SemaDecl.cpp revision 6bde1ae4b7e790691b3a8080a7f1a8fd8a943d3f
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/Analysis/PathSensitive/AnalysisContext.h" 18#include "clang/AST/APValue.h" 19#include "clang/AST/ASTConsumer.h" 20#include "clang/AST/ASTContext.h" 21#include "clang/Analysis/CFG.h" 22#include "clang/AST/CXXInheritance.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/DeclTemplate.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/AST/StmtCXX.h" 27#include "clang/AST/StmtObjC.h" 28#include "clang/Parse/DeclSpec.h" 29#include "clang/Parse/ParseDiagnostic.h" 30#include "clang/Parse/Template.h" 31#include "clang/Basic/PartialDiagnostic.h" 32#include "clang/Basic/SourceManager.h" 33#include "clang/Basic/TargetInfo.h" 34// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 35#include "clang/Lex/Preprocessor.h" 36#include "clang/Lex/HeaderSearch.h" 37#include "llvm/ADT/BitVector.h" 38#include "llvm/ADT/STLExtras.h" 39#include "llvm/ADT/Triple.h" 40#include <algorithm> 41#include <cstring> 42#include <functional> 43#include <queue> 44using namespace clang; 45 46/// getDeclName - Return a pretty name for the specified decl if possible, or 47/// an empty string if not. This is used for pretty crash reporting. 48std::string Sema::getDeclName(DeclPtrTy d) { 49 Decl *D = d.getAs<Decl>(); 50 if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D)) 51 return DN->getQualifiedNameAsString(); 52 return ""; 53} 54 55Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) { 56 return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>())); 57} 58 59/// \brief If the identifier refers to a type name within this scope, 60/// return the declaration of that type. 61/// 62/// This routine performs ordinary name lookup of the identifier II 63/// within the given scope, with optional C++ scope specifier SS, to 64/// determine whether the name refers to a type. If so, returns an 65/// opaque pointer (actually a QualType) corresponding to that 66/// type. Otherwise, returns NULL. 67/// 68/// If name lookup results in an ambiguity, this routine will complain 69/// and then return NULL. 70Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 71 Scope *S, const CXXScopeSpec *SS, 72 bool isClassName, 73 TypeTy *ObjectTypePtr) { 74 // Determine where we will perform name lookup. 75 DeclContext *LookupCtx = 0; 76 if (ObjectTypePtr) { 77 QualType ObjectType = QualType::getFromOpaquePtr(ObjectTypePtr); 78 if (ObjectType->isRecordType()) 79 LookupCtx = computeDeclContext(ObjectType); 80 } else if (SS && SS->isSet()) { 81 LookupCtx = computeDeclContext(*SS, false); 82 83 if (!LookupCtx) { 84 if (isDependentScopeSpecifier(*SS)) { 85 // C++ [temp.res]p3: 86 // A qualified-id that refers to a type and in which the 87 // nested-name-specifier depends on a template-parameter (14.6.2) 88 // shall be prefixed by the keyword typename to indicate that the 89 // qualified-id denotes a type, forming an 90 // elaborated-type-specifier (7.1.5.3). 91 // 92 // We therefore do not perform any name lookup if the result would 93 // refer to a member of an unknown specialization. 94 if (!isClassName) 95 return 0; 96 97 // We know from the grammar that this name refers to a type, so build a 98 // TypenameType node to describe the type. 99 // FIXME: Record somewhere that this TypenameType node has no "typename" 100 // keyword associated with it. 101 return CheckTypenameType((NestedNameSpecifier *)SS->getScopeRep(), 102 II, SS->getRange()).getAsOpaquePtr(); 103 } 104 105 return 0; 106 } 107 108 if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(*SS)) 109 return 0; 110 } 111 112 // FIXME: LookupNestedNameSpecifierName isn't the right kind of 113 // lookup for class-names. 114 LookupNameKind Kind = isClassName ? LookupNestedNameSpecifierName : 115 LookupOrdinaryName; 116 LookupResult Result(*this, &II, NameLoc, Kind); 117 if (LookupCtx) { 118 // Perform "qualified" name lookup into the declaration context we 119 // computed, which is either the type of the base of a member access 120 // expression or the declaration context associated with a prior 121 // nested-name-specifier. 122 LookupQualifiedName(Result, LookupCtx); 123 124 if (ObjectTypePtr && Result.empty()) { 125 // C++ [basic.lookup.classref]p3: 126 // If the unqualified-id is ~type-name, the type-name is looked up 127 // in the context of the entire postfix-expression. If the type T of 128 // the object expression is of a class type C, the type-name is also 129 // looked up in the scope of class C. At least one of the lookups shall 130 // find a name that refers to (possibly cv-qualified) T. 131 LookupName(Result, S); 132 } 133 } else { 134 // Perform unqualified name lookup. 135 LookupName(Result, S); 136 } 137 138 NamedDecl *IIDecl = 0; 139 switch (Result.getResultKind()) { 140 case LookupResult::NotFound: 141 case LookupResult::NotFoundInCurrentInstantiation: 142 case LookupResult::FoundOverloaded: 143 case LookupResult::FoundUnresolvedValue: 144 return 0; 145 146 case LookupResult::Ambiguous: 147 // Recover from type-hiding ambiguities by hiding the type. We'll 148 // do the lookup again when looking for an object, and we can 149 // diagnose the error then. If we don't do this, then the error 150 // about hiding the type will be immediately followed by an error 151 // that only makes sense if the identifier was treated like a type. 152 if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) { 153 Result.suppressDiagnostics(); 154 return 0; 155 } 156 157 // Look to see if we have a type anywhere in the list of results. 158 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); 159 Res != ResEnd; ++Res) { 160 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) { 161 if (!IIDecl || 162 (*Res)->getLocation().getRawEncoding() < 163 IIDecl->getLocation().getRawEncoding()) 164 IIDecl = *Res; 165 } 166 } 167 168 if (!IIDecl) { 169 // None of the entities we found is a type, so there is no way 170 // to even assume that the result is a type. In this case, don't 171 // complain about the ambiguity. The parser will either try to 172 // perform this lookup again (e.g., as an object name), which 173 // will produce the ambiguity, or will complain that it expected 174 // a type name. 175 Result.suppressDiagnostics(); 176 return 0; 177 } 178 179 // We found a type within the ambiguous lookup; diagnose the 180 // ambiguity and then return that type. This might be the right 181 // answer, or it might not be, but it suppresses any attempt to 182 // perform the name lookup again. 183 break; 184 185 case LookupResult::Found: 186 IIDecl = Result.getFoundDecl(); 187 break; 188 } 189 190 assert(IIDecl && "Didn't find decl"); 191 192 QualType T; 193 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 194 DiagnoseUseOfDecl(IIDecl, NameLoc); 195 196 // C++ [temp.local]p2: 197 // Within the scope of a class template specialization or 198 // partial specialization, when the injected-class-name is 199 // not followed by a <, it is equivalent to the 200 // injected-class-name followed by the template-argument s 201 // of the class template specialization or partial 202 // specialization enclosed in <>. 203 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) 204 if (RD->isInjectedClassName()) 205 if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate()) 206 T = Template->getInjectedClassNameType(Context); 207 208 if (T.isNull()) 209 T = Context.getTypeDeclType(TD); 210 211 if (SS) 212 T = getQualifiedNameType(*SS, T); 213 214 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 215 T = Context.getObjCInterfaceType(IDecl); 216 } else if (UnresolvedUsingTypenameDecl *UUDecl = 217 dyn_cast<UnresolvedUsingTypenameDecl>(IIDecl)) { 218 // FIXME: preserve source structure information. 219 T = Context.getTypenameType(UUDecl->getTargetNestedNameSpecifier(), &II); 220 } else { 221 // If it's not plausibly a type, suppress diagnostics. 222 Result.suppressDiagnostics(); 223 return 0; 224 } 225 226 return T.getAsOpaquePtr(); 227} 228 229/// isTagName() - This method is called *for error recovery purposes only* 230/// to determine if the specified name is a valid tag name ("struct foo"). If 231/// so, this returns the TST for the tag corresponding to it (TST_enum, 232/// TST_union, TST_struct, TST_class). This is used to diagnose cases in C 233/// where the user forgot to specify the tag. 234DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { 235 // Do a tag name lookup in this scope. 236 LookupResult R(*this, &II, SourceLocation(), LookupTagName); 237 LookupName(R, S, false); 238 R.suppressDiagnostics(); 239 if (R.getResultKind() == LookupResult::Found) 240 if (const TagDecl *TD = R.getAsSingle<TagDecl>()) { 241 switch (TD->getTagKind()) { 242 case TagDecl::TK_struct: return DeclSpec::TST_struct; 243 case TagDecl::TK_union: return DeclSpec::TST_union; 244 case TagDecl::TK_class: return DeclSpec::TST_class; 245 case TagDecl::TK_enum: return DeclSpec::TST_enum; 246 } 247 } 248 249 return DeclSpec::TST_unspecified; 250} 251 252bool Sema::DiagnoseUnknownTypeName(const IdentifierInfo &II, 253 SourceLocation IILoc, 254 Scope *S, 255 const CXXScopeSpec *SS, 256 TypeTy *&SuggestedType) { 257 // We don't have anything to suggest (yet). 258 SuggestedType = 0; 259 260 // There may have been a typo in the name of the type. Look up typo 261 // results, in case we have something that we can suggest. 262 LookupResult Lookup(*this, &II, IILoc, LookupOrdinaryName, 263 NotForRedeclaration); 264 265 // FIXME: It would be nice if we could correct for typos in built-in 266 // names, such as "itn" for "int". 267 268 if (CorrectTypo(Lookup, S, SS) && Lookup.isSingleResult()) { 269 NamedDecl *Result = Lookup.getAsSingle<NamedDecl>(); 270 if ((isa<TypeDecl>(Result) || isa<ObjCInterfaceDecl>(Result)) && 271 !Result->isInvalidDecl()) { 272 // We found a similarly-named type or interface; suggest that. 273 if (!SS || !SS->isSet()) 274 Diag(IILoc, diag::err_unknown_typename_suggest) 275 << &II << Lookup.getLookupName() 276 << CodeModificationHint::CreateReplacement(SourceRange(IILoc), 277 Result->getNameAsString()); 278 else if (DeclContext *DC = computeDeclContext(*SS, false)) 279 Diag(IILoc, diag::err_unknown_nested_typename_suggest) 280 << &II << DC << Lookup.getLookupName() << SS->getRange() 281 << CodeModificationHint::CreateReplacement(SourceRange(IILoc), 282 Result->getNameAsString()); 283 else 284 llvm_unreachable("could not have corrected a typo here"); 285 286 Diag(Result->getLocation(), diag::note_previous_decl) 287 << Result->getDeclName(); 288 289 SuggestedType = getTypeName(*Result->getIdentifier(), IILoc, S, SS); 290 return true; 291 } 292 } 293 294 // FIXME: Should we move the logic that tries to recover from a missing tag 295 // (struct, union, enum) from Parser::ParseImplicitInt here, instead? 296 297 if (!SS || (!SS->isSet() && !SS->isInvalid())) 298 Diag(IILoc, diag::err_unknown_typename) << &II; 299 else if (DeclContext *DC = computeDeclContext(*SS, false)) 300 Diag(IILoc, diag::err_typename_nested_not_found) 301 << &II << DC << SS->getRange(); 302 else if (isDependentScopeSpecifier(*SS)) { 303 Diag(SS->getRange().getBegin(), diag::err_typename_missing) 304 << (NestedNameSpecifier *)SS->getScopeRep() << II.getName() 305 << SourceRange(SS->getRange().getBegin(), IILoc) 306 << CodeModificationHint::CreateInsertion(SS->getRange().getBegin(), 307 "typename "); 308 SuggestedType = ActOnTypenameType(SourceLocation(), *SS, II, IILoc).get(); 309 } else { 310 assert(SS && SS->isInvalid() && 311 "Invalid scope specifier has already been diagnosed"); 312 } 313 314 return true; 315} 316 317// Determines the context to return to after temporarily entering a 318// context. This depends in an unnecessarily complicated way on the 319// exact ordering of callbacks from the parser. 320DeclContext *Sema::getContainingDC(DeclContext *DC) { 321 322 // Functions defined inline within classes aren't parsed until we've 323 // finished parsing the top-level class, so the top-level class is 324 // the context we'll need to return to. 325 if (isa<FunctionDecl>(DC)) { 326 DC = DC->getLexicalParent(); 327 328 // A function not defined within a class will always return to its 329 // lexical context. 330 if (!isa<CXXRecordDecl>(DC)) 331 return DC; 332 333 // A C++ inline method/friend is parsed *after* the topmost class 334 // it was declared in is fully parsed ("complete"); the topmost 335 // class is the context we need to return to. 336 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 337 DC = RD; 338 339 // Return the declaration context of the topmost class the inline method is 340 // declared in. 341 return DC; 342 } 343 344 if (isa<ObjCMethodDecl>(DC)) 345 return Context.getTranslationUnitDecl(); 346 347 return DC->getLexicalParent(); 348} 349 350void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 351 assert(getContainingDC(DC) == CurContext && 352 "The next DeclContext should be lexically contained in the current one."); 353 CurContext = DC; 354 S->setEntity(DC); 355} 356 357void Sema::PopDeclContext() { 358 assert(CurContext && "DeclContext imbalance!"); 359 360 CurContext = getContainingDC(CurContext); 361} 362 363/// EnterDeclaratorContext - Used when we must lookup names in the context 364/// of a declarator's nested name specifier. 365/// 366void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { 367 // C++0x [basic.lookup.unqual]p13: 368 // A name used in the definition of a static data member of class 369 // X (after the qualified-id of the static member) is looked up as 370 // if the name was used in a member function of X. 371 // C++0x [basic.lookup.unqual]p14: 372 // If a variable member of a namespace is defined outside of the 373 // scope of its namespace then any name used in the definition of 374 // the variable member (after the declarator-id) is looked up as 375 // if the definition of the variable member occurred in its 376 // namespace. 377 // Both of these imply that we should push a scope whose context 378 // is the semantic context of the declaration. We can't use 379 // PushDeclContext here because that context is not necessarily 380 // lexically contained in the current context. Fortunately, 381 // the containing scope should have the appropriate information. 382 383 assert(!S->getEntity() && "scope already has entity"); 384 385#ifndef NDEBUG 386 Scope *Ancestor = S->getParent(); 387 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent(); 388 assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch"); 389#endif 390 391 CurContext = DC; 392 S->setEntity(DC); 393} 394 395void Sema::ExitDeclaratorContext(Scope *S) { 396 assert(S->getEntity() == CurContext && "Context imbalance!"); 397 398 // Switch back to the lexical context. The safety of this is 399 // enforced by an assert in EnterDeclaratorContext. 400 Scope *Ancestor = S->getParent(); 401 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent(); 402 CurContext = (DeclContext*) Ancestor->getEntity(); 403 404 // We don't need to do anything with the scope, which is going to 405 // disappear. 406} 407 408/// \brief Determine whether we allow overloading of the function 409/// PrevDecl with another declaration. 410/// 411/// This routine determines whether overloading is possible, not 412/// whether some new function is actually an overload. It will return 413/// true in C++ (where we can always provide overloads) or, as an 414/// extension, in C when the previous function is already an 415/// overloaded function declaration or has the "overloadable" 416/// attribute. 417static bool AllowOverloadingOfFunction(LookupResult &Previous, 418 ASTContext &Context) { 419 if (Context.getLangOptions().CPlusPlus) 420 return true; 421 422 if (Previous.getResultKind() == LookupResult::FoundOverloaded) 423 return true; 424 425 return (Previous.getResultKind() == LookupResult::Found 426 && Previous.getFoundDecl()->hasAttr<OverloadableAttr>()); 427} 428 429/// Add this decl to the scope shadowed decl chains. 430void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) { 431 // Move up the scope chain until we find the nearest enclosing 432 // non-transparent context. The declaration will be introduced into this 433 // scope. 434 while (S->getEntity() && 435 ((DeclContext *)S->getEntity())->isTransparentContext()) 436 S = S->getParent(); 437 438 // Add scoped declarations into their context, so that they can be 439 // found later. Declarations without a context won't be inserted 440 // into any context. 441 if (AddToContext) 442 CurContext->addDecl(D); 443 444 // Out-of-line function and variable definitions should not be pushed into 445 // scope. 446 if ((isa<FunctionTemplateDecl>(D) && 447 cast<FunctionTemplateDecl>(D)->getTemplatedDecl()->isOutOfLine()) || 448 (isa<FunctionDecl>(D) && 449 (cast<FunctionDecl>(D)->isFunctionTemplateSpecialization() || 450 cast<FunctionDecl>(D)->isOutOfLine())) || 451 (isa<VarDecl>(D) && cast<VarDecl>(D)->isOutOfLine())) 452 return; 453 454 // If this replaces anything in the current scope, 455 IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()), 456 IEnd = IdResolver.end(); 457 for (; I != IEnd; ++I) { 458 if (S->isDeclScope(DeclPtrTy::make(*I)) && D->declarationReplaces(*I)) { 459 S->RemoveDecl(DeclPtrTy::make(*I)); 460 IdResolver.RemoveDecl(*I); 461 462 // Should only need to replace one decl. 463 break; 464 } 465 } 466 467 S->AddDecl(DeclPtrTy::make(D)); 468 IdResolver.AddDecl(D); 469} 470 471bool Sema::isDeclInScope(NamedDecl *&D, DeclContext *Ctx, Scope *S) { 472 return IdResolver.isDeclInScope(D, Ctx, Context, S); 473} 474 475static bool isOutOfScopePreviousDeclaration(NamedDecl *, 476 DeclContext*, 477 ASTContext&); 478 479/// Filters out lookup results that don't fall within the given scope 480/// as determined by isDeclInScope. 481static void FilterLookupForScope(Sema &SemaRef, LookupResult &R, 482 DeclContext *Ctx, Scope *S, 483 bool ConsiderLinkage) { 484 LookupResult::Filter F = R.makeFilter(); 485 while (F.hasNext()) { 486 NamedDecl *D = F.next(); 487 488 if (SemaRef.isDeclInScope(D, Ctx, S)) 489 continue; 490 491 if (ConsiderLinkage && 492 isOutOfScopePreviousDeclaration(D, Ctx, SemaRef.Context)) 493 continue; 494 495 F.erase(); 496 } 497 498 F.done(); 499} 500 501static bool isUsingDecl(NamedDecl *D) { 502 return isa<UsingShadowDecl>(D) || 503 isa<UnresolvedUsingTypenameDecl>(D) || 504 isa<UnresolvedUsingValueDecl>(D); 505} 506 507/// Removes using shadow declarations from the lookup results. 508static void RemoveUsingDecls(LookupResult &R) { 509 LookupResult::Filter F = R.makeFilter(); 510 while (F.hasNext()) 511 if (isUsingDecl(F.next())) 512 F.erase(); 513 514 F.done(); 515} 516 517static bool ShouldDiagnoseUnusedDecl(const NamedDecl *D) { 518 if (D->isUsed() || D->hasAttr<UnusedAttr>()) 519 return false; 520 521 if (const ValueDecl *VD = dyn_cast<ValueDecl>(D)) { 522 if (const RecordType *RT = VD->getType()->getAs<RecordType>()) { 523 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 524 if (!RD->hasTrivialConstructor()) 525 return false; 526 if (!RD->hasTrivialDestructor()) 527 return false; 528 } 529 } 530 } 531 532 return (isa<VarDecl>(D) && !isa<ParmVarDecl>(D) && 533 !isa<ImplicitParamDecl>(D) && 534 D->getDeclContext()->isFunctionOrMethod()); 535} 536 537void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 538 if (S->decl_empty()) return; 539 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 540 "Scope shouldn't contain decls!"); 541 542 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 543 I != E; ++I) { 544 Decl *TmpD = (*I).getAs<Decl>(); 545 assert(TmpD && "This decl didn't get pushed??"); 546 547 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 548 NamedDecl *D = cast<NamedDecl>(TmpD); 549 550 if (!D->getDeclName()) continue; 551 552 // Diagnose unused variables in this scope. 553 if (ShouldDiagnoseUnusedDecl(D)) 554 Diag(D->getLocation(), diag::warn_unused_variable) << D->getDeclName(); 555 556 // Remove this name from our lexical scope. 557 IdResolver.RemoveDecl(D); 558 } 559} 560 561/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 562/// return 0 if one not found. 563/// 564/// \param Id the name of the Objective-C class we're looking for. If 565/// typo-correction fixes this name, the Id will be updated 566/// to the fixed name. 567/// 568/// \param RecoverLoc if provided, this routine will attempt to 569/// recover from a typo in the name of an existing Objective-C class 570/// and, if successful, will return the lookup that results from 571/// typo-correction. 572ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id, 573 SourceLocation RecoverLoc) { 574 // The third "scope" argument is 0 since we aren't enabling lazy built-in 575 // creation from this context. 576 NamedDecl *IDecl = LookupSingleName(TUScope, Id, LookupOrdinaryName); 577 578 if (!IDecl && !RecoverLoc.isInvalid()) { 579 // Perform typo correction at the given location, but only if we 580 // find an Objective-C class name. 581 LookupResult R(*this, Id, RecoverLoc, LookupOrdinaryName); 582 if (CorrectTypo(R, TUScope, 0) && 583 (IDecl = R.getAsSingle<ObjCInterfaceDecl>())) { 584 Diag(RecoverLoc, diag::err_undef_interface_suggest) 585 << Id << IDecl->getDeclName() 586 << CodeModificationHint::CreateReplacement(RecoverLoc, 587 IDecl->getNameAsString()); 588 Diag(IDecl->getLocation(), diag::note_previous_decl) 589 << IDecl->getDeclName(); 590 591 Id = IDecl->getIdentifier(); 592 } 593 } 594 595 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 596} 597 598/// getNonFieldDeclScope - Retrieves the innermost scope, starting 599/// from S, where a non-field would be declared. This routine copes 600/// with the difference between C and C++ scoping rules in structs and 601/// unions. For example, the following code is well-formed in C but 602/// ill-formed in C++: 603/// @code 604/// struct S6 { 605/// enum { BAR } e; 606/// }; 607/// 608/// void test_S6() { 609/// struct S6 a; 610/// a.e = BAR; 611/// } 612/// @endcode 613/// For the declaration of BAR, this routine will return a different 614/// scope. The scope S will be the scope of the unnamed enumeration 615/// within S6. In C++, this routine will return the scope associated 616/// with S6, because the enumeration's scope is a transparent 617/// context but structures can contain non-field names. In C, this 618/// routine will return the translation unit scope, since the 619/// enumeration's scope is a transparent context and structures cannot 620/// contain non-field names. 621Scope *Sema::getNonFieldDeclScope(Scope *S) { 622 while (((S->getFlags() & Scope::DeclScope) == 0) || 623 (S->getEntity() && 624 ((DeclContext *)S->getEntity())->isTransparentContext()) || 625 (S->isClassScope() && !getLangOptions().CPlusPlus)) 626 S = S->getParent(); 627 return S; 628} 629 630void Sema::InitBuiltinVaListType() { 631 if (!Context.getBuiltinVaListType().isNull()) 632 return; 633 634 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 635 NamedDecl *VaDecl = LookupSingleName(TUScope, VaIdent, LookupOrdinaryName); 636 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 637 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 638} 639 640/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 641/// file scope. lazily create a decl for it. ForRedeclaration is true 642/// if we're creating this built-in in anticipation of redeclaring the 643/// built-in. 644NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 645 Scope *S, bool ForRedeclaration, 646 SourceLocation Loc) { 647 Builtin::ID BID = (Builtin::ID)bid; 648 649 if (Context.BuiltinInfo.hasVAListUse(BID)) 650 InitBuiltinVaListType(); 651 652 ASTContext::GetBuiltinTypeError Error; 653 QualType R = Context.GetBuiltinType(BID, Error); 654 switch (Error) { 655 case ASTContext::GE_None: 656 // Okay 657 break; 658 659 case ASTContext::GE_Missing_stdio: 660 if (ForRedeclaration) 661 Diag(Loc, diag::err_implicit_decl_requires_stdio) 662 << Context.BuiltinInfo.GetName(BID); 663 return 0; 664 665 case ASTContext::GE_Missing_setjmp: 666 if (ForRedeclaration) 667 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 668 << Context.BuiltinInfo.GetName(BID); 669 return 0; 670 } 671 672 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 673 Diag(Loc, diag::ext_implicit_lib_function_decl) 674 << Context.BuiltinInfo.GetName(BID) 675 << R; 676 if (Context.BuiltinInfo.getHeaderName(BID) && 677 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 678 != Diagnostic::Ignored) 679 Diag(Loc, diag::note_please_include_header) 680 << Context.BuiltinInfo.getHeaderName(BID) 681 << Context.BuiltinInfo.GetName(BID); 682 } 683 684 FunctionDecl *New = FunctionDecl::Create(Context, 685 Context.getTranslationUnitDecl(), 686 Loc, II, R, /*TInfo=*/0, 687 FunctionDecl::Extern, false, 688 /*hasPrototype=*/true); 689 New->setImplicit(); 690 691 // Create Decl objects for each parameter, adding them to the 692 // FunctionDecl. 693 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 694 llvm::SmallVector<ParmVarDecl*, 16> Params; 695 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 696 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 697 FT->getArgType(i), /*TInfo=*/0, 698 VarDecl::None, 0)); 699 New->setParams(Context, Params.data(), Params.size()); 700 } 701 702 AddKnownFunctionAttributes(New); 703 704 // TUScope is the translation-unit scope to insert this function into. 705 // FIXME: This is hideous. We need to teach PushOnScopeChains to 706 // relate Scopes to DeclContexts, and probably eliminate CurContext 707 // entirely, but we're not there yet. 708 DeclContext *SavedContext = CurContext; 709 CurContext = Context.getTranslationUnitDecl(); 710 PushOnScopeChains(New, TUScope); 711 CurContext = SavedContext; 712 return New; 713} 714 715/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 716/// same name and scope as a previous declaration 'Old'. Figure out 717/// how to resolve this situation, merging decls or emitting 718/// diagnostics as appropriate. If there was an error, set New to be invalid. 719/// 720void Sema::MergeTypeDefDecl(TypedefDecl *New, LookupResult &OldDecls) { 721 // If the new decl is known invalid already, don't bother doing any 722 // merging checks. 723 if (New->isInvalidDecl()) return; 724 725 // Allow multiple definitions for ObjC built-in typedefs. 726 // FIXME: Verify the underlying types are equivalent! 727 if (getLangOptions().ObjC1) { 728 const IdentifierInfo *TypeID = New->getIdentifier(); 729 switch (TypeID->getLength()) { 730 default: break; 731 case 2: 732 if (!TypeID->isStr("id")) 733 break; 734 Context.ObjCIdRedefinitionType = New->getUnderlyingType(); 735 // Install the built-in type for 'id', ignoring the current definition. 736 New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); 737 return; 738 case 5: 739 if (!TypeID->isStr("Class")) 740 break; 741 Context.ObjCClassRedefinitionType = New->getUnderlyingType(); 742 // Install the built-in type for 'Class', ignoring the current definition. 743 New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); 744 return; 745 case 3: 746 if (!TypeID->isStr("SEL")) 747 break; 748 Context.ObjCSelRedefinitionType = New->getUnderlyingType(); 749 // Install the built-in type for 'SEL', ignoring the current definition. 750 New->setTypeForDecl(Context.getObjCSelType().getTypePtr()); 751 return; 752 case 8: 753 if (!TypeID->isStr("Protocol")) 754 break; 755 Context.setObjCProtoType(New->getUnderlyingType()); 756 return; 757 } 758 // Fall through - the typedef name was not a builtin type. 759 } 760 761 // Verify the old decl was also a type. 762 TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>(); 763 if (!Old) { 764 Diag(New->getLocation(), diag::err_redefinition_different_kind) 765 << New->getDeclName(); 766 767 NamedDecl *OldD = OldDecls.getRepresentativeDecl(); 768 if (OldD->getLocation().isValid()) 769 Diag(OldD->getLocation(), diag::note_previous_definition); 770 771 return New->setInvalidDecl(); 772 } 773 774 // If the old declaration is invalid, just give up here. 775 if (Old->isInvalidDecl()) 776 return New->setInvalidDecl(); 777 778 // Determine the "old" type we'll use for checking and diagnostics. 779 QualType OldType; 780 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 781 OldType = OldTypedef->getUnderlyingType(); 782 else 783 OldType = Context.getTypeDeclType(Old); 784 785 // If the typedef types are not identical, reject them in all languages and 786 // with any extensions enabled. 787 788 if (OldType != New->getUnderlyingType() && 789 Context.getCanonicalType(OldType) != 790 Context.getCanonicalType(New->getUnderlyingType())) { 791 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 792 << New->getUnderlyingType() << OldType; 793 if (Old->getLocation().isValid()) 794 Diag(Old->getLocation(), diag::note_previous_definition); 795 return New->setInvalidDecl(); 796 } 797 798 // The types match. Link up the redeclaration chain if the old 799 // declaration was a typedef. 800 // FIXME: this is a potential source of wierdness if the type 801 // spellings don't match exactly. 802 if (isa<TypedefDecl>(Old)) 803 New->setPreviousDeclaration(cast<TypedefDecl>(Old)); 804 805 if (getLangOptions().Microsoft) 806 return; 807 808 if (getLangOptions().CPlusPlus) { 809 // C++ [dcl.typedef]p2: 810 // In a given non-class scope, a typedef specifier can be used to 811 // redefine the name of any type declared in that scope to refer 812 // to the type to which it already refers. 813 if (!isa<CXXRecordDecl>(CurContext)) 814 return; 815 816 // C++0x [dcl.typedef]p4: 817 // In a given class scope, a typedef specifier can be used to redefine 818 // any class-name declared in that scope that is not also a typedef-name 819 // to refer to the type to which it already refers. 