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_Aggregate_Accessibility (Aggr : Node_Id); 698 -- Apply legality rule of 6.5 (5.8) 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_Aggregate_Accessibility -- 707 ----------------------------------- 708 709 procedure Check_Aggregate_Accessibility (Aggr : Node_Id) is 710 Typ : constant Entity_Id := Etype (Aggr); 711 Assoc : Node_Id; 712 Discr : Entity_Id; 713 Expr : Node_Id; 714 Obj : Node_Id; 715 716 begin 717 if Is_Record_Type (Typ) and then Has_Discriminants (Typ) then 718 Discr := First_Discriminant (Typ); 719 Assoc := First (Component_Associations (Aggr)); 720 while Present (Discr) loop 721 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then 722 Expr := Expression (Assoc); 723 724 if Nkind (Expr) = N_Attribute_Reference 725 and then Attribute_Name (Expr) /= Name_Unrestricted_Access 726 then 727 Obj := Prefix (Expr); 728 while Nkind_In (Obj, N_Indexed_Component, 729 N_Selected_Component) 730 loop 731 Obj := Prefix (Obj); 732 end loop; 733 734 -- Do not check aliased formals or function calls. A 735 -- run-time check may still be needed ??? 736 737 if Is_Entity_Name (Obj) 738 and then Comes_From_Source (Obj) 739 then 740 if Is_Formal (Entity (Obj)) 741 and then Is_Aliased (Entity (Obj)) 742 then 743 null; 744 745 elsif Object_Access_Level (Obj) > 746 Scope_Depth (Scope (Scope_Id)) 747 then 748 Error_Msg_N 749 ("access discriminant in return aggregate would " 750 & "be a dangling reference", Obj); 751 end if; 752 end if; 753 end if; 754 end if; 755 756 Next_Discriminant (Discr); 757 end loop; 758 end if; 759 end Check_Aggregate_Accessibility; 760 761 ------------------------------------- 762 -- Check_Return_Subtype_Indication -- 763 ------------------------------------- 764 765 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is 766 Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl); 767 768 R_Stm_Type : constant Entity_Id := Etype (Return_Obj); 769 -- Subtype given in the extended return statement (must match R_Type) 770 771 Subtype_Ind : constant Node_Id := 772 Object_Definition (Original_Node (Obj_Decl)); 773 774 procedure Error_No_Match (N : Node_Id); 775 -- Output error messages for case where types do not statically 776 -- match. N is the location for the messages. 777 778 -------------------- 779 -- Error_No_Match -- 780 -------------------- 781 782 procedure Error_No_Match (N : Node_Id) is 783 begin 784 Error_Msg_N 785 ("subtype must statically match function result subtype", N); 786 787 if not Predicates_Match (R_Stm_Type, R_Type) then 788 Error_Msg_Node_2 := R_Type; 789 Error_Msg_NE 790 ("\predicate of& does not match predicate of&", 791 N, R_Stm_Type); 792 end if; 793 end Error_No_Match; 794 795 -- Start of processing for Check_Return_Subtype_Indication 796 797 begin 798 -- First, avoid cascaded errors 799 800 if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then 801 return; 802 end if; 803 804 -- "return access T" case; check that the return statement also has 805 -- "access T", and that the subtypes statically match: 806 -- if this is an access to subprogram the signatures must match. 807 808 if Is_Anonymous_Access_Type (R_Type) then 809 if Is_Anonymous_Access_Type (R_Stm_Type) then 810 if Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type 811 then 812 if Base_Type (Designated_Type (R_Stm_Type)) /= 813 Base_Type (Designated_Type (R_Type)) 814 or else not Subtypes_Statically_Match (R_Stm_Type, R_Type) 815 then 816 Error_No_Match (Subtype_Mark (Subtype_Ind)); 817 end if; 818 819 else 820 -- For two anonymous access to subprogram types, the types 821 -- themselves must be type conformant. 822 823 if not Conforming_Types 824 (R_Stm_Type, R_Type, Fully_Conformant) 825 then 826 Error_No_Match (Subtype_Ind); 827 end if; 828 end if; 829 830 else 831 Error_Msg_N ("must use anonymous access type", Subtype_Ind); 832 end if; 833 834 -- If the return object is of an anonymous access type, then report 835 -- an error if the function's result type is not also anonymous. 836 837 elsif Is_Anonymous_Access_Type (R_Stm_Type) then 838 pragma Assert (not Is_Anonymous_Access_Type (R_Type)); 839 Error_Msg_N 840 ("anonymous access not allowed for function with named access " 841 & "result", Subtype_Ind); 842 843 -- Subtype indication case: check that the return object's type is 844 -- covered by the result type, and that the subtypes statically match 845 -- when the result subtype is constrained. Also handle record types 846 -- with unknown discriminants for which we have built the underlying 847 -- record view. Coverage is needed to allow specific-type return 848 -- objects when the result type is class-wide (see AI05-32). 849 850 elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type)) 851 or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type)) 852 and then 853 Covers 854 (Base_Type (R_Type), 855 Underlying_Record_View (Base_Type (R_Stm_Type)))) 856 then 857 -- A null exclusion may be present on the return type, on the 858 -- function specification, on the object declaration or on the 859 -- subtype itself. 860 861 if Is_Access_Type (R_Type) 862 and then 863 (Can_Never_Be_Null (R_Type) 864 or else Null_Exclusion_Present (Parent (Scope_Id))) /= 865 Can_Never_Be_Null (R_Stm_Type) 866 then 867 Error_No_Match (Subtype_Ind); 868 end if; 869 870 -- AI05-103: for elementary types, subtypes must statically match 871 872 if Is_Constrained (R_Type) or else Is_Access_Type (R_Type) then 873 if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then 874 Error_No_Match (Subtype_Ind); 875 end if; 876 end if; 877 878 -- All remaining cases are illegal 879 880 -- Note: previous versions of this subprogram allowed the return 881 -- value to be the ancestor of the return type if the return type 882 -- was a null extension. This was plainly incorrect. 883 884 else 885 Error_Msg_N 886 ("wrong type for return_subtype_indication", Subtype_Ind); 887 end if; 888 end Check_Return_Subtype_Indication; 889 890 --------------------- 891 -- Local Variables -- 892 --------------------- 893 894 Expr : Node_Id; 895 Obj_Decl : Node_Id := Empty; 896 897 -- Start of processing for Analyze_Function_Return 898 899 begin 900 Set_Return_Present (Scope_Id); 901 902 if Nkind (N) = N_Simple_Return_Statement then 903 Expr := Expression (N); 904 905 -- Guard against a malformed expression. The parser may have tried to 906 -- recover but the node is not analyzable. 907 908 if Nkind (Expr) = N_Error then 909 Set_Etype (Expr, Any_Type); 910 Expander_Mode_Save_And_Set (False); 911 return; 912 913 else 914 -- The resolution of a controlled [extension] aggregate associated 915 -- with a return statement creates a temporary which needs to be 916 -- finalized on function exit. Wrap the return statement inside a 917 -- block so that the finalization machinery can detect this case. 918 -- This early expansion is done only when the return statement is 919 -- not part of a handled sequence of statements. 920 921 if Nkind_In (Expr, N_Aggregate, 922 N_Extension_Aggregate) 923 and then Needs_Finalization (R_Type) 924 and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements 925 then 926 Rewrite (N, 927 Make_Block_Statement (Loc, 928 Handled_Statement_Sequence => 929 Make_Handled_Sequence_Of_Statements (Loc, 930 Statements => New_List (Relocate_Node (N))))); 931 932 Analyze (N); 933 return; 934 end if; 935 936 Analyze (Expr); 937 938 -- Ada 2005 (AI-251): If the type of the returned object is 939 -- an access to an interface type then we add an implicit type 940 -- conversion to force the displacement of the "this" pointer to 941 -- reference the secondary dispatch table. We cannot delay the 942 -- generation of this implicit conversion until the expansion 943 -- because in this case the type resolution changes the decoration 944 -- of the expression node to match R_Type; by contrast, if the 945 -- returned object is a class-wide interface type then it is too 946 -- early to generate here the implicit conversion since the return 947 -- statement may be rewritten by the expander into an extended 948 -- return statement whose expansion takes care of adding the 949 -- implicit type conversion to displace the pointer to the object. 950 951 if Expander_Active 952 and then Serious_Errors_Detected = 0 953 and then Is_Access_Type (R_Type) 954 and then not Nkind_In (Expr, N_Null, N_Raise_Expression) 955 and then Is_Interface (Designated_Type (R_Type)) 956 and then Is_Progenitor (Designated_Type (R_Type), 957 Designated_Type (Etype (Expr))) 958 then 959 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); 960 Analyze (Expr); 961 end if; 962 963 Resolve (Expr, R_Type); 964 Check_Limited_Return (N, Expr, R_Type); 965 966 if Present (Expr) and then Nkind (Expr) = N_Aggregate then 967 Check_Aggregate_Accessibility (Expr); 968 end if; 969 end if; 970 971 -- RETURN only allowed in SPARK as the last statement in function 972 973 if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements 974 and then 975 (Nkind (Parent (Parent (N))) /= N_Subprogram_Body 976 or else Present (Next (N))) 977 then 978 Check_SPARK_05_Restriction 979 ("RETURN should be the last statement in function", N); 980 end if; 981 982 else 983 Check_SPARK_05_Restriction ("extended RETURN is not allowed", N); 984 Obj_Decl := Last (Return_Object_Declarations (N)); 985 986 -- Analyze parts specific to extended_return_statement: 987 988 declare 989 Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl); 990 HSS : constant Node_Id := Handled_Statement_Sequence (N); 991 992 begin 993 Expr := Expression (Obj_Decl); 994 995 -- Note: The check for OK_For_Limited_Init will happen in 996 -- Analyze_Object_Declaration; we treat it as a normal 997 -- object declaration. 998 999 Set_Is_Return_Object (Defining_Identifier (Obj_Decl)); 1000 Analyze (Obj_Decl); 1001 1002 Check_Return_Subtype_Indication (Obj_Decl); 1003 1004 if Present (HSS) then 1005 Analyze (HSS); 1006 1007 if Present (Exception_Handlers (HSS)) then 1008 1009 -- ???Has_Nested_Block_With_Handler needs to be set. 1010 -- Probably by creating an actual N_Block_Statement. 1011 -- Probably in Expand. 1012 1013 null; 1014 end if; 1015 end if; 1016 1017 -- Mark the return object as referenced, since the return is an 1018 -- implicit reference of the object. 1019 1020 Set_Referenced (Defining_Identifier (Obj_Decl)); 1021 1022 Check_References (Stm_Entity); 1023 1024 -- Check RM 6.5 (5.9/3) 1025 1026 if Has_Aliased then 1027 if Ada_Version < Ada_2012 then 1028 1029 -- Shouldn't this test Warn_On_Ada_2012_Compatibility ??? 1030 -- Can it really happen (extended return???) 1031 1032 Error_Msg_N 1033 ("aliased only allowed for limited return objects " 1034 & "in Ada 2012??", N); 1035 1036 elsif not Is_Limited_View (R_Type) then 1037 Error_Msg_N 1038 ("aliased only allowed for limited return objects", N); 1039 end if; 1040 end if; 1041 end; 1042 end if; 1043 1044 -- Case of Expr present 1045 1046 if Present (Expr) then 1047 1048 -- Defend against previous errors 1049 1050 if Nkind (Expr) = N_Empty 1051 or else No (Etype (Expr)) 1052 then 1053 return; 1054 end if; 1055 1056 -- Apply constraint check. Note that this is done before the implicit 1057 -- conversion of the expression done for anonymous access types to 1058 -- ensure correct generation of the null-excluding check associated 1059 -- with null-excluding expressions found in return statements. 1060 1061 Apply_Constraint_Check (Expr, R_Type); 1062 1063 -- The return value is converted to the return type of the function, 1064 -- which implies a predicate check if the return type is predicated. 1065 -- We do not apply the check to a case expression because it will 1066 -- be expanded into a series of return statements, each of which 1067 -- will receive a predicate check. 1068 1069 if Nkind (Expr) /= N_Case_Expression then 1070 Apply_Predicate_Check (Expr, R_Type); 1071 end if; 1072 1073 -- Ada 2005 (AI-318-02): When the result type is an anonymous access 1074 -- type, apply an implicit conversion of the expression to that type 1075 -- to force appropriate static and run-time accessibility checks. 1076 1077 if Ada_Version >= Ada_2005 1078 and then Ekind (R_Type) = E_Anonymous_Access_Type 1079 then 1080 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); 1081 Analyze_And_Resolve (Expr, R_Type); 1082 1083 -- If this is a local anonymous access to subprogram, the 1084 -- accessibility check can be applied statically. The return is 1085 -- illegal if the access type of the return expression is declared 1086 -- inside of the subprogram (except if it is the subtype indication 1087 -- of an extended return statement). 1088 1089 elsif Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type then 1090 if not Comes_From_Source (Current_Scope) 1091 or else Ekind (Current_Scope) = E_Return_Statement 1092 then 1093 null; 1094 1095 elsif 1096 Scope_Depth (Scope (Etype (Expr))) >= Scope_Depth (Scope_Id) 1097 then 1098 Error_Msg_N ("cannot return local access to subprogram", N); 1099 end if; 1100 1101 -- The expression cannot be of a formal incomplete type 1102 1103 elsif Ekind (Etype (Expr)) = E_Incomplete_Type 1104 and then Is_Generic_Type (Etype (Expr)) 1105 then 1106 Error_Msg_N 1107 ("cannot return expression of a formal incomplete type", N); 1108 end if; 1109 1110 -- If the result type is class-wide, then check that the return 1111 -- expression's type is not declared at a deeper level than the 1112 -- function (RM05-6.5(5.6/2)). 1113 1114 if Ada_Version >= Ada_2005 1115 and then Is_Class_Wide_Type (R_Type) 1116 then 1117 if Type_Access_Level (Etype (Expr)) > 1118 Subprogram_Access_Level (Scope_Id) 1119 then 1120 Error_Msg_N 1121 ("level of return expression type is deeper than " 1122 & "class-wide function!", Expr); 1123 end if; 1124 end if; 1125 1126 -- Check incorrect use of dynamically tagged expression 1127 1128 if Is_Tagged_Type (R_Type) then 1129 Check_Dynamically_Tagged_Expression 1130 (Expr => Expr, 1131 Typ => R_Type, 1132 Related_Nod => N); 1133 end if; 1134 1135 -- ??? A real run-time accessibility check is needed in cases 1136 -- involving dereferences of access parameters. For now we just 1137 -- check the static cases. 1138 1139 if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L) 1140 and then Is_Limited_View (Etype (Scope_Id)) 1141 and then Object_Access_Level (Expr) > 1142 Subprogram_Access_Level (Scope_Id) 1143 then 1144 -- Suppress the message in a generic, where the rewriting 1145 -- is irrelevant. 1146 1147 if Inside_A_Generic then 1148 null; 1149 1150 else 1151 Rewrite (N, 1152 Make_Raise_Program_Error (Loc, 1153 Reason => PE_Accessibility_Check_Failed)); 1154 Analyze (N); 1155 1156 Error_Msg_Warn := SPARK_Mode /= On; 1157 Error_Msg_N ("cannot return a local value by reference<<", N); 1158 Error_Msg_NE ("\& [<<", N, Standard_Program_Error); 1159 end if; 1160 end if; 1161 1162 if Known_Null (Expr) 1163 and then Nkind (Parent (Scope_Id)) = N_Function_Specification 1164 and then Null_Exclusion_Present (Parent (Scope_Id)) 1165 then 1166 Apply_Compile_Time_Constraint_Error 1167 (N => Expr, 1168 Msg => "(Ada 2005) null not allowed for " 1169 & "null-excluding return??", 1170 Reason => CE_Null_Not_Allowed); 1171 end if; 1172 1173 -- RM 6.5 (5.4/3): accessibility checks also apply if the return object 1174 -- has no initializing expression. 1175 1176 elsif Ada_Version > Ada_2005 and then Is_Class_Wide_Type (R_Type) then 1177 if Type_Access_Level (Etype (Defining_Identifier (Obj_Decl))) > 1178 Subprogram_Access_Level (Scope_Id) 1179 then 1180 Error_Msg_N 1181 ("level of return expression type is deeper than " 1182 & "class-wide function!", Obj_Decl); 1183 end if; 1184 end if; 1185 end Analyze_Function_Return; 1186 1187 ------------------------------------- 1188 -- Analyze_Generic_Subprogram_Body -- 1189 ------------------------------------- 1190 1191 procedure Analyze_Generic_Subprogram_Body 1192 (N : Node_Id; 1193 Gen_Id : Entity_Id) 1194 is 1195 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id); 1196 Kind : constant Entity_Kind := Ekind (Gen_Id); 1197 Body_Id : Entity_Id; 1198 New_N : Node_Id; 1199 Spec : Node_Id; 1200 1201 begin 1202 -- Copy body and disable expansion while analyzing the generic For a 1203 -- stub, do not copy the stub (which would load the proper body), this 1204 -- will be done when the proper body is analyzed. 1205 1206 if Nkind (N) /= N_Subprogram_Body_Stub then 1207 New_N := Copy_Generic_Node (N, Empty, Instantiating => False); 1208 Rewrite (N, New_N); 1209 1210 -- Once the contents of the generic copy and the template are 1211 -- swapped, do the same for their respective aspect specifications. 1212 1213 Exchange_Aspects (N, New_N); 1214 1215 -- Collect all contract-related source pragmas found within the 1216 -- template and attach them to the contract of the subprogram body. 1217 -- This contract is used in the capture of global references within 1218 -- annotations. 1219 1220 Create_Generic_Contract (N); 1221 1222 Start_Generic; 1223 end if; 1224 1225 Spec := Specification (N); 1226 1227 -- Within the body of the generic, the subprogram is callable, and 1228 -- behaves like the corresponding non-generic unit. 1229 1230 Body_Id := Defining_Entity (Spec); 1231 1232 if Kind = E_Generic_Procedure 1233 and then Nkind (Spec) /= N_Procedure_Specification 1234 then 1235 Error_Msg_N ("invalid body for generic procedure ", Body_Id); 1236 return; 1237 1238 elsif Kind = E_Generic_Function 1239 and then Nkind (Spec) /= N_Function_Specification 1240 then 1241 Error_Msg_N ("invalid body for generic function ", Body_Id); 1242 return; 1243 end if; 1244 1245 Set_Corresponding_Body (Gen_Decl, Body_Id); 1246 1247 if Has_Completion (Gen_Id) 1248 and then Nkind (Parent (N)) /= N_Subunit 1249 then 1250 Error_Msg_N ("duplicate generic body", N); 1251 return; 1252 else 1253 Set_Has_Completion (Gen_Id); 1254 end if; 1255 1256 if Nkind (N) = N_Subprogram_Body_Stub then 1257 Set_Ekind (Defining_Entity (Specification (N)), Kind); 1258 else 1259 Set_Corresponding_Spec (N, Gen_Id); 1260 end if; 1261 1262 if Nkind (Parent (N)) = N_Compilation_Unit then 1263 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N)); 1264 end if; 1265 1266 -- Make generic parameters immediately visible in the body. They are 1267 -- needed to process the formals declarations. Then make the formals 1268 -- visible in a separate step. 1269 1270 Push_Scope (Gen_Id); 1271 1272 declare 1273 E : Entity_Id; 1274 First_Ent : Entity_Id; 1275 1276 begin 1277 First_Ent := First_Entity (Gen_Id); 1278 1279 E := First_Ent; 1280 while Present (E) and then not Is_Formal (E) loop 1281 Install_Entity (E); 1282 Next_Entity (E); 1283 end loop; 1284 1285 Set_Use (Generic_Formal_Declarations (Gen_Decl)); 1286 1287 -- Now generic formals are visible, and the specification can be 1288 -- analyzed, for subsequent conformance check. 1289 1290 Body_Id := Analyze_Subprogram_Specification (Spec); 1291 1292 -- Make formal parameters visible 1293 1294 if Present (E) then 1295 1296 -- E is the first formal parameter, we loop through the formals 1297 -- installing them so that they will be visible. 1298 1299 Set_First_Entity (Gen_Id, E); 1300 while Present (E) loop 1301 Install_Entity (E); 1302 Next_Formal (E); 1303 end loop; 1304 end if; 1305 1306 -- Visible generic entity is callable within its own body 1307 1308 Set_Ekind (Gen_Id, Ekind (Body_Id)); 1309 Set_Ekind (Body_Id, E_Subprogram_Body); 1310 Set_Convention (Body_Id, Convention (Gen_Id)); 1311 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id)); 1312 Set_Scope (Body_Id, Scope (Gen_Id)); 1313 1314 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id); 1315 1316 if Nkind (N) = N_Subprogram_Body_Stub then 1317 1318 -- No body to analyze, so restore state of generic unit 1319 1320 Set_Ekind (Gen_Id, Kind); 1321 Set_Ekind (Body_Id, Kind); 1322 1323 if Present (First_Ent) then 1324 Set_First_Entity (Gen_Id, First_Ent); 1325 end if; 1326 1327 End_Scope; 1328 return; 1329 end if; 1330 1331 -- If this is a compilation unit, it must be made visible explicitly, 1332 -- because the compilation of the declaration, unlike other library 1333 -- unit declarations, does not. If it is not a unit, the following 1334 -- is redundant but harmless. 1335 1336 Set_Is_Immediately_Visible (Gen_Id); 1337 Reference_Body_Formals (Gen_Id, Body_Id); 1338 1339 if Is_Child_Unit (Gen_Id) then 1340 Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False); 1341 end if; 1342 1343 Set_Actual_Subtypes (N, Current_Scope); 1344 1345 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 1346 Set_SPARK_Pragma_Inherited (Body_Id); 1347 1348 -- Analyze any aspect specifications that appear on the generic 1349 -- subprogram body. 1350 1351 if Has_Aspects (N) then 1352 Analyze_Aspects_On_Subprogram_Body_Or_Stub (N); 1353 end if; 1354 1355 Analyze_Declarations (Declarations (N)); 1356 Check_Completion; 1357 1358 -- Process the contract of the subprogram body after all declarations 1359 -- have been analyzed. This ensures that any contract-related pragmas 1360 -- are available through the N_Contract node of the body. 1361 1362 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id); 1363 1364 Analyze (Handled_Statement_Sequence (N)); 1365 Save_Global_References (Original_Node (N)); 1366 1367 -- Prior to exiting the scope, include generic formals again (if any 1368 -- are present) in the set of local entities. 1369 1370 if Present (First_Ent) then 1371 Set_First_Entity (Gen_Id, First_Ent); 1372 end if; 1373 1374 Check_References (Gen_Id); 1375 end; 1376 1377 Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope); 1378 Update_Use_Clause_Chain; 1379 Validate_Categorization_Dependency (N, Gen_Id); 1380 End_Scope; 1381 Check_Subprogram_Order (N); 1382 1383 -- Outside of its body, unit is generic again 1384 1385 Set_Ekind (Gen_Id, Kind); 1386 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False); 1387 1388 if Style_Check then 1389 Style.Check_Identifier (Body_Id, Gen_Id); 1390 end if; 1391 1392 End_Generic; 1393 end Analyze_Generic_Subprogram_Body; 1394 1395 ---------------------------- 1396 -- Analyze_Null_Procedure -- 1397 ---------------------------- 1398 1399 -- WARNING: This routine manages Ghost regions. Return statements must be 1400 -- replaced by gotos that jump to the end of the routine and restore the 1401 -- Ghost mode. 1402 1403 procedure Analyze_Null_Procedure 1404 (N : Node_Id; 1405 Is_Completion : out Boolean) 1406 is 1407 Loc : constant Source_Ptr := Sloc (N); 1408 Spec : constant Node_Id := Specification (N); 1409 1410 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 1411 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 1412 Saved_ISMP : constant Boolean := 1413 Ignore_SPARK_Mode_Pragmas_In_Instance; 1414 -- Save the Ghost and SPARK mode-related data to restore on exit 1415 1416 Designator : Entity_Id; 1417 Form : Node_Id; 1418 Null_Body : Node_Id := Empty; 1419 Null_Stmt : Node_Id := Null_Statement (Spec); 1420 Prev : Entity_Id; 1421 1422 begin 1423 Prev := Current_Entity_In_Scope (Defining_Entity (Spec)); 1424 1425 -- A null procedure is Ghost when it is stand-alone and is subject to 1426 -- pragma Ghost, or when the corresponding spec is Ghost. Set the mode 1427 -- now, to ensure that any nodes generated during analysis and expansion 1428 -- are properly marked as Ghost. 1429 1430 if Present (Prev) then 1431 Mark_And_Set_Ghost_Body (N, Prev); 1432 end if; 1433 1434 -- Capture the profile of the null procedure before analysis, for 1435 -- expansion at the freeze point and at each point of call. The body is 1436 -- used if the procedure has preconditions, or if it is a completion. In 1437 -- the first case the body is analyzed at the freeze point, in the other 1438 -- it replaces the null procedure declaration. 1439 1440 -- For a null procedure that comes from source, a NULL statement is 1441 -- provided by the parser, which carries the source location of the 1442 -- NULL keyword, and has Comes_From_Source set. For a null procedure 1443 -- from expansion, create one now. 1444 1445 if No (Null_Stmt) then 1446 Null_Stmt := Make_Null_Statement (Loc); 1447 end if; 1448 1449 Null_Body := 1450 Make_Subprogram_Body (Loc, 1451 Specification => New_Copy_Tree (Spec), 1452 Declarations => New_List, 1453 Handled_Statement_Sequence => 1454 Make_Handled_Sequence_Of_Statements (Loc, 1455 Statements => New_List (Null_Stmt))); 1456 1457 -- Create new entities for body and formals 1458 1459 Set_Defining_Unit_Name (Specification (Null_Body), 1460 Make_Defining_Identifier 1461 (Sloc (Defining_Entity (N)), 1462 Chars (Defining_Entity (N)))); 1463 1464 Form := First (Parameter_Specifications (Specification (Null_Body))); 1465 while Present (Form) loop 1466 Set_Defining_Identifier (Form, 1467 Make_Defining_Identifier 1468 (Sloc (Defining_Identifier (Form)), 1469 Chars (Defining_Identifier (Form)))); 1470 Next (Form); 1471 end loop; 1472 1473 -- Determine whether the null procedure may be a completion of a generic 1474 -- suprogram, in which case we use the new null body as the completion 1475 -- and set minimal semantic information on the original declaration, 1476 -- which is rewritten as a null statement. 1477 1478 if Present (Prev) and then Is_Generic_Subprogram (Prev) then 1479 Insert_Before (N, Null_Body); 1480 Set_Ekind (Defining_Entity (N), Ekind (Prev)); 1481 1482 Rewrite (N, Make_Null_Statement (Loc)); 1483 Analyze_Generic_Subprogram_Body (Null_Body, Prev); 1484 Is_Completion := True; 1485 1486 goto Leave; 1487 1488 else 1489 -- Resolve the types of the formals now, because the freeze point may 1490 -- appear in a different context, e.g. an instantiation. 1491 1492 Form := First (Parameter_Specifications (Specification (Null_Body))); 1493 while Present (Form) loop 1494 if Nkind (Parameter_Type (Form)) /= N_Access_Definition then 1495 Find_Type (Parameter_Type (Form)); 1496 1497 elsif No (Access_To_Subprogram_Definition 1498 (Parameter_Type (Form))) 1499 then 1500 Find_Type (Subtype_Mark (Parameter_Type (Form))); 1501 1502 -- The case of a null procedure with a formal that is an 1503 -- access-to-subprogram type, and that is used as an actual 1504 -- in an instantiation is left to the enthusiastic reader. 1505 1506 else 1507 null; 1508 end if; 1509 1510 Next (Form); 1511 end loop; 1512 end if; 1513 1514 -- If there are previous overloadable entities with the same name, check 1515 -- whether any of them is completed by the null procedure. 1516 1517 if Present (Prev) and then Is_Overloadable (Prev) then 1518 Designator := Analyze_Subprogram_Specification (Spec); 1519 Prev := Find_Corresponding_Spec (N); 1520 end if; 1521 1522 if No (Prev) or else not Comes_From_Source (Prev) then 1523 Designator := Analyze_Subprogram_Specification (Spec); 1524 Set_Has_Completion (Designator); 1525 1526 -- Signal to caller that this is a procedure declaration 1527 1528 Is_Completion := False; 1529 1530 -- Null procedures are always inlined, but generic formal subprograms 1531 -- which appear as such in the internal instance of formal packages, 1532 -- need no completion and are not marked Inline. 1533 1534 if Expander_Active 1535 and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration 1536 then 1537 Set_Corresponding_Body (N, Defining_Entity (Null_Body)); 1538 Set_Body_To_Inline (N, Null_Body); 1539 Set_Is_Inlined (Designator); 1540 end if; 1541 1542 else 1543 -- The null procedure is a completion. We unconditionally rewrite 1544 -- this as a null body (even if expansion is not active), because 1545 -- there are various error checks that are applied on this body 1546 -- when it is analyzed (e.g. correct aspect placement). 1547 1548 if Has_Completion (Prev) then 1549 Error_Msg_Sloc := Sloc (Prev); 1550 Error_Msg_NE ("duplicate body for & declared#", N, Prev); 1551 end if; 1552 1553 Check_Previous_Null_Procedure (N, Prev); 1554 1555 Is_Completion := True; 1556 Rewrite (N, Null_Body); 1557 Analyze (N); 1558 end if; 1559 1560 <<Leave>> 1561 Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP; 1562 Restore_Ghost_Region (Saved_GM, Saved_IGR); 1563 end Analyze_Null_Procedure; 1564 1565 ----------------------------- 1566 -- Analyze_Operator_Symbol -- 1567 ----------------------------- 1568 1569 -- An operator symbol such as "+" or "and" may appear in context where the 1570 -- literal denotes an entity name, such as "+"(x, y) or in context when it 1571 -- is just a string, as in (conjunction = "or"). In these cases the parser 1572 -- generates this node, and the semantics does the disambiguation. Other 1573 -- such case are actuals in an instantiation, the generic unit in an 1574 -- instantiation, and pragma arguments. 1575 1576 procedure Analyze_Operator_Symbol (N : Node_Id) is 1577 Par : constant Node_Id := Parent (N); 1578 1579 begin 1580 if (Nkind (Par) = N_Function_Call and then N = Name (Par)) 1581 or else Nkind (Par) = N_Function_Instantiation 1582 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par)) 1583 or else (Nkind (Par) = N_Pragma_Argument_Association 1584 and then not Is_Pragma_String_Literal (Par)) 1585 or else Nkind (Par) = N_Subprogram_Renaming_Declaration 1586 or else (Nkind (Par) = N_Attribute_Reference 1587 and then Attribute_Name (Par) /= Name_Value) 1588 then 1589 Find_Direct_Name (N); 1590 1591 else 1592 Change_Operator_Symbol_To_String_Literal (N); 1593 Analyze (N); 1594 end if; 1595 end Analyze_Operator_Symbol; 1596 1597 ----------------------------------- 1598 -- Analyze_Parameter_Association -- 1599 ----------------------------------- 1600 1601 procedure Analyze_Parameter_Association (N : Node_Id) is 1602 begin 1603 Analyze (Explicit_Actual_Parameter (N)); 1604 end Analyze_Parameter_Association; 1605 1606 ---------------------------- 1607 -- Analyze_Procedure_Call -- 1608 ---------------------------- 1609 1610 -- WARNING: This routine manages Ghost regions. Return statements must be 1611 -- replaced by gotos that jump to the end of the routine and restore the 1612 -- Ghost mode. 1613 1614 procedure Analyze_Procedure_Call (N : Node_Id) is 1615 procedure Analyze_Call_And_Resolve; 1616 -- Do Analyze and Resolve calls for procedure call. At the end, check 1617 -- for illegal order dependence. 1618 -- ??? where is the check for illegal order dependencies? 1619 1620 ------------------------------ 1621 -- Analyze_Call_And_Resolve -- 1622 ------------------------------ 1623 1624 procedure Analyze_Call_And_Resolve is 1625 begin 1626 if Nkind (N) = N_Procedure_Call_Statement then 1627 Analyze_Call (N); 1628 Resolve (N, Standard_Void_Type); 1629 else 1630 Analyze (N); 1631 end if; 1632 end Analyze_Call_And_Resolve; 1633 1634 -- Local variables 1635 1636 Actuals : constant List_Id := Parameter_Associations (N); 1637 Loc : constant Source_Ptr := Sloc (N); 1638 P : constant Node_Id := Name (N); 1639 1640 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 1641 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 1642 -- Save the Ghost-related attributes to restore on exit 1643 1644 Actual : Node_Id; 1645 New_N : Node_Id; 1646 1647 -- Start of processing for Analyze_Procedure_Call 1648 1649 begin 1650 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote 1651 -- a procedure call or an entry call. The prefix may denote an access 1652 -- to subprogram type, in which case an implicit dereference applies. 1653 -- If the prefix is an indexed component (without implicit dereference) 1654 -- then the construct denotes a call to a member of an entire family. 1655 -- If the prefix is a simple name, it may still denote a call to a 1656 -- parameterless member of an entry family. Resolution of these various 1657 -- interpretations is delicate. 1658 1659 -- Do not analyze machine code statements to avoid rejecting them in 1660 -- CodePeer mode. 1661 1662 if CodePeer_Mode and then Nkind (P) = N_Qualified_Expression then 1663 Set_Etype (P, Standard_Void_Type); 1664 else 1665 Analyze (P); 1666 end if; 1667 1668 -- If this is a call of the form Obj.Op, the call may have been analyzed 1669 -- and possibly rewritten into a block, in which case we are done. 1670 1671 if Analyzed (N) then 1672 return; 1673 1674 -- If there is an error analyzing the name (which may have been 1675 -- rewritten if the original call was in prefix notation) then error 1676 -- has been emitted already, mark node and return. 1677 1678 elsif Error_Posted (N) or else Etype (Name (N)) = Any_Type then 1679 Set_Etype (N, Any_Type); 1680 return; 1681 end if; 1682 1683 -- A procedure call is Ghost when its name denotes a Ghost procedure. 1684 -- Set the mode now to ensure that any nodes generated during analysis 1685 -- and expansion are properly marked as Ghost. 1686 1687 Mark_And_Set_Ghost_Procedure_Call (N); 1688 1689 -- Otherwise analyze the parameters 1690 1691 if Present (Actuals) then 1692 Actual := First (Actuals); 1693 1694 while Present (Actual) loop 1695 Analyze (Actual); 1696 Check_Parameterless_Call (Actual); 1697 Next (Actual); 1698 end loop; 1699 end if; 1700 1701 -- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls 1702 1703 if Nkind (P) = N_Attribute_Reference 1704 and then Nam_In (Attribute_Name (P), Name_Elab_Spec, 1705 Name_Elab_Body, 1706 Name_Elab_Subp_Body) 1707 then 1708 if Present (Actuals) then 1709 Error_Msg_N 1710 ("no parameters allowed for this call", First (Actuals)); 1711 goto Leave; 1712 end if; 1713 1714 Set_Etype (N, Standard_Void_Type); 1715 Set_Analyzed (N); 1716 1717 elsif Is_Entity_Name (P) 1718 and then Is_Record_Type (Etype (Entity (P))) 1719 and then Remote_AST_I_Dereference (P) 1720 then 1721 goto Leave; 1722 1723 elsif Is_Entity_Name (P) 1724 and then Ekind (Entity (P)) /= E_Entry_Family 1725 then 1726 if Is_Access_Type (Etype (P)) 1727 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type 1728 and then No (Actuals) 1729 and then Comes_From_Source (N) 1730 then 1731 Error_Msg_N ("missing explicit dereference in call", N); 1732 end if; 1733 1734 Analyze_Call_And_Resolve; 1735 1736 -- If the prefix is the simple name of an entry family, this is a 1737 -- parameterless call from within the task body itself. 1738 1739 elsif Is_Entity_Name (P) 1740 and then Nkind (P) = N_Identifier 1741 and then Ekind (Entity (P)) = E_Entry_Family 1742 and then Present (Actuals) 1743 and then No (Next (First (Actuals))) 1744 then 1745 -- Can be call to parameterless entry family. What appears to be the 1746 -- sole argument is in fact the entry index. Rewrite prefix of node 1747 -- accordingly. Source representation is unchanged by this 1748 -- transformation. 1749 1750 New_N := 1751 Make_Indexed_Component (Loc, 1752 Prefix => 1753 Make_Selected_Component (Loc, 1754 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc), 1755 Selector_Name => New_Occurrence_Of (Entity (P), Loc)), 1756 Expressions => Actuals); 1757 Set_Name (N, New_N); 1758 Set_Etype (New_N, Standard_Void_Type); 1759 Set_Parameter_Associations (N, No_List); 1760 Analyze_Call_And_Resolve; 1761 1762 elsif Nkind (P) = N_Explicit_Dereference then 1763 if Ekind (Etype (P)) = E_Subprogram_Type then 1764 Analyze_Call_And_Resolve; 1765 else 1766 Error_Msg_N ("expect access to procedure in call", P); 1767 end if; 1768 1769 -- The name can be a selected component or an indexed component that 1770 -- yields an access to subprogram. Such a prefix is legal if the call 1771 -- has parameter associations. 1772 1773 elsif Is_Access_Type (Etype (P)) 1774 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type 1775 then 1776 if Present (Actuals) then 1777 Analyze_Call_And_Resolve; 1778 else 1779 Error_Msg_N ("missing explicit dereference in call ", N); 1780 end if; 1781 1782 -- If not an access to subprogram, then the prefix must resolve to the 1783 -- name of an entry, entry family, or protected operation. 1784 1785 -- For the case of a simple entry call, P is a selected component where 1786 -- the prefix is the task and the selector name is the entry. A call to 1787 -- a protected procedure will have the same syntax. If the protected 1788 -- object contains overloaded operations, the entity may appear as a 1789 -- function, the context will select the operation whose type is Void. 1790 1791 elsif Nkind (P) = N_Selected_Component 1792 and then Ekind_In (Entity (Selector_Name (P)), E_Entry, 1793 E_Function, 1794 E_Procedure) 1795 then 1796 -- When front-end inlining is enabled, as with SPARK_Mode, a call 1797 -- in prefix notation may still be missing its controlling argument, 1798 -- so perform the transformation now. 1799 1800 if SPARK_Mode = On and then In_Inlined_Body then 1801 declare 1802 Subp : constant Entity_Id := Entity (Selector_Name (P)); 1803 Typ : constant Entity_Id := Etype (Prefix (P)); 1804 1805 begin 1806 if Is_Tagged_Type (Typ) 1807 and then Present (First_Formal (Subp)) 1808 and then (Etype (First_Formal (Subp)) = Typ 1809 or else 1810 Class_Wide_Type (Etype (First_Formal (Subp))) = Typ) 1811 and then Try_Object_Operation (P) 1812 then 1813 return; 1814 1815 else 1816 Analyze_Call_And_Resolve; 1817 end if; 1818 end; 1819 1820 else 1821 Analyze_Call_And_Resolve; 1822 end if; 1823 1824 elsif Nkind (P) = N_Selected_Component 1825 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family 1826 and then Present (Actuals) 1827 and then No (Next (First (Actuals))) 1828 then 1829 -- Can be call to parameterless entry family. What appears to be the 1830 -- sole argument is in fact the entry index. Rewrite prefix of node 1831 -- accordingly. Source representation is unchanged by this 1832 -- transformation. 1833 1834 New_N := 1835 Make_Indexed_Component (Loc, 1836 Prefix => New_Copy (P), 1837 Expressions => Actuals); 1838 Set_Name (N, New_N); 1839 Set_Etype (New_N, Standard_Void_Type); 1840 Set_Parameter_Associations (N, No_List); 1841 Analyze_Call_And_Resolve; 1842 1843 -- For the case of a reference to an element of an entry family, P is 1844 -- an indexed component whose prefix is a selected component (task and 1845 -- entry family), and whose index is the entry family index. 1846 1847 elsif Nkind (P) = N_Indexed_Component 1848 and then Nkind (Prefix (P)) = N_Selected_Component 1849 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family 1850 then 1851 Analyze_Call_And_Resolve; 1852 1853 -- If the prefix is the name of an entry family, it is a call from 1854 -- within the task body itself. 1855 1856 elsif Nkind (P) = N_Indexed_Component 1857 and then Nkind (Prefix (P)) = N_Identifier 1858 and then Ekind (Entity (Prefix (P))) = E_Entry_Family 1859 then 1860 New_N := 1861 Make_Selected_Component (Loc, 1862 Prefix => 1863 New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc), 1864 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc)); 1865 Rewrite (Prefix (P), New_N); 1866 Analyze (P); 1867 Analyze_Call_And_Resolve; 1868 1869 -- In Ada 2012. a qualified expression is a name, but it cannot be a 1870 -- procedure name, so the construct can only be a qualified expression. 1871 1872 elsif Nkind (P) = N_Qualified_Expression 1873 and then Ada_Version >= Ada_2012 1874 then 1875 Rewrite (N, Make_Code_Statement (Loc, Expression => P)); 1876 Analyze (N); 1877 1878 -- Anything else is an error 1879 1880 else 1881 Error_Msg_N ("invalid procedure or entry call", N); 1882 end if; 1883 1884 <<Leave>> 1885 Restore_Ghost_Region (Saved_GM, Saved_IGR); 1886 end Analyze_Procedure_Call; 1887 1888 ------------------------------ 1889 -- Analyze_Return_Statement -- 1890 ------------------------------ 1891 1892 procedure Analyze_Return_Statement (N : Node_Id) is 1893 pragma Assert (Nkind_In (N, N_Extended_Return_Statement, 1894 N_Simple_Return_Statement)); 1895 1896 Returns_Object : constant Boolean := 1897 Nkind (N) = N_Extended_Return_Statement 1898 or else 1899 (Nkind (N) = N_Simple_Return_Statement 1900 and then Present (Expression (N))); 1901 -- True if we're returning something; that is, "return <expression>;" 1902 -- or "return Result : T [:= ...]". False for "return;". Used for error 1903 -- checking: If Returns_Object is True, N should apply to a function 1904 -- body; otherwise N should apply to a procedure body, entry body, 1905 -- accept statement, or extended return statement. 1906 1907 function Find_What_It_Applies_To return Entity_Id; 1908 -- Find the entity representing the innermost enclosing body, accept 1909 -- statement, or extended return statement. If the result is a callable 1910 -- construct or extended return statement, then this will be the value 1911 -- of the Return_Applies_To attribute. Otherwise, the program is 1912 -- illegal. See RM-6.5(4/2). 1913 1914 ----------------------------- 1915 -- Find_What_It_Applies_To -- 1916 ----------------------------- 1917 1918 function Find_What_It_Applies_To return Entity_Id is 1919 Result : Entity_Id := Empty; 1920 1921 begin 1922 -- Loop outward through the Scope_Stack, skipping blocks, loops, 1923 -- and postconditions. 1924 1925 for J in reverse 0 .. Scope_Stack.Last loop 1926 Result := Scope_Stack.Table (J).Entity; 1927 exit when not Ekind_In (Result, E_Block, E_Loop) 1928 and then Chars (Result) /= Name_uPostconditions; 1929 end loop; 1930 1931 pragma Assert (Present (Result)); 1932 return Result; 1933 end Find_What_It_Applies_To; 1934 1935 -- Local declarations 1936 1937 Scope_Id : constant Entity_Id := Find_What_It_Applies_To; 1938 Kind : constant Entity_Kind := Ekind (Scope_Id); 1939 Loc : constant Source_Ptr := Sloc (N); 1940 Stm_Entity : constant Entity_Id := 1941 New_Internal_Entity 1942 (E_Return_Statement, Current_Scope, Loc, 'R'); 1943 1944 -- Start of processing for Analyze_Return_Statement 1945 1946 begin 1947 Set_Return_Statement_Entity (N, Stm_Entity); 1948 1949 Set_Etype (Stm_Entity, Standard_Void_Type); 1950 Set_Return_Applies_To (Stm_Entity, Scope_Id); 1951 1952 -- Place Return entity on scope stack, to simplify enforcement of 6.5 1953 -- (4/2): an inner return statement will apply to this extended return. 1954 1955 if Nkind (N) = N_Extended_Return_Statement then 1956 Push_Scope (Stm_Entity); 1957 end if; 1958 1959 -- Check that pragma No_Return is obeyed. Don't complain about the 1960 -- implicitly-generated return that is placed at the end. 1961 1962 if No_Return (Scope_Id) and then Comes_From_Source (N) then 1963 Error_Msg_N ("RETURN statement not allowed (No_Return)", N); 1964 end if; 1965 1966 -- Warn on any unassigned OUT parameters if in procedure 1967 1968 if Ekind (Scope_Id) = E_Procedure then 1969 Warn_On_Unassigned_Out_Parameter (N, Scope_Id); 1970 end if; 1971 1972 -- Check that functions return objects, and other things do not 1973 1974 if Kind = E_Function or else Kind = E_Generic_Function then 1975 if not Returns_Object then 1976 Error_Msg_N ("missing expression in return from function", N); 1977 end if; 1978 1979 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then 1980 if Returns_Object then 1981 Error_Msg_N ("procedure cannot return value (use function)", N); 1982 end if; 1983 1984 elsif Kind = E_Entry or else Kind = E_Entry_Family then 1985 if Returns_Object then 1986 if Is_Protected_Type (Scope (Scope_Id)) then 1987 Error_Msg_N ("entry body cannot return value", N); 1988 else 1989 Error_Msg_N ("accept statement cannot return value", N); 1990 end if; 1991 end if; 1992 1993 elsif Kind = E_Return_Statement then 1994 1995 -- We are nested within another return statement, which must be an 1996 -- extended_return_statement. 1997 1998 if Returns_Object then 1999 if Nkind (N) = N_Extended_Return_Statement then 2000 Error_Msg_N 2001 ("extended return statement cannot be nested (use `RETURN;`)", 2002 N); 2003 2004 -- Case of a simple return statement with a value inside extended 2005 -- return statement. 2006 2007 else 2008 Error_Msg_N 2009 ("return nested in extended return statement cannot return " 2010 & "value (use `RETURN;`)", N); 2011 end if; 2012 end if; 2013 2014 else 2015 Error_Msg_N ("illegal context for return statement", N); 2016 end if; 2017 2018 if Ekind_In (Kind, E_Function, E_Generic_Function) then 2019 Analyze_Function_Return (N); 2020 2021 elsif Ekind_In (Kind, E_Procedure, E_Generic_Procedure) then 2022 Set_Return_Present (Scope_Id); 2023 end if; 2024 2025 if Nkind (N) = N_Extended_Return_Statement then 2026 End_Scope; 2027 end if; 2028 2029 Kill_Current_Values (Last_Assignment_Only => True); 2030 Check_Unreachable_Code (N); 2031 2032 Analyze_Dimension (N); 2033 end Analyze_Return_Statement; 2034 2035 ------------------------------------- 2036 -- Analyze_Simple_Return_Statement -- 2037 ------------------------------------- 2038 2039 procedure Analyze_Simple_Return_Statement (N : Node_Id) is 2040 begin 2041 if Present (Expression (N)) then 2042 Mark_Coextensions (N, Expression (N)); 2043 end if; 2044 2045 Analyze_Return_Statement (N); 2046 end Analyze_Simple_Return_Statement; 2047 2048 ------------------------- 2049 -- Analyze_Return_Type -- 2050 ------------------------- 2051 2052 procedure Analyze_Return_Type (N : Node_Id) is 2053 Designator : constant Entity_Id := Defining_Entity (N); 2054 Typ : Entity_Id := Empty; 2055 2056 begin 2057 -- Normal case where result definition does not indicate an error 2058 2059 if Result_Definition (N) /= Error then 2060 if Nkind (Result_Definition (N)) = N_Access_Definition then 2061 Check_SPARK_05_Restriction 2062 ("access result is not allowed", Result_Definition (N)); 2063 2064 -- Ada 2005 (AI-254): Handle anonymous access to subprograms 2065 2066 declare 2067 AD : constant Node_Id := 2068 Access_To_Subprogram_Definition (Result_Definition (N)); 2069 begin 2070 if Present (AD) and then Protected_Present (AD) then 2071 Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N); 2072 else 2073 Typ := Access_Definition (N, Result_Definition (N)); 2074 end if; 2075 end; 2076 2077 Set_Parent (Typ, Result_Definition (N)); 2078 Set_Is_Local_Anonymous_Access (Typ); 2079 Set_Etype (Designator, Typ); 2080 2081 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion 2082 2083 Null_Exclusion_Static_Checks (N); 2084 2085 -- Subtype_Mark case 2086 2087 else 2088 Find_Type (Result_Definition (N)); 2089 Typ := Entity (Result_Definition (N)); 2090 Set_Etype (Designator, Typ); 2091 2092 -- Unconstrained array as result is not allowed in SPARK 2093 2094 if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then 2095 Check_SPARK_05_Restriction 2096 ("returning an unconstrained array is not allowed", 2097 Result_Definition (N)); 2098 end if; 2099 2100 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion 2101 2102 Null_Exclusion_Static_Checks (N); 2103 2104 -- If a null exclusion is imposed on the result type, then create 2105 -- a null-excluding itype (an access subtype) and use it as the 2106 -- function's Etype. Note that the null exclusion checks are done 2107 -- right before this, because they don't get applied to types that 2108 -- do not come from source. 