SemaDeclCXX.cpp revision 416e46febcb7084e715fbe0b9bf2cab7a85f5242
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->getName() << 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->getName() << 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::err_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().getAsString() 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(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, Loc, D, BitWidth)); 490 else 491 Member = static_cast<Decl*>(ActOnDeclarator(S, D, LastInGroup)); 492 493 if (!Member) return LastInGroup; 494 495 assert((Name || isInstField) && "No identifier for non-field ?"); 496 497 // set/getAccess is not part of Decl's interface to avoid bloating it with C++ 498 // specific methods. Use a wrapper class that can be used with all C++ class 499 // member decls. 500 CXXClassMemberWrapper(Member).setAccess(AS); 501 502 // C++ [dcl.init.aggr]p1: 503 // An aggregate is an array or a class (clause 9) with [...] no 504 // private or protected non-static data members (clause 11). 505 if (isInstField && (AS == AS_private || AS == AS_protected)) 506 cast<CXXRecordDecl>(CurContext)->setAggregate(false); 507 508 if (DS.isVirtualSpecified()) { 509 if (!isFunc || DS.getStorageClassSpec() == DeclSpec::SCS_static) { 510 Diag(DS.getVirtualSpecLoc(), diag::err_virtual_non_function); 511 InvalidDecl = true; 512 } else { 513 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(CurContext); 514 CurClass->setAggregate(false); 515 CurClass->setPolymorphic(true); 516 } 517 } 518 519 if (BitWidth) { 520 // C++ 9.6p2: Only when declaring an unnamed bit-field may the 521 // constant-expression be a value equal to zero. 522 // FIXME: Check this. 523 524 if (D.isFunctionDeclarator()) { 525 // FIXME: Emit diagnostic about only constructors taking base initializers 526 // or something similar, when constructor support is in place. 527 Diag(Loc, diag::err_not_bitfield_type) 528 << Name.getAsString() << BitWidth->getSourceRange(); 529 InvalidDecl = true; 530 531 } else if (isInstField) { 532 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 533 if (!cast<FieldDecl>(Member)->getType()->isIntegralType()) { 534 Diag(Loc, diag::err_not_integral_type_bitfield) 535 << Name.getAsString() << BitWidth->getSourceRange(); 536 InvalidDecl = true; 537 } 538 539 } else if (isa<FunctionDecl>(Member)) { 540 // A function typedef ("typedef int f(); f a;"). 541 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 542 Diag(Loc, diag::err_not_integral_type_bitfield) 543 << Name.getAsString() << BitWidth->getSourceRange(); 544 InvalidDecl = true; 545 546 } else if (isa<TypedefDecl>(Member)) { 547 // "cannot declare 'A' to be a bit-field type" 548 Diag(Loc, diag::err_not_bitfield_type) 549 << Name.getAsString() << BitWidth->getSourceRange(); 550 InvalidDecl = true; 551 552 } else { 553 assert(isa<CXXClassVarDecl>(Member) && 554 "Didn't we cover all member kinds?"); 555 // C++ 9.6p3: A bit-field shall not be a static member. 556 // "static member 'A' cannot be a bit-field" 557 Diag(Loc, diag::err_static_not_bitfield) 558 << Name.getAsString() << BitWidth->getSourceRange(); 559 InvalidDecl = true; 560 } 561 } 562 563 if (Init) { 564 // C++ 9.2p4: A member-declarator can contain a constant-initializer only 565 // if it declares a static member of const integral or const enumeration 566 // type. 567 if (CXXClassVarDecl *CVD = dyn_cast<CXXClassVarDecl>(Member)) { 568 // ...static member of... 569 CVD->setInit(Init); 570 // ...const integral or const enumeration type. 571 if (Context.getCanonicalType(CVD->getType()).isConstQualified() && 572 CVD->getType()->isIntegralType()) { 573 // constant-initializer 574 if (CheckForConstantInitializer(Init, CVD->getType())) 575 InvalidDecl = true; 576 577 } else { 578 // not const integral. 579 Diag(Loc, diag::err_member_initialization) 580 << Name.getAsString() << Init->getSourceRange(); 581 InvalidDecl = true; 582 } 583 584 } else { 585 // not static member. 586 Diag(Loc, diag::err_member_initialization) 587 << Name.getAsString() << Init->getSourceRange(); 588 InvalidDecl = true; 589 } 590 } 591 592 if (InvalidDecl) 593 Member->setInvalidDecl(); 594 595 if (isInstField) { 596 FieldCollector->Add(cast<CXXFieldDecl>(Member)); 597 return LastInGroup; 598 } 599 return Member; 600} 601 602/// ActOnMemInitializer - Handle a C++ member initializer. 603Sema::MemInitResult 604Sema::ActOnMemInitializer(DeclTy *ConstructorD, 605 Scope *S, 606 IdentifierInfo *MemberOrBase, 607 SourceLocation IdLoc, 608 SourceLocation LParenLoc, 609 ExprTy **Args, unsigned NumArgs, 610 SourceLocation *CommaLocs, 611 SourceLocation RParenLoc) { 612 CXXConstructorDecl *Constructor 613 = dyn_cast<CXXConstructorDecl>((Decl*)ConstructorD); 614 if (!Constructor) { 615 // The user wrote a constructor initializer on a function that is 616 // not a C++ constructor. Ignore the error for now, because we may 617 // have more member initializers coming; we'll diagnose it just 618 // once in ActOnMemInitializers. 619 return true; 620 } 621 622 CXXRecordDecl *ClassDecl = Constructor->getParent(); 623 624 // C++ [class.base.init]p2: 625 // Names in a mem-initializer-id are looked up in the scope of the 626 // constructor’s class and, if not found in that scope, are looked 627 // up in the scope containing the constructor’s 628 // definition. [Note: if the constructor’s class contains a member 629 // with the same name as a direct or virtual base class of the 630 // class, a mem-initializer-id naming the member or base class and 631 // composed of a single identifier refers to the class member. A 632 // mem-initializer-id for the hidden base class may be specified 633 // using a qualified name. ] 634 // Look for a member, first. 635 CXXFieldDecl *Member = ClassDecl->getMember(MemberOrBase); 636 637 // FIXME: Handle members of an anonymous union. 638 639 if (Member) { 640 // FIXME: Perform direct initialization of the member. 641 return new CXXBaseOrMemberInitializer(Member, (Expr **)Args, NumArgs); 642 } 643 644 // It didn't name a member, so see if it names a class. 645 TypeTy *BaseTy = isTypeName(*MemberOrBase, S, 0/*SS*/); 646 if (!BaseTy) 647 return Diag(IdLoc, diag::err_mem_init_not_member_or_class) 648 << MemberOrBase << SourceRange(IdLoc, RParenLoc); 649 650 QualType BaseType = Context.getTypeDeclType((TypeDecl *)BaseTy); 651 if (!BaseType->isRecordType()) 652 return Diag(IdLoc, diag::err_base_init_does_not_name_class) 653 << BaseType.getAsString() << SourceRange(IdLoc, RParenLoc); 654 655 // C++ [class.base.init]p2: 656 // [...] Unless the mem-initializer-id names a nonstatic data 657 // member of the constructor’s class or a direct or virtual base 658 // of that class, the mem-initializer is ill-formed. A 659 // mem-initializer-list can initialize a base class using any 660 // name that denotes that base class type. 661 662 // First, check for a direct base class. 663 const CXXBaseSpecifier *DirectBaseSpec = 0; 664 for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(); 665 Base != ClassDecl->bases_end(); ++Base) { 666 if (Context.getCanonicalType(BaseType).getUnqualifiedType() == 667 Context.getCanonicalType(Base->getType()).getUnqualifiedType()) { 668 // We found a direct base of this type. That's what we're 669 // initializing. 670 DirectBaseSpec = &*Base; 671 break; 672 } 673 } 674 675 // Check for a virtual base class. 