SemaDecl.cpp revision 78d1583d0b36b7d6d8d10234cdc19ab94adf765a
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 "SemaInherit.h" 16#include "clang/AST/APValue.h" 17#include "clang/AST/ASTConsumer.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/DeclObjC.h" 20#include "clang/AST/DeclTemplate.h" 21#include "clang/AST/ExprCXX.h" 22#include "clang/AST/StmtCXX.h" 23#include "clang/Parse/DeclSpec.h" 24#include "clang/Basic/TargetInfo.h" 25#include "clang/Basic/SourceManager.h" 26// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 27#include "clang/Lex/Preprocessor.h" 28#include "clang/Lex/HeaderSearch.h" 29#include "llvm/ADT/SmallSet.h" 30#include "llvm/ADT/STLExtras.h" 31#include <algorithm> 32#include <functional> 33using namespace clang; 34 35/// getDeclName - Return a pretty name for the specified decl if possible, or 36/// an empty string if not. This is used for pretty crash reporting. 37std::string Sema::getDeclName(DeclPtrTy d) { 38 Decl *D = d.getAs<Decl>(); 39 if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D)) 40 return DN->getQualifiedNameAsString(); 41 return ""; 42} 43 44Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) { 45 return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>())); 46} 47 48/// \brief If the identifier refers to a type name within this scope, 49/// return the declaration of that type. 50/// 51/// This routine performs ordinary name lookup of the identifier II 52/// within the given scope, with optional C++ scope specifier SS, to 53/// determine whether the name refers to a type. If so, returns an 54/// opaque pointer (actually a QualType) corresponding to that 55/// type. Otherwise, returns NULL. 56/// 57/// If name lookup results in an ambiguity, this routine will complain 58/// and then return NULL. 59Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 60 Scope *S, const CXXScopeSpec *SS) { 61 // C++ [temp.res]p3: 62 // A qualified-id that refers to a type and in which the 63 // nested-name-specifier depends on a template-parameter (14.6.2) 64 // shall be prefixed by the keyword typename to indicate that the 65 // qualified-id denotes a type, forming an 66 // elaborated-type-specifier (7.1.5.3). 67 // 68 // We therefore do not perform any name lookup if the result would 69 // refer to a member of an unknown specialization. 70 if (SS && isUnknownSpecialization(*SS)) 71 return 0; 72 73 LookupResult Result 74 = LookupParsedName(S, SS, &II, LookupOrdinaryName, false, false); 75 76 NamedDecl *IIDecl = 0; 77 switch (Result.getKind()) { 78 case LookupResult::NotFound: 79 case LookupResult::FoundOverloaded: 80 return 0; 81 82 case LookupResult::AmbiguousBaseSubobjectTypes: 83 case LookupResult::AmbiguousBaseSubobjects: 84 case LookupResult::AmbiguousReference: { 85 // Look to see if we have a type anywhere in the list of results. 86 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); 87 Res != ResEnd; ++Res) { 88 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) { 89 if (!IIDecl || 90 (*Res)->getLocation().getRawEncoding() < 91 IIDecl->getLocation().getRawEncoding()) 92 IIDecl = *Res; 93 } 94 } 95 96 if (!IIDecl) { 97 // None of the entities we found is a type, so there is no way 98 // to even assume that the result is a type. In this case, don't 99 // complain about the ambiguity. The parser will either try to 100 // perform this lookup again (e.g., as an object name), which 101 // will produce the ambiguity, or will complain that it expected 102 // a type name. 103 Result.Destroy(); 104 return 0; 105 } 106 107 // We found a type within the ambiguous lookup; diagnose the 108 // ambiguity and then return that type. This might be the right 109 // answer, or it might not be, but it suppresses any attempt to 110 // perform the name lookup again. 111 DiagnoseAmbiguousLookup(Result, DeclarationName(&II), NameLoc); 112 break; 113 } 114 115 case LookupResult::Found: 116 IIDecl = Result.getAsDecl(); 117 break; 118 } 119 120 if (IIDecl) { 121 QualType T; 122 123 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 124 // Check whether we can use this type 125 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 126 127 if (getLangOptions().CPlusPlus) { 128 // C++ [temp.local]p2: 129 // Within the scope of a class template specialization or 130 // partial specialization, when the injected-class-name is 131 // not followed by a <, it is equivalent to the 132 // injected-class-name followed by the template-argument s 133 // of the class template specialization or partial 134 // specialization enclosed in <>. 135 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) 136 if (RD->isInjectedClassName()) 137 if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate()) 138 T = Template->getInjectedClassNameType(Context); 139 } 140 141 if (T.isNull()) 142 T = Context.getTypeDeclType(TD); 143 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 144 // Check whether we can use this interface. 145 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 146 147 T = Context.getObjCInterfaceType(IDecl); 148 } else 149 return 0; 150 151 if (SS) 152 T = getQualifiedNameType(*SS, T); 153 154 return T.getAsOpaquePtr(); 155 } 156 157 return 0; 158} 159 160/// isTagName() - This method is called *for error recovery purposes only* 161/// to determine if the specified name is a valid tag name ("struct foo"). If 162/// so, this returns the TST for the tag corresponding to it (TST_enum, 163/// TST_union, TST_struct, TST_class). This is used to diagnose cases in C 164/// where the user forgot to specify the tag. 165DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { 166 // Do a tag name lookup in this scope. 167 LookupResult R = LookupName(S, &II, LookupTagName, false, false); 168 if (R.getKind() == LookupResult::Found) 169 if (const TagDecl *TD = dyn_cast<TagDecl>(R.getAsDecl())) { 170 switch (TD->getTagKind()) { 171 case TagDecl::TK_struct: return DeclSpec::TST_struct; 172 case TagDecl::TK_union: return DeclSpec::TST_union; 173 case TagDecl::TK_class: return DeclSpec::TST_class; 174 case TagDecl::TK_enum: return DeclSpec::TST_enum; 175 } 176 } 177 178 return DeclSpec::TST_unspecified; 179} 180 181 182 183DeclContext *Sema::getContainingDC(DeclContext *DC) { 184 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 185 // A C++ out-of-line method will return to the file declaration context. 186 if (MD->isOutOfLineDefinition()) 187 return MD->getLexicalDeclContext(); 188 189 // A C++ inline method is parsed *after* the topmost class it was declared 190 // in is fully parsed (it's "complete"). 191 // The parsing of a C++ inline method happens at the declaration context of 192 // the topmost (non-nested) class it is lexically declared in. 193 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 194 DC = MD->getParent(); 195 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 196 DC = RD; 197 198 // Return the declaration context of the topmost class the inline method is 199 // declared in. 200 return DC; 201 } 202 203 if (isa<ObjCMethodDecl>(DC)) 204 return Context.getTranslationUnitDecl(); 205 206 return DC->getLexicalParent(); 207} 208 209void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 210 assert(getContainingDC(DC) == CurContext && 211 "The next DeclContext should be lexically contained in the current one."); 212 CurContext = DC; 213 S->setEntity(DC); 214} 215 216void Sema::PopDeclContext() { 217 assert(CurContext && "DeclContext imbalance!"); 218 219 CurContext = getContainingDC(CurContext); 220} 221 222/// \brief Determine whether we allow overloading of the function 223/// PrevDecl with another declaration. 224/// 225/// This routine determines whether overloading is possible, not 226/// whether some new function is actually an overload. It will return 227/// true in C++ (where we can always provide overloads) or, as an 228/// extension, in C when the previous function is already an 229/// overloaded function declaration or has the "overloadable" 230/// attribute. 231static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) { 232 if (Context.getLangOptions().CPlusPlus) 233 return true; 234 235 if (isa<OverloadedFunctionDecl>(PrevDecl)) 236 return true; 237 238 return PrevDecl->getAttr<OverloadableAttr>() != 0; 239} 240 241/// Add this decl to the scope shadowed decl chains. 242void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 243 // Move up the scope chain until we find the nearest enclosing 244 // non-transparent context. The declaration will be introduced into this 245 // scope. 246 while (S->getEntity() && 247 ((DeclContext *)S->getEntity())->isTransparentContext()) 248 S = S->getParent(); 249 250 S->AddDecl(DeclPtrTy::make(D)); 251 252 // Add scoped declarations into their context, so that they can be 253 // found later. Declarations without a context won't be inserted 254 // into any context. 255 CurContext->addDecl(Context, D); 256 257 // C++ [basic.scope]p4: 258 // -- exactly one declaration shall declare a class name or 259 // enumeration name that is not a typedef name and the other 260 // declarations shall all refer to the same object or 261 // enumerator, or all refer to functions and function templates; 262 // in this case the class name or enumeration name is hidden. 263 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 264 // We are pushing the name of a tag (enum or class). 265 if (CurContext->getLookupContext() 266 == TD->getDeclContext()->getLookupContext()) { 267 // We're pushing the tag into the current context, which might 268 // require some reshuffling in the identifier resolver. 269 IdentifierResolver::iterator 270 I = IdResolver.begin(TD->getDeclName()), 271 IEnd = IdResolver.end(); 272 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 273 NamedDecl *PrevDecl = *I; 274 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 275 PrevDecl = *I, ++I) { 276 if (TD->declarationReplaces(*I)) { 277 // This is a redeclaration. Remove it from the chain and 278 // break out, so that we'll add in the shadowed 279 // declaration. 280 S->RemoveDecl(DeclPtrTy::make(*I)); 281 if (PrevDecl == *I) { 282 IdResolver.RemoveDecl(*I); 283 IdResolver.AddDecl(TD); 284 return; 285 } else { 286 IdResolver.RemoveDecl(*I); 287 break; 288 } 289 } 290 } 291 292 // There is already a declaration with the same name in the same 293 // scope, which is not a tag declaration. It must be found 294 // before we find the new declaration, so insert the new 295 // declaration at the end of the chain. 296 IdResolver.AddShadowedDecl(TD, PrevDecl); 297 298 return; 299 } 300 } 301 } else if (isa<FunctionDecl>(D) && 302 AllowOverloadingOfFunction(D, Context)) { 303 // We are pushing the name of a function, which might be an 304 // overloaded name. 305 FunctionDecl *FD = cast<FunctionDecl>(D); 306 IdentifierResolver::iterator Redecl 307 = std::find_if(IdResolver.begin(FD->getDeclName()), 308 IdResolver.end(), 309 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 310 FD)); 311 if (Redecl != IdResolver.end() && 312 S->isDeclScope(DeclPtrTy::make(*Redecl))) { 313 // There is already a declaration of a function on our 314 // IdResolver chain. Replace it with this declaration. 315 S->RemoveDecl(DeclPtrTy::make(*Redecl)); 316 IdResolver.RemoveDecl(*Redecl); 317 } 318 } else if (isa<ObjCInterfaceDecl>(D)) { 319 // We're pushing an Objective-C interface into the current 320 // context. If there is already an alias declaration, remove it first. 321 for (IdentifierResolver::iterator 322 I = IdResolver.begin(D->getDeclName()), IEnd = IdResolver.end(); 323 I != IEnd; ++I) { 324 if (isa<ObjCCompatibleAliasDecl>(*I)) { 325 S->RemoveDecl(DeclPtrTy::make(*I)); 326 IdResolver.RemoveDecl(*I); 327 break; 328 } 329 } 330 } 331 332 IdResolver.AddDecl(D); 333} 334 335void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 336 if (S->decl_empty()) return; 337 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 338 "Scope shouldn't contain decls!"); 339 340 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 341 I != E; ++I) { 342 Decl *TmpD = (*I).getAs<Decl>(); 343 assert(TmpD && "This decl didn't get pushed??"); 344 345 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 346 NamedDecl *D = cast<NamedDecl>(TmpD); 347 348 if (!D->getDeclName()) continue; 349 350 // Remove this name from our lexical scope. 351 IdResolver.RemoveDecl(D); 352 } 353} 354 355/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 356/// return 0 if one not found. 357ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 358 // The third "scope" argument is 0 since we aren't enabling lazy built-in 359 // creation from this context. 360 NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName); 361 362 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 363} 364 365/// getNonFieldDeclScope - Retrieves the innermost scope, starting 366/// from S, where a non-field would be declared. This routine copes 367/// with the difference between C and C++ scoping rules in structs and 368/// unions. For example, the following code is well-formed in C but 369/// ill-formed in C++: 370/// @code 371/// struct S6 { 372/// enum { BAR } e; 373/// }; 374/// 375/// void test_S6() { 376/// struct S6 a; 377/// a.e = BAR; 378/// } 379/// @endcode 380/// For the declaration of BAR, this routine will return a different 381/// scope. The scope S will be the scope of the unnamed enumeration 382/// within S6. In C++, this routine will return the scope associated 383/// with S6, because the enumeration's scope is a transparent 384/// context but structures can contain non-field names. In C, this 385/// routine will return the translation unit scope, since the 386/// enumeration's scope is a transparent context and structures cannot 387/// contain non-field names. 388Scope *Sema::getNonFieldDeclScope(Scope *S) { 389 while (((S->getFlags() & Scope::DeclScope) == 0) || 390 (S->getEntity() && 391 ((DeclContext *)S->getEntity())->isTransparentContext()) || 392 (S->isClassScope() && !getLangOptions().CPlusPlus)) 393 S = S->getParent(); 394 return S; 395} 396 397void Sema::InitBuiltinVaListType() { 398 if (!Context.getBuiltinVaListType().isNull()) 399 return; 400 401 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 402 NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName); 403 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 404 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 405} 406 407/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 408/// file scope. lazily create a decl for it. ForRedeclaration is true 409/// if we're creating this built-in in anticipation of redeclaring the 410/// built-in. 411NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 412 Scope *S, bool ForRedeclaration, 413 SourceLocation Loc) { 414 Builtin::ID BID = (Builtin::ID)bid; 415 416 if (Context.BuiltinInfo.hasVAListUse(BID)) 417 InitBuiltinVaListType(); 418 419 Builtin::Context::GetBuiltinTypeError Error; 420 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context, Error); 421 switch (Error) { 422 case Builtin::Context::GE_None: 423 // Okay 424 break; 425 426 case Builtin::Context::GE_Missing_FILE: 427 if (ForRedeclaration) 428 Diag(Loc, diag::err_implicit_decl_requires_stdio) 429 << Context.BuiltinInfo.GetName(BID); 430 return 0; 431 } 432 433 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 434 Diag(Loc, diag::ext_implicit_lib_function_decl) 435 << Context.BuiltinInfo.GetName(BID) 436 << R; 437 if (Context.BuiltinInfo.getHeaderName(BID) && 438 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 439 != Diagnostic::Ignored) 440 Diag(Loc, diag::note_please_include_header) 441 << Context.BuiltinInfo.getHeaderName(BID) 442 << Context.BuiltinInfo.GetName(BID); 443 } 444 445 FunctionDecl *New = FunctionDecl::Create(Context, 446 Context.getTranslationUnitDecl(), 447 Loc, II, R, 448 FunctionDecl::Extern, false, 449 /*hasPrototype=*/true); 450 New->setImplicit(); 451 452 // Create Decl objects for each parameter, adding them to the 453 // FunctionDecl. 454 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 455 llvm::SmallVector<ParmVarDecl*, 16> Params; 456 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 457 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 458 FT->getArgType(i), VarDecl::None, 0)); 459 New->setParams(Context, Params.data(), Params.size()); 460 } 461 462 AddKnownFunctionAttributes(New); 463 464 // TUScope is the translation-unit scope to insert this function into. 465 // FIXME: This is hideous. We need to teach PushOnScopeChains to 466 // relate Scopes to DeclContexts, and probably eliminate CurContext 467 // entirely, but we're not there yet. 468 DeclContext *SavedContext = CurContext; 469 CurContext = Context.getTranslationUnitDecl(); 470 PushOnScopeChains(New, TUScope); 471 CurContext = SavedContext; 472 return New; 473} 474 475/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 476/// everything from the standard library is defined. 477NamespaceDecl *Sema::GetStdNamespace() { 478 if (!StdNamespace) { 479 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 480 DeclContext *Global = Context.getTranslationUnitDecl(); 481 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 482 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 483 } 484 return StdNamespace; 485} 486 487/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 488/// same name and scope as a previous declaration 'Old'. Figure out 489/// how to resolve this situation, merging decls or emitting 490/// diagnostics as appropriate. If there was an error, set New to be invalid. 491/// 492void Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 493 // If either decl is known invalid already, set the new one to be invalid and 494 // don't bother doing any merging checks. 495 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 496 return New->setInvalidDecl(); 497 498 bool objc_types = false; 499 500 // Allow multiple definitions for ObjC built-in typedefs. 501 // FIXME: Verify the underlying types are equivalent! 502 if (getLangOptions().ObjC1) { 503 const IdentifierInfo *TypeID = New->getIdentifier(); 504 switch (TypeID->getLength()) { 505 default: break; 506 case 2: 507 if (!TypeID->isStr("id")) 508 break; 509 Context.setObjCIdType(Context.getTypeDeclType(New)); 510 objc_types = true; 511 break; 512 case 5: 513 if (!TypeID->isStr("Class")) 514 break; 515 Context.setObjCClassType(Context.getTypeDeclType(New)); 516 return; 517 case 3: 518 if (!TypeID->isStr("SEL")) 519 break; 520 Context.setObjCSelType(Context.getTypeDeclType(New)); 521 return; 522 case 8: 523 if (!TypeID->isStr("Protocol")) 524 break; 525 Context.setObjCProtoType(New->getUnderlyingType()); 526 return; 527 } 528 // Fall through - the typedef name was not a builtin type. 529 } 530 // Verify the old decl was also a type. 531 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 532 if (!Old) { 533 Diag(New->getLocation(), diag::err_redefinition_different_kind) 534 << New->getDeclName(); 535 if (OldD->getLocation().isValid()) 536 Diag(OldD->getLocation(), diag::note_previous_definition); 537 return New->setInvalidDecl(); 538 } 539 540 // Determine the "old" type we'll use for checking and diagnostics. 541 QualType OldType; 542 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 543 OldType = OldTypedef->getUnderlyingType(); 544 else 545 OldType = Context.getTypeDeclType(Old); 546 547 // If the typedef types are not identical, reject them in all languages and 548 // with any extensions enabled. 549 550 if (OldType != New->getUnderlyingType() && 551 Context.getCanonicalType(OldType) != 552 Context.getCanonicalType(New->getUnderlyingType())) { 553 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 554 << New->getUnderlyingType() << OldType; 555 if (Old->getLocation().isValid()) 556 Diag(Old->getLocation(), diag::note_previous_definition); 557 return New->setInvalidDecl(); 558 } 559 560 if (objc_types || getLangOptions().Microsoft) 561 return; 562 563 // C++ [dcl.typedef]p2: 564 // In a given non-class scope, a typedef specifier can be used to 565 // redefine the name of any type declared in that scope to refer 566 // to the type to which it already refers. 