Old_Formal : Entity_Id; 5467 New_Formal : Entity_Id; 5468 Access_Types_Match : Boolean; 5469 Old_Formal_Base : Entity_Id; 5470 New_Formal_Base : Entity_Id; 5471 5472 -- Start of processing for Check_Conformance 5473 5474 begin 5475 Conforms := True; 5476 5477 -- We need a special case for operators, since they don't appear 5478 -- explicitly. 5479 5480 if Ctype = Type_Conformant then 5481 if Ekind (New_Id) = E_Operator 5482 and then Operator_Matches_Spec (New_Id, Old_Id) 5483 then 5484 return; 5485 end if; 5486 end if; 5487 5488 -- If both are functions/operators, check return types conform 5489 5490 if Old_Type /= Standard_Void_Type 5491 and then 5492 New_Type /= Standard_Void_Type 5493 then 5494 -- If we are checking interface conformance we omit controlling 5495 -- arguments and result, because we are only checking the conformance 5496 -- of the remaining parameters. 5497 5498 if Has_Controlling_Result (Old_Id) 5499 and then Has_Controlling_Result (New_Id) 5500 and then Skip_Controlling_Formals 5501 then 5502 null; 5503 5504 elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then 5505 if Ctype >= Subtype_Conformant 5506 and then not Predicates_Match (Old_Type, New_Type) 5507 then 5508 Conformance_Error 5509 ("\predicate of return type does not match!", New_Id); 5510 else 5511 Conformance_Error 5512 ("\return type does not match!", New_Id); 5513 end if; 5514 5515 return; 5516 end if; 5517 5518 -- Ada 2005 (AI-231): In case of anonymous access types check the 5519 -- null-exclusion and access-to-constant attributes match. 5520 5521 if Ada_Version >= Ada_2005 5522 and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type 5523 and then 5524 (Can_Never_Be_Null (Old_Type) /= Can_Never_Be_Null (New_Type) 5525 or else Is_Access_Constant (Etype (Old_Type)) /= 5526 Is_Access_Constant (Etype (New_Type))) 5527 then 5528 Conformance_Error ("\return type does not match!", New_Id); 5529 return; 5530 end if; 5531 5532 -- If either is a function/operator and the other isn't, error 5533 5534 elsif Old_Type /= Standard_Void_Type 5535 or else New_Type /= Standard_Void_Type 5536 then 5537 Conformance_Error ("\functions can only match functions!", New_Id); 5538 return; 5539 end if; 5540 5541 -- In subtype conformant case, conventions must match (RM 6.3.1(16)). 5542 -- If this is a renaming as body, refine error message to indicate that 5543 -- the conflict is with the original declaration. If the entity is not 5544 -- frozen, the conventions don't have to match, the one of the renamed 5545 -- entity is inherited. 5546 5547 if Ctype >= Subtype_Conformant then 5548 if not Conventions_Match (Old_Id, New_Id) then 5549 if not Is_Frozen (New_Id) then 5550 null; 5551 5552 elsif Present (Err_Loc) 5553 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration 5554 and then Present (Corresponding_Spec (Err_Loc)) 5555 then 5556 Error_Msg_Name_1 := Chars (New_Id); 5557 Error_Msg_Name_2 := 5558 Name_Ada + Convention_Id'Pos (Convention (New_Id)); 5559 Conformance_Error ("\prior declaration for% has convention %!"); 5560 5561 else 5562 Conformance_Error ("\calling conventions do not match!"); 5563 end if; 5564 5565 return; 5566 5567 elsif Is_Formal_Subprogram (Old_Id) 5568 or else Is_Formal_Subprogram (New_Id) 5569 or else (Is_Subprogram (New_Id) 5570 and then Present (Alias (New_Id)) 5571 and then Is_Formal_Subprogram (Alias (New_Id))) 5572 then 5573 Conformance_Error 5574 ("\formal subprograms are not subtype conformant " 5575 & "(RM 6.3.1 (17/3))"); 5576 end if; 5577 end if; 5578 5579 -- Deal with parameters 5580 5581 -- Note: we use the entity information, rather than going directly 5582 -- to the specification in the tree. This is not only simpler, but 5583 -- absolutely necessary for some cases of conformance tests between 5584 -- operators, where the declaration tree simply does not exist. 5585 5586 Old_Formal := First_Formal (Old_Id); 5587 New_Formal := First_Formal (New_Id); 5588 while Present (Old_Formal) and then Present (New_Formal) loop 5589 if Is_Controlling_Formal (Old_Formal) 5590 and then Is_Controlling_Formal (New_Formal) 5591 and then Skip_Controlling_Formals 5592 then 5593 -- The controlling formals will have different types when 5594 -- comparing an interface operation with its match, but both 5595 -- or neither must be access parameters. 5596 5597 if Is_Access_Type (Etype (Old_Formal)) 5598 = 5599 Is_Access_Type (Etype (New_Formal)) 5600 then 5601 goto Skip_Controlling_Formal; 5602 else 5603 Conformance_Error 5604 ("\access parameter does not match!", New_Formal); 5605 end if; 5606 end if; 5607 5608 -- Ada 2012: Mode conformance also requires that formal parameters 5609 -- be both aliased, or neither. 5610 5611 if Ctype >= Mode_Conformant and then Ada_Version >= Ada_2012 then 5612 if Is_Aliased (Old_Formal) /= Is_Aliased (New_Formal) then 5613 Conformance_Error 5614 ("\aliased parameter mismatch!", New_Formal); 5615 end if; 5616 end if; 5617 5618 if Ctype = Fully_Conformant then 5619 5620 -- Names must match. Error message is more accurate if we do 5621 -- this before checking that the types of the formals match. 5622 5623 if Chars (Old_Formal) /= Chars (New_Formal) then 5624 Conformance_Error ("\name& does not match!", New_Formal); 5625 5626 -- Set error posted flag on new formal as well to stop 5627 -- junk cascaded messages in some cases. 5628 5629 Set_Error_Posted (New_Formal); 5630 return; 5631 end if; 5632 5633 -- Null exclusion must match 5634 5635 if Null_Exclusion_Present (Parent (Old_Formal)) 5636 /= 5637 Null_Exclusion_Present (Parent (New_Formal)) 5638 then 5639 -- Only give error if both come from source. This should be 5640 -- investigated some time, since it should not be needed ??? 5641 5642 if Comes_From_Source (Old_Formal) 5643 and then 5644 Comes_From_Source (New_Formal) 5645 then 5646 Conformance_Error 5647 ("\null exclusion for& does not match", New_Formal); 5648 5649 -- Mark error posted on the new formal to avoid duplicated 5650 -- complaint about types not matching. 5651 5652 Set_Error_Posted (New_Formal); 5653 end if; 5654 end if; 5655 end if; 5656 5657 -- Ada 2005 (AI-423): Possible access [sub]type and itype match. This 5658 -- case occurs whenever a subprogram is being renamed and one of its 5659 -- parameters imposes a null exclusion. For example: 5660 5661 -- type T is null record; 5662 -- type Acc_T is access T; 5663 -- subtype Acc_T_Sub is Acc_T; 5664 5665 -- procedure P (Obj : not null Acc_T_Sub); -- itype 5666 -- procedure Ren_P (Obj : Acc_T_Sub) -- subtype 5667 -- renames P; 5668 5669 Old_Formal_Base := Etype (Old_Formal); 5670 New_Formal_Base := Etype (New_Formal); 5671 5672 if Get_Inst then 5673 Old_Formal_Base := Get_Instance_Of (Old_Formal_Base); 5674 New_Formal_Base := Get_Instance_Of (New_Formal_Base); 5675 end if; 5676 5677 Access_Types_Match := Ada_Version >= Ada_2005 5678 5679 -- Ensure that this rule is only applied when New_Id is a 5680 -- renaming of Old_Id. 5681 5682 and then Nkind (Parent (Parent (New_Id))) = 5683 N_Subprogram_Renaming_Declaration 5684 and then Nkind (Name (Parent (Parent (New_Id)))) in N_Has_Entity 5685 and then Present (Entity (Name (Parent (Parent (New_Id))))) 5686 and then Entity (Name (Parent (Parent (New_Id)))) = Old_Id 5687 5688 -- Now handle the allowed access-type case 5689 5690 and then Is_Access_Type (Old_Formal_Base) 5691 and then Is_Access_Type (New_Formal_Base) 5692 5693 -- The type kinds must match. The only exception occurs with 5694 -- multiple generics of the form: 5695 5696 -- generic generic 5697 -- type F is private; type A is private; 5698 -- type F_Ptr is access F; type A_Ptr is access A; 5699 -- with proc F_P (X : F_Ptr); with proc A_P (X : A_Ptr); 5700 -- package F_Pack is ... package A_Pack is 5701 -- package F_Inst is 5702 -- new F_Pack (A, A_Ptr, A_P); 5703 5704 -- When checking for conformance between the parameters of A_P 5705 -- and F_P, the type kinds of F_Ptr and A_Ptr will not match 5706 -- because the compiler has transformed A_Ptr into a subtype of 5707 -- F_Ptr. We catch this case in the code below. 5708 5709 and then (Ekind (Old_Formal_Base) = Ekind (New_Formal_Base) 5710 or else 5711 (Is_Generic_Type (Old_Formal_Base) 5712 and then Is_Generic_Type (New_Formal_Base) 5713 and then Is_Internal (New_Formal_Base) 5714 and then Etype (Etype (New_Formal_Base)) = 5715 Old_Formal_Base)) 5716 and then Directly_Designated_Type (Old_Formal_Base) = 5717 Directly_Designated_Type (New_Formal_Base) 5718 and then ((Is_Itype (Old_Formal_Base) 5719 and then (Can_Never_Be_Null (Old_Formal_Base) 5720 or else Is_Access_Constant 5721 (Old_Formal_Base))) 5722 or else 5723 (Is_Itype (New_Formal_Base) 5724 and then (Can_Never_Be_Null (New_Formal_Base) 5725 or else Is_Access_Constant 5726 (New_Formal_Base)))); 5727 5728 -- Types must always match. In the visible part of an instance, 5729 -- usual overloading rules for dispatching operations apply, and 5730 -- we check base types (not the actual subtypes). 5731 5732 if In_Instance_Visible_Part 5733 and then Is_Dispatching_Operation (New_Id) 5734 then 5735 if not Conforming_Types 5736 (T1 => Base_Type (Etype (Old_Formal)), 5737 T2 => Base_Type (Etype (New_Formal)), 5738 Ctype => Ctype, 5739 Get_Inst => Get_Inst) 5740 and then not Access_Types_Match 5741 then 5742 Conformance_Error ("\type of & does not match!", New_Formal); 5743 return; 5744 end if; 5745 5746 elsif not Conforming_Types 5747 (T1 => Old_Formal_Base, 5748 T2 => New_Formal_Base, 5749 Ctype => Ctype, 5750 Get_Inst => Get_Inst) 5751 and then not Access_Types_Match 5752 then 5753 -- Don't give error message if old type is Any_Type. This test 5754 -- avoids some cascaded errors, e.g. in case of a bad spec. 5755 5756 if Errmsg and then Old_Formal_Base = Any_Type then 5757 Conforms := False; 5758 else 5759 if Ctype >= Subtype_Conformant 5760 and then 5761 not Predicates_Match (Old_Formal_Base, New_Formal_Base) 5762 then 5763 Conformance_Error 5764 ("\predicate of & does not match!", New_Formal); 5765 else 5766 Conformance_Error 5767 ("\type of & does not match!", New_Formal); 5768 5769 if not Dimensions_Match (Old_Formal_Base, New_Formal_Base) 5770 then 5771 Error_Msg_N ("\dimensions mismatch!", New_Formal); 5772 end if; 5773 end if; 5774 end if; 5775 5776 return; 5777 end if; 5778 5779 -- For mode conformance, mode must match 5780 5781 if Ctype >= Mode_Conformant then 5782 if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then 5783 if not Ekind_In (New_Id, E_Function, E_Procedure) 5784 or else not Is_Primitive_Wrapper (New_Id) 5785 then 5786 Conformance_Error ("\mode of & does not match!", New_Formal); 5787 5788 else 5789 declare 5790 T : constant Entity_Id := Find_Dispatching_Type (New_Id); 5791 begin 5792 if Is_Protected_Type (Corresponding_Concurrent_Type (T)) 5793 then 5794 Error_Msg_PT (New_Id, Ultimate_Alias (Old_Id)); 5795 else 5796 Conformance_Error 5797 ("\mode of & does not match!", New_Formal); 5798 end if; 5799 end; 5800 end if; 5801 5802 return; 5803 5804 -- Part of mode conformance for access types is having the same 5805 -- constant modifier. 5806 5807 elsif Access_Types_Match 5808 and then Is_Access_Constant (Old_Formal_Base) /= 5809 Is_Access_Constant (New_Formal_Base) 5810 then 5811 Conformance_Error 5812 ("\constant modifier does not match!", New_Formal); 5813 return; 5814 end if; 5815 end if; 5816 5817 if Ctype >= Subtype_Conformant then 5818 5819 -- Ada 2005 (AI-231): In case of anonymous access types check 5820 -- the null-exclusion and access-to-constant attributes must 5821 -- match. For null exclusion, we test the types rather than the 5822 -- formals themselves, since the attribute is only set reliably 5823 -- on the formals in the Ada 95 case, and we exclude the case 5824 -- where Old_Formal is marked as controlling, to avoid errors 5825 -- when matching completing bodies with dispatching declarations 5826 -- (access formals in the bodies aren't marked Can_Never_Be_Null). 5827 5828 if Ada_Version >= Ada_2005 5829 and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type 5830 and then Ekind (Etype (New_Formal)) = E_Anonymous_Access_Type 5831 and then 5832 ((Can_Never_Be_Null (Etype (Old_Formal)) /= 5833 Can_Never_Be_Null (Etype (New_Formal)) 5834 and then 5835 not Is_Controlling_Formal (Old_Formal)) 5836 or else 5837 Is_Access_Constant (Etype (Old_Formal)) /= 5838 Is_Access_Constant (Etype (New_Formal))) 5839 5840 -- Do not complain if error already posted on New_Formal. This 5841 -- avoids some redundant error messages. 5842 5843 and then not Error_Posted (New_Formal) 5844 then 5845 -- It is allowed to omit the null-exclusion in case of stream 5846 -- attribute subprograms. We recognize stream subprograms 5847 -- through their TSS-generated suffix. 5848 5849 declare 5850 TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id); 5851 5852 begin 5853 if TSS_Name /= TSS_Stream_Read 5854 and then TSS_Name /= TSS_Stream_Write 5855 and then TSS_Name /= TSS_Stream_Input 5856 and then TSS_Name /= TSS_Stream_Output 5857 then 5858 -- Here we have a definite conformance error. It is worth 5859 -- special casing the error message for the case of a 5860 -- controlling formal (which excludes null). 5861 5862 if Is_Controlling_Formal (New_Formal) then 5863 Error_Msg_Node_2 := Scope (New_Formal); 5864 Conformance_Error 5865 ("\controlling formal & of & excludes null, " 5866 & "declaration must exclude null as well", 5867 New_Formal); 5868 5869 -- Normal case (couldn't we give more detail here???) 5870 5871 else 5872 Conformance_Error 5873 ("\type of & does not match!", New_Formal); 5874 end if; 5875 5876 return; 5877 end if; 5878 end; 5879 end if; 5880 end if; 5881 5882 -- Full conformance checks 5883 5884 if Ctype = Fully_Conformant then 5885 5886 -- We have checked already that names match 5887 5888 if Parameter_Mode (Old_Formal) = E_In_Parameter then 5889 5890 -- Check default expressions for in parameters 5891 5892 declare 5893 NewD : constant Boolean := 5894 Present (Default_Value (New_Formal)); 5895 OldD : constant Boolean := 5896 Present (Default_Value (Old_Formal)); 5897 begin 5898 if NewD or OldD then 5899 5900 -- The old default value has been analyzed because the 5901 -- current full declaration will have frozen everything 5902 -- before. The new default value has not been analyzed, 5903 -- so analyze it now before we check for conformance. 5904 5905 if NewD then 5906 Push_Scope (New_Id); 5907 Preanalyze_Spec_Expression 5908 (Default_Value (New_Formal), Etype (New_Formal)); 5909 End_Scope; 5910 end if; 5911 5912 if not (NewD and OldD) 5913 or else not Fully_Conformant_Expressions 5914 (Default_Value (Old_Formal), 5915 Default_Value (New_Formal)) 5916 then 5917 Conformance_Error 5918 ("\default expression for & does not match!", 5919 New_Formal); 5920 return; 5921 end if; 5922 end if; 5923 end; 5924 end if; 5925 end if; 5926 5927 -- A couple of special checks for Ada 83 mode. These checks are 5928 -- skipped if either entity is an operator in package Standard, 5929 -- or if either old or new instance is not from the source program. 5930 5931 if Ada_Version = Ada_83 5932 and then Sloc (Old_Id) > Standard_Location 5933 and then Sloc (New_Id) > Standard_Location 5934 and then Comes_From_Source (Old_Id) 5935 and then Comes_From_Source (New_Id) 5936 then 5937 declare 5938 Old_Param : constant Node_Id := Declaration_Node (Old_Formal); 5939 New_Param : constant Node_Id := Declaration_Node (New_Formal); 5940 5941 begin 5942 -- Explicit IN must be present or absent in both cases. This 5943 -- test is required only in the full conformance case. 5944 5945 if In_Present (Old_Param) /= In_Present (New_Param) 5946 and then Ctype = Fully_Conformant 5947 then 5948 Conformance_Error 5949 ("\(Ada 83) IN must appear in both declarations", 5950 New_Formal); 5951 return; 5952 end if; 5953 5954 -- Grouping (use of comma in param lists) must be the same 5955 -- This is where we catch a misconformance like: 5956 5957 -- A, B : Integer 5958 -- A : Integer; B : Integer 5959 5960 -- which are represented identically in the tree except 5961 -- for the setting of the flags More_Ids and Prev_Ids. 5962 5963 if More_Ids (Old_Param) /= More_Ids (New_Param) 5964 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param) 5965 then 5966 Conformance_Error 5967 ("\grouping of & does not match!", New_Formal); 5968 return; 5969 end if; 5970 end; 5971 end if; 5972 5973 -- This label is required when skipping controlling formals 5974 5975 <<Skip_Controlling_Formal>> 5976 5977 Next_Formal (Old_Formal); 5978 Next_Formal (New_Formal); 5979 end loop; 5980 5981 if Present (Old_Formal) then 5982 Conformance_Error ("\too few parameters!"); 5983 return; 5984 5985 elsif Present (New_Formal) then 5986 Conformance_Error ("\too many parameters!", New_Formal); 5987 return; 5988 end if; 5989 end Check_Conformance; 5990 5991 ----------------------- 5992 -- Check_Conventions -- 5993 ----------------------- 5994 5995 procedure Check_Conventions (Typ : Entity_Id) is 5996 Ifaces_List : Elist_Id; 5997 5998 procedure Check_Convention (Op : Entity_Id); 5999 -- Verify that the convention of inherited dispatching operation Op is 6000 -- consistent among all subprograms it overrides. In order to minimize 6001 -- the search, Search_From is utilized to designate a specific point in 6002 -- the list rather than iterating over the whole list once more. 6003 6004 ---------------------- 6005 -- Check_Convention -- 6006 ---------------------- 6007 6008 procedure Check_Convention (Op : Entity_Id) is 6009 Op_Conv : constant Convention_Id := Convention (Op); 6010 Iface_Conv : Convention_Id; 6011 Iface_Elmt : Elmt_Id; 6012 Iface_Prim_Elmt : Elmt_Id; 6013 Iface_Prim : Entity_Id; 6014 6015 begin 6016 Iface_Elmt := First_Elmt (Ifaces_List); 6017 while Present (Iface_Elmt) loop 6018 Iface_Prim_Elmt := 6019 First_Elmt (Primitive_Operations (Node (Iface_Elmt))); 6020 while Present (Iface_Prim_Elmt) loop 6021 Iface_Prim := Node (Iface_Prim_Elmt); 6022 Iface_Conv := Convention (Iface_Prim); 6023 6024 if Is_Interface_Conformant (Typ, Iface_Prim, Op) 6025 and then Iface_Conv /= Op_Conv 6026 then 6027 Error_Msg_N 6028 ("inconsistent conventions in primitive operations", Typ); 6029 6030 Error_Msg_Name_1 := Chars (Op); 6031 Error_Msg_Name_2 := Get_Convention_Name (Op_Conv); 6032 Error_Msg_Sloc := Sloc (Op); 6033 6034 if Comes_From_Source (Op) or else No (Alias (Op)) then 6035 if not Present (Overridden_Operation (Op)) then 6036 Error_Msg_N ("\\primitive % defined #", Typ); 6037 else 6038 Error_Msg_N 6039 ("\\overriding operation % with " 6040 & "convention % defined #", Typ); 6041 end if; 6042 6043 else pragma Assert (Present (Alias (Op))); 6044 Error_Msg_Sloc := Sloc (Alias (Op)); 6045 Error_Msg_N ("\\inherited operation % with " 6046 & "convention % defined #", Typ); 6047 end if; 6048 6049 Error_Msg_Name_1 := Chars (Op); 6050 Error_Msg_Name_2 := Get_Convention_Name (Iface_Conv); 6051 Error_Msg_Sloc := Sloc (Iface_Prim); 6052 Error_Msg_N ("\\overridden operation % with " 6053 & "convention % defined #", Typ); 6054 6055 -- Avoid cascading errors 6056 6057 return; 6058 end if; 6059 6060 Next_Elmt (Iface_Prim_Elmt); 6061 end loop; 6062 6063 Next_Elmt (Iface_Elmt); 6064 end loop; 6065 end Check_Convention; 6066 6067 -- Local variables 6068 6069 Prim_Op : Entity_Id; 6070 Prim_Op_Elmt : Elmt_Id; 6071 6072 -- Start of processing for Check_Conventions 6073 6074 begin 6075 if not Has_Interfaces (Typ) then 6076 return; 6077 end if; 6078 6079 Collect_Interfaces (Typ, Ifaces_List); 6080 6081 -- The algorithm checks every overriding dispatching operation against 6082 -- all the corresponding overridden dispatching operations, detecting 6083 -- differences in conventions. 6084 6085 Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ)); 6086 while Present (Prim_Op_Elmt) loop 6087 Prim_Op := Node (Prim_Op_Elmt); 6088 6089 -- A small optimization: skip the predefined dispatching operations 6090 -- since they always have the same convention. 6091 6092 if not Is_Predefined_Dispatching_Operation (Prim_Op) then 6093 Check_Convention (Prim_Op); 6094 end if; 6095 6096 Next_Elmt (Prim_Op_Elmt); 6097 end loop; 6098 end Check_Conventions; 6099 6100 ------------------------------ 6101 -- Check_Delayed_Subprogram -- 6102 ------------------------------ 6103 6104 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is 6105 procedure Possible_Freeze (T : Entity_Id); 6106 -- T is the type of either a formal parameter or of the return type. If 6107 -- T is not yet frozen and needs a delayed freeze, then the subprogram 6108 -- itself must be delayed. 6109 6110 --------------------- 6111 -- Possible_Freeze -- 6112 --------------------- 6113 6114 procedure Possible_Freeze (T : Entity_Id) is 6115 Scop : constant Entity_Id := Scope (Designator); 6116 6117 begin 6118 -- If the subprogram appears within a package instance (which may be 6119 -- the wrapper package of a subprogram instance) the freeze node for 6120 -- that package will freeze the subprogram at the proper place, so 6121 -- do not emit a freeze node for the subprogram, given that it may 6122 -- appear in the wrong scope. 6123 6124 if Ekind (Scop) = E_Package 6125 and then not Comes_From_Source (Scop) 6126 and then Is_Generic_Instance (Scop) 6127 then 6128 null; 6129 6130 elsif Has_Delayed_Freeze (T) and then not Is_Frozen (T) then 6131 Set_Has_Delayed_Freeze (Designator); 6132 6133 elsif Is_Access_Type (T) 6134 and then Has_Delayed_Freeze (Designated_Type (T)) 6135 and then not Is_Frozen (Designated_Type (T)) 6136 then 6137 Set_Has_Delayed_Freeze (Designator); 6138 end if; 6139 end Possible_Freeze; 6140 6141 -- Local variables 6142 6143 F : Entity_Id; 6144 6145 -- Start of processing for Check_Delayed_Subprogram 6146 6147 begin 6148 -- All subprograms, including abstract subprograms, may need a freeze 6149 -- node if some formal type or the return type needs one. 6150 6151 Possible_Freeze (Etype (Designator)); 6152 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ??? 6153 6154 -- Need delayed freeze if any of the formal types themselves need a 6155 -- delayed freeze and are not yet frozen. 6156 6157 F := First_Formal (Designator); 6158 while Present (F) loop 6159 Possible_Freeze (Etype (F)); 6160 Possible_Freeze (Base_Type (Etype (F))); -- needed ??? 6161 Next_Formal (F); 6162 end loop; 6163 6164 -- Mark functions that return by reference. Note that it cannot be done 6165 -- for delayed_freeze subprograms because the underlying returned type 6166 -- may not be known yet (for private types). 6167 6168 if not Has_Delayed_Freeze (Designator) and then Expander_Active then 6169 declare 6170 Typ : constant Entity_Id := Etype (Designator); 6171 Utyp : constant Entity_Id := Underlying_Type (Typ); 6172 6173 begin 6174 if Is_Limited_View (Typ) then 6175 Set_Returns_By_Ref (Designator); 6176 6177 elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then 6178 Set_Returns_By_Ref (Designator); 6179 end if; 6180 end; 6181 end if; 6182 end Check_Delayed_Subprogram; 6183 6184 ------------------------------------ 6185 -- Check_Discriminant_Conformance -- 6186 ------------------------------------ 6187 6188 procedure Check_Discriminant_Conformance 6189 (N : Node_Id; 6190 Prev : Entity_Id; 6191 Prev_Loc : Node_Id) 6192 is 6193 Old_Discr : Entity_Id := First_Discriminant (Prev); 6194 New_Discr : Node_Id := First (Discriminant_Specifications (N)); 6195 New_Discr_Id : Entity_Id; 6196 New_Discr_Type : Entity_Id; 6197 6198 procedure Conformance_Error (Msg : String; N : Node_Id); 6199 -- Post error message for conformance error on given node. Two messages 6200 -- are output. The first points to the previous declaration with a 6201 -- general "no conformance" message. The second is the detailed reason, 6202 -- supplied as Msg. The parameter N provide information for a possible 6203 -- & insertion in the message. 6204 6205 ----------------------- 6206 -- Conformance_Error -- 6207 ----------------------- 6208 6209 procedure Conformance_Error (Msg : String; N : Node_Id) is 6210 begin 6211 Error_Msg_Sloc := Sloc (Prev_Loc); 6212 Error_Msg_N -- CODEFIX 6213 ("not fully conformant with declaration#!", N); 6214 Error_Msg_NE (Msg, N, N); 6215 end Conformance_Error; 6216 6217 -- Start of processing for Check_Discriminant_Conformance 6218 6219 begin 6220 while Present (Old_Discr) and then Present (New_Discr) loop 6221 New_Discr_Id := Defining_Identifier (New_Discr); 6222 6223 -- The subtype mark of the discriminant on the full type has not 6224 -- been analyzed so we do it here. For an access discriminant a new 6225 -- type is created. 6226 6227 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then 6228 New_Discr_Type := 6229 Access_Definition (N, Discriminant_Type (New_Discr)); 6230 6231 else 6232 Find_Type (Discriminant_Type (New_Discr)); 6233 New_Discr_Type := Etype (Discriminant_Type (New_Discr)); 6234 6235 -- Ada 2005: if the discriminant definition carries a null 6236 -- exclusion, create an itype to check properly for consistency 6237 -- with partial declaration. 6238 6239 if Is_Access_Type (New_Discr_Type) 6240 and then Null_Exclusion_Present (New_Discr) 6241 then 6242 New_Discr_Type := 6243 Create_Null_Excluding_Itype 6244 (T => New_Discr_Type, 6245 Related_Nod => New_Discr, 6246 Scope_Id => Current_Scope); 6247 end if; 6248 end if; 6249 6250 if not Conforming_Types 6251 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant) 6252 then 6253 Conformance_Error ("type of & does not match!", New_Discr_Id); 6254 return; 6255 else 6256 -- Treat the new discriminant as an occurrence of the old one, 6257 -- for navigation purposes, and fill in some semantic 6258 -- information, for completeness. 6259 6260 Generate_Reference (Old_Discr, New_Discr_Id, 'r'); 6261 Set_Etype (New_Discr_Id, Etype (Old_Discr)); 6262 Set_Scope (New_Discr_Id, Scope (Old_Discr)); 6263 end if; 6264 6265 -- Names must match 6266 6267 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then 6268 Conformance_Error ("name & does not match!", New_Discr_Id); 6269 return; 6270 end if; 6271 6272 -- Default expressions must match 6273 6274 declare 6275 NewD : constant Boolean := 6276 Present (Expression (New_Discr)); 6277 OldD : constant Boolean := 6278 Present (Expression (Parent (Old_Discr))); 6279 6280 begin 6281 if NewD or OldD then 6282 6283 -- The old default value has been analyzed and expanded, 6284 -- because the current full declaration will have frozen 6285 -- everything before. The new default values have not been 6286 -- expanded, so expand now to check conformance. 6287 6288 if NewD then 6289 Preanalyze_Spec_Expression 6290 (Expression (New_Discr), New_Discr_Type); 6291 end if; 6292 6293 if not (NewD and OldD) 6294 or else not Fully_Conformant_Expressions 6295 (Expression (Parent (Old_Discr)), 6296 Expression (New_Discr)) 6297 6298 then 6299 Conformance_Error 6300 ("default expression for & does not match!", 6301 New_Discr_Id); 6302 return; 6303 end if; 6304 end if; 6305 end; 6306 6307 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X) 6308 6309 if Ada_Version = Ada_83 then 6310 declare 6311 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr); 6312 6313 begin 6314 -- Grouping (use of comma in param lists) must be the same 6315 -- This is where we catch a misconformance like: 6316 6317 -- A, B : Integer 6318 -- A : Integer; B : Integer 6319 6320 -- which are represented identically in the tree except 6321 -- for the setting of the flags More_Ids and Prev_Ids. 6322 6323 if More_Ids (Old_Disc) /= More_Ids (New_Discr) 6324 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr) 6325 then 6326 Conformance_Error 6327 ("grouping of & does not match!", New_Discr_Id); 6328 return; 6329 end if; 6330 end; 6331 end if; 6332 6333 Next_Discriminant (Old_Discr); 6334 Next (New_Discr); 6335 end loop; 6336 6337 if Present (Old_Discr) then 6338 Conformance_Error ("too few discriminants!", Defining_Identifier (N)); 6339 return; 6340 6341 elsif Present (New_Discr) then 6342 Conformance_Error 6343 ("too many discriminants!", Defining_Identifier (New_Discr)); 6344 return; 6345 end if; 6346 end Check_Discriminant_Conformance; 6347 6348 ---------------------------- 6349 -- Check_Fully_Conformant -- 6350 ---------------------------- 6351 6352 procedure Check_Fully_Conformant 6353 (New_Id : Entity_Id; 6354 Old_Id : Entity_Id; 6355 Err_Loc : Node_Id := Empty) 6356 is 6357 Result : Boolean; 6358 pragma Warnings (Off, Result); 6359 begin 6360 Check_Conformance 6361 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc); 6362 end Check_Fully_Conformant; 6363 6364 -------------------------- 6365 -- Check_Limited_Return -- 6366 -------------------------- 6367 6368 procedure Check_Limited_Return 6369 (N : Node_Id; 6370 Expr : Node_Id; 6371 R_Type : Entity_Id) 6372 is 6373 begin 6374 -- Ada 2005 (AI-318-02): Return-by-reference types have been removed and 6375 -- replaced by anonymous access results. This is an incompatibility with 6376 -- Ada 95. Not clear whether this should be enforced yet or perhaps 6377 -- controllable with special switch. ??? 