SemaDecl.cpp revision 3b2e16b3d25f6b311dba2871e2a566c96238c3d2
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/Analysis/CFG.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/StmtCXX.h" 24#include "clang/AST/StmtObjC.h" 25#include "clang/Parse/DeclSpec.h" 26#include "clang/Basic/TargetInfo.h" 27#include "clang/Basic/SourceManager.h" 28// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 29#include "clang/Lex/Preprocessor.h" 30#include "clang/Lex/HeaderSearch.h" 31#include "llvm/ADT/BitVector.h" 32#include "llvm/ADT/STLExtras.h" 33#include <algorithm> 34#include <functional> 35#include <queue> 36using namespace clang; 37 38/// getDeclName - Return a pretty name for the specified decl if possible, or 39/// an empty string if not. This is used for pretty crash reporting. 40std::string Sema::getDeclName(DeclPtrTy d) { 41 Decl *D = d.getAs<Decl>(); 42 if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D)) 43 return DN->getQualifiedNameAsString(); 44 return ""; 45} 46 47Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) { 48 return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>())); 49} 50 51/// \brief If the identifier refers to a type name within this scope, 52/// return the declaration of that type. 53/// 54/// This routine performs ordinary name lookup of the identifier II 55/// within the given scope, with optional C++ scope specifier SS, to 56/// determine whether the name refers to a type. If so, returns an 57/// opaque pointer (actually a QualType) corresponding to that 58/// type. Otherwise, returns NULL. 59/// 60/// If name lookup results in an ambiguity, this routine will complain 61/// and then return NULL. 62Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 63 Scope *S, const CXXScopeSpec *SS) { 64 // C++ [temp.res]p3: 65 // A qualified-id that refers to a type and in which the 66 // nested-name-specifier depends on a template-parameter (14.6.2) 67 // shall be prefixed by the keyword typename to indicate that the 68 // qualified-id denotes a type, forming an 69 // elaborated-type-specifier (7.1.5.3). 70 // 71 // We therefore do not perform any name lookup if the result would 72 // refer to a member of an unknown specialization. 73 if (SS && isUnknownSpecialization(*SS)) 74 return 0; 75 76 LookupResult Result 77 = LookupParsedName(S, SS, &II, LookupOrdinaryName, false, false); 78 79 NamedDecl *IIDecl = 0; 80 switch (Result.getKind()) { 81 case LookupResult::NotFound: 82 case LookupResult::FoundOverloaded: 83 return 0; 84 85 case LookupResult::AmbiguousBaseSubobjectTypes: 86 case LookupResult::AmbiguousBaseSubobjects: 87 case LookupResult::AmbiguousReference: { 88 // Look to see if we have a type anywhere in the list of results. 89 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); 90 Res != ResEnd; ++Res) { 91 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) { 92 if (!IIDecl || 93 (*Res)->getLocation().getRawEncoding() < 94 IIDecl->getLocation().getRawEncoding()) 95 IIDecl = *Res; 96 } 97 } 98 99 if (!IIDecl) { 100 // None of the entities we found is a type, so there is no way 101 // to even assume that the result is a type. In this case, don't 102 // complain about the ambiguity. The parser will either try to 103 // perform this lookup again (e.g., as an object name), which 104 // will produce the ambiguity, or will complain that it expected 105 // a type name. 106 Result.Destroy(); 107 return 0; 108 } 109 110 // We found a type within the ambiguous lookup; diagnose the 111 // ambiguity and then return that type. This might be the right 112 // answer, or it might not be, but it suppresses any attempt to 113 // perform the name lookup again. 114 DiagnoseAmbiguousLookup(Result, DeclarationName(&II), NameLoc); 115 break; 116 } 117 118 case LookupResult::Found: 119 IIDecl = Result.getAsDecl(); 120 break; 121 } 122 123 if (IIDecl) { 124 QualType T; 125 126 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 127 // Check whether we can use this type 128 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 129 130 if (getLangOptions().CPlusPlus) { 131 // C++ [temp.local]p2: 132 // Within the scope of a class template specialization or 133 // partial specialization, when the injected-class-name is 134 // not followed by a <, it is equivalent to the 135 // injected-class-name followed by the template-argument s 136 // of the class template specialization or partial 137 // specialization enclosed in <>. 138 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) 139 if (RD->isInjectedClassName()) 140 if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate()) 141 T = Template->getInjectedClassNameType(Context); 142 } 143 144 if (T.isNull()) 145 T = Context.getTypeDeclType(TD); 146 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 147 // Check whether we can use this interface. 148 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 149 150 T = Context.getObjCInterfaceType(IDecl); 151 } else 152 return 0; 153 154 if (SS) 155 T = getQualifiedNameType(*SS, T); 156 157 return T.getAsOpaquePtr(); 158 } 159 160 return 0; 161} 162 163/// isTagName() - This method is called *for error recovery purposes only* 164/// to determine if the specified name is a valid tag name ("struct foo"). If 165/// so, this returns the TST for the tag corresponding to it (TST_enum, 166/// TST_union, TST_struct, TST_class). This is used to diagnose cases in C 167/// where the user forgot to specify the tag. 168DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { 169 // Do a tag name lookup in this scope. 170 LookupResult R = LookupName(S, &II, LookupTagName, false, false); 171 if (R.getKind() == LookupResult::Found) 172 if (const TagDecl *TD = dyn_cast<TagDecl>(R.getAsDecl())) { 173 switch (TD->getTagKind()) { 174 case TagDecl::TK_struct: return DeclSpec::TST_struct; 175 case TagDecl::TK_union: return DeclSpec::TST_union; 176 case TagDecl::TK_class: return DeclSpec::TST_class; 177 case TagDecl::TK_enum: return DeclSpec::TST_enum; 178 } 179 } 180 181 return DeclSpec::TST_unspecified; 182} 183 184 185 186DeclContext *Sema::getContainingDC(DeclContext *DC) { 187 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 188 // A C++ out-of-line method will return to the file declaration context. 189 if (MD->isOutOfLine()) 190 return MD->getLexicalDeclContext(); 191 192 // A C++ inline method is parsed *after* the topmost class it was declared 193 // in is fully parsed (it's "complete"). 194 // The parsing of a C++ inline method happens at the declaration context of 195 // the topmost (non-nested) class it is lexically declared in. 196 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 197 DC = MD->getParent(); 198 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 199 DC = RD; 200 201 // Return the declaration context of the topmost class the inline method is 202 // declared in. 203 return DC; 204 } 205 206 if (isa<ObjCMethodDecl>(DC)) 207 return Context.getTranslationUnitDecl(); 208 209 return DC->getLexicalParent(); 210} 211 212void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 213 assert(getContainingDC(DC) == CurContext && 214 "The next DeclContext should be lexically contained in the current one."); 215 CurContext = DC; 216 S->setEntity(DC); 217} 218 219void Sema::PopDeclContext() { 220 assert(CurContext && "DeclContext imbalance!"); 221 222 CurContext = getContainingDC(CurContext); 223} 224 225/// EnterDeclaratorContext - Used when we must lookup names in the context 226/// of a declarator's nested name specifier. 227void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { 228 assert(PreDeclaratorDC == 0 && "Previous declarator context not popped?"); 229 PreDeclaratorDC = static_cast<DeclContext*>(S->getEntity()); 230 CurContext = DC; 231 assert(CurContext && "No context?"); 232 S->setEntity(CurContext); 233} 234 235void Sema::ExitDeclaratorContext(Scope *S) { 236 S->setEntity(PreDeclaratorDC); 237 PreDeclaratorDC = 0; 238 239 // Reset CurContext to the nearest enclosing context. 240 while (!S->getEntity() && S->getParent()) 241 S = S->getParent(); 242 CurContext = static_cast<DeclContext*>(S->getEntity()); 243 assert(CurContext && "No context?"); 244} 245 246/// \brief Determine whether we allow overloading of the function 247/// PrevDecl with another declaration. 248/// 249/// This routine determines whether overloading is possible, not 250/// whether some new function is actually an overload. It will return 251/// true in C++ (where we can always provide overloads) or, as an 252/// extension, in C when the previous function is already an 253/// overloaded function declaration or has the "overloadable" 254/// attribute. 255static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) { 256 if (Context.getLangOptions().CPlusPlus) 257 return true; 258 259 if (isa<OverloadedFunctionDecl>(PrevDecl)) 260 return true; 261 262 return PrevDecl->getAttr<OverloadableAttr>() != 0; 263} 264 265/// Add this decl to the scope shadowed decl chains. 266void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 267 // Move up the scope chain until we find the nearest enclosing 268 // non-transparent context. The declaration will be introduced into this 269 // scope. 270 while (S->getEntity() && 271 ((DeclContext *)S->getEntity())->isTransparentContext()) 272 S = S->getParent(); 273 274 S->AddDecl(DeclPtrTy::make(D)); 275 276 // Add scoped declarations into their context, so that they can be 277 // found later. Declarations without a context won't be inserted 278 // into any context. 279 CurContext->addDecl(D); 280 281 // C++ [basic.scope]p4: 282 // -- exactly one declaration shall declare a class name or 283 // enumeration name that is not a typedef name and the other 284 // declarations shall all refer to the same object or 285 // enumerator, or all refer to functions and function templates; 286 // in this case the class name or enumeration name is hidden. 287 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 288 // We are pushing the name of a tag (enum or class). 289 if (CurContext->getLookupContext() 290 == TD->getDeclContext()->getLookupContext()) { 291 // We're pushing the tag into the current context, which might 292 // require some reshuffling in the identifier resolver. 293 IdentifierResolver::iterator 294 I = IdResolver.begin(TD->getDeclName()), 295 IEnd = IdResolver.end(); 296 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 297 NamedDecl *PrevDecl = *I; 298 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 299 PrevDecl = *I, ++I) { 300 if (TD->declarationReplaces(*I)) { 301 // This is a redeclaration. Remove it from the chain and 302 // break out, so that we'll add in the shadowed 303 // declaration. 304 S->RemoveDecl(DeclPtrTy::make(*I)); 305 if (PrevDecl == *I) { 306 IdResolver.RemoveDecl(*I); 307 IdResolver.AddDecl(TD); 308 return; 309 } else { 310 IdResolver.RemoveDecl(*I); 311 break; 312 } 313 } 314 } 315 316 // There is already a declaration with the same name in the same 317 // scope, which is not a tag declaration. It must be found 318 // before we find the new declaration, so insert the new 319 // declaration at the end of the chain. 320 IdResolver.AddShadowedDecl(TD, PrevDecl); 321 322 return; 323 } 324 } 325 } else if ((isa<FunctionDecl>(D) && 326 AllowOverloadingOfFunction(D, Context)) || 327 isa<FunctionTemplateDecl>(D)) { 328 // We are pushing the name of a function or function template, 329 // which might be an overloaded name. 330 IdentifierResolver::iterator Redecl 331 = std::find_if(IdResolver.begin(D->getDeclName()), 332 IdResolver.end(), 333 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 334 D)); 335 if (Redecl != IdResolver.end() && 336 S->isDeclScope(DeclPtrTy::make(*Redecl))) { 337 // There is already a declaration of a function on our 338 // IdResolver chain. Replace it with this declaration. 339 S->RemoveDecl(DeclPtrTy::make(*Redecl)); 340 IdResolver.RemoveDecl(*Redecl); 341 } 342 } else if (isa<ObjCInterfaceDecl>(D)) { 343 // We're pushing an Objective-C interface into the current 344 // context. If there is already an alias declaration, remove it first. 345 for (IdentifierResolver::iterator 346 I = IdResolver.begin(D->getDeclName()), IEnd = IdResolver.end(); 347 I != IEnd; ++I) { 348 if (isa<ObjCCompatibleAliasDecl>(*I)) { 349 S->RemoveDecl(DeclPtrTy::make(*I)); 350 IdResolver.RemoveDecl(*I); 351 break; 352 } 353 } 354 } 355 356 IdResolver.AddDecl(D); 357} 358 359void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 360 if (S->decl_empty()) return; 361 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 362 "Scope shouldn't contain decls!"); 363 364 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 365 I != E; ++I) { 366 Decl *TmpD = (*I).getAs<Decl>(); 367 assert(TmpD && "This decl didn't get pushed??"); 368 369 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 370 NamedDecl *D = cast<NamedDecl>(TmpD); 371 372 if (!D->getDeclName()) continue; 373 374 // Remove this name from our lexical scope. 375 IdResolver.RemoveDecl(D); 376 } 377} 378 379/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 380/// return 0 if one not found. 381ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 382 // The third "scope" argument is 0 since we aren't enabling lazy built-in 383 // creation from this context. 384 NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName); 385 386 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 387} 388 389/// getNonFieldDeclScope - Retrieves the innermost scope, starting 390/// from S, where a non-field would be declared. This routine copes 391/// with the difference between C and C++ scoping rules in structs and 392/// unions. For example, the following code is well-formed in C but 393/// ill-formed in C++: 394/// @code 395/// struct S6 { 396/// enum { BAR } e; 397/// }; 398/// 399/// void test_S6() { 400/// struct S6 a; 401/// a.e = BAR; 402/// } 403/// @endcode 404/// For the declaration of BAR, this routine will return a different 405/// scope. The scope S will be the scope of the unnamed enumeration 406/// within S6. In C++, this routine will return the scope associated 407/// with S6, because the enumeration's scope is a transparent 408/// context but structures can contain non-field names. In C, this 409/// routine will return the translation unit scope, since the 410/// enumeration's scope is a transparent context and structures cannot 411/// contain non-field names. 412Scope *Sema::getNonFieldDeclScope(Scope *S) { 413 while (((S->getFlags() & Scope::DeclScope) == 0) || 414 (S->getEntity() && 415 ((DeclContext *)S->getEntity())->isTransparentContext()) || 416 (S->isClassScope() && !getLangOptions().CPlusPlus)) 417 S = S->getParent(); 418 return S; 419} 420 421void Sema::InitBuiltinVaListType() { 422 if (!Context.getBuiltinVaListType().isNull()) 423 return; 424 425 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 426 NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName); 427 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 428 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 429} 430 431/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 432/// file scope. lazily create a decl for it. ForRedeclaration is true 433/// if we're creating this built-in in anticipation of redeclaring the 434/// built-in. 435NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 436 Scope *S, bool ForRedeclaration, 437 SourceLocation Loc) { 438 Builtin::ID BID = (Builtin::ID)bid; 439 440 if (Context.BuiltinInfo.hasVAListUse(BID)) 441 InitBuiltinVaListType(); 442 443 ASTContext::GetBuiltinTypeError Error; 444 QualType R = Context.GetBuiltinType(BID, Error); 445 switch (Error) { 446 case ASTContext::GE_None: 447 // Okay 448 break; 449 450 case ASTContext::GE_Missing_stdio: 451 if (ForRedeclaration) 452 Diag(Loc, diag::err_implicit_decl_requires_stdio) 453 << Context.BuiltinInfo.GetName(BID); 454 return 0; 455 456 case ASTContext::GE_Missing_setjmp: 457 if (ForRedeclaration) 458 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 459 << Context.BuiltinInfo.GetName(BID); 460 return 0; 461 } 462 463 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 464 Diag(Loc, diag::ext_implicit_lib_function_decl) 465 << Context.BuiltinInfo.GetName(BID) 466 << R; 467 if (Context.BuiltinInfo.getHeaderName(BID) && 468 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 469 != Diagnostic::Ignored) 470 Diag(Loc, diag::note_please_include_header) 471 << Context.BuiltinInfo.getHeaderName(BID) 472 << Context.BuiltinInfo.GetName(BID); 473 } 474 475 FunctionDecl *New = FunctionDecl::Create(Context, 476 Context.getTranslationUnitDecl(), 477 Loc, II, R, 478 FunctionDecl::Extern, false, 479 /*hasPrototype=*/true); 480 New->setImplicit(); 481 482 // Create Decl objects for each parameter, adding them to the 483 // FunctionDecl. 484 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 485 llvm::SmallVector<ParmVarDecl*, 16> Params; 486 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 487 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 488 FT->getArgType(i), VarDecl::None, 0)); 489 New->setParams(Context, Params.data(), Params.size()); 490 } 491 492 AddKnownFunctionAttributes(New); 493 494 // TUScope is the translation-unit scope to insert this function into. 495 // FIXME: This is hideous. We need to teach PushOnScopeChains to 496 // relate Scopes to DeclContexts, and probably eliminate CurContext 497 // entirely, but we're not there yet. 498 DeclContext *SavedContext = CurContext; 499 CurContext = Context.getTranslationUnitDecl(); 500 PushOnScopeChains(New, TUScope); 501 CurContext = SavedContext; 502 return New; 503} 504 505/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 506/// everything from the standard library is defined. 507NamespaceDecl *Sema::GetStdNamespace() { 508 if (!StdNamespace) { 509 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 510 DeclContext *Global = Context.getTranslationUnitDecl(); 511 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 512 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 513 } 514 return StdNamespace; 515} 516 517/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 518/// same name and scope as a previous declaration 'Old'. Figure out 519/// how to resolve this situation, merging decls or emitting 520/// diagnostics as appropriate. If there was an error, set New to be invalid. 521/// 522void Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 523 // If either decl is known invalid already, set the new one to be invalid and 524 // don't bother doing any merging checks. 525 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 526 return New->setInvalidDecl(); 527 528 // Allow multiple definitions for ObjC built-in typedefs. 529 // FIXME: Verify the underlying types are equivalent! 530 if (getLangOptions().ObjC1) { 531 const IdentifierInfo *TypeID = New->getIdentifier(); 532 switch (TypeID->getLength()) { 533 default: break; 534 case 2: 535 if (!TypeID->isStr("id")) 536 break; 537 // Install the built-in type for 'id', ignoring the current definition. 538 New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); 539 return; 540 case 5: 541 if (!TypeID->isStr("Class")) 542 break; 543 // Install the built-in type for 'Class', ignoring the current definition. 544 New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); 545 return; 546 case 3: 547 if (!TypeID->isStr("SEL")) 548 break; 549 Context.setObjCSelType(Context.getTypeDeclType(New)); 550 return; 551 case 8: 552 if (!TypeID->isStr("Protocol")) 553 break; 554 Context.setObjCProtoType(New->getUnderlyingType()); 555 return; 556 } 557 // Fall through - the typedef name was not a builtin type. 558 } 559 // Verify the old decl was also a type. 560 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 561 if (!Old) { 562 Diag(New->getLocation(), diag::err_redefinition_different_kind) 563 << New->getDeclName(); 564 if (OldD->getLocation().isValid()) 565 Diag(OldD->getLocation(), diag::note_previous_definition); 566 return New->setInvalidDecl(); 567 } 568 569 // Determine the "old" type we'll use for checking and diagnostics. 570 QualType OldType; 571 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 572 OldType = OldTypedef->getUnderlyingType(); 573 else 574 OldType = Context.getTypeDeclType(Old); 575 576 // If the typedef types are not identical, reject them in all languages and 577 // with any extensions enabled. 578 579 if (OldType != New->getUnderlyingType() && 580 Context.getCanonicalType(OldType) != 581 Context.getCanonicalType(New->getUnderlyingType())) { 582 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 583 << New->getUnderlyingType() << OldType; 584 if (Old->getLocation().isValid()) 585 Diag(Old->getLocation(), diag::note_previous_definition); 586 return New->setInvalidDecl(); 587 } 588 589 if (getLangOptions().Microsoft) 590 return; 591 592 // C++ [dcl.typedef]p2: 593 // In a given non-class scope, a typedef specifier can be used to 594 // redefine the name of any type declared in that scope to refer 595 // to the type to which it already refers. 596 if (getLangOptions().CPlusPlus) { 597 if (!isa<CXXRecordDecl>(CurContext)) 598 return; 599 Diag(New->getLocation(), diag::err_redefinition) 600 << New->getDeclName(); 601 Diag(Old->getLocation(), diag::note_previous_definition); 602 return New->setInvalidDecl(); 603 } 604 605 // If we have a redefinition of a typedef in C, emit a warning. This warning 606 // is normally mapped to an error, but can be controlled with 607 // -Wtypedef-redefinition. If either the original or the redefinition is 608 // in a system header, don't emit this for compatibility with GCC. 609 if (PP.getDiagnostics().getSuppressSystemWarnings() && 610 (Context.getSourceManager().isInSystemHeader(Old->getLocation()) || 611 Context.getSourceManager().isInSystemHeader(New->getLocation()))) 612 return; 613 614 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 615 << New->getDeclName(); 616 Diag(Old->getLocation(), diag::note_previous_definition); 617 return; 618} 619 620/// DeclhasAttr - returns true if decl Declaration already has the target 621/// attribute. 622static bool 623DeclHasAttr(const Decl *decl, const Attr *target) { 624 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 625 if (attr->getKind() == target->getKind()) 626 return true; 627 628 return false; 629} 630 631/// MergeAttributes - append attributes from the Old decl to the New one. 632static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 633 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 634 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 635 Attr *NewAttr = attr->clone(C); 636 NewAttr->setInherited(true); 637 New->addAttr(NewAttr); 638 } 639 } 640} 641 642/// Used in MergeFunctionDecl to keep track of function parameters in 643/// C. 644struct GNUCompatibleParamWarning { 645 ParmVarDecl *OldParm; 646 ParmVarDecl *NewParm; 647 QualType PromotedType; 648}; 649 650/// MergeFunctionDecl - We just parsed a function 'New' from 651/// declarator D which has the same name and scope as a previous 652/// declaration 'Old'. Figure out how to resolve this situation, 653/// merging decls or emitting diagnostics as appropriate. 654/// 655/// In C++, New and Old must be declarations that are not 656/// overloaded. Use IsOverload to determine whether New and Old are 657/// overloaded, and to select the Old declaration that New should be 658/// merged with. 659/// 660/// Returns true if there was an error, false otherwise. 661bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 662 assert(!isa<OverloadedFunctionDecl>(OldD) && 663 "Cannot merge with an overloaded function declaration"); 664 665 // Verify the old decl was also a function. 666 FunctionDecl *Old = 0; 667 if (FunctionTemplateDecl *OldFunctionTemplate 668 = dyn_cast<FunctionTemplateDecl>(OldD)) 669 Old = OldFunctionTemplate->getTemplatedDecl(); 670 else 671 Old = dyn_cast<FunctionDecl>(OldD); 672 if (!Old) { 673 Diag(New->getLocation(), diag::err_redefinition_different_kind) 674 << New->getDeclName(); 675 Diag(OldD->getLocation(), diag::note_previous_definition); 676 return true; 677 } 678 679 // Determine whether the previous declaration was a definition, 680 // implicit declaration, or a declaration. 681 diag::kind PrevDiag; 682 if (Old->isThisDeclarationADefinition()) 683 PrevDiag = diag::note_previous_definition; 684 else if (Old->isImplicit()) 685 PrevDiag = diag::note_previous_implicit_declaration; 686 else 687 PrevDiag = diag::note_previous_declaration; 688 689 QualType OldQType = Context.getCanonicalType(Old->getType()); 690 QualType NewQType = Context.getCanonicalType(New->getType()); 691 692 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 693 New->getStorageClass() == FunctionDecl::Static && 694 Old->getStorageClass() != FunctionDecl::Static) { 695 Diag(New->getLocation(), diag::err_static_non_static) 696 << New; 697 Diag(Old->getLocation(), PrevDiag); 698 return true; 699 } 700 701 if (getLangOptions().CPlusPlus) { 702 // (C++98 13.1p2): 703 // Certain function declarations cannot be overloaded: 704 // -- Function declarations that differ only in the return type 705 // cannot be overloaded. 