820 // 821 // This wording came in via DR424, which was a correction to the 822 // wording in DR56, which accidentally banned code like: 823 // 824 // struct S { 825 // typedef struct A { } A; 826 // }; 827 // 828 // in the C++03 standard. We implement the C++0x semantics, which 829 // allow the above but disallow 830 // 831 // struct S { 832 // typedef int I; 833 // typedef int I; 834 // }; 835 // 836 // since that was the intent of DR56. 837 if (!isa<TypedefDecl >(Old)) 838 return; 839 840 Diag(New->getLocation(), diag::err_redefinition) 841 << New->getDeclName(); 842 Diag(Old->getLocation(), diag::note_previous_definition); 843 return New->setInvalidDecl(); 844 } 845 846 // If we have a redefinition of a typedef in C, emit a warning. This warning 847 // is normally mapped to an error, but can be controlled with 848 // -Wtypedef-redefinition. If either the original or the redefinition is 849 // in a system header, don't emit this for compatibility with GCC. 850 if (PP.getDiagnostics().getSuppressSystemWarnings() && 851 (Context.getSourceManager().isInSystemHeader(Old->getLocation()) || 852 Context.getSourceManager().isInSystemHeader(New->getLocation()))) 853 return; 854 855 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 856 << New->getDeclName(); 857 Diag(Old->getLocation(), diag::note_previous_definition); 858 return; 859} 860 861/// DeclhasAttr - returns true if decl Declaration already has the target 862/// attribute. 863static bool 864DeclHasAttr(const Decl *decl, const Attr *target) { 865 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 866 if (attr->getKind() == target->getKind()) 867 return true; 868 869 return false; 870} 871 872/// MergeAttributes - append attributes from the Old decl to the New one. 873static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 874 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 875 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 876 Attr *NewAttr = attr->clone(C); 877 NewAttr->setInherited(true); 878 New->addAttr(NewAttr); 879 } 880 } 881} 882 883/// Used in MergeFunctionDecl to keep track of function parameters in 884/// C. 885struct GNUCompatibleParamWarning { 886 ParmVarDecl *OldParm; 887 ParmVarDecl *NewParm; 888 QualType PromotedType; 889}; 890 891 892/// getSpecialMember - get the special member enum for a method. 893static Sema::CXXSpecialMember getSpecialMember(ASTContext &Ctx, 894 const CXXMethodDecl *MD) { 895 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) { 896 if (Ctor->isDefaultConstructor()) 897 return Sema::CXXDefaultConstructor; 898 if (Ctor->isCopyConstructor()) 899 return Sema::CXXCopyConstructor; 900 } 901 902 if (isa<CXXDestructorDecl>(MD)) 903 return Sema::CXXDestructor; 904 905 assert(MD->isCopyAssignment() && "Must have copy assignment operator"); 906 return Sema::CXXCopyAssignment; 907} 908 909/// MergeFunctionDecl - We just parsed a function 'New' from 910/// declarator D which has the same name and scope as a previous 911/// declaration 'Old'. Figure out how to resolve this situation, 912/// merging decls or emitting diagnostics as appropriate. 913/// 914/// In C++, New and Old must be declarations that are not 915/// overloaded. Use IsOverload to determine whether New and Old are 916/// overloaded, and to select the Old declaration that New should be 917/// merged with. 918/// 919/// Returns true if there was an error, false otherwise. 920bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 921 // Verify the old decl was also a function. 922 FunctionDecl *Old = 0; 923 if (FunctionTemplateDecl *OldFunctionTemplate 924 = dyn_cast<FunctionTemplateDecl>(OldD)) 925 Old = OldFunctionTemplate->getTemplatedDecl(); 926 else 927 Old = dyn_cast<FunctionDecl>(OldD); 928 if (!Old) { 929 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) { 930 Diag(New->getLocation(), diag::err_using_decl_conflict_reverse); 931 Diag(Shadow->getTargetDecl()->getLocation(), 932 diag::note_using_decl_target); 933 Diag(Shadow->getUsingDecl()->getLocation(), 934 diag::note_using_decl) << 0; 935 return true; 936 } 937 938 Diag(New->getLocation(), diag::err_redefinition_different_kind) 939 << New->getDeclName(); 940 Diag(OldD->getLocation(), diag::note_previous_definition); 941 return true; 942 } 943 944 // Determine whether the previous declaration was a definition, 945 // implicit declaration, or a declaration. 946 diag::kind PrevDiag; 947 if (Old->isThisDeclarationADefinition()) 948 PrevDiag = diag::note_previous_definition; 949 else if (Old->isImplicit()) 950 PrevDiag = diag::note_previous_implicit_declaration; 951 else 952 PrevDiag = diag::note_previous_declaration; 953 954 QualType OldQType = Context.getCanonicalType(Old->getType()); 955 QualType NewQType = Context.getCanonicalType(New->getType()); 956 957 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 958 New->getStorageClass() == FunctionDecl::Static && 959 Old->getStorageClass() != FunctionDecl::Static) { 960 Diag(New->getLocation(), diag::err_static_non_static) 961 << New; 962 Diag(Old->getLocation(), PrevDiag); 963 return true; 964 } 965 966 if (getLangOptions().CPlusPlus) { 967 // (C++98 13.1p2): 968 // Certain function declarations cannot be overloaded: 969 // -- Function declarations that differ only in the return type 970 // cannot be overloaded. 971 QualType OldReturnType 972 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 973 QualType NewReturnType 974 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 975 if (OldReturnType != NewReturnType) { 976 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 977 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 978 return true; 979 } 980 981 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 982 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 983 if (OldMethod && NewMethod) { 984 if (!NewMethod->getFriendObjectKind() && 985 NewMethod->getLexicalDeclContext()->isRecord()) { 986 // -- Member function declarations with the same name and the 987 // same parameter types cannot be overloaded if any of them 988 // is a static member function declaration. 989 if (OldMethod->isStatic() || NewMethod->isStatic()) { 990 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 991 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 992 return true; 993 } 994 995 // C++ [class.mem]p1: 996 // [...] A member shall not be declared twice in the 997 // member-specification, except that a nested class or member 998 // class template can be declared and then later defined. 999 unsigned NewDiag; 1000 if (isa<CXXConstructorDecl>(OldMethod)) 1001 NewDiag = diag::err_constructor_redeclared; 1002 else if (isa<CXXDestructorDecl>(NewMethod)) 1003 NewDiag = diag::err_destructor_redeclared; 1004 else if (isa<CXXConversionDecl>(NewMethod)) 1005 NewDiag = diag::err_conv_function_redeclared; 1006 else 1007 NewDiag = diag::err_member_redeclared; 1008 1009 Diag(New->getLocation(), NewDiag); 1010 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 1011 } else { 1012 if (OldMethod->isImplicit()) { 1013 Diag(NewMethod->getLocation(), 1014 diag::err_definition_of_implicitly_declared_member) 1015 << New << getSpecialMember(Context, OldMethod); 1016 1017 Diag(OldMethod->getLocation(), 1018 diag::note_previous_implicit_declaration); 1019 return true; 1020 } 1021 } 1022 } 1023 1024 // (C++98 8.3.5p3): 1025 // All declarations for a function shall agree exactly in both the 1026 // return type and the parameter-type-list. 1027 // attributes should be ignored when comparing. 1028 if (Context.getNoReturnType(OldQType, false) == 1029 Context.getNoReturnType(NewQType, false)) 1030 return MergeCompatibleFunctionDecls(New, Old); 1031 1032 // Fall through for conflicting redeclarations and redefinitions. 1033 } 1034 1035 // C: Function types need to be compatible, not identical. This handles 1036 // duplicate function decls like "void f(int); void f(enum X);" properly. 1037 if (!getLangOptions().CPlusPlus && 1038 Context.typesAreCompatible(OldQType, NewQType)) { 1039 const FunctionType *OldFuncType = OldQType->getAs<FunctionType>(); 1040 const FunctionType *NewFuncType = NewQType->getAs<FunctionType>(); 1041 const FunctionProtoType *OldProto = 0; 1042 if (isa<FunctionNoProtoType>(NewFuncType) && 1043 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 1044 // The old declaration provided a function prototype, but the 1045 // new declaration does not. Merge in the prototype. 1046 assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); 1047 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 1048 OldProto->arg_type_end()); 1049 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 1050 ParamTypes.data(), ParamTypes.size(), 1051 OldProto->isVariadic(), 1052 OldProto->getTypeQuals()); 1053 New->setType(NewQType); 1054 New->setHasInheritedPrototype(); 1055 1056 // Synthesize a parameter for each argument type. 1057 llvm::SmallVector<ParmVarDecl*, 16> Params; 1058 for (FunctionProtoType::arg_type_iterator 1059 ParamType = OldProto->arg_type_begin(), 1060 ParamEnd = OldProto->arg_type_end(); 1061 ParamType != ParamEnd; ++ParamType) { 1062 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 1063 SourceLocation(), 0, 1064 *ParamType, /*TInfo=*/0, 1065 VarDecl::None, 0); 1066 Param->setImplicit(); 1067 Params.push_back(Param); 1068 } 1069 1070 New->setParams(Context, Params.data(), Params.size()); 1071 } 1072 1073 return MergeCompatibleFunctionDecls(New, Old); 1074 } 1075 1076 // GNU C permits a K&R definition to follow a prototype declaration 1077 // if the declared types of the parameters in the K&R definition 1078 // match the types in the prototype declaration, even when the 1079 // promoted types of the parameters from the K&R definition differ 1080 // from the types in the prototype. GCC then keeps the types from 1081 // the prototype. 1082 // 1083 // If a variadic prototype is followed by a non-variadic K&R definition, 1084 // the K&R definition becomes variadic. This is sort of an edge case, but 1085 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and 1086 // C99 6.9.1p8. 1087 if (!getLangOptions().CPlusPlus && 1088 Old->hasPrototype() && !New->hasPrototype() && 1089 New->getType()->getAs<FunctionProtoType>() && 1090 Old->getNumParams() == New->getNumParams()) { 1091 llvm::SmallVector<QualType, 16> ArgTypes; 1092 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 1093 const FunctionProtoType *OldProto 1094 = Old->getType()->getAs<FunctionProtoType>(); 1095 const FunctionProtoType *NewProto 1096 = New->getType()->getAs<FunctionProtoType>(); 1097 1098 // Determine whether this is the GNU C extension. 1099 QualType MergedReturn = Context.mergeTypes(OldProto->getResultType(), 1100 NewProto->getResultType()); 1101 bool LooseCompatible = !MergedReturn.isNull(); 1102 for (unsigned Idx = 0, End = Old->getNumParams(); 1103 LooseCompatible && Idx != End; ++Idx) { 1104 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 1105 ParmVarDecl *NewParm = New->getParamDecl(Idx); 1106 if (Context.typesAreCompatible(OldParm->getType(), 1107 NewProto->getArgType(Idx))) { 1108 ArgTypes.push_back(NewParm->getType()); 1109 } else if (Context.typesAreCompatible(OldParm->getType(), 1110 NewParm->getType())) { 1111 GNUCompatibleParamWarning Warn 1112 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 1113 Warnings.push_back(Warn); 1114 ArgTypes.push_back(NewParm->getType()); 1115 } else 1116 LooseCompatible = false; 1117 } 1118 1119 if (LooseCompatible) { 1120 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 1121 Diag(Warnings[Warn].NewParm->getLocation(), 1122 diag::ext_param_promoted_not_compatible_with_prototype) 1123 << Warnings[Warn].PromotedType 1124 << Warnings[Warn].OldParm->getType(); 1125 Diag(Warnings[Warn].OldParm->getLocation(), 1126 diag::note_previous_declaration); 1127 } 1128 1129 New->setType(Context.getFunctionType(MergedReturn, &ArgTypes[0], 1130 ArgTypes.size(), 1131 OldProto->isVariadic(), 0)); 1132 return MergeCompatibleFunctionDecls(New, Old); 1133 } 1134 1135 // Fall through to diagnose conflicting types. 1136 } 1137 1138 // A function that has already been declared has been redeclared or defined 1139 // with a different type- show appropriate diagnostic 1140 if (unsigned BuiltinID = Old->getBuiltinID()) { 1141 // The user has declared a builtin function with an incompatible 1142 // signature. 1143 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 1144 // The function the user is redeclaring is a library-defined 1145 // function like 'malloc' or 'printf'. Warn about the 1146 // redeclaration, then pretend that we don't know about this 1147 // library built-in. 1148 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 1149 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 1150 << Old << Old->getType(); 1151 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 1152 Old->setInvalidDecl(); 1153 return false; 1154 } 1155 1156 PrevDiag = diag::note_previous_builtin_declaration; 1157 } 1158 1159 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 1160 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 1161 return true; 1162} 1163 1164/// \brief Completes the merge of two function declarations that are 1165/// known to be compatible. 1166/// 1167/// This routine handles the merging of attributes and other 1168/// properties of function declarations form the old declaration to 1169/// the new declaration, once we know that New is in fact a 1170/// redeclaration of Old. 1171/// 1172/// \returns false 1173bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 1174 // Merge the attributes 1175 MergeAttributes(New, Old, Context); 1176 1177 // Merge the storage class. 1178 if (Old->getStorageClass() != FunctionDecl::Extern && 1179 Old->getStorageClass() != FunctionDecl::None) 1180 New->setStorageClass(Old->getStorageClass()); 1181 1182 // Merge "pure" flag. 1183 if (Old->isPure()) 1184 New->setPure(); 1185 1186 // Merge the "deleted" flag. 1187 if (Old->isDeleted()) 1188 New->setDeleted(); 1189 1190 if (getLangOptions().CPlusPlus) 1191 return MergeCXXFunctionDecl(New, Old); 1192 1193 return false; 1194} 1195 1196/// MergeVarDecl - We just parsed a variable 'New' which has the same name 1197/// and scope as a previous declaration 'Old'. Figure out how to resolve this 1198/// situation, merging decls or emitting diagnostics as appropriate. 1199/// 1200/// Tentative definition rules (C99 6.9.2p2) are checked by 1201/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 1202/// definitions here, since the initializer hasn't been attached. 1203/// 1204void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) { 1205 // If the new decl is already invalid, don't do any other checking. 1206 if (New->isInvalidDecl()) 1207 return; 1208 1209 // Verify the old decl was also a variable. 1210 VarDecl *Old = 0; 1211 if (!Previous.isSingleResult() || 1212 !(Old = dyn_cast<VarDecl>(Previous.getFoundDecl()))) { 1213 Diag(New->getLocation(), diag::err_redefinition_different_kind) 1214 << New->getDeclName(); 1215 Diag(Previous.getRepresentativeDecl()->getLocation(), 1216 diag::note_previous_definition); 1217 return New->setInvalidDecl(); 1218 } 1219 1220 MergeAttributes(New, Old, Context); 1221 1222 // Merge the types 1223 QualType MergedT; 1224 if (getLangOptions().CPlusPlus) { 1225 if (Context.hasSameType(New->getType(), Old->getType())) 1226 MergedT = New->getType(); 1227 // C++ [basic.link]p10: 1228 // [...] the types specified by all declarations referring to a given 1229 // object or function shall be identical, except that declarations for an 1230 // array object can specify array types that differ by the presence or 1231 // absence of a major array bound (8.3.4). 1232 else if (Old->getType()->isIncompleteArrayType() && 1233 New->getType()->isArrayType()) { 1234 CanQual<ArrayType> OldArray 1235 = Context.getCanonicalType(Old->getType())->getAs<ArrayType>(); 1236 CanQual<ArrayType> NewArray 1237 = Context.getCanonicalType(New->getType())->getAs<ArrayType>(); 1238 if (OldArray->getElementType() == NewArray->getElementType()) 1239 MergedT = New->getType(); 1240 } else if (Old->getType()->isArrayType() && 1241 New->getType()->isIncompleteArrayType()) { 1242 CanQual<ArrayType> OldArray 1243 = Context.getCanonicalType(Old->getType())->getAs<ArrayType>(); 1244 CanQual<ArrayType> NewArray 1245 = Context.getCanonicalType(New->getType())->getAs<ArrayType>(); 1246 if (OldArray->getElementType() == NewArray->getElementType()) 1247 MergedT = Old->getType(); 1248 } 1249 } else { 1250 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 1251 } 1252 if (MergedT.isNull()) { 1253 Diag(New->getLocation(), diag::err_redefinition_different_type) 1254 << New->getDeclName(); 1255 Diag(Old->getLocation(), diag::note_previous_definition); 1256 return New->setInvalidDecl(); 1257 } 1258 New->setType(MergedT); 1259 1260 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 1261 if (New->getStorageClass() == VarDecl::Static && 1262 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 1263 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 1264 Diag(Old->getLocation(), diag::note_previous_definition); 1265 return New->setInvalidDecl(); 1266 } 1267 // C99 6.2.2p4: 1268 // For an identifier declared with the storage-class specifier 1269 // extern in a scope in which a prior declaration of that 1270 // identifier is visible,23) if the prior declaration specifies 1271 // internal or external linkage, the linkage of the identifier at 1272 // the later declaration is the same as the linkage specified at 1273 // the prior declaration. If no prior declaration is visible, or 1274 // if the prior declaration specifies no linkage, then the 1275 // identifier has external linkage. 1276 if (New->hasExternalStorage() && Old->hasLinkage()) 1277 /* Okay */; 1278 else if (New->getStorageClass() != VarDecl::Static && 1279 Old->getStorageClass() == VarDecl::Static) { 1280 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 1281 Diag(Old->getLocation(), diag::note_previous_definition); 1282 return New->setInvalidDecl(); 1283 } 1284 1285 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 1286 1287 // FIXME: The test for external storage here seems wrong? We still 1288 // need to check for mismatches. 1289 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 1290 // Don't complain about out-of-line definitions of static members. 1291 !(Old->getLexicalDeclContext()->isRecord() && 1292 !New->getLexicalDeclContext()->isRecord())) { 1293 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 1294 Diag(Old->getLocation(), diag::note_previous_definition); 1295 return New->setInvalidDecl(); 1296 } 1297 1298 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 1299 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 1300 Diag(Old->getLocation(), diag::note_previous_definition); 1301 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 1302 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 1303 Diag(Old->getLocation(), diag::note_previous_definition); 1304 } 1305 1306 // Keep a chain of previous declarations. 1307 New->setPreviousDeclaration(Old); 1308 1309 // Inherit access appropriately. 1310 New->setAccess(Old->getAccess()); 1311} 1312 1313// MarkLive - Mark all the blocks reachable from e as live. Returns the total 1314// number of blocks marked live. 1315static unsigned MarkLive(CFGBlock *e, llvm::BitVector &live) { 1316 unsigned count = 0; 1317 std::queue<CFGBlock*> workq; 1318 // Prep work queue 1319 live.set(e->getBlockID()); 1320 ++count; 1321 workq.push(e); 1322 // Solve 1323 while (!workq.empty()) { 1324 CFGBlock *item = workq.front(); 1325 workq.pop(); 1326 for (CFGBlock::succ_iterator I=item->succ_begin(), 1327 E=item->succ_end(); 1328 I != E; 1329 ++I) { 1330 if ((*I) && !live[(*I)->getBlockID()]) { 1331 live.set((*I)->getBlockID()); 1332 ++count; 1333 workq.push(*I); 1334 } 1335 } 1336 } 1337 return count; 1338} 1339 1340static SourceLocation GetUnreachableLoc(CFGBlock &b) { 1341 Stmt *S; 1342 if (!b.empty()) 1343 S = b[0].getStmt(); 1344 else if (b.getTerminator()) 1345 S = b.getTerminator(); 1346 else 1347 return SourceLocation(); 1348 1349 switch (S->getStmtClass()) { 1350 case Expr::BinaryOperatorClass: { 1351 if (b.size() < 2) { 1352 CFGBlock *n = &b; 1353 while (1) { 1354 if (n->getTerminator()) 1355 return n->getTerminator()->getLocStart(); 1356 if (n->succ_size() != 1) 1357 return SourceLocation(); 1358 n = n[0].succ_begin()[0]; 1359 if (n->pred_size() != 1) 1360 return SourceLocation(); 1361 if (!n->empty()) 1362 return n[0][0].getStmt()->getLocStart(); 1363 } 1364 } 1365 return b[1].getStmt()->getLocStart(); 1366 } 1367 default: ; 1368 } 1369 return S->getLocStart(); 1370} 1371 1372static SourceLocation MarkLiveTop(CFGBlock *e, llvm::BitVector &live, 1373 SourceManager &SM) { 1374 std::queue<CFGBlock*> workq; 1375 // Prep work queue 1376 workq.push(e); 1377 SourceLocation top = GetUnreachableLoc(*e); 1378 bool FromMainFile = false; 1379 bool FromSystemHeader = false; 1380 bool TopValid = false; 1381 if (top.isValid()) { 1382 FromMainFile = SM.isFromMainFile(top); 1383 FromSystemHeader = SM.isInSystemHeader(top); 1384 TopValid = true; 1385 } 1386 // Solve 1387 while (!workq.empty()) { 1388 CFGBlock *item = workq.front(); 1389 workq.pop(); 1390 SourceLocation c = GetUnreachableLoc(*item); 1391 if (c.isValid() 1392 && (!TopValid 1393 || (SM.isFromMainFile(c) && !FromMainFile) 1394 || (FromSystemHeader && !SM.isInSystemHeader(c)) 1395 || SM.isBeforeInTranslationUnit(c, top))) { 1396 top = c; 1397 FromMainFile = SM.isFromMainFile(top); 1398 FromSystemHeader = SM.isInSystemHeader(top); 1399 } 1400 live.set(item->getBlockID()); 1401 for (CFGBlock::succ_iterator I=item->succ_begin(), 1402 E=item->succ_end(); 1403 I != E; 1404 ++I) { 1405 if ((*I) && !live[(*I)->getBlockID()]) { 1406 live.set((*I)->getBlockID()); 1407 workq.push(*I); 1408 } 1409 } 1410 } 1411 return top; 1412} 1413 1414namespace { 1415class LineCmp { 1416 SourceManager &SM; 1417public: 1418 LineCmp(SourceManager &sm) : SM(sm) { 1419 } 1420 bool operator () (SourceLocation l1, SourceLocation l2) { 1421 return l1 < l2; 1422 } 1423}; 1424} 1425 1426/// CheckUnreachable - Check for unreachable code. 1427void Sema::CheckUnreachable(AnalysisContext &AC) { 1428 // We avoid checking when there are errors, as the CFG won't faithfully match 1429 // the user's code. 1430 if (getDiagnostics().hasErrorOccurred()) 1431 return; 1432 if (Diags.getDiagnosticLevel(diag::warn_unreachable) == Diagnostic::Ignored) 1433 return; 1434 1435 CFG *cfg = AC.getCFG(); 1436 if (cfg == 0) 1437 return; 1438 1439 llvm::BitVector live(cfg->getNumBlockIDs()); 1440 // Mark all live things first. 1441 if (MarkLive(&cfg->getEntry(), live) == cfg->getNumBlockIDs()) 1442 // If there are no dead blocks, we're done. 1443 return; 1444 1445 llvm::SmallVector<SourceLocation, 24> lines; 1446 // First, give warnings for blocks with no predecessors, as they 1447 // can't be part of a loop. 1448 for (CFG::iterator I = cfg->begin(), E = cfg->end(); I != E; ++I) { 1449 CFGBlock &b = **I; 1450 if (!live[b.getBlockID()]) { 1451 if (b.pred_begin() == b.pred_end()) { 1452 SourceLocation c = GetUnreachableLoc(b); 1453 if (!c.isValid()) { 1454 // Blocks without a location can't produce a warning, so don't mark 1455 // reachable blocks from here as live. 1456 live.set(b.getBlockID()); 1457 continue; 1458 } 1459 lines.push_back(c); 1460 // Avoid excessive errors by marking everything reachable from here 1461 MarkLive(&b, live); 1462 } 1463 } 1464 } 1465 1466 // And then give warnings for the tops of loops. 1467 for (CFG::iterator I = cfg->begin(), E = cfg->end(); I != E; ++I) { 1468 CFGBlock &b = **I; 1469 if (!live[b.getBlockID()]) 1470 // Avoid excessive errors by marking everything reachable from here 1471 lines.push_back(MarkLiveTop(&b, live, Context.getSourceManager())); 1472 } 1473 1474 std::sort(lines.begin(), lines.end(), LineCmp(Context.getSourceManager())); 1475 for (llvm::SmallVector<SourceLocation, 24>::iterator I = lines.begin(), 1476 E = lines.end(); 1477 I != E; 1478 ++I) 1479 if (I->isValid()) 1480 Diag(*I, diag::warn_unreachable); 1481} 1482 1483/// CheckFallThrough - Check that we don't fall off the end of a 1484/// Statement that should return a value. 1485/// 1486/// \returns AlwaysFallThrough iff we always fall off the end of the statement, 1487/// MaybeFallThrough iff we might or might not fall off the end, 1488/// NeverFallThroughOrReturn iff we never fall off the end of the statement or 1489/// return. We assume NeverFallThrough iff we never fall off the end of the 1490/// statement but we may return. We assume that functions not marked noreturn 1491/// will return. 1492Sema::ControlFlowKind Sema::CheckFallThrough(AnalysisContext &AC) { 1493 CFG *cfg = AC.getCFG(); 1494 if (cfg == 0) 1495 // FIXME: This should be NeverFallThrough 1496 return NeverFallThroughOrReturn; 1497 1498 // The CFG leaves in dead things, and we don't want to dead code paths to 1499 // confuse us, so we mark all live things first. 1500 std::queue<CFGBlock*> workq; 1501 llvm::BitVector live(cfg->getNumBlockIDs()); 1502 MarkLive(&cfg->getEntry(), live); 1503 1504 // Now we know what is live, we check the live precessors of the exit block 1505 // and look for fall through paths, being careful to ignore normal returns, 1506 // and exceptional paths. 1507 bool HasLiveReturn = false; 1508 bool HasFakeEdge = false; 1509 bool HasPlainEdge = false; 1510 bool HasAbnormalEdge = false; 1511 for (CFGBlock::pred_iterator I=cfg->getExit().pred_begin(), 1512 E = cfg->getExit().pred_end(); 1513 I != E; 1514 ++I) { 1515 CFGBlock& B = **I; 1516 if (!live[B.getBlockID()]) 1517 continue; 1518 if (B.size() == 0) { 1519 // A labeled empty statement, or the entry block... 1520 HasPlainEdge = true; 1521 continue; 1522 } 1523 Stmt *S = B[B.size()-1]; 1524 if (isa<ReturnStmt>(S)) { 1525 HasLiveReturn = true; 1526 continue; 1527 } 1528 if (isa<ObjCAtThrowStmt>(S)) { 1529 HasFakeEdge = true; 1530 continue; 1531 } 1532 if (isa<CXXThrowExpr>(S)) { 1533 HasFakeEdge = true; 1534 continue; 1535 } 1536 if (const AsmStmt *AS = dyn_cast<AsmStmt>(S)) { 1537 if (AS->isMSAsm()) { 1538 HasFakeEdge = true; 1539 HasLiveReturn = true; 1540 continue; 1541 } 1542 } 1543 if (isa<CXXTryStmt>(S)) { 1544 HasAbnormalEdge = true; 1545 continue; 1546 } 1547 1548 bool NoReturnEdge = false; 1549 if (CallExpr *C = dyn_cast<CallExpr>(S)) { 1550 if (B.succ_begin()[0] != &cfg->getExit()) { 1551 HasAbnormalEdge = true; 1552 continue; 1553 } 1554 Expr *CEE = C->getCallee()->IgnoreParenCasts(); 1555 if (CEE->getType().getNoReturnAttr()) { 1556 NoReturnEdge = true; 1557 HasFakeEdge = true; 1558 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) { 1559 ValueDecl *VD = DRE->getDecl(); 1560 if (VD->hasAttr<NoReturnAttr>()) { 1561 NoReturnEdge = true; 1562 HasFakeEdge = true; 1563 } 1564 } 1565 } 1566 // FIXME: Add noreturn message sends. 1567 if (NoReturnEdge == false) 1568 HasPlainEdge = true; 1569 } 1570 if (!HasPlainEdge) { 1571 if (HasLiveReturn) 1572 return NeverFallThrough; 1573 return NeverFallThroughOrReturn; 1574 } 1575 if (HasAbnormalEdge || HasFakeEdge || HasLiveReturn) 1576 return MaybeFallThrough; 1577 // This says AlwaysFallThrough for calls to functions that are not marked 1578 // noreturn, that don't return. If people would like this warning to be more 1579 // accurate, such functions should be marked as noreturn. 1580 return AlwaysFallThrough; 1581} 1582 1583/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a 1584/// function that should return a value. Check that we don't fall off the end 1585/// of a noreturn function. We assume that functions and blocks not marked 1586/// noreturn will return. 1587void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body, 1588 AnalysisContext &AC) { 1589 // FIXME: Would be nice if we had a better way to control cascading errors, 1590 // but for now, avoid them. The problem is that when Parse sees: 1591 // int foo() { return a; } 1592 // The return is eaten and the Sema code sees just: 1593 // int foo() { } 1594 // which this code would then warn about. 1595 if (getDiagnostics().hasErrorOccurred()) 1596 return; 1597 1598 bool ReturnsVoid = false; 1599 bool HasNoReturn = false; 1600 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1601 // If the result type of the function is a dependent type, we don't know 1602 // whether it will be void or not, so don't 1603 if (FD->getResultType()->isDependentType()) 1604 return; 1605 if (FD->getResultType()->isVoidType()) 1606 ReturnsVoid = true; 1607 if (FD->hasAttr<NoReturnAttr>()) 1608 HasNoReturn = true; 1609 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 1610 if (MD->getResultType()->isVoidType()) 1611 ReturnsVoid = true; 1612 if (MD->hasAttr<NoReturnAttr>()) 1613 HasNoReturn = true; 1614 } 1615 1616 // Short circuit for compilation speed. 1617 if ((Diags.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function) 1618 == Diagnostic::Ignored || ReturnsVoid) 1619 && (Diags.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr) 1620 == Diagnostic::Ignored || !HasNoReturn) 1621 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1622 == Diagnostic::Ignored || !ReturnsVoid)) 1623 return; 1624 // FIXME: Function try block 1625 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1626 switch (CheckFallThrough(AC)) { 1627 case MaybeFallThrough: 1628 if (HasNoReturn) 1629 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1630 else if (!ReturnsVoid) 1631 Diag(Compound->getRBracLoc(),diag::warn_maybe_falloff_nonvoid_function); 1632 break; 1633 case AlwaysFallThrough: 1634 if (HasNoReturn) 1635 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1636 else if (!ReturnsVoid) 1637 Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function); 1638 break; 1639 case NeverFallThroughOrReturn: 1640 if (ReturnsVoid && !HasNoReturn) 1641 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function); 1642 break; 1643 case NeverFallThrough: 1644 break; 1645 } 1646 } 1647} 1648 1649/// CheckFallThroughForBlock - Check that we don't fall off the end of a block 1650/// that should return a value. Check that we don't fall off the end of a 1651/// noreturn block. We assume that functions and blocks not marked noreturn 1652/// will return. 