SemaDecl.cpp revision 0a8bab019dbf980911fbefa56d7debd648b7b239
1//===--- SemaDecl.cpp - Semantic Analysis for 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 declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInit.h" 16#include "Lookup.h" 17#include "clang/AST/APValue.h" 18#include "clang/AST/ASTConsumer.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/Analysis/CFG.h" 21#include "clang/AST/CXXInheritance.h" 22#include "clang/AST/DeclObjC.h" 23#include "clang/AST/DeclTemplate.h" 24#include "clang/AST/ExprCXX.h" 25#include "clang/AST/StmtCXX.h" 26#include "clang/AST/StmtObjC.h" 27#include "clang/Parse/DeclSpec.h" 28#include "clang/Parse/ParseDiagnostic.h" 29#include "clang/Parse/Template.h" 30#include "clang/Basic/PartialDiagnostic.h" 31#include "clang/Basic/SourceManager.h" 32#include "clang/Basic/TargetInfo.h" 33// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 34#include "clang/Lex/Preprocessor.h" 35#include "clang/Lex/HeaderSearch.h" 36#include "llvm/ADT/BitVector.h" 37#include "llvm/ADT/STLExtras.h" 38#include <algorithm> 39#include <cstring> 40#include <functional> 41#include <queue> 42using namespace clang; 43 44/// getDeclName - Return a pretty name for the specified decl if possible, or 45/// an empty string if not. This is used for pretty crash reporting. 46std::string Sema::getDeclName(DeclPtrTy d) { 47 Decl *D = d.getAs<Decl>(); 48 if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D)) 49 return DN->getQualifiedNameAsString(); 50 return ""; 51} 52 53Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) { 54 return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>())); 55} 56 57/// \brief If the identifier refers to a type name within this scope, 58/// return the declaration of that type. 59/// 60/// This routine performs ordinary name lookup of the identifier II 61/// within the given scope, with optional C++ scope specifier SS, to 62/// determine whether the name refers to a type. If so, returns an 63/// opaque pointer (actually a QualType) corresponding to that 64/// type. Otherwise, returns NULL. 65/// 66/// If name lookup results in an ambiguity, this routine will complain 67/// and then return NULL. 68Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 69 Scope *S, const CXXScopeSpec *SS, 70 bool isClassName, 71 TypeTy *ObjectTypePtr) { 72 // Determine where we will perform name lookup. 73 DeclContext *LookupCtx = 0; 74 if (ObjectTypePtr) { 75 QualType ObjectType = QualType::getFromOpaquePtr(ObjectTypePtr); 76 if (ObjectType->isRecordType()) 77 LookupCtx = computeDeclContext(ObjectType); 78 } else if (SS && SS->isSet()) { 79 LookupCtx = computeDeclContext(*SS, false); 80 81 if (!LookupCtx) { 82 if (isDependentScopeSpecifier(*SS)) { 83 // C++ [temp.res]p3: 84 // A qualified-id that refers to a type and in which the 85 // nested-name-specifier depends on a template-parameter (14.6.2) 86 // shall be prefixed by the keyword typename to indicate that the 87 // qualified-id denotes a type, forming an 88 // elaborated-type-specifier (7.1.5.3). 89 // 90 // We therefore do not perform any name lookup if the result would 91 // refer to a member of an unknown specialization. 92 if (!isClassName) 93 return 0; 94 95 // We know from the grammar that this name refers to a type, so build a 96 // TypenameType node to describe the type. 97 // FIXME: Record somewhere that this TypenameType node has no "typename" 98 // keyword associated with it. 99 return CheckTypenameType((NestedNameSpecifier *)SS->getScopeRep(), 100 II, SS->getRange()).getAsOpaquePtr(); 101 } 102 103 return 0; 104 } 105 106 if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(*SS)) 107 return 0; 108 } 109 110 LookupResult Result(*this, &II, NameLoc, LookupOrdinaryName); 111 if (LookupCtx) { 112 // Perform "qualified" name lookup into the declaration context we 113 // computed, which is either the type of the base of a member access 114 // expression or the declaration context associated with a prior 115 // nested-name-specifier. 116 LookupQualifiedName(Result, LookupCtx); 117 118 if (ObjectTypePtr && Result.empty()) { 119 // C++ [basic.lookup.classref]p3: 120 // If the unqualified-id is ~type-name, the type-name is looked up 121 // in the context of the entire postfix-expression. If the type T of 122 // the object expression is of a class type C, the type-name is also 123 // looked up in the scope of class C. At least one of the lookups shall 124 // find a name that refers to (possibly cv-qualified) T. 125 LookupName(Result, S); 126 } 127 } else { 128 // Perform unqualified name lookup. 129 LookupName(Result, S); 130 } 131 132 NamedDecl *IIDecl = 0; 133 switch (Result.getResultKind()) { 134 case LookupResult::NotFound: 135 case LookupResult::FoundOverloaded: 136 case LookupResult::FoundUnresolvedValue: 137 return 0; 138 139 case LookupResult::Ambiguous: 140 // Recover from type-hiding ambiguities by hiding the type. We'll 141 // do the lookup again when looking for an object, and we can 142 // diagnose the error then. If we don't do this, then the error 143 // about hiding the type will be immediately followed by an error 144 // that only makes sense if the identifier was treated like a type. 145 if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) { 146 Result.suppressDiagnostics(); 147 return 0; 148 } 149 150 // Look to see if we have a type anywhere in the list of results. 151 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); 152 Res != ResEnd; ++Res) { 153 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) { 154 if (!IIDecl || 155 (*Res)->getLocation().getRawEncoding() < 156 IIDecl->getLocation().getRawEncoding()) 157 IIDecl = *Res; 158 } 159 } 160 161 if (!IIDecl) { 162 // None of the entities we found is a type, so there is no way 163 // to even assume that the result is a type. In this case, don't 164 // complain about the ambiguity. The parser will either try to 165 // perform this lookup again (e.g., as an object name), which 166 // will produce the ambiguity, or will complain that it expected 167 // a type name. 168 Result.suppressDiagnostics(); 169 return 0; 170 } 171 172 // We found a type within the ambiguous lookup; diagnose the 173 // ambiguity and then return that type. This might be the right 174 // answer, or it might not be, but it suppresses any attempt to 175 // perform the name lookup again. 176 break; 177 178 case LookupResult::Found: 179 IIDecl = Result.getFoundDecl(); 180 break; 181 } 182 183 assert(IIDecl && "Didn't find decl"); 184 185 QualType T; 186 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 187 DiagnoseUseOfDecl(IIDecl, NameLoc); 188 189 // C++ [temp.local]p2: 190 // Within the scope of a class template specialization or 191 // partial specialization, when the injected-class-name is 192 // not followed by a <, it is equivalent to the 193 // injected-class-name followed by the template-argument s 194 // of the class template specialization or partial 195 // specialization enclosed in <>. 196 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) 197 if (RD->isInjectedClassName()) 198 if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate()) 199 T = Template->getInjectedClassNameType(Context); 200 201 if (T.isNull()) 202 T = Context.getTypeDeclType(TD); 203 204 if (SS) 205 T = getQualifiedNameType(*SS, T); 206 207 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 208 T = Context.getObjCInterfaceType(IDecl); 209 } else if (UnresolvedUsingTypenameDecl *UUDecl = 210 dyn_cast<UnresolvedUsingTypenameDecl>(IIDecl)) { 211 // FIXME: preserve source structure information. 212 T = Context.getTypenameType(UUDecl->getTargetNestedNameSpecifier(), &II); 213 } else { 214 // If it's not plausibly a type, suppress diagnostics. 215 Result.suppressDiagnostics(); 216 return 0; 217 } 218 219 return T.getAsOpaquePtr(); 220} 221 222/// isTagName() - This method is called *for error recovery purposes only* 223/// to determine if the specified name is a valid tag name ("struct foo"). If 224/// so, this returns the TST for the tag corresponding to it (TST_enum, 225/// TST_union, TST_struct, TST_class). This is used to diagnose cases in C 226/// where the user forgot to specify the tag. 227DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { 228 // Do a tag name lookup in this scope. 229 LookupResult R(*this, &II, SourceLocation(), LookupTagName); 230 LookupName(R, S, false); 231 R.suppressDiagnostics(); 232 if (R.getResultKind() == LookupResult::Found) 233 if (const TagDecl *TD = R.getAsSingle<TagDecl>()) { 234 switch (TD->getTagKind()) { 235 case TagDecl::TK_struct: return DeclSpec::TST_struct; 236 case TagDecl::TK_union: return DeclSpec::TST_union; 237 case TagDecl::TK_class: return DeclSpec::TST_class; 238 case TagDecl::TK_enum: return DeclSpec::TST_enum; 239 } 240 } 241 242 return DeclSpec::TST_unspecified; 243} 244 245bool Sema::DiagnoseUnknownTypeName(const IdentifierInfo &II, 246 SourceLocation IILoc, 247 Scope *S, 248 const CXXScopeSpec *SS, 249 TypeTy *&SuggestedType) { 250 // We don't have anything to suggest (yet). 251 SuggestedType = 0; 252 253 // FIXME: Should we move the logic that tries to recover from a missing tag 254 // (struct, union, enum) from Parser::ParseImplicitInt here, instead? 255 256 if (!SS) 257 Diag(IILoc, diag::err_unknown_typename) << &II; 258 else if (DeclContext *DC = computeDeclContext(*SS, false)) 259 Diag(IILoc, diag::err_typename_nested_not_found) 260 << &II << DC << SS->getRange(); 261 else if (isDependentScopeSpecifier(*SS)) { 262 Diag(SS->getRange().getBegin(), diag::err_typename_missing) 263 << (NestedNameSpecifier *)SS->getScopeRep() << II.getName() 264 << SourceRange(SS->getRange().getBegin(), IILoc) 265 << CodeModificationHint::CreateInsertion(SS->getRange().getBegin(), 266 "typename "); 267 SuggestedType = ActOnTypenameType(SourceLocation(), *SS, II, IILoc).get(); 268 } else { 269 assert(SS && SS->isInvalid() && 270 "Invalid scope specifier has already been diagnosed"); 271 } 272 273 return true; 274} 275 276// Determines the context to return to after temporarily entering a 277// context. This depends in an unnecessarily complicated way on the 278// exact ordering of callbacks from the parser. 279DeclContext *Sema::getContainingDC(DeclContext *DC) { 280 281 // Functions defined inline within classes aren't parsed until we've 282 // finished parsing the top-level class, so the top-level class is 283 // the context we'll need to return to. 284 if (isa<FunctionDecl>(DC)) { 285 DC = DC->getLexicalParent(); 286 287 // A function not defined within a class will always return to its 288 // lexical context. 289 if (!isa<CXXRecordDecl>(DC)) 290 return DC; 291 292 // A C++ inline method/friend is parsed *after* the topmost class 293 // it was declared in is fully parsed ("complete"); the topmost 294 // class is the context we need to return to. 295 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 296 DC = RD; 297 298 // Return the declaration context of the topmost class the inline method is 299 // declared in. 300 return DC; 301 } 302 303 if (isa<ObjCMethodDecl>(DC)) 304 return Context.getTranslationUnitDecl(); 305 306 return DC->getLexicalParent(); 307} 308 309void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 310 assert(getContainingDC(DC) == CurContext && 311 "The next DeclContext should be lexically contained in the current one."); 312 CurContext = DC; 313 S->setEntity(DC); 314} 315 316void Sema::PopDeclContext() { 317 assert(CurContext && "DeclContext imbalance!"); 318 319 CurContext = getContainingDC(CurContext); 320} 321 322/// EnterDeclaratorContext - Used when we must lookup names in the context 323/// of a declarator's nested name specifier. 324void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { 325 assert(PreDeclaratorDC == 0 && "Previous declarator context not popped?"); 326 PreDeclaratorDC = static_cast<DeclContext*>(S->getEntity()); 327 CurContext = DC; 328 assert(CurContext && "No context?"); 329 S->setEntity(CurContext); 330} 331 332void Sema::ExitDeclaratorContext(Scope *S) { 333 S->setEntity(PreDeclaratorDC); 334 PreDeclaratorDC = 0; 335 336 // Reset CurContext to the nearest enclosing context. 337 while (!S->getEntity() && S->getParent()) 338 S = S->getParent(); 339 CurContext = static_cast<DeclContext*>(S->getEntity()); 340 assert(CurContext && "No context?"); 341} 342 343/// \brief Determine whether we allow overloading of the function 344/// PrevDecl with another declaration. 345/// 346/// This routine determines whether overloading is possible, not 347/// whether some new function is actually an overload. It will return 348/// true in C++ (where we can always provide overloads) or, as an 349/// extension, in C when the previous function is already an 350/// overloaded function declaration or has the "overloadable" 351/// attribute. 352static bool AllowOverloadingOfFunction(LookupResult &Previous, 353 ASTContext &Context) { 354 if (Context.getLangOptions().CPlusPlus) 355 return true; 356 357 if (Previous.getResultKind() == LookupResult::FoundOverloaded) 358 return true; 359 360 return (Previous.getResultKind() == LookupResult::Found 361 && Previous.getFoundDecl()->hasAttr<OverloadableAttr>()); 362} 363 364/// Add this decl to the scope shadowed decl chains. 365void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) { 366 // Move up the scope chain until we find the nearest enclosing 367 // non-transparent context. The declaration will be introduced into this 368 // scope. 369 while (S->getEntity() && 370 ((DeclContext *)S->getEntity())->isTransparentContext()) 371 S = S->getParent(); 372 373 // Add scoped declarations into their context, so that they can be 374 // found later. Declarations without a context won't be inserted 375 // into any context. 376 if (AddToContext) 377 CurContext->addDecl(D); 378 379 // Out-of-line function and variable definitions should not be pushed into 380 // scope. 381 if ((isa<FunctionTemplateDecl>(D) && 382 cast<FunctionTemplateDecl>(D)->getTemplatedDecl()->isOutOfLine()) || 383 (isa<FunctionDecl>(D) && 384 (cast<FunctionDecl>(D)->isFunctionTemplateSpecialization() || 385 cast<FunctionDecl>(D)->isOutOfLine())) || 386 (isa<VarDecl>(D) && cast<VarDecl>(D)->isOutOfLine())) 387 return; 388 389 // If this replaces anything in the current scope, 390 IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()), 391 IEnd = IdResolver.end(); 392 for (; I != IEnd; ++I) { 393 if (S->isDeclScope(DeclPtrTy::make(*I)) && D->declarationReplaces(*I)) { 394 S->RemoveDecl(DeclPtrTy::make(*I)); 395 IdResolver.RemoveDecl(*I); 396 397 // Should only need to replace one decl. 398 break; 399 } 400 } 401 402 S->AddDecl(DeclPtrTy::make(D)); 403 IdResolver.AddDecl(D); 404} 405 406bool Sema::isDeclInScope(NamedDecl *&D, DeclContext *Ctx, Scope *S) { 407 return IdResolver.isDeclInScope(D, Ctx, Context, S); 408} 409 410static bool isOutOfScopePreviousDeclaration(NamedDecl *, 411 DeclContext*, 412 ASTContext&); 413 414/// Filters out lookup results that don't fall within the given scope 415/// as determined by isDeclInScope. 416static void FilterLookupForScope(Sema &SemaRef, LookupResult &R, 417 DeclContext *Ctx, Scope *S, 418 bool ConsiderLinkage) { 419 LookupResult::Filter F = R.makeFilter(); 420 while (F.hasNext()) { 421 NamedDecl *D = F.next(); 422 423 if (SemaRef.isDeclInScope(D, Ctx, S)) 424 continue; 425 426 if (ConsiderLinkage && 427 isOutOfScopePreviousDeclaration(D, Ctx, SemaRef.Context)) 428 continue; 429 430 F.erase(); 431 } 432 433 F.done(); 434} 435 436static bool isUsingDecl(NamedDecl *D) { 437 return isa<UsingShadowDecl>(D) || 438 isa<UnresolvedUsingTypenameDecl>(D) || 439 isa<UnresolvedUsingValueDecl>(D); 440} 441 442/// Removes using shadow declarations from the lookup results. 443static void RemoveUsingDecls(LookupResult &R) { 444 LookupResult::Filter F = R.makeFilter(); 445 while (F.hasNext()) 446 if (isUsingDecl(F.next())) 447 F.erase(); 448 449 F.done(); 450} 451 452static bool ShouldDiagnoseUnusedDecl(const NamedDecl *D) { 453 if (D->isUsed() || D->hasAttr<UnusedAttr>()) 454 return false; 455 456 if (const ValueDecl *VD = dyn_cast<ValueDecl>(D)) { 457 if (const RecordType *RT = VD->getType()->getAs<RecordType>()) { 458 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 459 if (!RD->hasTrivialConstructor()) 460 return false; 461 if (!RD->hasTrivialDestructor()) 462 return false; 463 } 464 } 465 } 466 467 return (isa<VarDecl>(D) && !isa<ParmVarDecl>(D) && 468 !isa<ImplicitParamDecl>(D) && 469 D->getDeclContext()->isFunctionOrMethod()); 470} 471 472void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 473 if (S->decl_empty()) return; 474 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 475 "Scope shouldn't contain decls!"); 476 477 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 478 I != E; ++I) { 479 Decl *TmpD = (*I).getAs<Decl>(); 480 assert(TmpD && "This decl didn't get pushed??"); 481 482 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 483 NamedDecl *D = cast<NamedDecl>(TmpD); 484 485 if (!D->getDeclName()) continue; 486 487 // Diagnose unused variables in this scope. 488 if (ShouldDiagnoseUnusedDecl(D)) 489 Diag(D->getLocation(), diag::warn_unused_variable) << D->getDeclName(); 490 491 // Remove this name from our lexical scope. 492 IdResolver.RemoveDecl(D); 493 } 494} 495 496/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 497/// return 0 if one not found. 498ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 499 // The third "scope" argument is 0 since we aren't enabling lazy built-in 500 // creation from this context. 501 NamedDecl *IDecl = LookupSingleName(TUScope, Id, LookupOrdinaryName); 502 503 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 504} 505 506/// getNonFieldDeclScope - Retrieves the innermost scope, starting 507/// from S, where a non-field would be declared. This routine copes 508/// with the difference between C and C++ scoping rules in structs and 509/// unions. For example, the following code is well-formed in C but 510/// ill-formed in C++: 511/// @code 512/// struct S6 { 513/// enum { BAR } e; 514/// }; 515/// 516/// void test_S6() { 517/// struct S6 a; 518/// a.e = BAR; 519/// } 520/// @endcode 521/// For the declaration of BAR, this routine will return a different 522/// scope. The scope S will be the scope of the unnamed enumeration 523/// within S6. In C++, this routine will return the scope associated 524/// with S6, because the enumeration's scope is a transparent 525/// context but structures can contain non-field names. In C, this 526/// routine will return the translation unit scope, since the 527/// enumeration's scope is a transparent context and structures cannot 528/// contain non-field names. 529Scope *Sema::getNonFieldDeclScope(Scope *S) { 530 while (((S->getFlags() & Scope::DeclScope) == 0) || 531 (S->getEntity() && 532 ((DeclContext *)S->getEntity())->isTransparentContext()) || 533 (S->isClassScope() && !getLangOptions().CPlusPlus)) 534 S = S->getParent(); 535 return S; 536} 537 538void Sema::InitBuiltinVaListType() { 539 if (!Context.getBuiltinVaListType().isNull()) 540 return; 541 542 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 543 NamedDecl *VaDecl = LookupSingleName(TUScope, VaIdent, LookupOrdinaryName); 544 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 545 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 546} 547 548/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 549/// file scope. lazily create a decl for it. ForRedeclaration is true 550/// if we're creating this built-in in anticipation of redeclaring the 551/// built-in. 552NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 553 Scope *S, bool ForRedeclaration, 554 SourceLocation Loc) { 555 Builtin::ID BID = (Builtin::ID)bid; 556 557 if (Context.BuiltinInfo.hasVAListUse(BID)) 558 InitBuiltinVaListType(); 559 560 ASTContext::GetBuiltinTypeError Error; 561 QualType R = Context.GetBuiltinType(BID, Error); 562 switch (Error) { 563 case ASTContext::GE_None: 564 // Okay 565 break; 566 567 case ASTContext::GE_Missing_stdio: 568 if (ForRedeclaration) 569 Diag(Loc, diag::err_implicit_decl_requires_stdio) 570 << Context.BuiltinInfo.GetName(BID); 571 return 0; 572 573 case ASTContext::GE_Missing_setjmp: 574 if (ForRedeclaration) 575 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 576 << Context.BuiltinInfo.GetName(BID); 577 return 0; 578 } 579 580 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 581 Diag(Loc, diag::ext_implicit_lib_function_decl) 582 << Context.BuiltinInfo.GetName(BID) 583 << R; 584 if (Context.BuiltinInfo.getHeaderName(BID) && 585 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 586 != Diagnostic::Ignored) 587 Diag(Loc, diag::note_please_include_header) 588 << Context.BuiltinInfo.getHeaderName(BID) 589 << Context.BuiltinInfo.GetName(BID); 590 } 591 592 FunctionDecl *New = FunctionDecl::Create(Context, 593 Context.getTranslationUnitDecl(), 594 Loc, II, R, /*TInfo=*/0, 595 FunctionDecl::Extern, false, 596 /*hasPrototype=*/true); 597 New->setImplicit(); 598 599 // Create Decl objects for each parameter, adding them to the 600 // FunctionDecl. 601 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 602 llvm::SmallVector<ParmVarDecl*, 16> Params; 603 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 604 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 605 FT->getArgType(i), /*TInfo=*/0, 606 VarDecl::None, 0)); 607 New->setParams(Context, Params.data(), Params.size()); 608 } 609 610 AddKnownFunctionAttributes(New); 611 612 // TUScope is the translation-unit scope to insert this function into. 613 // FIXME: This is hideous. We need to teach PushOnScopeChains to 614 // relate Scopes to DeclContexts, and probably eliminate CurContext 615 // entirely, but we're not there yet. 616 DeclContext *SavedContext = CurContext; 617 CurContext = Context.getTranslationUnitDecl(); 618 PushOnScopeChains(New, TUScope); 619 CurContext = SavedContext; 620 return New; 621} 622 623/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 624/// same name and scope as a previous declaration 'Old'. Figure out 625/// how to resolve this situation, merging decls or emitting 626/// diagnostics as appropriate. If there was an error, set New to be invalid. 627/// 628void Sema::MergeTypeDefDecl(TypedefDecl *New, LookupResult &OldDecls) { 629 // If the new decl is known invalid already, don't bother doing any 630 // merging checks. 631 if (New->isInvalidDecl()) return; 632 633 // Allow multiple definitions for ObjC built-in typedefs. 634 // FIXME: Verify the underlying types are equivalent! 635 if (getLangOptions().ObjC1) { 636 const IdentifierInfo *TypeID = New->getIdentifier(); 637 switch (TypeID->getLength()) { 638 default: break; 639 case 2: 640 if (!TypeID->isStr("id")) 641 break; 642 Context.ObjCIdRedefinitionType = New->getUnderlyingType(); 643 // Install the built-in type for 'id', ignoring the current definition. 644 New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); 645 return; 646 case 5: 647 if (!TypeID->isStr("Class")) 648 break; 649 Context.ObjCClassRedefinitionType = New->getUnderlyingType(); 650 // Install the built-in type for 'Class', ignoring the current definition. 651 New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); 652 return; 653 case 3: 654 if (!TypeID->isStr("SEL")) 655 break; 656 Context.ObjCSelRedefinitionType = New->getUnderlyingType(); 657 // Install the built-in type for 'SEL', ignoring the current definition. 658 New->setTypeForDecl(Context.getObjCSelType().getTypePtr()); 659 return; 660 case 8: 661 if (!TypeID->isStr("Protocol")) 662 break; 663 Context.setObjCProtoType(New->getUnderlyingType()); 664 return; 665 } 666 // Fall through - the typedef name was not a builtin type. 667 } 668 669 // Verify the old decl was also a type. 670 TypeDecl *Old = 0; 671 if (!OldDecls.isSingleResult() || 672 !(Old = dyn_cast<TypeDecl>(OldDecls.getFoundDecl()))) { 673 Diag(New->getLocation(), diag::err_redefinition_different_kind) 674 << New->getDeclName(); 675 676 NamedDecl *OldD = OldDecls.getRepresentativeDecl(); 677 if (OldD->getLocation().isValid()) 678 Diag(OldD->getLocation(), diag::note_previous_definition); 679 680 return New->setInvalidDecl(); 681 } 682 683 // If the old declaration is invalid, just give up here. 684 if (Old->isInvalidDecl()) 685 return New->setInvalidDecl(); 686 687 // Determine the "old" type we'll use for checking and diagnostics. 688 QualType OldType; 689 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 690 OldType = OldTypedef->getUnderlyingType(); 691 else 692 OldType = Context.getTypeDeclType(Old); 693 694 // If the typedef types are not identical, reject them in all languages and 695 // with any extensions enabled. 696 697 if (OldType != New->getUnderlyingType() && 698 Context.getCanonicalType(OldType) != 699 Context.getCanonicalType(New->getUnderlyingType())) { 700 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 701 << New->getUnderlyingType() << OldType; 702 if (Old->getLocation().isValid()) 703 Diag(Old->getLocation(), diag::note_previous_definition); 704 return New->setInvalidDecl(); 705 } 706 707 if (getLangOptions().Microsoft) 708 return; 709 710 // C++ [dcl.typedef]p2: 711 // In a given non-class scope, a typedef specifier can be used to 712 // redefine the name of any type declared in that scope to refer 713 // to the type to which it already refers. 714 if (getLangOptions().CPlusPlus) { 715 if (!isa<CXXRecordDecl>(CurContext)) 716 return; 717 Diag(New->getLocation(), diag::err_redefinition) 718 << New->getDeclName(); 719 Diag(Old->getLocation(), diag::note_previous_definition); 720 return New->setInvalidDecl(); 721 } 722 723 // If we have a redefinition of a typedef in C, emit a warning. This warning 724 // is normally mapped to an error, but can be controlled with 725 // -Wtypedef-redefinition. If either the original or the redefinition is 726 // in a system header, don't emit this for compatibility with GCC. 727 if (PP.getDiagnostics().getSuppressSystemWarnings() && 728 (Context.getSourceManager().isInSystemHeader(Old->getLocation()) || 729 Context.getSourceManager().isInSystemHeader(New->getLocation()))) 730 return; 731 732 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 733 << New->getDeclName(); 734 Diag(Old->getLocation(), diag::note_previous_definition); 735 return; 736} 737 738/// DeclhasAttr - returns true if decl Declaration already has the target 739/// attribute. 740static bool 741DeclHasAttr(const Decl *decl, const Attr *target) { 742 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 743 if (attr->getKind() == target->getKind()) 744 return true; 745 746 return false; 747} 748 749/// MergeAttributes - append attributes from the Old decl to the New one. 750static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 751 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 752 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 753 Attr *NewAttr = attr->clone(C); 754 NewAttr->setInherited(true); 755 New->addAttr(NewAttr); 756 } 757 } 758} 759 760/// Used in MergeFunctionDecl to keep track of function parameters in 761/// C. 762struct GNUCompatibleParamWarning { 763 ParmVarDecl *OldParm; 764 ParmVarDecl *NewParm; 765 QualType PromotedType; 766}; 767 768 769/// getSpecialMember - get the special member enum for a method. 770static Sema::CXXSpecialMember getSpecialMember(ASTContext &Ctx, 771 const CXXMethodDecl *MD) { 772 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) { 773 if (Ctor->isDefaultConstructor()) 774 return Sema::CXXDefaultConstructor; 775 if (Ctor->isCopyConstructor(Ctx)) 776 return Sema::CXXCopyConstructor; 777 } 778 779 if (isa<CXXDestructorDecl>(MD)) 780 return Sema::CXXDestructor; 781 782 assert(MD->isCopyAssignment() && "Must have copy assignment operator"); 783 return Sema::CXXCopyAssignment; 784} 785 786/// MergeFunctionDecl - We just parsed a function 'New' from 787/// declarator D which has the same name and scope as a previous 788/// declaration 'Old'. Figure out how to resolve this situation, 789/// merging decls or emitting diagnostics as appropriate. 