SemaDeclCXX.cpp revision 9e7d9de3ef538c1473248238b76a6d7b16f5f684
1//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for C++ declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/TypeOrdering.h" 19#include "clang/AST/StmtVisitor.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Parse/DeclSpec.h" 23#include "llvm/Support/Compiler.h" 24#include <algorithm> // for std::equal 25#include <map> 26 27using namespace clang; 28 29//===----------------------------------------------------------------------===// 30// CheckDefaultArgumentVisitor 31//===----------------------------------------------------------------------===// 32 33namespace { 34 /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses 35 /// the default argument of a parameter to determine whether it 36 /// contains any ill-formed subexpressions. For example, this will 37 /// diagnose the use of local variables or parameters within the 38 /// default argument expression. 39 class VISIBILITY_HIDDEN CheckDefaultArgumentVisitor 40 : public StmtVisitor<CheckDefaultArgumentVisitor, bool> { 41 Expr *DefaultArg; 42 Sema *S; 43 44 public: 45 CheckDefaultArgumentVisitor(Expr *defarg, Sema *s) 46 : DefaultArg(defarg), S(s) {} 47 48 bool VisitExpr(Expr *Node); 49 bool VisitDeclRefExpr(DeclRefExpr *DRE); 50 bool VisitCXXThisExpr(CXXThisExpr *ThisE); 51 }; 52 53 /// VisitExpr - Visit all of the children of this expression. 54 bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) { 55 bool IsInvalid = false; 56 for (Stmt::child_iterator I = Node->child_begin(), 57 E = Node->child_end(); I != E; ++I) 58 IsInvalid |= Visit(*I); 59 return IsInvalid; 60 } 61 62 /// VisitDeclRefExpr - Visit a reference to a declaration, to 63 /// determine whether this declaration can be used in the default 64 /// argument expression. 65 bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) { 66 NamedDecl *Decl = DRE->getDecl(); 67 if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) { 68 // C++ [dcl.fct.default]p9 69 // Default arguments are evaluated each time the function is 70 // called. The order of evaluation of function arguments is 71 // unspecified. Consequently, parameters of a function shall not 72 // be used in default argument expressions, even if they are not 73 // evaluated. Parameters of a function declared before a default 74 // argument expression are in scope and can hide namespace and 75 // class member names. 76 return S->Diag(DRE->getSourceRange().getBegin(), 77 diag::err_param_default_argument_references_param) 78 << Param->getDeclName() << DefaultArg->getSourceRange(); 79 } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) { 80 // C++ [dcl.fct.default]p7 81 // Local variables shall not be used in default argument 82 // expressions. 83 if (VDecl->isBlockVarDecl()) 84 return S->Diag(DRE->getSourceRange().getBegin(), 85 diag::err_param_default_argument_references_local) 86 << VDecl->getDeclName() << DefaultArg->getSourceRange(); 87 } 88 89 return false; 90 } 91 92 /// VisitCXXThisExpr - Visit a C++ "this" expression. 93 bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) { 94 // C++ [dcl.fct.default]p8: 95 // The keyword this shall not be used in a default argument of a 96 // member function. 97 return S->Diag(ThisE->getSourceRange().getBegin(), 98 diag::err_param_default_argument_references_this) 99 << ThisE->getSourceRange(); 100 } 101} 102 103/// ActOnParamDefaultArgument - Check whether the default argument 104/// provided for a function parameter is well-formed. If so, attach it 105/// to the parameter declaration. 106void 107Sema::ActOnParamDefaultArgument(DeclTy *param, SourceLocation EqualLoc, 108 ExprTy *defarg) { 109 ParmVarDecl *Param = (ParmVarDecl *)param; 110 llvm::OwningPtr<Expr> DefaultArg((Expr *)defarg); 111 QualType ParamType = Param->getType(); 112 113 // Default arguments are only permitted in C++ 114 if (!getLangOptions().CPlusPlus) { 115 Diag(EqualLoc, diag::err_param_default_argument) 116 << DefaultArg->getSourceRange(); 117 return; 118 } 119 120 // C++ [dcl.fct.default]p5 121 // A default argument expression is implicitly converted (clause 122 // 4) to the parameter type. The default argument expression has 123 // the same semantic constraints as the initializer expression in 124 // a declaration of a variable of the parameter type, using the 125 // copy-initialization semantics (8.5). 126 Expr *DefaultArgPtr = DefaultArg.get(); 127 bool DefaultInitFailed = PerformCopyInitialization(DefaultArgPtr, ParamType, 128 "in default argument"); 129 if (DefaultArgPtr != DefaultArg.get()) { 130 DefaultArg.take(); 131 DefaultArg.reset(DefaultArgPtr); 132 } 133 if (DefaultInitFailed) { 134 return; 135 } 136 137 // Check that the default argument is well-formed 138 CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg.get(), this); 139 if (DefaultArgChecker.Visit(DefaultArg.get())) 140 return; 141 142 // Okay: add the default argument to the parameter 143 Param->setDefaultArg(DefaultArg.take()); 144} 145 146/// CheckExtraCXXDefaultArguments - Check for any extra default 147/// arguments in the declarator, which is not a function declaration 148/// or definition and therefore is not permitted to have default 149/// arguments. This routine should be invoked for every declarator 150/// that is not a function declaration or definition. 151void Sema::CheckExtraCXXDefaultArguments(Declarator &D) { 152 // C++ [dcl.fct.default]p3 153 // A default argument expression shall be specified only in the 154 // parameter-declaration-clause of a function declaration or in a 155 // template-parameter (14.1). It shall not be specified for a 156 // parameter pack. If it is specified in a 157 // parameter-declaration-clause, it shall not occur within a 158 // declarator or abstract-declarator of a parameter-declaration. 159 for (unsigned i = 0; i < D.getNumTypeObjects(); ++i) { 160 DeclaratorChunk &chunk = D.getTypeObject(i); 161 if (chunk.Kind == DeclaratorChunk::Function) { 162 for (unsigned argIdx = 0; argIdx < chunk.Fun.NumArgs; ++argIdx) { 163 ParmVarDecl *Param = (ParmVarDecl *)chunk.Fun.ArgInfo[argIdx].Param; 164 if (Param->getDefaultArg()) { 165 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc) 166 << Param->getDefaultArg()->getSourceRange(); 167 Param->setDefaultArg(0); 168 } 169 } 170 } 171 } 172} 173 174// MergeCXXFunctionDecl - Merge two declarations of the same C++ 175// function, once we already know that they have the same 176// type. Subroutine of MergeFunctionDecl. 177FunctionDecl * 178Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old) { 179 // C++ [dcl.fct.default]p4: 180 // 181 // For non-template functions, default arguments can be added in 182 // later declarations of a function in the same 183 // scope. Declarations in different scopes have completely 184 // distinct sets of default arguments. That is, declarations in 185 // inner scopes do not acquire default arguments from 186 // declarations in outer scopes, and vice versa. In a given 187 // function declaration, all parameters subsequent to a 188 // parameter with a default argument shall have default 189 // arguments supplied in this or previous declarations. A 190 // default argument shall not be redefined by a later 191 // declaration (not even to the same value). 192 for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) { 193 ParmVarDecl *OldParam = Old->getParamDecl(p); 194 ParmVarDecl *NewParam = New->getParamDecl(p); 195 196 if(OldParam->getDefaultArg() && NewParam->getDefaultArg()) { 197 Diag(NewParam->getLocation(), 198 diag::err_param_default_argument_redefinition) 199 << NewParam->getDefaultArg()->getSourceRange(); 200 Diag(OldParam->getLocation(), diag::note_previous_definition); 201 } else if (OldParam->getDefaultArg()) { 202 // Merge the old default argument into the new parameter 203 NewParam->setDefaultArg(OldParam->getDefaultArg()); 204 } 205 } 206 207 return New; 208} 209 210/// CheckCXXDefaultArguments - Verify that the default arguments for a 211/// function declaration are well-formed according to C++ 212/// [dcl.fct.default]. 213void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) { 214 unsigned NumParams = FD->getNumParams(); 215 unsigned p; 216 217 // Find first parameter with a default argument 218 for (p = 0; p < NumParams; ++p) { 219 ParmVarDecl *Param = FD->getParamDecl(p); 220 if (Param->getDefaultArg()) 221 break; 222 } 223 224 // C++ [dcl.fct.default]p4: 225 // In a given function declaration, all parameters 226 // subsequent to a parameter with a default argument shall 227 // have default arguments supplied in this or previous 228 // declarations. A default argument shall not be redefined 229 // by a later declaration (not even to the same value). 230 unsigned LastMissingDefaultArg = 0; 231 for(; p < NumParams; ++p) { 232 ParmVarDecl *Param = FD->getParamDecl(p); 233 if (!Param->getDefaultArg()) { 234 if (Param->getIdentifier()) 235 Diag(Param->getLocation(), 236 diag::err_param_default_argument_missing_name) 237 << Param->getIdentifier(); 238 else 239 Diag(Param->getLocation(), 240 diag::err_param_default_argument_missing); 241 242 LastMissingDefaultArg = p; 243 } 244 } 245 246 if (LastMissingDefaultArg > 0) { 247 // Some default arguments were missing. Clear out all of the 248 // default arguments up to (and including) the last missing 249 // default argument, so that we leave the function parameters 250 // in a semantically valid state. 