6378 6379 -- A limited interface that is not immutably limited is OK 6380 6381 if Is_Limited_Interface (R_Type) 6382 and then 6383 not (Is_Task_Interface (R_Type) 6384 or else Is_Protected_Interface (R_Type) 6385 or else Is_Synchronized_Interface (R_Type)) 6386 then 6387 null; 6388 6389 elsif Is_Limited_Type (R_Type) 6390 and then not Is_Interface (R_Type) 6391 and then Comes_From_Source (N) 6392 and then not In_Instance_Body 6393 and then not OK_For_Limited_Init_In_05 (R_Type, Expr) 6394 then 6395 -- Error in Ada 2005 6396 6397 if Ada_Version >= Ada_2005 6398 and then not Debug_Flag_Dot_L 6399 and then not GNAT_Mode 6400 then 6401 Error_Msg_N 6402 ("(Ada 2005) cannot copy object of a limited type " 6403 & "(RM-2005 6.5(5.5/2))", Expr); 6404 6405 if Is_Limited_View (R_Type) then 6406 Error_Msg_N 6407 ("\return by reference not permitted in Ada 2005", Expr); 6408 end if; 6409 6410 -- Warn in Ada 95 mode, to give folks a heads up about this 6411 -- incompatibility. 6412 6413 -- In GNAT mode, this is just a warning, to allow it to be evilly 6414 -- turned off. Otherwise it is a real error. 6415 6416 -- In a generic context, simplify the warning because it makes no 6417 -- sense to discuss pass-by-reference or copy. 6418 6419 elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then 6420 if Inside_A_Generic then 6421 Error_Msg_N 6422 ("return of limited object not permitted in Ada 2005 " 6423 & "(RM-2005 6.5(5.5/2))?y?", Expr); 6424 6425 elsif Is_Limited_View (R_Type) then 6426 Error_Msg_N 6427 ("return by reference not permitted in Ada 2005 " 6428 & "(RM-2005 6.5(5.5/2))?y?", Expr); 6429 else 6430 Error_Msg_N 6431 ("cannot copy object of a limited type in Ada 2005 " 6432 & "(RM-2005 6.5(5.5/2))?y?", Expr); 6433 end if; 6434 6435 -- Ada 95 mode, and compatibility warnings disabled 6436 6437 else 6438 pragma Assert (Ada_Version <= Ada_95); 6439 pragma Assert (not (Warn_On_Ada_2005_Compatibility or GNAT_Mode)); 6440 return; -- skip continuation messages below 6441 end if; 6442 6443 if not Inside_A_Generic then 6444 Error_Msg_N 6445 ("\consider switching to return of access type", Expr); 6446 Explain_Limited_Type (R_Type, Expr); 6447 end if; 6448 end if; 6449 end Check_Limited_Return; 6450 6451 --------------------------- 6452 -- Check_Mode_Conformant -- 6453 --------------------------- 6454 6455 procedure Check_Mode_Conformant 6456 (New_Id : Entity_Id; 6457 Old_Id : Entity_Id; 6458 Err_Loc : Node_Id := Empty; 6459 Get_Inst : Boolean := False) 6460 is 6461 Result : Boolean; 6462 pragma Warnings (Off, Result); 6463 begin 6464 Check_Conformance 6465 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst); 6466 end Check_Mode_Conformant; 6467 6468 -------------------------------- 6469 -- Check_Overriding_Indicator -- 6470 -------------------------------- 6471 6472 procedure Check_Overriding_Indicator 6473 (Subp : Entity_Id; 6474 Overridden_Subp : Entity_Id; 6475 Is_Primitive : Boolean) 6476 is 6477 Decl : Node_Id; 6478 Spec : Node_Id; 6479 6480 begin 6481 -- No overriding indicator for literals 6482 6483 if Ekind (Subp) = E_Enumeration_Literal then 6484 return; 6485 6486 elsif Ekind (Subp) = E_Entry then 6487 Decl := Parent (Subp); 6488 6489 -- No point in analyzing a malformed operator 6490 6491 elsif Nkind (Subp) = N_Defining_Operator_Symbol 6492 and then Error_Posted (Subp) 6493 then 6494 return; 6495 6496 else 6497 Decl := Unit_Declaration_Node (Subp); 6498 end if; 6499 6500 if Nkind_In (Decl, N_Subprogram_Body, 6501 N_Subprogram_Body_Stub, 6502 N_Subprogram_Declaration, 6503 N_Abstract_Subprogram_Declaration, 6504 N_Subprogram_Renaming_Declaration) 6505 then 6506 Spec := Specification (Decl); 6507 6508 elsif Nkind (Decl) = N_Entry_Declaration then 6509 Spec := Decl; 6510 6511 else 6512 return; 6513 end if; 6514 6515 -- The overriding operation is type conformant with the overridden one, 6516 -- but the names of the formals are not required to match. If the names 6517 -- appear permuted in the overriding operation, this is a possible 6518 -- source of confusion that is worth diagnosing. Controlling formals 6519 -- often carry names that reflect the type, and it is not worthwhile 6520 -- requiring that their names match. 6521 6522 if Present (Overridden_Subp) 6523 and then Nkind (Subp) /= N_Defining_Operator_Symbol 6524 then 6525 declare 6526 Form1 : Entity_Id; 6527 Form2 : Entity_Id; 6528 6529 begin 6530 Form1 := First_Formal (Subp); 6531 Form2 := First_Formal (Overridden_Subp); 6532 6533 -- If the overriding operation is a synchronized operation, skip 6534 -- the first parameter of the overridden operation, which is 6535 -- implicit in the new one. If the operation is declared in the 6536 -- body it is not primitive and all formals must match. 6537 6538 if Is_Concurrent_Type (Scope (Subp)) 6539 and then Is_Tagged_Type (Scope (Subp)) 6540 and then not Has_Completion (Scope (Subp)) 6541 then 6542 Form2 := Next_Formal (Form2); 6543 end if; 6544 6545 if Present (Form1) then 6546 Form1 := Next_Formal (Form1); 6547 Form2 := Next_Formal (Form2); 6548 end if; 6549 6550 while Present (Form1) loop 6551 if not Is_Controlling_Formal (Form1) 6552 and then Present (Next_Formal (Form2)) 6553 and then Chars (Form1) = Chars (Next_Formal (Form2)) 6554 then 6555 Error_Msg_Node_2 := Alias (Overridden_Subp); 6556 Error_Msg_Sloc := Sloc (Error_Msg_Node_2); 6557 Error_Msg_NE 6558 ("& does not match corresponding formal of&#", 6559 Form1, Form1); 6560 exit; 6561 end if; 6562 6563 Next_Formal (Form1); 6564 Next_Formal (Form2); 6565 end loop; 6566 end; 6567 end if; 6568 6569 -- If there is an overridden subprogram, then check that there is no 6570 -- "not overriding" indicator, and mark the subprogram as overriding. 6571 6572 -- This is not done if the overridden subprogram is marked as hidden, 6573 -- which can occur for the case of inherited controlled operations 6574 -- (see Derive_Subprogram), unless the inherited subprogram's parent 6575 -- subprogram is not itself hidden or we are within a generic instance, 6576 -- in which case the hidden flag may have been modified for the 6577 -- expansion of the instance. 6578 6579 -- (Note: This condition could probably be simplified, leaving out the 6580 -- testing for the specific controlled cases, but it seems safer and 6581 -- clearer this way, and echoes similar special-case tests of this 6582 -- kind in other places.) 6583 6584 if Present (Overridden_Subp) 6585 and then (not Is_Hidden (Overridden_Subp) 6586 or else 6587 (Nam_In (Chars (Overridden_Subp), Name_Initialize, 6588 Name_Adjust, 6589 Name_Finalize) 6590 and then Present (Alias (Overridden_Subp)) 6591 and then (not Is_Hidden (Alias (Overridden_Subp)) 6592 or else In_Instance))) 6593 then 6594 if Must_Not_Override (Spec) then 6595 Error_Msg_Sloc := Sloc (Overridden_Subp); 6596 6597 if Ekind (Subp) = E_Entry then 6598 Error_Msg_NE 6599 ("entry & overrides inherited operation #", Spec, Subp); 6600 else 6601 Error_Msg_NE 6602 ("subprogram & overrides inherited operation #", Spec, Subp); 6603 end if; 6604 6605 -- Special-case to fix a GNAT oddity: Limited_Controlled is declared 6606 -- as an extension of Root_Controlled, and thus has a useless Adjust 6607 -- operation. This operation should not be inherited by other limited 6608 -- controlled types. An explicit Adjust for them is not overriding. 6609 6610 elsif Must_Override (Spec) 6611 and then Chars (Overridden_Subp) = Name_Adjust 6612 and then Is_Limited_Type (Etype (First_Formal (Subp))) 6613 and then Present (Alias (Overridden_Subp)) 6614 and then In_Predefined_Unit (Alias (Overridden_Subp)) 6615 then 6616 Get_Name_String 6617 (Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp)))); 6618 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 6619 6620 elsif Is_Subprogram (Subp) then 6621 if Is_Init_Proc (Subp) then 6622 null; 6623 6624 elsif No (Overridden_Operation (Subp)) then 6625 6626 -- For entities generated by Derive_Subprograms the overridden 6627 -- operation is the inherited primitive (which is available 6628 -- through the attribute alias) 6629 6630 if (Is_Dispatching_Operation (Subp) 6631 or else Is_Dispatching_Operation (Overridden_Subp)) 6632 and then not Comes_From_Source (Overridden_Subp) 6633 and then Find_Dispatching_Type (Overridden_Subp) = 6634 Find_Dispatching_Type (Subp) 6635 and then Present (Alias (Overridden_Subp)) 6636 and then Comes_From_Source (Alias (Overridden_Subp)) 6637 then 6638 Set_Overridden_Operation (Subp, Alias (Overridden_Subp)); 6639 Inherit_Subprogram_Contract (Subp, Alias (Overridden_Subp)); 6640 6641 else 6642 Set_Overridden_Operation (Subp, Overridden_Subp); 6643 Inherit_Subprogram_Contract (Subp, Overridden_Subp); 6644 end if; 6645 end if; 6646 end if; 6647 6648 -- If primitive flag is set or this is a protected operation, then 6649 -- the operation is overriding at the point of its declaration, so 6650 -- warn if necessary. Otherwise it may have been declared before the 6651 -- operation it overrides and no check is required. 6652 6653 if Style_Check 6654 and then not Must_Override (Spec) 6655 and then (Is_Primitive 6656 or else Ekind (Scope (Subp)) = E_Protected_Type) 6657 then 6658 Style.Missing_Overriding (Decl, Subp); 6659 end if; 6660 6661 -- If Subp is an operator, it may override a predefined operation, if 6662 -- it is defined in the same scope as the type to which it applies. 6663 -- In that case Overridden_Subp is empty because of our implicit 6664 -- representation for predefined operators. We have to check whether the 6665 -- signature of Subp matches that of a predefined operator. Note that 6666 -- first argument provides the name of the operator, and the second 6667 -- argument the signature that may match that of a standard operation. 6668 -- If the indicator is overriding, then the operator must match a 6669 -- predefined signature, because we know already that there is no 6670 -- explicit overridden operation. 6671 6672 elsif Nkind (Subp) = N_Defining_Operator_Symbol then 6673 if Must_Not_Override (Spec) then 6674 6675 -- If this is not a primitive or a protected subprogram, then 6676 -- "not overriding" is illegal. 6677 6678 if not Is_Primitive 6679 and then Ekind (Scope (Subp)) /= E_Protected_Type 6680 then 6681 Error_Msg_N ("overriding indicator only allowed " 6682 & "if subprogram is primitive", Subp); 6683 6684 elsif Can_Override_Operator (Subp) then 6685 Error_Msg_NE 6686 ("subprogram& overrides predefined operator ", Spec, Subp); 6687 end if; 6688 6689 elsif Must_Override (Spec) then 6690 if No (Overridden_Operation (Subp)) 6691 and then not Can_Override_Operator (Subp) 6692 then 6693 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 6694 end if; 6695 6696 elsif not Error_Posted (Subp) 6697 and then Style_Check 6698 and then Can_Override_Operator (Subp) 6699 and then not In_Predefined_Unit (Subp) 6700 then 6701 -- If style checks are enabled, indicate that the indicator is 6702 -- missing. However, at the point of declaration, the type of 6703 -- which this is a primitive operation may be private, in which 6704 -- case the indicator would be premature. 6705 6706 if Has_Private_Declaration (Etype (Subp)) 6707 or else Has_Private_Declaration (Etype (First_Formal (Subp))) 6708 then 6709 null; 6710 else 6711 Style.Missing_Overriding (Decl, Subp); 6712 end if; 6713 end if; 6714 6715 elsif Must_Override (Spec) then 6716 if Ekind (Subp) = E_Entry then 6717 Error_Msg_NE ("entry & is not overriding", Spec, Subp); 6718 else 6719 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 6720 end if; 6721 6722 -- If the operation is marked "not overriding" and it's not primitive 6723 -- then an error is issued, unless this is an operation of a task or 6724 -- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding" 6725 -- has been specified have already been checked above. 6726 6727 elsif Must_Not_Override (Spec) 6728 and then not Is_Primitive 6729 and then Ekind (Subp) /= E_Entry 6730 and then Ekind (Scope (Subp)) /= E_Protected_Type 6731 then 6732 Error_Msg_N 6733 ("overriding indicator only allowed if subprogram is primitive", 6734 Subp); 6735 return; 6736 end if; 6737 end Check_Overriding_Indicator; 6738 6739 ------------------- 6740 -- Check_Returns -- 6741 ------------------- 6742 6743 -- Note: this procedure needs to know far too much about how the expander 6744 -- messes with exceptions. The use of the flag Exception_Junk and the 6745 -- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers 6746 -- works, but is not very clean. It would be better if the expansion 6747 -- routines would leave Original_Node working nicely, and we could use 6748 -- Original_Node here to ignore all the peculiar expander messing ??? 6749 6750 procedure Check_Returns 6751 (HSS : Node_Id; 6752 Mode : Character; 6753 Err : out Boolean; 6754 Proc : Entity_Id := Empty) 6755 is 6756 Handler : Node_Id; 6757 6758 procedure Check_Statement_Sequence (L : List_Id); 6759 -- Internal recursive procedure to check a list of statements for proper 6760 -- termination by a return statement (or a transfer of control or a 6761 -- compound statement that is itself internally properly terminated). 6762 6763 ------------------------------ 6764 -- Check_Statement_Sequence -- 6765 ------------------------------ 6766 6767 procedure Check_Statement_Sequence (L : List_Id) is 6768 Last_Stm : Node_Id; 6769 Stm : Node_Id; 6770 Kind : Node_Kind; 6771 6772 function Assert_False return Boolean; 6773 -- Returns True if Last_Stm is a pragma Assert (False) that has been 6774 -- rewritten as a null statement when assertions are off. The assert 6775 -- is not active, but it is still enough to kill the warning. 6776 6777 ------------------ 6778 -- Assert_False -- 6779 ------------------ 6780 6781 function Assert_False return Boolean is 6782 Orig : constant Node_Id := Original_Node (Last_Stm); 6783 6784 begin 6785 if Nkind (Orig) = N_Pragma 6786 and then Pragma_Name (Orig) = Name_Assert 6787 and then not Error_Posted (Orig) 6788 then 6789 declare 6790 Arg : constant Node_Id := 6791 First (Pragma_Argument_Associations (Orig)); 6792 Exp : constant Node_Id := Expression (Arg); 6793 begin 6794 return Nkind (Exp) = N_Identifier 6795 and then Chars (Exp) = Name_False; 6796 end; 6797 6798 else 6799 return False; 6800 end if; 6801 end Assert_False; 6802 6803 -- Local variables 6804 6805 Raise_Exception_Call : Boolean; 6806 -- Set True if statement sequence terminated by Raise_Exception call 6807 -- or a Reraise_Occurrence call. 6808 6809 -- Start of processing for Check_Statement_Sequence 6810 6811 begin 6812 Raise_Exception_Call := False; 6813 6814 -- Get last real statement 6815 6816 Last_Stm := Last (L); 6817 6818 -- Deal with digging out exception handler statement sequences that 6819 -- have been transformed by the local raise to goto optimization. 6820 -- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this 6821 -- optimization has occurred, we are looking at something like: 6822 6823 -- begin 6824 -- original stmts in block 6825 6826 -- exception \ 6827 -- when excep1 => | 6828 -- goto L1; | omitted if No_Exception_Propagation 6829 -- when excep2 => | 6830 -- goto L2; / 6831 -- end; 6832 6833 -- goto L3; -- skip handler when exception not raised 6834 6835 -- <<L1>> -- target label for local exception 6836 -- begin 6837 -- estmts1 6838 -- end; 6839 6840 -- goto L3; 6841 6842 -- <<L2>> 6843 -- begin 6844 -- estmts2 6845 -- end; 6846 6847 -- <<L3>> 6848 6849 -- and what we have to do is to dig out the estmts1 and estmts2 6850 -- sequences (which were the original sequences of statements in 6851 -- the exception handlers) and check them. 6852 6853 if Nkind (Last_Stm) = N_Label and then Exception_Junk (Last_Stm) then 6854 Stm := Last_Stm; 6855 loop 6856 Prev (Stm); 6857 exit when No (Stm); 6858 exit when Nkind (Stm) /= N_Block_Statement; 6859 exit when not Exception_Junk (Stm); 6860 Prev (Stm); 6861 exit when No (Stm); 6862 exit when Nkind (Stm) /= N_Label; 6863 exit when not Exception_Junk (Stm); 6864 Check_Statement_Sequence 6865 (Statements (Handled_Statement_Sequence (Next (Stm)))); 6866 6867 Prev (Stm); 6868 Last_Stm := Stm; 6869 exit when No (Stm); 6870 exit when Nkind (Stm) /= N_Goto_Statement; 6871 exit when not Exception_Junk (Stm); 6872 end loop; 6873 end if; 6874 6875 -- Don't count pragmas 6876 6877 while Nkind (Last_Stm) = N_Pragma 6878 6879 -- Don't count call to SS_Release (can happen after Raise_Exception) 6880 6881 or else 6882 (Nkind (Last_Stm) = N_Procedure_Call_Statement 6883 and then 6884 Nkind (Name (Last_Stm)) = N_Identifier 6885 and then 6886 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release)) 6887 6888 -- Don't count exception junk 6889 6890 or else 6891 (Nkind_In (Last_Stm, N_Goto_Statement, 6892 N_Label, 6893 N_Object_Declaration) 6894 and then Exception_Junk (Last_Stm)) 6895 or else Nkind (Last_Stm) in N_Push_xxx_Label 6896 or else Nkind (Last_Stm) in N_Pop_xxx_Label 6897 6898 -- Inserted code, such as finalization calls, is irrelevant: we only 6899 -- need to check original source. 6900 6901 or else Is_Rewrite_Insertion (Last_Stm) 6902 loop 6903 Prev (Last_Stm); 6904 end loop; 6905 6906 -- Here we have the "real" last statement 6907 6908 Kind := Nkind (Last_Stm); 6909 6910 -- Transfer of control, OK. Note that in the No_Return procedure 6911 -- case, we already diagnosed any explicit return statements, so 6912 -- we can treat them as OK in this context. 6913 6914 if Is_Transfer (Last_Stm) then 6915 return; 6916 6917 -- Check cases of explicit non-indirect procedure calls 6918 6919 elsif Kind = N_Procedure_Call_Statement 6920 and then Is_Entity_Name (Name (Last_Stm)) 6921 then 6922 -- Check call to Raise_Exception procedure which is treated 6923 -- specially, as is a call to Reraise_Occurrence. 6924 6925 -- We suppress the warning in these cases since it is likely that 6926 -- the programmer really does not expect to deal with the case 6927 -- of Null_Occurrence, and thus would find a warning about a 6928 -- missing return curious, and raising Program_Error does not 6929 -- seem such a bad behavior if this does occur. 6930 6931 -- Note that in the Ada 2005 case for Raise_Exception, the actual 6932 -- behavior will be to raise Constraint_Error (see AI-329). 6933 6934 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception) 6935 or else 6936 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence) 6937 then 6938 Raise_Exception_Call := True; 6939 6940 -- For Raise_Exception call, test first argument, if it is 6941 -- an attribute reference for a 'Identity call, then we know 6942 -- that the call cannot possibly return. 6943 6944 declare 6945 Arg : constant Node_Id := 6946 Original_Node (First_Actual (Last_Stm)); 6947 begin 6948 if Nkind (Arg) = N_Attribute_Reference 6949 and then Attribute_Name (Arg) = Name_Identity 6950 then 6951 return; 6952 end if; 6953 end; 6954 end if; 6955 6956 -- If statement, need to look inside if there is an else and check 6957 -- each constituent statement sequence for proper termination. 6958 6959 elsif Kind = N_If_Statement 6960 and then Present (Else_Statements (Last_Stm)) 6961 then 6962 Check_Statement_Sequence (Then_Statements (Last_Stm)); 6963 Check_Statement_Sequence (Else_Statements (Last_Stm)); 6964 6965 if Present (Elsif_Parts (Last_Stm)) then 6966 declare 6967 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm)); 6968 6969 begin 6970 while Present (Elsif_Part) loop 6971 Check_Statement_Sequence (Then_Statements (Elsif_Part)); 6972 Next (Elsif_Part); 6973 end loop; 6974 end; 6975 end if; 6976 6977 return; 6978 6979 -- Case statement, check each case for proper termination 6980 6981 elsif Kind = N_Case_Statement then 6982 declare 6983 Case_Alt : Node_Id; 6984 begin 6985 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm)); 6986 while Present (Case_Alt) loop 6987 Check_Statement_Sequence (Statements (Case_Alt)); 6988 Next_Non_Pragma (Case_Alt); 6989 end loop; 6990 end; 6991 6992 return; 6993 6994 -- Block statement, check its handled sequence of statements 6995 6996 elsif Kind = N_Block_Statement then 6997 declare 6998 Err1 : Boolean; 6999 7000 begin 7001 Check_Returns 7002 (Handled_Statement_Sequence (Last_Stm), Mode, Err1); 7003 7004 if Err1 then 7005 Err := True; 7006 end if; 7007 7008 return; 7009 end; 7010 7011 -- Loop statement. If there is an iteration scheme, we can definitely 7012 -- fall out of the loop. Similarly if there is an exit statement, we 7013 -- can fall out. In either case we need a following return. 7014 7015 elsif Kind = N_Loop_Statement then 7016 if Present (Iteration_Scheme (Last_Stm)) 7017 or else Has_Exit (Entity (Identifier (Last_Stm))) 7018 then 7019 null; 7020 7021 -- A loop with no exit statement or iteration scheme is either 7022 -- an infinite loop, or it has some other exit (raise/return). 7023 -- In either case, no warning is required. 7024 7025 else 7026 return; 7027 end if; 7028 7029 -- Timed entry call, check entry call and delay alternatives 7030 7031 -- Note: in expanded code, the timed entry call has been converted 7032 -- to a set of expanded statements on which the check will work 7033 -- correctly in any case. 7034 7035 elsif Kind = N_Timed_Entry_Call then 7036 declare 7037 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); 7038 DCA : constant Node_Id := Delay_Alternative (Last_Stm); 7039 7040 begin 7041 -- If statement sequence of entry call alternative is missing, 7042 -- then we can definitely fall through, and we post the error 7043 -- message on the entry call alternative itself. 7044 7045 if No (Statements (ECA)) then 7046 Last_Stm := ECA; 7047 7048 -- If statement sequence of delay alternative is missing, then 7049 -- we can definitely fall through, and we post the error 7050 -- message on the delay alternative itself. 7051 7052 -- Note: if both ECA and DCA are missing the return, then we 7053 -- post only one message, should be enough to fix the bugs. 7054 -- If not we will get a message next time on the DCA when the 7055 -- ECA is fixed. 7056 7057 elsif No (Statements (DCA)) then 7058 Last_Stm := DCA; 7059 7060 -- Else check both statement sequences 7061 7062 else 7063 Check_Statement_Sequence (Statements (ECA)); 7064 Check_Statement_Sequence (Statements (DCA)); 7065 return; 7066 end if; 7067 end; 7068 7069 -- Conditional entry call, check entry call and else part 7070 7071 -- Note: in expanded code, the conditional entry call has been 7072 -- converted to a set of expanded statements on which the check 7073 -- will work correctly in any case. 7074 7075 elsif Kind = N_Conditional_Entry_Call then 7076 declare 7077 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); 7078 7079 begin 7080 -- If statement sequence of entry call alternative is missing, 7081 -- then we can definitely fall through, and we post the error 7082 -- message on the entry call alternative itself. 7083 7084 if No (Statements (ECA)) then 7085 Last_Stm := ECA; 7086 7087 -- Else check statement sequence and else part 7088 7089 else 7090 Check_Statement_Sequence (Statements (ECA)); 7091 Check_Statement_Sequence (Else_Statements (Last_Stm)); 7092 return; 7093 end if; 7094 end; 7095 end if; 7096 7097 -- If we fall through, issue appropriate message 7098 7099 if Mode = 'F' then 7100 7101 -- Kill warning if last statement is a raise exception call, 7102 -- or a pragma Assert (False). Note that with assertions enabled, 7103 -- such a pragma has been converted into a raise exception call 7104 -- already, so the Assert_False is for the assertions off case. 7105 7106 if not Raise_Exception_Call and then not Assert_False then 7107 7108 -- In GNATprove mode, it is an error to have a missing return 7109 7110 Error_Msg_Warn := SPARK_Mode /= On; 7111 7112 -- Issue error message or warning 7113 7114 Error_Msg_N 7115 ("RETURN statement missing following this statement<<!", 7116 Last_Stm); 7117 Error_Msg_N 7118 ("\Program_Error ]<<!", Last_Stm); 7119 end if; 7120 7121 -- Note: we set Err even though we have not issued a warning 7122 -- because we still have a case of a missing return. This is 7123 -- an extremely marginal case, probably will never be noticed 7124 -- but we might as well get it right. 7125 7126 Err := True; 7127 7128 -- Otherwise we have the case of a procedure marked No_Return 7129 7130 else 7131 if not Raise_Exception_Call then 7132 if GNATprove_Mode then 7133 Error_Msg_N 7134 ("implied return after this statement would have raised " 7135 & "Program_Error", Last_Stm); 7136 7137 -- In normal compilation mode, do not warn on a generated call 7138 -- (e.g. in the body of a renaming as completion). 7139 7140 elsif Comes_From_Source (Last_Stm) then 7141 Error_Msg_N 7142 ("implied return after this statement will raise " 7143 & "Program_Error??", Last_Stm); 7144 end if; 7145 7146 Error_Msg_Warn := SPARK_Mode /= On; 7147 Error_Msg_NE 7148 ("\procedure & is marked as No_Return<<!", Last_Stm, Proc); 7149 end if; 7150 7151 declare 7152 RE : constant Node_Id := 7153 Make_Raise_Program_Error (Sloc (Last_Stm), 7154 Reason => PE_Implicit_Return); 7155 begin 7156 Insert_After (Last_Stm, RE); 7157 Analyze (RE); 7158 end; 7159 end if; 7160 end Check_Statement_Sequence; 7161 7162 -- Start of processing for Check_Returns 7163 7164 begin 7165 Err := False; 7166 Check_Statement_Sequence (Statements (HSS)); 7167 7168 if Present (Exception_Handlers (HSS)) then 7169 Handler := First_Non_Pragma (Exception_Handlers (HSS)); 7170 while Present (Handler) loop 7171 Check_Statement_Sequence (Statements (Handler)); 7172 Next_Non_Pragma (Handler); 7173 end loop; 7174 end if; 7175 end Check_Returns; 7176 7177 ---------------------------- 7178 -- Check_Subprogram_Order -- 7179 ---------------------------- 7180 7181 procedure Check_Subprogram_Order (N : Node_Id) is 7182 7183 function Subprogram_Name_Greater (S1, S2 : String) return Boolean; 7184 -- This is used to check if S1 > S2 in the sense required by this test, 7185 -- for example nameab < namec, but name2 < name10. 7186 7187 ----------------------------- 7188 -- Subprogram_Name_Greater -- 7189 ----------------------------- 7190 7191 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is 7192 L1, L2 : Positive; 7193 N1, N2 : Natural; 7194 7195 begin 7196 -- Deal with special case where names are identical except for a 7197 -- numerical suffix. These are handled specially, taking the numeric 7198 -- ordering from the suffix into account. 