SemaDecl.cpp revision 4d9d51ae3b868268082f94d84d0dff4c0b1ad435
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/SmallSet.h" 33#include "llvm/ADT/STLExtras.h" 34#include <algorithm> 35#include <functional> 36#include <queue> 37using namespace clang; 38 39/// getDeclName - Return a pretty name for the specified decl if possible, or 40/// an empty string if not. This is used for pretty crash reporting. 41std::string Sema::getDeclName(DeclPtrTy d) { 42 Decl *D = d.getAs<Decl>(); 43 if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D)) 44 return DN->getQualifiedNameAsString(); 45 return ""; 46} 47 48Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) { 49 return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>())); 50} 51 52/// \brief If the identifier refers to a type name within this scope, 53/// return the declaration of that type. 54/// 55/// This routine performs ordinary name lookup of the identifier II 56/// within the given scope, with optional C++ scope specifier SS, to 57/// determine whether the name refers to a type. If so, returns an 58/// opaque pointer (actually a QualType) corresponding to that 59/// type. Otherwise, returns NULL. 60/// 61/// If name lookup results in an ambiguity, this routine will complain 62/// and then return NULL. 63Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 64 Scope *S, const CXXScopeSpec *SS) { 65 // C++ [temp.res]p3: 66 // A qualified-id that refers to a type and in which the 67 // nested-name-specifier depends on a template-parameter (14.6.2) 68 // shall be prefixed by the keyword typename to indicate that the 69 // qualified-id denotes a type, forming an 70 // elaborated-type-specifier (7.1.5.3). 71 // 72 // We therefore do not perform any name lookup if the result would 73 // refer to a member of an unknown specialization. 74 if (SS && isUnknownSpecialization(*SS)) 75 return 0; 76 77 LookupResult Result 78 = LookupParsedName(S, SS, &II, LookupOrdinaryName, false, false); 79 80 NamedDecl *IIDecl = 0; 81 switch (Result.getKind()) { 82 case LookupResult::NotFound: 83 case LookupResult::FoundOverloaded: 84 return 0; 85 86 case LookupResult::AmbiguousBaseSubobjectTypes: 87 case LookupResult::AmbiguousBaseSubobjects: 88 case LookupResult::AmbiguousReference: { 89 // Look to see if we have a type anywhere in the list of results. 90 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); 91 Res != ResEnd; ++Res) { 92 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) { 93 if (!IIDecl || 94 (*Res)->getLocation().getRawEncoding() < 95 IIDecl->getLocation().getRawEncoding()) 96 IIDecl = *Res; 97 } 98 } 99 100 if (!IIDecl) { 101 // None of the entities we found is a type, so there is no way 102 // to even assume that the result is a type. In this case, don't 103 // complain about the ambiguity. The parser will either try to 104 // perform this lookup again (e.g., as an object name), which 105 // will produce the ambiguity, or will complain that it expected 106 // a type name. 107 Result.Destroy(); 108 return 0; 109 } 110 111 // We found a type within the ambiguous lookup; diagnose the 112 // ambiguity and then return that type. This might be the right 113 // answer, or it might not be, but it suppresses any attempt to 114 // perform the name lookup again. 115 DiagnoseAmbiguousLookup(Result, DeclarationName(&II), NameLoc); 116 break; 117 } 118 119 case LookupResult::Found: 120 IIDecl = Result.getAsDecl(); 121 break; 122 } 123 124 if (IIDecl) { 125 QualType T; 126 127 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 128 // Check whether we can use this type 129 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 130 131 if (getLangOptions().CPlusPlus) { 132 // C++ [temp.local]p2: 133 // Within the scope of a class template specialization or 134 // partial specialization, when the injected-class-name is 135 // not followed by a <, it is equivalent to the 136 // injected-class-name followed by the template-argument s 137 // of the class template specialization or partial 138 // specialization enclosed in <>. 139 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) 140 if (RD->isInjectedClassName()) 141 if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate()) 142 T = Template->getInjectedClassNameType(Context); 143 } 144 145 if (T.isNull()) 146 T = Context.getTypeDeclType(TD); 147 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 148 // Check whether we can use this interface. 149 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 150 151 T = Context.getObjCInterfaceType(IDecl); 152 } else 153 return 0; 154 155 if (SS) 156 T = getQualifiedNameType(*SS, T); 157 158 return T.getAsOpaquePtr(); 159 } 160 161 return 0; 162} 163 164/// isTagName() - This method is called *for error recovery purposes only* 165/// to determine if the specified name is a valid tag name ("struct foo"). If 166/// so, this returns the TST for the tag corresponding to it (TST_enum, 167/// TST_union, TST_struct, TST_class). This is used to diagnose cases in C 168/// where the user forgot to specify the tag. 169DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { 170 // Do a tag name lookup in this scope. 171 LookupResult R = LookupName(S, &II, LookupTagName, false, false); 172 if (R.getKind() == LookupResult::Found) 173 if (const TagDecl *TD = dyn_cast<TagDecl>(R.getAsDecl())) { 174 switch (TD->getTagKind()) { 175 case TagDecl::TK_struct: return DeclSpec::TST_struct; 176 case TagDecl::TK_union: return DeclSpec::TST_union; 177 case TagDecl::TK_class: return DeclSpec::TST_class; 178 case TagDecl::TK_enum: return DeclSpec::TST_enum; 179 } 180 } 181 182 return DeclSpec::TST_unspecified; 183} 184 185 186 187DeclContext *Sema::getContainingDC(DeclContext *DC) { 188 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 189 // A C++ out-of-line method will return to the file declaration context. 190 if (MD->isOutOfLine()) 191 return MD->getLexicalDeclContext(); 192 193 // A C++ inline method is parsed *after* the topmost class it was declared 194 // in is fully parsed (it's "complete"). 195 // The parsing of a C++ inline method happens at the declaration context of 196 // the topmost (non-nested) class it is lexically declared in. 197 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 198 DC = MD->getParent(); 199 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 200 DC = RD; 201 202 // Return the declaration context of the topmost class the inline method is 203 // declared in. 204 return DC; 205 } 206 207 if (isa<ObjCMethodDecl>(DC)) 208 return Context.getTranslationUnitDecl(); 209 210 return DC->getLexicalParent(); 211} 212 213void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 214 assert(getContainingDC(DC) == CurContext && 215 "The next DeclContext should be lexically contained in the current one."); 216 CurContext = DC; 217 S->setEntity(DC); 218} 219 220void Sema::PopDeclContext() { 221 assert(CurContext && "DeclContext imbalance!"); 222 223 CurContext = getContainingDC(CurContext); 224} 225 226/// EnterDeclaratorContext - Used when we must lookup names in the context 227/// of a declarator's nested name specifier. 228void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { 229 assert(PreDeclaratorDC == 0 && "Previous declarator context not popped?"); 230 PreDeclaratorDC = static_cast<DeclContext*>(S->getEntity()); 231 CurContext = DC; 232 assert(CurContext && "No context?"); 233 S->setEntity(CurContext); 234} 235 236void Sema::ExitDeclaratorContext(Scope *S) { 237 S->setEntity(PreDeclaratorDC); 238 PreDeclaratorDC = 0; 239 240 // Reset CurContext to the nearest enclosing context. 241 while (!S->getEntity() && S->getParent()) 242 S = S->getParent(); 243 CurContext = static_cast<DeclContext*>(S->getEntity()); 244 assert(CurContext && "No context?"); 245} 246 247/// \brief Determine whether we allow overloading of the function 248/// PrevDecl with another declaration. 249/// 250/// This routine determines whether overloading is possible, not 251/// whether some new function is actually an overload. It will return 252/// true in C++ (where we can always provide overloads) or, as an 253/// extension, in C when the previous function is already an 254/// overloaded function declaration or has the "overloadable" 255/// attribute. 256static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) { 257 if (Context.getLangOptions().CPlusPlus) 258 return true; 259 260 if (isa<OverloadedFunctionDecl>(PrevDecl)) 261 return true; 262 263 return PrevDecl->getAttr<OverloadableAttr>() != 0; 264} 265 266/// Add this decl to the scope shadowed decl chains. 267void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 268 // Move up the scope chain until we find the nearest enclosing 269 // non-transparent context. The declaration will be introduced into this 270 // scope. 271 while (S->getEntity() && 272 ((DeclContext *)S->getEntity())->isTransparentContext()) 273 S = S->getParent(); 274 275 S->AddDecl(DeclPtrTy::make(D)); 276 277 // Add scoped declarations into their context, so that they can be 278 // found later. Declarations without a context won't be inserted 279 // into any context. 280 CurContext->addDecl(D); 281 282 // C++ [basic.scope]p4: 283 // -- exactly one declaration shall declare a class name or 284 // enumeration name that is not a typedef name and the other 285 // declarations shall all refer to the same object or 286 // enumerator, or all refer to functions and function templates; 287 // in this case the class name or enumeration name is hidden. 288 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 289 // We are pushing the name of a tag (enum or class). 290 if (CurContext->getLookupContext() 291 == TD->getDeclContext()->getLookupContext()) { 292 // We're pushing the tag into the current context, which might 293 // require some reshuffling in the identifier resolver. 294 IdentifierResolver::iterator 295 I = IdResolver.begin(TD->getDeclName()), 296 IEnd = IdResolver.end(); 297 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 298 NamedDecl *PrevDecl = *I; 299 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 300 PrevDecl = *I, ++I) { 301 if (TD->declarationReplaces(*I)) { 302 // This is a redeclaration. Remove it from the chain and 303 // break out, so that we'll add in the shadowed 304 // declaration. 305 S->RemoveDecl(DeclPtrTy::make(*I)); 306 if (PrevDecl == *I) { 307 IdResolver.RemoveDecl(*I); 308 IdResolver.AddDecl(TD); 309 return; 310 } else { 311 IdResolver.RemoveDecl(*I); 312 break; 313 } 314 } 315 } 316 317 // There is already a declaration with the same name in the same 318 // scope, which is not a tag declaration. It must be found 319 // before we find the new declaration, so insert the new 320 // declaration at the end of the chain. 321 IdResolver.AddShadowedDecl(TD, PrevDecl); 322 323 return; 324 } 325 } 326 } else if ((isa<FunctionDecl>(D) && 327 AllowOverloadingOfFunction(D, Context)) || 328 isa<FunctionTemplateDecl>(D)) { 329 // We are pushing the name of a function or function template, 330 // which might be an overloaded name. 331 IdentifierResolver::iterator Redecl 332 = std::find_if(IdResolver.begin(D->getDeclName()), 333 IdResolver.end(), 334 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 335 D)); 336 if (Redecl != IdResolver.end() && 337 S->isDeclScope(DeclPtrTy::make(*Redecl))) { 338 // There is already a declaration of a function on our 339 // IdResolver chain. Replace it with this declaration. 340 S->RemoveDecl(DeclPtrTy::make(*Redecl)); 341 IdResolver.RemoveDecl(*Redecl); 342 } 343 } else if (isa<ObjCInterfaceDecl>(D)) { 344 // We're pushing an Objective-C interface into the current 345 // context. If there is already an alias declaration, remove it first. 346 for (IdentifierResolver::iterator 347 I = IdResolver.begin(D->getDeclName()), IEnd = IdResolver.end(); 348 I != IEnd; ++I) { 349 if (isa<ObjCCompatibleAliasDecl>(*I)) { 350 S->RemoveDecl(DeclPtrTy::make(*I)); 351 IdResolver.RemoveDecl(*I); 352 break; 353 } 354 } 355 } 356 357 IdResolver.AddDecl(D); 358} 359 360void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 361 if (S->decl_empty()) return; 362 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 363 "Scope shouldn't contain decls!"); 364 365 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 366 I != E; ++I) { 367 Decl *TmpD = (*I).getAs<Decl>(); 368 assert(TmpD && "This decl didn't get pushed??"); 369 370 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 371 NamedDecl *D = cast<NamedDecl>(TmpD); 372 373 if (!D->getDeclName()) continue; 374 375 // Remove this name from our lexical scope. 376 IdResolver.RemoveDecl(D); 377 } 378} 379 380/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 381/// return 0 if one not found. 382ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 383 // The third "scope" argument is 0 since we aren't enabling lazy built-in 384 // creation from this context. 385 NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName); 386 387 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 388} 389 390/// getNonFieldDeclScope - Retrieves the innermost scope, starting 391/// from S, where a non-field would be declared. This routine copes 392/// with the difference between C and C++ scoping rules in structs and 393/// unions. For example, the following code is well-formed in C but 394/// ill-formed in C++: 395/// @code 396/// struct S6 { 397/// enum { BAR } e; 398/// }; 399/// 400/// void test_S6() { 401/// struct S6 a; 402/// a.e = BAR; 403/// } 404/// @endcode 405/// For the declaration of BAR, this routine will return a different 406/// scope. The scope S will be the scope of the unnamed enumeration 407/// within S6. In C++, this routine will return the scope associated 408/// with S6, because the enumeration's scope is a transparent 409/// context but structures can contain non-field names. In C, this 410/// routine will return the translation unit scope, since the 411/// enumeration's scope is a transparent context and structures cannot 412/// contain non-field names. 413Scope *Sema::getNonFieldDeclScope(Scope *S) { 414 while (((S->getFlags() & Scope::DeclScope) == 0) || 415 (S->getEntity() && 416 ((DeclContext *)S->getEntity())->isTransparentContext()) || 417 (S->isClassScope() && !getLangOptions().CPlusPlus)) 418 S = S->getParent(); 419 return S; 420} 421 422void Sema::InitBuiltinVaListType() { 423 if (!Context.getBuiltinVaListType().isNull()) 424 return; 425 426 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 427 NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName); 428 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 429 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 430} 431 432/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 433/// file scope. lazily create a decl for it. ForRedeclaration is true 434/// if we're creating this built-in in anticipation of redeclaring the 435/// built-in. 436NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 437 Scope *S, bool ForRedeclaration, 438 SourceLocation Loc) { 439 Builtin::ID BID = (Builtin::ID)bid; 440 441 if (Context.BuiltinInfo.hasVAListUse(BID)) 442 InitBuiltinVaListType(); 443 444 ASTContext::GetBuiltinTypeError Error; 445 QualType R = Context.GetBuiltinType(BID, Error); 446 switch (Error) { 447 case ASTContext::GE_None: 448 // Okay 449 break; 450 451 case ASTContext::GE_Missing_FILE: 452 if (ForRedeclaration) 453 Diag(Loc, diag::err_implicit_decl_requires_stdio) 454 << Context.BuiltinInfo.GetName(BID); 455 return 0; 456 457 case ASTContext::GE_Missing_jmp_buf: 458 if (ForRedeclaration) 459 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 460 << Context.BuiltinInfo.GetName(BID); 461 return 0; 462 463 case ASTContext::GE_Missing_sigjmp_buf: 464 if (ForRedeclaration) 465 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 466 << Context.BuiltinInfo.GetName(BID); 467 return 0; 468 } 469 470 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 471 Diag(Loc, diag::ext_implicit_lib_function_decl) 472 << Context.BuiltinInfo.GetName(BID) 473 << R; 474 if (Context.BuiltinInfo.getHeaderName(BID) && 475 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 476 != Diagnostic::Ignored) 477 Diag(Loc, diag::note_please_include_header) 478 << Context.BuiltinInfo.getHeaderName(BID) 479 << Context.BuiltinInfo.GetName(BID); 480 } 481 482 FunctionDecl *New = FunctionDecl::Create(Context, 483 Context.getTranslationUnitDecl(), 484 Loc, II, R, 485 FunctionDecl::Extern, false, 486 /*hasPrototype=*/true); 487 New->setImplicit(); 488 489 // Create Decl objects for each parameter, adding them to the 490 // FunctionDecl. 491 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 492 llvm::SmallVector<ParmVarDecl*, 16> Params; 493 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 494 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 495 FT->getArgType(i), VarDecl::None, 0)); 496 New->setParams(Context, Params.data(), Params.size()); 497 } 498 499 AddKnownFunctionAttributes(New); 500 501 // TUScope is the translation-unit scope to insert this function into. 502 // FIXME: This is hideous. We need to teach PushOnScopeChains to 503 // relate Scopes to DeclContexts, and probably eliminate CurContext 504 // entirely, but we're not there yet. 505 DeclContext *SavedContext = CurContext; 506 CurContext = Context.getTranslationUnitDecl(); 507 PushOnScopeChains(New, TUScope); 508 CurContext = SavedContext; 509 return New; 510} 511 512/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 513/// everything from the standard library is defined. 514NamespaceDecl *Sema::GetStdNamespace() { 515 if (!StdNamespace) { 516 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 517 DeclContext *Global = Context.getTranslationUnitDecl(); 518 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 519 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 520 } 521 return StdNamespace; 522} 523 524/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 525/// same name and scope as a previous declaration 'Old'. Figure out 526/// how to resolve this situation, merging decls or emitting 527/// diagnostics as appropriate. If there was an error, set New to be invalid. 528/// 529void Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 530 // If either decl is known invalid already, set the new one to be invalid and 531 // don't bother doing any merging checks. 532 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 533 return New->setInvalidDecl(); 534 535 // Allow multiple definitions for ObjC built-in typedefs. 536 // FIXME: Verify the underlying types are equivalent! 537 if (getLangOptions().ObjC1) { 538 const IdentifierInfo *TypeID = New->getIdentifier(); 539 switch (TypeID->getLength()) { 540 default: break; 541 case 2: 542 if (!TypeID->isStr("id")) 543 break; 544 // Install the built-in type for 'id', ignoring the current definition. 545 New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); 546 return; 547 case 5: 548 if (!TypeID->isStr("Class")) 549 break; 550 // Install the built-in type for 'Class', ignoring the current definition. 551 New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); 552 return; 553 case 3: 554 if (!TypeID->isStr("SEL")) 555 break; 556 Context.setObjCSelType(Context.getTypeDeclType(New)); 557 return; 558 case 8: 559 if (!TypeID->isStr("Protocol")) 560 break; 561 Context.setObjCProtoType(New->getUnderlyingType()); 562 return; 563 } 564 // Fall through - the typedef name was not a builtin type. 565 } 566 // Verify the old decl was also a type. 567 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 568 if (!Old) { 569 Diag(New->getLocation(), diag::err_redefinition_different_kind) 570 << New->getDeclName(); 571 if (OldD->getLocation().isValid()) 572 Diag(OldD->getLocation(), diag::note_previous_definition); 573 return New->setInvalidDecl(); 574 } 575 576 // Determine the "old" type we'll use for checking and diagnostics. 577 QualType OldType; 578 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 579 OldType = OldTypedef->getUnderlyingType(); 580 else 581 OldType = Context.getTypeDeclType(Old); 582 583 // If the typedef types are not identical, reject them in all languages and 584 // with any extensions enabled. 585 586 if (OldType != New->getUnderlyingType() && 587 Context.getCanonicalType(OldType) != 588 Context.getCanonicalType(New->getUnderlyingType())) { 589 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 590 << New->getUnderlyingType() << OldType; 591 if (Old->getLocation().isValid()) 592 Diag(Old->getLocation(), diag::note_previous_definition); 593 return New->setInvalidDecl(); 594 } 595 596 if (getLangOptions().Microsoft) 597 return; 598 599 // C++ [dcl.typedef]p2: 600 // In a given non-class scope, a typedef specifier can be used to 601 // redefine the name of any type declared in that scope to refer 602 // to the type to which it already refers. 603 if (getLangOptions().CPlusPlus) { 604 if (!isa<CXXRecordDecl>(CurContext)) 605 return; 606 Diag(New->getLocation(), diag::err_redefinition) 607 << New->getDeclName(); 608 Diag(Old->getLocation(), diag::note_previous_definition); 609 return New->setInvalidDecl(); 610 } 611 612 // If we have a redefinition of a typedef in C, emit a warning. This warning 613 // is normally mapped to an error, but can be controlled with 614 // -Wtypedef-redefinition. If either the original or the redefinition is 615 // in a system header, don't emit this for compatibility with GCC. 616 if (PP.getDiagnostics().getSuppressSystemWarnings() && 617 (Context.getSourceManager().isInSystemHeader(Old->getLocation()) || 618 Context.getSourceManager().isInSystemHeader(New->getLocation()))) 619 return; 620 621 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 622 << New->getDeclName(); 623 Diag(Old->getLocation(), diag::note_previous_definition); 624 return; 625} 626 627/// DeclhasAttr - returns true if decl Declaration already has the target 628/// attribute. 629static bool 630DeclHasAttr(const Decl *decl, const Attr *target) { 631 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 632 if (attr->getKind() == target->getKind()) 633 return true; 634 635 return false; 636} 637 638/// MergeAttributes - append attributes from the Old decl to the New one. 639static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 640 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 641 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 642 Attr *NewAttr = attr->clone(C); 643 NewAttr->setInherited(true); 644 New->addAttr(NewAttr); 645 } 646 } 647} 648 649/// Used in MergeFunctionDecl to keep track of function parameters in 650/// C. 651struct GNUCompatibleParamWarning { 652 ParmVarDecl *OldParm; 653 ParmVarDecl *NewParm; 654 QualType PromotedType; 655}; 656 657/// MergeFunctionDecl - We just parsed a function 'New' from 658/// declarator D which has the same name and scope as a previous 659/// declaration 'Old'. Figure out how to resolve this situation, 660/// merging decls or emitting diagnostics as appropriate. 661/// 662/// In C++, New and Old must be declarations that are not 663/// overloaded. Use IsOverload to determine whether New and Old are 664/// overloaded, and to select the Old declaration that New should be 665/// merged with. 666/// 667/// Returns true if there was an error, false otherwise. 668bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 669 assert(!isa<OverloadedFunctionDecl>(OldD) && 670 "Cannot merge with an overloaded function declaration"); 671 672 // Verify the old decl was also a function. 673 FunctionDecl *Old = 0; 674 if (FunctionTemplateDecl *OldFunctionTemplate 675 = dyn_cast<FunctionTemplateDecl>(OldD)) 676 Old = OldFunctionTemplate->getTemplatedDecl(); 677 else 678 Old = dyn_cast<FunctionDecl>(OldD); 679 if (!Old) { 680 Diag(New->getLocation(), diag::err_redefinition_different_kind) 681 << New->getDeclName(); 682 Diag(OldD->getLocation(), diag::note_previous_definition); 683 return true; 684 } 685 686 // Determine whether the previous declaration was a definition, 687 // implicit declaration, or a declaration. 