251 for (p = 0; p <= LastMissingDefaultArg; ++p) { 252 ParmVarDecl *Param = FD->getParamDecl(p); 253 if (Param->getDefaultArg()) { 254 delete Param->getDefaultArg(); 255 Param->setDefaultArg(0); 256 } 257 } 258 } 259} 260 261/// isCurrentClassName - Determine whether the identifier II is the 262/// name of the class type currently being defined. In the case of 263/// nested classes, this will only return true if II is the name of 264/// the innermost class. 265bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *, 266 const CXXScopeSpec *SS) { 267 CXXRecordDecl *CurDecl; 268 if (SS) { 269 DeclContext *DC = static_cast<DeclContext*>(SS->getScopeRep()); 270 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC); 271 } else 272 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext); 273 274 if (CurDecl) 275 return &II == CurDecl->getIdentifier(); 276 else 277 return false; 278} 279 280/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is 281/// one entry in the base class list of a class specifier, for 282/// example: 283/// class foo : public bar, virtual private baz { 284/// 'public bar' and 'virtual private baz' are each base-specifiers. 285Sema::BaseResult 286Sema::ActOnBaseSpecifier(DeclTy *classdecl, SourceRange SpecifierRange, 287 bool Virtual, AccessSpecifier Access, 288 TypeTy *basetype, SourceLocation BaseLoc) { 289 RecordDecl *Decl = (RecordDecl*)classdecl; 290 QualType BaseType = Context.getTypeDeclType((TypeDecl*)basetype); 291 292 // Base specifiers must be record types. 293 if (!BaseType->isRecordType()) 294 return Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange; 295 296 // C++ [class.union]p1: 297 // A union shall not be used as a base class. 298 if (BaseType->isUnionType()) 299 return Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange; 300 301 // C++ [class.union]p1: 302 // A union shall not have base classes. 303 if (Decl->isUnion()) 304 return Diag(Decl->getLocation(), diag::err_base_clause_on_union) 305 << SpecifierRange; 306 307 // C++ [class.derived]p2: 308 // The class-name in a base-specifier shall not be an incompletely 309 // defined class. 310 if (BaseType->isIncompleteType()) 311 return Diag(BaseLoc, diag::err_incomplete_base_class) << SpecifierRange; 312 313 // If the base class is polymorphic, the new one is, too. 314 RecordDecl *BaseDecl = BaseType->getAsRecordType()->getDecl(); 315 assert(BaseDecl && "Record type has no declaration"); 316 BaseDecl = BaseDecl->getDefinition(Context); 317 assert(BaseDecl && "Base type is not incomplete, but has no definition"); 318 if (cast<CXXRecordDecl>(BaseDecl)->isPolymorphic()) 319 cast<CXXRecordDecl>(Decl)->setPolymorphic(true); 320 321 // Create the base specifier. 322 return new CXXBaseSpecifier(SpecifierRange, Virtual, 323 BaseType->isClassType(), Access, BaseType); 324} 325 326/// ActOnBaseSpecifiers - Attach the given base specifiers to the 327/// class, after checking whether there are any duplicate base 328/// classes. 329void Sema::ActOnBaseSpecifiers(DeclTy *ClassDecl, BaseTy **Bases, 330 unsigned NumBases) { 331 if (NumBases == 0) 332 return; 333 334 // Used to keep track of which base types we have already seen, so 335 // that we can properly diagnose redundant direct base types. Note 336 // that the key is always the unqualified canonical type of the base 337 // class. 338 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes; 339 340 // Copy non-redundant base specifiers into permanent storage. 341 CXXBaseSpecifier **BaseSpecs = (CXXBaseSpecifier **)Bases; 342 unsigned NumGoodBases = 0; 343 for (unsigned idx = 0; idx < NumBases; ++idx) { 344 QualType NewBaseType 345 = Context.getCanonicalType(BaseSpecs[idx]->getType()); 346 NewBaseType = NewBaseType.getUnqualifiedType(); 347 348 if (KnownBaseTypes[NewBaseType]) { 349 // C++ [class.mi]p3: 350 // A class shall not be specified as a direct base class of a 351 // derived class more than once. 352 Diag(BaseSpecs[idx]->getSourceRange().getBegin(), 353 diag::err_duplicate_base_class) 354 << KnownBaseTypes[NewBaseType]->getType() 355 << BaseSpecs[idx]->getSourceRange(); 356 357 // Delete the duplicate base class specifier; we're going to 358 // overwrite its pointer later. 359 delete BaseSpecs[idx]; 360 } else { 361 // Okay, add this new base class. 362 KnownBaseTypes[NewBaseType] = BaseSpecs[idx]; 363 BaseSpecs[NumGoodBases++] = BaseSpecs[idx]; 364 } 365 } 366 367 // Attach the remaining base class specifiers to the derived class. 368 CXXRecordDecl *Decl = (CXXRecordDecl*)ClassDecl; 369 Decl->setBases(BaseSpecs, NumGoodBases); 370 371 // Delete the remaining (good) base class specifiers, since their 372 // data has been copied into the CXXRecordDecl. 373 for (unsigned idx = 0; idx < NumGoodBases; ++idx) 374 delete BaseSpecs[idx]; 375} 376 377//===----------------------------------------------------------------------===// 378// C++ class member Handling 379//===----------------------------------------------------------------------===// 380 381/// ActOnStartCXXClassDef - This is called at the start of a class/struct/union 382/// definition, when on C++. 383void Sema::ActOnStartCXXClassDef(Scope *S, DeclTy *D, SourceLocation LBrace) { 384 CXXRecordDecl *Dcl = cast<CXXRecordDecl>(static_cast<Decl *>(D)); 385 PushDeclContext(S, Dcl); 386 FieldCollector->StartClass(); 387 388 if (Dcl->getIdentifier()) { 389 // C++ [class]p2: 390 // [...] The class-name is also inserted into the scope of the 391 // class itself; this is known as the injected-class-name. For 392 // purposes of access checking, the injected-class-name is treated 393 // as if it were a public member name. 394 PushOnScopeChains(Dcl, S); 395 } 396} 397 398/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member 399/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the 400/// bitfield width if there is one and 'InitExpr' specifies the initializer if 401/// any. 'LastInGroup' is non-null for cases where one declspec has multiple 402/// declarators on it. 403/// 404/// NOTE: Because of CXXFieldDecl's inability to be chained like ScopedDecls, if 405/// an instance field is declared, a new CXXFieldDecl is created but the method 406/// does *not* return it; it returns LastInGroup instead. The other C++ members 407/// (which are all ScopedDecls) are returned after appending them to 408/// LastInGroup. 409Sema::DeclTy * 410Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D, 411 ExprTy *BW, ExprTy *InitExpr, 412 DeclTy *LastInGroup) { 413 const DeclSpec &DS = D.getDeclSpec(); 414 DeclarationName Name = GetNameForDeclarator(D); 415 Expr *BitWidth = static_cast<Expr*>(BW); 416 Expr *Init = static_cast<Expr*>(InitExpr); 417 SourceLocation Loc = D.getIdentifierLoc(); 418 419 bool isFunc = D.isFunctionDeclarator(); 420 421 // C++ 9.2p6: A member shall not be declared to have automatic storage 422 // duration (auto, register) or with the extern storage-class-specifier. 423 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class 424 // data members and cannot be applied to names declared const or static, 425 // and cannot be applied to reference members. 426 switch (DS.getStorageClassSpec()) { 427 case DeclSpec::SCS_unspecified: 428 case DeclSpec::SCS_typedef: 429 case DeclSpec::SCS_static: 430 // FALL THROUGH. 431 break; 432 case DeclSpec::SCS_mutable: 433 if (isFunc) { 434 if (DS.getStorageClassSpecLoc().isValid()) 435 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function); 436 else 437 Diag(DS.getThreadSpecLoc(), diag::err_mutable_function); 438 439 // FIXME: It would be nicer if the keyword was ignored only for this 440 // declarator. Otherwise we could get follow-up errors. 441 D.getMutableDeclSpec().ClearStorageClassSpecs(); 442 } else { 443 QualType T = GetTypeForDeclarator(D, S); 444 diag::kind err = static_cast<diag::kind>(0); 445 if (T->isReferenceType()) 446 err = diag::err_mutable_reference; 447 else if (T.isConstQualified()) 448 err = diag::err_mutable_const; 449 if (err != 0) { 450 if (DS.getStorageClassSpecLoc().isValid()) 451 Diag(DS.getStorageClassSpecLoc(), err); 452 else 453 Diag(DS.getThreadSpecLoc(), err); 454 // FIXME: It would be nicer if the keyword was ignored only for this 455 // declarator. Otherwise we could get follow-up errors. 456 D.getMutableDeclSpec().ClearStorageClassSpecs(); 457 } 458 } 459 break; 460 default: 461 if (DS.getStorageClassSpecLoc().isValid()) 462 Diag(DS.getStorageClassSpecLoc(), 463 diag::err_storageclass_invalid_for_member); 464 else 465 Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member); 466 D.getMutableDeclSpec().ClearStorageClassSpecs(); 467 } 468 469 if (!isFunc && 470 D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_typedef && 471 D.getNumTypeObjects() == 0) { 472 // Check also for this case: 473 // 474 // typedef int f(); 475 // f a; 476 // 477 Decl *TD = static_cast<Decl *>(DS.getTypeRep()); 478 isFunc = Context.getTypeDeclType(cast<TypeDecl>(TD))->isFunctionType(); 479 } 480 481 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified || 482 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) && 483 !isFunc); 484 485 Decl *Member; 486 bool InvalidDecl = false; 487 488 if (isInstField) 489 Member = static_cast<Decl*>(ActOnField(S, cast<CXXRecordDecl>(CurContext), 490 Loc, D, BitWidth)); 491 else 492 Member = static_cast<Decl*>(ActOnDeclarator(S, D, LastInGroup)); 493 494 if (!Member) return LastInGroup; 495 496 assert((Name || isInstField) && "No identifier for non-field ?"); 497 498 // set/getAccess is not part of Decl's interface to avoid bloating it with C++ 499 // specific methods. Use a wrapper class that can be used with all C++ class 500 // member decls. 