706 QualType OldReturnType 707 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 708 QualType NewReturnType 709 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 710 if (OldReturnType != NewReturnType) { 711 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 712 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 713 return true; 714 } 715 716 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 717 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 718 if (OldMethod && NewMethod && 719 NewMethod->getLexicalDeclContext()->isRecord()) { 720 // -- Member function declarations with the same name and the 721 // same parameter types cannot be overloaded if any of them 722 // is a static member function declaration. 723 if (OldMethod->isStatic() || NewMethod->isStatic()) { 724 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 725 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 726 return true; 727 } 728 729 // C++ [class.mem]p1: 730 // [...] A member shall not be declared twice in the 731 // member-specification, except that a nested class or member 732 // class template can be declared and then later defined. 733 unsigned NewDiag; 734 if (isa<CXXConstructorDecl>(OldMethod)) 735 NewDiag = diag::err_constructor_redeclared; 736 else if (isa<CXXDestructorDecl>(NewMethod)) 737 NewDiag = diag::err_destructor_redeclared; 738 else if (isa<CXXConversionDecl>(NewMethod)) 739 NewDiag = diag::err_conv_function_redeclared; 740 else 741 NewDiag = diag::err_member_redeclared; 742 743 Diag(New->getLocation(), NewDiag); 744 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 745 } 746 747 // (C++98 8.3.5p3): 748 // All declarations for a function shall agree exactly in both the 749 // return type and the parameter-type-list. 750 if (OldQType == NewQType) 751 return MergeCompatibleFunctionDecls(New, Old); 752 753 // Fall through for conflicting redeclarations and redefinitions. 754 } 755 756 // C: Function types need to be compatible, not identical. This handles 757 // duplicate function decls like "void f(int); void f(enum X);" properly. 758 if (!getLangOptions().CPlusPlus && 759 Context.typesAreCompatible(OldQType, NewQType)) { 760 const FunctionType *OldFuncType = OldQType->getAsFunctionType(); 761 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 762 const FunctionProtoType *OldProto = 0; 763 if (isa<FunctionNoProtoType>(NewFuncType) && 764 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 765 // The old declaration provided a function prototype, but the 766 // new declaration does not. Merge in the prototype. 767 assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); 768 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 769 OldProto->arg_type_end()); 770 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 771 ParamTypes.data(), ParamTypes.size(), 772 OldProto->isVariadic(), 773 OldProto->getTypeQuals()); 774 New->setType(NewQType); 775 New->setHasInheritedPrototype(); 776 777 // Synthesize a parameter for each argument type. 778 llvm::SmallVector<ParmVarDecl*, 16> Params; 779 for (FunctionProtoType::arg_type_iterator 780 ParamType = OldProto->arg_type_begin(), 781 ParamEnd = OldProto->arg_type_end(); 782 ParamType != ParamEnd; ++ParamType) { 783 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 784 SourceLocation(), 0, 785 *ParamType, VarDecl::None, 786 0); 787 Param->setImplicit(); 788 Params.push_back(Param); 789 } 790 791 New->setParams(Context, Params.data(), Params.size()); 792 } 793 794 return MergeCompatibleFunctionDecls(New, Old); 795 } 796 797 // GNU C permits a K&R definition to follow a prototype declaration 798 // if the declared types of the parameters in the K&R definition 799 // match the types in the prototype declaration, even when the 800 // promoted types of the parameters from the K&R definition differ 801 // from the types in the prototype. GCC then keeps the types from 802 // the prototype. 803 // 804 // If a variadic prototype is followed by a non-variadic K&R definition, 805 // the K&R definition becomes variadic. This is sort of an edge case, but 806 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and 807 // C99 6.9.1p8. 808 if (!getLangOptions().CPlusPlus && 809 Old->hasPrototype() && !New->hasPrototype() && 810 New->getType()->getAsFunctionProtoType() && 811 Old->getNumParams() == New->getNumParams()) { 812 llvm::SmallVector<QualType, 16> ArgTypes; 813 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 814 const FunctionProtoType *OldProto 815 = Old->getType()->getAsFunctionProtoType(); 816 const FunctionProtoType *NewProto 817 = New->getType()->getAsFunctionProtoType(); 818 819 // Determine whether this is the GNU C extension. 820 QualType MergedReturn = Context.mergeTypes(OldProto->getResultType(), 821 NewProto->getResultType()); 822 bool LooseCompatible = !MergedReturn.isNull(); 823 for (unsigned Idx = 0, End = Old->getNumParams(); 824 LooseCompatible && Idx != End; ++Idx) { 825 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 826 ParmVarDecl *NewParm = New->getParamDecl(Idx); 827 if (Context.typesAreCompatible(OldParm->getType(), 828 NewProto->getArgType(Idx))) { 829 ArgTypes.push_back(NewParm->getType()); 830 } else if (Context.typesAreCompatible(OldParm->getType(), 831 NewParm->getType())) { 832 GNUCompatibleParamWarning Warn 833 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 834 Warnings.push_back(Warn); 835 ArgTypes.push_back(NewParm->getType()); 836 } else 837 LooseCompatible = false; 838 } 839 840 if (LooseCompatible) { 841 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 842 Diag(Warnings[Warn].NewParm->getLocation(), 843 diag::ext_param_promoted_not_compatible_with_prototype) 844 << Warnings[Warn].PromotedType 845 << Warnings[Warn].OldParm->getType(); 846 Diag(Warnings[Warn].OldParm->getLocation(), 847 diag::note_previous_declaration); 848 } 849 850 New->setType(Context.getFunctionType(MergedReturn, &ArgTypes[0], 851 ArgTypes.size(), 852 OldProto->isVariadic(), 0)); 853 return MergeCompatibleFunctionDecls(New, Old); 854 } 855 856 // Fall through to diagnose conflicting types. 857 } 858 859 // A function that has already been declared has been redeclared or defined 860 // with a different type- show appropriate diagnostic 861 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 862 // The user has declared a builtin function with an incompatible 863 // signature. 864 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 865 // The function the user is redeclaring is a library-defined 866 // function like 'malloc' or 'printf'. Warn about the 867 // redeclaration, then pretend that we don't know about this 868 // library built-in. 869 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 870 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 871 << Old << Old->getType(); 872 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 873 Old->setInvalidDecl(); 874 return false; 875 } 876 877 PrevDiag = diag::note_previous_builtin_declaration; 878 } 879 880 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 881 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 882 return true; 883} 884 885/// \brief Completes the merge of two function declarations that are 886/// known to be compatible. 887/// 888/// This routine handles the merging of attributes and other 889/// properties of function declarations form the old declaration to 890/// the new declaration, once we know that New is in fact a 891/// redeclaration of Old. 892/// 893/// \returns false 894bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 895 // Merge the attributes 896 MergeAttributes(New, Old, Context); 897 898 // Merge the storage class. 899 if (Old->getStorageClass() != FunctionDecl::Extern) 900 New->setStorageClass(Old->getStorageClass()); 901 902 // Merge "inline" 903 if (Old->isInline()) 904 New->setInline(true); 905 906 // If this function declaration by itself qualifies as a C99 inline 907 // definition (C99 6.7.4p6), but the previous definition did not, 908 // then the function is not a C99 inline definition. 909 if (New->isC99InlineDefinition() && !Old->isC99InlineDefinition()) 910 New->setC99InlineDefinition(false); 911 else if (Old->isC99InlineDefinition() && !New->isC99InlineDefinition()) { 912 // Mark all preceding definitions as not being C99 inline definitions. 913 for (const FunctionDecl *Prev = Old; Prev; 914 Prev = Prev->getPreviousDeclaration()) 915 const_cast<FunctionDecl *>(Prev)->setC99InlineDefinition(false); 916 } 917 918 // Merge "pure" flag. 919 if (Old->isPure()) 920 New->setPure(); 921 922 // Merge the "deleted" flag. 923 if (Old->isDeleted()) 924 New->setDeleted(); 925 926 if (getLangOptions().CPlusPlus) 927 return MergeCXXFunctionDecl(New, Old); 928 929 return false; 930} 931 932/// MergeVarDecl - We just parsed a variable 'New' which has the same name 933/// and scope as a previous declaration 'Old'. Figure out how to resolve this 934/// situation, merging decls or emitting diagnostics as appropriate. 935/// 936/// Tentative definition rules (C99 6.9.2p2) are checked by 937/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 938/// definitions here, since the initializer hasn't been attached. 939/// 940void Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 941 // If either decl is invalid, make sure the new one is marked invalid and 942 // don't do any other checking. 943 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 944 return New->setInvalidDecl(); 945 946 // Verify the old decl was also a variable. 947 VarDecl *Old = dyn_cast<VarDecl>(OldD); 948 if (!Old) { 949 Diag(New->getLocation(), diag::err_redefinition_different_kind) 950 << New->getDeclName(); 951 Diag(OldD->getLocation(), diag::note_previous_definition); 952 return New->setInvalidDecl(); 953 } 954 955 MergeAttributes(New, Old, Context); 956 957 // Merge the types 958 QualType MergedT; 959 if (getLangOptions().CPlusPlus) { 960 if (Context.hasSameType(New->getType(), Old->getType())) 961 MergedT = New->getType(); 962 } else { 963 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 964 } 965 if (MergedT.isNull()) { 966 Diag(New->getLocation(), diag::err_redefinition_different_type) 967 << New->getDeclName(); 968 Diag(Old->getLocation(), diag::note_previous_definition); 969 return New->setInvalidDecl(); 970 } 971 New->setType(MergedT); 972 973 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 974 if (New->getStorageClass() == VarDecl::Static && 975 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 976 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 977 Diag(Old->getLocation(), diag::note_previous_definition); 978 return New->setInvalidDecl(); 979 } 980 // C99 6.2.2p4: 981 // For an identifier declared with the storage-class specifier 982 // extern in a scope in which a prior declaration of that 983 // identifier is visible,23) if the prior declaration specifies 984 // internal or external linkage, the linkage of the identifier at 985 // the later declaration is the same as the linkage specified at 986 // the prior declaration. If no prior declaration is visible, or 987 // if the prior declaration specifies no linkage, then the 988 // identifier has external linkage. 989 if (New->hasExternalStorage() && Old->hasLinkage()) 990 /* Okay */; 991 else if (New->getStorageClass() != VarDecl::Static && 992 Old->getStorageClass() == VarDecl::Static) { 993 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 994 Diag(Old->getLocation(), diag::note_previous_definition); 995 return New->setInvalidDecl(); 996 } 997 998 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 999 1000 // FIXME: The test for external storage here seems wrong? We still 1001 // need to check for mismatches. 1002 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 1003 // Don't complain about out-of-line definitions of static members. 1004 !(Old->getLexicalDeclContext()->isRecord() && 1005 !New->getLexicalDeclContext()->isRecord())) { 1006 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 1007 Diag(Old->getLocation(), diag::note_previous_definition); 1008 return New->setInvalidDecl(); 1009 } 1010 1011 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 1012 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 1013 Diag(Old->getLocation(), diag::note_previous_definition); 1014 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 1015 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 1016 Diag(Old->getLocation(), diag::note_previous_definition); 1017 } 1018 1019 // Keep a chain of previous declarations. 1020 New->setPreviousDeclaration(Old); 1021} 1022 1023/// CheckFallThrough - Check that we don't fall off the end of a 1024/// Statement that should return a value. 1025/// 1026/// \returns AlwaysFallThrough iff we always fall off the end of the statement, 1027/// MaybeFallThrough iff we might or might not fall off the end and 1028/// NeverFallThrough iff we never fall off the end of the statement. We assume 1029/// that functions not marked noreturn will return. 1030Sema::ControlFlowKind Sema::CheckFallThrough(Stmt *Root) { 1031 llvm::OwningPtr<CFG> cfg (CFG::buildCFG(Root, &Context)); 1032 1033 // FIXME: They should never return 0, fix that, delete this code. 1034 if (cfg == 0) 1035 return NeverFallThrough; 1036 // The CFG leaves in dead things, and we don't want to dead code paths to 1037 // confuse us, so we mark all live things first. 1038 std::queue<CFGBlock*> workq; 1039 llvm::BitVector live(cfg->getNumBlockIDs()); 1040 // Prep work queue 1041 workq.push(&cfg->getEntry()); 1042 // Solve 1043 while (!workq.empty()) { 1044 CFGBlock *item = workq.front(); 1045 workq.pop(); 1046 live.set(item->getBlockID()); 1047 for (CFGBlock::succ_iterator I=item->succ_begin(), 1048 E=item->succ_end(); 1049 I != E; 1050 ++I) { 1051 if ((*I) && !live[(*I)->getBlockID()]) { 1052 live.set((*I)->getBlockID()); 1053 workq.push(*I); 1054 } 1055 } 1056 } 1057 1058 // Now we know what is live, we check the live precessors of the exit block 1059 // and look for fall through paths, being careful to ignore normal returns, 1060 // and exceptional paths. 1061 bool HasLiveReturn = false; 1062 bool HasFakeEdge = false; 1063 bool HasPlainEdge = false; 1064 for (CFGBlock::succ_iterator I=cfg->getExit().pred_begin(), 1065 E = cfg->getExit().pred_end(); 1066 I != E; 1067 ++I) { 1068 CFGBlock& B = **I; 1069 if (!live[B.getBlockID()]) 1070 continue; 1071 if (B.size() == 0) { 1072 // A labeled empty statement, or the entry block... 1073 HasPlainEdge = true; 1074 continue; 1075 } 1076 Stmt *S = B[B.size()-1]; 1077 if (isa<ReturnStmt>(S)) { 1078 HasLiveReturn = true; 1079 continue; 1080 } 1081 if (isa<ObjCAtThrowStmt>(S)) { 1082 HasFakeEdge = true; 1083 continue; 1084 } 1085 if (isa<CXXThrowExpr>(S)) { 1086 HasFakeEdge = true; 1087 continue; 1088 } 1089 bool NoReturnEdge = false; 1090 if (CallExpr *C = dyn_cast<CallExpr>(S)) { 1091 Expr *CEE = C->getCallee()->IgnoreParenCasts(); 1092 if (CEE->getType().getNoReturnAttr()) { 1093 NoReturnEdge = true; 1094 HasFakeEdge = true; 1095 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) { 1096 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 1097 if (FD->hasAttr<NoReturnAttr>()) { 1098 NoReturnEdge = true; 1099 HasFakeEdge = true; 1100 } 1101 } 1102 } 1103 } 1104 // FIXME: Add noreturn message sends. 1105 if (NoReturnEdge == false) 1106 HasPlainEdge = true; 1107 } 1108 if (!HasPlainEdge) 1109 return NeverFallThrough; 1110 if (HasFakeEdge || HasLiveReturn) 1111 return MaybeFallThrough; 1112 // This says AlwaysFallThrough for calls to functions that are not marked 1113 // noreturn, that don't return. If people would like this warning to be more 1114 // accurate, such functions should be marked as noreturn. 1115 return AlwaysFallThrough; 1116} 1117 1118/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a 1119/// function that should return a value. Check that we don't fall off the end 1120/// of a noreturn function. We assume that functions and blocks not marked 1121/// noreturn will return. 1122void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body) { 1123 // FIXME: Would be nice if we had a better way to control cascading errors, 1124 // but for now, avoid them. The problem is that when Parse sees: 1125 // int foo() { return a; } 1126 // The return is eaten and the Sema code sees just: 1127 // int foo() { } 1128 // which this code would then warn about. 1129 if (getDiagnostics().hasErrorOccurred()) 1130 return; 1131 bool ReturnsVoid = false; 1132 bool HasNoReturn = false; 1133 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1134 if (FD->getResultType()->isVoidType()) 1135 ReturnsVoid = true; 1136 if (FD->hasAttr<NoReturnAttr>()) 1137 HasNoReturn = true; 1138 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 1139 if (MD->getResultType()->isVoidType()) 1140 ReturnsVoid = true; 1141 if (MD->hasAttr<NoReturnAttr>()) 1142 HasNoReturn = true; 1143 } 1144 1145 // Short circuit for compilation speed. 1146 if ((Diags.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function) 1147 == Diagnostic::Ignored || ReturnsVoid) 1148 && (Diags.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr) 1149 == Diagnostic::Ignored || !HasNoReturn) 1150 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1151 == Diagnostic::Ignored || !ReturnsVoid)) 1152 return; 1153 // FIXME: Funtion try block 1154 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1155 switch (CheckFallThrough(Body)) { 1156 case MaybeFallThrough: 1157 if (HasNoReturn) 1158 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1159 else if (!ReturnsVoid) 1160 Diag(Compound->getRBracLoc(),diag::warn_maybe_falloff_nonvoid_function); 1161 break; 1162 case AlwaysFallThrough: 1163 if (HasNoReturn) 1164 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1165 else if (!ReturnsVoid) 1166 Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function); 1167 break; 1168 case NeverFallThrough: 1169 if (ReturnsVoid) 1170 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function); 1171 break; 1172 } 1173 } 1174} 1175 1176/// CheckFallThroughForBlock - Check that we don't fall off the end of a block 1177/// that should return a value. Check that we don't fall off the end of a 1178/// noreturn block. We assume that functions and blocks not marked noreturn 1179/// will return. 1180void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body) { 1181 // FIXME: Would be nice if we had a better way to control cascading errors, 1182 // but for now, avoid them. The problem is that when Parse sees: 1183 // int foo() { return a; } 1184 // The return is eaten and the Sema code sees just: 1185 // int foo() { } 1186 // which this code would then warn about. 1187 if (getDiagnostics().hasErrorOccurred()) 1188 return; 1189 bool ReturnsVoid = false; 1190 bool HasNoReturn = false; 1191 if (const FunctionType *FT = BlockTy->getPointeeType()->getAsFunctionType()) { 1192 if (FT->getResultType()->isVoidType()) 1193 ReturnsVoid = true; 1194 if (FT->getNoReturnAttr()) 1195 HasNoReturn = true; 1196 } 1197 1198 // Short circuit for compilation speed. 1199 if (ReturnsVoid 1200 && !HasNoReturn 1201 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1202 == Diagnostic::Ignored || !ReturnsVoid)) 1203 return; 1204 // FIXME: Funtion try block 1205 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1206 switch (CheckFallThrough(Body)) { 1207 case MaybeFallThrough: 1208 if (HasNoReturn) 1209 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1210 else if (!ReturnsVoid) 1211 Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block); 1212 break; 1213 case AlwaysFallThrough: 1214 if (HasNoReturn) 1215 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1216 else if (!ReturnsVoid) 1217 Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block); 1218 break; 1219 case NeverFallThrough: 1220 if (ReturnsVoid) 1221 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block); 1222 break; 1223 } 1224 } 1225} 1226 1227/// CheckParmsForFunctionDef - Check that the parameters of the given 1228/// function are appropriate for the definition of a function. This 1229/// takes care of any checks that cannot be performed on the 1230/// declaration itself, e.g., that the types of each of the function 1231/// parameters are complete. 1232bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 1233 bool HasInvalidParm = false; 1234 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1235 ParmVarDecl *Param = FD->getParamDecl(p); 1236 1237 // C99 6.7.5.3p4: the parameters in a parameter type list in a 1238 // function declarator that is part of a function definition of 1239 // that function shall not have incomplete type. 1240 // 1241 // This is also C++ [dcl.fct]p6. 1242 if (!Param->isInvalidDecl() && 1243 RequireCompleteType(Param->getLocation(), Param->getType(), 1244 diag::err_typecheck_decl_incomplete_type)) { 1245 Param->setInvalidDecl(); 1246 HasInvalidParm = true; 1247 } 1248 1249 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1250 // declaration of each parameter shall include an identifier. 1251 if (Param->getIdentifier() == 0 && 1252 !Param->isImplicit() && 1253 !getLangOptions().CPlusPlus) 1254 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1255 } 1256 1257 return HasInvalidParm; 1258} 1259 1260/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1261/// no declarator (e.g. "struct foo;") is parsed. 1262Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1263 // FIXME: Error on auto/register at file scope 1264 // FIXME: Error on inline/virtual/explicit 1265 // FIXME: Error on invalid restrict 1266 // FIXME: Warn on useless __thread 1267 // FIXME: Warn on useless const/volatile 1268 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1269 // FIXME: Warn on useless attributes 1270 TagDecl *Tag = 0; 1271 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1272 DS.getTypeSpecType() == DeclSpec::TST_struct || 1273 DS.getTypeSpecType() == DeclSpec::TST_union || 1274 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1275 if (!DS.getTypeRep()) // We probably had an error 1276 return DeclPtrTy(); 1277 1278 // Note that the above type specs guarantee that the 1279 // type rep is a Decl, whereas in many of the others 1280 // it's a Type. 1281 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 1282 } 1283 1284 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1285 if (!Record->getDeclName() && Record->isDefinition() && 1286 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1287 if (getLangOptions().CPlusPlus || 1288 Record->getDeclContext()->isRecord()) 1289 return BuildAnonymousStructOrUnion(S, DS, Record); 1290 1291 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1292 << DS.getSourceRange(); 1293 } 1294 1295 // Microsoft allows unnamed struct/union fields. Don't complain 1296 // about them. 1297 // FIXME: Should we support Microsoft's extensions in this area? 1298 if (Record->getDeclName() && getLangOptions().Microsoft) 1299 return DeclPtrTy::make(Tag); 1300 } 1301 1302 if (!DS.isMissingDeclaratorOk() && 1303 DS.getTypeSpecType() != DeclSpec::TST_error) { 1304 // Warn about typedefs of enums without names, since this is an 1305 // extension in both Microsoft an GNU. 1306 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1307 Tag && isa<EnumDecl>(Tag)) { 1308 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1309 << DS.getSourceRange(); 1310 return DeclPtrTy::make(Tag); 1311 } 1312 1313 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1314 << DS.getSourceRange(); 1315 return DeclPtrTy(); 1316 } 1317 1318 return DeclPtrTy::make(Tag); 1319} 1320 1321/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1322/// anonymous struct or union AnonRecord into the owning context Owner 1323/// and scope S. This routine will be invoked just after we realize 1324/// that an unnamed union or struct is actually an anonymous union or 1325/// struct, e.g., 1326/// 1327/// @code 1328/// union { 1329/// int i; 1330/// float f; 1331/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1332/// // f into the surrounding scope.x 1333/// @endcode 1334/// 1335/// This routine is recursive, injecting the names of nested anonymous 1336/// structs/unions into the owning context and scope as well. 1337bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1338 RecordDecl *AnonRecord) { 1339 bool Invalid = false; 1340 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 1341 FEnd = AnonRecord->field_end(); 1342 F != FEnd; ++F) { 1343 if ((*F)->getDeclName()) { 1344 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 1345 LookupOrdinaryName, true); 1346 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 1347 // C++ [class.union]p2: 1348 // The names of the members of an anonymous union shall be 1349 // distinct from the names of any other entity in the 1350 // scope in which the anonymous union is declared. 