567 if (getLangOptions().CPlusPlus) { 568 if (!isa<CXXRecordDecl>(CurContext)) 569 return; 570 Diag(New->getLocation(), diag::err_redefinition) 571 << New->getDeclName(); 572 Diag(Old->getLocation(), diag::note_previous_definition); 573 return New->setInvalidDecl(); 574 } 575 576 // If we have a redefinition of a typedef in C, emit a warning. This warning 577 // is normally mapped to an error, but can be controlled with 578 // -Wtypedef-redefinition. If either the original was in a system header, 579 // don't emit this for compatibility with GCC. 580 if (PP.getDiagnostics().getSuppressSystemWarnings() && 581 Context.getSourceManager().isInSystemHeader(Old->getLocation())) 582 return; 583 584 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 585 << New->getDeclName(); 586 Diag(Old->getLocation(), diag::note_previous_definition); 587 return; 588} 589 590/// DeclhasAttr - returns true if decl Declaration already has the target 591/// attribute. 592static bool DeclHasAttr(const Decl *decl, const Attr *target) { 593 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 594 if (attr->getKind() == target->getKind()) 595 return true; 596 597 return false; 598} 599 600/// MergeAttributes - append attributes from the Old decl to the New one. 601static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 602 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 603 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 604 Attr *NewAttr = attr->clone(C); 605 NewAttr->setInherited(true); 606 New->addAttr(NewAttr); 607 } 608 } 609} 610 611/// Used in MergeFunctionDecl to keep track of function parameters in 612/// C. 613struct GNUCompatibleParamWarning { 614 ParmVarDecl *OldParm; 615 ParmVarDecl *NewParm; 616 QualType PromotedType; 617}; 618 619/// MergeFunctionDecl - We just parsed a function 'New' from 620/// declarator D which has the same name and scope as a previous 621/// declaration 'Old'. Figure out how to resolve this situation, 622/// merging decls or emitting diagnostics as appropriate. 623/// 624/// In C++, New and Old must be declarations that are not 625/// overloaded. Use IsOverload to determine whether New and Old are 626/// overloaded, and to select the Old declaration that New should be 627/// merged with. 628/// 629/// Returns true if there was an error, false otherwise. 630bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 631 assert(!isa<OverloadedFunctionDecl>(OldD) && 632 "Cannot merge with an overloaded function declaration"); 633 634 // Verify the old decl was also a function. 635 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 636 if (!Old) { 637 Diag(New->getLocation(), diag::err_redefinition_different_kind) 638 << New->getDeclName(); 639 Diag(OldD->getLocation(), diag::note_previous_definition); 640 return true; 641 } 642 643 // Determine whether the previous declaration was a definition, 644 // implicit declaration, or a declaration. 645 diag::kind PrevDiag; 646 if (Old->isThisDeclarationADefinition()) 647 PrevDiag = diag::note_previous_definition; 648 else if (Old->isImplicit()) 649 PrevDiag = diag::note_previous_implicit_declaration; 650 else 651 PrevDiag = diag::note_previous_declaration; 652 653 QualType OldQType = Context.getCanonicalType(Old->getType()); 654 QualType NewQType = Context.getCanonicalType(New->getType()); 655 656 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 657 New->getStorageClass() == FunctionDecl::Static && 658 Old->getStorageClass() != FunctionDecl::Static) { 659 Diag(New->getLocation(), diag::err_static_non_static) 660 << New; 661 Diag(Old->getLocation(), PrevDiag); 662 return true; 663 } 664 665 if (getLangOptions().CPlusPlus) { 666 // (C++98 13.1p2): 667 // Certain function declarations cannot be overloaded: 668 // -- Function declarations that differ only in the return type 669 // cannot be overloaded. 670 QualType OldReturnType 671 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 672 QualType NewReturnType 673 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 674 if (OldReturnType != NewReturnType) { 675 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 676 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 677 return true; 678 } 679 680 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 681 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 682 if (OldMethod && NewMethod && 683 OldMethod->getLexicalDeclContext() == 684 NewMethod->getLexicalDeclContext()) { 685 // -- Member function declarations with the same name and the 686 // same parameter types cannot be overloaded if any of them 687 // is a static member function declaration. 688 if (OldMethod->isStatic() || NewMethod->isStatic()) { 689 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 690 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 691 return true; 692 } 693 694 // C++ [class.mem]p1: 695 // [...] A member shall not be declared twice in the 696 // member-specification, except that a nested class or member 697 // class template can be declared and then later defined. 698 unsigned NewDiag; 699 if (isa<CXXConstructorDecl>(OldMethod)) 700 NewDiag = diag::err_constructor_redeclared; 701 else if (isa<CXXDestructorDecl>(NewMethod)) 702 NewDiag = diag::err_destructor_redeclared; 703 else if (isa<CXXConversionDecl>(NewMethod)) 704 NewDiag = diag::err_conv_function_redeclared; 705 else 706 NewDiag = diag::err_member_redeclared; 707 708 Diag(New->getLocation(), NewDiag); 709 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 710 } 711 712 // (C++98 8.3.5p3): 713 // All declarations for a function shall agree exactly in both the 714 // return type and the parameter-type-list. 715 if (OldQType == NewQType) 716 return MergeCompatibleFunctionDecls(New, Old); 717 718 // Fall through for conflicting redeclarations and redefinitions. 719 } 720 721 // C: Function types need to be compatible, not identical. This handles 722 // duplicate function decls like "void f(int); void f(enum X);" properly. 723 if (!getLangOptions().CPlusPlus && 724 Context.typesAreCompatible(OldQType, NewQType)) { 725 const FunctionType *OldFuncType = OldQType->getAsFunctionType(); 726 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 727 const FunctionProtoType *OldProto = 0; 728 if (isa<FunctionNoProtoType>(NewFuncType) && 729 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 730 // The old declaration provided a function prototype, but the 731 // new declaration does not. Merge in the prototype. 732 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 733 OldProto->arg_type_end()); 734 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 735 ParamTypes.data(), ParamTypes.size(), 736 OldProto->isVariadic(), 737 OldProto->getTypeQuals()); 738 New->setType(NewQType); 739 New->setHasInheritedPrototype(); 740 741 // Synthesize a parameter for each argument type. 742 llvm::SmallVector<ParmVarDecl*, 16> Params; 743 for (FunctionProtoType::arg_type_iterator 744 ParamType = OldProto->arg_type_begin(), 745 ParamEnd = OldProto->arg_type_end(); 746 ParamType != ParamEnd; ++ParamType) { 747 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 748 SourceLocation(), 0, 749 *ParamType, VarDecl::None, 750 0); 751 Param->setImplicit(); 752 Params.push_back(Param); 753 } 754 755 New->setParams(Context, Params.data(), Params.size()); 756 } 757 758 return MergeCompatibleFunctionDecls(New, Old); 759 } 760 761 // GNU C permits a K&R definition to follow a prototype declaration 762 // if the declared types of the parameters in the K&R definition 763 // match the types in the prototype declaration, even when the 764 // promoted types of the parameters from the K&R definition differ 765 // from the types in the prototype. GCC then keeps the types from 766 // the prototype. 767 if (!getLangOptions().CPlusPlus && 768 Old->hasPrototype() && !New->hasPrototype() && 769 New->getType()->getAsFunctionProtoType() && 770 Old->getNumParams() == New->getNumParams()) { 771 llvm::SmallVector<QualType, 16> ArgTypes; 772 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 773 const FunctionProtoType *OldProto 774 = Old->getType()->getAsFunctionProtoType(); 775 const FunctionProtoType *NewProto 776 = New->getType()->getAsFunctionProtoType(); 777 778 // Determine whether this is the GNU C extension. 779 bool GNUCompatible = 780 Context.typesAreCompatible(OldProto->getResultType(), 781 NewProto->getResultType()) && 782 (OldProto->isVariadic() == NewProto->isVariadic()); 783 for (unsigned Idx = 0, End = Old->getNumParams(); 784 GNUCompatible && Idx != End; ++Idx) { 785 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 786 ParmVarDecl *NewParm = New->getParamDecl(Idx); 787 if (Context.typesAreCompatible(OldParm->getType(), 788 NewProto->getArgType(Idx))) { 789 ArgTypes.push_back(NewParm->getType()); 790 } else if (Context.typesAreCompatible(OldParm->getType(), 791 NewParm->getType())) { 792 GNUCompatibleParamWarning Warn 793 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 794 Warnings.push_back(Warn); 795 ArgTypes.push_back(NewParm->getType()); 796 } else 797 GNUCompatible = false; 798 } 799 800 if (GNUCompatible) { 801 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 802 Diag(Warnings[Warn].NewParm->getLocation(), 803 diag::ext_param_promoted_not_compatible_with_prototype) 804 << Warnings[Warn].PromotedType 805 << Warnings[Warn].OldParm->getType(); 806 Diag(Warnings[Warn].OldParm->getLocation(), 807 diag::note_previous_declaration); 808 } 809 810 New->setType(Context.getFunctionType(NewProto->getResultType(), 811 &ArgTypes[0], ArgTypes.size(), 812 NewProto->isVariadic(), 813 NewProto->getTypeQuals())); 814 return MergeCompatibleFunctionDecls(New, Old); 815 } 816 817 // Fall through to diagnose conflicting types. 818 } 819 820 // A function that has already been declared has been redeclared or defined 821 // with a different type- show appropriate diagnostic 822 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 823 // The user has declared a builtin function with an incompatible 824 // signature. 825 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 826 // The function the user is redeclaring is a library-defined 827 // function like 'malloc' or 'printf'. Warn about the 828 // redeclaration, then pretend that we don't know about this 829 // library built-in. 830 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 831 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 832 << Old << Old->getType(); 833 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 834 Old->setInvalidDecl(); 835 return false; 836 } 837 838 PrevDiag = diag::note_previous_builtin_declaration; 839 } 840 841 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 842 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 843 return true; 844} 845 846/// \brief Completes the merge of two function declarations that are 847/// known to be compatible. 848/// 849/// This routine handles the merging of attributes and other 850/// properties of function declarations form the old declaration to 851/// the new declaration, once we know that New is in fact a 852/// redeclaration of Old. 853/// 854/// \returns false 855bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 856 // Merge the attributes 857 MergeAttributes(New, Old, Context); 858 859 // Merge the storage class. 860 if (Old->getStorageClass() != FunctionDecl::Extern) 861 New->setStorageClass(Old->getStorageClass()); 862 863 // Merge "inline" 864 if (Old->isInline()) 865 New->setInline(true); 866 867 // If this function declaration by itself qualifies as a C99 inline 868 // definition (C99 6.7.4p6), but the previous definition did not, 869 // then the function is not a C99 inline definition. 870 if (New->isC99InlineDefinition() && !Old->isC99InlineDefinition()) 871 New->setC99InlineDefinition(false); 872 else if (Old->isC99InlineDefinition() && !New->isC99InlineDefinition()) { 873 // Mark all preceding definitions as not being C99 inline definitions. 874 for (const FunctionDecl *Prev = Old; Prev; 875 Prev = Prev->getPreviousDeclaration()) 876 const_cast<FunctionDecl *>(Prev)->setC99InlineDefinition(false); 877 } 878 879 // Merge "pure" flag. 880 if (Old->isPure()) 881 New->setPure(); 882 883 // Merge the "deleted" flag. 884 if (Old->isDeleted()) 885 New->setDeleted(); 886 887 if (getLangOptions().CPlusPlus) 888 return MergeCXXFunctionDecl(New, Old); 889 890 return false; 891} 892 893/// MergeVarDecl - We just parsed a variable 'New' which has the same name 894/// and scope as a previous declaration 'Old'. Figure out how to resolve this 895/// situation, merging decls or emitting diagnostics as appropriate. 896/// 897/// Tentative definition rules (C99 6.9.2p2) are checked by 898/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 899/// definitions here, since the initializer hasn't been attached. 900/// 901void Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 902 // If either decl is invalid, make sure the new one is marked invalid and 903 // don't do any other checking. 904 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 905 return New->setInvalidDecl(); 906 907 // Verify the old decl was also a variable. 908 VarDecl *Old = dyn_cast<VarDecl>(OldD); 909 if (!Old) { 910 Diag(New->getLocation(), diag::err_redefinition_different_kind) 911 << New->getDeclName(); 912 Diag(OldD->getLocation(), diag::note_previous_definition); 913 return New->setInvalidDecl(); 914 } 915 916 MergeAttributes(New, Old, Context); 917 918 // Merge the types 919 QualType MergedT; 920 if (getLangOptions().CPlusPlus) { 921 if (Context.hasSameType(New->getType(), Old->getType())) 922 MergedT = New->getType(); 923 } else { 924 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 925 } 926 if (MergedT.isNull()) { 927 Diag(New->getLocation(), diag::err_redefinition_different_type) 928 << New->getDeclName(); 929 Diag(Old->getLocation(), diag::note_previous_definition); 930 return New->setInvalidDecl(); 931 } 932 New->setType(MergedT); 933 934 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 935 if (New->getStorageClass() == VarDecl::Static && 936 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 937 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 938 Diag(Old->getLocation(), diag::note_previous_definition); 939 return New->setInvalidDecl(); 940 } 941 // C99 6.2.2p4: 942 // For an identifier declared with the storage-class specifier 943 // extern in a scope in which a prior declaration of that 944 // identifier is visible,23) if the prior declaration specifies 945 // internal or external linkage, the linkage of the identifier at 946 // the later declaration is the same as the linkage specified at 947 // the prior declaration. If no prior declaration is visible, or 948 // if the prior declaration specifies no linkage, then the 949 // identifier has external linkage. 950 if (New->hasExternalStorage() && Old->hasLinkage()) 951 /* Okay */; 952 else if (New->getStorageClass() != VarDecl::Static && 953 Old->getStorageClass() == VarDecl::Static) { 954 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 955 Diag(Old->getLocation(), diag::note_previous_definition); 956 return New->setInvalidDecl(); 957 } 958 959 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 960 961 // FIXME: The test for external storage here seems wrong? We still 962 // need to check for mismatches. 963 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 964 // Don't complain about out-of-line definitions of static members. 965 !(Old->getLexicalDeclContext()->isRecord() && 966 !New->getLexicalDeclContext()->isRecord())) { 967 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 968 Diag(Old->getLocation(), diag::note_previous_definition); 969 return New->setInvalidDecl(); 970 } 971 972 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 973 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 974 Diag(Old->getLocation(), diag::note_previous_definition); 975 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 976 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 977 Diag(Old->getLocation(), diag::note_previous_definition); 978 } 979 980 // Keep a chain of previous declarations. 981 New->setPreviousDeclaration(Old); 982} 983 984/// CheckParmsForFunctionDef - Check that the parameters of the given 985/// function are appropriate for the definition of a function. This 986/// takes care of any checks that cannot be performed on the 987/// declaration itself, e.g., that the types of each of the function 988/// parameters are complete. 989bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 990 bool HasInvalidParm = false; 991 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 992 ParmVarDecl *Param = FD->getParamDecl(p); 993 994 // C99 6.7.5.3p4: the parameters in a parameter type list in a 995 // function declarator that is part of a function definition of 996 // that function shall not have incomplete type. 997 // 998 // This is also C++ [dcl.fct]p6. 999 if (!Param->isInvalidDecl() && 1000 RequireCompleteType(Param->getLocation(), Param->getType(), 1001 diag::err_typecheck_decl_incomplete_type)) { 1002 Param->setInvalidDecl(); 1003 HasInvalidParm = true; 1004 } 1005 1006 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1007 // declaration of each parameter shall include an identifier. 1008 if (Param->getIdentifier() == 0 && 1009 !Param->isImplicit() && 1010 !getLangOptions().CPlusPlus) 1011 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1012 } 1013 1014 return HasInvalidParm; 1015} 1016 1017/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1018/// no declarator (e.g. "struct foo;") is parsed. 1019Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1020 // FIXME: Error on auto/register at file scope 1021 // FIXME: Error on inline/virtual/explicit 1022 // FIXME: Error on invalid restrict 1023 // FIXME: Warn on useless __thread 1024 // FIXME: Warn on useless const/volatile 1025 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1026 // FIXME: Warn on useless attributes 1027 TagDecl *Tag = 0; 1028 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1029 DS.getTypeSpecType() == DeclSpec::TST_struct || 1030 DS.getTypeSpecType() == DeclSpec::TST_union || 1031 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1032 if (!DS.getTypeRep()) // We probably had an error 1033 return DeclPtrTy(); 1034 1035 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 1036 } 1037 1038 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1039 if (!Record->getDeclName() && Record->isDefinition() && 1040 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1041 if (getLangOptions().CPlusPlus || 1042 Record->getDeclContext()->isRecord()) 1043 return BuildAnonymousStructOrUnion(S, DS, Record); 1044 1045 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1046 << DS.getSourceRange(); 1047 } 1048 1049 // Microsoft allows unnamed struct/union fields. Don't complain 1050 // about them. 1051 // FIXME: Should we support Microsoft's extensions in this area? 1052 if (Record->getDeclName() && getLangOptions().Microsoft) 1053 return DeclPtrTy::make(Tag); 1054 } 1055 1056 if (!DS.isMissingDeclaratorOk() && 1057 DS.getTypeSpecType() != DeclSpec::TST_error) { 1058 // Warn about typedefs of enums without names, since this is an 1059 // extension in both Microsoft an GNU. 1060 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1061 Tag && isa<EnumDecl>(Tag)) { 1062 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1063 << DS.getSourceRange(); 1064 return DeclPtrTy::make(Tag); 1065 } 1066 1067 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1068 << DS.getSourceRange(); 1069 return DeclPtrTy(); 1070 } 1071 1072 return DeclPtrTy::make(Tag); 1073} 1074 1075/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1076/// anonymous struct or union AnonRecord into the owning context Owner 1077/// and scope S. This routine will be invoked just after we realize 1078/// that an unnamed union or struct is actually an anonymous union or 1079/// struct, e.g., 1080/// 1081/// @code 1082/// union { 1083/// int i; 1084/// float f; 1085/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1086/// // f into the surrounding scope.x 1087/// @endcode 1088/// 1089/// This routine is recursive, injecting the names of nested anonymous 1090/// structs/unions into the owning context and scope as well. 1091bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1092 RecordDecl *AnonRecord) { 1093 bool Invalid = false; 1094 for (RecordDecl::field_iterator F = AnonRecord->field_begin(Context), 1095 FEnd = AnonRecord->field_end(Context); 1096 F != FEnd; ++F) { 1097 if ((*F)->getDeclName()) { 1098 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 1099 LookupOrdinaryName, true); 1100 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 1101 // C++ [class.union]p2: 1102 // The names of the members of an anonymous union shall be 1103 // distinct from the names of any other entity in the 1104 // scope in which the anonymous union is declared. 