2109 2110 if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then 2111 Set_Etype (Designator, 2112 Create_Null_Excluding_Itype 2113 (T => Typ, 2114 Related_Nod => N, 2115 Scope_Id => Scope (Current_Scope))); 2116 2117 -- The new subtype must be elaborated before use because 2118 -- it is visible outside of the function. However its base 2119 -- type may not be frozen yet, so the reference that will 2120 -- force elaboration must be attached to the freezing of 2121 -- the base type. 2122 2123 -- If the return specification appears on a proper body, 2124 -- the subtype will have been created already on the spec. 2125 2126 if Is_Frozen (Typ) then 2127 if Nkind (Parent (N)) = N_Subprogram_Body 2128 and then Nkind (Parent (Parent (N))) = N_Subunit 2129 then 2130 null; 2131 else 2132 Build_Itype_Reference (Etype (Designator), Parent (N)); 2133 end if; 2134 2135 else 2136 Ensure_Freeze_Node (Typ); 2137 2138 declare 2139 IR : constant Node_Id := Make_Itype_Reference (Sloc (N)); 2140 begin 2141 Set_Itype (IR, Etype (Designator)); 2142 Append_Freeze_Actions (Typ, New_List (IR)); 2143 end; 2144 end if; 2145 2146 else 2147 Set_Etype (Designator, Typ); 2148 end if; 2149 2150 if Ekind (Typ) = E_Incomplete_Type 2151 or else (Is_Class_Wide_Type (Typ) 2152 and then Ekind (Root_Type (Typ)) = E_Incomplete_Type) 2153 then 2154 -- AI05-0151: Tagged incomplete types are allowed in all formal 2155 -- parts. Untagged incomplete types are not allowed in bodies. 2156 -- As a consequence, limited views cannot appear in a basic 2157 -- declaration that is itself within a body, because there is 2158 -- no point at which the non-limited view will become visible. 2159 2160 if Ada_Version >= Ada_2012 then 2161 if From_Limited_With (Typ) and then In_Package_Body then 2162 Error_Msg_NE 2163 ("invalid use of incomplete type&", 2164 Result_Definition (N), Typ); 2165 2166 -- The return type of a subprogram body cannot be of a 2167 -- formal incomplete type. 2168 2169 elsif Is_Generic_Type (Typ) 2170 and then Nkind (Parent (N)) = N_Subprogram_Body 2171 then 2172 Error_Msg_N 2173 ("return type cannot be a formal incomplete type", 2174 Result_Definition (N)); 2175 2176 elsif Is_Class_Wide_Type (Typ) 2177 and then Is_Generic_Type (Root_Type (Typ)) 2178 and then Nkind (Parent (N)) = N_Subprogram_Body 2179 then 2180 Error_Msg_N 2181 ("return type cannot be a formal incomplete type", 2182 Result_Definition (N)); 2183 2184 elsif Is_Tagged_Type (Typ) then 2185 null; 2186 2187 -- Use is legal in a thunk generated for an operation 2188 -- inherited from a progenitor. 2189 2190 elsif Is_Thunk (Designator) 2191 and then Present (Non_Limited_View (Typ)) 2192 then 2193 null; 2194 2195 elsif Nkind (Parent (N)) = N_Subprogram_Body 2196 or else Nkind_In (Parent (Parent (N)), N_Accept_Statement, 2197 N_Entry_Body) 2198 then 2199 Error_Msg_NE 2200 ("invalid use of untagged incomplete type&", 2201 Designator, Typ); 2202 end if; 2203 2204 -- The type must be completed in the current package. This 2205 -- is checked at the end of the package declaration when 2206 -- Taft-amendment types are identified. If the return type 2207 -- is class-wide, there is no required check, the type can 2208 -- be a bona fide TAT. 2209 2210 if Ekind (Scope (Current_Scope)) = E_Package 2211 and then In_Private_Part (Scope (Current_Scope)) 2212 and then not Is_Class_Wide_Type (Typ) 2213 then 2214 Append_Elmt (Designator, Private_Dependents (Typ)); 2215 end if; 2216 2217 else 2218 Error_Msg_NE 2219 ("invalid use of incomplete type&", Designator, Typ); 2220 end if; 2221 end if; 2222 end if; 2223 2224 -- Case where result definition does indicate an error 2225 2226 else 2227 Set_Etype (Designator, Any_Type); 2228 end if; 2229 end Analyze_Return_Type; 2230 2231 ----------------------------- 2232 -- Analyze_Subprogram_Body -- 2233 ----------------------------- 2234 2235 procedure Analyze_Subprogram_Body (N : Node_Id) is 2236 Loc : constant Source_Ptr := Sloc (N); 2237 Body_Spec : constant Node_Id := Specification (N); 2238 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec); 2239 2240 begin 2241 if Debug_Flag_C then 2242 Write_Str ("==> subprogram body "); 2243 Write_Name (Chars (Body_Id)); 2244 Write_Str (" from "); 2245 Write_Location (Loc); 2246 Write_Eol; 2247 Indent; 2248 end if; 2249 2250 Trace_Scope (N, Body_Id, " Analyze subprogram: "); 2251 2252 -- The real work is split out into the helper, so it can do "return;" 2253 -- without skipping the debug output: 2254 2255 Analyze_Subprogram_Body_Helper (N); 2256 2257 if Debug_Flag_C then 2258 Outdent; 2259 Write_Str ("<== subprogram body "); 2260 Write_Name (Chars (Body_Id)); 2261 Write_Str (" from "); 2262 Write_Location (Loc); 2263 Write_Eol; 2264 end if; 2265 end Analyze_Subprogram_Body; 2266 2267 ------------------------------------ 2268 -- Analyze_Subprogram_Body_Helper -- 2269 ------------------------------------ 2270 2271 -- This procedure is called for regular subprogram bodies, generic bodies, 2272 -- and for subprogram stubs of both kinds. In the case of stubs, only the 2273 -- specification matters, and is used to create a proper declaration for 2274 -- the subprogram, or to perform conformance checks. 2275 2276 -- WARNING: This routine manages Ghost regions. Return statements must be 2277 -- replaced by gotos that jump to the end of the routine and restore the 2278 -- Ghost mode. 2279 2280 procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is 2281 Body_Spec : Node_Id := Specification (N); 2282 Body_Id : Entity_Id := Defining_Entity (Body_Spec); 2283 Loc : constant Source_Ptr := Sloc (N); 2284 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id); 2285 2286 Conformant : Boolean; 2287 Desig_View : Entity_Id := Empty; 2288 Exch_Views : Elist_Id := No_Elist; 2289 HSS : Node_Id; 2290 Mask_Types : Elist_Id := No_Elist; 2291 Prot_Typ : Entity_Id := Empty; 2292 Spec_Decl : Node_Id := Empty; 2293 Spec_Id : Entity_Id; 2294 2295 Last_Real_Spec_Entity : Entity_Id := Empty; 2296 -- When we analyze a separate spec, the entity chain ends up containing 2297 -- the formals, as well as any itypes generated during analysis of the 2298 -- default expressions for parameters, or the arguments of associated 2299 -- precondition/postcondition pragmas (which are analyzed in the context 2300 -- of the spec since they have visibility on formals). 2301 -- 2302 -- These entities belong with the spec and not the body. However we do 2303 -- the analysis of the body in the context of the spec (again to obtain 2304 -- visibility to the formals), and all the entities generated during 2305 -- this analysis end up also chained to the entity chain of the spec. 2306 -- But they really belong to the body, and there is circuitry to move 2307 -- them from the spec to the body. 2308 -- 2309 -- However, when we do this move, we don't want to move the real spec 2310 -- entities (first para above) to the body. The Last_Real_Spec_Entity 2311 -- variable points to the last real spec entity, so we only move those 2312 -- chained beyond that point. It is initialized to Empty to deal with 2313 -- the case where there is no separate spec. 2314 2315 function Body_Has_Contract return Boolean; 2316 -- Check whether unanalyzed body has an aspect or pragma that may 2317 -- generate a SPARK contract. 2318 2319 function Body_Has_SPARK_Mode_On return Boolean; 2320 -- Check whether SPARK_Mode On applies to the subprogram body, either 2321 -- because it is specified directly on the body, or because it is 2322 -- inherited from the enclosing subprogram or package. 2323 2324 procedure Build_Subprogram_Declaration; 2325 -- Create a matching subprogram declaration for subprogram body N 2326 2327 procedure Check_Anonymous_Return; 2328 -- Ada 2005: if a function returns an access type that denotes a task, 2329 -- or a type that contains tasks, we must create a master entity for 2330 -- the anonymous type, which typically will be used in an allocator 2331 -- in the body of the function. 2332 2333 procedure Check_Inline_Pragma (Spec : in out Node_Id); 2334 -- Look ahead to recognize a pragma that may appear after the body. 2335 -- If there is a previous spec, check that it appears in the same 2336 -- declarative part. If the pragma is Inline_Always, perform inlining 2337 -- unconditionally, otherwise only if Front_End_Inlining is requested. 2338 -- If the body acts as a spec, and inlining is required, we create a 2339 -- subprogram declaration for it, in order to attach the body to inline. 2340 -- If pragma does not appear after the body, check whether there is 2341 -- an inline pragma before any local declarations. 2342 2343 procedure Check_Missing_Return; 2344 -- Checks for a function with a no return statements, and also performs 2345 -- the warning checks implemented by Check_Returns. In formal mode, also 2346 -- verify that a function ends with a RETURN and that a procedure does 2347 -- not contain any RETURN. 2348 2349 function Disambiguate_Spec return Entity_Id; 2350 -- When a primitive is declared between the private view and the full 2351 -- view of a concurrent type which implements an interface, a special 2352 -- mechanism is used to find the corresponding spec of the primitive 2353 -- body. 2354 2355 function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id; 2356 -- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains 2357 -- incomplete types coming from a limited context and replace their 2358 -- limited views with the non-limited ones. Return the list of changes 2359 -- to be used to undo the transformation. 2360 2361 function Is_Private_Concurrent_Primitive 2362 (Subp_Id : Entity_Id) return Boolean; 2363 -- Determine whether subprogram Subp_Id is a primitive of a concurrent 2364 -- type that implements an interface and has a private view. 2365 2366 function Mask_Unfrozen_Types (Spec_Id : Entity_Id) return Elist_Id; 2367 -- N is the body generated for an expression function that is not a 2368 -- completion and Spec_Id the defining entity of its spec. Mark all 2369 -- the not-yet-frozen types referenced by the simple return statement 2370 -- of the function as formally frozen. 2371 2372 procedure Restore_Limited_Views (Restore_List : Elist_Id); 2373 -- Undo the transformation done by Exchange_Limited_Views. 2374 2375 procedure Set_Trivial_Subprogram (N : Node_Id); 2376 -- Sets the Is_Trivial_Subprogram flag in both spec and body of the 2377 -- subprogram whose body is being analyzed. N is the statement node 2378 -- causing the flag to be set, if the following statement is a return 2379 -- of an entity, we mark the entity as set in source to suppress any 2380 -- warning on the stylized use of function stubs with a dummy return. 2381 2382 procedure Unmask_Unfrozen_Types (Unmask_List : Elist_Id); 2383 -- Undo the transformation done by Mask_Unfrozen_Types 2384 2385 procedure Verify_Overriding_Indicator; 2386 -- If there was a previous spec, the entity has been entered in the 2387 -- current scope previously. If the body itself carries an overriding 2388 -- indicator, check that it is consistent with the known status of the 2389 -- entity. 2390 2391 ----------------------- 2392 -- Body_Has_Contract -- 2393 ----------------------- 2394 2395 function Body_Has_Contract return Boolean is 2396 Decls : constant List_Id := Declarations (N); 2397 Item : Node_Id; 2398 2399 begin 2400 -- Check for aspects that may generate a contract 2401 2402 if Present (Aspect_Specifications (N)) then 2403 Item := First (Aspect_Specifications (N)); 2404 while Present (Item) loop 2405 if Is_Subprogram_Contract_Annotation (Item) then 2406 return True; 2407 end if; 2408 2409 Next (Item); 2410 end loop; 2411 end if; 2412 2413 -- Check for pragmas that may generate a contract 2414 2415 if Present (Decls) then 2416 Item := First (Decls); 2417 while Present (Item) loop 2418 if Nkind (Item) = N_Pragma 2419 and then Is_Subprogram_Contract_Annotation (Item) 2420 then 2421 return True; 2422 end if; 2423 2424 Next (Item); 2425 end loop; 2426 end if; 2427 2428 return False; 2429 end Body_Has_Contract; 2430 2431 ---------------------------- 2432 -- Body_Has_SPARK_Mode_On -- 2433 ---------------------------- 2434 2435 function Body_Has_SPARK_Mode_On return Boolean is 2436 Decls : constant List_Id := Declarations (N); 2437 Item : Node_Id; 2438 2439 begin 2440 -- Check for SPARK_Mode aspect 2441 2442 if Present (Aspect_Specifications (N)) then 2443 Item := First (Aspect_Specifications (N)); 2444 while Present (Item) loop 2445 if Get_Aspect_Id (Item) = Aspect_SPARK_Mode then 2446 return Get_SPARK_Mode_From_Annotation (Item) = On; 2447 end if; 2448 2449 Next (Item); 2450 end loop; 2451 end if; 2452 2453 -- Check for SPARK_Mode pragma 2454 2455 if Present (Decls) then 2456 Item := First (Decls); 2457 while Present (Item) loop 2458 2459 -- Pragmas that apply to a subprogram body are usually grouped 2460 -- together. Look for a potential pragma SPARK_Mode among them. 2461 2462 if Nkind (Item) = N_Pragma then 2463 if Get_Pragma_Id (Item) = Pragma_SPARK_Mode then 2464 return Get_SPARK_Mode_From_Annotation (Item) = On; 2465 end if; 2466 2467 -- Otherwise the first non-pragma declarative item terminates 2468 -- the region where pragma SPARK_Mode may appear. 2469 2470 else 2471 exit; 2472 end if; 2473 2474 Next (Item); 2475 end loop; 2476 end if; 2477 2478 -- Otherwise, the applicable SPARK_Mode is inherited from the 2479 -- enclosing subprogram or package. 2480 2481 return SPARK_Mode = On; 2482 end Body_Has_SPARK_Mode_On; 2483 2484 ---------------------------------- 2485 -- Build_Subprogram_Declaration -- 2486 ---------------------------------- 2487 2488 procedure Build_Subprogram_Declaration is 2489 procedure Move_Pragmas (From : Node_Id; To : Node_Id); 2490 -- Relocate certain categorization pragmas from the declarative list 2491 -- of subprogram body From and insert them after node To. The pragmas 2492 -- in question are: 2493 -- Ghost 2494 -- Volatile_Function 2495 -- Also copy pragma SPARK_Mode if present in the declarative list 2496 -- of subprogram body From and insert it after node To. This pragma 2497 -- should not be moved, as it applies to the body too. 2498 2499 ------------------ 2500 -- Move_Pragmas -- 2501 ------------------ 2502 2503 procedure Move_Pragmas (From : Node_Id; To : Node_Id) is 2504 Decl : Node_Id; 2505 Next_Decl : Node_Id; 2506 2507 begin 2508 pragma Assert (Nkind (From) = N_Subprogram_Body); 2509 2510 -- The destination node must be part of a list, as the pragmas are 2511 -- inserted after it. 2512 2513 pragma Assert (Is_List_Member (To)); 2514 2515 -- Inspect the declarations of the subprogram body looking for 2516 -- specific pragmas. 2517 2518 Decl := First (Declarations (N)); 2519 while Present (Decl) loop 2520 Next_Decl := Next (Decl); 2521 2522 if Nkind (Decl) = N_Pragma then 2523 if Pragma_Name_Unmapped (Decl) = Name_SPARK_Mode then 2524 Insert_After (To, New_Copy_Tree (Decl)); 2525 2526 elsif Nam_In (Pragma_Name_Unmapped (Decl), 2527 Name_Ghost, 2528 Name_Volatile_Function) 2529 then 2530 Remove (Decl); 2531 Insert_After (To, Decl); 2532 end if; 2533 end if; 2534 2535 Decl := Next_Decl; 2536 end loop; 2537 end Move_Pragmas; 2538 2539 -- Local variables 2540 2541 Decl : Node_Id; 2542 Subp_Decl : Node_Id; 2543 2544 -- Start of processing for Build_Subprogram_Declaration 2545 2546 begin 2547 -- Create a matching subprogram spec using the profile of the body. 2548 -- The structure of the tree is identical, but has new entities for 2549 -- the defining unit name and formal parameters. 2550 2551 Subp_Decl := 2552 Make_Subprogram_Declaration (Loc, 2553 Specification => Copy_Subprogram_Spec (Body_Spec)); 2554 Set_Comes_From_Source (Subp_Decl, True); 2555 2556 -- Also mark parameters as coming from source 2557 2558 if Present (Parameter_Specifications (Specification (Subp_Decl))) then 2559 declare 2560 Form : Entity_Id; 2561 begin 2562 Form := 2563 First (Parameter_Specifications (Specification (Subp_Decl))); 2564 2565 while Present (Form) loop 2566 Set_Comes_From_Source (Defining_Identifier (Form), True); 2567 Next (Form); 2568 end loop; 2569 end; 2570 end if; 2571 2572 -- Relocate the aspects and relevant pragmas from the subprogram body 2573 -- to the generated spec because it acts as the initial declaration. 2574 2575 Insert_Before (N, Subp_Decl); 2576 Move_Aspects (N, To => Subp_Decl); 2577 Move_Pragmas (N, To => Subp_Decl); 2578 2579 -- Ensure that the generated corresponding spec and original body 2580 -- share the same SPARK_Mode pragma or aspect. As a result, both have 2581 -- the same SPARK_Mode attributes, and the global SPARK_Mode value is 2582 -- correctly set for local subprograms. 2583 2584 Copy_SPARK_Mode_Aspect (Subp_Decl, To => N); 2585 2586 Analyze (Subp_Decl); 2587 2588 -- Propagate the attributes Rewritten_For_C and Corresponding_Proc to 2589 -- the body since the expander may generate calls using that entity. 2590 -- Required to ensure that Expand_Call rewrites calls to this 2591 -- function by calls to the built procedure. 2592 2593 if Modify_Tree_For_C 2594 and then Nkind (Body_Spec) = N_Function_Specification 2595 and then 2596 Rewritten_For_C (Defining_Entity (Specification (Subp_Decl))) 2597 then 2598 Set_Rewritten_For_C (Defining_Entity (Body_Spec)); 2599 Set_Corresponding_Procedure (Defining_Entity (Body_Spec), 2600 Corresponding_Procedure 2601 (Defining_Entity (Specification (Subp_Decl)))); 2602 end if; 2603 2604 -- Analyze any relocated source pragmas or pragmas created for aspect 2605 -- specifications. 2606 2607 Decl := Next (Subp_Decl); 2608 while Present (Decl) loop 2609 2610 -- Stop the search for pragmas once the body has been reached as 2611 -- this terminates the region where pragmas may appear. 2612 2613 if Decl = N then 2614 exit; 2615 2616 elsif Nkind (Decl) = N_Pragma then 2617 Analyze (Decl); 2618 end if; 2619 2620 Next (Decl); 2621 end loop; 2622 2623 Spec_Id := Defining_Entity (Subp_Decl); 2624 Set_Corresponding_Spec (N, Spec_Id); 2625 2626 -- Mark the generated spec as a source construct to ensure that all 2627 -- calls to it are properly registered in ALI files for GNATprove. 2628 2629 Set_Comes_From_Source (Spec_Id, True); 2630 2631 -- Ensure that the specs of the subprogram declaration and its body 2632 -- are identical, otherwise they will appear non-conformant due to 2633 -- rewritings in the default values of formal parameters. 2634 2635 Body_Spec := Copy_Subprogram_Spec (Body_Spec); 2636 Set_Specification (N, Body_Spec); 2637 Body_Id := Analyze_Subprogram_Specification (Body_Spec); 2638 end Build_Subprogram_Declaration; 2639 2640 ---------------------------- 2641 -- Check_Anonymous_Return -- 2642 ---------------------------- 2643 2644 procedure Check_Anonymous_Return is 2645 Decl : Node_Id; 2646 Par : Node_Id; 2647 Scop : Entity_Id; 2648 2649 begin 2650 if Present (Spec_Id) then 2651 Scop := Spec_Id; 2652 else 2653 Scop := Body_Id; 2654 end if; 2655 2656 if Ekind (Scop) = E_Function 2657 and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type 2658 and then not Is_Thunk (Scop) 2659 2660 -- Skip internally built functions which handle the case of 2661 -- a null access (see Expand_Interface_Conversion) 2662 2663 and then not (Is_Interface (Designated_Type (Etype (Scop))) 2664 and then not Comes_From_Source (Parent (Scop))) 2665 2666 and then (Has_Task (Designated_Type (Etype (Scop))) 2667 or else 2668 (Is_Class_Wide_Type (Designated_Type (Etype (Scop))) 2669 and then 2670 Is_Limited_Record (Designated_Type (Etype (Scop))))) 2671 and then Expander_Active 2672 2673 -- Avoid cases with no tasking support 2674 2675 and then RTE_Available (RE_Current_Master) 2676 and then not Restriction_Active (No_Task_Hierarchy) 2677 then 2678 Decl := 2679 Make_Object_Declaration (Loc, 2680 Defining_Identifier => 2681 Make_Defining_Identifier (Loc, Name_uMaster), 2682 Constant_Present => True, 2683 Object_Definition => 2684 New_Occurrence_Of (RTE (RE_Master_Id), Loc), 2685 Expression => 2686 Make_Explicit_Dereference (Loc, 2687 New_Occurrence_Of (RTE (RE_Current_Master), Loc))); 2688 2689 if Present (Declarations (N)) then 2690 Prepend (Decl, Declarations (N)); 2691 else 2692 Set_Declarations (N, New_List (Decl)); 2693 end if; 2694 2695 Set_Master_Id (Etype (Scop), Defining_Identifier (Decl)); 2696 Set_Has_Master_Entity (Scop); 2697 2698 -- Now mark the containing scope as a task master 2699 2700 Par := N; 2701 while Nkind (Par) /= N_Compilation_Unit loop 2702 Par := Parent (Par); 2703 pragma Assert (Present (Par)); 2704 2705 -- If we fall off the top, we are at the outer level, and 2706 -- the environment task is our effective master, so nothing 2707 -- to mark. 2708 2709 if Nkind_In 2710 (Par, N_Task_Body, N_Block_Statement, N_Subprogram_Body) 2711 then 2712 Set_Is_Task_Master (Par, True); 2713 exit; 2714 end if; 2715 end loop; 2716 end if; 2717 end Check_Anonymous_Return; 2718 2719 ------------------------- 2720 -- Check_Inline_Pragma -- 2721 ------------------------- 2722 2723 procedure Check_Inline_Pragma (Spec : in out Node_Id) is 2724 Prag : Node_Id; 2725 Plist : List_Id; 2726 2727 function Is_Inline_Pragma (N : Node_Id) return Boolean; 2728 -- True when N is a pragma Inline or Inline_Always that applies 2729 -- to this subprogram. 2730 2731 ----------------------- 2732 -- Is_Inline_Pragma -- 2733 ----------------------- 2734 2735 function Is_Inline_Pragma (N : Node_Id) return Boolean is 2736 begin 2737 if Nkind (N) = N_Pragma 2738 and then 2739 (Pragma_Name_Unmapped (N) = Name_Inline_Always 2740 or else (Pragma_Name_Unmapped (N) = Name_Inline 2741 and then 2742 (Front_End_Inlining or else Optimization_Level > 0))) 2743 and then Present (Pragma_Argument_Associations (N)) 2744 then 2745 declare 2746 Pragma_Arg : Node_Id := 2747 Expression (First (Pragma_Argument_Associations (N))); 2748 begin 2749 if Nkind (Pragma_Arg) = N_Selected_Component then 2750 Pragma_Arg := Selector_Name (Pragma_Arg); 2751 end if; 2752 2753 return Chars (Pragma_Arg) = Chars (Body_Id); 2754 end; 2755 2756 else 2757 return False; 2758 end if; 2759 end Is_Inline_Pragma; 2760 2761 -- Start of processing for Check_Inline_Pragma 2762 2763 begin 2764 if not Expander_Active then 2765 return; 2766 end if; 2767 2768 if Is_List_Member (N) 2769 and then Present (Next (N)) 2770 and then Is_Inline_Pragma (Next (N)) 2771 then 2772 Prag := Next (N); 2773 2774 elsif Nkind (N) /= N_Subprogram_Body_Stub 2775 and then Present (Declarations (N)) 2776 and then Is_Inline_Pragma (First (Declarations (N))) 2777 then 2778 Prag := First (Declarations (N)); 2779 2780 else 2781 Prag := Empty; 2782 end if; 2783 2784 if Present (Prag) then 2785 if Present (Spec_Id) then 2786 if Is_List_Member (N) 2787 and then Is_List_Member (Unit_Declaration_Node (Spec_Id)) 2788 and then In_Same_List (N, Unit_Declaration_Node (Spec_Id)) 2789 then 2790 Analyze (Prag); 2791 end if; 2792 2793 else 2794 -- Create a subprogram declaration, to make treatment uniform. 2795 -- Make the sloc of the subprogram name that of the entity in 2796 -- the body, so that style checks find identical strings. 2797 2798 declare 2799 Subp : constant Entity_Id := 2800 Make_Defining_Identifier 2801 (Sloc (Body_Id), Chars (Body_Id)); 2802 Decl : constant Node_Id := 2803 Make_Subprogram_Declaration (Loc, 2804 Specification => 2805 New_Copy_Tree (Specification (N))); 2806 2807 begin 2808 -- Link the body and the generated spec 2809 2810 Set_Corresponding_Body (Decl, Body_Id); 2811 Set_Corresponding_Spec (N, Subp); 2812 2813 Set_Defining_Unit_Name (Specification (Decl), Subp); 2814 2815 -- To ensure proper coverage when body is inlined, indicate 2816 -- whether the subprogram comes from source. 2817 2818 Set_Comes_From_Source (Subp, Comes_From_Source (N)); 2819 2820 if Present (First_Formal (Body_Id)) then 2821 Plist := Copy_Parameter_List (Body_Id); 2822 Set_Parameter_Specifications 2823 (Specification (Decl), Plist); 2824 end if; 2825 2826 -- Move aspects to the new spec 2827 2828 if Has_Aspects (N) then 2829 Move_Aspects (N, To => Decl); 2830 end if; 2831 2832 Insert_Before (N, Decl); 2833 Analyze (Decl); 2834 Analyze (Prag); 2835 Set_Has_Pragma_Inline (Subp); 2836 2837 if Pragma_Name (Prag) = Name_Inline_Always then 2838 Set_Is_Inlined (Subp); 2839 Set_Has_Pragma_Inline_Always (Subp); 2840 end if; 2841 2842 -- Prior to copying the subprogram body to create a template 2843 -- for it for subsequent inlining, remove the pragma from 2844 -- the current body so that the copy that will produce the 2845 -- new body will start from a completely unanalyzed tree. 2846 2847 if Nkind (Parent (Prag)) = N_Subprogram_Body then 2848 Rewrite (Prag, Make_Null_Statement (Sloc (Prag))); 2849 end if; 2850 2851 Spec := Subp; 2852 end; 2853 end if; 2854 end if; 2855 end Check_Inline_Pragma; 2856 2857 -------------------------- 2858 -- Check_Missing_Return -- 2859 -------------------------- 2860 2861 procedure Check_Missing_Return is 2862 Id : Entity_Id; 2863 Missing_Ret : Boolean; 2864 2865 begin 2866 if Nkind (Body_Spec) = N_Function_Specification then 2867 if Present (Spec_Id) then 2868 Id := Spec_Id; 2869 else 2870 Id := Body_Id; 2871 end if; 2872 2873 if Return_Present (Id) then 2874 Check_Returns (HSS, 'F', Missing_Ret); 2875 2876 if Missing_Ret then 2877 Set_Has_Missing_Return (Id); 2878 end if; 2879 2880 -- Within a premature instantiation of a package with no body, we 2881 -- build completions of the functions therein, with a Raise 2882 -- statement. No point in complaining about a missing return in 2883 -- this case. 2884 2885 elsif Ekind (Id) = E_Function 2886 and then In_Instance 2887 and then Present (Statements (HSS)) 2888 and then Nkind (First (Statements (HSS))) = N_Raise_Program_Error 2889 then 2890 null; 2891 2892 elsif Is_Generic_Subprogram (Id) 2893 or else not Is_Machine_Code_Subprogram (Id) 2894 then 2895 Error_Msg_N ("missing RETURN statement in function body", N); 2896 end if; 2897 2898 -- If procedure with No_Return, check returns 2899 2900 elsif Nkind (Body_Spec) = N_Procedure_Specification then 2901 if Present (Spec_Id) then 2902 Id := Spec_Id; 2903 else 2904 Id := Body_Id; 2905 end if; 2906 2907 if No_Return (Id) then 2908 Check_Returns (HSS, 'P', Missing_Ret, Id); 2909 end if; 2910 end if; 2911 2912 -- Special checks in SPARK mode 2913 2914 if Nkind (Body_Spec) = N_Function_Specification then 2915 2916 -- In SPARK mode, last statement of a function should be a return 2917 2918 declare 2919 Stat : constant Node_Id := Last_Source_Statement (HSS); 2920 begin 2921 if Present (Stat) 2922 and then not Nkind_In (Stat, N_Simple_Return_Statement, 2923 N_Extended_Return_Statement) 2924 then 2925 Check_SPARK_05_Restriction 2926 ("last statement in function should be RETURN", Stat); 2927 end if; 2928 end; 2929 2930 -- In SPARK mode, verify that a procedure has no return 2931 2932 elsif Nkind (Body_Spec) = N_Procedure_Specification then 2933 if Present (Spec_Id) then 2934 Id := Spec_Id; 2935 else 2936 Id := Body_Id; 2937 end if; 2938 2939 -- Would be nice to point to return statement here, can we 2940 -- borrow the Check_Returns procedure here ??? 2941 2942 if Return_Present (Id) then 2943 Check_SPARK_05_Restriction 2944 ("procedure should not have RETURN", N); 2945 end if; 2946 end if; 2947 end Check_Missing_Return; 2948 2949 ----------------------- 2950 -- Disambiguate_Spec -- 2951 ----------------------- 2952 2953 function Disambiguate_Spec return Entity_Id is 2954 Priv_Spec : Entity_Id; 2955 Spec_N : Entity_Id; 2956 2957 procedure Replace_Types (To_Corresponding : Boolean); 2958 -- Depending on the flag, replace the type of formal parameters of 2959 -- Body_Id if it is a concurrent type implementing interfaces with 2960 -- the corresponding record type or the other way around. 2961 2962 procedure Replace_Types (To_Corresponding : Boolean) is 2963 Formal : Entity_Id; 2964 Formal_Typ : Entity_Id; 2965 2966 begin 2967 Formal := First_Formal (Body_Id); 2968 while Present (Formal) loop 2969 Formal_Typ := Etype (Formal); 2970 2971 if Is_Class_Wide_Type (Formal_Typ) then 2972 Formal_Typ := Root_Type (Formal_Typ); 2973 end if; 2974 2975 -- From concurrent type to corresponding record 2976 2977 if To_Corresponding then 2978 if Is_Concurrent_Type (Formal_Typ) 2979 and then Present (Corresponding_Record_Type (Formal_Typ)) 2980 and then 2981 Present (Interfaces 2982 (Corresponding_Record_Type (Formal_Typ))) 2983 then 2984 Set_Etype (Formal, 2985 Corresponding_Record_Type (Formal_Typ)); 2986 end if; 2987 2988 -- From corresponding record to concurrent type 2989 2990 else 2991 if Is_Concurrent_Record_Type (Formal_Typ) 2992 and then Present (Interfaces (Formal_Typ)) 2993 then 2994 Set_Etype (Formal, 2995 Corresponding_Concurrent_Type (Formal_Typ)); 2996 end if; 2997 end if; 2998 2999 Next_Formal (Formal); 3000 end loop; 3001 end Replace_Types; 3002 3003 -- Start of processing for Disambiguate_Spec 3004 3005 begin 3006 -- Try to retrieve the specification of the body as is. All error 3007 -- messages are suppressed because the body may not have a spec in 3008 -- its current state. 3009 3010 Spec_N := Find_Corresponding_Spec (N, False); 3011 3012 -- It is possible that this is the body of a primitive declared 3013 -- between a private and a full view of a concurrent type. The 3014 -- controlling parameter of the spec carries the concurrent type, 3015 -- not the corresponding record type as transformed by Analyze_ 3016 -- Subprogram_Specification. In such cases, we undo the change 3017 -- made by the analysis of the specification and try to find the 3018 -- spec again. 3019 3020 -- Note that wrappers already have their corresponding specs and 3021 -- bodies set during their creation, so if the candidate spec is 3022 -- a wrapper, then we definitely need to swap all types to their 3023 -- original concurrent status. 3024 3025 if No (Spec_N) 3026 or else Is_Primitive_Wrapper (Spec_N) 3027 then 3028 -- Restore all references of corresponding record types to the 3029 -- original concurrent types. 3030 3031 Replace_Types (To_Corresponding => False); 3032 Priv_Spec := Find_Corresponding_Spec (N, False); 3033 3034 -- The current body truly belongs to a primitive declared between 3035 -- a private and a full view. We leave the modified body as is, 3036 -- and return the true spec. 3037 3038 if Present (Priv_Spec) 3039 and then Is_Private_Primitive (Priv_Spec) 3040 then 3041 return Priv_Spec; 3042 end if; 3043 3044 -- In case that this is some sort of error, restore the original 3045 -- state of the body. 3046 3047 Replace_Types (To_Corresponding => True); 3048 end if; 3049 3050 return Spec_N; 3051 end Disambiguate_Spec; 3052 3053 ---------------------------- 3054 -- Exchange_Limited_Views -- 3055 ---------------------------- 3056 3057 function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id is 3058 Result : Elist_Id := No_Elist; 3059 3060 procedure Detect_And_Exchange (Id : Entity_Id); 3061 -- Determine whether Id's type denotes an incomplete type associated 3062 -- with a limited with clause and exchange the limited view with the 3063 -- non-limited one when available. Note that the non-limited view 3064 -- may exist because of a with_clause in another unit in the context, 3065 -- but cannot be used because the current view of the enclosing unit 3066 -- is still a limited view. 3067 3068 ------------------------- 3069 -- Detect_And_Exchange -- 3070 ------------------------- 3071 3072 procedure Detect_And_Exchange (Id : Entity_Id) is 3073 Typ : constant Entity_Id := Etype (Id); 3074 begin 3075 if From_Limited_With (Typ) 3076 and then Has_Non_Limited_View (Typ) 3077 and then not From_Limited_With (Scope (Typ)) 3078 then 3079 if No (Result) then 3080 Result := New_Elmt_List; 3081 end if; 3082 3083 Prepend_Elmt (Typ, Result); 3084 Prepend_Elmt (Id, Result); 3085 Set_Etype (Id, Non_Limited_View (Typ)); 3086 end if; 3087 end Detect_And_Exchange; 3088 3089 -- Local variables 3090 3091 Formal : Entity_Id; 3092 3093 -- Start of processing for Exchange_Limited_Views 3094 3095 begin 3096 -- Do not process subprogram bodies as they already use the non- 3097 -- limited view of types. 3098 3099 if not Ekind_In (Subp_Id, E_Function, E_Procedure) then 3100 return No_Elist; 3101 end if; 3102 3103 -- Examine all formals and swap views when applicable 3104 3105 Formal := First_Formal (Subp_Id); 3106 while Present (Formal) loop 3107 Detect_And_Exchange (Formal); 3108 3109 Next_Formal (Formal); 3110 end loop; 3111 3112 -- Process the return type of a function 3113 3114 if Ekind (Subp_Id) = E_Function then 3115 Detect_And_Exchange (Subp_Id); 3116 end if; 3117 3118 return Result; 3119 end Exchange_Limited_Views; 3120 3121 ------------------------------------- 3122 -- Is_Private_Concurrent_Primitive -- 3123 ------------------------------------- 3124 3125 function Is_Private_Concurrent_Primitive 3126 (Subp_Id : Entity_Id) return Boolean 3127 is 3128 Formal_Typ : Entity_Id; 3129 3130 begin 3131 if Present (First_Formal (Subp_Id)) then 3132 Formal_Typ := Etype (First_Formal (Subp_Id)); 3133 3134 if Is_Concurrent_Record_Type (Formal_Typ) then 3135 if Is_Class_Wide_Type (Formal_Typ) then 3136 Formal_Typ := Root_Type (Formal_Typ); 3137 end if; 3138 3139 Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ); 3140 end if; 3141 3142 -- The type of the first formal is a concurrent tagged type with 3143 -- a private view. 3144 3145 return 3146 Is_Concurrent_Type (Formal_Typ) 3147 and then Is_Tagged_Type (Formal_Typ) 3148 and then Has_Private_Declaration (Formal_Typ); 3149 end if; 3150 3151 return False; 3152 end Is_Private_Concurrent_Primitive; 3153 3154 ------------------------- 3155 -- Mask_Unfrozen_Types -- 3156 ------------------------- 3157 3158 function Mask_Unfrozen_Types (Spec_Id : Entity_Id) return Elist_Id is 3159 Result : Elist_Id := No_Elist; 3160 3161 function Mask_Type_Refs (Node : Node_Id) return Traverse_Result; 3162 -- Mask all types referenced in the subtree rooted at Node 3163 3164 -------------------- 3165 -- Mask_Type_Refs -- 3166 -------------------- 3167 3168 function Mask_Type_Refs (Node : Node_Id) return Traverse_Result is 3169 procedure Mask_Type (Typ : Entity_Id); 3170 -- ??? what does this do? 3171 3172 --------------- 3173 -- Mask_Type -- 3174 --------------- 3175 3176 procedure Mask_Type (Typ : Entity_Id) is 3177 begin 3178 -- Skip Itypes created by the preanalysis 3179 3180 if Is_Itype (Typ) 3181 and then Scope_Within_Or_Same (Scope (Typ), Spec_Id) 3182 then 3183 return; 3184 end if; 3185 3186 if not Is_Frozen (Typ) then 3187 if Scope (Typ) /= Current_Scope then 3188 Set_Is_Frozen (Typ); 3189 Append_New_Elmt (Typ, Result); 3190 else 3191 Freeze_Before (N, Typ); 3192 end if; 3193 end if; 3194 end Mask_Type; 3195 3196 -- Start of processing for Mask_Type_Refs 3197 3198 begin 3199 if Is_Entity_Name (Node) and then Present (Entity (Node)) then 3200 Mask_Type (Etype (Entity (Node))); 3201 3202 if Ekind_In (Entity (Node), E_Component, E_Discriminant) then 3203 Mask_Type (Scope (Entity (Node))); 3204 end if; 3205 3206 elsif Nkind_In (Node, N_Aggregate, N_Null, N_Type_Conversion) 3207 and then Present (Etype (Node)) 3208 then 3209 Mask_Type (Etype (Node)); 3210 end if; 3211 3212 return OK; 3213 end Mask_Type_Refs; 3214 3215 procedure Mask_References is new Traverse_Proc (Mask_Type_Refs); 3216 3217 -- Local variables 3218 3219 Return_Stmt : constant Node_Id := 3220 First (Statements (Handled_Statement_Sequence (N))); 3221 3222 -- Start of processing for Mask_Unfrozen_Types 3223 3224 begin 3225 pragma Assert (Nkind (Return_Stmt) = N_Simple_Return_Statement); 3226 3227 Mask_References (Expression (Return_Stmt)); 3228 3229 return Result; 3230 end Mask_Unfrozen_Types; 3231 3232 --------------------------- 3233 -- Restore_Limited_Views -- 3234 --------------------------- 3235 3236 procedure Restore_Limited_Views (Restore_List : Elist_Id) is 3237 Elmt : Elmt_Id := First_Elmt (Restore_List); 3238 Id : Entity_Id; 3239 3240 begin 3241 while Present (Elmt) loop 3242 Id := Node (Elmt); 3243 Next_Elmt (Elmt); 3244 Set_Etype (Id, Node (Elmt)); 3245 Next_Elmt (Elmt); 3246 end loop; 3247 end Restore_Limited_Views; 3248 3249 ---------------------------- 3250 -- Set_Trivial_Subprogram -- 3251 ---------------------------- 3252 3253 procedure Set_Trivial_Subprogram (N : Node_Id) is 3254 Nxt : constant Node_Id := Next (N); 3255 3256 begin 3257 Set_Is_Trivial_Subprogram (Body_Id); 3258 3259 if Present (Spec_Id) then 3260 Set_Is_Trivial_Subprogram (Spec_Id); 3261 end if; 3262 3263 if Present (Nxt) 3264 and then Nkind (Nxt) = N_Simple_Return_Statement 3265 and then No (Next (Nxt)) 3266 and then Present (Expression (Nxt)) 3267 and then Is_Entity_Name (Expression (Nxt)) 3268 then 3269 Set_Never_Set_In_Source (Entity (Expression (Nxt)), False); 3270 end if; 3271 end Set_Trivial_Subprogram; 3272 3273 --------------------------- 3274 -- Unmask_Unfrozen_Types -- 3275 --------------------------- 3276 3277 procedure Unmask_Unfrozen_Types (Unmask_List : Elist_Id) is 3278 Elmt : Elmt_Id := First_Elmt (Unmask_List); 3279 3280 begin 3281 while Present (Elmt) loop 3282 Set_Is_Frozen (Node (Elmt), False); 3283 Next_Elmt (Elmt); 3284 end loop; 3285 end Unmask_Unfrozen_Types; 3286 3287 --------------------------------- 3288 -- Verify_Overriding_Indicator -- 3289 --------------------------------- 3290 3291 procedure Verify_Overriding_Indicator is 3292 begin 3293 if Must_Override (Body_Spec) then 3294 if Nkind (Spec_Id) = N_Defining_Operator_Symbol 3295 and then Operator_Matches_Spec (Spec_Id, Spec_Id) 3296 then 3297 null; 3298 3299 elsif not Present (Overridden_Operation (Spec_Id)) then 3300 Error_Msg_NE 3301 ("subprogram& is not overriding", Body_Spec, Spec_Id); 3302 3303 -- Overriding indicators aren't allowed for protected subprogram 3304 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change 3305 -- this to a warning if -gnatd.E is enabled. 3306 3307 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then 3308 Error_Msg_Warn := Error_To_Warning; 3309 Error_Msg_N 3310 ("<<overriding indicator not allowed for protected " 3311 & "subprogram body", Body_Spec); 3312 end if; 3313 3314 elsif Must_Not_Override (Body_Spec) then 3315 if Present (Overridden_Operation (Spec_Id)) then 3316 Error_Msg_NE 3317 ("subprogram& overrides inherited operation", 3318 Body_Spec, Spec_Id); 3319 3320 elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol 3321 and then Operator_Matches_Spec (Spec_Id, Spec_Id) 3322 then 3323 Error_Msg_NE 3324 ("subprogram& overrides predefined operator ", 3325 Body_Spec, Spec_Id); 3326 3327 -- Overriding indicators aren't allowed for protected subprogram 3328 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change 3329 -- this to a warning if -gnatd.E is enabled. 3330 3331 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then 3332 Error_Msg_Warn := Error_To_Warning; 3333 3334 Error_Msg_N 3335 ("<<overriding indicator not allowed " 3336 & "for protected subprogram body", Body_Spec); 3337 3338 -- If this is not a primitive operation, then the overriding 3339 -- indicator is altogether illegal. 3340 3341 elsif not Is_Primitive (Spec_Id) then 3342 Error_Msg_N 3343 ("overriding indicator only allowed " 3344 & "if subprogram is primitive", Body_Spec); 3345 end if; 3346 3347 -- If checking the style rule and the operation overrides, then 3348 -- issue a warning about a missing overriding_indicator. Protected 3349 -- subprogram bodies are excluded from this style checking, since 3350 -- they aren't primitives (even though their declarations can 3351 -- override) and aren't allowed to have an overriding_indicator. 3352 3353 elsif Style_Check 3354 and then Present (Overridden_Operation (Spec_Id)) 3355 and then Ekind (Scope (Spec_Id)) /= E_Protected_Type 3356 then 3357 pragma Assert (Unit_Declaration_Node (Body_Id) = N); 3358 Style.Missing_Overriding (N, Body_Id); 3359 3360 elsif Style_Check 3361 and then Can_Override_Operator (Spec_Id) 3362 and then not In_Predefined_Unit (Spec_Id) 3363 then 3364 pragma Assert (Unit_Declaration_Node (Body_Id) = N); 3365 Style.Missing_Overriding (N, Body_Id); 3366 end if; 3367 end Verify_Overriding_Indicator; 3368 3369 -- Local variables 3370 3371 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; 3372 Saved_IGR : constant Node_Id := Ignored_Ghost_Region; 3373 Saved_EA : constant Boolean := Expander_Active; 3374 Saved_ISMP : constant Boolean := 3375 Ignore_SPARK_Mode_Pragmas_In_Instance; 3376 -- Save the Ghost and SPARK mode-related data to restore on exit 3377 3378 -- Start of processing for Analyze_Subprogram_Body_Helper 3379 3380 begin 3381 -- A [generic] subprogram body freezes the contract of the nearest 3382 -- enclosing package body and all other contracts encountered in the 3383 -- same declarative part up to and excluding the subprogram body: 3384 3385 -- package body Nearest_Enclosing_Package 3386 -- with Refined_State => (State => Constit) 3387 -- is 3388 -- Constit : ...; 3389 3390 -- procedure Freezes_Enclosing_Package_Body 3391 -- with Refined_Depends => (Input => Constit) ... 3392 3393 -- This ensures that any annotations referenced by the contract of the 3394 -- [generic] subprogram body are available. This form of freezing is 3395 -- decoupled from the usual Freeze_xxx mechanism because it must also 3396 -- work in the context of generics where normal freezing is disabled. 3397 3398 -- Only bodies coming from source should cause this type of freezing. 3399 -- Expression functions that act as bodies and complete an initial 3400 -- declaration must be included in this category, hence the use of 3401 -- Original_Node. 3402 3403 if Comes_From_Source (Original_Node (N)) then 3404 Freeze_Previous_Contracts (N); 3405 end if; 3406 3407 -- Generic subprograms are handled separately. They always have a 3408 -- generic specification. Determine whether current scope has a 3409 -- previous declaration. 3410 3411 -- If the subprogram body is defined within an instance of the same 3412 -- name, the instance appears as a package renaming, and will be hidden 3413 -- within the subprogram. 3414 3415 if Present (Prev_Id) 3416 and then not Is_Overloadable (Prev_Id) 3417 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration 3418 or else Comes_From_Source (Prev_Id)) 3419 then 3420 if Is_Generic_Subprogram (Prev_Id) then 3421 Spec_Id := Prev_Id; 3422 3423 -- A subprogram body is Ghost when it is stand-alone and subject 3424 -- to pragma Ghost or when the corresponding spec is Ghost. Set 3425 -- the mode now to ensure that any nodes generated during analysis 3426 -- and expansion are properly marked as Ghost. 3427 3428 Mark_And_Set_Ghost_Body (N, Spec_Id); 3429 3430 -- If the body completes the initial declaration of a compilation 3431 -- unit which is subject to pragma Elaboration_Checks, set the 3432 -- model specified by the pragma because it applies to all parts 3433 -- of the unit. 3434 3435 Install_Elaboration_Model (Spec_Id); 3436 3437 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 3438 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); 3439 3440 Analyze_Generic_Subprogram_Body (N, Spec_Id); 3441 3442 if Nkind (N) = N_Subprogram_Body then 3443 HSS := Handled_Statement_Sequence (N); 3444 Check_Missing_Return; 3445 end if; 3446 3447 goto Leave; 3448 3449 -- Otherwise a previous entity conflicts with the subprogram name. 3450 -- Attempting to enter name will post error. 3451 3452 else 3453 Enter_Name (Body_Id); 3454 goto Leave; 3455 end if; 3456 3457 -- Non-generic case, find the subprogram declaration, if one was seen, 3458 -- or enter new overloaded entity in the current scope. If the 3459 -- Current_Entity is the Body_Id itself, the unit is being analyzed as 3460 -- part of the context of one of its subunits. No need to redo the 3461 -- analysis. 3462 3463 elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then 3464 goto Leave; 3465 3466 else 3467 Body_Id := Analyze_Subprogram_Specification (Body_Spec); 3468 3469 if Nkind (N) = N_Subprogram_Body_Stub 3470 or else No (Corresponding_Spec (N)) 3471 then 3472 if Is_Private_Concurrent_Primitive (Body_Id) then 3473 Spec_Id := Disambiguate_Spec; 3474 3475 -- A subprogram body is Ghost when it is stand-alone and 3476 -- subject to pragma Ghost or when the corresponding spec is 3477 -- Ghost. Set the mode now to ensure that any nodes generated 3478 -- during analysis and expansion are properly marked as Ghost. 3479 3480 Mark_And_Set_Ghost_Body (N, Spec_Id); 3481 3482 -- If the body completes a compilation unit which is subject 3483 -- to pragma Elaboration_Checks, set the model specified by 3484 -- the pragma because it applies to all parts of the unit. 3485 3486 Install_Elaboration_Model (Spec_Id); 3487 3488 else 3489 Spec_Id := Find_Corresponding_Spec (N); 3490 3491 -- A subprogram body is Ghost when it is stand-alone and 3492 -- subject to pragma Ghost or when the corresponding spec is 3493 -- Ghost. Set the mode now to ensure that any nodes generated 3494 -- during analysis and expansion are properly marked as Ghost. 3495 3496 Mark_And_Set_Ghost_Body (N, Spec_Id); 3497 3498 -- If the body completes a compilation unit which is subject 3499 -- to pragma Elaboration_Checks, set the model specified by 3500 -- the pragma because it applies to all parts of the unit. 3501 3502 Install_Elaboration_Model (Spec_Id); 3503 3504 -- In GNATprove mode, if the body has no previous spec, create 3505 -- one so that the inlining machinery can operate properly. 3506 -- Transfer aspects, if any, to the new spec, so that they 3507 -- are legal and can be processed ahead of the body. 3508 -- We make two copies of the given spec, one for the new 3509 -- declaration, and one for the body. 3510 3511 if No (Spec_Id) and then GNATprove_Mode 3512 3513 -- Inlining does not apply during preanalysis of code 3514 3515 and then Full_Analysis 3516 3517 -- Inlining only applies to full bodies, not stubs 3518 3519 and then Nkind (N) /= N_Subprogram_Body_Stub 3520 3521 -- Inlining only applies to bodies in the source code, not to 3522 -- those generated by the compiler. In particular, expression 3523 -- functions, whose body is generated by the compiler, are 3524 -- treated specially by GNATprove. 