790/// 791/// In C++, New and Old must be declarations that are not 792/// overloaded. Use IsOverload to determine whether New and Old are 793/// overloaded, and to select the Old declaration that New should be 794/// merged with. 795/// 796/// Returns true if there was an error, false otherwise. 797bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 798 // Verify the old decl was also a function. 799 FunctionDecl *Old = 0; 800 if (FunctionTemplateDecl *OldFunctionTemplate 801 = dyn_cast<FunctionTemplateDecl>(OldD)) 802 Old = OldFunctionTemplate->getTemplatedDecl(); 803 else 804 Old = dyn_cast<FunctionDecl>(OldD); 805 if (!Old) { 806 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) { 807 Diag(New->getLocation(), diag::err_using_decl_conflict_reverse); 808 Diag(Shadow->getTargetDecl()->getLocation(), 809 diag::note_using_decl_target); 810 Diag(Shadow->getUsingDecl()->getLocation(), 811 diag::note_using_decl) << 0; 812 return true; 813 } 814 815 Diag(New->getLocation(), diag::err_redefinition_different_kind) 816 << New->getDeclName(); 817 Diag(OldD->getLocation(), diag::note_previous_definition); 818 return true; 819 } 820 821 // Determine whether the previous declaration was a definition, 822 // implicit declaration, or a declaration. 823 diag::kind PrevDiag; 824 if (Old->isThisDeclarationADefinition()) 825 PrevDiag = diag::note_previous_definition; 826 else if (Old->isImplicit()) 827 PrevDiag = diag::note_previous_implicit_declaration; 828 else 829 PrevDiag = diag::note_previous_declaration; 830 831 QualType OldQType = Context.getCanonicalType(Old->getType()); 832 QualType NewQType = Context.getCanonicalType(New->getType()); 833 834 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 835 New->getStorageClass() == FunctionDecl::Static && 836 Old->getStorageClass() != FunctionDecl::Static) { 837 Diag(New->getLocation(), diag::err_static_non_static) 838 << New; 839 Diag(Old->getLocation(), PrevDiag); 840 return true; 841 } 842 843 if (getLangOptions().CPlusPlus) { 844 // (C++98 13.1p2): 845 // Certain function declarations cannot be overloaded: 846 // -- Function declarations that differ only in the return type 847 // cannot be overloaded. 848 QualType OldReturnType 849 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 850 QualType NewReturnType 851 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 852 if (OldReturnType != NewReturnType) { 853 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 854 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 855 return true; 856 } 857 858 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 859 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 860 if (OldMethod && NewMethod) { 861 if (!NewMethod->getFriendObjectKind() && 862 NewMethod->getLexicalDeclContext()->isRecord()) { 863 // -- Member function declarations with the same name and the 864 // same parameter types cannot be overloaded if any of them 865 // is a static member function declaration. 866 if (OldMethod->isStatic() || NewMethod->isStatic()) { 867 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 868 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 869 return true; 870 } 871 872 // C++ [class.mem]p1: 873 // [...] A member shall not be declared twice in the 874 // member-specification, except that a nested class or member 875 // class template can be declared and then later defined. 876 unsigned NewDiag; 877 if (isa<CXXConstructorDecl>(OldMethod)) 878 NewDiag = diag::err_constructor_redeclared; 879 else if (isa<CXXDestructorDecl>(NewMethod)) 880 NewDiag = diag::err_destructor_redeclared; 881 else if (isa<CXXConversionDecl>(NewMethod)) 882 NewDiag = diag::err_conv_function_redeclared; 883 else 884 NewDiag = diag::err_member_redeclared; 885 886 Diag(New->getLocation(), NewDiag); 887 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 888 } else { 889 if (OldMethod->isImplicit()) { 890 Diag(NewMethod->getLocation(), 891 diag::err_definition_of_implicitly_declared_member) 892 << New << getSpecialMember(Context, OldMethod); 893 894 Diag(OldMethod->getLocation(), 895 diag::note_previous_implicit_declaration); 896 return true; 897 } 898 } 899 } 900 901 // (C++98 8.3.5p3): 902 // All declarations for a function shall agree exactly in both the 903 // return type and the parameter-type-list. 904 if (OldQType == NewQType) 905 return MergeCompatibleFunctionDecls(New, Old); 906 907 // Fall through for conflicting redeclarations and redefinitions. 908 } 909 910 // C: Function types need to be compatible, not identical. This handles 911 // duplicate function decls like "void f(int); void f(enum X);" properly. 912 if (!getLangOptions().CPlusPlus && 913 Context.typesAreCompatible(OldQType, NewQType)) { 914 const FunctionType *OldFuncType = OldQType->getAs<FunctionType>(); 915 const FunctionType *NewFuncType = NewQType->getAs<FunctionType>(); 916 const FunctionProtoType *OldProto = 0; 917 if (isa<FunctionNoProtoType>(NewFuncType) && 918 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 919 // The old declaration provided a function prototype, but the 920 // new declaration does not. Merge in the prototype. 921 assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); 922 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 923 OldProto->arg_type_end()); 924 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 925 ParamTypes.data(), ParamTypes.size(), 926 OldProto->isVariadic(), 927 OldProto->getTypeQuals()); 928 New->setType(NewQType); 929 New->setHasInheritedPrototype(); 930 931 // Synthesize a parameter for each argument type. 932 llvm::SmallVector<ParmVarDecl*, 16> Params; 933 for (FunctionProtoType::arg_type_iterator 934 ParamType = OldProto->arg_type_begin(), 935 ParamEnd = OldProto->arg_type_end(); 936 ParamType != ParamEnd; ++ParamType) { 937 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 938 SourceLocation(), 0, 939 *ParamType, /*TInfo=*/0, 940 VarDecl::None, 0); 941 Param->setImplicit(); 942 Params.push_back(Param); 943 } 944 945 New->setParams(Context, Params.data(), Params.size()); 946 } 947 948 return MergeCompatibleFunctionDecls(New, Old); 949 } 950 951 // GNU C permits a K&R definition to follow a prototype declaration 952 // if the declared types of the parameters in the K&R definition 953 // match the types in the prototype declaration, even when the 954 // promoted types of the parameters from the K&R definition differ 955 // from the types in the prototype. GCC then keeps the types from 956 // the prototype. 957 // 958 // If a variadic prototype is followed by a non-variadic K&R definition, 959 // the K&R definition becomes variadic. This is sort of an edge case, but 960 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and 961 // C99 6.9.1p8. 962 if (!getLangOptions().CPlusPlus && 963 Old->hasPrototype() && !New->hasPrototype() && 964 New->getType()->getAs<FunctionProtoType>() && 965 Old->getNumParams() == New->getNumParams()) { 966 llvm::SmallVector<QualType, 16> ArgTypes; 967 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 968 const FunctionProtoType *OldProto 969 = Old->getType()->getAs<FunctionProtoType>(); 970 const FunctionProtoType *NewProto 971 = New->getType()->getAs<FunctionProtoType>(); 972 973 // Determine whether this is the GNU C extension. 974 QualType MergedReturn = Context.mergeTypes(OldProto->getResultType(), 975 NewProto->getResultType()); 976 bool LooseCompatible = !MergedReturn.isNull(); 977 for (unsigned Idx = 0, End = Old->getNumParams(); 978 LooseCompatible && Idx != End; ++Idx) { 979 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 980 ParmVarDecl *NewParm = New->getParamDecl(Idx); 981 if (Context.typesAreCompatible(OldParm->getType(), 982 NewProto->getArgType(Idx))) { 983 ArgTypes.push_back(NewParm->getType()); 984 } else if (Context.typesAreCompatible(OldParm->getType(), 985 NewParm->getType())) { 986 GNUCompatibleParamWarning Warn 987 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 988 Warnings.push_back(Warn); 989 ArgTypes.push_back(NewParm->getType()); 990 } else 991 LooseCompatible = false; 992 } 993 994 if (LooseCompatible) { 995 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 996 Diag(Warnings[Warn].NewParm->getLocation(), 997 diag::ext_param_promoted_not_compatible_with_prototype) 998 << Warnings[Warn].PromotedType 999 << Warnings[Warn].OldParm->getType(); 1000 Diag(Warnings[Warn].OldParm->getLocation(), 1001 diag::note_previous_declaration); 1002 } 1003 1004 New->setType(Context.getFunctionType(MergedReturn, &ArgTypes[0], 1005 ArgTypes.size(), 1006 OldProto->isVariadic(), 0)); 1007 return MergeCompatibleFunctionDecls(New, Old); 1008 } 1009 1010 // Fall through to diagnose conflicting types. 1011 } 1012 1013 // A function that has already been declared has been redeclared or defined 1014 // with a different type- show appropriate diagnostic 1015 if (unsigned BuiltinID = Old->getBuiltinID()) { 1016 // The user has declared a builtin function with an incompatible 1017 // signature. 1018 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 1019 // The function the user is redeclaring is a library-defined 1020 // function like 'malloc' or 'printf'. Warn about the 1021 // redeclaration, then pretend that we don't know about this 1022 // library built-in. 1023 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 1024 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 1025 << Old << Old->getType(); 1026 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 1027 Old->setInvalidDecl(); 1028 return false; 1029 } 1030 1031 PrevDiag = diag::note_previous_builtin_declaration; 1032 } 1033 1034 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 1035 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 1036 return true; 1037} 1038 1039/// \brief Completes the merge of two function declarations that are 1040/// known to be compatible. 1041/// 1042/// This routine handles the merging of attributes and other 1043/// properties of function declarations form the old declaration to 1044/// the new declaration, once we know that New is in fact a 1045/// redeclaration of Old. 1046/// 1047/// \returns false 1048bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 1049 // Merge the attributes 1050 MergeAttributes(New, Old, Context); 1051 1052 // Merge the storage class. 1053 if (Old->getStorageClass() != FunctionDecl::Extern && 1054 Old->getStorageClass() != FunctionDecl::None) 1055 New->setStorageClass(Old->getStorageClass()); 1056 1057 // Merge "pure" flag. 1058 if (Old->isPure()) 1059 New->setPure(); 1060 1061 // Merge the "deleted" flag. 1062 if (Old->isDeleted()) 1063 New->setDeleted(); 1064 1065 if (getLangOptions().CPlusPlus) 1066 return MergeCXXFunctionDecl(New, Old); 1067 1068 return false; 1069} 1070 1071/// MergeVarDecl - We just parsed a variable 'New' which has the same name 1072/// and scope as a previous declaration 'Old'. Figure out how to resolve this 1073/// situation, merging decls or emitting diagnostics as appropriate. 1074/// 1075/// Tentative definition rules (C99 6.9.2p2) are checked by 1076/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 1077/// definitions here, since the initializer hasn't been attached. 1078/// 1079void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) { 1080 // If the new decl is already invalid, don't do any other checking. 1081 if (New->isInvalidDecl()) 1082 return; 1083 1084 // Verify the old decl was also a variable. 1085 VarDecl *Old = 0; 1086 if (!Previous.isSingleResult() || 1087 !(Old = dyn_cast<VarDecl>(Previous.getFoundDecl()))) { 1088 Diag(New->getLocation(), diag::err_redefinition_different_kind) 1089 << New->getDeclName(); 1090 Diag(Previous.getRepresentativeDecl()->getLocation(), 1091 diag::note_previous_definition); 1092 return New->setInvalidDecl(); 1093 } 1094 1095 MergeAttributes(New, Old, Context); 1096 1097 // Merge the types 1098 QualType MergedT; 1099 if (getLangOptions().CPlusPlus) { 1100 if (Context.hasSameType(New->getType(), Old->getType())) 1101 MergedT = New->getType(); 1102 // C++ [basic.link]p10: 1103 // [...] the types specified by all declarations referring to a given 1104 // object or function shall be identical, except that declarations for an 1105 // array object can specify array types that differ by the presence or 1106 // absence of a major array bound (8.3.4). 1107 else if (Old->getType()->isIncompleteArrayType() && 1108 New->getType()->isArrayType()) { 1109 CanQual<ArrayType> OldArray 1110 = Context.getCanonicalType(Old->getType())->getAs<ArrayType>(); 1111 CanQual<ArrayType> NewArray 1112 = Context.getCanonicalType(New->getType())->getAs<ArrayType>(); 1113 if (OldArray->getElementType() == NewArray->getElementType()) 1114 MergedT = New->getType(); 1115 } else if (Old->getType()->isArrayType() && 1116 New->getType()->isIncompleteArrayType()) { 1117 CanQual<ArrayType> OldArray 1118 = Context.getCanonicalType(Old->getType())->getAs<ArrayType>(); 1119 CanQual<ArrayType> NewArray 1120 = Context.getCanonicalType(New->getType())->getAs<ArrayType>(); 1121 if (OldArray->getElementType() == NewArray->getElementType()) 1122 MergedT = Old->getType(); 1123 } 1124 } else { 1125 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 1126 } 1127 if (MergedT.isNull()) { 1128 Diag(New->getLocation(), diag::err_redefinition_different_type) 1129 << New->getDeclName(); 1130 Diag(Old->getLocation(), diag::note_previous_definition); 1131 return New->setInvalidDecl(); 1132 } 1133 New->setType(MergedT); 1134 1135 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 1136 if (New->getStorageClass() == VarDecl::Static && 1137 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 1138 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 1139 Diag(Old->getLocation(), diag::note_previous_definition); 1140 return New->setInvalidDecl(); 1141 } 1142 // C99 6.2.2p4: 1143 // For an identifier declared with the storage-class specifier 1144 // extern in a scope in which a prior declaration of that 1145 // identifier is visible,23) if the prior declaration specifies 1146 // internal or external linkage, the linkage of the identifier at 1147 // the later declaration is the same as the linkage specified at 1148 // the prior declaration. If no prior declaration is visible, or 1149 // if the prior declaration specifies no linkage, then the 1150 // identifier has external linkage. 1151 if (New->hasExternalStorage() && Old->hasLinkage()) 1152 /* Okay */; 1153 else if (New->getStorageClass() != VarDecl::Static && 1154 Old->getStorageClass() == VarDecl::Static) { 1155 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 1156 Diag(Old->getLocation(), diag::note_previous_definition); 1157 return New->setInvalidDecl(); 1158 } 1159 1160 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 1161 1162 // FIXME: The test for external storage here seems wrong? We still 1163 // need to check for mismatches. 1164 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 1165 // Don't complain about out-of-line definitions of static members. 1166 !(Old->getLexicalDeclContext()->isRecord() && 1167 !New->getLexicalDeclContext()->isRecord())) { 1168 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 1169 Diag(Old->getLocation(), diag::note_previous_definition); 1170 return New->setInvalidDecl(); 1171 } 1172 1173 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 1174 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 1175 Diag(Old->getLocation(), diag::note_previous_definition); 1176 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 1177 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 1178 Diag(Old->getLocation(), diag::note_previous_definition); 1179 } 1180 1181 // Keep a chain of previous declarations. 1182 New->setPreviousDeclaration(Old); 1183} 1184 1185/// CheckFallThrough - Check that we don't fall off the end of a 1186/// Statement that should return a value. 1187/// 1188/// \returns AlwaysFallThrough iff we always fall off the end of the statement, 1189/// MaybeFallThrough iff we might or might not fall off the end, 1190/// NeverFallThroughOrReturn iff we never fall off the end of the statement or 1191/// return. We assume NeverFallThrough iff we never fall off the end of the 1192/// statement but we may return. We assume that functions not marked noreturn 1193/// will return. 1194Sema::ControlFlowKind Sema::CheckFallThrough(Stmt *Root) { 1195 // FIXME: Eventually share this CFG object when we have other warnings based 1196 // of the CFG. This can be done using AnalysisContext. 1197 llvm::OwningPtr<CFG> cfg (CFG::buildCFG(Root, &Context)); 1198 1199 // FIXME: They should never return 0, fix that, delete this code. 1200 if (cfg == 0) 1201 // FIXME: This should be NeverFallThrough 1202 return NeverFallThroughOrReturn; 1203 // The CFG leaves in dead things, and we don't want to dead code paths to 1204 // confuse us, so we mark all live things first. 1205 std::queue<CFGBlock*> workq; 1206 llvm::BitVector live(cfg->getNumBlockIDs()); 1207 // Prep work queue 1208 workq.push(&cfg->getEntry()); 1209 // Solve 1210 while (!workq.empty()) { 1211 CFGBlock *item = workq.front(); 1212 workq.pop(); 1213 live.set(item->getBlockID()); 1214 for (CFGBlock::succ_iterator I=item->succ_begin(), 1215 E=item->succ_end(); 1216 I != E; 1217 ++I) { 1218 if ((*I) && !live[(*I)->getBlockID()]) { 1219 live.set((*I)->getBlockID()); 1220 workq.push(*I); 1221 } 1222 } 1223 } 1224 1225 // Now we know what is live, we check the live precessors of the exit block 1226 // and look for fall through paths, being careful to ignore normal returns, 1227 // and exceptional paths. 1228 bool HasLiveReturn = false; 1229 bool HasFakeEdge = false; 1230 bool HasPlainEdge = false; 1231 for (CFGBlock::pred_iterator I=cfg->getExit().pred_begin(), 1232 E = cfg->getExit().pred_end(); 1233 I != E; 1234 ++I) { 1235 CFGBlock& B = **I; 1236 if (!live[B.getBlockID()]) 1237 continue; 1238 if (B.size() == 0) { 1239 // A labeled empty statement, or the entry block... 1240 HasPlainEdge = true; 1241 continue; 1242 } 1243 Stmt *S = B[B.size()-1]; 1244 if (isa<ReturnStmt>(S)) { 1245 HasLiveReturn = true; 1246 continue; 1247 } 1248 if (isa<ObjCAtThrowStmt>(S)) { 1249 HasFakeEdge = true; 1250 continue; 1251 } 1252 if (isa<CXXThrowExpr>(S)) { 1253 HasFakeEdge = true; 1254 continue; 1255 } 1256 if (isa<AsmStmt>(S)) { 1257 HasFakeEdge = true; 1258 HasLiveReturn = true; 1259 continue; 1260 } 1261 bool NoReturnEdge = false; 1262 if (CallExpr *C = dyn_cast<CallExpr>(S)) { 1263 Expr *CEE = C->getCallee()->IgnoreParenCasts(); 1264 if (CEE->getType().getNoReturnAttr()) { 1265 NoReturnEdge = true; 1266 HasFakeEdge = true; 1267 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) { 1268 ValueDecl *VD = DRE->getDecl(); 1269 if (VD->hasAttr<NoReturnAttr>()) { 1270 NoReturnEdge = true; 1271 HasFakeEdge = true; 1272 } 1273 } 1274 } 1275 // FIXME: Add noreturn message sends. 1276 if (NoReturnEdge == false) 1277 HasPlainEdge = true; 1278 } 1279 if (!HasPlainEdge) { 1280 if (HasLiveReturn) 1281 return NeverFallThrough; 1282 return NeverFallThroughOrReturn; 1283 } 1284 if (HasFakeEdge || HasLiveReturn) 1285 return MaybeFallThrough; 1286 // This says AlwaysFallThrough for calls to functions that are not marked 1287 // noreturn, that don't return. If people would like this warning to be more 1288 // accurate, such functions should be marked as noreturn. 1289 return AlwaysFallThrough; 1290} 1291 1292/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a 1293/// function that should return a value. Check that we don't fall off the end 1294/// of a noreturn function. We assume that functions and blocks not marked 1295/// noreturn will return. 1296void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body) { 1297 // FIXME: Would be nice if we had a better way to control cascading errors, 1298 // but for now, avoid them. The problem is that when Parse sees: 1299 // int foo() { return a; } 1300 // The return is eaten and the Sema code sees just: 1301 // int foo() { } 1302 // which this code would then warn about. 1303 if (getDiagnostics().hasErrorOccurred()) 1304 return; 1305 1306 bool ReturnsVoid = false; 1307 bool HasNoReturn = false; 1308 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1309 // If the result type of the function is a dependent type, we don't know 1310 // whether it will be void or not, so don't 1311 if (FD->getResultType()->isDependentType()) 1312 return; 1313 if (FD->getResultType()->isVoidType()) 1314 ReturnsVoid = true; 1315 if (FD->hasAttr<NoReturnAttr>()) 1316 HasNoReturn = true; 1317 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 1318 if (MD->getResultType()->isVoidType()) 1319 ReturnsVoid = true; 1320 if (MD->hasAttr<NoReturnAttr>()) 1321 HasNoReturn = true; 1322 } 1323 1324 // Short circuit for compilation speed. 1325 if ((Diags.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function) 1326 == Diagnostic::Ignored || ReturnsVoid) 1327 && (Diags.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr) 1328 == Diagnostic::Ignored || !HasNoReturn) 1329 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1330 == Diagnostic::Ignored || !ReturnsVoid)) 1331 return; 1332 // FIXME: Function try block 1333 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1334 switch (CheckFallThrough(Body)) { 1335 case MaybeFallThrough: 1336 if (HasNoReturn) 1337 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1338 else if (!ReturnsVoid) 1339 Diag(Compound->getRBracLoc(),diag::warn_maybe_falloff_nonvoid_function); 1340 break; 1341 case AlwaysFallThrough: 1342 if (HasNoReturn) 1343 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1344 else if (!ReturnsVoid) 1345 Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function); 1346 break; 1347 case NeverFallThroughOrReturn: 1348 if (ReturnsVoid && !HasNoReturn) 1349 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function); 1350 break; 1351 case NeverFallThrough: 1352 break; 1353 } 1354 } 1355} 1356 1357/// CheckFallThroughForBlock - Check that we don't fall off the end of a block 1358/// that should return a value. Check that we don't fall off the end of a 1359/// noreturn block. We assume that functions and blocks not marked noreturn 1360/// will return. 1361void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body) { 1362 // FIXME: Would be nice if we had a better way to control cascading errors, 1363 // but for now, avoid them. The problem is that when Parse sees: 1364 // int foo() { return a; } 1365 // The return is eaten and the Sema code sees just: 1366 // int foo() { } 1367 // which this code would then warn about. 1368 if (getDiagnostics().hasErrorOccurred()) 1369 return; 1370 bool ReturnsVoid = false; 1371 bool HasNoReturn = false; 1372 if (const FunctionType *FT =BlockTy->getPointeeType()->getAs<FunctionType>()){ 1373 if (FT->getResultType()->isVoidType()) 1374 ReturnsVoid = true; 1375 if (FT->getNoReturnAttr()) 1376 HasNoReturn = true; 1377 } 1378 1379 // Short circuit for compilation speed. 1380 if (ReturnsVoid 1381 && !HasNoReturn 1382 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1383 == Diagnostic::Ignored || !ReturnsVoid)) 1384 return; 1385 // FIXME: Funtion try block 1386 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1387 switch (CheckFallThrough(Body)) { 1388 case MaybeFallThrough: 1389 if (HasNoReturn) 1390 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1391 else if (!ReturnsVoid) 1392 Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block); 1393 break; 1394 case AlwaysFallThrough: 1395 if (HasNoReturn) 1396 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1397 else if (!ReturnsVoid) 1398 Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block); 1399 break; 1400 case NeverFallThroughOrReturn: 1401 if (ReturnsVoid) 1402 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block); 1403 break; 1404 case NeverFallThrough: 1405 break; 1406 } 1407 } 1408} 1409 1410/// CheckParmsForFunctionDef - Check that the parameters of the given 1411/// function are appropriate for the definition of a function. This 1412/// takes care of any checks that cannot be performed on the 1413/// declaration itself, e.g., that the types of each of the function 1414/// parameters are complete. 1415bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 1416 bool HasInvalidParm = false; 1417 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1418 ParmVarDecl *Param = FD->getParamDecl(p); 1419 1420 // C99 6.7.5.3p4: the parameters in a parameter type list in a 1421 // function declarator that is part of a function definition of 1422 // that function shall not have incomplete type. 1423 // 1424 // This is also C++ [dcl.fct]p6. 1425 if (!Param->isInvalidDecl() && 1426 RequireCompleteType(Param->getLocation(), Param->getType(), 1427 diag::err_typecheck_decl_incomplete_type)) { 1428 Param->setInvalidDecl(); 1429 HasInvalidParm = true; 1430 } 1431 1432 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1433 // declaration of each parameter shall include an identifier. 1434 if (Param->getIdentifier() == 0 && 1435 !Param->isImplicit() && 1436 !getLangOptions().CPlusPlus) 1437 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1438 } 1439 1440 return HasInvalidParm; 1441} 1442 1443/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1444/// no declarator (e.g. "struct foo;") is parsed. 1445Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1446 // FIXME: Error on auto/register at file scope 1447 // FIXME: Error on inline/virtual/explicit 1448 // FIXME: Warn on useless __thread 1449 // FIXME: Warn on useless const/volatile 1450 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1451 // FIXME: Warn on useless attributes 1452 Decl *TagD = 0; 1453 TagDecl *Tag = 0; 1454 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1455 DS.getTypeSpecType() == DeclSpec::TST_struct || 1456 DS.getTypeSpecType() == DeclSpec::TST_union || 1457 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1458 TagD = static_cast<Decl *>(DS.getTypeRep()); 1459 1460 if (!TagD) // We probably had an error 1461 return DeclPtrTy(); 1462 1463 // Note that the above type specs guarantee that the 1464 // type rep is a Decl, whereas in many of the others 1465 // it's a Type. 1466 Tag = dyn_cast<TagDecl>(TagD); 1467 } 1468 1469 if (unsigned TypeQuals = DS.getTypeQualifiers()) { 1470 // Enforce C99 6.7.3p2: "Types other than pointer types derived from object 1471 // or incomplete types shall not be restrict-qualified." 1472 if (TypeQuals & DeclSpec::TQ_restrict) 1473 Diag(DS.getRestrictSpecLoc(), 1474 diag::err_typecheck_invalid_restrict_not_pointer_noarg) 1475 << DS.getSourceRange(); 1476 } 1477 1478 if (DS.isFriendSpecified()) { 1479 // If we're dealing with a class template decl, assume that the 1480 // template routines are handling it. 1481 if (TagD && isa<ClassTemplateDecl>(TagD)) 1482 return DeclPtrTy(); 1483 return ActOnFriendTypeDecl(S, DS, MultiTemplateParamsArg(*this, 0, 0)); 1484 } 1485 1486 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1487 // If there are attributes in the DeclSpec, apply them to the record. 1488 if (const AttributeList *AL = DS.getAttributes()) 1489 ProcessDeclAttributeList(S, Record, AL); 1490 1491 if (!Record->getDeclName() && Record->isDefinition() && 1492 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1493 if (getLangOptions().CPlusPlus || 1494 Record->getDeclContext()->isRecord()) 1495 return BuildAnonymousStructOrUnion(S, DS, Record); 1496 1497 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1498 << DS.getSourceRange(); 1499 } 1500 1501 // Microsoft allows unnamed struct/union fields. Don't complain 1502 // about them. 1503 // FIXME: Should we support Microsoft's extensions in this area? 1504 if (Record->getDeclName() && getLangOptions().Microsoft) 1505 return DeclPtrTy::make(Tag); 1506 } 1507 1508 if (!DS.isMissingDeclaratorOk() && 1509 DS.getTypeSpecType() != DeclSpec::TST_error) { 1510 // Warn about typedefs of enums without names, since this is an 1511 // extension in both Microsoft an GNU. 1512 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1513 Tag && isa<EnumDecl>(Tag)) { 1514 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1515 << DS.getSourceRange(); 1516 return DeclPtrTy::make(Tag); 1517 } 1518 1519 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1520 << DS.getSourceRange(); 1521 return DeclPtrTy(); 1522 } 1523 1524 return DeclPtrTy::make(Tag); 1525} 1526 1527/// We are trying to introduce the given name into the given context; 1528/// check if there's an existing declaration that can't be overloaded. 