1105 unsigned diagKind 1106 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 1107 : diag::err_anonymous_struct_member_redecl; 1108 Diag((*F)->getLocation(), diagKind) 1109 << (*F)->getDeclName(); 1110 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1111 Invalid = true; 1112 } else { 1113 // C++ [class.union]p2: 1114 // For the purpose of name lookup, after the anonymous union 1115 // definition, the members of the anonymous union are 1116 // considered to have been defined in the scope in which the 1117 // anonymous union is declared. 1118 Owner->makeDeclVisibleInContext(Context, *F); 1119 S->AddDecl(DeclPtrTy::make(*F)); 1120 IdResolver.AddDecl(*F); 1121 } 1122 } else if (const RecordType *InnerRecordType 1123 = (*F)->getType()->getAsRecordType()) { 1124 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1125 if (InnerRecord->isAnonymousStructOrUnion()) 1126 Invalid = Invalid || 1127 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1128 } 1129 } 1130 1131 return Invalid; 1132} 1133 1134/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1135/// anonymous structure or union. Anonymous unions are a C++ feature 1136/// (C++ [class.union]) and a GNU C extension; anonymous structures 1137/// are a GNU C and GNU C++ extension. 1138Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1139 RecordDecl *Record) { 1140 DeclContext *Owner = Record->getDeclContext(); 1141 1142 // Diagnose whether this anonymous struct/union is an extension. 1143 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1144 Diag(Record->getLocation(), diag::ext_anonymous_union); 1145 else if (!Record->isUnion()) 1146 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1147 1148 // C and C++ require different kinds of checks for anonymous 1149 // structs/unions. 1150 bool Invalid = false; 1151 if (getLangOptions().CPlusPlus) { 1152 const char* PrevSpec = 0; 1153 // C++ [class.union]p3: 1154 // Anonymous unions declared in a named namespace or in the 1155 // global namespace shall be declared static. 1156 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1157 (isa<TranslationUnitDecl>(Owner) || 1158 (isa<NamespaceDecl>(Owner) && 1159 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1160 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1161 Invalid = true; 1162 1163 // Recover by adding 'static'. 1164 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec); 1165 } 1166 // C++ [class.union]p3: 1167 // A storage class is not allowed in a declaration of an 1168 // anonymous union in a class scope. 1169 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1170 isa<RecordDecl>(Owner)) { 1171 Diag(DS.getStorageClassSpecLoc(), 1172 diag::err_anonymous_union_with_storage_spec); 1173 Invalid = true; 1174 1175 // Recover by removing the storage specifier. 1176 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1177 PrevSpec); 1178 } 1179 1180 // C++ [class.union]p2: 1181 // The member-specification of an anonymous union shall only 1182 // define non-static data members. [Note: nested types and 1183 // functions cannot be declared within an anonymous union. ] 1184 for (DeclContext::decl_iterator Mem = Record->decls_begin(Context), 1185 MemEnd = Record->decls_end(Context); 1186 Mem != MemEnd; ++Mem) { 1187 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1188 // C++ [class.union]p3: 1189 // An anonymous union shall not have private or protected 1190 // members (clause 11). 1191 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1192 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1193 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1194 Invalid = true; 1195 } 1196 } else if ((*Mem)->isImplicit()) { 1197 // Any implicit members are fine. 1198 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1199 // This is a type that showed up in an 1200 // elaborated-type-specifier inside the anonymous struct or 1201 // union, but which actually declares a type outside of the 1202 // anonymous struct or union. It's okay. 1203 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1204 if (!MemRecord->isAnonymousStructOrUnion() && 1205 MemRecord->getDeclName()) { 1206 // This is a nested type declaration. 1207 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1208 << (int)Record->isUnion(); 1209 Invalid = true; 1210 } 1211 } else { 1212 // We have something that isn't a non-static data 1213 // member. Complain about it. 1214 unsigned DK = diag::err_anonymous_record_bad_member; 1215 if (isa<TypeDecl>(*Mem)) 1216 DK = diag::err_anonymous_record_with_type; 1217 else if (isa<FunctionDecl>(*Mem)) 1218 DK = diag::err_anonymous_record_with_function; 1219 else if (isa<VarDecl>(*Mem)) 1220 DK = diag::err_anonymous_record_with_static; 1221 Diag((*Mem)->getLocation(), DK) 1222 << (int)Record->isUnion(); 1223 Invalid = true; 1224 } 1225 } 1226 } 1227 1228 if (!Record->isUnion() && !Owner->isRecord()) { 1229 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1230 << (int)getLangOptions().CPlusPlus; 1231 Invalid = true; 1232 } 1233 1234 // Create a declaration for this anonymous struct/union. 1235 NamedDecl *Anon = 0; 1236 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1237 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1238 /*IdentifierInfo=*/0, 1239 Context.getTypeDeclType(Record), 1240 /*BitWidth=*/0, /*Mutable=*/false); 1241 Anon->setAccess(AS_public); 1242 if (getLangOptions().CPlusPlus) 1243 FieldCollector->Add(cast<FieldDecl>(Anon)); 1244 } else { 1245 VarDecl::StorageClass SC; 1246 switch (DS.getStorageClassSpec()) { 1247 default: assert(0 && "Unknown storage class!"); 1248 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1249 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1250 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1251 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1252 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1253 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1254 case DeclSpec::SCS_mutable: 1255 // mutable can only appear on non-static class members, so it's always 1256 // an error here 1257 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1258 Invalid = true; 1259 SC = VarDecl::None; 1260 break; 1261 } 1262 1263 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1264 /*IdentifierInfo=*/0, 1265 Context.getTypeDeclType(Record), 1266 SC, DS.getSourceRange().getBegin()); 1267 } 1268 Anon->setImplicit(); 1269 1270 // Add the anonymous struct/union object to the current 1271 // context. We'll be referencing this object when we refer to one of 1272 // its members. 1273 Owner->addDecl(Context, Anon); 1274 1275 // Inject the members of the anonymous struct/union into the owning 1276 // context and into the identifier resolver chain for name lookup 1277 // purposes. 1278 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1279 Invalid = true; 1280 1281 // Mark this as an anonymous struct/union type. Note that we do not 1282 // do this until after we have already checked and injected the 1283 // members of this anonymous struct/union type, because otherwise 1284 // the members could be injected twice: once by DeclContext when it 1285 // builds its lookup table, and once by 1286 // InjectAnonymousStructOrUnionMembers. 1287 Record->setAnonymousStructOrUnion(true); 1288 1289 if (Invalid) 1290 Anon->setInvalidDecl(); 1291 1292 return DeclPtrTy::make(Anon); 1293} 1294 1295 1296/// GetNameForDeclarator - Determine the full declaration name for the 1297/// given Declarator. 1298DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1299 switch (D.getKind()) { 1300 case Declarator::DK_Abstract: 1301 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1302 return DeclarationName(); 1303 1304 case Declarator::DK_Normal: 1305 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1306 return DeclarationName(D.getIdentifier()); 1307 1308 case Declarator::DK_Constructor: { 1309 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1310 Ty = Context.getCanonicalType(Ty); 1311 return Context.DeclarationNames.getCXXConstructorName(Ty); 1312 } 1313 1314 case Declarator::DK_Destructor: { 1315 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1316 Ty = Context.getCanonicalType(Ty); 1317 return Context.DeclarationNames.getCXXDestructorName(Ty); 1318 } 1319 1320 case Declarator::DK_Conversion: { 1321 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1322 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1323 Ty = Context.getCanonicalType(Ty); 1324 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1325 } 1326 1327 case Declarator::DK_Operator: 1328 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1329 return Context.DeclarationNames.getCXXOperatorName( 1330 D.getOverloadedOperator()); 1331 } 1332 1333 assert(false && "Unknown name kind"); 1334 return DeclarationName(); 1335} 1336 1337/// isNearlyMatchingFunction - Determine whether the C++ functions 1338/// Declaration and Definition are "nearly" matching. This heuristic 1339/// is used to improve diagnostics in the case where an out-of-line 1340/// function definition doesn't match any declaration within 1341/// the class or namespace. 1342static bool isNearlyMatchingFunction(ASTContext &Context, 1343 FunctionDecl *Declaration, 1344 FunctionDecl *Definition) { 1345 if (Declaration->param_size() != Definition->param_size()) 1346 return false; 1347 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1348 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1349 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1350 1351 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1352 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1353 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1354 return false; 1355 } 1356 1357 return true; 1358} 1359 1360Sema::DeclPtrTy 1361Sema::ActOnDeclarator(Scope *S, Declarator &D, bool IsFunctionDefinition) { 1362 DeclarationName Name = GetNameForDeclarator(D); 1363 1364 // All of these full declarators require an identifier. If it doesn't have 1365 // one, the ParsedFreeStandingDeclSpec action should be used. 1366 if (!Name) { 1367 if (!D.isInvalidType()) // Reject this if we think it is valid. 1368 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1369 diag::err_declarator_need_ident) 1370 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1371 return DeclPtrTy(); 1372 } 1373 1374 // The scope passed in may not be a decl scope. Zip up the scope tree until 1375 // we find one that is. 1376 while ((S->getFlags() & Scope::DeclScope) == 0 || 1377 (S->getFlags() & Scope::TemplateParamScope) != 0) 1378 S = S->getParent(); 1379 1380 DeclContext *DC; 1381 NamedDecl *PrevDecl; 1382 NamedDecl *New; 1383 1384 QualType R = GetTypeForDeclarator(D, S); 1385 1386 // See if this is a redefinition of a variable in the same scope. 1387 if (D.getCXXScopeSpec().isInvalid()) { 1388 DC = CurContext; 1389 PrevDecl = 0; 1390 D.setInvalidType(); 1391 } else if (!D.getCXXScopeSpec().isSet()) { 1392 LookupNameKind NameKind = LookupOrdinaryName; 1393 1394 // If the declaration we're planning to build will be a function 1395 // or object with linkage, then look for another declaration with 1396 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1397 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1398 /* Do nothing*/; 1399 else if (R->isFunctionType()) { 1400 if (CurContext->isFunctionOrMethod()) 1401 NameKind = LookupRedeclarationWithLinkage; 1402 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1403 NameKind = LookupRedeclarationWithLinkage; 1404 1405 DC = CurContext; 1406 PrevDecl = LookupName(S, Name, NameKind, true, 1407 D.getDeclSpec().getStorageClassSpec() != 1408 DeclSpec::SCS_static, 1409 D.getIdentifierLoc()); 1410 } else { // Something like "int foo::x;" 1411 DC = computeDeclContext(D.getCXXScopeSpec()); 1412 // FIXME: RequireCompleteDeclContext(D.getCXXScopeSpec()); ? 1413 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1414 1415 // C++ 7.3.1.2p2: 1416 // Members (including explicit specializations of templates) of a named 1417 // namespace can also be defined outside that namespace by explicit 1418 // qualification of the name being defined, provided that the entity being 1419 // defined was already declared in the namespace and the definition appears 1420 // after the point of declaration in a namespace that encloses the 1421 // declarations namespace. 1422 // 1423 // Note that we only check the context at this point. We don't yet 1424 // have enough information to make sure that PrevDecl is actually 1425 // the declaration we want to match. For example, given: 1426 // 1427 // class X { 1428 // void f(); 1429 // void f(float); 1430 // }; 1431 // 1432 // void X::f(int) { } // ill-formed 1433 // 1434 // In this case, PrevDecl will point to the overload set 1435 // containing the two f's declared in X, but neither of them 1436 // matches. 1437 1438 // First check whether we named the global scope. 1439 if (isa<TranslationUnitDecl>(DC)) { 1440 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1441 << Name << D.getCXXScopeSpec().getRange(); 1442 } else if (!CurContext->Encloses(DC)) { 1443 // The qualifying scope doesn't enclose the original declaration. 1444 // Emit diagnostic based on current scope. 1445 SourceLocation L = D.getIdentifierLoc(); 1446 SourceRange R = D.getCXXScopeSpec().getRange(); 1447 if (isa<FunctionDecl>(CurContext)) 1448 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1449 else 1450 Diag(L, diag::err_invalid_declarator_scope) 1451 << Name << cast<NamedDecl>(DC) << R; 1452 D.setInvalidType(); 1453 } 1454 } 1455 1456 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1457 // Maybe we will complain about the shadowed template parameter. 1458 if (!D.isInvalidType()) 1459 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl)) 1460 D.setInvalidType(); 1461 1462 // Just pretend that we didn't see the previous declaration. 1463 PrevDecl = 0; 1464 } 1465 1466 // In C++, the previous declaration we find might be a tag type 1467 // (class or enum). In this case, the new declaration will hide the 1468 // tag type. Note that this does does not apply if we're declaring a 1469 // typedef (C++ [dcl.typedef]p4). 1470 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1471 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1472 PrevDecl = 0; 1473 1474 bool Redeclaration = false; 1475 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1476 New = ActOnTypedefDeclarator(S, D, DC, R, PrevDecl, Redeclaration); 1477 } else if (R->isFunctionType()) { 1478 New = ActOnFunctionDeclarator(S, D, DC, R, PrevDecl, 1479 IsFunctionDefinition, Redeclaration); 1480 } else { 1481 New = ActOnVariableDeclarator(S, D, DC, R, PrevDecl, Redeclaration); 1482 } 1483 1484 if (New == 0) 1485 return DeclPtrTy(); 1486 1487 // If this has an identifier and is not an invalid redeclaration, 1488 // add it to the scope stack. 1489 if (Name && !(Redeclaration && New->isInvalidDecl())) 1490 PushOnScopeChains(New, S); 1491 1492 return DeclPtrTy::make(New); 1493} 1494 1495/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1496/// types into constant array types in certain situations which would otherwise 1497/// be errors (for GCC compatibility). 1498static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1499 ASTContext &Context, 1500 bool &SizeIsNegative) { 1501 // This method tries to turn a variable array into a constant 1502 // array even when the size isn't an ICE. This is necessary 1503 // for compatibility with code that depends on gcc's buggy 1504 // constant expression folding, like struct {char x[(int)(char*)2];} 1505 SizeIsNegative = false; 1506 1507 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1508 QualType Pointee = PTy->getPointeeType(); 1509 QualType FixedType = 1510 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1511 if (FixedType.isNull()) return FixedType; 1512 FixedType = Context.getPointerType(FixedType); 1513 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1514 return FixedType; 1515 } 1516 1517 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1518 if (!VLATy) 1519 return QualType(); 1520 // FIXME: We should probably handle this case 1521 if (VLATy->getElementType()->isVariablyModifiedType()) 1522 return QualType(); 1523 1524 Expr::EvalResult EvalResult; 1525 if (!VLATy->getSizeExpr() || 1526 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 1527 !EvalResult.Val.isInt()) 1528 return QualType(); 1529 1530 llvm::APSInt &Res = EvalResult.Val.getInt(); 1531 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1532 return Context.getConstantArrayType(VLATy->getElementType(), 1533 Res, ArrayType::Normal, 0); 1534 1535 SizeIsNegative = true; 1536 return QualType(); 1537} 1538 1539/// \brief Register the given locally-scoped external C declaration so 1540/// that it can be found later for redeclarations 1541void 1542Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, NamedDecl *PrevDecl, 1543 Scope *S) { 1544 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 1545 "Decl is not a locally-scoped decl!"); 1546 // Note that we have a locally-scoped external with this name. 1547 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 1548 1549 if (!PrevDecl) 1550 return; 1551 1552 // If there was a previous declaration of this variable, it may be 1553 // in our identifier chain. Update the identifier chain with the new 1554 // declaration. 1555 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 1556 // The previous declaration was found on the identifer resolver 1557 // chain, so remove it from its scope. 1558 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 1559 S = S->getParent(); 1560 1561 if (S) 1562 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 1563 } 1564} 1565 1566/// \brief Diagnose function specifiers on a declaration of an identifier that 1567/// does not identify a function. 1568void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 1569 // FIXME: We should probably indicate the identifier in question to avoid 1570 // confusion for constructs like "inline int a(), b;" 1571 if (D.getDeclSpec().isInlineSpecified()) 1572 Diag(D.getDeclSpec().getInlineSpecLoc(), 1573 diag::err_inline_non_function); 1574 1575 if (D.getDeclSpec().isVirtualSpecified()) 1576 Diag(D.getDeclSpec().getVirtualSpecLoc(), 1577 diag::err_virtual_non_function); 1578 1579 if (D.getDeclSpec().isExplicitSpecified()) 1580 Diag(D.getDeclSpec().getExplicitSpecLoc(), 1581 diag::err_explicit_non_function); 1582} 1583 1584NamedDecl* 1585Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1586 QualType R, Decl* PrevDecl, bool &Redeclaration) { 1587 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1588 if (D.getCXXScopeSpec().isSet()) { 1589 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1590 << D.getCXXScopeSpec().getRange(); 1591 D.setInvalidType(); 1592 // Pretend we didn't see the scope specifier. 1593 DC = 0; 1594 } 1595 1596 if (getLangOptions().CPlusPlus) { 1597 // Check that there are no default arguments (C++ only). 1598 CheckExtraCXXDefaultArguments(D); 1599 } 1600 1601 DiagnoseFunctionSpecifiers(D); 1602 1603 if (D.getDeclSpec().isThreadSpecified()) 1604 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 1605 1606 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R); 1607 if (!NewTD) return 0; 1608 1609 if (D.isInvalidType()) 1610 NewTD->setInvalidDecl(); 1611 1612 // Handle attributes prior to checking for duplicates in MergeVarDecl 1613 ProcessDeclAttributes(NewTD, D); 1614 // Merge the decl with the existing one if appropriate. If the decl is 1615 // in an outer scope, it isn't the same thing. 1616 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1617 Redeclaration = true; 1618 MergeTypeDefDecl(NewTD, PrevDecl); 1619 } 1620 1621 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1622 // then it shall have block scope. 1623 QualType T = NewTD->getUnderlyingType(); 1624 if (T->isVariablyModifiedType()) { 1625 CurFunctionNeedsScopeChecking = true; 1626 1627 if (S->getFnParent() == 0) { 1628 bool SizeIsNegative; 1629 QualType FixedTy = 1630 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1631 if (!FixedTy.isNull()) { 1632 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1633 NewTD->setUnderlyingType(FixedTy); 1634 } else { 1635 if (SizeIsNegative) 1636 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1637 else if (T->isVariableArrayType()) 1638 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1639 else 1640 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1641 NewTD->setInvalidDecl(); 1642 } 1643 } 1644 } 1645 return NewTD; 1646} 1647 1648/// \brief Determines whether the given declaration is an out-of-scope 1649/// previous declaration. 