688 diag::kind PrevDiag; 689 if (Old->isThisDeclarationADefinition()) 690 PrevDiag = diag::note_previous_definition; 691 else if (Old->isImplicit()) 692 PrevDiag = diag::note_previous_implicit_declaration; 693 else 694 PrevDiag = diag::note_previous_declaration; 695 696 QualType OldQType = Context.getCanonicalType(Old->getType()); 697 QualType NewQType = Context.getCanonicalType(New->getType()); 698 699 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 700 New->getStorageClass() == FunctionDecl::Static && 701 Old->getStorageClass() != FunctionDecl::Static) { 702 Diag(New->getLocation(), diag::err_static_non_static) 703 << New; 704 Diag(Old->getLocation(), PrevDiag); 705 return true; 706 } 707 708 if (getLangOptions().CPlusPlus) { 709 // (C++98 13.1p2): 710 // Certain function declarations cannot be overloaded: 711 // -- Function declarations that differ only in the return type 712 // cannot be overloaded. 713 QualType OldReturnType 714 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 715 QualType NewReturnType 716 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 717 if (OldReturnType != NewReturnType) { 718 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 719 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 720 return true; 721 } 722 723 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 724 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 725 if (OldMethod && NewMethod && 726 NewMethod->getLexicalDeclContext()->isRecord()) { 727 // -- Member function declarations with the same name and the 728 // same parameter types cannot be overloaded if any of them 729 // is a static member function declaration. 730 if (OldMethod->isStatic() || NewMethod->isStatic()) { 731 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 732 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 733 return true; 734 } 735 736 // C++ [class.mem]p1: 737 // [...] A member shall not be declared twice in the 738 // member-specification, except that a nested class or member 739 // class template can be declared and then later defined. 740 unsigned NewDiag; 741 if (isa<CXXConstructorDecl>(OldMethod)) 742 NewDiag = diag::err_constructor_redeclared; 743 else if (isa<CXXDestructorDecl>(NewMethod)) 744 NewDiag = diag::err_destructor_redeclared; 745 else if (isa<CXXConversionDecl>(NewMethod)) 746 NewDiag = diag::err_conv_function_redeclared; 747 else 748 NewDiag = diag::err_member_redeclared; 749 750 Diag(New->getLocation(), NewDiag); 751 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 752 } 753 754 // (C++98 8.3.5p3): 755 // All declarations for a function shall agree exactly in both the 756 // return type and the parameter-type-list. 757 if (OldQType == NewQType) 758 return MergeCompatibleFunctionDecls(New, Old); 759 760 // Fall through for conflicting redeclarations and redefinitions. 761 } 762 763 // C: Function types need to be compatible, not identical. This handles 764 // duplicate function decls like "void f(int); void f(enum X);" properly. 765 if (!getLangOptions().CPlusPlus && 766 Context.typesAreCompatible(OldQType, NewQType)) { 767 const FunctionType *OldFuncType = OldQType->getAsFunctionType(); 768 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 769 const FunctionProtoType *OldProto = 0; 770 if (isa<FunctionNoProtoType>(NewFuncType) && 771 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 772 // The old declaration provided a function prototype, but the 773 // new declaration does not. Merge in the prototype. 774 assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); 775 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 776 OldProto->arg_type_end()); 777 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 778 ParamTypes.data(), ParamTypes.size(), 779 OldProto->isVariadic(), 780 OldProto->getTypeQuals()); 781 New->setType(NewQType); 782 New->setHasInheritedPrototype(); 783 784 // Synthesize a parameter for each argument type. 785 llvm::SmallVector<ParmVarDecl*, 16> Params; 786 for (FunctionProtoType::arg_type_iterator 787 ParamType = OldProto->arg_type_begin(), 788 ParamEnd = OldProto->arg_type_end(); 789 ParamType != ParamEnd; ++ParamType) { 790 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 791 SourceLocation(), 0, 792 *ParamType, VarDecl::None, 793 0); 794 Param->setImplicit(); 795 Params.push_back(Param); 796 } 797 798 New->setParams(Context, Params.data(), Params.size()); 799 } 800 801 return MergeCompatibleFunctionDecls(New, Old); 802 } 803 804 // GNU C permits a K&R definition to follow a prototype declaration 805 // if the declared types of the parameters in the K&R definition 806 // match the types in the prototype declaration, even when the 807 // promoted types of the parameters from the K&R definition differ 808 // from the types in the prototype. GCC then keeps the types from 809 // the prototype. 810 // 811 // If a variadic prototype is followed by a non-variadic K&R definition, 812 // the K&R definition becomes variadic. This is sort of an edge case, but 813 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and 814 // C99 6.9.1p8. 815 if (!getLangOptions().CPlusPlus && 816 Old->hasPrototype() && !New->hasPrototype() && 817 New->getType()->getAsFunctionProtoType() && 818 Old->getNumParams() == New->getNumParams()) { 819 llvm::SmallVector<QualType, 16> ArgTypes; 820 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 821 const FunctionProtoType *OldProto 822 = Old->getType()->getAsFunctionProtoType(); 823 const FunctionProtoType *NewProto 824 = New->getType()->getAsFunctionProtoType(); 825 826 // Determine whether this is the GNU C extension. 827 QualType MergedReturn = Context.mergeTypes(OldProto->getResultType(), 828 NewProto->getResultType()); 829 bool LooseCompatible = !MergedReturn.isNull(); 830 for (unsigned Idx = 0, End = Old->getNumParams(); 831 LooseCompatible && Idx != End; ++Idx) { 832 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 833 ParmVarDecl *NewParm = New->getParamDecl(Idx); 834 if (Context.typesAreCompatible(OldParm->getType(), 835 NewProto->getArgType(Idx))) { 836 ArgTypes.push_back(NewParm->getType()); 837 } else if (Context.typesAreCompatible(OldParm->getType(), 838 NewParm->getType())) { 839 GNUCompatibleParamWarning Warn 840 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 841 Warnings.push_back(Warn); 842 ArgTypes.push_back(NewParm->getType()); 843 } else 844 LooseCompatible = false; 845 } 846 847 if (LooseCompatible) { 848 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 849 Diag(Warnings[Warn].NewParm->getLocation(), 850 diag::ext_param_promoted_not_compatible_with_prototype) 851 << Warnings[Warn].PromotedType 852 << Warnings[Warn].OldParm->getType(); 853 Diag(Warnings[Warn].OldParm->getLocation(), 854 diag::note_previous_declaration); 855 } 856 857 New->setType(Context.getFunctionType(MergedReturn, &ArgTypes[0], 858 ArgTypes.size(), 859 OldProto->isVariadic(), 0)); 860 return MergeCompatibleFunctionDecls(New, Old); 861 } 862 863 // Fall through to diagnose conflicting types. 864 } 865 866 // A function that has already been declared has been redeclared or defined 867 // with a different type- show appropriate diagnostic 868 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 869 // The user has declared a builtin function with an incompatible 870 // signature. 871 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 872 // The function the user is redeclaring is a library-defined 873 // function like 'malloc' or 'printf'. Warn about the 874 // redeclaration, then pretend that we don't know about this 875 // library built-in. 876 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 877 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 878 << Old << Old->getType(); 879 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 880 Old->setInvalidDecl(); 881 return false; 882 } 883 884 PrevDiag = diag::note_previous_builtin_declaration; 885 } 886 887 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 888 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 889 return true; 890} 891 892/// \brief Completes the merge of two function declarations that are 893/// known to be compatible. 894/// 895/// This routine handles the merging of attributes and other 896/// properties of function declarations form the old declaration to 897/// the new declaration, once we know that New is in fact a 898/// redeclaration of Old. 899/// 900/// \returns false 901bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 902 // Merge the attributes 903 MergeAttributes(New, Old, Context); 904 905 // Merge the storage class. 906 if (Old->getStorageClass() != FunctionDecl::Extern) 907 New->setStorageClass(Old->getStorageClass()); 908 909 // Merge "inline" 910 if (Old->isInline()) 911 New->setInline(true); 912 913 // If this function declaration by itself qualifies as a C99 inline 914 // definition (C99 6.7.4p6), but the previous definition did not, 915 // then the function is not a C99 inline definition. 916 if (New->isC99InlineDefinition() && !Old->isC99InlineDefinition()) 917 New->setC99InlineDefinition(false); 918 else if (Old->isC99InlineDefinition() && !New->isC99InlineDefinition()) { 919 // Mark all preceding definitions as not being C99 inline definitions. 920 for (const FunctionDecl *Prev = Old; Prev; 921 Prev = Prev->getPreviousDeclaration()) 922 const_cast<FunctionDecl *>(Prev)->setC99InlineDefinition(false); 923 } 924 925 // Merge "pure" flag. 926 if (Old->isPure()) 927 New->setPure(); 928 929 // Merge the "deleted" flag. 930 if (Old->isDeleted()) 931 New->setDeleted(); 932 933 if (getLangOptions().CPlusPlus) 934 return MergeCXXFunctionDecl(New, Old); 935 936 return false; 937} 938 939/// MergeVarDecl - We just parsed a variable 'New' which has the same name 940/// and scope as a previous declaration 'Old'. Figure out how to resolve this 941/// situation, merging decls or emitting diagnostics as appropriate. 942/// 943/// Tentative definition rules (C99 6.9.2p2) are checked by 944/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 945/// definitions here, since the initializer hasn't been attached. 946/// 947void Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 948 // If either decl is invalid, make sure the new one is marked invalid and 949 // don't do any other checking. 950 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 951 return New->setInvalidDecl(); 952 953 // Verify the old decl was also a variable. 954 VarDecl *Old = dyn_cast<VarDecl>(OldD); 955 if (!Old) { 956 Diag(New->getLocation(), diag::err_redefinition_different_kind) 957 << New->getDeclName(); 958 Diag(OldD->getLocation(), diag::note_previous_definition); 959 return New->setInvalidDecl(); 960 } 961 962 MergeAttributes(New, Old, Context); 963 964 // Merge the types 965 QualType MergedT; 966 if (getLangOptions().CPlusPlus) { 967 if (Context.hasSameType(New->getType(), Old->getType())) 968 MergedT = New->getType(); 969 } else { 970 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 971 } 972 if (MergedT.isNull()) { 973 Diag(New->getLocation(), diag::err_redefinition_different_type) 974 << New->getDeclName(); 975 Diag(Old->getLocation(), diag::note_previous_definition); 976 return New->setInvalidDecl(); 977 } 978 New->setType(MergedT); 979 980 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 981 if (New->getStorageClass() == VarDecl::Static && 982 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 983 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 984 Diag(Old->getLocation(), diag::note_previous_definition); 985 return New->setInvalidDecl(); 986 } 987 // C99 6.2.2p4: 988 // For an identifier declared with the storage-class specifier 989 // extern in a scope in which a prior declaration of that 990 // identifier is visible,23) if the prior declaration specifies 991 // internal or external linkage, the linkage of the identifier at 992 // the later declaration is the same as the linkage specified at 993 // the prior declaration. If no prior declaration is visible, or 994 // if the prior declaration specifies no linkage, then the 995 // identifier has external linkage. 996 if (New->hasExternalStorage() && Old->hasLinkage()) 997 /* Okay */; 998 else if (New->getStorageClass() != VarDecl::Static && 999 Old->getStorageClass() == VarDecl::Static) { 1000 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 1001 Diag(Old->getLocation(), diag::note_previous_definition); 1002 return New->setInvalidDecl(); 1003 } 1004 1005 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 1006 1007 // FIXME: The test for external storage here seems wrong? We still 1008 // need to check for mismatches. 1009 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 1010 // Don't complain about out-of-line definitions of static members. 1011 !(Old->getLexicalDeclContext()->isRecord() && 1012 !New->getLexicalDeclContext()->isRecord())) { 1013 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 1014 Diag(Old->getLocation(), diag::note_previous_definition); 1015 return New->setInvalidDecl(); 1016 } 1017 1018 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 1019 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 1020 Diag(Old->getLocation(), diag::note_previous_definition); 1021 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 1022 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 1023 Diag(Old->getLocation(), diag::note_previous_definition); 1024 } 1025 1026 // Keep a chain of previous declarations. 1027 New->setPreviousDeclaration(Old); 1028} 1029 1030/// CheckFallThrough - Check that we don't fall off the end of a 1031/// Statement that should return a value. 1032/// 1033/// \returns AlwaysFallThrough iff we always fall off the end of the statement, 1034/// MaybeFallThrough iff we might or might not fall off the end and 1035/// NeverFallThrough iff we never fall off the end of the statement. We assume 1036/// that functions not marked noreturn will return. 1037Sema::ControlFlowKind Sema::CheckFallThrough(Stmt *Root) { 1038 llvm::OwningPtr<CFG> cfg (CFG::buildCFG(Root, &Context)); 1039 1040 // FIXME: They should never return 0, fix that, delete this code. 1041 if (cfg == 0) 1042 return NeverFallThrough; 1043 // The CFG leaves in dead things, and we don't want to dead code paths to 1044 // confuse us, so we mark all live things first. 1045 std::queue<CFGBlock*> workq; 1046 llvm::BitVector live(cfg->getNumBlockIDs()); 1047 // Prep work queue 1048 workq.push(&cfg->getEntry()); 1049 // Solve 1050 while (!workq.empty()) { 1051 CFGBlock *item = workq.front(); 1052 workq.pop(); 1053 live.set(item->getBlockID()); 1054 for (CFGBlock::succ_iterator I=item->succ_begin(), 1055 E=item->succ_end(); 1056 I != E; 1057 ++I) { 1058 if ((*I) && !live[(*I)->getBlockID()]) { 1059 live.set((*I)->getBlockID()); 1060 workq.push(*I); 1061 } 1062 } 1063 } 1064 1065 // Now we know what is live, we check the live precessors of the exit block 1066 // and look for fall through paths, being careful to ignore normal returns, 1067 // and exceptional paths. 1068 bool HasLiveReturn = false; 1069 bool HasFakeEdge = false; 1070 bool HasPlainEdge = false; 1071 for (CFGBlock::succ_iterator I=cfg->getExit().pred_begin(), 1072 E = cfg->getExit().pred_end(); 1073 I != E; 1074 ++I) { 1075 CFGBlock& B = **I; 1076 if (!live[B.getBlockID()]) 1077 continue; 1078 if (B.size() == 0) { 1079 // A labeled empty statement, or the entry block... 1080 HasPlainEdge = true; 1081 continue; 1082 } 1083 Stmt *S = B[B.size()-1]; 1084 if (isa<ReturnStmt>(S)) { 1085 HasLiveReturn = true; 1086 continue; 1087 } 1088 if (isa<ObjCAtThrowStmt>(S)) { 1089 HasFakeEdge = true; 1090 continue; 1091 } 1092 if (isa<CXXThrowExpr>(S)) { 1093 HasFakeEdge = true; 1094 continue; 1095 } 1096 bool NoReturnEdge = false; 1097 if (CallExpr *C = dyn_cast<CallExpr>(S)) { 1098 Expr *CEE = C->getCallee()->IgnoreParenCasts(); 1099 if (CEE->getType().getNoReturnAttr()) { 1100 NoReturnEdge = true; 1101 HasFakeEdge = true; 1102 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) { 1103 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 1104 if (FD->hasAttr<NoReturnAttr>()) { 1105 NoReturnEdge = true; 1106 HasFakeEdge = true; 1107 } 1108 } 1109 } 1110 } 1111 // FIXME: Add noreturn message sends. 1112 if (NoReturnEdge == false) 1113 HasPlainEdge = true; 1114 } 1115 if (!HasPlainEdge) 1116 return NeverFallThrough; 1117 if (HasFakeEdge || HasLiveReturn) 1118 return MaybeFallThrough; 1119 // This says AlwaysFallThrough for calls to functions that are not marked 1120 // noreturn, that don't return. If people would like this warning to be more 1121 // accurate, such functions should be marked as noreturn. 1122 return AlwaysFallThrough; 1123} 1124 1125/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a 1126/// function that should return a value. Check that we don't fall off the end 1127/// of a noreturn function. We assume that functions and blocks not marked 1128/// noreturn will return. 1129void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body) { 1130 // FIXME: Would be nice if we had a better way to control cascading errors, 1131 // but for now, avoid them. The problem is that when Parse sees: 1132 // int foo() { return a; } 1133 // The return is eaten and the Sema code sees just: 1134 // int foo() { } 1135 // which this code would then warn about. 1136 if (getDiagnostics().hasErrorOccurred()) 1137 return; 1138 bool ReturnsVoid = false; 1139 bool HasNoReturn = false; 1140 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1141 if (FD->getResultType()->isVoidType()) 1142 ReturnsVoid = true; 1143 if (FD->hasAttr<NoReturnAttr>()) 1144 HasNoReturn = true; 1145 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 1146 if (MD->getResultType()->isVoidType()) 1147 ReturnsVoid = true; 1148 if (MD->hasAttr<NoReturnAttr>()) 1149 HasNoReturn = true; 1150 } 1151 1152 // Short circuit for compilation speed. 1153 if ((Diags.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function) 1154 == Diagnostic::Ignored || ReturnsVoid) 1155 && (Diags.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr) 1156 == Diagnostic::Ignored || !HasNoReturn) 1157 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1158 == Diagnostic::Ignored || !ReturnsVoid)) 1159 return; 1160 // FIXME: Funtion try block 1161 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1162 switch (CheckFallThrough(Body)) { 1163 case MaybeFallThrough: 1164 if (HasNoReturn) 1165 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1166 else if (!ReturnsVoid) 1167 Diag(Compound->getRBracLoc(),diag::warn_maybe_falloff_nonvoid_function); 1168 break; 1169 case AlwaysFallThrough: 1170 if (HasNoReturn) 1171 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1172 else if (!ReturnsVoid) 1173 Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function); 1174 break; 1175 case NeverFallThrough: 1176 if (ReturnsVoid) 1177 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function); 1178 break; 1179 } 1180 } 1181} 1182 1183/// CheckFallThroughForBlock - Check that we don't fall off the end of a block 1184/// that should return a value. Check that we don't fall off the end of a 1185/// noreturn block. We assume that functions and blocks not marked noreturn 1186/// will return. 1187void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body) { 1188 // FIXME: Would be nice if we had a better way to control cascading errors, 1189 // but for now, avoid them. The problem is that when Parse sees: 1190 // int foo() { return a; } 1191 // The return is eaten and the Sema code sees just: 1192 // int foo() { } 1193 // which this code would then warn about. 1194 if (getDiagnostics().hasErrorOccurred()) 1195 return; 1196 bool ReturnsVoid = false; 1197 bool HasNoReturn = false; 1198 if (const FunctionType *FT = BlockTy->getPointeeType()->getAsFunctionType()) { 1199 if (FT->getResultType()->isVoidType()) 1200 ReturnsVoid = true; 1201 if (FT->getNoReturnAttr()) 1202 HasNoReturn = true; 1203 } 1204 1205 // Short circuit for compilation speed. 1206 if (ReturnsVoid 1207 && !HasNoReturn 1208 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1209 == Diagnostic::Ignored || !ReturnsVoid)) 1210 return; 1211 // FIXME: Funtion try block 1212 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1213 switch (CheckFallThrough(Body)) { 1214 case MaybeFallThrough: 1215 if (HasNoReturn) 1216 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1217 else if (!ReturnsVoid) 1218 Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block); 1219 break; 1220 case AlwaysFallThrough: 1221 if (HasNoReturn) 1222 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1223 else if (!ReturnsVoid) 1224 Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block); 1225 break; 1226 case NeverFallThrough: 1227 if (ReturnsVoid) 1228 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block); 1229 break; 1230 } 1231 } 1232} 1233 1234/// CheckParmsForFunctionDef - Check that the parameters of the given 1235/// function are appropriate for the definition of a function. This 1236/// takes care of any checks that cannot be performed on the 1237/// declaration itself, e.g., that the types of each of the function 1238/// parameters are complete. 1239bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 1240 bool HasInvalidParm = false; 1241 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1242 ParmVarDecl *Param = FD->getParamDecl(p); 1243 1244 // C99 6.7.5.3p4: the parameters in a parameter type list in a 1245 // function declarator that is part of a function definition of 1246 // that function shall not have incomplete type. 1247 // 1248 // This is also C++ [dcl.fct]p6. 1249 if (!Param->isInvalidDecl() && 1250 RequireCompleteType(Param->getLocation(), Param->getType(), 1251 diag::err_typecheck_decl_incomplete_type)) { 1252 Param->setInvalidDecl(); 1253 HasInvalidParm = true; 1254 } 1255 1256 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1257 // declaration of each parameter shall include an identifier. 1258 if (Param->getIdentifier() == 0 && 1259 !Param->isImplicit() && 1260 !getLangOptions().CPlusPlus) 1261 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1262 } 1263 1264 return HasInvalidParm; 1265} 1266 1267/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1268/// no declarator (e.g. "struct foo;") is parsed. 1269Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1270 // FIXME: Error on auto/register at file scope 1271 // FIXME: Error on inline/virtual/explicit 1272 // FIXME: Error on invalid restrict 1273 // FIXME: Warn on useless __thread 1274 // FIXME: Warn on useless const/volatile 1275 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1276 // FIXME: Warn on useless attributes 1277 TagDecl *Tag = 0; 1278 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1279 DS.getTypeSpecType() == DeclSpec::TST_struct || 1280 DS.getTypeSpecType() == DeclSpec::TST_union || 1281 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1282 if (!DS.getTypeRep()) // We probably had an error 1283 return DeclPtrTy(); 1284 1285 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 1286 } 1287 1288 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1289 if (!Record->getDeclName() && Record->isDefinition() && 1290 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1291 if (getLangOptions().CPlusPlus || 1292 Record->getDeclContext()->isRecord()) 1293 return BuildAnonymousStructOrUnion(S, DS, Record); 1294 1295 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1296 << DS.getSourceRange(); 1297 } 1298 1299 // Microsoft allows unnamed struct/union fields. Don't complain 1300 // about them. 1301 // FIXME: Should we support Microsoft's extensions in this area? 1302 if (Record->getDeclName() && getLangOptions().Microsoft) 1303 return DeclPtrTy::make(Tag); 1304 } 1305 1306 if (!DS.isMissingDeclaratorOk() && 1307 DS.getTypeSpecType() != DeclSpec::TST_error) { 1308 // Warn about typedefs of enums without names, since this is an 1309 // extension in both Microsoft an GNU. 1310 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1311 Tag && isa<EnumDecl>(Tag)) { 1312 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1313 << DS.getSourceRange(); 1314 return DeclPtrTy::make(Tag); 1315 } 1316 1317 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1318 << DS.getSourceRange(); 1319 return DeclPtrTy(); 1320 } 1321 1322 return DeclPtrTy::make(Tag); 1323} 1324 1325/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1326/// anonymous struct or union AnonRecord into the owning context Owner 1327/// and scope S. This routine will be invoked just after we realize 1328/// that an unnamed union or struct is actually an anonymous union or 1329/// struct, e.g., 1330/// 1331/// @code 1332/// union { 1333/// int i; 1334/// float f; 1335/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1336/// // f into the surrounding scope.x 1337/// @endcode 1338/// 1339/// This routine is recursive, injecting the names of nested anonymous 1340/// structs/unions into the owning context and scope as well. 1341bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1342 RecordDecl *AnonRecord) { 1343 bool Invalid = false; 1344 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 1345 FEnd = AnonRecord->field_end(); 1346 F != FEnd; ++F) { 1347 if ((*F)->getDeclName()) { 1348 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 1349 LookupOrdinaryName, true); 1350 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 1351 // C++ [class.union]p2: 1352 // The names of the members of an anonymous union shall be 1353 // distinct from the names of any other entity in the 1354 // scope in which the anonymous union is declared. 