1529/// 1530/// \return true if this is a forbidden redeclaration 1531bool Sema::CheckRedeclaration(DeclContext *DC, 1532 DeclarationName Name, 1533 SourceLocation NameLoc, 1534 unsigned diagnostic) { 1535 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName, 1536 ForRedeclaration); 1537 LookupQualifiedName(R, DC); 1538 1539 if (R.empty()) return false; 1540 1541 if (R.getResultKind() == LookupResult::Found && 1542 isa<TagDecl>(R.getFoundDecl())) 1543 return false; 1544 1545 // Pick a representative declaration. 1546 NamedDecl *PrevDecl = (*R.begin())->getUnderlyingDecl(); 1547 1548 Diag(NameLoc, diagnostic) << Name; 1549 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1550 1551 return true; 1552} 1553 1554/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1555/// anonymous struct or union AnonRecord into the owning context Owner 1556/// and scope S. This routine will be invoked just after we realize 1557/// that an unnamed union or struct is actually an anonymous union or 1558/// struct, e.g., 1559/// 1560/// @code 1561/// union { 1562/// int i; 1563/// float f; 1564/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1565/// // f into the surrounding scope.x 1566/// @endcode 1567/// 1568/// This routine is recursive, injecting the names of nested anonymous 1569/// structs/unions into the owning context and scope as well. 1570bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1571 RecordDecl *AnonRecord) { 1572 unsigned diagKind 1573 = AnonRecord->isUnion() ? diag::err_anonymous_union_member_redecl 1574 : diag::err_anonymous_struct_member_redecl; 1575 1576 bool Invalid = false; 1577 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 1578 FEnd = AnonRecord->field_end(); 1579 F != FEnd; ++F) { 1580 if ((*F)->getDeclName()) { 1581 if (CheckRedeclaration(Owner, (*F)->getDeclName(), 1582 (*F)->getLocation(), diagKind)) { 1583 // C++ [class.union]p2: 1584 // The names of the members of an anonymous union shall be 1585 // distinct from the names of any other entity in the 1586 // scope in which the anonymous union is declared. 1587 Invalid = true; 1588 } else { 1589 // C++ [class.union]p2: 1590 // For the purpose of name lookup, after the anonymous union 1591 // definition, the members of the anonymous union are 1592 // considered to have been defined in the scope in which the 1593 // anonymous union is declared. 1594 Owner->makeDeclVisibleInContext(*F); 1595 S->AddDecl(DeclPtrTy::make(*F)); 1596 IdResolver.AddDecl(*F); 1597 } 1598 } else if (const RecordType *InnerRecordType 1599 = (*F)->getType()->getAs<RecordType>()) { 1600 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1601 if (InnerRecord->isAnonymousStructOrUnion()) 1602 Invalid = Invalid || 1603 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1604 } 1605 } 1606 1607 return Invalid; 1608} 1609 1610/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1611/// anonymous structure or union. Anonymous unions are a C++ feature 1612/// (C++ [class.union]) and a GNU C extension; anonymous structures 1613/// are a GNU C and GNU C++ extension. 1614Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1615 RecordDecl *Record) { 1616 DeclContext *Owner = Record->getDeclContext(); 1617 1618 // Diagnose whether this anonymous struct/union is an extension. 1619 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1620 Diag(Record->getLocation(), diag::ext_anonymous_union); 1621 else if (!Record->isUnion()) 1622 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1623 1624 // C and C++ require different kinds of checks for anonymous 1625 // structs/unions. 1626 bool Invalid = false; 1627 if (getLangOptions().CPlusPlus) { 1628 const char* PrevSpec = 0; 1629 unsigned DiagID; 1630 // C++ [class.union]p3: 1631 // Anonymous unions declared in a named namespace or in the 1632 // global namespace shall be declared static. 1633 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1634 (isa<TranslationUnitDecl>(Owner) || 1635 (isa<NamespaceDecl>(Owner) && 1636 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1637 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1638 Invalid = true; 1639 1640 // Recover by adding 'static'. 1641 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), 1642 PrevSpec, DiagID); 1643 } 1644 // C++ [class.union]p3: 1645 // A storage class is not allowed in a declaration of an 1646 // anonymous union in a class scope. 1647 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1648 isa<RecordDecl>(Owner)) { 1649 Diag(DS.getStorageClassSpecLoc(), 1650 diag::err_anonymous_union_with_storage_spec); 1651 Invalid = true; 1652 1653 // Recover by removing the storage specifier. 1654 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1655 PrevSpec, DiagID); 1656 } 1657 1658 // C++ [class.union]p2: 1659 // The member-specification of an anonymous union shall only 1660 // define non-static data members. [Note: nested types and 1661 // functions cannot be declared within an anonymous union. ] 1662 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 1663 MemEnd = Record->decls_end(); 1664 Mem != MemEnd; ++Mem) { 1665 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1666 // C++ [class.union]p3: 1667 // An anonymous union shall not have private or protected 1668 // members (clause 11). 1669 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1670 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1671 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1672 Invalid = true; 1673 } 1674 } else if ((*Mem)->isImplicit()) { 1675 // Any implicit members are fine. 1676 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1677 // This is a type that showed up in an 1678 // elaborated-type-specifier inside the anonymous struct or 1679 // union, but which actually declares a type outside of the 1680 // anonymous struct or union. It's okay. 1681 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1682 if (!MemRecord->isAnonymousStructOrUnion() && 1683 MemRecord->getDeclName()) { 1684 // This is a nested type declaration. 1685 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1686 << (int)Record->isUnion(); 1687 Invalid = true; 1688 } 1689 } else { 1690 // We have something that isn't a non-static data 1691 // member. Complain about it. 1692 unsigned DK = diag::err_anonymous_record_bad_member; 1693 if (isa<TypeDecl>(*Mem)) 1694 DK = diag::err_anonymous_record_with_type; 1695 else if (isa<FunctionDecl>(*Mem)) 1696 DK = diag::err_anonymous_record_with_function; 1697 else if (isa<VarDecl>(*Mem)) 1698 DK = diag::err_anonymous_record_with_static; 1699 Diag((*Mem)->getLocation(), DK) 1700 << (int)Record->isUnion(); 1701 Invalid = true; 1702 } 1703 } 1704 } 1705 1706 if (!Record->isUnion() && !Owner->isRecord()) { 1707 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1708 << (int)getLangOptions().CPlusPlus; 1709 Invalid = true; 1710 } 1711 1712 // Mock up a declarator. 1713 Declarator Dc(DS, Declarator::TypeNameContext); 1714 TypeSourceInfo *TInfo = 0; 1715 GetTypeForDeclarator(Dc, S, &TInfo); 1716 assert(TInfo && "couldn't build declarator info for anonymous struct/union"); 1717 1718 // Create a declaration for this anonymous struct/union. 1719 NamedDecl *Anon = 0; 1720 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1721 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1722 /*IdentifierInfo=*/0, 1723 Context.getTypeDeclType(Record), 1724 TInfo, 1725 /*BitWidth=*/0, /*Mutable=*/false); 1726 Anon->setAccess(AS_public); 1727 if (getLangOptions().CPlusPlus) 1728 FieldCollector->Add(cast<FieldDecl>(Anon)); 1729 } else { 1730 VarDecl::StorageClass SC; 1731 switch (DS.getStorageClassSpec()) { 1732 default: assert(0 && "Unknown storage class!"); 1733 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1734 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1735 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1736 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1737 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1738 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1739 case DeclSpec::SCS_mutable: 1740 // mutable can only appear on non-static class members, so it's always 1741 // an error here 1742 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1743 Invalid = true; 1744 SC = VarDecl::None; 1745 break; 1746 } 1747 1748 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1749 /*IdentifierInfo=*/0, 1750 Context.getTypeDeclType(Record), 1751 TInfo, 1752 SC); 1753 } 1754 Anon->setImplicit(); 1755 1756 // Add the anonymous struct/union object to the current 1757 // context. We'll be referencing this object when we refer to one of 1758 // its members. 1759 Owner->addDecl(Anon); 1760 1761 // Inject the members of the anonymous struct/union into the owning 1762 // context and into the identifier resolver chain for name lookup 1763 // purposes. 1764 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1765 Invalid = true; 1766 1767 // Mark this as an anonymous struct/union type. Note that we do not 1768 // do this until after we have already checked and injected the 1769 // members of this anonymous struct/union type, because otherwise 1770 // the members could be injected twice: once by DeclContext when it 1771 // builds its lookup table, and once by 1772 // InjectAnonymousStructOrUnionMembers. 1773 Record->setAnonymousStructOrUnion(true); 1774 1775 if (Invalid) 1776 Anon->setInvalidDecl(); 1777 1778 return DeclPtrTy::make(Anon); 1779} 1780 1781 1782/// GetNameForDeclarator - Determine the full declaration name for the 1783/// given Declarator. 1784DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1785 return GetNameFromUnqualifiedId(D.getName()); 1786} 1787 1788/// \brief Retrieves the canonicalized name from a parsed unqualified-id. 1789DeclarationName Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) { 1790 switch (Name.getKind()) { 1791 case UnqualifiedId::IK_Identifier: 1792 return DeclarationName(Name.Identifier); 1793 1794 case UnqualifiedId::IK_OperatorFunctionId: 1795 return Context.DeclarationNames.getCXXOperatorName( 1796 Name.OperatorFunctionId.Operator); 1797 1798 case UnqualifiedId::IK_LiteralOperatorId: 1799 return Context.DeclarationNames.getCXXLiteralOperatorName( 1800 Name.Identifier); 1801 1802 case UnqualifiedId::IK_ConversionFunctionId: { 1803 QualType Ty = GetTypeFromParser(Name.ConversionFunctionId); 1804 if (Ty.isNull()) 1805 return DeclarationName(); 1806 1807 return Context.DeclarationNames.getCXXConversionFunctionName( 1808 Context.getCanonicalType(Ty)); 1809 } 1810 1811 case UnqualifiedId::IK_ConstructorName: { 1812 QualType Ty = GetTypeFromParser(Name.ConstructorName); 1813 if (Ty.isNull()) 1814 return DeclarationName(); 1815 1816 return Context.DeclarationNames.getCXXConstructorName( 1817 Context.getCanonicalType(Ty)); 1818 } 1819 1820 case UnqualifiedId::IK_DestructorName: { 1821 QualType Ty = GetTypeFromParser(Name.DestructorName); 1822 if (Ty.isNull()) 1823 return DeclarationName(); 1824 1825 return Context.DeclarationNames.getCXXDestructorName( 1826 Context.getCanonicalType(Ty)); 1827 } 1828 1829 case UnqualifiedId::IK_TemplateId: { 1830 TemplateName TName 1831 = TemplateName::getFromVoidPointer(Name.TemplateId->Template); 1832 return Context.getNameForTemplate(TName); 1833 } 1834 } 1835 1836 assert(false && "Unknown name kind"); 1837 return DeclarationName(); 1838} 1839 1840/// isNearlyMatchingFunction - Determine whether the C++ functions 1841/// Declaration and Definition are "nearly" matching. This heuristic 1842/// is used to improve diagnostics in the case where an out-of-line 1843/// function definition doesn't match any declaration within 1844/// the class or namespace. 1845static bool isNearlyMatchingFunction(ASTContext &Context, 1846 FunctionDecl *Declaration, 1847 FunctionDecl *Definition) { 1848 if (Declaration->param_size() != Definition->param_size()) 1849 return false; 1850 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1851 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1852 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1853 1854 if (!Context.hasSameUnqualifiedType(DeclParamTy.getNonReferenceType(), 1855 DefParamTy.getNonReferenceType())) 1856 return false; 1857 } 1858 1859 return true; 1860} 1861 1862Sema::DeclPtrTy 1863Sema::HandleDeclarator(Scope *S, Declarator &D, 1864 MultiTemplateParamsArg TemplateParamLists, 1865 bool IsFunctionDefinition) { 1866 DeclarationName Name = GetNameForDeclarator(D); 1867 1868 // All of these full declarators require an identifier. If it doesn't have 1869 // one, the ParsedFreeStandingDeclSpec action should be used. 1870 if (!Name) { 1871 if (!D.isInvalidType()) // Reject this if we think it is valid. 1872 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1873 diag::err_declarator_need_ident) 1874 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1875 return DeclPtrTy(); 1876 } 1877 1878 // The scope passed in may not be a decl scope. Zip up the scope tree until 1879 // we find one that is. 1880 while ((S->getFlags() & Scope::DeclScope) == 0 || 1881 (S->getFlags() & Scope::TemplateParamScope) != 0) 1882 S = S->getParent(); 1883 1884 // If this is an out-of-line definition of a member of a class template 1885 // or class template partial specialization, we may need to rebuild the 1886 // type specifier in the declarator. See RebuildTypeInCurrentInstantiation() 1887 // for more information. 1888 // FIXME: cope with decltype(expr) and typeof(expr) once the rebuilder can 1889 // handle expressions properly. 1890 DeclSpec &DS = const_cast<DeclSpec&>(D.getDeclSpec()); 1891 if (D.getCXXScopeSpec().isSet() && !D.getCXXScopeSpec().isInvalid() && 1892 isDependentScopeSpecifier(D.getCXXScopeSpec()) && 1893 (DS.getTypeSpecType() == DeclSpec::TST_typename || 1894 DS.getTypeSpecType() == DeclSpec::TST_typeofType || 1895 DS.getTypeSpecType() == DeclSpec::TST_typeofExpr || 1896 DS.getTypeSpecType() == DeclSpec::TST_decltype)) { 1897 if (DeclContext *DC = computeDeclContext(D.getCXXScopeSpec(), true)) { 1898 // FIXME: Preserve type source info. 1899 QualType T = GetTypeFromParser(DS.getTypeRep()); 1900 EnterDeclaratorContext(S, DC); 1901 T = RebuildTypeInCurrentInstantiation(T, D.getIdentifierLoc(), Name); 1902 ExitDeclaratorContext(S); 1903 if (T.isNull()) 1904 return DeclPtrTy(); 1905 DS.UpdateTypeRep(T.getAsOpaquePtr()); 1906 } 1907 } 1908 1909 DeclContext *DC; 1910 NamedDecl *New; 1911 1912 TypeSourceInfo *TInfo = 0; 1913 QualType R = GetTypeForDeclarator(D, S, &TInfo); 1914 1915 LookupResult Previous(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName, 1916 ForRedeclaration); 1917 1918 // See if this is a redefinition of a variable in the same scope. 1919 if (D.getCXXScopeSpec().isInvalid()) { 1920 DC = CurContext; 1921 D.setInvalidType(); 1922 } else if (!D.getCXXScopeSpec().isSet()) { 1923 bool IsLinkageLookup = false; 1924 1925 // If the declaration we're planning to build will be a function 1926 // or object with linkage, then look for another declaration with 1927 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1928 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1929 /* Do nothing*/; 1930 else if (R->isFunctionType()) { 1931 if (CurContext->isFunctionOrMethod() || 1932 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1933 IsLinkageLookup = true; 1934 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1935 IsLinkageLookup = true; 1936 else if (CurContext->getLookupContext()->isTranslationUnit() && 1937 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1938 IsLinkageLookup = true; 1939 1940 if (IsLinkageLookup) 1941 Previous.clear(LookupRedeclarationWithLinkage); 1942 1943 DC = CurContext; 1944 LookupName(Previous, S, /* CreateBuiltins = */ IsLinkageLookup); 1945 } else { // Something like "int foo::x;" 1946 DC = computeDeclContext(D.getCXXScopeSpec(), true); 1947 1948 if (!DC) { 1949 // If we could not compute the declaration context, it's because the 1950 // declaration context is dependent but does not refer to a class, 1951 // class template, or class template partial specialization. Complain 1952 // and return early, to avoid the coming semantic disaster. 1953 Diag(D.getIdentifierLoc(), 1954 diag::err_template_qualified_declarator_no_match) 1955 << (NestedNameSpecifier*)D.getCXXScopeSpec().getScopeRep() 1956 << D.getCXXScopeSpec().getRange(); 1957 return DeclPtrTy(); 1958 } 1959 1960 if (!DC->isDependentContext() && 1961 RequireCompleteDeclContext(D.getCXXScopeSpec())) 1962 return DeclPtrTy(); 1963 1964 LookupQualifiedName(Previous, DC); 1965 1966 // Don't consider using declarations as previous declarations for 1967 // out-of-line members. 1968 RemoveUsingDecls(Previous); 1969 1970 // C++ 7.3.1.2p2: 1971 // Members (including explicit specializations of templates) of a named 1972 // namespace can also be defined outside that namespace by explicit 1973 // qualification of the name being defined, provided that the entity being 1974 // defined was already declared in the namespace and the definition appears 1975 // after the point of declaration in a namespace that encloses the 1976 // declarations namespace. 1977 // 1978 // Note that we only check the context at this point. We don't yet 1979 // have enough information to make sure that PrevDecl is actually 1980 // the declaration we want to match. For example, given: 1981 // 1982 // class X { 1983 // void f(); 1984 // void f(float); 1985 // }; 1986 // 1987 // void X::f(int) { } // ill-formed 1988 // 1989 // In this case, PrevDecl will point to the overload set 1990 // containing the two f's declared in X, but neither of them 1991 // matches. 1992 1993 // First check whether we named the global scope. 1994 if (isa<TranslationUnitDecl>(DC)) { 1995 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1996 << Name << D.getCXXScopeSpec().getRange(); 1997 } else { 1998 DeclContext *Cur = CurContext; 1999 while (isa<LinkageSpecDecl>(Cur)) 2000 Cur = Cur->getParent(); 2001 if (!Cur->Encloses(DC)) { 2002 // The qualifying scope doesn't enclose the original declaration. 2003 // Emit diagnostic based on current scope. 2004 SourceLocation L = D.getIdentifierLoc(); 2005 SourceRange R = D.getCXXScopeSpec().getRange(); 2006 if (isa<FunctionDecl>(Cur)) 2007 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 2008 else 2009 Diag(L, diag::err_invalid_declarator_scope) 2010 << Name << cast<NamedDecl>(DC) << R; 2011 D.setInvalidType(); 2012 } 2013 } 2014 } 2015 2016 if (Previous.isSingleResult() && 2017 Previous.getFoundDecl()->isTemplateParameter()) { 2018 // Maybe we will complain about the shadowed template parameter. 2019 if (!D.isInvalidType()) 2020 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), 2021 Previous.getFoundDecl())) 2022 D.setInvalidType(); 2023 2024 // Just pretend that we didn't see the previous declaration. 2025 Previous.clear(); 2026 } 2027 2028 // In C++, the previous declaration we find might be a tag type 2029 // (class or enum). In this case, the new declaration will hide the 2030 // tag type. Note that this does does not apply if we're declaring a 2031 // typedef (C++ [dcl.typedef]p4). 2032 if (Previous.isSingleTagDecl() && 2033 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 2034 Previous.clear(); 2035 2036 bool Redeclaration = false; 2037 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 2038 if (TemplateParamLists.size()) { 2039 Diag(D.getIdentifierLoc(), diag::err_template_typedef); 2040 return DeclPtrTy(); 2041 } 2042 2043 New = ActOnTypedefDeclarator(S, D, DC, R, TInfo, Previous, Redeclaration); 2044 } else if (R->isFunctionType()) { 2045 New = ActOnFunctionDeclarator(S, D, DC, R, TInfo, Previous, 2046 move(TemplateParamLists), 2047 IsFunctionDefinition, Redeclaration); 2048 } else { 2049 New = ActOnVariableDeclarator(S, D, DC, R, TInfo, Previous, 2050 move(TemplateParamLists), 2051 Redeclaration); 2052 } 2053 2054 if (New == 0) 2055 return DeclPtrTy(); 2056 2057 // If this has an identifier and is not an invalid redeclaration or 2058 // function template specialization, add it to the scope stack. 2059 if (Name && !(Redeclaration && New->isInvalidDecl())) 2060 PushOnScopeChains(New, S); 2061 2062 return DeclPtrTy::make(New); 2063} 2064 2065/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2066/// types into constant array types in certain situations which would otherwise 2067/// be errors (for GCC compatibility). 2068static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2069 ASTContext &Context, 2070 bool &SizeIsNegative) { 2071 // This method tries to turn a variable array into a constant 2072 // array even when the size isn't an ICE. This is necessary 2073 // for compatibility with code that depends on gcc's buggy 2074 // constant expression folding, like struct {char x[(int)(char*)2];} 2075 SizeIsNegative = false; 2076 2077 QualifierCollector Qs; 2078 const Type *Ty = Qs.strip(T); 2079 2080 if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) { 2081 QualType Pointee = PTy->getPointeeType(); 2082 QualType FixedType = 2083 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 2084 if (FixedType.isNull()) return FixedType; 2085 FixedType = Context.getPointerType(FixedType); 2086 return Qs.apply(FixedType); 2087 } 2088 2089 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2090 if (!VLATy) 2091 return QualType(); 2092 // FIXME: We should probably handle this case 2093 if (VLATy->getElementType()->isVariablyModifiedType()) 2094 return QualType(); 2095 2096 Expr::EvalResult EvalResult; 2097 if (!VLATy->getSizeExpr() || 2098 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 2099 !EvalResult.Val.isInt()) 2100 return QualType(); 2101 2102 llvm::APSInt &Res = EvalResult.Val.getInt(); 2103 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) { 2104 // TODO: preserve the size expression in declarator info 2105 return Context.getConstantArrayType(VLATy->getElementType(), 2106 Res, ArrayType::Normal, 0); 2107 } 2108 2109 SizeIsNegative = true; 2110 return QualType(); 2111} 2112 2113/// \brief Register the given locally-scoped external C declaration so 2114/// that it can be found later for redeclarations 2115void 2116Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, 2117 const LookupResult &Previous, 2118 Scope *S) { 2119 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 2120 "Decl is not a locally-scoped decl!"); 2121 // Note that we have a locally-scoped external with this name. 2122 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 2123 2124 if (!Previous.isSingleResult()) 2125 return; 2126 2127 NamedDecl *PrevDecl = Previous.getFoundDecl(); 2128 2129 // If there was a previous declaration of this variable, it may be 2130 // in our identifier chain. Update the identifier chain with the new 2131 // declaration. 2132 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 2133 // The previous declaration was found on the identifer resolver 2134 // chain, so remove it from its scope. 2135 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 2136 S = S->getParent(); 2137 2138 if (S) 2139 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 2140 } 2141} 2142 2143/// \brief Diagnose function specifiers on a declaration of an identifier that 2144/// does not identify a function. 2145void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 2146 // FIXME: We should probably indicate the identifier in question to avoid 2147 // confusion for constructs like "inline int a(), b;" 2148 if (D.getDeclSpec().isInlineSpecified()) 2149 Diag(D.getDeclSpec().getInlineSpecLoc(), 2150 diag::err_inline_non_function); 2151 2152 if (D.getDeclSpec().isVirtualSpecified()) 2153 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2154 diag::err_virtual_non_function); 2155 2156 if (D.getDeclSpec().isExplicitSpecified()) 2157 Diag(D.getDeclSpec().getExplicitSpecLoc(), 2158 diag::err_explicit_non_function); 2159} 2160 2161NamedDecl* 2162Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2163 QualType R, TypeSourceInfo *TInfo, 2164 LookupResult &Previous, bool &Redeclaration) { 2165 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 2166 if (D.getCXXScopeSpec().isSet()) { 2167 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 2168 << D.getCXXScopeSpec().getRange(); 2169 D.setInvalidType(); 2170 // Pretend we didn't see the scope specifier. 2171 DC = 0; 2172 } 2173 2174 if (getLangOptions().CPlusPlus) { 2175 // Check that there are no default arguments (C++ only). 2176 CheckExtraCXXDefaultArguments(D); 2177 } 2178 2179 DiagnoseFunctionSpecifiers(D); 2180 2181 if (D.getDeclSpec().isThreadSpecified()) 2182 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2183 2184 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, TInfo); 2185 if (!NewTD) return 0; 2186 2187 // Handle attributes prior to checking for duplicates in MergeVarDecl 2188 ProcessDeclAttributes(S, NewTD, D); 2189 2190 // Merge the decl with the existing one if appropriate. If the decl is 2191 // in an outer scope, it isn't the same thing. 2192 FilterLookupForScope(*this, Previous, DC, S, /*ConsiderLinkage*/ false); 2193 if (!Previous.empty()) { 2194 Redeclaration = true; 2195 MergeTypeDefDecl(NewTD, Previous); 2196 } 2197 2198 // C99 6.7.7p2: If a typedef name specifies a variably modified type 2199 // then it shall have block scope. 2200 QualType T = NewTD->getUnderlyingType(); 2201 if (T->isVariablyModifiedType()) { 2202 CurFunctionNeedsScopeChecking = true; 2203 2204 if (S->getFnParent() == 0) { 2205 bool SizeIsNegative; 2206 QualType FixedTy = 2207 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2208 if (!FixedTy.isNull()) { 2209 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 2210 NewTD->setTypeSourceInfo(Context.getTrivialTypeSourceInfo(FixedTy)); 2211 } else { 2212 if (SizeIsNegative) 2213 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 2214 else if (T->isVariableArrayType()) 2215 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 2216 else 2217 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 2218 NewTD->setInvalidDecl(); 2219 } 2220 } 2221 } 2222 2223 // If this is the C FILE type, notify the AST context. 2224 if (IdentifierInfo *II = NewTD->getIdentifier()) 2225 if (!NewTD->isInvalidDecl() && 2226 NewTD->getDeclContext()->getLookupContext()->isTranslationUnit()) { 2227 if (II->isStr("FILE")) 2228 Context.setFILEDecl(NewTD); 2229 else if (II->isStr("jmp_buf")) 2230 Context.setjmp_bufDecl(NewTD); 2231 else if (II->isStr("sigjmp_buf")) 2232 Context.setsigjmp_bufDecl(NewTD); 2233 } 2234 2235 return NewTD; 2236} 2237 2238/// \brief Determines whether the given declaration is an out-of-scope 2239/// previous declaration. 2240/// 2241/// This routine should be invoked when name lookup has found a 2242/// previous declaration (PrevDecl) that is not in the scope where a 2243/// new declaration by the same name is being introduced. If the new 2244/// declaration occurs in a local scope, previous declarations with 2245/// linkage may still be considered previous declarations (C99 2246/// 6.2.2p4-5, C++ [basic.link]p6). 2247/// 2248/// \param PrevDecl the previous declaration found by name 2249/// lookup 2250/// 2251/// \param DC the context in which the new declaration is being 2252/// declared. 2253/// 2254/// \returns true if PrevDecl is an out-of-scope previous declaration 2255/// for a new delcaration with the same name. 2256static bool 2257isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 2258 ASTContext &Context) { 2259 if (!PrevDecl) 2260 return 0; 2261 2262 if (!PrevDecl->hasLinkage()) 2263 return false; 2264 2265 if (Context.getLangOptions().CPlusPlus) { 2266 // C++ [basic.link]p6: 2267 // If there is a visible declaration of an entity with linkage 2268 // having the same name and type, ignoring entities declared 2269 // outside the innermost enclosing namespace scope, the block 2270 // scope declaration declares that same entity and receives the 2271 // linkage of the previous declaration. 