501 CXXClassMemberWrapper(Member).setAccess(AS); 502 503 // C++ [dcl.init.aggr]p1: 504 // An aggregate is an array or a class (clause 9) with [...] no 505 // private or protected non-static data members (clause 11). 506 if (isInstField && (AS == AS_private || AS == AS_protected)) 507 cast<CXXRecordDecl>(CurContext)->setAggregate(false); 508 509 if (DS.isVirtualSpecified()) { 510 if (!isFunc || DS.getStorageClassSpec() == DeclSpec::SCS_static) { 511 Diag(DS.getVirtualSpecLoc(), diag::err_virtual_non_function); 512 InvalidDecl = true; 513 } else { 514 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(CurContext); 515 CurClass->setAggregate(false); 516 CurClass->setPolymorphic(true); 517 } 518 } 519 520 if (BitWidth) { 521 // C++ 9.6p2: Only when declaring an unnamed bit-field may the 522 // constant-expression be a value equal to zero. 523 // FIXME: Check this. 524 525 if (D.isFunctionDeclarator()) { 526 // FIXME: Emit diagnostic about only constructors taking base initializers 527 // or something similar, when constructor support is in place. 528 Diag(Loc, diag::err_not_bitfield_type) 529 << Name << BitWidth->getSourceRange(); 530 InvalidDecl = true; 531 532 } else if (isInstField) { 533 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 534 if (!cast<FieldDecl>(Member)->getType()->isIntegralType()) { 535 Diag(Loc, diag::err_not_integral_type_bitfield) 536 << Name << BitWidth->getSourceRange(); 537 InvalidDecl = true; 538 } 539 540 } else if (isa<FunctionDecl>(Member)) { 541 // A function typedef ("typedef int f(); f a;"). 542 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 543 Diag(Loc, diag::err_not_integral_type_bitfield) 544 << Name << BitWidth->getSourceRange(); 545 InvalidDecl = true; 546 547 } else if (isa<TypedefDecl>(Member)) { 548 // "cannot declare 'A' to be a bit-field type" 549 Diag(Loc, diag::err_not_bitfield_type) 550 << Name << BitWidth->getSourceRange(); 551 InvalidDecl = true; 552 553 } else { 554 assert(isa<CXXClassVarDecl>(Member) && 555 "Didn't we cover all member kinds?"); 556 // C++ 9.6p3: A bit-field shall not be a static member. 557 // "static member 'A' cannot be a bit-field" 558 Diag(Loc, diag::err_static_not_bitfield) 559 << Name << BitWidth->getSourceRange(); 560 InvalidDecl = true; 561 } 562 } 563 564 if (Init) { 565 // C++ 9.2p4: A member-declarator can contain a constant-initializer only 566 // if it declares a static member of const integral or const enumeration 567 // type. 568 if (CXXClassVarDecl *CVD = dyn_cast<CXXClassVarDecl>(Member)) { 569 // ...static member of... 570 CVD->setInit(Init); 571 // ...const integral or const enumeration type. 572 if (Context.getCanonicalType(CVD->getType()).isConstQualified() && 573 CVD->getType()->isIntegralType()) { 574 // constant-initializer 575 if (CheckForConstantInitializer(Init, CVD->getType())) 576 InvalidDecl = true; 577 578 } else { 579 // not const integral. 580 Diag(Loc, diag::err_member_initialization) 581 << Name << Init->getSourceRange(); 582 InvalidDecl = true; 583 } 584 585 } else { 586 // not static member. 587 Diag(Loc, diag::err_member_initialization) 588 << Name << Init->getSourceRange(); 589 InvalidDecl = true; 590 } 591 } 592 593 if (InvalidDecl) 594 Member->setInvalidDecl(); 595 596 if (isInstField) { 597 FieldCollector->Add(cast<FieldDecl>(Member)); 598 return LastInGroup; 599 } 600 return Member; 601} 602 603/// ActOnMemInitializer - Handle a C++ member initializer. 604Sema::MemInitResult 605Sema::ActOnMemInitializer(DeclTy *ConstructorD, 606 Scope *S, 607 IdentifierInfo *MemberOrBase, 608 SourceLocation IdLoc, 609 SourceLocation LParenLoc, 610 ExprTy **Args, unsigned NumArgs, 611 SourceLocation *CommaLocs, 612 SourceLocation RParenLoc) { 613 CXXConstructorDecl *Constructor 614 = dyn_cast<CXXConstructorDecl>((Decl*)ConstructorD); 615 if (!Constructor) { 616 // The user wrote a constructor initializer on a function that is 617 // not a C++ constructor. Ignore the error for now, because we may 618 // have more member initializers coming; we'll diagnose it just 619 // once in ActOnMemInitializers. 620 return true; 621 } 622 623 CXXRecordDecl *ClassDecl = Constructor->getParent(); 624 625 // C++ [class.base.init]p2: 626 // Names in a mem-initializer-id are looked up in the scope of the 627 // constructor’s class and, if not found in that scope, are looked 628 // up in the scope containing the constructor’s 629 // definition. [Note: if the constructor’s class contains a member 630 // with the same name as a direct or virtual base class of the 631 // class, a mem-initializer-id naming the member or base class and 632 // composed of a single identifier refers to the class member. A 633 // mem-initializer-id for the hidden base class may be specified 634 // using a qualified name. ] 635 // Look for a member, first. 636 FieldDecl *Member = 0; 637 DeclContext::lookup_result Result = ClassDecl->lookup(Context, MemberOrBase); 638 if (Result.first != Result.second) 639 Member = dyn_cast<FieldDecl>(*Result.first); 640 641 // FIXME: Handle members of an anonymous union. 642 643 if (Member) { 644 // FIXME: Perform direct initialization of the member. 645 return new CXXBaseOrMemberInitializer(Member, (Expr **)Args, NumArgs); 646 } 647 648 // It didn't name a member, so see if it names a class. 649 TypeTy *BaseTy = isTypeName(*MemberOrBase, S, 0/*SS*/); 650 if (!BaseTy) 651 return Diag(IdLoc, diag::err_mem_init_not_member_or_class) 652 << MemberOrBase << SourceRange(IdLoc, RParenLoc); 653 654 QualType BaseType = Context.getTypeDeclType((TypeDecl *)BaseTy); 655 if (!BaseType->isRecordType()) 656 return Diag(IdLoc, diag::err_base_init_does_not_name_class) 657 << BaseType << SourceRange(IdLoc, RParenLoc); 658 659 // C++ [class.base.init]p2: 660 // [...] Unless the mem-initializer-id names a nonstatic data 661 // member of the constructor’s class or a direct or virtual base 662 // of that class, the mem-initializer is ill-formed. A 663 // mem-initializer-list can initialize a base class using any 664 // name that denotes that base class type. 665 666 // First, check for a direct base class. 667 const CXXBaseSpecifier *DirectBaseSpec = 0; 668 for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(); 669 Base != ClassDecl->bases_end(); ++Base) { 670 if (Context.getCanonicalType(BaseType).getUnqualifiedType() == 671 Context.getCanonicalType(Base->getType()).getUnqualifiedType()) { 672 // We found a direct base of this type. That's what we're 673 // initializing. 674 DirectBaseSpec = &*Base; 675 break; 676 } 677 } 678 679 // Check for a virtual base class. 680 // FIXME: We might be able to short-circuit this if we know in 681 // advance that there are no virtual bases. 682 const CXXBaseSpecifier *VirtualBaseSpec = 0; 683 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) { 684 // We haven't found a base yet; search the class hierarchy for a 685 // virtual base class. 686 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 687 /*DetectVirtual=*/false); 688 if (IsDerivedFrom(Context.getTypeDeclType(ClassDecl), BaseType, Paths)) { 689 for (BasePaths::paths_iterator Path = Paths.begin(); 690 Path != Paths.end(); ++Path) { 691 if (Path->back().Base->isVirtual()) { 692 VirtualBaseSpec = Path->back().Base; 693 break; 694 } 695 } 696 } 697 } 698 699 // C++ [base.class.init]p2: 700 // If a mem-initializer-id is ambiguous because it designates both 701 // a direct non-virtual base class and an inherited virtual base 702 // class, the mem-initializer is ill-formed. 703 if (DirectBaseSpec && VirtualBaseSpec) 704 return Diag(IdLoc, diag::err_base_init_direct_and_virtual) 705 << MemberOrBase << SourceRange(IdLoc, RParenLoc); 706 707 return new CXXBaseOrMemberInitializer(BaseType, (Expr **)Args, NumArgs); 708} 709 710 711void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc, 712 DeclTy *TagDecl, 713 SourceLocation LBrac, 714 SourceLocation RBrac) { 715 ActOnFields(S, RLoc, TagDecl, 716 (DeclTy**)FieldCollector->getCurFields(), 717 FieldCollector->getCurNumFields(), LBrac, RBrac, 0); 718} 719 720/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared 721/// special functions, such as the default constructor, copy 722/// constructor, or destructor, to the given C++ class (C++ 723/// [special]p1). This routine can only be executed just before the 724/// definition of the class is complete. 725void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) { 726 QualType ClassType = Context.getTypeDeclType(ClassDecl); 727 ClassType = Context.getCanonicalType(ClassType); 728 729 if (!ClassDecl->hasUserDeclaredConstructor()) { 730 // C++ [class.ctor]p5: 731 // A default constructor for a class X is a constructor of class X 732 // that can be called without an argument. If there is no 733 // user-declared constructor for class X, a default constructor is 734 // implicitly declared. An implicitly-declared default constructor 735 // is an inline public member of its class. 736 DeclarationName Name 737 = Context.DeclarationNames.getCXXConstructorName(ClassType); 738 CXXConstructorDecl *DefaultCon = 739 CXXConstructorDecl::Create(Context, ClassDecl, 740 ClassDecl->getLocation(), Name, 741 Context.getFunctionType(Context.VoidTy, 742 0, 0, false, 0), 743 /*isExplicit=*/false, 744 /*isInline=*/true, 745 /*isImplicitlyDeclared=*/true); 746 DefaultCon->setAccess(AS_public); 747 ClassDecl->addDecl(Context, DefaultCon); 748 749 // Notify the class that we've added a constructor. 