3525 3526 and then Comes_From_Source (Body_Id) 3527 3528 -- This cannot be done for a compilation unit, which is not 3529 -- in a context where we can insert a new spec. 3530 3531 and then Is_List_Member (N) 3532 3533 -- Inlining only applies to subprograms without contracts, 3534 -- as a contract is a sign that GNATprove should perform a 3535 -- modular analysis of the subprogram instead of a contextual 3536 -- analysis at each call site. The same test is performed in 3537 -- Inline.Can_Be_Inlined_In_GNATprove_Mode. It is repeated 3538 -- here in another form (because the contract has not been 3539 -- attached to the body) to avoid front-end errors in case 3540 -- pragmas are used instead of aspects, because the 3541 -- corresponding pragmas in the body would not be transferred 3542 -- to the spec, leading to legality errors. 3543 3544 and then not Body_Has_Contract 3545 and then not Inside_A_Generic 3546 then 3547 Build_Subprogram_Declaration; 3548 3549 -- If this is a function that returns a constrained array, and 3550 -- we are generating SPARK_For_C, create subprogram declaration 3551 -- to simplify subsequent C generation. 3552 3553 elsif No (Spec_Id) 3554 and then Modify_Tree_For_C 3555 and then Nkind (Body_Spec) = N_Function_Specification 3556 and then Is_Array_Type (Etype (Body_Id)) 3557 and then Is_Constrained (Etype (Body_Id)) 3558 then 3559 Build_Subprogram_Declaration; 3560 end if; 3561 end if; 3562 3563 -- If this is a duplicate body, no point in analyzing it 3564 3565 if Error_Posted (N) then 3566 goto Leave; 3567 end if; 3568 3569 -- A subprogram body should cause freezing of its own declaration, 3570 -- but if there was no previous explicit declaration, then the 3571 -- subprogram will get frozen too late (there may be code within 3572 -- the body that depends on the subprogram having been frozen, 3573 -- such as uses of extra formals), so we force it to be frozen 3574 -- here. Same holds if the body and spec are compilation units. 3575 -- Finally, if the return type is an anonymous access to protected 3576 -- subprogram, it must be frozen before the body because its 3577 -- expansion has generated an equivalent type that is used when 3578 -- elaborating the body. 3579 3580 -- An exception in the case of Ada 2012, AI05-177: The bodies 3581 -- created for expression functions do not freeze. 3582 3583 if No (Spec_Id) 3584 and then Nkind (Original_Node (N)) /= N_Expression_Function 3585 then 3586 Freeze_Before (N, Body_Id); 3587 3588 elsif Nkind (Parent (N)) = N_Compilation_Unit then 3589 Freeze_Before (N, Spec_Id); 3590 3591 elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then 3592 Freeze_Before (N, Etype (Body_Id)); 3593 end if; 3594 3595 else 3596 Spec_Id := Corresponding_Spec (N); 3597 3598 -- A subprogram body is Ghost when it is stand-alone and subject 3599 -- to pragma Ghost or when the corresponding spec is Ghost. Set 3600 -- the mode now to ensure that any nodes generated during analysis 3601 -- and expansion are properly marked as Ghost. 3602 3603 Mark_And_Set_Ghost_Body (N, Spec_Id); 3604 3605 -- If the body completes the initial declaration of a compilation 3606 -- unit which is subject to pragma Elaboration_Checks, set the 3607 -- model specified by the pragma because it applies to all parts 3608 -- of the unit. 3609 3610 Install_Elaboration_Model (Spec_Id); 3611 end if; 3612 end if; 3613 3614 -- Deactivate expansion inside the body of ignored Ghost entities, 3615 -- as this code will ultimately be ignored. This avoids requiring the 3616 -- presence of run-time units which are not needed. Only do this for 3617 -- user entities, as internally generated entitities might still need 3618 -- to be expanded (e.g. those generated for types). 3619 3620 if Present (Ignored_Ghost_Region) 3621 and then Comes_From_Source (Body_Id) 3622 then 3623 Expander_Active := False; 3624 end if; 3625 3626 -- Previously we scanned the body to look for nested subprograms, and 3627 -- rejected an inline directive if nested subprograms were present, 3628 -- because the back-end would generate conflicting symbols for the 3629 -- nested bodies. This is now unnecessary. 3630 3631 -- Look ahead to recognize a pragma Inline that appears after the body 3632 3633 Check_Inline_Pragma (Spec_Id); 3634 3635 -- Deal with special case of a fully private operation in the body of 3636 -- the protected type. We must create a declaration for the subprogram, 3637 -- in order to attach the protected subprogram that will be used in 3638 -- internal calls. We exclude compiler generated bodies from the 3639 -- expander since the issue does not arise for those cases. 3640 3641 if No (Spec_Id) 3642 and then Comes_From_Source (N) 3643 and then Is_Protected_Type (Current_Scope) 3644 then 3645 Spec_Id := Build_Private_Protected_Declaration (N); 3646 end if; 3647 3648 -- If we are generating C and this is a function returning a constrained 3649 -- array type for which we must create a procedure with an extra out 3650 -- parameter, build and analyze the body now. The procedure declaration 3651 -- has already been created. We reuse the source body of the function, 3652 -- because in an instance it may contain global references that cannot 3653 -- be reanalyzed. The source function itself is not used any further, 3654 -- so we mark it as having a completion. If the subprogram is a stub the 3655 -- transformation is done later, when the proper body is analyzed. 3656 3657 if Expander_Active 3658 and then Modify_Tree_For_C 3659 and then Present (Spec_Id) 3660 and then Ekind (Spec_Id) = E_Function 3661 and then Nkind (N) /= N_Subprogram_Body_Stub 3662 and then Rewritten_For_C (Spec_Id) 3663 then 3664 Set_Has_Completion (Spec_Id); 3665 3666 Rewrite (N, Build_Procedure_Body_Form (Spec_Id, N)); 3667 Analyze (N); 3668 3669 -- The entity for the created procedure must remain invisible, so it 3670 -- does not participate in resolution of subsequent references to the 3671 -- function. 3672 3673 Set_Is_Immediately_Visible (Corresponding_Spec (N), False); 3674 goto Leave; 3675 end if; 3676 3677 -- If a separate spec is present, then deal with freezing issues 3678 3679 if Present (Spec_Id) then 3680 Spec_Decl := Unit_Declaration_Node (Spec_Id); 3681 Verify_Overriding_Indicator; 3682 3683 -- In general, the spec will be frozen when we start analyzing the 3684 -- body. However, for internally generated operations, such as 3685 -- wrapper functions for inherited operations with controlling 3686 -- results, the spec may not have been frozen by the time we expand 3687 -- the freeze actions that include the bodies. In particular, extra 3688 -- formals for accessibility or for return-in-place may need to be 3689 -- generated. Freeze nodes, if any, are inserted before the current 3690 -- body. These freeze actions are also needed in ASIS mode and in 3691 -- Compile_Only mode to enable the proper back-end type annotations. 3692 -- They are necessary in any case to insure order of elaboration 3693 -- in gigi. 3694 3695 if Nkind (N) = N_Subprogram_Body 3696 and then Was_Expression_Function (N) 3697 and then not Has_Completion (Spec_Id) 3698 and then Serious_Errors_Detected = 0 3699 and then (Expander_Active 3700 or else ASIS_Mode 3701 or else Operating_Mode = Check_Semantics) 3702 then 3703 -- The body generated for an expression function that is not a 3704 -- completion is a freeze point neither for the profile nor for 3705 -- anything else. That's why, in order to prevent any freezing 3706 -- during analysis, we need to mask types declared outside the 3707 -- expression (and in an outer scope) that are not yet frozen. 3708 3709 Set_Is_Frozen (Spec_Id); 3710 Mask_Types := Mask_Unfrozen_Types (Spec_Id); 3711 3712 elsif not Is_Frozen (Spec_Id) 3713 and then Serious_Errors_Detected = 0 3714 then 3715 Set_Has_Delayed_Freeze (Spec_Id); 3716 Freeze_Before (N, Spec_Id); 3717 end if; 3718 end if; 3719 3720 -- If the subprogram has a class-wide clone, build its body as a copy 3721 -- of the original body, and rewrite body of original subprogram as a 3722 -- wrapper that calls the clone. If N is a stub, this construction will 3723 -- take place when the proper body is analyzed. No action needed if this 3724 -- subprogram has been eliminated. 3725 3726 if Present (Spec_Id) 3727 and then Present (Class_Wide_Clone (Spec_Id)) 3728 and then (Comes_From_Source (N) or else Was_Expression_Function (N)) 3729 and then Nkind (N) /= N_Subprogram_Body_Stub 3730 and then not (Expander_Active and then Is_Eliminated (Spec_Id)) 3731 then 3732 Build_Class_Wide_Clone_Body (Spec_Id, N); 3733 3734 -- This is the new body for the existing primitive operation 3735 3736 Rewrite (N, Build_Class_Wide_Clone_Call 3737 (Sloc (N), New_List, Spec_Id, Parent (Spec_Id))); 3738 Set_Has_Completion (Spec_Id, False); 3739 Analyze (N); 3740 return; 3741 end if; 3742 3743 -- Place subprogram on scope stack, and make formals visible. If there 3744 -- is a spec, the visible entity remains that of the spec. 3745 3746 if Present (Spec_Id) then 3747 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False); 3748 3749 if Is_Child_Unit (Spec_Id) then 3750 Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False); 3751 end if; 3752 3753 if Style_Check then 3754 Style.Check_Identifier (Body_Id, Spec_Id); 3755 end if; 3756 3757 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); 3758 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); 3759 3760 if Is_Abstract_Subprogram (Spec_Id) then 3761 Error_Msg_N ("an abstract subprogram cannot have a body", N); 3762 goto Leave; 3763 3764 else 3765 Set_Convention (Body_Id, Convention (Spec_Id)); 3766 Set_Has_Completion (Spec_Id); 3767 3768 if Is_Protected_Type (Scope (Spec_Id)) then 3769 Prot_Typ := Scope (Spec_Id); 3770 end if; 3771 3772 -- If this is a body generated for a renaming, do not check for 3773 -- full conformance. The check is redundant, because the spec of 3774 -- the body is a copy of the spec in the renaming declaration, 3775 -- and the test can lead to spurious errors on nested defaults. 3776 3777 if Present (Spec_Decl) 3778 and then not Comes_From_Source (N) 3779 and then 3780 (Nkind (Original_Node (Spec_Decl)) = 3781 N_Subprogram_Renaming_Declaration 3782 or else (Present (Corresponding_Body (Spec_Decl)) 3783 and then 3784 Nkind (Unit_Declaration_Node 3785 (Corresponding_Body (Spec_Decl))) = 3786 N_Subprogram_Renaming_Declaration)) 3787 then 3788 Conformant := True; 3789 3790 -- Conversely, the spec may have been generated for specless body 3791 -- with an inline pragma. The entity comes from source, which is 3792 -- both semantically correct and necessary for proper inlining. 3793 -- The subprogram declaration itself is not in the source. 3794 3795 elsif Comes_From_Source (N) 3796 and then Present (Spec_Decl) 3797 and then not Comes_From_Source (Spec_Decl) 3798 and then Has_Pragma_Inline (Spec_Id) 3799 then 3800 Conformant := True; 3801 3802 else 3803 Check_Conformance 3804 (Body_Id, Spec_Id, 3805 Fully_Conformant, True, Conformant, Body_Id); 3806 end if; 3807 3808 -- If the body is not fully conformant, we have to decide if we 3809 -- should analyze it or not. If it has a really messed up profile 3810 -- then we probably should not analyze it, since we will get too 3811 -- many bogus messages. 3812 3813 -- Our decision is to go ahead in the non-fully conformant case 3814 -- only if it is at least mode conformant with the spec. Note 3815 -- that the call to Check_Fully_Conformant has issued the proper 3816 -- error messages to complain about the lack of conformance. 3817 3818 if not Conformant 3819 and then not Mode_Conformant (Body_Id, Spec_Id) 3820 then 3821 goto Leave; 3822 end if; 3823 end if; 3824 3825 -- In the case we are dealing with an expression function we check 3826 -- the formals attached to the spec instead of the body - so we don't 3827 -- reference body formals. 3828 3829 if Spec_Id /= Body_Id 3830 and then not Is_Expression_Function (Spec_Id) 3831 then 3832 Reference_Body_Formals (Spec_Id, Body_Id); 3833 end if; 3834 3835 Set_Ekind (Body_Id, E_Subprogram_Body); 3836 3837 if Nkind (N) = N_Subprogram_Body_Stub then 3838 Set_Corresponding_Spec_Of_Stub (N, Spec_Id); 3839 3840 -- Regular body 3841 3842 else 3843 Set_Corresponding_Spec (N, Spec_Id); 3844 3845 -- Ada 2005 (AI-345): If the operation is a primitive operation 3846 -- of a concurrent type, the type of the first parameter has been 3847 -- replaced with the corresponding record, which is the proper 3848 -- run-time structure to use. However, within the body there may 3849 -- be uses of the formals that depend on primitive operations 3850 -- of the type (in particular calls in prefixed form) for which 3851 -- we need the original concurrent type. The operation may have 3852 -- several controlling formals, so the replacement must be done 3853 -- for all of them. 3854 3855 if Comes_From_Source (Spec_Id) 3856 and then Present (First_Entity (Spec_Id)) 3857 and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type 3858 and then Is_Tagged_Type (Etype (First_Entity (Spec_Id))) 3859 and then Present (Interfaces (Etype (First_Entity (Spec_Id)))) 3860 and then Present (Corresponding_Concurrent_Type 3861 (Etype (First_Entity (Spec_Id)))) 3862 then 3863 declare 3864 Typ : constant Entity_Id := Etype (First_Entity (Spec_Id)); 3865 Form : Entity_Id; 3866 3867 begin 3868 Form := First_Formal (Spec_Id); 3869 while Present (Form) loop 3870 if Etype (Form) = Typ then 3871 Set_Etype (Form, Corresponding_Concurrent_Type (Typ)); 3872 end if; 3873 3874 Next_Formal (Form); 3875 end loop; 3876 end; 3877 end if; 3878 3879 -- Make the formals visible, and place subprogram on scope stack. 3880 -- This is also the point at which we set Last_Real_Spec_Entity 3881 -- to mark the entities which will not be moved to the body. 3882 3883 Install_Formals (Spec_Id); 3884 Last_Real_Spec_Entity := Last_Entity (Spec_Id); 3885 3886 -- Within an instance, add local renaming declarations so that 3887 -- gdb can retrieve the values of actuals more easily. This is 3888 -- only relevant if generating code (and indeed we definitely 3889 -- do not want these definitions -gnatc mode, because that would 3890 -- confuse ASIS). 3891 3892 if Is_Generic_Instance (Spec_Id) 3893 and then Is_Wrapper_Package (Current_Scope) 3894 and then Expander_Active 3895 then 3896 Build_Subprogram_Instance_Renamings (N, Current_Scope); 3897 end if; 3898 3899 Push_Scope (Spec_Id); 3900 3901 -- Make sure that the subprogram is immediately visible. For 3902 -- child units that have no separate spec this is indispensable. 3903 -- Otherwise it is safe albeit redundant. 3904 3905 Set_Is_Immediately_Visible (Spec_Id); 3906 end if; 3907 3908 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id); 3909 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id)); 3910 Set_Scope (Body_Id, Scope (Spec_Id)); 3911 3912 -- Case of subprogram body with no previous spec 3913 3914 else 3915 -- Check for style warning required 3916 3917 if Style_Check 3918 3919 -- Only apply check for source level subprograms for which checks 3920 -- have not been suppressed. 3921 3922 and then Comes_From_Source (Body_Id) 3923 and then not Suppress_Style_Checks (Body_Id) 3924 3925 -- No warnings within an instance 3926 3927 and then not In_Instance 3928 3929 -- No warnings for expression functions 3930 3931 and then Nkind (Original_Node (N)) /= N_Expression_Function 3932 then 3933 Style.Body_With_No_Spec (N); 3934 end if; 3935 3936 New_Overloaded_Entity (Body_Id); 3937 3938 if Nkind (N) /= N_Subprogram_Body_Stub then 3939 Set_Acts_As_Spec (N); 3940 Generate_Definition (Body_Id); 3941 Generate_Reference 3942 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True); 3943 3944 -- If the body is an entry wrapper created for an entry with 3945 -- preconditions, it must be compiled in the context of the 3946 -- enclosing synchronized object, because it may mention other 3947 -- operations of the type. 3948 3949 if Is_Entry_Wrapper (Body_Id) then 3950 declare 3951 Prot : constant Entity_Id := Etype (First_Entity (Body_Id)); 3952 begin 3953 Push_Scope (Prot); 3954 Install_Declarations (Prot); 3955 end; 3956 end if; 3957 3958 Install_Formals (Body_Id); 3959 3960 Push_Scope (Body_Id); 3961 end if; 3962 3963 -- For stubs and bodies with no previous spec, generate references to 3964 -- formals. 3965 3966 Generate_Reference_To_Formals (Body_Id); 3967 end if; 3968 3969 -- Entry barrier functions are generated outside the protected type and 3970 -- should not carry the SPARK_Mode of the enclosing context. 3971 3972 if Nkind (N) = N_Subprogram_Body 3973 and then Is_Entry_Barrier_Function (N) 3974 then 3975 null; 3976 3977 -- The body is generated as part of expression function expansion. When 3978 -- the expression function appears in the visible declarations of a 3979 -- package, the body is added to the private declarations. Since both 3980 -- declarative lists may be subject to a different SPARK_Mode, inherit 3981 -- the mode of the spec. 3982 3983 -- package P with SPARK_Mode is 3984 -- function Expr_Func ... is (...); -- original 3985 -- [function Expr_Func ...;] -- generated spec 3986 -- -- mode is ON 3987 -- private 3988 -- pragma SPARK_Mode (Off); 3989 -- [function Expr_Func ... is return ...;] -- generated body 3990 -- end P; -- mode is ON 3991 3992 elsif not Comes_From_Source (N) 3993 and then Present (Spec_Id) 3994 and then Is_Expression_Function (Spec_Id) 3995 then 3996 Set_SPARK_Pragma (Body_Id, SPARK_Pragma (Spec_Id)); 3997 Set_SPARK_Pragma_Inherited 3998 (Body_Id, SPARK_Pragma_Inherited (Spec_Id)); 3999 4000 -- Set the SPARK_Mode from the current context (may be overwritten later 4001 -- with explicit pragma). Exclude the case where the SPARK_Mode appears 4002 -- initially on a stand-alone subprogram body, but is then relocated to 4003 -- a generated corresponding spec. In this scenario the mode is shared 4004 -- between the spec and body. 4005 4006 elsif No (SPARK_Pragma (Body_Id)) then 4007 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); 4008 Set_SPARK_Pragma_Inherited (Body_Id); 4009 end if; 4010 4011 -- A subprogram body may be instantiated or inlined at a later pass. 4012 -- Restore the state of Ignore_SPARK_Mode_Pragmas_In_Instance when it 4013 -- applied to the initial declaration of the body. 4014 4015 if Present (Spec_Id) then 4016 if Ignore_SPARK_Mode_Pragmas (Spec_Id) then 4017 Ignore_SPARK_Mode_Pragmas_In_Instance := True; 4018 end if; 4019 4020 else 4021 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in 4022 -- case the body is instantiated or inlined later and out of context. 4023 -- The body uses this attribute to restore the value of the global 4024 -- flag. 4025 4026 if Ignore_SPARK_Mode_Pragmas_In_Instance then 4027 Set_Ignore_SPARK_Mode_Pragmas (Body_Id); 4028 4029 elsif Ignore_SPARK_Mode_Pragmas (Body_Id) then 4030 Ignore_SPARK_Mode_Pragmas_In_Instance := True; 4031 end if; 4032 end if; 4033 4034 -- Preserve relevant elaboration-related attributes of the context which 4035 -- are no longer available or very expensive to recompute once analysis, 4036 -- resolution, and expansion are over. 4037 4038 if No (Spec_Id) then 4039 Mark_Elaboration_Attributes 4040 (N_Id => Body_Id, 4041 Checks => True, 4042 Warnings => True); 4043 end if; 4044 4045 -- If this is the proper body of a stub, we must verify that the stub 4046 -- conforms to the body, and to the previous spec if one was present. 4047 -- We know already that the body conforms to that spec. This test is 4048 -- only required for subprograms that come from source. 4049 4050 if Nkind (Parent (N)) = N_Subunit 4051 and then Comes_From_Source (N) 4052 and then not Error_Posted (Body_Id) 4053 and then Nkind (Corresponding_Stub (Parent (N))) = 4054 N_Subprogram_Body_Stub 4055 then 4056 declare 4057 Old_Id : constant Entity_Id := 4058 Defining_Entity 4059 (Specification (Corresponding_Stub (Parent (N)))); 4060 4061 Conformant : Boolean := False; 4062 4063 begin 4064 if No (Spec_Id) then 4065 Check_Fully_Conformant (Body_Id, Old_Id); 4066 4067 else 4068 Check_Conformance 4069 (Body_Id, Old_Id, Fully_Conformant, False, Conformant); 4070 4071 if not Conformant then 4072 4073 -- The stub was taken to be a new declaration. Indicate that 4074 -- it lacks a body. 4075 4076 Set_Has_Completion (Old_Id, False); 4077 end if; 4078 end if; 4079 end; 4080 end if; 4081 4082 Set_Has_Completion (Body_Id); 4083 Check_Eliminated (Body_Id); 4084 4085 -- Analyze any aspect specifications that appear on the subprogram body 4086 -- stub. Stop the analysis now as the stub does not have a declarative 4087 -- or a statement part, and it cannot be inlined. 4088 4089 if Nkind (N) = N_Subprogram_Body_Stub then 4090 if Has_Aspects (N) then 4091 Analyze_Aspects_On_Subprogram_Body_Or_Stub (N); 4092 end if; 4093 4094 goto Leave; 4095 end if; 4096 4097 -- Handle inlining 4098 4099 -- Note: Normally we don't do any inlining if expansion is off, since 4100 -- we won't generate code in any case. An exception arises in GNATprove 4101 -- mode where we want to expand some calls in place, even with expansion 4102 -- disabled, since the inlining eases formal verification. 4103 4104 if not GNATprove_Mode 4105 and then Expander_Active 4106 and then Serious_Errors_Detected = 0 4107 and then Present (Spec_Id) 4108 and then Has_Pragma_Inline (Spec_Id) 4109 then 4110 -- Legacy implementation (relying on front-end inlining) 4111 4112 if not Back_End_Inlining then 4113 if (Has_Pragma_Inline_Always (Spec_Id) 4114 and then not Opt.Disable_FE_Inline_Always) 4115 or else (Front_End_Inlining 4116 and then not Opt.Disable_FE_Inline) 4117 then 4118 Build_Body_To_Inline (N, Spec_Id); 4119 end if; 4120 4121 -- New implementation (relying on back-end inlining) 4122 4123 else 4124 if Has_Pragma_Inline_Always (Spec_Id) 4125 or else Optimization_Level > 0 4126 then 4127 -- Handle function returning an unconstrained type 4128 4129 if Comes_From_Source (Body_Id) 4130 and then Ekind (Spec_Id) = E_Function 4131 and then Returns_Unconstrained_Type (Spec_Id) 4132 4133 -- If function builds in place, i.e. returns a limited type, 4134 -- inlining cannot be done. 4135 4136 and then not Is_Limited_Type (Etype (Spec_Id)) 4137 then 4138 Check_And_Split_Unconstrained_Function (N, Spec_Id, Body_Id); 4139 4140 else 4141 declare 4142 Subp_Body : constant Node_Id := 4143 Unit_Declaration_Node (Body_Id); 4144 Subp_Decl : constant List_Id := Declarations (Subp_Body); 4145 4146 begin 4147 -- Do not pass inlining to the backend if the subprogram 4148 -- has declarations or statements which cannot be inlined 4149 -- by the backend. This check is done here to emit an 4150 -- error instead of the generic warning message reported 4151 -- by the GCC backend (ie. "function might not be 4152 -- inlinable"). 4153 4154 if Present (Subp_Decl) 4155 and then Has_Excluded_Declaration (Spec_Id, Subp_Decl) 4156 then 4157 null; 4158 4159 elsif Has_Excluded_Statement 4160 (Spec_Id, 4161 Statements 4162 (Handled_Statement_Sequence (Subp_Body))) 4163 then 4164 null; 4165 4166 -- If the backend inlining is available then at this 4167 -- stage we only have to mark the subprogram as inlined. 4168 -- The expander will take care of registering it in the 4169 -- table of subprograms inlined by the backend a part of 4170 -- processing calls to it (cf. Expand_Call) 4171 4172 else 4173 Set_Is_Inlined (Spec_Id); 4174 end if; 4175 end; 4176 end if; 4177 end if; 4178 end if; 4179 4180 -- In GNATprove mode, inline only when there is a separate subprogram 4181 -- declaration for now, as inlining of subprogram bodies acting as 4182 -- declarations, or subprogram stubs, are not supported by front-end 4183 -- inlining. This inlining should occur after analysis of the body, so 4184 -- that it is known whether the value of SPARK_Mode, which can be 4185 -- defined by a pragma inside the body, is applicable to the body. 4186 -- Inlining can be disabled with switch -gnatdm 4187 4188 elsif GNATprove_Mode 4189 and then Full_Analysis 4190 and then not Inside_A_Generic 4191 and then Present (Spec_Id) 4192 and then 4193 Nkind (Unit_Declaration_Node (Spec_Id)) = N_Subprogram_Declaration 4194 and then Body_Has_SPARK_Mode_On 4195 and then Can_Be_Inlined_In_GNATprove_Mode (Spec_Id, Body_Id) 4196 and then not Body_Has_Contract 4197 and then not Debug_Flag_M 4198 then 4199 Build_Body_To_Inline (N, Spec_Id); 4200 end if; 4201 4202 -- When generating code, inherited pre/postconditions are handled when 4203 -- expanding the corresponding contract. 4204 4205 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis 4206 -- of the specification we have to install the private withed units. 4207 -- This holds for child units as well. 4208 4209 if Is_Compilation_Unit (Body_Id) 4210 or else Nkind (Parent (N)) = N_Compilation_Unit 4211 then 4212 Install_Private_With_Clauses (Body_Id); 4213 end if; 4214 4215 Check_Anonymous_Return; 4216 4217 -- Set the Protected_Formal field of each extra formal of the protected 4218 -- subprogram to reference the corresponding extra formal of the 4219 -- subprogram that implements it. For regular formals this occurs when 4220 -- the protected subprogram's declaration is expanded, but the extra 4221 -- formals don't get created until the subprogram is frozen. We need to 4222 -- do this before analyzing the protected subprogram's body so that any 4223 -- references to the original subprogram's extra formals will be changed 4224 -- refer to the implementing subprogram's formals (see Expand_Formal). 4225 4226 if Present (Spec_Id) 4227 and then Is_Protected_Type (Scope (Spec_Id)) 4228 and then Present (Protected_Body_Subprogram (Spec_Id)) 4229 then 4230 declare 4231 Impl_Subp : constant Entity_Id := 4232 Protected_Body_Subprogram (Spec_Id); 4233 Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id); 4234 Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp); 4235 4236 begin 4237 while Present (Prot_Ext_Formal) loop 4238 pragma Assert (Present (Impl_Ext_Formal)); 4239 Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal); 4240 Next_Formal_With_Extras (Prot_Ext_Formal); 4241 Next_Formal_With_Extras (Impl_Ext_Formal); 4242 end loop; 4243 end; 4244 end if; 4245 4246 -- Now we can go on to analyze the body 4247 4248 HSS := Handled_Statement_Sequence (N); 4249 Set_Actual_Subtypes (N, Current_Scope); 4250 4251 -- Add a declaration for the Protection object, renaming declarations 4252 -- for discriminals and privals and finally a declaration for the entry 4253 -- family index (if applicable). This form of early expansion is done 4254 -- when the Expander is active because Install_Private_Data_Declarations 4255 -- references entities which were created during regular expansion. The 4256 -- subprogram entity must come from source, and not be an internally 4257 -- generated subprogram. 4258 4259 if Expander_Active 4260 and then Present (Prot_Typ) 4261 and then Present (Spec_Id) 4262 and then Comes_From_Source (Spec_Id) 4263 and then not Is_Eliminated (Spec_Id) 4264 then 4265 Install_Private_Data_Declarations 4266 (Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N)); 4267 end if; 4268 4269 -- Ada 2012 (AI05-0151): Incomplete types coming from a limited context 4270 -- may now appear in parameter and result profiles. Since the analysis 4271 -- of a subprogram body may use the parameter and result profile of the 4272 -- spec, swap any limited views with their non-limited counterpart. 4273 4274 if Ada_Version >= Ada_2012 and then Present (Spec_Id) then 4275 Exch_Views := Exchange_Limited_Views (Spec_Id); 4276 end if; 4277 4278 -- If the return type is an anonymous access type whose designated type 4279 -- is the limited view of a class-wide type and the non-limited view is 4280 -- available, update the return type accordingly. 4281 4282 if Ada_Version >= Ada_2005 and then Present (Spec_Id) then 4283 declare 4284 Etyp : Entity_Id; 4285 Rtyp : Entity_Id; 4286 4287 begin 4288 Rtyp := Etype (Spec_Id); 4289 4290 if Ekind (Rtyp) = E_Anonymous_Access_Type then 4291 Etyp := Directly_Designated_Type (Rtyp); 4292 4293 if Is_Class_Wide_Type (Etyp) 4294 and then From_Limited_With (Etyp) 4295 then 4296 Desig_View := Etyp; 4297 Set_Directly_Designated_Type (Rtyp, Available_View (Etyp)); 4298 end if; 4299 end if; 4300 end; 4301 end if; 4302 4303 -- Analyze any aspect specifications that appear on the subprogram body 4304 4305 if Has_Aspects (N) then 4306 Analyze_Aspects_On_Subprogram_Body_Or_Stub (N); 4307 end if; 4308 4309 Analyze_Declarations (Declarations (N)); 4310 4311 -- Verify that the SPARK_Mode of the body agrees with that of its spec 4312 4313 if Present (Spec_Id) and then Present (SPARK_Pragma (Body_Id)) then 4314 if Present (SPARK_Pragma (Spec_Id)) then 4315 if Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Spec_Id)) = Off 4316 and then 4317 Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = On 4318 then 4319 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 4320 Error_Msg_N ("incorrect application of SPARK_Mode#", N); 4321 Error_Msg_Sloc := Sloc (SPARK_Pragma (Spec_Id)); 4322 Error_Msg_NE 4323 ("\value Off was set for SPARK_Mode on & #", N, Spec_Id); 4324 end if; 4325 4326 elsif Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Body_Stub then 4327 null; 4328 4329 else 4330 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); 4331 Error_Msg_N ("incorrect application of SPARK_Mode #", N); 4332 Error_Msg_Sloc := Sloc (Spec_Id); 4333 Error_Msg_NE 4334 ("\no value was set for SPARK_Mode on & #", N, Spec_Id); 4335 end if; 4336 end if; 4337 4338 -- A subprogram body freezes its own contract. Analyze the contract 4339 -- after the declarations of the body have been processed as pragmas 4340 -- are now chained on the contract of the subprogram body. 4341 4342 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id); 4343 4344 -- Check completion, and analyze the statements 4345 4346 Check_Completion; 4347 Inspect_Deferred_Constant_Completion (Declarations (N)); 4348 Analyze (HSS); 4349 4350 -- Deal with end of scope processing for the body 4351 4352 Process_End_Label (HSS, 't', Current_Scope); 4353 Update_Use_Clause_Chain; 4354 End_Scope; 4355 4356 -- If we are compiling an entry wrapper, remove the enclosing 4357 -- synchronized object from the stack. 4358 4359 if Is_Entry_Wrapper (Body_Id) then 4360 End_Scope; 4361 end if; 4362 4363 Check_Subprogram_Order (N); 4364 Set_Analyzed (Body_Id); 4365 4366 -- If we have a separate spec, then the analysis of the declarations 4367 -- caused the entities in the body to be chained to the spec id, but 4368 -- we want them chained to the body id. Only the formal parameters 4369 -- end up chained to the spec id in this case. 4370 4371 if Present (Spec_Id) then 4372 4373 -- We must conform to the categorization of our spec 4374 4375 Validate_Categorization_Dependency (N, Spec_Id); 4376 4377 -- And if this is a child unit, the parent units must conform 4378 4379 if Is_Child_Unit (Spec_Id) then 4380 Validate_Categorization_Dependency 4381 (Unit_Declaration_Node (Spec_Id), Spec_Id); 4382 end if; 4383 4384 -- Here is where we move entities from the spec to the body 4385 4386 -- Case where there are entities that stay with the spec 4387 4388 if Present (Last_Real_Spec_Entity) then 4389 4390 -- No body entities (happens when the only real spec entities come 4391 -- from precondition and postcondition pragmas). 4392 4393 if No (Last_Entity (Body_Id)) then 4394 Set_First_Entity (Body_Id, Next_Entity (Last_Real_Spec_Entity)); 4395 4396 -- Body entities present (formals), so chain stuff past them 4397 4398 else 4399 Link_Entities 4400 (Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity)); 4401 end if; 4402 4403 Set_Next_Entity (Last_Real_Spec_Entity, Empty); 4404 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 4405 Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity); 4406 4407 -- Case where there are no spec entities, in this case there can be 4408 -- no body entities either, so just move everything. 4409 4410 -- If the body is generated for an expression function, it may have 4411 -- been preanalyzed already, if 'access was applied to it. 4412 4413 else 4414 if Nkind (Original_Node (Unit_Declaration_Node (Spec_Id))) /= 4415 N_Expression_Function 4416 then 4417 pragma Assert (No (Last_Entity (Body_Id))); 4418 null; 4419 end if; 4420 4421 Set_First_Entity (Body_Id, First_Entity (Spec_Id)); 4422 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); 4423 Set_First_Entity (Spec_Id, Empty); 4424 Set_Last_Entity (Spec_Id, Empty); 4425 end if; 4426 4427 -- Otherwise the body does not complete a previous declaration. Check 4428 -- the categorization of the body against the units it withs. 4429 4430 else 4431 Validate_Categorization_Dependency (N, Body_Id); 4432 end if; 4433 4434 Check_Missing_Return; 4435 4436 -- Now we are going to check for variables that are never modified in 4437 -- the body of the procedure. But first we deal with a special case 4438 -- where we want to modify this check. If the body of the subprogram 4439 -- starts with a raise statement or its equivalent, or if the body 4440 -- consists entirely of a null statement, then it is pretty obvious that 4441 -- it is OK to not reference the parameters. For example, this might be 4442 -- the following common idiom for a stubbed function: statement of the 4443 -- procedure raises an exception. In particular this deals with the 4444 -- common idiom of a stubbed function, which appears something like: 4445 4446 -- function F (A : Integer) return Some_Type; 4447 -- X : Some_Type; 4448 -- begin 4449 -- raise Program_Error; 4450 -- return X; 4451 -- end F; 4452 4453 -- Here the purpose of X is simply to satisfy the annoying requirement 4454 -- in Ada that there be at least one return, and we certainly do not 4455 -- want to go posting warnings on X that it is not initialized. On 4456 -- the other hand, if X is entirely unreferenced that should still 4457 -- get a warning. 4458 4459 -- What we do is to detect these cases, and if we find them, flag the 4460 -- subprogram as being Is_Trivial_Subprogram and then use that flag to 4461 -- suppress unwanted warnings. For the case of the function stub above 4462 -- we have a special test to set X as apparently assigned to suppress 4463 -- the warning. 4464 4465 declare 4466 Stm : Node_Id; 4467 4468 begin 4469 -- Skip call markers installed by the ABE mechanism, labels, and 4470 -- Push_xxx_Error_Label to find the first real statement. 4471 4472 Stm := First (Statements (HSS)); 4473 while Nkind_In (Stm, N_Call_Marker, N_Label) 4474 or else Nkind (Stm) in N_Push_xxx_Label 4475 loop 4476 Next (Stm); 4477 end loop; 4478 4479 -- Do the test on the original statement before expansion 4480 4481 declare 4482 Ostm : constant Node_Id := Original_Node (Stm); 4483 4484 begin 4485 -- If explicit raise statement, turn on flag 4486 4487 if Nkind (Ostm) = N_Raise_Statement then 4488 Set_Trivial_Subprogram (Stm); 4489 4490 -- If null statement, and no following statements, turn on flag 4491 4492 elsif Nkind (Stm) = N_Null_Statement 4493 and then Comes_From_Source (Stm) 4494 and then No (Next (Stm)) 4495 then 4496 Set_Trivial_Subprogram (Stm); 4497 4498 -- Check for explicit call cases which likely raise an exception 4499 4500 elsif Nkind (Ostm) = N_Procedure_Call_Statement then 4501 if Is_Entity_Name (Name (Ostm)) then 4502 declare 4503 Ent : constant Entity_Id := Entity (Name (Ostm)); 4504 4505 begin 4506 -- If the procedure is marked No_Return, then likely it 4507 -- raises an exception, but in any case it is not coming 4508 -- back here, so turn on the flag. 4509 4510 if Present (Ent) 4511 and then Ekind (Ent) = E_Procedure 4512 and then No_Return (Ent) 4513 then 4514 Set_Trivial_Subprogram (Stm); 4515 end if; 4516 end; 4517 end if; 4518 end if; 4519 end; 4520 end; 4521 4522 -- Check for variables that are never modified 4523 4524 declare 4525 E1 : Entity_Id; 4526 E2 : Entity_Id; 4527 4528 begin 4529 -- If there is a separate spec, then transfer Never_Set_In_Source 4530 -- flags from out parameters to the corresponding entities in the 4531 -- body. The reason we do that is we want to post error flags on 4532 -- the body entities, not the spec entities. 4533 4534 if Present (Spec_Id) then 4535 E1 := First_Entity (Spec_Id); 4536 while Present (E1) loop 4537 if Ekind (E1) = E_Out_Parameter then 4538 E2 := First_Entity (Body_Id); 4539 while Present (E2) loop 4540 exit when Chars (E1) = Chars (E2); 4541 Next_Entity (E2); 4542 end loop; 4543 4544 if Present (E2) then 4545 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1)); 4546 end if; 4547 end if; 4548 4549 Next_Entity (E1); 4550 end loop; 4551 end if; 4552 4553 -- Check references of the subprogram spec when we are dealing with 4554 -- an expression function due to it having a generated body. 4555 -- Otherwise, we simply check the formals of the subprogram body. 4556 4557 if Present (Spec_Id) 4558 and then Is_Expression_Function (Spec_Id) 4559 then 4560 Check_References (Spec_Id); 4561 else 4562 Check_References (Body_Id); 4563 end if; 4564 end; 4565 4566 -- Check for nested subprogram, and mark outer level subprogram if so 4567 4568 declare 4569 Ent : Entity_Id; 4570 4571 begin 4572 if Present (Spec_Id) then 4573 Ent := Spec_Id; 4574 else 4575 Ent := Body_Id; 4576 end if; 4577 4578 loop 4579 Ent := Enclosing_Subprogram (Ent); 4580 exit when No (Ent) or else Is_Subprogram (Ent); 4581 end loop; 4582 4583 if Present (Ent) then 4584 Set_Has_Nested_Subprogram (Ent); 4585 end if; 4586 end; 4587 4588 -- Restore the limited views in the spec, if any, to let the back end 4589 -- process it without running into circularities. 4590 4591 if Exch_Views /= No_Elist then 4592 Restore_Limited_Views (Exch_Views); 4593 end if; 4594 4595 if Mask_Types /= No_Elist then 4596 Unmask_Unfrozen_Types (Mask_Types); 4597 end if; 4598 4599 if Present (Desig_View) then 4600 Set_Directly_Designated_Type (Etype (Spec_Id), Desig_View); 4601 end if; 4602 4603 <<Leave>> 4604 if Present (Ignored_Ghost_Region) then 4605 Expander_Active := Saved_EA; 4606 end if; 4607 4608 Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP; 4609 Restore_Ghost_Region (Saved_GM, Saved_IGR); 4610 end Analyze_Subprogram_Body_Helper; 4611 4612 ------------------------------------ 4613 -- Analyze_Subprogram_Declaration -- 4614 ------------------------------------ 4615 4616 procedure Analyze_Subprogram_Declaration (N : Node_Id) is 4617 Scop : constant Entity_Id := Current_Scope; 4618 Designator : Entity_Id; 4619 4620 Is_Completion : Boolean; 4621 -- Indicates whether a null procedure declaration is a completion 4622 4623 begin 4624 -- Null procedures are not allowed in SPARK 4625 4626 if Nkind (Specification (N)) = N_Procedure_Specification 4627 and then Null_Present (Specification (N)) 4628 then 4629 Check_SPARK_05_Restriction ("null procedure is not allowed", N); 4630 4631 -- Null procedures are allowed in protected types, following the 4632 -- recent AI12-0147. 4633 4634 if Is_Protected_Type (Current_Scope) 4635 and then Ada_Version < Ada_2012 4636 then 4637 Error_Msg_N ("protected operation cannot be a null procedure", N); 4638 end if; 4639 4640 Analyze_Null_Procedure (N, Is_Completion); 4641 4642 -- The null procedure acts as a body, nothing further is needed 4643 4644 if Is_Completion then 4645 return; 4646 end if; 4647 end if; 4648 4649 Designator := Analyze_Subprogram_Specification (Specification (N)); 4650 4651 -- A reference may already have been generated for the unit name, in 4652 -- which case the following call is redundant. However it is needed for 4653 -- declarations that are the rewriting of an expression function. 4654 4655 Generate_Definition (Designator); 4656 4657 -- Set the SPARK mode from the current context (may be overwritten later 4658 -- with explicit pragma). This is not done for entry barrier functions 4659 -- because they are generated outside the protected type and should not 4660 -- carry the mode of the enclosing context. 4661 4662 if Nkind (N) = N_Subprogram_Declaration 4663 and then Is_Entry_Barrier_Function (N) 4664 then 4665 null; 4666 4667 else 4668 Set_SPARK_Pragma (Designator, SPARK_Mode_Pragma); 4669 Set_SPARK_Pragma_Inherited (Designator); 4670 end if; 4671 4672 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in case 4673 -- the body of this subprogram is instantiated or inlined later and out 4674 -- of context. The body uses this attribute to restore the value of the 4675 -- global flag. 4676 4677 if Ignore_SPARK_Mode_Pragmas_In_Instance then 4678 Set_Ignore_SPARK_Mode_Pragmas (Designator); 4679 end if; 4680 4681 -- Preserve relevant elaboration-related attributes of the context which 4682 -- are no longer available or very expensive to recompute once analysis, 4683 -- resolution, and expansion are over. 4684 4685 Mark_Elaboration_Attributes 4686 (N_Id => Designator, 4687 Checks => True, 4688 Warnings => True); 4689 4690 if Debug_Flag_C then 4691 Write_Str ("==> subprogram spec "); 4692 Write_Name (Chars (Designator)); 4693 Write_Str (" from "); 4694 Write_Location (Sloc (N)); 4695 Write_Eol; 4696 Indent; 4697 end if; 4698 4699 Validate_RCI_Subprogram_Declaration (N); 4700 New_Overloaded_Entity (Designator); 4701 Check_Delayed_Subprogram (Designator); 4702 4703 -- If the type of the first formal of the current subprogram is a non- 4704 -- generic tagged private type, mark the subprogram as being a private 4705 -- primitive. Ditto if this is a function with controlling result, and 4706 -- the return type is currently private. In both cases, the type of the 4707 -- controlling argument or result must be in the current scope for the 4708 -- operation to be primitive. 4709 4710 if Has_Controlling_Result (Designator) 4711 and then Is_Private_Type (Etype (Designator)) 4712 and then Scope (Etype (Designator)) = Current_Scope 4713 and then not Is_Generic_Actual_Type (Etype (Designator)) 4714 then 4715 Set_Is_Private_Primitive (Designator); 4716 4717 elsif Present (First_Formal (Designator)) then 4718 declare 4719 Formal_Typ : constant Entity_Id := 4720 Etype (First_Formal (Designator)); 4721 begin 4722 Set_Is_Private_Primitive (Designator, 4723 Is_Tagged_Type (Formal_Typ) 4724 and then Scope (Formal_Typ) = Current_Scope 4725 and then Is_Private_Type (Formal_Typ) 4726 and then not Is_Generic_Actual_Type (Formal_Typ)); 4727 end; 4728 end if; 4729 4730 -- Ada 2005 (AI-251): Abstract interface primitives must be abstract 4731 -- or null. 4732 4733 if Ada_Version >= Ada_2005 4734 and then Comes_From_Source (N) 4735 and then Is_Dispatching_Operation (Designator) 4736 then 4737 declare 4738 E : Entity_Id; 4739 Etyp : Entity_Id; 4740 4741 begin 4742 if Has_Controlling_Result (Designator) then 4743 Etyp := Etype (Designator); 4744 4745 else 4746 E := First_Entity (Designator); 4747 while Present (E) 4748 and then Is_Formal (E) 4749 and then not Is_Controlling_Formal (E) 4750 loop 4751 Next_Entity (E); 4752 end loop; 4753 4754 Etyp := Etype (E); 4755 end if; 4756 4757 if Is_Access_Type (Etyp) then 4758 Etyp := Directly_Designated_Type (Etyp); 4759 end if; 4760 4761 if Is_Interface (Etyp) 4762 and then not Is_Abstract_Subprogram (Designator) 4763 and then not (Ekind (Designator) = E_Procedure 4764 and then Null_Present (Specification (N))) 4765 then 4766 Error_Msg_Name_1 := Chars (Defining_Entity (N)); 4767 4768 -- Specialize error message based on procedures vs. functions, 4769 -- since functions can't be null subprograms. 4770 4771 if Ekind (Designator) = E_Procedure then 4772 Error_Msg_N 4773 ("interface procedure % must be abstract or null", N); 4774 else 4775 Error_Msg_N 4776 ("interface function % must be abstract", N); 4777 end if; 4778 end if; 4779 end; 4780 end if; 4781 4782 -- What is the following code for, it used to be 4783 4784 -- ??? Set_Suppress_Elaboration_Checks 4785 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator)); 4786 4787 -- The following seems equivalent, but a bit dubious 4788 4789 if Elaboration_Checks_Suppressed (Designator) then 4790 Set_Kill_Elaboration_Checks (Designator); 4791 end if; 4792 4793 -- For a compilation unit, set body required. This flag will only be 4794 -- reset if a valid Import or Interface pragma is processed later on. 4795 4796 if Nkind (Parent (N)) = N_Compilation_Unit then 4797 Set_Body_Required (Parent (N), True); 4798 4799 if Ada_Version >= Ada_2005 4800 and then Nkind (Specification (N)) = N_Procedure_Specification 4801 and then Null_Present (Specification (N)) 4802 then 4803 Error_Msg_N 4804 ("null procedure cannot be declared at library level", N); 4805 end if; 4806 end if; 4807 4808 Generate_Reference_To_Formals (Designator); 4809 Check_Eliminated (Designator); 4810 4811 if Debug_Flag_C then 4812 Outdent; 4813 Write_Str ("<== subprogram spec "); 4814 Write_Name (Chars (Designator)); 4815 Write_Str (" from "); 4816 Write_Location (Sloc (N)); 4817 Write_Eol; 4818 end if; 4819 4820 -- Indicate that this is a protected operation, because it may be used 4821 -- in subsequent declarations within the protected type. 4822 4823 if Is_Protected_Type (Current_Scope) then 4824 Set_Convention (Designator, Convention_Protected); 4825 end if; 4826 4827 List_Inherited_Pre_Post_Aspects (Designator); 4828 4829 -- Process the aspects before establishing the proper categorization in 4830 -- case the subprogram is a compilation unit and one of its aspects is 4831 -- converted into a categorization pragma. 4832 4833 if Has_Aspects (N) then 4834 Analyze_Aspect_Specifications (N, Designator); 4835 end if; 4836 4837 if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then 4838 Set_Categorization_From_Scope (Designator, Scop); 4839 4840 -- Otherwise the unit is a compilation unit and/or a child unit. Set the 4841 -- proper categorization of the unit based on its pragmas. 4842 4843 else 4844 Push_Scope (Designator); 4845 Set_Categorization_From_Pragmas (N); 4846 Validate_Categorization_Dependency (N, Designator); 4847 Pop_Scope; 4848 end if; 4849 end Analyze_Subprogram_Declaration; 4850 4851 -------------------------------------- 4852 -- Analyze_Subprogram_Specification -- 4853 -------------------------------------- 4854 4855 -- Reminder: N here really is a subprogram specification (not a subprogram 4856 -- declaration). This procedure is called to analyze the specification in 4857 -- both subprogram bodies and subprogram declarations (specs). 4858 4859 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is 4860 function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean; 4861 -- Determine whether entity E denotes the spec or body of an invariant 4862 -- procedure. 