676 // FIXME: We might be able to short-circuit this if we know in 677 // advance that there are no virtual bases. 678 const CXXBaseSpecifier *VirtualBaseSpec = 0; 679 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) { 680 // We haven't found a base yet; search the class hierarchy for a 681 // virtual base class. 682 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 683 /*DetectVirtual=*/false); 684 if (IsDerivedFrom(Context.getTypeDeclType(ClassDecl), BaseType, Paths)) { 685 for (BasePaths::paths_iterator Path = Paths.begin(); 686 Path != Paths.end(); ++Path) { 687 if (Path->back().Base->isVirtual()) { 688 VirtualBaseSpec = Path->back().Base; 689 break; 690 } 691 } 692 } 693 } 694 695 // C++ [base.class.init]p2: 696 // If a mem-initializer-id is ambiguous because it designates both 697 // a direct non-virtual base class and an inherited virtual base 698 // class, the mem-initializer is ill-formed. 699 if (DirectBaseSpec && VirtualBaseSpec) 700 return Diag(IdLoc, diag::err_base_init_direct_and_virtual) 701 << MemberOrBase << SourceRange(IdLoc, RParenLoc); 702 703 return new CXXBaseOrMemberInitializer(BaseType, (Expr **)Args, NumArgs); 704} 705 706 707void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc, 708 DeclTy *TagDecl, 709 SourceLocation LBrac, 710 SourceLocation RBrac) { 711 ActOnFields(S, RLoc, TagDecl, 712 (DeclTy**)FieldCollector->getCurFields(), 713 FieldCollector->getCurNumFields(), LBrac, RBrac, 0); 714} 715 716/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared 717/// special functions, such as the default constructor, copy 718/// constructor, or destructor, to the given C++ class (C++ 719/// [special]p1). This routine can only be executed just before the 720/// definition of the class is complete. 721void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) { 722 QualType ClassType = Context.getTypeDeclType(ClassDecl); 723 ClassType = Context.getCanonicalType(ClassType); 724 725 if (!ClassDecl->hasUserDeclaredConstructor()) { 726 // C++ [class.ctor]p5: 727 // A default constructor for a class X is a constructor of class X 728 // that can be called without an argument. If there is no 729 // user-declared constructor for class X, a default constructor is 730 // implicitly declared. An implicitly-declared default constructor 731 // is an inline public member of its class. 732 DeclarationName Name 733 = Context.DeclarationNames.getCXXConstructorName(ClassType); 734 CXXConstructorDecl *DefaultCon = 735 CXXConstructorDecl::Create(Context, ClassDecl, 736 ClassDecl->getLocation(), Name, 737 Context.getFunctionType(Context.VoidTy, 738 0, 0, false, 0), 739 /*isExplicit=*/false, 740 /*isInline=*/true, 741 /*isImplicitlyDeclared=*/true); 742 DefaultCon->setAccess(AS_public); 743 ClassDecl->addConstructor(Context, DefaultCon); 744 } 745 746 if (!ClassDecl->hasUserDeclaredCopyConstructor()) { 747 // C++ [class.copy]p4: 748 // If the class definition does not explicitly declare a copy 749 // constructor, one is declared implicitly. 750 751 // C++ [class.copy]p5: 752 // The implicitly-declared copy constructor for a class X will 753 // have the form 754 // 755 // X::X(const X&) 756 // 757 // if 758 bool HasConstCopyConstructor = true; 759 760 // -- each direct or virtual base class B of X has a copy 761 // constructor whose first parameter is of type const B& or 762 // const volatile B&, and 763 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 764 HasConstCopyConstructor && Base != ClassDecl->bases_end(); ++Base) { 765 const CXXRecordDecl *BaseClassDecl 766 = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl()); 767 HasConstCopyConstructor 768 = BaseClassDecl->hasConstCopyConstructor(Context); 769 } 770 771 // -- for all the nonstatic data members of X that are of a 772 // class type M (or array thereof), each such class type 773 // has a copy constructor whose first parameter is of type 774 // const M& or const volatile M&. 775 for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(); 776 HasConstCopyConstructor && Field != ClassDecl->field_end(); ++Field) { 777 QualType FieldType = (*Field)->getType(); 778 if (const ArrayType *Array = Context.getAsArrayType(FieldType)) 779 FieldType = Array->getElementType(); 780 if (const RecordType *FieldClassType = FieldType->getAsRecordType()) { 781 const CXXRecordDecl *FieldClassDecl 782 = cast<CXXRecordDecl>(FieldClassType->getDecl()); 783 HasConstCopyConstructor 784 = FieldClassDecl->hasConstCopyConstructor(Context); 785 } 786 } 787 788 // Otherwise, the implicitly declared copy constructor will have 789 // the form 790 // 791 // X::X(X&) 792 QualType ArgType = Context.getTypeDeclType(ClassDecl); 793 if (HasConstCopyConstructor) 794 ArgType = ArgType.withConst(); 795 ArgType = Context.getReferenceType(ArgType); 796 797 // An implicitly-declared copy constructor is an inline public 798 // member of its class. 799 DeclarationName Name 800 = Context.DeclarationNames.getCXXConstructorName(ClassType); 801 CXXConstructorDecl *CopyConstructor 802 = CXXConstructorDecl::Create(Context, ClassDecl, 803 ClassDecl->getLocation(), Name, 804 Context.getFunctionType(Context.VoidTy, 805 &ArgType, 1, 806 false, 0), 807 /*isExplicit=*/false, 808 /*isInline=*/true, 809 /*isImplicitlyDeclared=*/true); 810 CopyConstructor->setAccess(AS_public); 811 812 // Add the parameter to the constructor. 813 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor, 814 ClassDecl->getLocation(), 815 /*IdentifierInfo=*/0, 816 ArgType, VarDecl::None, 0, 0); 817 CopyConstructor->setParams(&FromParam, 1); 818 819 ClassDecl->addConstructor(Context, CopyConstructor); 820 } 821 822 if (!ClassDecl->getDestructor()) { 823 // C++ [class.dtor]p2: 824 // If a class has no user-declared destructor, a destructor is 825 // declared implicitly. An implicitly-declared destructor is an 826 // inline public member of its class. 827 DeclarationName Name 828 = Context.DeclarationNames.getCXXDestructorName(ClassType); 829 CXXDestructorDecl *Destructor 830 = CXXDestructorDecl::Create(Context, ClassDecl, 831 ClassDecl->getLocation(), Name, 832 Context.getFunctionType(Context.VoidTy, 833 0, 0, false, 0), 834 /*isInline=*/true, 835 /*isImplicitlyDeclared=*/true); 836 Destructor->setAccess(AS_public); 837 ClassDecl->setDestructor(Destructor); 838 } 839 840 // FIXME: Implicit copy assignment operator 841} 842 843void Sema::ActOnFinishCXXClassDef(DeclTy *D) { 844 CXXRecordDecl *Rec = cast<CXXRecordDecl>(static_cast<Decl *>(D)); 845 FieldCollector->FinishClass(); 846 AddImplicitlyDeclaredMembersToClass(Rec); 847 PopDeclContext(); 848 849 // Everything, including inline method definitions, have been parsed. 850 // Let the consumer know of the new TagDecl definition. 851 Consumer.HandleTagDeclDefinition(Rec); 852} 853 854/// CheckConstructorDeclarator - Called by ActOnDeclarator to check 855/// the well-formednes of the constructor declarator @p D with type @p 856/// R. If there are any errors in the declarator, this routine will 857/// emit diagnostics and return true. Otherwise, it will return 858/// false. Either way, the type @p R will be updated to reflect a 859/// well-formed type for the constructor. 