1650/// 1651/// This routine should be invoked when name lookup has found a 1652/// previous declaration (PrevDecl) that is not in the scope where a 1653/// new declaration by the same name is being introduced. If the new 1654/// declaration occurs in a local scope, previous declarations with 1655/// linkage may still be considered previous declarations (C99 1656/// 6.2.2p4-5, C++ [basic.link]p6). 1657/// 1658/// \param PrevDecl the previous declaration found by name 1659/// lookup 1660/// 1661/// \param DC the context in which the new declaration is being 1662/// declared. 1663/// 1664/// \returns true if PrevDecl is an out-of-scope previous declaration 1665/// for a new delcaration with the same name. 1666static bool 1667isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 1668 ASTContext &Context) { 1669 if (!PrevDecl) 1670 return 0; 1671 1672 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 1673 // case we need to check each of the overloaded functions. 1674 if (!PrevDecl->hasLinkage()) 1675 return false; 1676 1677 if (Context.getLangOptions().CPlusPlus) { 1678 // C++ [basic.link]p6: 1679 // If there is a visible declaration of an entity with linkage 1680 // having the same name and type, ignoring entities declared 1681 // outside the innermost enclosing namespace scope, the block 1682 // scope declaration declares that same entity and receives the 1683 // linkage of the previous declaration. 1684 DeclContext *OuterContext = DC->getLookupContext(); 1685 if (!OuterContext->isFunctionOrMethod()) 1686 // This rule only applies to block-scope declarations. 1687 return false; 1688 else { 1689 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 1690 if (PrevOuterContext->isRecord()) 1691 // We found a member function: ignore it. 1692 return false; 1693 else { 1694 // Find the innermost enclosing namespace for the new and 1695 // previous declarations. 1696 while (!OuterContext->isFileContext()) 1697 OuterContext = OuterContext->getParent(); 1698 while (!PrevOuterContext->isFileContext()) 1699 PrevOuterContext = PrevOuterContext->getParent(); 1700 1701 // The previous declaration is in a different namespace, so it 1702 // isn't the same function. 1703 if (OuterContext->getPrimaryContext() != 1704 PrevOuterContext->getPrimaryContext()) 1705 return false; 1706 } 1707 } 1708 } 1709 1710 return true; 1711} 1712 1713NamedDecl* 1714Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1715 QualType R,NamedDecl* PrevDecl, 1716 bool &Redeclaration) { 1717 DeclarationName Name = GetNameForDeclarator(D); 1718 1719 // Check that there are no default arguments (C++ only). 1720 if (getLangOptions().CPlusPlus) 1721 CheckExtraCXXDefaultArguments(D); 1722 1723 VarDecl *NewVD; 1724 VarDecl::StorageClass SC; 1725 switch (D.getDeclSpec().getStorageClassSpec()) { 1726 default: assert(0 && "Unknown storage class!"); 1727 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1728 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1729 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1730 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1731 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1732 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1733 case DeclSpec::SCS_mutable: 1734 // mutable can only appear on non-static class members, so it's always 1735 // an error here 1736 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1737 D.setInvalidType(); 1738 SC = VarDecl::None; 1739 break; 1740 } 1741 1742 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1743 if (!II) { 1744 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1745 << Name.getAsString(); 1746 return 0; 1747 } 1748 1749 DiagnoseFunctionSpecifiers(D); 1750 1751 if (!DC->isRecord() && S->getFnParent() == 0) { 1752 // C99 6.9p2: The storage-class specifiers auto and register shall not 1753 // appear in the declaration specifiers in an external declaration. 1754 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1755 1756 // If this is a register variable with an asm label specified, then this 1757 // is a GNU extension. 1758 if (SC == VarDecl::Register && D.getAsmLabel()) 1759 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 1760 else 1761 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 1762 D.setInvalidType(); 1763 } 1764 } 1765 if (DC->isRecord() && !CurContext->isRecord()) { 1766 // This is an out-of-line definition of a static data member. 1767 if (SC == VarDecl::Static) { 1768 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1769 diag::err_static_out_of_line) 1770 << CodeModificationHint::CreateRemoval( 1771 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 1772 } else if (SC == VarDecl::None) 1773 SC = VarDecl::Static; 1774 } 1775 1776 // The variable can not 1777 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1778 II, R, SC, 1779 // FIXME: Move to DeclGroup... 1780 D.getDeclSpec().getSourceRange().getBegin()); 1781 1782 if (D.isInvalidType()) 1783 NewVD->setInvalidDecl(); 1784 1785 if (D.getDeclSpec().isThreadSpecified()) { 1786 if (NewVD->hasLocalStorage()) 1787 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 1788 else if (!Context.Target.isTLSSupported()) 1789 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 1790 else 1791 NewVD->setThreadSpecified(true); 1792 } 1793 1794 // Set the lexical context. If the declarator has a C++ scope specifier, the 1795 // lexical context will be different from the semantic context. 1796 NewVD->setLexicalDeclContext(CurContext); 1797 1798 // Handle attributes prior to checking for duplicates in MergeVarDecl 1799 ProcessDeclAttributes(NewVD, D); 1800 1801 // Handle GNU asm-label extension (encoded as an attribute). 1802 if (Expr *E = (Expr*) D.getAsmLabel()) { 1803 // The parser guarantees this is a string. 1804 StringLiteral *SE = cast<StringLiteral>(E); 1805 NewVD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 1806 SE->getByteLength()))); 1807 } 1808 1809 // If name lookup finds a previous declaration that is not in the 1810 // same scope as the new declaration, this may still be an 1811 // acceptable redeclaration. 1812 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 1813 !(NewVD->hasLinkage() && 1814 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 1815 PrevDecl = 0; 1816 1817 // Merge the decl with the existing one if appropriate. 1818 if (PrevDecl) { 1819 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 1820 // The user tried to define a non-static data member 1821 // out-of-line (C++ [dcl.meaning]p1). 1822 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 1823 << D.getCXXScopeSpec().getRange(); 1824 PrevDecl = 0; 1825 NewVD->setInvalidDecl(); 1826 } 1827 } else if (D.getCXXScopeSpec().isSet()) { 1828 // No previous declaration in the qualifying scope. 1829 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 1830 << Name << D.getCXXScopeSpec().getRange(); 1831 NewVD->setInvalidDecl(); 1832 } 1833 1834 CheckVariableDeclaration(NewVD, PrevDecl, Redeclaration); 1835 1836 // If this is a locally-scoped extern C variable, update the map of 1837 // such variables. 1838 if (CurContext->isFunctionOrMethod() && NewVD->isExternC(Context) && 1839 !NewVD->isInvalidDecl()) 1840 RegisterLocallyScopedExternCDecl(NewVD, PrevDecl, S); 1841 1842 return NewVD; 1843} 1844 1845/// \brief Perform semantic checking on a newly-created variable 1846/// declaration. 1847/// 1848/// This routine performs all of the type-checking required for a 1849/// variable declaration once it has been built. It is used both to 1850/// check variables after they have been parsed and their declarators 1851/// have been translated into a declaration, and to check variables 1852/// that have been instantiated from a template. 1853/// 1854/// Sets NewVD->isInvalidDecl() if an error was encountered. 1855void Sema::CheckVariableDeclaration(VarDecl *NewVD, NamedDecl *PrevDecl, 1856 bool &Redeclaration) { 1857 // If the decl is already known invalid, don't check it. 1858 if (NewVD->isInvalidDecl()) 1859 return; 1860 1861 QualType T = NewVD->getType(); 1862 1863 if (T->isObjCInterfaceType()) { 1864 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 1865 return NewVD->setInvalidDecl(); 1866 } 1867 1868 // The variable can not have an abstract class type. 1869 if (RequireNonAbstractType(NewVD->getLocation(), T, 1870 diag::err_abstract_type_in_decl, 1871 AbstractVariableType)) 1872 return NewVD->setInvalidDecl(); 1873 1874 // Emit an error if an address space was applied to decl with local storage. 1875 // This includes arrays of objects with address space qualifiers, but not 1876 // automatic variables that point to other address spaces. 1877 // ISO/IEC TR 18037 S5.1.2 1878 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 1879 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 1880 return NewVD->setInvalidDecl(); 1881 } 1882 1883 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 1884 && !NewVD->hasAttr<BlocksAttr>()) 1885 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 1886 1887 bool isVM = T->isVariablyModifiedType(); 1888 if (isVM || NewVD->hasAttr<CleanupAttr>()) 1889 CurFunctionNeedsScopeChecking = true; 1890 1891 if ((isVM && NewVD->hasLinkage()) || 1892 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 1893 bool SizeIsNegative; 1894 QualType FixedTy = 1895 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1896 1897 if (FixedTy.isNull() && T->isVariableArrayType()) { 1898 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 1899 // FIXME: This won't give the correct result for 1900 // int a[10][n]; 1901 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 1902 1903 if (NewVD->isFileVarDecl()) 1904 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 1905 << SizeRange; 1906 else if (NewVD->getStorageClass() == VarDecl::Static) 1907 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 1908 << SizeRange; 1909 else 1910 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 1911 << SizeRange; 1912 return NewVD->setInvalidDecl(); 1913 } 1914 1915 if (FixedTy.isNull()) { 1916 if (NewVD->isFileVarDecl()) 1917 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 1918 else 1919 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 1920 return NewVD->setInvalidDecl(); 1921 } 1922 1923 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 1924 NewVD->setType(FixedTy); 1925 } 1926 1927 if (!PrevDecl && NewVD->isExternC(Context)) { 1928 // Since we did not find anything by this name and we're declaring 1929 // an extern "C" variable, look for a non-visible extern "C" 1930 // declaration with the same name. 1931 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 1932 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 1933 if (Pos != LocallyScopedExternalDecls.end()) 1934 PrevDecl = Pos->second; 1935 } 1936 1937 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 1938 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 1939 << T; 1940 return NewVD->setInvalidDecl(); 1941 } 1942 1943 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 1944 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 1945 return NewVD->setInvalidDecl(); 1946 } 1947 1948 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 1949 Diag(NewVD->getLocation(), diag::err_block_on_vm); 1950 return NewVD->setInvalidDecl(); 1951 } 1952 1953 if (PrevDecl) { 1954 Redeclaration = true; 1955 MergeVarDecl(NewVD, PrevDecl); 1956 } 1957} 1958 1959NamedDecl* 1960Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1961 QualType R, NamedDecl* PrevDecl, 1962 bool IsFunctionDefinition, bool &Redeclaration) { 1963 assert(R.getTypePtr()->isFunctionType()); 1964 1965 DeclarationName Name = GetNameForDeclarator(D); 1966 FunctionDecl::StorageClass SC = FunctionDecl::None; 1967 switch (D.getDeclSpec().getStorageClassSpec()) { 1968 default: assert(0 && "Unknown storage class!"); 1969 case DeclSpec::SCS_auto: 1970 case DeclSpec::SCS_register: 1971 case DeclSpec::SCS_mutable: 1972 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1973 diag::err_typecheck_sclass_func); 1974 D.setInvalidType(); 1975 break; 1976 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 1977 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 1978 case DeclSpec::SCS_static: { 1979 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 1980 // C99 6.7.1p5: 1981 // The declaration of an identifier for a function that has 1982 // block scope shall have no explicit storage-class specifier 1983 // other than extern 1984 // See also (C++ [dcl.stc]p4). 1985 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1986 diag::err_static_block_func); 1987 SC = FunctionDecl::None; 1988 } else 1989 SC = FunctionDecl::Static; 1990 break; 1991 } 1992 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 1993 } 1994 1995 if (D.getDeclSpec().isThreadSpecified()) 1996 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 1997 1998 bool isInline = D.getDeclSpec().isInlineSpecified(); 1999 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 2000 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 2001 2002 // Check that the return type is not an abstract class type. 2003 // For record types, this is done by the AbstractClassUsageDiagnoser once 2004 // the class has been completely parsed. 2005 if (!DC->isRecord() && 2006 RequireNonAbstractType(D.getIdentifierLoc(), 2007 R->getAsFunctionType()->getResultType(), 2008 diag::err_abstract_type_in_decl, 2009 AbstractReturnType)) 2010 D.setInvalidType(); 2011 2012 // Do not allow returning a objc interface by-value. 2013 if (R->getAsFunctionType()->getResultType()->isObjCInterfaceType()) { 2014 Diag(D.getIdentifierLoc(), 2015 diag::err_object_cannot_be_passed_returned_by_value) << 0 2016 << R->getAsFunctionType()->getResultType(); 2017 D.setInvalidType(); 2018 } 2019 2020 bool isVirtualOkay = false; 2021 FunctionDecl *NewFD; 2022 if (D.getKind() == Declarator::DK_Constructor) { 2023 // This is a C++ constructor declaration. 2024 assert(DC->isRecord() && 2025 "Constructors can only be declared in a member context"); 2026 2027 R = CheckConstructorDeclarator(D, R, SC); 2028 2029 // Create the new declaration 2030 NewFD = CXXConstructorDecl::Create(Context, 2031 cast<CXXRecordDecl>(DC), 2032 D.getIdentifierLoc(), Name, R, 2033 isExplicit, isInline, 2034 /*isImplicitlyDeclared=*/false); 2035 } else if (D.getKind() == Declarator::DK_Destructor) { 2036 // This is a C++ destructor declaration. 2037 if (DC->isRecord()) { 2038 R = CheckDestructorDeclarator(D, SC); 2039 2040 NewFD = CXXDestructorDecl::Create(Context, 2041 cast<CXXRecordDecl>(DC), 2042 D.getIdentifierLoc(), Name, R, 2043 isInline, 2044 /*isImplicitlyDeclared=*/false); 2045 2046 isVirtualOkay = true; 2047 } else { 2048 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 2049 2050 // Create a FunctionDecl to satisfy the function definition parsing 2051 // code path. 2052 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 2053 Name, R, SC, isInline, 2054 /*hasPrototype=*/true, 2055 // FIXME: Move to DeclGroup... 2056 D.getDeclSpec().getSourceRange().getBegin()); 2057 D.setInvalidType(); 2058 } 2059 } else if (D.getKind() == Declarator::DK_Conversion) { 2060 if (!DC->isRecord()) { 2061 Diag(D.getIdentifierLoc(), 2062 diag::err_conv_function_not_member); 2063 return 0; 2064 } 2065 2066 CheckConversionDeclarator(D, R, SC); 2067 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 2068 D.getIdentifierLoc(), Name, R, 2069 isInline, isExplicit); 2070 2071 isVirtualOkay = true; 2072 } else if (DC->isRecord()) { 2073 // If the of the function is the same as the name of the record, then this 2074 // must be an invalid constructor that has a return type. 2075 // (The parser checks for a return type and makes the declarator a 2076 // constructor if it has no return type). 2077 // must have an invalid constructor that has a return type 2078 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 2079 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 2080 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 2081 << SourceRange(D.getIdentifierLoc()); 2082 return 0; 2083 } 2084 2085 // This is a C++ method declaration. 2086 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 2087 D.getIdentifierLoc(), Name, R, 2088 (SC == FunctionDecl::Static), isInline); 2089 2090 isVirtualOkay = (SC != FunctionDecl::Static); 2091 } else { 2092 // Determine whether the function was written with a 2093 // prototype. This true when: 2094 // - we're in C++ (where every function has a prototype), 2095 // - there is a prototype in the declarator, or 2096 // - the type R of the function is some kind of typedef or other reference 2097 // to a type name (which eventually refers to a function type). 2098 bool HasPrototype = 2099 getLangOptions().CPlusPlus || 2100 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 2101 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 2102 2103 NewFD = FunctionDecl::Create(Context, DC, 2104 D.getIdentifierLoc(), 2105 Name, R, SC, isInline, HasPrototype, 2106 // FIXME: Move to DeclGroup... 2107 D.getDeclSpec().getSourceRange().getBegin()); 2108 } 2109 2110 if (D.isInvalidType()) 2111 NewFD->setInvalidDecl(); 2112 2113 // Set the lexical context. If the declarator has a C++ 2114 // scope specifier, the lexical context will be different 2115 // from the semantic context. 2116 NewFD->setLexicalDeclContext(CurContext); 2117 2118 // C++ [dcl.fct.spec]p5: 2119 // The virtual specifier shall only be used in declarations of 2120 // nonstatic class member functions that appear within a 2121 // member-specification of a class declaration; see 10.3. 2122 // 2123 if (isVirtual && !NewFD->isInvalidDecl()) { 2124 if (!isVirtualOkay) { 2125 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2126 diag::err_virtual_non_function); 2127 } else if (!CurContext->isRecord()) { 2128 // 'virtual' was specified outside of the class. 2129 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 2130 << CodeModificationHint::CreateRemoval( 2131 SourceRange(D.getDeclSpec().getVirtualSpecLoc())); 2132 } else { 2133 // Okay: Add virtual to the method. 2134 cast<CXXMethodDecl>(NewFD)->setVirtualAsWritten(true); 2135 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 2136 CurClass->setAggregate(false); 2137 CurClass->setPOD(false); 2138 CurClass->setPolymorphic(true); 2139 CurClass->setHasTrivialConstructor(false); 2140 } 2141 } 2142 2143 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD)) { 2144 // Look for virtual methods in base classes that this method might override. 2145 2146 BasePaths Paths; 2147 // FIXME: This will not include hidden member functions. 2148 if (LookupInBases(cast<CXXRecordDecl>(DC), 2149 MemberLookupCriteria(Name, LookupMemberName, 2150 // FIXME: Shouldn't IDNS_Member be 2151 // enough here? 2152 Decl::IDNS_Member | 2153 Decl::IDNS_Ordinary), Paths)) { 2154 for (BasePaths::decl_iterator I = Paths.found_decls_begin(), 2155 E = Paths.found_decls_end(); I != E; ++I) { 2156 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2157 OverloadedFunctionDecl::function_iterator MatchedDecl; 2158 // FIXME: Is this OK? Should it be done by LookupInBases? 2159 if (IsOverload(NewMD, OldMD, MatchedDecl)) 2160 continue; 2161 if (!OldMD->isVirtual()) 2162 continue; 2163 2164 if (!CheckOverridingFunctionReturnType(NewMD, OldMD)) 2165 NewMD->addOverriddenMethod(OldMD); 2166 } 2167 } 2168 } 2169 } 2170 2171 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 2172 !CurContext->isRecord()) { 2173 // C++ [class.static]p1: 2174 // A data or function member of a class may be declared static 2175 // in a class definition, in which case it is a static member of 2176 // the class. 2177 2178 // Complain about the 'static' specifier if it's on an out-of-line 2179 // member function definition. 2180 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2181 diag::err_static_out_of_line) 2182 << CodeModificationHint::CreateRemoval( 2183 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2184 } 2185 2186 // Handle GNU asm-label extension (encoded as an attribute). 2187 if (Expr *E = (Expr*) D.getAsmLabel()) { 2188 // The parser guarantees this is a string. 2189 StringLiteral *SE = cast<StringLiteral>(E); 2190 NewFD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2191 SE->getByteLength()))); 2192 } 2193 2194 // Copy the parameter declarations from the declarator D to the function 2195 // declaration NewFD, if they are available. First scavenge them into Params. 