1653void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body, 1654 AnalysisContext &AC) { 1655 // FIXME: Would be nice if we had a better way to control cascading errors, 1656 // but for now, avoid them. The problem is that when Parse sees: 1657 // int foo() { return a; } 1658 // The return is eaten and the Sema code sees just: 1659 // int foo() { } 1660 // which this code would then warn about. 1661 if (getDiagnostics().hasErrorOccurred()) 1662 return; 1663 bool ReturnsVoid = false; 1664 bool HasNoReturn = false; 1665 if (const FunctionType *FT =BlockTy->getPointeeType()->getAs<FunctionType>()){ 1666 if (FT->getResultType()->isVoidType()) 1667 ReturnsVoid = true; 1668 if (FT->getNoReturnAttr()) 1669 HasNoReturn = true; 1670 } 1671 1672 // Short circuit for compilation speed. 1673 if (ReturnsVoid 1674 && !HasNoReturn 1675 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1676 == Diagnostic::Ignored || !ReturnsVoid)) 1677 return; 1678 // FIXME: Funtion try block 1679 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1680 switch (CheckFallThrough(AC)) { 1681 case MaybeFallThrough: 1682 if (HasNoReturn) 1683 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1684 else if (!ReturnsVoid) 1685 Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block); 1686 break; 1687 case AlwaysFallThrough: 1688 if (HasNoReturn) 1689 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1690 else if (!ReturnsVoid) 1691 Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block); 1692 break; 1693 case NeverFallThroughOrReturn: 1694 if (ReturnsVoid) 1695 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block); 1696 break; 1697 case NeverFallThrough: 1698 break; 1699 } 1700 } 1701} 1702 1703/// CheckParmsForFunctionDef - Check that the parameters of the given 1704/// function are appropriate for the definition of a function. This 1705/// takes care of any checks that cannot be performed on the 1706/// declaration itself, e.g., that the types of each of the function 1707/// parameters are complete. 1708bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 1709 bool HasInvalidParm = false; 1710 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1711 ParmVarDecl *Param = FD->getParamDecl(p); 1712 1713 // C99 6.7.5.3p4: the parameters in a parameter type list in a 1714 // function declarator that is part of a function definition of 1715 // that function shall not have incomplete type. 1716 // 1717 // This is also C++ [dcl.fct]p6. 1718 if (!Param->isInvalidDecl() && 1719 RequireCompleteType(Param->getLocation(), Param->getType(), 1720 diag::err_typecheck_decl_incomplete_type)) { 1721 Param->setInvalidDecl(); 1722 HasInvalidParm = true; 1723 } 1724 1725 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1726 // declaration of each parameter shall include an identifier. 1727 if (Param->getIdentifier() == 0 && 1728 !Param->isImplicit() && 1729 !getLangOptions().CPlusPlus) 1730 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1731 } 1732 1733 return HasInvalidParm; 1734} 1735 1736/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1737/// no declarator (e.g. "struct foo;") is parsed. 1738Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1739 // FIXME: Error on auto/register at file scope 1740 // FIXME: Error on inline/virtual/explicit 1741 // FIXME: Warn on useless __thread 1742 // FIXME: Warn on useless const/volatile 1743 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1744 // FIXME: Warn on useless attributes 1745 Decl *TagD = 0; 1746 TagDecl *Tag = 0; 1747 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1748 DS.getTypeSpecType() == DeclSpec::TST_struct || 1749 DS.getTypeSpecType() == DeclSpec::TST_union || 1750 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1751 TagD = static_cast<Decl *>(DS.getTypeRep()); 1752 1753 if (!TagD) // We probably had an error 1754 return DeclPtrTy(); 1755 1756 // Note that the above type specs guarantee that the 1757 // type rep is a Decl, whereas in many of the others 1758 // it's a Type. 1759 Tag = dyn_cast<TagDecl>(TagD); 1760 } 1761 1762 if (unsigned TypeQuals = DS.getTypeQualifiers()) { 1763 // Enforce C99 6.7.3p2: "Types other than pointer types derived from object 1764 // or incomplete types shall not be restrict-qualified." 1765 if (TypeQuals & DeclSpec::TQ_restrict) 1766 Diag(DS.getRestrictSpecLoc(), 1767 diag::err_typecheck_invalid_restrict_not_pointer_noarg) 1768 << DS.getSourceRange(); 1769 } 1770 1771 if (DS.isFriendSpecified()) { 1772 // If we're dealing with a class template decl, assume that the 1773 // template routines are handling it. 1774 if (TagD && isa<ClassTemplateDecl>(TagD)) 1775 return DeclPtrTy(); 1776 return ActOnFriendTypeDecl(S, DS, MultiTemplateParamsArg(*this, 0, 0)); 1777 } 1778 1779 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1780 // If there are attributes in the DeclSpec, apply them to the record. 1781 if (const AttributeList *AL = DS.getAttributes()) 1782 ProcessDeclAttributeList(S, Record, AL); 1783 1784 if (!Record->getDeclName() && Record->isDefinition() && 1785 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1786 if (getLangOptions().CPlusPlus || 1787 Record->getDeclContext()->isRecord()) 1788 return BuildAnonymousStructOrUnion(S, DS, Record); 1789 1790 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1791 << DS.getSourceRange(); 1792 } 1793 1794 // Microsoft allows unnamed struct/union fields. Don't complain 1795 // about them. 1796 // FIXME: Should we support Microsoft's extensions in this area? 1797 if (Record->getDeclName() && getLangOptions().Microsoft) 1798 return DeclPtrTy::make(Tag); 1799 } 1800 1801 if (!DS.isMissingDeclaratorOk() && 1802 DS.getTypeSpecType() != DeclSpec::TST_error) { 1803 // Warn about typedefs of enums without names, since this is an 1804 // extension in both Microsoft an GNU. 1805 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1806 Tag && isa<EnumDecl>(Tag)) { 1807 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1808 << DS.getSourceRange(); 1809 return DeclPtrTy::make(Tag); 1810 } 1811 1812 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1813 << DS.getSourceRange(); 1814 return DeclPtrTy(); 1815 } 1816 1817 return DeclPtrTy::make(Tag); 1818} 1819 1820/// We are trying to inject an anonymous member into the given scope; 1821/// check if there's an existing declaration that can't be overloaded. 1822/// 1823/// \return true if this is a forbidden redeclaration 1824static bool CheckAnonMemberRedeclaration(Sema &SemaRef, 1825 Scope *S, 1826 DeclarationName Name, 1827 SourceLocation NameLoc, 1828 unsigned diagnostic) { 1829 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupMemberName, 1830 Sema::ForRedeclaration); 1831 if (!SemaRef.LookupName(R, S)) return false; 1832 1833 if (R.getAsSingle<TagDecl>()) 1834 return false; 1835 1836 // Pick a representative declaration. 1837 NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl(); 1838 1839 SemaRef.Diag(NameLoc, diagnostic) << Name; 1840 SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1841 1842 return true; 1843} 1844 1845/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1846/// anonymous struct or union AnonRecord into the owning context Owner 1847/// and scope S. This routine will be invoked just after we realize 1848/// that an unnamed union or struct is actually an anonymous union or 1849/// struct, e.g., 1850/// 1851/// @code 1852/// union { 1853/// int i; 1854/// float f; 1855/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1856/// // f into the surrounding scope.x 1857/// @endcode 1858/// 1859/// This routine is recursive, injecting the names of nested anonymous 1860/// structs/unions into the owning context and scope as well. 1861bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1862 RecordDecl *AnonRecord) { 1863 unsigned diagKind 1864 = AnonRecord->isUnion() ? diag::err_anonymous_union_member_redecl 1865 : diag::err_anonymous_struct_member_redecl; 1866 1867 bool Invalid = false; 1868 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 1869 FEnd = AnonRecord->field_end(); 1870 F != FEnd; ++F) { 1871 if ((*F)->getDeclName()) { 1872 if (CheckAnonMemberRedeclaration(*this, S, (*F)->getDeclName(), 1873 (*F)->getLocation(), diagKind)) { 1874 // C++ [class.union]p2: 1875 // The names of the members of an anonymous union shall be 1876 // distinct from the names of any other entity in the 1877 // scope in which the anonymous union is declared. 1878 Invalid = true; 1879 } else { 1880 // C++ [class.union]p2: 1881 // For the purpose of name lookup, after the anonymous union 1882 // definition, the members of the anonymous union are 1883 // considered to have been defined in the scope in which the 1884 // anonymous union is declared. 1885 Owner->makeDeclVisibleInContext(*F); 1886 S->AddDecl(DeclPtrTy::make(*F)); 1887 IdResolver.AddDecl(*F); 1888 } 1889 } else if (const RecordType *InnerRecordType 1890 = (*F)->getType()->getAs<RecordType>()) { 1891 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1892 if (InnerRecord->isAnonymousStructOrUnion()) 1893 Invalid = Invalid || 1894 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1895 } 1896 } 1897 1898 return Invalid; 1899} 1900 1901/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1902/// anonymous structure or union. Anonymous unions are a C++ feature 1903/// (C++ [class.union]) and a GNU C extension; anonymous structures 1904/// are a GNU C and GNU C++ extension. 1905Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1906 RecordDecl *Record) { 1907 DeclContext *Owner = Record->getDeclContext(); 1908 1909 // Diagnose whether this anonymous struct/union is an extension. 1910 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1911 Diag(Record->getLocation(), diag::ext_anonymous_union); 1912 else if (!Record->isUnion()) 1913 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1914 1915 // C and C++ require different kinds of checks for anonymous 1916 // structs/unions. 1917 bool Invalid = false; 1918 if (getLangOptions().CPlusPlus) { 1919 const char* PrevSpec = 0; 1920 unsigned DiagID; 1921 // C++ [class.union]p3: 1922 // Anonymous unions declared in a named namespace or in the 1923 // global namespace shall be declared static. 1924 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1925 (isa<TranslationUnitDecl>(Owner) || 1926 (isa<NamespaceDecl>(Owner) && 1927 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1928 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1929 Invalid = true; 1930 1931 // Recover by adding 'static'. 1932 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), 1933 PrevSpec, DiagID); 1934 } 1935 // C++ [class.union]p3: 1936 // A storage class is not allowed in a declaration of an 1937 // anonymous union in a class scope. 1938 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1939 isa<RecordDecl>(Owner)) { 1940 Diag(DS.getStorageClassSpecLoc(), 1941 diag::err_anonymous_union_with_storage_spec); 1942 Invalid = true; 1943 1944 // Recover by removing the storage specifier. 1945 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1946 PrevSpec, DiagID); 1947 } 1948 1949 // C++ [class.union]p2: 1950 // The member-specification of an anonymous union shall only 1951 // define non-static data members. [Note: nested types and 1952 // functions cannot be declared within an anonymous union. ] 1953 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 1954 MemEnd = Record->decls_end(); 1955 Mem != MemEnd; ++Mem) { 1956 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1957 // C++ [class.union]p3: 1958 // An anonymous union shall not have private or protected 1959 // members (clause 11). 1960 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1961 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1962 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1963 Invalid = true; 1964 } 1965 } else if ((*Mem)->isImplicit()) { 1966 // Any implicit members are fine. 1967 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1968 // This is a type that showed up in an 1969 // elaborated-type-specifier inside the anonymous struct or 1970 // union, but which actually declares a type outside of the 1971 // anonymous struct or union. It's okay. 1972 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1973 if (!MemRecord->isAnonymousStructOrUnion() && 1974 MemRecord->getDeclName()) { 1975 // This is a nested type declaration. 1976 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1977 << (int)Record->isUnion(); 1978 Invalid = true; 1979 } 1980 } else { 1981 // We have something that isn't a non-static data 1982 // member. Complain about it. 1983 unsigned DK = diag::err_anonymous_record_bad_member; 1984 if (isa<TypeDecl>(*Mem)) 1985 DK = diag::err_anonymous_record_with_type; 1986 else if (isa<FunctionDecl>(*Mem)) 1987 DK = diag::err_anonymous_record_with_function; 1988 else if (isa<VarDecl>(*Mem)) 1989 DK = diag::err_anonymous_record_with_static; 1990 Diag((*Mem)->getLocation(), DK) 1991 << (int)Record->isUnion(); 1992 Invalid = true; 1993 } 1994 } 1995 } 1996 1997 if (!Record->isUnion() && !Owner->isRecord()) { 1998 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1999 << (int)getLangOptions().CPlusPlus; 2000 Invalid = true; 2001 } 2002 2003 // Mock up a declarator. 2004 Declarator Dc(DS, Declarator::TypeNameContext); 2005 TypeSourceInfo *TInfo = 0; 2006 GetTypeForDeclarator(Dc, S, &TInfo); 2007 assert(TInfo && "couldn't build declarator info for anonymous struct/union"); 2008 2009 // Create a declaration for this anonymous struct/union. 2010 NamedDecl *Anon = 0; 2011 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 2012 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 2013 /*IdentifierInfo=*/0, 2014 Context.getTypeDeclType(Record), 2015 TInfo, 2016 /*BitWidth=*/0, /*Mutable=*/false); 2017 Anon->setAccess(AS_public); 2018 if (getLangOptions().CPlusPlus) 2019 FieldCollector->Add(cast<FieldDecl>(Anon)); 2020 } else { 2021 VarDecl::StorageClass SC; 2022 switch (DS.getStorageClassSpec()) { 2023 default: assert(0 && "Unknown storage class!"); 2024 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2025 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2026 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2027 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2028 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2029 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2030 case DeclSpec::SCS_mutable: 2031 // mutable can only appear on non-static class members, so it's always 2032 // an error here 2033 Diag(Record->getLocation(), diag::err_mutable_nonmember); 2034 Invalid = true; 2035 SC = VarDecl::None; 2036 break; 2037 } 2038 2039 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 2040 /*IdentifierInfo=*/0, 2041 Context.getTypeDeclType(Record), 2042 TInfo, 2043 SC); 2044 } 2045 Anon->setImplicit(); 2046 2047 // Add the anonymous struct/union object to the current 2048 // context. We'll be referencing this object when we refer to one of 2049 // its members. 2050 Owner->addDecl(Anon); 2051 2052 // Inject the members of the anonymous struct/union into the owning 2053 // context and into the identifier resolver chain for name lookup 2054 // purposes. 2055 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 2056 Invalid = true; 2057 2058 // Mark this as an anonymous struct/union type. Note that we do not 2059 // do this until after we have already checked and injected the 2060 // members of this anonymous struct/union type, because otherwise 2061 // the members could be injected twice: once by DeclContext when it 2062 // builds its lookup table, and once by 2063 // InjectAnonymousStructOrUnionMembers. 2064 Record->setAnonymousStructOrUnion(true); 2065 2066 if (Invalid) 2067 Anon->setInvalidDecl(); 2068 2069 return DeclPtrTy::make(Anon); 2070} 2071 2072 2073/// GetNameForDeclarator - Determine the full declaration name for the 2074/// given Declarator. 2075DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 2076 return GetNameFromUnqualifiedId(D.getName()); 2077} 2078 2079/// \brief Retrieves the canonicalized name from a parsed unqualified-id. 2080DeclarationName Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) { 2081 switch (Name.getKind()) { 2082 case UnqualifiedId::IK_Identifier: 2083 return DeclarationName(Name.Identifier); 2084 2085 case UnqualifiedId::IK_OperatorFunctionId: 2086 return Context.DeclarationNames.getCXXOperatorName( 2087 Name.OperatorFunctionId.Operator); 2088 2089 case UnqualifiedId::IK_LiteralOperatorId: 2090 return Context.DeclarationNames.getCXXLiteralOperatorName( 2091 Name.Identifier); 2092 2093 case UnqualifiedId::IK_ConversionFunctionId: { 2094 QualType Ty = GetTypeFromParser(Name.ConversionFunctionId); 2095 if (Ty.isNull()) 2096 return DeclarationName(); 2097 2098 return Context.DeclarationNames.getCXXConversionFunctionName( 2099 Context.getCanonicalType(Ty)); 2100 } 2101 2102 case UnqualifiedId::IK_ConstructorName: { 2103 QualType Ty = GetTypeFromParser(Name.ConstructorName); 2104 if (Ty.isNull()) 2105 return DeclarationName(); 2106 2107 return Context.DeclarationNames.getCXXConstructorName( 2108 Context.getCanonicalType(Ty)); 2109 } 2110 2111 case UnqualifiedId::IK_ConstructorTemplateId: { 2112 // In well-formed code, we can only have a constructor 2113 // template-id that refers to the current context, so go there 2114 // to find the actual type being constructed. 2115 CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(CurContext); 2116 if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name) 2117 return DeclarationName(); 2118 2119 // Determine the type of the class being constructed. 2120 QualType CurClassType; 2121 if (ClassTemplateDecl *ClassTemplate 2122 = CurClass->getDescribedClassTemplate()) 2123 CurClassType = ClassTemplate->getInjectedClassNameType(Context); 2124 else 2125 CurClassType = Context.getTypeDeclType(CurClass); 2126 2127 // FIXME: Check two things: that the template-id names the same type as 2128 // CurClassType, and that the template-id does not occur when the name 2129 // was qualified. 2130 2131 return Context.DeclarationNames.getCXXConstructorName( 2132 Context.getCanonicalType(CurClassType)); 2133 } 2134 2135 case UnqualifiedId::IK_DestructorName: { 2136 QualType Ty = GetTypeFromParser(Name.DestructorName); 2137 if (Ty.isNull()) 2138 return DeclarationName(); 2139 2140 return Context.DeclarationNames.getCXXDestructorName( 2141 Context.getCanonicalType(Ty)); 2142 } 2143 2144 case UnqualifiedId::IK_TemplateId: { 2145 TemplateName TName 2146 = TemplateName::getFromVoidPointer(Name.TemplateId->Template); 2147 return Context.getNameForTemplate(TName); 2148 } 2149 } 2150 2151 assert(false && "Unknown name kind"); 2152 return DeclarationName(); 2153} 2154 2155/// isNearlyMatchingFunction - Determine whether the C++ functions 2156/// Declaration and Definition are "nearly" matching. This heuristic 2157/// is used to improve diagnostics in the case where an out-of-line 2158/// function definition doesn't match any declaration within 2159/// the class or namespace. 2160static bool isNearlyMatchingFunction(ASTContext &Context, 2161 FunctionDecl *Declaration, 2162 FunctionDecl *Definition) { 2163 if (Declaration->param_size() != Definition->param_size()) 2164 return false; 2165 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 2166 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 2167 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 2168 2169 if (!Context.hasSameUnqualifiedType(DeclParamTy.getNonReferenceType(), 2170 DefParamTy.getNonReferenceType())) 2171 return false; 2172 } 2173 2174 return true; 2175} 2176 2177Sema::DeclPtrTy 2178Sema::HandleDeclarator(Scope *S, Declarator &D, 2179 MultiTemplateParamsArg TemplateParamLists, 2180 bool IsFunctionDefinition) { 2181 DeclarationName Name = GetNameForDeclarator(D); 2182 2183 // All of these full declarators require an identifier. If it doesn't have 2184 // one, the ParsedFreeStandingDeclSpec action should be used. 2185 if (!Name) { 2186 if (!D.isInvalidType()) // Reject this if we think it is valid. 2187 Diag(D.getDeclSpec().getSourceRange().getBegin(), 2188 diag::err_declarator_need_ident) 2189 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 2190 return DeclPtrTy(); 2191 } 2192 2193 // The scope passed in may not be a decl scope. Zip up the scope tree until 2194 // we find one that is. 2195 while ((S->getFlags() & Scope::DeclScope) == 0 || 2196 (S->getFlags() & Scope::TemplateParamScope) != 0) 2197 S = S->getParent(); 2198 2199 // If this is an out-of-line definition of a member of a class template 2200 // or class template partial specialization, we may need to rebuild the 2201 // type specifier in the declarator. See RebuildTypeInCurrentInstantiation() 2202 // for more information. 2203 // FIXME: cope with decltype(expr) and typeof(expr) once the rebuilder can 2204 // handle expressions properly. 2205 DeclSpec &DS = const_cast<DeclSpec&>(D.getDeclSpec()); 2206 if (D.getCXXScopeSpec().isSet() && !D.getCXXScopeSpec().isInvalid() && 2207 isDependentScopeSpecifier(D.getCXXScopeSpec()) && 2208 (DS.getTypeSpecType() == DeclSpec::TST_typename || 2209 DS.getTypeSpecType() == DeclSpec::TST_typeofType || 2210 DS.getTypeSpecType() == DeclSpec::TST_typeofExpr || 2211 DS.getTypeSpecType() == DeclSpec::TST_decltype)) { 2212 if (DeclContext *DC = computeDeclContext(D.getCXXScopeSpec(), true)) { 2213 // FIXME: Preserve type source info. 2214 QualType T = GetTypeFromParser(DS.getTypeRep()); 2215 2216 DeclContext *SavedContext = CurContext; 2217 CurContext = DC; 2218 T = RebuildTypeInCurrentInstantiation(T, D.getIdentifierLoc(), Name); 2219 CurContext = SavedContext; 2220 2221 if (T.isNull()) 2222 return DeclPtrTy(); 2223 DS.UpdateTypeRep(T.getAsOpaquePtr()); 2224 } 2225 } 2226 2227 DeclContext *DC; 2228 NamedDecl *New; 2229 2230 TypeSourceInfo *TInfo = 0; 2231 QualType R = GetTypeForDeclarator(D, S, &TInfo); 2232 2233 LookupResult Previous(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName, 2234 ForRedeclaration); 2235 2236 // See if this is a redefinition of a variable in the same scope. 2237 if (D.getCXXScopeSpec().isInvalid()) { 2238 DC = CurContext; 2239 D.setInvalidType(); 2240 } else if (!D.getCXXScopeSpec().isSet()) { 2241 bool IsLinkageLookup = false; 2242 2243 // If the declaration we're planning to build will be a function 2244 // or object with linkage, then look for another declaration with 2245 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 2246 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 2247 /* Do nothing*/; 2248 else if (R->isFunctionType()) { 2249 if (CurContext->isFunctionOrMethod() || 2250 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 2251 IsLinkageLookup = true; 2252 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 2253 IsLinkageLookup = true; 2254 else if (CurContext->getLookupContext()->isTranslationUnit() && 2255 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 2256 IsLinkageLookup = true; 2257 2258 if (IsLinkageLookup) 2259 Previous.clear(LookupRedeclarationWithLinkage); 2260 2261 DC = CurContext; 2262 LookupName(Previous, S, /* CreateBuiltins = */ IsLinkageLookup); 2263 } else { // Something like "int foo::x;" 2264 DC = computeDeclContext(D.getCXXScopeSpec(), true); 2265 2266 if (!DC) { 2267 // If we could not compute the declaration context, it's because the 2268 // declaration context is dependent but does not refer to a class, 2269 // class template, or class template partial specialization. Complain 2270 // and return early, to avoid the coming semantic disaster. 2271 Diag(D.getIdentifierLoc(), 2272 diag::err_template_qualified_declarator_no_match) 2273 << (NestedNameSpecifier*)D.getCXXScopeSpec().getScopeRep() 2274 << D.getCXXScopeSpec().getRange(); 2275 return DeclPtrTy(); 2276 } 2277 2278 if (!DC->isDependentContext() && 2279 RequireCompleteDeclContext(D.getCXXScopeSpec())) 2280 return DeclPtrTy(); 2281 2282 LookupQualifiedName(Previous, DC); 2283 2284 // Don't consider using declarations as previous declarations for 2285 // out-of-line members. 2286 RemoveUsingDecls(Previous); 2287 2288 // C++ 7.3.1.2p2: 2289 // Members (including explicit specializations of templates) of a named 2290 // namespace can also be defined outside that namespace by explicit 2291 // qualification of the name being defined, provided that the entity being 2292 // defined was already declared in the namespace and the definition appears 2293 // after the point of declaration in a namespace that encloses the 2294 // declarations namespace. 2295 // 2296 // Note that we only check the context at this point. We don't yet 2297 // have enough information to make sure that PrevDecl is actually 2298 // the declaration we want to match. For example, given: 2299 // 2300 // class X { 2301 // void f(); 2302 // void f(float); 2303 // }; 2304 // 2305 // void X::f(int) { } // ill-formed 2306 // 2307 // In this case, PrevDecl will point to the overload set 2308 // containing the two f's declared in X, but neither of them 2309 // matches. 2310 2311 // First check whether we named the global scope. 2312 if (isa<TranslationUnitDecl>(DC)) { 2313 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 2314 << Name << D.getCXXScopeSpec().getRange(); 2315 } else { 2316 DeclContext *Cur = CurContext; 2317 while (isa<LinkageSpecDecl>(Cur)) 2318 Cur = Cur->getParent(); 2319 if (!Cur->Encloses(DC)) { 2320 // The qualifying scope doesn't enclose the original declaration. 2321 // Emit diagnostic based on current scope. 2322 SourceLocation L = D.getIdentifierLoc(); 2323 SourceRange R = D.getCXXScopeSpec().getRange(); 2324 if (isa<FunctionDecl>(Cur)) 2325 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 2326 else 2327 Diag(L, diag::err_invalid_declarator_scope) 2328 << Name << cast<NamedDecl>(DC) << R; 2329 D.setInvalidType(); 2330 } 2331 } 2332 } 2333 2334 if (Previous.isSingleResult() && 2335 Previous.getFoundDecl()->isTemplateParameter()) { 2336 // Maybe we will complain about the shadowed template parameter. 2337 if (!D.isInvalidType()) 2338 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), 2339 Previous.getFoundDecl())) 2340 D.setInvalidType(); 2341 2342 // Just pretend that we didn't see the previous declaration. 2343 Previous.clear(); 2344 } 2345 2346 // In C++, the previous declaration we find might be a tag type 2347 // (class or enum). In this case, the new declaration will hide the 2348 // tag type. Note that this does does not apply if we're declaring a 2349 // typedef (C++ [dcl.typedef]p4). 2350 if (Previous.isSingleTagDecl() && 2351 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 2352 Previous.clear(); 2353 2354 bool Redeclaration = false; 2355 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 2356 if (TemplateParamLists.size()) { 2357 Diag(D.getIdentifierLoc(), diag::err_template_typedef); 2358 return DeclPtrTy(); 2359 } 2360 2361 New = ActOnTypedefDeclarator(S, D, DC, R, TInfo, Previous, Redeclaration); 2362 } else if (R->isFunctionType()) { 2363 New = ActOnFunctionDeclarator(S, D, DC, R, TInfo, Previous, 2364 move(TemplateParamLists), 2365 IsFunctionDefinition, Redeclaration); 2366 } else { 2367 New = ActOnVariableDeclarator(S, D, DC, R, TInfo, Previous, 2368 move(TemplateParamLists), 2369 Redeclaration); 2370 } 2371 2372 if (New == 0) 2373 return DeclPtrTy(); 2374 2375 // If this has an identifier and is not an invalid redeclaration or 2376 // function template specialization, add it to the scope stack. 2377 if (Name && !(Redeclaration && New->isInvalidDecl())) 2378 PushOnScopeChains(New, S); 2379 2380 return DeclPtrTy::make(New); 2381} 2382 2383/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2384/// types into constant array types in certain situations which would otherwise 2385/// be errors (for GCC compatibility). 2386static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2387 ASTContext &Context, 2388 bool &SizeIsNegative) { 2389 // This method tries to turn a variable array into a constant 2390 // array even when the size isn't an ICE. This is necessary 2391 // for compatibility with code that depends on gcc's buggy 2392 // constant expression folding, like struct {char x[(int)(char*)2];} 2393 SizeIsNegative = false; 2394 2395 QualifierCollector Qs; 2396 const Type *Ty = Qs.strip(T); 2397 2398 if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) { 2399 QualType Pointee = PTy->getPointeeType(); 2400 QualType FixedType = 2401 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 2402 if (FixedType.isNull()) return FixedType; 2403 FixedType = Context.getPointerType(FixedType); 2404 return Qs.apply(FixedType); 2405 } 2406 2407 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2408 if (!VLATy) 2409 return QualType(); 2410 // FIXME: We should probably handle this case 2411 if (VLATy->getElementType()->isVariablyModifiedType()) 2412 return QualType(); 2413 2414 Expr::EvalResult EvalResult; 2415 if (!VLATy->getSizeExpr() || 2416 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 2417 !EvalResult.Val.isInt()) 2418 return QualType(); 2419 2420 llvm::APSInt &Res = EvalResult.Val.getInt(); 2421 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) { 2422 // TODO: preserve the size expression in declarator info 2423 return Context.getConstantArrayType(VLATy->getElementType(), 2424 Res, ArrayType::Normal, 0); 2425 } 2426 2427 SizeIsNegative = true; 2428 return QualType(); 2429} 2430 2431/// \brief Register the given locally-scoped external C declaration so 2432/// that it can be found later for redeclarations 2433void 2434Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, 2435 const LookupResult &Previous, 2436 Scope *S) { 2437 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 2438 "Decl is not a locally-scoped decl!"); 2439 // Note that we have a locally-scoped external with this name. 2440 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 2441 2442 if (!Previous.isSingleResult()) 2443 return; 2444 2445 NamedDecl *PrevDecl = Previous.getFoundDecl(); 2446 2447 // If there was a previous declaration of this variable, it may be 2448 // in our identifier chain. Update the identifier chain with the new 2449 // declaration. 