4863 4864 ------------------------------------ 4865 -- Is_Invariant_Procedure_Or_Body -- 4866 ------------------------------------ 4867 4868 function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean is 4869 Decl : constant Node_Id := Unit_Declaration_Node (E); 4870 Spec : Entity_Id; 4871 4872 begin 4873 if Nkind (Decl) = N_Subprogram_Body then 4874 Spec := Corresponding_Spec (Decl); 4875 else 4876 Spec := E; 4877 end if; 4878 4879 return 4880 Present (Spec) 4881 and then Ekind (Spec) = E_Procedure 4882 and then (Is_Partial_Invariant_Procedure (Spec) 4883 or else Is_Invariant_Procedure (Spec)); 4884 end Is_Invariant_Procedure_Or_Body; 4885 4886 -- Local variables 4887 4888 Designator : constant Entity_Id := Defining_Entity (N); 4889 Formals : constant List_Id := Parameter_Specifications (N); 4890 4891 -- Start of processing for Analyze_Subprogram_Specification 4892 4893 begin 4894 -- User-defined operator is not allowed in SPARK, except as a renaming 4895 4896 if Nkind (Defining_Unit_Name (N)) = N_Defining_Operator_Symbol 4897 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration 4898 then 4899 Check_SPARK_05_Restriction 4900 ("user-defined operator is not allowed", N); 4901 end if; 4902 4903 -- Proceed with analysis. Do not emit a cross-reference entry if the 4904 -- specification comes from an expression function, because it may be 4905 -- the completion of a previous declaration. If it is not, the cross- 4906 -- reference entry will be emitted for the new subprogram declaration. 4907 4908 if Nkind (Parent (N)) /= N_Expression_Function then 4909 Generate_Definition (Designator); 4910 end if; 4911 4912 if Nkind (N) = N_Function_Specification then 4913 Set_Ekind (Designator, E_Function); 4914 Set_Mechanism (Designator, Default_Mechanism); 4915 else 4916 Set_Ekind (Designator, E_Procedure); 4917 Set_Etype (Designator, Standard_Void_Type); 4918 end if; 4919 4920 -- Flag Is_Inlined_Always is True by default, and reversed to False for 4921 -- those subprograms which could be inlined in GNATprove mode (because 4922 -- Body_To_Inline is non-Empty) but should not be inlined. 4923 4924 if GNATprove_Mode then 4925 Set_Is_Inlined_Always (Designator); 4926 end if; 4927 4928 -- Introduce new scope for analysis of the formals and the return type 4929 4930 Set_Scope (Designator, Current_Scope); 4931 4932 if Present (Formals) then 4933 Push_Scope (Designator); 4934 Process_Formals (Formals, N); 4935 4936 -- Check dimensions in N for formals with default expression 4937 4938 Analyze_Dimension_Formals (N, Formals); 4939 4940 -- Ada 2005 (AI-345): If this is an overriding operation of an 4941 -- inherited interface operation, and the controlling type is 4942 -- a synchronized type, replace the type with its corresponding 4943 -- record, to match the proper signature of an overriding operation. 4944 -- Same processing for an access parameter whose designated type is 4945 -- derived from a synchronized interface. 4946 4947 -- This modification is not done for invariant procedures because 4948 -- the corresponding record may not necessarely be visible when the 4949 -- concurrent type acts as the full view of a private type. 4950 4951 -- package Pack is 4952 -- type Prot is private with Type_Invariant => ...; 4953 -- procedure ConcInvariant (Obj : Prot); 4954 -- private 4955 -- protected type Prot is ...; 4956 -- type Concurrent_Record_Prot is record ...; 4957 -- procedure ConcInvariant (Obj : Prot) is 4958 -- ... 4959 -- end ConcInvariant; 4960 -- end Pack; 4961 4962 -- In the example above, both the spec and body of the invariant 4963 -- procedure must utilize the private type as the controlling type. 4964 4965 if Ada_Version >= Ada_2005 4966 and then not Is_Invariant_Procedure_Or_Body (Designator) 4967 then 4968 declare 4969 Formal : Entity_Id; 4970 Formal_Typ : Entity_Id; 4971 Rec_Typ : Entity_Id; 4972 Desig_Typ : Entity_Id; 4973 4974 begin 4975 Formal := First_Formal (Designator); 4976 while Present (Formal) loop 4977 Formal_Typ := Etype (Formal); 4978 4979 if Is_Concurrent_Type (Formal_Typ) 4980 and then Present (Corresponding_Record_Type (Formal_Typ)) 4981 then 4982 Rec_Typ := Corresponding_Record_Type (Formal_Typ); 4983 4984 if Present (Interfaces (Rec_Typ)) then 4985 Set_Etype (Formal, Rec_Typ); 4986 end if; 4987 4988 elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then 4989 Desig_Typ := Designated_Type (Formal_Typ); 4990 4991 if Is_Concurrent_Type (Desig_Typ) 4992 and then Present (Corresponding_Record_Type (Desig_Typ)) 4993 then 4994 Rec_Typ := Corresponding_Record_Type (Desig_Typ); 4995 4996 if Present (Interfaces (Rec_Typ)) then 4997 Set_Directly_Designated_Type (Formal_Typ, Rec_Typ); 4998 end if; 4999 end if; 5000 end if; 5001 5002 Next_Formal (Formal); 5003 end loop; 5004 end; 5005 end if; 5006 5007 End_Scope; 5008 5009 -- The subprogram scope is pushed and popped around the processing of 5010 -- the return type for consistency with call above to Process_Formals 5011 -- (which itself can call Analyze_Return_Type), and to ensure that any 5012 -- itype created for the return type will be associated with the proper 5013 -- scope. 5014 5015 elsif Nkind (N) = N_Function_Specification then 5016 Push_Scope (Designator); 5017 Analyze_Return_Type (N); 5018 End_Scope; 5019 end if; 5020 5021 -- Function case 5022 5023 if Nkind (N) = N_Function_Specification then 5024 5025 -- Deal with operator symbol case 5026 5027 if Nkind (Designator) = N_Defining_Operator_Symbol then 5028 Valid_Operator_Definition (Designator); 5029 end if; 5030 5031 May_Need_Actuals (Designator); 5032 5033 -- Ada 2005 (AI-251): If the return type is abstract, verify that 5034 -- the subprogram is abstract also. This does not apply to renaming 5035 -- declarations, where abstractness is inherited, and to subprogram 5036 -- bodies generated for stream operations, which become renamings as 5037 -- bodies. 5038 5039 -- In case of primitives associated with abstract interface types 5040 -- the check is applied later (see Analyze_Subprogram_Declaration). 5041 5042 if not Nkind_In (Original_Node (Parent (N)), 5043 N_Abstract_Subprogram_Declaration, 5044 N_Formal_Abstract_Subprogram_Declaration, 5045 N_Subprogram_Renaming_Declaration) 5046 then 5047 if Is_Abstract_Type (Etype (Designator)) 5048 and then not Is_Interface (Etype (Designator)) 5049 then 5050 Error_Msg_N 5051 ("function that returns abstract type must be abstract", N); 5052 5053 -- Ada 2012 (AI-0073): Extend this test to subprograms with an 5054 -- access result whose designated type is abstract. 5055 5056 elsif Ada_Version >= Ada_2012 5057 and then Nkind (Result_Definition (N)) = N_Access_Definition 5058 and then 5059 not Is_Class_Wide_Type (Designated_Type (Etype (Designator))) 5060 and then Is_Abstract_Type (Designated_Type (Etype (Designator))) 5061 then 5062 Error_Msg_N 5063 ("function whose access result designates abstract type " 5064 & "must be abstract", N); 5065 end if; 5066 end if; 5067 end if; 5068 5069 return Designator; 5070 end Analyze_Subprogram_Specification; 5071 5072 ----------------------- 5073 -- Check_Conformance -- 5074 ----------------------- 5075 5076 procedure Check_Conformance 5077 (New_Id : Entity_Id; 5078 Old_Id : Entity_Id; 5079 Ctype : Conformance_Type; 5080 Errmsg : Boolean; 5081 Conforms : out Boolean; 5082 Err_Loc : Node_Id := Empty; 5083 Get_Inst : Boolean := False; 5084 Skip_Controlling_Formals : Boolean := False) 5085 is 5086 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id); 5087 -- Sets Conforms to False. If Errmsg is False, then that's all it does. 5088 -- If Errmsg is True, then processing continues to post an error message 5089 -- for conformance error on given node. Two messages are output. The 5090 -- first message points to the previous declaration with a general "no 5091 -- conformance" message. The second is the detailed reason, supplied as 5092 -- Msg. The parameter N provide information for a possible & insertion 5093 -- in the message, and also provides the location for posting the 5094 -- message in the absence of a specified Err_Loc location. 5095 5096 function Conventions_Match 5097 (Id1 : Entity_Id; 5098 Id2 : Entity_Id) return Boolean; 5099 -- Determine whether the conventions of arbitrary entities Id1 and Id2 5100 -- match. 5101 5102 ----------------------- 5103 -- Conformance_Error -- 5104 ----------------------- 5105 5106 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is 5107 Enode : Node_Id; 5108 5109 begin 5110 Conforms := False; 5111 5112 if Errmsg then 5113 if No (Err_Loc) then 5114 Enode := N; 5115 else 5116 Enode := Err_Loc; 5117 end if; 5118 5119 Error_Msg_Sloc := Sloc (Old_Id); 5120 5121 case Ctype is 5122 when Type_Conformant => 5123 Error_Msg_N -- CODEFIX 5124 ("not type conformant with declaration#!", Enode); 5125 5126 when Mode_Conformant => 5127 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 5128 Error_Msg_N 5129 ("not mode conformant with operation inherited#!", 5130 Enode); 5131 else 5132 Error_Msg_N 5133 ("not mode conformant with declaration#!", Enode); 5134 end if; 5135 5136 when Subtype_Conformant => 5137 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 5138 Error_Msg_N 5139 ("not subtype conformant with operation inherited#!", 5140 Enode); 5141 else 5142 Error_Msg_N 5143 ("not subtype conformant with declaration#!", Enode); 5144 end if; 5145 5146 when Fully_Conformant => 5147 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then 5148 Error_Msg_N -- CODEFIX 5149 ("not fully conformant with operation inherited#!", 5150 Enode); 5151 else 5152 Error_Msg_N -- CODEFIX 5153 ("not fully conformant with declaration#!", Enode); 5154 end if; 5155 end case; 5156 5157 Error_Msg_NE (Msg, Enode, N); 5158 end if; 5159 end Conformance_Error; 5160 5161 ----------------------- 5162 -- Conventions_Match -- 5163 ----------------------- 5164 5165 function Conventions_Match 5166 (Id1 : Entity_Id; 5167 Id2 : Entity_Id) return Boolean 5168 is 5169 begin 5170 -- Ignore the conventions of anonymous access-to-subprogram types 5171 -- and subprogram types because these are internally generated and 5172 -- the only way these may receive a convention is if they inherit 5173 -- the convention of a related subprogram. 5174 5175 if Ekind_In (Id1, E_Anonymous_Access_Subprogram_Type, 5176 E_Subprogram_Type) 5177 or else 5178 Ekind_In (Id2, E_Anonymous_Access_Subprogram_Type, 5179 E_Subprogram_Type) 5180 then 5181 return True; 5182 5183 -- Otherwise compare the conventions directly 5184 5185 else 5186 return Convention (Id1) = Convention (Id2); 5187 end if; 5188 end Conventions_Match; 5189 5190 -- Local Variables 5191 5192 Old_Type : constant Entity_Id := Etype (Old_Id); 5193 New_Type : constant Entity_Id := Etype (New_Id); 5194 Old_Formal : Entity_Id; 5195 New_Formal : Entity_Id; 5196 Access_Types_Match : Boolean; 5197 Old_Formal_Base : Entity_Id; 5198 New_Formal_Base : Entity_Id; 5199 5200 -- Start of processing for Check_Conformance 5201 5202 begin 5203 Conforms := True; 5204 5205 -- We need a special case for operators, since they don't appear 5206 -- explicitly. 5207 5208 if Ctype = Type_Conformant then 5209 if Ekind (New_Id) = E_Operator 5210 and then Operator_Matches_Spec (New_Id, Old_Id) 5211 then 5212 return; 5213 end if; 5214 end if; 5215 5216 -- If both are functions/operators, check return types conform 5217 5218 if Old_Type /= Standard_Void_Type 5219 and then 5220 New_Type /= Standard_Void_Type 5221 then 5222 -- If we are checking interface conformance we omit controlling 5223 -- arguments and result, because we are only checking the conformance 5224 -- of the remaining parameters. 5225 5226 if Has_Controlling_Result (Old_Id) 5227 and then Has_Controlling_Result (New_Id) 5228 and then Skip_Controlling_Formals 5229 then 5230 null; 5231 5232 elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then 5233 if Ctype >= Subtype_Conformant 5234 and then not Predicates_Match (Old_Type, New_Type) 5235 then 5236 Conformance_Error 5237 ("\predicate of return type does not match!", New_Id); 5238 else 5239 Conformance_Error 5240 ("\return type does not match!", New_Id); 5241 end if; 5242 5243 return; 5244 end if; 5245 5246 -- Ada 2005 (AI-231): In case of anonymous access types check the 5247 -- null-exclusion and access-to-constant attributes match. 5248 5249 if Ada_Version >= Ada_2005 5250 and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type 5251 and then 5252 (Can_Never_Be_Null (Old_Type) /= Can_Never_Be_Null (New_Type) 5253 or else Is_Access_Constant (Etype (Old_Type)) /= 5254 Is_Access_Constant (Etype (New_Type))) 5255 then 5256 Conformance_Error ("\return type does not match!", New_Id); 5257 return; 5258 end if; 5259 5260 -- If either is a function/operator and the other isn't, error 5261 5262 elsif Old_Type /= Standard_Void_Type 5263 or else New_Type /= Standard_Void_Type 5264 then 5265 Conformance_Error ("\functions can only match functions!", New_Id); 5266 return; 5267 end if; 5268 5269 -- In subtype conformant case, conventions must match (RM 6.3.1(16)). 5270 -- If this is a renaming as body, refine error message to indicate that 5271 -- the conflict is with the original declaration. If the entity is not 5272 -- frozen, the conventions don't have to match, the one of the renamed 5273 -- entity is inherited. 5274 5275 if Ctype >= Subtype_Conformant then 5276 if not Conventions_Match (Old_Id, New_Id) then 5277 if not Is_Frozen (New_Id) then 5278 null; 5279 5280 elsif Present (Err_Loc) 5281 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration 5282 and then Present (Corresponding_Spec (Err_Loc)) 5283 then 5284 Error_Msg_Name_1 := Chars (New_Id); 5285 Error_Msg_Name_2 := 5286 Name_Ada + Convention_Id'Pos (Convention (New_Id)); 5287 Conformance_Error ("\prior declaration for% has convention %!"); 5288 5289 else 5290 Conformance_Error ("\calling conventions do not match!"); 5291 end if; 5292 5293 return; 5294 5295 elsif Is_Formal_Subprogram (Old_Id) 5296 or else Is_Formal_Subprogram (New_Id) 5297 or else (Is_Subprogram (New_Id) 5298 and then Present (Alias (New_Id)) 5299 and then Is_Formal_Subprogram (Alias (New_Id))) 5300 then 5301 Conformance_Error 5302 ("\formal subprograms are not subtype conformant " 5303 & "(RM 6.3.1 (17/3))"); 5304 end if; 5305 end if; 5306 5307 -- Deal with parameters 5308 5309 -- Note: we use the entity information, rather than going directly 5310 -- to the specification in the tree. This is not only simpler, but 5311 -- absolutely necessary for some cases of conformance tests between 5312 -- operators, where the declaration tree simply does not exist. 5313 5314 Old_Formal := First_Formal (Old_Id); 5315 New_Formal := First_Formal (New_Id); 5316 while Present (Old_Formal) and then Present (New_Formal) loop 5317 if Is_Controlling_Formal (Old_Formal) 5318 and then Is_Controlling_Formal (New_Formal) 5319 and then Skip_Controlling_Formals 5320 then 5321 -- The controlling formals will have different types when 5322 -- comparing an interface operation with its match, but both 5323 -- or neither must be access parameters. 5324 5325 if Is_Access_Type (Etype (Old_Formal)) 5326 = 5327 Is_Access_Type (Etype (New_Formal)) 5328 then 5329 goto Skip_Controlling_Formal; 5330 else 5331 Conformance_Error 5332 ("\access parameter does not match!", New_Formal); 5333 end if; 5334 end if; 5335 5336 -- Ada 2012: Mode conformance also requires that formal parameters 5337 -- be both aliased, or neither. 5338 5339 if Ctype >= Mode_Conformant and then Ada_Version >= Ada_2012 then 5340 if Is_Aliased (Old_Formal) /= Is_Aliased (New_Formal) then 5341 Conformance_Error 5342 ("\aliased parameter mismatch!", New_Formal); 5343 end if; 5344 end if; 5345 5346 if Ctype = Fully_Conformant then 5347 5348 -- Names must match. Error message is more accurate if we do 5349 -- this before checking that the types of the formals match. 5350 5351 if Chars (Old_Formal) /= Chars (New_Formal) then 5352 Conformance_Error ("\name& does not match!", New_Formal); 5353 5354 -- Set error posted flag on new formal as well to stop 5355 -- junk cascaded messages in some cases. 5356 5357 Set_Error_Posted (New_Formal); 5358 return; 5359 end if; 5360 5361 -- Null exclusion must match 5362 5363 if Null_Exclusion_Present (Parent (Old_Formal)) 5364 /= 5365 Null_Exclusion_Present (Parent (New_Formal)) 5366 then 5367 -- Only give error if both come from source. This should be 5368 -- investigated some time, since it should not be needed ??? 5369 5370 if Comes_From_Source (Old_Formal) 5371 and then 5372 Comes_From_Source (New_Formal) 5373 then 5374 Conformance_Error 5375 ("\null exclusion for& does not match", New_Formal); 5376 5377 -- Mark error posted on the new formal to avoid duplicated 5378 -- complaint about types not matching. 5379 5380 Set_Error_Posted (New_Formal); 5381 end if; 5382 end if; 5383 end if; 5384 5385 -- Ada 2005 (AI-423): Possible access [sub]type and itype match. This 5386 -- case occurs whenever a subprogram is being renamed and one of its 5387 -- parameters imposes a null exclusion. For example: 5388 5389 -- type T is null record; 5390 -- type Acc_T is access T; 5391 -- subtype Acc_T_Sub is Acc_T; 5392 5393 -- procedure P (Obj : not null Acc_T_Sub); -- itype 5394 -- procedure Ren_P (Obj : Acc_T_Sub) -- subtype 5395 -- renames P; 5396 5397 Old_Formal_Base := Etype (Old_Formal); 5398 New_Formal_Base := Etype (New_Formal); 5399 5400 if Get_Inst then 5401 Old_Formal_Base := Get_Instance_Of (Old_Formal_Base); 5402 New_Formal_Base := Get_Instance_Of (New_Formal_Base); 5403 end if; 5404 5405 Access_Types_Match := Ada_Version >= Ada_2005 5406 5407 -- Ensure that this rule is only applied when New_Id is a 5408 -- renaming of Old_Id. 5409 5410 and then Nkind (Parent (Parent (New_Id))) = 5411 N_Subprogram_Renaming_Declaration 5412 and then Nkind (Name (Parent (Parent (New_Id)))) in N_Has_Entity 5413 and then Present (Entity (Name (Parent (Parent (New_Id))))) 5414 and then Entity (Name (Parent (Parent (New_Id)))) = Old_Id 5415 5416 -- Now handle the allowed access-type case 5417 5418 and then Is_Access_Type (Old_Formal_Base) 5419 and then Is_Access_Type (New_Formal_Base) 5420 5421 -- The type kinds must match. The only exception occurs with 5422 -- multiple generics of the form: 5423 5424 -- generic generic 5425 -- type F is private; type A is private; 5426 -- type F_Ptr is access F; type A_Ptr is access A; 5427 -- with proc F_P (X : F_Ptr); with proc A_P (X : A_Ptr); 5428 -- package F_Pack is ... package A_Pack is 5429 -- package F_Inst is 5430 -- new F_Pack (A, A_Ptr, A_P); 5431 5432 -- When checking for conformance between the parameters of A_P 5433 -- and F_P, the type kinds of F_Ptr and A_Ptr will not match 5434 -- because the compiler has transformed A_Ptr into a subtype of 5435 -- F_Ptr. We catch this case in the code below. 5436 5437 and then (Ekind (Old_Formal_Base) = Ekind (New_Formal_Base) 5438 or else 5439 (Is_Generic_Type (Old_Formal_Base) 5440 and then Is_Generic_Type (New_Formal_Base) 5441 and then Is_Internal (New_Formal_Base) 5442 and then Etype (Etype (New_Formal_Base)) = 5443 Old_Formal_Base)) 5444 and then Directly_Designated_Type (Old_Formal_Base) = 5445 Directly_Designated_Type (New_Formal_Base) 5446 and then ((Is_Itype (Old_Formal_Base) 5447 and then Can_Never_Be_Null (Old_Formal_Base)) 5448 or else 5449 (Is_Itype (New_Formal_Base) 5450 and then Can_Never_Be_Null (New_Formal_Base))); 5451 5452 -- Types must always match. In the visible part of an instance, 5453 -- usual overloading rules for dispatching operations apply, and 5454 -- we check base types (not the actual subtypes). 5455 5456 if In_Instance_Visible_Part 5457 and then Is_Dispatching_Operation (New_Id) 5458 then 5459 if not Conforming_Types 5460 (T1 => Base_Type (Etype (Old_Formal)), 5461 T2 => Base_Type (Etype (New_Formal)), 5462 Ctype => Ctype, 5463 Get_Inst => Get_Inst) 5464 and then not Access_Types_Match 5465 then 5466 Conformance_Error ("\type of & does not match!", New_Formal); 5467 return; 5468 end if; 5469 5470 elsif not Conforming_Types 5471 (T1 => Old_Formal_Base, 5472 T2 => New_Formal_Base, 5473 Ctype => Ctype, 5474 Get_Inst => Get_Inst) 5475 and then not Access_Types_Match 5476 then 5477 -- Don't give error message if old type is Any_Type. This test 5478 -- avoids some cascaded errors, e.g. in case of a bad spec. 5479 5480 if Errmsg and then Old_Formal_Base = Any_Type then 5481 Conforms := False; 5482 else 5483 if Ctype >= Subtype_Conformant 5484 and then 5485 not Predicates_Match (Old_Formal_Base, New_Formal_Base) 5486 then 5487 Conformance_Error 5488 ("\predicate of & does not match!", New_Formal); 5489 else 5490 Conformance_Error 5491 ("\type of & does not match!", New_Formal); 5492 5493 if not Dimensions_Match (Old_Formal_Base, New_Formal_Base) 5494 then 5495 Error_Msg_N ("\dimensions mismatch!", New_Formal); 5496 end if; 5497 end if; 5498 end if; 5499 5500 return; 5501 end if; 5502 5503 -- For mode conformance, mode must match 5504 5505 if Ctype >= Mode_Conformant then 5506 if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then 5507 if not Ekind_In (New_Id, E_Function, E_Procedure) 5508 or else not Is_Primitive_Wrapper (New_Id) 5509 then 5510 Conformance_Error ("\mode of & does not match!", New_Formal); 5511 5512 else 5513 declare 5514 T : constant Entity_Id := Find_Dispatching_Type (New_Id); 5515 begin 5516 if Is_Protected_Type (Corresponding_Concurrent_Type (T)) 5517 then 5518 Error_Msg_PT (New_Id, Ultimate_Alias (Old_Id)); 5519 else 5520 Conformance_Error 5521 ("\mode of & does not match!", New_Formal); 5522 end if; 5523 end; 5524 end if; 5525 5526 return; 5527 5528 -- Part of mode conformance for access types is having the same 5529 -- constant modifier. 5530 5531 elsif Access_Types_Match 5532 and then Is_Access_Constant (Old_Formal_Base) /= 5533 Is_Access_Constant (New_Formal_Base) 5534 then 5535 Conformance_Error 5536 ("\constant modifier does not match!", New_Formal); 5537 return; 5538 end if; 5539 end if; 5540 5541 if Ctype >= Subtype_Conformant then 5542 5543 -- Ada 2005 (AI-231): In case of anonymous access types check 5544 -- the null-exclusion and access-to-constant attributes must 5545 -- match. For null exclusion, we test the types rather than the 5546 -- formals themselves, since the attribute is only set reliably 5547 -- on the formals in the Ada 95 case, and we exclude the case 5548 -- where Old_Formal is marked as controlling, to avoid errors 5549 -- when matching completing bodies with dispatching declarations 5550 -- (access formals in the bodies aren't marked Can_Never_Be_Null). 5551 5552 if Ada_Version >= Ada_2005 5553 and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type 5554 and then Ekind (Etype (New_Formal)) = E_Anonymous_Access_Type 5555 and then 5556 ((Can_Never_Be_Null (Etype (Old_Formal)) /= 5557 Can_Never_Be_Null (Etype (New_Formal)) 5558 and then 5559 not Is_Controlling_Formal (Old_Formal)) 5560 or else 5561 Is_Access_Constant (Etype (Old_Formal)) /= 5562 Is_Access_Constant (Etype (New_Formal))) 5563 5564 -- Do not complain if error already posted on New_Formal. This 5565 -- avoids some redundant error messages. 5566 5567 and then not Error_Posted (New_Formal) 5568 then 5569 -- It is allowed to omit the null-exclusion in case of stream 5570 -- attribute subprograms. We recognize stream subprograms 5571 -- through their TSS-generated suffix. 5572 5573 declare 5574 TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id); 5575 5576 begin 5577 if TSS_Name /= TSS_Stream_Read 5578 and then TSS_Name /= TSS_Stream_Write 5579 and then TSS_Name /= TSS_Stream_Input 5580 and then TSS_Name /= TSS_Stream_Output 5581 then 5582 -- Here we have a definite conformance error. It is worth 5583 -- special casing the error message for the case of a 5584 -- controlling formal (which excludes null). 5585 5586 if Is_Controlling_Formal (New_Formal) then 5587 Error_Msg_Node_2 := Scope (New_Formal); 5588 Conformance_Error 5589 ("\controlling formal & of & excludes null, " 5590 & "declaration must exclude null as well", 5591 New_Formal); 5592 5593 -- Normal case (couldn't we give more detail here???) 5594 5595 else 5596 Conformance_Error 5597 ("\type of & does not match!", New_Formal); 5598 end if; 5599 5600 return; 5601 end if; 5602 end; 5603 end if; 5604 end if; 5605 5606 -- Full conformance checks 5607 5608 if Ctype = Fully_Conformant then 5609 5610 -- We have checked already that names match 5611 5612 if Parameter_Mode (Old_Formal) = E_In_Parameter then 5613 5614 -- Check default expressions for in parameters 5615 5616 declare 5617 NewD : constant Boolean := 5618 Present (Default_Value (New_Formal)); 5619 OldD : constant Boolean := 5620 Present (Default_Value (Old_Formal)); 5621 begin 5622 if NewD or OldD then 5623 5624 -- The old default value has been analyzed because the 5625 -- current full declaration will have frozen everything 5626 -- before. The new default value has not been analyzed, 5627 -- so analyze it now before we check for conformance. 5628 5629 if NewD then 5630 Push_Scope (New_Id); 5631 Preanalyze_Spec_Expression 5632 (Default_Value (New_Formal), Etype (New_Formal)); 5633 End_Scope; 5634 end if; 5635 5636 if not (NewD and OldD) 5637 or else not Fully_Conformant_Expressions 5638 (Default_Value (Old_Formal), 5639 Default_Value (New_Formal)) 5640 then 5641 Conformance_Error 5642 ("\default expression for & does not match!", 5643 New_Formal); 5644 return; 5645 end if; 5646 end if; 5647 end; 5648 end if; 5649 end if; 5650 5651 -- A couple of special checks for Ada 83 mode. These checks are 5652 -- skipped if either entity is an operator in package Standard, 5653 -- or if either old or new instance is not from the source program. 5654 5655 if Ada_Version = Ada_83 5656 and then Sloc (Old_Id) > Standard_Location 5657 and then Sloc (New_Id) > Standard_Location 5658 and then Comes_From_Source (Old_Id) 5659 and then Comes_From_Source (New_Id) 5660 then 5661 declare 5662 Old_Param : constant Node_Id := Declaration_Node (Old_Formal); 5663 New_Param : constant Node_Id := Declaration_Node (New_Formal); 5664 5665 begin 5666 -- Explicit IN must be present or absent in both cases. This 5667 -- test is required only in the full conformance case. 5668 5669 if In_Present (Old_Param) /= In_Present (New_Param) 5670 and then Ctype = Fully_Conformant 5671 then 5672 Conformance_Error 5673 ("\(Ada 83) IN must appear in both declarations", 5674 New_Formal); 5675 return; 5676 end if; 5677 5678 -- Grouping (use of comma in param lists) must be the same 5679 -- This is where we catch a misconformance like: 5680 5681 -- A, B : Integer 5682 -- A : Integer; B : Integer 5683 5684 -- which are represented identically in the tree except 5685 -- for the setting of the flags More_Ids and Prev_Ids. 5686 5687 if More_Ids (Old_Param) /= More_Ids (New_Param) 5688 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param) 5689 then 5690 Conformance_Error 5691 ("\grouping of & does not match!", New_Formal); 5692 return; 5693 end if; 5694 end; 5695 end if; 5696 5697 -- This label is required when skipping controlling formals 5698 5699 <<Skip_Controlling_Formal>> 5700 5701 Next_Formal (Old_Formal); 5702 Next_Formal (New_Formal); 5703 end loop; 5704 5705 if Present (Old_Formal) then 5706 Conformance_Error ("\too few parameters!"); 5707 return; 5708 5709 elsif Present (New_Formal) then 5710 Conformance_Error ("\too many parameters!", New_Formal); 5711 return; 5712 end if; 5713 end Check_Conformance; 5714 5715 ----------------------- 5716 -- Check_Conventions -- 5717 ----------------------- 5718 5719 procedure Check_Conventions (Typ : Entity_Id) is 5720 Ifaces_List : Elist_Id; 5721 5722 procedure Check_Convention (Op : Entity_Id); 5723 -- Verify that the convention of inherited dispatching operation Op is 5724 -- consistent among all subprograms it overrides. In order to minimize 5725 -- the search, Search_From is utilized to designate a specific point in 5726 -- the list rather than iterating over the whole list once more. 5727 5728 ---------------------- 5729 -- Check_Convention -- 5730 ---------------------- 5731 5732 procedure Check_Convention (Op : Entity_Id) is 5733 Op_Conv : constant Convention_Id := Convention (Op); 5734 Iface_Conv : Convention_Id; 5735 Iface_Elmt : Elmt_Id; 5736 Iface_Prim_Elmt : Elmt_Id; 5737 Iface_Prim : Entity_Id; 5738 5739 begin 5740 Iface_Elmt := First_Elmt (Ifaces_List); 5741 while Present (Iface_Elmt) loop 5742 Iface_Prim_Elmt := 5743 First_Elmt (Primitive_Operations (Node (Iface_Elmt))); 5744 while Present (Iface_Prim_Elmt) loop 5745 Iface_Prim := Node (Iface_Prim_Elmt); 5746 Iface_Conv := Convention (Iface_Prim); 5747 5748 if Is_Interface_Conformant (Typ, Iface_Prim, Op) 5749 and then Iface_Conv /= Op_Conv 5750 then 5751 Error_Msg_N 5752 ("inconsistent conventions in primitive operations", Typ); 5753 5754 Error_Msg_Name_1 := Chars (Op); 5755 Error_Msg_Name_2 := Get_Convention_Name (Op_Conv); 5756 Error_Msg_Sloc := Sloc (Op); 5757 5758 if Comes_From_Source (Op) or else No (Alias (Op)) then 5759 if not Present (Overridden_Operation (Op)) then 5760 Error_Msg_N ("\\primitive % defined #", Typ); 5761 else 5762 Error_Msg_N 5763 ("\\overriding operation % with " 5764 & "convention % defined #", Typ); 5765 end if; 5766 5767 else pragma Assert (Present (Alias (Op))); 5768 Error_Msg_Sloc := Sloc (Alias (Op)); 5769 Error_Msg_N ("\\inherited operation % with " 5770 & "convention % defined #", Typ); 5771 end if; 5772 5773 Error_Msg_Name_1 := Chars (Op); 5774 Error_Msg_Name_2 := Get_Convention_Name (Iface_Conv); 5775 Error_Msg_Sloc := Sloc (Iface_Prim); 5776 Error_Msg_N ("\\overridden operation % with " 5777 & "convention % defined #", Typ); 5778 5779 -- Avoid cascading errors 5780 5781 return; 5782 end if; 5783 5784 Next_Elmt (Iface_Prim_Elmt); 5785 end loop; 5786 5787 Next_Elmt (Iface_Elmt); 5788 end loop; 5789 end Check_Convention; 5790 5791 -- Local variables 5792 5793 Prim_Op : Entity_Id; 5794 Prim_Op_Elmt : Elmt_Id; 5795 5796 -- Start of processing for Check_Conventions 5797 5798 begin 5799 if not Has_Interfaces (Typ) then 5800 return; 5801 end if; 5802 5803 Collect_Interfaces (Typ, Ifaces_List); 5804 5805 -- The algorithm checks every overriding dispatching operation against 5806 -- all the corresponding overridden dispatching operations, detecting 5807 -- differences in conventions. 5808 5809 Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ)); 5810 while Present (Prim_Op_Elmt) loop 5811 Prim_Op := Node (Prim_Op_Elmt); 5812 5813 -- A small optimization: skip the predefined dispatching operations 5814 -- since they always have the same convention. 5815 5816 if not Is_Predefined_Dispatching_Operation (Prim_Op) then 5817 Check_Convention (Prim_Op); 5818 end if; 5819 5820 Next_Elmt (Prim_Op_Elmt); 5821 end loop; 5822 end Check_Conventions; 5823 5824 ------------------------------ 5825 -- Check_Delayed_Subprogram -- 5826 ------------------------------ 5827 5828 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is 5829 procedure Possible_Freeze (T : Entity_Id); 5830 -- T is the type of either a formal parameter or of the return type. If 5831 -- T is not yet frozen and needs a delayed freeze, then the subprogram 5832 -- itself must be delayed. 5833 5834 --------------------- 5835 -- Possible_Freeze -- 5836 --------------------- 5837 5838 procedure Possible_Freeze (T : Entity_Id) is 5839 Scop : constant Entity_Id := Scope (Designator); 5840 5841 begin 5842 -- If the subprogram appears within a package instance (which may be 5843 -- the wrapper package of a subprogram instance) the freeze node for 5844 -- that package will freeze the subprogram at the proper place, so 5845 -- do not emit a freeze node for the subprogram, given that it may 5846 -- appear in the wrong scope. 5847 5848 if Ekind (Scop) = E_Package 5849 and then not Comes_From_Source (Scop) 5850 and then Is_Generic_Instance (Scop) 5851 then 5852 null; 5853 5854 elsif Has_Delayed_Freeze (T) and then not Is_Frozen (T) then 5855 Set_Has_Delayed_Freeze (Designator); 5856 5857 elsif Is_Access_Type (T) 5858 and then Has_Delayed_Freeze (Designated_Type (T)) 5859 and then not Is_Frozen (Designated_Type (T)) 5860 then 5861 Set_Has_Delayed_Freeze (Designator); 5862 end if; 5863 end Possible_Freeze; 5864 5865 -- Local variables 5866 5867 F : Entity_Id; 5868 5869 -- Start of processing for Check_Delayed_Subprogram 5870 5871 begin 5872 -- All subprograms, including abstract subprograms, may need a freeze 5873 -- node if some formal type or the return type needs one. 5874 5875 Possible_Freeze (Etype (Designator)); 5876 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ??? 5877 5878 -- Need delayed freeze if any of the formal types themselves need a 5879 -- delayed freeze and are not yet frozen. 5880 5881 F := First_Formal (Designator); 5882 while Present (F) loop 5883 Possible_Freeze (Etype (F)); 5884 Possible_Freeze (Base_Type (Etype (F))); -- needed ??? 5885 Next_Formal (F); 5886 end loop; 5887 5888 -- Mark functions that return by reference. Note that it cannot be done 5889 -- for delayed_freeze subprograms because the underlying returned type 5890 -- may not be known yet (for private types). 5891 5892 if not Has_Delayed_Freeze (Designator) and then Expander_Active then 5893 declare 5894 Typ : constant Entity_Id := Etype (Designator); 5895 Utyp : constant Entity_Id := Underlying_Type (Typ); 5896 5897 begin 5898 if Is_Limited_View (Typ) then 5899 Set_Returns_By_Ref (Designator); 5900 5901 elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then 5902 Set_Returns_By_Ref (Designator); 5903 end if; 5904 end; 5905 end if; 5906 end Check_Delayed_Subprogram; 5907 5908 ------------------------------------ 5909 -- Check_Discriminant_Conformance -- 5910 ------------------------------------ 5911 5912 procedure Check_Discriminant_Conformance 5913 (N : Node_Id; 5914 Prev : Entity_Id; 5915 Prev_Loc : Node_Id) 5916 is 5917 Old_Discr : Entity_Id := First_Discriminant (Prev); 5918 New_Discr : Node_Id := First (Discriminant_Specifications (N)); 5919 New_Discr_Id : Entity_Id; 5920 New_Discr_Type : Entity_Id; 5921 5922 procedure Conformance_Error (Msg : String; N : Node_Id); 5923 -- Post error message for conformance error on given node. Two messages 5924 -- are output. The first points to the previous declaration with a 5925 -- general "no conformance" message. The second is the detailed reason, 5926 -- supplied as Msg. The parameter N provide information for a possible 5927 -- & insertion in the message. 5928 5929 ----------------------- 5930 -- Conformance_Error -- 5931 ----------------------- 5932 5933 procedure Conformance_Error (Msg : String; N : Node_Id) is 5934 begin 5935 Error_Msg_Sloc := Sloc (Prev_Loc); 5936 Error_Msg_N -- CODEFIX 5937 ("not fully conformant with declaration#!", N); 5938 Error_Msg_NE (Msg, N, N); 5939 end Conformance_Error; 5940 5941 -- Start of processing for Check_Discriminant_Conformance 5942 5943 begin 5944 while Present (Old_Discr) and then Present (New_Discr) loop 5945 New_Discr_Id := Defining_Identifier (New_Discr); 5946 5947 -- The subtype mark of the discriminant on the full type has not 5948 -- been analyzed so we do it here. For an access discriminant a new 5949 -- type is created. 5950 5951 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then 5952 New_Discr_Type := 5953 Access_Definition (N, Discriminant_Type (New_Discr)); 5954 5955 else 5956 Analyze (Discriminant_Type (New_Discr)); 5957 New_Discr_Type := Etype (Discriminant_Type (New_Discr)); 5958 5959 -- Ada 2005: if the discriminant definition carries a null 5960 -- exclusion, create an itype to check properly for consistency 5961 -- with partial declaration. 5962 5963 if Is_Access_Type (New_Discr_Type) 5964 and then Null_Exclusion_Present (New_Discr) 5965 then 5966 New_Discr_Type := 5967 Create_Null_Excluding_Itype 5968 (T => New_Discr_Type, 5969 Related_Nod => New_Discr, 5970 Scope_Id => Current_Scope); 5971 end if; 5972 end if; 5973 5974 if not Conforming_Types 5975 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant) 5976 then 5977 Conformance_Error ("type of & does not match!", New_Discr_Id); 5978 return; 5979 else 5980 -- Treat the new discriminant as an occurrence of the old one, 5981 -- for navigation purposes, and fill in some semantic 5982 -- information, for completeness. 5983 5984 Generate_Reference (Old_Discr, New_Discr_Id, 'r'); 5985 Set_Etype (New_Discr_Id, Etype (Old_Discr)); 5986 Set_Scope (New_Discr_Id, Scope (Old_Discr)); 5987 end if; 5988 5989 -- Names must match 5990 5991 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then 5992 Conformance_Error ("name & does not match!", New_Discr_Id); 5993 return; 5994 end if; 5995 5996 -- Default expressions must match 5997 5998 declare 5999 NewD : constant Boolean := 6000 Present (Expression (New_Discr)); 6001 OldD : constant Boolean := 6002 Present (Expression (Parent (Old_Discr))); 6003 6004 begin 6005 if NewD or OldD then 6006 6007 -- The old default value has been analyzed and expanded, 6008 -- because the current full declaration will have frozen 6009 -- everything before. The new default values have not been 6010 -- expanded, so expand now to check conformance. 6011 6012 if NewD then 6013 Preanalyze_Spec_Expression 6014 (Expression (New_Discr), New_Discr_Type); 6015 end if; 6016 6017 if not (NewD and OldD) 6018 or else not Fully_Conformant_Expressions 6019 (Expression (Parent (Old_Discr)), 6020 Expression (New_Discr)) 6021 6022 then 6023 Conformance_Error 6024 ("default expression for & does not match!", 6025 New_Discr_Id); 6026 return; 6027 end if; 6028 end if; 6029 end; 6030 6031 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X) 6032 6033 if Ada_Version = Ada_83 then 6034 declare 6035 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr); 6036 6037 begin 6038 -- Grouping (use of comma in param lists) must be the same 6039 -- This is where we catch a misconformance like: 6040 6041 -- A, B : Integer 6042 -- A : Integer; B : Integer 6043 6044 -- which are represented identically in the tree except 6045 -- for the setting of the flags More_Ids and Prev_Ids. 6046 6047 if More_Ids (Old_Disc) /= More_Ids (New_Discr) 6048 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr) 6049 then 6050 Conformance_Error 6051 ("grouping of & does not match!", New_Discr_Id); 6052 return; 6053 end if; 6054 end; 6055 end if; 6056 6057 Next_Discriminant (Old_Discr); 6058 Next (New_Discr); 6059 end loop; 6060 6061 if Present (Old_Discr) then 6062 Conformance_Error ("too few discriminants!", Defining_Identifier (N)); 6063 return; 6064 6065 elsif Present (New_Discr) then 6066 Conformance_Error 6067 ("too many discriminants!", Defining_Identifier (New_Discr)); 6068 return; 6069 end if; 6070 end Check_Discriminant_Conformance; 6071 6072 ---------------------------- 6073 -- Check_Fully_Conformant -- 6074 ---------------------------- 6075 6076 procedure Check_Fully_Conformant 6077 (New_Id : Entity_Id; 6078 Old_Id : Entity_Id; 6079 Err_Loc : Node_Id := Empty) 6080 is 6081 Result : Boolean; 6082 pragma Warnings (Off, Result); 6083 begin 6084 Check_Conformance 6085 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc); 6086 end Check_Fully_Conformant; 6087 6088 -------------------------- 6089 -- Check_Limited_Return -- 6090 -------------------------- 6091 6092 procedure Check_Limited_Return 6093 (N : Node_Id; 6094 Expr : Node_Id; 6095 R_Type : Entity_Id) 6096 is 6097 begin 6098 -- Ada 2005 (AI-318-02): Return-by-reference types have been removed and 6099 -- replaced by anonymous access results. This is an incompatibility with 6100 -- Ada 95. Not clear whether this should be enforced yet or perhaps 6101 -- controllable with special switch. ??? 6102 6103 -- A limited interface that is not immutably limited is OK 6104 6105 if Is_Limited_Interface (R_Type) 6106 and then 6107 not (Is_Task_Interface (R_Type) 6108 or else Is_Protected_Interface (R_Type) 6109 or else Is_Synchronized_Interface (R_Type)) 6110 then 6111 null; 6112 6113 elsif Is_Limited_Type (R_Type) 6114 and then not Is_Interface (R_Type) 6115 and then Comes_From_Source (N) 6116 and then not In_Instance_Body 6117 and then not OK_For_Limited_Init_In_05 (R_Type, Expr) 6118 then 6119 -- Error in Ada 2005 6120 6121 if Ada_Version >= Ada_2005 6122 and then not Debug_Flag_Dot_L 6123 and then not GNAT_Mode 6124 then 6125 Error_Msg_N 6126 ("(Ada 2005) cannot copy object of a limited type " 6127 & "(RM-2005 6.5(5.5/2))", Expr); 6128 6129 if Is_Limited_View (R_Type) then 6130 Error_Msg_N 6131 ("\return by reference not permitted in Ada 2005", Expr); 6132 end if; 6133 6134 -- Warn in Ada 95 mode, to give folks a heads up about this 6135 -- incompatibility. 6136 6137 -- In GNAT mode, this is just a warning, to allow it to be evilly 6138 -- turned off. Otherwise it is a real error. 6139 6140 -- In a generic context, simplify the warning because it makes no 6141 -- sense to discuss pass-by-reference or copy. 6142 6143 elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then 6144 if Inside_A_Generic then 6145 Error_Msg_N 6146 ("return of limited object not permitted in Ada 2005 " 6147 & "(RM-2005 6.5(5.5/2))?y?", Expr); 6148 6149 elsif Is_Limited_View (R_Type) then 6150 Error_Msg_N 6151 ("return by reference not permitted in Ada 2005 " 6152 & "(RM-2005 6.5(5.5/2))?y?", Expr); 6153 else 6154 Error_Msg_N 6155 ("cannot copy object of a limited type in Ada 2005 " 6156 & "(RM-2005 6.5(5.5/2))?y?", Expr); 6157 end if; 6158 6159 -- Ada 95 mode, and compatibility warnings disabled 6160 6161 else 6162 pragma Assert (Ada_Version <= Ada_95); 6163 pragma Assert (not (Warn_On_Ada_2005_Compatibility or GNAT_Mode)); 6164 return; -- skip continuation messages below 6165 end if; 6166 6167 if not Inside_A_Generic then 6168 Error_Msg_N 6169 ("\consider switching to return of access type", Expr); 6170 Explain_Limited_Type (R_Type, Expr); 6171 end if; 6172 end if; 6173 end Check_Limited_Return; 6174 6175 --------------------------- 6176 -- Check_Mode_Conformant -- 6177 --------------------------- 6178 6179 procedure Check_Mode_Conformant 6180 (New_Id : Entity_Id; 6181 Old_Id : Entity_Id; 6182 Err_Loc : Node_Id := Empty; 6183 Get_Inst : Boolean := False) 6184 is 6185 Result : Boolean; 6186 pragma Warnings (Off, Result); 6187 begin 6188 Check_Conformance 6189 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst); 6190 end Check_Mode_Conformant; 6191 6192 -------------------------------- 6193 -- Check_Overriding_Indicator -- 6194 -------------------------------- 6195 6196 procedure Check_Overriding_Indicator 6197 (Subp : Entity_Id; 6198 Overridden_Subp : Entity_Id; 6199 Is_Primitive : Boolean) 6200 is 6201 Decl : Node_Id; 6202 Spec : Node_Id; 6203 6204 begin 6205 -- No overriding indicator for literals 6206 6207 if Ekind (Subp) = E_Enumeration_Literal then 6208 return; 6209 6210 elsif Ekind (Subp) = E_Entry then 6211 Decl := Parent (Subp); 6212 6213 -- No point in analyzing a malformed operator 6214 6215 elsif Nkind (Subp) = N_Defining_Operator_Symbol 6216 and then Error_Posted (Subp) 6217 then 6218 return; 6219 6220 else 6221 Decl := Unit_Declaration_Node (Subp); 6222 end if; 6223 6224 if Nkind_In (Decl, N_Subprogram_Body, 6225 N_Subprogram_Body_Stub, 6226 N_Subprogram_Declaration, 6227 N_Abstract_Subprogram_Declaration, 6228 N_Subprogram_Renaming_Declaration) 6229 then 6230 Spec := Specification (Decl); 6231 6232 elsif Nkind (Decl) = N_Entry_Declaration then 6233 Spec := Decl; 6234 6235 else 6236 return; 6237 end if; 6238 6239 -- The overriding operation is type conformant with the overridden one, 6240 -- but the names of the formals are not required to match. If the names 6241 -- appear permuted in the overriding operation, this is a possible 6242 -- source of confusion that is worth diagnosing. Controlling formals 6243 -- often carry names that reflect the type, and it is not worthwhile 6244 -- requiring that their names match. 6245 6246 if Present (Overridden_Subp) 6247 and then Nkind (Subp) /= N_Defining_Operator_Symbol 6248 then 6249 declare 6250 Form1 : Entity_Id; 6251 Form2 : Entity_Id; 6252 6253 begin 6254 Form1 := First_Formal (Subp); 6255 Form2 := First_Formal (Overridden_Subp); 6256 6257 -- If the overriding operation is a synchronized operation, skip 6258 -- the first parameter of the overridden operation, which is 6259 -- implicit in the new one. If the operation is declared in the 6260 -- body it is not primitive and all formals must match. 6261 6262 if Is_Concurrent_Type (Scope (Subp)) 6263 and then Is_Tagged_Type (Scope (Subp)) 6264 and then not Has_Completion (Scope (Subp)) 6265 then 6266 Form2 := Next_Formal (Form2); 6267 end if; 6268 6269 if Present (Form1) then 6270 Form1 := Next_Formal (Form1); 6271 Form2 := Next_Formal (Form2); 6272 end if; 6273 6274 while Present (Form1) loop 6275 if not Is_Controlling_Formal (Form1) 6276 and then Present (Next_Formal (Form2)) 6277 and then Chars (Form1) = Chars (Next_Formal (Form2)) 6278 then 6279 Error_Msg_Node_2 := Alias (Overridden_Subp); 6280 Error_Msg_Sloc := Sloc (Error_Msg_Node_2); 6281 Error_Msg_NE 6282 ("& does not match corresponding formal of&#", 6283 Form1, Form1); 6284 exit; 6285 end if; 6286 6287 Next_Formal (Form1); 6288 Next_Formal (Form2); 6289 end loop; 6290 end; 6291 end if; 6292 6293 -- If there is an overridden subprogram, then check that there is no 6294 -- "not overriding" indicator, and mark the subprogram as overriding. 6295 -- This is not done if the overridden subprogram is marked as hidden, 6296 -- which can occur for the case of inherited controlled operations 6297 -- (see Derive_Subprogram), unless the inherited subprogram's parent 6298 -- subprogram is not itself hidden. (Note: This condition could probably 6299 -- be simplified, leaving out the testing for the specific controlled 6300 -- cases, but it seems safer and clearer this way, and echoes similar 6301 -- special-case tests of this kind in other places.) 6302 6303 if Present (Overridden_Subp) 6304 and then (not Is_Hidden (Overridden_Subp) 6305 or else 6306 (Nam_In (Chars (Overridden_Subp), Name_Initialize, 6307 Name_Adjust, 6308 Name_Finalize) 6309 and then Present (Alias (Overridden_Subp)) 6310 and then not Is_Hidden (Alias (Overridden_Subp)))) 6311 then 6312 if Must_Not_Override (Spec) then 6313 Error_Msg_Sloc := Sloc (Overridden_Subp); 6314 6315 if Ekind (Subp) = E_Entry then 6316 Error_Msg_NE 6317 ("entry & overrides inherited operation #", Spec, Subp); 6318 else 6319 Error_Msg_NE 6320 ("subprogram & overrides inherited operation #", Spec, Subp); 6321 end if; 6322 6323 -- Special-case to fix a GNAT oddity: Limited_Controlled is declared 6324 -- as an extension of Root_Controlled, and thus has a useless Adjust 6325 -- operation. This operation should not be inherited by other limited 6326 -- controlled types. An explicit Adjust for them is not overriding. 