2272 DeclContext *OuterContext = DC->getLookupContext(); 2273 if (!OuterContext->isFunctionOrMethod()) 2274 // This rule only applies to block-scope declarations. 2275 return false; 2276 else { 2277 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 2278 if (PrevOuterContext->isRecord()) 2279 // We found a member function: ignore it. 2280 return false; 2281 else { 2282 // Find the innermost enclosing namespace for the new and 2283 // previous declarations. 2284 while (!OuterContext->isFileContext()) 2285 OuterContext = OuterContext->getParent(); 2286 while (!PrevOuterContext->isFileContext()) 2287 PrevOuterContext = PrevOuterContext->getParent(); 2288 2289 // The previous declaration is in a different namespace, so it 2290 // isn't the same function. 2291 if (OuterContext->getPrimaryContext() != 2292 PrevOuterContext->getPrimaryContext()) 2293 return false; 2294 } 2295 } 2296 } 2297 2298 return true; 2299} 2300 2301NamedDecl* 2302Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2303 QualType R, TypeSourceInfo *TInfo, 2304 LookupResult &Previous, 2305 MultiTemplateParamsArg TemplateParamLists, 2306 bool &Redeclaration) { 2307 DeclarationName Name = GetNameForDeclarator(D); 2308 2309 // Check that there are no default arguments (C++ only). 2310 if (getLangOptions().CPlusPlus) 2311 CheckExtraCXXDefaultArguments(D); 2312 2313 VarDecl *NewVD; 2314 VarDecl::StorageClass SC; 2315 switch (D.getDeclSpec().getStorageClassSpec()) { 2316 default: assert(0 && "Unknown storage class!"); 2317 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2318 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2319 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2320 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2321 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2322 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2323 case DeclSpec::SCS_mutable: 2324 // mutable can only appear on non-static class members, so it's always 2325 // an error here 2326 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 2327 D.setInvalidType(); 2328 SC = VarDecl::None; 2329 break; 2330 } 2331 2332 IdentifierInfo *II = Name.getAsIdentifierInfo(); 2333 if (!II) { 2334 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 2335 << Name.getAsString(); 2336 return 0; 2337 } 2338 2339 DiagnoseFunctionSpecifiers(D); 2340 2341 if (!DC->isRecord() && S->getFnParent() == 0) { 2342 // C99 6.9p2: The storage-class specifiers auto and register shall not 2343 // appear in the declaration specifiers in an external declaration. 2344 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 2345 2346 // If this is a register variable with an asm label specified, then this 2347 // is a GNU extension. 2348 if (SC == VarDecl::Register && D.getAsmLabel()) 2349 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 2350 else 2351 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 2352 D.setInvalidType(); 2353 } 2354 } 2355 if (DC->isRecord() && !CurContext->isRecord()) { 2356 // This is an out-of-line definition of a static data member. 2357 if (SC == VarDecl::Static) { 2358 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2359 diag::err_static_out_of_line) 2360 << CodeModificationHint::CreateRemoval( 2361 D.getDeclSpec().getStorageClassSpecLoc()); 2362 } else if (SC == VarDecl::None) 2363 SC = VarDecl::Static; 2364 } 2365 if (SC == VarDecl::Static) { 2366 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 2367 if (RD->isLocalClass()) 2368 Diag(D.getIdentifierLoc(), 2369 diag::err_static_data_member_not_allowed_in_local_class) 2370 << Name << RD->getDeclName(); 2371 } 2372 } 2373 2374 // Match up the template parameter lists with the scope specifier, then 2375 // determine whether we have a template or a template specialization. 2376 bool isExplicitSpecialization = false; 2377 if (TemplateParameterList *TemplateParams 2378 = MatchTemplateParametersToScopeSpecifier( 2379 D.getDeclSpec().getSourceRange().getBegin(), 2380 D.getCXXScopeSpec(), 2381 (TemplateParameterList**)TemplateParamLists.get(), 2382 TemplateParamLists.size(), 2383 isExplicitSpecialization)) { 2384 if (TemplateParams->size() > 0) { 2385 // There is no such thing as a variable template. 2386 Diag(D.getIdentifierLoc(), diag::err_template_variable) 2387 << II 2388 << SourceRange(TemplateParams->getTemplateLoc(), 2389 TemplateParams->getRAngleLoc()); 2390 return 0; 2391 } else { 2392 // There is an extraneous 'template<>' for this variable. Complain 2393 // about it, but allow the declaration of the variable. 2394 Diag(TemplateParams->getTemplateLoc(), 2395 diag::err_template_variable_noparams) 2396 << II 2397 << SourceRange(TemplateParams->getTemplateLoc(), 2398 TemplateParams->getRAngleLoc()); 2399 2400 isExplicitSpecialization = true; 2401 } 2402 } 2403 2404 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 2405 II, R, TInfo, SC); 2406 2407 if (D.isInvalidType()) 2408 NewVD->setInvalidDecl(); 2409 2410 if (D.getDeclSpec().isThreadSpecified()) { 2411 if (NewVD->hasLocalStorage()) 2412 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 2413 else if (!Context.Target.isTLSSupported()) 2414 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 2415 else 2416 NewVD->setThreadSpecified(true); 2417 } 2418 2419 // Set the lexical context. If the declarator has a C++ scope specifier, the 2420 // lexical context will be different from the semantic context. 2421 NewVD->setLexicalDeclContext(CurContext); 2422 2423 // Handle attributes prior to checking for duplicates in MergeVarDecl 2424 ProcessDeclAttributes(S, NewVD, D); 2425 2426 // Handle GNU asm-label extension (encoded as an attribute). 2427 if (Expr *E = (Expr*) D.getAsmLabel()) { 2428 // The parser guarantees this is a string. 2429 StringLiteral *SE = cast<StringLiteral>(E); 2430 NewVD->addAttr(::new (Context) AsmLabelAttr(SE->getString())); 2431 } 2432 2433 // Don't consider existing declarations that are in a different 2434 // scope and are out-of-semantic-context declarations (if the new 2435 // declaration has linkage). 2436 FilterLookupForScope(*this, Previous, DC, S, NewVD->hasLinkage()); 2437 2438 // Merge the decl with the existing one if appropriate. 2439 if (!Previous.empty()) { 2440 if (Previous.isSingleResult() && 2441 isa<FieldDecl>(Previous.getFoundDecl()) && 2442 D.getCXXScopeSpec().isSet()) { 2443 // The user tried to define a non-static data member 2444 // out-of-line (C++ [dcl.meaning]p1). 2445 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 2446 << D.getCXXScopeSpec().getRange(); 2447 Previous.clear(); 2448 NewVD->setInvalidDecl(); 2449 } 2450 } else if (D.getCXXScopeSpec().isSet()) { 2451 // No previous declaration in the qualifying scope. 2452 Diag(D.getIdentifierLoc(), diag::err_no_member) 2453 << Name << computeDeclContext(D.getCXXScopeSpec(), true) 2454 << D.getCXXScopeSpec().getRange(); 2455 NewVD->setInvalidDecl(); 2456 } 2457 2458 CheckVariableDeclaration(NewVD, Previous, Redeclaration); 2459 2460 // This is an explicit specialization of a static data member. Check it. 2461 if (isExplicitSpecialization && !NewVD->isInvalidDecl() && 2462 CheckMemberSpecialization(NewVD, Previous)) 2463 NewVD->setInvalidDecl(); 2464 2465 // attributes declared post-definition are currently ignored 2466 if (Previous.isSingleResult()) { 2467 const VarDecl *Def = 0; 2468 VarDecl *PrevDecl = dyn_cast<VarDecl>(Previous.getFoundDecl()); 2469 if (PrevDecl && PrevDecl->getDefinition(Def) && D.hasAttributes()) { 2470 Diag(NewVD->getLocation(), diag::warn_attribute_precede_definition); 2471 Diag(Def->getLocation(), diag::note_previous_definition); 2472 } 2473 } 2474 2475 // If this is a locally-scoped extern C variable, update the map of 2476 // such variables. 2477 if (CurContext->isFunctionOrMethod() && NewVD->isExternC() && 2478 !NewVD->isInvalidDecl()) 2479 RegisterLocallyScopedExternCDecl(NewVD, Previous, S); 2480 2481 return NewVD; 2482} 2483 2484/// \brief Perform semantic checking on a newly-created variable 2485/// declaration. 2486/// 2487/// This routine performs all of the type-checking required for a 2488/// variable declaration once it has been built. It is used both to 2489/// check variables after they have been parsed and their declarators 2490/// have been translated into a declaration, and to check variables 2491/// that have been instantiated from a template. 2492/// 2493/// Sets NewVD->isInvalidDecl() if an error was encountered. 2494void Sema::CheckVariableDeclaration(VarDecl *NewVD, 2495 LookupResult &Previous, 2496 bool &Redeclaration) { 2497 // If the decl is already known invalid, don't check it. 2498 if (NewVD->isInvalidDecl()) 2499 return; 2500 2501 QualType T = NewVD->getType(); 2502 2503 if (T->isObjCInterfaceType()) { 2504 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 2505 return NewVD->setInvalidDecl(); 2506 } 2507 2508 // Emit an error if an address space was applied to decl with local storage. 2509 // This includes arrays of objects with address space qualifiers, but not 2510 // automatic variables that point to other address spaces. 2511 // ISO/IEC TR 18037 S5.1.2 2512 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 2513 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 2514 return NewVD->setInvalidDecl(); 2515 } 2516 2517 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 2518 && !NewVD->hasAttr<BlocksAttr>()) 2519 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 2520 2521 bool isVM = T->isVariablyModifiedType(); 2522 if (isVM || NewVD->hasAttr<CleanupAttr>() || 2523 NewVD->hasAttr<BlocksAttr>()) 2524 CurFunctionNeedsScopeChecking = true; 2525 2526 if ((isVM && NewVD->hasLinkage()) || 2527 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 2528 bool SizeIsNegative; 2529 QualType FixedTy = 2530 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2531 2532 if (FixedTy.isNull() && T->isVariableArrayType()) { 2533 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2534 // FIXME: This won't give the correct result for 2535 // int a[10][n]; 2536 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2537 2538 if (NewVD->isFileVarDecl()) 2539 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 2540 << SizeRange; 2541 else if (NewVD->getStorageClass() == VarDecl::Static) 2542 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 2543 << SizeRange; 2544 else 2545 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 2546 << SizeRange; 2547 return NewVD->setInvalidDecl(); 2548 } 2549 2550 if (FixedTy.isNull()) { 2551 if (NewVD->isFileVarDecl()) 2552 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 2553 else 2554 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 2555 return NewVD->setInvalidDecl(); 2556 } 2557 2558 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 2559 NewVD->setType(FixedTy); 2560 } 2561 2562 if (Previous.empty() && NewVD->isExternC()) { 2563 // Since we did not find anything by this name and we're declaring 2564 // an extern "C" variable, look for a non-visible extern "C" 2565 // declaration with the same name. 2566 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2567 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 2568 if (Pos != LocallyScopedExternalDecls.end()) 2569 Previous.addDecl(Pos->second); 2570 } 2571 2572 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 2573 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 2574 << T; 2575 return NewVD->setInvalidDecl(); 2576 } 2577 2578 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 2579 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 2580 return NewVD->setInvalidDecl(); 2581 } 2582 2583 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 2584 Diag(NewVD->getLocation(), diag::err_block_on_vm); 2585 return NewVD->setInvalidDecl(); 2586 } 2587 2588 if (!Previous.empty()) { 2589 Redeclaration = true; 2590 MergeVarDecl(NewVD, Previous); 2591 } 2592} 2593 2594/// \brief Data used with FindOverriddenMethod 2595struct FindOverriddenMethodData { 2596 Sema *S; 2597 CXXMethodDecl *Method; 2598}; 2599 2600/// \brief Member lookup function that determines whether a given C++ 2601/// method overrides a method in a base class, to be used with 2602/// CXXRecordDecl::lookupInBases(). 2603static bool FindOverriddenMethod(const CXXBaseSpecifier *Specifier, 2604 CXXBasePath &Path, 2605 void *UserData) { 2606 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl(); 2607 2608 FindOverriddenMethodData *Data 2609 = reinterpret_cast<FindOverriddenMethodData*>(UserData); 2610 2611 DeclarationName Name = Data->Method->getDeclName(); 2612 2613 // FIXME: Do we care about other names here too? 2614 if (Name.getNameKind() == DeclarationName::CXXDestructorName) { 2615 // We really want to find the base class constructor here. 2616 QualType T = Data->S->Context.getTypeDeclType(BaseRecord); 2617 CanQualType CT = Data->S->Context.getCanonicalType(T); 2618 2619 Name = Data->S->Context.DeclarationNames.getCXXDestructorName(CT); 2620 } 2621 2622 for (Path.Decls = BaseRecord->lookup(Name); 2623 Path.Decls.first != Path.Decls.second; 2624 ++Path.Decls.first) { 2625 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*Path.Decls.first)) { 2626 if (MD->isVirtual() && !Data->S->IsOverload(Data->Method, MD)) 2627 return true; 2628 } 2629 } 2630 2631 return false; 2632} 2633 2634/// AddOverriddenMethods - See if a method overrides any in the base classes, 2635/// and if so, check that it's a valid override and remember it. 2636void Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) { 2637 // Look for virtual methods in base classes that this method might override. 2638 CXXBasePaths Paths; 2639 FindOverriddenMethodData Data; 2640 Data.Method = MD; 2641 Data.S = this; 2642 if (DC->lookupInBases(&FindOverriddenMethod, &Data, Paths)) { 2643 for (CXXBasePaths::decl_iterator I = Paths.found_decls_begin(), 2644 E = Paths.found_decls_end(); I != E; ++I) { 2645 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2646 if (!CheckOverridingFunctionReturnType(MD, OldMD) && 2647 !CheckOverridingFunctionExceptionSpec(MD, OldMD) && 2648 !CheckOverridingFunctionAttributes(MD, OldMD)) 2649 MD->addOverriddenMethod(OldMD->getCanonicalDecl()); 2650 } 2651 } 2652 } 2653} 2654 2655NamedDecl* 2656Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2657 QualType R, TypeSourceInfo *TInfo, 2658 LookupResult &Previous, 2659 MultiTemplateParamsArg TemplateParamLists, 2660 bool IsFunctionDefinition, bool &Redeclaration) { 2661 assert(R.getTypePtr()->isFunctionType()); 2662 2663 DeclarationName Name = GetNameForDeclarator(D); 2664 FunctionDecl::StorageClass SC = FunctionDecl::None; 2665 switch (D.getDeclSpec().getStorageClassSpec()) { 2666 default: assert(0 && "Unknown storage class!"); 2667 case DeclSpec::SCS_auto: 2668 case DeclSpec::SCS_register: 2669 case DeclSpec::SCS_mutable: 2670 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2671 diag::err_typecheck_sclass_func); 2672 D.setInvalidType(); 2673 break; 2674 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 2675 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 2676 case DeclSpec::SCS_static: { 2677 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 2678 // C99 6.7.1p5: 2679 // The declaration of an identifier for a function that has 2680 // block scope shall have no explicit storage-class specifier 2681 // other than extern 2682 // See also (C++ [dcl.stc]p4). 2683 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2684 diag::err_static_block_func); 2685 SC = FunctionDecl::None; 2686 } else 2687 SC = FunctionDecl::Static; 2688 break; 2689 } 2690 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 2691 } 2692 2693 if (D.getDeclSpec().isThreadSpecified()) 2694 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2695 2696 bool isFriend = D.getDeclSpec().isFriendSpecified(); 2697 bool isInline = D.getDeclSpec().isInlineSpecified(); 2698 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 2699 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 2700 2701 // Check that the return type is not an abstract class type. 2702 // For record types, this is done by the AbstractClassUsageDiagnoser once 2703 // the class has been completely parsed. 2704 if (!DC->isRecord() && 2705 RequireNonAbstractType(D.getIdentifierLoc(), 2706 R->getAs<FunctionType>()->getResultType(), 2707 diag::err_abstract_type_in_decl, 2708 AbstractReturnType)) 2709 D.setInvalidType(); 2710 2711 // Do not allow returning a objc interface by-value. 2712 if (R->getAs<FunctionType>()->getResultType()->isObjCInterfaceType()) { 2713 Diag(D.getIdentifierLoc(), 2714 diag::err_object_cannot_be_passed_returned_by_value) << 0 2715 << R->getAs<FunctionType>()->getResultType(); 2716 D.setInvalidType(); 2717 } 2718 2719 bool isVirtualOkay = false; 2720 FunctionDecl *NewFD; 2721 2722 if (isFriend) { 2723 // C++ [class.friend]p5 2724 // A function can be defined in a friend declaration of a 2725 // class . . . . Such a function is implicitly inline. 2726 isInline |= IsFunctionDefinition; 2727 } 2728 2729 if (Name.getNameKind() == DeclarationName::CXXConstructorName) { 2730 // This is a C++ constructor declaration. 2731 assert(DC->isRecord() && 2732 "Constructors can only be declared in a member context"); 2733 2734 R = CheckConstructorDeclarator(D, R, SC); 2735 2736 // Create the new declaration 2737 NewFD = CXXConstructorDecl::Create(Context, 2738 cast<CXXRecordDecl>(DC), 2739 D.getIdentifierLoc(), Name, R, TInfo, 2740 isExplicit, isInline, 2741 /*isImplicitlyDeclared=*/false); 2742 } else if (Name.getNameKind() == DeclarationName::CXXDestructorName) { 2743 // This is a C++ destructor declaration. 2744 if (DC->isRecord()) { 2745 R = CheckDestructorDeclarator(D, SC); 2746 2747 NewFD = CXXDestructorDecl::Create(Context, 2748 cast<CXXRecordDecl>(DC), 2749 D.getIdentifierLoc(), Name, R, 2750 isInline, 2751 /*isImplicitlyDeclared=*/false); 2752 2753 isVirtualOkay = true; 2754 } else { 2755 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 2756 2757 // Create a FunctionDecl to satisfy the function definition parsing 2758 // code path. 2759 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 2760 Name, R, TInfo, SC, isInline, 2761 /*hasPrototype=*/true); 2762 D.setInvalidType(); 2763 } 2764 } else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 2765 if (!DC->isRecord()) { 2766 Diag(D.getIdentifierLoc(), 2767 diag::err_conv_function_not_member); 2768 return 0; 2769 } 2770 2771 CheckConversionDeclarator(D, R, SC); 2772 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 2773 D.getIdentifierLoc(), Name, R, TInfo, 2774 isInline, isExplicit); 2775 2776 isVirtualOkay = true; 2777 } else if (DC->isRecord()) { 2778 // If the of the function is the same as the name of the record, then this 2779 // must be an invalid constructor that has a return type. 2780 // (The parser checks for a return type and makes the declarator a 2781 // constructor if it has no return type). 2782 // must have an invalid constructor that has a return type 2783 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 2784 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 2785 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 2786 << SourceRange(D.getIdentifierLoc()); 2787 return 0; 2788 } 2789 2790 bool isStatic = SC == FunctionDecl::Static; 2791 2792 // [class.free]p1: 2793 // Any allocation function for a class T is a static member 2794 // (even if not explicitly declared static). 2795 if (Name.getCXXOverloadedOperator() == OO_New || 2796 Name.getCXXOverloadedOperator() == OO_Array_New) 2797 isStatic = true; 2798 2799 // [class.free]p6 Any deallocation function for a class X is a static member 2800 // (even if not explicitly declared static). 2801 if (Name.getCXXOverloadedOperator() == OO_Delete || 2802 Name.getCXXOverloadedOperator() == OO_Array_Delete) 2803 isStatic = true; 2804 2805 // This is a C++ method declaration. 2806 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 2807 D.getIdentifierLoc(), Name, R, TInfo, 2808 isStatic, isInline); 2809 2810 isVirtualOkay = !isStatic; 2811 } else { 2812 // Determine whether the function was written with a 2813 // prototype. This true when: 2814 // - we're in C++ (where every function has a prototype), 2815 // - there is a prototype in the declarator, or 2816 // - the type R of the function is some kind of typedef or other reference 2817 // to a type name (which eventually refers to a function type). 2818 bool HasPrototype = 2819 getLangOptions().CPlusPlus || 2820 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 2821 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 2822 2823 NewFD = FunctionDecl::Create(Context, DC, 2824 D.getIdentifierLoc(), 2825 Name, R, TInfo, SC, isInline, HasPrototype); 2826 } 2827 2828 if (D.isInvalidType()) 2829 NewFD->setInvalidDecl(); 2830 2831 // Set the lexical context. If the declarator has a C++ 2832 // scope specifier, or is the object of a friend declaration, the 2833 // lexical context will be different from the semantic context. 2834 NewFD->setLexicalDeclContext(CurContext); 2835 2836 // Match up the template parameter lists with the scope specifier, then 2837 // determine whether we have a template or a template specialization. 2838 FunctionTemplateDecl *FunctionTemplate = 0; 2839 bool isExplicitSpecialization = false; 2840 bool isFunctionTemplateSpecialization = false; 2841 if (TemplateParameterList *TemplateParams 2842 = MatchTemplateParametersToScopeSpecifier( 2843 D.getDeclSpec().getSourceRange().getBegin(), 2844 D.getCXXScopeSpec(), 2845 (TemplateParameterList**)TemplateParamLists.get(), 2846 TemplateParamLists.size(), 2847 isExplicitSpecialization)) { 2848 if (TemplateParams->size() > 0) { 2849 // This is a function template 2850 2851 // Check that we can declare a template here. 2852 if (CheckTemplateDeclScope(S, TemplateParams)) 2853 return 0; 2854 2855 FunctionTemplate = FunctionTemplateDecl::Create(Context, DC, 2856 NewFD->getLocation(), 2857 Name, TemplateParams, 2858 NewFD); 2859 FunctionTemplate->setLexicalDeclContext(CurContext); 2860 NewFD->setDescribedFunctionTemplate(FunctionTemplate); 2861 } else { 2862 // This is a function template specialization. 2863 isFunctionTemplateSpecialization = true; 2864 } 2865 2866 // FIXME: Free this memory properly. 2867 TemplateParamLists.release(); 2868 } 2869 2870 // C++ [dcl.fct.spec]p5: 2871 // The virtual specifier shall only be used in declarations of 2872 // nonstatic class member functions that appear within a 2873 // member-specification of a class declaration; see 10.3. 2874 // 2875 if (isVirtual && !NewFD->isInvalidDecl()) { 2876 if (!isVirtualOkay) { 2877 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2878 diag::err_virtual_non_function); 2879 } else if (!CurContext->isRecord()) { 2880 // 'virtual' was specified outside of the class. 2881 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 2882 << CodeModificationHint::CreateRemoval( 2883 D.getDeclSpec().getVirtualSpecLoc()); 2884 } else { 2885 // Okay: Add virtual to the method. 2886 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 2887 CurClass->setMethodAsVirtual(NewFD); 2888 } 2889 } 2890 2891 // Filter out previous declarations that don't match the scope. 2892 FilterLookupForScope(*this, Previous, DC, S, NewFD->hasLinkage()); 2893 2894 if (isFriend) { 2895 // DC is the namespace in which the function is being declared. 2896 assert((DC->isFileContext() || !Previous.empty()) && 2897 "previously-undeclared friend function being created " 2898 "in a non-namespace context"); 2899 2900 if (FunctionTemplate) { 2901 FunctionTemplate->setObjectOfFriendDecl( 2902 /* PreviouslyDeclared= */ !Previous.empty()); 2903 FunctionTemplate->setAccess(AS_public); 2904 } 2905 else 2906 NewFD->setObjectOfFriendDecl(/* PreviouslyDeclared= */ !Previous.empty()); 2907 2908 NewFD->setAccess(AS_public); 2909 } 2910 2911 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 2912 !CurContext->isRecord()) { 2913 // C++ [class.static]p1: 2914 // A data or function member of a class may be declared static 2915 // in a class definition, in which case it is a static member of 2916 // the class. 2917 2918 // Complain about the 'static' specifier if it's on an out-of-line 2919 // member function definition. 2920 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2921 diag::err_static_out_of_line) 2922 << CodeModificationHint::CreateRemoval( 2923 D.getDeclSpec().getStorageClassSpecLoc()); 2924 } 2925 2926 // Handle GNU asm-label extension (encoded as an attribute). 2927 if (Expr *E = (Expr*) D.getAsmLabel()) { 2928 // The parser guarantees this is a string. 2929 StringLiteral *SE = cast<StringLiteral>(E); 2930 NewFD->addAttr(::new (Context) AsmLabelAttr(SE->getString())); 2931 } 2932 2933 // Copy the parameter declarations from the declarator D to the function 2934 // declaration NewFD, if they are available. First scavenge them into Params. 2935 llvm::SmallVector<ParmVarDecl*, 16> Params; 2936 if (D.getNumTypeObjects() > 0) { 2937 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2938 2939 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 2940 // function that takes no arguments, not a function that takes a 2941 // single void argument. 2942 // We let through "const void" here because Sema::GetTypeForDeclarator 2943 // already checks for that case. 2944 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 2945 FTI.ArgInfo[0].Param && 2946 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 2947 // Empty arg list, don't push any params. 2948 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 2949 2950 // In C++, the empty parameter-type-list must be spelled "void"; a 2951 // typedef of void is not permitted. 2952 if (getLangOptions().CPlusPlus && 2953 Param->getType().getUnqualifiedType() != Context.VoidTy) 2954 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 2955 // FIXME: Leaks decl? 2956 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 2957 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2958 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 2959 assert(Param->getDeclContext() != NewFD && "Was set before ?"); 2960 Param->setDeclContext(NewFD); 2961 Params.push_back(Param); 2962 } 2963 } 2964 2965 } else if (const FunctionProtoType *FT = R->getAs<FunctionProtoType>()) { 2966 // When we're declaring a function with a typedef, typeof, etc as in the 2967 // following example, we'll need to synthesize (unnamed) 2968 // parameters for use in the declaration. 2969 // 2970 // @code 2971 // typedef void fn(int); 2972 // fn f; 2973 // @endcode 2974 2975 // Synthesize a parameter for each argument type. 2976 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 2977 AE = FT->arg_type_end(); AI != AE; ++AI) { 2978 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 2979 SourceLocation(), 0, 2980 *AI, /*TInfo=*/0, 2981 VarDecl::None, 0); 2982 Param->setImplicit(); 2983 Params.push_back(Param); 2984 } 2985 } else { 2986 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 2987 "Should not need args for typedef of non-prototype fn"); 2988 } 2989 // Finally, we know we have the right number of parameters, install them. 2990 NewFD->setParams(Context, Params.data(), Params.size()); 2991 2992 // If the declarator is a template-id, translate the parser's template 2993 // argument list into our AST format. 2994 bool HasExplicitTemplateArgs = false; 2995 TemplateArgumentListInfo TemplateArgs; 2996 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 2997 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 2998 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc); 2999 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc); 3000 ASTTemplateArgsPtr TemplateArgsPtr(*this, 3001 TemplateId->getTemplateArgs(), 3002 TemplateId->NumArgs); 3003 translateTemplateArguments(TemplateArgsPtr, 3004 TemplateArgs); 3005 TemplateArgsPtr.release(); 3006 3007 HasExplicitTemplateArgs = true; 3008 3009 if (FunctionTemplate) { 3010 // FIXME: Diagnose function template with explicit template 3011 // arguments. 3012 HasExplicitTemplateArgs = false; 3013 } else if (!isFunctionTemplateSpecialization && 3014 !D.getDeclSpec().isFriendSpecified()) { 3015 // We have encountered something that the user meant to be a 3016 // specialization (because it has explicitly-specified template 3017 // arguments) but that was not introduced with a "template<>" (or had 3018 // too few of them). 