7199 7200 L1 := S1'Last; 7201 while S1 (L1) in '0' .. '9' loop 7202 L1 := L1 - 1; 7203 end loop; 7204 7205 L2 := S2'Last; 7206 while S2 (L2) in '0' .. '9' loop 7207 L2 := L2 - 1; 7208 end loop; 7209 7210 -- If non-numeric parts non-equal, do straight compare 7211 7212 if S1 (S1'First .. L1) /= S2 (S2'First .. L2) then 7213 return S1 > S2; 7214 7215 -- If non-numeric parts equal, compare suffixed numeric parts. Note 7216 -- that a missing suffix is treated as numeric zero in this test. 7217 7218 else 7219 N1 := 0; 7220 while L1 < S1'Last loop 7221 L1 := L1 + 1; 7222 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0'); 7223 end loop; 7224 7225 N2 := 0; 7226 while L2 < S2'Last loop 7227 L2 := L2 + 1; 7228 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0'); 7229 end loop; 7230 7231 return N1 > N2; 7232 end if; 7233 end Subprogram_Name_Greater; 7234 7235 -- Start of processing for Check_Subprogram_Order 7236 7237 begin 7238 -- Check body in alpha order if this is option 7239 7240 if Style_Check 7241 and then Style_Check_Order_Subprograms 7242 and then Nkind (N) = N_Subprogram_Body 7243 and then Comes_From_Source (N) 7244 and then In_Extended_Main_Source_Unit (N) 7245 then 7246 declare 7247 LSN : String_Ptr 7248 renames Scope_Stack.Table 7249 (Scope_Stack.Last).Last_Subprogram_Name; 7250 7251 Body_Id : constant Entity_Id := 7252 Defining_Entity (Specification (N)); 7253 7254 begin 7255 Get_Decoded_Name_String (Chars (Body_Id)); 7256 7257 if LSN /= null then 7258 if Subprogram_Name_Greater 7259 (LSN.all, Name_Buffer (1 .. Name_Len)) 7260 then 7261 Style.Subprogram_Not_In_Alpha_Order (Body_Id); 7262 end if; 7263 7264 Free (LSN); 7265 end if; 7266 7267 LSN := new String'(Name_Buffer (1 .. Name_Len)); 7268 end; 7269 end if; 7270 end Check_Subprogram_Order; 7271 7272 ------------------------------ 7273 -- Check_Subtype_Conformant -- 7274 ------------------------------ 7275 7276 procedure Check_Subtype_Conformant 7277 (New_Id : Entity_Id; 7278 Old_Id : Entity_Id; 7279 Err_Loc : Node_Id := Empty; 7280 Skip_Controlling_Formals : Boolean := False; 7281 Get_Inst : Boolean := False) 7282 is 7283 Result : Boolean; 7284 pragma Warnings (Off, Result); 7285 begin 7286 Check_Conformance 7287 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc, 7288 Skip_Controlling_Formals => Skip_Controlling_Formals, 7289 Get_Inst => Get_Inst); 7290 end Check_Subtype_Conformant; 7291 7292 ----------------------------------- 7293 -- Check_Synchronized_Overriding -- 7294 ----------------------------------- 7295 7296 procedure Check_Synchronized_Overriding 7297 (Def_Id : Entity_Id; 7298 Overridden_Subp : out Entity_Id) 7299 is 7300 Ifaces_List : Elist_Id; 7301 In_Scope : Boolean; 7302 Typ : Entity_Id; 7303 7304 function Is_Valid_Formal (F : Entity_Id) return Boolean; 7305 -- Predicate for legality rule in 9.4 (11.9/2): If an inherited 7306 -- subprogram is implemented by a protected procedure or entry, 7307 -- its first parameter must be out, in out, or access-to-variable. 7308 7309 function Matches_Prefixed_View_Profile 7310 (Prim_Params : List_Id; 7311 Iface_Params : List_Id) return Boolean; 7312 -- Determine whether a subprogram's parameter profile Prim_Params 7313 -- matches that of a potentially overridden interface subprogram 7314 -- Iface_Params. Also determine if the type of first parameter of 7315 -- Iface_Params is an implemented interface. 7316 7317 ---------------------- 7318 -- Is_Valid_Formal -- 7319 ---------------------- 7320 7321 function Is_Valid_Formal (F : Entity_Id) return Boolean is 7322 begin 7323 return 7324 Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter) 7325 or else 7326 (Nkind (Parameter_Type (Parent (F))) = N_Access_Definition 7327 and then not Constant_Present (Parameter_Type (Parent (F)))); 7328 end Is_Valid_Formal; 7329 7330 ----------------------------------- 7331 -- Matches_Prefixed_View_Profile -- 7332 ----------------------------------- 7333 7334 function Matches_Prefixed_View_Profile 7335 (Prim_Params : List_Id; 7336 Iface_Params : List_Id) return Boolean 7337 is 7338 function Is_Implemented 7339 (Ifaces_List : Elist_Id; 7340 Iface : Entity_Id) return Boolean; 7341 -- Determine if Iface is implemented by the current task or 7342 -- protected type. 7343 7344 -------------------- 7345 -- Is_Implemented -- 7346 -------------------- 7347 7348 function Is_Implemented 7349 (Ifaces_List : Elist_Id; 7350 Iface : Entity_Id) return Boolean 7351 is 7352 Iface_Elmt : Elmt_Id; 7353 7354 begin 7355 Iface_Elmt := First_Elmt (Ifaces_List); 7356 while Present (Iface_Elmt) loop 7357 if Node (Iface_Elmt) = Iface then 7358 return True; 7359 end if; 7360 7361 Next_Elmt (Iface_Elmt); 7362 end loop; 7363 7364 return False; 7365 end Is_Implemented; 7366 7367 -- Local variables 7368 7369 Iface_Id : Entity_Id; 7370 Iface_Param : Node_Id; 7371 Iface_Typ : Entity_Id; 7372 Prim_Id : Entity_Id; 7373 Prim_Param : Node_Id; 7374 Prim_Typ : Entity_Id; 7375 7376 -- Start of processing for Matches_Prefixed_View_Profile 7377 7378 begin 7379 Iface_Param := First (Iface_Params); 7380 Iface_Typ := Etype (Defining_Identifier (Iface_Param)); 7381 7382 if Is_Access_Type (Iface_Typ) then 7383 Iface_Typ := Designated_Type (Iface_Typ); 7384 end if; 7385 7386 Prim_Param := First (Prim_Params); 7387 7388 -- The first parameter of the potentially overridden subprogram must 7389 -- be an interface implemented by Prim. 7390 7391 if not Is_Interface (Iface_Typ) 7392 or else not Is_Implemented (Ifaces_List, Iface_Typ) 7393 then 7394 return False; 7395 end if; 7396 7397 -- The checks on the object parameters are done, so move on to the 7398 -- rest of the parameters. 7399 7400 if not In_Scope then 7401 Prim_Param := Next (Prim_Param); 7402 end if; 7403 7404 Iface_Param := Next (Iface_Param); 7405 while Present (Iface_Param) and then Present (Prim_Param) loop 7406 Iface_Id := Defining_Identifier (Iface_Param); 7407 Iface_Typ := Find_Parameter_Type (Iface_Param); 7408 7409 Prim_Id := Defining_Identifier (Prim_Param); 7410 Prim_Typ := Find_Parameter_Type (Prim_Param); 7411 7412 if Ekind (Iface_Typ) = E_Anonymous_Access_Type 7413 and then Ekind (Prim_Typ) = E_Anonymous_Access_Type 7414 and then Is_Concurrent_Type (Designated_Type (Prim_Typ)) 7415 then 7416 Iface_Typ := Designated_Type (Iface_Typ); 7417 Prim_Typ := Designated_Type (Prim_Typ); 7418 end if; 7419 7420 -- Case of multiple interface types inside a parameter profile 7421 7422 -- (Obj_Param : in out Iface; ...; Param : Iface) 7423 7424 -- If the interface type is implemented, then the matching type in 7425 -- the primitive should be the implementing record type. 7426 7427 if Ekind (Iface_Typ) = E_Record_Type 7428 and then Is_Interface (Iface_Typ) 7429 and then Is_Implemented (Ifaces_List, Iface_Typ) 7430 then 7431 if Prim_Typ /= Typ then 7432 return False; 7433 end if; 7434 7435 -- The two parameters must be both mode and subtype conformant 7436 7437 elsif Ekind (Iface_Id) /= Ekind (Prim_Id) 7438 or else not 7439 Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant) 7440 then 7441 return False; 7442 end if; 7443 7444 Next (Iface_Param); 7445 Next (Prim_Param); 7446 end loop; 7447 7448 -- One of the two lists contains more parameters than the other 7449 7450 if Present (Iface_Param) or else Present (Prim_Param) then 7451 return False; 7452 end if; 7453 7454 return True; 7455 end Matches_Prefixed_View_Profile; 7456 7457 -- Start of processing for Check_Synchronized_Overriding 7458 7459 begin 7460 Overridden_Subp := Empty; 7461 7462 -- Def_Id must be an entry or a subprogram. We should skip predefined 7463 -- primitives internally generated by the front end; however at this 7464 -- stage predefined primitives are still not fully decorated. As a 7465 -- minor optimization we skip here internally generated subprograms. 7466 7467 if (Ekind (Def_Id) /= E_Entry 7468 and then Ekind (Def_Id) /= E_Function 7469 and then Ekind (Def_Id) /= E_Procedure) 7470 or else not Comes_From_Source (Def_Id) 7471 then 7472 return; 7473 end if; 7474 7475 -- Search for the concurrent declaration since it contains the list of 7476 -- all implemented interfaces. In this case, the subprogram is declared 7477 -- within the scope of a protected or a task type. 7478 7479 if Present (Scope (Def_Id)) 7480 and then Is_Concurrent_Type (Scope (Def_Id)) 7481 and then not Is_Generic_Actual_Type (Scope (Def_Id)) 7482 then 7483 Typ := Scope (Def_Id); 7484 In_Scope := True; 7485 7486 -- The enclosing scope is not a synchronized type and the subprogram 7487 -- has no formals. 7488 7489 elsif No (First_Formal (Def_Id)) then 7490 return; 7491 7492 -- The subprogram has formals and hence it may be a primitive of a 7493 -- concurrent type. 7494 7495 else 7496 Typ := Etype (First_Formal (Def_Id)); 7497 7498 if Is_Access_Type (Typ) then 7499 Typ := Directly_Designated_Type (Typ); 7500 end if; 7501 7502 if Is_Concurrent_Type (Typ) 7503 and then not Is_Generic_Actual_Type (Typ) 7504 then 7505 In_Scope := False; 7506 7507 -- This case occurs when the concurrent type is declared within a 7508 -- generic unit. As a result the corresponding record has been built 7509 -- and used as the type of the first formal, we just have to retrieve 7510 -- the corresponding concurrent type. 7511 7512 elsif Is_Concurrent_Record_Type (Typ) 7513 and then not Is_Class_Wide_Type (Typ) 7514 and then Present (Corresponding_Concurrent_Type (Typ)) 7515 then 7516 Typ := Corresponding_Concurrent_Type (Typ); 7517 In_Scope := False; 7518 7519 else 7520 return; 7521 end if; 7522 end if; 7523 7524 -- There is no overriding to check if this is an inherited operation in 7525 -- a type derivation for a generic actual. 7526 7527 Collect_Interfaces (Typ, Ifaces_List); 7528 7529 if Is_Empty_Elmt_List (Ifaces_List) then 7530 return; 7531 end if; 7532 7533 -- Determine whether entry or subprogram Def_Id overrides a primitive 7534 -- operation that belongs to one of the interfaces in Ifaces_List. 7535 7536 declare 7537 Candidate : Entity_Id := Empty; 7538 Hom : Entity_Id := Empty; 7539 Subp : Entity_Id := Empty; 7540 7541 begin 7542 -- Traverse the homonym chain, looking for a potentially overridden 7543 -- subprogram that belongs to an implemented interface. 7544 7545 Hom := Current_Entity_In_Scope (Def_Id); 7546 while Present (Hom) loop 7547 Subp := Hom; 7548 7549 if Subp = Def_Id 7550 or else not Is_Overloadable (Subp) 7551 or else not Is_Primitive (Subp) 7552 or else not Is_Dispatching_Operation (Subp) 7553 or else not Present (Find_Dispatching_Type (Subp)) 7554 or else not Is_Interface (Find_Dispatching_Type (Subp)) 7555 then 7556 null; 7557 7558 -- Entries and procedures can override abstract or null interface 7559 -- procedures. 7560 7561 elsif Ekind_In (Def_Id, E_Entry, E_Procedure) 7562 and then Ekind (Subp) = E_Procedure 7563 and then Matches_Prefixed_View_Profile 7564 (Parameter_Specifications (Parent (Def_Id)), 7565 Parameter_Specifications (Parent (Subp))) 7566 then 7567 Candidate := Subp; 7568 7569 -- For an overridden subprogram Subp, check whether the mode 7570 -- of its first parameter is correct depending on the kind of 7571 -- synchronized type. 7572 7573 declare 7574 Formal : constant Node_Id := First_Formal (Candidate); 7575 7576 begin 7577 -- In order for an entry or a protected procedure to 7578 -- override, the first parameter of the overridden routine 7579 -- must be of mode "out", "in out", or access-to-variable. 7580 7581 if Ekind_In (Candidate, E_Entry, E_Procedure) 7582 and then Is_Protected_Type (Typ) 7583 and then not Is_Valid_Formal (Formal) 7584 then 7585 null; 7586 7587 -- All other cases are OK since a task entry or routine does 7588 -- not have a restriction on the mode of the first parameter 7589 -- of the overridden interface routine. 7590 7591 else 7592 Overridden_Subp := Candidate; 7593 return; 7594 end if; 7595 end; 7596 7597 -- Functions can override abstract interface functions. Return 7598 -- types must be subtype conformant. 7599 7600 elsif Ekind (Def_Id) = E_Function 7601 and then Ekind (Subp) = E_Function 7602 and then Matches_Prefixed_View_Profile 7603 (Parameter_Specifications (Parent (Def_Id)), 7604 Parameter_Specifications (Parent (Subp))) 7605 and then Conforming_Types 7606 (Etype (Def_Id), Etype (Subp), Subtype_Conformant) 7607 then 7608 Candidate := Subp; 7609 7610 -- If an inherited subprogram is implemented by a protected 7611 -- function, then the first parameter of the inherited 7612 -- subprogram shall be of mode in, but not an access-to- 7613 -- variable parameter (RM 9.4(11/9)). 7614 7615 if Present (First_Formal (Subp)) 7616 and then Ekind (First_Formal (Subp)) = E_In_Parameter 7617 and then 7618 (not Is_Access_Type (Etype (First_Formal (Subp))) 7619 or else 7620 Is_Access_Constant (Etype (First_Formal (Subp)))) 7621 then 7622 Overridden_Subp := Subp; 7623 return; 7624 end if; 7625 end if; 7626 7627 Hom := Homonym (Hom); 7628 end loop; 7629 7630 -- After examining all candidates for overriding, we are left with 7631 -- the best match, which is a mode-incompatible interface routine. 7632 7633 if In_Scope and then Present (Candidate) then 7634 Error_Msg_PT (Def_Id, Candidate); 7635 end if; 7636 7637 Overridden_Subp := Candidate; 7638 return; 7639 end; 7640 end Check_Synchronized_Overriding; 7641 7642 --------------------------- 7643 -- Check_Type_Conformant -- 7644 --------------------------- 7645 7646 procedure Check_Type_Conformant 7647 (New_Id : Entity_Id; 7648 Old_Id : Entity_Id; 7649 Err_Loc : Node_Id := Empty) 7650 is 7651 Result : Boolean; 7652 pragma Warnings (Off, Result); 7653 begin 7654 Check_Conformance 7655 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc); 7656 end Check_Type_Conformant; 7657 7658 --------------------------- 7659 -- Can_Override_Operator -- 7660 --------------------------- 7661 7662 function Can_Override_Operator (Subp : Entity_Id) return Boolean is 7663 Typ : Entity_Id; 7664 7665 begin 7666 if Nkind (Subp) /= N_Defining_Operator_Symbol then 7667 return False; 7668 7669 else 7670 Typ := Base_Type (Etype (First_Formal (Subp))); 7671 7672 -- Check explicitly that the operation is a primitive of the type 7673 7674 return Operator_Matches_Spec (Subp, Subp) 7675 and then not Is_Generic_Type (Typ) 7676 and then Scope (Subp) = Scope (Typ) 7677 and then not Is_Class_Wide_Type (Typ); 7678 end if; 7679 end Can_Override_Operator; 7680 7681 ---------------------- 7682 -- Conforming_Types -- 7683 ---------------------- 7684 7685 function Conforming_Types 7686 (T1 : Entity_Id; 7687 T2 : Entity_Id; 7688 Ctype : Conformance_Type; 7689 Get_Inst : Boolean := False) return Boolean 7690 is 7691 function Base_Types_Match 7692 (Typ_1 : Entity_Id; 7693 Typ_2 : Entity_Id) return Boolean; 7694 -- If neither Typ_1 nor Typ_2 are generic actual types, or if they are 7695 -- in different scopes (e.g. parent and child instances), then verify 7696 -- that the base types are equal. Otherwise Typ_1 and Typ_2 must be on 7697 -- the same subtype chain. The whole purpose of this procedure is to 7698 -- prevent spurious ambiguities in an instantiation that may arise if 7699 -- two distinct generic types are instantiated with the same actual. 7700 7701 function Find_Designated_Type (Typ : Entity_Id) return Entity_Id; 7702 -- An access parameter can designate an incomplete type. If the 7703 -- incomplete type is the limited view of a type from a limited_ 7704 -- with_clause, check whether the non-limited view is available. 7705 -- If it is a (non-limited) incomplete type, get the full view. 7706 7707 function Matches_Limited_With_View 7708 (Typ_1 : Entity_Id; 7709 Typ_2 : Entity_Id) return Boolean; 7710 -- Returns True if and only if either Typ_1 denotes a limited view of 7711 -- Typ_2 or Typ_2 denotes a limited view of Typ_1. This can arise when 7712 -- the limited with view of a type is used in a subprogram declaration 7713 -- and the subprogram body is in the scope of a regular with clause for 7714 -- the same unit. In such a case, the two type entities are considered 7715 -- identical for purposes of conformance checking. 7716 7717 ---------------------- 7718 -- Base_Types_Match -- 7719 ---------------------- 7720 7721 function Base_Types_Match 7722 (Typ_1 : Entity_Id; 7723 Typ_2 : Entity_Id) return Boolean 7724 is 7725 Base_1 : constant Entity_Id := Base_Type (Typ_1); 7726 Base_2 : constant Entity_Id := Base_Type (Typ_2); 7727 7728 begin 7729 if Typ_1 = Typ_2 then 7730 return True; 7731 7732 elsif Base_1 = Base_2 then 7733 7734 -- The following is too permissive. A more precise test should 7735 -- check that the generic actual is an ancestor subtype of the 7736 -- other ???. 7737 7738 -- See code in Find_Corresponding_Spec that applies an additional 7739 -- filter to handle accidental amiguities in instances. 7740 7741 return 7742 not Is_Generic_Actual_Type (Typ_1) 7743 or else not Is_Generic_Actual_Type (Typ_2) 7744 or else Scope (Typ_1) /= Scope (Typ_2); 7745 7746 -- If Typ_2 is a generic actual type it is declared as the subtype of 7747 -- the actual. If that actual is itself a subtype we need to use its 7748 -- own base type to check for compatibility. 7749 7750 elsif Ekind (Base_2) = Ekind (Typ_2) 7751 and then Base_1 = Base_Type (Base_2) 7752 then 7753 return True; 7754 7755 elsif Ekind (Base_1) = Ekind (Typ_1) 7756 and then Base_2 = Base_Type (Base_1) 7757 then 7758 return True; 7759 7760 else 7761 return False; 7762 end if; 7763 end Base_Types_Match; 7764 7765 -------------------------- 7766 -- Find_Designated_Type -- 7767 -------------------------- 7768 7769 function Find_Designated_Type (Typ : Entity_Id) return Entity_Id is 7770 Desig : Entity_Id; 7771 7772 begin 7773 Desig := Directly_Designated_Type (Typ); 7774 7775 if Ekind (Desig) = E_Incomplete_Type then 7776 7777 -- If regular incomplete type, get full view if available 7778 7779 if Present (Full_View (Desig)) then 7780 Desig := Full_View (Desig); 7781 7782 -- If limited view of a type, get non-limited view if available, 7783 -- and check again for a regular incomplete type. 7784 7785 elsif Present (Non_Limited_View (Desig)) then 7786 Desig := Get_Full_View (Non_Limited_View (Desig)); 7787 end if; 7788 end if; 7789 7790 return Desig; 7791 end Find_Designated_Type; 7792 7793 ------------------------------- 7794 -- Matches_Limited_With_View -- 7795 ------------------------------- 7796 7797 function Matches_Limited_With_View 7798 (Typ_1 : Entity_Id; 7799 Typ_2 : Entity_Id) return Boolean 7800 is 7801 function Is_Matching_Limited_View 7802 (Typ : Entity_Id; 7803 View : Entity_Id) return Boolean; 7804 -- Determine whether non-limited view View denotes type Typ in some 7805 -- conformant fashion. 7806 7807 ------------------------------ 7808 -- Is_Matching_Limited_View -- 7809 ------------------------------ 7810 7811 function Is_Matching_Limited_View 7812 (Typ : Entity_Id; 7813 View : Entity_Id) return Boolean 7814 is 7815 Root_Typ : Entity_Id; 7816 Root_View : Entity_Id; 7817 7818 begin 7819 -- The non-limited view directly denotes the type 7820 7821 if Typ = View then 7822 return True; 7823 7824 -- The type is a subtype of the non-limited view 7825 7826 elsif Is_Subtype_Of (Typ, View) then 7827 return True; 7828 7829 -- Both the non-limited view and the type denote class-wide types 7830 7831 elsif Is_Class_Wide_Type (Typ) 7832 and then Is_Class_Wide_Type (View) 7833 then 7834 Root_Typ := Root_Type (Typ); 7835 Root_View := Root_Type (View); 7836 7837 if Root_Typ = Root_View then 7838 return True; 7839 7840 -- An incomplete tagged type and its full view may receive two 7841 -- distinct class-wide types when the related package has not 7842 -- been analyzed yet. 7843 7844 -- package Pack is 7845 -- type T is tagged; -- CW_1 7846 -- type T is tagged null record; -- CW_2 7847 -- end Pack; 7848 7849 -- This is because the package lacks any semantic information 7850 -- that may eventually link both views of T. As a consequence, 7851 -- a client of the limited view of Pack will see CW_2 while a 7852 -- client of the non-limited view of Pack will see CW_1. 7853 7854 elsif Is_Incomplete_Type (Root_Typ) 7855 and then Present (Full_View (Root_Typ)) 7856 and then Full_View (Root_Typ) = Root_View 7857 then 7858 return True; 7859 7860 elsif Is_Incomplete_Type (Root_View) 7861 and then Present (Full_View (Root_View)) 7862 and then Full_View (Root_View) = Root_Typ 7863 then 7864 return True; 7865 end if; 7866 end if; 7867 7868 return False; 7869 end Is_Matching_Limited_View; 7870 7871 -- Start of processing for Matches_Limited_With_View 7872 7873 begin 7874 -- In some cases a type imported through a limited_with clause, and 7875 -- its non-limited view are both visible, for example in an anonymous 7876 -- access-to-class-wide type in a formal, or when building the body 7877 -- for a subprogram renaming after the subprogram has been frozen. 7878 -- In these cases both entities designate the same type. In addition, 7879 -- if one of them is an actual in an instance, it may be a subtype of 7880 -- the non-limited view of the other. 7881 7882 if From_Limited_With (Typ_1) 7883 and then From_Limited_With (Typ_2) 7884 and then Available_View (Typ_1) = Available_View (Typ_2) 7885 then 7886 return True; 7887 7888 elsif From_Limited_With (Typ_1) then 7889 return Is_Matching_Limited_View (Typ_2, Available_View (Typ_1)); 7890 7891 elsif From_Limited_With (Typ_2) then 7892 return Is_Matching_Limited_View (Typ_1, Available_View (Typ_2)); 7893 7894 else 7895 return False; 7896 end if; 7897 end Matches_Limited_With_View; 7898 7899 -- Local variables 7900 7901 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False; 7902 7903 Type_1 : Entity_Id := T1; 7904 Type_2 : Entity_Id := T2; 7905 7906 -- Start of processing for Conforming_Types 7907 7908 begin 7909 -- The context is an instance association for a formal access-to- 7910 -- subprogram type; the formal parameter types require mapping because 7911 -- they may denote other formal parameters of the generic unit. 7912 7913 if Get_Inst then 7914 Type_1 := Get_Instance_Of (T1); 7915 Type_2 := Get_Instance_Of (T2); 7916 end if; 7917 7918 -- If one of the types is a view of the other introduced by a limited 7919 -- with clause, treat these as conforming for all purposes. 7920 7921 if Matches_Limited_With_View (T1, T2) then 7922 return True; 7923 7924 elsif Base_Types_Match (Type_1, Type_2) then 7925 if Ctype <= Mode_Conformant then 7926 return True; 7927 7928 else 7929 return 7930 Subtypes_Statically_Match (Type_1, Type_2) 7931 and then Dimensions_Match (Type_1, Type_2); 7932 end if; 7933 7934 elsif Is_Incomplete_Or_Private_Type (Type_1) 7935 and then Present (Full_View (Type_1)) 7936 and then Base_Types_Match (Full_View (Type_1), Type_2) 7937 then 7938 return 7939 Ctype <= Mode_Conformant 7940 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2); 7941 7942 elsif Ekind (Type_2) = E_Incomplete_Type 7943 and then Present (Full_View (Type_2)) 7944 and then Base_Types_Match (Type_1, Full_View (Type_2)) 7945 then 7946 return 7947 Ctype <= Mode_Conformant 7948 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); 7949 7950 elsif Is_Private_Type (Type_2) 7951 and then In_Instance 7952 and then Present (Full_View (Type_2)) 7953 and then Base_Types_Match (Type_1, Full_View (Type_2)) 7954 then 7955 return 7956 Ctype <= Mode_Conformant 7957 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); 7958 7959 -- Another confusion between views in a nested instance with an 7960 -- actual private type whose full view is not in scope. 7961 7962 elsif Ekind (Type_2) = E_Private_Subtype 7963 and then In_Instance 7964 and then Etype (Type_2) = Type_1 7965 then 7966 return True; 7967 7968 -- In Ada 2012, incomplete types (including limited views) can appear 7969 -- as actuals in instantiations, where they are conformant to the 7970 -- corresponding incomplete formal. 7971 7972 elsif Is_Incomplete_Type (Type_1) 7973 and then Is_Incomplete_Type (Type_2) 7974 and then In_Instance 7975 and then (Used_As_Generic_Actual (Type_1) 7976 or else Used_As_Generic_Actual (Type_2)) 7977 then 7978 return True; 7979 end if; 7980 7981 -- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be 7982 -- treated recursively because they carry a signature. As far as 7983 -- conformance is concerned, convention plays no role, and either 7984 -- or both could be access to protected subprograms. 7985 7986 Are_Anonymous_Access_To_Subprogram_Types := 7987 Ekind_In (Type_1, E_Anonymous_Access_Subprogram_Type, 7988 E_Anonymous_Access_Protected_Subprogram_Type) 7989 and then 7990 Ekind_In (Type_2, E_Anonymous_Access_Subprogram_Type, 7991 E_Anonymous_Access_Protected_Subprogram_Type); 7992 7993 -- Test anonymous access type case. For this case, static subtype 7994 -- matching is required for mode conformance (RM 6.3.1(15)). We check 7995 -- the base types because we may have built internal subtype entities 7996 -- to handle null-excluding types (see Process_Formals). 7997 7998 if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type 7999 and then 8000 Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type) 8001 8002 -- Ada 2005 (AI-254) 8003 8004 or else Are_Anonymous_Access_To_Subprogram_Types 8005 then 8006 declare 8007 Desig_1 : Entity_Id; 8008 Desig_2 : Entity_Id; 8009 8010 begin 8011 -- In Ada 2005, access constant indicators must match for 8012 -- subtype conformance. 8013 8014 if Ada_Version >= Ada_2005 8015 and then Ctype >= Subtype_Conformant 8016 and then 8017 Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2) 8018 then 8019 return False; 8020 end if; 8021 8022 Desig_1 := Find_Designated_Type (Type_1); 8023 Desig_2 := Find_Designated_Type (Type_2); 8024 8025 -- If the context is an instance association for a formal 8026 -- access-to-subprogram type; formal access parameter designated 8027 -- types require mapping because they may denote other formal 8028 -- parameters of the generic unit. 8029 8030 if Get_Inst then 8031 Desig_1 := Get_Instance_Of (Desig_1); 8032 Desig_2 := Get_Instance_Of (Desig_2); 8033 end if; 8034 8035 -- It is possible for a Class_Wide_Type to be introduced for an 8036 -- incomplete type, in which case there is a separate class_ wide 8037 -- type for the full view. The types conform if their Etypes 8038 -- conform, i.e. one may be the full view of the other. This can 8039 -- only happen in the context of an access parameter, other uses 8040 -- of an incomplete Class_Wide_Type are illegal. 8041 8042 if Is_Class_Wide_Type (Desig_1) 8043 and then 8044 Is_Class_Wide_Type (Desig_2) 8045 then 8046 return 8047 Conforming_Types 8048 (Etype (Base_Type (Desig_1)), 8049 Etype (Base_Type (Desig_2)), Ctype); 8050 8051 elsif Are_Anonymous_Access_To_Subprogram_Types then 8052 if Ada_Version < Ada_2005 then 8053 return 8054 Ctype = Type_Conformant 8055 or else Subtypes_Statically_Match (Desig_1, Desig_2); 8056 8057 -- We must check the conformance of the signatures themselves 8058 8059 else 8060 declare 8061 Conformant : Boolean; 8062 begin 8063 Check_Conformance 8064 (Desig_1, Desig_2, Ctype, False, Conformant); 8065 return Conformant; 8066 end; 8067 end if; 8068 8069 -- A limited view of an actual matches the corresponding 8070 -- incomplete formal. 8071 8072 elsif Ekind (Desig_2) = E_Incomplete_Subtype 8073 and then From_Limited_With (Desig_2) 8074 and then Used_As_Generic_Actual (Etype (Desig_2)) 8075 then 8076 return True; 8077 8078 else 8079 return Base_Type (Desig_1) = Base_Type (Desig_2) 8080 and then (Ctype = Type_Conformant 8081 or else 8082 Subtypes_Statically_Match (Desig_1, Desig_2)); 8083 end if; 8084 end; 8085 8086 -- Otherwise definitely no match 8087 8088 else 8089 if ((Ekind (Type_1) = E_Anonymous_Access_Type 8090 and then Is_Access_Type (Type_2)) 8091 or else (Ekind (Type_2) = E_Anonymous_Access_Type 8092 and then Is_Access_Type (Type_1))) 8093 and then 8094 Conforming_Types 8095 (Designated_Type (Type_1), Designated_Type (Type_2), Ctype) 8096 then 8097 May_Hide_Profile := True; 8098 end if; 8099 8100 return False; 8101 end if; 8102 end Conforming_Types; 8103 8104 -------------------------- 8105 -- Create_Extra_Formals -- 8106 -------------------------- 8107 8108 procedure Create_Extra_Formals (E : Entity_Id) is 8109 First_Extra : Entity_Id := Empty; 8110 Formal : Entity_Id; 8111 Last_Extra : Entity_Id := Empty; 8112 8113 function Add_Extra_Formal 8114 (Assoc_Entity : Entity_Id; 8115 Typ : Entity_Id; 8116 Scope : Entity_Id; 8117 Suffix : String) return Entity_Id; 8118 -- Add an extra formal to the current list of formals and extra formals. 8119 -- The extra formal is added to the end of the list of extra formals, 8120 -- and also returned as the result. These formals are always of mode IN. 8121 -- The new formal has the type Typ, is declared in Scope, and its name 8122 -- is given by a concatenation of the name of Assoc_Entity and Suffix. 