6327 6328 elsif Must_Override (Spec) 6329 and then Chars (Overridden_Subp) = Name_Adjust 6330 and then Is_Limited_Type (Etype (First_Formal (Subp))) 6331 and then Present (Alias (Overridden_Subp)) 6332 and then In_Predefined_Unit (Alias (Overridden_Subp)) 6333 then 6334 Get_Name_String 6335 (Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp)))); 6336 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 6337 6338 elsif Is_Subprogram (Subp) then 6339 if Is_Init_Proc (Subp) then 6340 null; 6341 6342 elsif No (Overridden_Operation (Subp)) then 6343 6344 -- For entities generated by Derive_Subprograms the overridden 6345 -- operation is the inherited primitive (which is available 6346 -- through the attribute alias) 6347 6348 if (Is_Dispatching_Operation (Subp) 6349 or else Is_Dispatching_Operation (Overridden_Subp)) 6350 and then not Comes_From_Source (Overridden_Subp) 6351 and then Find_Dispatching_Type (Overridden_Subp) = 6352 Find_Dispatching_Type (Subp) 6353 and then Present (Alias (Overridden_Subp)) 6354 and then Comes_From_Source (Alias (Overridden_Subp)) 6355 then 6356 Set_Overridden_Operation (Subp, Alias (Overridden_Subp)); 6357 Inherit_Subprogram_Contract (Subp, Alias (Overridden_Subp)); 6358 6359 else 6360 Set_Overridden_Operation (Subp, Overridden_Subp); 6361 Inherit_Subprogram_Contract (Subp, Overridden_Subp); 6362 end if; 6363 end if; 6364 end if; 6365 6366 -- If primitive flag is set or this is a protected operation, then 6367 -- the operation is overriding at the point of its declaration, so 6368 -- warn if necessary. Otherwise it may have been declared before the 6369 -- operation it overrides and no check is required. 6370 6371 if Style_Check 6372 and then not Must_Override (Spec) 6373 and then (Is_Primitive 6374 or else Ekind (Scope (Subp)) = E_Protected_Type) 6375 then 6376 Style.Missing_Overriding (Decl, Subp); 6377 end if; 6378 6379 -- If Subp is an operator, it may override a predefined operation, if 6380 -- it is defined in the same scope as the type to which it applies. 6381 -- In that case Overridden_Subp is empty because of our implicit 6382 -- representation for predefined operators. We have to check whether the 6383 -- signature of Subp matches that of a predefined operator. Note that 6384 -- first argument provides the name of the operator, and the second 6385 -- argument the signature that may match that of a standard operation. 6386 -- If the indicator is overriding, then the operator must match a 6387 -- predefined signature, because we know already that there is no 6388 -- explicit overridden operation. 6389 6390 elsif Nkind (Subp) = N_Defining_Operator_Symbol then 6391 if Must_Not_Override (Spec) then 6392 6393 -- If this is not a primitive or a protected subprogram, then 6394 -- "not overriding" is illegal. 6395 6396 if not Is_Primitive 6397 and then Ekind (Scope (Subp)) /= E_Protected_Type 6398 then 6399 Error_Msg_N ("overriding indicator only allowed " 6400 & "if subprogram is primitive", Subp); 6401 6402 elsif Can_Override_Operator (Subp) then 6403 Error_Msg_NE 6404 ("subprogram& overrides predefined operator ", Spec, Subp); 6405 end if; 6406 6407 elsif Must_Override (Spec) then 6408 if No (Overridden_Operation (Subp)) 6409 and then not Can_Override_Operator (Subp) 6410 then 6411 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 6412 end if; 6413 6414 elsif not Error_Posted (Subp) 6415 and then Style_Check 6416 and then Can_Override_Operator (Subp) 6417 and then not In_Predefined_Unit (Subp) 6418 then 6419 -- If style checks are enabled, indicate that the indicator is 6420 -- missing. However, at the point of declaration, the type of 6421 -- which this is a primitive operation may be private, in which 6422 -- case the indicator would be premature. 6423 6424 if Has_Private_Declaration (Etype (Subp)) 6425 or else Has_Private_Declaration (Etype (First_Formal (Subp))) 6426 then 6427 null; 6428 else 6429 Style.Missing_Overriding (Decl, Subp); 6430 end if; 6431 end if; 6432 6433 elsif Must_Override (Spec) then 6434 if Ekind (Subp) = E_Entry then 6435 Error_Msg_NE ("entry & is not overriding", Spec, Subp); 6436 else 6437 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); 6438 end if; 6439 6440 -- If the operation is marked "not overriding" and it's not primitive 6441 -- then an error is issued, unless this is an operation of a task or 6442 -- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding" 6443 -- has been specified have already been checked above. 6444 6445 elsif Must_Not_Override (Spec) 6446 and then not Is_Primitive 6447 and then Ekind (Subp) /= E_Entry 6448 and then Ekind (Scope (Subp)) /= E_Protected_Type 6449 then 6450 Error_Msg_N 6451 ("overriding indicator only allowed if subprogram is primitive", 6452 Subp); 6453 return; 6454 end if; 6455 end Check_Overriding_Indicator; 6456 6457 ------------------- 6458 -- Check_Returns -- 6459 ------------------- 6460 6461 -- Note: this procedure needs to know far too much about how the expander 6462 -- messes with exceptions. The use of the flag Exception_Junk and the 6463 -- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers 6464 -- works, but is not very clean. It would be better if the expansion 6465 -- routines would leave Original_Node working nicely, and we could use 6466 -- Original_Node here to ignore all the peculiar expander messing ??? 6467 6468 procedure Check_Returns 6469 (HSS : Node_Id; 6470 Mode : Character; 6471 Err : out Boolean; 6472 Proc : Entity_Id := Empty) 6473 is 6474 Handler : Node_Id; 6475 6476 procedure Check_Statement_Sequence (L : List_Id); 6477 -- Internal recursive procedure to check a list of statements for proper 6478 -- termination by a return statement (or a transfer of control or a 6479 -- compound statement that is itself internally properly terminated). 6480 6481 ------------------------------ 6482 -- Check_Statement_Sequence -- 6483 ------------------------------ 6484 6485 procedure Check_Statement_Sequence (L : List_Id) is 6486 Last_Stm : Node_Id; 6487 Stm : Node_Id; 6488 Kind : Node_Kind; 6489 6490 function Assert_False return Boolean; 6491 -- Returns True if Last_Stm is a pragma Assert (False) that has been 6492 -- rewritten as a null statement when assertions are off. The assert 6493 -- is not active, but it is still enough to kill the warning. 6494 6495 ------------------ 6496 -- Assert_False -- 6497 ------------------ 6498 6499 function Assert_False return Boolean is 6500 Orig : constant Node_Id := Original_Node (Last_Stm); 6501 6502 begin 6503 if Nkind (Orig) = N_Pragma 6504 and then Pragma_Name (Orig) = Name_Assert 6505 and then not Error_Posted (Orig) 6506 then 6507 declare 6508 Arg : constant Node_Id := 6509 First (Pragma_Argument_Associations (Orig)); 6510 Exp : constant Node_Id := Expression (Arg); 6511 begin 6512 return Nkind (Exp) = N_Identifier 6513 and then Chars (Exp) = Name_False; 6514 end; 6515 6516 else 6517 return False; 6518 end if; 6519 end Assert_False; 6520 6521 -- Local variables 6522 6523 Raise_Exception_Call : Boolean; 6524 -- Set True if statement sequence terminated by Raise_Exception call 6525 -- or a Reraise_Occurrence call. 6526 6527 -- Start of processing for Check_Statement_Sequence 6528 6529 begin 6530 Raise_Exception_Call := False; 6531 6532 -- Get last real statement 6533 6534 Last_Stm := Last (L); 6535 6536 -- Deal with digging out exception handler statement sequences that 6537 -- have been transformed by the local raise to goto optimization. 6538 -- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this 6539 -- optimization has occurred, we are looking at something like: 6540 6541 -- begin 6542 -- original stmts in block 6543 6544 -- exception \ 6545 -- when excep1 => | 6546 -- goto L1; | omitted if No_Exception_Propagation 6547 -- when excep2 => | 6548 -- goto L2; / 6549 -- end; 6550 6551 -- goto L3; -- skip handler when exception not raised 6552 6553 -- <<L1>> -- target label for local exception 6554 -- begin 6555 -- estmts1 6556 -- end; 6557 6558 -- goto L3; 6559 6560 -- <<L2>> 6561 -- begin 6562 -- estmts2 6563 -- end; 6564 6565 -- <<L3>> 6566 6567 -- and what we have to do is to dig out the estmts1 and estmts2 6568 -- sequences (which were the original sequences of statements in 6569 -- the exception handlers) and check them. 6570 6571 if Nkind (Last_Stm) = N_Label and then Exception_Junk (Last_Stm) then 6572 Stm := Last_Stm; 6573 loop 6574 Prev (Stm); 6575 exit when No (Stm); 6576 exit when Nkind (Stm) /= N_Block_Statement; 6577 exit when not Exception_Junk (Stm); 6578 Prev (Stm); 6579 exit when No (Stm); 6580 exit when Nkind (Stm) /= N_Label; 6581 exit when not Exception_Junk (Stm); 6582 Check_Statement_Sequence 6583 (Statements (Handled_Statement_Sequence (Next (Stm)))); 6584 6585 Prev (Stm); 6586 Last_Stm := Stm; 6587 exit when No (Stm); 6588 exit when Nkind (Stm) /= N_Goto_Statement; 6589 exit when not Exception_Junk (Stm); 6590 end loop; 6591 end if; 6592 6593 -- Don't count pragmas 6594 6595 while Nkind (Last_Stm) = N_Pragma 6596 6597 -- Don't count call to SS_Release (can happen after Raise_Exception) 6598 6599 or else 6600 (Nkind (Last_Stm) = N_Procedure_Call_Statement 6601 and then 6602 Nkind (Name (Last_Stm)) = N_Identifier 6603 and then 6604 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release)) 6605 6606 -- Don't count exception junk 6607 6608 or else 6609 (Nkind_In (Last_Stm, N_Goto_Statement, 6610 N_Label, 6611 N_Object_Declaration) 6612 and then Exception_Junk (Last_Stm)) 6613 or else Nkind (Last_Stm) in N_Push_xxx_Label 6614 or else Nkind (Last_Stm) in N_Pop_xxx_Label 6615 6616 -- Inserted code, such as finalization calls, is irrelevant: we only 6617 -- need to check original source. 6618 6619 or else Is_Rewrite_Insertion (Last_Stm) 6620 loop 6621 Prev (Last_Stm); 6622 end loop; 6623 6624 -- Here we have the "real" last statement 6625 6626 Kind := Nkind (Last_Stm); 6627 6628 -- Transfer of control, OK. Note that in the No_Return procedure 6629 -- case, we already diagnosed any explicit return statements, so 6630 -- we can treat them as OK in this context. 6631 6632 if Is_Transfer (Last_Stm) then 6633 return; 6634 6635 -- Check cases of explicit non-indirect procedure calls 6636 6637 elsif Kind = N_Procedure_Call_Statement 6638 and then Is_Entity_Name (Name (Last_Stm)) 6639 then 6640 -- Check call to Raise_Exception procedure which is treated 6641 -- specially, as is a call to Reraise_Occurrence. 6642 6643 -- We suppress the warning in these cases since it is likely that 6644 -- the programmer really does not expect to deal with the case 6645 -- of Null_Occurrence, and thus would find a warning about a 6646 -- missing return curious, and raising Program_Error does not 6647 -- seem such a bad behavior if this does occur. 6648 6649 -- Note that in the Ada 2005 case for Raise_Exception, the actual 6650 -- behavior will be to raise Constraint_Error (see AI-329). 6651 6652 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception) 6653 or else 6654 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence) 6655 then 6656 Raise_Exception_Call := True; 6657 6658 -- For Raise_Exception call, test first argument, if it is 6659 -- an attribute reference for a 'Identity call, then we know 6660 -- that the call cannot possibly return. 6661 6662 declare 6663 Arg : constant Node_Id := 6664 Original_Node (First_Actual (Last_Stm)); 6665 begin 6666 if Nkind (Arg) = N_Attribute_Reference 6667 and then Attribute_Name (Arg) = Name_Identity 6668 then 6669 return; 6670 end if; 6671 end; 6672 end if; 6673 6674 -- If statement, need to look inside if there is an else and check 6675 -- each constituent statement sequence for proper termination. 6676 6677 elsif Kind = N_If_Statement 6678 and then Present (Else_Statements (Last_Stm)) 6679 then 6680 Check_Statement_Sequence (Then_Statements (Last_Stm)); 6681 Check_Statement_Sequence (Else_Statements (Last_Stm)); 6682 6683 if Present (Elsif_Parts (Last_Stm)) then 6684 declare 6685 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm)); 6686 6687 begin 6688 while Present (Elsif_Part) loop 6689 Check_Statement_Sequence (Then_Statements (Elsif_Part)); 6690 Next (Elsif_Part); 6691 end loop; 6692 end; 6693 end if; 6694 6695 return; 6696 6697 -- Case statement, check each case for proper termination 6698 6699 elsif Kind = N_Case_Statement then 6700 declare 6701 Case_Alt : Node_Id; 6702 begin 6703 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm)); 6704 while Present (Case_Alt) loop 6705 Check_Statement_Sequence (Statements (Case_Alt)); 6706 Next_Non_Pragma (Case_Alt); 6707 end loop; 6708 end; 6709 6710 return; 6711 6712 -- Block statement, check its handled sequence of statements 6713 6714 elsif Kind = N_Block_Statement then 6715 declare 6716 Err1 : Boolean; 6717 6718 begin 6719 Check_Returns 6720 (Handled_Statement_Sequence (Last_Stm), Mode, Err1); 6721 6722 if Err1 then 6723 Err := True; 6724 end if; 6725 6726 return; 6727 end; 6728 6729 -- Loop statement. If there is an iteration scheme, we can definitely 6730 -- fall out of the loop. Similarly if there is an exit statement, we 6731 -- can fall out. In either case we need a following return. 6732 6733 elsif Kind = N_Loop_Statement then 6734 if Present (Iteration_Scheme (Last_Stm)) 6735 or else Has_Exit (Entity (Identifier (Last_Stm))) 6736 then 6737 null; 6738 6739 -- A loop with no exit statement or iteration scheme is either 6740 -- an infinite loop, or it has some other exit (raise/return). 6741 -- In either case, no warning is required. 6742 6743 else 6744 return; 6745 end if; 6746 6747 -- Timed entry call, check entry call and delay alternatives 6748 6749 -- Note: in expanded code, the timed entry call has been converted 6750 -- to a set of expanded statements on which the check will work 6751 -- correctly in any case. 6752 6753 elsif Kind = N_Timed_Entry_Call then 6754 declare 6755 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); 6756 DCA : constant Node_Id := Delay_Alternative (Last_Stm); 6757 6758 begin 6759 -- If statement sequence of entry call alternative is missing, 6760 -- then we can definitely fall through, and we post the error 6761 -- message on the entry call alternative itself. 6762 6763 if No (Statements (ECA)) then 6764 Last_Stm := ECA; 6765 6766 -- If statement sequence of delay alternative is missing, then 6767 -- we can definitely fall through, and we post the error 6768 -- message on the delay alternative itself. 6769 6770 -- Note: if both ECA and DCA are missing the return, then we 6771 -- post only one message, should be enough to fix the bugs. 6772 -- If not we will get a message next time on the DCA when the 6773 -- ECA is fixed. 6774 6775 elsif No (Statements (DCA)) then 6776 Last_Stm := DCA; 6777 6778 -- Else check both statement sequences 6779 6780 else 6781 Check_Statement_Sequence (Statements (ECA)); 6782 Check_Statement_Sequence (Statements (DCA)); 6783 return; 6784 end if; 6785 end; 6786 6787 -- Conditional entry call, check entry call and else part 6788 6789 -- Note: in expanded code, the conditional entry call has been 6790 -- converted to a set of expanded statements on which the check 6791 -- will work correctly in any case. 6792 6793 elsif Kind = N_Conditional_Entry_Call then 6794 declare 6795 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); 6796 6797 begin 6798 -- If statement sequence of entry call alternative is missing, 6799 -- then we can definitely fall through, and we post the error 6800 -- message on the entry call alternative itself. 6801 6802 if No (Statements (ECA)) then 6803 Last_Stm := ECA; 6804 6805 -- Else check statement sequence and else part 6806 6807 else 6808 Check_Statement_Sequence (Statements (ECA)); 6809 Check_Statement_Sequence (Else_Statements (Last_Stm)); 6810 return; 6811 end if; 6812 end; 6813 end if; 6814 6815 -- If we fall through, issue appropriate message 6816 6817 if Mode = 'F' then 6818 6819 -- Kill warning if last statement is a raise exception call, 6820 -- or a pragma Assert (False). Note that with assertions enabled, 6821 -- such a pragma has been converted into a raise exception call 6822 -- already, so the Assert_False is for the assertions off case. 6823 6824 if not Raise_Exception_Call and then not Assert_False then 6825 6826 -- In GNATprove mode, it is an error to have a missing return 6827 6828 Error_Msg_Warn := SPARK_Mode /= On; 6829 6830 -- Issue error message or warning 6831 6832 Error_Msg_N 6833 ("RETURN statement missing following this statement<<!", 6834 Last_Stm); 6835 Error_Msg_N 6836 ("\Program_Error ]<<!", Last_Stm); 6837 end if; 6838 6839 -- Note: we set Err even though we have not issued a warning 6840 -- because we still have a case of a missing return. This is 6841 -- an extremely marginal case, probably will never be noticed 6842 -- but we might as well get it right. 6843 6844 Err := True; 6845 6846 -- Otherwise we have the case of a procedure marked No_Return 6847 6848 else 6849 if not Raise_Exception_Call then 6850 if GNATprove_Mode then 6851 Error_Msg_N 6852 ("implied return after this statement would have raised " 6853 & "Program_Error", Last_Stm); 6854 6855 -- In normal compilation mode, do not warn on a generated call 6856 -- (e.g. in the body of a renaming as completion). 6857 6858 elsif Comes_From_Source (Last_Stm) then 6859 Error_Msg_N 6860 ("implied return after this statement will raise " 6861 & "Program_Error??", Last_Stm); 6862 end if; 6863 6864 Error_Msg_Warn := SPARK_Mode /= On; 6865 Error_Msg_NE 6866 ("\procedure & is marked as No_Return<<!", Last_Stm, Proc); 6867 end if; 6868 6869 declare 6870 RE : constant Node_Id := 6871 Make_Raise_Program_Error (Sloc (Last_Stm), 6872 Reason => PE_Implicit_Return); 6873 begin 6874 Insert_After (Last_Stm, RE); 6875 Analyze (RE); 6876 end; 6877 end if; 6878 end Check_Statement_Sequence; 6879 6880 -- Start of processing for Check_Returns 6881 6882 begin 6883 Err := False; 6884 Check_Statement_Sequence (Statements (HSS)); 6885 6886 if Present (Exception_Handlers (HSS)) then 6887 Handler := First_Non_Pragma (Exception_Handlers (HSS)); 6888 while Present (Handler) loop 6889 Check_Statement_Sequence (Statements (Handler)); 6890 Next_Non_Pragma (Handler); 6891 end loop; 6892 end if; 6893 end Check_Returns; 6894 6895 ---------------------------- 6896 -- Check_Subprogram_Order -- 6897 ---------------------------- 6898 6899 procedure Check_Subprogram_Order (N : Node_Id) is 6900 6901 function Subprogram_Name_Greater (S1, S2 : String) return Boolean; 6902 -- This is used to check if S1 > S2 in the sense required by this test, 6903 -- for example nameab < namec, but name2 < name10. 6904 6905 ----------------------------- 6906 -- Subprogram_Name_Greater -- 6907 ----------------------------- 6908 6909 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is 6910 L1, L2 : Positive; 6911 N1, N2 : Natural; 6912 6913 begin 6914 -- Deal with special case where names are identical except for a 6915 -- numerical suffix. These are handled specially, taking the numeric 6916 -- ordering from the suffix into account. 6917 6918 L1 := S1'Last; 6919 while S1 (L1) in '0' .. '9' loop 6920 L1 := L1 - 1; 6921 end loop; 6922 6923 L2 := S2'Last; 6924 while S2 (L2) in '0' .. '9' loop 6925 L2 := L2 - 1; 6926 end loop; 6927 6928 -- If non-numeric parts non-equal, do straight compare 6929 6930 if S1 (S1'First .. L1) /= S2 (S2'First .. L2) then 6931 return S1 > S2; 6932 6933 -- If non-numeric parts equal, compare suffixed numeric parts. Note 6934 -- that a missing suffix is treated as numeric zero in this test. 6935 6936 else 6937 N1 := 0; 6938 while L1 < S1'Last loop 6939 L1 := L1 + 1; 6940 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0'); 6941 end loop; 6942 6943 N2 := 0; 6944 while L2 < S2'Last loop 6945 L2 := L2 + 1; 6946 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0'); 6947 end loop; 6948 6949 return N1 > N2; 6950 end if; 6951 end Subprogram_Name_Greater; 6952 6953 -- Start of processing for Check_Subprogram_Order 6954 6955 begin 6956 -- Check body in alpha order if this is option 6957 6958 if Style_Check 6959 and then Style_Check_Order_Subprograms 6960 and then Nkind (N) = N_Subprogram_Body 6961 and then Comes_From_Source (N) 6962 and then In_Extended_Main_Source_Unit (N) 6963 then 6964 declare 6965 LSN : String_Ptr 6966 renames Scope_Stack.Table 6967 (Scope_Stack.Last).Last_Subprogram_Name; 6968 6969 Body_Id : constant Entity_Id := 6970 Defining_Entity (Specification (N)); 6971 6972 begin 6973 Get_Decoded_Name_String (Chars (Body_Id)); 6974 6975 if LSN /= null then 6976 if Subprogram_Name_Greater 6977 (LSN.all, Name_Buffer (1 .. Name_Len)) 6978 then 6979 Style.Subprogram_Not_In_Alpha_Order (Body_Id); 6980 end if; 6981 6982 Free (LSN); 6983 end if; 6984 6985 LSN := new String'(Name_Buffer (1 .. Name_Len)); 6986 end; 6987 end if; 6988 end Check_Subprogram_Order; 6989 6990 ------------------------------ 6991 -- Check_Subtype_Conformant -- 6992 ------------------------------ 6993 6994 procedure Check_Subtype_Conformant 6995 (New_Id : Entity_Id; 6996 Old_Id : Entity_Id; 6997 Err_Loc : Node_Id := Empty; 6998 Skip_Controlling_Formals : Boolean := False; 6999 Get_Inst : Boolean := False) 7000 is 7001 Result : Boolean; 7002 pragma Warnings (Off, Result); 7003 begin 7004 Check_Conformance 7005 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc, 7006 Skip_Controlling_Formals => Skip_Controlling_Formals, 7007 Get_Inst => Get_Inst); 7008 end Check_Subtype_Conformant; 7009 7010 ----------------------------------- 7011 -- Check_Synchronized_Overriding -- 7012 ----------------------------------- 7013 7014 procedure Check_Synchronized_Overriding 7015 (Def_Id : Entity_Id; 7016 Overridden_Subp : out Entity_Id) 7017 is 7018 Ifaces_List : Elist_Id; 7019 In_Scope : Boolean; 7020 Typ : Entity_Id; 7021 7022 function Matches_Prefixed_View_Profile 7023 (Prim_Params : List_Id; 7024 Iface_Params : List_Id) return Boolean; 7025 -- Determine whether a subprogram's parameter profile Prim_Params 7026 -- matches that of a potentially overridden interface subprogram 7027 -- Iface_Params. Also determine if the type of first parameter of 7028 -- Iface_Params is an implemented interface. 7029 7030 ----------------------------------- 7031 -- Matches_Prefixed_View_Profile -- 7032 ----------------------------------- 7033 7034 function Matches_Prefixed_View_Profile 7035 (Prim_Params : List_Id; 7036 Iface_Params : List_Id) return Boolean 7037 is 7038 function Is_Implemented 7039 (Ifaces_List : Elist_Id; 7040 Iface : Entity_Id) return Boolean; 7041 -- Determine if Iface is implemented by the current task or 7042 -- protected type. 7043 7044 -------------------- 7045 -- Is_Implemented -- 7046 -------------------- 7047 7048 function Is_Implemented 7049 (Ifaces_List : Elist_Id; 7050 Iface : Entity_Id) return Boolean 7051 is 7052 Iface_Elmt : Elmt_Id; 7053 7054 begin 7055 Iface_Elmt := First_Elmt (Ifaces_List); 7056 while Present (Iface_Elmt) loop 7057 if Node (Iface_Elmt) = Iface then 7058 return True; 7059 end if; 7060 7061 Next_Elmt (Iface_Elmt); 7062 end loop; 7063 7064 return False; 7065 end Is_Implemented; 7066 7067 -- Local variables 7068 7069 Iface_Id : Entity_Id; 7070 Iface_Param : Node_Id; 7071 Iface_Typ : Entity_Id; 7072 Prim_Id : Entity_Id; 7073 Prim_Param : Node_Id; 7074 Prim_Typ : Entity_Id; 7075 7076 -- Start of processing for Matches_Prefixed_View_Profile 7077 7078 begin 7079 Iface_Param := First (Iface_Params); 7080 Iface_Typ := Etype (Defining_Identifier (Iface_Param)); 7081 7082 if Is_Access_Type (Iface_Typ) then 7083 Iface_Typ := Designated_Type (Iface_Typ); 7084 end if; 7085 7086 Prim_Param := First (Prim_Params); 7087 7088 -- The first parameter of the potentially overridden subprogram must 7089 -- be an interface implemented by Prim. 7090 7091 if not Is_Interface (Iface_Typ) 7092 or else not Is_Implemented (Ifaces_List, Iface_Typ) 7093 then 7094 return False; 7095 end if; 7096 7097 -- The checks on the object parameters are done, so move on to the 7098 -- rest of the parameters. 7099 7100 if not In_Scope then 7101 Prim_Param := Next (Prim_Param); 7102 end if; 7103 7104 Iface_Param := Next (Iface_Param); 7105 while Present (Iface_Param) and then Present (Prim_Param) loop 7106 Iface_Id := Defining_Identifier (Iface_Param); 7107 Iface_Typ := Find_Parameter_Type (Iface_Param); 7108 7109 Prim_Id := Defining_Identifier (Prim_Param); 7110 Prim_Typ := Find_Parameter_Type (Prim_Param); 7111 7112 if Ekind (Iface_Typ) = E_Anonymous_Access_Type 7113 and then Ekind (Prim_Typ) = E_Anonymous_Access_Type 7114 and then Is_Concurrent_Type (Designated_Type (Prim_Typ)) 7115 then 7116 Iface_Typ := Designated_Type (Iface_Typ); 7117 Prim_Typ := Designated_Type (Prim_Typ); 7118 end if; 7119 7120 -- Case of multiple interface types inside a parameter profile 7121 7122 -- (Obj_Param : in out Iface; ...; Param : Iface) 7123 7124 -- If the interface type is implemented, then the matching type in 7125 -- the primitive should be the implementing record type. 7126 7127 if Ekind (Iface_Typ) = E_Record_Type 7128 and then Is_Interface (Iface_Typ) 7129 and then Is_Implemented (Ifaces_List, Iface_Typ) 7130 then 7131 if Prim_Typ /= Typ then 7132 return False; 7133 end if; 7134 7135 -- The two parameters must be both mode and subtype conformant 7136 7137 elsif Ekind (Iface_Id) /= Ekind (Prim_Id) 7138 or else not 7139 Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant) 7140 then 7141 return False; 7142 end if; 7143 7144 Next (Iface_Param); 7145 Next (Prim_Param); 7146 end loop; 7147 7148 -- One of the two lists contains more parameters than the other 7149 7150 if Present (Iface_Param) or else Present (Prim_Param) then 7151 return False; 7152 end if; 7153 7154 return True; 7155 end Matches_Prefixed_View_Profile; 7156 7157 -- Start of processing for Check_Synchronized_Overriding 7158 7159 begin 7160 Overridden_Subp := Empty; 7161 7162 -- Def_Id must be an entry or a subprogram. We should skip predefined 7163 -- primitives internally generated by the front end; however at this 7164 -- stage predefined primitives are still not fully decorated. As a 7165 -- minor optimization we skip here internally generated subprograms. 7166 7167 if (Ekind (Def_Id) /= E_Entry 7168 and then Ekind (Def_Id) /= E_Function 7169 and then Ekind (Def_Id) /= E_Procedure) 7170 or else not Comes_From_Source (Def_Id) 7171 then 7172 return; 7173 end if; 7174 7175 -- Search for the concurrent declaration since it contains the list of 7176 -- all implemented interfaces. In this case, the subprogram is declared 7177 -- within the scope of a protected or a task type. 7178 7179 if Present (Scope (Def_Id)) 7180 and then Is_Concurrent_Type (Scope (Def_Id)) 7181 and then not Is_Generic_Actual_Type (Scope (Def_Id)) 7182 then 7183 Typ := Scope (Def_Id); 7184 In_Scope := True; 7185 7186 -- The enclosing scope is not a synchronized type and the subprogram 7187 -- has no formals. 7188 7189 elsif No (First_Formal (Def_Id)) then 7190 return; 7191 7192 -- The subprogram has formals and hence it may be a primitive of a 7193 -- concurrent type. 7194 7195 else 7196 Typ := Etype (First_Formal (Def_Id)); 7197 7198 if Is_Access_Type (Typ) then 7199 Typ := Directly_Designated_Type (Typ); 7200 end if; 7201 7202 if Is_Concurrent_Type (Typ) 7203 and then not Is_Generic_Actual_Type (Typ) 7204 then 7205 In_Scope := False; 7206 7207 -- This case occurs when the concurrent type is declared within a 7208 -- generic unit. As a result the corresponding record has been built 7209 -- and used as the type of the first formal, we just have to retrieve 7210 -- the corresponding concurrent type. 7211 7212 elsif Is_Concurrent_Record_Type (Typ) 7213 and then not Is_Class_Wide_Type (Typ) 7214 and then Present (Corresponding_Concurrent_Type (Typ)) 7215 then 7216 Typ := Corresponding_Concurrent_Type (Typ); 7217 In_Scope := False; 7218 7219 else 7220 return; 7221 end if; 7222 end if; 7223 7224 -- There is no overriding to check if this is an inherited operation in 7225 -- a type derivation for a generic actual. 7226 7227 Collect_Interfaces (Typ, Ifaces_List); 7228 7229 if Is_Empty_Elmt_List (Ifaces_List) then 7230 return; 7231 end if; 7232 7233 -- Determine whether entry or subprogram Def_Id overrides a primitive 7234 -- operation that belongs to one of the interfaces in Ifaces_List. 7235 7236 declare 7237 Candidate : Entity_Id := Empty; 7238 Hom : Entity_Id := Empty; 7239 Subp : Entity_Id := Empty; 7240 7241 begin 7242 -- Traverse the homonym chain, looking for a potentially overridden 7243 -- subprogram that belongs to an implemented interface. 7244 7245 Hom := Current_Entity_In_Scope (Def_Id); 7246 while Present (Hom) loop 7247 Subp := Hom; 7248 7249 if Subp = Def_Id 7250 or else not Is_Overloadable (Subp) 7251 or else not Is_Primitive (Subp) 7252 or else not Is_Dispatching_Operation (Subp) 7253 or else not Present (Find_Dispatching_Type (Subp)) 7254 or else not Is_Interface (Find_Dispatching_Type (Subp)) 7255 then 7256 null; 7257 7258 -- Entries and procedures can override abstract or null interface 7259 -- procedures. 7260 7261 elsif Ekind_In (Def_Id, E_Entry, E_Procedure) 7262 and then Ekind (Subp) = E_Procedure 7263 and then Matches_Prefixed_View_Profile 7264 (Parameter_Specifications (Parent (Def_Id)), 7265 Parameter_Specifications (Parent (Subp))) 7266 then 7267 Candidate := Subp; 7268 7269 -- For an overridden subprogram Subp, check whether the mode 7270 -- of its first parameter is correct depending on the kind of 7271 -- synchronized type. 7272 7273 declare 7274 Formal : constant Node_Id := First_Formal (Candidate); 7275 7276 begin 7277 -- In order for an entry or a protected procedure to 7278 -- override, the first parameter of the overridden routine 7279 -- must be of mode "out", "in out", or access-to-variable. 7280 7281 if Ekind_In (Candidate, E_Entry, E_Procedure) 7282 and then Is_Protected_Type (Typ) 7283 and then Ekind (Formal) /= E_In_Out_Parameter 7284 and then Ekind (Formal) /= E_Out_Parameter 7285 and then Nkind (Parameter_Type (Parent (Formal))) /= 7286 N_Access_Definition 7287 then 7288 null; 7289 7290 -- All other cases are OK since a task entry or routine does 7291 -- not have a restriction on the mode of the first parameter 7292 -- of the overridden interface routine. 7293 7294 else 7295 Overridden_Subp := Candidate; 7296 return; 7297 end if; 7298 end; 7299 7300 -- Functions can override abstract interface functions. Return 7301 -- types must be subtype conformant. 7302 7303 elsif Ekind (Def_Id) = E_Function 7304 and then Ekind (Subp) = E_Function 7305 and then Matches_Prefixed_View_Profile 7306 (Parameter_Specifications (Parent (Def_Id)), 7307 Parameter_Specifications (Parent (Subp))) 7308 and then Conforming_Types 7309 (Etype (Def_Id), Etype (Subp), Subtype_Conformant) 7310 then 7311 Candidate := Subp; 7312 7313 -- If an inherited subprogram is implemented by a protected 7314 -- function, then the first parameter of the inherited 7315 -- subprogram shall be of mode in, but not an access-to- 7316 -- variable parameter (RM 9.4(11/9)). 7317 7318 if Present (First_Formal (Subp)) 7319 and then Ekind (First_Formal (Subp)) = E_In_Parameter 7320 and then 7321 (not Is_Access_Type (Etype (First_Formal (Subp))) 7322 or else 7323 Is_Access_Constant (Etype (First_Formal (Subp)))) 7324 then 7325 Overridden_Subp := Subp; 7326 return; 7327 end if; 7328 end if; 7329 7330 Hom := Homonym (Hom); 7331 end loop; 7332 7333 -- After examining all candidates for overriding, we are left with 7334 -- the best match, which is a mode-incompatible interface routine. 7335 7336 if In_Scope and then Present (Candidate) then 7337 Error_Msg_PT (Def_Id, Candidate); 7338 end if; 7339 7340 Overridden_Subp := Candidate; 7341 return; 7342 end; 7343 end Check_Synchronized_Overriding; 7344 7345 --------------------------- 7346 -- Check_Type_Conformant -- 7347 --------------------------- 7348 7349 procedure Check_Type_Conformant 7350 (New_Id : Entity_Id; 7351 Old_Id : Entity_Id; 7352 Err_Loc : Node_Id := Empty) 7353 is 7354 Result : Boolean; 7355 pragma Warnings (Off, Result); 7356 begin 7357 Check_Conformance 7358 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc); 7359 end Check_Type_Conformant; 7360 7361 --------------------------- 7362 -- Can_Override_Operator -- 7363 --------------------------- 7364 7365 function Can_Override_Operator (Subp : Entity_Id) return Boolean is 7366 Typ : Entity_Id; 7367 7368 begin 7369 if Nkind (Subp) /= N_Defining_Operator_Symbol then 7370 return False; 7371 7372 else 7373 Typ := Base_Type (Etype (First_Formal (Subp))); 7374 7375 -- Check explicitly that the operation is a primitive of the type 7376 7377 return Operator_Matches_Spec (Subp, Subp) 7378 and then not Is_Generic_Type (Typ) 7379 and then Scope (Subp) = Scope (Typ) 7380 and then not Is_Class_Wide_Type (Typ); 7381 end if; 7382 end Can_Override_Operator; 7383 7384 ---------------------- 7385 -- Conforming_Types -- 7386 ---------------------- 7387 7388 function Conforming_Types 7389 (T1 : Entity_Id; 7390 T2 : Entity_Id; 7391 Ctype : Conformance_Type; 7392 Get_Inst : Boolean := False) return Boolean 7393 is 7394 function Base_Types_Match 7395 (Typ_1 : Entity_Id; 7396 Typ_2 : Entity_Id) return Boolean; 7397 -- If neither Typ_1 nor Typ_2 are generic actual types, or if they are 7398 -- in different scopes (e.g. parent and child instances), then verify 7399 -- that the base types are equal. Otherwise Typ_1 and Typ_2 must be on 7400 -- the same subtype chain. The whole purpose of this procedure is to 7401 -- prevent spurious ambiguities in an instantiation that may arise if 7402 -- two distinct generic types are instantiated with the same actual. 7403 7404 function Find_Designated_Type (Typ : Entity_Id) return Entity_Id; 7405 -- An access parameter can designate an incomplete type. If the 7406 -- incomplete type is the limited view of a type from a limited_ 7407 -- with_clause, check whether the non-limited view is available. 7408 -- If it is a (non-limited) incomplete type, get the full view. 7409 7410 function Matches_Limited_With_View 7411 (Typ_1 : Entity_Id; 7412 Typ_2 : Entity_Id) return Boolean; 7413 -- Returns True if and only if either Typ_1 denotes a limited view of 7414 -- Typ_2 or Typ_2 denotes a limited view of Typ_1. This can arise when 7415 -- the limited with view of a type is used in a subprogram declaration 7416 -- and the subprogram body is in the scope of a regular with clause for 7417 -- the same unit. In such a case, the two type entities are considered 7418 -- identical for purposes of conformance checking. 7419 7420 ---------------------- 7421 -- Base_Types_Match -- 7422 ---------------------- 7423 7424 function Base_Types_Match 7425 (Typ_1 : Entity_Id; 7426 Typ_2 : Entity_Id) return Boolean 7427 is 7428 Base_1 : constant Entity_Id := Base_Type (Typ_1); 7429 Base_2 : constant Entity_Id := Base_Type (Typ_2); 7430 7431 begin 7432 if Typ_1 = Typ_2 then 7433 return True; 7434 7435 elsif Base_1 = Base_2 then 7436 7437 -- The following is too permissive. A more precise test should 7438 -- check that the generic actual is an ancestor subtype of the 7439 -- other ???. 7440 7441 -- See code in Find_Corresponding_Spec that applies an additional 7442 -- filter to handle accidental amiguities in instances. 7443 7444 return 7445 not Is_Generic_Actual_Type (Typ_1) 7446 or else not Is_Generic_Actual_Type (Typ_2) 7447 or else Scope (Typ_1) /= Scope (Typ_2); 7448 7449 -- If Typ_2 is a generic actual type it is declared as the subtype of 7450 -- the actual. If that actual is itself a subtype we need to use its 7451 -- own base type to check for compatibility. 7452 7453 elsif Ekind (Base_2) = Ekind (Typ_2) 7454 and then Base_1 = Base_Type (Base_2) 7455 then 7456 return True; 7457 7458 elsif Ekind (Base_1) = Ekind (Typ_1) 7459 and then Base_2 = Base_Type (Base_1) 7460 then 7461 return True; 7462 7463 else 7464 return False; 7465 end if; 7466 end Base_Types_Match; 7467 7468 -------------------------- 7469 -- Find_Designated_Type -- 7470 -------------------------- 7471 7472 function Find_Designated_Type (Typ : Entity_Id) return Entity_Id is 7473 Desig : Entity_Id; 7474 7475 begin 7476 Desig := Directly_Designated_Type (Typ); 7477 7478 if Ekind (Desig) = E_Incomplete_Type then 7479 7480 -- If regular incomplete type, get full view if available 7481 7482 if Present (Full_View (Desig)) then 7483 Desig := Full_View (Desig); 7484 7485 -- If limited view of a type, get non-limited view if available, 7486 -- and check again for a regular incomplete type. 7487 7488 elsif Present (Non_Limited_View (Desig)) then 7489 Desig := Get_Full_View (Non_Limited_View (Desig)); 7490 end if; 7491 end if; 7492 7493 return Desig; 7494 end Find_Designated_Type; 7495 7496 ------------------------------- 7497 -- Matches_Limited_With_View -- 7498 ------------------------------- 7499 7500 function Matches_Limited_With_View 7501 (Typ_1 : Entity_Id; 7502 Typ_2 : Entity_Id) return Boolean 7503 is 7504 function Is_Matching_Limited_View 7505 (Typ : Entity_Id; 7506 View : Entity_Id) return Boolean; 7507 -- Determine whether non-limited view View denotes type Typ in some 7508 -- conformant fashion. 7509 7510 ------------------------------ 7511 -- Is_Matching_Limited_View -- 7512 ------------------------------ 7513 7514 function Is_Matching_Limited_View 7515 (Typ : Entity_Id; 7516 View : Entity_Id) return Boolean 7517 is 7518 Root_Typ : Entity_Id; 7519 Root_View : Entity_Id; 7520 7521 begin 7522 -- The non-limited view directly denotes the type 7523 7524 if Typ = View then 7525 return True; 7526 7527 -- The type is a subtype of the non-limited view 7528 7529 elsif Is_Subtype_Of (Typ, View) then 7530 return True; 7531 7532 -- Both the non-limited view and the type denote class-wide types 7533 7534 elsif Is_Class_Wide_Type (Typ) 7535 and then Is_Class_Wide_Type (View) 7536 then 7537 Root_Typ := Root_Type (Typ); 7538 Root_View := Root_Type (View); 7539 7540 if Root_Typ = Root_View then 7541 return True; 7542 7543 -- An incomplete tagged type and its full view may receive two 7544 -- distinct class-wide types when the related package has not 7545 -- been analyzed yet. 7546 7547 -- package Pack is 7548 -- type T is tagged; -- CW_1 7549 -- type T is tagged null record; -- CW_2 7550 -- end Pack; 7551 7552 -- This is because the package lacks any semantic information 7553 -- that may eventually link both views of T. As a consequence, 7554 -- a client of the limited view of Pack will see CW_2 while a 7555 -- client of the non-limited view of Pack will see CW_1. 7556 7557 elsif Is_Incomplete_Type (Root_Typ) 7558 and then Present (Full_View (Root_Typ)) 7559 and then Full_View (Root_Typ) = Root_View 7560 then 7561 return True; 7562 7563 elsif Is_Incomplete_Type (Root_View) 7564 and then Present (Full_View (Root_View)) 7565 and then Full_View (Root_View) = Root_Typ 7566 then 7567 return True; 7568 end if; 7569 end if; 7570 7571 return False; 7572 end Is_Matching_Limited_View; 7573 7574 -- Start of processing for Matches_Limited_With_View 7575 7576 begin 7577 -- In some cases a type imported through a limited_with clause, and 7578 -- its non-limited view are both visible, for example in an anonymous 7579 -- access-to-class-wide type in a formal, or when building the body 7580 -- for a subprogram renaming after the subprogram has been frozen. 7581 -- In these cases both entities designate the same type. In addition, 7582 -- if one of them is an actual in an instance, it may be a subtype of 7583 -- the non-limited view of the other. 7584 7585 if From_Limited_With (Typ_1) 7586 and then From_Limited_With (Typ_2) 7587 and then Available_View (Typ_1) = Available_View (Typ_2) 7588 then 7589 return True; 7590 7591 elsif From_Limited_With (Typ_1) then 7592 return Is_Matching_Limited_View (Typ_2, Available_View (Typ_1)); 7593 7594 elsif From_Limited_With (Typ_2) then 7595 return Is_Matching_Limited_View (Typ_1, Available_View (Typ_2)); 7596 7597 else 7598 return False; 7599 end if; 7600 end Matches_Limited_With_View; 7601 7602 -- Local variables 7603 7604 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False; 7605 7606 Type_1 : Entity_Id := T1; 7607 Type_2 : Entity_Id := T2; 7608 7609 -- Start of processing for Conforming_Types 7610 7611 begin 7612 -- The context is an instance association for a formal access-to- 7613 -- subprogram type; the formal parameter types require mapping because 7614 -- they may denote other formal parameters of the generic unit. 7615 7616 if Get_Inst then 7617 Type_1 := Get_Instance_Of (T1); 7618 Type_2 := Get_Instance_Of (T2); 7619 end if; 7620 7621 -- If one of the types is a view of the other introduced by a limited 7622 -- with clause, treat these as conforming for all purposes. 7623 7624 if Matches_Limited_With_View (T1, T2) then 7625 return True; 7626 7627 elsif Base_Types_Match (Type_1, Type_2) then 7628 if Ctype <= Mode_Conformant then 7629 return True; 7630 7631 else 7632 return 7633 Subtypes_Statically_Match (Type_1, Type_2) 7634 and then Dimensions_Match (Type_1, Type_2); 7635 end if; 7636 7637 elsif Is_Incomplete_Or_Private_Type (Type_1) 7638 and then Present (Full_View (Type_1)) 7639 and then Base_Types_Match (Full_View (Type_1), Type_2) 7640 then 7641 return 7642 Ctype <= Mode_Conformant 7643 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2); 7644 7645 elsif Ekind (Type_2) = E_Incomplete_Type 7646 and then Present (Full_View (Type_2)) 7647 and then Base_Types_Match (Type_1, Full_View (Type_2)) 7648 then 7649 return 7650 Ctype <= Mode_Conformant 7651 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); 7652 7653 elsif Is_Private_Type (Type_2) 7654 and then In_Instance 7655 and then Present (Full_View (Type_2)) 7656 and then Base_Types_Match (Type_1, Full_View (Type_2)) 7657 then 7658 return 7659 Ctype <= Mode_Conformant 7660 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); 7661 7662 -- Another confusion between views in a nested instance with an 7663 -- actual private type whose full view is not in scope. 7664 7665 elsif Ekind (Type_2) = E_Private_Subtype 7666 and then In_Instance 7667 and then Etype (Type_2) = Type_1 7668 then 7669 return True; 7670 7671 -- In Ada 2012, incomplete types (including limited views) can appear 7672 -- as actuals in instantiations, where they are conformant to the 7673 -- corresponding incomplete formal. 7674 7675 elsif Is_Incomplete_Type (Type_1) 7676 and then Is_Incomplete_Type (Type_2) 7677 and then In_Instance 7678 and then (Used_As_Generic_Actual (Type_1) 7679 or else Used_As_Generic_Actual (Type_2)) 7680 then 7681 return True; 7682 end if; 7683 7684 -- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be 7685 -- treated recursively because they carry a signature. As far as 7686 -- conformance is concerned, convention plays no role, and either 7687 -- or both could be access to protected subprograms. 7688 7689 Are_Anonymous_Access_To_Subprogram_Types := 7690 Ekind_In (Type_1, E_Anonymous_Access_Subprogram_Type, 7691 E_Anonymous_Access_Protected_Subprogram_Type) 7692 and then 7693 Ekind_In (Type_2, E_Anonymous_Access_Subprogram_Type, 7694 E_Anonymous_Access_Protected_Subprogram_Type); 7695 7696 -- Test anonymous access type case. For this case, static subtype 7697 -- matching is required for mode conformance (RM 6.3.1(15)). We check 7698 -- the base types because we may have built internal subtype entities 7699 -- to handle null-excluding types (see Process_Formals). 7700 7701 if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type 7702 and then 7703 Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type) 7704 7705 -- Ada 2005 (AI-254) 7706 7707 or else Are_Anonymous_Access_To_Subprogram_Types 7708 then 7709 declare 7710 Desig_1 : Entity_Id; 7711 Desig_2 : Entity_Id; 7712 7713 begin 7714 -- In Ada 2005, access constant indicators must match for 7715 -- subtype conformance. 7716 7717 if Ada_Version >= Ada_2005 7718 and then Ctype >= Subtype_Conformant 7719 and then 7720 Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2) 7721 then 7722 return False; 7723 end if; 7724 7725 Desig_1 := Find_Designated_Type (Type_1); 7726 Desig_2 := Find_Designated_Type (Type_2); 7727 7728 -- If the context is an instance association for a formal 7729 -- access-to-subprogram type; formal access parameter designated 7730 -- types require mapping because they may denote other formal 7731 -- parameters of the generic unit. 7732 7733 if Get_Inst then 7734 Desig_1 := Get_Instance_Of (Desig_1); 7735 Desig_2 := Get_Instance_Of (Desig_2); 7736 end if; 7737 7738 -- It is possible for a Class_Wide_Type to be introduced for an 7739 -- incomplete type, in which case there is a separate class_ wide 7740 -- type for the full view. The types conform if their Etypes 7741 -- conform, i.e. one may be the full view of the other. This can 7742 -- only happen in the context of an access parameter, other uses 7743 -- of an incomplete Class_Wide_Type are illegal. 7744 7745 if Is_Class_Wide_Type (Desig_1) 7746 and then 7747 Is_Class_Wide_Type (Desig_2) 7748 then 7749 return 7750 Conforming_Types 7751 (Etype (Base_Type (Desig_1)), 7752 Etype (Base_Type (Desig_2)), Ctype); 7753 7754 elsif Are_Anonymous_Access_To_Subprogram_Types then 7755 if Ada_Version < Ada_2005 then 7756 return 7757 Ctype = Type_Conformant 7758 or else Subtypes_Statically_Match (Desig_1, Desig_2); 7759 7760 -- We must check the conformance of the signatures themselves 7761 7762 else 7763 declare 7764 Conformant : Boolean; 7765 begin 7766 Check_Conformance 7767 (Desig_1, Desig_2, Ctype, False, Conformant); 7768 return Conformant; 7769 end; 7770 end if; 7771 7772 -- A limited view of an actual matches the corresponding 7773 -- incomplete formal. 