1351 unsigned diagKind 1352 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 1353 : diag::err_anonymous_struct_member_redecl; 1354 Diag((*F)->getLocation(), diagKind) 1355 << (*F)->getDeclName(); 1356 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1357 Invalid = true; 1358 } else { 1359 // C++ [class.union]p2: 1360 // For the purpose of name lookup, after the anonymous union 1361 // definition, the members of the anonymous union are 1362 // considered to have been defined in the scope in which the 1363 // anonymous union is declared. 1364 Owner->makeDeclVisibleInContext(*F); 1365 S->AddDecl(DeclPtrTy::make(*F)); 1366 IdResolver.AddDecl(*F); 1367 } 1368 } else if (const RecordType *InnerRecordType 1369 = (*F)->getType()->getAs<RecordType>()) { 1370 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1371 if (InnerRecord->isAnonymousStructOrUnion()) 1372 Invalid = Invalid || 1373 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1374 } 1375 } 1376 1377 return Invalid; 1378} 1379 1380/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1381/// anonymous structure or union. Anonymous unions are a C++ feature 1382/// (C++ [class.union]) and a GNU C extension; anonymous structures 1383/// are a GNU C and GNU C++ extension. 1384Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1385 RecordDecl *Record) { 1386 DeclContext *Owner = Record->getDeclContext(); 1387 1388 // Diagnose whether this anonymous struct/union is an extension. 1389 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1390 Diag(Record->getLocation(), diag::ext_anonymous_union); 1391 else if (!Record->isUnion()) 1392 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1393 1394 // C and C++ require different kinds of checks for anonymous 1395 // structs/unions. 1396 bool Invalid = false; 1397 if (getLangOptions().CPlusPlus) { 1398 const char* PrevSpec = 0; 1399 unsigned DiagID; 1400 // C++ [class.union]p3: 1401 // Anonymous unions declared in a named namespace or in the 1402 // global namespace shall be declared static. 1403 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1404 (isa<TranslationUnitDecl>(Owner) || 1405 (isa<NamespaceDecl>(Owner) && 1406 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1407 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1408 Invalid = true; 1409 1410 // Recover by adding 'static'. 1411 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), 1412 PrevSpec, DiagID); 1413 } 1414 // C++ [class.union]p3: 1415 // A storage class is not allowed in a declaration of an 1416 // anonymous union in a class scope. 1417 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1418 isa<RecordDecl>(Owner)) { 1419 Diag(DS.getStorageClassSpecLoc(), 1420 diag::err_anonymous_union_with_storage_spec); 1421 Invalid = true; 1422 1423 // Recover by removing the storage specifier. 1424 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1425 PrevSpec, DiagID); 1426 } 1427 1428 // C++ [class.union]p2: 1429 // The member-specification of an anonymous union shall only 1430 // define non-static data members. [Note: nested types and 1431 // functions cannot be declared within an anonymous union. ] 1432 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 1433 MemEnd = Record->decls_end(); 1434 Mem != MemEnd; ++Mem) { 1435 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1436 // C++ [class.union]p3: 1437 // An anonymous union shall not have private or protected 1438 // members (clause 11). 1439 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1440 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1441 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1442 Invalid = true; 1443 } 1444 } else if ((*Mem)->isImplicit()) { 1445 // Any implicit members are fine. 1446 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1447 // This is a type that showed up in an 1448 // elaborated-type-specifier inside the anonymous struct or 1449 // union, but which actually declares a type outside of the 1450 // anonymous struct or union. It's okay. 1451 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1452 if (!MemRecord->isAnonymousStructOrUnion() && 1453 MemRecord->getDeclName()) { 1454 // This is a nested type declaration. 1455 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1456 << (int)Record->isUnion(); 1457 Invalid = true; 1458 } 1459 } else { 1460 // We have something that isn't a non-static data 1461 // member. Complain about it. 1462 unsigned DK = diag::err_anonymous_record_bad_member; 1463 if (isa<TypeDecl>(*Mem)) 1464 DK = diag::err_anonymous_record_with_type; 1465 else if (isa<FunctionDecl>(*Mem)) 1466 DK = diag::err_anonymous_record_with_function; 1467 else if (isa<VarDecl>(*Mem)) 1468 DK = diag::err_anonymous_record_with_static; 1469 Diag((*Mem)->getLocation(), DK) 1470 << (int)Record->isUnion(); 1471 Invalid = true; 1472 } 1473 } 1474 } 1475 1476 if (!Record->isUnion() && !Owner->isRecord()) { 1477 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1478 << (int)getLangOptions().CPlusPlus; 1479 Invalid = true; 1480 } 1481 1482 // Create a declaration for this anonymous struct/union. 1483 NamedDecl *Anon = 0; 1484 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1485 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1486 /*IdentifierInfo=*/0, 1487 Context.getTypeDeclType(Record), 1488 /*BitWidth=*/0, /*Mutable=*/false, 1489 DS.getSourceRange().getBegin()); 1490 Anon->setAccess(AS_public); 1491 if (getLangOptions().CPlusPlus) 1492 FieldCollector->Add(cast<FieldDecl>(Anon)); 1493 } else { 1494 VarDecl::StorageClass SC; 1495 switch (DS.getStorageClassSpec()) { 1496 default: assert(0 && "Unknown storage class!"); 1497 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1498 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1499 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1500 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1501 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1502 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1503 case DeclSpec::SCS_mutable: 1504 // mutable can only appear on non-static class members, so it's always 1505 // an error here 1506 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1507 Invalid = true; 1508 SC = VarDecl::None; 1509 break; 1510 } 1511 1512 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1513 /*IdentifierInfo=*/0, 1514 Context.getTypeDeclType(Record), 1515 SC, DS.getSourceRange().getBegin()); 1516 } 1517 Anon->setImplicit(); 1518 1519 // Add the anonymous struct/union object to the current 1520 // context. We'll be referencing this object when we refer to one of 1521 // its members. 1522 Owner->addDecl(Anon); 1523 1524 // Inject the members of the anonymous struct/union into the owning 1525 // context and into the identifier resolver chain for name lookup 1526 // purposes. 1527 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1528 Invalid = true; 1529 1530 // Mark this as an anonymous struct/union type. Note that we do not 1531 // do this until after we have already checked and injected the 1532 // members of this anonymous struct/union type, because otherwise 1533 // the members could be injected twice: once by DeclContext when it 1534 // builds its lookup table, and once by 1535 // InjectAnonymousStructOrUnionMembers. 1536 Record->setAnonymousStructOrUnion(true); 1537 1538 if (Invalid) 1539 Anon->setInvalidDecl(); 1540 1541 return DeclPtrTy::make(Anon); 1542} 1543 1544 1545/// GetNameForDeclarator - Determine the full declaration name for the 1546/// given Declarator. 1547DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1548 switch (D.getKind()) { 1549 case Declarator::DK_Abstract: 1550 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1551 return DeclarationName(); 1552 1553 case Declarator::DK_Normal: 1554 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1555 return DeclarationName(D.getIdentifier()); 1556 1557 case Declarator::DK_Constructor: { 1558 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1559 return Context.DeclarationNames.getCXXConstructorName( 1560 Context.getCanonicalType(Ty)); 1561 } 1562 1563 case Declarator::DK_Destructor: { 1564 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1565 return Context.DeclarationNames.getCXXDestructorName( 1566 Context.getCanonicalType(Ty)); 1567 } 1568 1569 case Declarator::DK_Conversion: { 1570 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1571 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1572 return Context.DeclarationNames.getCXXConversionFunctionName( 1573 Context.getCanonicalType(Ty)); 1574 } 1575 1576 case Declarator::DK_Operator: 1577 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1578 return Context.DeclarationNames.getCXXOperatorName( 1579 D.getOverloadedOperator()); 1580 } 1581 1582 assert(false && "Unknown name kind"); 1583 return DeclarationName(); 1584} 1585 1586/// isNearlyMatchingFunction - Determine whether the C++ functions 1587/// Declaration and Definition are "nearly" matching. This heuristic 1588/// is used to improve diagnostics in the case where an out-of-line 1589/// function definition doesn't match any declaration within 1590/// the class or namespace. 1591static bool isNearlyMatchingFunction(ASTContext &Context, 1592 FunctionDecl *Declaration, 1593 FunctionDecl *Definition) { 1594 if (Declaration->param_size() != Definition->param_size()) 1595 return false; 1596 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1597 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1598 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1599 1600 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1601 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1602 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1603 return false; 1604 } 1605 1606 return true; 1607} 1608 1609Sema::DeclPtrTy 1610Sema::HandleDeclarator(Scope *S, Declarator &D, 1611 MultiTemplateParamsArg TemplateParamLists, 1612 bool IsFunctionDefinition) { 1613 DeclarationName Name = GetNameForDeclarator(D); 1614 1615 // All of these full declarators require an identifier. If it doesn't have 1616 // one, the ParsedFreeStandingDeclSpec action should be used. 1617 if (!Name) { 1618 if (!D.isInvalidType()) // Reject this if we think it is valid. 1619 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1620 diag::err_declarator_need_ident) 1621 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1622 return DeclPtrTy(); 1623 } 1624 1625 // The scope passed in may not be a decl scope. Zip up the scope tree until 1626 // we find one that is. 1627 while ((S->getFlags() & Scope::DeclScope) == 0 || 1628 (S->getFlags() & Scope::TemplateParamScope) != 0) 1629 S = S->getParent(); 1630 1631 // If this is an out-of-line definition of a member of a class template 1632 // or class template partial specialization, we may need to rebuild the 1633 // type specifier in the declarator. See RebuildTypeInCurrentInstantiation() 1634 // for more information. 1635 // FIXME: cope with decltype(expr) and typeof(expr) once the rebuilder can 1636 // handle expressions properly. 1637 DeclSpec &DS = const_cast<DeclSpec&>(D.getDeclSpec()); 1638 if (D.getCXXScopeSpec().isSet() && !D.getCXXScopeSpec().isInvalid() && 1639 isDependentScopeSpecifier(D.getCXXScopeSpec()) && 1640 (DS.getTypeSpecType() == DeclSpec::TST_typename || 1641 DS.getTypeSpecType() == DeclSpec::TST_typeofType || 1642 DS.getTypeSpecType() == DeclSpec::TST_typeofExpr || 1643 DS.getTypeSpecType() == DeclSpec::TST_decltype)) { 1644 if (DeclContext *DC = computeDeclContext(D.getCXXScopeSpec(), true)) { 1645 QualType T = QualType::getFromOpaquePtr(DS.getTypeRep()); 1646 EnterDeclaratorContext(S, DC); 1647 T = RebuildTypeInCurrentInstantiation(T, D.getIdentifierLoc(), Name); 1648 ExitDeclaratorContext(S); 1649 if (T.isNull()) 1650 return DeclPtrTy(); 1651 DS.UpdateTypeRep(T.getAsOpaquePtr()); 1652 } 1653 } 1654 1655 DeclContext *DC; 1656 NamedDecl *PrevDecl; 1657 NamedDecl *New; 1658 1659 QualType R = GetTypeForDeclarator(D, S); 1660 1661 // See if this is a redefinition of a variable in the same scope. 1662 if (D.getCXXScopeSpec().isInvalid()) { 1663 DC = CurContext; 1664 PrevDecl = 0; 1665 D.setInvalidType(); 1666 } else if (!D.getCXXScopeSpec().isSet()) { 1667 LookupNameKind NameKind = LookupOrdinaryName; 1668 1669 // If the declaration we're planning to build will be a function 1670 // or object with linkage, then look for another declaration with 1671 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1672 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1673 /* Do nothing*/; 1674 else if (R->isFunctionType()) { 1675 if (CurContext->isFunctionOrMethod() || 1676 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1677 NameKind = LookupRedeclarationWithLinkage; 1678 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1679 NameKind = LookupRedeclarationWithLinkage; 1680 else if (CurContext->getLookupContext()->isTranslationUnit() && 1681 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1682 NameKind = LookupRedeclarationWithLinkage; 1683 1684 DC = CurContext; 1685 PrevDecl = LookupName(S, Name, NameKind, true, 1686 NameKind == LookupRedeclarationWithLinkage, 1687 D.getIdentifierLoc()); 1688 } else { // Something like "int foo::x;" 1689 DC = computeDeclContext(D.getCXXScopeSpec(), true); 1690 // FIXME: RequireCompleteDeclContext(D.getCXXScopeSpec()); ? 1691 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1692 1693 // C++ 7.3.1.2p2: 1694 // Members (including explicit specializations of templates) of a named 1695 // namespace can also be defined outside that namespace by explicit 1696 // qualification of the name being defined, provided that the entity being 1697 // defined was already declared in the namespace and the definition appears 1698 // after the point of declaration in a namespace that encloses the 1699 // declarations namespace. 1700 // 1701 // Note that we only check the context at this point. We don't yet 1702 // have enough information to make sure that PrevDecl is actually 1703 // the declaration we want to match. For example, given: 1704 // 1705 // class X { 1706 // void f(); 1707 // void f(float); 1708 // }; 1709 // 1710 // void X::f(int) { } // ill-formed 1711 // 1712 // In this case, PrevDecl will point to the overload set 1713 // containing the two f's declared in X, but neither of them 1714 // matches. 1715 1716 // First check whether we named the global scope. 1717 if (isa<TranslationUnitDecl>(DC)) { 1718 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1719 << Name << D.getCXXScopeSpec().getRange(); 1720 } else if (!CurContext->Encloses(DC)) { 1721 // The qualifying scope doesn't enclose the original declaration. 1722 // Emit diagnostic based on current scope. 1723 SourceLocation L = D.getIdentifierLoc(); 1724 SourceRange R = D.getCXXScopeSpec().getRange(); 1725 if (isa<FunctionDecl>(CurContext)) 1726 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1727 else 1728 Diag(L, diag::err_invalid_declarator_scope) 1729 << Name << cast<NamedDecl>(DC) << R; 1730 D.setInvalidType(); 1731 } 1732 } 1733 1734 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1735 // Maybe we will complain about the shadowed template parameter. 1736 if (!D.isInvalidType()) 1737 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl)) 1738 D.setInvalidType(); 1739 1740 // Just pretend that we didn't see the previous declaration. 1741 PrevDecl = 0; 1742 } 1743 1744 // In C++, the previous declaration we find might be a tag type 1745 // (class or enum). In this case, the new declaration will hide the 1746 // tag type. Note that this does does not apply if we're declaring a 1747 // typedef (C++ [dcl.typedef]p4). 1748 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1749 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1750 PrevDecl = 0; 1751 1752 bool Redeclaration = false; 1753 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1754 if (TemplateParamLists.size()) { 1755 Diag(D.getIdentifierLoc(), diag::err_template_typedef); 1756 return DeclPtrTy(); 1757 } 1758 1759 New = ActOnTypedefDeclarator(S, D, DC, R, PrevDecl, Redeclaration); 1760 } else if (R->isFunctionType()) { 1761 New = ActOnFunctionDeclarator(S, D, DC, R, PrevDecl, 1762 move(TemplateParamLists), 1763 IsFunctionDefinition, Redeclaration); 1764 } else { 1765 New = ActOnVariableDeclarator(S, D, DC, R, PrevDecl, 1766 move(TemplateParamLists), 1767 Redeclaration); 1768 } 1769 1770 if (New == 0) 1771 return DeclPtrTy(); 1772 1773 // If this has an identifier and is not an invalid redeclaration, 1774 // add it to the scope stack. 1775 if (Name && !(Redeclaration && New->isInvalidDecl())) 1776 PushOnScopeChains(New, S); 1777 1778 return DeclPtrTy::make(New); 1779} 1780 1781/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1782/// types into constant array types in certain situations which would otherwise 1783/// be errors (for GCC compatibility). 1784static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1785 ASTContext &Context, 1786 bool &SizeIsNegative) { 1787 // This method tries to turn a variable array into a constant 1788 // array even when the size isn't an ICE. This is necessary 1789 // for compatibility with code that depends on gcc's buggy 1790 // constant expression folding, like struct {char x[(int)(char*)2];} 1791 SizeIsNegative = false; 1792 1793 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1794 QualType Pointee = PTy->getPointeeType(); 1795 QualType FixedType = 1796 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1797 if (FixedType.isNull()) return FixedType; 1798 FixedType = Context.getPointerType(FixedType); 1799 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1800 return FixedType; 1801 } 1802 1803 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1804 if (!VLATy) 1805 return QualType(); 1806 // FIXME: We should probably handle this case 1807 if (VLATy->getElementType()->isVariablyModifiedType()) 1808 return QualType(); 1809 1810 Expr::EvalResult EvalResult; 1811 if (!VLATy->getSizeExpr() || 1812 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 1813 !EvalResult.Val.isInt()) 1814 return QualType(); 1815 1816 llvm::APSInt &Res = EvalResult.Val.getInt(); 1817 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) { 1818 Expr* ArySizeExpr = VLATy->getSizeExpr(); 1819 // FIXME: here we could "steal" (how?) ArySizeExpr from the VLA, 1820 // so as to transfer ownership to the ConstantArrayWithExpr. 1821 // Alternatively, we could "clone" it (how?). 1822 // Since we don't know how to do things above, we just use the 1823 // very same Expr*. 1824 return Context.getConstantArrayWithExprType(VLATy->getElementType(), 1825 Res, ArySizeExpr, 1826 ArrayType::Normal, 0, 1827 VLATy->getBracketsRange()); 1828 } 1829 1830 SizeIsNegative = true; 1831 return QualType(); 1832} 1833 1834/// \brief Register the given locally-scoped external C declaration so 1835/// that it can be found later for redeclarations 1836void 1837Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, NamedDecl *PrevDecl, 1838 Scope *S) { 1839 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 1840 "Decl is not a locally-scoped decl!"); 1841 // Note that we have a locally-scoped external with this name. 1842 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 1843 1844 if (!PrevDecl) 1845 return; 1846 1847 // If there was a previous declaration of this variable, it may be 1848 // in our identifier chain. Update the identifier chain with the new 1849 // declaration. 1850 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 1851 // The previous declaration was found on the identifer resolver 1852 // chain, so remove it from its scope. 1853 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 1854 S = S->getParent(); 1855 1856 if (S) 1857 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 1858 } 1859} 1860 1861/// \brief Diagnose function specifiers on a declaration of an identifier that 1862/// does not identify a function. 1863void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 1864 // FIXME: We should probably indicate the identifier in question to avoid 1865 // confusion for constructs like "inline int a(), b;" 1866 if (D.getDeclSpec().isInlineSpecified()) 1867 Diag(D.getDeclSpec().getInlineSpecLoc(), 1868 diag::err_inline_non_function); 1869 1870 if (D.getDeclSpec().isVirtualSpecified()) 1871 Diag(D.getDeclSpec().getVirtualSpecLoc(), 1872 diag::err_virtual_non_function); 1873 1874 if (D.getDeclSpec().isExplicitSpecified()) 1875 Diag(D.getDeclSpec().getExplicitSpecLoc(), 1876 diag::err_explicit_non_function); 1877} 1878 1879NamedDecl* 1880Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1881 QualType R, Decl* PrevDecl, bool &Redeclaration) { 1882 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1883 if (D.getCXXScopeSpec().isSet()) { 1884 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1885 << D.getCXXScopeSpec().getRange(); 1886 D.setInvalidType(); 1887 // Pretend we didn't see the scope specifier. 1888 DC = 0; 1889 } 1890 1891 if (getLangOptions().CPlusPlus) { 1892 // Check that there are no default arguments (C++ only). 1893 CheckExtraCXXDefaultArguments(D); 1894 } 1895 1896 DiagnoseFunctionSpecifiers(D); 1897 1898 if (D.getDeclSpec().isThreadSpecified()) 1899 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 1900 1901 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R); 1902 if (!NewTD) return 0; 1903 1904 if (D.isInvalidType()) 1905 NewTD->setInvalidDecl(); 1906 1907 // Handle attributes prior to checking for duplicates in MergeVarDecl 1908 ProcessDeclAttributes(S, NewTD, D); 1909 // Merge the decl with the existing one if appropriate. If the decl is 1910 // in an outer scope, it isn't the same thing. 1911 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1912 Redeclaration = true; 1913 MergeTypeDefDecl(NewTD, PrevDecl); 1914 } 1915 1916 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1917 // then it shall have block scope. 1918 QualType T = NewTD->getUnderlyingType(); 1919 if (T->isVariablyModifiedType()) { 1920 CurFunctionNeedsScopeChecking = true; 1921 1922 if (S->getFnParent() == 0) { 1923 bool SizeIsNegative; 1924 QualType FixedTy = 1925 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1926 if (!FixedTy.isNull()) { 1927 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1928 NewTD->setUnderlyingType(FixedTy); 1929 } else { 1930 if (SizeIsNegative) 1931 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1932 else if (T->isVariableArrayType()) 1933 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1934 else 1935 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1936 NewTD->setInvalidDecl(); 1937 } 1938 } 1939 } 1940 1941 // If this is the C FILE type, notify the AST context. 1942 if (IdentifierInfo *II = NewTD->getIdentifier()) 1943 if (!NewTD->isInvalidDecl() && 1944 NewTD->getDeclContext()->getLookupContext()->isTranslationUnit()) { 1945 if (II->isStr("FILE")) 1946 Context.setFILEDecl(NewTD); 1947 else if (II->isStr("jmp_buf")) 1948 Context.setjmp_bufDecl(NewTD); 1949 else if (II->isStr("sigjmp_buf")) 1950 Context.setsigjmp_bufDecl(NewTD); 1951 } 1952 1953 return NewTD; 1954} 1955 1956/// \brief Determines whether the given declaration is an out-of-scope 1957/// previous declaration. 1958/// 1959/// This routine should be invoked when name lookup has found a 1960/// previous declaration (PrevDecl) that is not in the scope where a 1961/// new declaration by the same name is being introduced. If the new 1962/// declaration occurs in a local scope, previous declarations with 1963/// linkage may still be considered previous declarations (C99 1964/// 6.2.2p4-5, C++ [basic.link]p6). 1965/// 1966/// \param PrevDecl the previous declaration found by name 1967/// lookup 1968/// 1969/// \param DC the context in which the new declaration is being 1970/// declared. 1971/// 1972/// \returns true if PrevDecl is an out-of-scope previous declaration 1973/// for a new delcaration with the same name. 1974static bool 1975isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 1976 ASTContext &Context) { 1977 if (!PrevDecl) 1978 return 0; 1979 1980 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 1981 // case we need to check each of the overloaded functions. 