8123 -- The following suffixes are currently used. They should not be changed 8124 -- without coordinating with CodePeer, which makes use of these to 8125 -- provide better messages. 8126 8127 -- O denotes the Constrained bit. 8128 -- L denotes the accessibility level. 8129 -- BIP_xxx denotes an extra formal for a build-in-place function. See 8130 -- the full list in exp_ch6.BIP_Formal_Kind. 8131 8132 ---------------------- 8133 -- Add_Extra_Formal -- 8134 ---------------------- 8135 8136 function Add_Extra_Formal 8137 (Assoc_Entity : Entity_Id; 8138 Typ : Entity_Id; 8139 Scope : Entity_Id; 8140 Suffix : String) return Entity_Id 8141 is 8142 EF : constant Entity_Id := 8143 Make_Defining_Identifier (Sloc (Assoc_Entity), 8144 Chars => New_External_Name (Chars (Assoc_Entity), 8145 Suffix => Suffix)); 8146 8147 begin 8148 -- A little optimization. Never generate an extra formal for the 8149 -- _init operand of an initialization procedure, since it could 8150 -- never be used. 8151 8152 if Chars (Formal) = Name_uInit then 8153 return Empty; 8154 end if; 8155 8156 Set_Ekind (EF, E_In_Parameter); 8157 Set_Actual_Subtype (EF, Typ); 8158 Set_Etype (EF, Typ); 8159 Set_Scope (EF, Scope); 8160 Set_Mechanism (EF, Default_Mechanism); 8161 Set_Formal_Validity (EF); 8162 8163 if No (First_Extra) then 8164 First_Extra := EF; 8165 Set_Extra_Formals (Scope, EF); 8166 end if; 8167 8168 if Present (Last_Extra) then 8169 Set_Extra_Formal (Last_Extra, EF); 8170 end if; 8171 8172 Last_Extra := EF; 8173 8174 return EF; 8175 end Add_Extra_Formal; 8176 8177 -- Local variables 8178 8179 Formal_Type : Entity_Id; 8180 P_Formal : Entity_Id := Empty; 8181 8182 -- Start of processing for Create_Extra_Formals 8183 8184 begin 8185 -- We never generate extra formals if expansion is not active because we 8186 -- don't need them unless we are generating code. 8187 8188 if not Expander_Active then 8189 return; 8190 end if; 8191 8192 -- No need to generate extra formals in interface thunks whose target 8193 -- primitive has no extra formals. 8194 8195 if Is_Thunk (E) and then No (Extra_Formals (Thunk_Entity (E))) then 8196 return; 8197 end if; 8198 8199 -- If this is a derived subprogram then the subtypes of the parent 8200 -- subprogram's formal parameters will be used to determine the need 8201 -- for extra formals. 8202 8203 if Is_Overloadable (E) and then Present (Alias (E)) then 8204 P_Formal := First_Formal (Alias (E)); 8205 end if; 8206 8207 Formal := First_Formal (E); 8208 while Present (Formal) loop 8209 Last_Extra := Formal; 8210 Next_Formal (Formal); 8211 end loop; 8212 8213 -- If Extra_Formals were already created, don't do it again. This 8214 -- situation may arise for subprogram types created as part of 8215 -- dispatching calls (see Expand_Dispatching_Call). 8216 8217 if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then 8218 return; 8219 end if; 8220 8221 -- If the subprogram is a predefined dispatching subprogram then don't 8222 -- generate any extra constrained or accessibility level formals. In 8223 -- general we suppress these for internal subprograms (by not calling 8224 -- Freeze_Subprogram and Create_Extra_Formals at all), but internally 8225 -- generated stream attributes do get passed through because extra 8226 -- build-in-place formals are needed in some cases (limited 'Input). 8227 8228 if Is_Predefined_Internal_Operation (E) then 8229 goto Test_For_Func_Result_Extras; 8230 end if; 8231 8232 Formal := First_Formal (E); 8233 while Present (Formal) loop 8234 8235 -- Create extra formal for supporting the attribute 'Constrained. 8236 -- The case of a private type view without discriminants also 8237 -- requires the extra formal if the underlying type has defaulted 8238 -- discriminants. 8239 8240 if Ekind (Formal) /= E_In_Parameter then 8241 if Present (P_Formal) then 8242 Formal_Type := Etype (P_Formal); 8243 else 8244 Formal_Type := Etype (Formal); 8245 end if; 8246 8247 -- Do not produce extra formals for Unchecked_Union parameters. 8248 -- Jump directly to the end of the loop. 8249 8250 if Is_Unchecked_Union (Base_Type (Formal_Type)) then 8251 goto Skip_Extra_Formal_Generation; 8252 end if; 8253 8254 if not Has_Discriminants (Formal_Type) 8255 and then Ekind (Formal_Type) in Private_Kind 8256 and then Present (Underlying_Type (Formal_Type)) 8257 then 8258 Formal_Type := Underlying_Type (Formal_Type); 8259 end if; 8260 8261 -- Suppress the extra formal if formal's subtype is constrained or 8262 -- indefinite, or we're compiling for Ada 2012 and the underlying 8263 -- type is tagged and limited. In Ada 2012, a limited tagged type 8264 -- can have defaulted discriminants, but 'Constrained is required 8265 -- to return True, so the formal is never needed (see AI05-0214). 8266 -- Note that this ensures consistency of calling sequences for 8267 -- dispatching operations when some types in a class have defaults 8268 -- on discriminants and others do not (and requiring the extra 8269 -- formal would introduce distributed overhead). 8270 8271 -- If the type does not have a completion yet, treat as prior to 8272 -- Ada 2012 for consistency. 8273 8274 if Has_Discriminants (Formal_Type) 8275 and then not Is_Constrained (Formal_Type) 8276 and then Is_Definite_Subtype (Formal_Type) 8277 and then (Ada_Version < Ada_2012 8278 or else No (Underlying_Type (Formal_Type)) 8279 or else not 8280 (Is_Limited_Type (Formal_Type) 8281 and then 8282 (Is_Tagged_Type 8283 (Underlying_Type (Formal_Type))))) 8284 then 8285 Set_Extra_Constrained 8286 (Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O")); 8287 end if; 8288 end if; 8289 8290 -- Create extra formal for supporting accessibility checking. This 8291 -- is done for both anonymous access formals and formals of named 8292 -- access types that are marked as controlling formals. The latter 8293 -- case can occur when Expand_Dispatching_Call creates a subprogram 8294 -- type and substitutes the types of access-to-class-wide actuals 8295 -- for the anonymous access-to-specific-type of controlling formals. 8296 -- Base_Type is applied because in cases where there is a null 8297 -- exclusion the formal may have an access subtype. 8298 8299 -- This is suppressed if we specifically suppress accessibility 8300 -- checks at the package level for either the subprogram, or the 8301 -- package in which it resides. However, we do not suppress it 8302 -- simply if the scope has accessibility checks suppressed, since 8303 -- this could cause trouble when clients are compiled with a 8304 -- different suppression setting. The explicit checks at the 8305 -- package level are safe from this point of view. 8306 8307 if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type 8308 or else (Is_Controlling_Formal (Formal) 8309 and then Is_Access_Type (Base_Type (Etype (Formal))))) 8310 and then not 8311 (Explicit_Suppress (E, Accessibility_Check) 8312 or else 8313 Explicit_Suppress (Scope (E), Accessibility_Check)) 8314 and then 8315 (No (P_Formal) 8316 or else Present (Extra_Accessibility (P_Formal))) 8317 then 8318 Set_Extra_Accessibility 8319 (Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L")); 8320 end if; 8321 8322 -- This label is required when skipping extra formal generation for 8323 -- Unchecked_Union parameters. 8324 8325 <<Skip_Extra_Formal_Generation>> 8326 8327 if Present (P_Formal) then 8328 Next_Formal (P_Formal); 8329 end if; 8330 8331 Next_Formal (Formal); 8332 end loop; 8333 8334 <<Test_For_Func_Result_Extras>> 8335 8336 -- Ada 2012 (AI05-234): "the accessibility level of the result of a 8337 -- function call is ... determined by the point of call ...". 8338 8339 if Needs_Result_Accessibility_Level (E) then 8340 Set_Extra_Accessibility_Of_Result 8341 (E, Add_Extra_Formal (E, Standard_Natural, E, "L")); 8342 end if; 8343 8344 -- Ada 2005 (AI-318-02): In the case of build-in-place functions, add 8345 -- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind. 8346 8347 if Is_Build_In_Place_Function (E) then 8348 declare 8349 Result_Subt : constant Entity_Id := Etype (E); 8350 Formal_Typ : Entity_Id; 8351 Subp_Decl : Node_Id; 8352 Discard : Entity_Id; 8353 8354 begin 8355 -- In the case of functions with unconstrained result subtypes, 8356 -- add a 4-state formal indicating whether the return object is 8357 -- allocated by the caller (1), or should be allocated by the 8358 -- callee on the secondary stack (2), in the global heap (3), or 8359 -- in a user-defined storage pool (4). For the moment we just use 8360 -- Natural for the type of this formal. Note that this formal 8361 -- isn't usually needed in the case where the result subtype is 8362 -- constrained, but it is needed when the function has a tagged 8363 -- result, because generally such functions can be called in a 8364 -- dispatching context and such calls must be handled like calls 8365 -- to a class-wide function. 8366 8367 if Needs_BIP_Alloc_Form (E) then 8368 Discard := 8369 Add_Extra_Formal 8370 (E, Standard_Natural, 8371 E, BIP_Formal_Suffix (BIP_Alloc_Form)); 8372 8373 -- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to 8374 -- use a user-defined pool. This formal is not added on 8375 -- ZFP as those targets do not support pools. 8376 8377 if RTE_Available (RE_Root_Storage_Pool_Ptr) then 8378 Discard := 8379 Add_Extra_Formal 8380 (E, RTE (RE_Root_Storage_Pool_Ptr), 8381 E, BIP_Formal_Suffix (BIP_Storage_Pool)); 8382 end if; 8383 end if; 8384 8385 -- In the case of functions whose result type needs finalization, 8386 -- add an extra formal which represents the finalization master. 8387 8388 if Needs_BIP_Finalization_Master (E) then 8389 Discard := 8390 Add_Extra_Formal 8391 (E, RTE (RE_Finalization_Master_Ptr), 8392 E, BIP_Formal_Suffix (BIP_Finalization_Master)); 8393 end if; 8394 8395 -- When the result type contains tasks, add two extra formals: the 8396 -- master of the tasks to be created, and the caller's activation 8397 -- chain. 8398 8399 if Needs_BIP_Task_Actuals (E) then 8400 Discard := 8401 Add_Extra_Formal 8402 (E, RTE (RE_Master_Id), 8403 E, BIP_Formal_Suffix (BIP_Task_Master)); 8404 Discard := 8405 Add_Extra_Formal 8406 (E, RTE (RE_Activation_Chain_Access), 8407 E, BIP_Formal_Suffix (BIP_Activation_Chain)); 8408 end if; 8409 8410 -- All build-in-place functions get an extra formal that will be 8411 -- passed the address of the return object within the caller. 8412 8413 Formal_Typ := 8414 Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E)); 8415 8416 -- Incomplete_View_From_Limited_With is needed here because 8417 -- gigi gets confused if the designated type is the full view 8418 -- coming from a limited-with'ed package. In the normal case, 8419 -- (no limited with) Incomplete_View_From_Limited_With 8420 -- returns Result_Subt. 8421 8422 Set_Directly_Designated_Type 8423 (Formal_Typ, Incomplete_View_From_Limited_With (Result_Subt)); 8424 Set_Etype (Formal_Typ, Formal_Typ); 8425 Set_Depends_On_Private 8426 (Formal_Typ, Has_Private_Component (Formal_Typ)); 8427 Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ))); 8428 Set_Is_Access_Constant (Formal_Typ, False); 8429 8430 -- Ada 2005 (AI-50217): Propagate the attribute that indicates 8431 -- the designated type comes from the limited view (for back-end 8432 -- purposes). 8433 8434 Set_From_Limited_With 8435 (Formal_Typ, From_Limited_With (Result_Subt)); 8436 8437 Layout_Type (Formal_Typ); 8438 8439 -- Force the definition of the Itype in case of internal function 8440 -- calls within the same or nested scope. 8441 8442 if Is_Subprogram_Or_Generic_Subprogram (E) then 8443 Subp_Decl := Parent (E); 8444 8445 -- The insertion point for an Itype reference should be after 8446 -- the unit declaration node of the subprogram. An exception 8447 -- to this are inherited operations from a parent type in which 8448 -- case the derived type acts as their parent. 8449 8450 if Nkind_In (Subp_Decl, N_Function_Specification, 8451 N_Procedure_Specification) 8452 then 8453 Subp_Decl := Parent (Subp_Decl); 8454 end if; 8455 8456 Build_Itype_Reference (Formal_Typ, Subp_Decl); 8457 end if; 8458 8459 Discard := 8460 Add_Extra_Formal 8461 (E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access)); 8462 end; 8463 end if; 8464 8465 -- If this is an instance of a generic, we need to have extra formals 8466 -- for the Alias. 8467 8468 if Is_Generic_Instance (E) and then Present (Alias (E)) then 8469 Set_Extra_Formals (Alias (E), Extra_Formals (E)); 8470 end if; 8471 end Create_Extra_Formals; 8472 8473 ----------------------------- 8474 -- Enter_Overloaded_Entity -- 8475 ----------------------------- 8476 8477 procedure Enter_Overloaded_Entity (S : Entity_Id) is 8478 function Matches_Predefined_Op return Boolean; 8479 -- This returns an approximation of whether S matches a predefined 8480 -- operator, based on the operator symbol, and the parameter and result 8481 -- types. The rules are scattered throughout chapter 4 of the Ada RM. 8482 8483 --------------------------- 8484 -- Matches_Predefined_Op -- 8485 --------------------------- 8486 8487 function Matches_Predefined_Op return Boolean is 8488 Formal_1 : constant Entity_Id := First_Formal (S); 8489 Formal_2 : constant Entity_Id := Next_Formal (Formal_1); 8490 Op : constant Name_Id := Chars (S); 8491 Result_Type : constant Entity_Id := Base_Type (Etype (S)); 8492 Type_1 : constant Entity_Id := Base_Type (Etype (Formal_1)); 8493 8494 begin 8495 -- Binary operator 8496 8497 if Present (Formal_2) then 8498 declare 8499 Type_2 : constant Entity_Id := Base_Type (Etype (Formal_2)); 8500 8501 begin 8502 -- All but "&" and "**" have same-types parameters 8503 8504 case Op is 8505 when Name_Op_Concat 8506 | Name_Op_Expon 8507 => 8508 null; 8509 8510 when others => 8511 if Type_1 /= Type_2 then 8512 return False; 8513 end if; 8514 end case; 8515 8516 -- Check parameter and result types 8517 8518 case Op is 8519 when Name_Op_And 8520 | Name_Op_Or 8521 | Name_Op_Xor 8522 => 8523 return 8524 Is_Boolean_Type (Result_Type) 8525 and then Result_Type = Type_1; 8526 8527 when Name_Op_Mod 8528 | Name_Op_Rem 8529 => 8530 return 8531 Is_Integer_Type (Result_Type) 8532 and then Result_Type = Type_1; 8533 8534 when Name_Op_Add 8535 | Name_Op_Divide 8536 | Name_Op_Multiply 8537 | Name_Op_Subtract 8538 => 8539 return 8540 Is_Numeric_Type (Result_Type) 8541 and then Result_Type = Type_1; 8542 8543 when Name_Op_Eq 8544 | Name_Op_Ne 8545 => 8546 return 8547 Is_Boolean_Type (Result_Type) 8548 and then not Is_Limited_Type (Type_1); 8549 8550 when Name_Op_Ge 8551 | Name_Op_Gt 8552 | Name_Op_Le 8553 | Name_Op_Lt 8554 => 8555 return 8556 Is_Boolean_Type (Result_Type) 8557 and then (Is_Array_Type (Type_1) 8558 or else Is_Scalar_Type (Type_1)); 8559 8560 when Name_Op_Concat => 8561 return Is_Array_Type (Result_Type); 8562 8563 when Name_Op_Expon => 8564 return 8565 (Is_Integer_Type (Result_Type) 8566 or else Is_Floating_Point_Type (Result_Type)) 8567 and then Result_Type = Type_1 8568 and then Type_2 = Standard_Integer; 8569 8570 when others => 8571 raise Program_Error; 8572 end case; 8573 end; 8574 8575 -- Unary operator 8576 8577 else 8578 case Op is 8579 when Name_Op_Abs 8580 | Name_Op_Add 8581 | Name_Op_Subtract 8582 => 8583 return 8584 Is_Numeric_Type (Result_Type) 8585 and then Result_Type = Type_1; 8586 8587 when Name_Op_Not => 8588 return 8589 Is_Boolean_Type (Result_Type) 8590 and then Result_Type = Type_1; 8591 8592 when others => 8593 raise Program_Error; 8594 end case; 8595 end if; 8596 end Matches_Predefined_Op; 8597 8598 -- Local variables 8599 8600 E : Entity_Id := Current_Entity_In_Scope (S); 8601 C_E : Entity_Id := Current_Entity (S); 8602 8603 -- Start of processing for Enter_Overloaded_Entity 8604 8605 begin 8606 if Present (E) then 8607 Set_Has_Homonym (E); 8608 Set_Has_Homonym (S); 8609 end if; 8610 8611 Set_Is_Immediately_Visible (S); 8612 Set_Scope (S, Current_Scope); 8613 8614 -- Chain new entity if front of homonym in current scope, so that 8615 -- homonyms are contiguous. 8616 8617 if Present (E) and then E /= C_E then 8618 while Homonym (C_E) /= E loop 8619 C_E := Homonym (C_E); 8620 end loop; 8621 8622 Set_Homonym (C_E, S); 8623 8624 else 8625 E := C_E; 8626 Set_Current_Entity (S); 8627 end if; 8628 8629 Set_Homonym (S, E); 8630 8631 if Is_Inherited_Operation (S) then 8632 Append_Inherited_Subprogram (S); 8633 else 8634 Append_Entity (S, Current_Scope); 8635 end if; 8636 8637 Set_Public_Status (S); 8638 8639 if Debug_Flag_E then 8640 Write_Str ("New overloaded entity chain: "); 8641 Write_Name (Chars (S)); 8642 8643 E := S; 8644 while Present (E) loop 8645 Write_Str (" "); Write_Int (Int (E)); 8646 E := Homonym (E); 8647 end loop; 8648 8649 Write_Eol; 8650 end if; 8651 8652 -- Generate warning for hiding 8653 8654 if Warn_On_Hiding 8655 and then Comes_From_Source (S) 8656 and then In_Extended_Main_Source_Unit (S) 8657 then 8658 E := S; 8659 loop 8660 E := Homonym (E); 8661 exit when No (E); 8662 8663 -- Warn unless genuine overloading. Do not emit warning on 8664 -- hiding predefined operators in Standard (these are either an 8665 -- (artifact of our implicit declarations, or simple noise) but 8666 -- keep warning on a operator defined on a local subtype, because 8667 -- of the real danger that different operators may be applied in 8668 -- various parts of the program. 8669 8670 -- Note that if E and S have the same scope, there is never any 8671 -- hiding. Either the two conflict, and the program is illegal, 8672 -- or S is overriding an implicit inherited subprogram. 8673 8674 if Scope (E) /= Scope (S) 8675 and then (not Is_Overloadable (E) 8676 or else Subtype_Conformant (E, S)) 8677 and then (Is_Immediately_Visible (E) 8678 or else Is_Potentially_Use_Visible (S)) 8679 then 8680 if Scope (E) = Standard_Standard then 8681 if Nkind (S) = N_Defining_Operator_Symbol 8682 and then Scope (Base_Type (Etype (First_Formal (S)))) /= 8683 Scope (S) 8684 and then Matches_Predefined_Op 8685 then 8686 Error_Msg_N 8687 ("declaration of & hides predefined operator?h?", S); 8688 end if; 8689 8690 -- E not immediately within Standard 8691 8692 else 8693 Error_Msg_Sloc := Sloc (E); 8694 Error_Msg_N ("declaration of & hides one #?h?", S); 8695 end if; 8696 end if; 8697 end loop; 8698 end if; 8699 end Enter_Overloaded_Entity; 8700 8701 ----------------------------- 8702 -- Check_Untagged_Equality -- 8703 ----------------------------- 8704 8705 procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is 8706 Typ : constant Entity_Id := Etype (First_Formal (Eq_Op)); 8707 Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op); 8708 Obj_Decl : Node_Id; 8709 8710 begin 8711 -- This check applies only if we have a subprogram declaration with an 8712 -- untagged record type that is conformant to the predefined op. 8713 8714 if Nkind (Decl) /= N_Subprogram_Declaration 8715 or else not Is_Record_Type (Typ) 8716 or else Is_Tagged_Type (Typ) 8717 or else Etype (Next_Formal (First_Formal (Eq_Op))) /= Typ 8718 then 8719 return; 8720 end if; 8721 8722 -- In Ada 2012 case, we will output errors or warnings depending on 8723 -- the setting of debug flag -gnatd.E. 8724 8725 if Ada_Version >= Ada_2012 then 8726 Error_Msg_Warn := Debug_Flag_Dot_EE; 8727 8728 -- In earlier versions of Ada, nothing to do unless we are warning on 8729 -- Ada 2012 incompatibilities (Warn_On_Ada_2012_Incompatibility set). 8730 8731 else 8732 if not Warn_On_Ada_2012_Compatibility then 8733 return; 8734 end if; 8735 end if; 8736 8737 -- Cases where the type has already been frozen 8738 8739 if Is_Frozen (Typ) then 8740 8741 -- The check applies to a primitive operation, so check that type 8742 -- and equality operation are in the same scope. 8743 8744 if Scope (Typ) /= Current_Scope then 8745 return; 8746 8747 -- If the type is a generic actual (sub)type, the operation is not 8748 -- primitive either because the base type is declared elsewhere. 8749 8750 elsif Is_Generic_Actual_Type (Typ) then 8751 return; 8752 8753 -- Here we have a definite error of declaration after freezing 8754 8755 else 8756 if Ada_Version >= Ada_2012 then 8757 Error_Msg_NE 8758 ("equality operator must be declared before type & is " 8759 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)<<", Eq_Op, Typ); 8760 8761 -- In Ada 2012 mode with error turned to warning, output one 8762 -- more warning to warn that the equality operation may not 8763 -- compose. This is the consequence of ignoring the error. 8764 8765 if Error_Msg_Warn then 8766 Error_Msg_N ("\equality operation may not compose??", Eq_Op); 8767 end if; 8768 8769 else 8770 Error_Msg_NE 8771 ("equality operator must be declared before type& is " 8772 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)?y?", Eq_Op, Typ); 8773 end if; 8774 8775 -- If we are in the package body, we could just move the 8776 -- declaration to the package spec, so add a message saying that. 8777 8778 if In_Package_Body (Scope (Typ)) then 8779 if Ada_Version >= Ada_2012 then 8780 Error_Msg_N 8781 ("\move declaration to package spec<<", Eq_Op); 8782 else 8783 Error_Msg_N 8784 ("\move declaration to package spec (Ada 2012)?y?", Eq_Op); 8785 end if; 8786 8787 -- Otherwise try to find the freezing point for better message. 8788 8789 else 8790 Obj_Decl := Next (Parent (Typ)); 8791 while Present (Obj_Decl) and then Obj_Decl /= Decl loop 8792 if Nkind (Obj_Decl) = N_Object_Declaration 8793 and then Etype (Defining_Identifier (Obj_Decl)) = Typ 8794 then 8795 -- Freezing point, output warnings 8796 8797 if Ada_Version >= Ada_2012 then 8798 Error_Msg_NE 8799 ("type& is frozen by declaration??", Obj_Decl, Typ); 8800 Error_Msg_N 8801 ("\an equality operator cannot be declared after " 8802 & "this point??", 8803 Obj_Decl); 8804 else 8805 Error_Msg_NE 8806 ("type& is frozen by declaration (Ada 2012)?y?", 8807 Obj_Decl, Typ); 8808 Error_Msg_N 8809 ("\an equality operator cannot be declared after " 8810 & "this point (Ada 2012)?y?", 8811 Obj_Decl); 8812 end if; 8813 8814 exit; 8815 8816 -- If we reach generated code for subprogram declaration 8817 -- or body, it is the body that froze the type and the 8818 -- declaration is legal. 8819 8820 elsif Sloc (Obj_Decl) = Sloc (Decl) then 8821 return; 8822 end if; 8823 8824 Next (Obj_Decl); 8825 end loop; 8826 end if; 8827 end if; 8828 8829 -- Here if type is not frozen yet. It is illegal to have a primitive 8830 -- equality declared in the private part if the type is visible. 8831 8832 elsif not In_Same_List (Parent (Typ), Decl) 8833 and then not Is_Limited_Type (Typ) 8834 then 8835 -- Shouldn't we give an RM reference here??? 8836 8837 if Ada_Version >= Ada_2012 then 8838 Error_Msg_N 8839 ("equality operator appears too late<<", Eq_Op); 8840 else 8841 Error_Msg_N 8842 ("equality operator appears too late (Ada 2012)?y?", Eq_Op); 8843 end if; 8844 8845 -- No error detected 8846 8847 else 8848 return; 8849 end if; 8850 end Check_Untagged_Equality; 8851 8852 ----------------------------- 8853 -- Find_Corresponding_Spec -- 8854 ----------------------------- 8855 8856 function Find_Corresponding_Spec 8857 (N : Node_Id; 8858 Post_Error : Boolean := True) return Entity_Id 8859 is 8860 Spec : constant Node_Id := Specification (N); 8861 Designator : constant Entity_Id := Defining_Entity (Spec); 8862 8863 E : Entity_Id; 8864 8865 function Different_Generic_Profile (E : Entity_Id) return Boolean; 8866 -- Even if fully conformant, a body may depend on a generic actual when 8867 -- the spec does not, or vice versa, in which case they were distinct 8868 -- entities in the generic. 8869 8870 ------------------------------- 8871 -- Different_Generic_Profile -- 8872 ------------------------------- 8873 8874 function Different_Generic_Profile (E : Entity_Id) return Boolean is 8875 F1, F2 : Entity_Id; 8876 8877 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean; 8878 -- Check that the types of corresponding formals have the same 8879 -- generic actual if any. We have to account for subtypes of a 8880 -- generic formal, declared between a spec and a body, which may 8881 -- appear distinct in an instance but matched in the generic, and 8882 -- the subtype may be used either in the spec or the body of the 8883 -- subprogram being checked. 8884 8885 ------------------------- 8886 -- Same_Generic_Actual -- 8887 ------------------------- 8888 8889 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean is 8890 8891 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean; 8892 -- Predicate to check whether S1 is a subtype of S2 in the source 8893 -- of the instance. 8894 8895 ------------------------- 8896 -- Is_Declared_Subtype -- 8897 ------------------------- 8898 8899 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean is 8900 begin 8901 return Comes_From_Source (Parent (S1)) 8902 and then Nkind (Parent (S1)) = N_Subtype_Declaration 8903 and then Is_Entity_Name (Subtype_Indication (Parent (S1))) 8904 and then Entity (Subtype_Indication (Parent (S1))) = S2; 8905 end Is_Declared_Subtype; 8906 8907 -- Start of processing for Same_Generic_Actual 8908 8909 begin 8910 return Is_Generic_Actual_Type (T1) = Is_Generic_Actual_Type (T2) 8911 or else Is_Declared_Subtype (T1, T2) 8912 or else Is_Declared_Subtype (T2, T1); 8913 end Same_Generic_Actual; 8914 8915 -- Start of processing for Different_Generic_Profile 8916 8917 begin 8918 if not In_Instance then 8919 return False; 8920 8921 elsif Ekind (E) = E_Function 8922 and then not Same_Generic_Actual (Etype (E), Etype (Designator)) 8923 then 8924 return True; 8925 end if; 8926 8927 F1 := First_Formal (Designator); 8928 F2 := First_Formal (E); 8929 while Present (F1) loop 8930 if not Same_Generic_Actual (Etype (F1), Etype (F2)) then 8931 return True; 8932 end if; 8933 8934 Next_Formal (F1); 8935 Next_Formal (F2); 8936 end loop; 8937 8938 return False; 8939 end Different_Generic_Profile; 8940 8941 -- Start of processing for Find_Corresponding_Spec 8942 8943 begin 8944 E := Current_Entity (Designator); 8945 while Present (E) loop 8946 8947 -- We are looking for a matching spec. It must have the same scope, 8948 -- and the same name, and either be type conformant, or be the case 8949 -- of a library procedure spec and its body (which belong to one 8950 -- another regardless of whether they are type conformant or not). 8951 8952 if Scope (E) = Current_Scope then 8953 if Current_Scope = Standard_Standard 8954 or else (Ekind (E) = Ekind (Designator) 8955 and then Type_Conformant (E, Designator)) 8956 then 8957 -- Within an instantiation, we know that spec and body are 8958 -- subtype conformant, because they were subtype conformant in 8959 -- the generic. We choose the subtype-conformant entity here as 8960 -- well, to resolve spurious ambiguities in the instance that 8961 -- were not present in the generic (i.e. when two different 8962 -- types are given the same actual). If we are looking for a 8963 -- spec to match a body, full conformance is expected. 8964 8965 if In_Instance then 8966 8967 -- Inherit the convention and "ghostness" of the matching 8968 -- spec to ensure proper full and subtype conformance. 8969 8970 Set_Convention (Designator, Convention (E)); 8971 8972 -- Skip past subprogram bodies and subprogram renamings that 8973 -- may appear to have a matching spec, but that aren't fully 8974 -- conformant with it. That can occur in cases where an 8975 -- actual type causes unrelated homographs in the instance. 8976 8977 if Nkind_In (N, N_Subprogram_Body, 8978 N_Subprogram_Renaming_Declaration) 8979 and then Present (Homonym (E)) 8980 and then not Fully_Conformant (Designator, E) 8981 then 8982 goto Next_Entity; 8983 8984 elsif not Subtype_Conformant (Designator, E) then 8985 goto Next_Entity; 8986 8987 elsif Different_Generic_Profile (E) then 8988 goto Next_Entity; 8989 end if; 8990 end if; 8991 8992 -- Ada 2012 (AI05-0165): For internally generated bodies of 8993 -- null procedures locate the internally generated spec. We 8994 -- enforce mode conformance since a tagged type may inherit 8995 -- from interfaces several null primitives which differ only 8996 -- in the mode of the formals. 