7774 7775 elsif Ekind (Desig_2) = E_Incomplete_Subtype 7776 and then From_Limited_With (Desig_2) 7777 and then Used_As_Generic_Actual (Etype (Desig_2)) 7778 then 7779 return True; 7780 7781 else 7782 return Base_Type (Desig_1) = Base_Type (Desig_2) 7783 and then (Ctype = Type_Conformant 7784 or else 7785 Subtypes_Statically_Match (Desig_1, Desig_2)); 7786 end if; 7787 end; 7788 7789 -- Otherwise definitely no match 7790 7791 else 7792 if ((Ekind (Type_1) = E_Anonymous_Access_Type 7793 and then Is_Access_Type (Type_2)) 7794 or else (Ekind (Type_2) = E_Anonymous_Access_Type 7795 and then Is_Access_Type (Type_1))) 7796 and then 7797 Conforming_Types 7798 (Designated_Type (Type_1), Designated_Type (Type_2), Ctype) 7799 then 7800 May_Hide_Profile := True; 7801 end if; 7802 7803 return False; 7804 end if; 7805 end Conforming_Types; 7806 7807 -------------------------- 7808 -- Create_Extra_Formals -- 7809 -------------------------- 7810 7811 procedure Create_Extra_Formals (E : Entity_Id) is 7812 First_Extra : Entity_Id := Empty; 7813 Formal : Entity_Id; 7814 Last_Extra : Entity_Id := Empty; 7815 7816 function Add_Extra_Formal 7817 (Assoc_Entity : Entity_Id; 7818 Typ : Entity_Id; 7819 Scope : Entity_Id; 7820 Suffix : String) return Entity_Id; 7821 -- Add an extra formal to the current list of formals and extra formals. 7822 -- The extra formal is added to the end of the list of extra formals, 7823 -- and also returned as the result. These formals are always of mode IN. 7824 -- The new formal has the type Typ, is declared in Scope, and its name 7825 -- is given by a concatenation of the name of Assoc_Entity and Suffix. 7826 -- The following suffixes are currently used. They should not be changed 7827 -- without coordinating with CodePeer, which makes use of these to 7828 -- provide better messages. 7829 7830 -- O denotes the Constrained bit. 7831 -- L denotes the accessibility level. 7832 -- BIP_xxx denotes an extra formal for a build-in-place function. See 7833 -- the full list in exp_ch6.BIP_Formal_Kind. 7834 7835 ---------------------- 7836 -- Add_Extra_Formal -- 7837 ---------------------- 7838 7839 function Add_Extra_Formal 7840 (Assoc_Entity : Entity_Id; 7841 Typ : Entity_Id; 7842 Scope : Entity_Id; 7843 Suffix : String) return Entity_Id 7844 is 7845 EF : constant Entity_Id := 7846 Make_Defining_Identifier (Sloc (Assoc_Entity), 7847 Chars => New_External_Name (Chars (Assoc_Entity), 7848 Suffix => Suffix)); 7849 7850 begin 7851 -- A little optimization. Never generate an extra formal for the 7852 -- _init operand of an initialization procedure, since it could 7853 -- never be used. 7854 7855 if Chars (Formal) = Name_uInit then 7856 return Empty; 7857 end if; 7858 7859 Set_Ekind (EF, E_In_Parameter); 7860 Set_Actual_Subtype (EF, Typ); 7861 Set_Etype (EF, Typ); 7862 Set_Scope (EF, Scope); 7863 Set_Mechanism (EF, Default_Mechanism); 7864 Set_Formal_Validity (EF); 7865 7866 if No (First_Extra) then 7867 First_Extra := EF; 7868 Set_Extra_Formals (Scope, EF); 7869 end if; 7870 7871 if Present (Last_Extra) then 7872 Set_Extra_Formal (Last_Extra, EF); 7873 end if; 7874 7875 Last_Extra := EF; 7876 7877 return EF; 7878 end Add_Extra_Formal; 7879 7880 -- Local variables 7881 7882 Formal_Type : Entity_Id; 7883 P_Formal : Entity_Id := Empty; 7884 7885 -- Start of processing for Create_Extra_Formals 7886 7887 begin 7888 -- We never generate extra formals if expansion is not active because we 7889 -- don't need them unless we are generating code. 7890 7891 if not Expander_Active then 7892 return; 7893 end if; 7894 7895 -- No need to generate extra formals in interface thunks whose target 7896 -- primitive has no extra formals. 7897 7898 if Is_Thunk (E) and then No (Extra_Formals (Thunk_Entity (E))) then 7899 return; 7900 end if; 7901 7902 -- If this is a derived subprogram then the subtypes of the parent 7903 -- subprogram's formal parameters will be used to determine the need 7904 -- for extra formals. 7905 7906 if Is_Overloadable (E) and then Present (Alias (E)) then 7907 P_Formal := First_Formal (Alias (E)); 7908 end if; 7909 7910 Formal := First_Formal (E); 7911 while Present (Formal) loop 7912 Last_Extra := Formal; 7913 Next_Formal (Formal); 7914 end loop; 7915 7916 -- If Extra_Formals were already created, don't do it again. This 7917 -- situation may arise for subprogram types created as part of 7918 -- dispatching calls (see Expand_Dispatching_Call). 7919 7920 if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then 7921 return; 7922 end if; 7923 7924 -- If the subprogram is a predefined dispatching subprogram then don't 7925 -- generate any extra constrained or accessibility level formals. In 7926 -- general we suppress these for internal subprograms (by not calling 7927 -- Freeze_Subprogram and Create_Extra_Formals at all), but internally 7928 -- generated stream attributes do get passed through because extra 7929 -- build-in-place formals are needed in some cases (limited 'Input). 7930 7931 if Is_Predefined_Internal_Operation (E) then 7932 goto Test_For_Func_Result_Extras; 7933 end if; 7934 7935 Formal := First_Formal (E); 7936 while Present (Formal) loop 7937 7938 -- Create extra formal for supporting the attribute 'Constrained. 7939 -- The case of a private type view without discriminants also 7940 -- requires the extra formal if the underlying type has defaulted 7941 -- discriminants. 7942 7943 if Ekind (Formal) /= E_In_Parameter then 7944 if Present (P_Formal) then 7945 Formal_Type := Etype (P_Formal); 7946 else 7947 Formal_Type := Etype (Formal); 7948 end if; 7949 7950 -- Do not produce extra formals for Unchecked_Union parameters. 7951 -- Jump directly to the end of the loop. 7952 7953 if Is_Unchecked_Union (Base_Type (Formal_Type)) then 7954 goto Skip_Extra_Formal_Generation; 7955 end if; 7956 7957 if not Has_Discriminants (Formal_Type) 7958 and then Ekind (Formal_Type) in Private_Kind 7959 and then Present (Underlying_Type (Formal_Type)) 7960 then 7961 Formal_Type := Underlying_Type (Formal_Type); 7962 end if; 7963 7964 -- Suppress the extra formal if formal's subtype is constrained or 7965 -- indefinite, or we're compiling for Ada 2012 and the underlying 7966 -- type is tagged and limited. In Ada 2012, a limited tagged type 7967 -- can have defaulted discriminants, but 'Constrained is required 7968 -- to return True, so the formal is never needed (see AI05-0214). 7969 -- Note that this ensures consistency of calling sequences for 7970 -- dispatching operations when some types in a class have defaults 7971 -- on discriminants and others do not (and requiring the extra 7972 -- formal would introduce distributed overhead). 7973 7974 -- If the type does not have a completion yet, treat as prior to 7975 -- Ada 2012 for consistency. 7976 7977 if Has_Discriminants (Formal_Type) 7978 and then not Is_Constrained (Formal_Type) 7979 and then Is_Definite_Subtype (Formal_Type) 7980 and then (Ada_Version < Ada_2012 7981 or else No (Underlying_Type (Formal_Type)) 7982 or else not 7983 (Is_Limited_Type (Formal_Type) 7984 and then 7985 (Is_Tagged_Type 7986 (Underlying_Type (Formal_Type))))) 7987 then 7988 Set_Extra_Constrained 7989 (Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O")); 7990 end if; 7991 end if; 7992 7993 -- Create extra formal for supporting accessibility checking. This 7994 -- is done for both anonymous access formals and formals of named 7995 -- access types that are marked as controlling formals. The latter 7996 -- case can occur when Expand_Dispatching_Call creates a subprogram 7997 -- type and substitutes the types of access-to-class-wide actuals 7998 -- for the anonymous access-to-specific-type of controlling formals. 7999 -- Base_Type is applied because in cases where there is a null 8000 -- exclusion the formal may have an access subtype. 8001 8002 -- This is suppressed if we specifically suppress accessibility 8003 -- checks at the package level for either the subprogram, or the 8004 -- package in which it resides. However, we do not suppress it 8005 -- simply if the scope has accessibility checks suppressed, since 8006 -- this could cause trouble when clients are compiled with a 8007 -- different suppression setting. The explicit checks at the 8008 -- package level are safe from this point of view. 8009 8010 if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type 8011 or else (Is_Controlling_Formal (Formal) 8012 and then Is_Access_Type (Base_Type (Etype (Formal))))) 8013 and then not 8014 (Explicit_Suppress (E, Accessibility_Check) 8015 or else 8016 Explicit_Suppress (Scope (E), Accessibility_Check)) 8017 and then 8018 (No (P_Formal) 8019 or else Present (Extra_Accessibility (P_Formal))) 8020 then 8021 Set_Extra_Accessibility 8022 (Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L")); 8023 end if; 8024 8025 -- This label is required when skipping extra formal generation for 8026 -- Unchecked_Union parameters. 8027 8028 <<Skip_Extra_Formal_Generation>> 8029 8030 if Present (P_Formal) then 8031 Next_Formal (P_Formal); 8032 end if; 8033 8034 Next_Formal (Formal); 8035 end loop; 8036 8037 <<Test_For_Func_Result_Extras>> 8038 8039 -- Ada 2012 (AI05-234): "the accessibility level of the result of a 8040 -- function call is ... determined by the point of call ...". 8041 8042 if Needs_Result_Accessibility_Level (E) then 8043 Set_Extra_Accessibility_Of_Result 8044 (E, Add_Extra_Formal (E, Standard_Natural, E, "L")); 8045 end if; 8046 8047 -- Ada 2005 (AI-318-02): In the case of build-in-place functions, add 8048 -- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind. 8049 8050 if Is_Build_In_Place_Function (E) then 8051 declare 8052 Result_Subt : constant Entity_Id := Etype (E); 8053 Full_Subt : constant Entity_Id := Available_View (Result_Subt); 8054 Formal_Typ : Entity_Id; 8055 Subp_Decl : Node_Id; 8056 Discard : Entity_Id; 8057 8058 begin 8059 -- In the case of functions with unconstrained result subtypes, 8060 -- add a 4-state formal indicating whether the return object is 8061 -- allocated by the caller (1), or should be allocated by the 8062 -- callee on the secondary stack (2), in the global heap (3), or 8063 -- in a user-defined storage pool (4). For the moment we just use 8064 -- Natural for the type of this formal. Note that this formal 8065 -- isn't usually needed in the case where the result subtype is 8066 -- constrained, but it is needed when the function has a tagged 8067 -- result, because generally such functions can be called in a 8068 -- dispatching context and such calls must be handled like calls 8069 -- to a class-wide function. 8070 8071 if Needs_BIP_Alloc_Form (E) then 8072 Discard := 8073 Add_Extra_Formal 8074 (E, Standard_Natural, 8075 E, BIP_Formal_Suffix (BIP_Alloc_Form)); 8076 8077 -- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to 8078 -- use a user-defined pool. This formal is not added on 8079 -- ZFP as those targets do not support pools. 8080 8081 if RTE_Available (RE_Root_Storage_Pool_Ptr) then 8082 Discard := 8083 Add_Extra_Formal 8084 (E, RTE (RE_Root_Storage_Pool_Ptr), 8085 E, BIP_Formal_Suffix (BIP_Storage_Pool)); 8086 end if; 8087 end if; 8088 8089 -- In the case of functions whose result type needs finalization, 8090 -- add an extra formal which represents the finalization master. 8091 8092 if Needs_BIP_Finalization_Master (E) then 8093 Discard := 8094 Add_Extra_Formal 8095 (E, RTE (RE_Finalization_Master_Ptr), 8096 E, BIP_Formal_Suffix (BIP_Finalization_Master)); 8097 end if; 8098 8099 -- When the result type contains tasks, add two extra formals: the 8100 -- master of the tasks to be created, and the caller's activation 8101 -- chain. 8102 8103 if Has_Task (Full_Subt) then 8104 Discard := 8105 Add_Extra_Formal 8106 (E, RTE (RE_Master_Id), 8107 E, BIP_Formal_Suffix (BIP_Task_Master)); 8108 Discard := 8109 Add_Extra_Formal 8110 (E, RTE (RE_Activation_Chain_Access), 8111 E, BIP_Formal_Suffix (BIP_Activation_Chain)); 8112 end if; 8113 8114 -- All build-in-place functions get an extra formal that will be 8115 -- passed the address of the return object within the caller. 8116 8117 Formal_Typ := 8118 Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E)); 8119 8120 -- Incomplete_View_From_Limited_With is needed here because 8121 -- gigi gets confused if the designated type is the full view 8122 -- coming from a limited-with'ed package. In the normal case, 8123 -- (no limited with) Incomplete_View_From_Limited_With 8124 -- returns Result_Subt. 8125 8126 Set_Directly_Designated_Type 8127 (Formal_Typ, Incomplete_View_From_Limited_With (Result_Subt)); 8128 Set_Etype (Formal_Typ, Formal_Typ); 8129 Set_Depends_On_Private 8130 (Formal_Typ, Has_Private_Component (Formal_Typ)); 8131 Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ))); 8132 Set_Is_Access_Constant (Formal_Typ, False); 8133 8134 -- Ada 2005 (AI-50217): Propagate the attribute that indicates 8135 -- the designated type comes from the limited view (for back-end 8136 -- purposes). 8137 8138 Set_From_Limited_With 8139 (Formal_Typ, From_Limited_With (Result_Subt)); 8140 8141 Layout_Type (Formal_Typ); 8142 8143 -- Force the definition of the Itype in case of internal function 8144 -- calls within the same or nested scope. 8145 8146 if Is_Subprogram_Or_Generic_Subprogram (E) then 8147 Subp_Decl := Parent (E); 8148 8149 -- The insertion point for an Itype reference should be after 8150 -- the unit declaration node of the subprogram. An exception 8151 -- to this are inherited operations from a parent type in which 8152 -- case the derived type acts as their parent. 8153 8154 if Nkind_In (Subp_Decl, N_Function_Specification, 8155 N_Procedure_Specification) 8156 then 8157 Subp_Decl := Parent (Subp_Decl); 8158 end if; 8159 8160 Build_Itype_Reference (Formal_Typ, Subp_Decl); 8161 end if; 8162 8163 Discard := 8164 Add_Extra_Formal 8165 (E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access)); 8166 end; 8167 end if; 8168 8169 -- If this is an instance of a generic, we need to have extra formals 8170 -- for the Alias. 8171 8172 if Is_Generic_Instance (E) and then Present (Alias (E)) then 8173 Set_Extra_Formals (Alias (E), Extra_Formals (E)); 8174 end if; 8175 end Create_Extra_Formals; 8176 8177 ----------------------------- 8178 -- Enter_Overloaded_Entity -- 8179 ----------------------------- 8180 8181 procedure Enter_Overloaded_Entity (S : Entity_Id) is 8182 function Matches_Predefined_Op return Boolean; 8183 -- This returns an approximation of whether S matches a predefined 8184 -- operator, based on the operator symbol, and the parameter and result 8185 -- types. The rules are scattered throughout chapter 4 of the Ada RM. 8186 8187 --------------------------- 8188 -- Matches_Predefined_Op -- 8189 --------------------------- 8190 8191 function Matches_Predefined_Op return Boolean is 8192 Formal_1 : constant Entity_Id := First_Formal (S); 8193 Formal_2 : constant Entity_Id := Next_Formal (Formal_1); 8194 Op : constant Name_Id := Chars (S); 8195 Result_Type : constant Entity_Id := Base_Type (Etype (S)); 8196 Type_1 : constant Entity_Id := Base_Type (Etype (Formal_1)); 8197 8198 begin 8199 -- Binary operator 8200 8201 if Present (Formal_2) then 8202 declare 8203 Type_2 : constant Entity_Id := Base_Type (Etype (Formal_2)); 8204 8205 begin 8206 -- All but "&" and "**" have same-types parameters 8207 8208 case Op is 8209 when Name_Op_Concat 8210 | Name_Op_Expon 8211 => 8212 null; 8213 8214 when others => 8215 if Type_1 /= Type_2 then 8216 return False; 8217 end if; 8218 end case; 8219 8220 -- Check parameter and result types 8221 8222 case Op is 8223 when Name_Op_And 8224 | Name_Op_Or 8225 | Name_Op_Xor 8226 => 8227 return 8228 Is_Boolean_Type (Result_Type) 8229 and then Result_Type = Type_1; 8230 8231 when Name_Op_Mod 8232 | Name_Op_Rem 8233 => 8234 return 8235 Is_Integer_Type (Result_Type) 8236 and then Result_Type = Type_1; 8237 8238 when Name_Op_Add 8239 | Name_Op_Divide 8240 | Name_Op_Multiply 8241 | Name_Op_Subtract 8242 => 8243 return 8244 Is_Numeric_Type (Result_Type) 8245 and then Result_Type = Type_1; 8246 8247 when Name_Op_Eq 8248 | Name_Op_Ne 8249 => 8250 return 8251 Is_Boolean_Type (Result_Type) 8252 and then not Is_Limited_Type (Type_1); 8253 8254 when Name_Op_Ge 8255 | Name_Op_Gt 8256 | Name_Op_Le 8257 | Name_Op_Lt 8258 => 8259 return 8260 Is_Boolean_Type (Result_Type) 8261 and then (Is_Array_Type (Type_1) 8262 or else Is_Scalar_Type (Type_1)); 8263 8264 when Name_Op_Concat => 8265 return Is_Array_Type (Result_Type); 8266 8267 when Name_Op_Expon => 8268 return 8269 (Is_Integer_Type (Result_Type) 8270 or else Is_Floating_Point_Type (Result_Type)) 8271 and then Result_Type = Type_1 8272 and then Type_2 = Standard_Integer; 8273 8274 when others => 8275 raise Program_Error; 8276 end case; 8277 end; 8278 8279 -- Unary operator 8280 8281 else 8282 case Op is 8283 when Name_Op_Abs 8284 | Name_Op_Add 8285 | Name_Op_Subtract 8286 => 8287 return 8288 Is_Numeric_Type (Result_Type) 8289 and then Result_Type = Type_1; 8290 8291 when Name_Op_Not => 8292 return 8293 Is_Boolean_Type (Result_Type) 8294 and then Result_Type = Type_1; 8295 8296 when others => 8297 raise Program_Error; 8298 end case; 8299 end if; 8300 end Matches_Predefined_Op; 8301 8302 -- Local variables 8303 8304 E : Entity_Id := Current_Entity_In_Scope (S); 8305 C_E : Entity_Id := Current_Entity (S); 8306 8307 -- Start of processing for Enter_Overloaded_Entity 8308 8309 begin 8310 if Present (E) then 8311 Set_Has_Homonym (E); 8312 Set_Has_Homonym (S); 8313 end if; 8314 8315 Set_Is_Immediately_Visible (S); 8316 Set_Scope (S, Current_Scope); 8317 8318 -- Chain new entity if front of homonym in current scope, so that 8319 -- homonyms are contiguous. 8320 8321 if Present (E) and then E /= C_E then 8322 while Homonym (C_E) /= E loop 8323 C_E := Homonym (C_E); 8324 end loop; 8325 8326 Set_Homonym (C_E, S); 8327 8328 else 8329 E := C_E; 8330 Set_Current_Entity (S); 8331 end if; 8332 8333 Set_Homonym (S, E); 8334 8335 if Is_Inherited_Operation (S) then 8336 Append_Inherited_Subprogram (S); 8337 else 8338 Append_Entity (S, Current_Scope); 8339 end if; 8340 8341 Set_Public_Status (S); 8342 8343 if Debug_Flag_E then 8344 Write_Str ("New overloaded entity chain: "); 8345 Write_Name (Chars (S)); 8346 8347 E := S; 8348 while Present (E) loop 8349 Write_Str (" "); Write_Int (Int (E)); 8350 E := Homonym (E); 8351 end loop; 8352 8353 Write_Eol; 8354 end if; 8355 8356 -- Generate warning for hiding 8357 8358 if Warn_On_Hiding 8359 and then Comes_From_Source (S) 8360 and then In_Extended_Main_Source_Unit (S) 8361 then 8362 E := S; 8363 loop 8364 E := Homonym (E); 8365 exit when No (E); 8366 8367 -- Warn unless genuine overloading. Do not emit warning on 8368 -- hiding predefined operators in Standard (these are either an 8369 -- (artifact of our implicit declarations, or simple noise) but 8370 -- keep warning on a operator defined on a local subtype, because 8371 -- of the real danger that different operators may be applied in 8372 -- various parts of the program. 8373 8374 -- Note that if E and S have the same scope, there is never any 8375 -- hiding. Either the two conflict, and the program is illegal, 8376 -- or S is overriding an implicit inherited subprogram. 8377 8378 if Scope (E) /= Scope (S) 8379 and then (not Is_Overloadable (E) 8380 or else Subtype_Conformant (E, S)) 8381 and then (Is_Immediately_Visible (E) 8382 or else Is_Potentially_Use_Visible (S)) 8383 then 8384 if Scope (E) = Standard_Standard then 8385 if Nkind (S) = N_Defining_Operator_Symbol 8386 and then Scope (Base_Type (Etype (First_Formal (S)))) /= 8387 Scope (S) 8388 and then Matches_Predefined_Op 8389 then 8390 Error_Msg_N 8391 ("declaration of & hides predefined operator?h?", S); 8392 end if; 8393 8394 -- E not immediately within Standard 8395 8396 else 8397 Error_Msg_Sloc := Sloc (E); 8398 Error_Msg_N ("declaration of & hides one #?h?", S); 8399 end if; 8400 end if; 8401 end loop; 8402 end if; 8403 end Enter_Overloaded_Entity; 8404 8405 ----------------------------- 8406 -- Check_Untagged_Equality -- 8407 ----------------------------- 8408 8409 procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is 8410 Typ : constant Entity_Id := Etype (First_Formal (Eq_Op)); 8411 Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op); 8412 Obj_Decl : Node_Id; 8413 8414 begin 8415 -- This check applies only if we have a subprogram declaration with an 8416 -- untagged record type. 8417 8418 if Nkind (Decl) /= N_Subprogram_Declaration 8419 or else not Is_Record_Type (Typ) 8420 or else Is_Tagged_Type (Typ) 8421 then 8422 return; 8423 end if; 8424 8425 -- In Ada 2012 case, we will output errors or warnings depending on 8426 -- the setting of debug flag -gnatd.E. 8427 8428 if Ada_Version >= Ada_2012 then 8429 Error_Msg_Warn := Debug_Flag_Dot_EE; 8430 8431 -- In earlier versions of Ada, nothing to do unless we are warning on 8432 -- Ada 2012 incompatibilities (Warn_On_Ada_2012_Incompatibility set). 8433 8434 else 8435 if not Warn_On_Ada_2012_Compatibility then 8436 return; 8437 end if; 8438 end if; 8439 8440 -- Cases where the type has already been frozen 8441 8442 if Is_Frozen (Typ) then 8443 8444 -- The check applies to a primitive operation, so check that type 8445 -- and equality operation are in the same scope. 8446 8447 if Scope (Typ) /= Current_Scope then 8448 return; 8449 8450 -- If the type is a generic actual (sub)type, the operation is not 8451 -- primitive either because the base type is declared elsewhere. 8452 8453 elsif Is_Generic_Actual_Type (Typ) then 8454 return; 8455 8456 -- Here we have a definite error of declaration after freezing 8457 8458 else 8459 if Ada_Version >= Ada_2012 then 8460 Error_Msg_NE 8461 ("equality operator must be declared before type & is " 8462 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)<<", Eq_Op, Typ); 8463 8464 -- In Ada 2012 mode with error turned to warning, output one 8465 -- more warning to warn that the equality operation may not 8466 -- compose. This is the consequence of ignoring the error. 8467 8468 if Error_Msg_Warn then 8469 Error_Msg_N ("\equality operation may not compose??", Eq_Op); 8470 end if; 8471 8472 else 8473 Error_Msg_NE 8474 ("equality operator must be declared before type& is " 8475 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)?y?", Eq_Op, Typ); 8476 end if; 8477 8478 -- If we are in the package body, we could just move the 8479 -- declaration to the package spec, so add a message saying that. 8480 8481 if In_Package_Body (Scope (Typ)) then 8482 if Ada_Version >= Ada_2012 then 8483 Error_Msg_N 8484 ("\move declaration to package spec<<", Eq_Op); 8485 else 8486 Error_Msg_N 8487 ("\move declaration to package spec (Ada 2012)?y?", Eq_Op); 8488 end if; 8489 8490 -- Otherwise try to find the freezing point for better message. 8491 8492 else 8493 Obj_Decl := Next (Parent (Typ)); 8494 while Present (Obj_Decl) and then Obj_Decl /= Decl loop 8495 if Nkind (Obj_Decl) = N_Object_Declaration 8496 and then Etype (Defining_Identifier (Obj_Decl)) = Typ 8497 then 8498 -- Freezing point, output warnings 8499 8500 if Ada_Version >= Ada_2012 then 8501 Error_Msg_NE 8502 ("type& is frozen by declaration??", Obj_Decl, Typ); 8503 Error_Msg_N 8504 ("\an equality operator cannot be declared after " 8505 & "this point??", 8506 Obj_Decl); 8507 else 8508 Error_Msg_NE 8509 ("type& is frozen by declaration (Ada 2012)?y?", 8510 Obj_Decl, Typ); 8511 Error_Msg_N 8512 ("\an equality operator cannot be declared after " 8513 & "this point (Ada 2012)?y?", 8514 Obj_Decl); 8515 end if; 8516 8517 exit; 8518 8519 -- If we reach generated code for subprogram declaration 8520 -- or body, it is the body that froze the type and the 8521 -- declaration is legal. 8522 8523 elsif Sloc (Obj_Decl) = Sloc (Decl) then 8524 return; 8525 end if; 8526 8527 Next (Obj_Decl); 8528 end loop; 8529 end if; 8530 end if; 8531 8532 -- Here if type is not frozen yet. It is illegal to have a primitive 8533 -- equality declared in the private part if the type is visible. 8534 8535 elsif not In_Same_List (Parent (Typ), Decl) 8536 and then not Is_Limited_Type (Typ) 8537 then 8538 -- Shouldn't we give an RM reference here??? 8539 8540 if Ada_Version >= Ada_2012 then 8541 Error_Msg_N 8542 ("equality operator appears too late<<", Eq_Op); 8543 else 8544 Error_Msg_N 8545 ("equality operator appears too late (Ada 2012)?y?", Eq_Op); 8546 end if; 8547 8548 -- No error detected 8549 8550 else 8551 return; 8552 end if; 8553 end Check_Untagged_Equality; 8554 8555 ----------------------------- 8556 -- Find_Corresponding_Spec -- 8557 ----------------------------- 8558 8559 function Find_Corresponding_Spec 8560 (N : Node_Id; 8561 Post_Error : Boolean := True) return Entity_Id 8562 is 8563 Spec : constant Node_Id := Specification (N); 8564 Designator : constant Entity_Id := Defining_Entity (Spec); 8565 8566 E : Entity_Id; 8567 8568 function Different_Generic_Profile (E : Entity_Id) return Boolean; 8569 -- Even if fully conformant, a body may depend on a generic actual when 8570 -- the spec does not, or vice versa, in which case they were distinct 8571 -- entities in the generic. 8572 8573 ------------------------------- 8574 -- Different_Generic_Profile -- 8575 ------------------------------- 8576 8577 function Different_Generic_Profile (E : Entity_Id) return Boolean is 8578 F1, F2 : Entity_Id; 8579 8580 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean; 8581 -- Check that the types of corresponding formals have the same 8582 -- generic actual if any. We have to account for subtypes of a 8583 -- generic formal, declared between a spec and a body, which may 8584 -- appear distinct in an instance but matched in the generic, and 8585 -- the subtype may be used either in the spec or the body of the 8586 -- subprogram being checked. 8587 8588 ------------------------- 8589 -- Same_Generic_Actual -- 8590 ------------------------- 8591 8592 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean is 8593 8594 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean; 8595 -- Predicate to check whether S1 is a subtype of S2 in the source 8596 -- of the instance. 8597 8598 ------------------------- 8599 -- Is_Declared_Subtype -- 8600 ------------------------- 8601 8602 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean is 8603 begin 8604 return Comes_From_Source (Parent (S1)) 8605 and then Nkind (Parent (S1)) = N_Subtype_Declaration 8606 and then Is_Entity_Name (Subtype_Indication (Parent (S1))) 8607 and then Entity (Subtype_Indication (Parent (S1))) = S2; 8608 end Is_Declared_Subtype; 8609 8610 -- Start of processing for Same_Generic_Actual 8611 8612 begin 8613 return Is_Generic_Actual_Type (T1) = Is_Generic_Actual_Type (T2) 8614 or else Is_Declared_Subtype (T1, T2) 8615 or else Is_Declared_Subtype (T2, T1); 8616 end Same_Generic_Actual; 8617 8618 -- Start of processing for Different_Generic_Profile 8619 8620 begin 8621 if not In_Instance then 8622 return False; 8623 8624 elsif Ekind (E) = E_Function 8625 and then not Same_Generic_Actual (Etype (E), Etype (Designator)) 8626 then 8627 return True; 8628 end if; 8629 8630 F1 := First_Formal (Designator); 8631 F2 := First_Formal (E); 8632 while Present (F1) loop 8633 if not Same_Generic_Actual (Etype (F1), Etype (F2)) then 8634 return True; 8635 end if; 8636 8637 Next_Formal (F1); 8638 Next_Formal (F2); 8639 end loop; 8640 8641 return False; 8642 end Different_Generic_Profile; 8643 8644 -- Start of processing for Find_Corresponding_Spec 8645 8646 begin 8647 E := Current_Entity (Designator); 8648 while Present (E) loop 8649 8650 -- We are looking for a matching spec. It must have the same scope, 8651 -- and the same name, and either be type conformant, or be the case 8652 -- of a library procedure spec and its body (which belong to one 8653 -- another regardless of whether they are type conformant or not). 8654 8655 if Scope (E) = Current_Scope then 8656 if Current_Scope = Standard_Standard 8657 or else (Ekind (E) = Ekind (Designator) 8658 and then Type_Conformant (E, Designator)) 8659 then 8660 -- Within an instantiation, we know that spec and body are 8661 -- subtype conformant, because they were subtype conformant in 8662 -- the generic. We choose the subtype-conformant entity here as 8663 -- well, to resolve spurious ambiguities in the instance that 8664 -- were not present in the generic (i.e. when two different 8665 -- types are given the same actual). If we are looking for a 8666 -- spec to match a body, full conformance is expected. 8667 8668 if In_Instance then 8669 8670 -- Inherit the convention and "ghostness" of the matching 8671 -- spec to ensure proper full and subtype conformance. 8672 8673 Set_Convention (Designator, Convention (E)); 8674 8675 -- Skip past subprogram bodies and subprogram renamings that 8676 -- may appear to have a matching spec, but that aren't fully 8677 -- conformant with it. That can occur in cases where an 8678 -- actual type causes unrelated homographs in the instance. 8679 8680 if Nkind_In (N, N_Subprogram_Body, 8681 N_Subprogram_Renaming_Declaration) 8682 and then Present (Homonym (E)) 8683 and then not Fully_Conformant (Designator, E) 8684 then 8685 goto Next_Entity; 8686 8687 elsif not Subtype_Conformant (Designator, E) then 8688 goto Next_Entity; 8689 8690 elsif Different_Generic_Profile (E) then 8691 goto Next_Entity; 8692 end if; 8693 end if; 8694 8695 -- Ada 2012 (AI05-0165): For internally generated bodies of 8696 -- null procedures locate the internally generated spec. We 8697 -- enforce mode conformance since a tagged type may inherit 8698 -- from interfaces several null primitives which differ only 8699 -- in the mode of the formals. 8700 8701 if not (Comes_From_Source (E)) 8702 and then Is_Null_Procedure (E) 8703 and then not Mode_Conformant (Designator, E) 8704 then 8705 null; 8706 8707 -- For null procedures coming from source that are completions, 8708 -- analysis of the generated body will establish the link. 8709 8710 elsif Comes_From_Source (E) 8711 and then Nkind (Spec) = N_Procedure_Specification 8712 and then Null_Present (Spec) 8713 then 8714 return E; 8715 8716 -- Expression functions can be completions, but cannot be 8717 -- completed by an explicit body. 8718 8719 elsif Comes_From_Source (E) 8720 and then Comes_From_Source (N) 8721 and then Nkind (N) = N_Subprogram_Body 8722 and then Nkind (Original_Node (Unit_Declaration_Node (E))) = 8723 N_Expression_Function 8724 then 8725 Error_Msg_Sloc := Sloc (E); 8726 Error_Msg_N ("body conflicts with expression function#", N); 8727 return Empty; 8728 8729 elsif not Has_Completion (E) then 8730 if Nkind (N) /= N_Subprogram_Body_Stub then 8731 Set_Corresponding_Spec (N, E); 8732 end if; 8733 8734 Set_Has_Completion (E); 8735 return E; 8736 8737 elsif Nkind (Parent (N)) = N_Subunit then 8738 8739 -- If this is the proper body of a subunit, the completion 8740 -- flag is set when analyzing the stub. 8741 8742 return E; 8743 8744 -- If E is an internal function with a controlling result that 8745 -- was created for an operation inherited by a null extension, 8746 -- it may be overridden by a body without a previous spec (one 8747 -- more reason why these should be shunned). In that case we 8748 -- remove the generated body if present, because the current 8749 -- one is the explicit overriding. 8750 8751 elsif Ekind (E) = E_Function 8752 and then Ada_Version >= Ada_2005 8753 and then not Comes_From_Source (E) 8754 and then Has_Controlling_Result (E) 8755 and then Is_Null_Extension (Etype (E)) 8756 and then Comes_From_Source (Spec) 8757 then 8758 Set_Has_Completion (E, False); 8759 8760 if Expander_Active 8761 and then Nkind (Parent (E)) = N_Function_Specification 8762 then 8763 Remove 8764 (Unit_Declaration_Node 8765 (Corresponding_Body (Unit_Declaration_Node (E)))); 8766 8767 return E; 8768 8769 -- If expansion is disabled, or if the wrapper function has 8770 -- not been generated yet, this a late body overriding an 8771 -- inherited operation, or it is an overriding by some other 8772 -- declaration before the controlling result is frozen. In 8773 -- either case this is a declaration of a new entity. 8774 8775 else 8776 return Empty; 8777 end if; 8778 8779 -- If the body already exists, then this is an error unless 8780 -- the previous declaration is the implicit declaration of a 8781 -- derived subprogram. It is also legal for an instance to 8782 -- contain type conformant overloadable declarations (but the 8783 -- generic declaration may not), per 8.3(26/2). 8784 8785 elsif No (Alias (E)) 8786 and then not Is_Intrinsic_Subprogram (E) 8787 and then not In_Instance 8788 and then Post_Error 8789 then 8790 Error_Msg_Sloc := Sloc (E); 8791 8792 if Is_Imported (E) then 8793 Error_Msg_NE 8794 ("body not allowed for imported subprogram & declared#", 8795 N, E); 8796 else 8797 Error_Msg_NE ("duplicate body for & declared#", N, E); 8798 end if; 8799 end if; 8800 8801 -- Child units cannot be overloaded, so a conformance mismatch 8802 -- between body and a previous spec is an error. 8803 8804 elsif Is_Child_Unit (E) 8805 and then 8806 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body 8807 and then 8808 Nkind (Parent (Unit_Declaration_Node (Designator))) = 8809 N_Compilation_Unit 8810 and then Post_Error 8811 then 8812 Error_Msg_N 8813 ("body of child unit does not match previous declaration", N); 8814 end if; 8815 end if; 8816 8817 <<Next_Entity>> 8818 E := Homonym (E); 8819 end loop; 8820 8821 -- On exit, we know that no previous declaration of subprogram exists 8822 8823 return Empty; 8824 end Find_Corresponding_Spec; 8825 8826 ---------------------- 8827 -- Fully_Conformant -- 8828 ---------------------- 8829 8830 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is 8831 Result : Boolean; 8832 begin 8833 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result); 8834 return Result; 8835 end Fully_Conformant; 8836 8837 ---------------------------------- 8838 -- Fully_Conformant_Expressions -- 8839 ---------------------------------- 8840 8841 function Fully_Conformant_Expressions 8842 (Given_E1 : Node_Id; 8843 Given_E2 : Node_Id; 8844 Report : Boolean := False) return Boolean 8845 is 8846 E1 : constant Node_Id := Original_Node (Given_E1); 8847 E2 : constant Node_Id := Original_Node (Given_E2); 8848 -- We always test conformance on original nodes, since it is possible 8849 -- for analysis and/or expansion to make things look as though they 8850 -- conform when they do not, e.g. by converting 1+2 into 3. 8851 8852 function FCE (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean; 8853 -- ??? 8854 8855 function FCL (L1 : List_Id; L2 : List_Id) return Boolean; 8856 -- Compare elements of two lists for conformance. Elements have to be 8857 -- conformant, and actuals inserted as default parameters do not match 8858 -- explicit actuals with the same value. 8859 8860 function FCO (Op_Node : Node_Id; Call_Node : Node_Id) return Boolean; 8861 -- Compare an operator node with a function call 8862 8863 --------- 8864 -- FCE -- 8865 --------- 8866 8867 function FCE (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean is 8868 begin 8869 return Fully_Conformant_Expressions (Given_E1, Given_E2, Report); 8870 end FCE; 8871 8872 --------- 8873 -- FCL -- 8874 --------- 8875 8876 function FCL (L1 : List_Id; L2 : List_Id) return Boolean is 8877 N1 : Node_Id; 8878 N2 : Node_Id; 8879 8880 begin 8881 if L1 = No_List then 8882 N1 := Empty; 8883 else 8884 N1 := First (L1); 8885 end if; 8886 8887 if L2 = No_List then 8888 N2 := Empty; 8889 else 8890 N2 := First (L2); 8891 end if; 8892 8893 -- Compare two lists, skipping rewrite insertions (we want to compare 8894 -- the original trees, not the expanded versions). 8895 8896 loop 8897 if Is_Rewrite_Insertion (N1) then 8898 Next (N1); 8899 elsif Is_Rewrite_Insertion (N2) then 8900 Next (N2); 8901 elsif No (N1) then 8902 return No (N2); 8903 elsif No (N2) then 8904 return False; 8905 elsif not FCE (N1, N2) then 8906 return False; 8907 else 8908 Next (N1); 8909 Next (N2); 8910 end if; 8911 end loop; 8912 end FCL; 8913 8914 --------- 8915 -- FCO -- 8916 --------- 8917 8918 function FCO (Op_Node : Node_Id; Call_Node : Node_Id) return Boolean is 8919 Actuals : constant List_Id := Parameter_Associations (Call_Node); 8920 Act : Node_Id; 8921 8922 begin 8923 if No (Actuals) 8924 or else Entity (Op_Node) /= Entity (Name (Call_Node)) 8925 then 8926 return False; 8927 8928 else 8929 Act := First (Actuals); 8930 8931 if Nkind (Op_Node) in N_Binary_Op then 8932 if not FCE (Left_Opnd (Op_Node), Act) then 8933 return False; 8934 end if; 8935 8936 Next (Act); 8937 end if; 8938 8939 return Present (Act) 8940 and then FCE (Right_Opnd (Op_Node), Act) 8941 and then No (Next (Act)); 8942 end if; 8943 end FCO; 8944 8945 -- Local variables 8946 8947 Result : Boolean; 8948 8949 -- Start of processing for Fully_Conformant_Expressions 8950 8951 begin 8952 Result := True; 8953 8954 -- Nonconformant if paren count does not match. Note: if some idiot 8955 -- complains that we don't do this right for more than 3 levels of 8956 -- parentheses, they will be treated with the respect they deserve. 8957 8958 if Paren_Count (E1) /= Paren_Count (E2) then 8959 return False; 8960 8961 -- If same entities are referenced, then they are conformant even if 8962 -- they have different forms (RM 8.3.1(19-20)). 8963 8964 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then 8965 if Present (Entity (E1)) then 8966 Result := Entity (E1) = Entity (E2) 8967 8968 -- One may be a discriminant that has been replaced by the 8969 -- corresponding discriminal. 8970 8971 or else 8972 (Chars (Entity (E1)) = Chars (Entity (E2)) 8973 and then Ekind (Entity (E1)) = E_Discriminant 8974 and then Ekind (Entity (E2)) = E_In_Parameter) 8975 8976 -- The discriminant of a protected type is transformed into 8977 -- a local constant and then into a parameter of a protected 8978 -- operation. 8979 8980 or else 8981 (Ekind (Entity (E1)) = E_Constant 8982 and then Ekind (Entity (E2)) = E_In_Parameter 8983 and then Present (Discriminal_Link (Entity (E1))) 8984 and then Discriminal_Link (Entity (E1)) = 8985 Discriminal_Link (Entity (E2))) 8986 8987 -- AI12-050: The loop variables of quantified expressions match 8988 -- if they have the same identifier, even though they may have 8989 -- different entities. 8990 8991 or else 8992 (Chars (Entity (E1)) = Chars (Entity (E2)) 8993 and then Ekind (Entity (E1)) = E_Loop_Parameter 8994 and then Ekind (Entity (E2)) = E_Loop_Parameter) 8995 8996 -- A call to an instantiation of Unchecked_Conversion is 8997 -- rewritten with the name of the generated function created for 8998 -- the instance, and this must be special-cased. 8999 9000 or else 9001 (Ekind (Entity (E1)) = E_Function 9002 and then Is_Intrinsic_Subprogram (Entity (E1)) 9003 and then Is_Generic_Instance (Entity (E1)) 9004 and then Entity (E2) = Alias (Entity (E1))); 9005 if Report and not Result then 9006 Error_Msg_Sloc := 9007 Text_Ptr'Max (Sloc (Entity (E1)), Sloc (Entity (E2))); 9008 Error_Msg_NE 9009 ("Meaning of& differs because of declaration#", E1, E2); 9010 end if; 9011 9012 return Result; 9013 9014 elsif Nkind (E1) = N_Expanded_Name 9015 and then Nkind (E2) = N_Expanded_Name 9016 and then Nkind (Selector_Name (E1)) = N_Character_Literal 9017 and then Nkind (Selector_Name (E2)) = N_Character_Literal 9018 then 9019 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)); 9020 9021 else 9022 -- Identifiers in component associations don't always have 9023 -- entities, but their names must conform. 9024 9025 return Nkind (E1) = N_Identifier 9026 and then Nkind (E2) = N_Identifier 9027 and then Chars (E1) = Chars (E2); 9028 end if; 9029 9030 elsif Nkind (E1) = N_Character_Literal 9031 and then Nkind (E2) = N_Expanded_Name 9032 then 9033 return Nkind (Selector_Name (E2)) = N_Character_Literal 9034 and then Chars (E1) = Chars (Selector_Name (E2)); 9035 9036 elsif Nkind (E2) = N_Character_Literal 9037 and then Nkind (E1) = N_Expanded_Name 9038 then 9039 return Nkind (Selector_Name (E1)) = N_Character_Literal 9040 and then Chars (E2) = Chars (Selector_Name (E1)); 9041 9042 elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then 9043 return FCO (E1, E2); 9044 9045 elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then 9046 return FCO (E2, E1); 9047 9048 -- Otherwise we must have the same syntactic entity 9049 9050 elsif Nkind (E1) /= Nkind (E2) then 9051 return False; 9052 9053 -- At this point, we specialize by node type 9054 9055 else 9056 case Nkind (E1) is 9057 when N_Aggregate => 9058 return 9059 FCL (Expressions (E1), Expressions (E2)) 9060 and then 9061 FCL (Component_Associations (E1), 9062 Component_Associations (E2)); 9063 9064 when N_Allocator => 9065 if Nkind (Expression (E1)) = N_Qualified_Expression 9066 or else 9067 Nkind (Expression (E2)) = N_Qualified_Expression 9068 then 9069 return FCE (Expression (E1), Expression (E2)); 9070 9071 -- Check that the subtype marks and any constraints 9072 -- are conformant 9073 9074 else 9075 declare 9076 Indic1 : constant Node_Id := Expression (E1); 9077 Indic2 : constant Node_Id := Expression (E2); 9078 Elt1 : Node_Id; 9079 Elt2 : Node_Id; 9080 9081 begin 9082 if Nkind (Indic1) /= N_Subtype_Indication then 9083 return 9084 Nkind (Indic2) /= N_Subtype_Indication 9085 and then Entity (Indic1) = Entity (Indic2); 9086 9087 elsif Nkind (Indic2) /= N_Subtype_Indication then 9088 return 9089 Nkind (Indic1) /= N_Subtype_Indication 9090 and then Entity (Indic1) = Entity (Indic2); 9091 9092 else 9093 if Entity (Subtype_Mark (Indic1)) /= 9094 Entity (Subtype_Mark (Indic2)) 9095 then 9096 return False; 9097 end if; 9098 9099 Elt1 := First (Constraints (Constraint (Indic1))); 9100 Elt2 := First (Constraints (Constraint (Indic2))); 9101 while Present (Elt1) and then Present (Elt2) loop 9102 if not FCE (Elt1, Elt2) then 9103 return False; 9104 end if; 9105 9106 Next (Elt1); 9107 Next (Elt2); 9108 end loop; 9109 9110 return True; 9111 end if; 9112 end; 9113 end if; 9114 9115 when N_Attribute_Reference => 9116 return 9117 Attribute_Name (E1) = Attribute_Name (E2) 9118 and then FCL (Expressions (E1), Expressions (E2)); 9119 9120 when N_Binary_Op => 9121 return 9122 Entity (E1) = Entity (E2) 9123 and then FCE (Left_Opnd (E1), Left_Opnd (E2)) 9124 and then FCE (Right_Opnd (E1), Right_Opnd (E2)); 9125 9126 when N_Membership_Test 9127 | N_Short_Circuit 9128 => 9129 return 9130 FCE (Left_Opnd (E1), Left_Opnd (E2)) 9131 and then 9132 FCE (Right_Opnd (E1), Right_Opnd (E2)); 9133 9134 when N_Case_Expression => 9135 declare 9136 Alt1 : Node_Id; 9137 Alt2 : Node_Id; 9138 9139 begin 9140 if not FCE (Expression (E1), Expression (E2)) then 9141 return False; 9142 9143 else 9144 Alt1 := First (Alternatives (E1)); 9145 Alt2 := First (Alternatives (E2)); 9146 loop 9147 if Present (Alt1) /= Present (Alt2) then 9148 return False; 9149 elsif No (Alt1) then 9150 return True; 9151 end if; 9152 9153 if not FCE (Expression (Alt1), Expression (Alt2)) 9154 or else not FCL (Discrete_Choices (Alt1), 9155 Discrete_Choices (Alt2)) 9156 then 9157 return False; 9158 end if; 9159 9160 Next (Alt1); 9161 Next (Alt2); 9162 end loop; 9163 end if; 9164 end; 9165 9166 when N_Character_Literal => 9167 return 9168 Char_Literal_Value (E1) = Char_Literal_Value (E2); 9169 9170 when N_Component_Association => 9171 return 9172 FCL (Choices (E1), Choices (E2)) 9173 and then 9174 FCE (Expression (E1), Expression (E2)); 9175 9176 when N_Explicit_Dereference => 9177 return 9178 FCE (Prefix (E1), Prefix (E2)); 9179 9180 when N_Extension_Aggregate => 9181 return 9182 FCL (Expressions (E1), Expressions (E2)) 9183 and then Null_Record_Present (E1) = 9184 Null_Record_Present (E2) 9185 and then FCL (Component_Associations (E1), 9186 Component_Associations (E2)); 9187 9188 when N_Function_Call => 9189 return 9190 FCE (Name (E1), Name (E2)) 9191 and then 9192 FCL (Parameter_Associations (E1), 9193 Parameter_Associations (E2)); 9194 9195 when N_If_Expression => 9196 return 9197 FCL (Expressions (E1), Expressions (E2)); 9198 9199 when N_Indexed_Component => 9200 return 9201 FCE (Prefix (E1), Prefix (E2)) 9202 and then 9203 FCL (Expressions (E1), Expressions (E2)); 9204 9205 when N_Integer_Literal => 9206 return (Intval (E1) = Intval (E2)); 9207 9208 when N_Null => 9209 return True; 9210 9211 when N_Operator_Symbol => 9212 return 9213 Chars (E1) = Chars (E2); 9214 9215 when N_Others_Choice => 9216 return True; 9217 9218 when N_Parameter_Association => 9219 return 9220 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)) 9221 and then FCE (Explicit_Actual_Parameter (E1), 9222 Explicit_Actual_Parameter (E2)); 9223 9224 when N_Qualified_Expression 9225 | N_Type_Conversion 9226 | N_Unchecked_Type_Conversion 9227 => 9228 return 9229 FCE (Subtype_Mark (E1), Subtype_Mark (E2)) 9230 and then 9231 FCE (Expression (E1), Expression (E2)); 9232 9233 when N_Quantified_Expression => 9234 if not FCE (Condition (E1), Condition (E2)) then 9235 return False; 9236 end if; 9237 9238 if Present (Loop_Parameter_Specification (E1)) 9239 and then Present (Loop_Parameter_Specification (E2)) 9240 then 9241 declare 9242 L1 : constant Node_Id := 9243 Loop_Parameter_Specification (E1); 9244 L2 : constant Node_Id := 9245 Loop_Parameter_Specification (E2); 9246 9247 begin 9248 return 9249 Reverse_Present (L1) = Reverse_Present (L2) 9250 and then 9251 FCE (Defining_Identifier (L1), 9252 Defining_Identifier (L2)) 9253 and then 9254 FCE (Discrete_Subtype_Definition (L1), 9255 Discrete_Subtype_Definition (L2)); 9256 end; 9257 9258 elsif Present (Iterator_Specification (E1)) 9259 and then Present (Iterator_Specification (E2)) 9260 then 9261 declare 9262 I1 : constant Node_Id := Iterator_Specification (E1); 9263 I2 : constant Node_Id := Iterator_Specification (E2); 9264 9265 begin 9266 return 9267 FCE (Defining_Identifier (I1), 9268 Defining_Identifier (I2)) 9269 and then 9270 Of_Present (I1) = Of_Present (I2) 9271 and then 9272 Reverse_Present (I1) = Reverse_Present (I2) 9273 and then FCE (Name (I1), Name (I2)) 9274 and then FCE (Subtype_Indication (I1), 9275 Subtype_Indication (I2)); 9276 end; 9277 9278 -- The quantified expressions used different specifications to 9279 -- walk their respective ranges. 9280 9281 else 9282 return False; 9283 end if; 9284 9285 when N_Range => 9286 return 9287 FCE (Low_Bound (E1), Low_Bound (E2)) 9288 and then 9289 FCE (High_Bound (E1), High_Bound (E2)); 9290 9291 when N_Real_Literal => 9292 return (Realval (E1) = Realval (E2)); 9293 9294 when N_Selected_Component => 9295 return 9296 FCE (Prefix (E1), Prefix (E2)) 9297 and then 9298 FCE (Selector_Name (E1), Selector_Name (E2)); 9299 9300 when N_Slice => 9301 return 9302 FCE (Prefix (E1), Prefix (E2)) 9303 and then 9304 FCE (Discrete_Range (E1), Discrete_Range (E2)); 9305 9306 when N_String_Literal => 9307 declare 9308 S1 : constant String_Id := Strval (E1); 9309 S2 : constant String_Id := Strval (E2); 9310 L1 : constant Nat := String_Length (S1); 9311 L2 : constant Nat := String_Length (S2); 9312 9313 begin 9314 if L1 /= L2 then 9315 return False; 9316 9317 else 9318 for J in 1 .. L1 loop 9319 if Get_String_Char (S1, J) /= 9320 Get_String_Char (S2, J) 9321 then 9322 return False; 9323 end if; 9324 end loop; 9325 9326 return True; 9327 end if; 9328 end; 9329 9330 when N_Unary_Op => 9331 return 9332 Entity (E1) = Entity (E2) 9333 and then 9334 FCE (Right_Opnd (E1), Right_Opnd (E2)); 9335 9336 -- All other node types cannot appear in this context. Strictly 9337 -- we should raise a fatal internal error. Instead we just ignore 9338 -- the nodes. This means that if anyone makes a mistake in the 9339 -- expander and mucks an expression tree irretrievably, the result 9340 -- will be a failure to detect a (probably very obscure) case 9341 -- of non-conformance, which is better than bombing on some 9342 -- case where two expressions do in fact conform. 