2450 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 2451 // The previous declaration was found on the identifer resolver 2452 // chain, so remove it from its scope. 2453 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 2454 S = S->getParent(); 2455 2456 if (S) 2457 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 2458 } 2459} 2460 2461/// \brief Diagnose function specifiers on a declaration of an identifier that 2462/// does not identify a function. 2463void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 2464 // FIXME: We should probably indicate the identifier in question to avoid 2465 // confusion for constructs like "inline int a(), b;" 2466 if (D.getDeclSpec().isInlineSpecified()) 2467 Diag(D.getDeclSpec().getInlineSpecLoc(), 2468 diag::err_inline_non_function); 2469 2470 if (D.getDeclSpec().isVirtualSpecified()) 2471 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2472 diag::err_virtual_non_function); 2473 2474 if (D.getDeclSpec().isExplicitSpecified()) 2475 Diag(D.getDeclSpec().getExplicitSpecLoc(), 2476 diag::err_explicit_non_function); 2477} 2478 2479NamedDecl* 2480Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2481 QualType R, TypeSourceInfo *TInfo, 2482 LookupResult &Previous, bool &Redeclaration) { 2483 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 2484 if (D.getCXXScopeSpec().isSet()) { 2485 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 2486 << D.getCXXScopeSpec().getRange(); 2487 D.setInvalidType(); 2488 // Pretend we didn't see the scope specifier. 2489 DC = 0; 2490 } 2491 2492 if (getLangOptions().CPlusPlus) { 2493 // Check that there are no default arguments (C++ only). 2494 CheckExtraCXXDefaultArguments(D); 2495 } 2496 2497 DiagnoseFunctionSpecifiers(D); 2498 2499 if (D.getDeclSpec().isThreadSpecified()) 2500 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2501 2502 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, TInfo); 2503 if (!NewTD) return 0; 2504 2505 // Handle attributes prior to checking for duplicates in MergeVarDecl 2506 ProcessDeclAttributes(S, NewTD, D); 2507 2508 // Merge the decl with the existing one if appropriate. If the decl is 2509 // in an outer scope, it isn't the same thing. 2510 FilterLookupForScope(*this, Previous, DC, S, /*ConsiderLinkage*/ false); 2511 if (!Previous.empty()) { 2512 Redeclaration = true; 2513 MergeTypeDefDecl(NewTD, Previous); 2514 } 2515 2516 // C99 6.7.7p2: If a typedef name specifies a variably modified type 2517 // then it shall have block scope. 2518 QualType T = NewTD->getUnderlyingType(); 2519 if (T->isVariablyModifiedType()) { 2520 CurFunctionNeedsScopeChecking = true; 2521 2522 if (S->getFnParent() == 0) { 2523 bool SizeIsNegative; 2524 QualType FixedTy = 2525 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2526 if (!FixedTy.isNull()) { 2527 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 2528 NewTD->setTypeSourceInfo(Context.getTrivialTypeSourceInfo(FixedTy)); 2529 } else { 2530 if (SizeIsNegative) 2531 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 2532 else if (T->isVariableArrayType()) 2533 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 2534 else 2535 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 2536 NewTD->setInvalidDecl(); 2537 } 2538 } 2539 } 2540 2541 // If this is the C FILE type, notify the AST context. 2542 if (IdentifierInfo *II = NewTD->getIdentifier()) 2543 if (!NewTD->isInvalidDecl() && 2544 NewTD->getDeclContext()->getLookupContext()->isTranslationUnit()) { 2545 if (II->isStr("FILE")) 2546 Context.setFILEDecl(NewTD); 2547 else if (II->isStr("jmp_buf")) 2548 Context.setjmp_bufDecl(NewTD); 2549 else if (II->isStr("sigjmp_buf")) 2550 Context.setsigjmp_bufDecl(NewTD); 2551 } 2552 2553 return NewTD; 2554} 2555 2556/// \brief Determines whether the given declaration is an out-of-scope 2557/// previous declaration. 2558/// 2559/// This routine should be invoked when name lookup has found a 2560/// previous declaration (PrevDecl) that is not in the scope where a 2561/// new declaration by the same name is being introduced. If the new 2562/// declaration occurs in a local scope, previous declarations with 2563/// linkage may still be considered previous declarations (C99 2564/// 6.2.2p4-5, C++ [basic.link]p6). 2565/// 2566/// \param PrevDecl the previous declaration found by name 2567/// lookup 2568/// 2569/// \param DC the context in which the new declaration is being 2570/// declared. 2571/// 2572/// \returns true if PrevDecl is an out-of-scope previous declaration 2573/// for a new delcaration with the same name. 2574static bool 2575isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 2576 ASTContext &Context) { 2577 if (!PrevDecl) 2578 return 0; 2579 2580 if (!PrevDecl->hasLinkage()) 2581 return false; 2582 2583 if (Context.getLangOptions().CPlusPlus) { 2584 // C++ [basic.link]p6: 2585 // If there is a visible declaration of an entity with linkage 2586 // having the same name and type, ignoring entities declared 2587 // outside the innermost enclosing namespace scope, the block 2588 // scope declaration declares that same entity and receives the 2589 // linkage of the previous declaration. 2590 DeclContext *OuterContext = DC->getLookupContext(); 2591 if (!OuterContext->isFunctionOrMethod()) 2592 // This rule only applies to block-scope declarations. 2593 return false; 2594 else { 2595 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 2596 if (PrevOuterContext->isRecord()) 2597 // We found a member function: ignore it. 2598 return false; 2599 else { 2600 // Find the innermost enclosing namespace for the new and 2601 // previous declarations. 2602 while (!OuterContext->isFileContext()) 2603 OuterContext = OuterContext->getParent(); 2604 while (!PrevOuterContext->isFileContext()) 2605 PrevOuterContext = PrevOuterContext->getParent(); 2606 2607 // The previous declaration is in a different namespace, so it 2608 // isn't the same function. 2609 if (OuterContext->getPrimaryContext() != 2610 PrevOuterContext->getPrimaryContext()) 2611 return false; 2612 } 2613 } 2614 } 2615 2616 return true; 2617} 2618 2619NamedDecl* 2620Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2621 QualType R, TypeSourceInfo *TInfo, 2622 LookupResult &Previous, 2623 MultiTemplateParamsArg TemplateParamLists, 2624 bool &Redeclaration) { 2625 DeclarationName Name = GetNameForDeclarator(D); 2626 2627 // Check that there are no default arguments (C++ only). 2628 if (getLangOptions().CPlusPlus) 2629 CheckExtraCXXDefaultArguments(D); 2630 2631 VarDecl *NewVD; 2632 VarDecl::StorageClass SC; 2633 switch (D.getDeclSpec().getStorageClassSpec()) { 2634 default: assert(0 && "Unknown storage class!"); 2635 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2636 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2637 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2638 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2639 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2640 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2641 case DeclSpec::SCS_mutable: 2642 // mutable can only appear on non-static class members, so it's always 2643 // an error here 2644 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 2645 D.setInvalidType(); 2646 SC = VarDecl::None; 2647 break; 2648 } 2649 2650 IdentifierInfo *II = Name.getAsIdentifierInfo(); 2651 if (!II) { 2652 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 2653 << Name.getAsString(); 2654 return 0; 2655 } 2656 2657 DiagnoseFunctionSpecifiers(D); 2658 2659 if (!DC->isRecord() && S->getFnParent() == 0) { 2660 // C99 6.9p2: The storage-class specifiers auto and register shall not 2661 // appear in the declaration specifiers in an external declaration. 2662 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 2663 2664 // If this is a register variable with an asm label specified, then this 2665 // is a GNU extension. 2666 if (SC == VarDecl::Register && D.getAsmLabel()) 2667 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 2668 else 2669 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 2670 D.setInvalidType(); 2671 } 2672 } 2673 if (DC->isRecord() && !CurContext->isRecord()) { 2674 // This is an out-of-line definition of a static data member. 2675 if (SC == VarDecl::Static) { 2676 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2677 diag::err_static_out_of_line) 2678 << CodeModificationHint::CreateRemoval( 2679 D.getDeclSpec().getStorageClassSpecLoc()); 2680 } else if (SC == VarDecl::None) 2681 SC = VarDecl::Static; 2682 } 2683 if (SC == VarDecl::Static) { 2684 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 2685 if (RD->isLocalClass()) 2686 Diag(D.getIdentifierLoc(), 2687 diag::err_static_data_member_not_allowed_in_local_class) 2688 << Name << RD->getDeclName(); 2689 } 2690 } 2691 2692 // Match up the template parameter lists with the scope specifier, then 2693 // determine whether we have a template or a template specialization. 2694 bool isExplicitSpecialization = false; 2695 if (TemplateParameterList *TemplateParams 2696 = MatchTemplateParametersToScopeSpecifier( 2697 D.getDeclSpec().getSourceRange().getBegin(), 2698 D.getCXXScopeSpec(), 2699 (TemplateParameterList**)TemplateParamLists.get(), 2700 TemplateParamLists.size(), 2701 isExplicitSpecialization)) { 2702 if (TemplateParams->size() > 0) { 2703 // There is no such thing as a variable template. 2704 Diag(D.getIdentifierLoc(), diag::err_template_variable) 2705 << II 2706 << SourceRange(TemplateParams->getTemplateLoc(), 2707 TemplateParams->getRAngleLoc()); 2708 return 0; 2709 } else { 2710 // There is an extraneous 'template<>' for this variable. Complain 2711 // about it, but allow the declaration of the variable. 2712 Diag(TemplateParams->getTemplateLoc(), 2713 diag::err_template_variable_noparams) 2714 << II 2715 << SourceRange(TemplateParams->getTemplateLoc(), 2716 TemplateParams->getRAngleLoc()); 2717 2718 isExplicitSpecialization = true; 2719 } 2720 } 2721 2722 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 2723 II, R, TInfo, SC); 2724 2725 if (D.isInvalidType()) 2726 NewVD->setInvalidDecl(); 2727 2728 if (D.getDeclSpec().isThreadSpecified()) { 2729 if (NewVD->hasLocalStorage()) 2730 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 2731 else if (!Context.Target.isTLSSupported()) 2732 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 2733 else 2734 NewVD->setThreadSpecified(true); 2735 } 2736 2737 // Set the lexical context. If the declarator has a C++ scope specifier, the 2738 // lexical context will be different from the semantic context. 2739 NewVD->setLexicalDeclContext(CurContext); 2740 2741 // Handle attributes prior to checking for duplicates in MergeVarDecl 2742 ProcessDeclAttributes(S, NewVD, D); 2743 2744 // Handle GNU asm-label extension (encoded as an attribute). 2745 if (Expr *E = (Expr*) D.getAsmLabel()) { 2746 // The parser guarantees this is a string. 2747 StringLiteral *SE = cast<StringLiteral>(E); 2748 NewVD->addAttr(::new (Context) AsmLabelAttr(SE->getString())); 2749 } 2750 2751 // Don't consider existing declarations that are in a different 2752 // scope and are out-of-semantic-context declarations (if the new 2753 // declaration has linkage). 2754 FilterLookupForScope(*this, Previous, DC, S, NewVD->hasLinkage()); 2755 2756 // Merge the decl with the existing one if appropriate. 2757 if (!Previous.empty()) { 2758 if (Previous.isSingleResult() && 2759 isa<FieldDecl>(Previous.getFoundDecl()) && 2760 D.getCXXScopeSpec().isSet()) { 2761 // The user tried to define a non-static data member 2762 // out-of-line (C++ [dcl.meaning]p1). 2763 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 2764 << D.getCXXScopeSpec().getRange(); 2765 Previous.clear(); 2766 NewVD->setInvalidDecl(); 2767 } 2768 } else if (D.getCXXScopeSpec().isSet()) { 2769 // No previous declaration in the qualifying scope. 2770 Diag(D.getIdentifierLoc(), diag::err_no_member) 2771 << Name << computeDeclContext(D.getCXXScopeSpec(), true) 2772 << D.getCXXScopeSpec().getRange(); 2773 NewVD->setInvalidDecl(); 2774 } 2775 2776 CheckVariableDeclaration(NewVD, Previous, Redeclaration); 2777 2778 // This is an explicit specialization of a static data member. Check it. 2779 if (isExplicitSpecialization && !NewVD->isInvalidDecl() && 2780 CheckMemberSpecialization(NewVD, Previous)) 2781 NewVD->setInvalidDecl(); 2782 2783 // attributes declared post-definition are currently ignored 2784 if (Previous.isSingleResult()) { 2785 const VarDecl *Def = 0; 2786 VarDecl *PrevDecl = dyn_cast<VarDecl>(Previous.getFoundDecl()); 2787 if (PrevDecl && PrevDecl->getDefinition(Def) && D.hasAttributes()) { 2788 Diag(NewVD->getLocation(), diag::warn_attribute_precede_definition); 2789 Diag(Def->getLocation(), diag::note_previous_definition); 2790 } 2791 } 2792 2793 // If this is a locally-scoped extern C variable, update the map of 2794 // such variables. 2795 if (CurContext->isFunctionOrMethod() && NewVD->isExternC() && 2796 !NewVD->isInvalidDecl()) 2797 RegisterLocallyScopedExternCDecl(NewVD, Previous, S); 2798 2799 return NewVD; 2800} 2801 2802/// \brief Perform semantic checking on a newly-created variable 2803/// declaration. 2804/// 2805/// This routine performs all of the type-checking required for a 2806/// variable declaration once it has been built. It is used both to 2807/// check variables after they have been parsed and their declarators 2808/// have been translated into a declaration, and to check variables 2809/// that have been instantiated from a template. 2810/// 2811/// Sets NewVD->isInvalidDecl() if an error was encountered. 2812void Sema::CheckVariableDeclaration(VarDecl *NewVD, 2813 LookupResult &Previous, 2814 bool &Redeclaration) { 2815 // If the decl is already known invalid, don't check it. 2816 if (NewVD->isInvalidDecl()) 2817 return; 2818 2819 QualType T = NewVD->getType(); 2820 2821 if (T->isObjCInterfaceType()) { 2822 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 2823 return NewVD->setInvalidDecl(); 2824 } 2825 2826 // Emit an error if an address space was applied to decl with local storage. 2827 // This includes arrays of objects with address space qualifiers, but not 2828 // automatic variables that point to other address spaces. 2829 // ISO/IEC TR 18037 S5.1.2 2830 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 2831 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 2832 return NewVD->setInvalidDecl(); 2833 } 2834 2835 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 2836 && !NewVD->hasAttr<BlocksAttr>()) 2837 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 2838 2839 bool isVM = T->isVariablyModifiedType(); 2840 if (isVM || NewVD->hasAttr<CleanupAttr>() || 2841 NewVD->hasAttr<BlocksAttr>()) 2842 CurFunctionNeedsScopeChecking = true; 2843 2844 if ((isVM && NewVD->hasLinkage()) || 2845 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 2846 bool SizeIsNegative; 2847 QualType FixedTy = 2848 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2849 2850 if (FixedTy.isNull() && T->isVariableArrayType()) { 2851 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2852 // FIXME: This won't give the correct result for 2853 // int a[10][n]; 2854 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2855 2856 if (NewVD->isFileVarDecl()) 2857 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 2858 << SizeRange; 2859 else if (NewVD->getStorageClass() == VarDecl::Static) 2860 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 2861 << SizeRange; 2862 else 2863 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 2864 << SizeRange; 2865 return NewVD->setInvalidDecl(); 2866 } 2867 2868 if (FixedTy.isNull()) { 2869 if (NewVD->isFileVarDecl()) 2870 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 2871 else 2872 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 2873 return NewVD->setInvalidDecl(); 2874 } 2875 2876 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 2877 NewVD->setType(FixedTy); 2878 } 2879 2880 if (Previous.empty() && NewVD->isExternC()) { 2881 // Since we did not find anything by this name and we're declaring 2882 // an extern "C" variable, look for a non-visible extern "C" 2883 // declaration with the same name. 2884 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2885 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 2886 if (Pos != LocallyScopedExternalDecls.end()) 2887 Previous.addDecl(Pos->second); 2888 } 2889 2890 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 2891 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 2892 << T; 2893 return NewVD->setInvalidDecl(); 2894 } 2895 2896 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 2897 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 2898 return NewVD->setInvalidDecl(); 2899 } 2900 2901 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 2902 Diag(NewVD->getLocation(), diag::err_block_on_vm); 2903 return NewVD->setInvalidDecl(); 2904 } 2905 2906 if (!Previous.empty()) { 2907 Redeclaration = true; 2908 MergeVarDecl(NewVD, Previous); 2909 } 2910} 2911 2912/// \brief Data used with FindOverriddenMethod 2913struct FindOverriddenMethodData { 2914 Sema *S; 2915 CXXMethodDecl *Method; 2916}; 2917 2918/// \brief Member lookup function that determines whether a given C++ 2919/// method overrides a method in a base class, to be used with 2920/// CXXRecordDecl::lookupInBases(). 2921static bool FindOverriddenMethod(const CXXBaseSpecifier *Specifier, 2922 CXXBasePath &Path, 2923 void *UserData) { 2924 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl(); 2925 2926 FindOverriddenMethodData *Data 2927 = reinterpret_cast<FindOverriddenMethodData*>(UserData); 2928 2929 DeclarationName Name = Data->Method->getDeclName(); 2930 2931 // FIXME: Do we care about other names here too? 2932 if (Name.getNameKind() == DeclarationName::CXXDestructorName) { 2933 // We really want to find the base class constructor here. 2934 QualType T = Data->S->Context.getTypeDeclType(BaseRecord); 2935 CanQualType CT = Data->S->Context.getCanonicalType(T); 2936 2937 Name = Data->S->Context.DeclarationNames.getCXXDestructorName(CT); 2938 } 2939 2940 for (Path.Decls = BaseRecord->lookup(Name); 2941 Path.Decls.first != Path.Decls.second; 2942 ++Path.Decls.first) { 2943 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*Path.Decls.first)) { 2944 if (MD->isVirtual() && !Data->S->IsOverload(Data->Method, MD)) 2945 return true; 2946 } 2947 } 2948 2949 return false; 2950} 2951 2952/// AddOverriddenMethods - See if a method overrides any in the base classes, 2953/// and if so, check that it's a valid override and remember it. 2954void Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) { 2955 // Look for virtual methods in base classes that this method might override. 2956 CXXBasePaths Paths; 2957 FindOverriddenMethodData Data; 2958 Data.Method = MD; 2959 Data.S = this; 2960 if (DC->lookupInBases(&FindOverriddenMethod, &Data, Paths)) { 2961 for (CXXBasePaths::decl_iterator I = Paths.found_decls_begin(), 2962 E = Paths.found_decls_end(); I != E; ++I) { 2963 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2964 if (!CheckOverridingFunctionReturnType(MD, OldMD) && 2965 !CheckOverridingFunctionExceptionSpec(MD, OldMD) && 2966 !CheckOverridingFunctionAttributes(MD, OldMD)) 2967 MD->addOverriddenMethod(OldMD->getCanonicalDecl()); 2968 } 2969 } 2970 } 2971} 2972 2973NamedDecl* 2974Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2975 QualType R, TypeSourceInfo *TInfo, 2976 LookupResult &Previous, 2977 MultiTemplateParamsArg TemplateParamLists, 2978 bool IsFunctionDefinition, bool &Redeclaration) { 2979 assert(R.getTypePtr()->isFunctionType()); 2980 2981 DeclarationName Name = GetNameForDeclarator(D); 2982 FunctionDecl::StorageClass SC = FunctionDecl::None; 2983 switch (D.getDeclSpec().getStorageClassSpec()) { 2984 default: assert(0 && "Unknown storage class!"); 2985 case DeclSpec::SCS_auto: 2986 case DeclSpec::SCS_register: 2987 case DeclSpec::SCS_mutable: 2988 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2989 diag::err_typecheck_sclass_func); 2990 D.setInvalidType(); 2991 break; 2992 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 2993 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 2994 case DeclSpec::SCS_static: { 2995 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 2996 // C99 6.7.1p5: 2997 // The declaration of an identifier for a function that has 2998 // block scope shall have no explicit storage-class specifier 2999 // other than extern 3000 // See also (C++ [dcl.stc]p4). 3001 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 3002 diag::err_static_block_func); 3003 SC = FunctionDecl::None; 3004 } else 3005 SC = FunctionDecl::Static; 3006 break; 3007 } 3008 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 3009 } 3010 3011 if (D.getDeclSpec().isThreadSpecified()) 3012 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3013 3014 bool isFriend = D.getDeclSpec().isFriendSpecified(); 3015 bool isInline = D.getDeclSpec().isInlineSpecified(); 3016 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 3017 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 3018 3019 // Check that the return type is not an abstract class type. 3020 // For record types, this is done by the AbstractClassUsageDiagnoser once 3021 // the class has been completely parsed. 3022 if (!DC->isRecord() && 3023 RequireNonAbstractType(D.getIdentifierLoc(), 3024 R->getAs<FunctionType>()->getResultType(), 3025 diag::err_abstract_type_in_decl, 3026 AbstractReturnType)) 3027 D.setInvalidType(); 3028 3029 // Do not allow returning a objc interface by-value. 3030 if (R->getAs<FunctionType>()->getResultType()->isObjCInterfaceType()) { 3031 Diag(D.getIdentifierLoc(), 3032 diag::err_object_cannot_be_passed_returned_by_value) << 0 3033 << R->getAs<FunctionType>()->getResultType(); 3034 D.setInvalidType(); 3035 } 3036 3037 bool isVirtualOkay = false; 3038 FunctionDecl *NewFD; 3039 3040 if (isFriend) { 3041 // C++ [class.friend]p5 3042 // A function can be defined in a friend declaration of a 3043 // class . . . . Such a function is implicitly inline. 3044 isInline |= IsFunctionDefinition; 3045 } 3046 3047 if (Name.getNameKind() == DeclarationName::CXXConstructorName) { 3048 // This is a C++ constructor declaration. 3049 assert(DC->isRecord() && 3050 "Constructors can only be declared in a member context"); 3051 3052 R = CheckConstructorDeclarator(D, R, SC); 3053 3054 // Create the new declaration 3055 NewFD = CXXConstructorDecl::Create(Context, 3056 cast<CXXRecordDecl>(DC), 3057 D.getIdentifierLoc(), Name, R, TInfo, 3058 isExplicit, isInline, 3059 /*isImplicitlyDeclared=*/false); 3060 } else if (Name.getNameKind() == DeclarationName::CXXDestructorName) { 3061 // This is a C++ destructor declaration. 3062 if (DC->isRecord()) { 3063 R = CheckDestructorDeclarator(D, SC); 3064 3065 NewFD = CXXDestructorDecl::Create(Context, 3066 cast<CXXRecordDecl>(DC), 3067 D.getIdentifierLoc(), Name, R, 3068 isInline, 3069 /*isImplicitlyDeclared=*/false); 3070 3071 isVirtualOkay = true; 3072 } else { 3073 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 3074 3075 // Create a FunctionDecl to satisfy the function definition parsing 3076 // code path. 3077 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 3078 Name, R, TInfo, SC, isInline, 3079 /*hasPrototype=*/true); 3080 D.setInvalidType(); 3081 } 3082 } else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 3083 if (!DC->isRecord()) { 3084 Diag(D.getIdentifierLoc(), 3085 diag::err_conv_function_not_member); 3086 return 0; 3087 } 3088 3089 CheckConversionDeclarator(D, R, SC); 3090 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 3091 D.getIdentifierLoc(), Name, R, TInfo, 3092 isInline, isExplicit); 3093 3094 isVirtualOkay = true; 3095 } else if (DC->isRecord()) { 3096 // If the of the function is the same as the name of the record, then this 3097 // must be an invalid constructor that has a return type. 3098 // (The parser checks for a return type and makes the declarator a 3099 // constructor if it has no return type). 3100 // must have an invalid constructor that has a return type 3101 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 3102 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 3103 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 3104 << SourceRange(D.getIdentifierLoc()); 3105 return 0; 3106 } 3107 3108 bool isStatic = SC == FunctionDecl::Static; 3109 3110 // [class.free]p1: 3111 // Any allocation function for a class T is a static member 3112 // (even if not explicitly declared static). 3113 if (Name.getCXXOverloadedOperator() == OO_New || 3114 Name.getCXXOverloadedOperator() == OO_Array_New) 3115 isStatic = true; 3116 3117 // [class.free]p6 Any deallocation function for a class X is a static member 3118 // (even if not explicitly declared static). 3119 if (Name.getCXXOverloadedOperator() == OO_Delete || 3120 Name.getCXXOverloadedOperator() == OO_Array_Delete) 3121 isStatic = true; 3122 3123 // This is a C++ method declaration. 3124 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 3125 D.getIdentifierLoc(), Name, R, TInfo, 3126 isStatic, isInline); 3127 3128 isVirtualOkay = !isStatic; 3129 } else { 3130 // Determine whether the function was written with a 3131 // prototype. This true when: 3132 // - we're in C++ (where every function has a prototype), 3133 // - there is a prototype in the declarator, or 3134 // - the type R of the function is some kind of typedef or other reference 3135 // to a type name (which eventually refers to a function type). 3136 bool HasPrototype = 3137 getLangOptions().CPlusPlus || 3138 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 3139 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 3140 3141 NewFD = FunctionDecl::Create(Context, DC, 3142 D.getIdentifierLoc(), 3143 Name, R, TInfo, SC, isInline, HasPrototype); 3144 } 3145 3146 if (D.isInvalidType()) 3147 NewFD->setInvalidDecl(); 3148 3149 // Set the lexical context. If the declarator has a C++ 3150 // scope specifier, or is the object of a friend declaration, the 3151 // lexical context will be different from the semantic context. 3152 NewFD->setLexicalDeclContext(CurContext); 3153 3154 // Match up the template parameter lists with the scope specifier, then 3155 // determine whether we have a template or a template specialization. 3156 FunctionTemplateDecl *FunctionTemplate = 0; 3157 bool isExplicitSpecialization = false; 3158 bool isFunctionTemplateSpecialization = false; 3159 if (TemplateParameterList *TemplateParams 3160 = MatchTemplateParametersToScopeSpecifier( 3161 D.getDeclSpec().getSourceRange().getBegin(), 3162 D.getCXXScopeSpec(), 3163 (TemplateParameterList**)TemplateParamLists.get(), 3164 TemplateParamLists.size(), 3165 isExplicitSpecialization)) { 3166 if (TemplateParams->size() > 0) { 3167 // This is a function template 3168 3169 // Check that we can declare a template here. 3170 if (CheckTemplateDeclScope(S, TemplateParams)) 3171 return 0; 3172 3173 FunctionTemplate = FunctionTemplateDecl::Create(Context, DC, 3174 NewFD->getLocation(), 3175 Name, TemplateParams, 3176 NewFD); 3177 FunctionTemplate->setLexicalDeclContext(CurContext); 3178 NewFD->setDescribedFunctionTemplate(FunctionTemplate); 3179 } else { 3180 // This is a function template specialization. 3181 isFunctionTemplateSpecialization = true; 3182 } 3183 3184 // FIXME: Free this memory properly. 3185 TemplateParamLists.release(); 3186 } 3187 3188 // C++ [dcl.fct.spec]p5: 3189 // The virtual specifier shall only be used in declarations of 3190 // nonstatic class member functions that appear within a 3191 // member-specification of a class declaration; see 10.3. 3192 // 3193 if (isVirtual && !NewFD->isInvalidDecl()) { 3194 if (!isVirtualOkay) { 3195 Diag(D.getDeclSpec().getVirtualSpecLoc(), 3196 diag::err_virtual_non_function); 3197 } else if (!CurContext->isRecord()) { 3198 // 'virtual' was specified outside of the class. 3199 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 3200 << CodeModificationHint::CreateRemoval( 3201 D.getDeclSpec().getVirtualSpecLoc()); 3202 } else { 3203 // Okay: Add virtual to the method. 3204 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 3205 CurClass->setMethodAsVirtual(NewFD); 3206 } 3207 } 3208 3209 // Filter out previous declarations that don't match the scope. 3210 FilterLookupForScope(*this, Previous, DC, S, NewFD->hasLinkage()); 3211 3212 if (isFriend) { 3213 // DC is the namespace in which the function is being declared. 3214 assert((DC->isFileContext() || !Previous.empty()) && 3215 "previously-undeclared friend function being created " 3216 "in a non-namespace context"); 3217 3218 if (FunctionTemplate) { 3219 FunctionTemplate->setObjectOfFriendDecl( 3220 /* PreviouslyDeclared= */ !Previous.empty()); 3221 FunctionTemplate->setAccess(AS_public); 3222 } 3223 else 3224 NewFD->setObjectOfFriendDecl(/* PreviouslyDeclared= */ !Previous.empty()); 3225 3226 NewFD->setAccess(AS_public); 3227 } 3228 3229 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 3230 !CurContext->isRecord()) { 3231 // C++ [class.static]p1: 3232 // A data or function member of a class may be declared static 3233 // in a class definition, in which case it is a static member of 3234 // the class. 3235 3236 // Complain about the 'static' specifier if it's on an out-of-line 3237 // member function definition. 