1982 if (!PrevDecl->hasLinkage()) 1983 return false; 1984 1985 if (Context.getLangOptions().CPlusPlus) { 1986 // C++ [basic.link]p6: 1987 // If there is a visible declaration of an entity with linkage 1988 // having the same name and type, ignoring entities declared 1989 // outside the innermost enclosing namespace scope, the block 1990 // scope declaration declares that same entity and receives the 1991 // linkage of the previous declaration. 1992 DeclContext *OuterContext = DC->getLookupContext(); 1993 if (!OuterContext->isFunctionOrMethod()) 1994 // This rule only applies to block-scope declarations. 1995 return false; 1996 else { 1997 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 1998 if (PrevOuterContext->isRecord()) 1999 // We found a member function: ignore it. 2000 return false; 2001 else { 2002 // Find the innermost enclosing namespace for the new and 2003 // previous declarations. 2004 while (!OuterContext->isFileContext()) 2005 OuterContext = OuterContext->getParent(); 2006 while (!PrevOuterContext->isFileContext()) 2007 PrevOuterContext = PrevOuterContext->getParent(); 2008 2009 // The previous declaration is in a different namespace, so it 2010 // isn't the same function. 2011 if (OuterContext->getPrimaryContext() != 2012 PrevOuterContext->getPrimaryContext()) 2013 return false; 2014 } 2015 } 2016 } 2017 2018 return true; 2019} 2020 2021NamedDecl* 2022Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2023 QualType R,NamedDecl* PrevDecl, 2024 MultiTemplateParamsArg TemplateParamLists, 2025 bool &Redeclaration) { 2026 DeclarationName Name = GetNameForDeclarator(D); 2027 2028 // Check that there are no default arguments (C++ only). 2029 if (getLangOptions().CPlusPlus) 2030 CheckExtraCXXDefaultArguments(D); 2031 2032 VarDecl *NewVD; 2033 VarDecl::StorageClass SC; 2034 switch (D.getDeclSpec().getStorageClassSpec()) { 2035 default: assert(0 && "Unknown storage class!"); 2036 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2037 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2038 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2039 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2040 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2041 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2042 case DeclSpec::SCS_mutable: 2043 // mutable can only appear on non-static class members, so it's always 2044 // an error here 2045 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 2046 D.setInvalidType(); 2047 SC = VarDecl::None; 2048 break; 2049 } 2050 2051 IdentifierInfo *II = Name.getAsIdentifierInfo(); 2052 if (!II) { 2053 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 2054 << Name.getAsString(); 2055 return 0; 2056 } 2057 2058 DiagnoseFunctionSpecifiers(D); 2059 2060 if (!DC->isRecord() && S->getFnParent() == 0) { 2061 // C99 6.9p2: The storage-class specifiers auto and register shall not 2062 // appear in the declaration specifiers in an external declaration. 2063 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 2064 2065 // If this is a register variable with an asm label specified, then this 2066 // is a GNU extension. 2067 if (SC == VarDecl::Register && D.getAsmLabel()) 2068 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 2069 else 2070 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 2071 D.setInvalidType(); 2072 } 2073 } 2074 if (DC->isRecord() && !CurContext->isRecord()) { 2075 // This is an out-of-line definition of a static data member. 2076 if (SC == VarDecl::Static) { 2077 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2078 diag::err_static_out_of_line) 2079 << CodeModificationHint::CreateRemoval( 2080 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2081 } else if (SC == VarDecl::None) 2082 SC = VarDecl::Static; 2083 } 2084 if (SC == VarDecl::Static) { 2085 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 2086 if (RD->isLocalClass()) 2087 Diag(D.getIdentifierLoc(), 2088 diag::err_static_data_member_not_allowed_in_local_class) 2089 << Name << RD->getDeclName(); 2090 } 2091 } 2092 2093 // Check that we can declare a template here. 2094 if (TemplateParamLists.size() && 2095 CheckTemplateDeclScope(S, TemplateParamLists)) 2096 return 0; 2097 2098 // Match up the template parameter lists with the scope specifier, then 2099 // determine whether we have a template or a template specialization. 2100 if (TemplateParameterList *TemplateParams 2101 = MatchTemplateParametersToScopeSpecifier( 2102 D.getDeclSpec().getSourceRange().getBegin(), 2103 D.getCXXScopeSpec(), 2104 (TemplateParameterList**)TemplateParamLists.get(), 2105 TemplateParamLists.size())) { 2106 if (TemplateParams->size() > 0) { 2107 // There is no such thing as a variable template. 2108 Diag(D.getIdentifierLoc(), diag::err_template_variable) 2109 << II 2110 << SourceRange(TemplateParams->getTemplateLoc(), 2111 TemplateParams->getRAngleLoc()); 2112 return 0; 2113 } else { 2114 // There is an extraneous 'template<>' for this variable. Complain 2115 // about it, but allow the declaration of the variable. 2116 Diag(TemplateParams->getTemplateLoc(), 2117 diag::err_template_variable_noparams) 2118 << II 2119 << SourceRange(TemplateParams->getTemplateLoc(), 2120 TemplateParams->getRAngleLoc()); 2121 } 2122 } 2123 2124 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 2125 II, R, SC, 2126 // FIXME: Move to DeclGroup... 2127 D.getDeclSpec().getSourceRange().getBegin()); 2128 2129 if (D.isInvalidType()) 2130 NewVD->setInvalidDecl(); 2131 2132 if (D.getDeclSpec().isThreadSpecified()) { 2133 if (NewVD->hasLocalStorage()) 2134 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 2135 else if (!Context.Target.isTLSSupported()) 2136 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 2137 else 2138 NewVD->setThreadSpecified(true); 2139 } 2140 2141 // Set the lexical context. If the declarator has a C++ scope specifier, the 2142 // lexical context will be different from the semantic context. 2143 NewVD->setLexicalDeclContext(CurContext); 2144 2145 // Handle attributes prior to checking for duplicates in MergeVarDecl 2146 ProcessDeclAttributes(S, NewVD, D); 2147 2148 // Handle GNU asm-label extension (encoded as an attribute). 2149 if (Expr *E = (Expr*) D.getAsmLabel()) { 2150 // The parser guarantees this is a string. 2151 StringLiteral *SE = cast<StringLiteral>(E); 2152 NewVD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2153 SE->getByteLength()))); 2154 } 2155 2156 // If name lookup finds a previous declaration that is not in the 2157 // same scope as the new declaration, this may still be an 2158 // acceptable redeclaration. 2159 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2160 !(NewVD->hasLinkage() && 2161 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2162 PrevDecl = 0; 2163 2164 // Merge the decl with the existing one if appropriate. 2165 if (PrevDecl) { 2166 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 2167 // The user tried to define a non-static data member 2168 // out-of-line (C++ [dcl.meaning]p1). 2169 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 2170 << D.getCXXScopeSpec().getRange(); 2171 PrevDecl = 0; 2172 NewVD->setInvalidDecl(); 2173 } 2174 } else if (D.getCXXScopeSpec().isSet()) { 2175 // No previous declaration in the qualifying scope. 2176 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 2177 << Name << D.getCXXScopeSpec().getRange(); 2178 NewVD->setInvalidDecl(); 2179 } 2180 2181 CheckVariableDeclaration(NewVD, PrevDecl, Redeclaration); 2182 2183 // attributes declared post-definition are currently ignored 2184 if (PrevDecl) { 2185 const VarDecl *Def = 0, *PrevVD = dyn_cast<VarDecl>(PrevDecl); 2186 if (PrevVD->getDefinition(Def) && D.hasAttributes()) { 2187 Diag(NewVD->getLocation(), diag::warn_attribute_precede_definition); 2188 Diag(Def->getLocation(), diag::note_previous_definition); 2189 } 2190 } 2191 2192 // If this is a locally-scoped extern C variable, update the map of 2193 // such variables. 2194 if (CurContext->isFunctionOrMethod() && NewVD->isExternC(Context) && 2195 !NewVD->isInvalidDecl()) 2196 RegisterLocallyScopedExternCDecl(NewVD, PrevDecl, S); 2197 2198 return NewVD; 2199} 2200 2201/// \brief Perform semantic checking on a newly-created variable 2202/// declaration. 2203/// 2204/// This routine performs all of the type-checking required for a 2205/// variable declaration once it has been built. It is used both to 2206/// check variables after they have been parsed and their declarators 2207/// have been translated into a declaration, and to check variables 2208/// that have been instantiated from a template. 2209/// 2210/// Sets NewVD->isInvalidDecl() if an error was encountered. 2211void Sema::CheckVariableDeclaration(VarDecl *NewVD, NamedDecl *PrevDecl, 2212 bool &Redeclaration) { 2213 // If the decl is already known invalid, don't check it. 2214 if (NewVD->isInvalidDecl()) 2215 return; 2216 2217 QualType T = NewVD->getType(); 2218 2219 if (T->isObjCInterfaceType()) { 2220 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 2221 return NewVD->setInvalidDecl(); 2222 } 2223 2224 // The variable can not have an abstract class type. 2225 if (RequireNonAbstractType(NewVD->getLocation(), T, 2226 diag::err_abstract_type_in_decl, 2227 AbstractVariableType)) 2228 return NewVD->setInvalidDecl(); 2229 2230 // Emit an error if an address space was applied to decl with local storage. 2231 // This includes arrays of objects with address space qualifiers, but not 2232 // automatic variables that point to other address spaces. 2233 // ISO/IEC TR 18037 S5.1.2 2234 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 2235 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 2236 return NewVD->setInvalidDecl(); 2237 } 2238 2239 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 2240 && !NewVD->hasAttr<BlocksAttr>()) 2241 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 2242 2243 bool isVM = T->isVariablyModifiedType(); 2244 if (isVM || NewVD->hasAttr<CleanupAttr>() || 2245 NewVD->hasAttr<BlocksAttr>()) 2246 CurFunctionNeedsScopeChecking = true; 2247 2248 if ((isVM && NewVD->hasLinkage()) || 2249 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 2250 bool SizeIsNegative; 2251 QualType FixedTy = 2252 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2253 2254 if (FixedTy.isNull() && T->isVariableArrayType()) { 2255 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2256 // FIXME: This won't give the correct result for 2257 // int a[10][n]; 2258 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2259 2260 if (NewVD->isFileVarDecl()) 2261 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 2262 << SizeRange; 2263 else if (NewVD->getStorageClass() == VarDecl::Static) 2264 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 2265 << SizeRange; 2266 else 2267 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 2268 << SizeRange; 2269 return NewVD->setInvalidDecl(); 2270 } 2271 2272 if (FixedTy.isNull()) { 2273 if (NewVD->isFileVarDecl()) 2274 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 2275 else 2276 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 2277 return NewVD->setInvalidDecl(); 2278 } 2279 2280 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 2281 NewVD->setType(FixedTy); 2282 } 2283 2284 if (!PrevDecl && NewVD->isExternC(Context)) { 2285 // Since we did not find anything by this name and we're declaring 2286 // an extern "C" variable, look for a non-visible extern "C" 2287 // declaration with the same name. 2288 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2289 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 2290 if (Pos != LocallyScopedExternalDecls.end()) 2291 PrevDecl = Pos->second; 2292 } 2293 2294 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 2295 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 2296 << T; 2297 return NewVD->setInvalidDecl(); 2298 } 2299 2300 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 2301 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 2302 return NewVD->setInvalidDecl(); 2303 } 2304 2305 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 2306 Diag(NewVD->getLocation(), diag::err_block_on_vm); 2307 return NewVD->setInvalidDecl(); 2308 } 2309 2310 if (PrevDecl) { 2311 Redeclaration = true; 2312 MergeVarDecl(NewVD, PrevDecl); 2313 } 2314} 2315 2316NamedDecl* 2317Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2318 QualType R, NamedDecl* PrevDecl, 2319 MultiTemplateParamsArg TemplateParamLists, 2320 bool IsFunctionDefinition, bool &Redeclaration) { 2321 assert(R.getTypePtr()->isFunctionType()); 2322 2323 DeclarationName Name = GetNameForDeclarator(D); 2324 FunctionDecl::StorageClass SC = FunctionDecl::None; 2325 switch (D.getDeclSpec().getStorageClassSpec()) { 2326 default: assert(0 && "Unknown storage class!"); 2327 case DeclSpec::SCS_auto: 2328 case DeclSpec::SCS_register: 2329 case DeclSpec::SCS_mutable: 2330 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2331 diag::err_typecheck_sclass_func); 2332 D.setInvalidType(); 2333 break; 2334 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 2335 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 2336 case DeclSpec::SCS_static: { 2337 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 2338 // C99 6.7.1p5: 2339 // The declaration of an identifier for a function that has 2340 // block scope shall have no explicit storage-class specifier 2341 // other than extern 2342 // See also (C++ [dcl.stc]p4). 2343 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2344 diag::err_static_block_func); 2345 SC = FunctionDecl::None; 2346 } else 2347 SC = FunctionDecl::Static; 2348 break; 2349 } 2350 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 2351 } 2352 2353 if (D.getDeclSpec().isThreadSpecified()) 2354 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2355 2356 bool isInline = D.getDeclSpec().isInlineSpecified(); 2357 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 2358 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 2359 2360 // Check that the return type is not an abstract class type. 2361 // For record types, this is done by the AbstractClassUsageDiagnoser once 2362 // the class has been completely parsed. 2363 if (!DC->isRecord() && 2364 RequireNonAbstractType(D.getIdentifierLoc(), 2365 R->getAsFunctionType()->getResultType(), 2366 diag::err_abstract_type_in_decl, 2367 AbstractReturnType)) 2368 D.setInvalidType(); 2369 2370 // Do not allow returning a objc interface by-value. 2371 if (R->getAsFunctionType()->getResultType()->isObjCInterfaceType()) { 2372 Diag(D.getIdentifierLoc(), 2373 diag::err_object_cannot_be_passed_returned_by_value) << 0 2374 << R->getAsFunctionType()->getResultType(); 2375 D.setInvalidType(); 2376 } 2377 2378 // Check that we can declare a template here. 2379 if (TemplateParamLists.size() && 2380 CheckTemplateDeclScope(S, TemplateParamLists)) 2381 return 0; 2382 2383 bool isVirtualOkay = false; 2384 FunctionDecl *NewFD; 2385 if (D.getKind() == Declarator::DK_Constructor) { 2386 // This is a C++ constructor declaration. 2387 assert(DC->isRecord() && 2388 "Constructors can only be declared in a member context"); 2389 2390 R = CheckConstructorDeclarator(D, R, SC); 2391 2392 // Create the new declaration 2393 NewFD = CXXConstructorDecl::Create(Context, 2394 cast<CXXRecordDecl>(DC), 2395 D.getIdentifierLoc(), Name, R, 2396 isExplicit, isInline, 2397 /*isImplicitlyDeclared=*/false); 2398 } else if (D.getKind() == Declarator::DK_Destructor) { 2399 // This is a C++ destructor declaration. 2400 if (DC->isRecord()) { 2401 R = CheckDestructorDeclarator(D, SC); 2402 2403 NewFD = CXXDestructorDecl::Create(Context, 2404 cast<CXXRecordDecl>(DC), 2405 D.getIdentifierLoc(), Name, R, 2406 isInline, 2407 /*isImplicitlyDeclared=*/false); 2408 2409 isVirtualOkay = true; 2410 } else { 2411 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 2412 2413 // Create a FunctionDecl to satisfy the function definition parsing 2414 // code path. 2415 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 2416 Name, R, SC, isInline, 2417 /*hasPrototype=*/true, 2418 // FIXME: Move to DeclGroup... 2419 D.getDeclSpec().getSourceRange().getBegin()); 2420 D.setInvalidType(); 2421 } 2422 } else if (D.getKind() == Declarator::DK_Conversion) { 2423 if (!DC->isRecord()) { 2424 Diag(D.getIdentifierLoc(), 2425 diag::err_conv_function_not_member); 2426 return 0; 2427 } 2428 2429 CheckConversionDeclarator(D, R, SC); 2430 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 2431 D.getIdentifierLoc(), Name, R, 2432 isInline, isExplicit); 2433 2434 isVirtualOkay = true; 2435 } else if (DC->isRecord()) { 2436 // If the of the function is the same as the name of the record, then this 2437 // must be an invalid constructor that has a return type. 2438 // (The parser checks for a return type and makes the declarator a 2439 // constructor if it has no return type). 2440 // must have an invalid constructor that has a return type 2441 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 2442 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 2443 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 2444 << SourceRange(D.getIdentifierLoc()); 2445 return 0; 2446 } 2447 2448 // This is a C++ method declaration. 2449 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 2450 D.getIdentifierLoc(), Name, R, 2451 (SC == FunctionDecl::Static), isInline); 2452 2453 isVirtualOkay = (SC != FunctionDecl::Static); 2454 } else { 2455 // Determine whether the function was written with a 2456 // prototype. This true when: 2457 // - we're in C++ (where every function has a prototype), 2458 // - there is a prototype in the declarator, or 2459 // - the type R of the function is some kind of typedef or other reference 2460 // to a type name (which eventually refers to a function type). 2461 bool HasPrototype = 2462 getLangOptions().CPlusPlus || 2463 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 2464 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 2465 2466 NewFD = FunctionDecl::Create(Context, DC, 2467 D.getIdentifierLoc(), 2468 Name, R, SC, isInline, HasPrototype, 2469 // FIXME: Move to DeclGroup... 2470 D.getDeclSpec().getSourceRange().getBegin()); 2471 } 2472 2473 if (D.isInvalidType()) 2474 NewFD->setInvalidDecl(); 2475 2476 // Set the lexical context. If the declarator has a C++ 2477 // scope specifier, the lexical context will be different 2478 // from the semantic context. 2479 NewFD->setLexicalDeclContext(CurContext); 2480 2481 // Match up the template parameter lists with the scope specifier, then 2482 // determine whether we have a template or a template specialization. 2483 FunctionTemplateDecl *FunctionTemplate = 0; 2484 if (TemplateParameterList *TemplateParams 2485 = MatchTemplateParametersToScopeSpecifier( 2486 D.getDeclSpec().getSourceRange().getBegin(), 2487 D.getCXXScopeSpec(), 2488 (TemplateParameterList**)TemplateParamLists.get(), 2489 TemplateParamLists.size())) { 2490 if (TemplateParams->size() > 0) { 2491 // This is a function template 2492 FunctionTemplate = FunctionTemplateDecl::Create(Context, CurContext, 2493 NewFD->getLocation(), 2494 Name, TemplateParams, 2495 NewFD); 2496 NewFD->setDescribedFunctionTemplate(FunctionTemplate); 2497 } else { 2498 // FIXME: Handle function template specializations 2499 } 2500 2501 // FIXME: Free this memory properly. 2502 TemplateParamLists.release(); 2503 } 2504 2505 // C++ [dcl.fct.spec]p5: 2506 // The virtual specifier shall only be used in declarations of 2507 // nonstatic class member functions that appear within a 2508 // member-specification of a class declaration; see 10.3. 2509 // 2510 if (isVirtual && !NewFD->isInvalidDecl()) { 2511 if (!isVirtualOkay) { 2512 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2513 diag::err_virtual_non_function); 2514 } else if (!CurContext->isRecord()) { 2515 // 'virtual' was specified outside of the class. 2516 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 2517 << CodeModificationHint::CreateRemoval( 2518 SourceRange(D.getDeclSpec().getVirtualSpecLoc())); 2519 } else { 2520 // Okay: Add virtual to the method. 2521 cast<CXXMethodDecl>(NewFD)->setVirtualAsWritten(true); 2522 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 2523 CurClass->setAggregate(false); 2524 CurClass->setPOD(false); 2525 CurClass->setPolymorphic(true); 2526 CurClass->setHasTrivialConstructor(false); 2527 CurClass->setHasTrivialCopyConstructor(false); 2528 CurClass->setHasTrivialCopyAssignment(false); 2529 } 2530 } 2531 2532 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD)) { 2533 // Look for virtual methods in base classes that this method might override. 2534 2535 BasePaths Paths; 2536 if (LookupInBases(cast<CXXRecordDecl>(DC), 2537 MemberLookupCriteria(NewMD), Paths)) { 2538 for (BasePaths::decl_iterator I = Paths.found_decls_begin(), 2539 E = Paths.found_decls_end(); I != E; ++I) { 2540 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2541 if (!CheckOverridingFunctionReturnType(NewMD, OldMD) && 2542 !CheckOverridingFunctionExceptionSpec(NewMD, OldMD)) 2543 NewMD->addOverriddenMethod(OldMD); 2544 } 2545 } 2546 } 2547 } 2548 2549 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 2550 !CurContext->isRecord()) { 2551 // C++ [class.static]p1: 2552 // A data or function member of a class may be declared static 2553 // in a class definition, in which case it is a static member of 2554 // the class. 2555 2556 // Complain about the 'static' specifier if it's on an out-of-line 2557 // member function definition. 2558 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2559 diag::err_static_out_of_line) 2560 << CodeModificationHint::CreateRemoval( 2561 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2562 } 2563 2564 // Handle GNU asm-label extension (encoded as an attribute). 2565 if (Expr *E = (Expr*) D.getAsmLabel()) { 2566 // The parser guarantees this is a string. 2567 StringLiteral *SE = cast<StringLiteral>(E); 2568 NewFD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2569 SE->getByteLength()))); 2570 } 2571 2572 // Copy the parameter declarations from the declarator D to the function 2573 // declaration NewFD, if they are available. First scavenge them into Params. 2574 llvm::SmallVector<ParmVarDecl*, 16> Params; 2575 if (D.getNumTypeObjects() > 0) { 2576 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2577 2578 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 2579 // function that takes no arguments, not a function that takes a 2580 // single void argument. 2581 // We let through "const void" here because Sema::GetTypeForDeclarator 2582 // already checks for that case. 2583 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 2584 FTI.ArgInfo[0].Param && 2585 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 2586 // Empty arg list, don't push any params. 2587 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 2588 2589 // In C++, the empty parameter-type-list must be spelled "void"; a 2590 // typedef of void is not permitted. 2591 if (getLangOptions().CPlusPlus && 2592 Param->getType().getUnqualifiedType() != Context.VoidTy) 2593 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 2594 // FIXME: Leaks decl? 2595 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 2596 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2597 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 2598 assert(Param->getDeclContext() != NewFD && "Was set before ?"); 2599 Param->setDeclContext(NewFD); 2600 Params.push_back(Param); 2601 } 2602 } 2603 2604 } else if (const FunctionProtoType *FT = R->getAsFunctionProtoType()) { 2605 // When we're declaring a function with a typedef, typeof, etc as in the 2606 // following example, we'll need to synthesize (unnamed) 2607 // parameters for use in the declaration. 2608 // 2609 // @code 2610 // typedef void fn(int); 2611 // fn f; 2612 // @endcode 2613 2614 // Synthesize a parameter for each argument type. 2615 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 2616 AE = FT->arg_type_end(); AI != AE; ++AI) { 2617 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 2618 SourceLocation(), 0, 2619 *AI, VarDecl::None, 0); 2620 Param->setImplicit(); 2621 Params.push_back(Param); 2622 } 2623 } else { 2624 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 2625 "Should not need args for typedef of non-prototype fn"); 2626 } 2627 // Finally, we know we have the right number of parameters, install them. 2628 NewFD->setParams(Context, Params.data(), Params.size()); 2629 2630 // If name lookup finds a previous declaration that is not in the 2631 // same scope as the new declaration, this may still be an 2632 // acceptable redeclaration. 