2196 llvm::SmallVector<ParmVarDecl*, 16> Params; 2197 if (D.getNumTypeObjects() > 0) { 2198 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2199 2200 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 2201 // function that takes no arguments, not a function that takes a 2202 // single void argument. 2203 // We let through "const void" here because Sema::GetTypeForDeclarator 2204 // already checks for that case. 2205 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 2206 FTI.ArgInfo[0].Param && 2207 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 2208 // Empty arg list, don't push any params. 2209 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 2210 2211 // In C++, the empty parameter-type-list must be spelled "void"; a 2212 // typedef of void is not permitted. 2213 if (getLangOptions().CPlusPlus && 2214 Param->getType().getUnqualifiedType() != Context.VoidTy) 2215 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 2216 // FIXME: Leaks decl? 2217 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 2218 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 2219 Params.push_back(FTI.ArgInfo[i].Param.getAs<ParmVarDecl>()); 2220 } 2221 2222 } else if (const FunctionProtoType *FT = R->getAsFunctionProtoType()) { 2223 // When we're declaring a function with a typedef, typeof, etc as in the 2224 // following example, we'll need to synthesize (unnamed) 2225 // parameters for use in the declaration. 2226 // 2227 // @code 2228 // typedef void fn(int); 2229 // fn f; 2230 // @endcode 2231 2232 // Synthesize a parameter for each argument type. 2233 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 2234 AE = FT->arg_type_end(); AI != AE; ++AI) { 2235 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 2236 SourceLocation(), 0, 2237 *AI, VarDecl::None, 0); 2238 Param->setImplicit(); 2239 Params.push_back(Param); 2240 } 2241 } else { 2242 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 2243 "Should not need args for typedef of non-prototype fn"); 2244 } 2245 // Finally, we know we have the right number of parameters, install them. 2246 NewFD->setParams(Context, Params.data(), Params.size()); 2247 2248 2249 2250 // If name lookup finds a previous declaration that is not in the 2251 // same scope as the new declaration, this may still be an 2252 // acceptable redeclaration. 2253 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2254 !(NewFD->hasLinkage() && 2255 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2256 PrevDecl = 0; 2257 2258 // Perform semantic checking on the function declaration. 2259 bool OverloadableAttrRequired = false; // FIXME: HACK! 2260 CheckFunctionDeclaration(NewFD, PrevDecl, Redeclaration, 2261 /*FIXME:*/OverloadableAttrRequired); 2262 2263 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 2264 // An out-of-line member function declaration must also be a 2265 // definition (C++ [dcl.meaning]p1). 2266 if (!IsFunctionDefinition) { 2267 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2268 << D.getCXXScopeSpec().getRange(); 2269 NewFD->setInvalidDecl(); 2270 } else if (!Redeclaration) { 2271 // The user tried to provide an out-of-line definition for a 2272 // function that is a member of a class or namespace, but there 2273 // was no such member function declared (C++ [class.mfct]p2, 2274 // C++ [namespace.memdef]p2). For example: 2275 // 2276 // class X { 2277 // void f() const; 2278 // }; 2279 // 2280 // void X::f() { } // ill-formed 2281 // 2282 // Complain about this problem, and attempt to suggest close 2283 // matches (e.g., those that differ only in cv-qualifiers and 2284 // whether the parameter types are references). 2285 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 2286 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 2287 NewFD->setInvalidDecl(); 2288 2289 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 2290 true); 2291 assert(!Prev.isAmbiguous() && 2292 "Cannot have an ambiguity in previous-declaration lookup"); 2293 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 2294 Func != FuncEnd; ++Func) { 2295 if (isa<FunctionDecl>(*Func) && 2296 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 2297 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 2298 } 2299 2300 PrevDecl = 0; 2301 } 2302 } 2303 2304 // Handle attributes. We need to have merged decls when handling attributes 2305 // (for example to check for conflicts, etc). 2306 // FIXME: This needs to happen before we merge declarations. Then, 2307 // let attribute merging cope with attribute conflicts. 2308 ProcessDeclAttributes(NewFD, D); 2309 AddKnownFunctionAttributes(NewFD); 2310 2311 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 2312 // If a function name is overloadable in C, then every function 2313 // with that name must be marked "overloadable". 2314 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 2315 << Redeclaration << NewFD; 2316 if (PrevDecl) 2317 Diag(PrevDecl->getLocation(), 2318 diag::note_attribute_overloadable_prev_overload); 2319 NewFD->addAttr(::new (Context) OverloadableAttr()); 2320 } 2321 2322 // If this is a locally-scoped extern C function, update the 2323 // map of such names. 2324 if (CurContext->isFunctionOrMethod() && NewFD->isExternC(Context) 2325 && !NewFD->isInvalidDecl()) 2326 RegisterLocallyScopedExternCDecl(NewFD, PrevDecl, S); 2327 2328 return NewFD; 2329} 2330 2331/// \brief Perform semantic checking of a new function declaration. 2332/// 2333/// Performs semantic analysis of the new function declaration 2334/// NewFD. This routine performs all semantic checking that does not 2335/// require the actual declarator involved in the declaration, and is 2336/// used both for the declaration of functions as they are parsed 2337/// (called via ActOnDeclarator) and for the declaration of functions 2338/// that have been instantiated via C++ template instantiation (called 2339/// via InstantiateDecl). 2340/// 2341/// This sets NewFD->isInvalidDecl() to true if there was an error. 2342void Sema::CheckFunctionDeclaration(FunctionDecl *NewFD, NamedDecl *&PrevDecl, 2343 bool &Redeclaration, 2344 bool &OverloadableAttrRequired) { 2345 // If NewFD is already known erroneous, don't do any of this checking. 2346 if (NewFD->isInvalidDecl()) 2347 return; 2348 2349 if (NewFD->getResultType()->isVariablyModifiedType()) { 2350 // Functions returning a variably modified type violate C99 6.7.5.2p2 2351 // because all functions have linkage. 2352 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 2353 return NewFD->setInvalidDecl(); 2354 } 2355 2356 // Semantic checking for this function declaration (in isolation). 2357 if (getLangOptions().CPlusPlus) { 2358 // C++-specific checks. 2359 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 2360 CheckConstructor(Constructor); 2361 } else if (isa<CXXDestructorDecl>(NewFD)) { 2362 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 2363 Record->setUserDeclaredDestructor(true); 2364 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 2365 // user-defined destructor. 2366 Record->setPOD(false); 2367 2368 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 2369 // declared destructor. 2370 Record->setHasTrivialDestructor(false); 2371 } else if (CXXConversionDecl *Conversion 2372 = dyn_cast<CXXConversionDecl>(NewFD)) 2373 ActOnConversionDeclarator(Conversion); 2374 2375 // Extra checking for C++ overloaded operators (C++ [over.oper]). 2376 if (NewFD->isOverloadedOperator() && 2377 CheckOverloadedOperatorDeclaration(NewFD)) 2378 return NewFD->setInvalidDecl(); 2379 } 2380 2381 // C99 6.7.4p6: 2382 // [... ] For a function with external linkage, the following 2383 // restrictions apply: [...] If all of the file scope declarations 2384 // for a function in a translation unit include the inline 2385 // function specifier without extern, then the definition in that 2386 // translation unit is an inline definition. An inline definition 2387 // does not provide an external definition for the function, and 2388 // does not forbid an external definition in another translation 2389 // unit. 2390 // 2391 // Here we determine whether this function, in isolation, would be a 2392 // C99 inline definition. MergeCompatibleFunctionDecls looks at 2393 // previous declarations. 2394 if (NewFD->isInline() && getLangOptions().C99 && 2395 NewFD->getStorageClass() == FunctionDecl::None && 2396 NewFD->getDeclContext()->getLookupContext()->isTranslationUnit()) 2397 NewFD->setC99InlineDefinition(true); 2398 2399 // Check for a previous declaration of this name. 2400 if (!PrevDecl && NewFD->isExternC(Context)) { 2401 // Since we did not find anything by this name and we're declaring 2402 // an extern "C" function, look for a non-visible extern "C" 2403 // declaration with the same name. 2404 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2405 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 2406 if (Pos != LocallyScopedExternalDecls.end()) 2407 PrevDecl = Pos->second; 2408 } 2409 2410 // Merge or overload the declaration with an existing declaration of 2411 // the same name, if appropriate. 2412 if (PrevDecl) { 2413 // Determine whether NewFD is an overload of PrevDecl or 2414 // a declaration that requires merging. If it's an overload, 2415 // there's no more work to do here; we'll just add the new 2416 // function to the scope. 2417 OverloadedFunctionDecl::function_iterator MatchedDecl; 2418 2419 if (!getLangOptions().CPlusPlus && 2420 AllowOverloadingOfFunction(PrevDecl, Context)) { 2421 OverloadableAttrRequired = true; 2422 2423 // Functions marked "overloadable" must have a prototype (that 2424 // we can't get through declaration merging). 2425 if (!NewFD->getType()->getAsFunctionProtoType()) { 2426 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 2427 << NewFD; 2428 Redeclaration = true; 2429 2430 // Turn this into a variadic function with no parameters. 2431 QualType R = Context.getFunctionType( 2432 NewFD->getType()->getAsFunctionType()->getResultType(), 2433 0, 0, true, 0); 2434 NewFD->setType(R); 2435 return NewFD->setInvalidDecl(); 2436 } 2437 } 2438 2439 if (PrevDecl && 2440 (!AllowOverloadingOfFunction(PrevDecl, Context) || 2441 !IsOverload(NewFD, PrevDecl, MatchedDecl))) { 2442 Redeclaration = true; 2443 Decl *OldDecl = PrevDecl; 2444 2445 // If PrevDecl was an overloaded function, extract the 2446 // FunctionDecl that matched. 2447 if (isa<OverloadedFunctionDecl>(PrevDecl)) 2448 OldDecl = *MatchedDecl; 2449 2450 // NewFD and OldDecl represent declarations that need to be 2451 // merged. 2452 if (MergeFunctionDecl(NewFD, OldDecl)) 2453 return NewFD->setInvalidDecl(); 2454 2455 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 2456 } 2457 } 2458 2459 // In C++, check default arguments now that we have merged decls. Unless 2460 // the lexical context is the class, because in this case this is done 2461 // during delayed parsing anyway. 2462 if (getLangOptions().CPlusPlus && !CurContext->isRecord()) 2463 CheckCXXDefaultArguments(NewFD); 2464} 2465 2466bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2467 // FIXME: Need strict checking. In C89, we need to check for 2468 // any assignment, increment, decrement, function-calls, or 2469 // commas outside of a sizeof. In C99, it's the same list, 2470 // except that the aforementioned are allowed in unevaluated 2471 // expressions. Everything else falls under the 2472 // "may accept other forms of constant expressions" exception. 2473 // (We never end up here for C++, so the constant expression 2474 // rules there don't matter.) 2475 if (Init->isConstantInitializer(Context)) 2476 return false; 2477 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 2478 << Init->getSourceRange(); 2479 return true; 2480} 2481 2482void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init) { 2483 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 2484} 2485 2486/// AddInitializerToDecl - Adds the initializer Init to the 2487/// declaration dcl. If DirectInit is true, this is C++ direct 2488/// initialization rather than copy initialization. 2489void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 2490 Decl *RealDecl = dcl.getAs<Decl>(); 2491 // If there is no declaration, there was an error parsing it. Just ignore 2492 // the initializer. 2493 if (RealDecl == 0) 2494 return; 2495 2496 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 2497 // With declarators parsed the way they are, the parser cannot 2498 // distinguish between a normal initializer and a pure-specifier. 2499 // Thus this grotesque test. 2500 IntegerLiteral *IL; 2501 Expr *Init = static_cast<Expr *>(init.get()); 2502 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 2503 Context.getCanonicalType(IL->getType()) == Context.IntTy) { 2504 if (Method->isVirtualAsWritten()) { 2505 Method->setPure(); 2506 2507 // A class is abstract if at least one function is pure virtual. 2508 cast<CXXRecordDecl>(CurContext)->setAbstract(true); 2509 } else if (!Method->isInvalidDecl()) { 2510 Diag(Method->getLocation(), diag::err_non_virtual_pure) 2511 << Method->getDeclName() << Init->getSourceRange(); 2512 Method->setInvalidDecl(); 2513 } 2514 } else { 2515 Diag(Method->getLocation(), diag::err_member_function_initialization) 2516 << Method->getDeclName() << Init->getSourceRange(); 2517 Method->setInvalidDecl(); 2518 } 2519 return; 2520 } 2521 2522 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 2523 if (!VDecl) { 2524 if (getLangOptions().CPlusPlus && 2525 RealDecl->getLexicalDeclContext()->isRecord() && 2526 isa<NamedDecl>(RealDecl)) 2527 Diag(RealDecl->getLocation(), diag::err_member_initialization) 2528 << cast<NamedDecl>(RealDecl)->getDeclName(); 2529 else 2530 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 2531 RealDecl->setInvalidDecl(); 2532 return; 2533 } 2534 2535 if (!VDecl->getType()->isArrayType() && 2536 RequireCompleteType(VDecl->getLocation(), VDecl->getType(), 2537 diag::err_typecheck_decl_incomplete_type)) { 2538 RealDecl->setInvalidDecl(); 2539 return; 2540 } 2541 2542 const VarDecl *Def = 0; 2543 if (VDecl->getDefinition(Def)) { 2544 Diag(VDecl->getLocation(), diag::err_redefinition) 2545 << VDecl->getDeclName(); 2546 Diag(Def->getLocation(), diag::note_previous_definition); 2547 VDecl->setInvalidDecl(); 2548 return; 2549 } 2550 2551 // Take ownership of the expression, now that we're sure we have somewhere 2552 // to put it. 2553 Expr *Init = init.takeAs<Expr>(); 2554 assert(Init && "missing initializer"); 2555 2556 // Get the decls type and save a reference for later, since 2557 // CheckInitializerTypes may change it. 2558 QualType DclT = VDecl->getType(), SavT = DclT; 2559 if (VDecl->isBlockVarDecl()) { 2560 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 2561 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 2562 VDecl->setInvalidDecl(); 2563 } else if (!VDecl->isInvalidDecl()) { 2564 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2565 VDecl->getDeclName(), DirectInit)) 2566 VDecl->setInvalidDecl(); 2567 2568 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2569 // Don't check invalid declarations to avoid emitting useless diagnostics. 2570 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 2571 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 2572 CheckForConstantInitializer(Init, DclT); 2573 } 2574 } 2575 } else if (VDecl->isStaticDataMember() && 2576 VDecl->getLexicalDeclContext()->isRecord()) { 2577 // This is an in-class initialization for a static data member, e.g., 2578 // 2579 // struct S { 2580 // static const int value = 17; 2581 // }; 2582 2583 // Attach the initializer 2584 VDecl->setInit(Context, Init); 2585 2586 // C++ [class.mem]p4: 2587 // A member-declarator can contain a constant-initializer only 2588 // if it declares a static member (9.4) of const integral or 2589 // const enumeration type, see 9.4.2. 2590 QualType T = VDecl->getType(); 2591 if (!T->isDependentType() && 2592 (!Context.getCanonicalType(T).isConstQualified() || 2593 !T->isIntegralType())) { 2594 Diag(VDecl->getLocation(), diag::err_member_initialization) 2595 << VDecl->getDeclName() << Init->getSourceRange(); 2596 VDecl->setInvalidDecl(); 2597 } else { 2598 // C++ [class.static.data]p4: 2599 // If a static data member is of const integral or const 2600 // enumeration type, its declaration in the class definition 2601 // can specify a constant-initializer which shall be an 2602 // integral constant expression (5.19). 2603 if (!Init->isTypeDependent() && 2604 !Init->getType()->isIntegralType()) { 2605 // We have a non-dependent, non-integral or enumeration type. 2606 Diag(Init->getSourceRange().getBegin(), 2607 diag::err_in_class_initializer_non_integral_type) 2608 << Init->getType() << Init->getSourceRange(); 2609 VDecl->setInvalidDecl(); 2610 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 2611 // Check whether the expression is a constant expression. 2612 llvm::APSInt Value; 2613 SourceLocation Loc; 2614 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 2615 Diag(Loc, diag::err_in_class_initializer_non_constant) 2616 << Init->getSourceRange(); 2617 VDecl->setInvalidDecl(); 2618 } else if (!VDecl->getType()->isDependentType()) 2619 ImpCastExprToType(Init, VDecl->getType()); 2620 } 2621 } 2622 } else if (VDecl->isFileVarDecl()) { 2623 if (VDecl->getStorageClass() == VarDecl::Extern) 2624 Diag(VDecl->getLocation(), diag::warn_extern_init); 2625 if (!VDecl->isInvalidDecl()) 2626 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2627 VDecl->getDeclName(), DirectInit)) 2628 VDecl->setInvalidDecl(); 2629 2630 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2631 // Don't check invalid declarations to avoid emitting useless diagnostics. 2632 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 2633 // C99 6.7.8p4. All file scoped initializers need to be constant. 2634 CheckForConstantInitializer(Init, DclT); 2635 } 2636 } 2637 // If the type changed, it means we had an incomplete type that was 2638 // completed by the initializer. For example: 2639 // int ary[] = { 1, 3, 5 }; 2640 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 2641 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 2642 VDecl->setType(DclT); 2643 Init->setType(DclT); 2644 } 2645 2646 // Attach the initializer to the decl. 2647 VDecl->setInit(Context, Init); 2648 2649 // If the previous declaration of VDecl was a tentative definition, 2650 // remove it from the set of tentative definitions. 2651 if (VDecl->getPreviousDeclaration() && 2652 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 2653 llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos 2654 = TentativeDefinitions.find(VDecl->getDeclName()); 2655 assert(Pos != TentativeDefinitions.end() && 2656 "Unrecorded tentative definition?"); 2657 TentativeDefinitions.erase(Pos); 2658 } 2659 2660 return; 2661} 2662 2663void Sema::ActOnUninitializedDecl(DeclPtrTy dcl) { 2664 Decl *RealDecl = dcl.getAs<Decl>(); 2665 2666 // If there is no declaration, there was an error parsing it. Just ignore it. 2667 if (RealDecl == 0) 2668 return; 2669 2670 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 2671 QualType Type = Var->getType(); 2672 2673 // Record tentative definitions. 2674 if (Var->isTentativeDefinition(Context)) 2675 TentativeDefinitions[Var->getDeclName()] = Var; 2676 2677 // C++ [dcl.init.ref]p3: 2678 // The initializer can be omitted for a reference only in a 2679 // parameter declaration (8.3.5), in the declaration of a 2680 // function return type, in the declaration of a class member 2681 // within its class declaration (9.2), and where the extern 2682 // specifier is explicitly used. 2683 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 2684 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 2685 << Var->getDeclName() 2686 << SourceRange(Var->getLocation(), Var->getLocation()); 2687 Var->setInvalidDecl(); 2688 return; 2689 } 2690 2691 // C++ [dcl.init]p9: 2692 // 2693 // If no initializer is specified for an object, and the object 2694 // is of (possibly cv-qualified) non-POD class type (or array 2695 // thereof), the object shall be default-initialized; if the 2696 // object is of const-qualified type, the underlying class type 2697 // shall have a user-declared default constructor. 