9343 9344 when others => 9345 return True; 9346 end case; 9347 end if; 9348 end Fully_Conformant_Expressions; 9349 9350 ---------------------------------------- 9351 -- Fully_Conformant_Discrete_Subtypes -- 9352 ---------------------------------------- 9353 9354 function Fully_Conformant_Discrete_Subtypes 9355 (Given_S1 : Node_Id; 9356 Given_S2 : Node_Id) return Boolean 9357 is 9358 S1 : constant Node_Id := Original_Node (Given_S1); 9359 S2 : constant Node_Id := Original_Node (Given_S2); 9360 9361 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean; 9362 -- Special-case for a bound given by a discriminant, which in the body 9363 -- is replaced with the discriminal of the enclosing type. 9364 9365 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean; 9366 -- Check both bounds 9367 9368 ----------------------- 9369 -- Conforming_Bounds -- 9370 ----------------------- 9371 9372 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is 9373 begin 9374 if Is_Entity_Name (B1) 9375 and then Is_Entity_Name (B2) 9376 and then Ekind (Entity (B1)) = E_Discriminant 9377 then 9378 return Chars (B1) = Chars (B2); 9379 9380 else 9381 return Fully_Conformant_Expressions (B1, B2); 9382 end if; 9383 end Conforming_Bounds; 9384 9385 ----------------------- 9386 -- Conforming_Ranges -- 9387 ----------------------- 9388 9389 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is 9390 begin 9391 return 9392 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2)) 9393 and then 9394 Conforming_Bounds (High_Bound (R1), High_Bound (R2)); 9395 end Conforming_Ranges; 9396 9397 -- Start of processing for Fully_Conformant_Discrete_Subtypes 9398 9399 begin 9400 if Nkind (S1) /= Nkind (S2) then 9401 return False; 9402 9403 elsif Is_Entity_Name (S1) then 9404 return Entity (S1) = Entity (S2); 9405 9406 elsif Nkind (S1) = N_Range then 9407 return Conforming_Ranges (S1, S2); 9408 9409 elsif Nkind (S1) = N_Subtype_Indication then 9410 return 9411 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2)) 9412 and then 9413 Conforming_Ranges 9414 (Range_Expression (Constraint (S1)), 9415 Range_Expression (Constraint (S2))); 9416 else 9417 return True; 9418 end if; 9419 end Fully_Conformant_Discrete_Subtypes; 9420 9421 -------------------- 9422 -- Install_Entity -- 9423 -------------------- 9424 9425 procedure Install_Entity (E : Entity_Id) is 9426 Prev : constant Entity_Id := Current_Entity (E); 9427 begin 9428 Set_Is_Immediately_Visible (E); 9429 Set_Current_Entity (E); 9430 Set_Homonym (E, Prev); 9431 end Install_Entity; 9432 9433 --------------------- 9434 -- Install_Formals -- 9435 --------------------- 9436 9437 procedure Install_Formals (Id : Entity_Id) is 9438 F : Entity_Id; 9439 begin 9440 F := First_Formal (Id); 9441 while Present (F) loop 9442 Install_Entity (F); 9443 Next_Formal (F); 9444 end loop; 9445 end Install_Formals; 9446 9447 ----------------------------- 9448 -- Is_Interface_Conformant -- 9449 ----------------------------- 9450 9451 function Is_Interface_Conformant 9452 (Tagged_Type : Entity_Id; 9453 Iface_Prim : Entity_Id; 9454 Prim : Entity_Id) return Boolean 9455 is 9456 -- The operation may in fact be an inherited (implicit) operation 9457 -- rather than the original interface primitive, so retrieve the 9458 -- ultimate ancestor. 9459 9460 Iface : constant Entity_Id := 9461 Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)); 9462 Typ : constant Entity_Id := Find_Dispatching_Type (Prim); 9463 9464 function Controlling_Formal (Prim : Entity_Id) return Entity_Id; 9465 -- Return the controlling formal of Prim 9466 9467 ------------------------ 9468 -- Controlling_Formal -- 9469 ------------------------ 9470 9471 function Controlling_Formal (Prim : Entity_Id) return Entity_Id is 9472 E : Entity_Id; 9473 9474 begin 9475 E := First_Entity (Prim); 9476 while Present (E) loop 9477 if Is_Formal (E) and then Is_Controlling_Formal (E) then 9478 return E; 9479 end if; 9480 9481 Next_Entity (E); 9482 end loop; 9483 9484 return Empty; 9485 end Controlling_Formal; 9486 9487 -- Local variables 9488 9489 Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim); 9490 Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim); 9491 9492 -- Start of processing for Is_Interface_Conformant 9493 9494 begin 9495 pragma Assert (Is_Subprogram (Iface_Prim) 9496 and then Is_Subprogram (Prim) 9497 and then Is_Dispatching_Operation (Iface_Prim) 9498 and then Is_Dispatching_Operation (Prim)); 9499 9500 pragma Assert (Is_Interface (Iface) 9501 or else (Present (Alias (Iface_Prim)) 9502 and then 9503 Is_Interface 9504 (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim))))); 9505 9506 if Prim = Iface_Prim 9507 or else not Is_Subprogram (Prim) 9508 or else Ekind (Prim) /= Ekind (Iface_Prim) 9509 or else not Is_Dispatching_Operation (Prim) 9510 or else Scope (Prim) /= Scope (Tagged_Type) 9511 or else No (Typ) 9512 or else Base_Type (Typ) /= Base_Type (Tagged_Type) 9513 or else not Primitive_Names_Match (Iface_Prim, Prim) 9514 then 9515 return False; 9516 9517 -- The mode of the controlling formals must match 9518 9519 elsif Present (Iface_Ctrl_F) 9520 and then Present (Prim_Ctrl_F) 9521 and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F) 9522 then 9523 return False; 9524 9525 -- Case of a procedure, or a function whose result type matches the 9526 -- result type of the interface primitive, or a function that has no 9527 -- controlling result (I or access I). 9528 9529 elsif Ekind (Iface_Prim) = E_Procedure 9530 or else Etype (Prim) = Etype (Iface_Prim) 9531 or else not Has_Controlling_Result (Prim) 9532 then 9533 return Type_Conformant 9534 (Iface_Prim, Prim, Skip_Controlling_Formals => True); 9535 9536 -- Case of a function returning an interface, or an access to one. Check 9537 -- that the return types correspond. 9538 9539 elsif Implements_Interface (Typ, Iface) then 9540 if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type) 9541 /= 9542 (Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type) 9543 then 9544 return False; 9545 else 9546 return 9547 Type_Conformant (Prim, Ultimate_Alias (Iface_Prim), 9548 Skip_Controlling_Formals => True); 9549 end if; 9550 9551 else 9552 return False; 9553 end if; 9554 end Is_Interface_Conformant; 9555 9556 --------------------------------- 9557 -- Is_Non_Overriding_Operation -- 9558 --------------------------------- 9559 9560 function Is_Non_Overriding_Operation 9561 (Prev_E : Entity_Id; 9562 New_E : Entity_Id) return Boolean 9563 is 9564 Formal : Entity_Id; 9565 F_Typ : Entity_Id; 9566 G_Typ : Entity_Id := Empty; 9567 9568 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id; 9569 -- If F_Type is a derived type associated with a generic actual subtype, 9570 -- then return its Generic_Parent_Type attribute, else return Empty. 9571 9572 function Types_Correspond 9573 (P_Type : Entity_Id; 9574 N_Type : Entity_Id) return Boolean; 9575 -- Returns true if and only if the types (or designated types in the 9576 -- case of anonymous access types) are the same or N_Type is derived 9577 -- directly or indirectly from P_Type. 9578 9579 ----------------------------- 9580 -- Get_Generic_Parent_Type -- 9581 ----------------------------- 9582 9583 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is 9584 G_Typ : Entity_Id; 9585 Defn : Node_Id; 9586 Indic : Node_Id; 9587 9588 begin 9589 if Is_Derived_Type (F_Typ) 9590 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration 9591 then 9592 -- The tree must be traversed to determine the parent subtype in 9593 -- the generic unit, which unfortunately isn't always available 9594 -- via semantic attributes. ??? (Note: The use of Original_Node 9595 -- is needed for cases where a full derived type has been 9596 -- rewritten.) 9597 9598 -- If the parent type is a scalar type, the derivation creates 9599 -- an anonymous base type for it, and the source type is its 9600 -- first subtype. 9601 9602 if Is_Scalar_Type (F_Typ) 9603 and then not Comes_From_Source (F_Typ) 9604 then 9605 Defn := 9606 Type_Definition 9607 (Original_Node (Parent (First_Subtype (F_Typ)))); 9608 else 9609 Defn := Type_Definition (Original_Node (Parent (F_Typ))); 9610 end if; 9611 if Nkind (Defn) = N_Derived_Type_Definition then 9612 Indic := Subtype_Indication (Defn); 9613 9614 if Nkind (Indic) = N_Subtype_Indication then 9615 G_Typ := Entity (Subtype_Mark (Indic)); 9616 else 9617 G_Typ := Entity (Indic); 9618 end if; 9619 9620 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration 9621 and then Present (Generic_Parent_Type (Parent (G_Typ))) 9622 then 9623 return Generic_Parent_Type (Parent (G_Typ)); 9624 end if; 9625 end if; 9626 end if; 9627 9628 return Empty; 9629 end Get_Generic_Parent_Type; 9630 9631 ---------------------- 9632 -- Types_Correspond -- 9633 ---------------------- 9634 9635 function Types_Correspond 9636 (P_Type : Entity_Id; 9637 N_Type : Entity_Id) return Boolean 9638 is 9639 Prev_Type : Entity_Id := Base_Type (P_Type); 9640 New_Type : Entity_Id := Base_Type (N_Type); 9641 9642 begin 9643 if Ekind (Prev_Type) = E_Anonymous_Access_Type then 9644 Prev_Type := Designated_Type (Prev_Type); 9645 end if; 9646 9647 if Ekind (New_Type) = E_Anonymous_Access_Type then 9648 New_Type := Designated_Type (New_Type); 9649 end if; 9650 9651 if Prev_Type = New_Type then 9652 return True; 9653 9654 elsif not Is_Class_Wide_Type (New_Type) then 9655 while Etype (New_Type) /= New_Type loop 9656 New_Type := Etype (New_Type); 9657 9658 if New_Type = Prev_Type then 9659 return True; 9660 end if; 9661 end loop; 9662 end if; 9663 return False; 9664 end Types_Correspond; 9665 9666 -- Start of processing for Is_Non_Overriding_Operation 9667 9668 begin 9669 -- In the case where both operations are implicit derived subprograms 9670 -- then neither overrides the other. This can only occur in certain 9671 -- obscure cases (e.g., derivation from homographs created in a generic 9672 -- instantiation). 9673 9674 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then 9675 return True; 9676 9677 elsif Ekind (Current_Scope) = E_Package 9678 and then Is_Generic_Instance (Current_Scope) 9679 and then In_Private_Part (Current_Scope) 9680 and then Comes_From_Source (New_E) 9681 then 9682 -- We examine the formals and result type of the inherited operation, 9683 -- to determine whether their type is derived from (the instance of) 9684 -- a generic type. The first such formal or result type is the one 9685 -- tested. 9686 9687 Formal := First_Formal (Prev_E); 9688 F_Typ := Empty; 9689 while Present (Formal) loop 9690 F_Typ := Base_Type (Etype (Formal)); 9691 9692 if Ekind (F_Typ) = E_Anonymous_Access_Type then 9693 F_Typ := Designated_Type (F_Typ); 9694 end if; 9695 9696 G_Typ := Get_Generic_Parent_Type (F_Typ); 9697 exit when Present (G_Typ); 9698 9699 Next_Formal (Formal); 9700 end loop; 9701 9702 -- If the function dispatches on result check the result type 9703 9704 if No (G_Typ) and then Ekind (Prev_E) = E_Function then 9705 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E))); 9706 end if; 9707 9708 if No (G_Typ) then 9709 return False; 9710 end if; 9711 9712 -- If the generic type is a private type, then the original operation 9713 -- was not overriding in the generic, because there was no primitive 9714 -- operation to override. 9715 9716 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration 9717 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) = 9718 N_Formal_Private_Type_Definition 9719 then 9720 return True; 9721 9722 -- The generic parent type is the ancestor of a formal derived 9723 -- type declaration. We need to check whether it has a primitive 9724 -- operation that should be overridden by New_E in the generic. 9725 9726 else 9727 declare 9728 P_Formal : Entity_Id; 9729 N_Formal : Entity_Id; 9730 P_Typ : Entity_Id; 9731 N_Typ : Entity_Id; 9732 P_Prim : Entity_Id; 9733 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ)); 9734 9735 begin 9736 while Present (Prim_Elt) loop 9737 P_Prim := Node (Prim_Elt); 9738 9739 if Chars (P_Prim) = Chars (New_E) 9740 and then Ekind (P_Prim) = Ekind (New_E) 9741 then 9742 P_Formal := First_Formal (P_Prim); 9743 N_Formal := First_Formal (New_E); 9744 while Present (P_Formal) and then Present (N_Formal) loop 9745 P_Typ := Etype (P_Formal); 9746 N_Typ := Etype (N_Formal); 9747 9748 if not Types_Correspond (P_Typ, N_Typ) then 9749 exit; 9750 end if; 9751 9752 Next_Entity (P_Formal); 9753 Next_Entity (N_Formal); 9754 end loop; 9755 9756 -- Found a matching primitive operation belonging to the 9757 -- formal ancestor type, so the new subprogram is 9758 -- overriding. 9759 9760 if No (P_Formal) 9761 and then No (N_Formal) 9762 and then (Ekind (New_E) /= E_Function 9763 or else 9764 Types_Correspond 9765 (Etype (P_Prim), Etype (New_E))) 9766 then 9767 return False; 9768 end if; 9769 end if; 9770 9771 Next_Elmt (Prim_Elt); 9772 end loop; 9773 9774 -- If no match found, then the new subprogram does not override 9775 -- in the generic (nor in the instance). 9776 9777 -- If the type in question is not abstract, and the subprogram 9778 -- is, this will be an error if the new operation is in the 9779 -- private part of the instance. Emit a warning now, which will 9780 -- make the subsequent error message easier to understand. 9781 9782 if Present (F_Typ) and then not Is_Abstract_Type (F_Typ) 9783 and then Is_Abstract_Subprogram (Prev_E) 9784 and then In_Private_Part (Current_Scope) 9785 then 9786 Error_Msg_Node_2 := F_Typ; 9787 Error_Msg_NE 9788 ("private operation& in generic unit does not override " 9789 & "any primitive operation of& (RM 12.3 (18))??", 9790 New_E, New_E); 9791 end if; 9792 9793 return True; 9794 end; 9795 end if; 9796 else 9797 return False; 9798 end if; 9799 end Is_Non_Overriding_Operation; 9800 9801 ------------------------------------- 9802 -- List_Inherited_Pre_Post_Aspects -- 9803 ------------------------------------- 9804 9805 procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is 9806 begin 9807 if Opt.List_Inherited_Aspects 9808 and then Is_Subprogram_Or_Generic_Subprogram (E) 9809 then 9810 declare 9811 Subps : constant Subprogram_List := Inherited_Subprograms (E); 9812 Items : Node_Id; 9813 Prag : Node_Id; 9814 9815 begin 9816 for Index in Subps'Range loop 9817 Items := Contract (Subps (Index)); 9818 9819 if Present (Items) then 9820 Prag := Pre_Post_Conditions (Items); 9821 while Present (Prag) loop 9822 Error_Msg_Sloc := Sloc (Prag); 9823 9824 if Class_Present (Prag) 9825 and then not Split_PPC (Prag) 9826 then 9827 if Pragma_Name (Prag) = Name_Precondition then 9828 Error_Msg_N 9829 ("info: & inherits `Pre''Class` aspect from " 9830 & "#?L?", E); 9831 else 9832 Error_Msg_N 9833 ("info: & inherits `Post''Class` aspect from " 9834 & "#?L?", E); 9835 end if; 9836 end if; 9837 9838 Prag := Next_Pragma (Prag); 9839 end loop; 9840 end if; 9841 end loop; 9842 end; 9843 end if; 9844 end List_Inherited_Pre_Post_Aspects; 9845 9846 ------------------------------ 9847 -- Make_Inequality_Operator -- 9848 ------------------------------ 9849 9850 -- S is the defining identifier of an equality operator. We build a 9851 -- subprogram declaration with the right signature. This operation is 9852 -- intrinsic, because it is always expanded as the negation of the 9853 -- call to the equality function. 9854 9855 procedure Make_Inequality_Operator (S : Entity_Id) is 9856 Loc : constant Source_Ptr := Sloc (S); 9857 Decl : Node_Id; 9858 Formals : List_Id; 9859 Op_Name : Entity_Id; 9860 9861 FF : constant Entity_Id := First_Formal (S); 9862 NF : constant Entity_Id := Next_Formal (FF); 9863 9864 begin 9865 -- Check that equality was properly defined, ignore call if not 9866 9867 if No (NF) then 9868 return; 9869 end if; 9870 9871 declare 9872 A : constant Entity_Id := 9873 Make_Defining_Identifier (Sloc (FF), 9874 Chars => Chars (FF)); 9875 9876 B : constant Entity_Id := 9877 Make_Defining_Identifier (Sloc (NF), 9878 Chars => Chars (NF)); 9879 9880 begin 9881 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne); 9882 9883 Formals := New_List ( 9884 Make_Parameter_Specification (Loc, 9885 Defining_Identifier => A, 9886 Parameter_Type => 9887 New_Occurrence_Of (Etype (First_Formal (S)), 9888 Sloc (Etype (First_Formal (S))))), 9889 9890 Make_Parameter_Specification (Loc, 9891 Defining_Identifier => B, 9892 Parameter_Type => 9893 New_Occurrence_Of (Etype (Next_Formal (First_Formal (S))), 9894 Sloc (Etype (Next_Formal (First_Formal (S))))))); 9895 9896 Decl := 9897 Make_Subprogram_Declaration (Loc, 9898 Specification => 9899 Make_Function_Specification (Loc, 9900 Defining_Unit_Name => Op_Name, 9901 Parameter_Specifications => Formals, 9902 Result_Definition => 9903 New_Occurrence_Of (Standard_Boolean, Loc))); 9904 9905 -- Insert inequality right after equality if it is explicit or after 9906 -- the derived type when implicit. These entities are created only 9907 -- for visibility purposes, and eventually replaced in the course 9908 -- of expansion, so they do not need to be attached to the tree and 9909 -- seen by the back-end. Keeping them internal also avoids spurious 9910 -- freezing problems. The declaration is inserted in the tree for 9911 -- analysis, and removed afterwards. If the equality operator comes 9912 -- from an explicit declaration, attach the inequality immediately 9913 -- after. Else the equality is inherited from a derived type 9914 -- declaration, so insert inequality after that declaration. 9915 9916 if No (Alias (S)) then 9917 Insert_After (Unit_Declaration_Node (S), Decl); 9918 elsif Is_List_Member (Parent (S)) then 9919 Insert_After (Parent (S), Decl); 9920 else 9921 Insert_After (Parent (Etype (First_Formal (S))), Decl); 9922 end if; 9923 9924 Mark_Rewrite_Insertion (Decl); 9925 Set_Is_Intrinsic_Subprogram (Op_Name); 9926 Analyze (Decl); 9927 Remove (Decl); 9928 Set_Has_Completion (Op_Name); 9929 Set_Corresponding_Equality (Op_Name, S); 9930 Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S)); 9931 end; 9932 end Make_Inequality_Operator; 9933 9934 ---------------------- 9935 -- May_Need_Actuals -- 9936 ---------------------- 9937 9938 procedure May_Need_Actuals (Fun : Entity_Id) is 9939 F : Entity_Id; 9940 B : Boolean; 9941 9942 begin 9943 F := First_Formal (Fun); 9944 B := True; 9945 while Present (F) loop 9946 if No (Default_Value (F)) then 9947 B := False; 9948 exit; 9949 end if; 9950 9951 Next_Formal (F); 9952 end loop; 9953 9954 Set_Needs_No_Actuals (Fun, B); 9955 end May_Need_Actuals; 9956 9957 --------------------- 9958 -- Mode_Conformant -- 9959 --------------------- 9960 9961 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is 9962 Result : Boolean; 9963 begin 9964 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result); 9965 return Result; 9966 end Mode_Conformant; 9967 9968 --------------------------- 9969 -- New_Overloaded_Entity -- 9970 --------------------------- 9971 9972 procedure New_Overloaded_Entity 9973 (S : Entity_Id; 9974 Derived_Type : Entity_Id := Empty) 9975 is 9976 Overridden_Subp : Entity_Id := Empty; 9977 -- Set if the current scope has an operation that is type-conformant 9978 -- with S, and becomes hidden by S. 9979 9980 Is_Primitive_Subp : Boolean; 9981 -- Set to True if the new subprogram is primitive 9982 9983 E : Entity_Id; 9984 -- Entity that S overrides 9985 9986 procedure Check_For_Primitive_Subprogram 9987 (Is_Primitive : out Boolean; 9988 Is_Overriding : Boolean := False); 9989 -- If the subprogram being analyzed is a primitive operation of the type 9990 -- of a formal or result, set the Has_Primitive_Operations flag on the 9991 -- type, and set Is_Primitive to True (otherwise set to False). Set the 9992 -- corresponding flag on the entity itself for later use. 9993 9994 function Has_Matching_Entry_Or_Subprogram (E : Entity_Id) return Boolean; 9995 -- True if a) E is a subprogram whose first formal is a concurrent type 9996 -- defined in the scope of E that has some entry or subprogram whose 9997 -- profile matches E, or b) E is an internally built dispatching 9998 -- subprogram of a protected type and there is a matching subprogram 9999 -- defined in the enclosing scope of the protected type, or c) E is 10000 -- an entry of a synchronized type and a matching procedure has been 10001 -- previously defined in the enclosing scope of the synchronized type. 10002 10003 function Is_Private_Declaration (E : Entity_Id) return Boolean; 10004 -- Check that E is declared in the private part of the current package, 10005 -- or in the package body, where it may hide a previous declaration. 10006 -- We can't use In_Private_Part by itself because this flag is also 10007 -- set when freezing entities, so we must examine the place of the 10008 -- declaration in the tree, and recognize wrapper packages as well. 10009 10010 function Is_Overriding_Alias 10011 (Old_E : Entity_Id; 10012 New_E : Entity_Id) return Boolean; 10013 -- Check whether new subprogram and old subprogram are both inherited 10014 -- from subprograms that have distinct dispatch table entries. This can 10015 -- occur with derivations from instances with accidental homonyms. The 10016 -- function is conservative given that the converse is only true within 10017 -- instances that contain accidental overloadings. 10018 10019 procedure Report_Conflict (S : Entity_Id; E : Entity_Id); 10020 -- Report conflict between entities S and E 10021 10022 ------------------------------------ 10023 -- Check_For_Primitive_Subprogram -- 10024 ------------------------------------ 10025 10026 procedure Check_For_Primitive_Subprogram 10027 (Is_Primitive : out Boolean; 10028 Is_Overriding : Boolean := False) 10029 is 10030 Formal : Entity_Id; 10031 F_Typ : Entity_Id; 10032 B_Typ : Entity_Id; 10033 10034 function Visible_Part_Type (T : Entity_Id) return Boolean; 10035 -- Returns true if T is declared in the visible part of the current 10036 -- package scope; otherwise returns false. Assumes that T is declared 10037 -- in a package. 10038 10039 procedure Check_Private_Overriding (T : Entity_Id); 10040 -- Checks that if a primitive abstract subprogram of a visible 10041 -- abstract type is declared in a private part, then it must override 10042 -- an abstract subprogram declared in the visible part. Also checks 10043 -- that if a primitive function with a controlling result is declared 10044 -- in a private part, then it must override a function declared in 10045 -- the visible part. 10046 10047 ------------------------------ 10048 -- Check_Private_Overriding -- 10049 ------------------------------ 10050 10051 procedure Check_Private_Overriding (T : Entity_Id) is 10052 function Overrides_Private_Part_Op return Boolean; 10053 -- This detects the special case where the overriding subprogram 10054 -- is overriding a subprogram that was declared in the same 10055 -- private part. That case is illegal by 3.9.3(10). 10056 10057 function Overrides_Visible_Function 10058 (Partial_View : Entity_Id) return Boolean; 10059 -- True if S overrides a function in the visible part. The 10060 -- overridden function could be explicitly or implicitly declared. 10061 10062 ------------------------------- 10063 -- Overrides_Private_Part_Op -- 10064 ------------------------------- 10065 10066 function Overrides_Private_Part_Op return Boolean is 10067 Over_Decl : constant Node_Id := 10068 Unit_Declaration_Node (Overridden_Operation (S)); 10069 Subp_Decl : constant Node_Id := Unit_Declaration_Node (S); 10070 10071 begin 10072 pragma Assert (Is_Overriding); 10073 pragma Assert 10074 (Nkind (Over_Decl) = N_Abstract_Subprogram_Declaration); 10075 pragma Assert 10076 (Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration); 10077 10078 return In_Same_List (Over_Decl, Subp_Decl); 10079 end Overrides_Private_Part_Op; 10080 10081 -------------------------------- 10082 -- Overrides_Visible_Function -- 10083 -------------------------------- 10084 10085 function Overrides_Visible_Function 10086 (Partial_View : Entity_Id) return Boolean 10087 is 10088 begin 10089 if not Is_Overriding or else not Has_Homonym (S) then 10090 return False; 10091 end if; 10092 10093 if not Present (Partial_View) then 10094 return True; 10095 end if; 10096 10097 -- Search through all the homonyms H of S in the current 10098 -- package spec, and return True if we find one that matches. 10099 -- Note that Parent (H) will be the declaration of the 10100 -- partial view of T for a match. 10101 10102 declare 10103 H : Entity_Id := S; 10104 begin 10105 loop 10106 H := Homonym (H); 10107 exit when not Present (H) or else Scope (H) /= Scope (S); 10108 10109 if Nkind_In 10110 (Parent (H), 10111 N_Private_Extension_Declaration, 10112 N_Private_Type_Declaration) 10113 and then Defining_Identifier (Parent (H)) = Partial_View 10114 then 10115 return True; 10116 end if; 10117 end loop; 10118 end; 10119 10120 return False; 10121 end Overrides_Visible_Function; 10122 10123 -- Start of processing for Check_Private_Overriding 10124 10125 begin 10126 if Is_Package_Or_Generic_Package (Current_Scope) 10127 and then In_Private_Part (Current_Scope) 10128 and then Visible_Part_Type (T) 10129 and then not In_Instance 10130 then 10131 if Is_Abstract_Type (T) 10132 and then Is_Abstract_Subprogram (S) 10133 and then (not Is_Overriding 10134 or else not Is_Abstract_Subprogram (E) 10135 or else Overrides_Private_Part_Op) 10136 then 10137 Error_Msg_N 10138 ("abstract subprograms must be visible (RM 3.9.3(10))!", 10139 S); 10140 10141 elsif Ekind (S) = E_Function then 10142 declare 10143 Partial_View : constant Entity_Id := 10144 Incomplete_Or_Partial_View (T); 10145 10146 begin 10147 if not Overrides_Visible_Function (Partial_View) then 10148 10149 -- Here, S is "function ... return T;" declared in 10150 -- the private part, not overriding some visible 10151 -- operation. That's illegal in the tagged case 10152 -- (but not if the private type is untagged). 10153 10154 if ((Present (Partial_View) 10155 and then Is_Tagged_Type (Partial_View)) 10156 or else (not Present (Partial_View) 10157 and then Is_Tagged_Type (T))) 10158 and then T = Base_Type (Etype (S)) 10159 then 10160 Error_Msg_N 10161 ("private function with tagged result must" 10162 & " override visible-part function", S); 10163 Error_Msg_N 10164 ("\move subprogram to the visible part" 10165 & " (RM 3.9.3(10))", S); 10166 10167 -- AI05-0073: extend this test to the case of a 10168 -- function with a controlling access result. 10169 10170 elsif Ekind (Etype (S)) = E_Anonymous_Access_Type 10171 and then Is_Tagged_Type (Designated_Type (Etype (S))) 10172 and then 10173 not Is_Class_Wide_Type 10174 (Designated_Type (Etype (S))) 10175 and then Ada_Version >= Ada_2012 10176 then 10177 Error_Msg_N 10178 ("private function with controlling access " 10179 & "result must override visible-part function", 10180 S); 10181 Error_Msg_N 10182 ("\move subprogram to the visible part" 10183 & " (RM 3.9.3(10))", S); 10184 end if; 10185 end if; 10186 end; 10187 end if; 10188 end if; 10189 end Check_Private_Overriding; 10190 10191 ----------------------- 10192 -- Visible_Part_Type -- 10193 ----------------------- 10194 10195 function Visible_Part_Type (T : Entity_Id) return Boolean is 10196 P : constant Node_Id := Unit_Declaration_Node (Scope (T)); 10197 10198 begin 10199 -- If the entity is a private type, then it must be declared in a 10200 -- visible part. 10201 10202 if Ekind (T) in Private_Kind then 10203 return True; 10204 10205 elsif Is_Type (T) and then Has_Private_Declaration (T) then 10206 return True; 10207 10208 elsif Is_List_Member (Declaration_Node (T)) 10209 and then List_Containing (Declaration_Node (T)) = 10210 Visible_Declarations (Specification (P)) 10211 then 10212 return True; 10213 10214 else 10215 return False; 10216 end if; 10217 end Visible_Part_Type; 10218 10219 -- Start of processing for Check_For_Primitive_Subprogram 10220 10221 begin 10222 Is_Primitive := False; 10223 10224 if not Comes_From_Source (S) then 10225 null; 10226 10227 -- If subprogram is at library level, it is not primitive operation 10228 10229 elsif Current_Scope = Standard_Standard then 10230 null; 10231 10232 elsif (Is_Package_Or_Generic_Package (Current_Scope) 10233 and then not In_Package_Body (Current_Scope)) 10234 or else Is_Overriding 10235 then 10236 -- For function, check return type 10237 10238 if Ekind (S) = E_Function then 10239 if Ekind (Etype (S)) = E_Anonymous_Access_Type then 10240 F_Typ := Designated_Type (Etype (S)); 10241 else 10242 F_Typ := Etype (S); 10243 end if; 10244 10245 B_Typ := Base_Type (F_Typ); 10246 10247 if Scope (B_Typ) = Current_Scope 10248 and then not Is_Class_Wide_Type (B_Typ) 10249 and then not Is_Generic_Type (B_Typ) 10250 then 10251 Is_Primitive := True; 10252 Set_Has_Primitive_Operations (B_Typ); 10253 Set_Is_Primitive (S); 10254 Check_Private_Overriding (B_Typ); 10255 10256 -- The Ghost policy in effect at the point of declaration 10257 -- or a tagged type and a primitive operation must match 10258 -- (SPARK RM 6.9(16)). 10259 10260 Check_Ghost_Primitive (S, B_Typ); 10261 end if; 10262 end if; 10263 10264 -- For all subprograms, check formals 10265 10266 Formal := First_Formal (S); 10267 while Present (Formal) loop 10268 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then 10269 F_Typ := Designated_Type (Etype (Formal)); 10270 else 10271 F_Typ := Etype (Formal); 10272 end if; 10273 10274 B_Typ := Base_Type (F_Typ); 10275 10276 if Ekind (B_Typ) = E_Access_Subtype then 10277 B_Typ := Base_Type (B_Typ); 10278 end if; 10279 10280 if Scope (B_Typ) = Current_Scope 10281 and then not Is_Class_Wide_Type (B_Typ) 10282 and then not Is_Generic_Type (B_Typ) 10283 then 10284 Is_Primitive := True; 10285 Set_Is_Primitive (S); 10286 Set_Has_Primitive_Operations (B_Typ); 10287 Check_Private_Overriding (B_Typ); 10288 10289 -- The Ghost policy in effect at the point of declaration 10290 -- of a tagged type and a primitive operation must match 10291 -- (SPARK RM 6.9(16)). 10292 10293 Check_Ghost_Primitive (S, B_Typ); 10294 end if; 10295 10296 Next_Formal (Formal); 10297 end loop; 10298 10299 -- Special case: An equality function can be redefined for a type 10300 -- occurring in a declarative part, and won't otherwise be treated as 10301 -- a primitive because it doesn't occur in a package spec and doesn't 10302 -- override an inherited subprogram. It's important that we mark it 10303 -- primitive so it can be returned by Collect_Primitive_Operations 10304 -- and be used in composing the equality operation of later types 10305 -- that have a component of the type. 10306 10307 elsif Chars (S) = Name_Op_Eq 10308 and then Etype (S) = Standard_Boolean 10309 then 10310 B_Typ := Base_Type (Etype (First_Formal (S))); 10311 10312 if Scope (B_Typ) = Current_Scope 10313 and then 10314 Base_Type (Etype (Next_Formal (First_Formal (S)))) = B_Typ 10315 and then not Is_Limited_Type (B_Typ) 10316 then 10317 Is_Primitive := True; 10318 Set_Is_Primitive (S); 10319 Set_Has_Primitive_Operations (B_Typ); 10320 Check_Private_Overriding (B_Typ); 10321 10322 -- The Ghost policy in effect at the point of declaration of a 10323 -- tagged type and a primitive operation must match 10324 -- (SPARK RM 6.9(16)). 10325 10326 Check_Ghost_Primitive (S, B_Typ); 10327 end if; 10328 end if; 10329 end Check_For_Primitive_Subprogram; 10330 10331 -------------------------------------- 10332 -- Has_Matching_Entry_Or_Subprogram -- 10333 -------------------------------------- 10334 10335 function Has_Matching_Entry_Or_Subprogram 10336 (E : Entity_Id) return Boolean 10337 is 10338 function Check_Conforming_Parameters 10339 (E1_Param : Node_Id; 10340 E2_Param : Node_Id) return Boolean; 10341 -- Starting from the given parameters, check that all the parameters 10342 -- of two entries or subprograms are subtype conformant. Used to skip 10343 -- the check on the controlling argument. 10344 10345 function Matching_Entry_Or_Subprogram 10346 (Conc_Typ : Entity_Id; 10347 Subp : Entity_Id) return Entity_Id; 10348 -- Return the first entry or subprogram of the given concurrent type 10349 -- whose name matches the name of Subp and has a profile conformant 10350 -- with Subp; return Empty if not found. 10351 10352 function Matching_Dispatching_Subprogram 10353 (Conc_Typ : Entity_Id; 10354 Ent : Entity_Id) return Entity_Id; 10355 -- Return the first dispatching primitive of Conc_Type defined in the 10356 -- enclosing scope of Conc_Type (i.e. before the full definition of 10357 -- this concurrent type) whose name matches the entry Ent and has a 10358 -- profile conformant with the profile of the corresponding (not yet 10359 -- built) dispatching primitive of Ent; return Empty if not found. 10360 10361 function Matching_Original_Protected_Subprogram 10362 (Prot_Typ : Entity_Id; 10363 Subp : Entity_Id) return Entity_Id; 10364 -- Return the first subprogram defined in the enclosing scope of 10365 -- Prot_Typ (before the full definition of this protected type) 10366 -- whose name matches the original name of Subp and has a profile 10367 -- conformant with the profile of Subp; return Empty if not found. 10368 10369 --------------------------------- 10370 -- Check_Conforming_Parameters -- 10371 --------------------------------- 10372 10373 function Check_Conforming_Parameters 10374 (E1_Param : Node_Id; 10375 E2_Param : Node_Id) return Boolean 10376 is 10377 Param_E1 : Node_Id := E1_Param; 10378 Param_E2 : Node_Id := E2_Param; 10379 10380 begin 10381 while Present (Param_E1) and then Present (Param_E2) loop 10382 if Ekind (Defining_Identifier (Param_E1)) /= 10383 Ekind (Defining_Identifier (Param_E2)) 10384 or else not 10385 Conforming_Types 10386 (Find_Parameter_Type (Param_E1), 10387 Find_Parameter_Type (Param_E2), 10388 Subtype_Conformant) 10389 then 10390 return False; 10391 end if; 10392 10393 Next (Param_E1); 10394 Next (Param_E2); 10395 end loop; 10396 10397 -- The candidate is not valid if one of the two lists contains 10398 -- more parameters than the other 10399 10400 return No (Param_E1) and then No (Param_E2); 10401 end Check_Conforming_Parameters; 10402 10403 ---------------------------------- 10404 -- Matching_Entry_Or_Subprogram -- 10405 ---------------------------------- 10406 10407 function Matching_Entry_Or_Subprogram 10408 (Conc_Typ : Entity_Id; 10409 Subp : Entity_Id) return Entity_Id 10410 is 10411 E : Entity_Id; 10412 10413 begin 10414 E := First_Entity (Conc_Typ); 10415 while Present (E) loop 10416 if Chars (Subp) = Chars (E) 10417 and then (Ekind (E) = E_Entry or else Is_Subprogram (E)) 10418 and then 10419 Check_Conforming_Parameters 10420 (First (Parameter_Specifications (Parent (E))), 10421 Next (First (Parameter_Specifications (Parent (Subp))))) 10422 then 10423 return E; 10424 end if; 10425 10426 Next_Entity (E); 10427 end loop; 10428 10429 return Empty; 10430 end Matching_Entry_Or_Subprogram; 10431 10432 ------------------------------------- 10433 -- Matching_Dispatching_Subprogram -- 10434 ------------------------------------- 10435 10436 function Matching_Dispatching_Subprogram 10437 (Conc_Typ : Entity_Id; 10438 Ent : Entity_Id) return Entity_Id 10439 is 10440 E : Entity_Id; 10441 10442 begin 10443 -- Search for entities in the enclosing scope of this synchonized 10444 -- type. 10445 10446 pragma Assert (Is_Concurrent_Type (Conc_Typ)); 10447 Push_Scope (Scope (Conc_Typ)); 10448 E := Current_Entity_In_Scope (Ent); 10449 Pop_Scope; 10450 10451 while Present (E) loop 10452 if Scope (E) = Scope (Conc_Typ) 10453 and then Comes_From_Source (E) 10454 and then Ekind (E) = E_Procedure 10455 and then Present (First_Entity (E)) 10456 and then Is_Controlling_Formal (First_Entity (E)) 10457 and then Etype (First_Entity (E)) = Conc_Typ 10458 and then 10459 Check_Conforming_Parameters 10460 (First (Parameter_Specifications (Parent (Ent))), 10461 Next (First (Parameter_Specifications (Parent (E))))) 10462 then 10463 return E; 10464 end if; 10465 10466 E := Homonym (E); 10467 end loop; 10468 10469 return Empty; 10470 end Matching_Dispatching_Subprogram; 10471 10472 -------------------------------------------- 10473 -- Matching_Original_Protected_Subprogram -- 10474 -------------------------------------------- 10475 10476 function Matching_Original_Protected_Subprogram 10477 (Prot_Typ : Entity_Id; 10478 Subp : Entity_Id) return Entity_Id 10479 is 10480 ICF : constant Boolean := 10481 Is_Controlling_Formal (First_Entity (Subp)); 10482 E : Entity_Id; 10483 10484 begin 10485 -- Temporarily decorate the first parameter of Subp as controlling 10486 -- formal, required to invoke Subtype_Conformant. 10487 10488 Set_Is_Controlling_Formal (First_Entity (Subp)); 10489 10490 E := 10491 Current_Entity_In_Scope (Original_Protected_Subprogram (Subp)); 10492 10493 while Present (E) loop 10494 if Scope (E) = Scope (Prot_Typ) 10495 and then Comes_From_Source (E) 10496 and then Ekind (Subp) = Ekind (E) 10497 and then Present (First_Entity (E)) 10498 and then Is_Controlling_Formal (First_Entity (E)) 10499 and then Etype (First_Entity (E)) = Prot_Typ 10500 and then Subtype_Conformant (Subp, E, 10501 Skip_Controlling_Formals => True) 10502 then 10503 Set_Is_Controlling_Formal (First_Entity (Subp), ICF); 10504 return E; 10505 end if; 10506 10507 E := Homonym (E); 10508 end loop; 10509 10510 Set_Is_Controlling_Formal (First_Entity (Subp), ICF); 10511 10512 return Empty; 10513 end Matching_Original_Protected_Subprogram; 10514 10515 -- Start of processing for Has_Matching_Entry_Or_Subprogram 10516 10517 begin 10518 -- Case 1: E is a subprogram whose first formal is a concurrent type 10519 -- defined in the scope of E that has an entry or subprogram whose 10520 -- profile matches E. 10521 10522 if Comes_From_Source (E) 10523 and then Is_Subprogram (E) 10524 and then Present (First_Entity (E)) 10525 and then Is_Concurrent_Record_Type (Etype (First_Entity (E))) 10526 then 10527 if Scope (E) = 10528 Scope (Corresponding_Concurrent_Type 10529 (Etype (First_Entity (E)))) 10530 and then 10531 Present 10532 (Matching_Entry_Or_Subprogram 10533 (Corresponding_Concurrent_Type (Etype (First_Entity (E))), 10534 Subp => E)) 10535 then 10536 Report_Conflict (E, 10537 Matching_Entry_Or_Subprogram 10538 (Corresponding_Concurrent_Type (Etype (First_Entity (E))), 10539 Subp => E)); 10540 return True; 10541 end if; 10542 10543 -- Case 2: E is an internally built dispatching subprogram of a 10544 -- protected type and there is a subprogram defined in the enclosing 10545 -- scope of the protected type that has the original name of E and 10546 -- its profile is conformant with the profile of E. We check the 10547 -- name of the original protected subprogram associated with E since 10548 -- the expander builds dispatching primitives of protected functions 10549 -- and procedures with other names (see Exp_Ch9.Build_Selected_Name). 10550 10551 elsif not Comes_From_Source (E) 10552 and then Is_Subprogram (E) 10553 and then Present (First_Entity (E)) 10554 and then Is_Concurrent_Record_Type (Etype (First_Entity (E))) 10555 and then Present (Original_Protected_Subprogram (E)) 10556 and then 10557 Present 10558 (Matching_Original_Protected_Subprogram 10559 (Corresponding_Concurrent_Type (Etype (First_Entity (E))), 10560 Subp => E)) 10561 then 10562 Report_Conflict (E, 10563 Matching_Original_Protected_Subprogram 10564 (Corresponding_Concurrent_Type (Etype (First_Entity (E))), 10565 Subp => E)); 10566 return True; 10567 10568 -- Case 3: E is an entry of a synchronized type and a matching 10569 -- procedure has been previously defined in the enclosing scope 10570 -- of the synchronized type. 10571 10572 elsif Comes_From_Source (E) 10573 and then Ekind (E) = E_Entry 10574 and then 10575 Present (Matching_Dispatching_Subprogram (Current_Scope, E)) 10576 then 10577 Report_Conflict (E, 10578 Matching_Dispatching_Subprogram (Current_Scope, E)); 10579 return True; 10580 end if; 10581 10582 return False; 10583 end Has_Matching_Entry_Or_Subprogram; 10584 10585 ---------------------------- 10586 -- Is_Private_Declaration -- 10587 ---------------------------- 10588 10589 function Is_Private_Declaration (E : Entity_Id) return Boolean is 10590 Decl : constant Node_Id := Unit_Declaration_Node (E); 10591 Priv_Decls : List_Id; 10592 10593 begin 10594 if Is_Package_Or_Generic_Package (Current_Scope) 10595 and then In_Private_Part (Current_Scope) 10596 then 10597 Priv_Decls := 10598 Private_Declarations (Package_Specification (Current_Scope)); 10599 10600 return In_Package_Body (Current_Scope) 10601 or else 10602 (Is_List_Member (Decl) 10603 and then List_Containing (Decl) = Priv_Decls) 10604 or else (Nkind (Parent (Decl)) = N_Package_Specification 10605 and then not 10606 Is_Compilation_Unit 10607 (Defining_Entity (Parent (Decl))) 10608 and then List_Containing (Parent (Parent (Decl))) = 10609 Priv_Decls); 10610 else 10611 return False; 10612 end if; 10613 end Is_Private_Declaration; 10614 10615 -------------------------- 10616 -- Is_Overriding_Alias -- 10617 -------------------------- 10618 10619 function Is_Overriding_Alias 10620 (Old_E : Entity_Id; 10621 New_E : Entity_Id) return Boolean 10622 is 10623 AO : constant Entity_Id := Alias (Old_E); 10624 AN : constant Entity_Id := Alias (New_E); 10625 10626 begin 10627 return Scope (AO) /= Scope (AN) 10628 or else No (DTC_Entity (AO)) 10629 or else No (DTC_Entity (AN)) 10630 or else DT_Position (AO) = DT_Position (AN); 10631 end Is_Overriding_Alias; 10632 10633 --------------------- 10634 -- Report_Conflict -- 10635 --------------------- 10636 10637 procedure Report_Conflict (S : Entity_Id; E : Entity_Id) is 10638 begin 10639 Error_Msg_Sloc := Sloc (E); 10640 10641 -- Generate message, with useful additional warning if in generic 10642 10643 if Is_Generic_Unit (E) then 10644 Error_Msg_N ("previous generic unit cannot be overloaded", S); 10645 Error_Msg_N ("\& conflicts with declaration#", S); 10646 else 10647 Error_Msg_N ("& conflicts with declaration#", S); 10648 end if; 10649 end Report_Conflict; 10650 10651 -- Start of processing for New_Overloaded_Entity 10652 10653 begin 10654 -- We need to look for an entity that S may override. This must be a 10655 -- homonym in the current scope, so we look for the first homonym of 10656 -- S in the current scope as the starting point for the search. 10657 10658 E := Current_Entity_In_Scope (S); 10659 10660 -- Ada 2005 (AI-251): Derivation of abstract interface primitives. 10661 -- They are directly added to the list of primitive operations of 10662 -- Derived_Type, unless this is a rederivation in the private part 10663 -- of an operation that was already derived in the visible part of 10664 -- the current package. 10665 10666 if Ada_Version >= Ada_2005 10667 and then Present (Derived_Type) 10668 and then Present (Alias (S)) 10669 and then Is_Dispatching_Operation (Alias (S)) 10670 and then Present (Find_Dispatching_Type (Alias (S))) 10671 and then Is_Interface (Find_Dispatching_Type (Alias (S))) 10672 then 10673 -- For private types, when the full-view is processed we propagate to 10674 -- the full view the non-overridden entities whose attribute "alias" 10675 -- references an interface primitive. These entities were added by 10676 -- Derive_Subprograms to ensure that interface primitives are 10677 -- covered. 10678 10679 -- Inside_Freeze_Actions is non zero when S corresponds with an 10680 -- internal entity that links an interface primitive with its 10681 -- covering primitive through attribute Interface_Alias (see 10682 -- Add_Internal_Interface_Entities). 10683 10684 if Inside_Freezing_Actions = 0 10685 and then Is_Package_Or_Generic_Package (Current_Scope) 10686 and then In_Private_Part (Current_Scope) 10687 and then Nkind (Parent (E)) = N_Private_Extension_Declaration 10688 and then Nkind (Parent (S)) = N_Full_Type_Declaration 10689 and then Full_View (Defining_Identifier (Parent (E))) 10690 = Defining_Identifier (Parent (S)) 10691 and then Alias (E) = Alias (S) 10692 then 10693 Check_Operation_From_Private_View (S, E); 10694 Set_Is_Dispatching_Operation (S); 10695 10696 -- Common case 10697 10698 else 10699 Enter_Overloaded_Entity (S); 10700 Check_Dispatching_Operation (S, Empty); 10701 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 10702 end if; 10703 10704 return; 10705 end if; 10706 10707 -- For synchronized types check conflicts of this entity with previously 10708 -- defined entities. 10709 10710 if Ada_Version >= Ada_2005 10711 and then Has_Matching_Entry_Or_Subprogram (S) 10712 then 10713 return; 10714 end if; 10715 10716 -- If there is no homonym then this is definitely not overriding 10717 10718 if No (E) then 10719 Enter_Overloaded_Entity (S); 10720 Check_Dispatching_Operation (S, Empty); 10721 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 10722 10723 -- If subprogram has an explicit declaration, check whether it has an 10724 -- overriding indicator. 10725 10726 if Comes_From_Source (S) then 10727 Check_Synchronized_Overriding (S, Overridden_Subp); 10728 10729 -- (Ada 2012: AI05-0125-1): If S is a dispatching operation then 10730 -- it may have overridden some hidden inherited primitive. Update 10731 -- Overridden_Subp to avoid spurious errors when checking the 10732 -- overriding indicator. 10733 10734 if Ada_Version >= Ada_2012 10735 and then No (Overridden_Subp) 10736 and then Is_Dispatching_Operation (S) 10737 and then Present (Overridden_Operation (S)) 10738 then 10739 Overridden_Subp := Overridden_Operation (S); 10740 end if; 10741 10742 Check_Overriding_Indicator 10743 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); 10744 10745 -- The Ghost policy in effect at the point of declaration of a 10746 -- parent subprogram and an overriding subprogram must match 10747 -- (SPARK RM 6.9(17)). 