3019 Diag(D.getIdentifierLoc(), diag::err_template_spec_needs_header) 3020 << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc) 3021 << CodeModificationHint::CreateInsertion( 3022 D.getDeclSpec().getSourceRange().getBegin(), 3023 "template<> "); 3024 isFunctionTemplateSpecialization = true; 3025 } 3026 } 3027 3028 if (isFunctionTemplateSpecialization) { 3029 if (CheckFunctionTemplateSpecialization(NewFD, 3030 (HasExplicitTemplateArgs ? &TemplateArgs : 0), 3031 Previous)) 3032 NewFD->setInvalidDecl(); 3033 } else if (isExplicitSpecialization && isa<CXXMethodDecl>(NewFD) && 3034 CheckMemberSpecialization(NewFD, Previous)) 3035 NewFD->setInvalidDecl(); 3036 3037 // Perform semantic checking on the function declaration. 3038 bool OverloadableAttrRequired = false; // FIXME: HACK! 3039 CheckFunctionDeclaration(S, NewFD, Previous, isExplicitSpecialization, 3040 Redeclaration, /*FIXME:*/OverloadableAttrRequired); 3041 3042 assert((NewFD->isInvalidDecl() || !Redeclaration || 3043 Previous.getResultKind() != LookupResult::FoundOverloaded) && 3044 "previous declaration set still overloaded"); 3045 3046 // If we have a function template, check the template parameter 3047 // list. This will check and merge default template arguments. 3048 if (FunctionTemplate) { 3049 FunctionTemplateDecl *PrevTemplate = FunctionTemplate->getPreviousDeclaration(); 3050 CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(), 3051 PrevTemplate? PrevTemplate->getTemplateParameters() : 0, 3052 D.getDeclSpec().isFriendSpecified()? TPC_FriendFunctionTemplate 3053 : TPC_FunctionTemplate); 3054 } 3055 3056 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 3057 // An out-of-line member function declaration must also be a 3058 // definition (C++ [dcl.meaning]p1). 3059 // Note that this is not the case for explicit specializations of 3060 // function templates or member functions of class templates, per 3061 // C++ [temp.expl.spec]p2. 3062 if (!IsFunctionDefinition && !isFriend && 3063 !isFunctionTemplateSpecialization && !isExplicitSpecialization) { 3064 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 3065 << D.getCXXScopeSpec().getRange(); 3066 NewFD->setInvalidDecl(); 3067 } else if (!Redeclaration) { 3068 // The user tried to provide an out-of-line definition for a 3069 // function that is a member of a class or namespace, but there 3070 // was no such member function declared (C++ [class.mfct]p2, 3071 // C++ [namespace.memdef]p2). For example: 3072 // 3073 // class X { 3074 // void f() const; 3075 // }; 3076 // 3077 // void X::f() { } // ill-formed 3078 // 3079 // Complain about this problem, and attempt to suggest close 3080 // matches (e.g., those that differ only in cv-qualifiers and 3081 // whether the parameter types are references). 3082 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 3083 << Name << DC << D.getCXXScopeSpec().getRange(); 3084 NewFD->setInvalidDecl(); 3085 3086 LookupResult Prev(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName, 3087 ForRedeclaration); 3088 LookupQualifiedName(Prev, DC); 3089 assert(!Prev.isAmbiguous() && 3090 "Cannot have an ambiguity in previous-declaration lookup"); 3091 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 3092 Func != FuncEnd; ++Func) { 3093 if (isa<FunctionDecl>(*Func) && 3094 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 3095 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 3096 } 3097 } 3098 } 3099 3100 // Handle attributes. We need to have merged decls when handling attributes 3101 // (for example to check for conflicts, etc). 3102 // FIXME: This needs to happen before we merge declarations. Then, 3103 // let attribute merging cope with attribute conflicts. 3104 ProcessDeclAttributes(S, NewFD, D); 3105 3106 // attributes declared post-definition are currently ignored 3107 if (Redeclaration && Previous.isSingleResult()) { 3108 const FunctionDecl *Def; 3109 FunctionDecl *PrevFD = dyn_cast<FunctionDecl>(Previous.getFoundDecl()); 3110 if (PrevFD && PrevFD->getBody(Def) && D.hasAttributes()) { 3111 Diag(NewFD->getLocation(), diag::warn_attribute_precede_definition); 3112 Diag(Def->getLocation(), diag::note_previous_definition); 3113 } 3114 } 3115 3116 AddKnownFunctionAttributes(NewFD); 3117 3118 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 3119 // If a function name is overloadable in C, then every function 3120 // with that name must be marked "overloadable". 3121 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 3122 << Redeclaration << NewFD; 3123 if (!Previous.empty()) 3124 Diag(Previous.getRepresentativeDecl()->getLocation(), 3125 diag::note_attribute_overloadable_prev_overload); 3126 NewFD->addAttr(::new (Context) OverloadableAttr()); 3127 } 3128 3129 // If this is a locally-scoped extern C function, update the 3130 // map of such names. 3131 if (CurContext->isFunctionOrMethod() && NewFD->isExternC() 3132 && !NewFD->isInvalidDecl()) 3133 RegisterLocallyScopedExternCDecl(NewFD, Previous, S); 3134 3135 // Set this FunctionDecl's range up to the right paren. 3136 NewFD->setLocEnd(D.getSourceRange().getEnd()); 3137 3138 if (FunctionTemplate && NewFD->isInvalidDecl()) 3139 FunctionTemplate->setInvalidDecl(); 3140 3141 if (FunctionTemplate) 3142 return FunctionTemplate; 3143 3144 return NewFD; 3145} 3146 3147/// \brief Perform semantic checking of a new function declaration. 3148/// 3149/// Performs semantic analysis of the new function declaration 3150/// NewFD. This routine performs all semantic checking that does not 3151/// require the actual declarator involved in the declaration, and is 3152/// used both for the declaration of functions as they are parsed 3153/// (called via ActOnDeclarator) and for the declaration of functions 3154/// that have been instantiated via C++ template instantiation (called 3155/// via InstantiateDecl). 3156/// 3157/// \param IsExplicitSpecialiation whether this new function declaration is 3158/// an explicit specialization of the previous declaration. 3159/// 3160/// This sets NewFD->isInvalidDecl() to true if there was an error. 3161void Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD, 3162 LookupResult &Previous, 3163 bool IsExplicitSpecialization, 3164 bool &Redeclaration, 3165 bool &OverloadableAttrRequired) { 3166 // If NewFD is already known erroneous, don't do any of this checking. 3167 if (NewFD->isInvalidDecl()) 3168 return; 3169 3170 if (NewFD->getResultType()->isVariablyModifiedType()) { 3171 // Functions returning a variably modified type violate C99 6.7.5.2p2 3172 // because all functions have linkage. 3173 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 3174 return NewFD->setInvalidDecl(); 3175 } 3176 3177 if (NewFD->isMain()) 3178 CheckMain(NewFD); 3179 3180 // Check for a previous declaration of this name. 3181 if (Previous.empty() && NewFD->isExternC()) { 3182 // Since we did not find anything by this name and we're declaring 3183 // an extern "C" function, look for a non-visible extern "C" 3184 // declaration with the same name. 3185 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3186 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 3187 if (Pos != LocallyScopedExternalDecls.end()) 3188 Previous.addDecl(Pos->second); 3189 } 3190 3191 // Merge or overload the declaration with an existing declaration of 3192 // the same name, if appropriate. 3193 if (!Previous.empty()) { 3194 // Determine whether NewFD is an overload of PrevDecl or 3195 // a declaration that requires merging. If it's an overload, 3196 // there's no more work to do here; we'll just add the new 3197 // function to the scope. 3198 3199 NamedDecl *OldDecl = 0; 3200 if (!AllowOverloadingOfFunction(Previous, Context)) { 3201 Redeclaration = true; 3202 OldDecl = Previous.getFoundDecl(); 3203 } else { 3204 if (!getLangOptions().CPlusPlus) { 3205 OverloadableAttrRequired = true; 3206 3207 // Functions marked "overloadable" must have a prototype (that 3208 // we can't get through declaration merging). 3209 if (!NewFD->getType()->getAs<FunctionProtoType>()) { 3210 Diag(NewFD->getLocation(), 3211 diag::err_attribute_overloadable_no_prototype) 3212 << NewFD; 3213 Redeclaration = true; 3214 3215 // Turn this into a variadic function with no parameters. 3216 QualType R = Context.getFunctionType( 3217 NewFD->getType()->getAs<FunctionType>()->getResultType(), 3218 0, 0, true, 0); 3219 NewFD->setType(R); 3220 return NewFD->setInvalidDecl(); 3221 } 3222 } 3223 3224 switch (CheckOverload(NewFD, Previous, OldDecl)) { 3225 case Ovl_Match: 3226 Redeclaration = true; 3227 if (isa<UsingShadowDecl>(OldDecl) && CurContext->isRecord()) { 3228 HideUsingShadowDecl(S, cast<UsingShadowDecl>(OldDecl)); 3229 Redeclaration = false; 3230 } 3231 break; 3232 3233 case Ovl_NonFunction: 3234 Redeclaration = true; 3235 break; 3236 3237 case Ovl_Overload: 3238 Redeclaration = false; 3239 break; 3240 } 3241 } 3242 3243 if (Redeclaration) { 3244 // NewFD and OldDecl represent declarations that need to be 3245 // merged. 3246 if (MergeFunctionDecl(NewFD, OldDecl)) 3247 return NewFD->setInvalidDecl(); 3248 3249 Previous.clear(); 3250 Previous.addDecl(OldDecl); 3251 3252 if (FunctionTemplateDecl *OldTemplateDecl 3253 = dyn_cast<FunctionTemplateDecl>(OldDecl)) { 3254 NewFD->setPreviousDeclaration(OldTemplateDecl->getTemplatedDecl()); 3255 FunctionTemplateDecl *NewTemplateDecl 3256 = NewFD->getDescribedFunctionTemplate(); 3257 assert(NewTemplateDecl && "Template/non-template mismatch"); 3258 if (CXXMethodDecl *Method 3259 = dyn_cast<CXXMethodDecl>(NewTemplateDecl->getTemplatedDecl())) { 3260 Method->setAccess(OldTemplateDecl->getAccess()); 3261 NewTemplateDecl->setAccess(OldTemplateDecl->getAccess()); 3262 } 3263 3264 // If this is an explicit specialization of a member that is a function 3265 // template, mark it as a member specialization. 3266 if (IsExplicitSpecialization && 3267 NewTemplateDecl->getInstantiatedFromMemberTemplate()) { 3268 NewTemplateDecl->setMemberSpecialization(); 3269 assert(OldTemplateDecl->isMemberSpecialization()); 3270 } 3271 } else { 3272 if (isa<CXXMethodDecl>(NewFD)) // Set access for out-of-line definitions 3273 NewFD->setAccess(OldDecl->getAccess()); 3274 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 3275 } 3276 } 3277 } 3278 3279 // Semantic checking for this function declaration (in isolation). 3280 if (getLangOptions().CPlusPlus) { 3281 // C++-specific checks. 3282 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 3283 CheckConstructor(Constructor); 3284 } else if (CXXDestructorDecl *Destructor = 3285 dyn_cast<CXXDestructorDecl>(NewFD)) { 3286 CXXRecordDecl *Record = Destructor->getParent(); 3287 QualType ClassType = Context.getTypeDeclType(Record); 3288 3289 // FIXME: Shouldn't we be able to perform thisc heck even when the class 3290 // type is dependent? Both gcc and edg can handle that. 3291 if (!ClassType->isDependentType()) { 3292 DeclarationName Name 3293 = Context.DeclarationNames.getCXXDestructorName( 3294 Context.getCanonicalType(ClassType)); 3295 if (NewFD->getDeclName() != Name) { 3296 Diag(NewFD->getLocation(), diag::err_destructor_name); 3297 return NewFD->setInvalidDecl(); 3298 } 3299 } 3300 3301 Record->setUserDeclaredDestructor(true); 3302 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 3303 // user-defined destructor. 3304 Record->setPOD(false); 3305 3306 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 3307 // declared destructor. 3308 // FIXME: C++0x: don't do this for "= default" destructors 3309 Record->setHasTrivialDestructor(false); 3310 } else if (CXXConversionDecl *Conversion 3311 = dyn_cast<CXXConversionDecl>(NewFD)) { 3312 ActOnConversionDeclarator(Conversion); 3313 } 3314 3315 // Find any virtual functions that this function overrides. 3316 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD)) { 3317 if (!Method->isFunctionTemplateSpecialization() && 3318 !Method->getDescribedFunctionTemplate()) 3319 AddOverriddenMethods(Method->getParent(), Method); 3320 } 3321 3322 // Additional checks for the destructor; make sure we do this after we 3323 // figure out whether the destructor is virtual. 3324 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 3325 if (!Destructor->getParent()->isDependentType()) 3326 CheckDestructor(Destructor); 3327 3328 // Extra checking for C++ overloaded operators (C++ [over.oper]). 3329 if (NewFD->isOverloadedOperator() && 3330 CheckOverloadedOperatorDeclaration(NewFD)) 3331 return NewFD->setInvalidDecl(); 3332 3333 // In C++, check default arguments now that we have merged decls. Unless 3334 // the lexical context is the class, because in this case this is done 3335 // during delayed parsing anyway. 3336 if (!CurContext->isRecord()) 3337 CheckCXXDefaultArguments(NewFD); 3338 } 3339} 3340 3341void Sema::CheckMain(FunctionDecl* FD) { 3342 // C++ [basic.start.main]p3: A program that declares main to be inline 3343 // or static is ill-formed. 3344 // C99 6.7.4p4: In a hosted environment, the inline function specifier 3345 // shall not appear in a declaration of main. 3346 // static main is not an error under C99, but we should warn about it. 3347 bool isInline = FD->isInlineSpecified(); 3348 bool isStatic = FD->getStorageClass() == FunctionDecl::Static; 3349 if (isInline || isStatic) { 3350 unsigned diagID = diag::warn_unusual_main_decl; 3351 if (isInline || getLangOptions().CPlusPlus) 3352 diagID = diag::err_unusual_main_decl; 3353 3354 int which = isStatic + (isInline << 1) - 1; 3355 Diag(FD->getLocation(), diagID) << which; 3356 } 3357 3358 QualType T = FD->getType(); 3359 assert(T->isFunctionType() && "function decl is not of function type"); 3360 const FunctionType* FT = T->getAs<FunctionType>(); 3361 3362 if (!Context.hasSameUnqualifiedType(FT->getResultType(), Context.IntTy)) { 3363 // TODO: add a replacement fixit to turn the return type into 'int'. 3364 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint); 3365 FD->setInvalidDecl(true); 3366 } 3367 3368 // Treat protoless main() as nullary. 3369 if (isa<FunctionNoProtoType>(FT)) return; 3370 3371 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 3372 unsigned nparams = FTP->getNumArgs(); 3373 assert(FD->getNumParams() == nparams); 3374 3375 if (nparams > 3) { 3376 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 3377 FD->setInvalidDecl(true); 3378 nparams = 3; 3379 } 3380 3381 // FIXME: a lot of the following diagnostics would be improved 3382 // if we had some location information about types. 3383 3384 QualType CharPP = 3385 Context.getPointerType(Context.getPointerType(Context.CharTy)); 3386 QualType Expected[] = { Context.IntTy, CharPP, CharPP }; 3387 3388 for (unsigned i = 0; i < nparams; ++i) { 3389 QualType AT = FTP->getArgType(i); 3390 3391 bool mismatch = true; 3392 3393 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 3394 mismatch = false; 3395 else if (Expected[i] == CharPP) { 3396 // As an extension, the following forms are okay: 3397 // char const ** 3398 // char const * const * 3399 // char * const * 3400 3401 QualifierCollector qs; 3402 const PointerType* PT; 3403 if ((PT = qs.strip(AT)->getAs<PointerType>()) && 3404 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) && 3405 (QualType(qs.strip(PT->getPointeeType()), 0) == Context.CharTy)) { 3406 qs.removeConst(); 3407 mismatch = !qs.empty(); 3408 } 3409 } 3410 3411 if (mismatch) { 3412 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 3413 // TODO: suggest replacing given type with expected type 3414 FD->setInvalidDecl(true); 3415 } 3416 } 3417 3418 if (nparams == 1 && !FD->isInvalidDecl()) { 3419 Diag(FD->getLocation(), diag::warn_main_one_arg); 3420 } 3421} 3422 3423bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 3424 // FIXME: Need strict checking. In C89, we need to check for 3425 // any assignment, increment, decrement, function-calls, or 3426 // commas outside of a sizeof. In C99, it's the same list, 3427 // except that the aforementioned are allowed in unevaluated 3428 // expressions. Everything else falls under the 3429 // "may accept other forms of constant expressions" exception. 3430 // (We never end up here for C++, so the constant expression 3431 // rules there don't matter.) 3432 if (Init->isConstantInitializer(Context)) 3433 return false; 3434 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 3435 << Init->getSourceRange(); 3436 return true; 3437} 3438 3439void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init) { 3440 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 3441} 3442 3443/// AddInitializerToDecl - Adds the initializer Init to the 3444/// declaration dcl. If DirectInit is true, this is C++ direct 3445/// initialization rather than copy initialization. 3446void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 3447 Decl *RealDecl = dcl.getAs<Decl>(); 3448 // If there is no declaration, there was an error parsing it. Just ignore 3449 // the initializer. 3450 if (RealDecl == 0) 3451 return; 3452 3453 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 3454 // With declarators parsed the way they are, the parser cannot 3455 // distinguish between a normal initializer and a pure-specifier. 3456 // Thus this grotesque test. 3457 IntegerLiteral *IL; 3458 Expr *Init = static_cast<Expr *>(init.get()); 3459 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 3460 Context.getCanonicalType(IL->getType()) == Context.IntTy) 3461 CheckPureMethod(Method, Init->getSourceRange()); 3462 else { 3463 Diag(Method->getLocation(), diag::err_member_function_initialization) 3464 << Method->getDeclName() << Init->getSourceRange(); 3465 Method->setInvalidDecl(); 3466 } 3467 return; 3468 } 3469 3470 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 3471 if (!VDecl) { 3472 if (getLangOptions().CPlusPlus && 3473 RealDecl->getLexicalDeclContext()->isRecord() && 3474 isa<NamedDecl>(RealDecl)) 3475 Diag(RealDecl->getLocation(), diag::err_member_initialization) 3476 << cast<NamedDecl>(RealDecl)->getDeclName(); 3477 else 3478 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 3479 RealDecl->setInvalidDecl(); 3480 return; 3481 } 3482 3483 // A definition must end up with a complete type, which means it must be 3484 // complete with the restriction that an array type might be completed by the 3485 // initializer; note that later code assumes this restriction. 3486 QualType BaseDeclType = VDecl->getType(); 3487 if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType)) 3488 BaseDeclType = Array->getElementType(); 3489 if (RequireCompleteType(VDecl->getLocation(), BaseDeclType, 3490 diag::err_typecheck_decl_incomplete_type)) { 3491 RealDecl->setInvalidDecl(); 3492 return; 3493 } 3494 3495 // The variable can not have an abstract class type. 3496 if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(), 3497 diag::err_abstract_type_in_decl, 3498 AbstractVariableType)) 3499 VDecl->setInvalidDecl(); 3500 3501 const VarDecl *Def = 0; 3502 if (VDecl->getDefinition(Def)) { 3503 Diag(VDecl->getLocation(), diag::err_redefinition) 3504 << VDecl->getDeclName(); 3505 Diag(Def->getLocation(), diag::note_previous_definition); 3506 VDecl->setInvalidDecl(); 3507 return; 3508 } 3509 3510 // Take ownership of the expression, now that we're sure we have somewhere 3511 // to put it. 3512 Expr *Init = init.takeAs<Expr>(); 3513 assert(Init && "missing initializer"); 3514 3515 // Capture the variable that is being initialized and the style of 3516 // initialization. 3517 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl); 3518 3519 // FIXME: Poor source location information. 3520 InitializationKind Kind 3521 = DirectInit? InitializationKind::CreateDirect(VDecl->getLocation(), 3522 Init->getLocStart(), 3523 Init->getLocEnd()) 3524 : InitializationKind::CreateCopy(VDecl->getLocation(), 3525 Init->getLocStart()); 3526 3527 // Get the decls type and save a reference for later, since 3528 // CheckInitializerTypes may change it. 3529 QualType DclT = VDecl->getType(), SavT = DclT; 3530 if (VDecl->isBlockVarDecl()) { 3531 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 3532 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 3533 VDecl->setInvalidDecl(); 3534 } else if (!VDecl->isInvalidDecl()) { 3535 if (VDecl->getType()->isReferenceType() 3536 || isa<InitListExpr>(Init)) { 3537 InitializationSequence InitSeq(*this, Entity, Kind, &Init, 1); 3538 if (InitSeq) { 3539 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3540 MultiExprArg(*this, (void**)&Init, 1), 3541 &DclT); 3542 if (Result.isInvalid()) { 3543 VDecl->setInvalidDecl(); 3544 return; 3545 } 3546 3547 Init = Result.takeAs<Expr>(); 3548 } else { 3549 InitSeq.Diagnose(*this, Entity, Kind, &Init, 1); 3550 VDecl->setInvalidDecl(); 3551 return; 3552 } 3553 } else if (CheckInitializerTypes(Init, DclT, Entity, Kind)) 3554 VDecl->setInvalidDecl(); 3555 3556 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3557 // Don't check invalid declarations to avoid emitting useless diagnostics. 3558 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3559 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 3560 CheckForConstantInitializer(Init, DclT); 3561 } 3562 } 3563 } else if (VDecl->isStaticDataMember() && 3564 VDecl->getLexicalDeclContext()->isRecord()) { 3565 // This is an in-class initialization for a static data member, e.g., 3566 // 3567 // struct S { 3568 // static const int value = 17; 3569 // }; 3570 3571 // Attach the initializer 3572 VDecl->setInit(Context, Init); 3573 3574 // C++ [class.mem]p4: 3575 // A member-declarator can contain a constant-initializer only 3576 // if it declares a static member (9.4) of const integral or 3577 // const enumeration type, see 9.4.2. 3578 QualType T = VDecl->getType(); 3579 if (!T->isDependentType() && 3580 (!Context.getCanonicalType(T).isConstQualified() || 3581 !T->isIntegralType())) { 3582 Diag(VDecl->getLocation(), diag::err_member_initialization) 3583 << VDecl->getDeclName() << Init->getSourceRange(); 3584 VDecl->setInvalidDecl(); 3585 } else { 3586 // C++ [class.static.data]p4: 3587 // If a static data member is of const integral or const 3588 // enumeration type, its declaration in the class definition 3589 // can specify a constant-initializer which shall be an 3590 // integral constant expression (5.19). 3591 if (!Init->isTypeDependent() && 3592 !Init->getType()->isIntegralType()) { 3593 // We have a non-dependent, non-integral or enumeration type. 3594 Diag(Init->getSourceRange().getBegin(), 3595 diag::err_in_class_initializer_non_integral_type) 3596 << Init->getType() << Init->getSourceRange(); 3597 VDecl->setInvalidDecl(); 3598 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 3599 // Check whether the expression is a constant expression. 3600 llvm::APSInt Value; 3601 SourceLocation Loc; 3602 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 3603 Diag(Loc, diag::err_in_class_initializer_non_constant) 3604 << Init->getSourceRange(); 3605 VDecl->setInvalidDecl(); 3606 } else if (!VDecl->getType()->isDependentType()) 3607 ImpCastExprToType(Init, VDecl->getType(), CastExpr::CK_IntegralCast); 3608 } 3609 } 3610 } else if (VDecl->isFileVarDecl()) { 3611 if (VDecl->getStorageClass() == VarDecl::Extern) 3612 Diag(VDecl->getLocation(), diag::warn_extern_init); 3613 if (!VDecl->isInvalidDecl()) 3614 if (CheckInitializerTypes(Init, DclT, Entity, Kind)) 3615 VDecl->setInvalidDecl(); 3616 3617 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3618 // Don't check invalid declarations to avoid emitting useless diagnostics. 3619 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3620 // C99 6.7.8p4. All file scoped initializers need to be constant. 3621 CheckForConstantInitializer(Init, DclT); 3622 } 3623 } 3624 // If the type changed, it means we had an incomplete type that was 3625 // completed by the initializer. For example: 3626 // int ary[] = { 1, 3, 5 }; 3627 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 3628 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 3629 VDecl->setType(DclT); 3630 Init->setType(DclT); 3631 } 3632 3633 Init = MaybeCreateCXXExprWithTemporaries(Init); 3634 // Attach the initializer to the decl. 3635 VDecl->setInit(Context, Init); 3636 3637 // If the previous declaration of VDecl was a tentative definition, 3638 // remove it from the set of tentative definitions. 3639 if (VDecl->getPreviousDeclaration() && 3640 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 3641 bool Deleted = TentativeDefinitions.erase(VDecl->getDeclName()); 3642 assert(Deleted && "Unrecorded tentative definition?"); Deleted=Deleted; 3643 } 3644 3645 return; 3646} 3647 3648void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 3649 bool TypeContainsUndeducedAuto) { 3650 Decl *RealDecl = dcl.getAs<Decl>(); 3651 3652 // If there is no declaration, there was an error parsing it. Just ignore it. 3653 if (RealDecl == 0) 3654 return; 3655 3656 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 3657 QualType Type = Var->getType(); 3658 3659 // Record tentative definitions. 3660 if (Var->isTentativeDefinition(Context)) { 3661 std::pair<llvm::DenseMap<DeclarationName, VarDecl *>::iterator, bool> 3662 InsertPair = 3663 TentativeDefinitions.insert(std::make_pair(Var->getDeclName(), Var)); 3664 3665 // Keep the latest definition in the map. If we see 'int i; int i;' we 3666 // want the second one in the map. 3667 InsertPair.first->second = Var; 3668 3669 // However, for the list, we don't care about the order, just make sure 3670 // that there are no dupes for a given declaration name. 3671 if (InsertPair.second) 3672 TentativeDefinitionList.push_back(Var->getDeclName()); 3673 } 3674 3675 // C++ [dcl.init.ref]p3: 3676 // The initializer can be omitted for a reference only in a 3677 // parameter declaration (8.3.5), in the declaration of a 3678 // function return type, in the declaration of a class member 3679 // within its class declaration (9.2), and where the extern 3680 // specifier is explicitly used. 3681 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 3682 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 3683 << Var->getDeclName() 3684 << SourceRange(Var->getLocation(), Var->getLocation()); 3685 Var->setInvalidDecl(); 3686 return; 3687 } 3688 3689 // C++0x [dcl.spec.auto]p3 3690 if (TypeContainsUndeducedAuto) { 3691 Diag(Var->getLocation(), diag::err_auto_var_requires_init) 3692 << Var->getDeclName() << Type; 3693 Var->setInvalidDecl(); 3694 return; 3695 } 3696 3697 // An array without size is an incomplete type, and there are no special 3698 // rules in C++ to make such a definition acceptable. 3699 if (getLangOptions().CPlusPlus && Type->isIncompleteArrayType() && 3700 !Var->hasExternalStorage()) { 3701 Diag(Var->getLocation(), 3702 diag::err_typecheck_incomplete_array_needs_initializer); 3703 Var->setInvalidDecl(); 3704 return; 3705 } 3706 3707 // C++ [temp.expl.spec]p15: 3708 // An explicit specialization of a static data member of a template is a 3709 // definition if the declaration includes an initializer; otherwise, it 3710 // is a declaration. 3711 if (Var->isStaticDataMember() && 3712 Var->getInstantiatedFromStaticDataMember() && 3713 Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) 3714 return; 3715 3716 // C++ [dcl.init]p9: 3717 // If no initializer is specified for an object, and the object 3718 // is of (possibly cv-qualified) non-POD class type (or array 3719 // thereof), the object shall be default-initialized; if the 3720 // object is of const-qualified type, the underlying class type 3721 // shall have a user-declared default constructor. 3722 // 3723 // FIXME: Diagnose the "user-declared default constructor" bit. 3724 if (getLangOptions().CPlusPlus) { 3725 QualType InitType = Type; 3726 if (const ArrayType *Array = Context.getAsArrayType(Type)) 3727 InitType = Context.getBaseElementType(Array); 3728 if ((!Var->hasExternalStorage() && !Var->isExternC()) && 3729 InitType->isRecordType() && !InitType->isDependentType()) { 3730 if (!RequireCompleteType(Var->getLocation(), InitType, 3731 diag::err_invalid_incomplete_type_use)) { 3732 ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this); 3733 3734 CXXConstructorDecl *Constructor 3735 = PerformInitializationByConstructor(InitType, 3736 MultiExprArg(*this, 0, 0), 3737 Var->getLocation(), 3738 SourceRange(Var->getLocation(), 3739 Var->getLocation()), 3740 Var->getDeclName(), 3741 InitializationKind::CreateDefault(Var->getLocation()), 3742 ConstructorArgs); 3743 3744 // FIXME: Location info for the variable initialization? 