750 ClassDecl->addedConstructor(Context, DefaultCon); 751 } 752 753 if (!ClassDecl->hasUserDeclaredCopyConstructor()) { 754 // C++ [class.copy]p4: 755 // If the class definition does not explicitly declare a copy 756 // constructor, one is declared implicitly. 757 758 // C++ [class.copy]p5: 759 // The implicitly-declared copy constructor for a class X will 760 // have the form 761 // 762 // X::X(const X&) 763 // 764 // if 765 bool HasConstCopyConstructor = true; 766 767 // -- each direct or virtual base class B of X has a copy 768 // constructor whose first parameter is of type const B& or 769 // const volatile B&, and 770 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 771 HasConstCopyConstructor && Base != ClassDecl->bases_end(); ++Base) { 772 const CXXRecordDecl *BaseClassDecl 773 = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl()); 774 HasConstCopyConstructor 775 = BaseClassDecl->hasConstCopyConstructor(Context); 776 } 777 778 // -- for all the nonstatic data members of X that are of a 779 // class type M (or array thereof), each such class type 780 // has a copy constructor whose first parameter is of type 781 // const M& or const volatile M&. 782 for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(); 783 HasConstCopyConstructor && Field != ClassDecl->field_end(); ++Field) { 784 QualType FieldType = (*Field)->getType(); 785 if (const ArrayType *Array = Context.getAsArrayType(FieldType)) 786 FieldType = Array->getElementType(); 787 if (const RecordType *FieldClassType = FieldType->getAsRecordType()) { 788 const CXXRecordDecl *FieldClassDecl 789 = cast<CXXRecordDecl>(FieldClassType->getDecl()); 790 HasConstCopyConstructor 791 = FieldClassDecl->hasConstCopyConstructor(Context); 792 } 793 } 794 795 // Otherwise, the implicitly declared copy constructor will have 796 // the form 797 // 798 // X::X(X&) 799 QualType ArgType = Context.getTypeDeclType(ClassDecl); 800 if (HasConstCopyConstructor) 801 ArgType = ArgType.withConst(); 802 ArgType = Context.getReferenceType(ArgType); 803 804 // An implicitly-declared copy constructor is an inline public 805 // member of its class. 806 DeclarationName Name 807 = Context.DeclarationNames.getCXXConstructorName(ClassType); 808 CXXConstructorDecl *CopyConstructor 809 = CXXConstructorDecl::Create(Context, ClassDecl, 810 ClassDecl->getLocation(), Name, 811 Context.getFunctionType(Context.VoidTy, 812 &ArgType, 1, 813 false, 0), 814 /*isExplicit=*/false, 815 /*isInline=*/true, 816 /*isImplicitlyDeclared=*/true); 817 CopyConstructor->setAccess(AS_public); 818 819 // Add the parameter to the constructor. 820 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor, 821 ClassDecl->getLocation(), 822 /*IdentifierInfo=*/0, 823 ArgType, VarDecl::None, 0, 0); 824 CopyConstructor->setParams(&FromParam, 1); 825 826 ClassDecl->addedConstructor(Context, CopyConstructor); 827 DeclContext::lookup_result Lookup = ClassDecl->lookup(Context, Name); 828 if (Lookup.first == Lookup.second 829 || (!isa<CXXConstructorDecl>(*Lookup.first) && 830 !isa<OverloadedFunctionDecl>(*Lookup.first))) 831 ClassDecl->addDecl(Context, CopyConstructor); 832 else { 833 OverloadedFunctionDecl *Ovl 834 = dyn_cast<OverloadedFunctionDecl>(*Lookup.first); 835 if (!Ovl) { 836 Ovl = OverloadedFunctionDecl::Create(Context, ClassDecl, Name); 837 Ovl->addOverload(cast<CXXConstructorDecl>(*Lookup.first)); 838 ClassDecl->insert(Context, Ovl); 839 } 840 841 Ovl->addOverload(CopyConstructor); 842 ClassDecl->addDecl(Context, CopyConstructor, false); 843 } 844 } 845 846 if (!ClassDecl->hasUserDeclaredDestructor()) { 847 // C++ [class.dtor]p2: 848 // If a class has no user-declared destructor, a destructor is 849 // declared implicitly. An implicitly-declared destructor is an 850 // inline public member of its class. 851 DeclarationName Name 852 = Context.DeclarationNames.getCXXDestructorName(ClassType); 853 CXXDestructorDecl *Destructor 854 = CXXDestructorDecl::Create(Context, ClassDecl, 855 ClassDecl->getLocation(), Name, 856 Context.getFunctionType(Context.VoidTy, 857 0, 0, false, 0), 858 /*isInline=*/true, 859 /*isImplicitlyDeclared=*/true); 860 Destructor->setAccess(AS_public); 861 ClassDecl->addDecl(Context, Destructor); 862 } 863 864 // FIXME: Implicit copy assignment operator 865} 866 867void Sema::ActOnFinishCXXClassDef(DeclTy *D) { 868 CXXRecordDecl *Rec = cast<CXXRecordDecl>(static_cast<Decl *>(D)); 869 FieldCollector->FinishClass(); 870 AddImplicitlyDeclaredMembersToClass(Rec); 871 PopDeclContext(); 872 873 // Everything, including inline method definitions, have been parsed. 874 // Let the consumer know of the new TagDecl definition. 875 Consumer.HandleTagDeclDefinition(Rec); 876} 877 878/// CheckConstructorDeclarator - Called by ActOnDeclarator to check 879/// the well-formednes of the constructor declarator @p D with type @p 880/// R. If there are any errors in the declarator, this routine will 881/// emit diagnostics and return true. Otherwise, it will return 882/// false. Either way, the type @p R will be updated to reflect a 883/// well-formed type for the constructor. 884bool Sema::CheckConstructorDeclarator(Declarator &D, QualType &R, 885 FunctionDecl::StorageClass& SC) { 886 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 887 bool isInvalid = false; 888 889 // C++ [class.ctor]p3: 890 // A constructor shall not be virtual (10.3) or static (9.4). A 891 // constructor can be invoked for a const, volatile or const 892 // volatile object. A constructor shall not be declared const, 893 // volatile, or const volatile (9.3.2). 894 if (isVirtual) { 895 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) 896 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc()) 897 << SourceRange(D.getIdentifierLoc()); 898 isInvalid = true; 899 } 900 if (SC == FunctionDecl::Static) { 901 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) 902 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 903 << SourceRange(D.getIdentifierLoc()); 904 isInvalid = true; 905 SC = FunctionDecl::None; 906 } 907 if (D.getDeclSpec().hasTypeSpecifier()) { 908 // Constructors don't have return types, but the parser will 909 // happily parse something like: 910 // 911 // class X { 912 // float X(float); 913 // }; 914 // 915 // The return type will be eliminated later. 916 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 917 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 918 << SourceRange(D.getIdentifierLoc()); 919 } 920 if (R->getAsFunctionTypeProto()->getTypeQuals() != 0) { 921 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 922 if (FTI.TypeQuals & QualType::Const) 923 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) 924 << "const" << SourceRange(D.getIdentifierLoc()); 925 if (FTI.TypeQuals & QualType::Volatile) 926 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) 927 << "volatile" << SourceRange(D.getIdentifierLoc()); 928 if (FTI.TypeQuals & QualType::Restrict) 929 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) 930 << "restrict" << SourceRange(D.getIdentifierLoc()); 931 } 932 933 // Rebuild the function type "R" without any type qualifiers (in 934 // case any of the errors above fired) and with "void" as the 935 // return type, since constructors don't have return types. We 936 // *always* have to do this, because GetTypeForDeclarator will 937 // put in a result type of "int" when none was specified. 938 const FunctionTypeProto *Proto = R->getAsFunctionTypeProto(); 939 R = Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(), 940 Proto->getNumArgs(), 941 Proto->isVariadic(), 942 0); 943 944 return isInvalid; 945} 946 947/// CheckDestructorDeclarator - Called by ActOnDeclarator to check 948/// the well-formednes of the destructor declarator @p D with type @p 949/// R. If there are any errors in the declarator, this routine will 950/// emit diagnostics and return true. Otherwise, it will return 951/// false. Either way, the type @p R will be updated to reflect a 952/// well-formed type for the destructor. 953bool Sema::CheckDestructorDeclarator(Declarator &D, QualType &R, 954 FunctionDecl::StorageClass& SC) { 955 bool isInvalid = false; 956 957 // C++ [class.dtor]p1: 958 // [...] A typedef-name that names a class is a class-name 959 // (7.1.3); however, a typedef-name that names a class shall not 960 // be used as the identifier in the declarator for a destructor 961 // declaration. 962 TypeDecl *DeclaratorTypeD = (TypeDecl *)D.getDeclaratorIdType(); 963 if (const TypedefDecl *TypedefD = dyn_cast<TypedefDecl>(DeclaratorTypeD)) { 964 Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name) 965 << TypedefD->getDeclName(); 966 isInvalid = true; 967 } 968 969 // C++ [class.dtor]p2: 970 // A destructor is used to destroy objects of its class type. A 971 // destructor takes no parameters, and no return type can be 972 // specified for it (not even void). The address of a destructor 973 // shall not be taken. A destructor shall not be static. A 974 // destructor can be invoked for a const, volatile or const 975 // volatile object. A destructor shall not be declared const, 976 // volatile or const volatile (9.3.2). 