2633 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2634 !(NewFD->hasLinkage() && 2635 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2636 PrevDecl = 0; 2637 2638 // Perform semantic checking on the function declaration. 2639 bool OverloadableAttrRequired = false; // FIXME: HACK! 2640 CheckFunctionDeclaration(NewFD, PrevDecl, Redeclaration, 2641 /*FIXME:*/OverloadableAttrRequired); 2642 2643 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 2644 // An out-of-line member function declaration must also be a 2645 // definition (C++ [dcl.meaning]p1). 2646 if (!IsFunctionDefinition) { 2647 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2648 << D.getCXXScopeSpec().getRange(); 2649 NewFD->setInvalidDecl(); 2650 } else if (!Redeclaration && (!PrevDecl || !isa<UsingDecl>(PrevDecl))) { 2651 // The user tried to provide an out-of-line definition for a 2652 // function that is a member of a class or namespace, but there 2653 // was no such member function declared (C++ [class.mfct]p2, 2654 // C++ [namespace.memdef]p2). For example: 2655 // 2656 // class X { 2657 // void f() const; 2658 // }; 2659 // 2660 // void X::f() { } // ill-formed 2661 // 2662 // Complain about this problem, and attempt to suggest close 2663 // matches (e.g., those that differ only in cv-qualifiers and 2664 // whether the parameter types are references). 2665 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 2666 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 2667 NewFD->setInvalidDecl(); 2668 2669 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 2670 true); 2671 assert(!Prev.isAmbiguous() && 2672 "Cannot have an ambiguity in previous-declaration lookup"); 2673 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 2674 Func != FuncEnd; ++Func) { 2675 if (isa<FunctionDecl>(*Func) && 2676 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 2677 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 2678 } 2679 2680 PrevDecl = 0; 2681 } 2682 } 2683 2684 // Handle attributes. We need to have merged decls when handling attributes 2685 // (for example to check for conflicts, etc). 2686 // FIXME: This needs to happen before we merge declarations. Then, 2687 // let attribute merging cope with attribute conflicts. 2688 ProcessDeclAttributes(S, NewFD, D); 2689 2690 // attributes declared post-definition are currently ignored 2691 if (PrevDecl) { 2692 const FunctionDecl *Def, *PrevFD = dyn_cast<FunctionDecl>(PrevDecl); 2693 if (PrevFD && PrevFD->getBody(Def) && D.hasAttributes()) { 2694 Diag(NewFD->getLocation(), diag::warn_attribute_precede_definition); 2695 Diag(Def->getLocation(), diag::note_previous_definition); 2696 } 2697 } 2698 2699 AddKnownFunctionAttributes(NewFD); 2700 2701 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 2702 // If a function name is overloadable in C, then every function 2703 // with that name must be marked "overloadable". 2704 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 2705 << Redeclaration << NewFD; 2706 if (PrevDecl) 2707 Diag(PrevDecl->getLocation(), 2708 diag::note_attribute_overloadable_prev_overload); 2709 NewFD->addAttr(::new (Context) OverloadableAttr()); 2710 } 2711 2712 // If this is a locally-scoped extern C function, update the 2713 // map of such names. 2714 if (CurContext->isFunctionOrMethod() && NewFD->isExternC(Context) 2715 && !NewFD->isInvalidDecl()) 2716 RegisterLocallyScopedExternCDecl(NewFD, PrevDecl, S); 2717 2718 // Set this FunctionDecl's range up to the right paren. 2719 NewFD->setLocEnd(D.getSourceRange().getEnd()); 2720 2721 if (FunctionTemplate && NewFD->isInvalidDecl()) 2722 FunctionTemplate->setInvalidDecl(); 2723 2724 if (FunctionTemplate) 2725 return FunctionTemplate; 2726 2727 return NewFD; 2728} 2729 2730/// \brief Perform semantic checking of a new function declaration. 2731/// 2732/// Performs semantic analysis of the new function declaration 2733/// NewFD. This routine performs all semantic checking that does not 2734/// require the actual declarator involved in the declaration, and is 2735/// used both for the declaration of functions as they are parsed 2736/// (called via ActOnDeclarator) and for the declaration of functions 2737/// that have been instantiated via C++ template instantiation (called 2738/// via InstantiateDecl). 2739/// 2740/// This sets NewFD->isInvalidDecl() to true if there was an error. 2741void Sema::CheckFunctionDeclaration(FunctionDecl *NewFD, NamedDecl *&PrevDecl, 2742 bool &Redeclaration, 2743 bool &OverloadableAttrRequired) { 2744 // If NewFD is already known erroneous, don't do any of this checking. 2745 if (NewFD->isInvalidDecl()) 2746 return; 2747 2748 if (NewFD->getResultType()->isVariablyModifiedType()) { 2749 // Functions returning a variably modified type violate C99 6.7.5.2p2 2750 // because all functions have linkage. 2751 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 2752 return NewFD->setInvalidDecl(); 2753 } 2754 2755 if (NewFD->isMain()) CheckMain(NewFD); 2756 2757 // Semantic checking for this function declaration (in isolation). 2758 if (getLangOptions().CPlusPlus) { 2759 // C++-specific checks. 2760 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 2761 CheckConstructor(Constructor); 2762 } else if (isa<CXXDestructorDecl>(NewFD)) { 2763 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 2764 QualType ClassType = Context.getTypeDeclType(Record); 2765 if (!ClassType->isDependentType()) { 2766 DeclarationName Name 2767 = Context.DeclarationNames.getCXXDestructorName( 2768 Context.getCanonicalType(ClassType)); 2769 if (NewFD->getDeclName() != Name) { 2770 Diag(NewFD->getLocation(), diag::err_destructor_name); 2771 return NewFD->setInvalidDecl(); 2772 } 2773 } 2774 Record->setUserDeclaredDestructor(true); 2775 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 2776 // user-defined destructor. 2777 Record->setPOD(false); 2778 2779 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 2780 // declared destructor. 2781 // FIXME: C++0x: don't do this for "= default" destructors 2782 Record->setHasTrivialDestructor(false); 2783 } else if (CXXConversionDecl *Conversion 2784 = dyn_cast<CXXConversionDecl>(NewFD)) 2785 ActOnConversionDeclarator(Conversion); 2786 2787 // Extra checking for C++ overloaded operators (C++ [over.oper]). 2788 if (NewFD->isOverloadedOperator() && 2789 CheckOverloadedOperatorDeclaration(NewFD)) 2790 return NewFD->setInvalidDecl(); 2791 } 2792 2793 // C99 6.7.4p6: 2794 // [... ] For a function with external linkage, the following 2795 // restrictions apply: [...] If all of the file scope declarations 2796 // for a function in a translation unit include the inline 2797 // function specifier without extern, then the definition in that 2798 // translation unit is an inline definition. An inline definition 2799 // does not provide an external definition for the function, and 2800 // does not forbid an external definition in another translation 2801 // unit. 2802 // 2803 // Here we determine whether this function, in isolation, would be a 2804 // C99 inline definition. MergeCompatibleFunctionDecls looks at 2805 // previous declarations. 2806 if (NewFD->isInline() && getLangOptions().C99 && 2807 NewFD->getStorageClass() == FunctionDecl::None && 2808 NewFD->getDeclContext()->getLookupContext()->isTranslationUnit()) 2809 NewFD->setC99InlineDefinition(true); 2810 2811 // Check for a previous declaration of this name. 2812 if (!PrevDecl && NewFD->isExternC(Context)) { 2813 // Since we did not find anything by this name and we're declaring 2814 // an extern "C" function, look for a non-visible extern "C" 2815 // declaration with the same name. 2816 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2817 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 2818 if (Pos != LocallyScopedExternalDecls.end()) 2819 PrevDecl = Pos->second; 2820 } 2821 2822 // Merge or overload the declaration with an existing declaration of 2823 // the same name, if appropriate. 2824 if (PrevDecl) { 2825 // Determine whether NewFD is an overload of PrevDecl or 2826 // a declaration that requires merging. If it's an overload, 2827 // there's no more work to do here; we'll just add the new 2828 // function to the scope. 2829 OverloadedFunctionDecl::function_iterator MatchedDecl; 2830 2831 if (!getLangOptions().CPlusPlus && 2832 AllowOverloadingOfFunction(PrevDecl, Context)) { 2833 OverloadableAttrRequired = true; 2834 2835 // Functions marked "overloadable" must have a prototype (that 2836 // we can't get through declaration merging). 2837 if (!NewFD->getType()->getAsFunctionProtoType()) { 2838 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 2839 << NewFD; 2840 Redeclaration = true; 2841 2842 // Turn this into a variadic function with no parameters. 2843 QualType R = Context.getFunctionType( 2844 NewFD->getType()->getAsFunctionType()->getResultType(), 2845 0, 0, true, 0); 2846 NewFD->setType(R); 2847 return NewFD->setInvalidDecl(); 2848 } 2849 } 2850 2851 if (PrevDecl && 2852 (!AllowOverloadingOfFunction(PrevDecl, Context) || 2853 !IsOverload(NewFD, PrevDecl, MatchedDecl)) && 2854 !isa<UsingDecl>(PrevDecl)) { 2855 Redeclaration = true; 2856 Decl *OldDecl = PrevDecl; 2857 2858 // If PrevDecl was an overloaded function, extract the 2859 // FunctionDecl that matched. 2860 if (isa<OverloadedFunctionDecl>(PrevDecl)) 2861 OldDecl = *MatchedDecl; 2862 2863 // NewFD and OldDecl represent declarations that need to be 2864 // merged. 2865 if (MergeFunctionDecl(NewFD, OldDecl)) 2866 return NewFD->setInvalidDecl(); 2867 2868 if (FunctionTemplateDecl *OldTemplateDecl 2869 = dyn_cast<FunctionTemplateDecl>(OldDecl)) 2870 NewFD->setPreviousDeclaration(OldTemplateDecl->getTemplatedDecl()); 2871 else { 2872 if (isa<CXXMethodDecl>(NewFD)) // Set access for out-of-line definitions 2873 NewFD->setAccess(OldDecl->getAccess()); 2874 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 2875 } 2876 } 2877 } 2878 2879 // In C++, check default arguments now that we have merged decls. Unless 2880 // the lexical context is the class, because in this case this is done 2881 // during delayed parsing anyway. 2882 if (getLangOptions().CPlusPlus && !CurContext->isRecord()) 2883 CheckCXXDefaultArguments(NewFD); 2884} 2885 2886void Sema::CheckMain(FunctionDecl* FD) { 2887 // C++ [basic.start.main]p3: A program that declares main to be inline 2888 // or static is ill-formed. 2889 // C99 6.7.4p4: In a hosted environment, the inline function specifier 2890 // shall not appear in a declaration of main. 2891 // static main is not an error under C99, but we should warn about it. 2892 bool isInline = FD->isInline(); 2893 bool isStatic = FD->getStorageClass() == FunctionDecl::Static; 2894 if (isInline || isStatic) { 2895 unsigned diagID = diag::warn_unusual_main_decl; 2896 if (isInline || getLangOptions().CPlusPlus) 2897 diagID = diag::err_unusual_main_decl; 2898 2899 int which = isStatic + (isInline << 1) - 1; 2900 Diag(FD->getLocation(), diagID) << which; 2901 } 2902 2903 QualType T = FD->getType(); 2904 assert(T->isFunctionType() && "function decl is not of function type"); 2905 const FunctionType* FT = T->getAsFunctionType(); 2906 2907 if (!Context.hasSameUnqualifiedType(FT->getResultType(), Context.IntTy)) { 2908 // TODO: add a replacement fixit to turn the return type into 'int'. 2909 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint); 2910 FD->setInvalidDecl(true); 2911 } 2912 2913 // Treat protoless main() as nullary. 2914 if (isa<FunctionNoProtoType>(FT)) return; 2915 2916 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 2917 unsigned nparams = FTP->getNumArgs(); 2918 assert(FD->getNumParams() == nparams); 2919 2920 if (nparams > 3) { 2921 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 2922 FD->setInvalidDecl(true); 2923 nparams = 3; 2924 } 2925 2926 // FIXME: a lot of the following diagnostics would be improved 2927 // if we had some location information about types. 2928 2929 QualType CharPP = 2930 Context.getPointerType(Context.getPointerType(Context.CharTy)); 2931 QualType Expected[] = { Context.IntTy, CharPP, CharPP }; 2932 2933 for (unsigned i = 0; i < nparams; ++i) { 2934 QualType AT = FTP->getArgType(i); 2935 2936 bool mismatch = true; 2937 2938 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 2939 mismatch = false; 2940 else if (Expected[i] == CharPP) { 2941 // As an extension, the following forms are okay: 2942 // char const ** 2943 // char const * const * 2944 // char * const * 2945 2946 QualifierSet qs; 2947 const PointerType* PT; 2948 if ((PT = qs.strip(AT)->getAs<PointerType>()) && 2949 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) && 2950 (QualType(qs.strip(PT->getPointeeType()), 0) == Context.CharTy)) { 2951 qs.removeConst(); 2952 mismatch = !qs.empty(); 2953 } 2954 } 2955 2956 if (mismatch) { 2957 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 2958 // TODO: suggest replacing given type with expected type 2959 FD->setInvalidDecl(true); 2960 } 2961 } 2962 2963 if (nparams == 1 && !FD->isInvalidDecl()) { 2964 Diag(FD->getLocation(), diag::warn_main_one_arg); 2965 } 2966} 2967 2968bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2969 // FIXME: Need strict checking. In C89, we need to check for 2970 // any assignment, increment, decrement, function-calls, or 2971 // commas outside of a sizeof. In C99, it's the same list, 2972 // except that the aforementioned are allowed in unevaluated 2973 // expressions. Everything else falls under the 2974 // "may accept other forms of constant expressions" exception. 2975 // (We never end up here for C++, so the constant expression 2976 // rules there don't matter.) 2977 if (Init->isConstantInitializer(Context)) 2978 return false; 2979 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 2980 << Init->getSourceRange(); 2981 return true; 2982} 2983 2984void Sema::AddInitializerToDecl(DeclPtrTy dcl, FullExprArg init) { 2985 AddInitializerToDecl(dcl, init.release(), /*DirectInit=*/false); 2986} 2987 2988/// AddInitializerToDecl - Adds the initializer Init to the 2989/// declaration dcl. If DirectInit is true, this is C++ direct 2990/// initialization rather than copy initialization. 2991void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 2992 Decl *RealDecl = dcl.getAs<Decl>(); 2993 // If there is no declaration, there was an error parsing it. Just ignore 2994 // the initializer. 2995 if (RealDecl == 0) 2996 return; 2997 2998 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 2999 // With declarators parsed the way they are, the parser cannot 3000 // distinguish between a normal initializer and a pure-specifier. 3001 // Thus this grotesque test. 3002 IntegerLiteral *IL; 3003 Expr *Init = static_cast<Expr *>(init.get()); 3004 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 3005 Context.getCanonicalType(IL->getType()) == Context.IntTy) { 3006 if (Method->isVirtualAsWritten()) { 3007 Method->setPure(); 3008 3009 // A class is abstract if at least one function is pure virtual. 3010 cast<CXXRecordDecl>(CurContext)->setAbstract(true); 3011 } else if (!Method->isInvalidDecl()) { 3012 Diag(Method->getLocation(), diag::err_non_virtual_pure) 3013 << Method->getDeclName() << Init->getSourceRange(); 3014 Method->setInvalidDecl(); 3015 } 3016 } else { 3017 Diag(Method->getLocation(), diag::err_member_function_initialization) 3018 << Method->getDeclName() << Init->getSourceRange(); 3019 Method->setInvalidDecl(); 3020 } 3021 return; 3022 } 3023 3024 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 3025 if (!VDecl) { 3026 if (getLangOptions().CPlusPlus && 3027 RealDecl->getLexicalDeclContext()->isRecord() && 3028 isa<NamedDecl>(RealDecl)) 3029 Diag(RealDecl->getLocation(), diag::err_member_initialization) 3030 << cast<NamedDecl>(RealDecl)->getDeclName(); 3031 else 3032 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 3033 RealDecl->setInvalidDecl(); 3034 return; 3035 } 3036 3037 if (!VDecl->getType()->isArrayType() && 3038 RequireCompleteType(VDecl->getLocation(), VDecl->getType(), 3039 diag::err_typecheck_decl_incomplete_type)) { 3040 RealDecl->setInvalidDecl(); 3041 return; 3042 } 3043 3044 const VarDecl *Def = 0; 3045 if (VDecl->getDefinition(Def)) { 3046 Diag(VDecl->getLocation(), diag::err_redefinition) 3047 << VDecl->getDeclName(); 3048 Diag(Def->getLocation(), diag::note_previous_definition); 3049 VDecl->setInvalidDecl(); 3050 return; 3051 } 3052 3053 // Take ownership of the expression, now that we're sure we have somewhere 3054 // to put it. 3055 Expr *Init = init.takeAs<Expr>(); 3056 assert(Init && "missing initializer"); 3057 3058 // Get the decls type and save a reference for later, since 3059 // CheckInitializerTypes may change it. 3060 QualType DclT = VDecl->getType(), SavT = DclT; 3061 if (VDecl->isBlockVarDecl()) { 3062 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 3063 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 3064 VDecl->setInvalidDecl(); 3065 } else if (!VDecl->isInvalidDecl()) { 3066 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3067 VDecl->getDeclName(), DirectInit)) 3068 VDecl->setInvalidDecl(); 3069 3070 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3071 // Don't check invalid declarations to avoid emitting useless diagnostics. 3072 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3073 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 3074 CheckForConstantInitializer(Init, DclT); 3075 } 3076 } 3077 } else if (VDecl->isStaticDataMember() && 3078 VDecl->getLexicalDeclContext()->isRecord()) { 3079 // This is an in-class initialization for a static data member, e.g., 3080 // 3081 // struct S { 3082 // static const int value = 17; 3083 // }; 3084 3085 // Attach the initializer 3086 VDecl->setInit(Context, Init); 3087 3088 // C++ [class.mem]p4: 3089 // A member-declarator can contain a constant-initializer only 3090 // if it declares a static member (9.4) of const integral or 3091 // const enumeration type, see 9.4.2. 3092 QualType T = VDecl->getType(); 3093 if (!T->isDependentType() && 3094 (!Context.getCanonicalType(T).isConstQualified() || 3095 !T->isIntegralType())) { 3096 Diag(VDecl->getLocation(), diag::err_member_initialization) 3097 << VDecl->getDeclName() << Init->getSourceRange(); 3098 VDecl->setInvalidDecl(); 3099 } else { 3100 // C++ [class.static.data]p4: 3101 // If a static data member is of const integral or const 3102 // enumeration type, its declaration in the class definition 3103 // can specify a constant-initializer which shall be an 3104 // integral constant expression (5.19). 3105 if (!Init->isTypeDependent() && 3106 !Init->getType()->isIntegralType()) { 3107 // We have a non-dependent, non-integral or enumeration type. 3108 Diag(Init->getSourceRange().getBegin(), 3109 diag::err_in_class_initializer_non_integral_type) 3110 << Init->getType() << Init->getSourceRange(); 3111 VDecl->setInvalidDecl(); 3112 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 3113 // Check whether the expression is a constant expression. 3114 llvm::APSInt Value; 3115 SourceLocation Loc; 3116 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 3117 Diag(Loc, diag::err_in_class_initializer_non_constant) 3118 << Init->getSourceRange(); 3119 VDecl->setInvalidDecl(); 3120 } else if (!VDecl->getType()->isDependentType()) 3121 ImpCastExprToType(Init, VDecl->getType()); 3122 } 3123 } 3124 } else if (VDecl->isFileVarDecl()) { 3125 if (VDecl->getStorageClass() == VarDecl::Extern) 3126 Diag(VDecl->getLocation(), diag::warn_extern_init); 3127 if (!VDecl->isInvalidDecl()) 3128 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3129 VDecl->getDeclName(), DirectInit)) 3130 VDecl->setInvalidDecl(); 3131 3132 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3133 // Don't check invalid declarations to avoid emitting useless diagnostics. 3134 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3135 // C99 6.7.8p4. All file scoped initializers need to be constant. 3136 CheckForConstantInitializer(Init, DclT); 3137 } 3138 } 3139 // If the type changed, it means we had an incomplete type that was 3140 // completed by the initializer. For example: 3141 // int ary[] = { 1, 3, 5 }; 3142 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 3143 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 3144 VDecl->setType(DclT); 3145 Init->setType(DclT); 3146 } 3147 3148 // Attach the initializer to the decl. 3149 VDecl->setInit(Context, Init); 3150 3151 // If the previous declaration of VDecl was a tentative definition, 3152 // remove it from the set of tentative definitions. 3153 if (VDecl->getPreviousDeclaration() && 3154 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 3155 llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos 3156 = TentativeDefinitions.find(VDecl->getDeclName()); 3157 assert(Pos != TentativeDefinitions.end() && 3158 "Unrecorded tentative definition?"); 3159 TentativeDefinitions.erase(Pos); 3160 } 3161 3162 return; 3163} 3164 3165void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 3166 bool TypeContainsUndeducedAuto) { 3167 Decl *RealDecl = dcl.getAs<Decl>(); 3168 3169 // If there is no declaration, there was an error parsing it. Just ignore it. 3170 if (RealDecl == 0) 3171 return; 3172 3173 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 3174 QualType Type = Var->getType(); 3175 3176 // Record tentative definitions. 3177 if (Var->isTentativeDefinition(Context)) 3178 TentativeDefinitions[Var->getDeclName()] = Var; 3179 3180 // C++ [dcl.init.ref]p3: 3181 // The initializer can be omitted for a reference only in a 3182 // parameter declaration (8.3.5), in the declaration of a 3183 // function return type, in the declaration of a class member 3184 // within its class declaration (9.2), and where the extern 3185 // specifier is explicitly used. 3186 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 3187 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 3188 << Var->getDeclName() 3189 << SourceRange(Var->getLocation(), Var->getLocation()); 3190 Var->setInvalidDecl(); 3191 return; 3192 } 3193 3194 // C++0x [dcl.spec.auto]p3 3195 if (TypeContainsUndeducedAuto) { 3196 Diag(Var->getLocation(), diag::err_auto_var_requires_init) 3197 << Var->getDeclName() << Type; 3198 Var->setInvalidDecl(); 3199 return; 3200 } 3201 3202 // C++ [dcl.init]p9: 3203 // 3204 // If no initializer is specified for an object, and the object 3205 // is of (possibly cv-qualified) non-POD class type (or array 3206 // thereof), the object shall be default-initialized; if the 3207 // object is of const-qualified type, the underlying class type 3208 // shall have a user-declared default constructor. 3209 if (getLangOptions().CPlusPlus) { 3210 QualType InitType = Type; 3211 if (const ArrayType *Array = Context.getAsArrayType(Type)) 3212 InitType = Array->getElementType(); 3213 if ((!Var->hasExternalStorage() && !Var->isExternC(Context)) && 3214 InitType->isRecordType() && !InitType->isDependentType()) { 3215 CXXRecordDecl *RD = 3216 cast<CXXRecordDecl>(InitType->getAs<RecordType>()->getDecl()); 3217 CXXConstructorDecl *Constructor = 0; 3218 if (!RequireCompleteType(Var->getLocation(), InitType, 3219 diag::err_invalid_incomplete_type_use)) 3220 Constructor 3221 = PerformInitializationByConstructor(InitType, 0, 0, 3222 Var->getLocation(), 3223 SourceRange(Var->getLocation(), 3224 Var->getLocation()), 3225 Var->getDeclName(), 3226 IK_Default); 3227 if (!Constructor) 3228 Var->setInvalidDecl(); 3229 else { 3230 if (!RD->hasTrivialConstructor() || !RD->hasTrivialDestructor()) 3231 InitializeVarWithConstructor(Var, Constructor, InitType, 0, 0); 3232 FinalizeVarWithDestructor(Var, InitType); 3233 } 3234 } 3235 } 3236 3237#if 0 3238 // FIXME: Temporarily disabled because we are not properly parsing 3239 // linkage specifications on declarations, e.g., 3240 // 3241 // extern "C" const CGPoint CGPointerZero; 3242 // 3243 // C++ [dcl.init]p9: 3244 // 3245 // If no initializer is specified for an object, and the 3246 // object is of (possibly cv-qualified) non-POD class type (or 3247 // array thereof), the object shall be default-initialized; if 3248 // the object is of const-qualified type, the underlying class 3249 // type shall have a user-declared default 3250 // constructor. Otherwise, if no initializer is specified for 3251 // an object, the object and its subobjects, if any, have an 3252 // indeterminate initial value; if the object or any of its 3253 // subobjects are of const-qualified type, the program is 3254 // ill-formed. 3255 // 3256 // This isn't technically an error in C, so we don't diagnose it. 3257 // 3258 // FIXME: Actually perform the POD/user-defined default 3259 // constructor check. 