3745 if (!Constructor) 3746 Var->setInvalidDecl(); 3747 else { 3748 // FIXME: Cope with initialization of arrays 3749 if (!Constructor->isTrivial() && 3750 InitializeVarWithConstructor(Var, Constructor, 3751 move_arg(ConstructorArgs))) 3752 Var->setInvalidDecl(); 3753 3754 FinalizeVarWithDestructor(Var, InitType); 3755 } 3756 } else { 3757 Var->setInvalidDecl(); 3758 } 3759 } 3760 3761 // The variable can not have an abstract class type. 3762 if (RequireNonAbstractType(Var->getLocation(), Type, 3763 diag::err_abstract_type_in_decl, 3764 AbstractVariableType)) 3765 Var->setInvalidDecl(); 3766 } 3767 3768#if 0 3769 // FIXME: Temporarily disabled because we are not properly parsing 3770 // linkage specifications on declarations, e.g., 3771 // 3772 // extern "C" const CGPoint CGPointerZero; 3773 // 3774 // C++ [dcl.init]p9: 3775 // 3776 // If no initializer is specified for an object, and the 3777 // object is of (possibly cv-qualified) non-POD class type (or 3778 // array thereof), the object shall be default-initialized; if 3779 // the object is of const-qualified type, the underlying class 3780 // type shall have a user-declared default 3781 // constructor. Otherwise, if no initializer is specified for 3782 // an object, the object and its subobjects, if any, have an 3783 // indeterminate initial value; if the object or any of its 3784 // subobjects are of const-qualified type, the program is 3785 // ill-formed. 3786 // 3787 // This isn't technically an error in C, so we don't diagnose it. 3788 // 3789 // FIXME: Actually perform the POD/user-defined default 3790 // constructor check. 3791 if (getLangOptions().CPlusPlus && 3792 Context.getCanonicalType(Type).isConstQualified() && 3793 !Var->hasExternalStorage()) 3794 Diag(Var->getLocation(), diag::err_const_var_requires_init) 3795 << Var->getName() 3796 << SourceRange(Var->getLocation(), Var->getLocation()); 3797#endif 3798 } 3799} 3800 3801Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 3802 DeclPtrTy *Group, 3803 unsigned NumDecls) { 3804 llvm::SmallVector<Decl*, 8> Decls; 3805 3806 if (DS.isTypeSpecOwned()) 3807 Decls.push_back((Decl*)DS.getTypeRep()); 3808 3809 for (unsigned i = 0; i != NumDecls; ++i) 3810 if (Decl *D = Group[i].getAs<Decl>()) 3811 Decls.push_back(D); 3812 3813 // Perform semantic analysis that depends on having fully processed both 3814 // the declarator and initializer. 3815 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 3816 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 3817 if (!IDecl) 3818 continue; 3819 QualType T = IDecl->getType(); 3820 3821 // Block scope. C99 6.7p7: If an identifier for an object is declared with 3822 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 3823 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 3824 if (T->isDependentType()) { 3825 // If T is dependent, we should not require a complete type. 3826 // (RequireCompleteType shouldn't be called with dependent types.) 3827 // But we still can at least check if we've got an array of unspecified 3828 // size without an initializer. 3829 if (!IDecl->isInvalidDecl() && T->isIncompleteArrayType() && 3830 !IDecl->getInit()) { 3831 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type) 3832 << T; 3833 IDecl->setInvalidDecl(); 3834 } 3835 } else if (!IDecl->isInvalidDecl()) { 3836 // If T is an incomplete array type with an initializer list that is 3837 // dependent on something, its size has not been fixed. We could attempt 3838 // to fix the size for such arrays, but we would still have to check 3839 // here for initializers containing a C++0x vararg expansion, e.g. 3840 // template <typename... Args> void f(Args... args) { 3841 // int vals[] = { args }; 3842 // } 3843 const IncompleteArrayType *IAT = Context.getAsIncompleteArrayType(T); 3844 Expr *Init = IDecl->getInit(); 3845 if (IAT && Init && 3846 (Init->isTypeDependent() || Init->isValueDependent())) { 3847 // Check that the member type of the array is complete, at least. 3848 if (RequireCompleteType(IDecl->getLocation(), IAT->getElementType(), 3849 diag::err_typecheck_decl_incomplete_type)) 3850 IDecl->setInvalidDecl(); 3851 } else if (RequireCompleteType(IDecl->getLocation(), T, 3852 diag::err_typecheck_decl_incomplete_type)) 3853 IDecl->setInvalidDecl(); 3854 } 3855 } 3856 // File scope. C99 6.9.2p2: A declaration of an identifier for an 3857 // object that has file scope without an initializer, and without a 3858 // storage-class specifier or with the storage-class specifier "static", 3859 // constitutes a tentative definition. Note: A tentative definition with 3860 // external linkage is valid (C99 6.2.2p5). 3861 if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) { 3862 if (const IncompleteArrayType *ArrayT 3863 = Context.getAsIncompleteArrayType(T)) { 3864 if (RequireCompleteType(IDecl->getLocation(), 3865 ArrayT->getElementType(), 3866 diag::err_illegal_decl_array_incomplete_type)) 3867 IDecl->setInvalidDecl(); 3868 } else if (IDecl->getStorageClass() == VarDecl::Static) { 3869 // C99 6.9.2p3: If the declaration of an identifier for an object is 3870 // a tentative definition and has internal linkage (C99 6.2.2p3), the 3871 // declared type shall not be an incomplete type. 3872 // NOTE: code such as the following 3873 // static struct s; 3874 // struct s { int a; }; 3875 // is accepted by gcc. Hence here we issue a warning instead of 3876 // an error and we do not invalidate the static declaration. 3877 // NOTE: to avoid multiple warnings, only check the first declaration. 3878 if (IDecl->getPreviousDeclaration() == 0) 3879 RequireCompleteType(IDecl->getLocation(), T, 3880 diag::ext_typecheck_decl_incomplete_type); 3881 } 3882 } 3883 } 3884 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 3885 Decls.data(), Decls.size())); 3886} 3887 3888 3889/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 3890/// to introduce parameters into function prototype scope. 3891Sema::DeclPtrTy 3892Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 3893 const DeclSpec &DS = D.getDeclSpec(); 3894 3895 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 3896 VarDecl::StorageClass StorageClass = VarDecl::None; 3897 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 3898 StorageClass = VarDecl::Register; 3899 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 3900 Diag(DS.getStorageClassSpecLoc(), 3901 diag::err_invalid_storage_class_in_func_decl); 3902 D.getMutableDeclSpec().ClearStorageClassSpecs(); 3903 } 3904 3905 if (D.getDeclSpec().isThreadSpecified()) 3906 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3907 3908 DiagnoseFunctionSpecifiers(D); 3909 3910 // Check that there are no default arguments inside the type of this 3911 // parameter (C++ only). 3912 if (getLangOptions().CPlusPlus) 3913 CheckExtraCXXDefaultArguments(D); 3914 3915 TypeSourceInfo *TInfo = 0; 3916 TagDecl *OwnedDecl = 0; 3917 QualType parmDeclType = GetTypeForDeclarator(D, S, &TInfo, &OwnedDecl); 3918 3919 if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) { 3920 // C++ [dcl.fct]p6: 3921 // Types shall not be defined in return or parameter types. 3922 Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type) 3923 << Context.getTypeDeclType(OwnedDecl); 3924 } 3925 3926 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 3927 // Can this happen for params? We already checked that they don't conflict 3928 // among each other. Here they can only shadow globals, which is ok. 3929 IdentifierInfo *II = D.getIdentifier(); 3930 if (II) { 3931 if (NamedDecl *PrevDecl = LookupSingleName(S, II, LookupOrdinaryName)) { 3932 if (PrevDecl->isTemplateParameter()) { 3933 // Maybe we will complain about the shadowed template parameter. 3934 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 3935 // Just pretend that we didn't see the previous declaration. 3936 PrevDecl = 0; 3937 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 3938 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 3939 3940 // Recover by removing the name 3941 II = 0; 3942 D.SetIdentifier(0, D.getIdentifierLoc()); 3943 } 3944 } 3945 } 3946 3947 // Parameters can not be abstract class types. 3948 // For record types, this is done by the AbstractClassUsageDiagnoser once 3949 // the class has been completely parsed. 3950 if (!CurContext->isRecord() && 3951 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 3952 diag::err_abstract_type_in_decl, 3953 AbstractParamType)) 3954 D.setInvalidType(true); 3955 3956 QualType T = adjustParameterType(parmDeclType); 3957 3958 ParmVarDecl *New 3959 = ParmVarDecl::Create(Context, CurContext, D.getIdentifierLoc(), II, 3960 T, TInfo, StorageClass, 0); 3961 3962 if (D.isInvalidType()) 3963 New->setInvalidDecl(); 3964 3965 // Parameter declarators cannot be interface types. All ObjC objects are 3966 // passed by reference. 3967 if (T->isObjCInterfaceType()) { 3968 Diag(D.getIdentifierLoc(), 3969 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 3970 New->setInvalidDecl(); 3971 } 3972 3973 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 3974 if (D.getCXXScopeSpec().isSet()) { 3975 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 3976 << D.getCXXScopeSpec().getRange(); 3977 New->setInvalidDecl(); 3978 } 3979 3980 // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage 3981 // duration shall not be qualified by an address-space qualifier." 3982 // Since all parameters have automatic store duration, they can not have 3983 // an address space. 3984 if (T.getAddressSpace() != 0) { 3985 Diag(D.getIdentifierLoc(), 3986 diag::err_arg_with_address_space); 3987 New->setInvalidDecl(); 3988 } 3989 3990 3991 // Add the parameter declaration into this scope. 3992 S->AddDecl(DeclPtrTy::make(New)); 3993 if (II) 3994 IdResolver.AddDecl(New); 3995 3996 ProcessDeclAttributes(S, New, D); 3997 3998 if (New->hasAttr<BlocksAttr>()) { 3999 Diag(New->getLocation(), diag::err_block_on_nonlocal); 4000 } 4001 return DeclPtrTy::make(New); 4002} 4003 4004void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 4005 SourceLocation LocAfterDecls) { 4006 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 4007 "Not a function declarator!"); 4008 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 4009 4010 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 4011 // for a K&R function. 4012 if (!FTI.hasPrototype) { 4013 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 4014 --i; 4015 if (FTI.ArgInfo[i].Param == 0) { 4016 llvm::SmallString<256> Code; 4017 llvm::raw_svector_ostream(Code) << " int " 4018 << FTI.ArgInfo[i].Ident->getName() 4019 << ";\n"; 4020 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 4021 << FTI.ArgInfo[i].Ident 4022 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code.str()); 4023 4024 // Implicitly declare the argument as type 'int' for lack of a better 4025 // type. 4026 DeclSpec DS; 4027 const char* PrevSpec; // unused 4028 unsigned DiagID; // unused 4029 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 4030 PrevSpec, DiagID); 4031 Declarator ParamD(DS, Declarator::KNRTypeListContext); 4032 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 4033 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 4034 } 4035 } 4036 } 4037} 4038 4039Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 4040 Declarator &D) { 4041 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 4042 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 4043 "Not a function declarator!"); 4044 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 4045 4046 if (FTI.hasPrototype) { 4047 // FIXME: Diagnose arguments without names in C. 4048 } 4049 4050 Scope *ParentScope = FnBodyScope->getParent(); 4051 4052 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 4053 MultiTemplateParamsArg(*this), 4054 /*IsFunctionDefinition=*/true); 4055 return ActOnStartOfFunctionDef(FnBodyScope, DP); 4056} 4057 4058static bool ShouldWarnAboutMissingPrototype(const FunctionDecl *FD) { 4059 // Don't warn about invalid declarations. 4060 if (FD->isInvalidDecl()) 4061 return false; 4062 4063 // Or declarations that aren't global. 4064 if (!FD->isGlobal()) 4065 return false; 4066 4067 // Don't warn about C++ member functions. 4068 if (isa<CXXMethodDecl>(FD)) 4069 return false; 4070 4071 // Don't warn about 'main'. 4072 if (FD->isMain()) 4073 return false; 4074 4075 // Don't warn about inline functions. 4076 if (FD->isInlineSpecified()) 4077 return false; 4078 4079 // Don't warn about function templates. 4080 if (FD->getDescribedFunctionTemplate()) 4081 return false; 4082 4083 // Don't warn about function template specializations. 4084 if (FD->isFunctionTemplateSpecialization()) 4085 return false; 4086 4087 bool MissingPrototype = true; 4088 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 4089 Prev; Prev = Prev->getPreviousDeclaration()) { 4090 // Ignore any declarations that occur in function or method 4091 // scope, because they aren't visible from the header. 4092 if (Prev->getDeclContext()->isFunctionOrMethod()) 4093 continue; 4094 4095 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 4096 break; 4097 } 4098 4099 return MissingPrototype; 4100} 4101 4102Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 4103 // Clear the last template instantiation error context. 4104 LastTemplateInstantiationErrorContext = ActiveTemplateInstantiation(); 4105 4106 if (!D) 4107 return D; 4108 FunctionDecl *FD = 0; 4109 4110 if (FunctionTemplateDecl *FunTmpl 4111 = dyn_cast<FunctionTemplateDecl>(D.getAs<Decl>())) 4112 FD = FunTmpl->getTemplatedDecl(); 4113 else 4114 FD = cast<FunctionDecl>(D.getAs<Decl>()); 4115 4116 CurFunctionNeedsScopeChecking = false; 4117 4118 // See if this is a redefinition. 4119 const FunctionDecl *Definition; 4120 if (FD->getBody(Definition)) { 4121 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 4122 Diag(Definition->getLocation(), diag::note_previous_definition); 4123 } 4124 4125 // Builtin functions cannot be defined. 4126 if (unsigned BuiltinID = FD->getBuiltinID()) { 4127 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 4128 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 4129 FD->setInvalidDecl(); 4130 } 4131 } 4132 4133 // The return type of a function definition must be complete 4134 // (C99 6.9.1p3, C++ [dcl.fct]p6). 4135 QualType ResultType = FD->getResultType(); 4136 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 4137 !FD->isInvalidDecl() && 4138 RequireCompleteType(FD->getLocation(), ResultType, 4139 diag::err_func_def_incomplete_result)) 4140 FD->setInvalidDecl(); 4141 4142 // GNU warning -Wmissing-prototypes: 4143 // Warn if a global function is defined without a previous 4144 // prototype declaration. This warning is issued even if the 4145 // definition itself provides a prototype. The aim is to detect 4146 // global functions that fail to be declared in header files. 4147 if (ShouldWarnAboutMissingPrototype(FD)) 4148 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 4149 4150 if (FnBodyScope) 4151 PushDeclContext(FnBodyScope, FD); 4152 4153 // Check the validity of our function parameters 4154 CheckParmsForFunctionDef(FD); 4155 4156 // Introduce our parameters into the function scope 4157 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 4158 ParmVarDecl *Param = FD->getParamDecl(p); 4159 Param->setOwningFunction(FD); 4160 4161 // If this has an identifier, add it to the scope stack. 4162 if (Param->getIdentifier() && FnBodyScope) 4163 PushOnScopeChains(Param, FnBodyScope); 4164 } 4165 4166 // Checking attributes of current function definition 4167 // dllimport attribute. 4168 if (FD->getAttr<DLLImportAttr>() && 4169 (!FD->getAttr<DLLExportAttr>())) { 4170 // dllimport attribute cannot be applied to definition. 4171 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 4172 Diag(FD->getLocation(), 4173 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 4174 << "dllimport"; 4175 FD->setInvalidDecl(); 4176 return DeclPtrTy::make(FD); 4177 } else { 4178 // If a symbol previously declared dllimport is later defined, the 4179 // attribute is ignored in subsequent references, and a warning is 4180 // emitted. 4181 Diag(FD->getLocation(), 4182 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 4183 << FD->getNameAsCString() << "dllimport"; 4184 } 4185 } 4186 return DeclPtrTy::make(FD); 4187} 4188 4189Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 4190 return ActOnFinishFunctionBody(D, move(BodyArg), false); 4191} 4192 4193Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 4194 bool IsInstantiation) { 4195 Decl *dcl = D.getAs<Decl>(); 4196 Stmt *Body = BodyArg.takeAs<Stmt>(); 4197 4198 FunctionDecl *FD = 0; 4199 FunctionTemplateDecl *FunTmpl = dyn_cast_or_null<FunctionTemplateDecl>(dcl); 4200 if (FunTmpl) 4201 FD = FunTmpl->getTemplatedDecl(); 4202 else 4203 FD = dyn_cast_or_null<FunctionDecl>(dcl); 4204 4205 if (FD) { 4206 FD->setBody(Body); 4207 if (FD->isMain()) 4208 // C and C++ allow for main to automagically return 0. 4209 // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3. 4210 FD->setHasImplicitReturnZero(true); 4211 else 4212 CheckFallThroughForFunctionDef(FD, Body); 4213 4214 if (!FD->isInvalidDecl()) 4215 DiagnoseUnusedParameters(FD->param_begin(), FD->param_end()); 4216 4217 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 4218 MaybeMarkVirtualMembersReferenced(Method->getLocation(), Method); 4219 4220 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 4221 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 4222 assert(MD == getCurMethodDecl() && "Method parsing confused"); 4223 MD->setBody(Body); 4224 CheckFallThroughForFunctionDef(MD, Body); 4225 MD->setEndLoc(Body->getLocEnd()); 4226 4227 if (!MD->isInvalidDecl()) 4228 DiagnoseUnusedParameters(MD->param_begin(), MD->param_end()); 4229 } else { 4230 Body->Destroy(Context); 4231 return DeclPtrTy(); 4232 } 4233 if (!IsInstantiation) 4234 PopDeclContext(); 4235 4236 // Verify and clean out per-function state. 4237 4238 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 4239 4240 // Check goto/label use. 4241 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 4242 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 4243 LabelStmt *L = I->second; 4244 4245 // Verify that we have no forward references left. If so, there was a goto 4246 // or address of a label taken, but no definition of it. Label fwd 4247 // definitions are indicated with a null substmt. 4248 if (L->getSubStmt() != 0) 4249 continue; 4250 4251 // Emit error. 4252 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 4253 4254 // At this point, we have gotos that use the bogus label. Stitch it into 4255 // the function body so that they aren't leaked and that the AST is well 4256 // formed. 4257 if (Body == 0) { 4258 // The whole function wasn't parsed correctly, just delete this. 4259 L->Destroy(Context); 4260 continue; 4261 } 4262 4263 // Otherwise, the body is valid: we want to stitch the label decl into the 4264 // function somewhere so that it is properly owned and so that the goto 4265 // has a valid target. Do this by creating a new compound stmt with the 4266 // label in it. 4267 4268 // Give the label a sub-statement. 4269 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 4270 4271 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 4272 cast<CXXTryStmt>(Body)->getTryBlock() : 4273 cast<CompoundStmt>(Body); 4274 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 4275 Elements.push_back(L); 4276 Compound->setStmts(Context, &Elements[0], Elements.size()); 4277 } 4278 FunctionLabelMap.clear(); 4279 4280 if (!Body) return D; 4281 4282 // Verify that that gotos and switch cases don't jump into scopes illegally. 4283 if (CurFunctionNeedsScopeChecking) 4284 DiagnoseInvalidJumps(Body); 4285 4286 // C++ constructors that have function-try-blocks can't have return 4287 // statements in the handlers of that block. (C++ [except.handle]p14) 4288 // Verify this. 4289 if (FD && isa<CXXConstructorDecl>(FD) && isa<CXXTryStmt>(Body)) 4290 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 4291 4292 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) 4293 MarkBaseAndMemberDestructorsReferenced(Destructor); 4294 4295 // If any errors have occurred, clear out any temporaries that may have 4296 // been leftover. This ensures that these temporaries won't be picked up for 4297 // deletion in some later function. 4298 if (PP.getDiagnostics().hasErrorOccurred()) 4299 ExprTemporaries.clear(); 4300 4301 assert(ExprTemporaries.empty() && "Leftover temporaries in function"); 4302 return D; 4303} 4304 4305/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 4306/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 4307NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 4308 IdentifierInfo &II, Scope *S) { 4309 // Before we produce a declaration for an implicitly defined 4310 // function, see whether there was a locally-scoped declaration of 4311 // this name as a function or variable. If so, use that 4312 // (non-visible) declaration, and complain about it. 4313 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 4314 = LocallyScopedExternalDecls.find(&II); 4315 if (Pos != LocallyScopedExternalDecls.end()) { 4316 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 4317 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 4318 return Pos->second; 4319 } 4320 4321 // Extension in C99. Legal in C90, but warn about it. 4322 if (II.getName().startswith("__builtin_")) 4323 Diag(Loc, diag::warn_builtin_unknown) << &II; 4324 else if (getLangOptions().C99) 4325 Diag(Loc, diag::ext_implicit_function_decl) << &II; 4326 else 4327 Diag(Loc, diag::warn_implicit_function_decl) << &II; 4328 4329 // Set a Declarator for the implicit definition: int foo(); 4330 const char *Dummy; 4331 DeclSpec DS; 4332 unsigned DiagID; 4333 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID); 4334 Error = Error; // Silence warning. 4335 assert(!Error && "Error setting up implicit decl!"); 4336 Declarator D(DS, Declarator::BlockContext); 4337 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 4338 0, 0, false, SourceLocation(), 4339 false, 0,0,0, Loc, Loc, D), 4340 SourceLocation()); 4341 D.SetIdentifier(&II, Loc); 4342 4343 // Insert this function into translation-unit scope. 4344 4345 DeclContext *PrevDC = CurContext; 4346 CurContext = Context.getTranslationUnitDecl(); 4347 4348 FunctionDecl *FD = 4349 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D).getAs<Decl>()); 4350 FD->setImplicit(); 4351 4352 CurContext = PrevDC; 4353 4354 AddKnownFunctionAttributes(FD); 4355 4356 return FD; 4357} 4358 4359/// \brief Adds any function attributes that we know a priori based on 4360/// the declaration of this function. 4361/// 4362/// These attributes can apply both to implicitly-declared builtins 4363/// (like __builtin___printf_chk) or to library-declared functions 4364/// like NSLog or printf. 4365void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 4366 if (FD->isInvalidDecl()) 4367 return; 4368 4369 // If this is a built-in function, map its builtin attributes to 4370 // actual attributes. 4371 if (unsigned BuiltinID = FD->getBuiltinID()) { 4372 // Handle printf-formatting attributes. 4373 unsigned FormatIdx; 4374 bool HasVAListArg; 4375 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 4376 if (!FD->getAttr<FormatAttr>()) 4377 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 4378 HasVAListArg ? 0 : FormatIdx + 2)); 4379 } 4380 4381 // Mark const if we don't care about errno and that is the only 4382 // thing preventing the function from being const. This allows 4383 // IRgen to use LLVM intrinsics for such functions. 4384 if (!getLangOptions().MathErrno && 4385 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 4386 if (!FD->getAttr<ConstAttr>()) 4387 FD->addAttr(::new (Context) ConstAttr()); 4388 } 4389 4390 if (Context.BuiltinInfo.isNoReturn(BuiltinID)) 4391 FD->addAttr(::new (Context) NoReturnAttr()); 4392 } 4393 4394 IdentifierInfo *Name = FD->getIdentifier(); 4395 if (!Name) 4396 return; 4397 if ((!getLangOptions().CPlusPlus && 4398 FD->getDeclContext()->isTranslationUnit()) || 4399 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 4400 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 4401 LinkageSpecDecl::lang_c)) { 4402 // Okay: this could be a libc/libm/Objective-C function we know 4403 // about. 4404 } else 4405 return; 4406 4407 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 4408 // FIXME: NSLog and NSLogv should be target specific 4409 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 4410 // FIXME: We known better than our headers. 4411 const_cast<FormatAttr *>(Format)->setType("printf"); 4412 } else 4413 FD->addAttr(::new (Context) FormatAttr("printf", 1, 4414 Name->isStr("NSLogv") ? 0 : 2)); 4415 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 4416 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 4417 // target-specific builtins, perhaps? 4418 if (!FD->getAttr<FormatAttr>()) 4419 FD->addAttr(::new (Context) FormatAttr("printf", 2, 4420 Name->isStr("vasprintf") ? 0 : 3)); 4421 } 4422} 4423 4424TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 4425 TypeSourceInfo *TInfo) { 4426 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 4427 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 4428 4429 if (!TInfo) { 4430 assert(D.isInvalidType() && "no declarator info for valid type"); 4431 TInfo = Context.getTrivialTypeSourceInfo(T); 4432 } 4433 4434 // Scope manipulation handled by caller. 4435 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 4436 D.getIdentifierLoc(), 4437 D.getIdentifier(), 4438 TInfo); 4439 4440 if (const TagType *TT = T->getAs<TagType>()) { 4441 TagDecl *TD = TT->getDecl(); 4442 4443 // If the TagDecl that the TypedefDecl points to is an anonymous decl 4444 // keep track of the TypedefDecl. 4445 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 4446 TD->setTypedefForAnonDecl(NewTD); 4447 } 4448 4449 if (D.isInvalidType()) 4450 NewTD->setInvalidDecl(); 4451 return NewTD; 4452} 4453 4454 4455/// \brief Determine whether a tag with a given kind is acceptable 4456/// as a redeclaration of the given tag declaration. 4457/// 4458/// \returns true if the new tag kind is acceptable, false otherwise. 4459bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 4460 TagDecl::TagKind NewTag, 4461 SourceLocation NewTagLoc, 4462 const IdentifierInfo &Name) { 4463 // C++ [dcl.type.elab]p3: 4464 // The class-key or enum keyword present in the 4465 // elaborated-type-specifier shall agree in kind with the 4466 // declaration to which the name in theelaborated-type-specifier 4467 // refers. This rule also applies to the form of 4468 // elaborated-type-specifier that declares a class-name or 4469 // friend class since it can be construed as referring to the 4470 // definition of the class. Thus, in any 4471 // elaborated-type-specifier, the enum keyword shall be used to 4472 // refer to an enumeration (7.2), the union class-keyshall be 4473 // used to refer to a union (clause 9), and either the class or 4474 // struct class-key shall be used to refer to a class (clause 9) 4475 // declared using the class or struct class-key. 4476 TagDecl::TagKind OldTag = Previous->getTagKind(); 4477 if (OldTag == NewTag) 4478 return true; 4479 4480 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 4481 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 4482 // Warn about the struct/class tag mismatch. 