977 if (SC == FunctionDecl::Static) { 978 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be) 979 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 980 << SourceRange(D.getIdentifierLoc()); 981 isInvalid = true; 982 SC = FunctionDecl::None; 983 } 984 if (D.getDeclSpec().hasTypeSpecifier()) { 985 // Destructors don't have return types, but the parser will 986 // happily parse something like: 987 // 988 // class X { 989 // float ~X(); 990 // }; 991 // 992 // The return type will be eliminated later. 993 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type) 994 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 995 << SourceRange(D.getIdentifierLoc()); 996 } 997 if (R->getAsFunctionTypeProto()->getTypeQuals() != 0) { 998 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 999 if (FTI.TypeQuals & QualType::Const) 1000 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) 1001 << "const" << SourceRange(D.getIdentifierLoc()); 1002 if (FTI.TypeQuals & QualType::Volatile) 1003 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) 1004 << "volatile" << SourceRange(D.getIdentifierLoc()); 1005 if (FTI.TypeQuals & QualType::Restrict) 1006 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) 1007 << "restrict" << SourceRange(D.getIdentifierLoc()); 1008 } 1009 1010 // Make sure we don't have any parameters. 1011 if (R->getAsFunctionTypeProto()->getNumArgs() > 0) { 1012 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params); 1013 1014 // Delete the parameters. 1015 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1016 if (FTI.NumArgs) { 1017 delete [] FTI.ArgInfo; 1018 FTI.NumArgs = 0; 1019 FTI.ArgInfo = 0; 1020 } 1021 } 1022 1023 // Make sure the destructor isn't variadic. 1024 if (R->getAsFunctionTypeProto()->isVariadic()) 1025 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic); 1026 1027 // Rebuild the function type "R" without any type qualifiers or 1028 // parameters (in case any of the errors above fired) and with 1029 // "void" as the return type, since destructors don't have return 1030 // types. We *always* have to do this, because GetTypeForDeclarator 1031 // will put in a result type of "int" when none was specified. 1032 R = Context.getFunctionType(Context.VoidTy, 0, 0, false, 0); 1033 1034 return isInvalid; 1035} 1036 1037/// CheckConversionDeclarator - Called by ActOnDeclarator to check the 1038/// well-formednes of the conversion function declarator @p D with 1039/// type @p R. If there are any errors in the declarator, this routine 1040/// will emit diagnostics and return true. Otherwise, it will return 1041/// false. Either way, the type @p R will be updated to reflect a 1042/// well-formed type for the conversion operator. 1043bool Sema::CheckConversionDeclarator(Declarator &D, QualType &R, 1044 FunctionDecl::StorageClass& SC) { 1045 bool isInvalid = false; 1046 1047 // C++ [class.conv.fct]p1: 1048 // Neither parameter types nor return type can be specified. The 1049 // type of a conversion function (8.3.5) is “function taking no 1050 // parameter returning conversion-type-id.” 1051 if (SC == FunctionDecl::Static) { 1052 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member) 1053 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 1054 << SourceRange(D.getIdentifierLoc()); 1055 isInvalid = true; 1056 SC = FunctionDecl::None; 1057 } 1058 if (D.getDeclSpec().hasTypeSpecifier()) { 1059 // Conversion functions don't have return types, but the parser will 1060 // happily parse something like: 1061 // 1062 // class X { 1063 // float operator bool(); 1064 // }; 1065 // 1066 // The return type will be changed later anyway. 1067 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type) 1068 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 1069 << SourceRange(D.getIdentifierLoc()); 1070 } 1071 1072 // Make sure we don't have any parameters. 1073 if (R->getAsFunctionTypeProto()->getNumArgs() > 0) { 1074 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params); 1075 1076 // Delete the parameters. 1077 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1078 if (FTI.NumArgs) { 1079 delete [] FTI.ArgInfo; 1080 FTI.NumArgs = 0; 1081 FTI.ArgInfo = 0; 1082 } 1083 } 1084 1085 // Make sure the conversion function isn't variadic. 1086 if (R->getAsFunctionTypeProto()->isVariadic()) 1087 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic); 1088 1089 // C++ [class.conv.fct]p4: 1090 // The conversion-type-id shall not represent a function type nor 1091 // an array type. 1092 QualType ConvType = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1093 if (ConvType->isArrayType()) { 1094 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array); 1095 ConvType = Context.getPointerType(ConvType); 1096 } else if (ConvType->isFunctionType()) { 1097 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function); 1098 ConvType = Context.getPointerType(ConvType); 1099 } 1100 1101 // Rebuild the function type "R" without any parameters (in case any 1102 // of the errors above fired) and with the conversion type as the 1103 // return type. 1104 R = Context.getFunctionType(ConvType, 0, 0, false, 1105 R->getAsFunctionTypeProto()->getTypeQuals()); 1106 1107 return isInvalid; 1108} 1109 1110/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete 1111/// the declaration of the given C++ conversion function. This routine 1112/// is responsible for recording the conversion function in the C++ 1113/// class, if possible. 1114Sema::DeclTy *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) { 1115 assert(Conversion && "Expected to receive a conversion function declaration"); 1116 1117 // Set the lexical context of this conversion function 1118 Conversion->setLexicalDeclContext(CurContext); 1119 1120 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext()); 1121 1122 // Make sure we aren't redeclaring the conversion function. 1123 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType()); 1124 OverloadedFunctionDecl *Conversions = ClassDecl->getConversionFunctions(); 1125 for (OverloadedFunctionDecl::function_iterator Func 1126 = Conversions->function_begin(); 1127 Func != Conversions->function_end(); ++Func) { 1128 CXXConversionDecl *OtherConv = cast<CXXConversionDecl>(*Func); 1129 if (ConvType == Context.getCanonicalType(OtherConv->getConversionType())) { 1130 Diag(Conversion->getLocation(), diag::err_conv_function_redeclared); 1131 Diag(OtherConv->getLocation(), 1132 OtherConv->isThisDeclarationADefinition()? 1133 diag::note_previous_definition 1134 : diag::note_previous_declaration); 1135 Conversion->setInvalidDecl(); 1136 return (DeclTy *)Conversion; 1137 } 1138 } 1139 1140 // C++ [class.conv.fct]p1: 1141 // [...] A conversion function is never used to convert a 1142 // (possibly cv-qualified) object to the (possibly cv-qualified) 1143 // same object type (or a reference to it), to a (possibly 1144 // cv-qualified) base class of that type (or a reference to it), 1145 // or to (possibly cv-qualified) void. 1146 // FIXME: Suppress this warning if the conversion function ends up 1147 // being a virtual function that overrides a virtual function in a 1148 // base class. 1149 QualType ClassType 1150 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); 1151 if (const ReferenceType *ConvTypeRef = ConvType->getAsReferenceType()) 1152 ConvType = ConvTypeRef->getPointeeType(); 1153 if (ConvType->isRecordType()) { 1154 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType(); 1155 if (ConvType == ClassType) 1156 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used) 1157 << ClassType; 1158 else if (IsDerivedFrom(ClassType, ConvType)) 1159 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used) 1160 << ClassType << ConvType; 1161 } else if (ConvType->isVoidType()) { 1162 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used) 1163 << ClassType << ConvType; 1164 } 1165 1166 ClassDecl->addConversionFunction(Context, Conversion); 1167 1168 return (DeclTy *)Conversion; 1169} 1170 1171//===----------------------------------------------------------------------===// 1172// Namespace Handling 1173//===----------------------------------------------------------------------===// 1174 1175/// ActOnStartNamespaceDef - This is called at the start of a namespace 1176/// definition. 1177Sema::DeclTy *Sema::ActOnStartNamespaceDef(Scope *NamespcScope, 1178 SourceLocation IdentLoc, 1179 IdentifierInfo *II, 1180 SourceLocation LBrace) { 1181 NamespaceDecl *Namespc = 1182 NamespaceDecl::Create(Context, CurContext, IdentLoc, II); 1183 Namespc->setLBracLoc(LBrace); 1184 1185 Scope *DeclRegionScope = NamespcScope->getParent(); 1186 1187 if (II) { 1188 // C++ [namespace.def]p2: 1189 // The identifier in an original-namespace-definition shall not have been 1190 // previously defined in the declarative region in which the 1191 // original-namespace-definition appears. The identifier in an 1192 // original-namespace-definition is the name of the namespace. Subsequently 1193 // in that declarative region, it is treated as an original-namespace-name. 1194 1195 Decl *PrevDecl = 1196 LookupDecl(II, Decl::IDNS_Tag | Decl::IDNS_Ordinary, DeclRegionScope, 0, 1197 /*enableLazyBuiltinCreation=*/false, 1198 /*LookupInParent=*/false); 1199 1200 if (NamespaceDecl *OrigNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl)) { 1201 // This is an extended namespace definition. 1202 // Attach this namespace decl to the chain of extended namespace 1203 // definitions. 1204 OrigNS->setNextNamespace(Namespc); 1205 Namespc->setOriginalNamespace(OrigNS->getOriginalNamespace()); 1206 1207 // Remove the previous declaration from the scope. 