3238 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 3239 diag::err_static_out_of_line) 3240 << CodeModificationHint::CreateRemoval( 3241 D.getDeclSpec().getStorageClassSpecLoc()); 3242 } 3243 3244 // Handle GNU asm-label extension (encoded as an attribute). 3245 if (Expr *E = (Expr*) D.getAsmLabel()) { 3246 // The parser guarantees this is a string. 3247 StringLiteral *SE = cast<StringLiteral>(E); 3248 NewFD->addAttr(::new (Context) AsmLabelAttr(SE->getString())); 3249 } 3250 3251 // Copy the parameter declarations from the declarator D to the function 3252 // declaration NewFD, if they are available. First scavenge them into Params. 3253 llvm::SmallVector<ParmVarDecl*, 16> Params; 3254 if (D.getNumTypeObjects() > 0) { 3255 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3256 3257 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 3258 // function that takes no arguments, not a function that takes a 3259 // single void argument. 3260 // We let through "const void" here because Sema::GetTypeForDeclarator 3261 // already checks for that case. 3262 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 3263 FTI.ArgInfo[0].Param && 3264 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 3265 // Empty arg list, don't push any params. 3266 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 3267 3268 // In C++, the empty parameter-type-list must be spelled "void"; a 3269 // typedef of void is not permitted. 3270 if (getLangOptions().CPlusPlus && 3271 Param->getType().getUnqualifiedType() != Context.VoidTy) 3272 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 3273 // FIXME: Leaks decl? 3274 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 3275 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 3276 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 3277 assert(Param->getDeclContext() != NewFD && "Was set before ?"); 3278 Param->setDeclContext(NewFD); 3279 Params.push_back(Param); 3280 } 3281 } 3282 3283 } else if (const FunctionProtoType *FT = R->getAs<FunctionProtoType>()) { 3284 // When we're declaring a function with a typedef, typeof, etc as in the 3285 // following example, we'll need to synthesize (unnamed) 3286 // parameters for use in the declaration. 3287 // 3288 // @code 3289 // typedef void fn(int); 3290 // fn f; 3291 // @endcode 3292 3293 // Synthesize a parameter for each argument type. 3294 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 3295 AE = FT->arg_type_end(); AI != AE; ++AI) { 3296 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 3297 SourceLocation(), 0, 3298 *AI, /*TInfo=*/0, 3299 VarDecl::None, 0); 3300 Param->setImplicit(); 3301 Params.push_back(Param); 3302 } 3303 } else { 3304 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 3305 "Should not need args for typedef of non-prototype fn"); 3306 } 3307 // Finally, we know we have the right number of parameters, install them. 3308 NewFD->setParams(Context, Params.data(), Params.size()); 3309 3310 // If the declarator is a template-id, translate the parser's template 3311 // argument list into our AST format. 3312 bool HasExplicitTemplateArgs = false; 3313 TemplateArgumentListInfo TemplateArgs; 3314 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 3315 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 3316 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc); 3317 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc); 3318 ASTTemplateArgsPtr TemplateArgsPtr(*this, 3319 TemplateId->getTemplateArgs(), 3320 TemplateId->NumArgs); 3321 translateTemplateArguments(TemplateArgsPtr, 3322 TemplateArgs); 3323 TemplateArgsPtr.release(); 3324 3325 HasExplicitTemplateArgs = true; 3326 3327 if (FunctionTemplate) { 3328 // FIXME: Diagnose function template with explicit template 3329 // arguments. 3330 HasExplicitTemplateArgs = false; 3331 } else if (!isFunctionTemplateSpecialization && 3332 !D.getDeclSpec().isFriendSpecified()) { 3333 // We have encountered something that the user meant to be a 3334 // specialization (because it has explicitly-specified template 3335 // arguments) but that was not introduced with a "template<>" (or had 3336 // too few of them). 3337 Diag(D.getIdentifierLoc(), diag::err_template_spec_needs_header) 3338 << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc) 3339 << CodeModificationHint::CreateInsertion( 3340 D.getDeclSpec().getSourceRange().getBegin(), 3341 "template<> "); 3342 isFunctionTemplateSpecialization = true; 3343 } 3344 } 3345 3346 if (isFunctionTemplateSpecialization) { 3347 if (CheckFunctionTemplateSpecialization(NewFD, 3348 (HasExplicitTemplateArgs ? &TemplateArgs : 0), 3349 Previous)) 3350 NewFD->setInvalidDecl(); 3351 } else if (isExplicitSpecialization && isa<CXXMethodDecl>(NewFD) && 3352 CheckMemberSpecialization(NewFD, Previous)) 3353 NewFD->setInvalidDecl(); 3354 3355 // Perform semantic checking on the function declaration. 3356 bool OverloadableAttrRequired = false; // FIXME: HACK! 3357 CheckFunctionDeclaration(S, NewFD, Previous, isExplicitSpecialization, 3358 Redeclaration, /*FIXME:*/OverloadableAttrRequired); 3359 3360 assert((NewFD->isInvalidDecl() || !Redeclaration || 3361 Previous.getResultKind() != LookupResult::FoundOverloaded) && 3362 "previous declaration set still overloaded"); 3363 3364 // If we have a function template, check the template parameter 3365 // list. This will check and merge default template arguments. 3366 if (FunctionTemplate) { 3367 FunctionTemplateDecl *PrevTemplate = FunctionTemplate->getPreviousDeclaration(); 3368 CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(), 3369 PrevTemplate? PrevTemplate->getTemplateParameters() : 0, 3370 D.getDeclSpec().isFriendSpecified()? TPC_FriendFunctionTemplate 3371 : TPC_FunctionTemplate); 3372 } 3373 3374 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 3375 // Fake up an access specifier if it's supposed to be a class member. 3376 if (isa<CXXRecordDecl>(NewFD->getDeclContext())) 3377 NewFD->setAccess(AS_public); 3378 3379 // An out-of-line member function declaration must also be a 3380 // definition (C++ [dcl.meaning]p1). 3381 // Note that this is not the case for explicit specializations of 3382 // function templates or member functions of class templates, per 3383 // C++ [temp.expl.spec]p2. 3384 if (!IsFunctionDefinition && !isFriend && 3385 !isFunctionTemplateSpecialization && !isExplicitSpecialization) { 3386 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 3387 << D.getCXXScopeSpec().getRange(); 3388 NewFD->setInvalidDecl(); 3389 } else if (!Redeclaration && 3390 !(isFriend && CurContext->isDependentContext())) { 3391 // The user tried to provide an out-of-line definition for a 3392 // function that is a member of a class or namespace, but there 3393 // was no such member function declared (C++ [class.mfct]p2, 3394 // C++ [namespace.memdef]p2). For example: 3395 // 3396 // class X { 3397 // void f() const; 3398 // }; 3399 // 3400 // void X::f() { } // ill-formed 3401 // 3402 // Complain about this problem, and attempt to suggest close 3403 // matches (e.g., those that differ only in cv-qualifiers and 3404 // whether the parameter types are references). 3405 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 3406 << Name << DC << D.getCXXScopeSpec().getRange(); 3407 NewFD->setInvalidDecl(); 3408 3409 LookupResult Prev(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName, 3410 ForRedeclaration); 3411 LookupQualifiedName(Prev, DC); 3412 assert(!Prev.isAmbiguous() && 3413 "Cannot have an ambiguity in previous-declaration lookup"); 3414 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 3415 Func != FuncEnd; ++Func) { 3416 if (isa<FunctionDecl>(*Func) && 3417 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 3418 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 3419 } 3420 } 3421 } 3422 3423 // Handle attributes. We need to have merged decls when handling attributes 3424 // (for example to check for conflicts, etc). 3425 // FIXME: This needs to happen before we merge declarations. Then, 3426 // let attribute merging cope with attribute conflicts. 3427 ProcessDeclAttributes(S, NewFD, D); 3428 3429 // attributes declared post-definition are currently ignored 3430 if (Redeclaration && Previous.isSingleResult()) { 3431 const FunctionDecl *Def; 3432 FunctionDecl *PrevFD = dyn_cast<FunctionDecl>(Previous.getFoundDecl()); 3433 if (PrevFD && PrevFD->getBody(Def) && D.hasAttributes()) { 3434 Diag(NewFD->getLocation(), diag::warn_attribute_precede_definition); 3435 Diag(Def->getLocation(), diag::note_previous_definition); 3436 } 3437 } 3438 3439 AddKnownFunctionAttributes(NewFD); 3440 3441 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 3442 // If a function name is overloadable in C, then every function 3443 // with that name must be marked "overloadable". 3444 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 3445 << Redeclaration << NewFD; 3446 if (!Previous.empty()) 3447 Diag(Previous.getRepresentativeDecl()->getLocation(), 3448 diag::note_attribute_overloadable_prev_overload); 3449 NewFD->addAttr(::new (Context) OverloadableAttr()); 3450 } 3451 3452 // If this is a locally-scoped extern C function, update the 3453 // map of such names. 3454 if (CurContext->isFunctionOrMethod() && NewFD->isExternC() 3455 && !NewFD->isInvalidDecl()) 3456 RegisterLocallyScopedExternCDecl(NewFD, Previous, S); 3457 3458 // Set this FunctionDecl's range up to the right paren. 3459 NewFD->setLocEnd(D.getSourceRange().getEnd()); 3460 3461 if (FunctionTemplate && NewFD->isInvalidDecl()) 3462 FunctionTemplate->setInvalidDecl(); 3463 3464 if (FunctionTemplate) 3465 return FunctionTemplate; 3466 3467 return NewFD; 3468} 3469 3470/// \brief Perform semantic checking of a new function declaration. 3471/// 3472/// Performs semantic analysis of the new function declaration 3473/// NewFD. This routine performs all semantic checking that does not 3474/// require the actual declarator involved in the declaration, and is 3475/// used both for the declaration of functions as they are parsed 3476/// (called via ActOnDeclarator) and for the declaration of functions 3477/// that have been instantiated via C++ template instantiation (called 3478/// via InstantiateDecl). 3479/// 3480/// \param IsExplicitSpecialiation whether this new function declaration is 3481/// an explicit specialization of the previous declaration. 3482/// 3483/// This sets NewFD->isInvalidDecl() to true if there was an error. 3484void Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD, 3485 LookupResult &Previous, 3486 bool IsExplicitSpecialization, 3487 bool &Redeclaration, 3488 bool &OverloadableAttrRequired) { 3489 // If NewFD is already known erroneous, don't do any of this checking. 3490 if (NewFD->isInvalidDecl()) 3491 return; 3492 3493 if (NewFD->getResultType()->isVariablyModifiedType()) { 3494 // Functions returning a variably modified type violate C99 6.7.5.2p2 3495 // because all functions have linkage. 3496 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 3497 return NewFD->setInvalidDecl(); 3498 } 3499 3500 if (NewFD->isMain()) 3501 CheckMain(NewFD); 3502 3503 // Check for a previous declaration of this name. 3504 if (Previous.empty() && NewFD->isExternC()) { 3505 // Since we did not find anything by this name and we're declaring 3506 // an extern "C" function, look for a non-visible extern "C" 3507 // declaration with the same name. 3508 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3509 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 3510 if (Pos != LocallyScopedExternalDecls.end()) 3511 Previous.addDecl(Pos->second); 3512 } 3513 3514 // Merge or overload the declaration with an existing declaration of 3515 // the same name, if appropriate. 3516 if (!Previous.empty()) { 3517 // Determine whether NewFD is an overload of PrevDecl or 3518 // a declaration that requires merging. If it's an overload, 3519 // there's no more work to do here; we'll just add the new 3520 // function to the scope. 3521 3522 NamedDecl *OldDecl = 0; 3523 if (!AllowOverloadingOfFunction(Previous, Context)) { 3524 Redeclaration = true; 3525 OldDecl = Previous.getFoundDecl(); 3526 } else { 3527 if (!getLangOptions().CPlusPlus) { 3528 OverloadableAttrRequired = true; 3529 3530 // Functions marked "overloadable" must have a prototype (that 3531 // we can't get through declaration merging). 3532 if (!NewFD->getType()->getAs<FunctionProtoType>()) { 3533 Diag(NewFD->getLocation(), 3534 diag::err_attribute_overloadable_no_prototype) 3535 << NewFD; 3536 Redeclaration = true; 3537 3538 // Turn this into a variadic function with no parameters. 3539 QualType R = Context.getFunctionType( 3540 NewFD->getType()->getAs<FunctionType>()->getResultType(), 3541 0, 0, true, 0); 3542 NewFD->setType(R); 3543 return NewFD->setInvalidDecl(); 3544 } 3545 } 3546 3547 switch (CheckOverload(NewFD, Previous, OldDecl)) { 3548 case Ovl_Match: 3549 Redeclaration = true; 3550 if (isa<UsingShadowDecl>(OldDecl) && CurContext->isRecord()) { 3551 HideUsingShadowDecl(S, cast<UsingShadowDecl>(OldDecl)); 3552 Redeclaration = false; 3553 } 3554 break; 3555 3556 case Ovl_NonFunction: 3557 Redeclaration = true; 3558 break; 3559 3560 case Ovl_Overload: 3561 Redeclaration = false; 3562 break; 3563 } 3564 } 3565 3566 if (Redeclaration) { 3567 // NewFD and OldDecl represent declarations that need to be 3568 // merged. 3569 if (MergeFunctionDecl(NewFD, OldDecl)) 3570 return NewFD->setInvalidDecl(); 3571 3572 Previous.clear(); 3573 Previous.addDecl(OldDecl); 3574 3575 if (FunctionTemplateDecl *OldTemplateDecl 3576 = dyn_cast<FunctionTemplateDecl>(OldDecl)) { 3577 NewFD->setPreviousDeclaration(OldTemplateDecl->getTemplatedDecl()); 3578 FunctionTemplateDecl *NewTemplateDecl 3579 = NewFD->getDescribedFunctionTemplate(); 3580 assert(NewTemplateDecl && "Template/non-template mismatch"); 3581 if (CXXMethodDecl *Method 3582 = dyn_cast<CXXMethodDecl>(NewTemplateDecl->getTemplatedDecl())) { 3583 Method->setAccess(OldTemplateDecl->getAccess()); 3584 NewTemplateDecl->setAccess(OldTemplateDecl->getAccess()); 3585 } 3586 3587 // If this is an explicit specialization of a member that is a function 3588 // template, mark it as a member specialization. 3589 if (IsExplicitSpecialization && 3590 NewTemplateDecl->getInstantiatedFromMemberTemplate()) { 3591 NewTemplateDecl->setMemberSpecialization(); 3592 assert(OldTemplateDecl->isMemberSpecialization()); 3593 } 3594 } else { 3595 if (isa<CXXMethodDecl>(NewFD)) // Set access for out-of-line definitions 3596 NewFD->setAccess(OldDecl->getAccess()); 3597 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 3598 } 3599 } 3600 } 3601 3602 // Semantic checking for this function declaration (in isolation). 3603 if (getLangOptions().CPlusPlus) { 3604 // C++-specific checks. 3605 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 3606 CheckConstructor(Constructor); 3607 } else if (CXXDestructorDecl *Destructor = 3608 dyn_cast<CXXDestructorDecl>(NewFD)) { 3609 CXXRecordDecl *Record = Destructor->getParent(); 3610 QualType ClassType = Context.getTypeDeclType(Record); 3611 3612 // FIXME: Shouldn't we be able to perform thisc heck even when the class 3613 // type is dependent? Both gcc and edg can handle that. 3614 if (!ClassType->isDependentType()) { 3615 DeclarationName Name 3616 = Context.DeclarationNames.getCXXDestructorName( 3617 Context.getCanonicalType(ClassType)); 3618 if (NewFD->getDeclName() != Name) { 3619 Diag(NewFD->getLocation(), diag::err_destructor_name); 3620 return NewFD->setInvalidDecl(); 3621 } 3622 } 3623 3624 Record->setUserDeclaredDestructor(true); 3625 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 3626 // user-defined destructor. 3627 Record->setPOD(false); 3628 3629 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 3630 // declared destructor. 3631 // FIXME: C++0x: don't do this for "= default" destructors 3632 Record->setHasTrivialDestructor(false); 3633 } else if (CXXConversionDecl *Conversion 3634 = dyn_cast<CXXConversionDecl>(NewFD)) { 3635 ActOnConversionDeclarator(Conversion); 3636 } 3637 3638 // Find any virtual functions that this function overrides. 3639 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD)) { 3640 if (!Method->isFunctionTemplateSpecialization() && 3641 !Method->getDescribedFunctionTemplate()) 3642 AddOverriddenMethods(Method->getParent(), Method); 3643 } 3644 3645 // Additional checks for the destructor; make sure we do this after we 3646 // figure out whether the destructor is virtual. 3647 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 3648 if (!Destructor->getParent()->isDependentType()) 3649 CheckDestructor(Destructor); 3650 3651 // Extra checking for C++ overloaded operators (C++ [over.oper]). 3652 if (NewFD->isOverloadedOperator() && 3653 CheckOverloadedOperatorDeclaration(NewFD)) 3654 return NewFD->setInvalidDecl(); 3655 3656 // Extra checking for C++0x literal operators (C++0x [over.literal]). 3657 if (NewFD->getLiteralIdentifier() && 3658 CheckLiteralOperatorDeclaration(NewFD)) 3659 return NewFD->setInvalidDecl(); 3660 3661 // In C++, check default arguments now that we have merged decls. Unless 3662 // the lexical context is the class, because in this case this is done 3663 // during delayed parsing anyway. 3664 if (!CurContext->isRecord()) 3665 CheckCXXDefaultArguments(NewFD); 3666 } 3667} 3668 3669void Sema::CheckMain(FunctionDecl* FD) { 3670 // C++ [basic.start.main]p3: A program that declares main to be inline 3671 // or static is ill-formed. 3672 // C99 6.7.4p4: In a hosted environment, the inline function specifier 3673 // shall not appear in a declaration of main. 3674 // static main is not an error under C99, but we should warn about it. 3675 bool isInline = FD->isInlineSpecified(); 3676 bool isStatic = FD->getStorageClass() == FunctionDecl::Static; 3677 if (isInline || isStatic) { 3678 unsigned diagID = diag::warn_unusual_main_decl; 3679 if (isInline || getLangOptions().CPlusPlus) 3680 diagID = diag::err_unusual_main_decl; 3681 3682 int which = isStatic + (isInline << 1) - 1; 3683 Diag(FD->getLocation(), diagID) << which; 3684 } 3685 3686 QualType T = FD->getType(); 3687 assert(T->isFunctionType() && "function decl is not of function type"); 3688 const FunctionType* FT = T->getAs<FunctionType>(); 3689 3690 if (!Context.hasSameUnqualifiedType(FT->getResultType(), Context.IntTy)) { 3691 // TODO: add a replacement fixit to turn the return type into 'int'. 3692 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint); 3693 FD->setInvalidDecl(true); 3694 } 3695 3696 // Treat protoless main() as nullary. 3697 if (isa<FunctionNoProtoType>(FT)) return; 3698 3699 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 3700 unsigned nparams = FTP->getNumArgs(); 3701 assert(FD->getNumParams() == nparams); 3702 3703 bool HasExtraParameters = (nparams > 3); 3704 3705 // Darwin passes an undocumented fourth argument of type char**. If 3706 // other platforms start sprouting these, the logic below will start 3707 // getting shifty. 3708 if (nparams == 4 && 3709 Context.Target.getTriple().getOS() == llvm::Triple::Darwin) 3710 HasExtraParameters = false; 3711 3712 if (HasExtraParameters) { 3713 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 3714 FD->setInvalidDecl(true); 3715 nparams = 3; 3716 } 3717 3718 // FIXME: a lot of the following diagnostics would be improved 3719 // if we had some location information about types. 3720 3721 QualType CharPP = 3722 Context.getPointerType(Context.getPointerType(Context.CharTy)); 3723 QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP }; 3724 3725 for (unsigned i = 0; i < nparams; ++i) { 3726 QualType AT = FTP->getArgType(i); 3727 3728 bool mismatch = true; 3729 3730 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 3731 mismatch = false; 3732 else if (Expected[i] == CharPP) { 3733 // As an extension, the following forms are okay: 3734 // char const ** 3735 // char const * const * 3736 // char * const * 3737 3738 QualifierCollector qs; 3739 const PointerType* PT; 3740 if ((PT = qs.strip(AT)->getAs<PointerType>()) && 3741 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) && 3742 (QualType(qs.strip(PT->getPointeeType()), 0) == Context.CharTy)) { 3743 qs.removeConst(); 3744 mismatch = !qs.empty(); 3745 } 3746 } 3747 3748 if (mismatch) { 3749 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 3750 // TODO: suggest replacing given type with expected type 3751 FD->setInvalidDecl(true); 3752 } 3753 } 3754 3755 if (nparams == 1 && !FD->isInvalidDecl()) { 3756 Diag(FD->getLocation(), diag::warn_main_one_arg); 3757 } 3758} 3759 3760bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 3761 // FIXME: Need strict checking. In C89, we need to check for 3762 // any assignment, increment, decrement, function-calls, or 3763 // commas outside of a sizeof. In C99, it's the same list, 3764 // except that the aforementioned are allowed in unevaluated 3765 // expressions. Everything else falls under the 3766 // "may accept other forms of constant expressions" exception. 3767 // (We never end up here for C++, so the constant expression 3768 // rules there don't matter.) 3769 if (Init->isConstantInitializer(Context)) 3770 return false; 3771 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 3772 << Init->getSourceRange(); 3773 return true; 3774} 3775 3776void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init) { 3777 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 3778} 3779 3780/// AddInitializerToDecl - Adds the initializer Init to the 3781/// declaration dcl. If DirectInit is true, this is C++ direct 3782/// initialization rather than copy initialization. 3783void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 3784 Decl *RealDecl = dcl.getAs<Decl>(); 3785 // If there is no declaration, there was an error parsing it. Just ignore 3786 // the initializer. 3787 if (RealDecl == 0) 3788 return; 3789 3790 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 3791 // With declarators parsed the way they are, the parser cannot 3792 // distinguish between a normal initializer and a pure-specifier. 3793 // Thus this grotesque test. 3794 IntegerLiteral *IL; 3795 Expr *Init = static_cast<Expr *>(init.get()); 3796 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 3797 Context.getCanonicalType(IL->getType()) == Context.IntTy) 3798 CheckPureMethod(Method, Init->getSourceRange()); 3799 else { 3800 Diag(Method->getLocation(), diag::err_member_function_initialization) 3801 << Method->getDeclName() << Init->getSourceRange(); 3802 Method->setInvalidDecl(); 3803 } 3804 return; 3805 } 3806 3807 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 3808 if (!VDecl) { 3809 if (getLangOptions().CPlusPlus && 3810 RealDecl->getLexicalDeclContext()->isRecord() && 3811 isa<NamedDecl>(RealDecl)) 3812 Diag(RealDecl->getLocation(), diag::err_member_initialization) 3813 << cast<NamedDecl>(RealDecl)->getDeclName(); 3814 else 3815 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 3816 RealDecl->setInvalidDecl(); 3817 return; 3818 } 3819 3820 // A definition must end up with a complete type, which means it must be 3821 // complete with the restriction that an array type might be completed by the 3822 // initializer; note that later code assumes this restriction. 3823 QualType BaseDeclType = VDecl->getType(); 3824 if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType)) 3825 BaseDeclType = Array->getElementType(); 3826 if (RequireCompleteType(VDecl->getLocation(), BaseDeclType, 3827 diag::err_typecheck_decl_incomplete_type)) { 3828 RealDecl->setInvalidDecl(); 3829 return; 3830 } 3831 3832 // The variable can not have an abstract class type. 3833 if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(), 3834 diag::err_abstract_type_in_decl, 3835 AbstractVariableType)) 3836 VDecl->setInvalidDecl(); 3837 3838 const VarDecl *Def = 0; 3839 if (VDecl->getDefinition(Def)) { 3840 Diag(VDecl->getLocation(), diag::err_redefinition) 3841 << VDecl->getDeclName(); 3842 Diag(Def->getLocation(), diag::note_previous_definition); 3843 VDecl->setInvalidDecl(); 3844 return; 3845 } 3846 3847 // Take ownership of the expression, now that we're sure we have somewhere 3848 // to put it. 3849 Expr *Init = init.takeAs<Expr>(); 3850 assert(Init && "missing initializer"); 3851 3852 // Capture the variable that is being initialized and the style of 3853 // initialization. 3854 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl); 3855 3856 // FIXME: Poor source location information. 3857 InitializationKind Kind 3858 = DirectInit? InitializationKind::CreateDirect(VDecl->getLocation(), 3859 Init->getLocStart(), 3860 Init->getLocEnd()) 3861 : InitializationKind::CreateCopy(VDecl->getLocation(), 3862 Init->getLocStart()); 3863 3864 // Get the decls type and save a reference for later, since 3865 // CheckInitializerTypes may change it. 3866 QualType DclT = VDecl->getType(), SavT = DclT; 3867 if (VDecl->isBlockVarDecl()) { 3868 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 3869 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 3870 VDecl->setInvalidDecl(); 3871 } else if (!VDecl->isInvalidDecl()) { 3872 InitializationSequence InitSeq(*this, Entity, Kind, &Init, 1); 3873 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3874 MultiExprArg(*this, (void**)&Init, 1), 3875 &DclT); 3876 if (Result.isInvalid()) { 3877 VDecl->setInvalidDecl(); 3878 return; 3879 } 3880 3881 Init = Result.takeAs<Expr>(); 3882 3883 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3884 // Don't check invalid declarations to avoid emitting useless diagnostics. 3885 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3886 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 3887 CheckForConstantInitializer(Init, DclT); 3888 } 3889 } 3890 } else if (VDecl->isStaticDataMember() && 3891 VDecl->getLexicalDeclContext()->isRecord()) { 3892 // This is an in-class initialization for a static data member, e.g., 3893 // 3894 // struct S { 3895 // static const int value = 17; 3896 // }; 3897 3898 // Attach the initializer 3899 VDecl->setInit(Context, Init); 3900 3901 // C++ [class.mem]p4: 3902 // A member-declarator can contain a constant-initializer only 3903 // if it declares a static member (9.4) of const integral or 3904 // const enumeration type, see 9.4.2. 3905 QualType T = VDecl->getType(); 3906 if (!T->isDependentType() && 3907 (!Context.getCanonicalType(T).isConstQualified() || 3908 !T->isIntegralType())) { 3909 Diag(VDecl->getLocation(), diag::err_member_initialization) 3910 << VDecl->getDeclName() << Init->getSourceRange(); 3911 VDecl->setInvalidDecl(); 3912 } else { 3913 // C++ [class.static.data]p4: 3914 // If a static data member is of const integral or const 3915 // enumeration type, its declaration in the class definition 3916 // can specify a constant-initializer which shall be an 3917 // integral constant expression (5.19). 3918 if (!Init->isTypeDependent() && 3919 !Init->getType()->isIntegralType()) { 3920 // We have a non-dependent, non-integral or enumeration type. 3921 Diag(Init->getSourceRange().getBegin(), 3922 diag::err_in_class_initializer_non_integral_type) 3923 << Init->getType() << Init->getSourceRange(); 3924 VDecl->setInvalidDecl(); 3925 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 3926 // Check whether the expression is a constant expression. 3927 llvm::APSInt Value; 3928 SourceLocation Loc; 3929 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 3930 Diag(Loc, diag::err_in_class_initializer_non_constant) 3931 << Init->getSourceRange(); 3932 VDecl->setInvalidDecl(); 3933 } else if (!VDecl->getType()->isDependentType()) 3934 ImpCastExprToType(Init, VDecl->getType(), CastExpr::CK_IntegralCast); 3935 } 3936 } 3937 } else if (VDecl->isFileVarDecl()) { 3938 if (VDecl->getStorageClass() == VarDecl::Extern) 3939 Diag(VDecl->getLocation(), diag::warn_extern_init); 3940 if (!VDecl->isInvalidDecl()) { 3941 InitializationSequence InitSeq(*this, Entity, Kind, &Init, 1); 3942 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3943 MultiExprArg(*this, (void**)&Init, 1), 3944 &DclT); 3945 if (Result.isInvalid()) { 3946 VDecl->setInvalidDecl(); 3947 return; 3948 } 3949 3950 Init = Result.takeAs<Expr>(); 3951 } 3952 3953 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3954 // Don't check invalid declarations to avoid emitting useless diagnostics. 3955 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3956 // C99 6.7.8p4. All file scoped initializers need to be constant. 3957 CheckForConstantInitializer(Init, DclT); 3958 } 3959 } 3960 // If the type changed, it means we had an incomplete type that was 3961 // completed by the initializer. For example: 3962 // int ary[] = { 1, 3, 5 }; 3963 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 3964 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 3965 VDecl->setType(DclT); 3966 Init->setType(DclT); 3967 } 3968 3969 Init = MaybeCreateCXXExprWithTemporaries(Init); 3970 // Attach the initializer to the decl. 3971 VDecl->setInit(Context, Init); 3972 3973 // If the previous declaration of VDecl was a tentative definition, 3974 // remove it from the set of tentative definitions. 3975 if (VDecl->getPreviousDeclaration() && 3976 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 3977 bool Deleted = TentativeDefinitions.erase(VDecl->getDeclName()); 3978 assert(Deleted && "Unrecorded tentative definition?"); Deleted=Deleted; 3979 } 3980 3981 if (getLangOptions().CPlusPlus) { 3982 // Make sure we mark the destructor as used if necessary. 3983 QualType InitType = VDecl->getType(); 3984 while (const ArrayType *Array = Context.getAsArrayType(InitType)) 3985 InitType = Context.getBaseElementType(Array); 3986 if (InitType->isRecordType()) 3987 FinalizeVarWithDestructor(VDecl, InitType); 3988 } 3989 3990 return; 3991} 3992 3993void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 3994 bool TypeContainsUndeducedAuto) { 3995 Decl *RealDecl = dcl.getAs<Decl>(); 3996 3997 // If there is no declaration, there was an error parsing it. Just ignore it. 3998 if (RealDecl == 0) 3999 return; 4000 4001 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 4002 QualType Type = Var->getType(); 4003 4004 // Record tentative definitions. 