1355 unsigned diagKind 1356 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 1357 : diag::err_anonymous_struct_member_redecl; 1358 Diag((*F)->getLocation(), diagKind) 1359 << (*F)->getDeclName(); 1360 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1361 Invalid = true; 1362 } else { 1363 // C++ [class.union]p2: 1364 // For the purpose of name lookup, after the anonymous union 1365 // definition, the members of the anonymous union are 1366 // considered to have been defined in the scope in which the 1367 // anonymous union is declared. 1368 Owner->makeDeclVisibleInContext(*F); 1369 S->AddDecl(DeclPtrTy::make(*F)); 1370 IdResolver.AddDecl(*F); 1371 } 1372 } else if (const RecordType *InnerRecordType 1373 = (*F)->getType()->getAsRecordType()) { 1374 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1375 if (InnerRecord->isAnonymousStructOrUnion()) 1376 Invalid = Invalid || 1377 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1378 } 1379 } 1380 1381 return Invalid; 1382} 1383 1384/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1385/// anonymous structure or union. Anonymous unions are a C++ feature 1386/// (C++ [class.union]) and a GNU C extension; anonymous structures 1387/// are a GNU C and GNU C++ extension. 1388Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1389 RecordDecl *Record) { 1390 DeclContext *Owner = Record->getDeclContext(); 1391 1392 // Diagnose whether this anonymous struct/union is an extension. 1393 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1394 Diag(Record->getLocation(), diag::ext_anonymous_union); 1395 else if (!Record->isUnion()) 1396 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1397 1398 // C and C++ require different kinds of checks for anonymous 1399 // structs/unions. 1400 bool Invalid = false; 1401 if (getLangOptions().CPlusPlus) { 1402 const char* PrevSpec = 0; 1403 // C++ [class.union]p3: 1404 // Anonymous unions declared in a named namespace or in the 1405 // global namespace shall be declared static. 1406 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1407 (isa<TranslationUnitDecl>(Owner) || 1408 (isa<NamespaceDecl>(Owner) && 1409 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1410 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1411 Invalid = true; 1412 1413 // Recover by adding 'static'. 1414 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec); 1415 } 1416 // C++ [class.union]p3: 1417 // A storage class is not allowed in a declaration of an 1418 // anonymous union in a class scope. 1419 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1420 isa<RecordDecl>(Owner)) { 1421 Diag(DS.getStorageClassSpecLoc(), 1422 diag::err_anonymous_union_with_storage_spec); 1423 Invalid = true; 1424 1425 // Recover by removing the storage specifier. 1426 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1427 PrevSpec); 1428 } 1429 1430 // C++ [class.union]p2: 1431 // The member-specification of an anonymous union shall only 1432 // define non-static data members. [Note: nested types and 1433 // functions cannot be declared within an anonymous union. ] 1434 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 1435 MemEnd = Record->decls_end(); 1436 Mem != MemEnd; ++Mem) { 1437 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1438 // C++ [class.union]p3: 1439 // An anonymous union shall not have private or protected 1440 // members (clause 11). 1441 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1442 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1443 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1444 Invalid = true; 1445 } 1446 } else if ((*Mem)->isImplicit()) { 1447 // Any implicit members are fine. 1448 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1449 // This is a type that showed up in an 1450 // elaborated-type-specifier inside the anonymous struct or 1451 // union, but which actually declares a type outside of the 1452 // anonymous struct or union. It's okay. 1453 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1454 if (!MemRecord->isAnonymousStructOrUnion() && 1455 MemRecord->getDeclName()) { 1456 // This is a nested type declaration. 1457 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1458 << (int)Record->isUnion(); 1459 Invalid = true; 1460 } 1461 } else { 1462 // We have something that isn't a non-static data 1463 // member. Complain about it. 1464 unsigned DK = diag::err_anonymous_record_bad_member; 1465 if (isa<TypeDecl>(*Mem)) 1466 DK = diag::err_anonymous_record_with_type; 1467 else if (isa<FunctionDecl>(*Mem)) 1468 DK = diag::err_anonymous_record_with_function; 1469 else if (isa<VarDecl>(*Mem)) 1470 DK = diag::err_anonymous_record_with_static; 1471 Diag((*Mem)->getLocation(), DK) 1472 << (int)Record->isUnion(); 1473 Invalid = true; 1474 } 1475 } 1476 } 1477 1478 if (!Record->isUnion() && !Owner->isRecord()) { 1479 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1480 << (int)getLangOptions().CPlusPlus; 1481 Invalid = true; 1482 } 1483 1484 // Create a declaration for this anonymous struct/union. 1485 NamedDecl *Anon = 0; 1486 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1487 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1488 /*IdentifierInfo=*/0, 1489 Context.getTypeDeclType(Record), 1490 /*BitWidth=*/0, /*Mutable=*/false, 1491 DS.getSourceRange().getBegin()); 1492 Anon->setAccess(AS_public); 1493 if (getLangOptions().CPlusPlus) 1494 FieldCollector->Add(cast<FieldDecl>(Anon)); 1495 } else { 1496 VarDecl::StorageClass SC; 1497 switch (DS.getStorageClassSpec()) { 1498 default: assert(0 && "Unknown storage class!"); 1499 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1500 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1501 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1502 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1503 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1504 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1505 case DeclSpec::SCS_mutable: 1506 // mutable can only appear on non-static class members, so it's always 1507 // an error here 1508 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1509 Invalid = true; 1510 SC = VarDecl::None; 1511 break; 1512 } 1513 1514 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1515 /*IdentifierInfo=*/0, 1516 Context.getTypeDeclType(Record), 1517 SC, DS.getSourceRange().getBegin()); 1518 } 1519 Anon->setImplicit(); 1520 1521 // Add the anonymous struct/union object to the current 1522 // context. We'll be referencing this object when we refer to one of 1523 // its members. 1524 Owner->addDecl(Anon); 1525 1526 // Inject the members of the anonymous struct/union into the owning 1527 // context and into the identifier resolver chain for name lookup 1528 // purposes. 1529 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1530 Invalid = true; 1531 1532 // Mark this as an anonymous struct/union type. Note that we do not 1533 // do this until after we have already checked and injected the 1534 // members of this anonymous struct/union type, because otherwise 1535 // the members could be injected twice: once by DeclContext when it 1536 // builds its lookup table, and once by 1537 // InjectAnonymousStructOrUnionMembers. 1538 Record->setAnonymousStructOrUnion(true); 1539 1540 if (Invalid) 1541 Anon->setInvalidDecl(); 1542 1543 return DeclPtrTy::make(Anon); 1544} 1545 1546 1547/// GetNameForDeclarator - Determine the full declaration name for the 1548/// given Declarator. 1549DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1550 switch (D.getKind()) { 1551 case Declarator::DK_Abstract: 1552 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1553 return DeclarationName(); 1554 1555 case Declarator::DK_Normal: 1556 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1557 return DeclarationName(D.getIdentifier()); 1558 1559 case Declarator::DK_Constructor: { 1560 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1561 Ty = Context.getCanonicalType(Ty); 1562 return Context.DeclarationNames.getCXXConstructorName(Ty); 1563 } 1564 1565 case Declarator::DK_Destructor: { 1566 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1567 Ty = Context.getCanonicalType(Ty); 1568 return Context.DeclarationNames.getCXXDestructorName(Ty); 1569 } 1570 1571 case Declarator::DK_Conversion: { 1572 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1573 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1574 Ty = Context.getCanonicalType(Ty); 1575 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1576 } 1577 1578 case Declarator::DK_Operator: 1579 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1580 return Context.DeclarationNames.getCXXOperatorName( 1581 D.getOverloadedOperator()); 1582 } 1583 1584 assert(false && "Unknown name kind"); 1585 return DeclarationName(); 1586} 1587 1588/// isNearlyMatchingFunction - Determine whether the C++ functions 1589/// Declaration and Definition are "nearly" matching. This heuristic 1590/// is used to improve diagnostics in the case where an out-of-line 1591/// function definition doesn't match any declaration within 1592/// the class or namespace. 1593static bool isNearlyMatchingFunction(ASTContext &Context, 1594 FunctionDecl *Declaration, 1595 FunctionDecl *Definition) { 1596 if (Declaration->param_size() != Definition->param_size()) 1597 return false; 1598 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1599 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1600 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1601 1602 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1603 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1604 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1605 return false; 1606 } 1607 1608 return true; 1609} 1610 1611Sema::DeclPtrTy 1612Sema::HandleDeclarator(Scope *S, Declarator &D, 1613 MultiTemplateParamsArg TemplateParamLists, 1614 bool IsFunctionDefinition) { 1615 DeclarationName Name = GetNameForDeclarator(D); 1616 1617 // All of these full declarators require an identifier. If it doesn't have 1618 // one, the ParsedFreeStandingDeclSpec action should be used. 1619 if (!Name) { 1620 if (!D.isInvalidType()) // Reject this if we think it is valid. 1621 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1622 diag::err_declarator_need_ident) 1623 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1624 return DeclPtrTy(); 1625 } 1626 1627 // The scope passed in may not be a decl scope. Zip up the scope tree until 1628 // we find one that is. 1629 while ((S->getFlags() & Scope::DeclScope) == 0 || 1630 (S->getFlags() & Scope::TemplateParamScope) != 0) 1631 S = S->getParent(); 1632 1633 DeclContext *DC; 1634 NamedDecl *PrevDecl; 1635 NamedDecl *New; 1636 1637 QualType R = GetTypeForDeclarator(D, S); 1638 1639 // See if this is a redefinition of a variable in the same scope. 1640 if (D.getCXXScopeSpec().isInvalid()) { 1641 DC = CurContext; 1642 PrevDecl = 0; 1643 D.setInvalidType(); 1644 } else if (!D.getCXXScopeSpec().isSet()) { 1645 LookupNameKind NameKind = LookupOrdinaryName; 1646 1647 // If the declaration we're planning to build will be a function 1648 // or object with linkage, then look for another declaration with 1649 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1650 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1651 /* Do nothing*/; 1652 else if (R->isFunctionType()) { 1653 if (CurContext->isFunctionOrMethod() || 1654 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1655 NameKind = LookupRedeclarationWithLinkage; 1656 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1657 NameKind = LookupRedeclarationWithLinkage; 1658 else if (CurContext->getLookupContext()->isTranslationUnit() && 1659 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1660 NameKind = LookupRedeclarationWithLinkage; 1661 1662 DC = CurContext; 1663 PrevDecl = LookupName(S, Name, NameKind, true, 1664 NameKind == LookupRedeclarationWithLinkage, 1665 D.getIdentifierLoc()); 1666 } else { // Something like "int foo::x;" 1667 DC = computeDeclContext(D.getCXXScopeSpec(), true); 1668 // FIXME: RequireCompleteDeclContext(D.getCXXScopeSpec()); ? 1669 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1670 1671 // C++ 7.3.1.2p2: 1672 // Members (including explicit specializations of templates) of a named 1673 // namespace can also be defined outside that namespace by explicit 1674 // qualification of the name being defined, provided that the entity being 1675 // defined was already declared in the namespace and the definition appears 1676 // after the point of declaration in a namespace that encloses the 1677 // declarations namespace. 1678 // 1679 // Note that we only check the context at this point. We don't yet 1680 // have enough information to make sure that PrevDecl is actually 1681 // the declaration we want to match. For example, given: 1682 // 1683 // class X { 1684 // void f(); 1685 // void f(float); 1686 // }; 1687 // 1688 // void X::f(int) { } // ill-formed 1689 // 1690 // In this case, PrevDecl will point to the overload set 1691 // containing the two f's declared in X, but neither of them 1692 // matches. 1693 1694 // First check whether we named the global scope. 1695 if (isa<TranslationUnitDecl>(DC)) { 1696 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1697 << Name << D.getCXXScopeSpec().getRange(); 1698 } else if (!CurContext->Encloses(DC)) { 1699 // The qualifying scope doesn't enclose the original declaration. 1700 // Emit diagnostic based on current scope. 1701 SourceLocation L = D.getIdentifierLoc(); 1702 SourceRange R = D.getCXXScopeSpec().getRange(); 1703 if (isa<FunctionDecl>(CurContext)) 1704 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1705 else 1706 Diag(L, diag::err_invalid_declarator_scope) 1707 << Name << cast<NamedDecl>(DC) << R; 1708 D.setInvalidType(); 1709 } 1710 } 1711 1712 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1713 // Maybe we will complain about the shadowed template parameter. 1714 if (!D.isInvalidType()) 1715 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl)) 1716 D.setInvalidType(); 1717 1718 // Just pretend that we didn't see the previous declaration. 1719 PrevDecl = 0; 1720 } 1721 1722 // In C++, the previous declaration we find might be a tag type 1723 // (class or enum). In this case, the new declaration will hide the 1724 // tag type. Note that this does does not apply if we're declaring a 1725 // typedef (C++ [dcl.typedef]p4). 1726 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1727 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1728 PrevDecl = 0; 1729 1730 bool Redeclaration = false; 1731 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1732 if (TemplateParamLists.size()) { 1733 Diag(D.getIdentifierLoc(), diag::err_template_typedef); 1734 return DeclPtrTy(); 1735 } 1736 1737 New = ActOnTypedefDeclarator(S, D, DC, R, PrevDecl, Redeclaration); 1738 } else if (R->isFunctionType()) { 1739 New = ActOnFunctionDeclarator(S, D, DC, R, PrevDecl, 1740 move(TemplateParamLists), 1741 IsFunctionDefinition, Redeclaration); 1742 } else { 1743 New = ActOnVariableDeclarator(S, D, DC, R, PrevDecl, 1744 move(TemplateParamLists), 1745 Redeclaration); 1746 } 1747 1748 if (New == 0) 1749 return DeclPtrTy(); 1750 1751 // If this has an identifier and is not an invalid redeclaration, 1752 // add it to the scope stack. 1753 if (Name && !(Redeclaration && New->isInvalidDecl())) 1754 PushOnScopeChains(New, S); 1755 1756 return DeclPtrTy::make(New); 1757} 1758 1759/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1760/// types into constant array types in certain situations which would otherwise 1761/// be errors (for GCC compatibility). 1762static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1763 ASTContext &Context, 1764 bool &SizeIsNegative) { 1765 // This method tries to turn a variable array into a constant 1766 // array even when the size isn't an ICE. This is necessary 1767 // for compatibility with code that depends on gcc's buggy 1768 // constant expression folding, like struct {char x[(int)(char*)2];} 1769 SizeIsNegative = false; 1770 1771 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1772 QualType Pointee = PTy->getPointeeType(); 1773 QualType FixedType = 1774 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1775 if (FixedType.isNull()) return FixedType; 1776 FixedType = Context.getPointerType(FixedType); 1777 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1778 return FixedType; 1779 } 1780 1781 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1782 if (!VLATy) 1783 return QualType(); 1784 // FIXME: We should probably handle this case 1785 if (VLATy->getElementType()->isVariablyModifiedType()) 1786 return QualType(); 1787 1788 Expr::EvalResult EvalResult; 1789 if (!VLATy->getSizeExpr() || 1790 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 1791 !EvalResult.Val.isInt()) 1792 return QualType(); 1793 1794 llvm::APSInt &Res = EvalResult.Val.getInt(); 1795 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) { 1796 Expr* ArySizeExpr = VLATy->getSizeExpr(); 1797 // FIXME: here we could "steal" (how?) ArySizeExpr from the VLA, 1798 // so as to transfer ownership to the ConstantArrayWithExpr. 1799 // Alternatively, we could "clone" it (how?). 1800 // Since we don't know how to do things above, we just use the 1801 // very same Expr*. 1802 return Context.getConstantArrayWithExprType(VLATy->getElementType(), 1803 Res, ArySizeExpr, 1804 ArrayType::Normal, 0, 1805 VLATy->getBracketsRange()); 1806 } 1807 1808 SizeIsNegative = true; 1809 return QualType(); 1810} 1811 1812/// \brief Register the given locally-scoped external C declaration so 1813/// that it can be found later for redeclarations 1814void 1815Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, NamedDecl *PrevDecl, 1816 Scope *S) { 1817 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 1818 "Decl is not a locally-scoped decl!"); 1819 // Note that we have a locally-scoped external with this name. 1820 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 1821 1822 if (!PrevDecl) 1823 return; 1824 1825 // If there was a previous declaration of this variable, it may be 1826 // in our identifier chain. Update the identifier chain with the new 1827 // declaration. 1828 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 1829 // The previous declaration was found on the identifer resolver 1830 // chain, so remove it from its scope. 1831 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 1832 S = S->getParent(); 1833 1834 if (S) 1835 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 1836 } 1837} 1838 1839/// \brief Diagnose function specifiers on a declaration of an identifier that 1840/// does not identify a function. 1841void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 1842 // FIXME: We should probably indicate the identifier in question to avoid 1843 // confusion for constructs like "inline int a(), b;" 1844 if (D.getDeclSpec().isInlineSpecified()) 1845 Diag(D.getDeclSpec().getInlineSpecLoc(), 1846 diag::err_inline_non_function); 1847 1848 if (D.getDeclSpec().isVirtualSpecified()) 1849 Diag(D.getDeclSpec().getVirtualSpecLoc(), 1850 diag::err_virtual_non_function); 1851 1852 if (D.getDeclSpec().isExplicitSpecified()) 1853 Diag(D.getDeclSpec().getExplicitSpecLoc(), 1854 diag::err_explicit_non_function); 1855} 1856 1857NamedDecl* 1858Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1859 QualType R, Decl* PrevDecl, bool &Redeclaration) { 1860 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1861 if (D.getCXXScopeSpec().isSet()) { 1862 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1863 << D.getCXXScopeSpec().getRange(); 1864 D.setInvalidType(); 1865 // Pretend we didn't see the scope specifier. 1866 DC = 0; 1867 } 1868 1869 if (getLangOptions().CPlusPlus) { 1870 // Check that there are no default arguments (C++ only). 1871 CheckExtraCXXDefaultArguments(D); 1872 } 1873 1874 DiagnoseFunctionSpecifiers(D); 1875 1876 if (D.getDeclSpec().isThreadSpecified()) 1877 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 1878 1879 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R); 1880 if (!NewTD) return 0; 1881 1882 if (D.isInvalidType()) 1883 NewTD->setInvalidDecl(); 1884 1885 // Handle attributes prior to checking for duplicates in MergeVarDecl 1886 ProcessDeclAttributes(S, NewTD, D); 1887 // Merge the decl with the existing one if appropriate. If the decl is 1888 // in an outer scope, it isn't the same thing. 1889 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1890 Redeclaration = true; 1891 MergeTypeDefDecl(NewTD, PrevDecl); 1892 } 1893 1894 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1895 // then it shall have block scope. 1896 QualType T = NewTD->getUnderlyingType(); 1897 if (T->isVariablyModifiedType()) { 1898 CurFunctionNeedsScopeChecking = true; 1899 1900 if (S->getFnParent() == 0) { 1901 bool SizeIsNegative; 1902 QualType FixedTy = 1903 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1904 if (!FixedTy.isNull()) { 1905 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1906 NewTD->setUnderlyingType(FixedTy); 1907 } else { 1908 if (SizeIsNegative) 1909 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1910 else if (T->isVariableArrayType()) 1911 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1912 else 1913 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1914 NewTD->setInvalidDecl(); 1915 } 1916 } 1917 } 1918 1919 // If this is the C FILE type, notify the AST context. 1920 if (IdentifierInfo *II = NewTD->getIdentifier()) 1921 if (!NewTD->isInvalidDecl() && 1922 NewTD->getDeclContext()->getLookupContext()->isTranslationUnit()) { 1923 if (II->isStr("FILE")) 1924 Context.setFILEDecl(NewTD); 1925 else if (II->isStr("jmp_buf")) 1926 Context.setjmp_bufDecl(NewTD); 1927 else if (II->isStr("sigjmp_buf")) 1928 Context.setsigjmp_bufDecl(NewTD); 1929 } 1930 1931 return NewTD; 1932} 1933 1934/// \brief Determines whether the given declaration is an out-of-scope 1935/// previous declaration. 1936/// 1937/// This routine should be invoked when name lookup has found a 1938/// previous declaration (PrevDecl) that is not in the scope where a 1939/// new declaration by the same name is being introduced. If the new 1940/// declaration occurs in a local scope, previous declarations with 1941/// linkage may still be considered previous declarations (C99 1942/// 6.2.2p4-5, C++ [basic.link]p6). 1943/// 1944/// \param PrevDecl the previous declaration found by name 1945/// lookup 1946/// 1947/// \param DC the context in which the new declaration is being 1948/// declared. 