3260 if (getLangOptions().CPlusPlus && 3261 Context.getCanonicalType(Type).isConstQualified() && 3262 !Var->hasExternalStorage()) 3263 Diag(Var->getLocation(), diag::err_const_var_requires_init) 3264 << Var->getName() 3265 << SourceRange(Var->getLocation(), Var->getLocation()); 3266#endif 3267 } 3268} 3269 3270Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 3271 DeclPtrTy *Group, 3272 unsigned NumDecls) { 3273 llvm::SmallVector<Decl*, 8> Decls; 3274 3275 if (DS.isTypeSpecOwned()) 3276 Decls.push_back((Decl*)DS.getTypeRep()); 3277 3278 for (unsigned i = 0; i != NumDecls; ++i) 3279 if (Decl *D = Group[i].getAs<Decl>()) 3280 Decls.push_back(D); 3281 3282 // Perform semantic analysis that depends on having fully processed both 3283 // the declarator and initializer. 3284 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 3285 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 3286 if (!IDecl) 3287 continue; 3288 QualType T = IDecl->getType(); 3289 3290 // Block scope. C99 6.7p7: If an identifier for an object is declared with 3291 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 3292 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 3293 if (!IDecl->isInvalidDecl() && 3294 RequireCompleteType(IDecl->getLocation(), T, 3295 diag::err_typecheck_decl_incomplete_type)) 3296 IDecl->setInvalidDecl(); 3297 } 3298 // File scope. C99 6.9.2p2: A declaration of an identifier for an 3299 // object that has file scope without an initializer, and without a 3300 // storage-class specifier or with the storage-class specifier "static", 3301 // constitutes a tentative definition. Note: A tentative definition with 3302 // external linkage is valid (C99 6.2.2p5). 3303 if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) { 3304 if (const IncompleteArrayType *ArrayT 3305 = Context.getAsIncompleteArrayType(T)) { 3306 if (RequireCompleteType(IDecl->getLocation(), 3307 ArrayT->getElementType(), 3308 diag::err_illegal_decl_array_incomplete_type)) 3309 IDecl->setInvalidDecl(); 3310 } else if (IDecl->getStorageClass() == VarDecl::Static) { 3311 // C99 6.9.2p3: If the declaration of an identifier for an object is 3312 // a tentative definition and has internal linkage (C99 6.2.2p3), the 3313 // declared type shall not be an incomplete type. 3314 // NOTE: code such as the following 3315 // static struct s; 3316 // struct s { int a; }; 3317 // is accepted by gcc. Hence here we issue a warning instead of 3318 // an error and we do not invalidate the static declaration. 3319 // NOTE: to avoid multiple warnings, only check the first declaration. 3320 if (IDecl->getPreviousDeclaration() == 0) 3321 RequireCompleteType(IDecl->getLocation(), T, 3322 diag::ext_typecheck_decl_incomplete_type); 3323 } 3324 } 3325 } 3326 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 3327 Decls.data(), Decls.size())); 3328} 3329 3330 3331/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 3332/// to introduce parameters into function prototype scope. 3333Sema::DeclPtrTy 3334Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 3335 const DeclSpec &DS = D.getDeclSpec(); 3336 3337 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 3338 VarDecl::StorageClass StorageClass = VarDecl::None; 3339 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 3340 StorageClass = VarDecl::Register; 3341 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 3342 Diag(DS.getStorageClassSpecLoc(), 3343 diag::err_invalid_storage_class_in_func_decl); 3344 D.getMutableDeclSpec().ClearStorageClassSpecs(); 3345 } 3346 3347 if (D.getDeclSpec().isThreadSpecified()) 3348 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3349 3350 DiagnoseFunctionSpecifiers(D); 3351 3352 // Check that there are no default arguments inside the type of this 3353 // parameter (C++ only). 3354 if (getLangOptions().CPlusPlus) 3355 CheckExtraCXXDefaultArguments(D); 3356 3357 TagDecl *OwnedDecl = 0; 3358 QualType parmDeclType = GetTypeForDeclarator(D, S, /*Skip=*/0, &OwnedDecl); 3359 3360 if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) { 3361 // C++ [dcl.fct]p6: 3362 // Types shall not be defined in return or parameter types. 3363 Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type) 3364 << Context.getTypeDeclType(OwnedDecl); 3365 } 3366 3367 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 3368 // Can this happen for params? We already checked that they don't conflict 3369 // among each other. Here they can only shadow globals, which is ok. 3370 IdentifierInfo *II = D.getIdentifier(); 3371 if (II) { 3372 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 3373 if (PrevDecl->isTemplateParameter()) { 3374 // Maybe we will complain about the shadowed template parameter. 3375 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 3376 // Just pretend that we didn't see the previous declaration. 3377 PrevDecl = 0; 3378 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 3379 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 3380 3381 // Recover by removing the name 3382 II = 0; 3383 D.SetIdentifier(0, D.getIdentifierLoc()); 3384 } 3385 } 3386 } 3387 3388 // Parameters can not be abstract class types. 3389 // For record types, this is done by the AbstractClassUsageDiagnoser once 3390 // the class has been completely parsed. 3391 if (!CurContext->isRecord() && 3392 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 3393 diag::err_abstract_type_in_decl, 3394 AbstractParamType)) 3395 D.setInvalidType(true); 3396 3397 QualType T = adjustParameterType(parmDeclType); 3398 3399 ParmVarDecl *New; 3400 if (T == parmDeclType) // parameter type did not need adjustment 3401 New = ParmVarDecl::Create(Context, CurContext, 3402 D.getIdentifierLoc(), II, 3403 parmDeclType, StorageClass, 3404 0); 3405 else // keep track of both the adjusted and unadjusted types 3406 New = OriginalParmVarDecl::Create(Context, CurContext, 3407 D.getIdentifierLoc(), II, T, 3408 parmDeclType, StorageClass, 0); 3409 3410 if (D.isInvalidType()) 3411 New->setInvalidDecl(); 3412 3413 // Parameter declarators cannot be interface types. All ObjC objects are 3414 // passed by reference. 3415 if (T->isObjCInterfaceType()) { 3416 Diag(D.getIdentifierLoc(), 3417 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 3418 New->setInvalidDecl(); 3419 } 3420 3421 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 3422 if (D.getCXXScopeSpec().isSet()) { 3423 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 3424 << D.getCXXScopeSpec().getRange(); 3425 New->setInvalidDecl(); 3426 } 3427 3428 // Add the parameter declaration into this scope. 3429 S->AddDecl(DeclPtrTy::make(New)); 3430 if (II) 3431 IdResolver.AddDecl(New); 3432 3433 ProcessDeclAttributes(S, New, D); 3434 3435 if (New->hasAttr<BlocksAttr>()) { 3436 Diag(New->getLocation(), diag::err_block_on_nonlocal); 3437 } 3438 return DeclPtrTy::make(New); 3439} 3440 3441void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 3442 SourceLocation LocAfterDecls) { 3443 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3444 "Not a function declarator!"); 3445 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3446 3447 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 3448 // for a K&R function. 3449 if (!FTI.hasPrototype) { 3450 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 3451 --i; 3452 if (FTI.ArgInfo[i].Param == 0) { 3453 std::string Code = " int "; 3454 Code += FTI.ArgInfo[i].Ident->getName(); 3455 Code += ";\n"; 3456 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 3457 << FTI.ArgInfo[i].Ident 3458 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code); 3459 3460 // Implicitly declare the argument as type 'int' for lack of a better 3461 // type. 3462 DeclSpec DS; 3463 const char* PrevSpec; // unused 3464 unsigned DiagID; // unused 3465 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 3466 PrevSpec, DiagID); 3467 Declarator ParamD(DS, Declarator::KNRTypeListContext); 3468 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 3469 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 3470 } 3471 } 3472 } 3473} 3474 3475Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 3476 Declarator &D) { 3477 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 3478 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3479 "Not a function declarator!"); 3480 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3481 3482 if (FTI.hasPrototype) { 3483 // FIXME: Diagnose arguments without names in C. 3484 } 3485 3486 Scope *ParentScope = FnBodyScope->getParent(); 3487 3488 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 3489 MultiTemplateParamsArg(*this), 3490 /*IsFunctionDefinition=*/true); 3491 return ActOnStartOfFunctionDef(FnBodyScope, DP); 3492} 3493 3494Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 3495 if (!D) 3496 return D; 3497 FunctionDecl *FD = cast<FunctionDecl>(D.getAs<Decl>()); 3498 3499 CurFunctionNeedsScopeChecking = false; 3500 3501 // See if this is a redefinition. 3502 const FunctionDecl *Definition; 3503 if (FD->getBody(Definition)) { 3504 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 3505 Diag(Definition->getLocation(), diag::note_previous_definition); 3506 } 3507 3508 // Builtin functions cannot be defined. 3509 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3510 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 3511 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 3512 FD->setInvalidDecl(); 3513 } 3514 } 3515 3516 // The return type of a function definition must be complete 3517 // (C99 6.9.1p3, C++ [dcl.fct]p6). 3518 QualType ResultType = FD->getResultType(); 3519 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 3520 !FD->isInvalidDecl() && 3521 RequireCompleteType(FD->getLocation(), ResultType, 3522 diag::err_func_def_incomplete_result)) 3523 FD->setInvalidDecl(); 3524 3525 // GNU warning -Wmissing-prototypes: 3526 // Warn if a global function is defined without a previous 3527 // prototype declaration. This warning is issued even if the 3528 // definition itself provides a prototype. The aim is to detect 3529 // global functions that fail to be declared in header files. 3530 if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) && 3531 !FD->isMain()) { 3532 bool MissingPrototype = true; 3533 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 3534 Prev; Prev = Prev->getPreviousDeclaration()) { 3535 // Ignore any declarations that occur in function or method 3536 // scope, because they aren't visible from the header. 3537 if (Prev->getDeclContext()->isFunctionOrMethod()) 3538 continue; 3539 3540 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 3541 break; 3542 } 3543 3544 if (MissingPrototype) 3545 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 3546 } 3547 3548 if (FnBodyScope) 3549 PushDeclContext(FnBodyScope, FD); 3550 3551 // Check the validity of our function parameters 3552 CheckParmsForFunctionDef(FD); 3553 3554 // Introduce our parameters into the function scope 3555 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 3556 ParmVarDecl *Param = FD->getParamDecl(p); 3557 Param->setOwningFunction(FD); 3558 3559 // If this has an identifier, add it to the scope stack. 3560 if (Param->getIdentifier() && FnBodyScope) 3561 PushOnScopeChains(Param, FnBodyScope); 3562 } 3563 3564 // Checking attributes of current function definition 3565 // dllimport attribute. 3566 if (FD->getAttr<DLLImportAttr>() && 3567 (!FD->getAttr<DLLExportAttr>())) { 3568 // dllimport attribute cannot be applied to definition. 3569 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 3570 Diag(FD->getLocation(), 3571 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 3572 << "dllimport"; 3573 FD->setInvalidDecl(); 3574 return DeclPtrTy::make(FD); 3575 } else { 3576 // If a symbol previously declared dllimport is later defined, the 3577 // attribute is ignored in subsequent references, and a warning is 3578 // emitted. 3579 Diag(FD->getLocation(), 3580 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3581 << FD->getNameAsCString() << "dllimport"; 3582 } 3583 } 3584 return DeclPtrTy::make(FD); 3585} 3586 3587Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 3588 return ActOnFinishFunctionBody(D, move(BodyArg), false); 3589} 3590 3591Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 3592 bool IsInstantiation) { 3593 Decl *dcl = D.getAs<Decl>(); 3594 Stmt *Body = BodyArg.takeAs<Stmt>(); 3595 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3596 FD->setBody(Body); 3597 if (FD->isMain()) 3598 // C and C++ allow for main to automagically return 0. 3599 // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3. 3600 FD->setHasImplicitReturnZero(true); 3601 else 3602 CheckFallThroughForFunctionDef(FD, Body); 3603 3604 if (!FD->isInvalidDecl()) 3605 DiagnoseUnusedParameters(FD->param_begin(), FD->param_end()); 3606 3607 // C++ [basic.def.odr]p2: 3608 // [...] A virtual member function is used if it is not pure. [...] 3609 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 3610 if (Method->isVirtual() && !Method->isPure()) 3611 MarkDeclarationReferenced(Method->getLocation(), Method); 3612 3613 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3614 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3615 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3616 MD->setBody(Body); 3617 CheckFallThroughForFunctionDef(MD, Body); 3618 MD->setEndLoc(Body->getLocEnd()); 3619 3620 if (!MD->isInvalidDecl()) 3621 DiagnoseUnusedParameters(MD->param_begin(), MD->param_end()); 3622 } else { 3623 Body->Destroy(Context); 3624 return DeclPtrTy(); 3625 } 3626 if (!IsInstantiation) 3627 PopDeclContext(); 3628 3629 // Verify and clean out per-function state. 3630 3631 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 3632 3633 // Check goto/label use. 3634 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3635 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 3636 LabelStmt *L = I->second; 3637 3638 // Verify that we have no forward references left. If so, there was a goto 3639 // or address of a label taken, but no definition of it. Label fwd 3640 // definitions are indicated with a null substmt. 3641 if (L->getSubStmt() != 0) 3642 continue; 3643 3644 // Emit error. 3645 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3646 3647 // At this point, we have gotos that use the bogus label. Stitch it into 3648 // the function body so that they aren't leaked and that the AST is well 3649 // formed. 3650 if (Body == 0) { 3651 // The whole function wasn't parsed correctly, just delete this. 3652 L->Destroy(Context); 3653 continue; 3654 } 3655 3656 // Otherwise, the body is valid: we want to stitch the label decl into the 3657 // function somewhere so that it is properly owned and so that the goto 3658 // has a valid target. Do this by creating a new compound stmt with the 3659 // label in it. 3660 3661 // Give the label a sub-statement. 3662 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3663 3664 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 3665 cast<CXXTryStmt>(Body)->getTryBlock() : 3666 cast<CompoundStmt>(Body); 3667 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 3668 Elements.push_back(L); 3669 Compound->setStmts(Context, &Elements[0], Elements.size()); 3670 } 3671 FunctionLabelMap.clear(); 3672 3673 if (!Body) return D; 3674 3675 // Verify that that gotos and switch cases don't jump into scopes illegally. 3676 if (CurFunctionNeedsScopeChecking) 3677 DiagnoseInvalidJumps(Body); 3678 3679 // C++ constructors that have function-try-blocks can't have return 3680 // statements in the handlers of that block. (C++ [except.handle]p14) 3681 // Verify this. 3682 if (isa<CXXConstructorDecl>(dcl) && isa<CXXTryStmt>(Body)) 3683 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 3684 3685 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) 3686 Destructor->computeBaseOrMembersToDestroy(Context); 3687 return D; 3688} 3689 3690/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3691/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3692NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3693 IdentifierInfo &II, Scope *S) { 3694 // Before we produce a declaration for an implicitly defined 3695 // function, see whether there was a locally-scoped declaration of 3696 // this name as a function or variable. If so, use that 3697 // (non-visible) declaration, and complain about it. 3698 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3699 = LocallyScopedExternalDecls.find(&II); 3700 if (Pos != LocallyScopedExternalDecls.end()) { 3701 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 3702 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 3703 return Pos->second; 3704 } 3705 3706 // Extension in C99. Legal in C90, but warn about it. 3707 if (getLangOptions().C99) 3708 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3709 else 3710 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3711 3712 // FIXME: handle stuff like: 3713 // void foo() { extern float X(); } 3714 // void bar() { X(); } <-- implicit decl for X in another scope. 3715 3716 // Set a Declarator for the implicit definition: int foo(); 3717 const char *Dummy; 3718 DeclSpec DS; 3719 unsigned DiagID; 3720 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID); 3721 Error = Error; // Silence warning. 3722 assert(!Error && "Error setting up implicit decl!"); 3723 Declarator D(DS, Declarator::BlockContext); 3724 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 3725 0, 0, false, SourceLocation(), 3726 false, 0,0,0, Loc, D), 3727 SourceLocation()); 3728 D.SetIdentifier(&II, Loc); 3729 3730 // Insert this function into translation-unit scope. 3731 3732 DeclContext *PrevDC = CurContext; 3733 CurContext = Context.getTranslationUnitDecl(); 3734 3735 FunctionDecl *FD = 3736 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D).getAs<Decl>()); 3737 FD->setImplicit(); 3738 3739 CurContext = PrevDC; 3740 3741 AddKnownFunctionAttributes(FD); 3742 3743 return FD; 3744} 3745 3746/// \brief Adds any function attributes that we know a priori based on 3747/// the declaration of this function. 3748/// 3749/// These attributes can apply both to implicitly-declared builtins 3750/// (like __builtin___printf_chk) or to library-declared functions 3751/// like NSLog or printf. 3752void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3753 if (FD->isInvalidDecl()) 3754 return; 3755 3756 // If this is a built-in function, map its builtin attributes to 3757 // actual attributes. 3758 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3759 // Handle printf-formatting attributes. 3760 unsigned FormatIdx; 3761 bool HasVAListArg; 3762 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3763 if (!FD->getAttr<FormatAttr>()) 3764 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 3765 HasVAListArg ? 0 : FormatIdx + 2)); 3766 } 3767 3768 // Mark const if we don't care about errno and that is the only 3769 // thing preventing the function from being const. This allows 3770 // IRgen to use LLVM intrinsics for such functions. 3771 if (!getLangOptions().MathErrno && 3772 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3773 if (!FD->getAttr<ConstAttr>()) 3774 FD->addAttr(::new (Context) ConstAttr()); 3775 } 3776 3777 if (Context.BuiltinInfo.isNoReturn(BuiltinID)) 3778 FD->addAttr(::new (Context) NoReturnAttr()); 3779 } 3780 3781 IdentifierInfo *Name = FD->getIdentifier(); 3782 if (!Name) 3783 return; 3784 if ((!getLangOptions().CPlusPlus && 3785 FD->getDeclContext()->isTranslationUnit()) || 3786 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3787 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3788 LinkageSpecDecl::lang_c)) { 3789 // Okay: this could be a libc/libm/Objective-C function we know 3790 // about. 3791 } else 3792 return; 3793 3794 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 3795 // FIXME: NSLog and NSLogv should be target specific 3796 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3797 // FIXME: We known better than our headers. 3798 const_cast<FormatAttr *>(Format)->setType("printf"); 3799 } else 3800 FD->addAttr(::new (Context) FormatAttr("printf", 1, 3801 Name->isStr("NSLogv") ? 0 : 2)); 3802 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 3803 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 3804 // target-specific builtins, perhaps? 3805 if (!FD->getAttr<FormatAttr>()) 3806 FD->addAttr(::new (Context) FormatAttr("printf", 2, 3807 Name->isStr("vasprintf") ? 0 : 3)); 3808 } 3809} 3810 3811TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T) { 3812 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3813 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3814 3815 // Scope manipulation handled by caller. 3816 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3817 D.getIdentifierLoc(), 3818 D.getIdentifier(), 3819 T); 3820 3821 if (TagType *TT = dyn_cast<TagType>(T)) { 3822 TagDecl *TD = TT->getDecl(); 3823 3824 // If the TagDecl that the TypedefDecl points to is an anonymous decl 3825 // keep track of the TypedefDecl. 3826 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 3827 TD->setTypedefForAnonDecl(NewTD); 3828 } 3829 3830 if (D.isInvalidType()) 3831 NewTD->setInvalidDecl(); 3832 return NewTD; 3833} 3834 3835 3836/// \brief Determine whether a tag with a given kind is acceptable 3837/// as a redeclaration of the given tag declaration. 3838/// 3839/// \returns true if the new tag kind is acceptable, false otherwise. 3840bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 3841 TagDecl::TagKind NewTag, 3842 SourceLocation NewTagLoc, 3843 const IdentifierInfo &Name) { 3844 // C++ [dcl.type.elab]p3: 3845 // The class-key or enum keyword present in the 3846 // elaborated-type-specifier shall agree in kind with the 3847 // declaration to which the name in theelaborated-type-specifier 3848 // refers. This rule also applies to the form of 3849 // elaborated-type-specifier that declares a class-name or 3850 // friend class since it can be construed as referring to the 3851 // definition of the class. Thus, in any 3852 // elaborated-type-specifier, the enum keyword shall be used to 3853 // refer to an enumeration (7.2), the union class-keyshall be 3854 // used to refer to a union (clause 9), and either the class or 3855 // struct class-key shall be used to refer to a class (clause 9) 3856 // declared using the class or struct class-key. 3857 TagDecl::TagKind OldTag = Previous->getTagKind(); 3858 if (OldTag == NewTag) 3859 return true; 3860 3861 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 3862 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 3863 // Warn about the struct/class tag mismatch. 3864 bool isTemplate = false; 3865 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 3866 isTemplate = Record->getDescribedClassTemplate(); 3867 3868 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 3869 << (NewTag == TagDecl::TK_class) 3870 << isTemplate << &Name 3871 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 3872 OldTag == TagDecl::TK_class? "class" : "struct"); 3873 Diag(Previous->getLocation(), diag::note_previous_use); 3874 return true; 3875 } 3876 return false; 3877} 3878 3879/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3880/// former case, Name will be non-null. In the later case, Name will be null. 3881/// TagSpec indicates what kind of tag this is. TUK indicates whether this is a 3882/// reference/declaration/definition of a tag. 3883Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 3884 SourceLocation KWLoc, const CXXScopeSpec &SS, 3885 IdentifierInfo *Name, SourceLocation NameLoc, 3886 AttributeList *Attr, AccessSpecifier AS, 3887 MultiTemplateParamsArg TemplateParameterLists, 3888 bool &OwnedDecl) { 3889 // If this is not a definition, it must have a name. 3890 assert((Name != 0 || TUK == TUK_Definition) && 3891 "Nameless record must be a definition!"); 3892 3893 OwnedDecl = false; 3894 TagDecl::TagKind Kind; 3895 switch (TagSpec) { 3896 default: assert(0 && "Unknown tag type!"); 3897 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3898 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3899 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3900 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3901 } 3902 3903 if (TUK != TUK_Reference) { 3904 if (TemplateParameterList *TemplateParams 3905 = MatchTemplateParametersToScopeSpecifier(KWLoc, SS, 3906 (TemplateParameterList**)TemplateParameterLists.get(), 3907 TemplateParameterLists.size())) { 3908 if (TemplateParams->size() > 0) { 3909 // This is a declaration or definition of a class template (which may 3910 // be a member of another template). 