1208 if (DeclRegionScope->isDeclScope(OrigNS)) { 1209 IdResolver.RemoveDecl(OrigNS); 1210 DeclRegionScope->RemoveDecl(OrigNS); 1211 } 1212 } else if (PrevDecl) { 1213 // This is an invalid name redefinition. 1214 Diag(Namespc->getLocation(), diag::err_redefinition_different_kind) 1215 << Namespc->getDeclName(); 1216 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 1217 Namespc->setInvalidDecl(); 1218 // Continue on to push Namespc as current DeclContext and return it. 1219 } 1220 1221 PushOnScopeChains(Namespc, DeclRegionScope); 1222 } else { 1223 // FIXME: Handle anonymous namespaces 1224 } 1225 1226 // Although we could have an invalid decl (i.e. the namespace name is a 1227 // redefinition), push it as current DeclContext and try to continue parsing. 1228 // FIXME: We should be able to push Namespc here, so that the 1229 // each DeclContext for the namespace has the declarations 1230 // that showed up in that particular namespace definition. 1231 PushDeclContext(NamespcScope, Namespc); 1232 return Namespc; 1233} 1234 1235/// ActOnFinishNamespaceDef - This callback is called after a namespace is 1236/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef. 1237void Sema::ActOnFinishNamespaceDef(DeclTy *D, SourceLocation RBrace) { 1238 Decl *Dcl = static_cast<Decl *>(D); 1239 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl); 1240 assert(Namespc && "Invalid parameter, expected NamespaceDecl"); 1241 Namespc->setRBracLoc(RBrace); 1242 PopDeclContext(); 1243} 1244 1245 1246/// AddCXXDirectInitializerToDecl - This action is called immediately after 1247/// ActOnDeclarator, when a C++ direct initializer is present. 1248/// e.g: "int x(1);" 1249void Sema::AddCXXDirectInitializerToDecl(DeclTy *Dcl, SourceLocation LParenLoc, 1250 ExprTy **ExprTys, unsigned NumExprs, 1251 SourceLocation *CommaLocs, 1252 SourceLocation RParenLoc) { 1253 assert(NumExprs != 0 && ExprTys && "missing expressions"); 1254 Decl *RealDecl = static_cast<Decl *>(Dcl); 1255 1256 // If there is no declaration, there was an error parsing it. Just ignore 1257 // the initializer. 1258 if (RealDecl == 0) { 1259 for (unsigned i = 0; i != NumExprs; ++i) 1260 delete static_cast<Expr *>(ExprTys[i]); 1261 return; 1262 } 1263 1264 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1265 if (!VDecl) { 1266 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 1267 RealDecl->setInvalidDecl(); 1268 return; 1269 } 1270 1271 // We will treat direct-initialization as a copy-initialization: 1272 // int x(1); -as-> int x = 1; 1273 // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c); 1274 // 1275 // Clients that want to distinguish between the two forms, can check for 1276 // direct initializer using VarDecl::hasCXXDirectInitializer(). 1277 // A major benefit is that clients that don't particularly care about which 1278 // exactly form was it (like the CodeGen) can handle both cases without 1279 // special case code. 1280 1281 // C++ 8.5p11: 1282 // The form of initialization (using parentheses or '=') is generally 1283 // insignificant, but does matter when the entity being initialized has a 1284 // class type. 1285 QualType DeclInitType = VDecl->getType(); 1286 if (const ArrayType *Array = Context.getAsArrayType(DeclInitType)) 1287 DeclInitType = Array->getElementType(); 1288 1289 if (VDecl->getType()->isRecordType()) { 1290 CXXConstructorDecl *Constructor 1291 = PerformInitializationByConstructor(DeclInitType, 1292 (Expr **)ExprTys, NumExprs, 1293 VDecl->getLocation(), 1294 SourceRange(VDecl->getLocation(), 1295 RParenLoc), 1296 VDecl->getDeclName(), 1297 IK_Direct); 1298 if (!Constructor) { 1299 RealDecl->setInvalidDecl(); 1300 } 1301 1302 // Let clients know that initialization was done with a direct 1303 // initializer. 1304 VDecl->setCXXDirectInitializer(true); 1305 1306 // FIXME: Add ExprTys and Constructor to the RealDecl as part of 1307 // the initializer. 1308 return; 1309 } 1310 1311 if (NumExprs > 1) { 1312 Diag(CommaLocs[0], diag::err_builtin_direct_init_more_than_one_arg) 1313 << SourceRange(VDecl->getLocation(), RParenLoc); 1314 RealDecl->setInvalidDecl(); 1315 return; 1316 } 1317 1318 // Let clients know that initialization was done with a direct initializer. 1319 VDecl->setCXXDirectInitializer(true); 1320 1321 assert(NumExprs == 1 && "Expected 1 expression"); 1322 // Set the init expression, handles conversions. 1323 AddInitializerToDecl(Dcl, ExprArg(*this, ExprTys[0])); 1324} 1325 1326/// PerformInitializationByConstructor - Perform initialization by 1327/// constructor (C++ [dcl.init]p14), which may occur as part of 1328/// direct-initialization or copy-initialization. We are initializing 1329/// an object of type @p ClassType with the given arguments @p 1330/// Args. @p Loc is the location in the source code where the 1331/// initializer occurs (e.g., a declaration, member initializer, 1332/// functional cast, etc.) while @p Range covers the whole 1333/// initialization. @p InitEntity is the entity being initialized, 1334/// which may by the name of a declaration or a type. @p Kind is the 1335/// kind of initialization we're performing, which affects whether 1336/// explicit constructors will be considered. When successful, returns 1337/// the constructor that will be used to perform the initialization; 1338/// when the initialization fails, emits a diagnostic and returns 1339/// null. 1340CXXConstructorDecl * 1341Sema::PerformInitializationByConstructor(QualType ClassType, 1342 Expr **Args, unsigned NumArgs, 1343 SourceLocation Loc, SourceRange Range, 1344 DeclarationName InitEntity, 1345 InitializationKind Kind) { 1346 const RecordType *ClassRec = ClassType->getAsRecordType(); 1347 assert(ClassRec && "Can only initialize a class type here"); 1348 1349 // C++ [dcl.init]p14: 1350 // 1351 // If the initialization is direct-initialization, or if it is 1352 // copy-initialization where the cv-unqualified version of the 1353 // source type is the same class as, or a derived class of, the 1354 // class of the destination, constructors are considered. The 1355 // applicable constructors are enumerated (13.3.1.3), and the 1356 // best one is chosen through overload resolution (13.3). The 1357 // constructor so selected is called to initialize the object, 1358 // with the initializer expression(s) as its argument(s). If no 1359 // constructor applies, or the overload resolution is ambiguous, 1360 // the initialization is ill-formed. 1361 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 1362 OverloadCandidateSet CandidateSet; 1363 1364 // Add constructors to the overload set. 1365 DeclarationName ConstructorName 1366 = Context.DeclarationNames.getCXXConstructorName( 1367 Context.getCanonicalType(ClassType.getUnqualifiedType())); 1368 DeclContext::lookup_const_result Lookup 1369 = ClassDecl->lookup(Context, ConstructorName); 1370 if (Lookup.first == Lookup.second) 1371 /* No constructors */; 1372 else if (OverloadedFunctionDecl *Constructors 1373 = dyn_cast<OverloadedFunctionDecl>(*Lookup.first)) { 1374 for (OverloadedFunctionDecl::function_iterator Con 1375 = Constructors->function_begin(); 1376 Con != Constructors->function_end(); ++Con) { 1377 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1378 if ((Kind == IK_Direct) || 1379 (Kind == IK_Copy && Constructor->isConvertingConstructor()) || 1380 (Kind == IK_Default && Constructor->isDefaultConstructor())) 1381 AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet); 1382 } 1383 } else if (CXXConstructorDecl *Constructor 1384 = dyn_cast<CXXConstructorDecl>(*Lookup.first)) { 1385 if ((Kind == IK_Direct) || 1386 (Kind == IK_Copy && Constructor->isConvertingConstructor()) || 1387 (Kind == IK_Default && Constructor->isDefaultConstructor())) 1388 AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet); 1389 } 1390 1391 // FIXME: When we decide not to synthesize the implicitly-declared 1392 // constructors, we'll need to make them appear here. 1393 1394 OverloadCandidateSet::iterator Best; 1395 switch (BestViableFunction(CandidateSet, Best)) { 1396 case OR_Success: 1397 // We found a constructor. Return it. 1398 return cast<CXXConstructorDecl>(Best->Function); 1399 1400 case OR_No_Viable_Function: 1401 Diag(Loc, diag::err_ovl_no_viable_function_in_init) 1402 << InitEntity << (unsigned)CandidateSet.size() << Range; 1403 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1404 return 0; 1405 1406 case OR_Ambiguous: 1407 Diag(Loc, diag::err_ovl_ambiguous_init) << InitEntity << Range; 1408 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 1409 return 0; 1410 } 1411 1412 return 0; 1413} 1414 1415/// CompareReferenceRelationship - Compare the two types T1 and T2 to 1416/// determine whether they are reference-related, 1417/// reference-compatible, reference-compatible with added 1418/// qualification, or incompatible, for use in C++ initialization by 1419/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 1420/// type, and the first type (T1) is the pointee type of the reference 1421/// type being initialized. 