860bool Sema::CheckConstructorDeclarator(Declarator &D, QualType &R, 861 FunctionDecl::StorageClass& SC) { 862 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 863 bool isInvalid = false; 864 865 // C++ [class.ctor]p3: 866 // A constructor shall not be virtual (10.3) or static (9.4). A 867 // constructor can be invoked for a const, volatile or const 868 // volatile object. A constructor shall not be declared const, 869 // volatile, or const volatile (9.3.2). 870 if (isVirtual) { 871 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) 872 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc()) 873 << SourceRange(D.getIdentifierLoc()); 874 isInvalid = true; 875 } 876 if (SC == FunctionDecl::Static) { 877 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) 878 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 879 << SourceRange(D.getIdentifierLoc()); 880 isInvalid = true; 881 SC = FunctionDecl::None; 882 } 883 if (D.getDeclSpec().hasTypeSpecifier()) { 884 // Constructors don't have return types, but the parser will 885 // happily parse something like: 886 // 887 // class X { 888 // float X(float); 889 // }; 890 // 891 // The return type will be eliminated later. 892 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 893 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 894 << SourceRange(D.getIdentifierLoc()); 895 } 896 if (R->getAsFunctionTypeProto()->getTypeQuals() != 0) { 897 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 898 if (FTI.TypeQuals & QualType::Const) 899 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) 900 << "const" << SourceRange(D.getIdentifierLoc()); 901 if (FTI.TypeQuals & QualType::Volatile) 902 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) 903 << "volatile" << SourceRange(D.getIdentifierLoc()); 904 if (FTI.TypeQuals & QualType::Restrict) 905 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) 906 << "restrict" << SourceRange(D.getIdentifierLoc()); 907 } 908 909 // Rebuild the function type "R" without any type qualifiers (in 910 // case any of the errors above fired) and with "void" as the 911 // return type, since constructors don't have return types. We 912 // *always* have to do this, because GetTypeForDeclarator will 913 // put in a result type of "int" when none was specified. 914 const FunctionTypeProto *Proto = R->getAsFunctionTypeProto(); 915 R = Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(), 916 Proto->getNumArgs(), 917 Proto->isVariadic(), 918 0); 919 920 return isInvalid; 921} 922 923/// CheckDestructorDeclarator - Called by ActOnDeclarator to check 924/// the well-formednes of the destructor declarator @p D with type @p 925/// R. If there are any errors in the declarator, this routine will 926/// emit diagnostics and return true. Otherwise, it will return 927/// false. Either way, the type @p R will be updated to reflect a 928/// well-formed type for the destructor. 929bool Sema::CheckDestructorDeclarator(Declarator &D, QualType &R, 930 FunctionDecl::StorageClass& SC) { 931 bool isInvalid = false; 932 933 // C++ [class.dtor]p1: 934 // [...] A typedef-name that names a class is a class-name 935 // (7.1.3); however, a typedef-name that names a class shall not 936 // be used as the identifier in the declarator for a destructor 937 // declaration. 938 TypeDecl *DeclaratorTypeD = (TypeDecl *)D.getDeclaratorIdType(); 939 if (const TypedefDecl *TypedefD = dyn_cast<TypedefDecl>(DeclaratorTypeD)) { 940 Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name) 941 << TypedefD->getName(); 942 isInvalid = true; 943 } 944 945 // C++ [class.dtor]p2: 946 // A destructor is used to destroy objects of its class type. A 947 // destructor takes no parameters, and no return type can be 948 // specified for it (not even void). The address of a destructor 949 // shall not be taken. A destructor shall not be static. A 950 // destructor can be invoked for a const, volatile or const 951 // volatile object. A destructor shall not be declared const, 952 // volatile or const volatile (9.3.2). 953 if (SC == FunctionDecl::Static) { 954 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be) 955 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 956 << SourceRange(D.getIdentifierLoc()); 957 isInvalid = true; 958 SC = FunctionDecl::None; 959 } 960 if (D.getDeclSpec().hasTypeSpecifier()) { 961 // Destructors don't have return types, but the parser will 962 // happily parse something like: 963 // 964 // class X { 965 // float ~X(); 966 // }; 967 // 968 // The return type will be eliminated later. 969 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type) 970 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 971 << SourceRange(D.getIdentifierLoc()); 972 } 973 if (R->getAsFunctionTypeProto()->getTypeQuals() != 0) { 974 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 975 if (FTI.TypeQuals & QualType::Const) 976 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) 977 << "const" << SourceRange(D.getIdentifierLoc()); 978 if (FTI.TypeQuals & QualType::Volatile) 979 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) 980 << "volatile" << SourceRange(D.getIdentifierLoc()); 981 if (FTI.TypeQuals & QualType::Restrict) 982 Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) 983 << "restrict" << SourceRange(D.getIdentifierLoc()); 984 } 985 986 // Make sure we don't have any parameters. 987 if (R->getAsFunctionTypeProto()->getNumArgs() > 0) { 988 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params); 989 990 // Delete the parameters. 991 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 992 if (FTI.NumArgs) { 993 delete [] FTI.ArgInfo; 994 FTI.NumArgs = 0; 995 FTI.ArgInfo = 0; 996 } 997 } 998 999 // Make sure the destructor isn't variadic. 1000 if (R->getAsFunctionTypeProto()->isVariadic()) 1001 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic); 1002 1003 // Rebuild the function type "R" without any type qualifiers or 1004 // parameters (in case any of the errors above fired) and with 1005 // "void" as the return type, since destructors don't have return 1006 // types. We *always* have to do this, because GetTypeForDeclarator 1007 // will put in a result type of "int" when none was specified. 1008 R = Context.getFunctionType(Context.VoidTy, 0, 0, false, 0); 1009 1010 return isInvalid; 1011} 1012 1013/// CheckConversionDeclarator - Called by ActOnDeclarator to check the 1014/// well-formednes of the conversion function declarator @p D with 1015/// type @p R. If there are any errors in the declarator, this routine 1016/// will emit diagnostics and return true. Otherwise, it will return 1017/// false. Either way, the type @p R will be updated to reflect a 1018/// well-formed type for the conversion operator. 1019bool Sema::CheckConversionDeclarator(Declarator &D, QualType &R, 1020 FunctionDecl::StorageClass& SC) { 1021 bool isInvalid = false; 1022 1023 // C++ [class.conv.fct]p1: 1024 // Neither parameter types nor return type can be specified. The 1025 // type of a conversion function (8.3.5) is “function taking no 1026 // parameter returning conversion-type-id.” 1027 if (SC == FunctionDecl::Static) { 1028 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member) 1029 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 1030 << SourceRange(D.getIdentifierLoc()); 1031 isInvalid = true; 1032 SC = FunctionDecl::None; 1033 } 1034 if (D.getDeclSpec().hasTypeSpecifier()) { 1035 // Conversion functions don't have return types, but the parser will 1036 // happily parse something like: 1037 // 1038 // class X { 1039 // float operator bool(); 1040 // }; 1041 // 1042 // The return type will be changed later anyway. 