8997 8998 if not (Comes_From_Source (E)) 8999 and then Is_Null_Procedure (E) 9000 and then not Mode_Conformant (Designator, E) 9001 then 9002 null; 9003 9004 -- For null procedures coming from source that are completions, 9005 -- analysis of the generated body will establish the link. 9006 9007 elsif Comes_From_Source (E) 9008 and then Nkind (Spec) = N_Procedure_Specification 9009 and then Null_Present (Spec) 9010 then 9011 return E; 9012 9013 -- Expression functions can be completions, but cannot be 9014 -- completed by an explicit body. 9015 9016 elsif Comes_From_Source (E) 9017 and then Comes_From_Source (N) 9018 and then Nkind (N) = N_Subprogram_Body 9019 and then Nkind (Original_Node (Unit_Declaration_Node (E))) = 9020 N_Expression_Function 9021 then 9022 Error_Msg_Sloc := Sloc (E); 9023 Error_Msg_N ("body conflicts with expression function#", N); 9024 return Empty; 9025 9026 elsif not Has_Completion (E) then 9027 if Nkind (N) /= N_Subprogram_Body_Stub then 9028 Set_Corresponding_Spec (N, E); 9029 end if; 9030 9031 Set_Has_Completion (E); 9032 return E; 9033 9034 elsif Nkind (Parent (N)) = N_Subunit then 9035 9036 -- If this is the proper body of a subunit, the completion 9037 -- flag is set when analyzing the stub. 9038 9039 return E; 9040 9041 -- If E is an internal function with a controlling result that 9042 -- was created for an operation inherited by a null extension, 9043 -- it may be overridden by a body without a previous spec (one 9044 -- more reason why these should be shunned). In that case we 9045 -- remove the generated body if present, because the current 9046 -- one is the explicit overriding. 9047 9048 elsif Ekind (E) = E_Function 9049 and then Ada_Version >= Ada_2005 9050 and then not Comes_From_Source (E) 9051 and then Has_Controlling_Result (E) 9052 and then Is_Null_Extension (Etype (E)) 9053 and then Comes_From_Source (Spec) 9054 then 9055 Set_Has_Completion (E, False); 9056 9057 if Expander_Active 9058 and then Nkind (Parent (E)) = N_Function_Specification 9059 then 9060 Remove 9061 (Unit_Declaration_Node 9062 (Corresponding_Body (Unit_Declaration_Node (E)))); 9063 9064 return E; 9065 9066 -- If expansion is disabled, or if the wrapper function has 9067 -- not been generated yet, this a late body overriding an 9068 -- inherited operation, or it is an overriding by some other 9069 -- declaration before the controlling result is frozen. In 9070 -- either case this is a declaration of a new entity. 9071 9072 else 9073 return Empty; 9074 end if; 9075 9076 -- If the body already exists, then this is an error unless 9077 -- the previous declaration is the implicit declaration of a 9078 -- derived subprogram. It is also legal for an instance to 9079 -- contain type conformant overloadable declarations (but the 9080 -- generic declaration may not), per 8.3(26/2). 9081 9082 elsif No (Alias (E)) 9083 and then not Is_Intrinsic_Subprogram (E) 9084 and then not In_Instance 9085 and then Post_Error 9086 then 9087 Error_Msg_Sloc := Sloc (E); 9088 9089 if Is_Imported (E) then 9090 Error_Msg_NE 9091 ("body not allowed for imported subprogram & declared#", 9092 N, E); 9093 else 9094 Error_Msg_NE ("duplicate body for & declared#", N, E); 9095 end if; 9096 end if; 9097 9098 -- Child units cannot be overloaded, so a conformance mismatch 9099 -- between body and a previous spec is an error. 9100 9101 elsif Is_Child_Unit (E) 9102 and then 9103 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body 9104 and then 9105 Nkind (Parent (Unit_Declaration_Node (Designator))) = 9106 N_Compilation_Unit 9107 and then Post_Error 9108 then 9109 Error_Msg_N 9110 ("body of child unit does not match previous declaration", N); 9111 end if; 9112 end if; 9113 9114 <<Next_Entity>> 9115 E := Homonym (E); 9116 end loop; 9117 9118 -- On exit, we know that no previous declaration of subprogram exists 9119 9120 return Empty; 9121 end Find_Corresponding_Spec; 9122 9123 ---------------------- 9124 -- Fully_Conformant -- 9125 ---------------------- 9126 9127 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is 9128 Result : Boolean; 9129 begin 9130 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result); 9131 return Result; 9132 end Fully_Conformant; 9133 9134 ---------------------------------- 9135 -- Fully_Conformant_Expressions -- 9136 ---------------------------------- 9137 9138 function Fully_Conformant_Expressions 9139 (Given_E1 : Node_Id; 9140 Given_E2 : Node_Id; 9141 Report : Boolean := False) return Boolean 9142 is 9143 E1 : constant Node_Id := Original_Node (Given_E1); 9144 E2 : constant Node_Id := Original_Node (Given_E2); 9145 -- We always test conformance on original nodes, since it is possible 9146 -- for analysis and/or expansion to make things look as though they 9147 -- conform when they do not, e.g. by converting 1+2 into 3. 9148 9149 function FCE (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean; 9150 -- ??? 9151 9152 function FCL (L1 : List_Id; L2 : List_Id) return Boolean; 9153 -- Compare elements of two lists for conformance. Elements have to be 9154 -- conformant, and actuals inserted as default parameters do not match 9155 -- explicit actuals with the same value. 9156 9157 function FCO (Op_Node : Node_Id; Call_Node : Node_Id) return Boolean; 9158 -- Compare an operator node with a function call 9159 9160 --------- 9161 -- FCE -- 9162 --------- 9163 9164 function FCE (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean is 9165 begin 9166 return Fully_Conformant_Expressions (Given_E1, Given_E2, Report); 9167 end FCE; 9168 9169 --------- 9170 -- FCL -- 9171 --------- 9172 9173 function FCL (L1 : List_Id; L2 : List_Id) return Boolean is 9174 N1 : Node_Id; 9175 N2 : Node_Id; 9176 9177 begin 9178 if L1 = No_List then 9179 N1 := Empty; 9180 else 9181 N1 := First (L1); 9182 end if; 9183 9184 if L2 = No_List then 9185 N2 := Empty; 9186 else 9187 N2 := First (L2); 9188 end if; 9189 9190 -- Compare two lists, skipping rewrite insertions (we want to compare 9191 -- the original trees, not the expanded versions). 9192 9193 loop 9194 if Is_Rewrite_Insertion (N1) then 9195 Next (N1); 9196 elsif Is_Rewrite_Insertion (N2) then 9197 Next (N2); 9198 elsif No (N1) then 9199 return No (N2); 9200 elsif No (N2) then 9201 return False; 9202 elsif not FCE (N1, N2) then 9203 return False; 9204 else 9205 Next (N1); 9206 Next (N2); 9207 end if; 9208 end loop; 9209 end FCL; 9210 9211 --------- 9212 -- FCO -- 9213 --------- 9214 9215 function FCO (Op_Node : Node_Id; Call_Node : Node_Id) return Boolean is 9216 Actuals : constant List_Id := Parameter_Associations (Call_Node); 9217 Act : Node_Id; 9218 9219 begin 9220 if No (Actuals) 9221 or else Entity (Op_Node) /= Entity (Name (Call_Node)) 9222 then 9223 return False; 9224 9225 else 9226 Act := First (Actuals); 9227 9228 if Nkind (Op_Node) in N_Binary_Op then 9229 if not FCE (Left_Opnd (Op_Node), Act) then 9230 return False; 9231 end if; 9232 9233 Next (Act); 9234 end if; 9235 9236 return Present (Act) 9237 and then FCE (Right_Opnd (Op_Node), Act) 9238 and then No (Next (Act)); 9239 end if; 9240 end FCO; 9241 9242 -- Local variables 9243 9244 Result : Boolean; 9245 9246 -- Start of processing for Fully_Conformant_Expressions 9247 9248 begin 9249 Result := True; 9250 9251 -- Nonconformant if paren count does not match. Note: if some idiot 9252 -- complains that we don't do this right for more than 3 levels of 9253 -- parentheses, they will be treated with the respect they deserve. 9254 9255 if Paren_Count (E1) /= Paren_Count (E2) then 9256 return False; 9257 9258 -- If same entities are referenced, then they are conformant even if 9259 -- they have different forms (RM 8.3.1(19-20)). 9260 9261 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then 9262 if Present (Entity (E1)) then 9263 Result := Entity (E1) = Entity (E2) 9264 9265 -- One may be a discriminant that has been replaced by the 9266 -- corresponding discriminal. 9267 9268 or else 9269 (Chars (Entity (E1)) = Chars (Entity (E2)) 9270 and then Ekind (Entity (E1)) = E_Discriminant 9271 and then Ekind (Entity (E2)) = E_In_Parameter) 9272 9273 -- The discriminant of a protected type is transformed into 9274 -- a local constant and then into a parameter of a protected 9275 -- operation. 9276 9277 or else 9278 (Ekind (Entity (E1)) = E_Constant 9279 and then Ekind (Entity (E2)) = E_In_Parameter 9280 and then Present (Discriminal_Link (Entity (E1))) 9281 and then Discriminal_Link (Entity (E1)) = 9282 Discriminal_Link (Entity (E2))) 9283 9284 -- AI12-050: The loop variables of quantified expressions match 9285 -- if they have the same identifier, even though they may have 9286 -- different entities. 9287 9288 or else 9289 (Chars (Entity (E1)) = Chars (Entity (E2)) 9290 and then Ekind (Entity (E1)) = E_Loop_Parameter 9291 and then Ekind (Entity (E2)) = E_Loop_Parameter) 9292 9293 -- A call to an instantiation of Unchecked_Conversion is 9294 -- rewritten with the name of the generated function created for 9295 -- the instance, and this must be special-cased. 9296 9297 or else 9298 (Ekind (Entity (E1)) = E_Function 9299 and then Is_Intrinsic_Subprogram (Entity (E1)) 9300 and then Is_Generic_Instance (Entity (E1)) 9301 and then Entity (E2) = Alias (Entity (E1))); 9302 if Report and not Result then 9303 Error_Msg_Sloc := 9304 Text_Ptr'Max (Sloc (Entity (E1)), Sloc (Entity (E2))); 9305 Error_Msg_NE 9306 ("Meaning of& differs because of declaration#", E1, E2); 9307 end if; 9308 9309 return Result; 9310 9311 elsif Nkind (E1) = N_Expanded_Name 9312 and then Nkind (E2) = N_Expanded_Name 9313 and then Nkind (Selector_Name (E1)) = N_Character_Literal 9314 and then Nkind (Selector_Name (E2)) = N_Character_Literal 9315 then 9316 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)); 9317 9318 else 9319 -- Identifiers in component associations don't always have 9320 -- entities, but their names must conform. 9321 9322 return Nkind (E1) = N_Identifier 9323 and then Nkind (E2) = N_Identifier 9324 and then Chars (E1) = Chars (E2); 9325 end if; 9326 9327 elsif Nkind (E1) = N_Character_Literal 9328 and then Nkind (E2) = N_Expanded_Name 9329 then 9330 return Nkind (Selector_Name (E2)) = N_Character_Literal 9331 and then Chars (E1) = Chars (Selector_Name (E2)); 9332 9333 elsif Nkind (E2) = N_Character_Literal 9334 and then Nkind (E1) = N_Expanded_Name 9335 then 9336 return Nkind (Selector_Name (E1)) = N_Character_Literal 9337 and then Chars (E2) = Chars (Selector_Name (E1)); 9338 9339 elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then 9340 return FCO (E1, E2); 9341 9342 elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then 9343 return FCO (E2, E1); 9344 9345 -- Otherwise we must have the same syntactic entity 9346 9347 elsif Nkind (E1) /= Nkind (E2) then 9348 return False; 9349 9350 -- At this point, we specialize by node type 9351 9352 else 9353 case Nkind (E1) is 9354 when N_Aggregate => 9355 return 9356 FCL (Expressions (E1), Expressions (E2)) 9357 and then 9358 FCL (Component_Associations (E1), 9359 Component_Associations (E2)); 9360 9361 when N_Allocator => 9362 if Nkind (Expression (E1)) = N_Qualified_Expression 9363 or else 9364 Nkind (Expression (E2)) = N_Qualified_Expression 9365 then 9366 return FCE (Expression (E1), Expression (E2)); 9367 9368 -- Check that the subtype marks and any constraints 9369 -- are conformant 9370 9371 else 9372 declare 9373 Indic1 : constant Node_Id := Expression (E1); 9374 Indic2 : constant Node_Id := Expression (E2); 9375 Elt1 : Node_Id; 9376 Elt2 : Node_Id; 9377 9378 begin 9379 if Nkind (Indic1) /= N_Subtype_Indication then 9380 return 9381 Nkind (Indic2) /= N_Subtype_Indication 9382 and then Entity (Indic1) = Entity (Indic2); 9383 9384 elsif Nkind (Indic2) /= N_Subtype_Indication then 9385 return 9386 Nkind (Indic1) /= N_Subtype_Indication 9387 and then Entity (Indic1) = Entity (Indic2); 9388 9389 else 9390 if Entity (Subtype_Mark (Indic1)) /= 9391 Entity (Subtype_Mark (Indic2)) 9392 then 9393 return False; 9394 end if; 9395 9396 Elt1 := First (Constraints (Constraint (Indic1))); 9397 Elt2 := First (Constraints (Constraint (Indic2))); 9398 while Present (Elt1) and then Present (Elt2) loop 9399 if not FCE (Elt1, Elt2) then 9400 return False; 9401 end if; 9402 9403 Next (Elt1); 9404 Next (Elt2); 9405 end loop; 9406 9407 return True; 9408 end if; 9409 end; 9410 end if; 9411 9412 when N_Attribute_Reference => 9413 return 9414 Attribute_Name (E1) = Attribute_Name (E2) 9415 and then FCL (Expressions (E1), Expressions (E2)); 9416 9417 when N_Binary_Op => 9418 return 9419 Entity (E1) = Entity (E2) 9420 and then FCE (Left_Opnd (E1), Left_Opnd (E2)) 9421 and then FCE (Right_Opnd (E1), Right_Opnd (E2)); 9422 9423 when N_Membership_Test 9424 | N_Short_Circuit 9425 => 9426 return 9427 FCE (Left_Opnd (E1), Left_Opnd (E2)) 9428 and then 9429 FCE (Right_Opnd (E1), Right_Opnd (E2)); 9430 9431 when N_Case_Expression => 9432 declare 9433 Alt1 : Node_Id; 9434 Alt2 : Node_Id; 9435 9436 begin 9437 if not FCE (Expression (E1), Expression (E2)) then 9438 return False; 9439 9440 else 9441 Alt1 := First (Alternatives (E1)); 9442 Alt2 := First (Alternatives (E2)); 9443 loop 9444 if Present (Alt1) /= Present (Alt2) then 9445 return False; 9446 elsif No (Alt1) then 9447 return True; 9448 end if; 9449 9450 if not FCE (Expression (Alt1), Expression (Alt2)) 9451 or else not FCL (Discrete_Choices (Alt1), 9452 Discrete_Choices (Alt2)) 9453 then 9454 return False; 9455 end if; 9456 9457 Next (Alt1); 9458 Next (Alt2); 9459 end loop; 9460 end if; 9461 end; 9462 9463 when N_Character_Literal => 9464 return 9465 Char_Literal_Value (E1) = Char_Literal_Value (E2); 9466 9467 when N_Component_Association => 9468 return 9469 FCL (Choices (E1), Choices (E2)) 9470 and then 9471 FCE (Expression (E1), Expression (E2)); 9472 9473 when N_Explicit_Dereference => 9474 return 9475 FCE (Prefix (E1), Prefix (E2)); 9476 9477 when N_Extension_Aggregate => 9478 return 9479 FCL (Expressions (E1), Expressions (E2)) 9480 and then Null_Record_Present (E1) = 9481 Null_Record_Present (E2) 9482 and then FCL (Component_Associations (E1), 9483 Component_Associations (E2)); 9484 9485 when N_Function_Call => 9486 return 9487 FCE (Name (E1), Name (E2)) 9488 and then 9489 FCL (Parameter_Associations (E1), 9490 Parameter_Associations (E2)); 9491 9492 when N_If_Expression => 9493 return 9494 FCL (Expressions (E1), Expressions (E2)); 9495 9496 when N_Indexed_Component => 9497 return 9498 FCE (Prefix (E1), Prefix (E2)) 9499 and then 9500 FCL (Expressions (E1), Expressions (E2)); 9501 9502 when N_Integer_Literal => 9503 return (Intval (E1) = Intval (E2)); 9504 9505 when N_Null => 9506 return True; 9507 9508 when N_Operator_Symbol => 9509 return 9510 Chars (E1) = Chars (E2); 9511 9512 when N_Others_Choice => 9513 return True; 9514 9515 when N_Parameter_Association => 9516 return 9517 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)) 9518 and then FCE (Explicit_Actual_Parameter (E1), 9519 Explicit_Actual_Parameter (E2)); 9520 9521 when N_Qualified_Expression 9522 | N_Type_Conversion 9523 | N_Unchecked_Type_Conversion 9524 => 9525 return 9526 FCE (Subtype_Mark (E1), Subtype_Mark (E2)) 9527 and then 9528 FCE (Expression (E1), Expression (E2)); 9529 9530 when N_Quantified_Expression => 9531 if not FCE (Condition (E1), Condition (E2)) then 9532 return False; 9533 end if; 9534 9535 if Present (Loop_Parameter_Specification (E1)) 9536 and then Present (Loop_Parameter_Specification (E2)) 9537 then 9538 declare 9539 L1 : constant Node_Id := 9540 Loop_Parameter_Specification (E1); 9541 L2 : constant Node_Id := 9542 Loop_Parameter_Specification (E2); 9543 9544 begin 9545 return 9546 Reverse_Present (L1) = Reverse_Present (L2) 9547 and then 9548 FCE (Defining_Identifier (L1), 9549 Defining_Identifier (L2)) 9550 and then 9551 FCE (Discrete_Subtype_Definition (L1), 9552 Discrete_Subtype_Definition (L2)); 9553 end; 9554 9555 elsif Present (Iterator_Specification (E1)) 9556 and then Present (Iterator_Specification (E2)) 9557 then 9558 declare 9559 I1 : constant Node_Id := Iterator_Specification (E1); 9560 I2 : constant Node_Id := Iterator_Specification (E2); 9561 9562 begin 9563 return 9564 FCE (Defining_Identifier (I1), 9565 Defining_Identifier (I2)) 9566 and then 9567 Of_Present (I1) = Of_Present (I2) 9568 and then 9569 Reverse_Present (I1) = Reverse_Present (I2) 9570 and then FCE (Name (I1), Name (I2)) 9571 and then FCE (Subtype_Indication (I1), 9572 Subtype_Indication (I2)); 9573 end; 9574 9575 -- The quantified expressions used different specifications to 9576 -- walk their respective ranges. 9577 9578 else 9579 return False; 9580 end if; 9581 9582 when N_Range => 9583 return 9584 FCE (Low_Bound (E1), Low_Bound (E2)) 9585 and then 9586 FCE (High_Bound (E1), High_Bound (E2)); 9587 9588 when N_Real_Literal => 9589 return (Realval (E1) = Realval (E2)); 9590 9591 when N_Selected_Component => 9592 return 9593 FCE (Prefix (E1), Prefix (E2)) 9594 and then 9595 FCE (Selector_Name (E1), Selector_Name (E2)); 9596 9597 when N_Slice => 9598 return 9599 FCE (Prefix (E1), Prefix (E2)) 9600 and then 9601 FCE (Discrete_Range (E1), Discrete_Range (E2)); 9602 9603 when N_String_Literal => 9604 declare 9605 S1 : constant String_Id := Strval (E1); 9606 S2 : constant String_Id := Strval (E2); 9607 L1 : constant Nat := String_Length (S1); 9608 L2 : constant Nat := String_Length (S2); 9609 9610 begin 9611 if L1 /= L2 then 9612 return False; 9613 9614 else 9615 for J in 1 .. L1 loop 9616 if Get_String_Char (S1, J) /= 9617 Get_String_Char (S2, J) 9618 then 9619 return False; 9620 end if; 9621 end loop; 9622 9623 return True; 9624 end if; 9625 end; 9626 9627 when N_Unary_Op => 9628 return 9629 Entity (E1) = Entity (E2) 9630 and then 9631 FCE (Right_Opnd (E1), Right_Opnd (E2)); 9632 9633 -- All other node types cannot appear in this context. Strictly 9634 -- we should raise a fatal internal error. Instead we just ignore 9635 -- the nodes. This means that if anyone makes a mistake in the 9636 -- expander and mucks an expression tree irretrievably, the result 9637 -- will be a failure to detect a (probably very obscure) case 9638 -- of non-conformance, which is better than bombing on some 9639 -- case where two expressions do in fact conform. 9640 9641 when others => 9642 return True; 9643 end case; 9644 end if; 9645 end Fully_Conformant_Expressions; 9646 9647 ---------------------------------------- 9648 -- Fully_Conformant_Discrete_Subtypes -- 9649 ---------------------------------------- 9650 9651 function Fully_Conformant_Discrete_Subtypes 9652 (Given_S1 : Node_Id; 9653 Given_S2 : Node_Id) return Boolean 9654 is 9655 S1 : constant Node_Id := Original_Node (Given_S1); 9656 S2 : constant Node_Id := Original_Node (Given_S2); 9657 9658 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean; 9659 -- Special-case for a bound given by a discriminant, which in the body 9660 -- is replaced with the discriminal of the enclosing type. 9661 9662 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean; 9663 -- Check both bounds 9664 9665 ----------------------- 9666 -- Conforming_Bounds -- 9667 ----------------------- 9668 9669 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is 9670 begin 9671 if Is_Entity_Name (B1) 9672 and then Is_Entity_Name (B2) 9673 and then Ekind (Entity (B1)) = E_Discriminant 9674 then 9675 return Chars (B1) = Chars (B2); 9676 9677 else 9678 return Fully_Conformant_Expressions (B1, B2); 9679 end if; 9680 end Conforming_Bounds; 9681 9682 ----------------------- 9683 -- Conforming_Ranges -- 9684 ----------------------- 9685 9686 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is 9687 begin 9688 return 9689 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2)) 9690 and then 9691 Conforming_Bounds (High_Bound (R1), High_Bound (R2)); 9692 end Conforming_Ranges; 9693 9694 -- Start of processing for Fully_Conformant_Discrete_Subtypes 9695 9696 begin 9697 if Nkind (S1) /= Nkind (S2) then 9698 return False; 9699 9700 elsif Is_Entity_Name (S1) then 9701 return Entity (S1) = Entity (S2); 9702 9703 elsif Nkind (S1) = N_Range then 9704 return Conforming_Ranges (S1, S2); 9705 9706 elsif Nkind (S1) = N_Subtype_Indication then 9707 return 9708 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2)) 9709 and then 9710 Conforming_Ranges 9711 (Range_Expression (Constraint (S1)), 9712 Range_Expression (Constraint (S2))); 9713 else 9714 return True; 9715 end if; 9716 end Fully_Conformant_Discrete_Subtypes; 9717 9718 -------------------- 9719 -- Install_Entity -- 9720 -------------------- 9721 9722 procedure Install_Entity (E : Entity_Id) is 9723 Prev : constant Entity_Id := Current_Entity (E); 9724 begin 9725 Set_Is_Immediately_Visible (E); 9726 Set_Current_Entity (E); 9727 Set_Homonym (E, Prev); 9728 end Install_Entity; 9729 9730 --------------------- 9731 -- Install_Formals -- 9732 --------------------- 9733 9734 procedure Install_Formals (Id : Entity_Id) is 9735 F : Entity_Id; 9736 begin 9737 F := First_Formal (Id); 9738 while Present (F) loop 9739 Install_Entity (F); 9740 Next_Formal (F); 9741 end loop; 9742 end Install_Formals; 9743 9744 ----------------------------- 9745 -- Is_Interface_Conformant -- 9746 ----------------------------- 9747 9748 function Is_Interface_Conformant 9749 (Tagged_Type : Entity_Id; 9750 Iface_Prim : Entity_Id; 9751 Prim : Entity_Id) return Boolean 9752 is 9753 -- The operation may in fact be an inherited (implicit) operation 9754 -- rather than the original interface primitive, so retrieve the 9755 -- ultimate ancestor. 9756 9757 Iface : constant Entity_Id := 9758 Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)); 9759 Typ : constant Entity_Id := Find_Dispatching_Type (Prim); 9760 9761 function Controlling_Formal (Prim : Entity_Id) return Entity_Id; 9762 -- Return the controlling formal of Prim 9763 9764 ------------------------ 9765 -- Controlling_Formal -- 9766 ------------------------ 9767 9768 function Controlling_Formal (Prim : Entity_Id) return Entity_Id is 9769 E : Entity_Id; 9770 9771 begin 9772 E := First_Entity (Prim); 9773 while Present (E) loop 9774 if Is_Formal (E) and then Is_Controlling_Formal (E) then 9775 return E; 9776 end if; 9777 9778 Next_Entity (E); 9779 end loop; 9780 9781 return Empty; 9782 end Controlling_Formal; 9783 9784 -- Local variables 9785 9786 Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim); 9787 Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim); 9788 9789 -- Start of processing for Is_Interface_Conformant 9790 9791 begin 9792 pragma Assert (Is_Subprogram (Iface_Prim) 9793 and then Is_Subprogram (Prim) 9794 and then Is_Dispatching_Operation (Iface_Prim) 9795 and then Is_Dispatching_Operation (Prim)); 9796 9797 pragma Assert (Is_Interface (Iface) 9798 or else (Present (Alias (Iface_Prim)) 9799 and then 9800 Is_Interface 9801 (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim))))); 9802 9803 if Prim = Iface_Prim 9804 or else not Is_Subprogram (Prim) 9805 or else Ekind (Prim) /= Ekind (Iface_Prim) 9806 or else not Is_Dispatching_Operation (Prim) 9807 or else Scope (Prim) /= Scope (Tagged_Type) 9808 or else No (Typ) 9809 or else Base_Type (Typ) /= Base_Type (Tagged_Type) 9810 or else not Primitive_Names_Match (Iface_Prim, Prim) 9811 then 9812 return False; 9813 9814 -- The mode of the controlling formals must match 9815 9816 elsif Present (Iface_Ctrl_F) 9817 and then Present (Prim_Ctrl_F) 9818 and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F) 9819 then 9820 return False; 9821 9822 -- Case of a procedure, or a function whose result type matches the 9823 -- result type of the interface primitive, or a function that has no 9824 -- controlling result (I or access I). 9825 9826 elsif Ekind (Iface_Prim) = E_Procedure 9827 or else Etype (Prim) = Etype (Iface_Prim) 9828 or else not Has_Controlling_Result (Prim) 9829 then 9830 return Type_Conformant 9831 (Iface_Prim, Prim, Skip_Controlling_Formals => True); 9832 9833 -- Case of a function returning an interface, or an access to one. Check 9834 -- that the return types correspond. 9835 9836 elsif Implements_Interface (Typ, Iface) then 9837 if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type) 9838 /= 9839 (Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type) 9840 then 9841 return False; 9842 else 9843 return 9844 Type_Conformant (Prim, Ultimate_Alias (Iface_Prim), 9845 Skip_Controlling_Formals => True); 9846 end if; 9847 9848 else 9849 return False; 9850 end if; 9851 end Is_Interface_Conformant; 9852 9853 --------------------------------- 9854 -- Is_Non_Overriding_Operation -- 9855 --------------------------------- 9856 9857 function Is_Non_Overriding_Operation 9858 (Prev_E : Entity_Id; 9859 New_E : Entity_Id) return Boolean 9860 is 9861 Formal : Entity_Id; 9862 F_Typ : Entity_Id; 9863 G_Typ : Entity_Id := Empty; 9864 9865 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id; 9866 -- If F_Type is a derived type associated with a generic actual subtype, 9867 -- then return its Generic_Parent_Type attribute, else return Empty. 9868 9869 function Types_Correspond 9870 (P_Type : Entity_Id; 9871 N_Type : Entity_Id) return Boolean; 9872 -- Returns true if and only if the types (or designated types in the 9873 -- case of anonymous access types) are the same or N_Type is derived 9874 -- directly or indirectly from P_Type. 9875 9876 ----------------------------- 9877 -- Get_Generic_Parent_Type -- 9878 ----------------------------- 9879 9880 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is 9881 G_Typ : Entity_Id; 9882 Defn : Node_Id; 9883 Indic : Node_Id; 9884 9885 begin 9886 if Is_Derived_Type (F_Typ) 9887 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration 9888 then 9889 -- The tree must be traversed to determine the parent subtype in 9890 -- the generic unit, which unfortunately isn't always available 9891 -- via semantic attributes. ??? (Note: The use of Original_Node 9892 -- is needed for cases where a full derived type has been 9893 -- rewritten.) 9894 9895 -- If the parent type is a scalar type, the derivation creates 9896 -- an anonymous base type for it, and the source type is its 9897 -- first subtype. 9898 9899 if Is_Scalar_Type (F_Typ) 9900 and then not Comes_From_Source (F_Typ) 9901 then 9902 Defn := 9903 Type_Definition 9904 (Original_Node (Parent (First_Subtype (F_Typ)))); 9905 else 9906 Defn := Type_Definition (Original_Node (Parent (F_Typ))); 9907 end if; 9908 if Nkind (Defn) = N_Derived_Type_Definition then 9909 Indic := Subtype_Indication (Defn); 9910 9911 if Nkind (Indic) = N_Subtype_Indication then 9912 G_Typ := Entity (Subtype_Mark (Indic)); 9913 else 9914 G_Typ := Entity (Indic); 9915 end if; 9916 9917 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration 9918 and then Present (Generic_Parent_Type (Parent (G_Typ))) 9919 then 9920 return Generic_Parent_Type (Parent (G_Typ)); 9921 end if; 9922 end if; 9923 end if; 9924 9925 return Empty; 9926 end Get_Generic_Parent_Type; 9927 9928 ---------------------- 9929 -- Types_Correspond -- 9930 ---------------------- 9931 9932 function Types_Correspond 9933 (P_Type : Entity_Id; 9934 N_Type : Entity_Id) return Boolean 9935 is 9936 Prev_Type : Entity_Id := Base_Type (P_Type); 9937 New_Type : Entity_Id := Base_Type (N_Type); 9938 9939 begin 9940 if Ekind (Prev_Type) = E_Anonymous_Access_Type then 9941 Prev_Type := Designated_Type (Prev_Type); 9942 end if; 9943 9944 if Ekind (New_Type) = E_Anonymous_Access_Type then 9945 New_Type := Designated_Type (New_Type); 9946 end if; 9947 9948 if Prev_Type = New_Type then 9949 return True; 9950 9951 elsif not Is_Class_Wide_Type (New_Type) then 9952 while Etype (New_Type) /= New_Type loop 9953 New_Type := Etype (New_Type); 9954 9955 if New_Type = Prev_Type then 9956 return True; 9957 end if; 9958 end loop; 9959 end if; 9960 return False; 9961 end Types_Correspond; 9962 9963 -- Start of processing for Is_Non_Overriding_Operation 9964 9965 begin 9966 -- In the case where both operations are implicit derived subprograms 9967 -- then neither overrides the other. This can only occur in certain 9968 -- obscure cases (e.g., derivation from homographs created in a generic 9969 -- instantiation). 