1422Sema::ReferenceCompareResult 1423Sema::CompareReferenceRelationship(QualType T1, QualType T2, 1424 bool& DerivedToBase) { 1425 assert(!T1->isReferenceType() && "T1 must be the pointee type of the reference type"); 1426 assert(!T2->isReferenceType() && "T2 cannot be a reference type"); 1427 1428 T1 = Context.getCanonicalType(T1); 1429 T2 = Context.getCanonicalType(T2); 1430 QualType UnqualT1 = T1.getUnqualifiedType(); 1431 QualType UnqualT2 = T2.getUnqualifiedType(); 1432 1433 // C++ [dcl.init.ref]p4: 1434 // Given types “cv1 T1” and “cv2 T2,” “cv1 T1” is 1435 // reference-related to “cv2 T2” if T1 is the same type as T2, or 1436 // T1 is a base class of T2. 1437 if (UnqualT1 == UnqualT2) 1438 DerivedToBase = false; 1439 else if (IsDerivedFrom(UnqualT2, UnqualT1)) 1440 DerivedToBase = true; 1441 else 1442 return Ref_Incompatible; 1443 1444 // At this point, we know that T1 and T2 are reference-related (at 1445 // least). 1446 1447 // C++ [dcl.init.ref]p4: 1448 // "cv1 T1” is reference-compatible with “cv2 T2” if T1 is 1449 // reference-related to T2 and cv1 is the same cv-qualification 1450 // as, or greater cv-qualification than, cv2. For purposes of 1451 // overload resolution, cases for which cv1 is greater 1452 // cv-qualification than cv2 are identified as 1453 // reference-compatible with added qualification (see 13.3.3.2). 1454 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1455 return Ref_Compatible; 1456 else if (T1.isMoreQualifiedThan(T2)) 1457 return Ref_Compatible_With_Added_Qualification; 1458 else 1459 return Ref_Related; 1460} 1461 1462/// CheckReferenceInit - Check the initialization of a reference 1463/// variable with the given initializer (C++ [dcl.init.ref]). Init is 1464/// the initializer (either a simple initializer or an initializer 1465/// list), and DeclType is the type of the declaration. When ICS is 1466/// non-null, this routine will compute the implicit conversion 1467/// sequence according to C++ [over.ics.ref] and will not produce any 1468/// diagnostics; when ICS is null, it will emit diagnostics when any 1469/// errors are found. Either way, a return value of true indicates 1470/// that there was a failure, a return value of false indicates that 1471/// the reference initialization succeeded. 1472/// 1473/// When @p SuppressUserConversions, user-defined conversions are 1474/// suppressed. 1475bool 1476Sema::CheckReferenceInit(Expr *&Init, QualType &DeclType, 1477 ImplicitConversionSequence *ICS, 1478 bool SuppressUserConversions) { 1479 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 1480 1481 QualType T1 = DeclType->getAsReferenceType()->getPointeeType(); 1482 QualType T2 = Init->getType(); 1483 1484 // If the initializer is the address of an overloaded function, try 1485 // to resolve the overloaded function. If all goes well, T2 is the 1486 // type of the resulting function. 1487 if (T2->isOverloadType()) { 1488 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Init, DeclType, 1489 ICS != 0); 1490 if (Fn) { 1491 // Since we're performing this reference-initialization for 1492 // real, update the initializer with the resulting function. 1493 if (!ICS) 1494 FixOverloadedFunctionReference(Init, Fn); 1495 1496 T2 = Fn->getType(); 1497 } 1498 } 1499 1500 // Compute some basic properties of the types and the initializer. 1501 bool DerivedToBase = false; 1502 Expr::isLvalueResult InitLvalue = Init->isLvalue(Context); 1503 ReferenceCompareResult RefRelationship 1504 = CompareReferenceRelationship(T1, T2, DerivedToBase); 1505 1506 // Most paths end in a failed conversion. 1507 if (ICS) 1508 ICS->ConversionKind = ImplicitConversionSequence::BadConversion; 1509 1510 // C++ [dcl.init.ref]p5: 1511 // A reference to type “cv1 T1” is initialized by an expression 1512 // of type “cv2 T2” as follows: 1513 1514 // -- If the initializer expression 1515 1516 bool BindsDirectly = false; 1517 // -- is an lvalue (but is not a bit-field), and “cv1 T1” is 1518 // reference-compatible with “cv2 T2,” or 1519 // 1520 // Note that the bit-field check is skipped if we are just computing 1521 // the implicit conversion sequence (C++ [over.best.ics]p2). 1522 if (InitLvalue == Expr::LV_Valid && (ICS || !Init->isBitField()) && 1523 RefRelationship >= Ref_Compatible_With_Added_Qualification) { 1524 BindsDirectly = true; 1525 1526 if (ICS) { 1527 // C++ [over.ics.ref]p1: 1528 // When a parameter of reference type binds directly (8.5.3) 1529 // to an argument expression, the implicit conversion sequence 1530 // is the identity conversion, unless the argument expression 1531 // has a type that is a derived class of the parameter type, 1532 // in which case the implicit conversion sequence is a 1533 // derived-to-base Conversion (13.3.3.1). 1534 ICS->ConversionKind = ImplicitConversionSequence::StandardConversion; 1535 ICS->Standard.First = ICK_Identity; 1536 ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 1537 ICS->Standard.Third = ICK_Identity; 1538 ICS->Standard.FromTypePtr = T2.getAsOpaquePtr(); 1539 ICS->Standard.ToTypePtr = T1.getAsOpaquePtr(); 1540 ICS->Standard.ReferenceBinding = true; 1541 ICS->Standard.DirectBinding = true; 1542 1543 // Nothing more to do: the inaccessibility/ambiguity check for 1544 // derived-to-base conversions is suppressed when we're 1545 // computing the implicit conversion sequence (C++ 1546 // [over.best.ics]p2). 1547 return false; 1548 } else { 1549 // Perform the conversion. 1550 // FIXME: Binding to a subobject of the lvalue is going to require 1551 // more AST annotation than this. 1552 ImpCastExprToType(Init, T1, /*isLvalue=*/true); 1553 } 1554 } 1555 1556 // -- has a class type (i.e., T2 is a class type) and can be 1557 // implicitly converted to an lvalue of type “cv3 T3,” 1558 // where “cv1 T1” is reference-compatible with “cv3 T3” 1559 // 92) (this conversion is selected by enumerating the 1560 // applicable conversion functions (13.3.1.6) and choosing 1561 // the best one through overload resolution (13.3)), 1562 if (!SuppressUserConversions && T2->isRecordType()) { 1563 // FIXME: Look for conversions in base classes! 1564 CXXRecordDecl *T2RecordDecl 1565 = dyn_cast<CXXRecordDecl>(T2->getAsRecordType()->getDecl()); 1566 1567 OverloadCandidateSet CandidateSet; 1568 OverloadedFunctionDecl *Conversions 1569 = T2RecordDecl->getConversionFunctions(); 1570 for (OverloadedFunctionDecl::function_iterator Func 1571 = Conversions->function_begin(); 1572 Func != Conversions->function_end(); ++Func) { 1573 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1574 1575 // If the conversion function doesn't return a reference type, 1576 // it can't be considered for this conversion. 1577 // FIXME: This will change when we support rvalue references. 1578 if (Conv->getConversionType()->isReferenceType()) 1579 AddConversionCandidate(Conv, Init, DeclType, CandidateSet); 1580 } 1581 1582 OverloadCandidateSet::iterator Best; 1583 switch (BestViableFunction(CandidateSet, Best)) { 1584 case OR_Success: 1585 // This is a direct binding. 1586 BindsDirectly = true; 1587 1588 if (ICS) { 1589 // C++ [over.ics.ref]p1: 1590 // 1591 // [...] If the parameter binds directly to the result of 1592 // applying a conversion function to the argument 1593 // expression, the implicit conversion sequence is a 1594 // user-defined conversion sequence (13.3.3.1.2), with the 1595 // second standard conversion sequence either an identity 1596 // conversion or, if the conversion function returns an 1597 // entity of a type that is a derived class of the parameter 1598 // type, a derived-to-base Conversion. 1599 ICS->ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 1600 ICS->UserDefined.Before = Best->Conversions[0].Standard; 1601 ICS->UserDefined.After = Best->FinalConversion; 1602 ICS->UserDefined.ConversionFunction = Best->Function; 1603 assert(ICS->UserDefined.After.ReferenceBinding && 1604 ICS->UserDefined.After.DirectBinding && 1605 "Expected a direct reference binding!"); 1606 return false; 1607 } else { 1608 // Perform the conversion. 1609 // FIXME: Binding to a subobject of the lvalue is going to require 1610 // more AST annotation than this. 1611 ImpCastExprToType(Init, T1, /*isLvalue=*/true); 1612 } 1613 break; 1614 1615 case OR_Ambiguous: 1616 assert(false && "Ambiguous reference binding conversions not implemented."); 1617 return true; 1618 1619 case OR_No_Viable_Function: 1620 // There was no suitable conversion; continue with other checks. 1621 break; 1622 } 1623 } 1624 1625 if (BindsDirectly) { 1626 // C++ [dcl.init.ref]p4: 1627 // [...] In all cases where the reference-related or 1628 // reference-compatible relationship of two types is used to 1629 // establish the validity of a reference binding, and T1 is a 1630 // base class of T2, a program that necessitates such a binding 1631 // is ill-formed if T1 is an inaccessible (clause 11) or 1632 // ambiguous (10.2) base class of T2. 1633 // 1634 // Note that we only check this condition when we're allowed to 1635 // complain about errors, because we should not be checking for 1636 // ambiguity (or inaccessibility) unless the reference binding 1637 // actually happens. 1638 if (DerivedToBase) 1639 return CheckDerivedToBaseConversion(T2, T1, 1640 Init->getSourceRange().getBegin(), 1641 Init->getSourceRange()); 1642 else 1643 return false; 1644 } 1645 1646 // -- Otherwise, the reference shall be to a non-volatile const 1647 // type (i.e., cv1 shall be const). 