1043 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type) 1044 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 1045 << SourceRange(D.getIdentifierLoc()); 1046 } 1047 1048 // Make sure we don't have any parameters. 1049 if (R->getAsFunctionTypeProto()->getNumArgs() > 0) { 1050 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params); 1051 1052 // Delete the parameters. 1053 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1054 if (FTI.NumArgs) { 1055 delete [] FTI.ArgInfo; 1056 FTI.NumArgs = 0; 1057 FTI.ArgInfo = 0; 1058 } 1059 } 1060 1061 // Make sure the conversion function isn't variadic. 1062 if (R->getAsFunctionTypeProto()->isVariadic()) 1063 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic); 1064 1065 // C++ [class.conv.fct]p4: 1066 // The conversion-type-id shall not represent a function type nor 1067 // an array type. 1068 QualType ConvType = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1069 if (ConvType->isArrayType()) { 1070 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array); 1071 ConvType = Context.getPointerType(ConvType); 1072 } else if (ConvType->isFunctionType()) { 1073 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function); 1074 ConvType = Context.getPointerType(ConvType); 1075 } 1076 1077 // Rebuild the function type "R" without any parameters (in case any 1078 // of the errors above fired) and with the conversion type as the 1079 // return type. 1080 R = Context.getFunctionType(ConvType, 0, 0, false, 1081 R->getAsFunctionTypeProto()->getTypeQuals()); 1082 1083 return isInvalid; 1084} 1085 1086/// ActOnConstructorDeclarator - Called by ActOnDeclarator to complete 1087/// the declaration of the given C++ constructor ConDecl that was 1088/// built from declarator D. This routine is responsible for checking 1089/// that the newly-created constructor declaration is well-formed and 1090/// for recording it in the C++ class. Example: 1091/// 1092/// @code 1093/// class X { 1094/// X(); // X::X() will be the ConDecl. 1095/// }; 1096/// @endcode 1097Sema::DeclTy *Sema::ActOnConstructorDeclarator(CXXConstructorDecl *ConDecl) { 1098 assert(ConDecl && "Expected to receive a constructor declaration"); 1099 1100 // Check default arguments on the constructor 1101 CheckCXXDefaultArguments(ConDecl); 1102 1103 CXXRecordDecl *ClassDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext); 1104 if (!ClassDecl) { 1105 ConDecl->setInvalidDecl(); 1106 return ConDecl; 1107 } 1108 1109 // Make sure this constructor is an overload of the existing 1110 // constructors. 1111 OverloadedFunctionDecl::function_iterator MatchedDecl; 1112 if (!IsOverload(ConDecl, ClassDecl->getConstructors(), MatchedDecl)) { 1113 Diag(ConDecl->getLocation(), diag::err_constructor_redeclared) 1114 << SourceRange(ConDecl->getLocation()); 1115 Diag((*MatchedDecl)->getLocation(), diag::err_previous_declaration) 1116 << SourceRange((*MatchedDecl)->getLocation()); 1117 ConDecl->setInvalidDecl(); 1118 return ConDecl; 1119 } 1120 1121 1122 // C++ [class.copy]p3: 1123 // A declaration of a constructor for a class X is ill-formed if 1124 // its first parameter is of type (optionally cv-qualified) X and 1125 // either there are no other parameters or else all other 1126 // parameters have default arguments. 1127 if ((ConDecl->getNumParams() == 1) || 1128 (ConDecl->getNumParams() > 1 && 1129 ConDecl->getParamDecl(1)->getDefaultArg() != 0)) { 1130 QualType ParamType = ConDecl->getParamDecl(0)->getType(); 1131 QualType ClassTy = Context.getTagDeclType( 1132 const_cast<CXXRecordDecl*>(ConDecl->getParent())); 1133 if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) { 1134 Diag(ConDecl->getLocation(), diag::err_constructor_byvalue_arg) 1135 << SourceRange(ConDecl->getParamDecl(0)->getLocation()); 1136 ConDecl->setInvalidDecl(); 1137 return ConDecl; 1138 } 1139 } 1140 1141 // Add this constructor to the set of constructors of the current 1142 // class. 1143 ClassDecl->addConstructor(Context, ConDecl); 1144 return (DeclTy *)ConDecl; 1145} 1146 1147/// ActOnDestructorDeclarator - Called by ActOnDeclarator to complete 1148/// the declaration of the given C++ @p Destructor. This routine is 1149/// responsible for recording the destructor in the C++ class, if 1150/// possible. 1151Sema::DeclTy *Sema::ActOnDestructorDeclarator(CXXDestructorDecl *Destructor) { 1152 assert(Destructor && "Expected to receive a destructor declaration"); 1153 1154 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(CurContext); 1155 1156 // Make sure we aren't redeclaring the destructor. 1157 if (CXXDestructorDecl *PrevDestructor = ClassDecl->getDestructor()) { 1158 Diag(Destructor->getLocation(), diag::err_destructor_redeclared); 1159 Diag(PrevDestructor->getLocation(), 1160 PrevDestructor->isThisDeclarationADefinition()? 1161 diag::err_previous_definition 1162 : diag::err_previous_declaration); 1163 Destructor->setInvalidDecl(); 1164 return Destructor; 1165 } 1166 1167 ClassDecl->setDestructor(Destructor); 1168 return (DeclTy *)Destructor; 1169} 1170 1171/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete 1172/// the declaration of the given C++ conversion function. This routine 1173/// is responsible for recording the conversion function in the C++ 1174/// class, if possible. 1175Sema::DeclTy *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) { 1176 assert(Conversion && "Expected to receive a conversion function declaration"); 1177 1178 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(CurContext); 1179 1180 // Make sure we aren't redeclaring the conversion function. 1181 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType()); 1182 OverloadedFunctionDecl *Conversions = ClassDecl->getConversionFunctions(); 1183 for (OverloadedFunctionDecl::function_iterator Func 1184 = Conversions->function_begin(); 1185 Func != Conversions->function_end(); ++Func) { 1186 CXXConversionDecl *OtherConv = cast<CXXConversionDecl>(*Func); 1187 if (ConvType == Context.getCanonicalType(OtherConv->getConversionType())) { 1188 Diag(Conversion->getLocation(), diag::err_conv_function_redeclared); 1189 Diag(OtherConv->getLocation(), 1190 OtherConv->isThisDeclarationADefinition()? 1191 diag::err_previous_definition 1192 : diag::err_previous_declaration); 1193 Conversion->setInvalidDecl(); 1194 return (DeclTy *)Conversion; 1195 } 1196 } 1197 1198 // C++ [class.conv.fct]p1: 1199 // [...] A conversion function is never used to convert a 1200 // (possibly cv-qualified) object to the (possibly cv-qualified) 1201 // same object type (or a reference to it), to a (possibly 1202 // cv-qualified) base class of that type (or a reference to it), 1203 // or to (possibly cv-qualified) void. 1204 // FIXME: Suppress this warning if the conversion function ends up 1205 // being a virtual function that overrides a virtual function in a 1206 // base class. 