4005 if (Var->isTentativeDefinition(Context)) { 4006 std::pair<llvm::DenseMap<DeclarationName, VarDecl *>::iterator, bool> 4007 InsertPair = 4008 TentativeDefinitions.insert(std::make_pair(Var->getDeclName(), Var)); 4009 4010 // Keep the latest definition in the map. If we see 'int i; int i;' we 4011 // want the second one in the map. 4012 InsertPair.first->second = Var; 4013 4014 // However, for the list, we don't care about the order, just make sure 4015 // that there are no dupes for a given declaration name. 4016 if (InsertPair.second) 4017 TentativeDefinitionList.push_back(Var->getDeclName()); 4018 } 4019 4020 // C++ [dcl.init.ref]p3: 4021 // The initializer can be omitted for a reference only in a 4022 // parameter declaration (8.3.5), in the declaration of a 4023 // function return type, in the declaration of a class member 4024 // within its class declaration (9.2), and where the extern 4025 // specifier is explicitly used. 4026 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 4027 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 4028 << Var->getDeclName() 4029 << SourceRange(Var->getLocation(), Var->getLocation()); 4030 Var->setInvalidDecl(); 4031 return; 4032 } 4033 4034 // C++0x [dcl.spec.auto]p3 4035 if (TypeContainsUndeducedAuto) { 4036 Diag(Var->getLocation(), diag::err_auto_var_requires_init) 4037 << Var->getDeclName() << Type; 4038 Var->setInvalidDecl(); 4039 return; 4040 } 4041 4042 // An array without size is an incomplete type, and there are no special 4043 // rules in C++ to make such a definition acceptable. 4044 if (getLangOptions().CPlusPlus && Type->isIncompleteArrayType() && 4045 !Var->hasExternalStorage()) { 4046 Diag(Var->getLocation(), 4047 diag::err_typecheck_incomplete_array_needs_initializer); 4048 Var->setInvalidDecl(); 4049 return; 4050 } 4051 4052 // C++ [temp.expl.spec]p15: 4053 // An explicit specialization of a static data member of a template is a 4054 // definition if the declaration includes an initializer; otherwise, it 4055 // is a declaration. 4056 if (Var->isStaticDataMember() && 4057 Var->getInstantiatedFromStaticDataMember() && 4058 Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) 4059 return; 4060 4061 // C++ [dcl.init]p9: 4062 // If no initializer is specified for an object, and the object 4063 // is of (possibly cv-qualified) non-POD class type (or array 4064 // thereof), the object shall be default-initialized; if the 4065 // object is of const-qualified type, the underlying class type 4066 // shall have a user-declared default constructor. 4067 // 4068 // FIXME: Diagnose the "user-declared default constructor" bit. 4069 if (getLangOptions().CPlusPlus) { 4070 QualType InitType = Type; 4071 if (const ArrayType *Array = Context.getAsArrayType(Type)) 4072 InitType = Context.getBaseElementType(Array); 4073 if ((!Var->hasExternalStorage() && !Var->isExternC()) && 4074 InitType->isRecordType() && !InitType->isDependentType()) { 4075 if (!RequireCompleteType(Var->getLocation(), InitType, 4076 diag::err_invalid_incomplete_type_use)) { 4077 InitializedEntity Entity 4078 = InitializedEntity::InitializeVariable(Var); 4079 InitializationKind Kind 4080 = InitializationKind::CreateDefault(Var->getLocation()); 4081 4082 InitializationSequence InitSeq(*this, Entity, Kind, 0, 0); 4083 OwningExprResult Init = InitSeq.Perform(*this, Entity, Kind, 4084 MultiExprArg(*this, 0, 0)); 4085 if (Init.isInvalid()) 4086 Var->setInvalidDecl(); 4087 else { 4088 Var->setInit(Context, 4089 MaybeCreateCXXExprWithTemporaries(Init.takeAs<Expr>())); 4090 FinalizeVarWithDestructor(Var, InitType); 4091 } 4092 } else { 4093 Var->setInvalidDecl(); 4094 } 4095 } 4096 4097 // The variable can not have an abstract class type. 4098 if (RequireNonAbstractType(Var->getLocation(), Type, 4099 diag::err_abstract_type_in_decl, 4100 AbstractVariableType)) 4101 Var->setInvalidDecl(); 4102 } 4103 4104#if 0 4105 // FIXME: Temporarily disabled because we are not properly parsing 4106 // linkage specifications on declarations, e.g., 4107 // 4108 // extern "C" const CGPoint CGPointerZero; 4109 // 4110 // C++ [dcl.init]p9: 4111 // 4112 // If no initializer is specified for an object, and the 4113 // object is of (possibly cv-qualified) non-POD class type (or 4114 // array thereof), the object shall be default-initialized; if 4115 // the object is of const-qualified type, the underlying class 4116 // type shall have a user-declared default 4117 // constructor. Otherwise, if no initializer is specified for 4118 // an object, the object and its subobjects, if any, have an 4119 // indeterminate initial value; if the object or any of its 4120 // subobjects are of const-qualified type, the program is 4121 // ill-formed. 4122 // 4123 // This isn't technically an error in C, so we don't diagnose it. 4124 // 4125 // FIXME: Actually perform the POD/user-defined default 4126 // constructor check. 4127 if (getLangOptions().CPlusPlus && 4128 Context.getCanonicalType(Type).isConstQualified() && 4129 !Var->hasExternalStorage()) 4130 Diag(Var->getLocation(), diag::err_const_var_requires_init) 4131 << Var->getName() 4132 << SourceRange(Var->getLocation(), Var->getLocation()); 4133#endif 4134 } 4135} 4136 4137Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 4138 DeclPtrTy *Group, 4139 unsigned NumDecls) { 4140 llvm::SmallVector<Decl*, 8> Decls; 4141 4142 if (DS.isTypeSpecOwned()) 4143 Decls.push_back((Decl*)DS.getTypeRep()); 4144 4145 for (unsigned i = 0; i != NumDecls; ++i) 4146 if (Decl *D = Group[i].getAs<Decl>()) 4147 Decls.push_back(D); 4148 4149 // Perform semantic analysis that depends on having fully processed both 4150 // the declarator and initializer. 4151 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 4152 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 4153 if (!IDecl) 4154 continue; 4155 QualType T = IDecl->getType(); 4156 4157 // Block scope. C99 6.7p7: If an identifier for an object is declared with 4158 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 4159 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 4160 if (T->isDependentType()) { 4161 // If T is dependent, we should not require a complete type. 4162 // (RequireCompleteType shouldn't be called with dependent types.) 4163 // But we still can at least check if we've got an array of unspecified 4164 // size without an initializer. 4165 if (!IDecl->isInvalidDecl() && T->isIncompleteArrayType() && 4166 !IDecl->getInit()) { 4167 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type) 4168 << T; 4169 IDecl->setInvalidDecl(); 4170 } 4171 } else if (!IDecl->isInvalidDecl()) { 4172 // If T is an incomplete array type with an initializer list that is 4173 // dependent on something, its size has not been fixed. We could attempt 4174 // to fix the size for such arrays, but we would still have to check 4175 // here for initializers containing a C++0x vararg expansion, e.g. 4176 // template <typename... Args> void f(Args... args) { 4177 // int vals[] = { args }; 4178 // } 4179 const IncompleteArrayType *IAT = Context.getAsIncompleteArrayType(T); 4180 Expr *Init = IDecl->getInit(); 4181 if (IAT && Init && 4182 (Init->isTypeDependent() || Init->isValueDependent())) { 4183 // Check that the member type of the array is complete, at least. 4184 if (RequireCompleteType(IDecl->getLocation(), IAT->getElementType(), 4185 diag::err_typecheck_decl_incomplete_type)) 4186 IDecl->setInvalidDecl(); 4187 } else if (RequireCompleteType(IDecl->getLocation(), T, 4188 diag::err_typecheck_decl_incomplete_type)) 4189 IDecl->setInvalidDecl(); 4190 } 4191 } 4192 // File scope. C99 6.9.2p2: A declaration of an identifier for an 4193 // object that has file scope without an initializer, and without a 4194 // storage-class specifier or with the storage-class specifier "static", 4195 // constitutes a tentative definition. Note: A tentative definition with 4196 // external linkage is valid (C99 6.2.2p5). 4197 if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) { 4198 if (const IncompleteArrayType *ArrayT 4199 = Context.getAsIncompleteArrayType(T)) { 4200 if (RequireCompleteType(IDecl->getLocation(), 4201 ArrayT->getElementType(), 4202 diag::err_illegal_decl_array_incomplete_type)) 4203 IDecl->setInvalidDecl(); 4204 } else if (IDecl->getStorageClass() == VarDecl::Static) { 4205 // C99 6.9.2p3: If the declaration of an identifier for an object is 4206 // a tentative definition and has internal linkage (C99 6.2.2p3), the 4207 // declared type shall not be an incomplete type. 4208 // NOTE: code such as the following 4209 // static struct s; 4210 // struct s { int a; }; 4211 // is accepted by gcc. Hence here we issue a warning instead of 4212 // an error and we do not invalidate the static declaration. 4213 // NOTE: to avoid multiple warnings, only check the first declaration. 4214 if (IDecl->getPreviousDeclaration() == 0) 4215 RequireCompleteType(IDecl->getLocation(), T, 4216 diag::ext_typecheck_decl_incomplete_type); 4217 } 4218 } 4219 } 4220 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 4221 Decls.data(), Decls.size())); 4222} 4223 4224 4225/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 4226/// to introduce parameters into function prototype scope. 4227Sema::DeclPtrTy 4228Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 4229 const DeclSpec &DS = D.getDeclSpec(); 4230 4231 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 4232 VarDecl::StorageClass StorageClass = VarDecl::None; 4233 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 4234 StorageClass = VarDecl::Register; 4235 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 4236 Diag(DS.getStorageClassSpecLoc(), 4237 diag::err_invalid_storage_class_in_func_decl); 4238 D.getMutableDeclSpec().ClearStorageClassSpecs(); 4239 } 4240 4241 if (D.getDeclSpec().isThreadSpecified()) 4242 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 4243 4244 DiagnoseFunctionSpecifiers(D); 4245 4246 // Check that there are no default arguments inside the type of this 4247 // parameter (C++ only). 4248 if (getLangOptions().CPlusPlus) 4249 CheckExtraCXXDefaultArguments(D); 4250 4251 TypeSourceInfo *TInfo = 0; 4252 TagDecl *OwnedDecl = 0; 4253 QualType parmDeclType = GetTypeForDeclarator(D, S, &TInfo, &OwnedDecl); 4254 4255 if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) { 4256 // C++ [dcl.fct]p6: 4257 // Types shall not be defined in return or parameter types. 4258 Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type) 4259 << Context.getTypeDeclType(OwnedDecl); 4260 } 4261 4262 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 4263 // Can this happen for params? We already checked that they don't conflict 4264 // among each other. Here they can only shadow globals, which is ok. 4265 IdentifierInfo *II = D.getIdentifier(); 4266 if (II) { 4267 if (NamedDecl *PrevDecl = LookupSingleName(S, II, LookupOrdinaryName)) { 4268 if (PrevDecl->isTemplateParameter()) { 4269 // Maybe we will complain about the shadowed template parameter. 4270 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 4271 // Just pretend that we didn't see the previous declaration. 4272 PrevDecl = 0; 4273 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 4274 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 4275 4276 // Recover by removing the name 4277 II = 0; 4278 D.SetIdentifier(0, D.getIdentifierLoc()); 4279 } 4280 } 4281 } 4282 4283 // Parameters can not be abstract class types. 4284 // For record types, this is done by the AbstractClassUsageDiagnoser once 4285 // the class has been completely parsed. 4286 if (!CurContext->isRecord() && 4287 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 4288 diag::err_abstract_type_in_decl, 4289 AbstractParamType)) 4290 D.setInvalidType(true); 4291 4292 QualType T = adjustParameterType(parmDeclType); 4293 4294 ParmVarDecl *New 4295 = ParmVarDecl::Create(Context, CurContext, D.getIdentifierLoc(), II, 4296 T, TInfo, StorageClass, 0); 4297 4298 if (D.isInvalidType()) 4299 New->setInvalidDecl(); 4300 4301 // Parameter declarators cannot be interface types. All ObjC objects are 4302 // passed by reference. 4303 if (T->isObjCInterfaceType()) { 4304 Diag(D.getIdentifierLoc(), 4305 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 4306 New->setInvalidDecl(); 4307 } 4308 4309 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 4310 if (D.getCXXScopeSpec().isSet()) { 4311 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 4312 << D.getCXXScopeSpec().getRange(); 4313 New->setInvalidDecl(); 4314 } 4315 4316 // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage 4317 // duration shall not be qualified by an address-space qualifier." 4318 // Since all parameters have automatic store duration, they can not have 4319 // an address space. 4320 if (T.getAddressSpace() != 0) { 4321 Diag(D.getIdentifierLoc(), 4322 diag::err_arg_with_address_space); 4323 New->setInvalidDecl(); 4324 } 4325 4326 4327 // Add the parameter declaration into this scope. 4328 S->AddDecl(DeclPtrTy::make(New)); 4329 if (II) 4330 IdResolver.AddDecl(New); 4331 4332 ProcessDeclAttributes(S, New, D); 4333 4334 if (New->hasAttr<BlocksAttr>()) { 4335 Diag(New->getLocation(), diag::err_block_on_nonlocal); 4336 } 4337 return DeclPtrTy::make(New); 4338} 4339 4340void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 4341 SourceLocation LocAfterDecls) { 4342 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 4343 "Not a function declarator!"); 4344 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 4345 4346 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 4347 // for a K&R function. 4348 if (!FTI.hasPrototype) { 4349 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 4350 --i; 4351 if (FTI.ArgInfo[i].Param == 0) { 4352 llvm::SmallString<256> Code; 4353 llvm::raw_svector_ostream(Code) << " int " 4354 << FTI.ArgInfo[i].Ident->getName() 4355 << ";\n"; 4356 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 4357 << FTI.ArgInfo[i].Ident 4358 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code.str()); 4359 4360 // Implicitly declare the argument as type 'int' for lack of a better 4361 // type. 4362 DeclSpec DS; 4363 const char* PrevSpec; // unused 4364 unsigned DiagID; // unused 4365 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 4366 PrevSpec, DiagID); 4367 Declarator ParamD(DS, Declarator::KNRTypeListContext); 4368 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 4369 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 4370 } 4371 } 4372 } 4373} 4374 4375Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 4376 Declarator &D) { 4377 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 4378 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 4379 "Not a function declarator!"); 4380 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 4381 4382 if (FTI.hasPrototype) { 4383 // FIXME: Diagnose arguments without names in C. 4384 } 4385 4386 Scope *ParentScope = FnBodyScope->getParent(); 4387 4388 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 4389 MultiTemplateParamsArg(*this), 4390 /*IsFunctionDefinition=*/true); 4391 return ActOnStartOfFunctionDef(FnBodyScope, DP); 4392} 4393 4394static bool ShouldWarnAboutMissingPrototype(const FunctionDecl *FD) { 4395 // Don't warn about invalid declarations. 4396 if (FD->isInvalidDecl()) 4397 return false; 4398 4399 // Or declarations that aren't global. 4400 if (!FD->isGlobal()) 4401 return false; 4402 4403 // Don't warn about C++ member functions. 4404 if (isa<CXXMethodDecl>(FD)) 4405 return false; 4406 4407 // Don't warn about 'main'. 4408 if (FD->isMain()) 4409 return false; 4410 4411 // Don't warn about inline functions. 4412 if (FD->isInlineSpecified()) 4413 return false; 4414 4415 // Don't warn about function templates. 4416 if (FD->getDescribedFunctionTemplate()) 4417 return false; 4418 4419 // Don't warn about function template specializations. 4420 if (FD->isFunctionTemplateSpecialization()) 4421 return false; 4422 4423 bool MissingPrototype = true; 4424 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 4425 Prev; Prev = Prev->getPreviousDeclaration()) { 4426 // Ignore any declarations that occur in function or method 4427 // scope, because they aren't visible from the header. 4428 if (Prev->getDeclContext()->isFunctionOrMethod()) 4429 continue; 4430 4431 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 4432 break; 4433 } 4434 4435 return MissingPrototype; 4436} 4437 4438Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 4439 // Clear the last template instantiation error context. 4440 LastTemplateInstantiationErrorContext = ActiveTemplateInstantiation(); 4441 4442 if (!D) 4443 return D; 4444 FunctionDecl *FD = 0; 4445 4446 if (FunctionTemplateDecl *FunTmpl 4447 = dyn_cast<FunctionTemplateDecl>(D.getAs<Decl>())) 4448 FD = FunTmpl->getTemplatedDecl(); 4449 else 4450 FD = cast<FunctionDecl>(D.getAs<Decl>()); 4451 4452 CurFunctionNeedsScopeChecking = false; 4453 4454 // See if this is a redefinition. 4455 const FunctionDecl *Definition; 4456 if (FD->getBody(Definition)) { 4457 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 4458 Diag(Definition->getLocation(), diag::note_previous_definition); 4459 } 4460 4461 // Builtin functions cannot be defined. 4462 if (unsigned BuiltinID = FD->getBuiltinID()) { 4463 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 4464 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 4465 FD->setInvalidDecl(); 4466 } 4467 } 4468 4469 // The return type of a function definition must be complete 4470 // (C99 6.9.1p3, C++ [dcl.fct]p6). 4471 QualType ResultType = FD->getResultType(); 4472 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 4473 !FD->isInvalidDecl() && 4474 RequireCompleteType(FD->getLocation(), ResultType, 4475 diag::err_func_def_incomplete_result)) 4476 FD->setInvalidDecl(); 4477 4478 // GNU warning -Wmissing-prototypes: 4479 // Warn if a global function is defined without a previous 4480 // prototype declaration. This warning is issued even if the 4481 // definition itself provides a prototype. The aim is to detect 4482 // global functions that fail to be declared in header files. 4483 if (ShouldWarnAboutMissingPrototype(FD)) 4484 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 4485 4486 if (FnBodyScope) 4487 PushDeclContext(FnBodyScope, FD); 4488 4489 // Check the validity of our function parameters 4490 CheckParmsForFunctionDef(FD); 4491 4492 // Introduce our parameters into the function scope 4493 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 4494 ParmVarDecl *Param = FD->getParamDecl(p); 4495 Param->setOwningFunction(FD); 4496 4497 // If this has an identifier, add it to the scope stack. 4498 if (Param->getIdentifier() && FnBodyScope) 4499 PushOnScopeChains(Param, FnBodyScope); 4500 } 4501 4502 // Checking attributes of current function definition 4503 // dllimport attribute. 4504 if (FD->getAttr<DLLImportAttr>() && 4505 (!FD->getAttr<DLLExportAttr>())) { 4506 // dllimport attribute cannot be applied to definition. 4507 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 4508 Diag(FD->getLocation(), 4509 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 4510 << "dllimport"; 4511 FD->setInvalidDecl(); 4512 return DeclPtrTy::make(FD); 4513 } else { 4514 // If a symbol previously declared dllimport is later defined, the 4515 // attribute is ignored in subsequent references, and a warning is 4516 // emitted. 4517 Diag(FD->getLocation(), 4518 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 4519 << FD->getNameAsCString() << "dllimport"; 4520 } 4521 } 4522 return DeclPtrTy::make(FD); 4523} 4524 4525Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 4526 return ActOnFinishFunctionBody(D, move(BodyArg), false); 4527} 4528 4529Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 4530 bool IsInstantiation) { 4531 Decl *dcl = D.getAs<Decl>(); 4532 Stmt *Body = BodyArg.takeAs<Stmt>(); 4533 4534 AnalysisContext AC(dcl); 4535 FunctionDecl *FD = 0; 4536 FunctionTemplateDecl *FunTmpl = dyn_cast_or_null<FunctionTemplateDecl>(dcl); 4537 if (FunTmpl) 4538 FD = FunTmpl->getTemplatedDecl(); 4539 else 4540 FD = dyn_cast_or_null<FunctionDecl>(dcl); 4541 4542 if (FD) { 4543 FD->setBody(Body); 4544 if (FD->isMain()) 4545 // C and C++ allow for main to automagically return 0. 4546 // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3. 4547 FD->setHasImplicitReturnZero(true); 4548 else 4549 CheckFallThroughForFunctionDef(FD, Body, AC); 4550 4551 if (!FD->isInvalidDecl()) 4552 DiagnoseUnusedParameters(FD->param_begin(), FD->param_end()); 4553 4554 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 4555 MaybeMarkVirtualMembersReferenced(Method->getLocation(), Method); 4556 4557 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 4558 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 4559 assert(MD == getCurMethodDecl() && "Method parsing confused"); 4560 MD->setBody(Body); 4561 CheckFallThroughForFunctionDef(MD, Body, AC); 4562 MD->setEndLoc(Body->getLocEnd()); 4563 4564 if (!MD->isInvalidDecl()) 4565 DiagnoseUnusedParameters(MD->param_begin(), MD->param_end()); 4566 } else { 4567 Body->Destroy(Context); 4568 return DeclPtrTy(); 4569 } 4570 if (!IsInstantiation) 4571 PopDeclContext(); 4572 4573 // Verify and clean out per-function state. 4574 4575 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 4576 4577 // Check goto/label use. 4578 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 4579 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 4580 LabelStmt *L = I->second; 4581 4582 // Verify that we have no forward references left. If so, there was a goto 4583 // or address of a label taken, but no definition of it. Label fwd 4584 // definitions are indicated with a null substmt. 4585 if (L->getSubStmt() != 0) 4586 continue; 4587 4588 // Emit error. 4589 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 4590 4591 // At this point, we have gotos that use the bogus label. Stitch it into 4592 // the function body so that they aren't leaked and that the AST is well 4593 // formed. 4594 if (Body == 0) { 4595 // The whole function wasn't parsed correctly, just delete this. 4596 L->Destroy(Context); 4597 continue; 4598 } 4599 4600 // Otherwise, the body is valid: we want to stitch the label decl into the 4601 // function somewhere so that it is properly owned and so that the goto 4602 // has a valid target. Do this by creating a new compound stmt with the 4603 // label in it. 4604 4605 // Give the label a sub-statement. 4606 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 4607 4608 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 4609 cast<CXXTryStmt>(Body)->getTryBlock() : 4610 cast<CompoundStmt>(Body); 4611 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 4612 Elements.push_back(L); 4613 Compound->setStmts(Context, &Elements[0], Elements.size()); 4614 } 4615 FunctionLabelMap.clear(); 4616 4617 if (!Body) return D; 4618 4619 CheckUnreachable(AC); 4620 4621 // Verify that that gotos and switch cases don't jump into scopes illegally. 4622 if (CurFunctionNeedsScopeChecking) 4623 DiagnoseInvalidJumps(Body); 4624 4625 // C++ constructors that have function-try-blocks can't have return 4626 // statements in the handlers of that block. (C++ [except.handle]p14) 4627 // Verify this. 4628 if (FD && isa<CXXConstructorDecl>(FD) && isa<CXXTryStmt>(Body)) 4629 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 4630 4631 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) 4632 MarkBaseAndMemberDestructorsReferenced(Destructor); 4633 4634 // If any errors have occurred, clear out any temporaries that may have 4635 // been leftover. This ensures that these temporaries won't be picked up for 4636 // deletion in some later function. 4637 if (PP.getDiagnostics().hasErrorOccurred()) 4638 ExprTemporaries.clear(); 4639 4640 assert(ExprTemporaries.empty() && "Leftover temporaries in function"); 4641 return D; 4642} 4643 4644/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 4645/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 4646NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 4647 IdentifierInfo &II, Scope *S) { 4648 // Before we produce a declaration for an implicitly defined 4649 // function, see whether there was a locally-scoped declaration of 4650 // this name as a function or variable. If so, use that 4651 // (non-visible) declaration, and complain about it. 4652 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 4653 = LocallyScopedExternalDecls.find(&II); 4654 if (Pos != LocallyScopedExternalDecls.end()) { 4655 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 4656 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 4657 return Pos->second; 4658 } 4659 4660 // Extension in C99. Legal in C90, but warn about it. 4661 if (II.getName().startswith("__builtin_")) 4662 Diag(Loc, diag::warn_builtin_unknown) << &II; 4663 else if (getLangOptions().C99) 4664 Diag(Loc, diag::ext_implicit_function_decl) << &II; 4665 else 4666 Diag(Loc, diag::warn_implicit_function_decl) << &II; 4667 4668 // Set a Declarator for the implicit definition: int foo(); 4669 const char *Dummy; 4670 DeclSpec DS; 4671 unsigned DiagID; 4672 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID); 4673 Error = Error; // Silence warning. 4674 assert(!Error && "Error setting up implicit decl!"); 4675 Declarator D(DS, Declarator::BlockContext); 4676 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 4677 0, 0, false, SourceLocation(), 4678 false, 0,0,0, Loc, Loc, D), 4679 SourceLocation()); 4680 D.SetIdentifier(&II, Loc); 4681 4682 // Insert this function into translation-unit scope. 4683 4684 DeclContext *PrevDC = CurContext; 4685 CurContext = Context.getTranslationUnitDecl(); 4686 4687 FunctionDecl *FD = 4688 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D).getAs<Decl>()); 4689 FD->setImplicit(); 4690 4691 CurContext = PrevDC; 4692 4693 AddKnownFunctionAttributes(FD); 4694 4695 return FD; 4696} 4697 4698/// \brief Adds any function attributes that we know a priori based on 4699/// the declaration of this function. 4700/// 4701/// These attributes can apply both to implicitly-declared builtins 4702/// (like __builtin___printf_chk) or to library-declared functions 4703/// like NSLog or printf. 4704void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 4705 if (FD->isInvalidDecl()) 4706 return; 4707 4708 // If this is a built-in function, map its builtin attributes to 4709 // actual attributes. 4710 if (unsigned BuiltinID = FD->getBuiltinID()) { 4711 // Handle printf-formatting attributes. 4712 unsigned FormatIdx; 4713 bool HasVAListArg; 4714 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 4715 if (!FD->getAttr<FormatAttr>()) 4716 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 4717 HasVAListArg ? 0 : FormatIdx + 2)); 4718 } 4719 4720 // Mark const if we don't care about errno and that is the only 4721 // thing preventing the function from being const. This allows 4722 // IRgen to use LLVM intrinsics for such functions. 4723 if (!getLangOptions().MathErrno && 4724 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 4725 if (!FD->getAttr<ConstAttr>()) 4726 FD->addAttr(::new (Context) ConstAttr()); 4727 } 4728 4729 if (Context.BuiltinInfo.isNoReturn(BuiltinID)) 4730 FD->addAttr(::new (Context) NoReturnAttr()); 4731 if (Context.BuiltinInfo.isNoThrow(BuiltinID)) 4732 FD->addAttr(::new (Context) NoThrowAttr()); 4733 if (Context.BuiltinInfo.isConst(BuiltinID)) 4734 FD->addAttr(::new (Context) ConstAttr()); 4735 } 4736 4737 IdentifierInfo *Name = FD->getIdentifier(); 4738 if (!Name) 4739 return; 4740 if ((!getLangOptions().CPlusPlus && 4741 FD->getDeclContext()->isTranslationUnit()) || 4742 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 4743 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 4744 LinkageSpecDecl::lang_c)) { 4745 // Okay: this could be a libc/libm/Objective-C function we know 4746 // about. 4747 } else 4748 return; 4749 4750 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 4751 // FIXME: NSLog and NSLogv should be target specific 4752 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 4753 // FIXME: We known better than our headers. 4754 const_cast<FormatAttr *>(Format)->setType("printf"); 4755 } else 4756 FD->addAttr(::new (Context) FormatAttr("printf", 1, 4757 Name->isStr("NSLogv") ? 0 : 2)); 4758 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 4759 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 4760 // target-specific builtins, perhaps? 4761 if (!FD->getAttr<FormatAttr>()) 4762 FD->addAttr(::new (Context) FormatAttr("printf", 2, 4763 Name->isStr("vasprintf") ? 0 : 3)); 4764 } 4765} 4766 4767TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 4768 TypeSourceInfo *TInfo) { 4769 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 4770 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 4771 4772 if (!TInfo) { 4773 assert(D.isInvalidType() && "no declarator info for valid type"); 4774 TInfo = Context.getTrivialTypeSourceInfo(T); 4775 } 4776 4777 // Scope manipulation handled by caller. 4778 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 4779 D.getIdentifierLoc(), 4780 D.getIdentifier(), 4781 TInfo); 4782 4783 if (const TagType *TT = T->getAs<TagType>()) { 4784 TagDecl *TD = TT->getDecl(); 4785 4786 // If the TagDecl that the TypedefDecl points to is an anonymous decl 4787 // keep track of the TypedefDecl. 4788 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 4789 TD->setTypedefForAnonDecl(NewTD); 4790 } 4791 4792 if (D.isInvalidType()) 4793 NewTD->setInvalidDecl(); 4794 return NewTD; 4795} 4796 4797 4798/// \brief Determine whether a tag with a given kind is acceptable 4799/// as a redeclaration of the given tag declaration. 