1648 if (T1.getCVRQualifiers() != QualType::Const) { 1649 if (!ICS) 1650 Diag(Init->getSourceRange().getBegin(), 1651 diag::err_not_reference_to_const_init) 1652 << T1 << (InitLvalue != Expr::LV_Valid? "temporary" : "value") 1653 << T2 << Init->getSourceRange(); 1654 return true; 1655 } 1656 1657 // -- If the initializer expression is an rvalue, with T2 a 1658 // class type, and “cv1 T1” is reference-compatible with 1659 // “cv2 T2,” the reference is bound in one of the 1660 // following ways (the choice is implementation-defined): 1661 // 1662 // -- The reference is bound to the object represented by 1663 // the rvalue (see 3.10) or to a sub-object within that 1664 // object. 1665 // 1666 // -- A temporary of type “cv1 T2” [sic] is created, and 1667 // a constructor is called to copy the entire rvalue 1668 // object into the temporary. The reference is bound to 1669 // the temporary or to a sub-object within the 1670 // temporary. 1671 // 1672 // 1673 // The constructor that would be used to make the copy 1674 // shall be callable whether or not the copy is actually 1675 // done. 1676 // 1677 // Note that C++0x [dcl.ref.init]p5 takes away this implementation 1678 // freedom, so we will always take the first option and never build 1679 // a temporary in this case. FIXME: We will, however, have to check 1680 // for the presence of a copy constructor in C++98/03 mode. 1681 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 1682 RefRelationship >= Ref_Compatible_With_Added_Qualification) { 1683 if (ICS) { 1684 ICS->ConversionKind = ImplicitConversionSequence::StandardConversion; 1685 ICS->Standard.First = ICK_Identity; 1686 ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 1687 ICS->Standard.Third = ICK_Identity; 1688 ICS->Standard.FromTypePtr = T2.getAsOpaquePtr(); 1689 ICS->Standard.ToTypePtr = T1.getAsOpaquePtr(); 1690 ICS->Standard.ReferenceBinding = true; 1691 ICS->Standard.DirectBinding = false; 1692 } else { 1693 // FIXME: Binding to a subobject of the rvalue is going to require 1694 // more AST annotation than this. 1695 ImpCastExprToType(Init, T1, /*isLvalue=*/true); 1696 } 1697 return false; 1698 } 1699 1700 // -- Otherwise, a temporary of type “cv1 T1” is created and 1701 // initialized from the initializer expression using the 1702 // rules for a non-reference copy initialization (8.5). The 1703 // reference is then bound to the temporary. If T1 is 1704 // reference-related to T2, cv1 must be the same 1705 // cv-qualification as, or greater cv-qualification than, 1706 // cv2; otherwise, the program is ill-formed. 1707 if (RefRelationship == Ref_Related) { 1708 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 1709 // we would be reference-compatible or reference-compatible with 1710 // added qualification. But that wasn't the case, so the reference 1711 // initialization fails. 1712 if (!ICS) 1713 Diag(Init->getSourceRange().getBegin(), 1714 diag::err_reference_init_drops_quals) 1715 << T1 << (InitLvalue != Expr::LV_Valid? "temporary" : "value") 1716 << T2 << Init->getSourceRange(); 1717 return true; 1718 } 1719 1720 // Actually try to convert the initializer to T1. 1721 if (ICS) { 1722 /// C++ [over.ics.ref]p2: 1723 /// 1724 /// When a parameter of reference type is not bound directly to 1725 /// an argument expression, the conversion sequence is the one 1726 /// required to convert the argument expression to the 1727 /// underlying type of the reference according to 1728 /// 13.3.3.1. Conceptually, this conversion sequence corresponds 1729 /// to copy-initializing a temporary of the underlying type with 1730 /// the argument expression. Any difference in top-level 1731 /// cv-qualification is subsumed by the initialization itself 1732 /// and does not constitute a conversion. 1733 *ICS = TryImplicitConversion(Init, T1, SuppressUserConversions); 1734 return ICS->ConversionKind == ImplicitConversionSequence::BadConversion; 1735 } else { 1736 return PerformImplicitConversion(Init, T1); 1737 } 1738} 1739 1740/// CheckOverloadedOperatorDeclaration - Check whether the declaration 1741/// of this overloaded operator is well-formed. If so, returns false; 1742/// otherwise, emits appropriate diagnostics and returns true. 1743bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) { 1744 assert(FnDecl && FnDecl->isOverloadedOperator() && 1745 "Expected an overloaded operator declaration"); 1746 1747 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator(); 1748 1749 // C++ [over.oper]p5: 1750 // The allocation and deallocation functions, operator new, 1751 // operator new[], operator delete and operator delete[], are 1752 // described completely in 3.7.3. The attributes and restrictions 1753 // found in the rest of this subclause do not apply to them unless 1754 // explicitly stated in 3.7.3. 1755 // FIXME: Write a separate routine for checking this. For now, just 1756 // allow it. 1757 if (Op == OO_New || Op == OO_Array_New || 1758 Op == OO_Delete || Op == OO_Array_Delete) 1759 return false; 1760 1761 // C++ [over.oper]p6: 1762 // An operator function shall either be a non-static member 1763 // function or be a non-member function and have at least one 1764 // parameter whose type is a class, a reference to a class, an 1765 // enumeration, or a reference to an enumeration. 1766 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) { 1767 if (MethodDecl->isStatic()) 1768 return Diag(FnDecl->getLocation(), 1769 diag::err_operator_overload_static) << FnDecl->getDeclName(); 1770 } else { 1771 bool ClassOrEnumParam = false; 1772 for (FunctionDecl::param_iterator Param = FnDecl->param_begin(), 1773 ParamEnd = FnDecl->param_end(); 1774 Param != ParamEnd; ++Param) { 1775 QualType ParamType = (*Param)->getType().getNonReferenceType(); 1776 if (ParamType->isRecordType() || ParamType->isEnumeralType()) { 1777 ClassOrEnumParam = true; 1778 break; 1779 } 1780 } 1781 1782 if (!ClassOrEnumParam) 1783 return Diag(FnDecl->getLocation(), 1784 diag::err_operator_overload_needs_class_or_enum) 1785 << FnDecl->getDeclName(); 1786 } 1787 1788 // C++ [over.oper]p8: 1789 // An operator function cannot have default arguments (8.3.6), 1790 // except where explicitly stated below. 1791 // 1792 // Only the function-call operator allows default arguments 1793 // (C++ [over.call]p1). 1794 if (Op != OO_Call) { 1795 for (FunctionDecl::param_iterator Param = FnDecl->param_begin(); 1796 Param != FnDecl->param_end(); ++Param) { 1797 if (Expr *DefArg = (*Param)->getDefaultArg()) 1798 return Diag((*Param)->getLocation(), 1799 diag::err_operator_overload_default_arg) 1800 << FnDecl->getDeclName() << DefArg->getSourceRange(); 1801 } 1802 } 1803 1804 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = { 1805 { false, false, false } 1806#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \ 1807 , { Unary, Binary, MemberOnly } 1808#include "clang/Basic/OperatorKinds.def" 1809 }; 1810 1811 bool CanBeUnaryOperator = OperatorUses[Op][0]; 1812 bool CanBeBinaryOperator = OperatorUses[Op][1]; 1813 bool MustBeMemberOperator = OperatorUses[Op][2]; 1814 1815 // C++ [over.oper]p8: 1816 // [...] Operator functions cannot have more or fewer parameters 1817 // than the number required for the corresponding operator, as 1818 // described in the rest of this subclause. 1819 unsigned NumParams = FnDecl->getNumParams() 1820 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0); 1821 if (Op != OO_Call && 1822 ((NumParams == 1 && !CanBeUnaryOperator) || 1823 (NumParams == 2 && !CanBeBinaryOperator) || 1824 (NumParams < 1) || (NumParams > 2))) { 1825 // We have the wrong number of parameters. 1826 unsigned ErrorKind; 1827 if (CanBeUnaryOperator && CanBeBinaryOperator) { 1828 ErrorKind = 2; // 2 -> unary or binary. 1829 } else if (CanBeUnaryOperator) { 1830 ErrorKind = 0; // 0 -> unary 1831 } else { 1832 assert(CanBeBinaryOperator && 1833 "All non-call overloaded operators are unary or binary!"); 1834 ErrorKind = 1; // 1 -> binary 1835 } 1836 1837 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be) 1838 << FnDecl->getDeclName() << NumParams << ErrorKind; 1839 } 1840 1841 // Overloaded operators other than operator() cannot be variadic. 1842 if (Op != OO_Call && 1843 FnDecl->getType()->getAsFunctionTypeProto()->isVariadic()) { 1844 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic) 1845 << FnDecl->getDeclName(); 1846 } 1847 1848 // Some operators must be non-static member functions. 1849 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) { 1850 return Diag(FnDecl->getLocation(), 1851 diag::err_operator_overload_must_be_member) 1852 << FnDecl->getDeclName(); 1853 } 1854 1855 // C++ [over.inc]p1: 1856 // The user-defined function called operator++ implements the 1857 // prefix and postfix ++ operator. If this function is a member 1858 // function with no parameters, or a non-member function with one 1859 // parameter of class or enumeration type, it defines the prefix 1860 // increment operator ++ for objects of that type. If the function 1861 // is a member function with one parameter (which shall be of type 1862 // int) or a non-member function with two parameters (the second 1863 // of which shall be of type int), it defines the postfix 1864 // increment operator ++ for objects of that type. 1865 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) { 1866 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1); 1867 bool ParamIsInt = false; 1868 if (const BuiltinType *BT = LastParam->getType()->getAsBuiltinType()) 1869 ParamIsInt = BT->getKind() == BuiltinType::Int; 1870 1871 if (!ParamIsInt) 1872 return Diag(LastParam->getLocation(), 1873 diag::err_operator_overload_post_incdec_must_be_int) 1874 << LastParam->getType() << (Op == OO_MinusMinus); 1875 } 1876 1877 return false; 1878} 1879