1949/// 1950/// \returns true if PrevDecl is an out-of-scope previous declaration 1951/// for a new delcaration with the same name. 1952static bool 1953isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 1954 ASTContext &Context) { 1955 if (!PrevDecl) 1956 return 0; 1957 1958 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 1959 // case we need to check each of the overloaded functions. 1960 if (!PrevDecl->hasLinkage()) 1961 return false; 1962 1963 if (Context.getLangOptions().CPlusPlus) { 1964 // C++ [basic.link]p6: 1965 // If there is a visible declaration of an entity with linkage 1966 // having the same name and type, ignoring entities declared 1967 // outside the innermost enclosing namespace scope, the block 1968 // scope declaration declares that same entity and receives the 1969 // linkage of the previous declaration. 1970 DeclContext *OuterContext = DC->getLookupContext(); 1971 if (!OuterContext->isFunctionOrMethod()) 1972 // This rule only applies to block-scope declarations. 1973 return false; 1974 else { 1975 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 1976 if (PrevOuterContext->isRecord()) 1977 // We found a member function: ignore it. 1978 return false; 1979 else { 1980 // Find the innermost enclosing namespace for the new and 1981 // previous declarations. 1982 while (!OuterContext->isFileContext()) 1983 OuterContext = OuterContext->getParent(); 1984 while (!PrevOuterContext->isFileContext()) 1985 PrevOuterContext = PrevOuterContext->getParent(); 1986 1987 // The previous declaration is in a different namespace, so it 1988 // isn't the same function. 1989 if (OuterContext->getPrimaryContext() != 1990 PrevOuterContext->getPrimaryContext()) 1991 return false; 1992 } 1993 } 1994 } 1995 1996 return true; 1997} 1998 1999NamedDecl* 2000Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2001 QualType R,NamedDecl* PrevDecl, 2002 MultiTemplateParamsArg TemplateParamLists, 2003 bool &Redeclaration) { 2004 DeclarationName Name = GetNameForDeclarator(D); 2005 2006 // Check that there are no default arguments (C++ only). 2007 if (getLangOptions().CPlusPlus) 2008 CheckExtraCXXDefaultArguments(D); 2009 2010 VarDecl *NewVD; 2011 VarDecl::StorageClass SC; 2012 switch (D.getDeclSpec().getStorageClassSpec()) { 2013 default: assert(0 && "Unknown storage class!"); 2014 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2015 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2016 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2017 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2018 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2019 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2020 case DeclSpec::SCS_mutable: 2021 // mutable can only appear on non-static class members, so it's always 2022 // an error here 2023 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 2024 D.setInvalidType(); 2025 SC = VarDecl::None; 2026 break; 2027 } 2028 2029 IdentifierInfo *II = Name.getAsIdentifierInfo(); 2030 if (!II) { 2031 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 2032 << Name.getAsString(); 2033 return 0; 2034 } 2035 2036 DiagnoseFunctionSpecifiers(D); 2037 2038 if (!DC->isRecord() && S->getFnParent() == 0) { 2039 // C99 6.9p2: The storage-class specifiers auto and register shall not 2040 // appear in the declaration specifiers in an external declaration. 2041 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 2042 2043 // If this is a register variable with an asm label specified, then this 2044 // is a GNU extension. 2045 if (SC == VarDecl::Register && D.getAsmLabel()) 2046 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 2047 else 2048 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 2049 D.setInvalidType(); 2050 } 2051 } 2052 if (DC->isRecord() && !CurContext->isRecord()) { 2053 // This is an out-of-line definition of a static data member. 2054 if (SC == VarDecl::Static) { 2055 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2056 diag::err_static_out_of_line) 2057 << CodeModificationHint::CreateRemoval( 2058 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2059 } else if (SC == VarDecl::None) 2060 SC = VarDecl::Static; 2061 } 2062 if (SC == VarDecl::Static) { 2063 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 2064 if (RD->isLocalClass()) 2065 Diag(D.getIdentifierLoc(), 2066 diag::err_static_data_member_not_allowed_in_local_class) 2067 << Name << RD->getDeclName(); 2068 } 2069 } 2070 2071 // Check that we can declare a template here. 2072 if (TemplateParamLists.size() && 2073 CheckTemplateDeclScope(S, TemplateParamLists)) 2074 return 0; 2075 2076 // Match up the template parameter lists with the scope specifier, then 2077 // determine whether we have a template or a template specialization. 2078 if (TemplateParameterList *TemplateParams 2079 = MatchTemplateParametersToScopeSpecifier( 2080 D.getDeclSpec().getSourceRange().getBegin(), 2081 D.getCXXScopeSpec(), 2082 (TemplateParameterList**)TemplateParamLists.get(), 2083 TemplateParamLists.size())) { 2084 if (TemplateParams->size() > 0) { 2085 // There is no such thing as a variable template. 2086 Diag(D.getIdentifierLoc(), diag::err_template_variable) 2087 << II 2088 << SourceRange(TemplateParams->getTemplateLoc(), 2089 TemplateParams->getRAngleLoc()); 2090 return 0; 2091 } else { 2092 // There is an extraneous 'template<>' for this variable. Complain 2093 // about it, but allow the declaration of the variable. 2094 Diag(TemplateParams->getTemplateLoc(), 2095 diag::err_template_variable_noparams) 2096 << II 2097 << SourceRange(TemplateParams->getTemplateLoc(), 2098 TemplateParams->getRAngleLoc()); 2099 } 2100 } 2101 2102 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 2103 II, R, SC, 2104 // FIXME: Move to DeclGroup... 2105 D.getDeclSpec().getSourceRange().getBegin()); 2106 2107 if (D.isInvalidType()) 2108 NewVD->setInvalidDecl(); 2109 2110 if (D.getDeclSpec().isThreadSpecified()) { 2111 if (NewVD->hasLocalStorage()) 2112 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 2113 else if (!Context.Target.isTLSSupported()) 2114 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 2115 else 2116 NewVD->setThreadSpecified(true); 2117 } 2118 2119 // Set the lexical context. If the declarator has a C++ scope specifier, the 2120 // lexical context will be different from the semantic context. 2121 NewVD->setLexicalDeclContext(CurContext); 2122 2123 // Handle attributes prior to checking for duplicates in MergeVarDecl 2124 ProcessDeclAttributes(S, NewVD, D); 2125 2126 // Handle GNU asm-label extension (encoded as an attribute). 2127 if (Expr *E = (Expr*) D.getAsmLabel()) { 2128 // The parser guarantees this is a string. 2129 StringLiteral *SE = cast<StringLiteral>(E); 2130 NewVD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2131 SE->getByteLength()))); 2132 } 2133 2134 // If name lookup finds a previous declaration that is not in the 2135 // same scope as the new declaration, this may still be an 2136 // acceptable redeclaration. 2137 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2138 !(NewVD->hasLinkage() && 2139 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2140 PrevDecl = 0; 2141 2142 // Merge the decl with the existing one if appropriate. 2143 if (PrevDecl) { 2144 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 2145 // The user tried to define a non-static data member 2146 // out-of-line (C++ [dcl.meaning]p1). 2147 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 2148 << D.getCXXScopeSpec().getRange(); 2149 PrevDecl = 0; 2150 NewVD->setInvalidDecl(); 2151 } 2152 } else if (D.getCXXScopeSpec().isSet()) { 2153 // No previous declaration in the qualifying scope. 2154 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 2155 << Name << D.getCXXScopeSpec().getRange(); 2156 NewVD->setInvalidDecl(); 2157 } 2158 2159 CheckVariableDeclaration(NewVD, PrevDecl, Redeclaration); 2160 2161 // attributes declared post-definition are currently ignored 2162 if (PrevDecl) { 2163 const VarDecl *Def = 0, *PrevVD = dyn_cast<VarDecl>(PrevDecl); 2164 if (PrevVD->getDefinition(Def) && D.hasAttributes()) { 2165 Diag(NewVD->getLocation(), diag::warn_attribute_precede_definition); 2166 Diag(Def->getLocation(), diag::note_previous_definition); 2167 } 2168 } 2169 2170 // If this is a locally-scoped extern C variable, update the map of 2171 // such variables. 2172 if (CurContext->isFunctionOrMethod() && NewVD->isExternC(Context) && 2173 !NewVD->isInvalidDecl()) 2174 RegisterLocallyScopedExternCDecl(NewVD, PrevDecl, S); 2175 2176 return NewVD; 2177} 2178 2179/// \brief Perform semantic checking on a newly-created variable 2180/// declaration. 2181/// 2182/// This routine performs all of the type-checking required for a 2183/// variable declaration once it has been built. It is used both to 2184/// check variables after they have been parsed and their declarators 2185/// have been translated into a declaration, and to check variables 2186/// that have been instantiated from a template. 2187/// 2188/// Sets NewVD->isInvalidDecl() if an error was encountered. 2189void Sema::CheckVariableDeclaration(VarDecl *NewVD, NamedDecl *PrevDecl, 2190 bool &Redeclaration) { 2191 // If the decl is already known invalid, don't check it. 2192 if (NewVD->isInvalidDecl()) 2193 return; 2194 2195 QualType T = NewVD->getType(); 2196 2197 if (T->isObjCInterfaceType()) { 2198 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 2199 return NewVD->setInvalidDecl(); 2200 } 2201 2202 // The variable can not have an abstract class type. 2203 if (RequireNonAbstractType(NewVD->getLocation(), T, 2204 diag::err_abstract_type_in_decl, 2205 AbstractVariableType)) 2206 return NewVD->setInvalidDecl(); 2207 2208 // Emit an error if an address space was applied to decl with local storage. 2209 // This includes arrays of objects with address space qualifiers, but not 2210 // automatic variables that point to other address spaces. 2211 // ISO/IEC TR 18037 S5.1.2 2212 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 2213 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 2214 return NewVD->setInvalidDecl(); 2215 } 2216 2217 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 2218 && !NewVD->hasAttr<BlocksAttr>()) 2219 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 2220 2221 bool isVM = T->isVariablyModifiedType(); 2222 if (isVM || NewVD->hasAttr<CleanupAttr>() || 2223 NewVD->hasAttr<BlocksAttr>()) 2224 CurFunctionNeedsScopeChecking = true; 2225 2226 if ((isVM && NewVD->hasLinkage()) || 2227 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 2228 bool SizeIsNegative; 2229 QualType FixedTy = 2230 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2231 2232 if (FixedTy.isNull() && T->isVariableArrayType()) { 2233 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2234 // FIXME: This won't give the correct result for 2235 // int a[10][n]; 2236 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2237 2238 if (NewVD->isFileVarDecl()) 2239 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 2240 << SizeRange; 2241 else if (NewVD->getStorageClass() == VarDecl::Static) 2242 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 2243 << SizeRange; 2244 else 2245 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 2246 << SizeRange; 2247 return NewVD->setInvalidDecl(); 2248 } 2249 2250 if (FixedTy.isNull()) { 2251 if (NewVD->isFileVarDecl()) 2252 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 2253 else 2254 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 2255 return NewVD->setInvalidDecl(); 2256 } 2257 2258 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 2259 NewVD->setType(FixedTy); 2260 } 2261 2262 if (!PrevDecl && NewVD->isExternC(Context)) { 2263 // Since we did not find anything by this name and we're declaring 2264 // an extern "C" variable, look for a non-visible extern "C" 2265 // declaration with the same name. 2266 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2267 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 2268 if (Pos != LocallyScopedExternalDecls.end()) 2269 PrevDecl = Pos->second; 2270 } 2271 2272 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 2273 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 2274 << T; 2275 return NewVD->setInvalidDecl(); 2276 } 2277 2278 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 2279 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 2280 return NewVD->setInvalidDecl(); 2281 } 2282 2283 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 2284 Diag(NewVD->getLocation(), diag::err_block_on_vm); 2285 return NewVD->setInvalidDecl(); 2286 } 2287 2288 if (PrevDecl) { 2289 Redeclaration = true; 2290 MergeVarDecl(NewVD, PrevDecl); 2291 } 2292} 2293 2294NamedDecl* 2295Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2296 QualType R, NamedDecl* PrevDecl, 2297 MultiTemplateParamsArg TemplateParamLists, 2298 bool IsFunctionDefinition, bool &Redeclaration) { 2299 assert(R.getTypePtr()->isFunctionType()); 2300 2301 DeclarationName Name = GetNameForDeclarator(D); 2302 FunctionDecl::StorageClass SC = FunctionDecl::None; 2303 switch (D.getDeclSpec().getStorageClassSpec()) { 2304 default: assert(0 && "Unknown storage class!"); 2305 case DeclSpec::SCS_auto: 2306 case DeclSpec::SCS_register: 2307 case DeclSpec::SCS_mutable: 2308 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2309 diag::err_typecheck_sclass_func); 2310 D.setInvalidType(); 2311 break; 2312 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 2313 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 2314 case DeclSpec::SCS_static: { 2315 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 2316 // C99 6.7.1p5: 2317 // The declaration of an identifier for a function that has 2318 // block scope shall have no explicit storage-class specifier 2319 // other than extern 2320 // See also (C++ [dcl.stc]p4). 2321 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2322 diag::err_static_block_func); 2323 SC = FunctionDecl::None; 2324 } else 2325 SC = FunctionDecl::Static; 2326 break; 2327 } 2328 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 2329 } 2330 2331 if (D.getDeclSpec().isThreadSpecified()) 2332 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2333 2334 bool isInline = D.getDeclSpec().isInlineSpecified(); 2335 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 2336 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 2337 2338 // Check that the return type is not an abstract class type. 2339 // For record types, this is done by the AbstractClassUsageDiagnoser once 2340 // the class has been completely parsed. 2341 if (!DC->isRecord() && 2342 RequireNonAbstractType(D.getIdentifierLoc(), 2343 R->getAsFunctionType()->getResultType(), 2344 diag::err_abstract_type_in_decl, 2345 AbstractReturnType)) 2346 D.setInvalidType(); 2347 2348 // Do not allow returning a objc interface by-value. 2349 if (R->getAsFunctionType()->getResultType()->isObjCInterfaceType()) { 2350 Diag(D.getIdentifierLoc(), 2351 diag::err_object_cannot_be_passed_returned_by_value) << 0 2352 << R->getAsFunctionType()->getResultType(); 2353 D.setInvalidType(); 2354 } 2355 2356 // Check that we can declare a template here. 2357 if (TemplateParamLists.size() && 2358 CheckTemplateDeclScope(S, TemplateParamLists)) 2359 return 0; 2360 2361 bool isVirtualOkay = false; 2362 FunctionDecl *NewFD; 2363 if (D.getKind() == Declarator::DK_Constructor) { 2364 // This is a C++ constructor declaration. 2365 assert(DC->isRecord() && 2366 "Constructors can only be declared in a member context"); 2367 2368 R = CheckConstructorDeclarator(D, R, SC); 2369 2370 // Create the new declaration 2371 NewFD = CXXConstructorDecl::Create(Context, 2372 cast<CXXRecordDecl>(DC), 2373 D.getIdentifierLoc(), Name, R, 2374 isExplicit, isInline, 2375 /*isImplicitlyDeclared=*/false); 2376 } else if (D.getKind() == Declarator::DK_Destructor) { 2377 // This is a C++ destructor declaration. 2378 if (DC->isRecord()) { 2379 R = CheckDestructorDeclarator(D, SC); 2380 2381 NewFD = CXXDestructorDecl::Create(Context, 2382 cast<CXXRecordDecl>(DC), 2383 D.getIdentifierLoc(), Name, R, 2384 isInline, 2385 /*isImplicitlyDeclared=*/false); 2386 2387 isVirtualOkay = true; 2388 } else { 2389 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 2390 2391 // Create a FunctionDecl to satisfy the function definition parsing 2392 // code path. 2393 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 2394 Name, R, SC, isInline, 2395 /*hasPrototype=*/true, 2396 // FIXME: Move to DeclGroup... 2397 D.getDeclSpec().getSourceRange().getBegin()); 2398 D.setInvalidType(); 2399 } 2400 } else if (D.getKind() == Declarator::DK_Conversion) { 2401 if (!DC->isRecord()) { 2402 Diag(D.getIdentifierLoc(), 2403 diag::err_conv_function_not_member); 2404 return 0; 2405 } 2406 2407 CheckConversionDeclarator(D, R, SC); 2408 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 2409 D.getIdentifierLoc(), Name, R, 2410 isInline, isExplicit); 2411 2412 isVirtualOkay = true; 2413 } else if (DC->isRecord()) { 2414 // If the of the function is the same as the name of the record, then this 2415 // must be an invalid constructor that has a return type. 2416 // (The parser checks for a return type and makes the declarator a 2417 // constructor if it has no return type). 2418 // must have an invalid constructor that has a return type 2419 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 2420 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 2421 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 2422 << SourceRange(D.getIdentifierLoc()); 2423 return 0; 2424 } 2425 2426 // This is a C++ method declaration. 2427 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 2428 D.getIdentifierLoc(), Name, R, 2429 (SC == FunctionDecl::Static), isInline); 2430 2431 isVirtualOkay = (SC != FunctionDecl::Static); 2432 } else { 2433 // Determine whether the function was written with a 2434 // prototype. This true when: 2435 // - we're in C++ (where every function has a prototype), 2436 // - there is a prototype in the declarator, or 2437 // - the type R of the function is some kind of typedef or other reference 2438 // to a type name (which eventually refers to a function type). 2439 bool HasPrototype = 2440 getLangOptions().CPlusPlus || 2441 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 2442 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 2443 2444 NewFD = FunctionDecl::Create(Context, DC, 2445 D.getIdentifierLoc(), 2446 Name, R, SC, isInline, HasPrototype, 2447 // FIXME: Move to DeclGroup... 2448 D.getDeclSpec().getSourceRange().getBegin()); 2449 } 2450 2451 if (D.isInvalidType()) 2452 NewFD->setInvalidDecl(); 2453 2454 // Set the lexical context. If the declarator has a C++ 2455 // scope specifier, the lexical context will be different 2456 // from the semantic context. 2457 NewFD->setLexicalDeclContext(CurContext); 2458 2459 // Match up the template parameter lists with the scope specifier, then 2460 // determine whether we have a template or a template specialization. 2461 FunctionTemplateDecl *FunctionTemplate = 0; 2462 if (TemplateParameterList *TemplateParams 2463 = MatchTemplateParametersToScopeSpecifier( 2464 D.getDeclSpec().getSourceRange().getBegin(), 2465 D.getCXXScopeSpec(), 2466 (TemplateParameterList**)TemplateParamLists.get(), 2467 TemplateParamLists.size())) { 2468 if (TemplateParams->size() > 0) { 2469 // This is a function template 2470 FunctionTemplate = FunctionTemplateDecl::Create(Context, CurContext, 2471 NewFD->getLocation(), 2472 Name, TemplateParams, 2473 NewFD); 2474 NewFD->setDescribedFunctionTemplate(FunctionTemplate); 2475 } else { 2476 // FIXME: Handle function template specializations 2477 } 2478 2479 // FIXME: Free this memory properly. 2480 TemplateParamLists.release(); 2481 } 2482 2483 // C++ [dcl.fct.spec]p5: 2484 // The virtual specifier shall only be used in declarations of 2485 // nonstatic class member functions that appear within a 2486 // member-specification of a class declaration; see 10.3. 2487 // 2488 if (isVirtual && !NewFD->isInvalidDecl()) { 2489 if (!isVirtualOkay) { 2490 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2491 diag::err_virtual_non_function); 2492 } else if (!CurContext->isRecord()) { 2493 // 'virtual' was specified outside of the class. 2494 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 2495 << CodeModificationHint::CreateRemoval( 2496 SourceRange(D.getDeclSpec().getVirtualSpecLoc())); 2497 } else { 2498 // Okay: Add virtual to the method. 2499 cast<CXXMethodDecl>(NewFD)->setVirtualAsWritten(true); 2500 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 2501 CurClass->setAggregate(false); 2502 CurClass->setPOD(false); 2503 CurClass->setPolymorphic(true); 2504 CurClass->setHasTrivialConstructor(false); 2505 CurClass->setHasTrivialCopyConstructor(false); 2506 CurClass->setHasTrivialCopyAssignment(false); 2507 } 2508 } 2509 2510 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD)) { 2511 // Look for virtual methods in base classes that this method might override. 2512 2513 BasePaths Paths; 2514 if (LookupInBases(cast<CXXRecordDecl>(DC), 2515 MemberLookupCriteria(NewMD), Paths)) { 2516 for (BasePaths::decl_iterator I = Paths.found_decls_begin(), 2517 E = Paths.found_decls_end(); I != E; ++I) { 2518 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2519 if (!CheckOverridingFunctionReturnType(NewMD, OldMD) && 2520 !CheckOverridingFunctionExceptionSpec(NewMD, OldMD)) 2521 NewMD->addOverriddenMethod(OldMD); 2522 } 2523 } 2524 } 2525 } 2526 2527 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 2528 !CurContext->isRecord()) { 2529 // C++ [class.static]p1: 2530 // A data or function member of a class may be declared static 2531 // in a class definition, in which case it is a static member of 2532 // the class. 2533 2534 // Complain about the 'static' specifier if it's on an out-of-line 2535 // member function definition. 2536 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2537 diag::err_static_out_of_line) 2538 << CodeModificationHint::CreateRemoval( 2539 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2540 } 2541 2542 // Handle GNU asm-label extension (encoded as an attribute). 2543 if (Expr *E = (Expr*) D.getAsmLabel()) { 2544 // The parser guarantees this is a string. 2545 StringLiteral *SE = cast<StringLiteral>(E); 2546 NewFD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2547 SE->getByteLength()))); 2548 } 2549 2550 // Copy the parameter declarations from the declarator D to the function 2551 // declaration NewFD, if they are available. First scavenge them into Params. 2552 llvm::SmallVector<ParmVarDecl*, 16> Params; 2553 if (D.getNumTypeObjects() > 0) { 2554 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2555 2556 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 2557 // function that takes no arguments, not a function that takes a 2558 // single void argument. 2559 // We let through "const void" here because Sema::GetTypeForDeclarator 2560 // already checks for that case. 2561 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 2562 FTI.ArgInfo[0].Param && 2563 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 2564 // Empty arg list, don't push any params. 2565 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 2566 2567 // In C++, the empty parameter-type-list must be spelled "void"; a 2568 // typedef of void is not permitted. 2569 if (getLangOptions().CPlusPlus && 2570 Param->getType().getUnqualifiedType() != Context.VoidTy) 2571 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 2572 // FIXME: Leaks decl? 2573 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 2574 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2575 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 2576 assert(Param->getDeclContext() != NewFD && "Was set before ?"); 2577 Param->setDeclContext(NewFD); 2578 Params.push_back(Param); 2579 } 2580 } 2581 2582 } else if (const FunctionProtoType *FT = R->getAsFunctionProtoType()) { 2583 // When we're declaring a function with a typedef, typeof, etc as in the 2584 // following example, we'll need to synthesize (unnamed) 2585 // parameters for use in the declaration. 