3911 OwnedDecl = false; 3912 DeclResult Result = CheckClassTemplate(S, TagSpec, TUK, KWLoc, 3913 SS, Name, NameLoc, Attr, 3914 move(TemplateParameterLists), 3915 AS); 3916 return Result.get(); 3917 } else { 3918 // FIXME: diagnose the extraneous 'template<>', once we recover 3919 // slightly better in ParseTemplate.cpp from bogus template 3920 // parameters. 3921 } 3922 } 3923 } 3924 3925 DeclContext *SearchDC = CurContext; 3926 DeclContext *DC = CurContext; 3927 NamedDecl *PrevDecl = 0; 3928 3929 bool Invalid = false; 3930 3931 if (Name && SS.isNotEmpty()) { 3932 // We have a nested-name tag ('struct foo::bar'). 3933 3934 // Check for invalid 'foo::'. 3935 if (SS.isInvalid()) { 3936 Name = 0; 3937 goto CreateNewDecl; 3938 } 3939 3940 if (RequireCompleteDeclContext(SS)) 3941 return DeclPtrTy::make((Decl *)0); 3942 3943 DC = computeDeclContext(SS, true); 3944 SearchDC = DC; 3945 // Look-up name inside 'foo::'. 3946 PrevDecl 3947 = dyn_cast_or_null<TagDecl>( 3948 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 3949 3950 // A tag 'foo::bar' must already exist. 3951 if (PrevDecl == 0) { 3952 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 3953 Name = 0; 3954 Invalid = true; 3955 goto CreateNewDecl; 3956 } 3957 } else if (Name) { 3958 // If this is a named struct, check to see if there was a previous forward 3959 // declaration or definition. 3960 // FIXME: We're looking into outer scopes here, even when we 3961 // shouldn't be. Doing so can result in ambiguities that we 3962 // shouldn't be diagnosing. 3963 LookupResult R = LookupName(S, Name, LookupTagName, 3964 /*RedeclarationOnly=*/(TUK != TUK_Reference)); 3965 if (R.isAmbiguous()) { 3966 DiagnoseAmbiguousLookup(R, Name, NameLoc); 3967 // FIXME: This is not best way to recover from case like: 3968 // 3969 // struct S s; 3970 // 3971 // causes needless "incomplete type" error later. 3972 Name = 0; 3973 PrevDecl = 0; 3974 Invalid = true; 3975 } else 3976 PrevDecl = R; 3977 3978 if (!getLangOptions().CPlusPlus && TUK != TUK_Reference) { 3979 // FIXME: This makes sure that we ignore the contexts associated 3980 // with C structs, unions, and enums when looking for a matching 3981 // tag declaration or definition. See the similar lookup tweak 3982 // in Sema::LookupName; is there a better way to deal with this? 3983 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 3984 SearchDC = SearchDC->getParent(); 3985 } 3986 } 3987 3988 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3989 // Maybe we will complain about the shadowed template parameter. 3990 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 3991 // Just pretend that we didn't see the previous declaration. 3992 PrevDecl = 0; 3993 } 3994 3995 if (PrevDecl) { 3996 // Check whether the previous declaration is usable. 3997 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 3998 3999 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 4000 // If this is a use of a previous tag, or if the tag is already declared 4001 // in the same scope (so that the definition/declaration completes or 4002 // rementions the tag), reuse the decl. 4003 if (TUK == TUK_Reference || TUK == TUK_Friend || 4004 isDeclInScope(PrevDecl, SearchDC, S)) { 4005 // Make sure that this wasn't declared as an enum and now used as a 4006 // struct or something similar. 4007 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 4008 bool SafeToContinue 4009 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 4010 Kind != TagDecl::TK_enum); 4011 if (SafeToContinue) 4012 Diag(KWLoc, diag::err_use_with_wrong_tag) 4013 << Name 4014 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 4015 PrevTagDecl->getKindName()); 4016 else 4017 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 4018 Diag(PrevDecl->getLocation(), diag::note_previous_use); 4019 4020 if (SafeToContinue) 4021 Kind = PrevTagDecl->getTagKind(); 4022 else { 4023 // Recover by making this an anonymous redefinition. 4024 Name = 0; 4025 PrevDecl = 0; 4026 Invalid = true; 4027 } 4028 } 4029 4030 if (!Invalid) { 4031 // If this is a use, just return the declaration we found. 4032 4033 // FIXME: In the future, return a variant or some other clue 4034 // for the consumer of this Decl to know it doesn't own it. 4035 // For our current ASTs this shouldn't be a problem, but will 4036 // need to be changed with DeclGroups. 4037 if (TUK == TUK_Reference) 4038 return DeclPtrTy::make(PrevDecl); 4039 4040 // If this is a friend, make sure we create the new 4041 // declaration in the appropriate semantic context. 4042 if (TUK == TUK_Friend) 4043 SearchDC = PrevDecl->getDeclContext(); 4044 4045 // Diagnose attempts to redefine a tag. 4046 if (TUK == TUK_Definition) { 4047 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 4048 Diag(NameLoc, diag::err_redefinition) << Name; 4049 Diag(Def->getLocation(), diag::note_previous_definition); 4050 // If this is a redefinition, recover by making this 4051 // struct be anonymous, which will make any later 4052 // references get the previous definition. 4053 Name = 0; 4054 PrevDecl = 0; 4055 Invalid = true; 4056 } else { 4057 // If the type is currently being defined, complain 4058 // about a nested redefinition. 4059 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 4060 if (Tag->isBeingDefined()) { 4061 Diag(NameLoc, diag::err_nested_redefinition) << Name; 4062 Diag(PrevTagDecl->getLocation(), 4063 diag::note_previous_definition); 4064 Name = 0; 4065 PrevDecl = 0; 4066 Invalid = true; 4067 } 4068 } 4069 4070 // Okay, this is definition of a previously declared or referenced 4071 // tag PrevDecl. We're going to create a new Decl for it. 4072 } 4073 } 4074 // If we get here we have (another) forward declaration or we 4075 // have a definition. Just create a new decl. 4076 4077 } else { 4078 // If we get here, this is a definition of a new tag type in a nested 4079 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 4080 // new decl/type. We set PrevDecl to NULL so that the entities 4081 // have distinct types. 4082 PrevDecl = 0; 4083 } 4084 // If we get here, we're going to create a new Decl. If PrevDecl 4085 // is non-NULL, it's a definition of the tag declared by 4086 // PrevDecl. If it's NULL, we have a new definition. 4087 } else { 4088 // PrevDecl is a namespace, template, or anything else 4089 // that lives in the IDNS_Tag identifier namespace. 4090 if (isDeclInScope(PrevDecl, SearchDC, S)) { 4091 // The tag name clashes with a namespace name, issue an error and 4092 // recover by making this tag be anonymous. 4093 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 4094 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4095 Name = 0; 4096 PrevDecl = 0; 4097 Invalid = true; 4098 } else { 4099 // The existing declaration isn't relevant to us; we're in a 4100 // new scope, so clear out the previous declaration. 4101 PrevDecl = 0; 4102 } 4103 } 4104 } else if (TUK == TUK_Reference && SS.isEmpty() && Name && 4105 (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) { 4106 // C++ [basic.scope.pdecl]p5: 4107 // -- for an elaborated-type-specifier of the form 4108 // 4109 // class-key identifier 4110 // 4111 // if the elaborated-type-specifier is used in the 4112 // decl-specifier-seq or parameter-declaration-clause of a 4113 // function defined in namespace scope, the identifier is 4114 // declared as a class-name in the namespace that contains 4115 // the declaration; otherwise, except as a friend 4116 // declaration, the identifier is declared in the smallest 4117 // non-class, non-function-prototype scope that contains the 4118 // declaration. 4119 // 4120 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 4121 // C structs and unions. 4122 // 4123 // GNU C also supports this behavior as part of its incomplete 4124 // enum types extension, while GNU C++ does not. 4125 // 4126 // Find the context where we'll be declaring the tag. 4127 // FIXME: We would like to maintain the current DeclContext as the 4128 // lexical context, 4129 while (SearchDC->isRecord()) 4130 SearchDC = SearchDC->getParent(); 4131 4132 // Find the scope where we'll be declaring the tag. 4133 while (S->isClassScope() || 4134 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 4135 ((S->getFlags() & Scope::DeclScope) == 0) || 4136 (S->getEntity() && 4137 ((DeclContext *)S->getEntity())->isTransparentContext())) 4138 S = S->getParent(); 4139 4140 } else if (TUK == TUK_Friend && SS.isEmpty() && Name) { 4141 // C++ [namespace.memdef]p3: 4142 // If a friend declaration in a non-local class first declares a 4143 // class or function, the friend class or function is a member of 4144 // the innermost enclosing namespace. 4145 while (!SearchDC->isNamespace() && !SearchDC->isTranslationUnit()) 4146 SearchDC = SearchDC->getParent(); 4147 4148 // The entity of a decl scope is a DeclContext; see PushDeclContext. 4149 while (S->getEntity() != SearchDC) 4150 S = S->getParent(); 4151 } 4152 4153CreateNewDecl: 4154 4155 // If there is an identifier, use the location of the identifier as the 4156 // location of the decl, otherwise use the location of the struct/union 4157 // keyword. 4158 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 4159 4160 // Otherwise, create a new declaration. If there is a previous 4161 // declaration of the same entity, the two will be linked via 4162 // PrevDecl. 4163 TagDecl *New; 4164 4165 if (Kind == TagDecl::TK_enum) { 4166 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4167 // enum X { A, B, C } D; D should chain to X. 4168 New = EnumDecl::Create(Context, SearchDC, Loc, Name, KWLoc, 4169 cast_or_null<EnumDecl>(PrevDecl)); 4170 // If this is an undefined enum, warn. 4171 if (TUK != TUK_Definition && !Invalid) { 4172 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 4173 : diag::ext_forward_ref_enum; 4174 Diag(Loc, DK); 4175 } 4176 } else { 4177 // struct/union/class 4178 4179 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4180 // struct X { int A; } D; D should chain to X. 4181 if (getLangOptions().CPlusPlus) 4182 // FIXME: Look for a way to use RecordDecl for simple structs. 4183 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4184 cast_or_null<CXXRecordDecl>(PrevDecl)); 4185 else 4186 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4187 cast_or_null<RecordDecl>(PrevDecl)); 4188 } 4189 4190 if (Kind != TagDecl::TK_enum) { 4191 // Handle #pragma pack: if the #pragma pack stack has non-default 4192 // alignment, make up a packed attribute for this decl. These 4193 // attributes are checked when the ASTContext lays out the 4194 // structure. 4195 // 4196 // It is important for implementing the correct semantics that this 4197 // happen here (in act on tag decl). The #pragma pack stack is 4198 // maintained as a result of parser callbacks which can occur at 4199 // many points during the parsing of a struct declaration (because 4200 // the #pragma tokens are effectively skipped over during the 4201 // parsing of the struct). 4202 if (unsigned Alignment = getPragmaPackAlignment()) 4203 New->addAttr(::new (Context) PragmaPackAttr(Alignment * 8)); 4204 } 4205 4206 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 4207 // C++ [dcl.typedef]p3: 4208 // [...] Similarly, in a given scope, a class or enumeration 4209 // shall not be declared with the same name as a typedef-name 4210 // that is declared in that scope and refers to a type other 4211 // than the class or enumeration itself. 4212 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 4213 TypedefDecl *PrevTypedef = 0; 4214 if (Lookup.getKind() == LookupResult::Found) 4215 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 4216 4217 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 4218 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 4219 Context.getCanonicalType(Context.getTypeDeclType(New))) { 4220 Diag(Loc, diag::err_tag_definition_of_typedef) 4221 << Context.getTypeDeclType(New) 4222 << PrevTypedef->getUnderlyingType(); 4223 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 4224 Invalid = true; 4225 } 4226 } 4227 4228 if (Invalid) 4229 New->setInvalidDecl(); 4230 4231 if (Attr) 4232 ProcessDeclAttributeList(S, New, Attr); 4233 4234 // If we're declaring or defining a tag in function prototype scope 4235 // in C, note that this type can only be used within the function. 4236 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 4237 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 4238 4239 // Set the lexical context. If the tag has a C++ scope specifier, the 4240 // lexical context will be different from the semantic context. 4241 New->setLexicalDeclContext(CurContext); 4242 4243 // Set the access specifier. 4244 if (!Invalid && TUK != TUK_Friend) 4245 SetMemberAccessSpecifier(New, PrevDecl, AS); 4246 4247 if (TUK == TUK_Definition) 4248 New->startDefinition(); 4249 4250 // If this has an identifier, add it to the scope stack. 4251 if (Name && TUK != TUK_Friend) { 4252 S = getNonFieldDeclScope(S); 4253 PushOnScopeChains(New, S); 4254 } else { 4255 CurContext->addDecl(New); 4256 } 4257 4258 // If this is the C FILE type, notify the AST context. 4259 if (IdentifierInfo *II = New->getIdentifier()) 4260 if (!New->isInvalidDecl() && 4261 New->getDeclContext()->getLookupContext()->isTranslationUnit() && 4262 II->isStr("FILE")) 4263 Context.setFILEDecl(New); 4264 4265 OwnedDecl = true; 4266 return DeclPtrTy::make(New); 4267} 4268 4269void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 4270 AdjustDeclIfTemplate(TagD); 4271 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4272 4273 // Enter the tag context. 4274 PushDeclContext(S, Tag); 4275 4276 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 4277 FieldCollector->StartClass(); 4278 4279 if (Record->getIdentifier()) { 4280 // C++ [class]p2: 4281 // [...] The class-name is also inserted into the scope of the 4282 // class itself; this is known as the injected-class-name. For 4283 // purposes of access checking, the injected-class-name is treated 4284 // as if it were a public member name. 4285 CXXRecordDecl *InjectedClassName 4286 = CXXRecordDecl::Create(Context, Record->getTagKind(), 4287 CurContext, Record->getLocation(), 4288 Record->getIdentifier(), 4289 Record->getTagKeywordLoc(), 4290 Record); 4291 InjectedClassName->setImplicit(); 4292 InjectedClassName->setAccess(AS_public); 4293 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 4294 InjectedClassName->setDescribedClassTemplate(Template); 4295 PushOnScopeChains(InjectedClassName, S); 4296 assert(InjectedClassName->isInjectedClassName() && 4297 "Broken injected-class-name"); 4298 } 4299 } 4300} 4301 4302void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD, 4303 SourceLocation RBraceLoc) { 4304 AdjustDeclIfTemplate(TagD); 4305 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4306 Tag->setRBraceLoc(RBraceLoc); 4307 4308 if (isa<CXXRecordDecl>(Tag)) 4309 FieldCollector->FinishClass(); 4310 4311 // Exit this scope of this tag's definition. 4312 PopDeclContext(); 4313 4314 // Notify the consumer that we've defined a tag. 4315 Consumer.HandleTagDeclDefinition(Tag); 4316} 4317 4318// Note that FieldName may be null for anonymous bitfields. 4319bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 4320 QualType FieldTy, const Expr *BitWidth) { 4321 4322 // C99 6.7.2.1p4 - verify the field type. 4323 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 4324 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 4325 // Handle incomplete types with specific error. 4326 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 4327 return true; 4328 if (FieldName) 4329 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 4330 << FieldName << FieldTy << BitWidth->getSourceRange(); 4331 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 4332 << FieldTy << BitWidth->getSourceRange(); 4333 } 4334 4335 // If the bit-width is type- or value-dependent, don't try to check 4336 // it now. 4337 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 4338 return false; 4339 4340 llvm::APSInt Value; 4341 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 4342 return true; 4343 4344 // Zero-width bitfield is ok for anonymous field. 4345 if (Value == 0 && FieldName) 4346 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 4347 4348 if (Value.isSigned() && Value.isNegative()) { 4349 if (FieldName) 4350 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 4351 << FieldName << Value.toString(10); 4352 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 4353 << Value.toString(10); 4354 } 4355 4356 if (!FieldTy->isDependentType()) { 4357 uint64_t TypeSize = Context.getTypeSize(FieldTy); 4358 if (Value.getZExtValue() > TypeSize) { 4359 if (FieldName) 4360 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 4361 << FieldName << (unsigned)TypeSize; 4362 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 4363 << (unsigned)TypeSize; 4364 } 4365 } 4366 4367 return false; 4368} 4369 4370/// ActOnField - Each field of a struct/union/class is passed into this in order 4371/// to create a FieldDecl object for it. 4372Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 4373 SourceLocation DeclStart, 4374 Declarator &D, ExprTy *BitfieldWidth) { 4375 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 4376 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 4377 AS_public); 4378 return DeclPtrTy::make(Res); 4379} 4380 4381/// HandleField - Analyze a field of a C struct or a C++ data member. 4382/// 4383FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 4384 SourceLocation DeclStart, 4385 Declarator &D, Expr *BitWidth, 4386 AccessSpecifier AS) { 4387 IdentifierInfo *II = D.getIdentifier(); 4388 SourceLocation Loc = DeclStart; 4389 if (II) Loc = D.getIdentifierLoc(); 4390 4391 QualType T = GetTypeForDeclarator(D, S); 4392 if (getLangOptions().CPlusPlus) 4393 CheckExtraCXXDefaultArguments(D); 4394 4395 DiagnoseFunctionSpecifiers(D); 4396 4397 if (D.getDeclSpec().isThreadSpecified()) 4398 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 4399 4400 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4401 4402 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4403 // Maybe we will complain about the shadowed template parameter. 4404 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 4405 // Just pretend that we didn't see the previous declaration. 4406 PrevDecl = 0; 4407 } 4408 4409 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 4410 PrevDecl = 0; 4411 4412 bool Mutable 4413 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 4414 SourceLocation TSSL = D.getSourceRange().getBegin(); 4415 FieldDecl *NewFD 4416 = CheckFieldDecl(II, T, Record, Loc, Mutable, BitWidth, TSSL, 4417 AS, PrevDecl, &D); 4418 if (NewFD->isInvalidDecl() && PrevDecl) { 4419 // Don't introduce NewFD into scope; there's already something 4420 // with the same name in the same scope. 4421 } else if (II) { 4422 PushOnScopeChains(NewFD, S); 4423 } else 4424 Record->addDecl(NewFD); 4425 4426 return NewFD; 4427} 4428 4429/// \brief Build a new FieldDecl and check its well-formedness. 4430/// 4431/// This routine builds a new FieldDecl given the fields name, type, 4432/// record, etc. \p PrevDecl should refer to any previous declaration 4433/// with the same name and in the same scope as the field to be 4434/// created. 4435/// 4436/// \returns a new FieldDecl. 4437/// 4438/// \todo The Declarator argument is a hack. It will be removed once 4439FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 4440 RecordDecl *Record, SourceLocation Loc, 4441 bool Mutable, Expr *BitWidth, 4442 SourceLocation TSSL, 4443 AccessSpecifier AS, NamedDecl *PrevDecl, 4444 Declarator *D) { 4445 IdentifierInfo *II = Name.getAsIdentifierInfo(); 4446 bool InvalidDecl = false; 4447 if (D) InvalidDecl = D->isInvalidType(); 4448 4449 // If we receive a broken type, recover by assuming 'int' and 4450 // marking this declaration as invalid. 4451 if (T.isNull()) { 4452 InvalidDecl = true; 4453 T = Context.IntTy; 4454 } 4455 4456 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4457 // than a variably modified type. 4458 if (T->isVariablyModifiedType()) { 4459 bool SizeIsNegative; 4460 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 4461 SizeIsNegative); 4462 if (!FixedTy.isNull()) { 4463 Diag(Loc, diag::warn_illegal_constant_array_size); 4464 T = FixedTy; 4465 } else { 4466 if (SizeIsNegative) 4467 Diag(Loc, diag::err_typecheck_negative_array_size); 4468 else 4469 Diag(Loc, diag::err_typecheck_field_variable_size); 4470 InvalidDecl = true; 4471 } 4472 } 4473 4474 // Fields can not have abstract class types 4475 if (RequireNonAbstractType(Loc, T, diag::err_abstract_type_in_decl, 4476 AbstractFieldType)) 4477 InvalidDecl = true; 4478 4479 // If this is declared as a bit-field, check the bit-field. 4480 if (BitWidth && VerifyBitField(Loc, II, T, BitWidth)) { 4481 InvalidDecl = true; 4482 DeleteExpr(BitWidth); 4483 BitWidth = 0; 4484 } 4485 4486 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, BitWidth, 4487 Mutable, TSSL); 4488 if (InvalidDecl) 4489 NewFD->setInvalidDecl(); 4490 4491 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 4492 Diag(Loc, diag::err_duplicate_member) << II; 4493 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4494 NewFD->setInvalidDecl(); 4495 } 4496 4497 if (getLangOptions().CPlusPlus) { 4498 QualType EltTy = Context.getBaseElementType(T); 4499 4500 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 4501 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 4502 4503 if (!RDecl->hasTrivialConstructor()) 4504 cast<CXXRecordDecl>(Record)->setHasTrivialConstructor(false); 4505 if (!RDecl->hasTrivialCopyConstructor()) 4506 cast<CXXRecordDecl>(Record)->setHasTrivialCopyConstructor(false); 4507 if (!RDecl->hasTrivialCopyAssignment()) 4508 cast<CXXRecordDecl>(Record)->setHasTrivialCopyAssignment(false); 4509 if (!RDecl->hasTrivialDestructor()) 4510 cast<CXXRecordDecl>(Record)->setHasTrivialDestructor(false); 4511 4512 // C++ 9.5p1: An object of a class with a non-trivial 4513 // constructor, a non-trivial copy constructor, a non-trivial 4514 // destructor, or a non-trivial copy assignment operator 4515 // cannot be a member of a union, nor can an array of such 4516 // objects. 4517 // TODO: C++0x alters this restriction significantly. 4518 if (Record->isUnion()) { 4519 // We check for copy constructors before constructors 4520 // because otherwise we'll never get complaints about 4521 // copy constructors. 4522 4523 const CXXSpecialMember invalid = (CXXSpecialMember) -1; 4524 4525 CXXSpecialMember member; 4526 if (!RDecl->hasTrivialCopyConstructor()) 4527 member = CXXCopyConstructor; 4528 else if (!RDecl->hasTrivialConstructor()) 4529 member = CXXDefaultConstructor; 4530 else if (!RDecl->hasTrivialCopyAssignment()) 4531 member = CXXCopyAssignment; 4532 else if (!RDecl->hasTrivialDestructor()) 4533 member = CXXDestructor; 4534 else 4535 member = invalid; 4536 4537 if (member != invalid) { 4538 Diag(Loc, diag::err_illegal_union_member) << Name << member; 4539 DiagnoseNontrivial(RT, member); 4540 NewFD->setInvalidDecl(); 4541 } 4542 } 4543 } 4544 } 4545 4546 if (getLangOptions().CPlusPlus && !T->isPODType()) 4547 cast<CXXRecordDecl>(Record)->setPOD(false); 4548 4549 // FIXME: We need to pass in the attributes given an AST 4550 // representation, not a parser representation. 4551 if (D) 4552 // FIXME: What to pass instead of TUScope? 4553 ProcessDeclAttributes(TUScope, NewFD, *D); 4554 4555 if (T.isObjCGCWeak()) 4556 Diag(Loc, diag::warn_attribute_weak_on_field); 4557 4558 NewFD->setAccess(AS); 4559 4560 // C++ [dcl.init.aggr]p1: 4561 // An aggregate is an array or a class (clause 9) with [...] no 4562 // private or protected non-static data members (clause 11). 4563 // A POD must be an aggregate. 4564 if (getLangOptions().CPlusPlus && 4565 (AS == AS_private || AS == AS_protected)) { 4566 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 4567 CXXRecord->setAggregate(false); 4568 CXXRecord->setPOD(false); 4569 } 4570 4571 return NewFD; 4572} 4573 4574/// DiagnoseNontrivial - Given that a class has a non-trivial 4575/// special member, figure out why. 4576void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) { 4577 QualType QT(T, 0U); 4578 CXXRecordDecl* RD = cast<CXXRecordDecl>(T->getDecl()); 4579 4580 // Check whether the member was user-declared. 