1207 QualType ClassType 1208 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); 1209 if (const ReferenceType *ConvTypeRef = ConvType->getAsReferenceType()) 1210 ConvType = ConvTypeRef->getPointeeType(); 1211 if (ConvType->isRecordType()) { 1212 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType(); 1213 if (ConvType == ClassType) 1214 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used) 1215 << ClassType.getAsString(); 1216 else if (IsDerivedFrom(ClassType, ConvType)) 1217 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used) 1218 << ClassType.getAsString() << ConvType.getAsString(); 1219 } else if (ConvType->isVoidType()) { 1220 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used) 1221 << ClassType.getAsString() << ConvType.getAsString(); 1222 } 1223 1224 ClassDecl->addConversionFunction(Context, Conversion); 1225 1226 return (DeclTy *)Conversion; 1227} 1228 1229//===----------------------------------------------------------------------===// 1230// Namespace Handling 1231//===----------------------------------------------------------------------===// 1232 1233/// ActOnStartNamespaceDef - This is called at the start of a namespace 1234/// definition. 1235Sema::DeclTy *Sema::ActOnStartNamespaceDef(Scope *NamespcScope, 1236 SourceLocation IdentLoc, 1237 IdentifierInfo *II, 1238 SourceLocation LBrace) { 1239 NamespaceDecl *Namespc = 1240 NamespaceDecl::Create(Context, CurContext, IdentLoc, II); 1241 Namespc->setLBracLoc(LBrace); 1242 1243 Scope *DeclRegionScope = NamespcScope->getParent(); 1244 1245 if (II) { 1246 // C++ [namespace.def]p2: 1247 // The identifier in an original-namespace-definition shall not have been 1248 // previously defined in the declarative region in which the 1249 // original-namespace-definition appears. The identifier in an 1250 // original-namespace-definition is the name of the namespace. Subsequently 1251 // in that declarative region, it is treated as an original-namespace-name. 1252 1253 Decl *PrevDecl = 1254 LookupDecl(II, Decl::IDNS_Tag | Decl::IDNS_Ordinary, DeclRegionScope, 0, 1255 /*enableLazyBuiltinCreation=*/false); 1256 1257 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, DeclRegionScope)) { 1258 if (NamespaceDecl *OrigNS = dyn_cast<NamespaceDecl>(PrevDecl)) { 1259 // This is an extended namespace definition. 1260 // Attach this namespace decl to the chain of extended namespace 1261 // definitions. 1262 NamespaceDecl *NextNS = OrigNS; 1263 while (NextNS->getNextNamespace()) 1264 NextNS = NextNS->getNextNamespace(); 1265 1266 NextNS->setNextNamespace(Namespc); 1267 Namespc->setOriginalNamespace(OrigNS); 1268 1269 // We won't add this decl to the current scope. We want the namespace 1270 // name to return the original namespace decl during a name lookup. 1271 } else { 1272 // This is an invalid name redefinition. 1273 Diag(Namespc->getLocation(), diag::err_redefinition_different_kind) 1274 << Namespc->getName(); 1275 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1276 Namespc->setInvalidDecl(); 1277 // Continue on to push Namespc as current DeclContext and return it. 1278 } 1279 } else { 1280 // This namespace name is declared for the first time. 1281 PushOnScopeChains(Namespc, DeclRegionScope); 1282 } 1283 } 1284 else { 1285 // FIXME: Handle anonymous namespaces 1286 } 1287 1288 // Although we could have an invalid decl (i.e. the namespace name is a 1289 // redefinition), push it as current DeclContext and try to continue parsing. 1290 PushDeclContext(Namespc->getOriginalNamespace()); 1291 return Namespc; 1292} 1293 1294/// ActOnFinishNamespaceDef - This callback is called after a namespace is 1295/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef. 1296void Sema::ActOnFinishNamespaceDef(DeclTy *D, SourceLocation RBrace) { 1297 Decl *Dcl = static_cast<Decl *>(D); 1298 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl); 1299 assert(Namespc && "Invalid parameter, expected NamespaceDecl"); 1300 Namespc->setRBracLoc(RBrace); 1301 PopDeclContext(); 1302} 1303 1304 1305/// AddCXXDirectInitializerToDecl - This action is called immediately after 1306/// ActOnDeclarator, when a C++ direct initializer is present. 1307/// e.g: "int x(1);" 1308void Sema::AddCXXDirectInitializerToDecl(DeclTy *Dcl, SourceLocation LParenLoc, 1309 ExprTy **ExprTys, unsigned NumExprs, 1310 SourceLocation *CommaLocs, 1311 SourceLocation RParenLoc) { 1312 assert(NumExprs != 0 && ExprTys && "missing expressions"); 1313 Decl *RealDecl = static_cast<Decl *>(Dcl); 1314 1315 // If there is no declaration, there was an error parsing it. Just ignore 1316 // the initializer. 1317 if (RealDecl == 0) { 1318 for (unsigned i = 0; i != NumExprs; ++i) 1319 delete static_cast<Expr *>(ExprTys[i]); 1320 return; 1321 } 1322 1323 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1324 if (!VDecl) { 1325 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 1326 RealDecl->setInvalidDecl(); 1327 return; 1328 } 1329 1330 // We will treat direct-initialization as a copy-initialization: 1331 // int x(1); -as-> int x = 1; 1332 // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c); 1333 // 1334 // Clients that want to distinguish between the two forms, can check for 1335 // direct initializer using VarDecl::hasCXXDirectInitializer(). 1336 // A major benefit is that clients that don't particularly care about which 1337 // exactly form was it (like the CodeGen) can handle both cases without 1338 // special case code. 1339 1340 // C++ 8.5p11: 1341 // The form of initialization (using parentheses or '=') is generally 1342 // insignificant, but does matter when the entity being initialized has a 1343 // class type. 1344 QualType DeclInitType = VDecl->getType(); 1345 if (const ArrayType *Array = Context.getAsArrayType(DeclInitType)) 1346 DeclInitType = Array->getElementType(); 1347 1348 if (VDecl->getType()->isRecordType()) { 1349 CXXConstructorDecl *Constructor 1350 = PerformInitializationByConstructor(DeclInitType, 1351 (Expr **)ExprTys, NumExprs, 1352 VDecl->getLocation(), 1353 SourceRange(VDecl->getLocation(), 1354 RParenLoc), 1355 VDecl->getName(), 1356 IK_Direct); 1357 if (!Constructor) { 1358 RealDecl->setInvalidDecl(); 1359 } 1360 1361 // Let clients know that initialization was done with a direct 1362 // initializer. 1363 VDecl->setCXXDirectInitializer(true); 1364 1365 // FIXME: Add ExprTys and Constructor to the RealDecl as part of 1366 // the initializer. 1367 return; 1368 } 1369 1370 if (NumExprs > 1) { 1371 Diag(CommaLocs[0], diag::err_builtin_direct_init_more_than_one_arg) 1372 << SourceRange(VDecl->getLocation(), RParenLoc); 1373 RealDecl->setInvalidDecl(); 1374 return; 1375 } 1376 1377 // Let clients know that initialization was done with a direct initializer. 1378 VDecl->setCXXDirectInitializer(true); 1379 1380 assert(NumExprs == 1 && "Expected 1 expression"); 1381 // Set the init expression, handles conversions. 1382 AddInitializerToDecl(Dcl, ExprTys[0]); 1383} 1384 1385/// PerformInitializationByConstructor - Perform initialization by 1386/// constructor (C++ [dcl.init]p14), which may occur as part of 1387/// direct-initialization or copy-initialization. We are initializing 1388/// an object of type @p ClassType with the given arguments @p 1389/// Args. @p Loc is the location in the source code where the 1390/// initializer occurs (e.g., a declaration, member initializer, 1391/// functional cast, etc.) while @p Range covers the whole 1392/// initialization. @p InitEntity is the entity being initialized, 1393/// which may by the name of a declaration or a type. @p Kind is the 1394/// kind of initialization we're performing, which affects whether 1395/// explicit constructors will be considered. When successful, returns 1396/// the constructor that will be used to perform the initialization; 1397/// when the initialization fails, emits a diagnostic and returns 1398/// null. 1399CXXConstructorDecl * 1400Sema::PerformInitializationByConstructor(QualType ClassType, 1401 Expr **Args, unsigned NumArgs, 1402 SourceLocation Loc, SourceRange Range, 1403 std::string InitEntity, 1404 InitializationKind Kind) { 1405 const RecordType *ClassRec = ClassType->getAsRecordType(); 1406 assert(ClassRec && "Can only initialize a class type here"); 1407 1408 // C++ [dcl.init]p14: 1409 // 1410 // If the initialization is direct-initialization, or if it is 1411 // copy-initialization where the cv-unqualified version of the 1412 // source type is the same class as, or a derived class of, the 1413 // class of the destination, constructors are considered. The 1414 // applicable constructors are enumerated (13.3.1.3), and the 1415 // best one is chosen through overload resolution (13.3). The 1416 // constructor so selected is called to initialize the object, 1417 // with the initializer expression(s) as its argument(s). If no 1418 // constructor applies, or the overload resolution is ambiguous, 1419 // the initialization is ill-formed. 