2586 // 2587 // @code 2588 // typedef void fn(int); 2589 // fn f; 2590 // @endcode 2591 2592 // Synthesize a parameter for each argument type. 2593 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 2594 AE = FT->arg_type_end(); AI != AE; ++AI) { 2595 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 2596 SourceLocation(), 0, 2597 *AI, VarDecl::None, 0); 2598 Param->setImplicit(); 2599 Params.push_back(Param); 2600 } 2601 } else { 2602 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 2603 "Should not need args for typedef of non-prototype fn"); 2604 } 2605 // Finally, we know we have the right number of parameters, install them. 2606 NewFD->setParams(Context, Params.data(), Params.size()); 2607 2608 // If name lookup finds a previous declaration that is not in the 2609 // same scope as the new declaration, this may still be an 2610 // acceptable redeclaration. 2611 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2612 !(NewFD->hasLinkage() && 2613 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2614 PrevDecl = 0; 2615 2616 // Perform semantic checking on the function declaration. 2617 bool OverloadableAttrRequired = false; // FIXME: HACK! 2618 CheckFunctionDeclaration(NewFD, PrevDecl, Redeclaration, 2619 /*FIXME:*/OverloadableAttrRequired); 2620 2621 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 2622 // An out-of-line member function declaration must also be a 2623 // definition (C++ [dcl.meaning]p1). 2624 if (!IsFunctionDefinition) { 2625 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2626 << D.getCXXScopeSpec().getRange(); 2627 NewFD->setInvalidDecl(); 2628 } else if (!Redeclaration && (!PrevDecl || !isa<UsingDecl>(PrevDecl))) { 2629 // The user tried to provide an out-of-line definition for a 2630 // function that is a member of a class or namespace, but there 2631 // was no such member function declared (C++ [class.mfct]p2, 2632 // C++ [namespace.memdef]p2). For example: 2633 // 2634 // class X { 2635 // void f() const; 2636 // }; 2637 // 2638 // void X::f() { } // ill-formed 2639 // 2640 // Complain about this problem, and attempt to suggest close 2641 // matches (e.g., those that differ only in cv-qualifiers and 2642 // whether the parameter types are references). 2643 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 2644 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 2645 NewFD->setInvalidDecl(); 2646 2647 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 2648 true); 2649 assert(!Prev.isAmbiguous() && 2650 "Cannot have an ambiguity in previous-declaration lookup"); 2651 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 2652 Func != FuncEnd; ++Func) { 2653 if (isa<FunctionDecl>(*Func) && 2654 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 2655 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 2656 } 2657 2658 PrevDecl = 0; 2659 } 2660 } 2661 2662 // Handle attributes. We need to have merged decls when handling attributes 2663 // (for example to check for conflicts, etc). 2664 // FIXME: This needs to happen before we merge declarations. Then, 2665 // let attribute merging cope with attribute conflicts. 2666 ProcessDeclAttributes(S, NewFD, D); 2667 2668 // attributes declared post-definition are currently ignored 2669 if (PrevDecl) { 2670 const FunctionDecl *Def, *PrevFD = dyn_cast<FunctionDecl>(PrevDecl); 2671 if (PrevFD && PrevFD->getBody(Def) && D.hasAttributes()) { 2672 Diag(NewFD->getLocation(), diag::warn_attribute_precede_definition); 2673 Diag(Def->getLocation(), diag::note_previous_definition); 2674 } 2675 } 2676 2677 AddKnownFunctionAttributes(NewFD); 2678 2679 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 2680 // If a function name is overloadable in C, then every function 2681 // with that name must be marked "overloadable". 2682 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 2683 << Redeclaration << NewFD; 2684 if (PrevDecl) 2685 Diag(PrevDecl->getLocation(), 2686 diag::note_attribute_overloadable_prev_overload); 2687 NewFD->addAttr(::new (Context) OverloadableAttr()); 2688 } 2689 2690 // If this is a locally-scoped extern C function, update the 2691 // map of such names. 2692 if (CurContext->isFunctionOrMethod() && NewFD->isExternC(Context) 2693 && !NewFD->isInvalidDecl()) 2694 RegisterLocallyScopedExternCDecl(NewFD, PrevDecl, S); 2695 2696 // Set this FunctionDecl's range up to the right paren. 2697 NewFD->setLocEnd(D.getSourceRange().getEnd()); 2698 2699 if (FunctionTemplate && NewFD->isInvalidDecl()) 2700 FunctionTemplate->setInvalidDecl(); 2701 2702 if (FunctionTemplate) 2703 return FunctionTemplate; 2704 2705 return NewFD; 2706} 2707 2708/// \brief Perform semantic checking of a new function declaration. 2709/// 2710/// Performs semantic analysis of the new function declaration 2711/// NewFD. This routine performs all semantic checking that does not 2712/// require the actual declarator involved in the declaration, and is 2713/// used both for the declaration of functions as they are parsed 2714/// (called via ActOnDeclarator) and for the declaration of functions 2715/// that have been instantiated via C++ template instantiation (called 2716/// via InstantiateDecl). 2717/// 2718/// This sets NewFD->isInvalidDecl() to true if there was an error. 2719void Sema::CheckFunctionDeclaration(FunctionDecl *NewFD, NamedDecl *&PrevDecl, 2720 bool &Redeclaration, 2721 bool &OverloadableAttrRequired) { 2722 // If NewFD is already known erroneous, don't do any of this checking. 2723 if (NewFD->isInvalidDecl()) 2724 return; 2725 2726 if (NewFD->getResultType()->isVariablyModifiedType()) { 2727 // Functions returning a variably modified type violate C99 6.7.5.2p2 2728 // because all functions have linkage. 2729 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 2730 return NewFD->setInvalidDecl(); 2731 } 2732 2733 if (NewFD->isMain()) CheckMain(NewFD); 2734 2735 // Semantic checking for this function declaration (in isolation). 2736 if (getLangOptions().CPlusPlus) { 2737 // C++-specific checks. 2738 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 2739 CheckConstructor(Constructor); 2740 } else if (isa<CXXDestructorDecl>(NewFD)) { 2741 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 2742 QualType ClassType = Context.getTypeDeclType(Record); 2743 if (!ClassType->isDependentType()) { 2744 ClassType = Context.getCanonicalType(ClassType); 2745 DeclarationName Name 2746 = Context.DeclarationNames.getCXXDestructorName(ClassType); 2747 if (NewFD->getDeclName() != Name) { 2748 Diag(NewFD->getLocation(), diag::err_destructor_name); 2749 return NewFD->setInvalidDecl(); 2750 } 2751 } 2752 Record->setUserDeclaredDestructor(true); 2753 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 2754 // user-defined destructor. 2755 Record->setPOD(false); 2756 2757 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 2758 // declared destructor. 2759 // FIXME: C++0x: don't do this for "= default" destructors 2760 Record->setHasTrivialDestructor(false); 2761 } else if (CXXConversionDecl *Conversion 2762 = dyn_cast<CXXConversionDecl>(NewFD)) 2763 ActOnConversionDeclarator(Conversion); 2764 2765 // Extra checking for C++ overloaded operators (C++ [over.oper]). 2766 if (NewFD->isOverloadedOperator() && 2767 CheckOverloadedOperatorDeclaration(NewFD)) 2768 return NewFD->setInvalidDecl(); 2769 } 2770 2771 // C99 6.7.4p6: 2772 // [... ] For a function with external linkage, the following 2773 // restrictions apply: [...] If all of the file scope declarations 2774 // for a function in a translation unit include the inline 2775 // function specifier without extern, then the definition in that 2776 // translation unit is an inline definition. An inline definition 2777 // does not provide an external definition for the function, and 2778 // does not forbid an external definition in another translation 2779 // unit. 2780 // 2781 // Here we determine whether this function, in isolation, would be a 2782 // C99 inline definition. MergeCompatibleFunctionDecls looks at 2783 // previous declarations. 2784 if (NewFD->isInline() && getLangOptions().C99 && 2785 NewFD->getStorageClass() == FunctionDecl::None && 2786 NewFD->getDeclContext()->getLookupContext()->isTranslationUnit()) 2787 NewFD->setC99InlineDefinition(true); 2788 2789 // Check for a previous declaration of this name. 2790 if (!PrevDecl && NewFD->isExternC(Context)) { 2791 // Since we did not find anything by this name and we're declaring 2792 // an extern "C" function, look for a non-visible extern "C" 2793 // declaration with the same name. 2794 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2795 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 2796 if (Pos != LocallyScopedExternalDecls.end()) 2797 PrevDecl = Pos->second; 2798 } 2799 2800 // Merge or overload the declaration with an existing declaration of 2801 // the same name, if appropriate. 2802 if (PrevDecl) { 2803 // Determine whether NewFD is an overload of PrevDecl or 2804 // a declaration that requires merging. If it's an overload, 2805 // there's no more work to do here; we'll just add the new 2806 // function to the scope. 2807 OverloadedFunctionDecl::function_iterator MatchedDecl; 2808 2809 if (!getLangOptions().CPlusPlus && 2810 AllowOverloadingOfFunction(PrevDecl, Context)) { 2811 OverloadableAttrRequired = true; 2812 2813 // Functions marked "overloadable" must have a prototype (that 2814 // we can't get through declaration merging). 2815 if (!NewFD->getType()->getAsFunctionProtoType()) { 2816 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 2817 << NewFD; 2818 Redeclaration = true; 2819 2820 // Turn this into a variadic function with no parameters. 2821 QualType R = Context.getFunctionType( 2822 NewFD->getType()->getAsFunctionType()->getResultType(), 2823 0, 0, true, 0); 2824 NewFD->setType(R); 2825 return NewFD->setInvalidDecl(); 2826 } 2827 } 2828 2829 if (PrevDecl && 2830 (!AllowOverloadingOfFunction(PrevDecl, Context) || 2831 !IsOverload(NewFD, PrevDecl, MatchedDecl)) && 2832 !isa<UsingDecl>(PrevDecl)) { 2833 Redeclaration = true; 2834 Decl *OldDecl = PrevDecl; 2835 2836 // If PrevDecl was an overloaded function, extract the 2837 // FunctionDecl that matched. 2838 if (isa<OverloadedFunctionDecl>(PrevDecl)) 2839 OldDecl = *MatchedDecl; 2840 2841 // NewFD and OldDecl represent declarations that need to be 2842 // merged. 2843 if (MergeFunctionDecl(NewFD, OldDecl)) 2844 return NewFD->setInvalidDecl(); 2845 2846 if (FunctionTemplateDecl *OldTemplateDecl 2847 = dyn_cast<FunctionTemplateDecl>(OldDecl)) 2848 NewFD->setPreviousDeclaration(OldTemplateDecl->getTemplatedDecl()); 2849 else { 2850 if (isa<CXXMethodDecl>(NewFD)) // Set access for out-of-line definitions 2851 NewFD->setAccess(OldDecl->getAccess()); 2852 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 2853 } 2854 } 2855 } 2856 2857 // In C++, check default arguments now that we have merged decls. Unless 2858 // the lexical context is the class, because in this case this is done 2859 // during delayed parsing anyway. 2860 if (getLangOptions().CPlusPlus && !CurContext->isRecord()) 2861 CheckCXXDefaultArguments(NewFD); 2862} 2863 2864void Sema::CheckMain(FunctionDecl* FD) { 2865 // C++ [basic.start.main]p3: A program that declares main to be inline 2866 // or static is ill-formed. 2867 // C99 6.7.4p4: In a hosted environment, the inline function specifier 2868 // shall not appear in a declaration of main. 2869 // static main is not an error under C99, but we should warn about it. 2870 bool isInline = FD->isInline(); 2871 bool isStatic = FD->getStorageClass() == FunctionDecl::Static; 2872 if (isInline || isStatic) { 2873 unsigned diagID = diag::warn_unusual_main_decl; 2874 if (isInline || getLangOptions().CPlusPlus) 2875 diagID = diag::err_unusual_main_decl; 2876 2877 int which = isStatic + (isInline << 1) - 1; 2878 Diag(FD->getLocation(), diagID) << which; 2879 } 2880 2881 QualType T = FD->getType(); 2882 assert(T->isFunctionType() && "function decl is not of function type"); 2883 const FunctionType* FT = T->getAsFunctionType(); 2884 2885 if (!Context.hasSameUnqualifiedType(FT->getResultType(), Context.IntTy)) { 2886 // TODO: add a replacement fixit to turn the return type into 'int'. 2887 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint); 2888 FD->setInvalidDecl(true); 2889 } 2890 2891 // Treat protoless main() as nullary. 2892 if (isa<FunctionNoProtoType>(FT)) return; 2893 2894 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 2895 unsigned nparams = FTP->getNumArgs(); 2896 assert(FD->getNumParams() == nparams); 2897 2898 if (nparams > 3) { 2899 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 2900 FD->setInvalidDecl(true); 2901 nparams = 3; 2902 } 2903 2904 // FIXME: a lot of the following diagnostics would be improved 2905 // if we had some location information about types. 2906 2907 QualType CharPP = 2908 Context.getPointerType(Context.getPointerType(Context.CharTy)); 2909 QualType Expected[] = { Context.IntTy, CharPP, CharPP }; 2910 2911 for (unsigned i = 0; i < nparams; ++i) { 2912 QualType AT = FTP->getArgType(i); 2913 2914 bool mismatch = true; 2915 2916 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 2917 mismatch = false; 2918 else if (Expected[i] == CharPP) { 2919 // As an extension, the following forms are okay: 2920 // char const ** 2921 // char const * const * 2922 // char * const * 2923 2924 QualifierSet qs; 2925 const PointerType* PT; 2926 if ((PT = qs.strip(AT)->getAsPointerType()) && 2927 (PT = qs.strip(PT->getPointeeType())->getAsPointerType()) && 2928 (QualType(qs.strip(PT->getPointeeType()), 0) == Context.CharTy)) { 2929 qs.removeConst(); 2930 mismatch = !qs.empty(); 2931 } 2932 } 2933 2934 if (mismatch) { 2935 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 2936 // TODO: suggest replacing given type with expected type 2937 FD->setInvalidDecl(true); 2938 } 2939 } 2940 2941 if (nparams == 1 && !FD->isInvalidDecl()) { 2942 Diag(FD->getLocation(), diag::warn_main_one_arg); 2943 } 2944} 2945 2946bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2947 // FIXME: Need strict checking. In C89, we need to check for 2948 // any assignment, increment, decrement, function-calls, or 2949 // commas outside of a sizeof. In C99, it's the same list, 2950 // except that the aforementioned are allowed in unevaluated 2951 // expressions. Everything else falls under the 2952 // "may accept other forms of constant expressions" exception. 2953 // (We never end up here for C++, so the constant expression 2954 // rules there don't matter.) 2955 if (Init->isConstantInitializer(Context)) 2956 return false; 2957 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 2958 << Init->getSourceRange(); 2959 return true; 2960} 2961 2962void Sema::AddInitializerToDecl(DeclPtrTy dcl, FullExprArg init) { 2963 AddInitializerToDecl(dcl, init.release(), /*DirectInit=*/false); 2964} 2965 2966/// AddInitializerToDecl - Adds the initializer Init to the 2967/// declaration dcl. If DirectInit is true, this is C++ direct 2968/// initialization rather than copy initialization. 2969void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 2970 Decl *RealDecl = dcl.getAs<Decl>(); 2971 // If there is no declaration, there was an error parsing it. Just ignore 2972 // the initializer. 2973 if (RealDecl == 0) 2974 return; 2975 2976 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 2977 // With declarators parsed the way they are, the parser cannot 2978 // distinguish between a normal initializer and a pure-specifier. 2979 // Thus this grotesque test. 2980 IntegerLiteral *IL; 2981 Expr *Init = static_cast<Expr *>(init.get()); 2982 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 2983 Context.getCanonicalType(IL->getType()) == Context.IntTy) { 2984 if (Method->isVirtualAsWritten()) { 2985 Method->setPure(); 2986 2987 // A class is abstract if at least one function is pure virtual. 2988 cast<CXXRecordDecl>(CurContext)->setAbstract(true); 2989 } else if (!Method->isInvalidDecl()) { 2990 Diag(Method->getLocation(), diag::err_non_virtual_pure) 2991 << Method->getDeclName() << Init->getSourceRange(); 2992 Method->setInvalidDecl(); 2993 } 2994 } else { 2995 Diag(Method->getLocation(), diag::err_member_function_initialization) 2996 << Method->getDeclName() << Init->getSourceRange(); 2997 Method->setInvalidDecl(); 2998 } 2999 return; 3000 } 3001 3002 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 3003 if (!VDecl) { 3004 if (getLangOptions().CPlusPlus && 3005 RealDecl->getLexicalDeclContext()->isRecord() && 3006 isa<NamedDecl>(RealDecl)) 3007 Diag(RealDecl->getLocation(), diag::err_member_initialization) 3008 << cast<NamedDecl>(RealDecl)->getDeclName(); 3009 else 3010 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 3011 RealDecl->setInvalidDecl(); 3012 return; 3013 } 3014 3015 if (!VDecl->getType()->isArrayType() && 3016 RequireCompleteType(VDecl->getLocation(), VDecl->getType(), 3017 diag::err_typecheck_decl_incomplete_type)) { 3018 RealDecl->setInvalidDecl(); 3019 return; 3020 } 3021 3022 const VarDecl *Def = 0; 3023 if (VDecl->getDefinition(Def)) { 3024 Diag(VDecl->getLocation(), diag::err_redefinition) 3025 << VDecl->getDeclName(); 3026 Diag(Def->getLocation(), diag::note_previous_definition); 3027 VDecl->setInvalidDecl(); 3028 return; 3029 } 3030 3031 // Take ownership of the expression, now that we're sure we have somewhere 3032 // to put it. 3033 Expr *Init = init.takeAs<Expr>(); 3034 assert(Init && "missing initializer"); 3035 3036 // Get the decls type and save a reference for later, since 3037 // CheckInitializerTypes may change it. 3038 QualType DclT = VDecl->getType(), SavT = DclT; 3039 if (VDecl->isBlockVarDecl()) { 3040 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 3041 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 3042 VDecl->setInvalidDecl(); 3043 } else if (!VDecl->isInvalidDecl()) { 3044 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3045 VDecl->getDeclName(), DirectInit)) 3046 VDecl->setInvalidDecl(); 3047 3048 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3049 // Don't check invalid declarations to avoid emitting useless diagnostics. 3050 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3051 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 3052 CheckForConstantInitializer(Init, DclT); 3053 } 3054 } 3055 } else if (VDecl->isStaticDataMember() && 3056 VDecl->getLexicalDeclContext()->isRecord()) { 3057 // This is an in-class initialization for a static data member, e.g., 3058 // 3059 // struct S { 3060 // static const int value = 17; 3061 // }; 3062 3063 // Attach the initializer 3064 VDecl->setInit(Context, Init); 3065 3066 // C++ [class.mem]p4: 3067 // A member-declarator can contain a constant-initializer only 3068 // if it declares a static member (9.4) of const integral or 3069 // const enumeration type, see 9.4.2. 3070 QualType T = VDecl->getType(); 3071 if (!T->isDependentType() && 3072 (!Context.getCanonicalType(T).isConstQualified() || 3073 !T->isIntegralType())) { 3074 Diag(VDecl->getLocation(), diag::err_member_initialization) 3075 << VDecl->getDeclName() << Init->getSourceRange(); 3076 VDecl->setInvalidDecl(); 3077 } else { 3078 // C++ [class.static.data]p4: 3079 // If a static data member is of const integral or const 3080 // enumeration type, its declaration in the class definition 3081 // can specify a constant-initializer which shall be an 3082 // integral constant expression (5.19). 3083 if (!Init->isTypeDependent() && 3084 !Init->getType()->isIntegralType()) { 3085 // We have a non-dependent, non-integral or enumeration type. 3086 Diag(Init->getSourceRange().getBegin(), 3087 diag::err_in_class_initializer_non_integral_type) 3088 << Init->getType() << Init->getSourceRange(); 3089 VDecl->setInvalidDecl(); 3090 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 3091 // Check whether the expression is a constant expression. 3092 llvm::APSInt Value; 3093 SourceLocation Loc; 3094 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 3095 Diag(Loc, diag::err_in_class_initializer_non_constant) 3096 << Init->getSourceRange(); 3097 VDecl->setInvalidDecl(); 3098 } else if (!VDecl->getType()->isDependentType()) 3099 ImpCastExprToType(Init, VDecl->getType()); 3100 } 3101 } 3102 } else if (VDecl->isFileVarDecl()) { 3103 if (VDecl->getStorageClass() == VarDecl::Extern) 3104 Diag(VDecl->getLocation(), diag::warn_extern_init); 3105 if (!VDecl->isInvalidDecl()) 3106 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3107 VDecl->getDeclName(), DirectInit)) 3108 VDecl->setInvalidDecl(); 3109 3110 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3111 // Don't check invalid declarations to avoid emitting useless diagnostics. 3112 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3113 // C99 6.7.8p4. All file scoped initializers need to be constant. 3114 CheckForConstantInitializer(Init, DclT); 3115 } 3116 } 3117 // If the type changed, it means we had an incomplete type that was 3118 // completed by the initializer. For example: 3119 // int ary[] = { 1, 3, 5 }; 3120 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 3121 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 3122 VDecl->setType(DclT); 3123 Init->setType(DclT); 3124 } 3125 3126 // Attach the initializer to the decl. 3127 VDecl->setInit(Context, Init); 3128 3129 // If the previous declaration of VDecl was a tentative definition, 3130 // remove it from the set of tentative definitions. 3131 if (VDecl->getPreviousDeclaration() && 3132 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 3133 llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos 3134 = TentativeDefinitions.find(VDecl->getDeclName()); 3135 assert(Pos != TentativeDefinitions.end() && 3136 "Unrecorded tentative definition?"); 3137 TentativeDefinitions.erase(Pos); 3138 } 3139 3140 return; 3141} 3142 3143void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 3144 bool TypeContainsUndeducedAuto) { 3145 Decl *RealDecl = dcl.getAs<Decl>(); 3146 3147 // If there is no declaration, there was an error parsing it. Just ignore it. 3148 if (RealDecl == 0) 3149 return; 3150 3151 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 3152 QualType Type = Var->getType(); 3153 3154 // Record tentative definitions. 3155 if (Var->isTentativeDefinition(Context)) 3156 TentativeDefinitions[Var->getDeclName()] = Var; 3157 3158 // C++ [dcl.init.ref]p3: 3159 // The initializer can be omitted for a reference only in a 3160 // parameter declaration (8.3.5), in the declaration of a 3161 // function return type, in the declaration of a class member 3162 // within its class declaration (9.2), and where the extern 3163 // specifier is explicitly used. 3164 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 3165 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 3166 << Var->getDeclName() 3167 << SourceRange(Var->getLocation(), Var->getLocation()); 3168 Var->setInvalidDecl(); 3169 return; 3170 } 3171 3172 // C++0x [dcl.spec.auto]p3 3173 if (TypeContainsUndeducedAuto) { 3174 Diag(Var->getLocation(), diag::err_auto_var_requires_init) 3175 << Var->getDeclName() << Type; 3176 Var->setInvalidDecl(); 3177 return; 3178 } 3179 3180 // C++ [dcl.init]p9: 3181 // 3182 // If no initializer is specified for an object, and the object 3183 // is of (possibly cv-qualified) non-POD class type (or array 3184 // thereof), the object shall be default-initialized; if the 3185 // object is of const-qualified type, the underlying class type 3186 // shall have a user-declared default constructor. 