2698 if (getLangOptions().CPlusPlus) { 2699 QualType InitType = Type; 2700 if (const ArrayType *Array = Context.getAsArrayType(Type)) 2701 InitType = Array->getElementType(); 2702 if ((!Var->hasExternalStorage() && !Var->isExternC(Context)) && 2703 InitType->isRecordType()) { 2704 CXXRecordDecl *RD = 2705 cast<CXXRecordDecl>(InitType->getAsRecordType()->getDecl()); 2706 CXXConstructorDecl *Constructor = 0; 2707 if (!RequireCompleteType(Var->getLocation(), InitType, 2708 diag::err_invalid_incomplete_type_use)) 2709 Constructor 2710 = PerformInitializationByConstructor(InitType, 0, 0, 2711 Var->getLocation(), 2712 SourceRange(Var->getLocation(), 2713 Var->getLocation()), 2714 Var->getDeclName(), 2715 IK_Default); 2716 if (!Constructor) 2717 Var->setInvalidDecl(); 2718 else if (!RD->hasTrivialConstructor()) 2719 InitializeVarWithConstructor(Var, Constructor, InitType, 0, 0); 2720 } 2721 } 2722 2723#if 0 2724 // FIXME: Temporarily disabled because we are not properly parsing 2725 // linkage specifications on declarations, e.g., 2726 // 2727 // extern "C" const CGPoint CGPointerZero; 2728 // 2729 // C++ [dcl.init]p9: 2730 // 2731 // If no initializer is specified for an object, and the 2732 // object is of (possibly cv-qualified) non-POD class type (or 2733 // array thereof), the object shall be default-initialized; if 2734 // the object is of const-qualified type, the underlying class 2735 // type shall have a user-declared default 2736 // constructor. Otherwise, if no initializer is specified for 2737 // an object, the object and its subobjects, if any, have an 2738 // indeterminate initial value; if the object or any of its 2739 // subobjects are of const-qualified type, the program is 2740 // ill-formed. 2741 // 2742 // This isn't technically an error in C, so we don't diagnose it. 2743 // 2744 // FIXME: Actually perform the POD/user-defined default 2745 // constructor check. 2746 if (getLangOptions().CPlusPlus && 2747 Context.getCanonicalType(Type).isConstQualified() && 2748 !Var->hasExternalStorage()) 2749 Diag(Var->getLocation(), diag::err_const_var_requires_init) 2750 << Var->getName() 2751 << SourceRange(Var->getLocation(), Var->getLocation()); 2752#endif 2753 } 2754} 2755 2756Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, DeclPtrTy *Group, 2757 unsigned NumDecls) { 2758 llvm::SmallVector<Decl*, 8> Decls; 2759 2760 for (unsigned i = 0; i != NumDecls; ++i) 2761 if (Decl *D = Group[i].getAs<Decl>()) 2762 Decls.push_back(D); 2763 2764 // Perform semantic analysis that depends on having fully processed both 2765 // the declarator and initializer. 2766 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 2767 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 2768 if (!IDecl) 2769 continue; 2770 QualType T = IDecl->getType(); 2771 2772 // Block scope. C99 6.7p7: If an identifier for an object is declared with 2773 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 2774 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 2775 if (!IDecl->isInvalidDecl() && 2776 RequireCompleteType(IDecl->getLocation(), T, 2777 diag::err_typecheck_decl_incomplete_type)) 2778 IDecl->setInvalidDecl(); 2779 } 2780 // File scope. C99 6.9.2p2: A declaration of an identifier for and 2781 // object that has file scope without an initializer, and without a 2782 // storage-class specifier or with the storage-class specifier "static", 2783 // constitutes a tentative definition. Note: A tentative definition with 2784 // external linkage is valid (C99 6.2.2p5). 2785 if (IDecl->isTentativeDefinition(Context)) { 2786 QualType CheckType = T; 2787 unsigned DiagID = diag::err_typecheck_decl_incomplete_type; 2788 2789 const IncompleteArrayType *ArrayT = Context.getAsIncompleteArrayType(T); 2790 if (ArrayT) { 2791 CheckType = ArrayT->getElementType(); 2792 DiagID = diag::err_illegal_decl_array_incomplete_type; 2793 } 2794 2795 if (IDecl->isInvalidDecl()) { 2796 // Do nothing with invalid declarations 2797 } else if ((ArrayT || IDecl->getStorageClass() == VarDecl::Static) && 2798 RequireCompleteType(IDecl->getLocation(), CheckType, DiagID)) { 2799 // C99 6.9.2p3: If the declaration of an identifier for an object is 2800 // a tentative definition and has internal linkage (C99 6.2.2p3), the 2801 // declared type shall not be an incomplete type. 2802 IDecl->setInvalidDecl(); 2803 } 2804 } 2805 } 2806 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 2807 Decls.data(), Decls.size())); 2808} 2809 2810 2811/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 2812/// to introduce parameters into function prototype scope. 2813Sema::DeclPtrTy 2814Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 2815 const DeclSpec &DS = D.getDeclSpec(); 2816 2817 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 2818 VarDecl::StorageClass StorageClass = VarDecl::None; 2819 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 2820 StorageClass = VarDecl::Register; 2821 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 2822 Diag(DS.getStorageClassSpecLoc(), 2823 diag::err_invalid_storage_class_in_func_decl); 2824 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2825 } 2826 2827 if (D.getDeclSpec().isThreadSpecified()) 2828 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2829 2830 DiagnoseFunctionSpecifiers(D); 2831 2832 // Check that there are no default arguments inside the type of this 2833 // parameter (C++ only). 2834 if (getLangOptions().CPlusPlus) 2835 CheckExtraCXXDefaultArguments(D); 2836 2837 QualType parmDeclType = GetTypeForDeclarator(D, S); 2838 2839 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 2840 // Can this happen for params? We already checked that they don't conflict 2841 // among each other. Here they can only shadow globals, which is ok. 2842 IdentifierInfo *II = D.getIdentifier(); 2843 if (II) { 2844 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 2845 if (PrevDecl->isTemplateParameter()) { 2846 // Maybe we will complain about the shadowed template parameter. 2847 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 2848 // Just pretend that we didn't see the previous declaration. 2849 PrevDecl = 0; 2850 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 2851 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 2852 2853 // Recover by removing the name 2854 II = 0; 2855 D.SetIdentifier(0, D.getIdentifierLoc()); 2856 } 2857 } 2858 } 2859 2860 // Parameters can not be abstract class types. 2861 // For record types, this is done by the AbstractClassUsageDiagnoser once 2862 // the class has been completely parsed. 2863 if (!CurContext->isRecord() && 2864 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 2865 diag::err_abstract_type_in_decl, 2866 AbstractParamType)) 2867 D.setInvalidType(true); 2868 2869 QualType T = adjustParameterType(parmDeclType); 2870 2871 ParmVarDecl *New; 2872 if (T == parmDeclType) // parameter type did not need adjustment 2873 New = ParmVarDecl::Create(Context, CurContext, 2874 D.getIdentifierLoc(), II, 2875 parmDeclType, StorageClass, 2876 0); 2877 else // keep track of both the adjusted and unadjusted types 2878 New = OriginalParmVarDecl::Create(Context, CurContext, 2879 D.getIdentifierLoc(), II, T, 2880 parmDeclType, StorageClass, 0); 2881 2882 if (D.isInvalidType()) 2883 New->setInvalidDecl(); 2884 2885 // Parameter declarators cannot be interface types. All ObjC objects are 2886 // passed by reference. 2887 if (T->isObjCInterfaceType()) { 2888 Diag(D.getIdentifierLoc(), 2889 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 2890 New->setInvalidDecl(); 2891 } 2892 2893 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 2894 if (D.getCXXScopeSpec().isSet()) { 2895 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 2896 << D.getCXXScopeSpec().getRange(); 2897 New->setInvalidDecl(); 2898 } 2899 2900 // Add the parameter declaration into this scope. 2901 S->AddDecl(DeclPtrTy::make(New)); 2902 if (II) 2903 IdResolver.AddDecl(New); 2904 2905 ProcessDeclAttributes(New, D); 2906 2907 if (New->hasAttr<BlocksAttr>()) { 2908 Diag(New->getLocation(), diag::err_block_on_nonlocal); 2909 } 2910 return DeclPtrTy::make(New); 2911} 2912 2913void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 2914 SourceLocation LocAfterDecls) { 2915 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2916 "Not a function declarator!"); 2917 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2918 2919 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2920 // for a K&R function. 2921 if (!FTI.hasPrototype) { 2922 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 2923 --i; 2924 if (FTI.ArgInfo[i].Param == 0) { 2925 std::string Code = " int "; 2926 Code += FTI.ArgInfo[i].Ident->getName(); 2927 Code += ";\n"; 2928 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2929 << FTI.ArgInfo[i].Ident 2930 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code); 2931 2932 // Implicitly declare the argument as type 'int' for lack of a better 2933 // type. 2934 DeclSpec DS; 2935 const char* PrevSpec; // unused 2936 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2937 PrevSpec); 2938 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2939 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2940 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 2941 } 2942 } 2943 } 2944} 2945 2946Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 2947 Declarator &D) { 2948 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2949 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2950 "Not a function declarator!"); 2951 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2952 2953 if (FTI.hasPrototype) { 2954 // FIXME: Diagnose arguments without names in C. 2955 } 2956 2957 Scope *ParentScope = FnBodyScope->getParent(); 2958 2959 DeclPtrTy DP = ActOnDeclarator(ParentScope, D, /*IsFunctionDefinition=*/true); 2960 return ActOnStartOfFunctionDef(FnBodyScope, DP); 2961} 2962 2963Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 2964 FunctionDecl *FD = cast<FunctionDecl>(D.getAs<Decl>()); 2965 2966 CurFunctionNeedsScopeChecking = false; 2967 2968 // See if this is a redefinition. 2969 const FunctionDecl *Definition; 2970 if (FD->getBody(Context, Definition)) { 2971 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 2972 Diag(Definition->getLocation(), diag::note_previous_definition); 2973 } 2974 2975 // Builtin functions cannot be defined. 2976 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 2977 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 2978 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 2979 FD->setInvalidDecl(); 2980 } 2981 } 2982 2983 // The return type of a function definition must be complete 2984 // (C99 6.9.1p3, C++ [dcl.fct]p6). 2985 QualType ResultType = FD->getResultType(); 2986 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 2987 !FD->isInvalidDecl() && 2988 RequireCompleteType(FD->getLocation(), ResultType, 2989 diag::err_func_def_incomplete_result)) 2990 FD->setInvalidDecl(); 2991 2992 // GNU warning -Wmissing-prototypes: 2993 // Warn if a global function is defined without a previous 2994 // prototype declaration. This warning is issued even if the 2995 // definition itself provides a prototype. The aim is to detect 2996 // global functions that fail to be declared in header files. 2997 if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) && 2998 !FD->isMain()) { 2999 bool MissingPrototype = true; 3000 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 3001 Prev; Prev = Prev->getPreviousDeclaration()) { 3002 // Ignore any declarations that occur in function or method 3003 // scope, because they aren't visible from the header. 3004 if (Prev->getDeclContext()->isFunctionOrMethod()) 3005 continue; 3006 3007 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 3008 break; 3009 } 3010 3011 if (MissingPrototype) 3012 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 3013 } 3014 3015 if (FnBodyScope) 3016 PushDeclContext(FnBodyScope, FD); 3017 3018 // Check the validity of our function parameters 3019 CheckParmsForFunctionDef(FD); 3020 3021 // Introduce our parameters into the function scope 3022 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 3023 ParmVarDecl *Param = FD->getParamDecl(p); 3024 Param->setOwningFunction(FD); 3025 3026 // If this has an identifier, add it to the scope stack. 3027 if (Param->getIdentifier() && FnBodyScope) 3028 PushOnScopeChains(Param, FnBodyScope); 3029 } 3030 3031 // Checking attributes of current function definition 3032 // dllimport attribute. 3033 if (FD->getAttr<DLLImportAttr>() && (!FD->getAttr<DLLExportAttr>())) { 3034 // dllimport attribute cannot be applied to definition. 3035 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 3036 Diag(FD->getLocation(), 3037 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 3038 << "dllimport"; 3039 FD->setInvalidDecl(); 3040 return DeclPtrTy::make(FD); 3041 } else { 3042 // If a symbol previously declared dllimport is later defined, the 3043 // attribute is ignored in subsequent references, and a warning is 3044 // emitted. 3045 Diag(FD->getLocation(), 3046 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3047 << FD->getNameAsCString() << "dllimport"; 3048 } 3049 } 3050 return DeclPtrTy::make(FD); 3051} 3052 3053Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 3054 return ActOnFinishFunctionBody(D, move(BodyArg), false); 3055} 3056 3057Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 3058 bool IsInstantiation) { 3059 Decl *dcl = D.getAs<Decl>(); 3060 Stmt *Body = BodyArg.takeAs<Stmt>(); 3061 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3062 FD->setBody(Body); 3063 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3064 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3065 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3066 MD->setBody(Body); 3067 } else { 3068 Body->Destroy(Context); 3069 return DeclPtrTy(); 3070 } 3071 if (!IsInstantiation) 3072 PopDeclContext(); 3073 3074 // Verify and clean out per-function state. 3075 3076 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 3077 3078 // Check goto/label use. 3079 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3080 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 3081 LabelStmt *L = I->second; 3082 3083 // Verify that we have no forward references left. If so, there was a goto 3084 // or address of a label taken, but no definition of it. Label fwd 3085 // definitions are indicated with a null substmt. 3086 if (L->getSubStmt() != 0) 3087 continue; 3088 3089 // Emit error. 3090 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3091 3092 // At this point, we have gotos that use the bogus label. Stitch it into 3093 // the function body so that they aren't leaked and that the AST is well 3094 // formed. 3095 if (Body == 0) { 3096 // The whole function wasn't parsed correctly, just delete this. 3097 L->Destroy(Context); 3098 continue; 3099 } 3100 3101 // Otherwise, the body is valid: we want to stitch the label decl into the 3102 // function somewhere so that it is properly owned and so that the goto 3103 // has a valid target. Do this by creating a new compound stmt with the 3104 // label in it. 3105 3106 // Give the label a sub-statement. 3107 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3108 3109 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 3110 cast<CXXTryStmt>(Body)->getTryBlock() : 3111 cast<CompoundStmt>(Body); 3112 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 3113 Elements.push_back(L); 3114 Compound->setStmts(Context, &Elements[0], Elements.size()); 3115 } 3116 FunctionLabelMap.clear(); 3117 3118 if (!Body) return D; 3119 3120 // Verify that that gotos and switch cases don't jump into scopes illegally. 3121 if (CurFunctionNeedsScopeChecking) 3122 DiagnoseInvalidJumps(Body); 3123 3124 // C++ constructors that have function-try-blocks can't have return statements 3125 // in the handlers of that block. (C++ [except.handle]p14) Verify this. 3126 if (isa<CXXConstructorDecl>(dcl) && isa<CXXTryStmt>(Body)) 3127 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 3128 3129 return D; 3130} 3131 3132/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3133/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3134NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3135 IdentifierInfo &II, Scope *S) { 3136 // Before we produce a declaration for an implicitly defined 3137 // function, see whether there was a locally-scoped declaration of 3138 // this name as a function or variable. If so, use that 3139 // (non-visible) declaration, and complain about it. 3140 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3141 = LocallyScopedExternalDecls.find(&II); 3142 if (Pos != LocallyScopedExternalDecls.end()) { 3143 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 3144 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 3145 return Pos->second; 3146 } 3147 3148 // Extension in C99. Legal in C90, but warn about it. 3149 if (getLangOptions().C99) 3150 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3151 else 3152 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3153 3154 // FIXME: handle stuff like: 3155 // void foo() { extern float X(); } 3156 // void bar() { X(); } <-- implicit decl for X in another scope. 3157 3158 // Set a Declarator for the implicit definition: int foo(); 3159 const char *Dummy; 3160 DeclSpec DS; 3161 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 3162 Error = Error; // Silence warning. 3163 assert(!Error && "Error setting up implicit decl!"); 3164 Declarator D(DS, Declarator::BlockContext); 3165 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 3166 0, 0, false, false, 0, 0, Loc, D), 3167 SourceLocation()); 3168 D.SetIdentifier(&II, Loc); 3169 3170 // Insert this function into translation-unit scope. 3171 3172 DeclContext *PrevDC = CurContext; 3173 CurContext = Context.getTranslationUnitDecl(); 3174 3175 FunctionDecl *FD = 3176 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D, DeclPtrTy()).getAs<Decl>()); 3177 FD->setImplicit(); 3178 3179 CurContext = PrevDC; 3180 3181 AddKnownFunctionAttributes(FD); 3182 3183 return FD; 3184} 3185 3186/// \brief Adds any function attributes that we know a priori based on 3187/// the declaration of this function. 3188/// 3189/// These attributes can apply both to implicitly-declared builtins 3190/// (like __builtin___printf_chk) or to library-declared functions 3191/// like NSLog or printf. 3192void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3193 if (FD->isInvalidDecl()) 3194 return; 3195 3196 // If this is a built-in function, map its builtin attributes to 3197 // actual attributes. 3198 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3199 // Handle printf-formatting attributes. 3200 unsigned FormatIdx; 3201 bool HasVAListArg; 3202 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3203 if (!FD->getAttr<FormatAttr>()) 3204 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 3205 FormatIdx + 2)); 3206 } 3207 3208 // Mark const if we don't care about errno and that is the only 3209 // thing preventing the function from being const. This allows 3210 // IRgen to use LLVM intrinsics for such functions. 3211 if (!getLangOptions().MathErrno && 3212 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3213 if (!FD->getAttr<ConstAttr>()) 3214 FD->addAttr(::new (Context) ConstAttr()); 3215 } 3216 } 3217 3218 IdentifierInfo *Name = FD->getIdentifier(); 3219 if (!Name) 3220 return; 3221 if ((!getLangOptions().CPlusPlus && 3222 FD->getDeclContext()->isTranslationUnit()) || 3223 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3224 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3225 LinkageSpecDecl::lang_c)) { 3226 // Okay: this could be a libc/libm/Objective-C function we know 3227 // about. 3228 } else 3229 return; 3230 3231 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 3232 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3233 // FIXME: We known better than our headers. 3234 const_cast<FormatAttr *>(Format)->setType("printf"); 3235 } else 3236 FD->addAttr(::new (Context) FormatAttr("printf", 1, 2)); 3237 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 3238 if (!FD->getAttr<FormatAttr>()) 3239 FD->addAttr(::new (Context) FormatAttr("printf", 2, 3)); 3240 } 3241} 3242 3243TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T) { 3244 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3245 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3246 3247 // Scope manipulation handled by caller. 3248 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3249 D.getIdentifierLoc(), 3250 D.getIdentifier(), 3251 T); 3252 3253 if (TagType *TT = dyn_cast<TagType>(T)) { 3254 TagDecl *TD = TT->getDecl(); 3255 3256 // If the TagDecl that the TypedefDecl points to is an anonymous decl 3257 // keep track of the TypedefDecl. 