1420 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 1421 OverloadCandidateSet CandidateSet; 1422 1423 // Add constructors to the overload set. 1424 OverloadedFunctionDecl *Constructors 1425 = const_cast<OverloadedFunctionDecl *>(ClassDecl->getConstructors()); 1426 for (OverloadedFunctionDecl::function_iterator Con 1427 = Constructors->function_begin(); 1428 Con != Constructors->function_end(); ++Con) { 1429 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1430 if ((Kind == IK_Direct) || 1431 (Kind == IK_Copy && Constructor->isConvertingConstructor()) || 1432 (Kind == IK_Default && Constructor->isDefaultConstructor())) 1433 AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet); 1434 } 1435 1436 OverloadCandidateSet::iterator Best; 1437 switch (BestViableFunction(CandidateSet, Best)) { 1438 case OR_Success: 1439 // We found a constructor. Return it. 1440 return cast<CXXConstructorDecl>(Best->Function); 1441 1442 case OR_No_Viable_Function: 1443 if (CandidateSet.empty()) 1444 Diag(Loc, diag::err_ovl_no_viable_function_in_init) << InitEntity <<Range; 1445 else { 1446 Diag(Loc, diag::err_ovl_no_viable_function_in_init_with_cands) 1447 << InitEntity << Range; 1448 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1449 } 1450 return 0; 1451 1452 case OR_Ambiguous: 1453 Diag(Loc, diag::err_ovl_ambiguous_init) << InitEntity << Range; 1454 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 1455 return 0; 1456 } 1457 1458 return 0; 1459} 1460 1461/// CompareReferenceRelationship - Compare the two types T1 and T2 to 1462/// determine whether they are reference-related, 1463/// reference-compatible, reference-compatible with added 1464/// qualification, or incompatible, for use in C++ initialization by 1465/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 1466/// type, and the first type (T1) is the pointee type of the reference 1467/// type being initialized. 1468Sema::ReferenceCompareResult 1469Sema::CompareReferenceRelationship(QualType T1, QualType T2, 1470 bool& DerivedToBase) { 1471 assert(!T1->isReferenceType() && "T1 must be the pointee type of the reference type"); 1472 assert(!T2->isReferenceType() && "T2 cannot be a reference type"); 1473 1474 T1 = Context.getCanonicalType(T1); 1475 T2 = Context.getCanonicalType(T2); 1476 QualType UnqualT1 = T1.getUnqualifiedType(); 1477 QualType UnqualT2 = T2.getUnqualifiedType(); 1478 1479 // C++ [dcl.init.ref]p4: 1480 // Given types “cv1 T1” and “cv2 T2,” “cv1 T1” is 1481 // reference-related to “cv2 T2” if T1 is the same type as T2, or 1482 // T1 is a base class of T2. 1483 if (UnqualT1 == UnqualT2) 1484 DerivedToBase = false; 1485 else if (IsDerivedFrom(UnqualT2, UnqualT1)) 1486 DerivedToBase = true; 1487 else 1488 return Ref_Incompatible; 1489 1490 // At this point, we know that T1 and T2 are reference-related (at 1491 // least). 1492 1493 // C++ [dcl.init.ref]p4: 1494 // "cv1 T1” is reference-compatible with “cv2 T2” if T1 is 1495 // reference-related to T2 and cv1 is the same cv-qualification 1496 // as, or greater cv-qualification than, cv2. For purposes of 1497 // overload resolution, cases for which cv1 is greater 1498 // cv-qualification than cv2 are identified as 1499 // reference-compatible with added qualification (see 13.3.3.2). 1500 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1501 return Ref_Compatible; 1502 else if (T1.isMoreQualifiedThan(T2)) 1503 return Ref_Compatible_With_Added_Qualification; 1504 else 1505 return Ref_Related; 1506} 1507 1508/// CheckReferenceInit - Check the initialization of a reference 1509/// variable with the given initializer (C++ [dcl.init.ref]). Init is 1510/// the initializer (either a simple initializer or an initializer 1511/// list), and DeclType is the type of the declaration. When ICS is 1512/// non-null, this routine will compute the implicit conversion 1513/// sequence according to C++ [over.ics.ref] and will not produce any 1514/// diagnostics; when ICS is null, it will emit diagnostics when any 1515/// errors are found. Either way, a return value of true indicates 1516/// that there was a failure, a return value of false indicates that 1517/// the reference initialization succeeded. 1518/// 1519/// When @p SuppressUserConversions, user-defined conversions are 1520/// suppressed. 1521bool 1522Sema::CheckReferenceInit(Expr *&Init, QualType &DeclType, 1523 ImplicitConversionSequence *ICS, 1524 bool SuppressUserConversions) { 1525 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 1526 1527 QualType T1 = DeclType->getAsReferenceType()->getPointeeType(); 1528 QualType T2 = Init->getType(); 1529 1530 // If the initializer is the address of an overloaded function, try 1531 // to resolve the overloaded function. If all goes well, T2 is the 1532 // type of the resulting function. 1533 if (T2->isOverloadType()) { 1534 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Init, DeclType, 1535 ICS != 0); 1536 if (Fn) { 1537 // Since we're performing this reference-initialization for 1538 // real, update the initializer with the resulting function. 1539 if (!ICS) 1540 FixOverloadedFunctionReference(Init, Fn); 1541 1542 T2 = Fn->getType(); 1543 } 1544 } 1545 1546 // Compute some basic properties of the types and the initializer. 1547 bool DerivedToBase = false; 1548 Expr::isLvalueResult InitLvalue = Init->isLvalue(Context); 1549 ReferenceCompareResult RefRelationship 1550 = CompareReferenceRelationship(T1, T2, DerivedToBase); 1551 1552 // Most paths end in a failed conversion. 1553 if (ICS) 1554 ICS->ConversionKind = ImplicitConversionSequence::BadConversion; 1555 1556 // C++ [dcl.init.ref]p5: 1557 // A reference to type “cv1 T1” is initialized by an expression 1558 // of type “cv2 T2” as follows: 1559 1560 // -- If the initializer expression 1561 1562 bool BindsDirectly = false; 1563 // -- is an lvalue (but is not a bit-field), and “cv1 T1” is 1564 // reference-compatible with “cv2 T2,” or 1565 // 1566 // Note that the bit-field check is skipped if we are just computing 1567 // the implicit conversion sequence (C++ [over.best.ics]p2). 1568 if (InitLvalue == Expr::LV_Valid && (ICS || !Init->isBitField()) && 1569 RefRelationship >= Ref_Compatible_With_Added_Qualification) { 1570 BindsDirectly = true; 1571 1572 if (ICS) { 1573 // C++ [over.ics.ref]p1: 1574 // When a parameter of reference type binds directly (8.5.3) 1575 // to an argument expression, the implicit conversion sequence 1576 // is the identity conversion, unless the argument expression 1577 // has a type that is a derived class of the parameter type, 1578 // in which case the implicit conversion sequence is a 1579 // derived-to-base Conversion (13.3.3.1). 