4800/// 4801/// \returns true if the new tag kind is acceptable, false otherwise. 4802bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 4803 TagDecl::TagKind NewTag, 4804 SourceLocation NewTagLoc, 4805 const IdentifierInfo &Name) { 4806 // C++ [dcl.type.elab]p3: 4807 // The class-key or enum keyword present in the 4808 // elaborated-type-specifier shall agree in kind with the 4809 // declaration to which the name in theelaborated-type-specifier 4810 // refers. This rule also applies to the form of 4811 // elaborated-type-specifier that declares a class-name or 4812 // friend class since it can be construed as referring to the 4813 // definition of the class. Thus, in any 4814 // elaborated-type-specifier, the enum keyword shall be used to 4815 // refer to an enumeration (7.2), the union class-keyshall be 4816 // used to refer to a union (clause 9), and either the class or 4817 // struct class-key shall be used to refer to a class (clause 9) 4818 // declared using the class or struct class-key. 4819 TagDecl::TagKind OldTag = Previous->getTagKind(); 4820 if (OldTag == NewTag) 4821 return true; 4822 4823 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 4824 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 4825 // Warn about the struct/class tag mismatch. 4826 bool isTemplate = false; 4827 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 4828 isTemplate = Record->getDescribedClassTemplate(); 4829 4830 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 4831 << (NewTag == TagDecl::TK_class) 4832 << isTemplate << &Name 4833 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 4834 OldTag == TagDecl::TK_class? "class" : "struct"); 4835 Diag(Previous->getLocation(), diag::note_previous_use); 4836 return true; 4837 } 4838 return false; 4839} 4840 4841/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 4842/// former case, Name will be non-null. In the later case, Name will be null. 4843/// TagSpec indicates what kind of tag this is. TUK indicates whether this is a 4844/// reference/declaration/definition of a tag. 4845Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 4846 SourceLocation KWLoc, const CXXScopeSpec &SS, 4847 IdentifierInfo *Name, SourceLocation NameLoc, 4848 AttributeList *Attr, AccessSpecifier AS, 4849 MultiTemplateParamsArg TemplateParameterLists, 4850 bool &OwnedDecl, bool &IsDependent) { 4851 // If this is not a definition, it must have a name. 4852 assert((Name != 0 || TUK == TUK_Definition) && 4853 "Nameless record must be a definition!"); 4854 4855 OwnedDecl = false; 4856 TagDecl::TagKind Kind = TagDecl::getTagKindForTypeSpec(TagSpec); 4857 4858 // FIXME: Check explicit specializations more carefully. 4859 bool isExplicitSpecialization = false; 4860 if (TUK != TUK_Reference) { 4861 if (TemplateParameterList *TemplateParams 4862 = MatchTemplateParametersToScopeSpecifier(KWLoc, SS, 4863 (TemplateParameterList**)TemplateParameterLists.get(), 4864 TemplateParameterLists.size(), 4865 isExplicitSpecialization)) { 4866 if (TemplateParams->size() > 0) { 4867 // This is a declaration or definition of a class template (which may 4868 // be a member of another template). 4869 OwnedDecl = false; 4870 DeclResult Result = CheckClassTemplate(S, TagSpec, TUK, KWLoc, 4871 SS, Name, NameLoc, Attr, 4872 TemplateParams, 4873 AS); 4874 TemplateParameterLists.release(); 4875 return Result.get(); 4876 } else { 4877 // The "template<>" header is extraneous. 4878 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) 4879 << ElaboratedType::getNameForTagKind(Kind) << Name; 4880 isExplicitSpecialization = true; 4881 } 4882 } 4883 4884 TemplateParameterLists.release(); 4885 } 4886 4887 DeclContext *SearchDC = CurContext; 4888 DeclContext *DC = CurContext; 4889 bool isStdBadAlloc = false; 4890 bool Invalid = false; 4891 4892 RedeclarationKind Redecl = (TUK != TUK_Reference ? ForRedeclaration 4893 : NotForRedeclaration); 4894 4895 LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl); 4896 4897 if (Name && SS.isNotEmpty()) { 4898 // We have a nested-name tag ('struct foo::bar'). 4899 4900 // Check for invalid 'foo::'. 4901 if (SS.isInvalid()) { 4902 Name = 0; 4903 goto CreateNewDecl; 4904 } 4905 4906 // If this is a friend or a reference to a class in a dependent 4907 // context, don't try to make a decl for it. 4908 if (TUK == TUK_Friend || TUK == TUK_Reference) { 4909 DC = computeDeclContext(SS, false); 4910 if (!DC) { 4911 IsDependent = true; 4912 return DeclPtrTy(); 4913 } 4914 } 4915 4916 if (RequireCompleteDeclContext(SS)) 4917 return DeclPtrTy::make((Decl *)0); 4918 4919 DC = computeDeclContext(SS, true); 4920 SearchDC = DC; 4921 // Look-up name inside 'foo::'. 4922 LookupQualifiedName(Previous, DC); 4923 4924 if (Previous.isAmbiguous()) 4925 return DeclPtrTy(); 4926 4927 if (Previous.empty()) { 4928 // Name lookup did not find anything. However, if the 4929 // nested-name-specifier refers to the current instantiation, 4930 // and that current instantiation has any dependent base 4931 // classes, we might find something at instantiation time: treat 4932 // this as a dependent elaborated-type-specifier. 4933 if (Previous.wasNotFoundInCurrentInstantiation()) { 4934 IsDependent = true; 4935 return DeclPtrTy(); 4936 } 4937 4938 // A tag 'foo::bar' must already exist. 4939 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 4940 Name = 0; 4941 Invalid = true; 4942 goto CreateNewDecl; 4943 } 4944 } else if (Name) { 4945 // If this is a named struct, check to see if there was a previous forward 4946 // declaration or definition. 4947 // FIXME: We're looking into outer scopes here, even when we 4948 // shouldn't be. Doing so can result in ambiguities that we 4949 // shouldn't be diagnosing. 4950 LookupName(Previous, S); 4951 4952 // Note: there used to be some attempt at recovery here. 4953 if (Previous.isAmbiguous()) 4954 return DeclPtrTy(); 4955 4956 if (!getLangOptions().CPlusPlus && TUK != TUK_Reference) { 4957 // FIXME: This makes sure that we ignore the contexts associated 4958 // with C structs, unions, and enums when looking for a matching 4959 // tag declaration or definition. See the similar lookup tweak 4960 // in Sema::LookupName; is there a better way to deal with this? 4961 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 4962 SearchDC = SearchDC->getParent(); 4963 } 4964 } 4965 4966 if (Previous.isSingleResult() && 4967 Previous.getFoundDecl()->isTemplateParameter()) { 4968 // Maybe we will complain about the shadowed template parameter. 4969 DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl()); 4970 // Just pretend that we didn't see the previous declaration. 4971 Previous.clear(); 4972 } 4973 4974 if (getLangOptions().CPlusPlus && Name && DC && StdNamespace && 4975 DC->Equals(StdNamespace) && Name->isStr("bad_alloc")) { 4976 // This is a declaration of or a reference to "std::bad_alloc". 4977 isStdBadAlloc = true; 4978 4979 if (Previous.empty() && StdBadAlloc) { 4980 // std::bad_alloc has been implicitly declared (but made invisible to 4981 // name lookup). Fill in this implicit declaration as the previous 4982 // declaration, so that the declarations get chained appropriately. 4983 Previous.addDecl(StdBadAlloc); 4984 } 4985 } 4986 4987 if (!Previous.empty()) { 4988 assert(Previous.isSingleResult()); 4989 NamedDecl *PrevDecl = Previous.getFoundDecl(); 4990 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 4991 // If this is a use of a previous tag, or if the tag is already declared 4992 // in the same scope (so that the definition/declaration completes or 4993 // rementions the tag), reuse the decl. 4994 if (TUK == TUK_Reference || TUK == TUK_Friend || 4995 isDeclInScope(PrevDecl, SearchDC, S)) { 4996 // Make sure that this wasn't declared as an enum and now used as a 4997 // struct or something similar. 4998 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 4999 bool SafeToContinue 5000 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 5001 Kind != TagDecl::TK_enum); 5002 if (SafeToContinue) 5003 Diag(KWLoc, diag::err_use_with_wrong_tag) 5004 << Name 5005 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 5006 PrevTagDecl->getKindName()); 5007 else 5008 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 5009 Diag(PrevTagDecl->getLocation(), diag::note_previous_use); 5010 5011 if (SafeToContinue) 5012 Kind = PrevTagDecl->getTagKind(); 5013 else { 5014 // Recover by making this an anonymous redefinition. 5015 Name = 0; 5016 Previous.clear(); 5017 Invalid = true; 5018 } 5019 } 5020 5021 if (!Invalid) { 5022 // If this is a use, just return the declaration we found. 5023 5024 // FIXME: In the future, return a variant or some other clue 5025 // for the consumer of this Decl to know it doesn't own it. 5026 // For our current ASTs this shouldn't be a problem, but will 5027 // need to be changed with DeclGroups. 5028 if (TUK == TUK_Reference || TUK == TUK_Friend) 5029 return DeclPtrTy::make(PrevTagDecl); 5030 5031 // Diagnose attempts to redefine a tag. 5032 if (TUK == TUK_Definition) { 5033 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 5034 // If we're defining a specialization and the previous definition 5035 // is from an implicit instantiation, don't emit an error 5036 // here; we'll catch this in the general case below. 5037 if (!isExplicitSpecialization || 5038 !isa<CXXRecordDecl>(Def) || 5039 cast<CXXRecordDecl>(Def)->getTemplateSpecializationKind() 5040 == TSK_ExplicitSpecialization) { 5041 Diag(NameLoc, diag::err_redefinition) << Name; 5042 Diag(Def->getLocation(), diag::note_previous_definition); 5043 // If this is a redefinition, recover by making this 5044 // struct be anonymous, which will make any later 5045 // references get the previous definition. 5046 Name = 0; 5047 Previous.clear(); 5048 Invalid = true; 5049 } 5050 } else { 5051 // If the type is currently being defined, complain 5052 // about a nested redefinition. 5053 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 5054 if (Tag->isBeingDefined()) { 5055 Diag(NameLoc, diag::err_nested_redefinition) << Name; 5056 Diag(PrevTagDecl->getLocation(), 5057 diag::note_previous_definition); 5058 Name = 0; 5059 Previous.clear(); 5060 Invalid = true; 5061 } 5062 } 5063 5064 // Okay, this is definition of a previously declared or referenced 5065 // tag PrevDecl. We're going to create a new Decl for it. 5066 } 5067 } 5068 // If we get here we have (another) forward declaration or we 5069 // have a definition. Just create a new decl. 5070 5071 } else { 5072 // If we get here, this is a definition of a new tag type in a nested 5073 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 5074 // new decl/type. We set PrevDecl to NULL so that the entities 5075 // have distinct types. 5076 Previous.clear(); 5077 } 5078 // If we get here, we're going to create a new Decl. If PrevDecl 5079 // is non-NULL, it's a definition of the tag declared by 5080 // PrevDecl. If it's NULL, we have a new definition. 5081 } else { 5082 // PrevDecl is a namespace, template, or anything else 5083 // that lives in the IDNS_Tag identifier namespace. 5084 if (isDeclInScope(PrevDecl, SearchDC, S)) { 5085 // The tag name clashes with a namespace name, issue an error and 5086 // recover by making this tag be anonymous. 5087 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 5088 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 5089 Name = 0; 5090 Previous.clear(); 5091 Invalid = true; 5092 } else { 5093 // The existing declaration isn't relevant to us; we're in a 5094 // new scope, so clear out the previous declaration. 5095 Previous.clear(); 5096 } 5097 } 5098 } else if (TUK == TUK_Reference && SS.isEmpty() && Name) { 5099 // C++ [basic.scope.pdecl]p5: 5100 // -- for an elaborated-type-specifier of the form 5101 // 5102 // class-key identifier 5103 // 5104 // if the elaborated-type-specifier is used in the 5105 // decl-specifier-seq or parameter-declaration-clause of a 5106 // function defined in namespace scope, the identifier is 5107 // declared as a class-name in the namespace that contains 5108 // the declaration; otherwise, except as a friend 5109 // declaration, the identifier is declared in the smallest 5110 // non-class, non-function-prototype scope that contains the 5111 // declaration. 5112 // 5113 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 5114 // C structs and unions. 5115 // 5116 // It is an error in C++ to declare (rather than define) an enum 5117 // type, including via an elaborated type specifier. We'll 5118 // diagnose that later; for now, declare the enum in the same 5119 // scope as we would have picked for any other tag type. 5120 // 5121 // GNU C also supports this behavior as part of its incomplete 5122 // enum types extension, while GNU C++ does not. 5123 // 5124 // Find the context where we'll be declaring the tag. 5125 // FIXME: We would like to maintain the current DeclContext as the 5126 // lexical context, 5127 while (SearchDC->isRecord()) 5128 SearchDC = SearchDC->getParent(); 5129 5130 // Find the scope where we'll be declaring the tag. 5131 while (S->isClassScope() || 5132 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 5133 ((S->getFlags() & Scope::DeclScope) == 0) || 5134 (S->getEntity() && 5135 ((DeclContext *)S->getEntity())->isTransparentContext())) 5136 S = S->getParent(); 5137 5138 } else if (TUK == TUK_Friend && SS.isEmpty() && Name) { 5139 // C++ [namespace.memdef]p3: 5140 // If a friend declaration in a non-local class first declares a 5141 // class or function, the friend class or function is a member of 5142 // the innermost enclosing namespace. 5143 while (!SearchDC->isFileContext()) 5144 SearchDC = SearchDC->getParent(); 5145 5146 // The entity of a decl scope is a DeclContext; see PushDeclContext. 5147 while (S->getEntity() != SearchDC) 5148 S = S->getParent(); 5149 } 5150 5151CreateNewDecl: 5152 5153 TagDecl *PrevDecl = 0; 5154 if (Previous.isSingleResult()) 5155 PrevDecl = cast<TagDecl>(Previous.getFoundDecl()); 5156 5157 // If there is an identifier, use the location of the identifier as the 5158 // location of the decl, otherwise use the location of the struct/union 5159 // keyword. 5160 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 5161 5162 // Otherwise, create a new declaration. If there is a previous 5163 // declaration of the same entity, the two will be linked via 5164 // PrevDecl. 5165 TagDecl *New; 5166 5167 if (Kind == TagDecl::TK_enum) { 5168 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 5169 // enum X { A, B, C } D; D should chain to X. 5170 New = EnumDecl::Create(Context, SearchDC, Loc, Name, KWLoc, 5171 cast_or_null<EnumDecl>(PrevDecl)); 5172 // If this is an undefined enum, warn. 5173 if (TUK != TUK_Definition && !Invalid) { 5174 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 5175 : diag::ext_forward_ref_enum; 5176 Diag(Loc, DK); 5177 } 5178 } else { 5179 // struct/union/class 5180 5181 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 5182 // struct X { int A; } D; D should chain to X. 5183 if (getLangOptions().CPlusPlus) { 5184 // FIXME: Look for a way to use RecordDecl for simple structs. 5185 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 5186 cast_or_null<CXXRecordDecl>(PrevDecl)); 5187 5188 if (isStdBadAlloc && (!StdBadAlloc || StdBadAlloc->isImplicit())) 5189 StdBadAlloc = cast<CXXRecordDecl>(New); 5190 } else 5191 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 5192 cast_or_null<RecordDecl>(PrevDecl)); 5193 } 5194 5195 if (Kind != TagDecl::TK_enum) { 5196 // Handle #pragma pack: if the #pragma pack stack has non-default 5197 // alignment, make up a packed attribute for this decl. These 5198 // attributes are checked when the ASTContext lays out the 5199 // structure. 5200 // 5201 // It is important for implementing the correct semantics that this 5202 // happen here (in act on tag decl). The #pragma pack stack is 5203 // maintained as a result of parser callbacks which can occur at 5204 // many points during the parsing of a struct declaration (because 5205 // the #pragma tokens are effectively skipped over during the 5206 // parsing of the struct). 5207 if (unsigned Alignment = getPragmaPackAlignment()) 5208 New->addAttr(::new (Context) PragmaPackAttr(Alignment * 8)); 5209 } 5210 5211 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 5212 // C++ [dcl.typedef]p3: 5213 // [...] Similarly, in a given scope, a class or enumeration 5214 // shall not be declared with the same name as a typedef-name 5215 // that is declared in that scope and refers to a type other 5216 // than the class or enumeration itself. 5217 LookupResult Lookup(*this, Name, NameLoc, LookupOrdinaryName, 5218 ForRedeclaration); 5219 LookupName(Lookup, S); 5220 TypedefDecl *PrevTypedef = Lookup.getAsSingle<TypedefDecl>(); 5221 NamedDecl *PrevTypedefNamed = PrevTypedef; 5222 if (PrevTypedef && isDeclInScope(PrevTypedefNamed, SearchDC, S) && 5223 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 5224 Context.getCanonicalType(Context.getTypeDeclType(New))) { 5225 Diag(Loc, diag::err_tag_definition_of_typedef) 5226 << Context.getTypeDeclType(New) 5227 << PrevTypedef->getUnderlyingType(); 5228 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 5229 Invalid = true; 5230 } 5231 } 5232 5233 // If this is a specialization of a member class (of a class template), 5234 // check the specialization. 5235 if (isExplicitSpecialization && CheckMemberSpecialization(New, Previous)) 5236 Invalid = true; 5237 5238 if (Invalid) 5239 New->setInvalidDecl(); 5240 5241 if (Attr) 5242 ProcessDeclAttributeList(S, New, Attr); 5243 5244 // If we're declaring or defining a tag in function prototype scope 5245 // in C, note that this type can only be used within the function. 5246 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 5247 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 5248 5249 // Set the lexical context. If the tag has a C++ scope specifier, the 5250 // lexical context will be different from the semantic context. 5251 New->setLexicalDeclContext(CurContext); 5252 5253 // Mark this as a friend decl if applicable. 5254 if (TUK == TUK_Friend) 5255 New->setObjectOfFriendDecl(/* PreviouslyDeclared = */ !Previous.empty()); 5256 5257 // Set the access specifier. 5258 if (!Invalid && TUK != TUK_Friend) 5259 SetMemberAccessSpecifier(New, PrevDecl, AS); 5260 5261 if (TUK == TUK_Definition) 5262 New->startDefinition(); 5263 5264 // If this has an identifier, add it to the scope stack. 5265 if (TUK == TUK_Friend) { 5266 // We might be replacing an existing declaration in the lookup tables; 5267 // if so, borrow its access specifier. 5268 if (PrevDecl) 5269 New->setAccess(PrevDecl->getAccess()); 5270 5271 // Friend tag decls are visible in fairly strange ways. 5272 if (!CurContext->isDependentContext()) { 5273 DeclContext *DC = New->getDeclContext()->getLookupContext(); 5274 DC->makeDeclVisibleInContext(New, /* Recoverable = */ false); 5275 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 5276 PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false); 5277 } 5278 } else if (Name) { 5279 S = getNonFieldDeclScope(S); 5280 PushOnScopeChains(New, S); 5281 } else { 5282 CurContext->addDecl(New); 5283 } 5284 5285 // If this is the C FILE type, notify the AST context. 5286 if (IdentifierInfo *II = New->getIdentifier()) 5287 if (!New->isInvalidDecl() && 5288 New->getDeclContext()->getLookupContext()->isTranslationUnit() && 5289 II->isStr("FILE")) 5290 Context.setFILEDecl(New); 5291 5292 OwnedDecl = true; 5293 return DeclPtrTy::make(New); 5294} 5295 5296void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 5297 AdjustDeclIfTemplate(TagD); 5298 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 5299 5300 // Enter the tag context. 5301 PushDeclContext(S, Tag); 5302} 5303 5304void Sema::ActOnStartCXXMemberDeclarations(Scope *S, DeclPtrTy TagD, 5305 SourceLocation LBraceLoc) { 5306 AdjustDeclIfTemplate(TagD); 5307 CXXRecordDecl *Record = cast<CXXRecordDecl>(TagD.getAs<Decl>()); 5308 5309 FieldCollector->StartClass(); 5310 5311 if (!Record->getIdentifier()) 5312 return; 5313 5314 // C++ [class]p2: 5315 // [...] The class-name is also inserted into the scope of the 5316 // class itself; this is known as the injected-class-name. For 5317 // purposes of access checking, the injected-class-name is treated 5318 // as if it were a public member name. 5319 CXXRecordDecl *InjectedClassName 5320 = CXXRecordDecl::Create(Context, Record->getTagKind(), 5321 CurContext, Record->getLocation(), 5322 Record->getIdentifier(), 5323 Record->getTagKeywordLoc(), 5324 Record); 5325 InjectedClassName->setImplicit(); 5326 InjectedClassName->setAccess(AS_public); 5327 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 5328 InjectedClassName->setDescribedClassTemplate(Template); 5329 PushOnScopeChains(InjectedClassName, S); 5330 assert(InjectedClassName->isInjectedClassName() && 5331 "Broken injected-class-name"); 5332} 5333 5334// Traverses the class and any nested classes, making a note of any 5335// dynamic classes that have no key function so that we can mark all of 5336// their virtual member functions as "used" at the end of the translation 5337// unit. This ensures that all functions needed by the vtable will get 5338// instantiated/synthesized. 5339static void 5340RecordDynamicClassesWithNoKeyFunction(Sema &S, CXXRecordDecl *Record, 5341 SourceLocation Loc) { 5342 // We don't look at dependent or undefined classes. 5343 if (Record->isDependentContext() || !Record->isDefinition()) 5344 return; 5345 5346 if (Record->isDynamicClass() && !S.Context.getKeyFunction(Record)) 5347 S.ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(Record, Loc)); 5348 5349 for (DeclContext::decl_iterator D = Record->decls_begin(), 5350 DEnd = Record->decls_end(); 5351 D != DEnd; ++D) { 5352 if (CXXRecordDecl *Nested = dyn_cast<CXXRecordDecl>(*D)) 5353 RecordDynamicClassesWithNoKeyFunction(S, Nested, Loc); 5354 } 5355} 5356 5357void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD, 5358 SourceLocation RBraceLoc) { 5359 AdjustDeclIfTemplate(TagD); 5360 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 5361 Tag->setRBraceLoc(RBraceLoc); 5362 5363 if (isa<CXXRecordDecl>(Tag)) 5364 FieldCollector->FinishClass(); 5365 5366 // Exit this scope of this tag's definition. 5367 PopDeclContext(); 5368 5369 if (isa<CXXRecordDecl>(Tag) && !Tag->getDeclContext()->isRecord()) 5370 RecordDynamicClassesWithNoKeyFunction(*this, cast<CXXRecordDecl>(Tag), 5371 RBraceLoc); 5372 5373 // Notify the consumer that we've defined a tag. 5374 Consumer.HandleTagDeclDefinition(Tag); 5375} 5376 5377// Note that FieldName may be null for anonymous bitfields. 5378bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 5379 QualType FieldTy, const Expr *BitWidth, 5380 bool *ZeroWidth) { 5381 // Default to true; that shouldn't confuse checks for emptiness 5382 if (ZeroWidth) 5383 *ZeroWidth = true; 5384 5385 // C99 6.7.2.1p4 - verify the field type. 5386 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 5387 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 5388 // Handle incomplete types with specific error. 5389 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 5390 return true; 5391 if (FieldName) 5392 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 5393 << FieldName << FieldTy << BitWidth->getSourceRange(); 5394 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 5395 << FieldTy << BitWidth->getSourceRange(); 5396 } 5397 5398 // If the bit-width is type- or value-dependent, don't try to check 5399 // it now. 5400 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 5401 return false; 5402 5403 llvm::APSInt Value; 5404 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 5405 return true; 5406 5407 if (Value != 0 && ZeroWidth) 5408 *ZeroWidth = false; 5409 5410 // Zero-width bitfield is ok for anonymous field. 5411 if (Value == 0 && FieldName) 5412 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 5413 5414 if (Value.isSigned() && Value.isNegative()) { 5415 if (FieldName) 5416 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 5417 << FieldName << Value.toString(10); 5418 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 5419 << Value.toString(10); 5420 } 5421 5422 if (!FieldTy->isDependentType()) { 5423 uint64_t TypeSize = Context.getTypeSize(FieldTy); 5424 if (Value.getZExtValue() > TypeSize) { 5425 if (FieldName) 5426 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 5427 << FieldName << (unsigned)TypeSize; 5428 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 5429 << (unsigned)TypeSize; 5430 } 5431 } 5432 5433 return false; 5434} 5435 5436/// ActOnField - Each field of a struct/union/class is passed into this in order 5437/// to create a FieldDecl object for it. 5438Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 5439 SourceLocation DeclStart, 5440 Declarator &D, ExprTy *BitfieldWidth) { 5441 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 5442 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 5443 AS_public); 5444 return DeclPtrTy::make(Res); 5445} 5446 5447/// HandleField - Analyze a field of a C struct or a C++ data member. 5448/// 5449FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 5450 SourceLocation DeclStart, 5451 Declarator &D, Expr *BitWidth, 5452 AccessSpecifier AS) { 5453 IdentifierInfo *II = D.getIdentifier(); 5454 SourceLocation Loc = DeclStart; 5455 if (II) Loc = D.getIdentifierLoc(); 5456 5457 TypeSourceInfo *TInfo = 0; 5458 QualType T = GetTypeForDeclarator(D, S, &TInfo); 5459 if (getLangOptions().CPlusPlus) 5460 CheckExtraCXXDefaultArguments(D); 5461 5462 DiagnoseFunctionSpecifiers(D); 5463 5464 if (D.getDeclSpec().isThreadSpecified()) 5465 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 5466 5467 NamedDecl *PrevDecl = LookupSingleName(S, II, LookupMemberName, 5468 ForRedeclaration); 5469 5470 if (PrevDecl && PrevDecl->isTemplateParameter()) { 5471 // Maybe we will complain about the shadowed template parameter. 5472 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 5473 // Just pretend that we didn't see the previous declaration. 5474 PrevDecl = 0; 5475 } 5476 5477 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 5478 PrevDecl = 0; 5479 5480 bool Mutable 5481 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 5482 SourceLocation TSSL = D.getSourceRange().getBegin(); 5483 FieldDecl *NewFD 5484 = CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, TSSL, 5485 AS, PrevDecl, &D); 5486 if (NewFD->isInvalidDecl() && PrevDecl) { 5487 // Don't introduce NewFD into scope; there's already something 5488 // with the same name in the same scope. 5489 } else if (II) { 5490 PushOnScopeChains(NewFD, S); 5491 } else 5492 Record->addDecl(NewFD); 5493 5494 return NewFD; 5495} 5496 5497/// \brief Build a new FieldDecl and check its well-formedness. 5498/// 5499/// This routine builds a new FieldDecl given the fields name, type, 5500/// record, etc. \p PrevDecl should refer to any previous declaration 5501/// with the same name and in the same scope as the field to be 5502/// created. 5503/// 5504/// \returns a new FieldDecl. 5505/// 5506/// \todo The Declarator argument is a hack. It will be removed once 5507FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 5508 TypeSourceInfo *TInfo, 5509 RecordDecl *Record, SourceLocation Loc, 5510 bool Mutable, Expr *BitWidth, 5511 SourceLocation TSSL, 5512 AccessSpecifier AS, NamedDecl *PrevDecl, 5513 Declarator *D) { 5514 IdentifierInfo *II = Name.getAsIdentifierInfo(); 5515 bool InvalidDecl = false; 5516 if (D) InvalidDecl = D->isInvalidType(); 5517 5518 // If we receive a broken type, recover by assuming 'int' and 5519 // marking this declaration as invalid. 5520 if (T.isNull()) { 5521 InvalidDecl = true; 5522 T = Context.IntTy; 5523 } 5524 5525 QualType EltTy = Context.getBaseElementType(T); 5526 if (!EltTy->isDependentType() && 5527 RequireCompleteType(Loc, EltTy, diag::err_field_incomplete)) 5528 InvalidDecl = true; 5529 5530 // C99 6.7.2.1p8: A member of a structure or union may have any type other 5531 // than a variably modified type. 5532 if (!InvalidDecl && T->isVariablyModifiedType()) { 5533 bool SizeIsNegative; 5534 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 5535 SizeIsNegative); 5536 if (!FixedTy.isNull()) { 5537 Diag(Loc, diag::warn_illegal_constant_array_size); 5538 T = FixedTy; 5539 } else { 5540 if (SizeIsNegative) 5541 Diag(Loc, diag::err_typecheck_negative_array_size); 5542 else 5543 Diag(Loc, diag::err_typecheck_field_variable_size); 5544 InvalidDecl = true; 5545 } 5546 } 5547 5548 // Fields can not have abstract class types 5549 if (!InvalidDecl && RequireNonAbstractType(Loc, T, 5550 diag::err_abstract_type_in_decl, 5551 AbstractFieldType)) 5552 InvalidDecl = true; 5553 5554 bool ZeroWidth = false; 5555 // If this is declared as a bit-field, check the bit-field. 5556 if (!InvalidDecl && BitWidth && 5557 VerifyBitField(Loc, II, T, BitWidth, &ZeroWidth)) { 5558 InvalidDecl = true; 5559 DeleteExpr(BitWidth); 5560 BitWidth = 0; 5561 ZeroWidth = false; 5562 } 5563 5564 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, TInfo, 5565 BitWidth, Mutable); 5566 if (InvalidDecl) 5567 NewFD->setInvalidDecl(); 5568 5569 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 5570 Diag(Loc, diag::err_duplicate_member) << II; 5571 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 5572 NewFD->setInvalidDecl(); 5573 } 5574 5575 if (getLangOptions().CPlusPlus) { 5576 CXXRecordDecl* CXXRecord = cast<CXXRecordDecl>(Record); 5577 5578 if (!T->isPODType()) 5579 CXXRecord->setPOD(false); 5580 if (!ZeroWidth) 5581 CXXRecord->setEmpty(false); 5582 5583 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 5584 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 5585 5586 if (!RDecl->hasTrivialConstructor()) 5587 CXXRecord->setHasTrivialConstructor(false); 5588 if (!RDecl->hasTrivialCopyConstructor()) 5589 CXXRecord->setHasTrivialCopyConstructor(false); 5590 if (!RDecl->hasTrivialCopyAssignment()) 5591 CXXRecord->setHasTrivialCopyAssignment(false); 5592 if (!RDecl->hasTrivialDestructor()) 5593 CXXRecord->setHasTrivialDestructor(false); 5594 5595 // C++ 9.5p1: An object of a class with a non-trivial 5596 // constructor, a non-trivial copy constructor, a non-trivial 5597 // destructor, or a non-trivial copy assignment operator 5598 // cannot be a member of a union, nor can an array of such 5599 // objects. 