4483 bool isTemplate = false; 4484 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 4485 isTemplate = Record->getDescribedClassTemplate(); 4486 4487 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 4488 << (NewTag == TagDecl::TK_class) 4489 << isTemplate << &Name 4490 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 4491 OldTag == TagDecl::TK_class? "class" : "struct"); 4492 Diag(Previous->getLocation(), diag::note_previous_use); 4493 return true; 4494 } 4495 return false; 4496} 4497 4498/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 4499/// former case, Name will be non-null. In the later case, Name will be null. 4500/// TagSpec indicates what kind of tag this is. TUK indicates whether this is a 4501/// reference/declaration/definition of a tag. 4502Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 4503 SourceLocation KWLoc, const CXXScopeSpec &SS, 4504 IdentifierInfo *Name, SourceLocation NameLoc, 4505 AttributeList *Attr, AccessSpecifier AS, 4506 MultiTemplateParamsArg TemplateParameterLists, 4507 bool &OwnedDecl, bool &IsDependent) { 4508 // If this is not a definition, it must have a name. 4509 assert((Name != 0 || TUK == TUK_Definition) && 4510 "Nameless record must be a definition!"); 4511 4512 OwnedDecl = false; 4513 TagDecl::TagKind Kind = TagDecl::getTagKindForTypeSpec(TagSpec); 4514 4515 // FIXME: Check explicit specializations more carefully. 4516 bool isExplicitSpecialization = false; 4517 if (TUK != TUK_Reference) { 4518 if (TemplateParameterList *TemplateParams 4519 = MatchTemplateParametersToScopeSpecifier(KWLoc, SS, 4520 (TemplateParameterList**)TemplateParameterLists.get(), 4521 TemplateParameterLists.size(), 4522 isExplicitSpecialization)) { 4523 if (TemplateParams->size() > 0) { 4524 // This is a declaration or definition of a class template (which may 4525 // be a member of another template). 4526 OwnedDecl = false; 4527 DeclResult Result = CheckClassTemplate(S, TagSpec, TUK, KWLoc, 4528 SS, Name, NameLoc, Attr, 4529 TemplateParams, 4530 AS); 4531 TemplateParameterLists.release(); 4532 return Result.get(); 4533 } else { 4534 // The "template<>" header is extraneous. 4535 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) 4536 << ElaboratedType::getNameForTagKind(Kind) << Name; 4537 isExplicitSpecialization = true; 4538 } 4539 } 4540 4541 TemplateParameterLists.release(); 4542 } 4543 4544 DeclContext *SearchDC = CurContext; 4545 DeclContext *DC = CurContext; 4546 bool isStdBadAlloc = false; 4547 bool Invalid = false; 4548 4549 RedeclarationKind Redecl = (TUK != TUK_Reference ? ForRedeclaration 4550 : NotForRedeclaration); 4551 4552 LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl); 4553 4554 if (Name && SS.isNotEmpty()) { 4555 // We have a nested-name tag ('struct foo::bar'). 4556 4557 // Check for invalid 'foo::'. 4558 if (SS.isInvalid()) { 4559 Name = 0; 4560 goto CreateNewDecl; 4561 } 4562 4563 // If this is a friend or a reference to a class in a dependent 4564 // context, don't try to make a decl for it. 4565 if (TUK == TUK_Friend || TUK == TUK_Reference) { 4566 DC = computeDeclContext(SS, false); 4567 if (!DC) { 4568 IsDependent = true; 4569 return DeclPtrTy(); 4570 } 4571 } 4572 4573 if (RequireCompleteDeclContext(SS)) 4574 return DeclPtrTy::make((Decl *)0); 4575 4576 DC = computeDeclContext(SS, true); 4577 SearchDC = DC; 4578 // Look-up name inside 'foo::'. 4579 LookupQualifiedName(Previous, DC); 4580 4581 if (Previous.isAmbiguous()) 4582 return DeclPtrTy(); 4583 4584 // A tag 'foo::bar' must already exist. 4585 if (Previous.empty()) { 4586 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 4587 Name = 0; 4588 Invalid = true; 4589 goto CreateNewDecl; 4590 } 4591 } else if (Name) { 4592 // If this is a named struct, check to see if there was a previous forward 4593 // declaration or definition. 4594 // FIXME: We're looking into outer scopes here, even when we 4595 // shouldn't be. Doing so can result in ambiguities that we 4596 // shouldn't be diagnosing. 4597 LookupName(Previous, S); 4598 4599 // Note: there used to be some attempt at recovery here. 4600 if (Previous.isAmbiguous()) 4601 return DeclPtrTy(); 4602 4603 if (!getLangOptions().CPlusPlus && TUK != TUK_Reference) { 4604 // FIXME: This makes sure that we ignore the contexts associated 4605 // with C structs, unions, and enums when looking for a matching 4606 // tag declaration or definition. See the similar lookup tweak 4607 // in Sema::LookupName; is there a better way to deal with this? 4608 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 4609 SearchDC = SearchDC->getParent(); 4610 } 4611 } 4612 4613 if (Previous.isSingleResult() && 4614 Previous.getFoundDecl()->isTemplateParameter()) { 4615 // Maybe we will complain about the shadowed template parameter. 4616 DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl()); 4617 // Just pretend that we didn't see the previous declaration. 4618 Previous.clear(); 4619 } 4620 4621 if (getLangOptions().CPlusPlus && Name && DC && StdNamespace && 4622 DC->Equals(StdNamespace) && Name->isStr("bad_alloc")) { 4623 // This is a declaration of or a reference to "std::bad_alloc". 4624 isStdBadAlloc = true; 4625 4626 if (Previous.empty() && StdBadAlloc) { 4627 // std::bad_alloc has been implicitly declared (but made invisible to 4628 // name lookup). Fill in this implicit declaration as the previous 4629 // declaration, so that the declarations get chained appropriately. 4630 Previous.addDecl(StdBadAlloc); 4631 } 4632 } 4633 4634 if (!Previous.empty()) { 4635 assert(Previous.isSingleResult()); 4636 NamedDecl *PrevDecl = Previous.getFoundDecl(); 4637 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 4638 // If this is a use of a previous tag, or if the tag is already declared 4639 // in the same scope (so that the definition/declaration completes or 4640 // rementions the tag), reuse the decl. 4641 if (TUK == TUK_Reference || TUK == TUK_Friend || 4642 isDeclInScope(PrevDecl, SearchDC, S)) { 4643 // Make sure that this wasn't declared as an enum and now used as a 4644 // struct or something similar. 4645 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 4646 bool SafeToContinue 4647 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 4648 Kind != TagDecl::TK_enum); 4649 if (SafeToContinue) 4650 Diag(KWLoc, diag::err_use_with_wrong_tag) 4651 << Name 4652 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 4653 PrevTagDecl->getKindName()); 4654 else 4655 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 4656 Diag(PrevTagDecl->getLocation(), diag::note_previous_use); 4657 4658 if (SafeToContinue) 4659 Kind = PrevTagDecl->getTagKind(); 4660 else { 4661 // Recover by making this an anonymous redefinition. 4662 Name = 0; 4663 Previous.clear(); 4664 Invalid = true; 4665 } 4666 } 4667 4668 if (!Invalid) { 4669 // If this is a use, just return the declaration we found. 4670 4671 // FIXME: In the future, return a variant or some other clue 4672 // for the consumer of this Decl to know it doesn't own it. 4673 // For our current ASTs this shouldn't be a problem, but will 4674 // need to be changed with DeclGroups. 4675 if (TUK == TUK_Reference || TUK == TUK_Friend) 4676 return DeclPtrTy::make(PrevTagDecl); 4677 4678 // Diagnose attempts to redefine a tag. 4679 if (TUK == TUK_Definition) { 4680 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 4681 // If we're defining a specialization and the previous definition 4682 // is from an implicit instantiation, don't emit an error 4683 // here; we'll catch this in the general case below. 4684 if (!isExplicitSpecialization || 4685 !isa<CXXRecordDecl>(Def) || 4686 cast<CXXRecordDecl>(Def)->getTemplateSpecializationKind() 4687 == TSK_ExplicitSpecialization) { 4688 Diag(NameLoc, diag::err_redefinition) << Name; 4689 Diag(Def->getLocation(), diag::note_previous_definition); 4690 // If this is a redefinition, recover by making this 4691 // struct be anonymous, which will make any later 4692 // references get the previous definition. 4693 Name = 0; 4694 Previous.clear(); 4695 Invalid = true; 4696 } 4697 } else { 4698 // If the type is currently being defined, complain 4699 // about a nested redefinition. 4700 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 4701 if (Tag->isBeingDefined()) { 4702 Diag(NameLoc, diag::err_nested_redefinition) << Name; 4703 Diag(PrevTagDecl->getLocation(), 4704 diag::note_previous_definition); 4705 Name = 0; 4706 Previous.clear(); 4707 Invalid = true; 4708 } 4709 } 4710 4711 // Okay, this is definition of a previously declared or referenced 4712 // tag PrevDecl. We're going to create a new Decl for it. 4713 } 4714 } 4715 // If we get here we have (another) forward declaration or we 4716 // have a definition. Just create a new decl. 4717 4718 } else { 4719 // If we get here, this is a definition of a new tag type in a nested 4720 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 4721 // new decl/type. We set PrevDecl to NULL so that the entities 4722 // have distinct types. 4723 Previous.clear(); 4724 } 4725 // If we get here, we're going to create a new Decl. If PrevDecl 4726 // is non-NULL, it's a definition of the tag declared by 4727 // PrevDecl. If it's NULL, we have a new definition. 4728 } else { 4729 // PrevDecl is a namespace, template, or anything else 4730 // that lives in the IDNS_Tag identifier namespace. 4731 if (isDeclInScope(PrevDecl, SearchDC, S)) { 4732 // The tag name clashes with a namespace name, issue an error and 4733 // recover by making this tag be anonymous. 4734 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 4735 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4736 Name = 0; 4737 Previous.clear(); 4738 Invalid = true; 4739 } else { 4740 // The existing declaration isn't relevant to us; we're in a 4741 // new scope, so clear out the previous declaration. 4742 Previous.clear(); 4743 } 4744 } 4745 } else if (TUK == TUK_Reference && SS.isEmpty() && Name) { 4746 // C++ [basic.scope.pdecl]p5: 4747 // -- for an elaborated-type-specifier of the form 4748 // 4749 // class-key identifier 4750 // 4751 // if the elaborated-type-specifier is used in the 4752 // decl-specifier-seq or parameter-declaration-clause of a 4753 // function defined in namespace scope, the identifier is 4754 // declared as a class-name in the namespace that contains 4755 // the declaration; otherwise, except as a friend 4756 // declaration, the identifier is declared in the smallest 4757 // non-class, non-function-prototype scope that contains the 4758 // declaration. 4759 // 4760 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 4761 // C structs and unions. 4762 // 4763 // It is an error in C++ to declare (rather than define) an enum 4764 // type, including via an elaborated type specifier. We'll 4765 // diagnose that later; for now, declare the enum in the same 4766 // scope as we would have picked for any other tag type. 4767 // 4768 // GNU C also supports this behavior as part of its incomplete 4769 // enum types extension, while GNU C++ does not. 4770 // 4771 // Find the context where we'll be declaring the tag. 4772 // FIXME: We would like to maintain the current DeclContext as the 4773 // lexical context, 4774 while (SearchDC->isRecord()) 4775 SearchDC = SearchDC->getParent(); 4776 4777 // Find the scope where we'll be declaring the tag. 4778 while (S->isClassScope() || 4779 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 4780 ((S->getFlags() & Scope::DeclScope) == 0) || 4781 (S->getEntity() && 4782 ((DeclContext *)S->getEntity())->isTransparentContext())) 4783 S = S->getParent(); 4784 4785 } else if (TUK == TUK_Friend && SS.isEmpty() && Name) { 4786 // C++ [namespace.memdef]p3: 4787 // If a friend declaration in a non-local class first declares a 4788 // class or function, the friend class or function is a member of 4789 // the innermost enclosing namespace. 4790 while (!SearchDC->isFileContext()) 4791 SearchDC = SearchDC->getParent(); 4792 4793 // The entity of a decl scope is a DeclContext; see PushDeclContext. 4794 while (S->getEntity() != SearchDC) 4795 S = S->getParent(); 4796 } 4797 4798CreateNewDecl: 4799 4800 TagDecl *PrevDecl = 0; 4801 if (Previous.isSingleResult()) 4802 PrevDecl = cast<TagDecl>(Previous.getFoundDecl()); 4803 4804 // If there is an identifier, use the location of the identifier as the 4805 // location of the decl, otherwise use the location of the struct/union 4806 // keyword. 4807 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 4808 4809 // Otherwise, create a new declaration. If there is a previous 4810 // declaration of the same entity, the two will be linked via 4811 // PrevDecl. 4812 TagDecl *New; 4813 4814 if (Kind == TagDecl::TK_enum) { 4815 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4816 // enum X { A, B, C } D; D should chain to X. 4817 New = EnumDecl::Create(Context, SearchDC, Loc, Name, KWLoc, 4818 cast_or_null<EnumDecl>(PrevDecl)); 4819 // If this is an undefined enum, warn. 4820 if (TUK != TUK_Definition && !Invalid) { 4821 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 4822 : diag::ext_forward_ref_enum; 4823 Diag(Loc, DK); 4824 } 4825 } else { 4826 // struct/union/class 4827 4828 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4829 // struct X { int A; } D; D should chain to X. 4830 if (getLangOptions().CPlusPlus) { 4831 // FIXME: Look for a way to use RecordDecl for simple structs. 4832 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4833 cast_or_null<CXXRecordDecl>(PrevDecl)); 4834 4835 if (isStdBadAlloc && (!StdBadAlloc || StdBadAlloc->isImplicit())) 4836 StdBadAlloc = cast<CXXRecordDecl>(New); 4837 } else 4838 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4839 cast_or_null<RecordDecl>(PrevDecl)); 4840 } 4841 4842 if (Kind != TagDecl::TK_enum) { 4843 // Handle #pragma pack: if the #pragma pack stack has non-default 4844 // alignment, make up a packed attribute for this decl. These 4845 // attributes are checked when the ASTContext lays out the 4846 // structure. 4847 // 4848 // It is important for implementing the correct semantics that this 4849 // happen here (in act on tag decl). The #pragma pack stack is 4850 // maintained as a result of parser callbacks which can occur at 4851 // many points during the parsing of a struct declaration (because 4852 // the #pragma tokens are effectively skipped over during the 4853 // parsing of the struct). 4854 if (unsigned Alignment = getPragmaPackAlignment()) 4855 New->addAttr(::new (Context) PragmaPackAttr(Alignment * 8)); 4856 } 4857 4858 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 4859 // C++ [dcl.typedef]p3: 4860 // [...] Similarly, in a given scope, a class or enumeration 4861 // shall not be declared with the same name as a typedef-name 4862 // that is declared in that scope and refers to a type other 4863 // than the class or enumeration itself. 4864 LookupResult Lookup(*this, Name, NameLoc, LookupOrdinaryName, 4865 ForRedeclaration); 4866 LookupName(Lookup, S); 4867 TypedefDecl *PrevTypedef = Lookup.getAsSingle<TypedefDecl>(); 4868 NamedDecl *PrevTypedefNamed = PrevTypedef; 4869 if (PrevTypedef && isDeclInScope(PrevTypedefNamed, SearchDC, S) && 4870 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 4871 Context.getCanonicalType(Context.getTypeDeclType(New))) { 4872 Diag(Loc, diag::err_tag_definition_of_typedef) 4873 << Context.getTypeDeclType(New) 4874 << PrevTypedef->getUnderlyingType(); 4875 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 4876 Invalid = true; 4877 } 4878 } 4879 4880 // If this is a specialization of a member class (of a class template), 4881 // check the specialization. 4882 if (isExplicitSpecialization && CheckMemberSpecialization(New, Previous)) 4883 Invalid = true; 4884 4885 if (Invalid) 4886 New->setInvalidDecl(); 4887 4888 if (Attr) 4889 ProcessDeclAttributeList(S, New, Attr); 4890 4891 // If we're declaring or defining a tag in function prototype scope 4892 // in C, note that this type can only be used within the function. 4893 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 4894 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 4895 4896 // Set the lexical context. If the tag has a C++ scope specifier, the 4897 // lexical context will be different from the semantic context. 4898 New->setLexicalDeclContext(CurContext); 4899 4900 // Mark this as a friend decl if applicable. 4901 if (TUK == TUK_Friend) 4902 New->setObjectOfFriendDecl(/* PreviouslyDeclared = */ !Previous.empty()); 4903 4904 // Set the access specifier. 4905 if (!Invalid && TUK != TUK_Friend) 4906 SetMemberAccessSpecifier(New, PrevDecl, AS); 4907 4908 if (TUK == TUK_Definition) 4909 New->startDefinition(); 4910 4911 // If this has an identifier, add it to the scope stack. 4912 if (TUK == TUK_Friend) { 4913 // We might be replacing an existing declaration in the lookup tables; 4914 // if so, borrow its access specifier. 4915 if (PrevDecl) 4916 New->setAccess(PrevDecl->getAccess()); 4917 4918 // Friend tag decls are visible in fairly strange ways. 4919 if (!CurContext->isDependentContext()) { 4920 DeclContext *DC = New->getDeclContext()->getLookupContext(); 4921 DC->makeDeclVisibleInContext(New, /* Recoverable = */ false); 4922 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 4923 PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false); 4924 } 4925 } else if (Name) { 4926 S = getNonFieldDeclScope(S); 4927 PushOnScopeChains(New, S); 4928 } else { 4929 CurContext->addDecl(New); 4930 } 4931 4932 // If this is the C FILE type, notify the AST context. 4933 if (IdentifierInfo *II = New->getIdentifier()) 4934 if (!New->isInvalidDecl() && 4935 New->getDeclContext()->getLookupContext()->isTranslationUnit() && 4936 II->isStr("FILE")) 4937 Context.setFILEDecl(New); 4938 4939 OwnedDecl = true; 4940 return DeclPtrTy::make(New); 4941} 4942 4943void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 4944 AdjustDeclIfTemplate(TagD); 4945 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4946 4947 // Enter the tag context. 4948 PushDeclContext(S, Tag); 4949 4950 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 4951 FieldCollector->StartClass(); 4952 4953 if (Record->getIdentifier()) { 4954 // C++ [class]p2: 4955 // [...] The class-name is also inserted into the scope of the 4956 // class itself; this is known as the injected-class-name. For 4957 // purposes of access checking, the injected-class-name is treated 4958 // as if it were a public member name. 4959 CXXRecordDecl *InjectedClassName 4960 = CXXRecordDecl::Create(Context, Record->getTagKind(), 4961 CurContext, Record->getLocation(), 4962 Record->getIdentifier(), 4963 Record->getTagKeywordLoc(), 4964 Record); 4965 InjectedClassName->setImplicit(); 4966 InjectedClassName->setAccess(AS_public); 4967 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 4968 InjectedClassName->setDescribedClassTemplate(Template); 4969 PushOnScopeChains(InjectedClassName, S); 4970 assert(InjectedClassName->isInjectedClassName() && 4971 "Broken injected-class-name"); 4972 } 4973 } 4974} 4975 4976void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD, 4977 SourceLocation RBraceLoc) { 4978 AdjustDeclIfTemplate(TagD); 4979 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4980 Tag->setRBraceLoc(RBraceLoc); 4981 4982 if (isa<CXXRecordDecl>(Tag)) 4983 FieldCollector->FinishClass(); 4984 4985 // Exit this scope of this tag's definition. 4986 PopDeclContext(); 4987 4988 // Notify the consumer that we've defined a tag. 4989 Consumer.HandleTagDeclDefinition(Tag); 4990} 4991 4992// Note that FieldName may be null for anonymous bitfields. 4993bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 4994 QualType FieldTy, const Expr *BitWidth, 4995 bool *ZeroWidth) { 4996 // Default to true; that shouldn't confuse checks for emptiness 4997 if (ZeroWidth) 4998 *ZeroWidth = true; 4999 5000 // C99 6.7.2.1p4 - verify the field type. 5001 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 5002 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 5003 // Handle incomplete types with specific error. 5004 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 5005 return true; 5006 if (FieldName) 5007 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 5008 << FieldName << FieldTy << BitWidth->getSourceRange(); 5009 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 5010 << FieldTy << BitWidth->getSourceRange(); 5011 } 5012 5013 // If the bit-width is type- or value-dependent, don't try to check 5014 // it now. 5015 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 5016 return false; 5017 5018 llvm::APSInt Value; 5019 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 5020 return true; 5021 5022 if (Value != 0 && ZeroWidth) 5023 *ZeroWidth = false; 5024 5025 // Zero-width bitfield is ok for anonymous field. 5026 if (Value == 0 && FieldName) 5027 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 5028 5029 if (Value.isSigned() && Value.isNegative()) { 5030 if (FieldName) 5031 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 5032 << FieldName << Value.toString(10); 5033 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 5034 << Value.toString(10); 5035 } 5036 5037 if (!FieldTy->isDependentType()) { 5038 uint64_t TypeSize = Context.getTypeSize(FieldTy); 5039 if (Value.getZExtValue() > TypeSize) { 5040 if (FieldName) 5041 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 5042 << FieldName << (unsigned)TypeSize; 5043 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 5044 << (unsigned)TypeSize; 5045 } 5046 } 5047 5048 return false; 5049} 5050 5051/// ActOnField - Each field of a struct/union/class is passed into this in order 5052/// to create a FieldDecl object for it. 5053Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 5054 SourceLocation DeclStart, 5055 Declarator &D, ExprTy *BitfieldWidth) { 5056 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 5057 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 5058 AS_public); 5059 return DeclPtrTy::make(Res); 5060} 5061 5062/// HandleField - Analyze a field of a C struct or a C++ data member. 5063/// 5064FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 5065 SourceLocation DeclStart, 5066 Declarator &D, Expr *BitWidth, 5067 AccessSpecifier AS) { 5068 IdentifierInfo *II = D.getIdentifier(); 5069 SourceLocation Loc = DeclStart; 5070 if (II) Loc = D.getIdentifierLoc(); 5071 5072 TypeSourceInfo *TInfo = 0; 5073 QualType T = GetTypeForDeclarator(D, S, &TInfo); 5074 if (getLangOptions().CPlusPlus) 5075 CheckExtraCXXDefaultArguments(D); 5076 5077 DiagnoseFunctionSpecifiers(D); 5078 5079 if (D.getDeclSpec().isThreadSpecified()) 5080 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 5081 5082 NamedDecl *PrevDecl = LookupSingleName(S, II, LookupMemberName, 5083 ForRedeclaration); 5084 5085 if (PrevDecl && PrevDecl->isTemplateParameter()) { 5086 // Maybe we will complain about the shadowed template parameter. 5087 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 5088 // Just pretend that we didn't see the previous declaration. 5089 PrevDecl = 0; 5090 } 5091 5092 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 5093 PrevDecl = 0; 5094 5095 bool Mutable 5096 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 5097 SourceLocation TSSL = D.getSourceRange().getBegin(); 5098 FieldDecl *NewFD 5099 = CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, TSSL, 5100 AS, PrevDecl, &D); 5101 if (NewFD->isInvalidDecl() && PrevDecl) { 5102 // Don't introduce NewFD into scope; there's already something 5103 // with the same name in the same scope. 5104 } else if (II) { 5105 PushOnScopeChains(NewFD, S); 5106 } else 5107 Record->addDecl(NewFD); 5108 5109 return NewFD; 5110} 5111 5112/// \brief Build a new FieldDecl and check its well-formedness. 5113/// 5114/// This routine builds a new FieldDecl given the fields name, type, 5115/// record, etc. \p PrevDecl should refer to any previous declaration 5116/// with the same name and in the same scope as the field to be 5117/// created. 5118/// 5119/// \returns a new FieldDecl. 5120/// 5121/// \todo The Declarator argument is a hack. It will be removed once 5122FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 5123 TypeSourceInfo *TInfo, 5124 RecordDecl *Record, SourceLocation Loc, 5125 bool Mutable, Expr *BitWidth, 5126 SourceLocation TSSL, 5127 AccessSpecifier AS, NamedDecl *PrevDecl, 5128 Declarator *D) { 5129 IdentifierInfo *II = Name.getAsIdentifierInfo(); 5130 bool InvalidDecl = false; 5131 if (D) InvalidDecl = D->isInvalidType(); 5132 5133 // If we receive a broken type, recover by assuming 'int' and 5134 // marking this declaration as invalid. 5135 if (T.isNull()) { 5136 InvalidDecl = true; 5137 T = Context.IntTy; 5138 } 5139 5140 QualType EltTy = Context.getBaseElementType(T); 5141 if (!EltTy->isDependentType() && 5142 RequireCompleteType(Loc, EltTy, diag::err_field_incomplete)) 5143 InvalidDecl = true; 5144 5145 // C99 6.7.2.1p8: A member of a structure or union may have any type other 5146 // than a variably modified type. 5147 if (!InvalidDecl && T->isVariablyModifiedType()) { 5148 bool SizeIsNegative; 5149 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 5150 SizeIsNegative); 5151 if (!FixedTy.isNull()) { 5152 Diag(Loc, diag::warn_illegal_constant_array_size); 5153 T = FixedTy; 5154 } else { 5155 if (SizeIsNegative) 5156 Diag(Loc, diag::err_typecheck_negative_array_size); 5157 else 5158 Diag(Loc, diag::err_typecheck_field_variable_size); 5159 InvalidDecl = true; 5160 } 5161 } 5162 5163 // Fields can not have abstract class types 5164 if (!InvalidDecl && RequireNonAbstractType(Loc, T, 5165 diag::err_abstract_type_in_decl, 5166 AbstractFieldType)) 5167 InvalidDecl = true; 5168 5169 bool ZeroWidth = false; 5170 // If this is declared as a bit-field, check the bit-field. 5171 if (!InvalidDecl && BitWidth && 5172 VerifyBitField(Loc, II, T, BitWidth, &ZeroWidth)) { 5173 InvalidDecl = true; 5174 DeleteExpr(BitWidth); 5175 BitWidth = 0; 5176 ZeroWidth = false; 5177 } 5178 5179 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, TInfo, 5180 BitWidth, Mutable); 5181 if (InvalidDecl) 5182 NewFD->setInvalidDecl(); 5183 5184 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 5185 Diag(Loc, diag::err_duplicate_member) << II; 5186 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 5187 NewFD->setInvalidDecl(); 5188 } 5189 5190 if (getLangOptions().CPlusPlus) { 5191 CXXRecordDecl* CXXRecord = cast<CXXRecordDecl>(Record); 5192 5193 if (!T->isPODType()) 5194 CXXRecord->setPOD(false); 5195 if (!ZeroWidth) 5196 CXXRecord->setEmpty(false); 5197 5198 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 5199 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 5200 5201 if (!RDecl->hasTrivialConstructor()) 5202 CXXRecord->setHasTrivialConstructor(false); 5203 if (!RDecl->hasTrivialCopyConstructor()) 5204 CXXRecord->setHasTrivialCopyConstructor(false); 5205 if (!RDecl->hasTrivialCopyAssignment()) 5206 CXXRecord->setHasTrivialCopyAssignment(false); 5207 if (!RDecl->hasTrivialDestructor()) 5208 CXXRecord->setHasTrivialDestructor(false); 5209 5210 // C++ 9.5p1: An object of a class with a non-trivial 5211 // constructor, a non-trivial copy constructor, a non-trivial 5212 // destructor, or a non-trivial copy assignment operator 5213 // cannot be a member of a union, nor can an array of such 5214 // objects. 5215 // TODO: C++0x alters this restriction significantly. 5216 if (Record->isUnion()) { 5217 // We check for copy constructors before constructors 5218 // because otherwise we'll never get complaints about 5219 // copy constructors. 5220 5221 const CXXSpecialMember invalid = (CXXSpecialMember) -1; 5222 5223 CXXSpecialMember member; 5224 if (!RDecl->hasTrivialCopyConstructor()) 5225 member = CXXCopyConstructor; 5226 else if (!RDecl->hasTrivialConstructor()) 5227 member = CXXDefaultConstructor; 5228 else if (!RDecl->hasTrivialCopyAssignment()) 5229 member = CXXCopyAssignment; 5230 else if (!RDecl->hasTrivialDestructor()) 5231 member = CXXDestructor; 5232 else 5233 member = invalid; 5234 5235 if (member != invalid) { 5236 Diag(Loc, diag::err_illegal_union_member) << Name << member; 5237 DiagnoseNontrivial(RT, member); 5238 NewFD->setInvalidDecl(); 5239 } 5240 } 5241 } 5242 } 5243 5244 // FIXME: We need to pass in the attributes given an AST 5245 // representation, not a parser representation. 5246 if (D) 5247 // FIXME: What to pass instead of TUScope? 