10748 10749 Check_Ghost_Overriding (S, Overridden_Subp); 10750 end if; 10751 10752 -- If there is a homonym that is not overloadable, then we have an 10753 -- error, except for the special cases checked explicitly below. 10754 10755 elsif not Is_Overloadable (E) then 10756 10757 -- Check for spurious conflict produced by a subprogram that has the 10758 -- same name as that of the enclosing generic package. The conflict 10759 -- occurs within an instance, between the subprogram and the renaming 10760 -- declaration for the package. After the subprogram, the package 10761 -- renaming declaration becomes hidden. 10762 10763 if Ekind (E) = E_Package 10764 and then Present (Renamed_Object (E)) 10765 and then Renamed_Object (E) = Current_Scope 10766 and then Nkind (Parent (Renamed_Object (E))) = 10767 N_Package_Specification 10768 and then Present (Generic_Parent (Parent (Renamed_Object (E)))) 10769 then 10770 Set_Is_Hidden (E); 10771 Set_Is_Immediately_Visible (E, False); 10772 Enter_Overloaded_Entity (S); 10773 Set_Homonym (S, Homonym (E)); 10774 Check_Dispatching_Operation (S, Empty); 10775 Check_Overriding_Indicator (S, Empty, Is_Primitive => False); 10776 10777 -- If the subprogram is implicit it is hidden by the previous 10778 -- declaration. However if it is dispatching, it must appear in the 10779 -- dispatch table anyway, because it can be dispatched to even if it 10780 -- cannot be called directly. 10781 10782 elsif Present (Alias (S)) and then not Comes_From_Source (S) then 10783 Set_Scope (S, Current_Scope); 10784 10785 if Is_Dispatching_Operation (Alias (S)) then 10786 Check_Dispatching_Operation (S, Empty); 10787 end if; 10788 10789 return; 10790 10791 else 10792 Report_Conflict (S, E); 10793 return; 10794 end if; 10795 10796 -- E exists and is overloadable 10797 10798 else 10799 Check_Synchronized_Overriding (S, Overridden_Subp); 10800 10801 -- Loop through E and its homonyms to determine if any of them is 10802 -- the candidate for overriding by S. 10803 10804 while Present (E) loop 10805 10806 -- Definitely not interesting if not in the current scope 10807 10808 if Scope (E) /= Current_Scope then 10809 null; 10810 10811 -- A function can overload the name of an abstract state. The 10812 -- state can be viewed as a function with a profile that cannot 10813 -- be matched by anything. 10814 10815 elsif Ekind (S) = E_Function 10816 and then Ekind (E) = E_Abstract_State 10817 then 10818 Enter_Overloaded_Entity (S); 10819 return; 10820 10821 -- Ada 2012 (AI05-0165): For internally generated bodies of null 10822 -- procedures locate the internally generated spec. We enforce 10823 -- mode conformance since a tagged type may inherit from 10824 -- interfaces several null primitives which differ only in 10825 -- the mode of the formals. 10826 10827 elsif not Comes_From_Source (S) 10828 and then Is_Null_Procedure (S) 10829 and then not Mode_Conformant (E, S) 10830 then 10831 null; 10832 10833 -- Check if we have type conformance 10834 10835 elsif Type_Conformant (E, S) then 10836 10837 -- If the old and new entities have the same profile and one 10838 -- is not the body of the other, then this is an error, unless 10839 -- one of them is implicitly declared. 10840 10841 -- There are some cases when both can be implicit, for example 10842 -- when both a literal and a function that overrides it are 10843 -- inherited in a derivation, or when an inherited operation 10844 -- of a tagged full type overrides the inherited operation of 10845 -- a private extension. Ada 83 had a special rule for the 10846 -- literal case. In Ada 95, the later implicit operation hides 10847 -- the former, and the literal is always the former. In the 10848 -- odd case where both are derived operations declared at the 10849 -- same point, both operations should be declared, and in that 10850 -- case we bypass the following test and proceed to the next 10851 -- part. This can only occur for certain obscure cases in 10852 -- instances, when an operation on a type derived from a formal 10853 -- private type does not override a homograph inherited from 10854 -- the actual. In subsequent derivations of such a type, the 10855 -- DT positions of these operations remain distinct, if they 10856 -- have been set. 10857 10858 if Present (Alias (S)) 10859 and then (No (Alias (E)) 10860 or else Comes_From_Source (E) 10861 or else Is_Abstract_Subprogram (S) 10862 or else 10863 (Is_Dispatching_Operation (E) 10864 and then Is_Overriding_Alias (E, S))) 10865 and then Ekind (E) /= E_Enumeration_Literal 10866 then 10867 -- When an derived operation is overloaded it may be due to 10868 -- the fact that the full view of a private extension 10869 -- re-inherits. It has to be dealt with. 10870 10871 if Is_Package_Or_Generic_Package (Current_Scope) 10872 and then In_Private_Part (Current_Scope) 10873 then 10874 Check_Operation_From_Private_View (S, E); 10875 end if; 10876 10877 -- In any case the implicit operation remains hidden by the 10878 -- existing declaration, which is overriding. Indicate that 10879 -- E overrides the operation from which S is inherited. 10880 10881 if Present (Alias (S)) then 10882 Set_Overridden_Operation (E, Alias (S)); 10883 Inherit_Subprogram_Contract (E, Alias (S)); 10884 10885 else 10886 Set_Overridden_Operation (E, S); 10887 Inherit_Subprogram_Contract (E, S); 10888 end if; 10889 10890 if Comes_From_Source (E) then 10891 Check_Overriding_Indicator (E, S, Is_Primitive => False); 10892 10893 -- The Ghost policy in effect at the point of declaration 10894 -- of a parent subprogram and an overriding subprogram 10895 -- must match (SPARK RM 6.9(17)). 10896 10897 Check_Ghost_Overriding (E, S); 10898 end if; 10899 10900 return; 10901 10902 -- Within an instance, the renaming declarations for actual 10903 -- subprograms may become ambiguous, but they do not hide each 10904 -- other. 10905 10906 elsif Ekind (E) /= E_Entry 10907 and then not Comes_From_Source (E) 10908 and then not Is_Generic_Instance (E) 10909 and then (Present (Alias (E)) 10910 or else Is_Intrinsic_Subprogram (E)) 10911 and then (not In_Instance 10912 or else No (Parent (E)) 10913 or else Nkind (Unit_Declaration_Node (E)) /= 10914 N_Subprogram_Renaming_Declaration) 10915 then 10916 -- A subprogram child unit is not allowed to override an 10917 -- inherited subprogram (10.1.1(20)). 10918 10919 if Is_Child_Unit (S) then 10920 Error_Msg_N 10921 ("child unit overrides inherited subprogram in parent", 10922 S); 10923 return; 10924 end if; 10925 10926 if Is_Non_Overriding_Operation (E, S) then 10927 Enter_Overloaded_Entity (S); 10928 10929 if No (Derived_Type) 10930 or else Is_Tagged_Type (Derived_Type) 10931 then 10932 Check_Dispatching_Operation (S, Empty); 10933 end if; 10934 10935 return; 10936 end if; 10937 10938 -- E is a derived operation or an internal operator which 10939 -- is being overridden. Remove E from further visibility. 10940 -- Furthermore, if E is a dispatching operation, it must be 10941 -- replaced in the list of primitive operations of its type 10942 -- (see Override_Dispatching_Operation). 10943 10944 Overridden_Subp := E; 10945 10946 -- It is possible for E to be in the current scope and 10947 -- yet not in the entity chain. This can only occur in a 10948 -- generic context where E is an implicit concatenation 10949 -- in the formal part, because in a generic body the 10950 -- entity chain starts with the formals. 10951 10952 -- In GNATprove mode, a wrapper for an operation with 10953 -- axiomatization may be a homonym of another declaration 10954 -- for an actual subprogram (needs refinement ???). 10955 10956 if No (Prev_Entity (E)) then 10957 if In_Instance 10958 and then GNATprove_Mode 10959 and then 10960 Nkind (Original_Node (Unit_Declaration_Node (S))) = 10961 N_Subprogram_Renaming_Declaration 10962 then 10963 return; 10964 else 10965 pragma Assert (Chars (E) = Name_Op_Concat); 10966 null; 10967 end if; 10968 end if; 10969 10970 -- E must be removed both from the entity_list of the 10971 -- current scope, and from the visibility chain. 10972 10973 if Debug_Flag_E then 10974 Write_Str ("Override implicit operation "); 10975 Write_Int (Int (E)); 10976 Write_Eol; 10977 end if; 10978 10979 -- If E is a predefined concatenation, it stands for four 10980 -- different operations. As a result, a single explicit 10981 -- declaration does not hide it. In a possible ambiguous 10982 -- situation, Disambiguate chooses the user-defined op, 10983 -- so it is correct to retain the previous internal one. 10984 10985 if Chars (E) /= Name_Op_Concat 10986 or else Ekind (E) /= E_Operator 10987 then 10988 -- For nondispatching derived operations that are 10989 -- overridden by a subprogram declared in the private 10990 -- part of a package, we retain the derived subprogram 10991 -- but mark it as not immediately visible. If the 10992 -- derived operation was declared in the visible part 10993 -- then this ensures that it will still be visible 10994 -- outside the package with the proper signature 10995 -- (calls from outside must also be directed to this 10996 -- version rather than the overriding one, unlike the 10997 -- dispatching case). Calls from inside the package 10998 -- will still resolve to the overriding subprogram 10999 -- since the derived one is marked as not visible 11000 -- within the package. 11001 11002 -- If the private operation is dispatching, we achieve 11003 -- the overriding by keeping the implicit operation 11004 -- but setting its alias to be the overriding one. In 11005 -- this fashion the proper body is executed in all 11006 -- cases, but the original signature is used outside 11007 -- of the package. 11008 11009 -- If the overriding is not in the private part, we 11010 -- remove the implicit operation altogether. 11011 11012 if Is_Private_Declaration (S) then 11013 if not Is_Dispatching_Operation (E) then 11014 Set_Is_Immediately_Visible (E, False); 11015 else 11016 -- Work done in Override_Dispatching_Operation, so 11017 -- nothing else needs to be done here. 11018 11019 null; 11020 end if; 11021 11022 else 11023 Remove_Entity_And_Homonym (E); 11024 end if; 11025 end if; 11026 11027 Enter_Overloaded_Entity (S); 11028 11029 -- For entities generated by Derive_Subprograms the 11030 -- overridden operation is the inherited primitive 11031 -- (which is available through the attribute alias). 11032 11033 if not (Comes_From_Source (E)) 11034 and then Is_Dispatching_Operation (E) 11035 and then Find_Dispatching_Type (E) = 11036 Find_Dispatching_Type (S) 11037 and then Present (Alias (E)) 11038 and then Comes_From_Source (Alias (E)) 11039 then 11040 Set_Overridden_Operation (S, Alias (E)); 11041 Inherit_Subprogram_Contract (S, Alias (E)); 11042 11043 -- Normal case of setting entity as overridden 11044 11045 -- Note: Static_Initialization and Overridden_Operation 11046 -- attributes use the same field in subprogram entities. 11047 -- Static_Initialization is only defined for internal 11048 -- initialization procedures, where Overridden_Operation 11049 -- is irrelevant. Therefore the setting of this attribute 11050 -- must check whether the target is an init_proc. 11051 11052 elsif not Is_Init_Proc (S) then 11053 Set_Overridden_Operation (S, E); 11054 Inherit_Subprogram_Contract (S, E); 11055 end if; 11056 11057 Check_Overriding_Indicator (S, E, Is_Primitive => True); 11058 11059 -- The Ghost policy in effect at the point of declaration 11060 -- of a parent subprogram and an overriding subprogram 11061 -- must match (SPARK RM 6.9(17)). 11062 11063 Check_Ghost_Overriding (S, E); 11064 11065 -- If S is a user-defined subprogram or a null procedure 11066 -- expanded to override an inherited null procedure, or a 11067 -- predefined dispatching primitive then indicate that E 11068 -- overrides the operation from which S is inherited. 11069 11070 if Comes_From_Source (S) 11071 or else 11072 (Present (Parent (S)) 11073 and then Nkind (Parent (S)) = N_Procedure_Specification 11074 and then Null_Present (Parent (S))) 11075 or else 11076 (Present (Alias (E)) 11077 and then 11078 Is_Predefined_Dispatching_Operation (Alias (E))) 11079 then 11080 if Present (Alias (E)) then 11081 Set_Overridden_Operation (S, Alias (E)); 11082 Inherit_Subprogram_Contract (S, Alias (E)); 11083 end if; 11084 end if; 11085 11086 if Is_Dispatching_Operation (E) then 11087 11088 -- An overriding dispatching subprogram inherits the 11089 -- convention of the overridden subprogram (AI-117). 11090 11091 Set_Convention (S, Convention (E)); 11092 Check_Dispatching_Operation (S, E); 11093 11094 else 11095 Check_Dispatching_Operation (S, Empty); 11096 end if; 11097 11098 Check_For_Primitive_Subprogram 11099 (Is_Primitive_Subp, Is_Overriding => True); 11100 goto Check_Inequality; 11101 11102 -- Apparent redeclarations in instances can occur when two 11103 -- formal types get the same actual type. The subprograms in 11104 -- in the instance are legal, even if not callable from the 11105 -- outside. Calls from within are disambiguated elsewhere. 11106 -- For dispatching operations in the visible part, the usual 11107 -- rules apply, and operations with the same profile are not 11108 -- legal (B830001). 11109 11110 elsif (In_Instance_Visible_Part 11111 and then not Is_Dispatching_Operation (E)) 11112 or else In_Instance_Not_Visible 11113 then 11114 null; 11115 11116 -- Here we have a real error (identical profile) 11117 11118 else 11119 Error_Msg_Sloc := Sloc (E); 11120 11121 -- Avoid cascaded errors if the entity appears in 11122 -- subsequent calls. 11123 11124 Set_Scope (S, Current_Scope); 11125 11126 -- Generate error, with extra useful warning for the case 11127 -- of a generic instance with no completion. 11128 11129 if Is_Generic_Instance (S) 11130 and then not Has_Completion (E) 11131 then 11132 Error_Msg_N 11133 ("instantiation cannot provide body for&", S); 11134 Error_Msg_N ("\& conflicts with declaration#", S); 11135 else 11136 Error_Msg_N ("& conflicts with declaration#", S); 11137 end if; 11138 11139 return; 11140 end if; 11141 11142 else 11143 -- If one subprogram has an access parameter and the other 11144 -- a parameter of an access type, calls to either might be 11145 -- ambiguous. Verify that parameters match except for the 11146 -- access parameter. 11147 11148 if May_Hide_Profile then 11149 declare 11150 F1 : Entity_Id; 11151 F2 : Entity_Id; 11152 11153 begin 11154 F1 := First_Formal (S); 11155 F2 := First_Formal (E); 11156 while Present (F1) and then Present (F2) loop 11157 if Is_Access_Type (Etype (F1)) then 11158 if not Is_Access_Type (Etype (F2)) 11159 or else not Conforming_Types 11160 (Designated_Type (Etype (F1)), 11161 Designated_Type (Etype (F2)), 11162 Type_Conformant) 11163 then 11164 May_Hide_Profile := False; 11165 end if; 11166 11167 elsif 11168 not Conforming_Types 11169 (Etype (F1), Etype (F2), Type_Conformant) 11170 then 11171 May_Hide_Profile := False; 11172 end if; 11173 11174 Next_Formal (F1); 11175 Next_Formal (F2); 11176 end loop; 11177 11178 if May_Hide_Profile 11179 and then No (F1) 11180 and then No (F2) 11181 then 11182 Error_Msg_NE ("calls to& may be ambiguous??", S, S); 11183 end if; 11184 end; 11185 end if; 11186 end if; 11187 11188 E := Homonym (E); 11189 end loop; 11190 11191 -- On exit, we know that S is a new entity 11192 11193 Enter_Overloaded_Entity (S); 11194 Check_For_Primitive_Subprogram (Is_Primitive_Subp); 11195 Check_Overriding_Indicator 11196 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); 11197 11198 -- The Ghost policy in effect at the point of declaration of a parent 11199 -- subprogram and an overriding subprogram must match 11200 -- (SPARK RM 6.9(17)). 11201 11202 Check_Ghost_Overriding (S, Overridden_Subp); 11203 11204 -- Overloading is not allowed in SPARK, except for operators 11205 11206 if Nkind (S) /= N_Defining_Operator_Symbol then 11207 Error_Msg_Sloc := Sloc (Homonym (S)); 11208 Check_SPARK_05_Restriction 11209 ("overloading not allowed with entity#", S); 11210 end if; 11211 11212 -- If S is a derived operation for an untagged type then by 11213 -- definition it's not a dispatching operation (even if the parent 11214 -- operation was dispatching), so Check_Dispatching_Operation is not 11215 -- called in that case. 11216 11217 if No (Derived_Type) 11218 or else Is_Tagged_Type (Derived_Type) 11219 then 11220 Check_Dispatching_Operation (S, Empty); 11221 end if; 11222 end if; 11223 11224 -- If this is a user-defined equality operator that is not a derived 11225 -- subprogram, create the corresponding inequality. If the operation is 11226 -- dispatching, the expansion is done elsewhere, and we do not create 11227 -- an explicit inequality operation. 11228 11229 <<Check_Inequality>> 11230 if Chars (S) = Name_Op_Eq 11231 and then Etype (S) = Standard_Boolean 11232 and then Present (Parent (S)) 11233 and then not Is_Dispatching_Operation (S) 11234 then 11235 Make_Inequality_Operator (S); 11236 Check_Untagged_Equality (S); 11237 end if; 11238 end New_Overloaded_Entity; 11239 11240 ---------------------------------- 11241 -- Preanalyze_Formal_Expression -- 11242 ---------------------------------- 11243 11244 procedure Preanalyze_Formal_Expression (N : Node_Id; T : Entity_Id) is 11245 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression; 11246 begin 11247 In_Spec_Expression := True; 11248 Preanalyze_With_Freezing_And_Resolve (N, T); 11249 In_Spec_Expression := Save_In_Spec_Expression; 11250 end Preanalyze_Formal_Expression; 11251 11252 --------------------- 11253 -- Process_Formals -- 11254 --------------------- 11255 11256 procedure Process_Formals 11257 (T : List_Id; 11258 Related_Nod : Node_Id) 11259 is 11260 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean; 11261 -- Determine whether an access type designates a type coming from a 11262 -- limited view. 11263 11264 function Is_Class_Wide_Default (D : Node_Id) return Boolean; 11265 -- Check whether the default has a class-wide type. After analysis the 11266 -- default has the type of the formal, so we must also check explicitly 11267 -- for an access attribute. 11268 11269 ---------------------------------- 11270 -- Designates_From_Limited_With -- 11271 ---------------------------------- 11272 11273 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean is 11274 Desig : Entity_Id := Typ; 11275 11276 begin 11277 if Is_Access_Type (Desig) then 11278 Desig := Directly_Designated_Type (Desig); 11279 end if; 11280 11281 if Is_Class_Wide_Type (Desig) then 11282 Desig := Root_Type (Desig); 11283 end if; 11284 11285 return 11286 Ekind (Desig) = E_Incomplete_Type 11287 and then From_Limited_With (Desig); 11288 end Designates_From_Limited_With; 11289 11290 --------------------------- 11291 -- Is_Class_Wide_Default -- 11292 --------------------------- 11293 11294 function Is_Class_Wide_Default (D : Node_Id) return Boolean is 11295 begin 11296 return Is_Class_Wide_Type (Designated_Type (Etype (D))) 11297 or else (Nkind (D) = N_Attribute_Reference 11298 and then Attribute_Name (D) = Name_Access 11299 and then Is_Class_Wide_Type (Etype (Prefix (D)))); 11300 end Is_Class_Wide_Default; 11301 11302 -- Local variables 11303 11304 Context : constant Node_Id := Parent (Parent (T)); 11305 Default : Node_Id; 11306 Formal : Entity_Id; 11307 Formal_Type : Entity_Id; 11308 Param_Spec : Node_Id; 11309 Ptype : Entity_Id; 11310 11311 Num_Out_Params : Nat := 0; 11312 First_Out_Param : Entity_Id := Empty; 11313 -- Used for setting Is_Only_Out_Parameter 11314 11315 -- Start of processing for Process_Formals 11316 11317 begin 11318 -- In order to prevent premature use of the formals in the same formal 11319 -- part, the Ekind is left undefined until all default expressions are 11320 -- analyzed. The Ekind is established in a separate loop at the end. 11321 11322 Param_Spec := First (T); 11323 while Present (Param_Spec) loop 11324 Formal := Defining_Identifier (Param_Spec); 11325 Set_Never_Set_In_Source (Formal, True); 11326 Enter_Name (Formal); 11327 11328 -- Case of ordinary parameters 11329 11330 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then 11331 Find_Type (Parameter_Type (Param_Spec)); 11332 Ptype := Parameter_Type (Param_Spec); 11333 11334 if Ptype = Error then 11335 goto Continue; 11336 end if; 11337 11338 Formal_Type := Entity (Ptype); 11339 11340 if Is_Incomplete_Type (Formal_Type) 11341 or else 11342 (Is_Class_Wide_Type (Formal_Type) 11343 and then Is_Incomplete_Type (Root_Type (Formal_Type))) 11344 then 11345 -- Ada 2005 (AI-326): Tagged incomplete types allowed in 11346 -- primitive operations, as long as their completion is 11347 -- in the same declarative part. If in the private part 11348 -- this means that the type cannot be a Taft-amendment type. 11349 -- Check is done on package exit. For access to subprograms, 11350 -- the use is legal for Taft-amendment types. 11351 11352 -- Ada 2012: tagged incomplete types are allowed as generic 11353 -- formal types. They do not introduce dependencies and the 11354 -- corresponding generic subprogram does not have a delayed 11355 -- freeze, because it does not need a freeze node. However, 11356 -- it is still the case that untagged incomplete types cannot 11357 -- be Taft-amendment types and must be completed in private 11358 -- part, so the subprogram must appear in the list of private 11359 -- dependents of the type. 11360 11361 if Is_Tagged_Type (Formal_Type) 11362 or else (Ada_Version >= Ada_2012 11363 and then not From_Limited_With (Formal_Type) 11364 and then not Is_Generic_Type (Formal_Type)) 11365 then 11366 if Ekind (Scope (Current_Scope)) = E_Package 11367 and then not Is_Generic_Type (Formal_Type) 11368 and then not Is_Class_Wide_Type (Formal_Type) 11369 then 11370 if not Nkind_In 11371 (Parent (T), N_Access_Function_Definition, 11372 N_Access_Procedure_Definition) 11373 then 11374 Append_Elmt (Current_Scope, 11375 Private_Dependents (Base_Type (Formal_Type))); 11376 11377 -- Freezing is delayed to ensure that Register_Prim 11378 -- will get called for this operation, which is needed 11379 -- in cases where static dispatch tables aren't built. 11380 -- (Note that the same is done for controlling access 11381 -- parameter cases in function Access_Definition.) 11382 11383 if not Is_Thunk (Current_Scope) then 11384 Set_Has_Delayed_Freeze (Current_Scope); 11385 end if; 11386 end if; 11387 end if; 11388 11389 elsif not Nkind_In (Parent (T), N_Access_Function_Definition, 11390 N_Access_Procedure_Definition) 11391 then 11392 -- AI05-0151: Tagged incomplete types are allowed in all 11393 -- formal parts. Untagged incomplete types are not allowed 11394 -- in bodies. Limited views of either kind are not allowed 11395 -- if there is no place at which the non-limited view can 11396 -- become available. 11397 11398 -- Incomplete formal untagged types are not allowed in 11399 -- subprogram bodies (but are legal in their declarations). 11400 -- This excludes bodies created for null procedures, which 11401 -- are basic declarations. 11402 11403 if Is_Generic_Type (Formal_Type) 11404 and then not Is_Tagged_Type (Formal_Type) 11405 and then Nkind (Parent (Related_Nod)) = N_Subprogram_Body 11406 then 11407 Error_Msg_N 11408 ("invalid use of formal incomplete type", Param_Spec); 11409 11410 elsif Ada_Version >= Ada_2012 then 11411 if Is_Tagged_Type (Formal_Type) 11412 and then (not From_Limited_With (Formal_Type) 11413 or else not In_Package_Body) 11414 then 11415 null; 11416 11417 elsif Nkind_In (Context, N_Accept_Statement, 11418 N_Accept_Alternative, 11419 N_Entry_Body) 11420 or else (Nkind (Context) = N_Subprogram_Body 11421 and then Comes_From_Source (Context)) 11422 then 11423 Error_Msg_NE 11424 ("invalid use of untagged incomplete type &", 11425 Ptype, Formal_Type); 11426 end if; 11427 11428 else 11429 Error_Msg_NE 11430 ("invalid use of incomplete type&", 11431 Param_Spec, Formal_Type); 11432 11433 -- Further checks on the legality of incomplete types 11434 -- in formal parts are delayed until the freeze point 11435 -- of the enclosing subprogram or access to subprogram. 11436 end if; 11437 end if; 11438 11439 elsif Ekind (Formal_Type) = E_Void then 11440 Error_Msg_NE 11441 ("premature use of&", 11442 Parameter_Type (Param_Spec), Formal_Type); 11443 end if; 11444 11445 -- Ada 2012 (AI-142): Handle aliased parameters 11446 11447 if Ada_Version >= Ada_2012 11448 and then Aliased_Present (Param_Spec) 11449 then 11450 Set_Is_Aliased (Formal); 11451 end if; 11452 11453 -- Ada 2005 (AI-231): Create and decorate an internal subtype 11454 -- declaration corresponding to the null-excluding type of the 11455 -- formal in the enclosing scope. Finally, replace the parameter 11456 -- type of the formal with the internal subtype. 11457 11458 if Ada_Version >= Ada_2005 11459 and then Null_Exclusion_Present (Param_Spec) 11460 then 11461 if not Is_Access_Type (Formal_Type) then 11462 Error_Msg_N 11463 ("`NOT NULL` allowed only for an access type", Param_Spec); 11464 11465 else 11466 if Can_Never_Be_Null (Formal_Type) 11467 and then Comes_From_Source (Related_Nod) 11468 then 11469 Error_Msg_NE 11470 ("`NOT NULL` not allowed (& already excludes null)", 11471 Param_Spec, Formal_Type); 11472 end if; 11473 11474 Formal_Type := 11475 Create_Null_Excluding_Itype 11476 (T => Formal_Type, 11477 Related_Nod => Related_Nod, 11478 Scope_Id => Scope (Current_Scope)); 11479 11480 -- If the designated type of the itype is an itype that is 11481 -- not frozen yet, we set the Has_Delayed_Freeze attribute 11482 -- on the access subtype, to prevent order-of-elaboration 11483 -- issues in the backend. 11484 11485 -- Example: 11486 -- type T is access procedure; 11487 -- procedure Op (O : not null T); 11488 11489 if Is_Itype (Directly_Designated_Type (Formal_Type)) 11490 and then 11491 not Is_Frozen (Directly_Designated_Type (Formal_Type)) 11492 then 11493 Set_Has_Delayed_Freeze (Formal_Type); 11494 end if; 11495 end if; 11496 end if; 11497 11498 -- An access formal type 11499 11500 else 11501 Formal_Type := 11502 Access_Definition (Related_Nod, Parameter_Type (Param_Spec)); 11503 11504 -- No need to continue if we already notified errors 11505 11506 if not Present (Formal_Type) then 11507 return; 11508 end if; 11509 11510 -- Ada 2005 (AI-254) 11511 11512 declare 11513 AD : constant Node_Id := 11514 Access_To_Subprogram_Definition 11515 (Parameter_Type (Param_Spec)); 11516 begin 11517 if Present (AD) and then Protected_Present (AD) then 11518 Formal_Type := 11519 Replace_Anonymous_Access_To_Protected_Subprogram 11520 (Param_Spec); 11521 end if; 11522 end; 11523 end if; 11524 11525 Set_Etype (Formal, Formal_Type); 11526 11527 -- Deal with default expression if present 11528 11529 Default := Expression (Param_Spec); 11530 11531 if Present (Default) then 11532 Check_SPARK_05_Restriction 11533 ("default expression is not allowed", Default); 11534 11535 if Out_Present (Param_Spec) then 11536 Error_Msg_N 11537 ("default initialization only allowed for IN parameters", 11538 Param_Spec); 11539 end if; 11540 11541 -- Do the special preanalysis of the expression (see section on 11542 -- "Handling of Default Expressions" in the spec of package Sem). 11543 11544 Preanalyze_Formal_Expression (Default, Formal_Type); 11545 11546 -- An access to constant cannot be the default for 11547 -- an access parameter that is an access to variable. 11548 11549 if Ekind (Formal_Type) = E_Anonymous_Access_Type 11550 and then not Is_Access_Constant (Formal_Type) 11551 and then Is_Access_Type (Etype (Default)) 11552 and then Is_Access_Constant (Etype (Default)) 11553 then 11554 Error_Msg_N 11555 ("formal that is access to variable cannot be initialized " 11556 & "with an access-to-constant expression", Default); 11557 end if; 11558 11559 -- Check that the designated type of an access parameter's default 11560 -- is not a class-wide type unless the parameter's designated type 11561 -- is also class-wide. 11562 11563 if Ekind (Formal_Type) = E_Anonymous_Access_Type 11564 and then not Designates_From_Limited_With (Formal_Type) 11565 and then Is_Class_Wide_Default (Default) 11566 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type)) 11567 then 11568 Error_Msg_N 11569 ("access to class-wide expression not allowed here", Default); 11570 end if; 11571 11572 -- Check incorrect use of dynamically tagged expressions 11573 11574 if Is_Tagged_Type (Formal_Type) then 11575 Check_Dynamically_Tagged_Expression 11576 (Expr => Default, 11577 Typ => Formal_Type, 11578 Related_Nod => Default); 11579 end if; 11580 end if; 11581 11582 -- Ada 2005 (AI-231): Static checks 11583 11584 if Ada_Version >= Ada_2005 11585 and then Is_Access_Type (Etype (Formal)) 11586 and then Can_Never_Be_Null (Etype (Formal)) 11587 then 11588 Null_Exclusion_Static_Checks (Param_Spec); 11589 end if; 11590 11591 -- The following checks are relevant only when SPARK_Mode is on as 11592 -- these are not standard Ada legality rules. 11593 11594 if SPARK_Mode = On then 11595 if Ekind_In (Scope (Formal), E_Function, E_Generic_Function) then 11596 11597 -- A function cannot have a parameter of mode IN OUT or OUT 11598 -- (SPARK RM 6.1). 11599 11600 if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then 11601 Error_Msg_N 11602 ("function cannot have parameter of mode `OUT` or " 11603 & "`IN OUT`", Formal); 11604 end if; 11605 11606 -- A procedure cannot have an effectively volatile formal 11607 -- parameter of mode IN because it behaves as a constant 11608 -- (SPARK RM 7.1.3(6)). -- ??? maybe 7.1.3(4) 11609 11610 elsif Ekind (Scope (Formal)) = E_Procedure 11611 and then Ekind (Formal) = E_In_Parameter 11612 and then Is_Effectively_Volatile (Formal) 11613 then 11614 Error_Msg_N 11615 ("formal parameter of mode `IN` cannot be volatile", Formal); 11616 end if; 11617 end if; 11618 11619 <<Continue>> 11620 Next (Param_Spec); 11621 end loop; 11622 11623 -- If this is the formal part of a function specification, analyze the 11624 -- subtype mark in the context where the formals are visible but not 11625 -- yet usable, and may hide outer homographs. 11626 11627 if Nkind (Related_Nod) = N_Function_Specification then 11628 Analyze_Return_Type (Related_Nod); 11629 end if; 11630 11631 -- Now set the kind (mode) of each formal 11632 11633 Param_Spec := First (T); 11634 while Present (Param_Spec) loop 11635 Formal := Defining_Identifier (Param_Spec); 11636 Set_Formal_Mode (Formal); 11637 11638 if Ekind (Formal) = E_In_Parameter then 11639 Set_Default_Value (Formal, Expression (Param_Spec)); 11640 11641 if Present (Expression (Param_Spec)) then 11642 Default := Expression (Param_Spec); 11643 11644 if Is_Scalar_Type (Etype (Default)) then 11645 if Nkind (Parameter_Type (Param_Spec)) /= 11646 N_Access_Definition 11647 then 11648 Formal_Type := Entity (Parameter_Type (Param_Spec)); 11649 else 11650 Formal_Type := 11651 Access_Definition 11652 (Related_Nod, Parameter_Type (Param_Spec)); 11653 end if; 11654 11655 Apply_Scalar_Range_Check (Default, Formal_Type); 11656 end if; 11657 end if; 11658 11659 elsif Ekind (Formal) = E_Out_Parameter then 11660 Num_Out_Params := Num_Out_Params + 1; 11661 11662 if Num_Out_Params = 1 then 11663 First_Out_Param := Formal; 11664 end if; 11665 11666 elsif Ekind (Formal) = E_In_Out_Parameter then 11667 Num_Out_Params := Num_Out_Params + 1; 11668 end if; 11669 11670 -- Skip remaining processing if formal type was in error 11671 11672 if Etype (Formal) = Any_Type or else Error_Posted (Formal) then 11673 goto Next_Parameter; 11674 end if; 11675 11676 -- Force call by reference if aliased 11677 11678 declare 11679 Conv : constant Convention_Id := Convention (Etype (Formal)); 11680 begin 11681 if Is_Aliased (Formal) then 11682 Set_Mechanism (Formal, By_Reference); 11683 11684 -- Warn if user asked this to be passed by copy 11685 11686 if Conv = Convention_Ada_Pass_By_Copy then 11687 Error_Msg_N 11688 ("cannot pass aliased parameter & by copy??", Formal); 11689 end if; 11690 11691 -- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy 11692 11693 elsif Conv = Convention_Ada_Pass_By_Copy then 11694 Set_Mechanism (Formal, By_Copy); 11695 11696 elsif Conv = Convention_Ada_Pass_By_Reference then 11697 Set_Mechanism (Formal, By_Reference); 11698 end if; 11699 end; 11700 11701 <<Next_Parameter>> 11702 Next (Param_Spec); 11703 end loop; 11704 11705 if Present (First_Out_Param) and then Num_Out_Params = 1 then 11706 Set_Is_Only_Out_Parameter (First_Out_Param); 11707 end if; 11708 end Process_Formals; 11709 11710 ---------------------------- 11711 -- Reference_Body_Formals -- 11712 ---------------------------- 11713 11714 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is 11715 Fs : Entity_Id; 11716 Fb : Entity_Id; 11717 11718 begin 11719 if Error_Posted (Spec) then 11720 return; 11721 end if; 11722 11723 -- Iterate over both lists. They may be of different lengths if the two 11724 -- specs are not conformant. 11725 11726 Fs := First_Formal (Spec); 11727 Fb := First_Formal (Bod); 11728 while Present (Fs) and then Present (Fb) loop 11729 Generate_Reference (Fs, Fb, 'b'); 11730 11731 if Style_Check then 11732 Style.Check_Identifier (Fb, Fs); 11733 end if; 11734 11735 Set_Spec_Entity (Fb, Fs); 11736 Set_Referenced (Fs, False); 11737 Next_Formal (Fs); 11738 Next_Formal (Fb); 11739 end loop; 11740 end Reference_Body_Formals; 11741 11742 ------------------------- 11743 -- Set_Actual_Subtypes -- 11744 ------------------------- 11745 11746 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is 11747 Decl : Node_Id; 11748 Formal : Entity_Id; 11749 T : Entity_Id; 11750 First_Stmt : Node_Id := Empty; 11751 AS_Needed : Boolean; 11752 11753 begin 11754 -- If this is an empty initialization procedure, no need to create 11755 -- actual subtypes (small optimization). 11756 11757 if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then 11758 return; 11759 11760 -- Within a predicate function we do not want to generate local 11761 -- subtypes that may generate nested predicate functions. 11762 11763 elsif Is_Subprogram (Subp) and then Is_Predicate_Function (Subp) then 11764 return; 11765 end if; 11766 11767 -- The subtype declarations may freeze the formals. The body generated 11768 -- for an expression function is not a freeze point, so do not emit 11769 -- these declarations (small loss of efficiency in rare cases). 11770 11771 if Nkind (N) = N_Subprogram_Body 11772 and then Was_Expression_Function (N) 11773 then 11774 return; 11775 end if; 11776 11777 Formal := First_Formal (Subp); 11778 while Present (Formal) loop 11779 T := Etype (Formal); 11780 11781 -- We never need an actual subtype for a constrained formal 11782 11783 if Is_Constrained (T) then 11784 AS_Needed := False; 11785 11786 -- If we have unknown discriminants, then we do not need an actual 11787 -- subtype, or more accurately we cannot figure it out. Note that 11788 -- all class-wide types have unknown discriminants. 11789 11790 elsif Has_Unknown_Discriminants (T) then 11791 AS_Needed := False; 11792 11793 -- At this stage we have an unconstrained type that may need an 11794 -- actual subtype. For sure the actual subtype is needed if we have 11795 -- an unconstrained array type. However, in an instance, the type 11796 -- may appear as a subtype of the full view, while the actual is 11797 -- in fact private (in which case no actual subtype is needed) so 11798 -- check the kind of the base type. 11799 11800 elsif Is_Array_Type (Base_Type (T)) then 11801 AS_Needed := True; 11802 11803 -- The only other case needing an actual subtype is an unconstrained 11804 -- record type which is an IN parameter (we cannot generate actual 11805 -- subtypes for the OUT or IN OUT case, since an assignment can 11806 -- change the discriminant values. However we exclude the case of 11807 -- initialization procedures, since discriminants are handled very 11808 -- specially in this context, see the section entitled "Handling of 11809 -- Discriminants" in Einfo. 11810 11811 -- We also exclude the case of Discrim_SO_Functions (functions used 11812 -- in front-end layout mode for size/offset values), since in such 11813 -- functions only discriminants are referenced, and not only are such 11814 -- subtypes not needed, but they cannot always be generated, because 11815 -- of order of elaboration issues. 11816 11817 elsif Is_Record_Type (T) 11818 and then Ekind (Formal) = E_In_Parameter 11819 and then Chars (Formal) /= Name_uInit 11820 and then not Is_Unchecked_Union (T) 11821 and then not Is_Discrim_SO_Function (Subp) 11822 then 11823 AS_Needed := True; 11824 11825 -- All other cases do not need an actual subtype 11826 11827 else 11828 AS_Needed := False; 11829 end if; 11830 11831 -- Generate actual subtypes for unconstrained arrays and 11832 -- unconstrained discriminated records. 11833 11834 if AS_Needed then 11835 if Nkind (N) = N_Accept_Statement then 11836 11837 -- If expansion is active, the formal is replaced by a local 11838 -- variable that renames the corresponding entry of the 11839 -- parameter block, and it is this local variable that may 11840 -- require an actual subtype. 11841 11842 if Expander_Active then 11843 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal)); 11844 else 11845 Decl := Build_Actual_Subtype (T, Formal); 11846 end if; 11847 11848 if Present (Handled_Statement_Sequence (N)) then 11849 First_Stmt := 11850 First (Statements (Handled_Statement_Sequence (N))); 11851 Prepend (Decl, Statements (Handled_Statement_Sequence (N))); 11852 Mark_Rewrite_Insertion (Decl); 11853 else 11854 -- If the accept statement has no body, there will be no 11855 -- reference to the actuals, so no need to compute actual 11856 -- subtypes. 11857 11858 return; 11859 end if; 11860 11861 else 11862 Decl := Build_Actual_Subtype (T, Formal); 11863 Prepend (Decl, Declarations (N)); 11864 Mark_Rewrite_Insertion (Decl); 11865 end if; 11866 11867 -- The declaration uses the bounds of an existing object, and 11868 -- therefore needs no constraint checks. 11869 11870 Analyze (Decl, Suppress => All_Checks); 11871 Set_Is_Actual_Subtype (Defining_Identifier (Decl)); 11872 11873 -- We need to freeze manually the generated type when it is 11874 -- inserted anywhere else than in a declarative part. 11875 11876 if Present (First_Stmt) then 11877 Insert_List_Before_And_Analyze (First_Stmt, 11878 Freeze_Entity (Defining_Identifier (Decl), N)); 11879 11880 -- Ditto if the type has a dynamic predicate, because the 11881 -- generated function will mention the actual subtype. The 11882 -- predicate may come from an explicit aspect of be inherited. 11883 11884 elsif Has_Predicates (T) then 11885 Insert_List_Before_And_Analyze (Decl, 11886 Freeze_Entity (Defining_Identifier (Decl), N)); 11887 end if; 11888 11889 if Nkind (N) = N_Accept_Statement 11890 and then Expander_Active 11891 then 11892 Set_Actual_Subtype (Renamed_Object (Formal), 11893 Defining_Identifier (Decl)); 11894 else 11895 Set_Actual_Subtype (Formal, Defining_Identifier (Decl)); 11896 end if; 11897 end if; 11898 11899 Next_Formal (Formal); 11900 end loop; 11901 end Set_Actual_Subtypes; 11902 11903 --------------------- 11904 -- Set_Formal_Mode -- 11905 --------------------- 11906 11907 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is 11908 Spec : constant Node_Id := Parent (Formal_Id); 11909 Id : constant Entity_Id := Scope (Formal_Id); 11910 11911 begin 11912 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters 11913 -- since we ensure that corresponding actuals are always valid at the 11914 -- point of the call. 11915 11916 if Out_Present (Spec) then 11917 if Ekind_In (Id, E_Entry, E_Entry_Family) 11918 or else Is_Subprogram_Or_Generic_Subprogram (Id) 11919 then 11920 Set_Has_Out_Or_In_Out_Parameter (Id, True); 11921 end if; 11922 11923 if Ekind_In (Id, E_Function, E_Generic_Function) then 11924 11925 -- [IN] OUT parameters allowed for functions in Ada 2012 11926 11927 if Ada_Version >= Ada_2012 then 11928 11929 -- Even in Ada 2012 operators can only have IN parameters 11930 11931 if Is_Operator_Symbol_Name (Chars (Scope (Formal_Id))) then 11932 Error_Msg_N ("operators can only have IN parameters", Spec); 11933 end if; 11934 11935 if In_Present (Spec) then 11936 Set_Ekind (Formal_Id, E_In_Out_Parameter); 11937 else 11938 Set_Ekind (Formal_Id, E_Out_Parameter); 11939 end if; 11940 11941 -- But not in earlier versions of Ada 11942 11943 else 11944 Error_Msg_N ("functions can only have IN parameters", Spec); 11945 Set_Ekind (Formal_Id, E_In_Parameter); 11946 end if; 11947 11948 elsif In_Present (Spec) then 11949 Set_Ekind (Formal_Id, E_In_Out_Parameter); 11950 11951 else 11952 Set_Ekind (Formal_Id, E_Out_Parameter); 11953 Set_Never_Set_In_Source (Formal_Id, True); 11954 Set_Is_True_Constant (Formal_Id, False); 11955 Set_Current_Value (Formal_Id, Empty); 11956 end if; 11957 11958 else 11959 Set_Ekind (Formal_Id, E_In_Parameter); 11960 end if; 11961 11962 -- Set Is_Known_Non_Null for access parameters since the language 11963 -- guarantees that access parameters are always non-null. We also set 11964 -- Can_Never_Be_Null, since there is no way to change the value. 11965 11966 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then 11967 11968 -- Ada 2005 (AI-231): In Ada 95, access parameters are always non- 11969 -- null; In Ada 2005, only if then null_exclusion is explicit. 11970 11971 if Ada_Version < Ada_2005 11972 or else Can_Never_Be_Null (Etype (Formal_Id)) 11973 then 11974 Set_Is_Known_Non_Null (Formal_Id); 11975 Set_Can_Never_Be_Null (Formal_Id); 11976 end if; 11977 11978 -- Ada 2005 (AI-231): Null-exclusion access subtype 11979 11980 elsif Is_Access_Type (Etype (Formal_Id)) 11981 and then Can_Never_Be_Null (Etype (Formal_Id)) 11982 then 11983 Set_Is_Known_Non_Null (Formal_Id); 11984 11985 -- We can also set Can_Never_Be_Null (thus preventing some junk 11986 -- access checks) for the case of an IN parameter, which cannot 11987 -- be changed, or for an IN OUT parameter, which can be changed but 11988 -- not to a null value. But for an OUT parameter, the initial value 11989 -- passed in can be null, so we can't set this flag in that case. 11990 11991 if Ekind (Formal_Id) /= E_Out_Parameter then 11992 Set_Can_Never_Be_Null (Formal_Id); 11993 end if; 11994 end if; 11995 11996 Set_Mechanism (Formal_Id, Default_Mechanism); 11997 Set_Formal_Validity (Formal_Id); 11998 end Set_Formal_Mode; 11999 12000 ------------------------- 12001 -- Set_Formal_Validity -- 12002 ------------------------- 12003 12004 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is 12005 begin 12006 -- If no validity checking, then we cannot assume anything about the 12007 -- validity of parameters, since we do not know there is any checking 12008 -- of the validity on the call side. 12009 12010 if not Validity_Checks_On then 12011 return; 12012 12013 -- If validity checking for parameters is enabled, this means we are 12014 -- not supposed to make any assumptions about argument values. 12015 12016 elsif Validity_Check_Parameters then 12017 return; 12018 12019 -- If we are checking in parameters, we will assume that the caller is 12020 -- also checking parameters, so we can assume the parameter is valid. 12021 12022 elsif Ekind (Formal_Id) = E_In_Parameter 12023 and then Validity_Check_In_Params 12024 then 12025 Set_Is_Known_Valid (Formal_Id, True); 12026 12027 -- Similar treatment for IN OUT parameters 12028 12029 elsif Ekind (Formal_Id) = E_In_Out_Parameter 12030 and then Validity_Check_In_Out_Params 12031 then 12032 Set_Is_Known_Valid (Formal_Id, True); 12033 end if; 12034 end Set_Formal_Validity; 12035 12036 ------------------------ 12037 -- Subtype_Conformant -- 12038 ------------------------ 12039 12040 function Subtype_Conformant 12041 (New_Id : Entity_Id; 12042 Old_Id : Entity_Id; 12043 Skip_Controlling_Formals : Boolean := False) return Boolean 12044 is 12045 Result : Boolean; 12046 begin 12047 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result, 12048 Skip_Controlling_Formals => Skip_Controlling_Formals); 12049 return Result; 12050 end Subtype_Conformant; 12051 12052 --------------------- 12053 -- Type_Conformant -- 12054 --------------------- 12055 12056 function Type_Conformant 12057 (New_Id : Entity_Id; 12058 Old_Id : Entity_Id; 12059 Skip_Controlling_Formals : Boolean := False) return Boolean 12060 is 12061 Result : Boolean; 12062 begin 12063 May_Hide_Profile := False; 12064 Check_Conformance 12065 (New_Id, Old_Id, Type_Conformant, False, Result, 12066 Skip_Controlling_Formals => Skip_Controlling_Formals); 12067 return Result; 12068 end Type_Conformant; 12069 12070 ------------------------------- 12071 -- Valid_Operator_Definition -- 12072 ------------------------------- 12073 12074 procedure Valid_Operator_Definition (Designator : Entity_Id) is 12075 N : Integer := 0; 12076 F : Entity_Id; 12077 Id : constant Name_Id := Chars (Designator); 12078 N_OK : Boolean; 12079 12080 begin 12081 F := First_Formal (Designator); 12082 while Present (F) loop 12083 N := N + 1; 12084 12085 if Present (Default_Value (F)) then 12086 Error_Msg_N 12087 ("default values not allowed for operator parameters", 12088 Parent (F)); 12089 12090 -- For function instantiations that are operators, we must check 12091 -- separately that the corresponding generic only has in-parameters. 12092 -- For subprogram declarations this is done in Set_Formal_Mode. Such 12093 -- an error could not arise in earlier versions of the language. 12094 12095 elsif Ekind (F) /= E_In_Parameter then 12096 Error_Msg_N ("operators can only have IN parameters", F); 12097 end if; 12098 12099 Next_Formal (F); 12100 end loop; 12101 12102 -- Verify that user-defined operators have proper number of arguments 12103 -- First case of operators which can only be unary 12104 12105 if Nam_In (Id, Name_Op_Not, Name_Op_Abs) then 12106 N_OK := (N = 1); 12107 12108 -- Case of operators which can be unary or binary 12109 12110 elsif Nam_In (Id, Name_Op_Add, Name_Op_Subtract) then 12111 N_OK := (N in 1 .. 2); 12112 12113 -- All other operators can only be binary 12114 12115 else 12116 N_OK := (N = 2); 12117 end if; 12118 12119 if not N_OK then 12120 Error_Msg_N 12121 ("incorrect number of arguments for operator", Designator); 12122 end if; 12123 12124 if Id = Name_Op_Ne 12125 and then Base_Type (Etype (Designator)) = Standard_Boolean 12126 and then not Is_Intrinsic_Subprogram (Designator) 12127 then 12128 Error_Msg_N 12129 ("explicit definition of inequality not allowed", Designator); 12130 end if; 12131 end Valid_Operator_Definition; 12132 12133end Sem_Ch6; 12134