9970 9971 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then 9972 return True; 9973 9974 elsif Ekind (Current_Scope) = E_Package 9975 and then Is_Generic_Instance (Current_Scope) 9976 and then In_Private_Part (Current_Scope) 9977 and then Comes_From_Source (New_E) 9978 then 9979 -- We examine the formals and result type of the inherited operation, 9980 -- to determine whether their type is derived from (the instance of) 9981 -- a generic type. The first such formal or result type is the one 9982 -- tested. 9983 9984 Formal := First_Formal (Prev_E); 9985 F_Typ := Empty; 9986 while Present (Formal) loop 9987 F_Typ := Base_Type (Etype (Formal)); 9988 9989 if Ekind (F_Typ) = E_Anonymous_Access_Type then 9990 F_Typ := Designated_Type (F_Typ); 9991 end if; 9992 9993 G_Typ := Get_Generic_Parent_Type (F_Typ); 9994 exit when Present (G_Typ); 9995 9996 Next_Formal (Formal); 9997 end loop; 9998 9999 -- If the function dispatches on result check the result type 10000 10001 if No (G_Typ) and then Ekind (Prev_E) = E_Function then 10002 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E))); 10003 end if; 10004 10005 if No (G_Typ) then 10006 return False; 10007 end if; 10008 10009 -- If the generic type is a private type, then the original operation 10010 -- was not overriding in the generic, because there was no primitive 10011 -- operation to override. 10012 10013 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration 10014 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) = 10015 N_Formal_Private_Type_Definition 10016 then 10017 return True; 10018 10019 -- The generic parent type is the ancestor of a formal derived 10020 -- type declaration. We need to check whether it has a primitive 10021 -- operation that should be overridden by New_E in the generic. 10022 10023 else 10024 declare 10025 P_Formal : Entity_Id; 10026 N_Formal : Entity_Id; 10027 P_Typ : Entity_Id; 10028 N_Typ : Entity_Id; 10029 P_Prim : Entity_Id; 10030 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ)); 10031 10032 begin 10033 while Present (Prim_Elt) loop 10034 P_Prim := Node (Prim_Elt); 10035 10036 if Chars (P_Prim) = Chars (New_E) 10037 and then Ekind (P_Prim) = Ekind (New_E) 10038 then 10039 P_Formal := First_Formal (P_Prim); 10040 N_Formal := First_Formal (New_E); 10041 while Present (P_Formal) and then Present (N_Formal) loop 10042 P_Typ := Etype (P_Formal); 10043 N_Typ := Etype (N_Formal); 10044 10045 if not Types_Correspond (P_Typ, N_Typ) then 10046 exit; 10047 end if; 10048 10049 Next_Entity (P_Formal); 10050 Next_Entity (N_Formal); 10051 end loop; 10052 10053 -- Found a matching primitive operation belonging to the 10054 -- formal ancestor type, so the new subprogram is 10055 -- overriding. 10056 10057 if No (P_Formal) 10058 and then No (N_Formal) 10059 and then (Ekind (New_E) /= E_Function 10060 or else 10061 Types_Correspond 10062 (Etype (P_Prim), Etype (New_E))) 10063 then 10064 return False; 10065 end if; 10066 end if; 10067 10068 Next_Elmt (Prim_Elt); 10069 end loop; 10070 10071 -- If no match found, then the new subprogram does not override 10072 -- in the generic (nor in the instance). 10073 10074 -- If the type in question is not abstract, and the subprogram 10075 -- is, this will be an error if the new operation is in the 10076 -- private part of the instance. Emit a warning now, which will 10077 -- make the subsequent error message easier to understand. 10078 10079 if Present (F_Typ) and then not Is_Abstract_Type (F_Typ) 10080 and then Is_Abstract_Subprogram (Prev_E) 10081 and then In_Private_Part (Current_Scope) 10082 then 10083 Error_Msg_Node_2 := F_Typ; 10084 Error_Msg_NE 10085 ("private operation& in generic unit does not override " 10086 & "any primitive operation of& (RM 12.3 (18))??", 10087 New_E, New_E); 10088 end if; 10089 10090 return True; 10091 end; 10092 end if; 10093 else 10094 return False; 10095 end if; 10096 end Is_Non_Overriding_Operation; 10097 10098 ------------------------------------- 10099 -- List_Inherited_Pre_Post_Aspects -- 10100 ------------------------------------- 10101 10102 procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is 10103 begin 10104 if Opt.List_Inherited_Aspects 10105 and then Is_Subprogram_Or_Generic_Subprogram (E) 10106 then 10107 declare 10108 Subps : constant Subprogram_List := Inherited_Subprograms (E); 10109 Items : Node_Id; 10110 Prag : Node_Id; 10111 10112 begin 10113 for Index in Subps'Range loop 10114 Items := Contract (Subps (Index)); 10115 10116 if Present (Items) then 10117 Prag := Pre_Post_Conditions (Items); 10118 while Present (Prag) loop 10119 Error_Msg_Sloc := Sloc (Prag); 10120 10121 if Class_Present (Prag) 10122 and then not Split_PPC (Prag) 10123 then 10124 if Pragma_Name (Prag) = Name_Precondition then 10125 Error_Msg_N 10126 ("info: & inherits `Pre''Class` aspect from " 10127 & "#?L?", E); 10128 else 10129 Error_Msg_N 10130 ("info: & inherits `Post''Class` aspect from " 10131 & "#?L?", E); 10132 end if; 10133 end if; 10134 10135 Prag := Next_Pragma (Prag); 10136 end loop; 10137 end if; 10138 end loop; 10139 end; 10140 end if; 10141 end List_Inherited_Pre_Post_Aspects; 10142 10143 ------------------------------ 10144 -- Make_Inequality_Operator -- 10145 ------------------------------ 10146 10147 -- S is the defining identifier of an equality operator. We build a 10148 -- subprogram declaration with the right signature. This operation is 10149 -- intrinsic, because it is always expanded as the negation of the 10150 -- call to the equality function. 10151 10152 procedure Make_Inequality_Operator (S : Entity_Id) is 10153 Loc : constant Source_Ptr := Sloc (S); 10154 Decl : Node_Id; 10155 Formals : List_Id; 10156 Op_Name : Entity_Id; 10157 10158 FF : constant Entity_Id := First_Formal (S); 10159 NF : constant Entity_Id := Next_Formal (FF); 10160 10161 begin 10162 -- Check that equality was properly defined, ignore call if not 10163 10164 if No (NF) then 10165 return; 10166 end if; 10167 10168 declare 10169 A : constant Entity_Id := 10170 Make_Defining_Identifier (Sloc (FF), 10171 Chars => Chars (FF)); 10172 10173 B : constant Entity_Id := 10174 Make_Defining_Identifier (Sloc (NF), 10175 Chars => Chars (NF)); 10176 10177 begin 10178 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne); 10179 10180 Formals := New_List ( 10181 Make_Parameter_Specification (Loc, 10182 Defining_Identifier => A, 10183 Parameter_Type => 10184 New_Occurrence_Of (Etype (First_Formal (S)), 10185 Sloc (Etype (First_Formal (S))))), 10186 10187 Make_Parameter_Specification (Loc, 10188 Defining_Identifier => B, 10189 Parameter_Type => 10190 New_Occurrence_Of (Etype (Next_Formal (First_Formal (S))), 10191 Sloc (Etype (Next_Formal (First_Formal (S))))))); 10192 10193 Decl := 10194 Make_Subprogram_Declaration (Loc, 10195 Specification => 10196 Make_Function_Specification (Loc, 10197 Defining_Unit_Name => Op_Name, 10198 Parameter_Specifications => Formals, 10199 Result_Definition => 10200 New_Occurrence_Of (Standard_Boolean, Loc))); 10201 10202 -- Insert inequality right after equality if it is explicit or after 10203 -- the derived type when implicit. These entities are created only 10204 -- for visibility purposes, and eventually replaced in the course 10205 -- of expansion, so they do not need to be attached to the tree and 10206 -- seen by the back-end. Keeping them internal also avoids spurious 10207 -- freezing problems. The declaration is inserted in the tree for 10208 -- analysis, and removed afterwards. If the equality operator comes 10209 -- from an explicit declaration, attach the inequality immediately 10210 -- after. Else the equality is inherited from a derived type 10211 -- declaration, so insert inequality after that declaration. 10212 10213 if No (Alias (S)) then 10214 Insert_After (Unit_Declaration_Node (S), Decl); 10215 elsif Is_List_Member (Parent (S)) then 10216 Insert_After (Parent (S), Decl); 10217 else 10218 Insert_After (Parent (Etype (First_Formal (S))), Decl); 10219 end if; 10220 10221 Mark_Rewrite_Insertion (Decl); 10222 Set_Is_Intrinsic_Subprogram (Op_Name); 10223 Analyze (Decl); 10224 Remove (Decl); 10225 Set_Has_Completion (Op_Name); 10226 Set_Corresponding_Equality (Op_Name, S); 10227 Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S)); 10228 end; 10229 end Make_Inequality_Operator; 10230 10231 ---------------------- 10232 -- May_Need_Actuals -- 10233 ---------------------- 10234 10235 procedure May_Need_Actuals (Fun : Entity_Id) is 10236 F : Entity_Id; 10237 B : Boolean; 10238 10239 begin 10240 F := First_Formal (Fun); 10241 B := True; 10242 while Present (F) loop 10243 if No (Default_Value (F)) then 10244 B := False; 10245 exit; 10246 end if; 10247 10248 Next_Formal (F); 10249 end loop; 10250 10251 Set_Needs_No_Actuals (Fun, B); 10252 end May_Need_Actuals; 10253 10254 --------------------- 10255 -- Mode_Conformant -- 10256 --------------------- 10257 10258 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is 10259 Result : Boolean; 10260 begin 10261 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result); 10262 return Result; 10263 end Mode_Conformant; 10264 10265 --------------------------- 10266 -- New_Overloaded_Entity -- 10267 --------------------------- 10268 10269 procedure New_Overloaded_Entity 10270 (S : Entity_Id; 10271 Derived_Type : Entity_Id := Empty) 10272 is 10273 Overridden_Subp : Entity_Id := Empty; 10274 -- Set if the current scope has an operation that is type-conformant 10275 -- with S, and becomes hidden by S. 10276 10277 Is_Primitive_Subp : Boolean; 10278 -- Set to True if the new subprogram is primitive 10279 10280 E : Entity_Id; 10281 -- Entity that S overrides 10282 10283 procedure Check_For_Primitive_Subprogram 10284 (Is_Primitive : out Boolean; 10285 Is_Overriding : Boolean := False); 10286 -- If the subprogram being analyzed is a primitive operation of the type 10287 -- of a formal or result, set the Has_Primitive_Operations flag on the 10288 -- type, and set Is_Primitive to True (otherwise set to False). Set the 10289 -- corresponding flag on the entity itself for later use. 10290 10291 function Has_Matching_Entry_Or_Subprogram (E : Entity_Id) return Boolean; 10292 -- True if a) E is a subprogram whose first formal is a concurrent type 10293 -- defined in the scope of E that has some entry or subprogram whose 10294 -- profile matches E, or b) E is an internally built dispatching 10295 -- subprogram of a protected type and there is a matching subprogram 10296 -- defined in the enclosing scope of the protected type, or c) E is 10297 -- an entry of a synchronized type and a matching procedure has been 10298 -- previously defined in the enclosing scope of the synchronized type. 10299 10300 function Is_Private_Declaration (E : Entity_Id) return Boolean; 10301 -- Check that E is declared in the private part of the current package, 10302 -- or in the package body, where it may hide a previous declaration. 10303 -- We can't use In_Private_Part by itself because this flag is also 10304 -- set when freezing entities, so we must examine the place of the 10305 -- declaration in the tree, and recognize wrapper packages as well. 10306 10307 function Is_Overriding_Alias 10308 (Old_E : Entity_Id; 10309 New_E : Entity_Id) return Boolean; 10310 -- Check whether new subprogram and old subprogram are both inherited 10311 -- from subprograms that have distinct dispatch table entries. This can 10312 -- occur with derivations from instances with accidental homonyms. The 10313 -- function is conservative given that the converse is only true within 10314 -- instances that contain accidental overloadings. 10315 10316 procedure Report_Conflict (S : Entity_Id; E : Entity_Id); 10317 -- Report conflict between entities S and E 10318 10319 ------------------------------------ 10320 -- Check_For_Primitive_Subprogram -- 10321 ------------------------------------ 10322 10323 procedure Check_For_Primitive_Subprogram 10324 (Is_Primitive : out Boolean; 10325 Is_Overriding : Boolean := False) 10326 is 10327 Formal : Entity_Id; 10328 F_Typ : Entity_Id; 10329 B_Typ : Entity_Id; 10330 10331 function Visible_Part_Type (T : Entity_Id) return Boolean; 10332 -- Returns true if T is declared in the visible part of the current 10333 -- package scope; otherwise returns false. Assumes that T is declared 10334 -- in a package. 10335 10336 procedure Check_Private_Overriding (T : Entity_Id); 10337 -- Checks that if a primitive abstract subprogram of a visible 10338 -- abstract type is declared in a private part, then it must override 10339 -- an abstract subprogram declared in the visible part. Also checks 10340 -- that if a primitive function with a controlling result is declared 10341 -- in a private part, then it must override a function declared in 10342 -- the visible part. 10343 10344 ------------------------------ 10345 -- Check_Private_Overriding -- 10346 ------------------------------ 10347 10348 procedure Check_Private_Overriding (T : Entity_Id) is 10349 function Overrides_Private_Part_Op return Boolean; 10350 -- This detects the special case where the overriding subprogram 10351 -- is overriding a subprogram that was declared in the same 10352 -- private part. That case is illegal by 3.9.3(10). 10353 10354 function Overrides_Visible_Function 10355 (Partial_View : Entity_Id) return Boolean; 10356 -- True if S overrides a function in the visible part. The 10357 -- overridden function could be explicitly or implicitly declared. 10358 10359 ------------------------------- 10360 -- Overrides_Private_Part_Op -- 10361 ------------------------------- 10362 10363 function Overrides_Private_Part_Op return Boolean is 10364 Over_Decl : constant Node_Id := 10365 Unit_Declaration_Node (Overridden_Operation (S)); 10366 Subp_Decl : constant Node_Id := Unit_Declaration_Node (S); 10367 10368 begin 10369 pragma Assert (Is_Overriding); 10370 pragma Assert 10371 (Nkind (Over_Decl) = N_Abstract_Subprogram_Declaration); 10372 pragma Assert 10373 (Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration); 10374 10375 return In_Same_List (Over_Decl, Subp_Decl); 10376 end Overrides_Private_Part_Op; 10377 10378 -------------------------------- 10379 -- Overrides_Visible_Function -- 10380 -------------------------------- 10381 10382 function Overrides_Visible_Function 10383 (Partial_View : Entity_Id) return Boolean 10384 is 10385 begin 10386 if not Is_Overriding or else not Has_Homonym (S) then 10387 return False; 10388 end if; 10389 10390 if not Present (Partial_View) then 10391 return True; 10392 end if; 10393 10394 -- Search through all the homonyms H of S in the current 10395 -- package spec, and return True if we find one that matches. 10396 -- Note that Parent (H) will be the declaration of the 10397 -- partial view of T for a match. 10398 10399 declare 10400 H : Entity_Id := S; 10401 begin 10402 loop 10403 H := Homonym (H); 10404 exit when not Present (H) or else Scope (H) /= Scope (S); 10405 10406 if Nkind_In 10407 (Parent (H), 10408 N_Private_Extension_Declaration, 10409 N_Private_Type_Declaration) 10410 and then Defining_Identifier (Parent (H)) = Partial_View 10411 then 10412 return True; 10413 end if; 10414 end loop; 10415 end; 10416 10417 return False; 10418 end Overrides_Visible_Function; 10419 10420 -- Start of processing for Check_Private_Overriding 10421 10422 begin 10423 if Is_Package_Or_Generic_Package (Current_Scope) 10424 and then In_Private_Part (Current_Scope) 10425 and then Visible_Part_Type (T) 10426 and then not In_Instance 10427 then 10428 if Is_Abstract_Type (T) 10429 and then Is_Abstract_Subprogram (S) 10430 and then (not Is_Overriding 10431 or else not Is_Abstract_Subprogram (E) 10432 or else Overrides_Private_Part_Op) 10433 then 10434 Error_Msg_N 10435 ("abstract subprograms must be visible (RM 3.9.3(10))!", 10436 S); 10437 10438 elsif Ekind (S) = E_Function then 10439 declare 10440 Partial_View : constant Entity_Id := 10441 Incomplete_Or_Partial_View (T); 10442 10443 begin 10444 if not Overrides_Visible_Function (Partial_View) then 10445 10446 -- Here, S is "function ... return T;" declared in 10447 -- the private part, not overriding some visible 10448 -- operation. That's illegal in the tagged case 10449 -- (but not if the private type is untagged). 10450 10451 if ((Present (Partial_View) 10452 and then Is_Tagged_Type (Partial_View)) 10453 or else (not Present (Partial_View) 10454 and then Is_Tagged_Type (T))) 10455 and then T = Base_Type (Etype (S)) 10456 then 10457 Error_Msg_N 10458 ("private function with tagged result must" 10459 & " override visible-part function", S); 10460 Error_Msg_N 10461 ("\move subprogram to the visible part" 10462 & " (RM 3.9.3(10))", S); 10463 10464 -- AI05-0073: extend this test to the case of a 10465 -- function with a controlling access result. 10466 10467 elsif Ekind (Etype (S)) = E_Anonymous_Access_Type 10468 and then Is_Tagged_Type (Designated_Type (Etype (S))) 10469 and then 10470 not Is_Class_Wide_Type 10471 (Designated_Type (Etype (S))) 10472 and then Ada_Version >= Ada_2012 10473 then 10474 Error_Msg_N 10475 ("private function with controlling access " 10476 & "result must override visible-part function", 10477 S); 10478 Error_Msg_N 10479 ("\move subprogram to the visible part" 10480 & " (RM 3.9.3(10))", S); 10481 end if; 10482 end if; 10483 end; 10484 end if; 10485 end if; 10486 end Check_Private_Overriding; 10487 10488 ----------------------- 10489 -- Visible_Part_Type -- 10490 ----------------------- 10491 10492 function Visible_Part_Type (T : Entity_Id) return Boolean is 10493 P : constant Node_Id := Unit_Declaration_Node (Scope (T)); 10494 10495 begin 10496 -- If the entity is a private type, then it must be declared in a 10497 -- visible part. 10498 10499 if Ekind (T) in Private_Kind then 10500 return True; 10501 10502 elsif Is_Type (T) and then Has_Private_Declaration (T) then 10503 return True; 10504 10505 elsif Is_List_Member (Declaration_Node (T)) 10506 and then List_Containing (Declaration_Node (T)) = 10507 Visible_Declarations (Specification (P)) 10508 then 10509 return True; 10510 10511 else 10512 return False; 10513 end if; 10514 end Visible_Part_Type; 10515 10516 -- Start of processing for Check_For_Primitive_Subprogram 10517 10518 begin 10519 Is_Primitive := False; 10520 10521 if not Comes_From_Source (S) then 10522 null; 10523 10524 -- If subprogram is at library level, it is not primitive operation 10525 10526 elsif Current_Scope = Standard_Standard then 10527 null; 10528 10529 elsif (Is_Package_Or_Generic_Package (Current_Scope) 10530 and then not In_Package_Body (Current_Scope)) 10531 or else Is_Overriding 10532 then 10533 -- For function, check return type 10534 10535 if Ekind (S) = E_Function then 10536 if Ekind (Etype (S)) = E_Anonymous_Access_Type then 10537 F_Typ := Designated_Type (Etype (S)); 10538 else 10539 F_Typ := Etype (S); 10540 end if; 10541 10542 B_Typ := Base_Type (F_Typ); 10543 10544 if Scope (B_Typ) = Current_Scope 10545 and then not Is_Class_Wide_Type (B_Typ) 10546 and then not Is_Generic_Type (B_Typ) 10547 then 10548 Is_Primitive := True; 10549 Set_Has_Primitive_Operations (B_Typ); 10550 Set_Is_Primitive (S); 10551 Check_Private_Overriding (B_Typ); 10552 10553 -- The Ghost policy in effect at the point of declaration 10554 -- or a tagged type and a primitive operation must match 10555 -- (SPARK RM 6.9(16)). 10556 10557 Check_Ghost_Primitive (S, B_Typ); 10558 end if; 10559 end if; 10560 10561 -- For all subprograms, check formals 10562 10563 Formal := First_Formal (S); 10564 while Present (Formal) loop 10565 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then 10566 F_Typ := Designated_Type (Etype (Formal)); 10567 else 10568 F_Typ := Etype (Formal); 10569 end if; 10570 10571 B_Typ := Base_Type (F_Typ); 10572 10573 if Ekind (B_Typ) = E_Access_Subtype then 10574 B_Typ := Base_Type (B_Typ); 10575 end if; 10576 10577 if Scope (B_Typ) = Current_Scope 10578 and then not Is_Class_Wide_Type (B_Typ) 10579 and then not Is_Generic_Type (B_Typ) 10580 then 10581 Is_Primitive := True; 10582 Set_Is_Primitive (S); 10583 Set_Has_Primitive_Operations (B_Typ); 10584 Check_Private_Overriding (B_Typ); 10585 10586 -- The Ghost policy in effect at the point of declaration 10587 -- of a tagged type and a primitive operation must match 10588 -- (SPARK RM 6.9(16)). 10589 10590 Check_Ghost_Primitive (S, B_Typ); 10591 end if; 10592 10593 Next_Formal (Formal); 10594 end loop; 10595 10596 -- Special case: An equality function can be redefined for a type 10597 -- occurring in a declarative part, and won't otherwise be treated as 10598 -- a primitive because it doesn't occur in a package spec and doesn't 10599 -- override an inherited subprogram. It's important that we mark it 10600 -- primitive so it can be returned by Collect_Primitive_Operations 10601 -- and be used in composing the equality operation of later types 10602 -- that have a component of the type. 10603 10604 elsif Chars (S) = Name_Op_Eq 10605 and then Etype (S) = Standard_Boolean 10606 then 10607 B_Typ := Base_Type (Etype (First_Formal (S))); 10608 10609 if Scope (B_Typ) = Current_Scope 10610 and then 10611 Base_Type (Etype (Next_Formal (First_Formal (S)))) = B_Typ 10612 and then not Is_Limited_Type (B_Typ) 10613 then 10614 Is_Primitive := True; 10615 Set_Is_Primitive (S); 10616 Set_Has_Primitive_Operations (B_Typ); 10617 Check_Private_Overriding (B_Typ); 10618 10619 -- The Ghost policy in effect at the point of declaration of a 10620 -- tagged type and a primitive operation must match 10621 -- (SPARK RM 6.9(16)). 10622 10623 Check_Ghost_Primitive (S, B_Typ); 10624 end if; 10625 end if; 10626 end Check_For_Primitive_Subprogram; 10627 10628 -------------------------------------- 10629 -- Has_Matching_Entry_Or_Subprogram -- 10630 -------------------------------------- 10631 10632 function Has_Matching_Entry_Or_Subprogram 10633 (E : Entity_Id) return Boolean 10634 is 10635 function Check_Conforming_Parameters 10636 (E1_Param : Node_Id; 10637 E2_Param : Node_Id; 10638 Ctype : Conformance_Type) return Boolean; 10639 -- Starting from the given parameters, check that all the parameters 10640 -- of two entries or subprograms are conformant. Used to skip 10641 -- the check on the controlling argument. 10642 10643 function Matching_Entry_Or_Subprogram 10644 (Conc_Typ : Entity_Id; 10645 Subp : Entity_Id) return Entity_Id; 10646 -- Return the first entry or subprogram of the given concurrent type 10647 -- whose name matches the name of Subp and has a profile conformant 10648 -- with Subp; return Empty if not found. 10649 10650 function Matching_Dispatching_Subprogram 10651 (Conc_Typ : Entity_Id; 10652 Ent : Entity_Id) return Entity_Id; 10653 -- Return the first dispatching primitive of Conc_Type defined in the 10654 -- enclosing scope of Conc_Type (i.e. before the full definition of 10655 -- this concurrent type) whose name matches the entry Ent and has a 10656 -- profile conformant with the profile of the corresponding (not yet 10657 -- built) dispatching primitive of Ent; return Empty if not found. 10658 10659 function Matching_Original_Protected_Subprogram 10660 (Prot_Typ : Entity_Id; 10661 Subp : Entity_Id) return Entity_Id; 10662 -- Return the first subprogram defined in the enclosing scope of 10663 -- Prot_Typ (before the full definition of this protected type) 10664 -- whose name matches the original name of Subp and has a profile 10665 -- conformant with the profile of Subp; return Empty if not found. 10666 10667 function Normalized_First_Parameter_Type 10668 (E : Entity_Id) return Entity_Id; 10669 -- Return the type of the first parameter unless that type 10670 -- is an anonymous access type, in which case return the 10671 -- designated type. Used to treat anonymous-access-to-synchronized 10672 -- the same as synchronized for purposes of checking for 10673 -- prefixed view profile conflicts. 10674 10675 --------------------------------- 10676 -- Check_Conforming_Parameters -- 10677 --------------------------------- 10678 10679 function Check_Conforming_Parameters 10680 (E1_Param : Node_Id; 10681 E2_Param : Node_Id; 10682 Ctype : Conformance_Type) return Boolean 10683 is 10684 Param_E1 : Node_Id := E1_Param; 10685 Param_E2 : Node_Id := E2_Param; 10686 10687 begin 10688 while Present (Param_E1) and then Present (Param_E2) loop 10689 if (Ctype >= Mode_Conformant) and then 10690 Ekind (Defining_Identifier (Param_E1)) /= 10691 Ekind (Defining_Identifier (Param_E2)) 10692 then 10693 return False; 10694 elsif not 10695 Conforming_Types 10696 (Find_Parameter_Type (Param_E1), 10697 Find_Parameter_Type (Param_E2), 10698 Ctype) 10699 then 10700 return False; 10701 end if; 10702 10703 Next (Param_E1); 10704 Next (Param_E2); 10705 end loop; 10706 10707 -- The candidate is not valid if one of the two lists contains 10708 -- more parameters than the other 10709 10710 return No (Param_E1) and then No (Param_E2); 10711 end Check_Conforming_Parameters; 10712 10713 ---------------------------------- 10714 -- Matching_Entry_Or_Subprogram -- 10715 ---------------------------------- 10716 10717 function Matching_Entry_Or_Subprogram 10718 (Conc_Typ : Entity_Id; 10719 Subp : Entity_Id) return Entity_Id 10720 is 10721 E : Entity_Id; 10722 10723 begin 10724 E := First_Entity (Conc_Typ); 10725 while Present (E) loop 10726 if Chars (Subp) = Chars (E) 10727 and then (Ekind (E) = E_Entry or else Is_Subprogram (E)) 10728 and then 10729 Check_Conforming_Parameters 10730 (First (Parameter_Specifications (Parent (E))), 10731 Next (First (Parameter_Specifications (Parent (Subp)))), 10732 Type_Conformant) 10733 then 10734 return E; 10735 end if; 10736 10737 Next_Entity (E); 10738 end loop; 10739 10740 return Empty; 10741 end Matching_Entry_Or_Subprogram; 10742 10743 ------------------------------------- 10744 -- Matching_Dispatching_Subprogram -- 10745 ------------------------------------- 10746 10747 function Matching_Dispatching_Subprogram 10748 (Conc_Typ : Entity_Id; 10749 Ent : Entity_Id) return Entity_Id 10750 is 10751 E : Entity_Id; 10752 10753 begin 10754 -- Search for entities in the enclosing scope of this synchonized 10755 -- type. 10756 10757 pragma Assert (Is_Concurrent_Type (Conc_Typ)); 10758 Push_Scope (Scope (Conc_Typ)); 10759 E := Current_Entity_In_Scope (Ent); 10760 Pop_Scope; 10761 10762 while Present (E) loop 10763 if Scope (E) = Scope (Conc_Typ) 10764 and then Comes_From_Source (E) 10765 and then Ekind (E) = E_Procedure 10766 and then Present (First_Entity (E)) 10767 and then Is_Controlling_Formal (First_Entity (E)) 10768 and then Etype (First_Entity (E)) = Conc_Typ 10769 and then 10770 Check_Conforming_Parameters 10771 (First (Parameter_Specifications (Parent (Ent))), 10772 Next (First (Parameter_Specifications (Parent (E)))), 10773 Subtype_Conformant) 10774 then 10775 return E; 10776 end if; 10777 10778 E := Homonym (E); 10779 end loop; 10780 10781 return Empty; 10782 end Matching_Dispatching_Subprogram; 10783 10784 -------------------------------------------- 10785 -- Matching_Original_Protected_Subprogram -- 10786 -------------------------------------------- 10787 10788 function Matching_Original_Protected_Subprogram 10789 (Prot_Typ : Entity_Id; 10790 Subp : Entity_Id) return Entity_Id 10791 is 10792 ICF : constant Boolean := 10793 Is_Controlling_Formal (First_Entity (Subp)); 10794 E : Entity_Id; 10795 10796 begin 10797 -- Temporarily decorate the first parameter of Subp as controlling 10798 -- formal, required to invoke Subtype_Conformant. 