5248 ProcessDeclAttributes(TUScope, NewFD, *D); 5249 5250 if (T.isObjCGCWeak()) 5251 Diag(Loc, diag::warn_attribute_weak_on_field); 5252 5253 NewFD->setAccess(AS); 5254 5255 // C++ [dcl.init.aggr]p1: 5256 // An aggregate is an array or a class (clause 9) with [...] no 5257 // private or protected non-static data members (clause 11). 5258 // A POD must be an aggregate. 5259 if (getLangOptions().CPlusPlus && 5260 (AS == AS_private || AS == AS_protected)) { 5261 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 5262 CXXRecord->setAggregate(false); 5263 CXXRecord->setPOD(false); 5264 } 5265 5266 return NewFD; 5267} 5268 5269/// DiagnoseNontrivial - Given that a class has a non-trivial 5270/// special member, figure out why. 5271void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) { 5272 QualType QT(T, 0U); 5273 CXXRecordDecl* RD = cast<CXXRecordDecl>(T->getDecl()); 5274 5275 // Check whether the member was user-declared. 5276 switch (member) { 5277 case CXXDefaultConstructor: 5278 if (RD->hasUserDeclaredConstructor()) { 5279 typedef CXXRecordDecl::ctor_iterator ctor_iter; 5280 for (ctor_iter ci = RD->ctor_begin(), ce = RD->ctor_end(); ci != ce;++ci){ 5281 const FunctionDecl *body = 0; 5282 ci->getBody(body); 5283 if (!body || 5284 !cast<CXXConstructorDecl>(body)->isImplicitlyDefined(Context)) { 5285 SourceLocation CtorLoc = ci->getLocation(); 5286 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 5287 return; 5288 } 5289 } 5290 5291 assert(0 && "found no user-declared constructors"); 5292 return; 5293 } 5294 break; 5295 5296 case CXXCopyConstructor: 5297 if (RD->hasUserDeclaredCopyConstructor()) { 5298 SourceLocation CtorLoc = 5299 RD->getCopyConstructor(Context, 0)->getLocation(); 5300 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 5301 return; 5302 } 5303 break; 5304 5305 case CXXCopyAssignment: 5306 if (RD->hasUserDeclaredCopyAssignment()) { 5307 // FIXME: this should use the location of the copy 5308 // assignment, not the type. 5309 SourceLocation TyLoc = RD->getSourceRange().getBegin(); 5310 Diag(TyLoc, diag::note_nontrivial_user_defined) << QT << member; 5311 return; 5312 } 5313 break; 5314 5315 case CXXDestructor: 5316 if (RD->hasUserDeclaredDestructor()) { 5317 SourceLocation DtorLoc = RD->getDestructor(Context)->getLocation(); 5318 Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member; 5319 return; 5320 } 5321 break; 5322 } 5323 5324 typedef CXXRecordDecl::base_class_iterator base_iter; 5325 5326 // Virtual bases and members inhibit trivial copying/construction, 5327 // but not trivial destruction. 5328 if (member != CXXDestructor) { 5329 // Check for virtual bases. vbases includes indirect virtual bases, 5330 // so we just iterate through the direct bases. 5331 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) 5332 if (bi->isVirtual()) { 5333 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 5334 Diag(BaseLoc, diag::note_nontrivial_has_virtual) << QT << 1; 5335 return; 5336 } 5337 5338 // Check for virtual methods. 5339 typedef CXXRecordDecl::method_iterator meth_iter; 5340 for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; 5341 ++mi) { 5342 if (mi->isVirtual()) { 5343 SourceLocation MLoc = mi->getSourceRange().getBegin(); 5344 Diag(MLoc, diag::note_nontrivial_has_virtual) << QT << 0; 5345 return; 5346 } 5347 } 5348 } 5349 5350 bool (CXXRecordDecl::*hasTrivial)() const; 5351 switch (member) { 5352 case CXXDefaultConstructor: 5353 hasTrivial = &CXXRecordDecl::hasTrivialConstructor; break; 5354 case CXXCopyConstructor: 5355 hasTrivial = &CXXRecordDecl::hasTrivialCopyConstructor; break; 5356 case CXXCopyAssignment: 5357 hasTrivial = &CXXRecordDecl::hasTrivialCopyAssignment; break; 5358 case CXXDestructor: 5359 hasTrivial = &CXXRecordDecl::hasTrivialDestructor; break; 5360 default: 5361 assert(0 && "unexpected special member"); return; 5362 } 5363 5364 // Check for nontrivial bases (and recurse). 5365 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) { 5366 const RecordType *BaseRT = bi->getType()->getAs<RecordType>(); 5367 assert(BaseRT && "Don't know how to handle dependent bases"); 5368 CXXRecordDecl *BaseRecTy = cast<CXXRecordDecl>(BaseRT->getDecl()); 5369 if (!(BaseRecTy->*hasTrivial)()) { 5370 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 5371 Diag(BaseLoc, diag::note_nontrivial_has_nontrivial) << QT << 1 << member; 5372 DiagnoseNontrivial(BaseRT, member); 5373 return; 5374 } 5375 } 5376 5377 // Check for nontrivial members (and recurse). 5378 typedef RecordDecl::field_iterator field_iter; 5379 for (field_iter fi = RD->field_begin(), fe = RD->field_end(); fi != fe; 5380 ++fi) { 5381 QualType EltTy = Context.getBaseElementType((*fi)->getType()); 5382 if (const RecordType *EltRT = EltTy->getAs<RecordType>()) { 5383 CXXRecordDecl* EltRD = cast<CXXRecordDecl>(EltRT->getDecl()); 5384 5385 if (!(EltRD->*hasTrivial)()) { 5386 SourceLocation FLoc = (*fi)->getLocation(); 5387 Diag(FLoc, diag::note_nontrivial_has_nontrivial) << QT << 0 << member; 5388 DiagnoseNontrivial(EltRT, member); 5389 return; 5390 } 5391 } 5392 } 5393 5394 assert(0 && "found no explanation for non-trivial member"); 5395} 5396 5397/// TranslateIvarVisibility - Translate visibility from a token ID to an 5398/// AST enum value. 5399static ObjCIvarDecl::AccessControl 5400TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 5401 switch (ivarVisibility) { 5402 default: assert(0 && "Unknown visitibility kind"); 5403 case tok::objc_private: return ObjCIvarDecl::Private; 5404 case tok::objc_public: return ObjCIvarDecl::Public; 5405 case tok::objc_protected: return ObjCIvarDecl::Protected; 5406 case tok::objc_package: return ObjCIvarDecl::Package; 5407 } 5408} 5409 5410/// ActOnIvar - Each ivar field of an objective-c class is passed into this 5411/// in order to create an IvarDecl object for it. 5412Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 5413 SourceLocation DeclStart, 5414 DeclPtrTy IntfDecl, 5415 Declarator &D, ExprTy *BitfieldWidth, 5416 tok::ObjCKeywordKind Visibility) { 5417 5418 IdentifierInfo *II = D.getIdentifier(); 5419 Expr *BitWidth = (Expr*)BitfieldWidth; 5420 SourceLocation Loc = DeclStart; 5421 if (II) Loc = D.getIdentifierLoc(); 5422 5423 // FIXME: Unnamed fields can be handled in various different ways, for 5424 // example, unnamed unions inject all members into the struct namespace! 5425 5426 TypeSourceInfo *TInfo = 0; 5427 QualType T = GetTypeForDeclarator(D, S, &TInfo); 5428 5429 if (BitWidth) { 5430 // 6.7.2.1p3, 6.7.2.1p4 5431 if (VerifyBitField(Loc, II, T, BitWidth)) { 5432 D.setInvalidType(); 5433 DeleteExpr(BitWidth); 5434 BitWidth = 0; 5435 } 5436 } else { 5437 // Not a bitfield. 5438 5439 // validate II. 5440 5441 } 5442 5443 // C99 6.7.2.1p8: A member of a structure or union may have any type other 5444 // than a variably modified type. 5445 if (T->isVariablyModifiedType()) { 5446 Diag(Loc, diag::err_typecheck_ivar_variable_size); 5447 D.setInvalidType(); 5448 } 5449 5450 // Get the visibility (access control) for this ivar. 5451 ObjCIvarDecl::AccessControl ac = 5452 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 5453 : ObjCIvarDecl::None; 5454 // Must set ivar's DeclContext to its enclosing interface. 5455 Decl *EnclosingDecl = IntfDecl.getAs<Decl>(); 5456 DeclContext *EnclosingContext; 5457 if (ObjCImplementationDecl *IMPDecl = 5458 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 5459 // Case of ivar declared in an implementation. Context is that of its class. 5460 ObjCInterfaceDecl* IDecl = IMPDecl->getClassInterface(); 5461 assert(IDecl && "No class- ActOnIvar"); 5462 EnclosingContext = cast_or_null<DeclContext>(IDecl); 5463 } else 5464 EnclosingContext = dyn_cast<DeclContext>(EnclosingDecl); 5465 assert(EnclosingContext && "null DeclContext for ivar - ActOnIvar"); 5466 5467 // Construct the decl. 5468 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, 5469 EnclosingContext, Loc, II, T, 5470 TInfo, ac, (Expr *)BitfieldWidth); 5471 5472 if (II) { 5473 NamedDecl *PrevDecl = LookupSingleName(S, II, LookupMemberName, 5474 ForRedeclaration); 5475 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 5476 && !isa<TagDecl>(PrevDecl)) { 5477 Diag(Loc, diag::err_duplicate_member) << II; 5478 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 5479 NewID->setInvalidDecl(); 5480 } 5481 } 5482 5483 // Process attributes attached to the ivar. 5484 ProcessDeclAttributes(S, NewID, D); 5485 5486 if (D.isInvalidType()) 5487 NewID->setInvalidDecl(); 5488 5489 if (II) { 5490 // FIXME: When interfaces are DeclContexts, we'll need to add 5491 // these to the interface. 5492 S->AddDecl(DeclPtrTy::make(NewID)); 5493 IdResolver.AddDecl(NewID); 5494 } 5495 5496 return DeclPtrTy::make(NewID); 5497} 5498 5499void Sema::ActOnFields(Scope* S, 5500 SourceLocation RecLoc, DeclPtrTy RecDecl, 5501 DeclPtrTy *Fields, unsigned NumFields, 5502 SourceLocation LBrac, SourceLocation RBrac, 5503 AttributeList *Attr) { 5504 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 5505 assert(EnclosingDecl && "missing record or interface decl"); 5506 5507 // If the decl this is being inserted into is invalid, then it may be a 5508 // redeclaration or some other bogus case. Don't try to add fields to it. 5509 if (EnclosingDecl->isInvalidDecl()) { 5510 // FIXME: Deallocate fields? 5511 return; 5512 } 5513 5514 5515 // Verify that all the fields are okay. 5516 unsigned NumNamedMembers = 0; 5517 llvm::SmallVector<FieldDecl*, 32> RecFields; 5518 5519 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 5520 for (unsigned i = 0; i != NumFields; ++i) { 5521 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 5522 5523 // Get the type for the field. 5524 Type *FDTy = FD->getType().getTypePtr(); 5525 5526 if (!FD->isAnonymousStructOrUnion()) { 5527 // Remember all fields written by the user. 5528 RecFields.push_back(FD); 5529 } 5530 5531 // If the field is already invalid for some reason, don't emit more 5532 // diagnostics about it. 5533 if (FD->isInvalidDecl()) { 5534 EnclosingDecl->setInvalidDecl(); 5535 continue; 5536 } 5537 5538 // C99 6.7.2.1p2: 5539 // A structure or union shall not contain a member with 5540 // incomplete or function type (hence, a structure shall not 5541 // contain an instance of itself, but may contain a pointer to 5542 // an instance of itself), except that the last member of a 5543 // structure with more than one named member may have incomplete 5544 // array type; such a structure (and any union containing, 5545 // possibly recursively, a member that is such a structure) 5546 // shall not be a member of a structure or an element of an 5547 // array. 5548 if (FDTy->isFunctionType()) { 5549 // Field declared as a function. 5550 Diag(FD->getLocation(), diag::err_field_declared_as_function) 5551 << FD->getDeclName(); 5552 FD->setInvalidDecl(); 5553 EnclosingDecl->setInvalidDecl(); 5554 continue; 5555 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 5556 Record && Record->isStruct()) { 5557 // Flexible array member. 5558 if (NumNamedMembers < 1) { 5559 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 5560 << FD->getDeclName(); 5561 FD->setInvalidDecl(); 5562 EnclosingDecl->setInvalidDecl(); 5563 continue; 5564 } 5565 // Okay, we have a legal flexible array member at the end of the struct. 5566 if (Record) 5567 Record->setHasFlexibleArrayMember(true); 5568 } else if (!FDTy->isDependentType() && 5569 RequireCompleteType(FD->getLocation(), FD->getType(), 5570 diag::err_field_incomplete)) { 5571 // Incomplete type 5572 FD->setInvalidDecl(); 5573 EnclosingDecl->setInvalidDecl(); 5574 continue; 5575 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) { 5576 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 5577 // If this is a member of a union, then entire union becomes "flexible". 5578 if (Record && Record->isUnion()) { 5579 Record->setHasFlexibleArrayMember(true); 5580 } else { 5581 // If this is a struct/class and this is not the last element, reject 5582 // it. Note that GCC supports variable sized arrays in the middle of 5583 // structures. 5584 if (i != NumFields-1) 5585 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 5586 << FD->getDeclName() << FD->getType(); 5587 else { 5588 // We support flexible arrays at the end of structs in 5589 // other structs as an extension. 5590 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 5591 << FD->getDeclName(); 5592 if (Record) 5593 Record->setHasFlexibleArrayMember(true); 5594 } 5595 } 5596 } 5597 if (Record && FDTTy->getDecl()->hasObjectMember()) 5598 Record->setHasObjectMember(true); 5599 } else if (FDTy->isObjCInterfaceType()) { 5600 /// A field cannot be an Objective-c object 5601 Diag(FD->getLocation(), diag::err_statically_allocated_object); 5602 FD->setInvalidDecl(); 5603 EnclosingDecl->setInvalidDecl(); 5604 continue; 5605 } else if (getLangOptions().ObjC1 && 5606 getLangOptions().getGCMode() != LangOptions::NonGC && 5607 Record && 5608 (FD->getType()->isObjCObjectPointerType() || 5609 FD->getType().isObjCGCStrong())) 5610 Record->setHasObjectMember(true); 5611 // Keep track of the number of named members. 5612 if (FD->getIdentifier()) 5613 ++NumNamedMembers; 5614 } 5615 5616 // Okay, we successfully defined 'Record'. 5617 if (Record) { 5618 Record->completeDefinition(Context); 5619 } else { 5620 ObjCIvarDecl **ClsFields = 5621 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 5622 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 5623 ID->setIVarList(ClsFields, RecFields.size(), Context); 5624 ID->setLocEnd(RBrac); 5625 // Add ivar's to class's DeclContext. 5626 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 5627 ClsFields[i]->setLexicalDeclContext(ID); 5628 ID->addDecl(ClsFields[i]); 5629 } 5630 // Must enforce the rule that ivars in the base classes may not be 5631 // duplicates. 5632 if (ID->getSuperClass()) { 5633 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 5634 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 5635 ObjCIvarDecl* Ivar = (*IVI); 5636 5637 if (IdentifierInfo *II = Ivar->getIdentifier()) { 5638 ObjCIvarDecl* prevIvar = 5639 ID->getSuperClass()->lookupInstanceVariable(II); 5640 if (prevIvar) { 5641 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 5642 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 5643 } 5644 } 5645 } 5646 } 5647 } else if (ObjCImplementationDecl *IMPDecl = 5648 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 5649 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 5650 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 5651 // Ivar declared in @implementation never belongs to the implementation. 5652 // Only it is in implementation's lexical context. 5653 ClsFields[I]->setLexicalDeclContext(IMPDecl); 5654 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 5655 } 5656 } 5657 5658 if (Attr) 5659 ProcessDeclAttributeList(S, Record, Attr); 5660} 5661 5662EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 5663 EnumConstantDecl *LastEnumConst, 5664 SourceLocation IdLoc, 5665 IdentifierInfo *Id, 5666 ExprArg val) { 5667 Expr *Val = (Expr *)val.get(); 5668 5669 llvm::APSInt EnumVal(32); 5670 QualType EltTy; 5671 if (Val) { 5672 if (Enum->isDependentType()) 5673 EltTy = Context.DependentTy; 5674 else { 5675 // Make sure to promote the operand type to int. 5676 UsualUnaryConversions(Val); 5677 if (Val != val.get()) { 5678 val.release(); 5679 val = Val; 5680 } 5681 5682 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 5683 SourceLocation ExpLoc; 5684 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 5685 Val = 0; 5686 } else { 5687 EltTy = Val->getType(); 5688 } 5689 } 5690 } 5691 5692 if (!Val) { 5693 if (Enum->isDependentType()) 5694 EltTy = Context.DependentTy; 5695 else if (LastEnumConst) { 5696 // Assign the last value + 1. 5697 EnumVal = LastEnumConst->getInitVal(); 5698 ++EnumVal; 5699 5700 // Check for overflow on increment. 5701 if (EnumVal < LastEnumConst->getInitVal()) 5702 Diag(IdLoc, diag::warn_enum_value_overflow); 5703 5704 EltTy = LastEnumConst->getType(); 5705 } else { 5706 // First value, set to zero. 5707 EltTy = Context.IntTy; 5708 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 5709 EnumVal.setIsSigned(true); 5710 } 5711 } 5712 5713 assert(!EltTy.isNull() && "Enum constant with NULL type"); 5714 5715 val.release(); 5716 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 5717 Val, EnumVal); 5718} 5719 5720 5721Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 5722 DeclPtrTy lastEnumConst, 5723 SourceLocation IdLoc, 5724 IdentifierInfo *Id, 5725 SourceLocation EqualLoc, ExprTy *val) { 5726 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 5727 EnumConstantDecl *LastEnumConst = 5728 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 5729 Expr *Val = static_cast<Expr*>(val); 5730 5731 // The scope passed in may not be a decl scope. Zip up the scope tree until 5732 // we find one that is. 5733 S = getNonFieldDeclScope(S); 5734 5735 // Verify that there isn't already something declared with this name in this 5736 // scope. 5737 NamedDecl *PrevDecl = LookupSingleName(S, Id, LookupOrdinaryName); 5738 if (PrevDecl && PrevDecl->isTemplateParameter()) { 5739 // Maybe we will complain about the shadowed template parameter. 5740 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 5741 // Just pretend that we didn't see the previous declaration. 5742 PrevDecl = 0; 5743 } 5744 5745 if (PrevDecl) { 5746 // When in C++, we may get a TagDecl with the same name; in this case the 5747 // enum constant will 'hide' the tag. 5748 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 5749 "Received TagDecl when not in C++!"); 5750 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 5751 if (isa<EnumConstantDecl>(PrevDecl)) 5752 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 5753 else 5754 Diag(IdLoc, diag::err_redefinition) << Id; 5755 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 5756 if (Val) Val->Destroy(Context); 5757 return DeclPtrTy(); 5758 } 5759 } 5760 5761 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 5762 IdLoc, Id, Owned(Val)); 5763 5764 // Register this decl in the current scope stack. 5765 if (New) 5766 PushOnScopeChains(New, S); 5767 5768 return DeclPtrTy::make(New); 5769} 5770 5771void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 5772 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 5773 DeclPtrTy *Elements, unsigned NumElements, 5774 Scope *S, AttributeList *Attr) { 5775 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 5776 QualType EnumType = Context.getTypeDeclType(Enum); 5777 5778 if (Attr) 5779 ProcessDeclAttributeList(S, Enum, Attr); 5780 5781 if (Enum->isDependentType()) { 5782 for (unsigned i = 0; i != NumElements; ++i) { 5783 EnumConstantDecl *ECD = 5784 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5785 if (!ECD) continue; 5786 5787 ECD->setType(EnumType); 5788 } 5789 5790 Enum->completeDefinition(Context, Context.DependentTy, Context.DependentTy); 5791 return; 5792 } 5793 5794 // TODO: If the result value doesn't fit in an int, it must be a long or long 5795 // long value. ISO C does not support this, but GCC does as an extension, 5796 // emit a warning. 5797 unsigned IntWidth = Context.Target.getIntWidth(); 5798 unsigned CharWidth = Context.Target.getCharWidth(); 5799 unsigned ShortWidth = Context.Target.getShortWidth(); 5800 5801 // Verify that all the values are okay, compute the size of the values, and 5802 // reverse the list. 5803 unsigned NumNegativeBits = 0; 5804 unsigned NumPositiveBits = 0; 5805 5806 // Keep track of whether all elements have type int. 5807 bool AllElementsInt = true; 5808 5809 for (unsigned i = 0; i != NumElements; ++i) { 5810 EnumConstantDecl *ECD = 5811 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5812 if (!ECD) continue; // Already issued a diagnostic. 5813 5814 // If the enum value doesn't fit in an int, emit an extension warning. 5815 const llvm::APSInt &InitVal = ECD->getInitVal(); 5816 assert(InitVal.getBitWidth() >= IntWidth && 5817 "Should have promoted value to int"); 5818 if (!getLangOptions().CPlusPlus && InitVal.getBitWidth() > IntWidth) { 5819 llvm::APSInt V(InitVal); 5820 V.trunc(IntWidth); 5821 V.extend(InitVal.getBitWidth()); 5822 if (V != InitVal) 5823 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 5824 << InitVal.toString(10); 5825 } 5826 5827 // Keep track of the size of positive and negative values. 5828 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 5829 NumPositiveBits = std::max(NumPositiveBits, 5830 (unsigned)InitVal.getActiveBits()); 5831 else 5832 NumNegativeBits = std::max(NumNegativeBits, 5833 (unsigned)InitVal.getMinSignedBits()); 5834 5835 // Keep track of whether every enum element has type int (very commmon). 5836 if (AllElementsInt) 5837 AllElementsInt = ECD->getType() == Context.IntTy; 5838 } 5839 5840 // Figure out the type that should be used for this enum. 5841 // FIXME: Support -fshort-enums. 5842 QualType BestType; 5843 unsigned BestWidth; 5844 5845 // C++0x N3000 [conv.prom]p3: 5846 // An rvalue of an unscoped enumeration type whose underlying 5847 // type is not fixed can be converted to an rvalue of the first 5848 // of the following types that can represent all the values of 5849 // the enumeration: int, unsigned int, long int, unsigned long 5850 // int, long long int, or unsigned long long int. 5851 // C99 6.4.4.3p2: 5852 // An identifier declared as an enumeration constant has type int. 5853 // The C99 rule is modified by a gcc extension 5854 QualType BestPromotionType; 5855 5856 bool Packed = Enum->getAttr<PackedAttr>() ? true : false; 5857 5858 if (NumNegativeBits) { 5859 // If there is a negative value, figure out the smallest integer type (of 5860 // int/long/longlong) that fits. 5861 // If it's packed, check also if it fits a char or a short. 5862 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) { 5863 BestType = Context.SignedCharTy; 5864 BestWidth = CharWidth; 5865 } else if (Packed && NumNegativeBits <= ShortWidth && 5866 NumPositiveBits < ShortWidth) { 5867 BestType = Context.ShortTy; 5868 BestWidth = ShortWidth; 5869 } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 5870 BestType = Context.IntTy; 5871 BestWidth = IntWidth; 5872 } else { 5873 BestWidth = Context.Target.getLongWidth(); 5874 5875 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) { 5876 BestType = Context.LongTy; 5877 } else { 5878 BestWidth = Context.Target.getLongLongWidth(); 5879 5880 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 5881 Diag(Enum->getLocation(), diag::warn_enum_too_large); 5882 BestType = Context.LongLongTy; 5883 } 5884 } 5885 BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType); 5886 } else { 5887 // If there is no negative value, figure out which of uint, ulong, ulonglong 5888 // fits. 5889 // If it's packed, check also if it fits a char or a short. 5890 if (Packed && NumPositiveBits <= CharWidth) { 5891 BestType = Context.UnsignedCharTy; 5892 BestPromotionType = Context.IntTy; 5893 BestWidth = CharWidth; 5894 } else if (Packed && NumPositiveBits <= ShortWidth) { 5895 BestType = Context.UnsignedShortTy; 5896 BestPromotionType = Context.IntTy; 5897 BestWidth = ShortWidth; 5898 } else if (NumPositiveBits <= IntWidth) { 5899 BestType = Context.UnsignedIntTy; 5900 BestWidth = IntWidth; 5901 BestPromotionType = (NumPositiveBits == BestWidth 5902 ? Context.UnsignedIntTy : Context.IntTy); 5903 } else if (NumPositiveBits <= 5904 (BestWidth = Context.Target.getLongWidth())) { 5905 BestType = Context.UnsignedLongTy; 5906 BestPromotionType = (NumPositiveBits == BestWidth 5907 ? Context.UnsignedLongTy : Context.LongTy); 5908 } else { 5909 BestWidth = Context.Target.getLongLongWidth(); 5910 assert(NumPositiveBits <= BestWidth && 5911 "How could an initializer get larger than ULL?"); 5912 BestType = Context.UnsignedLongLongTy; 5913 BestPromotionType = (NumPositiveBits == BestWidth 5914 ? Context.UnsignedLongLongTy : Context.LongLongTy); 5915 } 5916 } 5917 5918 // If we're in C and the promotion type is larger than an int, just 5919 // use the underlying type, which is generally the unsigned integer 5920 // type of the same rank as the promotion type. This is how the gcc 5921 // extension works. 5922 if (!getLangOptions().CPlusPlus && BestPromotionType != Context.IntTy) 5923 BestPromotionType = BestType; 5924 5925 // Loop over all of the enumerator constants, changing their types to match 5926 // the type of the enum if needed. 5927 for (unsigned i = 0; i != NumElements; ++i) { 5928 EnumConstantDecl *ECD = 5929 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5930 if (!ECD) continue; // Already issued a diagnostic. 5931 5932 // Standard C says the enumerators have int type, but we allow, as an 5933 // extension, the enumerators to be larger than int size. If each 5934 // enumerator value fits in an int, type it as an int, otherwise type it the 5935 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 5936 // that X has type 'int', not 'unsigned'. 5937 if (!getLangOptions().CPlusPlus && ECD->getType() == Context.IntTy) 5938 continue; 5939 5940 // Determine whether the value fits into an int. 5941 llvm::APSInt InitVal = ECD->getInitVal(); 5942 bool FitsInInt; 5943 if (InitVal.isUnsigned() || !InitVal.isNegative()) 5944 FitsInInt = InitVal.getActiveBits() < IntWidth; 5945 else 5946 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 5947 5948 // If it fits into an integer type, force it. Otherwise force it to match 5949 // the enum decl type. 5950 QualType NewTy; 5951 unsigned NewWidth; 5952 bool NewSign; 5953 if (FitsInInt && !getLangOptions().CPlusPlus) { 5954 NewTy = Context.IntTy; 5955 NewWidth = IntWidth; 5956 NewSign = true; 5957 } else if (ECD->getType() == BestType) { 5958 // Already the right type! 5959 if (getLangOptions().CPlusPlus) 5960 // C++ [dcl.enum]p4: Following the closing brace of an 5961 // enum-specifier, each enumerator has the type of its 5962 // enumeration. 5963 ECD->setType(EnumType); 5964 continue; 5965 } else { 5966 NewTy = BestType; 5967 NewWidth = BestWidth; 5968 NewSign = BestType->isSignedIntegerType(); 5969 } 5970 5971 // Adjust the APSInt value. 5972 InitVal.extOrTrunc(NewWidth); 5973 InitVal.setIsSigned(NewSign); 5974 ECD->setInitVal(InitVal); 5975 5976 // Adjust the Expr initializer and type. 5977 if (ECD->getInitExpr()) 5978 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, 5979 CastExpr::CK_IntegralCast, 5980 ECD->getInitExpr(), 5981 /*isLvalue=*/false)); 5982 if (getLangOptions().CPlusPlus) 5983 // C++ [dcl.enum]p4: Following the closing brace of an 5984 // enum-specifier, each enumerator has the type of its 5985 // enumeration. 5986 ECD->setType(EnumType); 5987 else 5988 ECD->setType(NewTy); 5989 } 5990 5991 Enum->completeDefinition(Context, BestType, BestPromotionType); 5992} 5993 5994Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 5995 ExprArg expr) { 5996 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 5997 5998 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 5999 Loc, AsmString); 6000 CurContext->addDecl(New); 6001 return DeclPtrTy::make(New); 6002} 6003 6004void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 6005 SourceLocation PragmaLoc, 6006 SourceLocation NameLoc) { 6007 Decl *PrevDecl = LookupSingleName(TUScope, Name, LookupOrdinaryName); 6008 6009 if (PrevDecl) { 6010 PrevDecl->addAttr(::new (Context) WeakAttr()); 6011 } else { 6012 (void)WeakUndeclaredIdentifiers.insert( 6013 std::pair<IdentifierInfo*,WeakInfo> 6014 (Name, WeakInfo((IdentifierInfo*)0, NameLoc))); 6015 } 6016} 6017 6018void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 6019 IdentifierInfo* AliasName, 6020 SourceLocation PragmaLoc, 6021 SourceLocation NameLoc, 6022 SourceLocation AliasNameLoc) { 6023 Decl *PrevDecl = LookupSingleName(TUScope, AliasName, LookupOrdinaryName); 6024 WeakInfo W = WeakInfo(Name, NameLoc); 6025 6026 if (PrevDecl) { 6027 if (!PrevDecl->hasAttr<AliasAttr>()) 6028 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl)) 6029 DeclApplyPragmaWeak(TUScope, ND, W); 6030 } else { 6031 (void)WeakUndeclaredIdentifiers.insert( 6032 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W)); 6033 } 6034} 6035