3258 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 3259 TD->setTypedefForAnonDecl(NewTD); 3260 } 3261 3262 if (D.isInvalidType()) 3263 NewTD->setInvalidDecl(); 3264 return NewTD; 3265} 3266 3267 3268/// \brief Determine whether a tag with a given kind is acceptable 3269/// as a redeclaration of the given tag declaration. 3270/// 3271/// \returns true if the new tag kind is acceptable, false otherwise. 3272bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 3273 TagDecl::TagKind NewTag, 3274 SourceLocation NewTagLoc, 3275 const IdentifierInfo &Name) { 3276 // C++ [dcl.type.elab]p3: 3277 // The class-key or enum keyword present in the 3278 // elaborated-type-specifier shall agree in kind with the 3279 // declaration to which the name in theelaborated-type-specifier 3280 // refers. This rule also applies to the form of 3281 // elaborated-type-specifier that declares a class-name or 3282 // friend class since it can be construed as referring to the 3283 // definition of the class. Thus, in any 3284 // elaborated-type-specifier, the enum keyword shall be used to 3285 // refer to an enumeration (7.2), the union class-keyshall be 3286 // used to refer to a union (clause 9), and either the class or 3287 // struct class-key shall be used to refer to a class (clause 9) 3288 // declared using the class or struct class-key. 3289 TagDecl::TagKind OldTag = Previous->getTagKind(); 3290 if (OldTag == NewTag) 3291 return true; 3292 3293 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 3294 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 3295 // Warn about the struct/class tag mismatch. 3296 bool isTemplate = false; 3297 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 3298 isTemplate = Record->getDescribedClassTemplate(); 3299 3300 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 3301 << (NewTag == TagDecl::TK_class) 3302 << isTemplate << &Name 3303 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 3304 OldTag == TagDecl::TK_class? "class" : "struct"); 3305 Diag(Previous->getLocation(), diag::note_previous_use); 3306 return true; 3307 } 3308 return false; 3309} 3310 3311/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3312/// former case, Name will be non-null. In the later case, Name will be null. 3313/// TagSpec indicates what kind of tag this is. TK indicates whether this is a 3314/// reference/declaration/definition of a tag. 3315Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK, 3316 SourceLocation KWLoc, const CXXScopeSpec &SS, 3317 IdentifierInfo *Name, SourceLocation NameLoc, 3318 AttributeList *Attr, AccessSpecifier AS) { 3319 // If this is not a definition, it must have a name. 3320 assert((Name != 0 || TK == TK_Definition) && 3321 "Nameless record must be a definition!"); 3322 3323 TagDecl::TagKind Kind; 3324 switch (TagSpec) { 3325 default: assert(0 && "Unknown tag type!"); 3326 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3327 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3328 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3329 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3330 } 3331 3332 DeclContext *SearchDC = CurContext; 3333 DeclContext *DC = CurContext; 3334 NamedDecl *PrevDecl = 0; 3335 3336 bool Invalid = false; 3337 3338 if (Name && SS.isNotEmpty()) { 3339 // We have a nested-name tag ('struct foo::bar'). 3340 3341 // Check for invalid 'foo::'. 3342 if (SS.isInvalid()) { 3343 Name = 0; 3344 goto CreateNewDecl; 3345 } 3346 3347 if (RequireCompleteDeclContext(SS)) 3348 return DeclPtrTy::make((Decl *)0); 3349 3350 DC = computeDeclContext(SS); 3351 SearchDC = DC; 3352 // Look-up name inside 'foo::'. 3353 PrevDecl 3354 = dyn_cast_or_null<TagDecl>( 3355 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 3356 3357 // A tag 'foo::bar' must already exist. 3358 if (PrevDecl == 0) { 3359 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 3360 Name = 0; 3361 goto CreateNewDecl; 3362 } 3363 } else if (Name) { 3364 // If this is a named struct, check to see if there was a previous forward 3365 // declaration or definition. 3366 // FIXME: We're looking into outer scopes here, even when we 3367 // shouldn't be. Doing so can result in ambiguities that we 3368 // shouldn't be diagnosing. 3369 LookupResult R = LookupName(S, Name, LookupTagName, 3370 /*RedeclarationOnly=*/(TK != TK_Reference)); 3371 if (R.isAmbiguous()) { 3372 DiagnoseAmbiguousLookup(R, Name, NameLoc); 3373 // FIXME: This is not best way to recover from case like: 3374 // 3375 // struct S s; 3376 // 3377 // causes needless "incomplete type" error later. 3378 Name = 0; 3379 PrevDecl = 0; 3380 Invalid = true; 3381 } 3382 else 3383 PrevDecl = R; 3384 3385 if (!getLangOptions().CPlusPlus && TK != TK_Reference) { 3386 // FIXME: This makes sure that we ignore the contexts associated 3387 // with C structs, unions, and enums when looking for a matching 3388 // tag declaration or definition. See the similar lookup tweak 3389 // in Sema::LookupName; is there a better way to deal with this? 3390 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 3391 SearchDC = SearchDC->getParent(); 3392 } 3393 } 3394 3395 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3396 // Maybe we will complain about the shadowed template parameter. 3397 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 3398 // Just pretend that we didn't see the previous declaration. 3399 PrevDecl = 0; 3400 } 3401 3402 if (PrevDecl) { 3403 // Check whether the previous declaration is usable. 3404 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 3405 3406 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 3407 // If this is a use of a previous tag, or if the tag is already declared 3408 // in the same scope (so that the definition/declaration completes or 3409 // rementions the tag), reuse the decl. 3410 if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 3411 // Make sure that this wasn't declared as an enum and now used as a 3412 // struct or something similar. 3413 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 3414 bool SafeToContinue 3415 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 3416 Kind != TagDecl::TK_enum); 3417 if (SafeToContinue) 3418 Diag(KWLoc, diag::err_use_with_wrong_tag) 3419 << Name 3420 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 3421 PrevTagDecl->getKindName()); 3422 else 3423 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 3424 Diag(PrevDecl->getLocation(), diag::note_previous_use); 3425 3426 if (SafeToContinue) 3427 Kind = PrevTagDecl->getTagKind(); 3428 else { 3429 // Recover by making this an anonymous redefinition. 3430 Name = 0; 3431 PrevDecl = 0; 3432 Invalid = true; 3433 } 3434 } 3435 3436 if (!Invalid) { 3437 // If this is a use, just return the declaration we found. 3438 3439 // FIXME: In the future, return a variant or some other clue 3440 // for the consumer of this Decl to know it doesn't own it. 3441 // For our current ASTs this shouldn't be a problem, but will 3442 // need to be changed with DeclGroups. 3443 if (TK == TK_Reference) 3444 return DeclPtrTy::make(PrevDecl); 3445 3446 // Diagnose attempts to redefine a tag. 3447 if (TK == TK_Definition) { 3448 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 3449 Diag(NameLoc, diag::err_redefinition) << Name; 3450 Diag(Def->getLocation(), diag::note_previous_definition); 3451 // If this is a redefinition, recover by making this 3452 // struct be anonymous, which will make any later 3453 // references get the previous definition. 3454 Name = 0; 3455 PrevDecl = 0; 3456 Invalid = true; 3457 } else { 3458 // If the type is currently being defined, complain 3459 // about a nested redefinition. 3460 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 3461 if (Tag->isBeingDefined()) { 3462 Diag(NameLoc, diag::err_nested_redefinition) << Name; 3463 Diag(PrevTagDecl->getLocation(), 3464 diag::note_previous_definition); 3465 Name = 0; 3466 PrevDecl = 0; 3467 Invalid = true; 3468 } 3469 } 3470 3471 // Okay, this is definition of a previously declared or referenced 3472 // tag PrevDecl. We're going to create a new Decl for it. 3473 } 3474 } 3475 // If we get here we have (another) forward declaration or we 3476 // have a definition. Just create a new decl. 3477 } else { 3478 // If we get here, this is a definition of a new tag type in a nested 3479 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 3480 // new decl/type. We set PrevDecl to NULL so that the entities 3481 // have distinct types. 3482 PrevDecl = 0; 3483 } 3484 // If we get here, we're going to create a new Decl. If PrevDecl 3485 // is non-NULL, it's a definition of the tag declared by 3486 // PrevDecl. If it's NULL, we have a new definition. 3487 } else { 3488 // PrevDecl is a namespace, template, or anything else 3489 // that lives in the IDNS_Tag identifier namespace. 3490 if (isDeclInScope(PrevDecl, SearchDC, S)) { 3491 // The tag name clashes with a namespace name, issue an error and 3492 // recover by making this tag be anonymous. 3493 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 3494 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3495 Name = 0; 3496 PrevDecl = 0; 3497 Invalid = true; 3498 } else { 3499 // The existing declaration isn't relevant to us; we're in a 3500 // new scope, so clear out the previous declaration. 3501 PrevDecl = 0; 3502 } 3503 } 3504 } else if (TK == TK_Reference && SS.isEmpty() && Name && 3505 (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) { 3506 // C++ [basic.scope.pdecl]p5: 3507 // -- for an elaborated-type-specifier of the form 3508 // 3509 // class-key identifier 3510 // 3511 // if the elaborated-type-specifier is used in the 3512 // decl-specifier-seq or parameter-declaration-clause of a 3513 // function defined in namespace scope, the identifier is 3514 // declared as a class-name in the namespace that contains 3515 // the declaration; otherwise, except as a friend 3516 // declaration, the identifier is declared in the smallest 3517 // non-class, non-function-prototype scope that contains the 3518 // declaration. 3519 // 3520 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 3521 // C structs and unions. 3522 // 3523 // GNU C also supports this behavior as part of its incomplete 3524 // enum types extension, while GNU C++ does not. 3525 // 3526 // Find the context where we'll be declaring the tag. 3527 // FIXME: We would like to maintain the current DeclContext as the 3528 // lexical context, 3529 while (SearchDC->isRecord()) 3530 SearchDC = SearchDC->getParent(); 3531 3532 // Find the scope where we'll be declaring the tag. 3533 while (S->isClassScope() || 3534 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 3535 ((S->getFlags() & Scope::DeclScope) == 0) || 3536 (S->getEntity() && 3537 ((DeclContext *)S->getEntity())->isTransparentContext())) 3538 S = S->getParent(); 3539 } 3540 3541CreateNewDecl: 3542 3543 // If there is an identifier, use the location of the identifier as the 3544 // location of the decl, otherwise use the location of the struct/union 3545 // keyword. 3546 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 3547 3548 // Otherwise, create a new declaration. If there is a previous 3549 // declaration of the same entity, the two will be linked via 3550 // PrevDecl. 3551 TagDecl *New; 3552 3553 if (Kind == TagDecl::TK_enum) { 3554 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3555 // enum X { A, B, C } D; D should chain to X. 3556 New = EnumDecl::Create(Context, SearchDC, Loc, Name, 3557 cast_or_null<EnumDecl>(PrevDecl)); 3558 // If this is an undefined enum, warn. 3559 if (TK != TK_Definition && !Invalid) { 3560 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 3561 : diag::ext_forward_ref_enum; 3562 Diag(Loc, DK); 3563 } 3564 } else { 3565 // struct/union/class 3566 3567 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3568 // struct X { int A; } D; D should chain to X. 3569 if (getLangOptions().CPlusPlus) 3570 // FIXME: Look for a way to use RecordDecl for simple structs. 3571 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, 3572 cast_or_null<CXXRecordDecl>(PrevDecl)); 3573 else 3574 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, 3575 cast_or_null<RecordDecl>(PrevDecl)); 3576 } 3577 3578 if (Kind != TagDecl::TK_enum) { 3579 // Handle #pragma pack: if the #pragma pack stack has non-default 3580 // alignment, make up a packed attribute for this decl. These 3581 // attributes are checked when the ASTContext lays out the 3582 // structure. 3583 // 3584 // It is important for implementing the correct semantics that this 3585 // happen here (in act on tag decl). The #pragma pack stack is 3586 // maintained as a result of parser callbacks which can occur at 3587 // many points during the parsing of a struct declaration (because 3588 // the #pragma tokens are effectively skipped over during the 3589 // parsing of the struct). 3590 if (unsigned Alignment = getPragmaPackAlignment()) 3591 New->addAttr(::new (Context) PackedAttr(Alignment * 8)); 3592 } 3593 3594 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 3595 // C++ [dcl.typedef]p3: 3596 // [...] Similarly, in a given scope, a class or enumeration 3597 // shall not be declared with the same name as a typedef-name 3598 // that is declared in that scope and refers to a type other 3599 // than the class or enumeration itself. 3600 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 3601 TypedefDecl *PrevTypedef = 0; 3602 if (Lookup.getKind() == LookupResult::Found) 3603 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 3604 3605 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 3606 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 3607 Context.getCanonicalType(Context.getTypeDeclType(New))) { 3608 Diag(Loc, diag::err_tag_definition_of_typedef) 3609 << Context.getTypeDeclType(New) 3610 << PrevTypedef->getUnderlyingType(); 3611 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 3612 Invalid = true; 3613 } 3614 } 3615 3616 if (Invalid) 3617 New->setInvalidDecl(); 3618 3619 if (Attr) 3620 ProcessDeclAttributeList(New, Attr); 3621 3622 // If we're declaring or defining a tag in function prototype scope 3623 // in C, note that this type can only be used within the function. 3624 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 3625 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 3626 3627 // Set the lexical context. If the tag has a C++ scope specifier, the 3628 // lexical context will be different from the semantic context. 3629 New->setLexicalDeclContext(CurContext); 3630 3631 // Set the access specifier. 3632 SetMemberAccessSpecifier(New, PrevDecl, AS); 3633 3634 if (TK == TK_Definition) 3635 New->startDefinition(); 3636 3637 // If this has an identifier, add it to the scope stack. 3638 if (Name) { 3639 S = getNonFieldDeclScope(S); 3640 PushOnScopeChains(New, S); 3641 } else { 3642 CurContext->addDecl(Context, New); 3643 } 3644 3645 return DeclPtrTy::make(New); 3646} 3647 3648void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 3649 AdjustDeclIfTemplate(TagD); 3650 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 3651 3652 // Enter the tag context. 3653 PushDeclContext(S, Tag); 3654 3655 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 3656 FieldCollector->StartClass(); 3657 3658 if (Record->getIdentifier()) { 3659 // C++ [class]p2: 3660 // [...] The class-name is also inserted into the scope of the 3661 // class itself; this is known as the injected-class-name. For 3662 // purposes of access checking, the injected-class-name is treated 3663 // as if it were a public member name. 3664 CXXRecordDecl *InjectedClassName 3665 = CXXRecordDecl::Create(Context, Record->getTagKind(), 3666 CurContext, Record->getLocation(), 3667 Record->getIdentifier(), Record); 3668 InjectedClassName->setImplicit(); 3669 InjectedClassName->setAccess(AS_public); 3670 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 3671 InjectedClassName->setDescribedClassTemplate(Template); 3672 PushOnScopeChains(InjectedClassName, S); 3673 assert(InjectedClassName->isInjectedClassName() && 3674 "Broken injected-class-name"); 3675 } 3676 } 3677} 3678 3679void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD) { 3680 AdjustDeclIfTemplate(TagD); 3681 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 3682 3683 if (isa<CXXRecordDecl>(Tag)) 3684 FieldCollector->FinishClass(); 3685 3686 // Exit this scope of this tag's definition. 3687 PopDeclContext(); 3688 3689 // Notify the consumer that we've defined a tag. 3690 Consumer.HandleTagDeclDefinition(Tag); 3691} 3692 3693// Note that FieldName may be null for anonymous bitfields. 3694bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 3695 QualType FieldTy, const Expr *BitWidth) { 3696 3697 // C99 6.7.2.1p4 - verify the field type. 3698 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 3699 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 3700 // Handle incomplete types with specific error. 3701 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 3702 return true; 3703 if (FieldName) 3704 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 3705 << FieldName << FieldTy << BitWidth->getSourceRange(); 3706 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 3707 << FieldTy << BitWidth->getSourceRange(); 3708 } 3709 3710 // If the bit-width is type- or value-dependent, don't try to check 3711 // it now. 3712 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 3713 return false; 3714 3715 llvm::APSInt Value; 3716 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 3717 return true; 3718 3719 // Zero-width bitfield is ok for anonymous field. 3720 if (Value == 0 && FieldName) 3721 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 3722 3723 if (Value.isSigned() && Value.isNegative()) { 3724 if (FieldName) 3725 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 3726 << FieldName << Value.toString(10); 3727 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 3728 << Value.toString(10); 3729 } 3730 3731 if (!FieldTy->isDependentType()) { 3732 uint64_t TypeSize = Context.getTypeSize(FieldTy); 3733 if (Value.getZExtValue() > TypeSize) { 3734 if (FieldName) 3735 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 3736 << FieldName << (unsigned)TypeSize; 3737 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 3738 << (unsigned)TypeSize; 3739 } 3740 } 3741 3742 return false; 3743} 3744 3745/// ActOnField - Each field of a struct/union/class is passed into this in order 3746/// to create a FieldDecl object for it. 3747Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 3748 SourceLocation DeclStart, 3749 Declarator &D, ExprTy *BitfieldWidth) { 3750 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 3751 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 3752 AS_public); 3753 return DeclPtrTy::make(Res); 3754} 3755 3756/// HandleField - Analyze a field of a C struct or a C++ data member. 3757/// 3758FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 3759 SourceLocation DeclStart, 3760 Declarator &D, Expr *BitWidth, 3761 AccessSpecifier AS) { 3762 IdentifierInfo *II = D.getIdentifier(); 3763 SourceLocation Loc = DeclStart; 3764 if (II) Loc = D.getIdentifierLoc(); 3765 3766 QualType T = GetTypeForDeclarator(D, S); 3767 if (getLangOptions().CPlusPlus) 3768 CheckExtraCXXDefaultArguments(D); 3769 3770 DiagnoseFunctionSpecifiers(D); 3771 3772 if (D.getDeclSpec().isThreadSpecified()) 3773 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3774 3775 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 3776 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 3777 PrevDecl = 0; 3778 3779 FieldDecl *NewFD 3780 = CheckFieldDecl(II, T, Record, Loc, 3781 D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable, 3782 BitWidth, AS, PrevDecl, &D); 3783 if (NewFD->isInvalidDecl() && PrevDecl) { 3784 // Don't introduce NewFD into scope; there's already something 3785 // with the same name in the same scope. 3786 } else if (II) { 3787 PushOnScopeChains(NewFD, S); 3788 } else 3789 Record->addDecl(Context, NewFD); 3790 3791 return NewFD; 3792} 3793 3794/// \brief Build a new FieldDecl and check its well-formedness. 3795/// 3796/// This routine builds a new FieldDecl given the fields name, type, 3797/// record, etc. \p PrevDecl should refer to any previous declaration 3798/// with the same name and in the same scope as the field to be 3799/// created. 3800/// 3801/// \returns a new FieldDecl. 