1580 ICS->ConversionKind = ImplicitConversionSequence::StandardConversion; 1581 ICS->Standard.First = ICK_Identity; 1582 ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 1583 ICS->Standard.Third = ICK_Identity; 1584 ICS->Standard.FromTypePtr = T2.getAsOpaquePtr(); 1585 ICS->Standard.ToTypePtr = T1.getAsOpaquePtr(); 1586 ICS->Standard.ReferenceBinding = true; 1587 ICS->Standard.DirectBinding = true; 1588 1589 // Nothing more to do: the inaccessibility/ambiguity check for 1590 // derived-to-base conversions is suppressed when we're 1591 // computing the implicit conversion sequence (C++ 1592 // [over.best.ics]p2). 1593 return false; 1594 } else { 1595 // Perform the conversion. 1596 // FIXME: Binding to a subobject of the lvalue is going to require 1597 // more AST annotation than this. 1598 ImpCastExprToType(Init, T1, /*isLvalue=*/true); 1599 } 1600 } 1601 1602 // -- has a class type (i.e., T2 is a class type) and can be 1603 // implicitly converted to an lvalue of type “cv3 T3,” 1604 // where “cv1 T1” is reference-compatible with “cv3 T3” 1605 // 92) (this conversion is selected by enumerating the 1606 // applicable conversion functions (13.3.1.6) and choosing 1607 // the best one through overload resolution (13.3)), 1608 if (!SuppressUserConversions && T2->isRecordType()) { 1609 // FIXME: Look for conversions in base classes! 1610 CXXRecordDecl *T2RecordDecl 1611 = dyn_cast<CXXRecordDecl>(T2->getAsRecordType()->getDecl()); 1612 1613 OverloadCandidateSet CandidateSet; 1614 OverloadedFunctionDecl *Conversions 1615 = T2RecordDecl->getConversionFunctions(); 1616 for (OverloadedFunctionDecl::function_iterator Func 1617 = Conversions->function_begin(); 1618 Func != Conversions->function_end(); ++Func) { 1619 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1620 1621 // If the conversion function doesn't return a reference type, 1622 // it can't be considered for this conversion. 1623 // FIXME: This will change when we support rvalue references. 1624 if (Conv->getConversionType()->isReferenceType()) 1625 AddConversionCandidate(Conv, Init, DeclType, CandidateSet); 1626 } 1627 1628 OverloadCandidateSet::iterator Best; 1629 switch (BestViableFunction(CandidateSet, Best)) { 1630 case OR_Success: 1631 // This is a direct binding. 1632 BindsDirectly = true; 1633 1634 if (ICS) { 1635 // C++ [over.ics.ref]p1: 1636 // 1637 // [...] If the parameter binds directly to the result of 1638 // applying a conversion function to the argument 1639 // expression, the implicit conversion sequence is a 1640 // user-defined conversion sequence (13.3.3.1.2), with the 1641 // second standard conversion sequence either an identity 1642 // conversion or, if the conversion function returns an 1643 // entity of a type that is a derived class of the parameter 1644 // type, a derived-to-base Conversion. 1645 ICS->ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 1646 ICS->UserDefined.Before = Best->Conversions[0].Standard; 1647 ICS->UserDefined.After = Best->FinalConversion; 1648 ICS->UserDefined.ConversionFunction = Best->Function; 1649 assert(ICS->UserDefined.After.ReferenceBinding && 1650 ICS->UserDefined.After.DirectBinding && 1651 "Expected a direct reference binding!"); 1652 return false; 1653 } else { 1654 // Perform the conversion. 1655 // FIXME: Binding to a subobject of the lvalue is going to require 1656 // more AST annotation than this. 1657 ImpCastExprToType(Init, T1, /*isLvalue=*/true); 1658 } 1659 break; 1660 1661 case OR_Ambiguous: 1662 assert(false && "Ambiguous reference binding conversions not implemented."); 1663 return true; 1664 1665 case OR_No_Viable_Function: 1666 // There was no suitable conversion; continue with other checks. 1667 break; 1668 } 1669 } 1670 1671 if (BindsDirectly) { 1672 // C++ [dcl.init.ref]p4: 1673 // [...] In all cases where the reference-related or 1674 // reference-compatible relationship of two types is used to 1675 // establish the validity of a reference binding, and T1 is a 1676 // base class of T2, a program that necessitates such a binding 1677 // is ill-formed if T1 is an inaccessible (clause 11) or 1678 // ambiguous (10.2) base class of T2. 1679 // 1680 // Note that we only check this condition when we're allowed to 1681 // complain about errors, because we should not be checking for 1682 // ambiguity (or inaccessibility) unless the reference binding 1683 // actually happens. 1684 if (DerivedToBase) 1685 return CheckDerivedToBaseConversion(T2, T1, 1686 Init->getSourceRange().getBegin(), 1687 Init->getSourceRange()); 1688 else 1689 return false; 1690 } 1691 1692 // -- Otherwise, the reference shall be to a non-volatile const 1693 // type (i.e., cv1 shall be const). 1694 if (T1.getCVRQualifiers() != QualType::Const) { 1695 if (!ICS) 1696 Diag(Init->getSourceRange().getBegin(), 1697 diag::err_not_reference_to_const_init) 1698 << T1.getAsString() 1699 << (InitLvalue != Expr::LV_Valid? "temporary" : "value") 1700 << T2.getAsString() << Init->getSourceRange(); 1701 return true; 1702 } 1703 1704 // -- If the initializer expression is an rvalue, with T2 a 1705 // class type, and “cv1 T1” is reference-compatible with 1706 // “cv2 T2,” the reference is bound in one of the 1707 // following ways (the choice is implementation-defined): 1708 // 1709 // -- The reference is bound to the object represented by 1710 // the rvalue (see 3.10) or to a sub-object within that 1711 // object. 1712 // 1713 // -- A temporary of type “cv1 T2” [sic] is created, and 1714 // a constructor is called to copy the entire rvalue 1715 // object into the temporary. The reference is bound to 1716 // the temporary or to a sub-object within the 1717 // temporary. 1718 // 1719 // 1720 // The constructor that would be used to make the copy 1721 // shall be callable whether or not the copy is actually 1722 // done. 1723 // 1724 // Note that C++0x [dcl.ref.init]p5 takes away this implementation 1725 // freedom, so we will always take the first option and never build 1726 // a temporary in this case. FIXME: We will, however, have to check 1727 // for the presence of a copy constructor in C++98/03 mode. 1728 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 1729 RefRelationship >= Ref_Compatible_With_Added_Qualification) { 1730 if (ICS) { 1731 ICS->ConversionKind = ImplicitConversionSequence::StandardConversion; 1732 ICS->Standard.First = ICK_Identity; 1733 ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 1734 ICS->Standard.Third = ICK_Identity; 1735 ICS->Standard.FromTypePtr = T2.getAsOpaquePtr(); 1736 ICS->Standard.ToTypePtr = T1.getAsOpaquePtr(); 1737 ICS->Standard.ReferenceBinding = true; 1738 ICS->Standard.DirectBinding = false; 1739 } else { 1740 // FIXME: Binding to a subobject of the rvalue is going to require 1741 // more AST annotation than this. 1742 ImpCastExprToType(Init, T1, /*isLvalue=*/true); 1743 } 1744 return false; 1745 } 1746 1747 // -- Otherwise, a temporary of type “cv1 T1” is created and 1748 // initialized from the initializer expression using the 1749 // rules for a non-reference copy initialization (8.5). The 1750 // reference is then bound to the temporary. If T1 is 1751 // reference-related to T2, cv1 must be the same 1752 // cv-qualification as, or greater cv-qualification than, 1753 // cv2; otherwise, the program is ill-formed. 