3187 if (getLangOptions().CPlusPlus) { 3188 QualType InitType = Type; 3189 if (const ArrayType *Array = Context.getAsArrayType(Type)) 3190 InitType = Array->getElementType(); 3191 if ((!Var->hasExternalStorage() && !Var->isExternC(Context)) && 3192 InitType->isRecordType() && !InitType->isDependentType()) { 3193 CXXRecordDecl *RD = 3194 cast<CXXRecordDecl>(InitType->getAsRecordType()->getDecl()); 3195 CXXConstructorDecl *Constructor = 0; 3196 if (!RequireCompleteType(Var->getLocation(), InitType, 3197 diag::err_invalid_incomplete_type_use)) 3198 Constructor 3199 = PerformInitializationByConstructor(InitType, 0, 0, 3200 Var->getLocation(), 3201 SourceRange(Var->getLocation(), 3202 Var->getLocation()), 3203 Var->getDeclName(), 3204 IK_Default); 3205 if (!Constructor) 3206 Var->setInvalidDecl(); 3207 else { 3208 if (!RD->hasTrivialConstructor()) 3209 InitializeVarWithConstructor(Var, Constructor, InitType, 0, 0); 3210 // FIXME. Must do all that is needed to destroy the object 3211 // on scope exit. For now, just mark the destructor as used. 3212 MarkDestructorReferenced(Var->getLocation(), InitType); 3213 } 3214 } 3215 } 3216 3217#if 0 3218 // FIXME: Temporarily disabled because we are not properly parsing 3219 // linkage specifications on declarations, e.g., 3220 // 3221 // extern "C" const CGPoint CGPointerZero; 3222 // 3223 // C++ [dcl.init]p9: 3224 // 3225 // If no initializer is specified for an object, and the 3226 // object is of (possibly cv-qualified) non-POD class type (or 3227 // array thereof), the object shall be default-initialized; if 3228 // the object is of const-qualified type, the underlying class 3229 // type shall have a user-declared default 3230 // constructor. Otherwise, if no initializer is specified for 3231 // an object, the object and its subobjects, if any, have an 3232 // indeterminate initial value; if the object or any of its 3233 // subobjects are of const-qualified type, the program is 3234 // ill-formed. 3235 // 3236 // This isn't technically an error in C, so we don't diagnose it. 3237 // 3238 // FIXME: Actually perform the POD/user-defined default 3239 // constructor check. 3240 if (getLangOptions().CPlusPlus && 3241 Context.getCanonicalType(Type).isConstQualified() && 3242 !Var->hasExternalStorage()) 3243 Diag(Var->getLocation(), diag::err_const_var_requires_init) 3244 << Var->getName() 3245 << SourceRange(Var->getLocation(), Var->getLocation()); 3246#endif 3247 } 3248} 3249 3250Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 3251 DeclPtrTy *Group, 3252 unsigned NumDecls) { 3253 llvm::SmallVector<Decl*, 8> Decls; 3254 3255 if (DS.isTypeSpecOwned()) 3256 Decls.push_back((Decl*)DS.getTypeRep()); 3257 3258 for (unsigned i = 0; i != NumDecls; ++i) 3259 if (Decl *D = Group[i].getAs<Decl>()) 3260 Decls.push_back(D); 3261 3262 // Perform semantic analysis that depends on having fully processed both 3263 // the declarator and initializer. 3264 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 3265 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 3266 if (!IDecl) 3267 continue; 3268 QualType T = IDecl->getType(); 3269 3270 // Block scope. C99 6.7p7: If an identifier for an object is declared with 3271 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 3272 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 3273 if (!IDecl->isInvalidDecl() && 3274 RequireCompleteType(IDecl->getLocation(), T, 3275 diag::err_typecheck_decl_incomplete_type)) 3276 IDecl->setInvalidDecl(); 3277 } 3278 // File scope. C99 6.9.2p2: A declaration of an identifier for an 3279 // object that has file scope without an initializer, and without a 3280 // storage-class specifier or with the storage-class specifier "static", 3281 // constitutes a tentative definition. Note: A tentative definition with 3282 // external linkage is valid (C99 6.2.2p5). 3283 if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) { 3284 if (const IncompleteArrayType *ArrayT 3285 = Context.getAsIncompleteArrayType(T)) { 3286 if (RequireCompleteType(IDecl->getLocation(), 3287 ArrayT->getElementType(), 3288 diag::err_illegal_decl_array_incomplete_type)) 3289 IDecl->setInvalidDecl(); 3290 } 3291 else if (IDecl->getStorageClass() == VarDecl::Static) { 3292 // C99 6.9.2p3: If the declaration of an identifier for an object is 3293 // a tentative definition and has internal linkage (C99 6.2.2p3), the 3294 // declared type shall not be an incomplete type. 3295 // NOTE: code such as the following 3296 // static struct s; 3297 // struct s { int a; }; 3298 // is accepted by gcc. Hence here we issue a warning instead of 3299 // an error and we do not invalidate the static declaration. 3300 // NOTE: to avoid multiple warnings, only check the first declaration. 3301 if (IDecl->getPreviousDeclaration() == 0) 3302 RequireCompleteType(IDecl->getLocation(), T, 3303 diag::ext_typecheck_decl_incomplete_type); 3304 } 3305 } 3306 } 3307 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 3308 Decls.data(), Decls.size())); 3309} 3310 3311 3312/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 3313/// to introduce parameters into function prototype scope. 3314Sema::DeclPtrTy 3315Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 3316 const DeclSpec &DS = D.getDeclSpec(); 3317 3318 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 3319 VarDecl::StorageClass StorageClass = VarDecl::None; 3320 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 3321 StorageClass = VarDecl::Register; 3322 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 3323 Diag(DS.getStorageClassSpecLoc(), 3324 diag::err_invalid_storage_class_in_func_decl); 3325 D.getMutableDeclSpec().ClearStorageClassSpecs(); 3326 } 3327 3328 if (D.getDeclSpec().isThreadSpecified()) 3329 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3330 3331 DiagnoseFunctionSpecifiers(D); 3332 3333 // Check that there are no default arguments inside the type of this 3334 // parameter (C++ only). 3335 if (getLangOptions().CPlusPlus) 3336 CheckExtraCXXDefaultArguments(D); 3337 3338 TagDecl *OwnedDecl = 0; 3339 QualType parmDeclType = GetTypeForDeclarator(D, S, /*Skip=*/0, &OwnedDecl); 3340 3341 if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) { 3342 // C++ [dcl.fct]p6: 3343 // Types shall not be defined in return or parameter types. 3344 Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type) 3345 << Context.getTypeDeclType(OwnedDecl); 3346 } 3347 3348 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 3349 // Can this happen for params? We already checked that they don't conflict 3350 // among each other. Here they can only shadow globals, which is ok. 3351 IdentifierInfo *II = D.getIdentifier(); 3352 if (II) { 3353 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 3354 if (PrevDecl->isTemplateParameter()) { 3355 // Maybe we will complain about the shadowed template parameter. 3356 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 3357 // Just pretend that we didn't see the previous declaration. 3358 PrevDecl = 0; 3359 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 3360 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 3361 3362 // Recover by removing the name 3363 II = 0; 3364 D.SetIdentifier(0, D.getIdentifierLoc()); 3365 } 3366 } 3367 } 3368 3369 // Parameters can not be abstract class types. 3370 // For record types, this is done by the AbstractClassUsageDiagnoser once 3371 // the class has been completely parsed. 3372 if (!CurContext->isRecord() && 3373 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 3374 diag::err_abstract_type_in_decl, 3375 AbstractParamType)) 3376 D.setInvalidType(true); 3377 3378 QualType T = adjustParameterType(parmDeclType); 3379 3380 ParmVarDecl *New; 3381 if (T == parmDeclType) // parameter type did not need adjustment 3382 New = ParmVarDecl::Create(Context, CurContext, 3383 D.getIdentifierLoc(), II, 3384 parmDeclType, StorageClass, 3385 0); 3386 else // keep track of both the adjusted and unadjusted types 3387 New = OriginalParmVarDecl::Create(Context, CurContext, 3388 D.getIdentifierLoc(), II, T, 3389 parmDeclType, StorageClass, 0); 3390 3391 if (D.isInvalidType()) 3392 New->setInvalidDecl(); 3393 3394 // Parameter declarators cannot be interface types. All ObjC objects are 3395 // passed by reference. 3396 if (T->isObjCInterfaceType()) { 3397 Diag(D.getIdentifierLoc(), 3398 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 3399 New->setInvalidDecl(); 3400 } 3401 3402 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 3403 if (D.getCXXScopeSpec().isSet()) { 3404 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 3405 << D.getCXXScopeSpec().getRange(); 3406 New->setInvalidDecl(); 3407 } 3408 3409 // Add the parameter declaration into this scope. 3410 S->AddDecl(DeclPtrTy::make(New)); 3411 if (II) 3412 IdResolver.AddDecl(New); 3413 3414 ProcessDeclAttributes(S, New, D); 3415 3416 if (New->hasAttr<BlocksAttr>()) { 3417 Diag(New->getLocation(), diag::err_block_on_nonlocal); 3418 } 3419 return DeclPtrTy::make(New); 3420} 3421 3422void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 3423 SourceLocation LocAfterDecls) { 3424 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3425 "Not a function declarator!"); 3426 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3427 3428 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 3429 // for a K&R function. 3430 if (!FTI.hasPrototype) { 3431 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 3432 --i; 3433 if (FTI.ArgInfo[i].Param == 0) { 3434 std::string Code = " int "; 3435 Code += FTI.ArgInfo[i].Ident->getName(); 3436 Code += ";\n"; 3437 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 3438 << FTI.ArgInfo[i].Ident 3439 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code); 3440 3441 // Implicitly declare the argument as type 'int' for lack of a better 3442 // type. 3443 DeclSpec DS; 3444 const char* PrevSpec; // unused 3445 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 3446 PrevSpec); 3447 Declarator ParamD(DS, Declarator::KNRTypeListContext); 3448 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 3449 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 3450 } 3451 } 3452 } 3453} 3454 3455Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 3456 Declarator &D) { 3457 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 3458 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3459 "Not a function declarator!"); 3460 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3461 3462 if (FTI.hasPrototype) { 3463 // FIXME: Diagnose arguments without names in C. 3464 } 3465 3466 Scope *ParentScope = FnBodyScope->getParent(); 3467 3468 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 3469 MultiTemplateParamsArg(*this), 3470 /*IsFunctionDefinition=*/true); 3471 return ActOnStartOfFunctionDef(FnBodyScope, DP); 3472} 3473 3474Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 3475 if (!D) 3476 return D; 3477 FunctionDecl *FD = cast<FunctionDecl>(D.getAs<Decl>()); 3478 3479 CurFunctionNeedsScopeChecking = false; 3480 3481 // See if this is a redefinition. 3482 const FunctionDecl *Definition; 3483 if (FD->getBody(Definition)) { 3484 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 3485 Diag(Definition->getLocation(), diag::note_previous_definition); 3486 } 3487 3488 // Builtin functions cannot be defined. 3489 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3490 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 3491 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 3492 FD->setInvalidDecl(); 3493 } 3494 } 3495 3496 // The return type of a function definition must be complete 3497 // (C99 6.9.1p3, C++ [dcl.fct]p6). 3498 QualType ResultType = FD->getResultType(); 3499 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 3500 !FD->isInvalidDecl() && 3501 RequireCompleteType(FD->getLocation(), ResultType, 3502 diag::err_func_def_incomplete_result)) 3503 FD->setInvalidDecl(); 3504 3505 // GNU warning -Wmissing-prototypes: 3506 // Warn if a global function is defined without a previous 3507 // prototype declaration. This warning is issued even if the 3508 // definition itself provides a prototype. The aim is to detect 3509 // global functions that fail to be declared in header files. 3510 if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) && 3511 !FD->isMain()) { 3512 bool MissingPrototype = true; 3513 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 3514 Prev; Prev = Prev->getPreviousDeclaration()) { 3515 // Ignore any declarations that occur in function or method 3516 // scope, because they aren't visible from the header. 3517 if (Prev->getDeclContext()->isFunctionOrMethod()) 3518 continue; 3519 3520 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 3521 break; 3522 } 3523 3524 if (MissingPrototype) 3525 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 3526 } 3527 3528 if (FnBodyScope) 3529 PushDeclContext(FnBodyScope, FD); 3530 3531 // Check the validity of our function parameters 3532 CheckParmsForFunctionDef(FD); 3533 3534 // Introduce our parameters into the function scope 3535 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 3536 ParmVarDecl *Param = FD->getParamDecl(p); 3537 Param->setOwningFunction(FD); 3538 3539 // If this has an identifier, add it to the scope stack. 3540 if (Param->getIdentifier() && FnBodyScope) 3541 PushOnScopeChains(Param, FnBodyScope); 3542 } 3543 3544 // Checking attributes of current function definition 3545 // dllimport attribute. 3546 if (FD->getAttr<DLLImportAttr>() && 3547 (!FD->getAttr<DLLExportAttr>())) { 3548 // dllimport attribute cannot be applied to definition. 3549 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 3550 Diag(FD->getLocation(), 3551 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 3552 << "dllimport"; 3553 FD->setInvalidDecl(); 3554 return DeclPtrTy::make(FD); 3555 } else { 3556 // If a symbol previously declared dllimport is later defined, the 3557 // attribute is ignored in subsequent references, and a warning is 3558 // emitted. 3559 Diag(FD->getLocation(), 3560 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3561 << FD->getNameAsCString() << "dllimport"; 3562 } 3563 } 3564 return DeclPtrTy::make(FD); 3565} 3566 3567Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 3568 return ActOnFinishFunctionBody(D, move(BodyArg), false); 3569} 3570 3571Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 3572 bool IsInstantiation) { 3573 Decl *dcl = D.getAs<Decl>(); 3574 Stmt *Body = BodyArg.takeAs<Stmt>(); 3575 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3576 FD->setBody(Body); 3577 if (FD->isMain()) 3578 // C and C++ allow for main to automagically return 0. 3579 // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3. 3580 FD->setHasImplicitReturnZero(true); 3581 else 3582 CheckFallThroughForFunctionDef(FD, Body); 3583 3584 if (!FD->isInvalidDecl()) 3585 DiagnoseUnusedParameters(FD->param_begin(), FD->param_end()); 3586 3587 // C++ [basic.def.odr]p2: 3588 // [...] A virtual member function is used if it is not pure. [...] 3589 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 3590 if (Method->isVirtual() && !Method->isPure()) 3591 MarkDeclarationReferenced(Method->getLocation(), Method); 3592 3593 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3594 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3595 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3596 MD->setBody(Body); 3597 CheckFallThroughForFunctionDef(MD, Body); 3598 MD->setEndLoc(Body->getLocEnd()); 3599 3600 if (!MD->isInvalidDecl()) 3601 DiagnoseUnusedParameters(MD->param_begin(), MD->param_end()); 3602 } else { 3603 Body->Destroy(Context); 3604 return DeclPtrTy(); 3605 } 3606 if (!IsInstantiation) 3607 PopDeclContext(); 3608 3609 // Verify and clean out per-function state. 3610 3611 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 3612 3613 // Check goto/label use. 3614 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3615 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 3616 LabelStmt *L = I->second; 3617 3618 // Verify that we have no forward references left. If so, there was a goto 3619 // or address of a label taken, but no definition of it. Label fwd 3620 // definitions are indicated with a null substmt. 3621 if (L->getSubStmt() != 0) 3622 continue; 3623 3624 // Emit error. 3625 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3626 3627 // At this point, we have gotos that use the bogus label. Stitch it into 3628 // the function body so that they aren't leaked and that the AST is well 3629 // formed. 3630 if (Body == 0) { 3631 // The whole function wasn't parsed correctly, just delete this. 3632 L->Destroy(Context); 3633 continue; 3634 } 3635 3636 // Otherwise, the body is valid: we want to stitch the label decl into the 3637 // function somewhere so that it is properly owned and so that the goto 3638 // has a valid target. Do this by creating a new compound stmt with the 3639 // label in it. 3640 3641 // Give the label a sub-statement. 3642 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3643 3644 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 3645 cast<CXXTryStmt>(Body)->getTryBlock() : 3646 cast<CompoundStmt>(Body); 3647 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 3648 Elements.push_back(L); 3649 Compound->setStmts(Context, &Elements[0], Elements.size()); 3650 } 3651 FunctionLabelMap.clear(); 3652 3653 if (!Body) return D; 3654 3655 // Verify that that gotos and switch cases don't jump into scopes illegally. 3656 if (CurFunctionNeedsScopeChecking) 3657 DiagnoseInvalidJumps(Body); 3658 3659 // C++ constructors that have function-try-blocks can't have return 3660 // statements in the handlers of that block. (C++ [except.handle]p14) 3661 // Verify this. 3662 if (isa<CXXConstructorDecl>(dcl) && isa<CXXTryStmt>(Body)) 3663 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 3664 3665 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) 3666 Destructor->computeBaseOrMembersToDestroy(Context); 3667 return D; 3668} 3669 3670/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3671/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3672NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3673 IdentifierInfo &II, Scope *S) { 3674 // Before we produce a declaration for an implicitly defined 3675 // function, see whether there was a locally-scoped declaration of 3676 // this name as a function or variable. If so, use that 3677 // (non-visible) declaration, and complain about it. 3678 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3679 = LocallyScopedExternalDecls.find(&II); 3680 if (Pos != LocallyScopedExternalDecls.end()) { 3681 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 3682 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 3683 return Pos->second; 3684 } 3685 3686 // Extension in C99. Legal in C90, but warn about it. 3687 if (getLangOptions().C99) 3688 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3689 else 3690 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3691 3692 // FIXME: handle stuff like: 3693 // void foo() { extern float X(); } 3694 // void bar() { X(); } <-- implicit decl for X in another scope. 3695 3696 // Set a Declarator for the implicit definition: int foo(); 3697 const char *Dummy; 3698 DeclSpec DS; 3699 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 3700 Error = Error; // Silence warning. 3701 assert(!Error && "Error setting up implicit decl!"); 3702 Declarator D(DS, Declarator::BlockContext); 3703 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 3704 0, 0, false, SourceLocation(), 3705 false, 0,0,0, Loc, D), 3706 SourceLocation()); 3707 D.SetIdentifier(&II, Loc); 3708 3709 // Insert this function into translation-unit scope. 3710 3711 DeclContext *PrevDC = CurContext; 3712 CurContext = Context.getTranslationUnitDecl(); 3713 3714 FunctionDecl *FD = 3715 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D).getAs<Decl>()); 3716 FD->setImplicit(); 3717 3718 CurContext = PrevDC; 3719 3720 AddKnownFunctionAttributes(FD); 3721 3722 return FD; 3723} 3724 3725/// \brief Adds any function attributes that we know a priori based on 3726/// the declaration of this function. 3727/// 3728/// These attributes can apply both to implicitly-declared builtins 3729/// (like __builtin___printf_chk) or to library-declared functions 3730/// like NSLog or printf. 3731void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3732 if (FD->isInvalidDecl()) 3733 return; 3734 3735 // If this is a built-in function, map its builtin attributes to 3736 // actual attributes. 3737 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3738 // Handle printf-formatting attributes. 3739 unsigned FormatIdx; 3740 bool HasVAListArg; 3741 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3742 if (!FD->getAttr<FormatAttr>()) 3743 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 3744 HasVAListArg ? 0 : FormatIdx + 2)); 3745 } 3746 3747 // Mark const if we don't care about errno and that is the only 3748 // thing preventing the function from being const. This allows 3749 // IRgen to use LLVM intrinsics for such functions. 3750 if (!getLangOptions().MathErrno && 3751 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3752 if (!FD->getAttr<ConstAttr>()) 3753 FD->addAttr(::new (Context) ConstAttr()); 3754 } 3755 3756 if (Context.BuiltinInfo.isNoReturn(BuiltinID)) 3757 FD->addAttr(::new (Context) NoReturnAttr()); 3758 } 3759 3760 IdentifierInfo *Name = FD->getIdentifier(); 3761 if (!Name) 3762 return; 3763 if ((!getLangOptions().CPlusPlus && 3764 FD->getDeclContext()->isTranslationUnit()) || 3765 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3766 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3767 LinkageSpecDecl::lang_c)) { 3768 // Okay: this could be a libc/libm/Objective-C function we know 3769 // about. 3770 } else 3771 return; 3772 3773 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 3774 // FIXME: NSLog and NSLogv should be target specific 3775 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3776 // FIXME: We known better than our headers. 3777 const_cast<FormatAttr *>(Format)->setType("printf"); 3778 } else 3779 FD->addAttr(::new (Context) FormatAttr("printf", 1, 3780 Name->isStr("NSLogv") ? 0 : 2)); 3781 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 3782 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 3783 // target-specific builtins, perhaps? 3784 if (!FD->getAttr<FormatAttr>()) 3785 FD->addAttr(::new (Context) FormatAttr("printf", 2, 3786 Name->isStr("vasprintf") ? 0 : 3)); 3787 } 3788} 3789 3790TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T) { 3791 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3792 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3793 3794 // Scope manipulation handled by caller. 3795 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3796 D.getIdentifierLoc(), 3797 D.getIdentifier(), 3798 T); 3799 3800 if (TagType *TT = dyn_cast<TagType>(T)) { 3801 TagDecl *TD = TT->getDecl(); 3802 3803 // If the TagDecl that the TypedefDecl points to is an anonymous decl 3804 // keep track of the TypedefDecl. 3805 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 3806 TD->setTypedefForAnonDecl(NewTD); 3807 } 3808 3809 if (D.isInvalidType()) 3810 NewTD->setInvalidDecl(); 3811 return NewTD; 3812} 3813 3814 3815/// \brief Determine whether a tag with a given kind is acceptable 3816/// as a redeclaration of the given tag declaration. 3817/// 3818/// \returns true if the new tag kind is acceptable, false otherwise. 3819bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 3820 TagDecl::TagKind NewTag, 3821 SourceLocation NewTagLoc, 3822 const IdentifierInfo &Name) { 3823 // C++ [dcl.type.elab]p3: 3824 // The class-key or enum keyword present in the 3825 // elaborated-type-specifier shall agree in kind with the 3826 // declaration to which the name in theelaborated-type-specifier 3827 // refers. This rule also applies to the form of 3828 // elaborated-type-specifier that declares a class-name or 3829 // friend class since it can be construed as referring to the 3830 // definition of the class. Thus, in any 3831 // elaborated-type-specifier, the enum keyword shall be used to 3832 // refer to an enumeration (7.2), the union class-keyshall be 3833 // used to refer to a union (clause 9), and either the class or 3834 // struct class-key shall be used to refer to a class (clause 9) 3835 // declared using the class or struct class-key. 3836 TagDecl::TagKind OldTag = Previous->getTagKind(); 3837 if (OldTag == NewTag) 3838 return true; 3839 3840 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 3841 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 3842 // Warn about the struct/class tag mismatch. 