4581 switch (member) { 4582 case CXXDefaultConstructor: 4583 if (RD->hasUserDeclaredConstructor()) { 4584 typedef CXXRecordDecl::ctor_iterator ctor_iter; 4585 for (ctor_iter ci = RD->ctor_begin(), ce = RD->ctor_end(); ci != ce; ++ci) 4586 if (!ci->isImplicitlyDefined(Context)) { 4587 SourceLocation CtorLoc = ci->getLocation(); 4588 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4589 return; 4590 } 4591 4592 assert(0 && "found no user-declared constructors"); 4593 return; 4594 } 4595 break; 4596 4597 case CXXCopyConstructor: 4598 if (RD->hasUserDeclaredCopyConstructor()) { 4599 SourceLocation CtorLoc = 4600 RD->getCopyConstructor(Context, 0)->getLocation(); 4601 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4602 return; 4603 } 4604 break; 4605 4606 case CXXCopyAssignment: 4607 if (RD->hasUserDeclaredCopyAssignment()) { 4608 // FIXME: this should use the location of the copy 4609 // assignment, not the type. 4610 SourceLocation TyLoc = RD->getSourceRange().getBegin(); 4611 Diag(TyLoc, diag::note_nontrivial_user_defined) << QT << member; 4612 return; 4613 } 4614 break; 4615 4616 case CXXDestructor: 4617 if (RD->hasUserDeclaredDestructor()) { 4618 SourceLocation DtorLoc = RD->getDestructor(Context)->getLocation(); 4619 Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4620 return; 4621 } 4622 break; 4623 } 4624 4625 typedef CXXRecordDecl::base_class_iterator base_iter; 4626 4627 // Virtual bases and members inhibit trivial copying/construction, 4628 // but not trivial destruction. 4629 if (member != CXXDestructor) { 4630 // Check for virtual bases. vbases includes indirect virtual bases, 4631 // so we just iterate through the direct bases. 4632 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) 4633 if (bi->isVirtual()) { 4634 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4635 Diag(BaseLoc, diag::note_nontrivial_has_virtual) << QT << 1; 4636 return; 4637 } 4638 4639 // Check for virtual methods. 4640 typedef CXXRecordDecl::method_iterator meth_iter; 4641 for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; 4642 ++mi) { 4643 if (mi->isVirtual()) { 4644 SourceLocation MLoc = mi->getSourceRange().getBegin(); 4645 Diag(MLoc, diag::note_nontrivial_has_virtual) << QT << 0; 4646 return; 4647 } 4648 } 4649 } 4650 4651 bool (CXXRecordDecl::*hasTrivial)() const; 4652 switch (member) { 4653 case CXXDefaultConstructor: 4654 hasTrivial = &CXXRecordDecl::hasTrivialConstructor; break; 4655 case CXXCopyConstructor: 4656 hasTrivial = &CXXRecordDecl::hasTrivialCopyConstructor; break; 4657 case CXXCopyAssignment: 4658 hasTrivial = &CXXRecordDecl::hasTrivialCopyAssignment; break; 4659 case CXXDestructor: 4660 hasTrivial = &CXXRecordDecl::hasTrivialDestructor; break; 4661 default: 4662 assert(0 && "unexpected special member"); return; 4663 } 4664 4665 // Check for nontrivial bases (and recurse). 4666 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) { 4667 const RecordType *BaseRT = bi->getType()->getAs<RecordType>(); 4668 assert(BaseRT); 4669 CXXRecordDecl *BaseRecTy = cast<CXXRecordDecl>(BaseRT->getDecl()); 4670 if (!(BaseRecTy->*hasTrivial)()) { 4671 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4672 Diag(BaseLoc, diag::note_nontrivial_has_nontrivial) << QT << 1 << member; 4673 DiagnoseNontrivial(BaseRT, member); 4674 return; 4675 } 4676 } 4677 4678 // Check for nontrivial members (and recurse). 4679 typedef RecordDecl::field_iterator field_iter; 4680 for (field_iter fi = RD->field_begin(), fe = RD->field_end(); fi != fe; 4681 ++fi) { 4682 QualType EltTy = Context.getBaseElementType((*fi)->getType()); 4683 if (const RecordType *EltRT = EltTy->getAs<RecordType>()) { 4684 CXXRecordDecl* EltRD = cast<CXXRecordDecl>(EltRT->getDecl()); 4685 4686 if (!(EltRD->*hasTrivial)()) { 4687 SourceLocation FLoc = (*fi)->getLocation(); 4688 Diag(FLoc, diag::note_nontrivial_has_nontrivial) << QT << 0 << member; 4689 DiagnoseNontrivial(EltRT, member); 4690 return; 4691 } 4692 } 4693 } 4694 4695 assert(0 && "found no explanation for non-trivial member"); 4696} 4697 4698/// TranslateIvarVisibility - Translate visibility from a token ID to an 4699/// AST enum value. 4700static ObjCIvarDecl::AccessControl 4701TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 4702 switch (ivarVisibility) { 4703 default: assert(0 && "Unknown visitibility kind"); 4704 case tok::objc_private: return ObjCIvarDecl::Private; 4705 case tok::objc_public: return ObjCIvarDecl::Public; 4706 case tok::objc_protected: return ObjCIvarDecl::Protected; 4707 case tok::objc_package: return ObjCIvarDecl::Package; 4708 } 4709} 4710 4711/// ActOnIvar - Each ivar field of an objective-c class is passed into this 4712/// in order to create an IvarDecl object for it. 4713Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 4714 SourceLocation DeclStart, 4715 DeclPtrTy IntfDecl, 4716 Declarator &D, ExprTy *BitfieldWidth, 4717 tok::ObjCKeywordKind Visibility) { 4718 4719 IdentifierInfo *II = D.getIdentifier(); 4720 Expr *BitWidth = (Expr*)BitfieldWidth; 4721 SourceLocation Loc = DeclStart; 4722 if (II) Loc = D.getIdentifierLoc(); 4723 4724 // FIXME: Unnamed fields can be handled in various different ways, for 4725 // example, unnamed unions inject all members into the struct namespace! 4726 4727 QualType T = GetTypeForDeclarator(D, S); 4728 4729 if (BitWidth) { 4730 // 6.7.2.1p3, 6.7.2.1p4 4731 if (VerifyBitField(Loc, II, T, BitWidth)) { 4732 D.setInvalidType(); 4733 DeleteExpr(BitWidth); 4734 BitWidth = 0; 4735 } 4736 } else { 4737 // Not a bitfield. 4738 4739 // validate II. 4740 4741 } 4742 4743 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4744 // than a variably modified type. 4745 if (T->isVariablyModifiedType()) { 4746 Diag(Loc, diag::err_typecheck_ivar_variable_size); 4747 D.setInvalidType(); 4748 } 4749 4750 // Get the visibility (access control) for this ivar. 4751 ObjCIvarDecl::AccessControl ac = 4752 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 4753 : ObjCIvarDecl::None; 4754 // Must set ivar's DeclContext to its enclosing interface. 4755 Decl *EnclosingDecl = IntfDecl.getAs<Decl>(); 4756 DeclContext *EnclosingContext; 4757 if (ObjCImplementationDecl *IMPDecl = 4758 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4759 // Case of ivar declared in an implementation. Context is that of its class. 4760 ObjCInterfaceDecl* IDecl = IMPDecl->getClassInterface(); 4761 assert(IDecl && "No class- ActOnIvar"); 4762 EnclosingContext = cast_or_null<DeclContext>(IDecl); 4763 } else 4764 EnclosingContext = dyn_cast<DeclContext>(EnclosingDecl); 4765 assert(EnclosingContext && "null DeclContext for ivar - ActOnIvar"); 4766 4767 // Construct the decl. 4768 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, 4769 EnclosingContext, Loc, II, T,ac, 4770 (Expr *)BitfieldWidth); 4771 4772 if (II) { 4773 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4774 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 4775 && !isa<TagDecl>(PrevDecl)) { 4776 Diag(Loc, diag::err_duplicate_member) << II; 4777 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4778 NewID->setInvalidDecl(); 4779 } 4780 } 4781 4782 // Process attributes attached to the ivar. 4783 ProcessDeclAttributes(S, NewID, D); 4784 4785 if (D.isInvalidType()) 4786 NewID->setInvalidDecl(); 4787 4788 if (II) { 4789 // FIXME: When interfaces are DeclContexts, we'll need to add 4790 // these to the interface. 4791 S->AddDecl(DeclPtrTy::make(NewID)); 4792 IdResolver.AddDecl(NewID); 4793 } 4794 4795 return DeclPtrTy::make(NewID); 4796} 4797 4798void Sema::ActOnFields(Scope* S, 4799 SourceLocation RecLoc, DeclPtrTy RecDecl, 4800 DeclPtrTy *Fields, unsigned NumFields, 4801 SourceLocation LBrac, SourceLocation RBrac, 4802 AttributeList *Attr) { 4803 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 4804 assert(EnclosingDecl && "missing record or interface decl"); 4805 4806 // If the decl this is being inserted into is invalid, then it may be a 4807 // redeclaration or some other bogus case. Don't try to add fields to it. 4808 if (EnclosingDecl->isInvalidDecl()) { 4809 // FIXME: Deallocate fields? 4810 return; 4811 } 4812 4813 4814 // Verify that all the fields are okay. 4815 unsigned NumNamedMembers = 0; 4816 llvm::SmallVector<FieldDecl*, 32> RecFields; 4817 4818 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 4819 for (unsigned i = 0; i != NumFields; ++i) { 4820 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 4821 4822 // Get the type for the field. 4823 Type *FDTy = FD->getType().getTypePtr(); 4824 4825 if (!FD->isAnonymousStructOrUnion()) { 4826 // Remember all fields written by the user. 4827 RecFields.push_back(FD); 4828 } 4829 4830 // If the field is already invalid for some reason, don't emit more 4831 // diagnostics about it. 4832 if (FD->isInvalidDecl()) 4833 continue; 4834 4835 // C99 6.7.2.1p2: 4836 // A structure or union shall not contain a member with 4837 // incomplete or function type (hence, a structure shall not 4838 // contain an instance of itself, but may contain a pointer to 4839 // an instance of itself), except that the last member of a 4840 // structure with more than one named member may have incomplete 4841 // array type; such a structure (and any union containing, 4842 // possibly recursively, a member that is such a structure) 4843 // shall not be a member of a structure or an element of an 4844 // array. 4845 if (FDTy->isFunctionType()) { 4846 // Field declared as a function. 4847 Diag(FD->getLocation(), diag::err_field_declared_as_function) 4848 << FD->getDeclName(); 4849 FD->setInvalidDecl(); 4850 EnclosingDecl->setInvalidDecl(); 4851 continue; 4852 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 4853 Record && Record->isStruct()) { 4854 // Flexible array member. 4855 if (NumNamedMembers < 1) { 4856 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 4857 << FD->getDeclName(); 4858 FD->setInvalidDecl(); 4859 EnclosingDecl->setInvalidDecl(); 4860 continue; 4861 } 4862 // Okay, we have a legal flexible array member at the end of the struct. 4863 if (Record) 4864 Record->setHasFlexibleArrayMember(true); 4865 } else if (!FDTy->isDependentType() && 4866 RequireCompleteType(FD->getLocation(), FD->getType(), 4867 diag::err_field_incomplete)) { 4868 // Incomplete type 4869 FD->setInvalidDecl(); 4870 EnclosingDecl->setInvalidDecl(); 4871 continue; 4872 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) { 4873 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 4874 // If this is a member of a union, then entire union becomes "flexible". 4875 if (Record && Record->isUnion()) { 4876 Record->setHasFlexibleArrayMember(true); 4877 } else { 4878 // If this is a struct/class and this is not the last element, reject 4879 // it. Note that GCC supports variable sized arrays in the middle of 4880 // structures. 4881 if (i != NumFields-1) 4882 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 4883 << FD->getDeclName() << FD->getType(); 4884 else { 4885 // We support flexible arrays at the end of structs in 4886 // other structs as an extension. 4887 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 4888 << FD->getDeclName(); 4889 if (Record) 4890 Record->setHasFlexibleArrayMember(true); 4891 } 4892 } 4893 } 4894 if (Record && FDTTy->getDecl()->hasObjectMember()) 4895 Record->setHasObjectMember(true); 4896 } else if (FDTy->isObjCInterfaceType()) { 4897 /// A field cannot be an Objective-c object 4898 Diag(FD->getLocation(), diag::err_statically_allocated_object); 4899 FD->setInvalidDecl(); 4900 EnclosingDecl->setInvalidDecl(); 4901 continue; 4902 } else if (getLangOptions().ObjC1 && 4903 getLangOptions().getGCMode() != LangOptions::NonGC && 4904 Record && 4905 (FD->getType()->isObjCObjectPointerType() || 4906 FD->getType().isObjCGCStrong())) 4907 Record->setHasObjectMember(true); 4908 // Keep track of the number of named members. 4909 if (FD->getIdentifier()) 4910 ++NumNamedMembers; 4911 } 4912 4913 // Okay, we successfully defined 'Record'. 4914 if (Record) { 4915 Record->completeDefinition(Context); 4916 } else { 4917 ObjCIvarDecl **ClsFields = 4918 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 4919 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 4920 ID->setIVarList(ClsFields, RecFields.size(), Context); 4921 ID->setLocEnd(RBrac); 4922 // Add ivar's to class's DeclContext. 4923 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 4924 ClsFields[i]->setLexicalDeclContext(ID); 4925 ID->addDecl(ClsFields[i]); 4926 } 4927 // Must enforce the rule that ivars in the base classes may not be 4928 // duplicates. 4929 if (ID->getSuperClass()) { 4930 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 4931 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 4932 ObjCIvarDecl* Ivar = (*IVI); 4933 4934 if (IdentifierInfo *II = Ivar->getIdentifier()) { 4935 ObjCIvarDecl* prevIvar = 4936 ID->getSuperClass()->lookupInstanceVariable(II); 4937 if (prevIvar) { 4938 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 4939 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 4940 } 4941 } 4942 } 4943 } 4944 } else if (ObjCImplementationDecl *IMPDecl = 4945 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4946 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 4947 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 4948 // Ivar declared in @implementation never belongs to the implementation. 4949 // Only it is in implementation's lexical context. 4950 ClsFields[I]->setLexicalDeclContext(IMPDecl); 4951 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 4952 } 4953 } 4954 4955 if (Attr) 4956 ProcessDeclAttributeList(S, Record, Attr); 4957} 4958 4959EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 4960 EnumConstantDecl *LastEnumConst, 4961 SourceLocation IdLoc, 4962 IdentifierInfo *Id, 4963 ExprArg val) { 4964 Expr *Val = (Expr *)val.get(); 4965 4966 llvm::APSInt EnumVal(32); 4967 QualType EltTy; 4968 if (Val && !Val->isTypeDependent()) { 4969 // Make sure to promote the operand type to int. 4970 UsualUnaryConversions(Val); 4971 if (Val != val.get()) { 4972 val.release(); 4973 val = Val; 4974 } 4975 4976 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 4977 SourceLocation ExpLoc; 4978 if (!Val->isValueDependent() && 4979 VerifyIntegerConstantExpression(Val, &EnumVal)) { 4980 Val = 0; 4981 } else { 4982 EltTy = Val->getType(); 4983 } 4984 } 4985 4986 if (!Val) { 4987 if (LastEnumConst) { 4988 // Assign the last value + 1. 4989 EnumVal = LastEnumConst->getInitVal(); 4990 ++EnumVal; 4991 4992 // Check for overflow on increment. 4993 if (EnumVal < LastEnumConst->getInitVal()) 4994 Diag(IdLoc, diag::warn_enum_value_overflow); 4995 4996 EltTy = LastEnumConst->getType(); 4997 } else { 4998 // First value, set to zero. 4999 EltTy = Context.IntTy; 5000 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 5001 } 5002 } 5003 5004 val.release(); 5005 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 5006 Val, EnumVal); 5007} 5008 5009 5010Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 5011 DeclPtrTy lastEnumConst, 5012 SourceLocation IdLoc, 5013 IdentifierInfo *Id, 5014 SourceLocation EqualLoc, ExprTy *val) { 5015 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 5016 EnumConstantDecl *LastEnumConst = 5017 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 5018 Expr *Val = static_cast<Expr*>(val); 5019 5020 // The scope passed in may not be a decl scope. Zip up the scope tree until 5021 // we find one that is. 5022 S = getNonFieldDeclScope(S); 5023 5024 // Verify that there isn't already something declared with this name in this 5025 // scope. 5026 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 5027 if (PrevDecl && PrevDecl->isTemplateParameter()) { 5028 // Maybe we will complain about the shadowed template parameter. 5029 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 5030 // Just pretend that we didn't see the previous declaration. 5031 PrevDecl = 0; 5032 } 5033 5034 if (PrevDecl) { 5035 // When in C++, we may get a TagDecl with the same name; in this case the 5036 // enum constant will 'hide' the tag. 5037 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 5038 "Received TagDecl when not in C++!"); 5039 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 5040 if (isa<EnumConstantDecl>(PrevDecl)) 5041 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 5042 else 5043 Diag(IdLoc, diag::err_redefinition) << Id; 5044 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 5045 if (Val) Val->Destroy(Context); 5046 return DeclPtrTy(); 5047 } 5048 } 5049 5050 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 5051 IdLoc, Id, Owned(Val)); 5052 5053 // Register this decl in the current scope stack. 5054 if (New) 5055 PushOnScopeChains(New, S); 5056 5057 return DeclPtrTy::make(New); 5058} 5059 5060void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 5061 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 5062 DeclPtrTy *Elements, unsigned NumElements, 5063 Scope *S, AttributeList *Attr) { 5064 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 5065 QualType EnumType = Context.getTypeDeclType(Enum); 5066 5067 if (Attr) 5068 ProcessDeclAttributeList(S, Enum, Attr); 5069 5070 // TODO: If the result value doesn't fit in an int, it must be a long or long 5071 // long value. ISO C does not support this, but GCC does as an extension, 5072 // emit a warning. 5073 unsigned IntWidth = Context.Target.getIntWidth(); 5074 unsigned CharWidth = Context.Target.getCharWidth(); 5075 unsigned ShortWidth = Context.Target.getShortWidth(); 5076 5077 // Verify that all the values are okay, compute the size of the values, and 5078 // reverse the list. 5079 unsigned NumNegativeBits = 0; 5080 unsigned NumPositiveBits = 0; 5081 5082 // Keep track of whether all elements have type int. 5083 bool AllElementsInt = true; 5084 5085 for (unsigned i = 0; i != NumElements; ++i) { 5086 EnumConstantDecl *ECD = 5087 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5088 if (!ECD) continue; // Already issued a diagnostic. 5089 5090 // If the enum value doesn't fit in an int, emit an extension warning. 5091 const llvm::APSInt &InitVal = ECD->getInitVal(); 5092 assert(InitVal.getBitWidth() >= IntWidth && 5093 "Should have promoted value to int"); 5094 if (InitVal.getBitWidth() > IntWidth) { 5095 llvm::APSInt V(InitVal); 5096 V.trunc(IntWidth); 5097 V.extend(InitVal.getBitWidth()); 5098 if (V != InitVal) 5099 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 5100 << InitVal.toString(10); 5101 } 5102 5103 // Keep track of the size of positive and negative values. 5104 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 5105 NumPositiveBits = std::max(NumPositiveBits, 5106 (unsigned)InitVal.getActiveBits()); 5107 else 5108 NumNegativeBits = std::max(NumNegativeBits, 5109 (unsigned)InitVal.getMinSignedBits()); 5110 5111 // Keep track of whether every enum element has type int (very commmon). 5112 if (AllElementsInt) 5113 AllElementsInt = ECD->getType() == Context.IntTy; 5114 } 5115 5116 // Figure out the type that should be used for this enum. 5117 // FIXME: Support -fshort-enums. 5118 QualType BestType; 5119 unsigned BestWidth; 5120 5121 bool Packed = Enum->getAttr<PackedAttr>() ? true : false; 5122 5123 if (NumNegativeBits) { 5124 // If there is a negative value, figure out the smallest integer type (of 5125 // int/long/longlong) that fits. 5126 // If it's packed, check also if it fits a char or a short. 5127 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) { 5128 BestType = Context.SignedCharTy; 5129 BestWidth = CharWidth; 5130 } else if (Packed && NumNegativeBits <= ShortWidth && 5131 NumPositiveBits < ShortWidth) { 5132 BestType = Context.ShortTy; 5133 BestWidth = ShortWidth; 5134 } 5135 else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 5136 BestType = Context.IntTy; 5137 BestWidth = IntWidth; 5138 } else { 5139 BestWidth = Context.Target.getLongWidth(); 5140 5141 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 5142 BestType = Context.LongTy; 5143 else { 5144 BestWidth = Context.Target.getLongLongWidth(); 5145 5146 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 5147 Diag(Enum->getLocation(), diag::warn_enum_too_large); 5148 BestType = Context.LongLongTy; 5149 } 5150 } 5151 } else { 5152 // If there is no negative value, figure out which of uint, ulong, ulonglong 5153 // fits. 5154 // If it's packed, check also if it fits a char or a short. 5155 if (Packed && NumPositiveBits <= CharWidth) { 5156 BestType = Context.UnsignedCharTy; 5157 BestWidth = CharWidth; 5158 } else if (Packed && NumPositiveBits <= ShortWidth) { 5159 BestType = Context.UnsignedShortTy; 5160 BestWidth = ShortWidth; 5161 } 5162 else if (NumPositiveBits <= IntWidth) { 5163 BestType = Context.UnsignedIntTy; 5164 BestWidth = IntWidth; 5165 } else if (NumPositiveBits <= 5166 (BestWidth = Context.Target.getLongWidth())) { 5167 BestType = Context.UnsignedLongTy; 5168 } else { 5169 BestWidth = Context.Target.getLongLongWidth(); 5170 assert(NumPositiveBits <= BestWidth && 5171 "How could an initializer get larger than ULL?"); 5172 BestType = Context.UnsignedLongLongTy; 5173 } 5174 } 5175 5176 // Loop over all of the enumerator constants, changing their types to match 5177 // the type of the enum if needed. 5178 for (unsigned i = 0; i != NumElements; ++i) { 5179 EnumConstantDecl *ECD = 5180 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5181 if (!ECD) continue; // Already issued a diagnostic. 5182 5183 // Standard C says the enumerators have int type, but we allow, as an 5184 // extension, the enumerators to be larger than int size. If each 5185 // enumerator value fits in an int, type it as an int, otherwise type it the 5186 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 5187 // that X has type 'int', not 'unsigned'. 5188 if (ECD->getType() == Context.IntTy) { 5189 // Make sure the init value is signed. 5190 llvm::APSInt IV = ECD->getInitVal(); 5191 IV.setIsSigned(true); 5192 ECD->setInitVal(IV); 5193 5194 if (getLangOptions().CPlusPlus) 5195 // C++ [dcl.enum]p4: Following the closing brace of an 5196 // enum-specifier, each enumerator has the type of its 5197 // enumeration. 5198 ECD->setType(EnumType); 5199 continue; // Already int type. 5200 } 5201 5202 // Determine whether the value fits into an int. 5203 llvm::APSInt InitVal = ECD->getInitVal(); 5204 bool FitsInInt; 5205 if (InitVal.isUnsigned() || !InitVal.isNegative()) 5206 FitsInInt = InitVal.getActiveBits() < IntWidth; 5207 else 5208 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 5209 5210 // If it fits into an integer type, force it. Otherwise force it to match 5211 // the enum decl type. 5212 QualType NewTy; 5213 unsigned NewWidth; 5214 bool NewSign; 5215 if (FitsInInt) { 5216 NewTy = Context.IntTy; 5217 NewWidth = IntWidth; 5218 NewSign = true; 5219 } else if (ECD->getType() == BestType) { 5220 // Already the right type! 5221 if (getLangOptions().CPlusPlus) 5222 // C++ [dcl.enum]p4: Following the closing brace of an 5223 // enum-specifier, each enumerator has the type of its 5224 // enumeration. 5225 ECD->setType(EnumType); 5226 continue; 5227 } else { 5228 NewTy = BestType; 5229 NewWidth = BestWidth; 5230 NewSign = BestType->isSignedIntegerType(); 5231 } 5232 5233 // Adjust the APSInt value. 5234 InitVal.extOrTrunc(NewWidth); 5235 InitVal.setIsSigned(NewSign); 5236 ECD->setInitVal(InitVal); 5237 5238 // Adjust the Expr initializer and type. 5239 if (ECD->getInitExpr()) 5240 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, 5241 CastExpr::CK_Unknown, 5242 ECD->getInitExpr(), 5243 /*isLvalue=*/false)); 5244 if (getLangOptions().CPlusPlus) 5245 // C++ [dcl.enum]p4: Following the closing brace of an 5246 // enum-specifier, each enumerator has the type of its 5247 // enumeration. 5248 ECD->setType(EnumType); 5249 else 5250 ECD->setType(NewTy); 5251 } 5252 5253 Enum->completeDefinition(Context, BestType); 5254} 5255 5256Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 5257 ExprArg expr) { 5258 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 5259 5260 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 5261 Loc, AsmString); 5262 CurContext->addDecl(New); 5263 return DeclPtrTy::make(New); 5264} 5265 5266void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 5267 SourceLocation PragmaLoc, 5268 SourceLocation NameLoc) { 5269 Decl *PrevDecl = LookupName(TUScope, Name, LookupOrdinaryName); 5270 5271 if (PrevDecl) { 5272 PrevDecl->addAttr(::new (Context) WeakAttr()); 5273 } else { 5274 (void)WeakUndeclaredIdentifiers.insert( 5275 std::pair<IdentifierInfo*,WeakInfo> 5276 (Name, WeakInfo((IdentifierInfo*)0, NameLoc))); 5277 } 5278} 5279 5280void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 5281 IdentifierInfo* AliasName, 5282 SourceLocation PragmaLoc, 5283 SourceLocation NameLoc, 5284 SourceLocation AliasNameLoc) { 5285 Decl *PrevDecl = LookupName(TUScope, AliasName, LookupOrdinaryName); 5286 WeakInfo W = WeakInfo(Name, NameLoc); 5287 5288 if (PrevDecl) { 5289 if (!PrevDecl->hasAttr<AliasAttr>()) 5290 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl)) 5291 DeclApplyPragmaWeak(TUScope, ND, W); 5292 } else { 5293 (void)WeakUndeclaredIdentifiers.insert( 5294 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W)); 5295 } 5296} 5297