10799 10800 Set_Is_Controlling_Formal (First_Entity (Subp)); 10801 10802 E := 10803 Current_Entity_In_Scope (Original_Protected_Subprogram (Subp)); 10804 10805 while Present (E) loop 10806 if Scope (E) = Scope (Prot_Typ) 10807 and then Comes_From_Source (E) 10808 and then Ekind (Subp) = Ekind (E) 10809 and then Present (First_Entity (E)) 10810 and then Is_Controlling_Formal (First_Entity (E)) 10811 and then Etype (First_Entity (E)) = Prot_Typ 10812 and then Subtype_Conformant (Subp, E, 10813 Skip_Controlling_Formals => True) 10814 then 10815 Set_Is_Controlling_Formal (First_Entity (Subp), ICF); 10816 return E; 10817 end if; 10818 10819 E := Homonym (E); 10820 end loop; 10821 10822 Set_Is_Controlling_Formal (First_Entity (Subp), ICF); 10823 10824 return Empty; 10825 end Matching_Original_Protected_Subprogram; 10826 10827 ------------------------------------- 10828 -- Normalized_First_Parameter_Type -- 10829 ------------------------------------- 10830 10831 function Normalized_First_Parameter_Type 10832 (E : Entity_Id) return Entity_Id 10833 is 10834 Result : Entity_Id := Etype (First_Entity (E)); 10835 begin 10836 if Ekind (Result) = E_Anonymous_Access_Type then 10837 Result := Designated_Type (Result); 10838 end if; 10839 return Result; 10840 end Normalized_First_Parameter_Type; 10841 10842 -- Start of processing for Has_Matching_Entry_Or_Subprogram 10843 10844 begin 10845 -- Case 1: E is a subprogram whose first formal is a concurrent type 10846 -- defined in the scope of E that has an entry or subprogram whose 10847 -- profile matches E. 10848 10849 if Comes_From_Source (E) 10850 and then Is_Subprogram (E) 10851 and then Present (First_Entity (E)) 10852 and then Is_Concurrent_Record_Type 10853 (Normalized_First_Parameter_Type (E)) 10854 then 10855 if Scope (E) = 10856 Scope (Corresponding_Concurrent_Type 10857 (Normalized_First_Parameter_Type (E))) 10858 and then 10859 Present 10860 (Matching_Entry_Or_Subprogram 10861 (Corresponding_Concurrent_Type 10862 (Normalized_First_Parameter_Type (E)), 10863 Subp => E)) 10864 then 10865 Report_Conflict (E, 10866 Matching_Entry_Or_Subprogram 10867 (Corresponding_Concurrent_Type 10868 (Normalized_First_Parameter_Type (E)), 10869 Subp => E)); 10870 return True; 10871 end if; 10872 10873 -- Case 2: E is an internally built dispatching subprogram of a 10874 -- protected type and there is a subprogram defined in the enclosing 10875 -- scope of the protected type that has the original name of E and 10876 -- its profile is conformant with the profile of E. We check the 10877 -- name of the original protected subprogram associated with E since 10878 -- the expander builds dispatching primitives of protected functions 10879 -- and procedures with other names (see Exp_Ch9.Build_Selected_Name). 10880 10881 elsif not Comes_From_Source (E) 10882 and then Is_Subprogram (E) 10883 and then Present (First_Entity (E)) 10884 and then Is_Concurrent_Record_Type (Etype (First_Entity (E))) 10885 and then Present (Original_Protected_Subprogram (E)) 10886 and then 10887 Present 10888 (Matching_Original_Protected_Subprogram 10889 (Corresponding_Concurrent_Type (Etype (First_Entity (E))), 10890 Subp => E)) 10891 then 10892 Report_Conflict (E, 10893 Matching_Original_Protected_Subprogram 10894 (Corresponding_Concurrent_Type (Etype (First_Entity (E))), 10895 Subp => E)); 10896 return True; 10897 10898 -- Case 3: E is an entry of a synchronized type and a matching 10899 -- procedure has been previously defined in the enclosing scope 10900 -- of the synchronized type. 10901 10902 elsif Comes_From_Source (E) 10903 and then Ekind (E) = E_Entry 10904 and then 10905 Present (Matching_Dispatching_Subprogram (Current_Scope, E)) 10906 then 10907 Report_Conflict (E, 10908 Matching_Dispatching_Subprogram (Current_Scope, E)); 10909 return True; 10910 end if; 10911 10912 return False; 10913 end Has_Matching_Entry_Or_Subprogram; 10914 10915 ---------------------------- 10916 -- Is_Private_Declaration -- 10917 ---------------------------- 10918 10919 function Is_Private_Declaration (E : Entity_Id) return Boolean is 10920 Decl : constant Node_Id := Unit_Declaration_Node (E); 10921 Priv_Decls : List_Id; 10922 10923 begin 10924 if Is_Package_Or_Generic_Package (Current_Scope) 10925 and then In_Private_Part (Current_Scope) 10926 then 10927 Priv_Decls := 10928 Private_Declarations (Package_Specification (Current_Scope)); 10929 10930 return In_Package_Body (Current_Scope) 10931 or else 10932 (Is_List_Member (Decl) 10933 and then List_Containing (Decl) = Priv_Decls) 10934 or else (Nkind (Parent (Decl)) = N_Package_Specification 10935 and then not 10936 Is_Compilation_Unit 10937 (Defining_Entity (Parent (Decl))) 10938 and then List_Containing (Parent (Parent (Decl))) = 10939 Priv_Decls); 10940 else 10941 return False; 10942 end if; 10943 end Is_Private_Declaration; 10944 10945 -------------------------- 10946 -- Is_Overriding_Alias -- 10947 -------------------------- 10948 10949 function Is_Overriding_Alias 10950 (Old_E : Entity_Id; 10951 New_E : Entity_Id) return Boolean 10952 is 10953 AO : constant Entity_Id := Alias (Old_E); 10954 AN : constant Entity_Id := Alias (New_E); 10955 10956 begin 10957 return Scope (AO) /= Scope (AN) 10958 or else No (DTC_Entity (AO)) 10959 or else No (DTC_Entity (AN)) 10960 or else DT_Position (AO) = DT_Position (AN); 10961 end Is_Overriding_Alias; 10962 10963 --------------------- 10964 -- Report_Conflict -- 10965 --------------------- 10966 10967 procedure Report_Conflict (S : Entity_Id; E : Entity_Id) is 10968 begin 10969 Error_Msg_Sloc := Sloc (E); 10970 10971 -- Generate message, with useful additional warning if in generic 10972 10973 if Is_Generic_Unit (E) then 10974 Error_Msg_N ("previous generic unit cannot be overloaded", S); 10975 Error_Msg_N ("\& conflicts with declaration#", S); 10976 else 10977 Error_Msg_N ("& conflicts with declaration#", S); 10978 end if; 10979 end Report_Conflict; 10980 10981 -- Start of processing for New_Overloaded_Entity 10982 10983 begin 10984 -- We need to look for an entity that S may override. This must be a 10985 -- homonym in the current scope, so we look for the first homonym of 10986 -- S in the current scope as the starting point for the search. 10987 10988 E := Current_Entity_In_Scope (S); 10989 10990 -- Ada 2005 (AI-251): Derivation of abstract interface primitives. 10991 -- They are directly added to the list of primitive operations of 10992 -- Derived_Type, unless this is a rederivation in the private part 10993 -- of an operation that was already derived in the visible part of 10994 -- the current package. 10995 10996 if Ada_Version >= Ada_2005 10997 and then Present (Derived_Type) 10998 and then Present (Alias (S)) 10999 and then Is_Dispatching_Operation (Alias (S)) 11000 and then Present (Find_Dispatching_Type (Alias (S))) 11001 and then Is_Interface (Find_Dispatching_Type (Alias (S))) 11002 then 11003 -- For private types, when the full-view is processed we propagate to 11004 -- the full view the non-overridden entities whose attribute "alias" 11005 -- references an interface primitive. These entities were added by 11006 -- Derive_Subprograms to ensure that interface primitives are 11007 -- covered. 11008 11009 -- Inside_Freeze_Actions is non zero when S corresponds with an 11010 -- internal entity that links an interface primitive with its 11011 -- covering primitive through attribute Interface_Alias (see 11012 -- Add_Internal_Interface_Entities). 11013 11014 if Inside_Freezing_Actions = 0 11015 and then Is_Package_Or_Generic_Package (Current_Scope) 11016 and then In_Private_Part (Current_Scope) 11017 and then Nkind (Parent (E)) = N_Private_Extension_Declaration 11018 and then Nkind (Parent (S)) = N_Full_Type_Declaration 11019 and then Full_View (Defining_Identifier (Parent (E))) 11020 = Defining_Identifier (Parent (S)) 11021 and then Alias (E) = Alias (S) 11022 then 11023 Check_Operation_From_Private_View (S, E); 11024 Set_Is_Dispatching_Operation (S); 11025 11026 -- Common case 11027 11028 else 11029 Enter_Overloaded_Entity (S); 11030 Check_Dispatching_Operation (S, Empty); 11031 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 11032 end if; 11033 11034 return; 11035 end if; 11036 11037 -- For synchronized types check conflicts of this entity with previously 11038 -- defined entities. 11039 11040 if Ada_Version >= Ada_2005 11041 and then Has_Matching_Entry_Or_Subprogram (S) 11042 then 11043 return; 11044 end if; 11045 11046 -- If there is no homonym then this is definitely not overriding 11047 11048 if No (E) then 11049 Enter_Overloaded_Entity (S); 11050 Check_Dispatching_Operation (S, Empty); 11051 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 11052 11053 -- If subprogram has an explicit declaration, check whether it has an 11054 -- overriding indicator. 11055 11056 if Comes_From_Source (S) then 11057 Check_Synchronized_Overriding (S, Overridden_Subp); 11058 11059 -- (Ada 2012: AI05-0125-1): If S is a dispatching operation then 11060 -- it may have overridden some hidden inherited primitive. Update 11061 -- Overridden_Subp to avoid spurious errors when checking the 11062 -- overriding indicator. 11063 11064 if Ada_Version >= Ada_2012 11065 and then No (Overridden_Subp) 11066 and then Is_Dispatching_Operation (S) 11067 and then Present (Overridden_Operation (S)) 11068 then 11069 Overridden_Subp := Overridden_Operation (S); 11070 end if; 11071 11072 Check_Overriding_Indicator 11073 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); 11074 11075 -- The Ghost policy in effect at the point of declaration of a 11076 -- parent subprogram and an overriding subprogram must match 11077 -- (SPARK RM 6.9(17)). 11078 11079 Check_Ghost_Overriding (S, Overridden_Subp); 11080 end if; 11081 11082 -- If there is a homonym that is not overloadable, then we have an 11083 -- error, except for the special cases checked explicitly below. 11084 11085 elsif not Is_Overloadable (E) then 11086 11087 -- Check for spurious conflict produced by a subprogram that has the 11088 -- same name as that of the enclosing generic package. The conflict 11089 -- occurs within an instance, between the subprogram and the renaming 11090 -- declaration for the package. After the subprogram, the package 11091 -- renaming declaration becomes hidden. 11092 11093 if Ekind (E) = E_Package 11094 and then Present (Renamed_Object (E)) 11095 and then Renamed_Object (E) = Current_Scope 11096 and then Nkind (Parent (Renamed_Object (E))) = 11097 N_Package_Specification 11098 and then Present (Generic_Parent (Parent (Renamed_Object (E)))) 11099 then 11100 Set_Is_Hidden (E); 11101 Set_Is_Immediately_Visible (E, False); 11102 Enter_Overloaded_Entity (S); 11103 Set_Homonym (S, Homonym (E)); 11104 Check_Dispatching_Operation (S, Empty); 11105 Check_Overriding_Indicator (S, Empty, Is_Primitive => False); 11106 11107 -- If the subprogram is implicit it is hidden by the previous 11108 -- declaration. However if it is dispatching, it must appear in the 11109 -- dispatch table anyway, because it can be dispatched to even if it 11110 -- cannot be called directly. 11111 11112 elsif Present (Alias (S)) and then not Comes_From_Source (S) then 11113 Set_Scope (S, Current_Scope); 11114 11115 if Is_Dispatching_Operation (Alias (S)) then 11116 Check_Dispatching_Operation (S, Empty); 11117 end if; 11118 11119 return; 11120 11121 else 11122 Report_Conflict (S, E); 11123 return; 11124 end if; 11125 11126 -- E exists and is overloadable 11127 11128 else 11129 Check_Synchronized_Overriding (S, Overridden_Subp); 11130 11131 -- Loop through E and its homonyms to determine if any of them is 11132 -- the candidate for overriding by S. 11133 11134 while Present (E) loop 11135 11136 -- Definitely not interesting if not in the current scope 11137 11138 if Scope (E) /= Current_Scope then 11139 null; 11140 11141 -- A function can overload the name of an abstract state. The 11142 -- state can be viewed as a function with a profile that cannot 11143 -- be matched by anything. 11144 11145 elsif Ekind (S) = E_Function 11146 and then Ekind (E) = E_Abstract_State 11147 then 11148 Enter_Overloaded_Entity (S); 11149 return; 11150 11151 -- Ada 2012 (AI05-0165): For internally generated bodies of null 11152 -- procedures locate the internally generated spec. We enforce 11153 -- mode conformance since a tagged type may inherit from 11154 -- interfaces several null primitives which differ only in 11155 -- the mode of the formals. 11156 11157 elsif not Comes_From_Source (S) 11158 and then Is_Null_Procedure (S) 11159 and then not Mode_Conformant (E, S) 11160 then 11161 null; 11162 11163 -- Check if we have type conformance 11164 11165 elsif Type_Conformant (E, S) then 11166 11167 -- If the old and new entities have the same profile and one 11168 -- is not the body of the other, then this is an error, unless 11169 -- one of them is implicitly declared. 11170 11171 -- There are some cases when both can be implicit, for example 11172 -- when both a literal and a function that overrides it are 11173 -- inherited in a derivation, or when an inherited operation 11174 -- of a tagged full type overrides the inherited operation of 11175 -- a private extension. Ada 83 had a special rule for the 11176 -- literal case. In Ada 95, the later implicit operation hides 11177 -- the former, and the literal is always the former. In the 11178 -- odd case where both are derived operations declared at the 11179 -- same point, both operations should be declared, and in that 11180 -- case we bypass the following test and proceed to the next 11181 -- part. This can only occur for certain obscure cases in 11182 -- instances, when an operation on a type derived from a formal 11183 -- private type does not override a homograph inherited from 11184 -- the actual. In subsequent derivations of such a type, the 11185 -- DT positions of these operations remain distinct, if they 11186 -- have been set. 11187 11188 if Present (Alias (S)) 11189 and then (No (Alias (E)) 11190 or else Comes_From_Source (E) 11191 or else Is_Abstract_Subprogram (S) 11192 or else 11193 (Is_Dispatching_Operation (E) 11194 and then Is_Overriding_Alias (E, S))) 11195 and then Ekind (E) /= E_Enumeration_Literal 11196 then 11197 -- When an derived operation is overloaded it may be due to 11198 -- the fact that the full view of a private extension 11199 -- re-inherits. It has to be dealt with. 11200 11201 if Is_Package_Or_Generic_Package (Current_Scope) 11202 and then In_Private_Part (Current_Scope) 11203 then 11204 Check_Operation_From_Private_View (S, E); 11205 end if; 11206 11207 -- In any case the implicit operation remains hidden by the 11208 -- existing declaration, which is overriding. Indicate that 11209 -- E overrides the operation from which S is inherited. 11210 11211 if Present (Alias (S)) then 11212 Set_Overridden_Operation (E, Alias (S)); 11213 Inherit_Subprogram_Contract (E, Alias (S)); 11214 11215 else 11216 Set_Overridden_Operation (E, S); 11217 Inherit_Subprogram_Contract (E, S); 11218 end if; 11219 11220 if Comes_From_Source (E) then 11221 Check_Overriding_Indicator (E, S, Is_Primitive => False); 11222 11223 -- The Ghost policy in effect at the point of declaration 11224 -- of a parent subprogram and an overriding subprogram 11225 -- must match (SPARK RM 6.9(17)). 11226 11227 Check_Ghost_Overriding (E, S); 11228 end if; 11229 11230 return; 11231 11232 -- Within an instance, the renaming declarations for actual 11233 -- subprograms may become ambiguous, but they do not hide each 11234 -- other. 11235 11236 elsif Ekind (E) /= E_Entry 11237 and then not Comes_From_Source (E) 11238 and then not Is_Generic_Instance (E) 11239 and then (Present (Alias (E)) 11240 or else Is_Intrinsic_Subprogram (E)) 11241 and then (not In_Instance 11242 or else No (Parent (E)) 11243 or else Nkind (Unit_Declaration_Node (E)) /= 11244 N_Subprogram_Renaming_Declaration) 11245 then 11246 -- A subprogram child unit is not allowed to override an 11247 -- inherited subprogram (10.1.1(20)). 11248 11249 if Is_Child_Unit (S) then 11250 Error_Msg_N 11251 ("child unit overrides inherited subprogram in parent", 11252 S); 11253 return; 11254 end if; 11255 11256 if Is_Non_Overriding_Operation (E, S) then 11257 Enter_Overloaded_Entity (S); 11258 11259 if No (Derived_Type) 11260 or else Is_Tagged_Type (Derived_Type) 11261 then 11262 Check_Dispatching_Operation (S, Empty); 11263 end if; 11264 11265 return; 11266 end if; 11267 11268 -- E is a derived operation or an internal operator which 11269 -- is being overridden. Remove E from further visibility. 11270 -- Furthermore, if E is a dispatching operation, it must be 11271 -- replaced in the list of primitive operations of its type 11272 -- (see Override_Dispatching_Operation). 11273 11274 Overridden_Subp := E; 11275 11276 -- It is possible for E to be in the current scope and 11277 -- yet not in the entity chain. This can only occur in a 11278 -- generic context where E is an implicit concatenation 11279 -- in the formal part, because in a generic body the 11280 -- entity chain starts with the formals. 11281 11282 -- In GNATprove mode, a wrapper for an operation with 11283 -- axiomatization may be a homonym of another declaration 11284 -- for an actual subprogram (needs refinement ???). 11285 11286 if No (Prev_Entity (E)) then 11287 if In_Instance 11288 and then GNATprove_Mode 11289 and then 11290 Nkind (Original_Node (Unit_Declaration_Node (S))) = 11291 N_Subprogram_Renaming_Declaration 11292 then 11293 return; 11294 else 11295 pragma Assert (Chars (E) = Name_Op_Concat); 11296 null; 11297 end if; 11298 end if; 11299 11300 -- E must be removed both from the entity_list of the 11301 -- current scope, and from the visibility chain. 11302 11303 if Debug_Flag_E then 11304 Write_Str ("Override implicit operation "); 11305 Write_Int (Int (E)); 11306 Write_Eol; 11307 end if; 11308 11309 -- If E is a predefined concatenation, it stands for four 11310 -- different operations. As a result, a single explicit 11311 -- declaration does not hide it. In a possible ambiguous 11312 -- situation, Disambiguate chooses the user-defined op, 11313 -- so it is correct to retain the previous internal one. 11314 11315 if Chars (E) /= Name_Op_Concat 11316 or else Ekind (E) /= E_Operator 11317 then 11318 -- For nondispatching derived operations that are 11319 -- overridden by a subprogram declared in the private 11320 -- part of a package, we retain the derived subprogram 11321 -- but mark it as not immediately visible. If the 11322 -- derived operation was declared in the visible part 11323 -- then this ensures that it will still be visible 11324 -- outside the package with the proper signature 11325 -- (calls from outside must also be directed to this 11326 -- version rather than the overriding one, unlike the 11327 -- dispatching case). Calls from inside the package 11328 -- will still resolve to the overriding subprogram 11329 -- since the derived one is marked as not visible 11330 -- within the package. 11331 11332 -- If the private operation is dispatching, we achieve 11333 -- the overriding by keeping the implicit operation 11334 -- but setting its alias to be the overriding one. In 11335 -- this fashion the proper body is executed in all 11336 -- cases, but the original signature is used outside 11337 -- of the package. 11338 11339 -- If the overriding is not in the private part, we 11340 -- remove the implicit operation altogether. 11341 11342 if Is_Private_Declaration (S) then 11343 if not Is_Dispatching_Operation (E) then 11344 Set_Is_Immediately_Visible (E, False); 11345 else 11346 -- Work done in Override_Dispatching_Operation, so 11347 -- nothing else needs to be done here. 11348 11349 null; 11350 end if; 11351 11352 else 11353 Remove_Entity_And_Homonym (E); 11354 end if; 11355 end if; 11356 11357 Enter_Overloaded_Entity (S); 11358 11359 -- For entities generated by Derive_Subprograms the 11360 -- overridden operation is the inherited primitive 11361 -- (which is available through the attribute alias). 11362 11363 if not (Comes_From_Source (E)) 11364 and then Is_Dispatching_Operation (E) 11365 and then Find_Dispatching_Type (E) = 11366 Find_Dispatching_Type (S) 11367 and then Present (Alias (E)) 11368 and then Comes_From_Source (Alias (E)) 11369 then 11370 Set_Overridden_Operation (S, Alias (E)); 11371 Inherit_Subprogram_Contract (S, Alias (E)); 11372 11373 -- Normal case of setting entity as overridden 11374 11375 -- Note: Static_Initialization and Overridden_Operation 11376 -- attributes use the same field in subprogram entities. 11377 -- Static_Initialization is only defined for internal 11378 -- initialization procedures, where Overridden_Operation 11379 -- is irrelevant. Therefore the setting of this attribute 11380 -- must check whether the target is an init_proc. 11381 11382 elsif not Is_Init_Proc (S) then 11383 Set_Overridden_Operation (S, E); 11384 Inherit_Subprogram_Contract (S, E); 11385 end if; 11386 11387 Check_Overriding_Indicator (S, E, Is_Primitive => True); 11388 11389 -- The Ghost policy in effect at the point of declaration 11390 -- of a parent subprogram and an overriding subprogram 11391 -- must match (SPARK RM 6.9(17)). 11392 11393 Check_Ghost_Overriding (S, E); 11394 11395 -- If S is a user-defined subprogram or a null procedure 11396 -- expanded to override an inherited null procedure, or a 11397 -- predefined dispatching primitive then indicate that E 11398 -- overrides the operation from which S is inherited. 11399 11400 if Comes_From_Source (S) 11401 or else 11402 (Present (Parent (S)) 11403 and then Nkind (Parent (S)) = N_Procedure_Specification 11404 and then Null_Present (Parent (S))) 11405 or else 11406 (Present (Alias (E)) 11407 and then 11408 Is_Predefined_Dispatching_Operation (Alias (E))) 11409 then 11410 if Present (Alias (E)) then 11411 Set_Overridden_Operation (S, Alias (E)); 11412 Inherit_Subprogram_Contract (S, Alias (E)); 11413 end if; 11414 end if; 11415 11416 if Is_Dispatching_Operation (E) then 11417 11418 -- An overriding dispatching subprogram inherits the 11419 -- convention of the overridden subprogram (AI-117). 11420 11421 Set_Convention (S, Convention (E)); 11422 Check_Dispatching_Operation (S, E); 11423 11424 else 11425 Check_Dispatching_Operation (S, Empty); 11426 end if; 11427 11428 Check_For_Primitive_Subprogram 11429 (Is_Primitive_Subp, Is_Overriding => True); 11430 goto Check_Inequality; 11431 11432 -- Apparent redeclarations in instances can occur when two 11433 -- formal types get the same actual type. The subprograms in 11434 -- in the instance are legal, even if not callable from the 11435 -- outside. Calls from within are disambiguated elsewhere. 11436 -- For dispatching operations in the visible part, the usual 11437 -- rules apply, and operations with the same profile are not 11438 -- legal (B830001). 11439 11440 elsif (In_Instance_Visible_Part 11441 and then not Is_Dispatching_Operation (E)) 11442 or else In_Instance_Not_Visible 11443 then 11444 null; 11445 11446 -- Here we have a real error (identical profile) 11447 11448 else 11449 Error_Msg_Sloc := Sloc (E); 11450 11451 -- Avoid cascaded errors if the entity appears in 11452 -- subsequent calls. 11453 11454 Set_Scope (S, Current_Scope); 11455 11456 -- Generate error, with extra useful warning for the case 11457 -- of a generic instance with no completion. 11458 11459 if Is_Generic_Instance (S) 11460 and then not Has_Completion (E) 11461 then 11462 Error_Msg_N 11463 ("instantiation cannot provide body for&", S); 11464 Error_Msg_N ("\& conflicts with declaration#", S); 11465 else 11466 Error_Msg_N ("& conflicts with declaration#", S); 11467 end if; 11468 11469 return; 11470 end if; 11471 11472 else 11473 -- If one subprogram has an access parameter and the other 11474 -- a parameter of an access type, calls to either might be 11475 -- ambiguous. Verify that parameters match except for the 11476 -- access parameter. 11477 11478 if May_Hide_Profile then 11479 declare 11480 F1 : Entity_Id; 11481 F2 : Entity_Id; 11482 11483 begin 11484 F1 := First_Formal (S); 11485 F2 := First_Formal (E); 11486 while Present (F1) and then Present (F2) loop 11487 if Is_Access_Type (Etype (F1)) then 11488 if not Is_Access_Type (Etype (F2)) 11489 or else not Conforming_Types 11490 (Designated_Type (Etype (F1)), 11491 Designated_Type (Etype (F2)), 11492 Type_Conformant) 11493 then 11494 May_Hide_Profile := False; 11495 end if; 11496 11497 elsif 11498 not Conforming_Types 11499 (Etype (F1), Etype (F2), Type_Conformant) 11500 then 11501 May_Hide_Profile := False; 11502 end if; 11503 11504 Next_Formal (F1); 11505 Next_Formal (F2); 11506 end loop; 11507 11508 if May_Hide_Profile 11509 and then No (F1) 11510 and then No (F2) 11511 then 11512 Error_Msg_NE ("calls to& may be ambiguous??", S, S); 11513 end if; 11514 end; 11515 end if; 11516 end if; 11517 11518 E := Homonym (E); 11519 end loop; 11520 11521 -- On exit, we know that S is a new entity 11522 11523 Enter_Overloaded_Entity (S); 11524 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 11525 Check_Overriding_Indicator 11526 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); 11527 11528 -- The Ghost policy in effect at the point of declaration of a parent 11529 -- subprogram and an overriding subprogram must match 11530 -- (SPARK RM 6.9(17)). 11531 11532 Check_Ghost_Overriding (S, Overridden_Subp); 11533 11534 -- Overloading is not allowed in SPARK, except for operators 11535 11536 if Nkind (S) /= N_Defining_Operator_Symbol then 11537 Error_Msg_Sloc := Sloc (Homonym (S)); 11538 Check_SPARK_05_Restriction 11539 ("overloading not allowed with entity#", S); 11540 end if; 11541 11542 -- If S is a derived operation for an untagged type then by 11543 -- definition it's not a dispatching operation (even if the parent 11544 -- operation was dispatching), so Check_Dispatching_Operation is not 11545 -- called in that case. 11546 11547 if No (Derived_Type) 11548 or else Is_Tagged_Type (Derived_Type) 11549 then 11550 Check_Dispatching_Operation (S, Empty); 11551 end if; 11552 end if; 11553 11554 -- If this is a user-defined equality operator that is not a derived 11555 -- subprogram, create the corresponding inequality. If the operation is 11556 -- dispatching, the expansion is done elsewhere, and we do not create 11557 -- an explicit inequality operation. 11558 11559 <<Check_Inequality>> 11560 if Chars (S) = Name_Op_Eq 11561 and then Etype (S) = Standard_Boolean 11562 and then Present (Parent (S)) 11563 and then not Is_Dispatching_Operation (S) 11564 then 11565 Make_Inequality_Operator (S); 11566 Check_Untagged_Equality (S); 11567 end if; 11568 end New_Overloaded_Entity; 11569 11570 ---------------------------------- 11571 -- Preanalyze_Formal_Expression -- 11572 ---------------------------------- 11573 11574 procedure Preanalyze_Formal_Expression (N : Node_Id; T : Entity_Id) is 11575 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression; 11576 begin 11577 In_Spec_Expression := True; 11578 Preanalyze_With_Freezing_And_Resolve (N, T); 11579 In_Spec_Expression := Save_In_Spec_Expression; 11580 end Preanalyze_Formal_Expression; 11581 11582 --------------------- 11583 -- Process_Formals -- 11584 --------------------- 11585 11586 procedure Process_Formals 11587 (T : List_Id; 11588 Related_Nod : Node_Id) 11589 is 11590 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean; 11591 -- Determine whether an access type designates a type coming from a 11592 -- limited view. 11593 11594 function Is_Class_Wide_Default (D : Node_Id) return Boolean; 11595 -- Check whether the default has a class-wide type. After analysis the 11596 -- default has the type of the formal, so we must also check explicitly 11597 -- for an access attribute. 