3843 bool isTemplate = false; 3844 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 3845 isTemplate = Record->getDescribedClassTemplate(); 3846 3847 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 3848 << (NewTag == TagDecl::TK_class) 3849 << isTemplate << &Name 3850 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 3851 OldTag == TagDecl::TK_class? "class" : "struct"); 3852 Diag(Previous->getLocation(), diag::note_previous_use); 3853 return true; 3854 } 3855 return false; 3856} 3857 3858/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3859/// former case, Name will be non-null. In the later case, Name will be null. 3860/// TagSpec indicates what kind of tag this is. TK indicates whether this is a 3861/// reference/declaration/definition of a tag. 3862Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK, 3863 SourceLocation KWLoc, const CXXScopeSpec &SS, 3864 IdentifierInfo *Name, SourceLocation NameLoc, 3865 AttributeList *Attr, AccessSpecifier AS, 3866 MultiTemplateParamsArg TemplateParameterLists, 3867 bool &OwnedDecl) { 3868 // If this is not a definition, it must have a name. 3869 assert((Name != 0 || TK == TK_Definition) && 3870 "Nameless record must be a definition!"); 3871 3872 OwnedDecl = false; 3873 TagDecl::TagKind Kind; 3874 switch (TagSpec) { 3875 default: assert(0 && "Unknown tag type!"); 3876 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3877 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3878 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3879 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3880 } 3881 3882 if (TK != TK_Reference) { 3883 if (TemplateParameterList *TemplateParams 3884 = MatchTemplateParametersToScopeSpecifier(KWLoc, SS, 3885 (TemplateParameterList**)TemplateParameterLists.get(), 3886 TemplateParameterLists.size())) { 3887 if (TemplateParams->size() > 0) { 3888 // This is a declaration or definition of a class template (which may 3889 // be a member of another template). 3890 OwnedDecl = false; 3891 DeclResult Result = CheckClassTemplate(S, TagSpec, TK, KWLoc, 3892 SS, Name, NameLoc, Attr, 3893 move(TemplateParameterLists), 3894 AS); 3895 return Result.get(); 3896 } else { 3897 // FIXME: diagnose the extraneous 'template<>', once we recover 3898 // slightly better in ParseTemplate.cpp from bogus template 3899 // parameters. 3900 } 3901 } 3902 } 3903 3904 DeclContext *SearchDC = CurContext; 3905 DeclContext *DC = CurContext; 3906 NamedDecl *PrevDecl = 0; 3907 3908 bool Invalid = false; 3909 3910 if (Name && SS.isNotEmpty()) { 3911 // We have a nested-name tag ('struct foo::bar'). 3912 3913 // Check for invalid 'foo::'. 3914 if (SS.isInvalid()) { 3915 Name = 0; 3916 goto CreateNewDecl; 3917 } 3918 3919 if (RequireCompleteDeclContext(SS)) 3920 return DeclPtrTy::make((Decl *)0); 3921 3922 DC = computeDeclContext(SS, true); 3923 SearchDC = DC; 3924 // Look-up name inside 'foo::'. 3925 PrevDecl 3926 = dyn_cast_or_null<TagDecl>( 3927 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 3928 3929 // A tag 'foo::bar' must already exist. 3930 if (PrevDecl == 0) { 3931 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 3932 Name = 0; 3933 Invalid = true; 3934 goto CreateNewDecl; 3935 } 3936 } else if (Name) { 3937 // If this is a named struct, check to see if there was a previous forward 3938 // declaration or definition. 3939 // FIXME: We're looking into outer scopes here, even when we 3940 // shouldn't be. Doing so can result in ambiguities that we 3941 // shouldn't be diagnosing. 3942 LookupResult R = LookupName(S, Name, LookupTagName, 3943 /*RedeclarationOnly=*/(TK != TK_Reference)); 3944 if (R.isAmbiguous()) { 3945 DiagnoseAmbiguousLookup(R, Name, NameLoc); 3946 // FIXME: This is not best way to recover from case like: 3947 // 3948 // struct S s; 3949 // 3950 // causes needless "incomplete type" error later. 3951 Name = 0; 3952 PrevDecl = 0; 3953 Invalid = true; 3954 } 3955 else 3956 PrevDecl = R; 3957 3958 if (!getLangOptions().CPlusPlus && TK != TK_Reference) { 3959 // FIXME: This makes sure that we ignore the contexts associated 3960 // with C structs, unions, and enums when looking for a matching 3961 // tag declaration or definition. See the similar lookup tweak 3962 // in Sema::LookupName; is there a better way to deal with this? 3963 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 3964 SearchDC = SearchDC->getParent(); 3965 } 3966 } 3967 3968 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3969 // Maybe we will complain about the shadowed template parameter. 3970 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 3971 // Just pretend that we didn't see the previous declaration. 3972 PrevDecl = 0; 3973 } 3974 3975 if (PrevDecl) { 3976 // Check whether the previous declaration is usable. 3977 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 3978 3979 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 3980 // If this is a use of a previous tag, or if the tag is already declared 3981 // in the same scope (so that the definition/declaration completes or 3982 // rementions the tag), reuse the decl. 3983 if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 3984 // Make sure that this wasn't declared as an enum and now used as a 3985 // struct or something similar. 3986 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 3987 bool SafeToContinue 3988 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 3989 Kind != TagDecl::TK_enum); 3990 if (SafeToContinue) 3991 Diag(KWLoc, diag::err_use_with_wrong_tag) 3992 << Name 3993 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 3994 PrevTagDecl->getKindName()); 3995 else 3996 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 3997 Diag(PrevDecl->getLocation(), diag::note_previous_use); 3998 3999 if (SafeToContinue) 4000 Kind = PrevTagDecl->getTagKind(); 4001 else { 4002 // Recover by making this an anonymous redefinition. 4003 Name = 0; 4004 PrevDecl = 0; 4005 Invalid = true; 4006 } 4007 } 4008 4009 if (!Invalid) { 4010 // If this is a use, just return the declaration we found. 4011 4012 // FIXME: In the future, return a variant or some other clue 4013 // for the consumer of this Decl to know it doesn't own it. 4014 // For our current ASTs this shouldn't be a problem, but will 4015 // need to be changed with DeclGroups. 4016 if (TK == TK_Reference) 4017 return DeclPtrTy::make(PrevDecl); 4018 4019 // Diagnose attempts to redefine a tag. 4020 if (TK == TK_Definition) { 4021 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 4022 Diag(NameLoc, diag::err_redefinition) << Name; 4023 Diag(Def->getLocation(), diag::note_previous_definition); 4024 // If this is a redefinition, recover by making this 4025 // struct be anonymous, which will make any later 4026 // references get the previous definition. 4027 Name = 0; 4028 PrevDecl = 0; 4029 Invalid = true; 4030 } else { 4031 // If the type is currently being defined, complain 4032 // about a nested redefinition. 4033 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 4034 if (Tag->isBeingDefined()) { 4035 Diag(NameLoc, diag::err_nested_redefinition) << Name; 4036 Diag(PrevTagDecl->getLocation(), 4037 diag::note_previous_definition); 4038 Name = 0; 4039 PrevDecl = 0; 4040 Invalid = true; 4041 } 4042 } 4043 4044 // Okay, this is definition of a previously declared or referenced 4045 // tag PrevDecl. We're going to create a new Decl for it. 4046 } 4047 } 4048 // If we get here we have (another) forward declaration or we 4049 // have a definition. Just create a new decl. 4050 } else { 4051 // If we get here, this is a definition of a new tag type in a nested 4052 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 4053 // new decl/type. We set PrevDecl to NULL so that the entities 4054 // have distinct types. 4055 PrevDecl = 0; 4056 } 4057 // If we get here, we're going to create a new Decl. If PrevDecl 4058 // is non-NULL, it's a definition of the tag declared by 4059 // PrevDecl. If it's NULL, we have a new definition. 4060 } else { 4061 // PrevDecl is a namespace, template, or anything else 4062 // that lives in the IDNS_Tag identifier namespace. 4063 if (isDeclInScope(PrevDecl, SearchDC, S)) { 4064 // The tag name clashes with a namespace name, issue an error and 4065 // recover by making this tag be anonymous. 4066 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 4067 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4068 Name = 0; 4069 PrevDecl = 0; 4070 Invalid = true; 4071 } else { 4072 // The existing declaration isn't relevant to us; we're in a 4073 // new scope, so clear out the previous declaration. 4074 PrevDecl = 0; 4075 } 4076 } 4077 } else if (TK == TK_Reference && SS.isEmpty() && Name && 4078 (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) { 4079 // C++ [basic.scope.pdecl]p5: 4080 // -- for an elaborated-type-specifier of the form 4081 // 4082 // class-key identifier 4083 // 4084 // if the elaborated-type-specifier is used in the 4085 // decl-specifier-seq or parameter-declaration-clause of a 4086 // function defined in namespace scope, the identifier is 4087 // declared as a class-name in the namespace that contains 4088 // the declaration; otherwise, except as a friend 4089 // declaration, the identifier is declared in the smallest 4090 // non-class, non-function-prototype scope that contains the 4091 // declaration. 4092 // 4093 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 4094 // C structs and unions. 4095 // 4096 // GNU C also supports this behavior as part of its incomplete 4097 // enum types extension, while GNU C++ does not. 4098 // 4099 // Find the context where we'll be declaring the tag. 4100 // FIXME: We would like to maintain the current DeclContext as the 4101 // lexical context, 4102 while (SearchDC->isRecord()) 4103 SearchDC = SearchDC->getParent(); 4104 4105 // Find the scope where we'll be declaring the tag. 4106 while (S->isClassScope() || 4107 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 4108 ((S->getFlags() & Scope::DeclScope) == 0) || 4109 (S->getEntity() && 4110 ((DeclContext *)S->getEntity())->isTransparentContext())) 4111 S = S->getParent(); 4112 } 4113 4114CreateNewDecl: 4115 4116 // If there is an identifier, use the location of the identifier as the 4117 // location of the decl, otherwise use the location of the struct/union 4118 // keyword. 4119 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 4120 4121 // Otherwise, create a new declaration. If there is a previous 4122 // declaration of the same entity, the two will be linked via 4123 // PrevDecl. 4124 TagDecl *New; 4125 4126 if (Kind == TagDecl::TK_enum) { 4127 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4128 // enum X { A, B, C } D; D should chain to X. 4129 New = EnumDecl::Create(Context, SearchDC, Loc, Name, KWLoc, 4130 cast_or_null<EnumDecl>(PrevDecl)); 4131 // If this is an undefined enum, warn. 4132 if (TK != TK_Definition && !Invalid) { 4133 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 4134 : diag::ext_forward_ref_enum; 4135 Diag(Loc, DK); 4136 } 4137 } else { 4138 // struct/union/class 4139 4140 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4141 // struct X { int A; } D; D should chain to X. 4142 if (getLangOptions().CPlusPlus) 4143 // FIXME: Look for a way to use RecordDecl for simple structs. 4144 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4145 cast_or_null<CXXRecordDecl>(PrevDecl)); 4146 else 4147 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4148 cast_or_null<RecordDecl>(PrevDecl)); 4149 } 4150 4151 if (Kind != TagDecl::TK_enum) { 4152 // Handle #pragma pack: if the #pragma pack stack has non-default 4153 // alignment, make up a packed attribute for this decl. These 4154 // attributes are checked when the ASTContext lays out the 4155 // structure. 4156 // 4157 // It is important for implementing the correct semantics that this 4158 // happen here (in act on tag decl). The #pragma pack stack is 4159 // maintained as a result of parser callbacks which can occur at 4160 // many points during the parsing of a struct declaration (because 4161 // the #pragma tokens are effectively skipped over during the 4162 // parsing of the struct). 4163 if (unsigned Alignment = getPragmaPackAlignment()) 4164 New->addAttr(::new (Context) PackedAttr(Alignment * 8)); 4165 } 4166 4167 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 4168 // C++ [dcl.typedef]p3: 4169 // [...] Similarly, in a given scope, a class or enumeration 4170 // shall not be declared with the same name as a typedef-name 4171 // that is declared in that scope and refers to a type other 4172 // than the class or enumeration itself. 4173 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 4174 TypedefDecl *PrevTypedef = 0; 4175 if (Lookup.getKind() == LookupResult::Found) 4176 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 4177 4178 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 4179 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 4180 Context.getCanonicalType(Context.getTypeDeclType(New))) { 4181 Diag(Loc, diag::err_tag_definition_of_typedef) 4182 << Context.getTypeDeclType(New) 4183 << PrevTypedef->getUnderlyingType(); 4184 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 4185 Invalid = true; 4186 } 4187 } 4188 4189 if (Invalid) 4190 New->setInvalidDecl(); 4191 4192 if (Attr) 4193 ProcessDeclAttributeList(S, New, Attr); 4194 4195 // If we're declaring or defining a tag in function prototype scope 4196 // in C, note that this type can only be used within the function. 4197 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 4198 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 4199 4200 // Set the lexical context. If the tag has a C++ scope specifier, the 4201 // lexical context will be different from the semantic context. 4202 New->setLexicalDeclContext(CurContext); 4203 4204 // Set the access specifier. 4205 if (!Invalid) 4206 SetMemberAccessSpecifier(New, PrevDecl, AS); 4207 4208 if (TK == TK_Definition) 4209 New->startDefinition(); 4210 4211 // If this has an identifier, add it to the scope stack. 4212 if (Name) { 4213 S = getNonFieldDeclScope(S); 4214 PushOnScopeChains(New, S); 4215 } else { 4216 CurContext->addDecl(New); 4217 } 4218 4219 // If this is the C FILE type, notify the AST context. 4220 if (IdentifierInfo *II = New->getIdentifier()) 4221 if (!New->isInvalidDecl() && 4222 New->getDeclContext()->getLookupContext()->isTranslationUnit() && 4223 II->isStr("FILE")) 4224 Context.setFILEDecl(New); 4225 4226 OwnedDecl = true; 4227 return DeclPtrTy::make(New); 4228} 4229 4230void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 4231 AdjustDeclIfTemplate(TagD); 4232 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4233 4234 // Enter the tag context. 4235 PushDeclContext(S, Tag); 4236 4237 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 4238 FieldCollector->StartClass(); 4239 4240 if (Record->getIdentifier()) { 4241 // C++ [class]p2: 4242 // [...] The class-name is also inserted into the scope of the 4243 // class itself; this is known as the injected-class-name. For 4244 // purposes of access checking, the injected-class-name is treated 4245 // as if it were a public member name. 4246 CXXRecordDecl *InjectedClassName 4247 = CXXRecordDecl::Create(Context, Record->getTagKind(), 4248 CurContext, Record->getLocation(), 4249 Record->getIdentifier(), 4250 Record->getTagKeywordLoc(), 4251 Record); 4252 InjectedClassName->setImplicit(); 4253 InjectedClassName->setAccess(AS_public); 4254 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 4255 InjectedClassName->setDescribedClassTemplate(Template); 4256 PushOnScopeChains(InjectedClassName, S); 4257 assert(InjectedClassName->isInjectedClassName() && 4258 "Broken injected-class-name"); 4259 } 4260 } 4261} 4262 4263void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD, 4264 SourceLocation RBraceLoc) { 4265 AdjustDeclIfTemplate(TagD); 4266 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4267 Tag->setRBraceLoc(RBraceLoc); 4268 4269 if (isa<CXXRecordDecl>(Tag)) 4270 FieldCollector->FinishClass(); 4271 4272 // Exit this scope of this tag's definition. 4273 PopDeclContext(); 4274 4275 // Notify the consumer that we've defined a tag. 4276 Consumer.HandleTagDeclDefinition(Tag); 4277} 4278 4279// Note that FieldName may be null for anonymous bitfields. 4280bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 4281 QualType FieldTy, const Expr *BitWidth) { 4282 4283 // C99 6.7.2.1p4 - verify the field type. 4284 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 4285 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 4286 // Handle incomplete types with specific error. 4287 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 4288 return true; 4289 if (FieldName) 4290 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 4291 << FieldName << FieldTy << BitWidth->getSourceRange(); 4292 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 4293 << FieldTy << BitWidth->getSourceRange(); 4294 } 4295 4296 // If the bit-width is type- or value-dependent, don't try to check 4297 // it now. 4298 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 4299 return false; 4300 4301 llvm::APSInt Value; 4302 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 4303 return true; 4304 4305 // Zero-width bitfield is ok for anonymous field. 4306 if (Value == 0 && FieldName) 4307 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 4308 4309 if (Value.isSigned() && Value.isNegative()) { 4310 if (FieldName) 4311 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 4312 << FieldName << Value.toString(10); 4313 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 4314 << Value.toString(10); 4315 } 4316 4317 if (!FieldTy->isDependentType()) { 4318 uint64_t TypeSize = Context.getTypeSize(FieldTy); 4319 if (Value.getZExtValue() > TypeSize) { 4320 if (FieldName) 4321 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 4322 << FieldName << (unsigned)TypeSize; 4323 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 4324 << (unsigned)TypeSize; 4325 } 4326 } 4327 4328 return false; 4329} 4330 4331/// ActOnField - Each field of a struct/union/class is passed into this in order 4332/// to create a FieldDecl object for it. 4333Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 4334 SourceLocation DeclStart, 4335 Declarator &D, ExprTy *BitfieldWidth) { 4336 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 4337 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 4338 AS_public); 4339 return DeclPtrTy::make(Res); 4340} 4341 4342/// HandleField - Analyze a field of a C struct or a C++ data member. 4343/// 4344FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 4345 SourceLocation DeclStart, 4346 Declarator &D, Expr *BitWidth, 4347 AccessSpecifier AS) { 4348 IdentifierInfo *II = D.getIdentifier(); 4349 SourceLocation Loc = DeclStart; 4350 if (II) Loc = D.getIdentifierLoc(); 4351 4352 QualType T = GetTypeForDeclarator(D, S); 4353 if (getLangOptions().CPlusPlus) 4354 CheckExtraCXXDefaultArguments(D); 4355 4356 DiagnoseFunctionSpecifiers(D); 4357 4358 if (D.getDeclSpec().isThreadSpecified()) 4359 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 4360 4361 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4362 4363 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4364 // Maybe we will complain about the shadowed template parameter. 4365 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 4366 // Just pretend that we didn't see the previous declaration. 4367 PrevDecl = 0; 4368 } 4369 4370 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 4371 PrevDecl = 0; 4372 4373 bool Mutable 4374 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 4375 SourceLocation TSSL = D.getSourceRange().getBegin(); 4376 FieldDecl *NewFD 4377 = CheckFieldDecl(II, T, Record, Loc, Mutable, BitWidth, TSSL, 4378 AS, PrevDecl, &D); 4379 if (NewFD->isInvalidDecl() && PrevDecl) { 4380 // Don't introduce NewFD into scope; there's already something 4381 // with the same name in the same scope. 4382 } else if (II) { 4383 PushOnScopeChains(NewFD, S); 4384 } else 4385 Record->addDecl(NewFD); 4386 4387 return NewFD; 4388} 4389 4390/// \brief Build a new FieldDecl and check its well-formedness. 4391/// 4392/// This routine builds a new FieldDecl given the fields name, type, 4393/// record, etc. \p PrevDecl should refer to any previous declaration 4394/// with the same name and in the same scope as the field to be 4395/// created. 4396/// 4397/// \returns a new FieldDecl. 4398/// 4399/// \todo The Declarator argument is a hack. It will be removed once 4400FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 4401 RecordDecl *Record, SourceLocation Loc, 4402 bool Mutable, Expr *BitWidth, 4403 SourceLocation TSSL, 4404 AccessSpecifier AS, NamedDecl *PrevDecl, 4405 Declarator *D) { 4406 IdentifierInfo *II = Name.getAsIdentifierInfo(); 4407 bool InvalidDecl = false; 4408 if (D) InvalidDecl = D->isInvalidType(); 4409 4410 // If we receive a broken type, recover by assuming 'int' and 4411 // marking this declaration as invalid. 4412 if (T.isNull()) { 4413 InvalidDecl = true; 4414 T = Context.IntTy; 4415 } 4416 4417 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4418 // than a variably modified type. 4419 if (T->isVariablyModifiedType()) { 4420 bool SizeIsNegative; 4421 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 4422 SizeIsNegative); 4423 if (!FixedTy.isNull()) { 4424 Diag(Loc, diag::warn_illegal_constant_array_size); 4425 T = FixedTy; 4426 } else { 4427 if (SizeIsNegative) 4428 Diag(Loc, diag::err_typecheck_negative_array_size); 4429 else 4430 Diag(Loc, diag::err_typecheck_field_variable_size); 4431 InvalidDecl = true; 4432 } 4433 } 4434 4435 // Fields can not have abstract class types 4436 if (RequireNonAbstractType(Loc, T, diag::err_abstract_type_in_decl, 4437 AbstractFieldType)) 4438 InvalidDecl = true; 4439 4440 // If this is declared as a bit-field, check the bit-field. 4441 if (BitWidth && VerifyBitField(Loc, II, T, BitWidth)) { 4442 InvalidDecl = true; 4443 DeleteExpr(BitWidth); 4444 BitWidth = 0; 4445 } 4446 4447 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, BitWidth, 4448 Mutable, TSSL); 4449 if (InvalidDecl) 4450 NewFD->setInvalidDecl(); 4451 4452 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 4453 Diag(Loc, diag::err_duplicate_member) << II; 4454 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4455 NewFD->setInvalidDecl(); 4456 } 4457 4458 if (getLangOptions().CPlusPlus) { 4459 QualType EltTy = Context.getBaseElementType(T); 4460 4461 if (const RecordType *RT = EltTy->getAsRecordType()) { 4462 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 4463 4464 if (!RDecl->hasTrivialConstructor()) 4465 cast<CXXRecordDecl>(Record)->setHasTrivialConstructor(false); 4466 if (!RDecl->hasTrivialCopyConstructor()) 4467 cast<CXXRecordDecl>(Record)->setHasTrivialCopyConstructor(false); 4468 if (!RDecl->hasTrivialCopyAssignment()) 4469 cast<CXXRecordDecl>(Record)->setHasTrivialCopyAssignment(false); 4470 if (!RDecl->hasTrivialDestructor()) 4471 cast<CXXRecordDecl>(Record)->setHasTrivialDestructor(false); 4472 4473 // C++ 9.5p1: An object of a class with a non-trivial 4474 // constructor, a non-trivial copy constructor, a non-trivial 4475 // destructor, or a non-trivial copy assignment operator 4476 // cannot be a member of a union, nor can an array of such 4477 // objects. 4478 // TODO: C++0x alters this restriction significantly. 4479 if (Record->isUnion()) { 4480 // We check for copy constructors before constructors 4481 // because otherwise we'll never get complaints about 4482 // copy constructors. 