1754 if (RefRelationship == Ref_Related) { 1755 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 1756 // we would be reference-compatible or reference-compatible with 1757 // added qualification. But that wasn't the case, so the reference 1758 // initialization fails. 1759 if (!ICS) 1760 Diag(Init->getSourceRange().getBegin(), 1761 diag::err_reference_init_drops_quals) 1762 << T1.getAsString() 1763 << (InitLvalue != Expr::LV_Valid? "temporary" : "value") 1764 << T2.getAsString() << Init->getSourceRange(); 1765 return true; 1766 } 1767 1768 // Actually try to convert the initializer to T1. 1769 if (ICS) { 1770 /// C++ [over.ics.ref]p2: 1771 /// 1772 /// When a parameter of reference type is not bound directly to 1773 /// an argument expression, the conversion sequence is the one 1774 /// required to convert the argument expression to the 1775 /// underlying type of the reference according to 1776 /// 13.3.3.1. Conceptually, this conversion sequence corresponds 1777 /// to copy-initializing a temporary of the underlying type with 1778 /// the argument expression. Any difference in top-level 1779 /// cv-qualification is subsumed by the initialization itself 1780 /// and does not constitute a conversion. 1781 *ICS = TryImplicitConversion(Init, T1, SuppressUserConversions); 1782 return ICS->ConversionKind == ImplicitConversionSequence::BadConversion; 1783 } else { 1784 return PerformImplicitConversion(Init, T1); 1785 } 1786} 1787 1788/// CheckOverloadedOperatorDeclaration - Check whether the declaration 1789/// of this overloaded operator is well-formed. If so, returns false; 1790/// otherwise, emits appropriate diagnostics and returns true. 1791bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) { 1792 assert(FnDecl && FnDecl->isOverloadedOperator() && 1793 "Expected an overloaded operator declaration"); 1794 1795 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator(); 1796 1797 // C++ [over.oper]p5: 1798 // The allocation and deallocation functions, operator new, 1799 // operator new[], operator delete and operator delete[], are 1800 // described completely in 3.7.3. The attributes and restrictions 1801 // found in the rest of this subclause do not apply to them unless 1802 // explicitly stated in 3.7.3. 1803 // FIXME: Write a separate routine for checking this. For now, just 1804 // allow it. 1805 if (Op == OO_New || Op == OO_Array_New || 1806 Op == OO_Delete || Op == OO_Array_Delete) 1807 return false; 1808 1809 // C++ [over.oper]p6: 1810 // An operator function shall either be a non-static member 1811 // function or be a non-member function and have at least one 1812 // parameter whose type is a class, a reference to a class, an 1813 // enumeration, or a reference to an enumeration. 1814 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) { 1815 if (MethodDecl->isStatic()) 1816 return Diag(FnDecl->getLocation(), 1817 diag::err_operator_overload_static) 1818 << FnDecl->getName(); 1819 } else { 1820 bool ClassOrEnumParam = false; 1821 for (FunctionDecl::param_iterator Param = FnDecl->param_begin(), 1822 ParamEnd = FnDecl->param_end(); 1823 Param != ParamEnd; ++Param) { 1824 QualType ParamType = (*Param)->getType().getNonReferenceType(); 1825 if (ParamType->isRecordType() || ParamType->isEnumeralType()) { 1826 ClassOrEnumParam = true; 1827 break; 1828 } 1829 } 1830 1831 if (!ClassOrEnumParam) 1832 return Diag(FnDecl->getLocation(), 1833 diag::err_operator_overload_needs_class_or_enum) 1834 << FnDecl->getName(); 1835 } 1836 1837 // C++ [over.oper]p8: 1838 // An operator function cannot have default arguments (8.3.6), 1839 // except where explicitly stated below. 1840 // 1841 // Only the function-call operator allows default arguments 1842 // (C++ [over.call]p1). 1843 if (Op != OO_Call) { 1844 for (FunctionDecl::param_iterator Param = FnDecl->param_begin(); 1845 Param != FnDecl->param_end(); ++Param) { 1846 if (Expr *DefArg = (*Param)->getDefaultArg()) 1847 return Diag((*Param)->getLocation(), 1848 diag::err_operator_overload_default_arg) 1849 << FnDecl->getName() << DefArg->getSourceRange(); 1850 } 1851 } 1852 1853 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = { 1854 { false, false, false } 1855#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \ 1856 , { Unary, Binary, MemberOnly } 1857#include "clang/Basic/OperatorKinds.def" 1858 }; 1859 1860 bool CanBeUnaryOperator = OperatorUses[Op][0]; 1861 bool CanBeBinaryOperator = OperatorUses[Op][1]; 1862 bool MustBeMemberOperator = OperatorUses[Op][2]; 1863 1864 // C++ [over.oper]p8: 1865 // [...] Operator functions cannot have more or fewer parameters 1866 // than the number required for the corresponding operator, as 1867 // described in the rest of this subclause. 1868 unsigned NumParams = FnDecl->getNumParams() 1869 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0); 1870 if (Op != OO_Call && 1871 ((NumParams == 1 && !CanBeUnaryOperator) || 1872 (NumParams == 2 && !CanBeBinaryOperator) || 1873 (NumParams < 1) || (NumParams > 2))) { 1874 // We have the wrong number of parameters. 1875 unsigned ErrorKind; 1876 if (CanBeUnaryOperator && CanBeBinaryOperator) { 1877 ErrorKind = 2; // 2 -> unary or binary. 1878 } else if (CanBeUnaryOperator) { 1879 ErrorKind = 0; // 0 -> unary 1880 } else { 1881 assert(CanBeBinaryOperator && 1882 "All non-call overloaded operators are unary or binary!"); 1883 ErrorKind = 1; // 1 -> binary 1884 } 1885 1886 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be) 1887 << FnDecl->getName() << NumParams << ErrorKind; 1888 } 1889 1890 // Overloaded operators other than operator() cannot be variadic. 1891 if (Op != OO_Call && 1892 FnDecl->getType()->getAsFunctionTypeProto()->isVariadic()) { 1893 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic) 1894 << FnDecl->getName(); 1895 } 1896 1897 // Some operators must be non-static member functions. 1898 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) { 1899 return Diag(FnDecl->getLocation(), 1900 diag::err_operator_overload_must_be_member) 1901 << FnDecl->getName(); 1902 } 1903 1904 // C++ [over.inc]p1: 1905 // The user-defined function called operator++ implements the 1906 // prefix and postfix ++ operator. If this function is a member 1907 // function with no parameters, or a non-member function with one 1908 // parameter of class or enumeration type, it defines the prefix 1909 // increment operator ++ for objects of that type. If the function 1910 // is a member function with one parameter (which shall be of type 1911 // int) or a non-member function with two parameters (the second 1912 // of which shall be of type int), it defines the postfix 1913 // increment operator ++ for objects of that type. 1914 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) { 1915 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1); 1916 bool ParamIsInt = false; 1917 if (const BuiltinType *BT = LastParam->getType()->getAsBuiltinType()) 1918 ParamIsInt = BT->getKind() == BuiltinType::Int; 1919 1920 if (!ParamIsInt) 1921 return Diag(LastParam->getLocation(), 1922 diag::err_operator_overload_post_incdec_must_be_int) 1923 << LastParam->getType().getAsString() << (Op == OO_MinusMinus); 1924 } 1925 1926 return false; 1927} 1928