3802/// 3803/// \todo The Declarator argument is a hack. It will be removed once 3804FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 3805 RecordDecl *Record, SourceLocation Loc, 3806 bool Mutable, Expr *BitWidth, 3807 AccessSpecifier AS, NamedDecl *PrevDecl, 3808 Declarator *D) { 3809 IdentifierInfo *II = Name.getAsIdentifierInfo(); 3810 bool InvalidDecl = false; 3811 if (D) InvalidDecl = D->isInvalidType(); 3812 3813 // If we receive a broken type, recover by assuming 'int' and 3814 // marking this declaration as invalid. 3815 if (T.isNull()) { 3816 InvalidDecl = true; 3817 T = Context.IntTy; 3818 } 3819 3820 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3821 // than a variably modified type. 3822 if (T->isVariablyModifiedType()) { 3823 bool SizeIsNegative; 3824 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 3825 SizeIsNegative); 3826 if (!FixedTy.isNull()) { 3827 Diag(Loc, diag::warn_illegal_constant_array_size); 3828 T = FixedTy; 3829 } else { 3830 if (SizeIsNegative) 3831 Diag(Loc, diag::err_typecheck_negative_array_size); 3832 else 3833 Diag(Loc, diag::err_typecheck_field_variable_size); 3834 T = Context.IntTy; 3835 InvalidDecl = true; 3836 } 3837 } 3838 3839 // Fields can not have abstract class types 3840 if (RequireNonAbstractType(Loc, T, diag::err_abstract_type_in_decl, 3841 AbstractFieldType)) 3842 InvalidDecl = true; 3843 3844 // If this is declared as a bit-field, check the bit-field. 3845 if (BitWidth && VerifyBitField(Loc, II, T, BitWidth)) { 3846 InvalidDecl = true; 3847 DeleteExpr(BitWidth); 3848 BitWidth = 0; 3849 } 3850 3851 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, BitWidth, 3852 Mutable); 3853 if (InvalidDecl) 3854 NewFD->setInvalidDecl(); 3855 3856 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 3857 Diag(Loc, diag::err_duplicate_member) << II; 3858 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3859 NewFD->setInvalidDecl(); 3860 } 3861 3862 if (getLangOptions().CPlusPlus && !T->isPODType()) 3863 cast<CXXRecordDecl>(Record)->setPOD(false); 3864 3865 // FIXME: We need to pass in the attributes given an AST 3866 // representation, not a parser representation. 3867 if (D) 3868 ProcessDeclAttributes(NewFD, *D); 3869 3870 if (T.isObjCGCWeak()) 3871 Diag(Loc, diag::warn_attribute_weak_on_field); 3872 3873 NewFD->setAccess(AS); 3874 3875 // C++ [dcl.init.aggr]p1: 3876 // An aggregate is an array or a class (clause 9) with [...] no 3877 // private or protected non-static data members (clause 11). 3878 // A POD must be an aggregate. 3879 if (getLangOptions().CPlusPlus && 3880 (AS == AS_private || AS == AS_protected)) { 3881 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 3882 CXXRecord->setAggregate(false); 3883 CXXRecord->setPOD(false); 3884 } 3885 3886 return NewFD; 3887} 3888 3889/// TranslateIvarVisibility - Translate visibility from a token ID to an 3890/// AST enum value. 3891static ObjCIvarDecl::AccessControl 3892TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 3893 switch (ivarVisibility) { 3894 default: assert(0 && "Unknown visitibility kind"); 3895 case tok::objc_private: return ObjCIvarDecl::Private; 3896 case tok::objc_public: return ObjCIvarDecl::Public; 3897 case tok::objc_protected: return ObjCIvarDecl::Protected; 3898 case tok::objc_package: return ObjCIvarDecl::Package; 3899 } 3900} 3901 3902/// ActOnIvar - Each ivar field of an objective-c class is passed into this 3903/// in order to create an IvarDecl object for it. 3904Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 3905 SourceLocation DeclStart, 3906 Declarator &D, ExprTy *BitfieldWidth, 3907 tok::ObjCKeywordKind Visibility) { 3908 3909 IdentifierInfo *II = D.getIdentifier(); 3910 Expr *BitWidth = (Expr*)BitfieldWidth; 3911 SourceLocation Loc = DeclStart; 3912 if (II) Loc = D.getIdentifierLoc(); 3913 3914 // FIXME: Unnamed fields can be handled in various different ways, for 3915 // example, unnamed unions inject all members into the struct namespace! 3916 3917 QualType T = GetTypeForDeclarator(D, S); 3918 3919 if (BitWidth) { 3920 // 6.7.2.1p3, 6.7.2.1p4 3921 if (VerifyBitField(Loc, II, T, BitWidth)) { 3922 D.setInvalidType(); 3923 DeleteExpr(BitWidth); 3924 BitWidth = 0; 3925 } 3926 } else { 3927 // Not a bitfield. 3928 3929 // validate II. 3930 3931 } 3932 3933 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3934 // than a variably modified type. 3935 if (T->isVariablyModifiedType()) { 3936 Diag(Loc, diag::err_typecheck_ivar_variable_size); 3937 D.setInvalidType(); 3938 } 3939 3940 // Get the visibility (access control) for this ivar. 3941 ObjCIvarDecl::AccessControl ac = 3942 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 3943 : ObjCIvarDecl::None; 3944 3945 // Construct the decl. 3946 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, CurContext, Loc, II, T,ac, 3947 (Expr *)BitfieldWidth); 3948 3949 if (II) { 3950 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 3951 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3952 && !isa<TagDecl>(PrevDecl)) { 3953 Diag(Loc, diag::err_duplicate_member) << II; 3954 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3955 NewID->setInvalidDecl(); 3956 } 3957 } 3958 3959 // Process attributes attached to the ivar. 3960 ProcessDeclAttributes(NewID, D); 3961 3962 if (D.isInvalidType()) 3963 NewID->setInvalidDecl(); 3964 3965 if (II) { 3966 // FIXME: When interfaces are DeclContexts, we'll need to add 3967 // these to the interface. 3968 S->AddDecl(DeclPtrTy::make(NewID)); 3969 IdResolver.AddDecl(NewID); 3970 } 3971 3972 return DeclPtrTy::make(NewID); 3973} 3974 3975void Sema::ActOnFields(Scope* S, 3976 SourceLocation RecLoc, DeclPtrTy RecDecl, 3977 DeclPtrTy *Fields, unsigned NumFields, 3978 SourceLocation LBrac, SourceLocation RBrac, 3979 AttributeList *Attr) { 3980 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 3981 assert(EnclosingDecl && "missing record or interface decl"); 3982 3983 // If the decl this is being inserted into is invalid, then it may be a 3984 // redeclaration or some other bogus case. Don't try to add fields to it. 3985 if (EnclosingDecl->isInvalidDecl()) { 3986 // FIXME: Deallocate fields? 3987 return; 3988 } 3989 3990 3991 // Verify that all the fields are okay. 3992 unsigned NumNamedMembers = 0; 3993 llvm::SmallVector<FieldDecl*, 32> RecFields; 3994 3995 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 3996 for (unsigned i = 0; i != NumFields; ++i) { 3997 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 3998 3999 // Get the type for the field. 4000 Type *FDTy = FD->getType().getTypePtr(); 4001 4002 if (!FD->isAnonymousStructOrUnion()) { 4003 // Remember all fields written by the user. 4004 RecFields.push_back(FD); 4005 } 4006 4007 // If the field is already invalid for some reason, don't emit more 4008 // diagnostics about it. 4009 if (FD->isInvalidDecl()) 4010 continue; 4011 4012 // C99 6.7.2.1p2: 4013 // A structure or union shall not contain a member with 4014 // incomplete or function type (hence, a structure shall not 4015 // contain an instance of itself, but may contain a pointer to 4016 // an instance of itself), except that the last member of a 4017 // structure with more than one named member may have incomplete 4018 // array type; such a structure (and any union containing, 4019 // possibly recursively, a member that is such a structure) 4020 // shall not be a member of a structure or an element of an 4021 // array. 4022 if (FDTy->isFunctionType()) { 4023 // Field declared as a function. 4024 Diag(FD->getLocation(), diag::err_field_declared_as_function) 4025 << FD->getDeclName(); 4026 FD->setInvalidDecl(); 4027 EnclosingDecl->setInvalidDecl(); 4028 continue; 4029 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 4030 Record && Record->isStruct()) { 4031 // Flexible array member. 4032 if (NumNamedMembers < 1) { 4033 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 4034 << FD->getDeclName(); 4035 FD->setInvalidDecl(); 4036 EnclosingDecl->setInvalidDecl(); 4037 continue; 4038 } 4039 // Okay, we have a legal flexible array member at the end of the struct. 4040 if (Record) 4041 Record->setHasFlexibleArrayMember(true); 4042 } else if (!FDTy->isDependentType() && 4043 RequireCompleteType(FD->getLocation(), FD->getType(), 4044 diag::err_field_incomplete)) { 4045 // Incomplete type 4046 FD->setInvalidDecl(); 4047 EnclosingDecl->setInvalidDecl(); 4048 continue; 4049 } else if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 4050 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 4051 // If this is a member of a union, then entire union becomes "flexible". 4052 if (Record && Record->isUnion()) { 4053 Record->setHasFlexibleArrayMember(true); 4054 } else { 4055 // If this is a struct/class and this is not the last element, reject 4056 // it. Note that GCC supports variable sized arrays in the middle of 4057 // structures. 4058 if (i != NumFields-1) 4059 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 4060 << FD->getDeclName() << FD->getType(); 4061 else { 4062 // We support flexible arrays at the end of structs in 4063 // other structs as an extension. 4064 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 4065 << FD->getDeclName(); 4066 if (Record) 4067 Record->setHasFlexibleArrayMember(true); 4068 } 4069 } 4070 } 4071 } else if (FDTy->isObjCInterfaceType()) { 4072 /// A field cannot be an Objective-c object 4073 Diag(FD->getLocation(), diag::err_statically_allocated_object); 4074 FD->setInvalidDecl(); 4075 EnclosingDecl->setInvalidDecl(); 4076 continue; 4077 } 4078 // Keep track of the number of named members. 4079 if (FD->getIdentifier()) 4080 ++NumNamedMembers; 4081 } 4082 4083 // Okay, we successfully defined 'Record'. 4084 if (Record) { 4085 Record->completeDefinition(Context); 4086 } else { 4087 ObjCIvarDecl **ClsFields = 4088 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 4089 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 4090 ID->setIVarList(ClsFields, RecFields.size(), Context); 4091 ID->setLocEnd(RBrac); 4092 4093 // Must enforce the rule that ivars in the base classes may not be 4094 // duplicates. 4095 if (ID->getSuperClass()) { 4096 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 4097 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 4098 ObjCIvarDecl* Ivar = (*IVI); 4099 4100 if (IdentifierInfo *II = Ivar->getIdentifier()) { 4101 ObjCIvarDecl* prevIvar = 4102 ID->getSuperClass()->lookupInstanceVariable(Context, II); 4103 if (prevIvar) { 4104 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 4105 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 4106 } 4107 } 4108 } 4109 } 4110 } else if (ObjCImplementationDecl *IMPDecl = 4111 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4112 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 4113 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) { 4114 // FIXME: Set the DeclContext correctly when we build the 4115 // declarations. 4116 ClsFields[I]->setLexicalDeclContext(IMPDecl); 4117 IMPDecl->addDecl(Context, ClsFields[I]); 4118 } 4119 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 4120 } 4121 } 4122 4123 if (Attr) 4124 ProcessDeclAttributeList(Record, Attr); 4125} 4126 4127EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 4128 EnumConstantDecl *LastEnumConst, 4129 SourceLocation IdLoc, 4130 IdentifierInfo *Id, 4131 ExprArg val) { 4132 Expr *Val = (Expr *)val.get(); 4133 4134 llvm::APSInt EnumVal(32); 4135 QualType EltTy; 4136 if (Val && !Val->isTypeDependent()) { 4137 // Make sure to promote the operand type to int. 4138 UsualUnaryConversions(Val); 4139 if (Val != val.get()) { 4140 val.release(); 4141 val = Val; 4142 } 4143 4144 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 4145 SourceLocation ExpLoc; 4146 if (!Val->isValueDependent() && 4147 VerifyIntegerConstantExpression(Val, &EnumVal)) { 4148 Val = 0; 4149 } else { 4150 EltTy = Val->getType(); 4151 } 4152 } 4153 4154 if (!Val) { 4155 if (LastEnumConst) { 4156 // Assign the last value + 1. 4157 EnumVal = LastEnumConst->getInitVal(); 4158 ++EnumVal; 4159 4160 // Check for overflow on increment. 4161 if (EnumVal < LastEnumConst->getInitVal()) 4162 Diag(IdLoc, diag::warn_enum_value_overflow); 4163 4164 EltTy = LastEnumConst->getType(); 4165 } else { 4166 // First value, set to zero. 4167 EltTy = Context.IntTy; 4168 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 4169 } 4170 } 4171 4172 val.release(); 4173 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 4174 Val, EnumVal); 4175} 4176 4177 4178Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 4179 DeclPtrTy lastEnumConst, 4180 SourceLocation IdLoc, 4181 IdentifierInfo *Id, 4182 SourceLocation EqualLoc, ExprTy *val) { 4183 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 4184 EnumConstantDecl *LastEnumConst = 4185 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 4186 Expr *Val = static_cast<Expr*>(val); 4187 4188 // The scope passed in may not be a decl scope. Zip up the scope tree until 4189 // we find one that is. 4190 S = getNonFieldDeclScope(S); 4191 4192 // Verify that there isn't already something declared with this name in this 4193 // scope. 4194 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 4195 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4196 // Maybe we will complain about the shadowed template parameter. 4197 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 4198 // Just pretend that we didn't see the previous declaration. 4199 PrevDecl = 0; 4200 } 4201 4202 if (PrevDecl) { 4203 // When in C++, we may get a TagDecl with the same name; in this case the 4204 // enum constant will 'hide' the tag. 4205 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 4206 "Received TagDecl when not in C++!"); 4207 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 4208 if (isa<EnumConstantDecl>(PrevDecl)) 4209 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 4210 else 4211 Diag(IdLoc, diag::err_redefinition) << Id; 4212 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4213 if (Val) Val->Destroy(Context); 4214 return DeclPtrTy(); 4215 } 4216 } 4217 4218 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 4219 IdLoc, Id, Owned(Val)); 4220 4221 // Register this decl in the current scope stack. 4222 if (New) 4223 PushOnScopeChains(New, S); 4224 4225 return DeclPtrTy::make(New); 4226} 4227 4228void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 4229 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 4230 DeclPtrTy *Elements, unsigned NumElements) { 4231 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 4232 QualType EnumType = Context.getTypeDeclType(Enum); 4233 4234 // TODO: If the result value doesn't fit in an int, it must be a long or long 4235 // long value. ISO C does not support this, but GCC does as an extension, 4236 // emit a warning. 4237 unsigned IntWidth = Context.Target.getIntWidth(); 4238 4239 // Verify that all the values are okay, compute the size of the values, and 4240 // reverse the list. 4241 unsigned NumNegativeBits = 0; 4242 unsigned NumPositiveBits = 0; 4243 4244 // Keep track of whether all elements have type int. 4245 bool AllElementsInt = true; 4246 4247 for (unsigned i = 0; i != NumElements; ++i) { 4248 EnumConstantDecl *ECD = 4249 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 4250 if (!ECD) continue; // Already issued a diagnostic. 4251 4252 // If the enum value doesn't fit in an int, emit an extension warning. 4253 const llvm::APSInt &InitVal = ECD->getInitVal(); 4254 assert(InitVal.getBitWidth() >= IntWidth && 4255 "Should have promoted value to int"); 4256 if (InitVal.getBitWidth() > IntWidth) { 4257 llvm::APSInt V(InitVal); 4258 V.trunc(IntWidth); 4259 V.extend(InitVal.getBitWidth()); 4260 if (V != InitVal) 4261 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 4262 << InitVal.toString(10); 4263 } 4264 4265 // Keep track of the size of positive and negative values. 4266 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 4267 NumPositiveBits = std::max(NumPositiveBits, 4268 (unsigned)InitVal.getActiveBits()); 4269 else 4270 NumNegativeBits = std::max(NumNegativeBits, 4271 (unsigned)InitVal.getMinSignedBits()); 4272 4273 // Keep track of whether every enum element has type int (very commmon). 4274 if (AllElementsInt) 4275 AllElementsInt = ECD->getType() == Context.IntTy; 4276 } 4277 4278 // Figure out the type that should be used for this enum. 4279 // FIXME: Support attribute(packed) on enums and -fshort-enums. 4280 QualType BestType; 4281 unsigned BestWidth; 4282 4283 if (NumNegativeBits) { 4284 // If there is a negative value, figure out the smallest integer type (of 4285 // int/long/longlong) that fits. 4286 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 4287 BestType = Context.IntTy; 4288 BestWidth = IntWidth; 4289 } else { 4290 BestWidth = Context.Target.getLongWidth(); 4291 4292 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 4293 BestType = Context.LongTy; 4294 else { 4295 BestWidth = Context.Target.getLongLongWidth(); 4296 4297 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 4298 Diag(Enum->getLocation(), diag::warn_enum_too_large); 4299 BestType = Context.LongLongTy; 4300 } 4301 } 4302 } else { 4303 // If there is no negative value, figure out which of uint, ulong, ulonglong 4304 // fits. 4305 if (NumPositiveBits <= IntWidth) { 4306 BestType = Context.UnsignedIntTy; 4307 BestWidth = IntWidth; 4308 } else if (NumPositiveBits <= 4309 (BestWidth = Context.Target.getLongWidth())) { 4310 BestType = Context.UnsignedLongTy; 4311 } else { 4312 BestWidth = Context.Target.getLongLongWidth(); 4313 assert(NumPositiveBits <= BestWidth && 4314 "How could an initializer get larger than ULL?"); 4315 BestType = Context.UnsignedLongLongTy; 4316 } 4317 } 4318 4319 // Loop over all of the enumerator constants, changing their types to match 4320 // the type of the enum if needed. 4321 for (unsigned i = 0; i != NumElements; ++i) { 4322 EnumConstantDecl *ECD = 4323 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 4324 if (!ECD) continue; // Already issued a diagnostic. 4325 4326 // Standard C says the enumerators have int type, but we allow, as an 4327 // extension, the enumerators to be larger than int size. If each 4328 // enumerator value fits in an int, type it as an int, otherwise type it the 4329 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 4330 // that X has type 'int', not 'unsigned'. 4331 if (ECD->getType() == Context.IntTy) { 4332 // Make sure the init value is signed. 4333 llvm::APSInt IV = ECD->getInitVal(); 4334 IV.setIsSigned(true); 4335 ECD->setInitVal(IV); 4336 4337 if (getLangOptions().CPlusPlus) 4338 // C++ [dcl.enum]p4: Following the closing brace of an 4339 // enum-specifier, each enumerator has the type of its 4340 // enumeration. 4341 ECD->setType(EnumType); 4342 continue; // Already int type. 4343 } 4344 4345 // Determine whether the value fits into an int. 4346 llvm::APSInt InitVal = ECD->getInitVal(); 4347 bool FitsInInt; 4348 if (InitVal.isUnsigned() || !InitVal.isNegative()) 4349 FitsInInt = InitVal.getActiveBits() < IntWidth; 4350 else 4351 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 4352 4353 // If it fits into an integer type, force it. Otherwise force it to match 4354 // the enum decl type. 4355 QualType NewTy; 4356 unsigned NewWidth; 4357 bool NewSign; 4358 if (FitsInInt) { 4359 NewTy = Context.IntTy; 4360 NewWidth = IntWidth; 4361 NewSign = true; 4362 } else if (ECD->getType() == BestType) { 4363 // Already the right type! 4364 if (getLangOptions().CPlusPlus) 4365 // C++ [dcl.enum]p4: Following the closing brace of an 4366 // enum-specifier, each enumerator has the type of its 4367 // enumeration. 4368 ECD->setType(EnumType); 4369 continue; 4370 } else { 4371 NewTy = BestType; 4372 NewWidth = BestWidth; 4373 NewSign = BestType->isSignedIntegerType(); 4374 } 4375 4376 // Adjust the APSInt value. 4377 InitVal.extOrTrunc(NewWidth); 4378 InitVal.setIsSigned(NewSign); 4379 ECD->setInitVal(InitVal); 4380 4381 // Adjust the Expr initializer and type. 4382 if (ECD->getInitExpr()) 4383 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, ECD->getInitExpr(), 4384 /*isLvalue=*/false)); 4385 if (getLangOptions().CPlusPlus) 4386 // C++ [dcl.enum]p4: Following the closing brace of an 4387 // enum-specifier, each enumerator has the type of its 4388 // enumeration. 4389 ECD->setType(EnumType); 4390 else 4391 ECD->setType(NewTy); 4392 } 4393 4394 Enum->completeDefinition(Context, BestType); 4395} 4396 4397Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 4398 ExprArg expr) { 4399 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 4400 4401 return DeclPtrTy::make(FileScopeAsmDecl::Create(Context, CurContext, 4402 Loc, AsmString)); 4403} 4404