5600 // TODO: C++0x alters this restriction significantly. 5601 if (Record->isUnion()) { 5602 // We check for copy constructors before constructors 5603 // because otherwise we'll never get complaints about 5604 // copy constructors. 5605 5606 const CXXSpecialMember invalid = (CXXSpecialMember) -1; 5607 5608 CXXSpecialMember member; 5609 if (!RDecl->hasTrivialCopyConstructor()) 5610 member = CXXCopyConstructor; 5611 else if (!RDecl->hasTrivialConstructor()) 5612 member = CXXDefaultConstructor; 5613 else if (!RDecl->hasTrivialCopyAssignment()) 5614 member = CXXCopyAssignment; 5615 else if (!RDecl->hasTrivialDestructor()) 5616 member = CXXDestructor; 5617 else 5618 member = invalid; 5619 5620 if (member != invalid) { 5621 Diag(Loc, diag::err_illegal_union_member) << Name << member; 5622 DiagnoseNontrivial(RT, member); 5623 NewFD->setInvalidDecl(); 5624 } 5625 } 5626 } 5627 } 5628 5629 // FIXME: We need to pass in the attributes given an AST 5630 // representation, not a parser representation. 5631 if (D) 5632 // FIXME: What to pass instead of TUScope? 5633 ProcessDeclAttributes(TUScope, NewFD, *D); 5634 5635 if (T.isObjCGCWeak()) 5636 Diag(Loc, diag::warn_attribute_weak_on_field); 5637 5638 NewFD->setAccess(AS); 5639 5640 // C++ [dcl.init.aggr]p1: 5641 // An aggregate is an array or a class (clause 9) with [...] no 5642 // private or protected non-static data members (clause 11). 5643 // A POD must be an aggregate. 5644 if (getLangOptions().CPlusPlus && 5645 (AS == AS_private || AS == AS_protected)) { 5646 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 5647 CXXRecord->setAggregate(false); 5648 CXXRecord->setPOD(false); 5649 } 5650 5651 return NewFD; 5652} 5653 5654/// DiagnoseNontrivial - Given that a class has a non-trivial 5655/// special member, figure out why. 5656void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) { 5657 QualType QT(T, 0U); 5658 CXXRecordDecl* RD = cast<CXXRecordDecl>(T->getDecl()); 5659 5660 // Check whether the member was user-declared. 5661 switch (member) { 5662 case CXXDefaultConstructor: 5663 if (RD->hasUserDeclaredConstructor()) { 5664 typedef CXXRecordDecl::ctor_iterator ctor_iter; 5665 for (ctor_iter ci = RD->ctor_begin(), ce = RD->ctor_end(); ci != ce;++ci){ 5666 const FunctionDecl *body = 0; 5667 ci->getBody(body); 5668 if (!body || 5669 !cast<CXXConstructorDecl>(body)->isImplicitlyDefined(Context)) { 5670 SourceLocation CtorLoc = ci->getLocation(); 5671 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 5672 return; 5673 } 5674 } 5675 5676 assert(0 && "found no user-declared constructors"); 5677 return; 5678 } 5679 break; 5680 5681 case CXXCopyConstructor: 5682 if (RD->hasUserDeclaredCopyConstructor()) { 5683 SourceLocation CtorLoc = 5684 RD->getCopyConstructor(Context, 0)->getLocation(); 5685 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 5686 return; 5687 } 5688 break; 5689 5690 case CXXCopyAssignment: 5691 if (RD->hasUserDeclaredCopyAssignment()) { 5692 // FIXME: this should use the location of the copy 5693 // assignment, not the type. 5694 SourceLocation TyLoc = RD->getSourceRange().getBegin(); 5695 Diag(TyLoc, diag::note_nontrivial_user_defined) << QT << member; 5696 return; 5697 } 5698 break; 5699 5700 case CXXDestructor: 5701 if (RD->hasUserDeclaredDestructor()) { 5702 SourceLocation DtorLoc = RD->getDestructor(Context)->getLocation(); 5703 Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member; 5704 return; 5705 } 5706 break; 5707 } 5708 5709 typedef CXXRecordDecl::base_class_iterator base_iter; 5710 5711 // Virtual bases and members inhibit trivial copying/construction, 5712 // but not trivial destruction. 5713 if (member != CXXDestructor) { 5714 // Check for virtual bases. vbases includes indirect virtual bases, 5715 // so we just iterate through the direct bases. 5716 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) 5717 if (bi->isVirtual()) { 5718 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 5719 Diag(BaseLoc, diag::note_nontrivial_has_virtual) << QT << 1; 5720 return; 5721 } 5722 5723 // Check for virtual methods. 5724 typedef CXXRecordDecl::method_iterator meth_iter; 5725 for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; 5726 ++mi) { 5727 if (mi->isVirtual()) { 5728 SourceLocation MLoc = mi->getSourceRange().getBegin(); 5729 Diag(MLoc, diag::note_nontrivial_has_virtual) << QT << 0; 5730 return; 5731 } 5732 } 5733 } 5734 5735 bool (CXXRecordDecl::*hasTrivial)() const; 5736 switch (member) { 5737 case CXXDefaultConstructor: 5738 hasTrivial = &CXXRecordDecl::hasTrivialConstructor; break; 5739 case CXXCopyConstructor: 5740 hasTrivial = &CXXRecordDecl::hasTrivialCopyConstructor; break; 5741 case CXXCopyAssignment: 5742 hasTrivial = &CXXRecordDecl::hasTrivialCopyAssignment; break; 5743 case CXXDestructor: 5744 hasTrivial = &CXXRecordDecl::hasTrivialDestructor; break; 5745 default: 5746 assert(0 && "unexpected special member"); return; 5747 } 5748 5749 // Check for nontrivial bases (and recurse). 5750 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) { 5751 const RecordType *BaseRT = bi->getType()->getAs<RecordType>(); 5752 assert(BaseRT && "Don't know how to handle dependent bases"); 5753 CXXRecordDecl *BaseRecTy = cast<CXXRecordDecl>(BaseRT->getDecl()); 5754 if (!(BaseRecTy->*hasTrivial)()) { 5755 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 5756 Diag(BaseLoc, diag::note_nontrivial_has_nontrivial) << QT << 1 << member; 5757 DiagnoseNontrivial(BaseRT, member); 5758 return; 5759 } 5760 } 5761 5762 // Check for nontrivial members (and recurse). 5763 typedef RecordDecl::field_iterator field_iter; 5764 for (field_iter fi = RD->field_begin(), fe = RD->field_end(); fi != fe; 5765 ++fi) { 5766 QualType EltTy = Context.getBaseElementType((*fi)->getType()); 5767 if (const RecordType *EltRT = EltTy->getAs<RecordType>()) { 5768 CXXRecordDecl* EltRD = cast<CXXRecordDecl>(EltRT->getDecl()); 5769 5770 if (!(EltRD->*hasTrivial)()) { 5771 SourceLocation FLoc = (*fi)->getLocation(); 5772 Diag(FLoc, diag::note_nontrivial_has_nontrivial) << QT << 0 << member; 5773 DiagnoseNontrivial(EltRT, member); 5774 return; 5775 } 5776 } 5777 } 5778 5779 assert(0 && "found no explanation for non-trivial member"); 5780} 5781 5782/// TranslateIvarVisibility - Translate visibility from a token ID to an 5783/// AST enum value. 5784static ObjCIvarDecl::AccessControl 5785TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 5786 switch (ivarVisibility) { 5787 default: assert(0 && "Unknown visitibility kind"); 5788 case tok::objc_private: return ObjCIvarDecl::Private; 5789 case tok::objc_public: return ObjCIvarDecl::Public; 5790 case tok::objc_protected: return ObjCIvarDecl::Protected; 5791 case tok::objc_package: return ObjCIvarDecl::Package; 5792 } 5793} 5794 5795/// ActOnIvar - Each ivar field of an objective-c class is passed into this 5796/// in order to create an IvarDecl object for it. 5797Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 5798 SourceLocation DeclStart, 5799 DeclPtrTy IntfDecl, 5800 Declarator &D, ExprTy *BitfieldWidth, 5801 tok::ObjCKeywordKind Visibility) { 5802 5803 IdentifierInfo *II = D.getIdentifier(); 5804 Expr *BitWidth = (Expr*)BitfieldWidth; 5805 SourceLocation Loc = DeclStart; 5806 if (II) Loc = D.getIdentifierLoc(); 5807 5808 // FIXME: Unnamed fields can be handled in various different ways, for 5809 // example, unnamed unions inject all members into the struct namespace! 5810 5811 TypeSourceInfo *TInfo = 0; 5812 QualType T = GetTypeForDeclarator(D, S, &TInfo); 5813 5814 if (BitWidth) { 5815 // 6.7.2.1p3, 6.7.2.1p4 5816 if (VerifyBitField(Loc, II, T, BitWidth)) { 5817 D.setInvalidType(); 5818 DeleteExpr(BitWidth); 5819 BitWidth = 0; 5820 } 5821 } else { 5822 // Not a bitfield. 5823 5824 // validate II. 5825 5826 } 5827 5828 // C99 6.7.2.1p8: A member of a structure or union may have any type other 5829 // than a variably modified type. 5830 if (T->isVariablyModifiedType()) { 5831 Diag(Loc, diag::err_typecheck_ivar_variable_size); 5832 D.setInvalidType(); 5833 } 5834 5835 // Get the visibility (access control) for this ivar. 5836 ObjCIvarDecl::AccessControl ac = 5837 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 5838 : ObjCIvarDecl::None; 5839 // Must set ivar's DeclContext to its enclosing interface. 5840 Decl *EnclosingDecl = IntfDecl.getAs<Decl>(); 5841 DeclContext *EnclosingContext; 5842 if (ObjCImplementationDecl *IMPDecl = 5843 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 5844 // Case of ivar declared in an implementation. Context is that of its class. 5845 ObjCInterfaceDecl* IDecl = IMPDecl->getClassInterface(); 5846 assert(IDecl && "No class- ActOnIvar"); 5847 EnclosingContext = cast_or_null<DeclContext>(IDecl); 5848 } else 5849 EnclosingContext = dyn_cast<DeclContext>(EnclosingDecl); 5850 assert(EnclosingContext && "null DeclContext for ivar - ActOnIvar"); 5851 5852 // Construct the decl. 5853 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, 5854 EnclosingContext, Loc, II, T, 5855 TInfo, ac, (Expr *)BitfieldWidth); 5856 5857 if (II) { 5858 NamedDecl *PrevDecl = LookupSingleName(S, II, LookupMemberName, 5859 ForRedeclaration); 5860 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 5861 && !isa<TagDecl>(PrevDecl)) { 5862 Diag(Loc, diag::err_duplicate_member) << II; 5863 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 5864 NewID->setInvalidDecl(); 5865 } 5866 } 5867 5868 // Process attributes attached to the ivar. 5869 ProcessDeclAttributes(S, NewID, D); 5870 5871 if (D.isInvalidType()) 5872 NewID->setInvalidDecl(); 5873 5874 if (II) { 5875 // FIXME: When interfaces are DeclContexts, we'll need to add 5876 // these to the interface. 5877 S->AddDecl(DeclPtrTy::make(NewID)); 5878 IdResolver.AddDecl(NewID); 5879 } 5880 5881 return DeclPtrTy::make(NewID); 5882} 5883 5884void Sema::ActOnFields(Scope* S, 5885 SourceLocation RecLoc, DeclPtrTy RecDecl, 5886 DeclPtrTy *Fields, unsigned NumFields, 5887 SourceLocation LBrac, SourceLocation RBrac, 5888 AttributeList *Attr) { 5889 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 5890 assert(EnclosingDecl && "missing record or interface decl"); 5891 5892 // If the decl this is being inserted into is invalid, then it may be a 5893 // redeclaration or some other bogus case. Don't try to add fields to it. 5894 if (EnclosingDecl->isInvalidDecl()) { 5895 // FIXME: Deallocate fields? 5896 return; 5897 } 5898 5899 5900 // Verify that all the fields are okay. 5901 unsigned NumNamedMembers = 0; 5902 llvm::SmallVector<FieldDecl*, 32> RecFields; 5903 5904 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 5905 for (unsigned i = 0; i != NumFields; ++i) { 5906 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 5907 5908 // Get the type for the field. 5909 Type *FDTy = FD->getType().getTypePtr(); 5910 5911 if (!FD->isAnonymousStructOrUnion()) { 5912 // Remember all fields written by the user. 5913 RecFields.push_back(FD); 5914 } 5915 5916 // If the field is already invalid for some reason, don't emit more 5917 // diagnostics about it. 5918 if (FD->isInvalidDecl()) { 5919 EnclosingDecl->setInvalidDecl(); 5920 continue; 5921 } 5922 5923 // C99 6.7.2.1p2: 5924 // A structure or union shall not contain a member with 5925 // incomplete or function type (hence, a structure shall not 5926 // contain an instance of itself, but may contain a pointer to 5927 // an instance of itself), except that the last member of a 5928 // structure with more than one named member may have incomplete 5929 // array type; such a structure (and any union containing, 5930 // possibly recursively, a member that is such a structure) 5931 // shall not be a member of a structure or an element of an 5932 // array. 5933 if (FDTy->isFunctionType()) { 5934 // Field declared as a function. 5935 Diag(FD->getLocation(), diag::err_field_declared_as_function) 5936 << FD->getDeclName(); 5937 FD->setInvalidDecl(); 5938 EnclosingDecl->setInvalidDecl(); 5939 continue; 5940 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 5941 Record && Record->isStruct()) { 5942 // Flexible array member. 5943 if (NumNamedMembers < 1) { 5944 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 5945 << FD->getDeclName(); 5946 FD->setInvalidDecl(); 5947 EnclosingDecl->setInvalidDecl(); 5948 continue; 5949 } 5950 // Okay, we have a legal flexible array member at the end of the struct. 5951 if (Record) 5952 Record->setHasFlexibleArrayMember(true); 5953 } else if (!FDTy->isDependentType() && 5954 RequireCompleteType(FD->getLocation(), FD->getType(), 5955 diag::err_field_incomplete)) { 5956 // Incomplete type 5957 FD->setInvalidDecl(); 5958 EnclosingDecl->setInvalidDecl(); 5959 continue; 5960 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) { 5961 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 5962 // If this is a member of a union, then entire union becomes "flexible". 5963 if (Record && Record->isUnion()) { 5964 Record->setHasFlexibleArrayMember(true); 5965 } else { 5966 // If this is a struct/class and this is not the last element, reject 5967 // it. Note that GCC supports variable sized arrays in the middle of 5968 // structures. 5969 if (i != NumFields-1) 5970 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 5971 << FD->getDeclName() << FD->getType(); 5972 else { 5973 // We support flexible arrays at the end of structs in 5974 // other structs as an extension. 5975 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 5976 << FD->getDeclName(); 5977 if (Record) 5978 Record->setHasFlexibleArrayMember(true); 5979 } 5980 } 5981 } 5982 if (Record && FDTTy->getDecl()->hasObjectMember()) 5983 Record->setHasObjectMember(true); 5984 } else if (FDTy->isObjCInterfaceType()) { 5985 /// A field cannot be an Objective-c object 5986 Diag(FD->getLocation(), diag::err_statically_allocated_object); 5987 FD->setInvalidDecl(); 5988 EnclosingDecl->setInvalidDecl(); 5989 continue; 5990 } else if (getLangOptions().ObjC1 && 5991 getLangOptions().getGCMode() != LangOptions::NonGC && 5992 Record && 5993 (FD->getType()->isObjCObjectPointerType() || 5994 FD->getType().isObjCGCStrong())) 5995 Record->setHasObjectMember(true); 5996 // Keep track of the number of named members. 5997 if (FD->getIdentifier()) 5998 ++NumNamedMembers; 5999 } 6000 6001 // Okay, we successfully defined 'Record'. 6002 if (Record) { 6003 Record->completeDefinition(Context); 6004 } else { 6005 ObjCIvarDecl **ClsFields = 6006 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 6007 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 6008 ID->setIVarList(ClsFields, RecFields.size(), Context); 6009 ID->setLocEnd(RBrac); 6010 // Add ivar's to class's DeclContext. 6011 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 6012 ClsFields[i]->setLexicalDeclContext(ID); 6013 ID->addDecl(ClsFields[i]); 6014 } 6015 // Must enforce the rule that ivars in the base classes may not be 6016 // duplicates. 6017 if (ID->getSuperClass()) { 6018 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 6019 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 6020 ObjCIvarDecl* Ivar = (*IVI); 6021 6022 if (IdentifierInfo *II = Ivar->getIdentifier()) { 6023 ObjCIvarDecl* prevIvar = 6024 ID->getSuperClass()->lookupInstanceVariable(II); 6025 if (prevIvar) { 6026 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 6027 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 6028 } 6029 } 6030 } 6031 } 6032 } else if (ObjCImplementationDecl *IMPDecl = 6033 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 6034 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 6035 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 6036 // Ivar declared in @implementation never belongs to the implementation. 6037 // Only it is in implementation's lexical context. 6038 ClsFields[I]->setLexicalDeclContext(IMPDecl); 6039 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 6040 } 6041 } 6042 6043 if (Attr) 6044 ProcessDeclAttributeList(S, Record, Attr); 6045} 6046 6047EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 6048 EnumConstantDecl *LastEnumConst, 6049 SourceLocation IdLoc, 6050 IdentifierInfo *Id, 6051 ExprArg val) { 6052 Expr *Val = (Expr *)val.get(); 6053 6054 llvm::APSInt EnumVal(32); 6055 QualType EltTy; 6056 if (Val) { 6057 if (Enum->isDependentType()) 6058 EltTy = Context.DependentTy; 6059 else { 6060 // Make sure to promote the operand type to int. 6061 UsualUnaryConversions(Val); 6062 if (Val != val.get()) { 6063 val.release(); 6064 val = Val; 6065 } 6066 6067 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 6068 SourceLocation ExpLoc; 6069 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 6070 Val = 0; 6071 } else { 6072 EltTy = Val->getType(); 6073 } 6074 } 6075 } 6076 6077 if (!Val) { 6078 if (Enum->isDependentType()) 6079 EltTy = Context.DependentTy; 6080 else if (LastEnumConst) { 6081 // Assign the last value + 1. 6082 EnumVal = LastEnumConst->getInitVal(); 6083 ++EnumVal; 6084 6085 // Check for overflow on increment. 6086 if (EnumVal < LastEnumConst->getInitVal()) 6087 Diag(IdLoc, diag::warn_enum_value_overflow); 6088 6089 EltTy = LastEnumConst->getType(); 6090 } else { 6091 // First value, set to zero. 6092 EltTy = Context.IntTy; 6093 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 6094 EnumVal.setIsSigned(true); 6095 } 6096 } 6097 6098 assert(!EltTy.isNull() && "Enum constant with NULL type"); 6099 6100 val.release(); 6101 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 6102 Val, EnumVal); 6103} 6104 6105 6106Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 6107 DeclPtrTy lastEnumConst, 6108 SourceLocation IdLoc, 6109 IdentifierInfo *Id, 6110 SourceLocation EqualLoc, ExprTy *val) { 6111 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 6112 EnumConstantDecl *LastEnumConst = 6113 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 6114 Expr *Val = static_cast<Expr*>(val); 6115 6116 // The scope passed in may not be a decl scope. Zip up the scope tree until 6117 // we find one that is. 6118 S = getNonFieldDeclScope(S); 6119 6120 // Verify that there isn't already something declared with this name in this 6121 // scope. 6122 NamedDecl *PrevDecl = LookupSingleName(S, Id, LookupOrdinaryName, 6123 ForRedeclaration); 6124 if (PrevDecl && PrevDecl->isTemplateParameter()) { 6125 // Maybe we will complain about the shadowed template parameter. 6126 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 6127 // Just pretend that we didn't see the previous declaration. 6128 PrevDecl = 0; 6129 } 6130 6131 if (PrevDecl) { 6132 // When in C++, we may get a TagDecl with the same name; in this case the 6133 // enum constant will 'hide' the tag. 6134 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 6135 "Received TagDecl when not in C++!"); 6136 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 6137 if (isa<EnumConstantDecl>(PrevDecl)) 6138 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 6139 else 6140 Diag(IdLoc, diag::err_redefinition) << Id; 6141 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 6142 if (Val) Val->Destroy(Context); 6143 return DeclPtrTy(); 6144 } 6145 } 6146 6147 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 6148 IdLoc, Id, Owned(Val)); 6149 6150 // Register this decl in the current scope stack. 6151 if (New) 6152 PushOnScopeChains(New, S); 6153 6154 return DeclPtrTy::make(New); 6155} 6156 6157void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 6158 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 6159 DeclPtrTy *Elements, unsigned NumElements, 6160 Scope *S, AttributeList *Attr) { 6161 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 6162 QualType EnumType = Context.getTypeDeclType(Enum); 6163 6164 if (Attr) 6165 ProcessDeclAttributeList(S, Enum, Attr); 6166 6167 if (Enum->isDependentType()) { 6168 for (unsigned i = 0; i != NumElements; ++i) { 6169 EnumConstantDecl *ECD = 6170 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 6171 if (!ECD) continue; 6172 6173 ECD->setType(EnumType); 6174 } 6175 6176 Enum->completeDefinition(Context, Context.DependentTy, Context.DependentTy); 6177 return; 6178 } 6179 6180 // TODO: If the result value doesn't fit in an int, it must be a long or long 6181 // long value. ISO C does not support this, but GCC does as an extension, 6182 // emit a warning. 6183 unsigned IntWidth = Context.Target.getIntWidth(); 6184 unsigned CharWidth = Context.Target.getCharWidth(); 6185 unsigned ShortWidth = Context.Target.getShortWidth(); 6186 6187 // Verify that all the values are okay, compute the size of the values, and 6188 // reverse the list. 6189 unsigned NumNegativeBits = 0; 6190 unsigned NumPositiveBits = 0; 6191 6192 // Keep track of whether all elements have type int. 6193 bool AllElementsInt = true; 6194 6195 for (unsigned i = 0; i != NumElements; ++i) { 6196 EnumConstantDecl *ECD = 6197 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 6198 if (!ECD) continue; // Already issued a diagnostic. 6199 6200 // If the enum value doesn't fit in an int, emit an extension warning. 6201 const llvm::APSInt &InitVal = ECD->getInitVal(); 6202 assert(InitVal.getBitWidth() >= IntWidth && 6203 "Should have promoted value to int"); 6204 if (!getLangOptions().CPlusPlus && InitVal.getBitWidth() > IntWidth) { 6205 llvm::APSInt V(InitVal); 6206 V.trunc(IntWidth); 6207 V.extend(InitVal.getBitWidth()); 6208 if (V != InitVal) 6209 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 6210 << InitVal.toString(10); 6211 } 6212 6213 // Keep track of the size of positive and negative values. 6214 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 6215 NumPositiveBits = std::max(NumPositiveBits, 6216 (unsigned)InitVal.getActiveBits()); 6217 else 6218 NumNegativeBits = std::max(NumNegativeBits, 6219 (unsigned)InitVal.getMinSignedBits()); 6220 6221 // Keep track of whether every enum element has type int (very commmon). 6222 if (AllElementsInt) 6223 AllElementsInt = ECD->getType() == Context.IntTy; 6224 } 6225 6226 // Figure out the type that should be used for this enum. 6227 // FIXME: Support -fshort-enums. 6228 QualType BestType; 6229 unsigned BestWidth; 6230 6231 // C++0x N3000 [conv.prom]p3: 6232 // An rvalue of an unscoped enumeration type whose underlying 6233 // type is not fixed can be converted to an rvalue of the first 6234 // of the following types that can represent all the values of 6235 // the enumeration: int, unsigned int, long int, unsigned long 6236 // int, long long int, or unsigned long long int. 6237 // C99 6.4.4.3p2: 6238 // An identifier declared as an enumeration constant has type int. 6239 // The C99 rule is modified by a gcc extension 6240 QualType BestPromotionType; 6241 6242 bool Packed = Enum->getAttr<PackedAttr>() ? true : false; 6243 6244 if (NumNegativeBits) { 6245 // If there is a negative value, figure out the smallest integer type (of 6246 // int/long/longlong) that fits. 6247 // If it's packed, check also if it fits a char or a short. 6248 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) { 6249 BestType = Context.SignedCharTy; 6250 BestWidth = CharWidth; 6251 } else if (Packed && NumNegativeBits <= ShortWidth && 6252 NumPositiveBits < ShortWidth) { 6253 BestType = Context.ShortTy; 6254 BestWidth = ShortWidth; 6255 } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 6256 BestType = Context.IntTy; 6257 BestWidth = IntWidth; 6258 } else { 6259 BestWidth = Context.Target.getLongWidth(); 6260 6261 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) { 6262 BestType = Context.LongTy; 6263 } else { 6264 BestWidth = Context.Target.getLongLongWidth(); 6265 6266 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 6267 Diag(Enum->getLocation(), diag::warn_enum_too_large); 6268 BestType = Context.LongLongTy; 6269 } 6270 } 6271 BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType); 6272 } else { 6273 // If there is no negative value, figure out which of uint, ulong, ulonglong 6274 // fits. 6275 // If it's packed, check also if it fits a char or a short. 6276 if (Packed && NumPositiveBits <= CharWidth) { 6277 BestType = Context.UnsignedCharTy; 6278 BestPromotionType = Context.IntTy; 6279 BestWidth = CharWidth; 6280 } else if (Packed && NumPositiveBits <= ShortWidth) { 6281 BestType = Context.UnsignedShortTy; 6282 BestPromotionType = Context.IntTy; 6283 BestWidth = ShortWidth; 6284 } else if (NumPositiveBits <= IntWidth) { 6285 BestType = Context.UnsignedIntTy; 6286 BestWidth = IntWidth; 6287 BestPromotionType = (NumPositiveBits == BestWidth 6288 ? Context.UnsignedIntTy : Context.IntTy); 6289 } else if (NumPositiveBits <= 6290 (BestWidth = Context.Target.getLongWidth())) { 6291 BestType = Context.UnsignedLongTy; 6292 BestPromotionType = (NumPositiveBits == BestWidth 6293 ? Context.UnsignedLongTy : Context.LongTy); 6294 } else { 6295 BestWidth = Context.Target.getLongLongWidth(); 6296 assert(NumPositiveBits <= BestWidth && 6297 "How could an initializer get larger than ULL?"); 6298 BestType = Context.UnsignedLongLongTy; 6299 BestPromotionType = (NumPositiveBits == BestWidth 6300 ? Context.UnsignedLongLongTy : Context.LongLongTy); 6301 } 6302 } 6303 6304 // If we're in C and the promotion type is larger than an int, just 6305 // use the underlying type, which is generally the unsigned integer 6306 // type of the same rank as the promotion type. This is how the gcc 6307 // extension works. 6308 if (!getLangOptions().CPlusPlus && BestPromotionType != Context.IntTy) 6309 BestPromotionType = BestType; 6310 6311 // Loop over all of the enumerator constants, changing their types to match 6312 // the type of the enum if needed. 6313 for (unsigned i = 0; i != NumElements; ++i) { 6314 EnumConstantDecl *ECD = 6315 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 6316 if (!ECD) continue; // Already issued a diagnostic. 6317 6318 // Standard C says the enumerators have int type, but we allow, as an 6319 // extension, the enumerators to be larger than int size. If each 6320 // enumerator value fits in an int, type it as an int, otherwise type it the 6321 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 6322 // that X has type 'int', not 'unsigned'. 6323 if (!getLangOptions().CPlusPlus && ECD->getType() == Context.IntTy) 6324 continue; 6325 6326 // Determine whether the value fits into an int. 6327 llvm::APSInt InitVal = ECD->getInitVal(); 6328 bool FitsInInt; 6329 if (InitVal.isUnsigned() || !InitVal.isNegative()) 6330 FitsInInt = InitVal.getActiveBits() < IntWidth; 6331 else 6332 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 6333 6334 // If it fits into an integer type, force it. Otherwise force it to match 6335 // the enum decl type. 6336 QualType NewTy; 6337 unsigned NewWidth; 6338 bool NewSign; 6339 if (FitsInInt && !getLangOptions().CPlusPlus) { 6340 NewTy = Context.IntTy; 6341 NewWidth = IntWidth; 6342 NewSign = true; 6343 } else if (ECD->getType() == BestType) { 6344 // Already the right type! 6345 if (getLangOptions().CPlusPlus) 6346 // C++ [dcl.enum]p4: Following the closing brace of an 6347 // enum-specifier, each enumerator has the type of its 6348 // enumeration. 6349 ECD->setType(EnumType); 6350 continue; 6351 } else { 6352 NewTy = BestType; 6353 NewWidth = BestWidth; 6354 NewSign = BestType->isSignedIntegerType(); 6355 } 6356 6357 // Adjust the APSInt value. 6358 InitVal.extOrTrunc(NewWidth); 6359 InitVal.setIsSigned(NewSign); 6360 ECD->setInitVal(InitVal); 6361 6362 // Adjust the Expr initializer and type. 6363 if (ECD->getInitExpr()) 6364 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, 6365 CastExpr::CK_IntegralCast, 6366 ECD->getInitExpr(), 6367 /*isLvalue=*/false)); 6368 if (getLangOptions().CPlusPlus) 6369 // C++ [dcl.enum]p4: Following the closing brace of an 6370 // enum-specifier, each enumerator has the type of its 6371 // enumeration. 6372 ECD->setType(EnumType); 6373 else 6374 ECD->setType(NewTy); 6375 } 6376 6377 Enum->completeDefinition(Context, BestType, BestPromotionType); 6378} 6379 6380Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 6381 ExprArg expr) { 6382 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 6383 6384 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 6385 Loc, AsmString); 6386 CurContext->addDecl(New); 6387 return DeclPtrTy::make(New); 6388} 6389 6390void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 6391 SourceLocation PragmaLoc, 6392 SourceLocation NameLoc) { 6393 Decl *PrevDecl = LookupSingleName(TUScope, Name, LookupOrdinaryName); 6394 6395 if (PrevDecl) { 6396 PrevDecl->addAttr(::new (Context) WeakAttr()); 6397 } else { 6398 (void)WeakUndeclaredIdentifiers.insert( 6399 std::pair<IdentifierInfo*,WeakInfo> 6400 (Name, WeakInfo((IdentifierInfo*)0, NameLoc))); 6401 } 6402} 6403 6404void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 6405 IdentifierInfo* AliasName, 6406 SourceLocation PragmaLoc, 6407 SourceLocation NameLoc, 6408 SourceLocation AliasNameLoc) { 6409 Decl *PrevDecl = LookupSingleName(TUScope, AliasName, LookupOrdinaryName); 6410 WeakInfo W = WeakInfo(Name, NameLoc); 6411 6412 if (PrevDecl) { 6413 if (!PrevDecl->hasAttr<AliasAttr>()) 6414 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl)) 6415 DeclApplyPragmaWeak(TUScope, ND, W); 6416 } else { 6417 (void)WeakUndeclaredIdentifiers.insert( 6418 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W)); 6419 } 6420} 6421