11598 11599 ---------------------------------- 11600 -- Designates_From_Limited_With -- 11601 ---------------------------------- 11602 11603 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean is 11604 Desig : Entity_Id := Typ; 11605 11606 begin 11607 if Is_Access_Type (Desig) then 11608 Desig := Directly_Designated_Type (Desig); 11609 end if; 11610 11611 if Is_Class_Wide_Type (Desig) then 11612 Desig := Root_Type (Desig); 11613 end if; 11614 11615 return 11616 Ekind (Desig) = E_Incomplete_Type 11617 and then From_Limited_With (Desig); 11618 end Designates_From_Limited_With; 11619 11620 --------------------------- 11621 -- Is_Class_Wide_Default -- 11622 --------------------------- 11623 11624 function Is_Class_Wide_Default (D : Node_Id) return Boolean is 11625 begin 11626 return Is_Class_Wide_Type (Designated_Type (Etype (D))) 11627 or else (Nkind (D) = N_Attribute_Reference 11628 and then Attribute_Name (D) = Name_Access 11629 and then Is_Class_Wide_Type (Etype (Prefix (D)))); 11630 end Is_Class_Wide_Default; 11631 11632 -- Local variables 11633 11634 Context : constant Node_Id := Parent (Parent (T)); 11635 Default : Node_Id; 11636 Formal : Entity_Id; 11637 Formal_Type : Entity_Id; 11638 Param_Spec : Node_Id; 11639 Ptype : Entity_Id; 11640 11641 Num_Out_Params : Nat := 0; 11642 First_Out_Param : Entity_Id := Empty; 11643 -- Used for setting Is_Only_Out_Parameter 11644 11645 -- Start of processing for Process_Formals 11646 11647 begin 11648 -- In order to prevent premature use of the formals in the same formal 11649 -- part, the Ekind is left undefined until all default expressions are 11650 -- analyzed. The Ekind is established in a separate loop at the end. 11651 11652 Param_Spec := First (T); 11653 while Present (Param_Spec) loop 11654 Formal := Defining_Identifier (Param_Spec); 11655 Set_Never_Set_In_Source (Formal, True); 11656 Enter_Name (Formal); 11657 11658 -- Case of ordinary parameters 11659 11660 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then 11661 Find_Type (Parameter_Type (Param_Spec)); 11662 Ptype := Parameter_Type (Param_Spec); 11663 11664 if Ptype = Error then 11665 goto Continue; 11666 end if; 11667 11668 -- Protect against malformed parameter types 11669 11670 if Nkind (Ptype) not in N_Has_Entity then 11671 Formal_Type := Any_Type; 11672 else 11673 Formal_Type := Entity (Ptype); 11674 end if; 11675 11676 if Is_Incomplete_Type (Formal_Type) 11677 or else 11678 (Is_Class_Wide_Type (Formal_Type) 11679 and then Is_Incomplete_Type (Root_Type (Formal_Type))) 11680 then 11681 -- Ada 2005 (AI-326): Tagged incomplete types allowed in 11682 -- primitive operations, as long as their completion is 11683 -- in the same declarative part. If in the private part 11684 -- this means that the type cannot be a Taft-amendment type. 11685 -- Check is done on package exit. For access to subprograms, 11686 -- the use is legal for Taft-amendment types. 11687 11688 -- Ada 2012: tagged incomplete types are allowed as generic 11689 -- formal types. They do not introduce dependencies and the 11690 -- corresponding generic subprogram does not have a delayed 11691 -- freeze, because it does not need a freeze node. However, 11692 -- it is still the case that untagged incomplete types cannot 11693 -- be Taft-amendment types and must be completed in private 11694 -- part, so the subprogram must appear in the list of private 11695 -- dependents of the type. 11696 11697 if Is_Tagged_Type (Formal_Type) 11698 or else (Ada_Version >= Ada_2012 11699 and then not From_Limited_With (Formal_Type) 11700 and then not Is_Generic_Type (Formal_Type)) 11701 then 11702 if Ekind (Scope (Current_Scope)) = E_Package 11703 and then not Is_Generic_Type (Formal_Type) 11704 and then not Is_Class_Wide_Type (Formal_Type) 11705 then 11706 if not Nkind_In 11707 (Parent (T), N_Access_Function_Definition, 11708 N_Access_Procedure_Definition) 11709 then 11710 Append_Elmt (Current_Scope, 11711 Private_Dependents (Base_Type (Formal_Type))); 11712 11713 -- Freezing is delayed to ensure that Register_Prim 11714 -- will get called for this operation, which is needed 11715 -- in cases where static dispatch tables aren't built. 11716 -- (Note that the same is done for controlling access 11717 -- parameter cases in function Access_Definition.) 11718 11719 if not Is_Thunk (Current_Scope) then 11720 Set_Has_Delayed_Freeze (Current_Scope); 11721 end if; 11722 end if; 11723 end if; 11724 11725 elsif not Nkind_In (Parent (T), N_Access_Function_Definition, 11726 N_Access_Procedure_Definition) 11727 then 11728 -- AI05-0151: Tagged incomplete types are allowed in all 11729 -- formal parts. Untagged incomplete types are not allowed 11730 -- in bodies. Limited views of either kind are not allowed 11731 -- if there is no place at which the non-limited view can 11732 -- become available. 11733 11734 -- Incomplete formal untagged types are not allowed in 11735 -- subprogram bodies (but are legal in their declarations). 11736 -- This excludes bodies created for null procedures, which 11737 -- are basic declarations. 11738 11739 if Is_Generic_Type (Formal_Type) 11740 and then not Is_Tagged_Type (Formal_Type) 11741 and then Nkind (Parent (Related_Nod)) = N_Subprogram_Body 11742 then 11743 Error_Msg_N 11744 ("invalid use of formal incomplete type", Param_Spec); 11745 11746 elsif Ada_Version >= Ada_2012 then 11747 if Is_Tagged_Type (Formal_Type) 11748 and then (not From_Limited_With (Formal_Type) 11749 or else not In_Package_Body) 11750 then 11751 null; 11752 11753 elsif Nkind_In (Context, N_Accept_Statement, 11754 N_Accept_Alternative, 11755 N_Entry_Body) 11756 or else (Nkind (Context) = N_Subprogram_Body 11757 and then Comes_From_Source (Context)) 11758 then 11759 Error_Msg_NE 11760 ("invalid use of untagged incomplete type &", 11761 Ptype, Formal_Type); 11762 end if; 11763 11764 else 11765 Error_Msg_NE 11766 ("invalid use of incomplete type&", 11767 Param_Spec, Formal_Type); 11768 11769 -- Further checks on the legality of incomplete types 11770 -- in formal parts are delayed until the freeze point 11771 -- of the enclosing subprogram or access to subprogram. 11772 end if; 11773 end if; 11774 11775 elsif Ekind (Formal_Type) = E_Void then 11776 Error_Msg_NE 11777 ("premature use of&", 11778 Parameter_Type (Param_Spec), Formal_Type); 11779 end if; 11780 11781 -- Ada 2012 (AI-142): Handle aliased parameters 11782 11783 if Ada_Version >= Ada_2012 11784 and then Aliased_Present (Param_Spec) 11785 then 11786 Set_Is_Aliased (Formal); 11787 11788 -- AI12-001: All aliased objects are considered to be specified 11789 -- as independently addressable (RM C.6(8.1/4)). 11790 11791 Set_Is_Independent (Formal); 11792 end if; 11793 11794 -- Ada 2005 (AI-231): Create and decorate an internal subtype 11795 -- declaration corresponding to the null-excluding type of the 11796 -- formal in the enclosing scope. Finally, replace the parameter 11797 -- type of the formal with the internal subtype. 11798 11799 if Ada_Version >= Ada_2005 11800 and then Null_Exclusion_Present (Param_Spec) 11801 then 11802 if not Is_Access_Type (Formal_Type) then 11803 Error_Msg_N 11804 ("`NOT NULL` allowed only for an access type", Param_Spec); 11805 11806 else 11807 if Can_Never_Be_Null (Formal_Type) 11808 and then Comes_From_Source (Related_Nod) 11809 then 11810 Error_Msg_NE 11811 ("`NOT NULL` not allowed (& already excludes null)", 11812 Param_Spec, Formal_Type); 11813 end if; 11814 11815 Formal_Type := 11816 Create_Null_Excluding_Itype 11817 (T => Formal_Type, 11818 Related_Nod => Related_Nod, 11819 Scope_Id => Scope (Current_Scope)); 11820 11821 -- If the designated type of the itype is an itype that is 11822 -- not frozen yet, we set the Has_Delayed_Freeze attribute 11823 -- on the access subtype, to prevent order-of-elaboration 11824 -- issues in the backend. 11825 11826 -- Example: 11827 -- type T is access procedure; 11828 -- procedure Op (O : not null T); 11829 11830 if Is_Itype (Directly_Designated_Type (Formal_Type)) 11831 and then 11832 not Is_Frozen (Directly_Designated_Type (Formal_Type)) 11833 then 11834 Set_Has_Delayed_Freeze (Formal_Type); 11835 end if; 11836 end if; 11837 end if; 11838 11839 -- An access formal type 11840 11841 else 11842 Formal_Type := 11843 Access_Definition (Related_Nod, Parameter_Type (Param_Spec)); 11844 11845 -- No need to continue if we already notified errors 11846 11847 if not Present (Formal_Type) then 11848 return; 11849 end if; 11850 11851 -- Ada 2005 (AI-254) 11852 11853 declare 11854 AD : constant Node_Id := 11855 Access_To_Subprogram_Definition 11856 (Parameter_Type (Param_Spec)); 11857 begin 11858 if Present (AD) and then Protected_Present (AD) then 11859 Formal_Type := 11860 Replace_Anonymous_Access_To_Protected_Subprogram 11861 (Param_Spec); 11862 end if; 11863 end; 11864 end if; 11865 11866 Set_Etype (Formal, Formal_Type); 11867 11868 -- Deal with default expression if present 11869 11870 Default := Expression (Param_Spec); 11871 11872 if Present (Default) then 11873 Check_SPARK_05_Restriction 11874 ("default expression is not allowed", Default); 11875 11876 if Out_Present (Param_Spec) then 11877 Error_Msg_N 11878 ("default initialization only allowed for IN parameters", 11879 Param_Spec); 11880 end if; 11881 11882 -- Do the special preanalysis of the expression (see section on 11883 -- "Handling of Default Expressions" in the spec of package Sem). 11884 11885 Preanalyze_Formal_Expression (Default, Formal_Type); 11886 11887 -- An access to constant cannot be the default for 11888 -- an access parameter that is an access to variable. 11889 11890 if Ekind (Formal_Type) = E_Anonymous_Access_Type 11891 and then not Is_Access_Constant (Formal_Type) 11892 and then Is_Access_Type (Etype (Default)) 11893 and then Is_Access_Constant (Etype (Default)) 11894 then 11895 Error_Msg_N 11896 ("formal that is access to variable cannot be initialized " 11897 & "with an access-to-constant expression", Default); 11898 end if; 11899 11900 -- Check that the designated type of an access parameter's default 11901 -- is not a class-wide type unless the parameter's designated type 11902 -- is also class-wide. 11903 11904 if Ekind (Formal_Type) = E_Anonymous_Access_Type 11905 and then not Designates_From_Limited_With (Formal_Type) 11906 and then Is_Class_Wide_Default (Default) 11907 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type)) 11908 then 11909 Error_Msg_N 11910 ("access to class-wide expression not allowed here", Default); 11911 end if; 11912 11913 -- Check incorrect use of dynamically tagged expressions 11914 11915 if Is_Tagged_Type (Formal_Type) then 11916 Check_Dynamically_Tagged_Expression 11917 (Expr => Default, 11918 Typ => Formal_Type, 11919 Related_Nod => Default); 11920 end if; 11921 end if; 11922 11923 -- Ada 2005 (AI-231): Static checks 11924 11925 if Ada_Version >= Ada_2005 11926 and then Is_Access_Type (Etype (Formal)) 11927 and then Can_Never_Be_Null (Etype (Formal)) 11928 then 11929 Null_Exclusion_Static_Checks (Param_Spec); 11930 end if; 11931 11932 -- The following checks are relevant only when SPARK_Mode is on as 11933 -- these are not standard Ada legality rules. 11934 11935 if SPARK_Mode = On then 11936 if Ekind_In (Scope (Formal), E_Function, E_Generic_Function) then 11937 11938 -- A function cannot have a parameter of mode IN OUT or OUT 11939 -- (SPARK RM 6.1). 11940 11941 if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then 11942 Error_Msg_N 11943 ("function cannot have parameter of mode `OUT` or " 11944 & "`IN OUT`", Formal); 11945 end if; 11946 11947 -- A procedure cannot have an effectively volatile formal 11948 -- parameter of mode IN because it behaves as a constant 11949 -- (SPARK RM 7.1.3(6)). -- ??? maybe 7.1.3(4) 11950 11951 elsif Ekind (Scope (Formal)) = E_Procedure 11952 and then Ekind (Formal) = E_In_Parameter 11953 and then Is_Effectively_Volatile (Formal) 11954 then 11955 Error_Msg_N 11956 ("formal parameter of mode `IN` cannot be volatile", Formal); 11957 end if; 11958 end if; 11959 11960 <<Continue>> 11961 Next (Param_Spec); 11962 end loop; 11963 11964 -- If this is the formal part of a function specification, analyze the 11965 -- subtype mark in the context where the formals are visible but not 11966 -- yet usable, and may hide outer homographs. 11967 11968 if Nkind (Related_Nod) = N_Function_Specification then 11969 Analyze_Return_Type (Related_Nod); 11970 end if; 11971 11972 -- Now set the kind (mode) of each formal 11973 11974 Param_Spec := First (T); 11975 while Present (Param_Spec) loop 11976 Formal := Defining_Identifier (Param_Spec); 11977 Set_Formal_Mode (Formal); 11978 11979 if Ekind (Formal) = E_In_Parameter then 11980 Set_Default_Value (Formal, Expression (Param_Spec)); 11981 11982 if Present (Expression (Param_Spec)) then 11983 Default := Expression (Param_Spec); 11984 11985 if Is_Scalar_Type (Etype (Default)) then 11986 if Nkind (Parameter_Type (Param_Spec)) /= 11987 N_Access_Definition 11988 then 11989 Formal_Type := Entity (Parameter_Type (Param_Spec)); 11990 else 11991 Formal_Type := 11992 Access_Definition 11993 (Related_Nod, Parameter_Type (Param_Spec)); 11994 end if; 11995 11996 Apply_Scalar_Range_Check (Default, Formal_Type); 11997 end if; 11998 end if; 11999 12000 elsif Ekind (Formal) = E_Out_Parameter then 12001 Num_Out_Params := Num_Out_Params + 1; 12002 12003 if Num_Out_Params = 1 then 12004 First_Out_Param := Formal; 12005 end if; 12006 12007 elsif Ekind (Formal) = E_In_Out_Parameter then 12008 Num_Out_Params := Num_Out_Params + 1; 12009 end if; 12010 12011 -- Skip remaining processing if formal type was in error 12012 12013 if Etype (Formal) = Any_Type or else Error_Posted (Formal) then 12014 goto Next_Parameter; 12015 end if; 12016 12017 -- Force call by reference if aliased 12018 12019 declare 12020 Conv : constant Convention_Id := Convention (Etype (Formal)); 12021 begin 12022 if Is_Aliased (Formal) then 12023 Set_Mechanism (Formal, By_Reference); 12024 12025 -- Warn if user asked this to be passed by copy 12026 12027 if Conv = Convention_Ada_Pass_By_Copy then 12028 Error_Msg_N 12029 ("cannot pass aliased parameter & by copy??", Formal); 12030 end if; 12031 12032 -- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy 12033 12034 elsif Conv = Convention_Ada_Pass_By_Copy then 12035 Set_Mechanism (Formal, By_Copy); 12036 12037 elsif Conv = Convention_Ada_Pass_By_Reference then 12038 Set_Mechanism (Formal, By_Reference); 12039 end if; 12040 end; 12041 12042 <<Next_Parameter>> 12043 Next (Param_Spec); 12044 end loop; 12045 12046 if Present (First_Out_Param) and then Num_Out_Params = 1 then 12047 Set_Is_Only_Out_Parameter (First_Out_Param); 12048 end if; 12049 end Process_Formals; 12050 12051 ---------------------------- 12052 -- Reference_Body_Formals -- 12053 ---------------------------- 12054 12055 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is 12056 Fs : Entity_Id; 12057 Fb : Entity_Id; 12058 12059 begin 12060 if Error_Posted (Spec) then 12061 return; 12062 end if; 12063 12064 -- Iterate over both lists. They may be of different lengths if the two 12065 -- specs are not conformant. 12066 12067 Fs := First_Formal (Spec); 12068 Fb := First_Formal (Bod); 12069 while Present (Fs) and then Present (Fb) loop 12070 Generate_Reference (Fs, Fb, 'b'); 12071 12072 if Style_Check then 12073 Style.Check_Identifier (Fb, Fs); 12074 end if; 12075 12076 Set_Spec_Entity (Fb, Fs); 12077 Set_Referenced (Fs, False); 12078 Next_Formal (Fs); 12079 Next_Formal (Fb); 12080 end loop; 12081 end Reference_Body_Formals; 12082 12083 ------------------------- 12084 -- Set_Actual_Subtypes -- 12085 ------------------------- 12086 12087 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is 12088 Decl : Node_Id; 12089 Formal : Entity_Id; 12090 T : Entity_Id; 12091 First_Stmt : Node_Id := Empty; 12092 AS_Needed : Boolean; 12093 12094 begin 12095 -- If this is an empty initialization procedure, no need to create 12096 -- actual subtypes (small optimization). 12097 12098 if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then 12099 return; 12100 12101 -- Within a predicate function we do not want to generate local 12102 -- subtypes that may generate nested predicate functions. 12103 12104 elsif Is_Subprogram (Subp) and then Is_Predicate_Function (Subp) then 12105 return; 12106 end if; 12107 12108 -- The subtype declarations may freeze the formals. The body generated 12109 -- for an expression function is not a freeze point, so do not emit 12110 -- these declarations (small loss of efficiency in rare cases). 12111 12112 if Nkind (N) = N_Subprogram_Body 12113 and then Was_Expression_Function (N) 12114 then 12115 return; 12116 end if; 12117 12118 Formal := First_Formal (Subp); 12119 while Present (Formal) loop 12120 T := Etype (Formal); 12121 12122 -- We never need an actual subtype for a constrained formal 12123 12124 if Is_Constrained (T) then 12125 AS_Needed := False; 12126 12127 -- If we have unknown discriminants, then we do not need an actual 12128 -- subtype, or more accurately we cannot figure it out. Note that 12129 -- all class-wide types have unknown discriminants. 12130 12131 elsif Has_Unknown_Discriminants (T) then 12132 AS_Needed := False; 12133 12134 -- At this stage we have an unconstrained type that may need an 12135 -- actual subtype. For sure the actual subtype is needed if we have 12136 -- an unconstrained array type. However, in an instance, the type 12137 -- may appear as a subtype of the full view, while the actual is 12138 -- in fact private (in which case no actual subtype is needed) so 12139 -- check the kind of the base type. 12140 12141 elsif Is_Array_Type (Base_Type (T)) then 12142 AS_Needed := True; 12143 12144 -- The only other case needing an actual subtype is an unconstrained 12145 -- record type which is an IN parameter (we cannot generate actual 12146 -- subtypes for the OUT or IN OUT case, since an assignment can 12147 -- change the discriminant values. However we exclude the case of 12148 -- initialization procedures, since discriminants are handled very 12149 -- specially in this context, see the section entitled "Handling of 12150 -- Discriminants" in Einfo. 12151 12152 -- We also exclude the case of Discrim_SO_Functions (functions used 12153 -- in front-end layout mode for size/offset values), since in such 12154 -- functions only discriminants are referenced, and not only are such 12155 -- subtypes not needed, but they cannot always be generated, because 12156 -- of order of elaboration issues. 12157 12158 elsif Is_Record_Type (T) 12159 and then Ekind (Formal) = E_In_Parameter 12160 and then Chars (Formal) /= Name_uInit 12161 and then not Is_Unchecked_Union (T) 12162 and then not Is_Discrim_SO_Function (Subp) 12163 then 12164 AS_Needed := True; 12165 12166 -- All other cases do not need an actual subtype 12167 12168 else 12169 AS_Needed := False; 12170 end if; 12171 12172 -- Generate actual subtypes for unconstrained arrays and 12173 -- unconstrained discriminated records. 12174 12175 if AS_Needed then 12176 if Nkind (N) = N_Accept_Statement then 12177 12178 -- If expansion is active, the formal is replaced by a local 12179 -- variable that renames the corresponding entry of the 12180 -- parameter block, and it is this local variable that may 12181 -- require an actual subtype. 12182 12183 if Expander_Active then 12184 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal)); 12185 else 12186 Decl := Build_Actual_Subtype (T, Formal); 12187 end if; 12188 12189 if Present (Handled_Statement_Sequence (N)) then 12190 First_Stmt := 12191 First (Statements (Handled_Statement_Sequence (N))); 12192 Prepend (Decl, Statements (Handled_Statement_Sequence (N))); 12193 Mark_Rewrite_Insertion (Decl); 12194 else 12195 -- If the accept statement has no body, there will be no 12196 -- reference to the actuals, so no need to compute actual 12197 -- subtypes. 12198 12199 return; 12200 end if; 12201 12202 else 12203 Decl := Build_Actual_Subtype (T, Formal); 12204 Prepend (Decl, Declarations (N)); 12205 Mark_Rewrite_Insertion (Decl); 12206 end if; 12207 12208 -- The declaration uses the bounds of an existing object, and 12209 -- therefore needs no constraint checks. 12210 12211 Analyze (Decl, Suppress => All_Checks); 12212 Set_Is_Actual_Subtype (Defining_Identifier (Decl)); 12213 12214 -- We need to freeze manually the generated type when it is 12215 -- inserted anywhere else than in a declarative part. 12216 12217 if Present (First_Stmt) then 12218 Insert_List_Before_And_Analyze (First_Stmt, 12219 Freeze_Entity (Defining_Identifier (Decl), N)); 12220 12221 -- Ditto if the type has a dynamic predicate, because the 12222 -- generated function will mention the actual subtype. The 12223 -- predicate may come from an explicit aspect of be inherited. 12224 12225 elsif Has_Predicates (T) then 12226 Insert_List_After_And_Analyze (Decl, 12227 Freeze_Entity (Defining_Identifier (Decl), N)); 12228 end if; 12229 12230 if Nkind (N) = N_Accept_Statement 12231 and then Expander_Active 12232 then 12233 Set_Actual_Subtype (Renamed_Object (Formal), 12234 Defining_Identifier (Decl)); 12235 else 12236 Set_Actual_Subtype (Formal, Defining_Identifier (Decl)); 12237 end if; 12238 end if; 12239 12240 Next_Formal (Formal); 12241 end loop; 12242 end Set_Actual_Subtypes; 12243 12244 --------------------- 12245 -- Set_Formal_Mode -- 12246 --------------------- 12247 12248 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is 12249 Spec : constant Node_Id := Parent (Formal_Id); 12250 Id : constant Entity_Id := Scope (Formal_Id); 12251 12252 begin 12253 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters 12254 -- since we ensure that corresponding actuals are always valid at the 12255 -- point of the call. 12256 12257 if Out_Present (Spec) then 12258 if Ekind_In (Id, E_Entry, E_Entry_Family) 12259 or else Is_Subprogram_Or_Generic_Subprogram (Id) 12260 then 12261 Set_Has_Out_Or_In_Out_Parameter (Id, True); 12262 end if; 12263 12264 if Ekind_In (Id, E_Function, E_Generic_Function) then 12265 12266 -- [IN] OUT parameters allowed for functions in Ada 2012 12267 12268 if Ada_Version >= Ada_2012 then 12269 12270 -- Even in Ada 2012 operators can only have IN parameters 12271 12272 if Is_Operator_Symbol_Name (Chars (Scope (Formal_Id))) then 12273 Error_Msg_N ("operators can only have IN parameters", Spec); 12274 end if; 12275 12276 if In_Present (Spec) then 12277 Set_Ekind (Formal_Id, E_In_Out_Parameter); 12278 else 12279 Set_Ekind (Formal_Id, E_Out_Parameter); 12280 end if; 12281 12282 -- But not in earlier versions of Ada 12283 12284 else 12285 Error_Msg_N ("functions can only have IN parameters", Spec); 12286 Set_Ekind (Formal_Id, E_In_Parameter); 12287 end if; 12288 12289 elsif In_Present (Spec) then 12290 Set_Ekind (Formal_Id, E_In_Out_Parameter); 12291 12292 else 12293 Set_Ekind (Formal_Id, E_Out_Parameter); 12294 Set_Never_Set_In_Source (Formal_Id, True); 12295 Set_Is_True_Constant (Formal_Id, False); 12296 Set_Current_Value (Formal_Id, Empty); 12297 end if; 12298 12299 else 12300 Set_Ekind (Formal_Id, E_In_Parameter); 12301 end if; 12302 12303 -- Set Is_Known_Non_Null for access parameters since the language 12304 -- guarantees that access parameters are always non-null. We also set 12305 -- Can_Never_Be_Null, since there is no way to change the value. 12306 12307 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then 12308 12309 -- Ada 2005 (AI-231): In Ada 95, access parameters are always non- 12310 -- null; In Ada 2005, only if then null_exclusion is explicit. 12311 12312 if Ada_Version < Ada_2005 12313 or else Can_Never_Be_Null (Etype (Formal_Id)) 12314 then 12315 Set_Is_Known_Non_Null (Formal_Id); 12316 Set_Can_Never_Be_Null (Formal_Id); 12317 end if; 12318 12319 -- Ada 2005 (AI-231): Null-exclusion access subtype 12320 12321 elsif Is_Access_Type (Etype (Formal_Id)) 12322 and then Can_Never_Be_Null (Etype (Formal_Id)) 12323 then 12324 Set_Is_Known_Non_Null (Formal_Id); 12325 12326 -- We can also set Can_Never_Be_Null (thus preventing some junk 12327 -- access checks) for the case of an IN parameter, which cannot 12328 -- be changed, or for an IN OUT parameter, which can be changed but 12329 -- not to a null value. But for an OUT parameter, the initial value 12330 -- passed in can be null, so we can't set this flag in that case. 12331 12332 if Ekind (Formal_Id) /= E_Out_Parameter then 12333 Set_Can_Never_Be_Null (Formal_Id); 12334 end if; 12335 end if; 12336 12337 Set_Mechanism (Formal_Id, Default_Mechanism); 12338 Set_Formal_Validity (Formal_Id); 12339 end Set_Formal_Mode; 12340 12341 ------------------------- 12342 -- Set_Formal_Validity -- 12343 ------------------------- 12344 12345 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is 12346 begin 12347 -- If no validity checking, then we cannot assume anything about the 12348 -- validity of parameters, since we do not know there is any checking 12349 -- of the validity on the call side. 12350 12351 if not Validity_Checks_On then 12352 return; 12353 12354 -- If validity checking for parameters is enabled, this means we are 12355 -- not supposed to make any assumptions about argument values. 12356 12357 elsif Validity_Check_Parameters then 12358 return; 12359 12360 -- If we are checking in parameters, we will assume that the caller is 12361 -- also checking parameters, so we can assume the parameter is valid. 12362 12363 elsif Ekind (Formal_Id) = E_In_Parameter 12364 and then Validity_Check_In_Params 12365 then 12366 Set_Is_Known_Valid (Formal_Id, True); 12367 12368 -- Similar treatment for IN OUT parameters 12369 12370 elsif Ekind (Formal_Id) = E_In_Out_Parameter 12371 and then Validity_Check_In_Out_Params 12372 then 12373 Set_Is_Known_Valid (Formal_Id, True); 12374 end if; 12375 end Set_Formal_Validity; 12376 12377 ------------------------ 12378 -- Subtype_Conformant -- 12379 ------------------------ 12380 12381 function Subtype_Conformant 12382 (New_Id : Entity_Id; 12383 Old_Id : Entity_Id; 12384 Skip_Controlling_Formals : Boolean := False) return Boolean 12385 is 12386 Result : Boolean; 12387 begin 12388 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result, 12389 Skip_Controlling_Formals => Skip_Controlling_Formals); 12390 return Result; 12391 end Subtype_Conformant; 12392 12393 --------------------- 12394 -- Type_Conformant -- 12395 --------------------- 12396 12397 function Type_Conformant 12398 (New_Id : Entity_Id; 12399 Old_Id : Entity_Id; 12400 Skip_Controlling_Formals : Boolean := False) return Boolean 12401 is 12402 Result : Boolean; 12403 begin 12404 May_Hide_Profile := False; 12405 Check_Conformance 12406 (New_Id, Old_Id, Type_Conformant, False, Result, 12407 Skip_Controlling_Formals => Skip_Controlling_Formals); 12408 return Result; 12409 end Type_Conformant; 12410 12411 ------------------------------- 12412 -- Valid_Operator_Definition -- 12413 ------------------------------- 12414 12415 procedure Valid_Operator_Definition (Designator : Entity_Id) is 12416 N : Integer := 0; 12417 F : Entity_Id; 12418 Id : constant Name_Id := Chars (Designator); 12419 N_OK : Boolean; 12420 12421 begin 12422 F := First_Formal (Designator); 12423 while Present (F) loop 12424 N := N + 1; 12425 12426 if Present (Default_Value (F)) then 12427 Error_Msg_N 12428 ("default values not allowed for operator parameters", 12429 Parent (F)); 12430 12431 -- For function instantiations that are operators, we must check 12432 -- separately that the corresponding generic only has in-parameters. 12433 -- For subprogram declarations this is done in Set_Formal_Mode. Such 12434 -- an error could not arise in earlier versions of the language. 12435 12436 elsif Ekind (F) /= E_In_Parameter then 12437 Error_Msg_N ("operators can only have IN parameters", F); 12438 end if; 12439 12440 Next_Formal (F); 12441 end loop; 12442 12443 -- Verify that user-defined operators have proper number of arguments 12444 -- First case of operators which can only be unary 12445 12446 if Nam_In (Id, Name_Op_Not, Name_Op_Abs) then 12447 N_OK := (N = 1); 12448 12449 -- Case of operators which can be unary or binary 12450 12451 elsif Nam_In (Id, Name_Op_Add, Name_Op_Subtract) then 12452 N_OK := (N in 1 .. 2); 12453 12454 -- All other operators can only be binary 12455 12456 else 12457 N_OK := (N = 2); 12458 end if; 12459 12460 if not N_OK then 12461 Error_Msg_N 12462 ("incorrect number of arguments for operator", Designator); 12463 end if; 12464 12465 if Id = Name_Op_Ne 12466 and then Base_Type (Etype (Designator)) = Standard_Boolean 12467 and then not Is_Intrinsic_Subprogram (Designator) 12468 then 12469 Error_Msg_N 12470 ("explicit definition of inequality not allowed", Designator); 12471 end if; 12472 end Valid_Operator_Definition; 12473 12474end Sem_Ch6; 12475