4483 4484 const CXXSpecialMember invalid = (CXXSpecialMember) -1; 4485 4486 CXXSpecialMember member; 4487 if (!RDecl->hasTrivialCopyConstructor()) 4488 member = CXXCopyConstructor; 4489 else if (!RDecl->hasTrivialConstructor()) 4490 member = CXXDefaultConstructor; 4491 else if (!RDecl->hasTrivialCopyAssignment()) 4492 member = CXXCopyAssignment; 4493 else if (!RDecl->hasTrivialDestructor()) 4494 member = CXXDestructor; 4495 else 4496 member = invalid; 4497 4498 if (member != invalid) { 4499 Diag(Loc, diag::err_illegal_union_member) << Name << member; 4500 DiagnoseNontrivial(RT, member); 4501 NewFD->setInvalidDecl(); 4502 } 4503 } 4504 } 4505 } 4506 4507 if (getLangOptions().CPlusPlus && !T->isPODType()) 4508 cast<CXXRecordDecl>(Record)->setPOD(false); 4509 4510 // FIXME: We need to pass in the attributes given an AST 4511 // representation, not a parser representation. 4512 if (D) 4513 // FIXME: What to pass instead of TUScope? 4514 ProcessDeclAttributes(TUScope, NewFD, *D); 4515 4516 if (T.isObjCGCWeak()) 4517 Diag(Loc, diag::warn_attribute_weak_on_field); 4518 4519 NewFD->setAccess(AS); 4520 4521 // C++ [dcl.init.aggr]p1: 4522 // An aggregate is an array or a class (clause 9) with [...] no 4523 // private or protected non-static data members (clause 11). 4524 // A POD must be an aggregate. 4525 if (getLangOptions().CPlusPlus && 4526 (AS == AS_private || AS == AS_protected)) { 4527 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 4528 CXXRecord->setAggregate(false); 4529 CXXRecord->setPOD(false); 4530 } 4531 4532 return NewFD; 4533} 4534 4535/// DiagnoseNontrivial - Given that a class has a non-trivial 4536/// special member, figure out why. 4537void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) { 4538 QualType QT(T, 0U); 4539 CXXRecordDecl* RD = cast<CXXRecordDecl>(T->getDecl()); 4540 4541 // Check whether the member was user-declared. 4542 switch (member) { 4543 case CXXDefaultConstructor: 4544 if (RD->hasUserDeclaredConstructor()) { 4545 typedef CXXRecordDecl::ctor_iterator ctor_iter; 4546 for (ctor_iter ci = RD->ctor_begin(), ce = RD->ctor_end(); ci != ce; ++ci) 4547 if (!ci->isImplicitlyDefined(Context)) { 4548 SourceLocation CtorLoc = ci->getLocation(); 4549 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4550 return; 4551 } 4552 4553 assert(0 && "found no user-declared constructors"); 4554 return; 4555 } 4556 break; 4557 4558 case CXXCopyConstructor: 4559 if (RD->hasUserDeclaredCopyConstructor()) { 4560 SourceLocation CtorLoc = 4561 RD->getCopyConstructor(Context, 0)->getLocation(); 4562 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4563 return; 4564 } 4565 break; 4566 4567 case CXXCopyAssignment: 4568 if (RD->hasUserDeclaredCopyAssignment()) { 4569 // FIXME: this should use the location of the copy 4570 // assignment, not the type. 4571 SourceLocation TyLoc = RD->getSourceRange().getBegin(); 4572 Diag(TyLoc, diag::note_nontrivial_user_defined) << QT << member; 4573 return; 4574 } 4575 break; 4576 4577 case CXXDestructor: 4578 if (RD->hasUserDeclaredDestructor()) { 4579 SourceLocation DtorLoc = RD->getDestructor(Context)->getLocation(); 4580 Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4581 return; 4582 } 4583 break; 4584 } 4585 4586 typedef CXXRecordDecl::base_class_iterator base_iter; 4587 4588 // Virtual bases and members inhibit trivial copying/construction, 4589 // but not trivial destruction. 4590 if (member != CXXDestructor) { 4591 // Check for virtual bases. vbases includes indirect virtual bases, 4592 // so we just iterate through the direct bases. 4593 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) 4594 if (bi->isVirtual()) { 4595 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4596 Diag(BaseLoc, diag::note_nontrivial_has_virtual) << QT << 1; 4597 return; 4598 } 4599 4600 // Check for virtual methods. 4601 typedef CXXRecordDecl::method_iterator meth_iter; 4602 for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; 4603 ++mi) { 4604 if (mi->isVirtual()) { 4605 SourceLocation MLoc = mi->getSourceRange().getBegin(); 4606 Diag(MLoc, diag::note_nontrivial_has_virtual) << QT << 0; 4607 return; 4608 } 4609 } 4610 } 4611 4612 bool (CXXRecordDecl::*hasTrivial)() const; 4613 switch (member) { 4614 case CXXDefaultConstructor: 4615 hasTrivial = &CXXRecordDecl::hasTrivialConstructor; break; 4616 case CXXCopyConstructor: 4617 hasTrivial = &CXXRecordDecl::hasTrivialCopyConstructor; break; 4618 case CXXCopyAssignment: 4619 hasTrivial = &CXXRecordDecl::hasTrivialCopyAssignment; break; 4620 case CXXDestructor: 4621 hasTrivial = &CXXRecordDecl::hasTrivialDestructor; break; 4622 default: 4623 assert(0 && "unexpected special member"); return; 4624 } 4625 4626 // Check for nontrivial bases (and recurse). 4627 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) { 4628 const RecordType *BaseRT = bi->getType()->getAsRecordType(); 4629 assert(BaseRT); 4630 CXXRecordDecl *BaseRecTy = cast<CXXRecordDecl>(BaseRT->getDecl()); 4631 if (!(BaseRecTy->*hasTrivial)()) { 4632 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4633 Diag(BaseLoc, diag::note_nontrivial_has_nontrivial) << QT << 1 << member; 4634 DiagnoseNontrivial(BaseRT, member); 4635 return; 4636 } 4637 } 4638 4639 // Check for nontrivial members (and recurse). 4640 typedef RecordDecl::field_iterator field_iter; 4641 for (field_iter fi = RD->field_begin(), fe = RD->field_end(); fi != fe; 4642 ++fi) { 4643 QualType EltTy = Context.getBaseElementType((*fi)->getType()); 4644 if (const RecordType *EltRT = EltTy->getAsRecordType()) { 4645 CXXRecordDecl* EltRD = cast<CXXRecordDecl>(EltRT->getDecl()); 4646 4647 if (!(EltRD->*hasTrivial)()) { 4648 SourceLocation FLoc = (*fi)->getLocation(); 4649 Diag(FLoc, diag::note_nontrivial_has_nontrivial) << QT << 0 << member; 4650 DiagnoseNontrivial(EltRT, member); 4651 return; 4652 } 4653 } 4654 } 4655 4656 assert(0 && "found no explanation for non-trivial member"); 4657} 4658 4659/// TranslateIvarVisibility - Translate visibility from a token ID to an 4660/// AST enum value. 4661static ObjCIvarDecl::AccessControl 4662TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 4663 switch (ivarVisibility) { 4664 default: assert(0 && "Unknown visitibility kind"); 4665 case tok::objc_private: return ObjCIvarDecl::Private; 4666 case tok::objc_public: return ObjCIvarDecl::Public; 4667 case tok::objc_protected: return ObjCIvarDecl::Protected; 4668 case tok::objc_package: return ObjCIvarDecl::Package; 4669 } 4670} 4671 4672/// ActOnIvar - Each ivar field of an objective-c class is passed into this 4673/// in order to create an IvarDecl object for it. 4674Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 4675 SourceLocation DeclStart, 4676 DeclPtrTy IntfDecl, 4677 Declarator &D, ExprTy *BitfieldWidth, 4678 tok::ObjCKeywordKind Visibility) { 4679 4680 IdentifierInfo *II = D.getIdentifier(); 4681 Expr *BitWidth = (Expr*)BitfieldWidth; 4682 SourceLocation Loc = DeclStart; 4683 if (II) Loc = D.getIdentifierLoc(); 4684 4685 // FIXME: Unnamed fields can be handled in various different ways, for 4686 // example, unnamed unions inject all members into the struct namespace! 4687 4688 QualType T = GetTypeForDeclarator(D, S); 4689 4690 if (BitWidth) { 4691 // 6.7.2.1p3, 6.7.2.1p4 4692 if (VerifyBitField(Loc, II, T, BitWidth)) { 4693 D.setInvalidType(); 4694 DeleteExpr(BitWidth); 4695 BitWidth = 0; 4696 } 4697 } else { 4698 // Not a bitfield. 4699 4700 // validate II. 4701 4702 } 4703 4704 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4705 // than a variably modified type. 4706 if (T->isVariablyModifiedType()) { 4707 Diag(Loc, diag::err_typecheck_ivar_variable_size); 4708 D.setInvalidType(); 4709 } 4710 4711 // Get the visibility (access control) for this ivar. 4712 ObjCIvarDecl::AccessControl ac = 4713 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 4714 : ObjCIvarDecl::None; 4715 // Must set ivar's DeclContext to its enclosing interface. 4716 Decl *EnclosingDecl = IntfDecl.getAs<Decl>(); 4717 DeclContext *EnclosingContext; 4718 if (ObjCImplementationDecl *IMPDecl = 4719 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4720 // Case of ivar declared in an implementation. Context is that of its class. 4721 ObjCInterfaceDecl* IDecl = IMPDecl->getClassInterface(); 4722 assert(IDecl && "No class- ActOnIvar"); 4723 EnclosingContext = cast_or_null<DeclContext>(IDecl); 4724 } 4725 else 4726 EnclosingContext = dyn_cast<DeclContext>(EnclosingDecl); 4727 assert(EnclosingContext && "null DeclContext for ivar - ActOnIvar"); 4728 4729 // Construct the decl. 4730 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, 4731 EnclosingContext, Loc, II, T,ac, 4732 (Expr *)BitfieldWidth); 4733 4734 if (II) { 4735 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4736 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 4737 && !isa<TagDecl>(PrevDecl)) { 4738 Diag(Loc, diag::err_duplicate_member) << II; 4739 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4740 NewID->setInvalidDecl(); 4741 } 4742 } 4743 4744 // Process attributes attached to the ivar. 4745 ProcessDeclAttributes(S, NewID, D); 4746 4747 if (D.isInvalidType()) 4748 NewID->setInvalidDecl(); 4749 4750 if (II) { 4751 // FIXME: When interfaces are DeclContexts, we'll need to add 4752 // these to the interface. 4753 S->AddDecl(DeclPtrTy::make(NewID)); 4754 IdResolver.AddDecl(NewID); 4755 } 4756 4757 return DeclPtrTy::make(NewID); 4758} 4759 4760void Sema::ActOnFields(Scope* S, 4761 SourceLocation RecLoc, DeclPtrTy RecDecl, 4762 DeclPtrTy *Fields, unsigned NumFields, 4763 SourceLocation LBrac, SourceLocation RBrac, 4764 AttributeList *Attr) { 4765 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 4766 assert(EnclosingDecl && "missing record or interface decl"); 4767 4768 // If the decl this is being inserted into is invalid, then it may be a 4769 // redeclaration or some other bogus case. Don't try to add fields to it. 4770 if (EnclosingDecl->isInvalidDecl()) { 4771 // FIXME: Deallocate fields? 4772 return; 4773 } 4774 4775 4776 // Verify that all the fields are okay. 4777 unsigned NumNamedMembers = 0; 4778 llvm::SmallVector<FieldDecl*, 32> RecFields; 4779 4780 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 4781 for (unsigned i = 0; i != NumFields; ++i) { 4782 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 4783 4784 // Get the type for the field. 4785 Type *FDTy = FD->getType().getTypePtr(); 4786 4787 if (!FD->isAnonymousStructOrUnion()) { 4788 // Remember all fields written by the user. 4789 RecFields.push_back(FD); 4790 } 4791 4792 // If the field is already invalid for some reason, don't emit more 4793 // diagnostics about it. 4794 if (FD->isInvalidDecl()) 4795 continue; 4796 4797 // C99 6.7.2.1p2: 4798 // A structure or union shall not contain a member with 4799 // incomplete or function type (hence, a structure shall not 4800 // contain an instance of itself, but may contain a pointer to 4801 // an instance of itself), except that the last member of a 4802 // structure with more than one named member may have incomplete 4803 // array type; such a structure (and any union containing, 4804 // possibly recursively, a member that is such a structure) 4805 // shall not be a member of a structure or an element of an 4806 // array. 4807 if (FDTy->isFunctionType()) { 4808 // Field declared as a function. 4809 Diag(FD->getLocation(), diag::err_field_declared_as_function) 4810 << FD->getDeclName(); 4811 FD->setInvalidDecl(); 4812 EnclosingDecl->setInvalidDecl(); 4813 continue; 4814 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 4815 Record && Record->isStruct()) { 4816 // Flexible array member. 4817 if (NumNamedMembers < 1) { 4818 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 4819 << FD->getDeclName(); 4820 FD->setInvalidDecl(); 4821 EnclosingDecl->setInvalidDecl(); 4822 continue; 4823 } 4824 // Okay, we have a legal flexible array member at the end of the struct. 4825 if (Record) 4826 Record->setHasFlexibleArrayMember(true); 4827 } else if (!FDTy->isDependentType() && 4828 RequireCompleteType(FD->getLocation(), FD->getType(), 4829 diag::err_field_incomplete)) { 4830 // Incomplete type 4831 FD->setInvalidDecl(); 4832 EnclosingDecl->setInvalidDecl(); 4833 continue; 4834 } else if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 4835 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 4836 // If this is a member of a union, then entire union becomes "flexible". 4837 if (Record && Record->isUnion()) { 4838 Record->setHasFlexibleArrayMember(true); 4839 } else { 4840 // If this is a struct/class and this is not the last element, reject 4841 // it. Note that GCC supports variable sized arrays in the middle of 4842 // structures. 4843 if (i != NumFields-1) 4844 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 4845 << FD->getDeclName() << FD->getType(); 4846 else { 4847 // We support flexible arrays at the end of structs in 4848 // other structs as an extension. 4849 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 4850 << FD->getDeclName(); 4851 if (Record) 4852 Record->setHasFlexibleArrayMember(true); 4853 } 4854 } 4855 } 4856 if (Record && FDTTy->getDecl()->hasObjectMember()) 4857 Record->setHasObjectMember(true); 4858 } else if (FDTy->isObjCInterfaceType()) { 4859 /// A field cannot be an Objective-c object 4860 Diag(FD->getLocation(), diag::err_statically_allocated_object); 4861 FD->setInvalidDecl(); 4862 EnclosingDecl->setInvalidDecl(); 4863 continue; 4864 } 4865 else if (getLangOptions().ObjC1 && 4866 getLangOptions().getGCMode() != LangOptions::NonGC && 4867 Record && 4868 (FD->getType()->isObjCObjectPointerType() || 4869 FD->getType().isObjCGCStrong())) 4870 Record->setHasObjectMember(true); 4871 // Keep track of the number of named members. 4872 if (FD->getIdentifier()) 4873 ++NumNamedMembers; 4874 } 4875 4876 // Okay, we successfully defined 'Record'. 4877 if (Record) { 4878 Record->completeDefinition(Context); 4879 } else { 4880 ObjCIvarDecl **ClsFields = 4881 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 4882 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 4883 ID->setIVarList(ClsFields, RecFields.size(), Context); 4884 ID->setLocEnd(RBrac); 4885 // Add ivar's to class's DeclContext. 4886 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 4887 ClsFields[i]->setLexicalDeclContext(ID); 4888 ID->addDecl(ClsFields[i]); 4889 } 4890 // Must enforce the rule that ivars in the base classes may not be 4891 // duplicates. 4892 if (ID->getSuperClass()) { 4893 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 4894 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 4895 ObjCIvarDecl* Ivar = (*IVI); 4896 4897 if (IdentifierInfo *II = Ivar->getIdentifier()) { 4898 ObjCIvarDecl* prevIvar = 4899 ID->getSuperClass()->lookupInstanceVariable(II); 4900 if (prevIvar) { 4901 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 4902 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 4903 } 4904 } 4905 } 4906 } 4907 } else if (ObjCImplementationDecl *IMPDecl = 4908 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4909 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 4910 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 4911 // Ivar declared in @implementation never belongs to the implementation. 4912 // Only it is in implementation's lexical context. 4913 ClsFields[I]->setLexicalDeclContext(IMPDecl); 4914 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 4915 } 4916 } 4917 4918 if (Attr) 4919 ProcessDeclAttributeList(S, Record, Attr); 4920} 4921 4922EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 4923 EnumConstantDecl *LastEnumConst, 4924 SourceLocation IdLoc, 4925 IdentifierInfo *Id, 4926 ExprArg val) { 4927 Expr *Val = (Expr *)val.get(); 4928 4929 llvm::APSInt EnumVal(32); 4930 QualType EltTy; 4931 if (Val && !Val->isTypeDependent()) { 4932 // Make sure to promote the operand type to int. 4933 UsualUnaryConversions(Val); 4934 if (Val != val.get()) { 4935 val.release(); 4936 val = Val; 4937 } 4938 4939 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 4940 SourceLocation ExpLoc; 4941 if (!Val->isValueDependent() && 4942 VerifyIntegerConstantExpression(Val, &EnumVal)) { 4943 Val = 0; 4944 } else { 4945 EltTy = Val->getType(); 4946 } 4947 } 4948 4949 if (!Val) { 4950 if (LastEnumConst) { 4951 // Assign the last value + 1. 4952 EnumVal = LastEnumConst->getInitVal(); 4953 ++EnumVal; 4954 4955 // Check for overflow on increment. 4956 if (EnumVal < LastEnumConst->getInitVal()) 4957 Diag(IdLoc, diag::warn_enum_value_overflow); 4958 4959 EltTy = LastEnumConst->getType(); 4960 } else { 4961 // First value, set to zero. 4962 EltTy = Context.IntTy; 4963 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 4964 } 4965 } 4966 4967 val.release(); 4968 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 4969 Val, EnumVal); 4970} 4971 4972 4973Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 4974 DeclPtrTy lastEnumConst, 4975 SourceLocation IdLoc, 4976 IdentifierInfo *Id, 4977 SourceLocation EqualLoc, ExprTy *val) { 4978 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 4979 EnumConstantDecl *LastEnumConst = 4980 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 4981 Expr *Val = static_cast<Expr*>(val); 4982 4983 // The scope passed in may not be a decl scope. Zip up the scope tree until 4984 // we find one that is. 4985 S = getNonFieldDeclScope(S); 4986 4987 // Verify that there isn't already something declared with this name in this 4988 // scope. 4989 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 4990 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4991 // Maybe we will complain about the shadowed template parameter. 4992 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 4993 // Just pretend that we didn't see the previous declaration. 4994 PrevDecl = 0; 4995 } 4996 4997 if (PrevDecl) { 4998 // When in C++, we may get a TagDecl with the same name; in this case the 4999 // enum constant will 'hide' the tag. 5000 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 5001 "Received TagDecl when not in C++!"); 5002 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 5003 if (isa<EnumConstantDecl>(PrevDecl)) 5004 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 5005 else 5006 Diag(IdLoc, diag::err_redefinition) << Id; 5007 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 5008 if (Val) Val->Destroy(Context); 5009 return DeclPtrTy(); 5010 } 5011 } 5012 5013 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 5014 IdLoc, Id, Owned(Val)); 5015 5016 // Register this decl in the current scope stack. 5017 if (New) 5018 PushOnScopeChains(New, S); 5019 5020 return DeclPtrTy::make(New); 5021} 5022 5023void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 5024 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 5025 DeclPtrTy *Elements, unsigned NumElements) { 5026 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 5027 QualType EnumType = Context.getTypeDeclType(Enum); 5028 5029 // TODO: If the result value doesn't fit in an int, it must be a long or long 5030 // long value. ISO C does not support this, but GCC does as an extension, 5031 // emit a warning. 5032 unsigned IntWidth = Context.Target.getIntWidth(); 5033 5034 // Verify that all the values are okay, compute the size of the values, and 5035 // reverse the list. 5036 unsigned NumNegativeBits = 0; 5037 unsigned NumPositiveBits = 0; 5038 5039 // Keep track of whether all elements have type int. 5040 bool AllElementsInt = true; 5041 5042 for (unsigned i = 0; i != NumElements; ++i) { 5043 EnumConstantDecl *ECD = 5044 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5045 if (!ECD) continue; // Already issued a diagnostic. 5046 5047 // If the enum value doesn't fit in an int, emit an extension warning. 5048 const llvm::APSInt &InitVal = ECD->getInitVal(); 5049 assert(InitVal.getBitWidth() >= IntWidth && 5050 "Should have promoted value to int"); 5051 if (InitVal.getBitWidth() > IntWidth) { 5052 llvm::APSInt V(InitVal); 5053 V.trunc(IntWidth); 5054 V.extend(InitVal.getBitWidth()); 5055 if (V != InitVal) 5056 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 5057 << InitVal.toString(10); 5058 } 5059 5060 // Keep track of the size of positive and negative values. 5061 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 5062 NumPositiveBits = std::max(NumPositiveBits, 5063 (unsigned)InitVal.getActiveBits()); 5064 else 5065 NumNegativeBits = std::max(NumNegativeBits, 5066 (unsigned)InitVal.getMinSignedBits()); 5067 5068 // Keep track of whether every enum element has type int (very commmon). 5069 if (AllElementsInt) 5070 AllElementsInt = ECD->getType() == Context.IntTy; 5071 } 5072 5073 // Figure out the type that should be used for this enum. 5074 // FIXME: Support attribute(packed) on enums and -fshort-enums. 5075 QualType BestType; 5076 unsigned BestWidth; 5077 5078 if (NumNegativeBits) { 5079 // If there is a negative value, figure out the smallest integer type (of 5080 // int/long/longlong) that fits. 5081 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 5082 BestType = Context.IntTy; 5083 BestWidth = IntWidth; 5084 } else { 5085 BestWidth = Context.Target.getLongWidth(); 5086 5087 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 5088 BestType = Context.LongTy; 5089 else { 5090 BestWidth = Context.Target.getLongLongWidth(); 5091 5092 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 5093 Diag(Enum->getLocation(), diag::warn_enum_too_large); 5094 BestType = Context.LongLongTy; 5095 } 5096 } 5097 } else { 5098 // If there is no negative value, figure out which of uint, ulong, ulonglong 5099 // fits. 5100 if (NumPositiveBits <= IntWidth) { 5101 BestType = Context.UnsignedIntTy; 5102 BestWidth = IntWidth; 5103 } else if (NumPositiveBits <= 5104 (BestWidth = Context.Target.getLongWidth())) { 5105 BestType = Context.UnsignedLongTy; 5106 } else { 5107 BestWidth = Context.Target.getLongLongWidth(); 5108 assert(NumPositiveBits <= BestWidth && 5109 "How could an initializer get larger than ULL?"); 5110 BestType = Context.UnsignedLongLongTy; 5111 } 5112 } 5113 5114 // Loop over all of the enumerator constants, changing their types to match 5115 // the type of the enum if needed. 5116 for (unsigned i = 0; i != NumElements; ++i) { 5117 EnumConstantDecl *ECD = 5118 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5119 if (!ECD) continue; // Already issued a diagnostic. 5120 5121 // Standard C says the enumerators have int type, but we allow, as an 5122 // extension, the enumerators to be larger than int size. If each 5123 // enumerator value fits in an int, type it as an int, otherwise type it the 5124 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 5125 // that X has type 'int', not 'unsigned'. 5126 if (ECD->getType() == Context.IntTy) { 5127 // Make sure the init value is signed. 5128 llvm::APSInt IV = ECD->getInitVal(); 5129 IV.setIsSigned(true); 5130 ECD->setInitVal(IV); 5131 5132 if (getLangOptions().CPlusPlus) 5133 // C++ [dcl.enum]p4: Following the closing brace of an 5134 // enum-specifier, each enumerator has the type of its 5135 // enumeration. 5136 ECD->setType(EnumType); 5137 continue; // Already int type. 5138 } 5139 5140 // Determine whether the value fits into an int. 5141 llvm::APSInt InitVal = ECD->getInitVal(); 5142 bool FitsInInt; 5143 if (InitVal.isUnsigned() || !InitVal.isNegative()) 5144 FitsInInt = InitVal.getActiveBits() < IntWidth; 5145 else 5146 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 5147 5148 // If it fits into an integer type, force it. Otherwise force it to match 5149 // the enum decl type. 5150 QualType NewTy; 5151 unsigned NewWidth; 5152 bool NewSign; 5153 if (FitsInInt) { 5154 NewTy = Context.IntTy; 5155 NewWidth = IntWidth; 5156 NewSign = true; 5157 } else if (ECD->getType() == BestType) { 5158 // Already the right type! 5159 if (getLangOptions().CPlusPlus) 5160 // C++ [dcl.enum]p4: Following the closing brace of an 5161 // enum-specifier, each enumerator has the type of its 5162 // enumeration. 5163 ECD->setType(EnumType); 5164 continue; 5165 } else { 5166 NewTy = BestType; 5167 NewWidth = BestWidth; 5168 NewSign = BestType->isSignedIntegerType(); 5169 } 5170 5171 // Adjust the APSInt value. 5172 InitVal.extOrTrunc(NewWidth); 5173 InitVal.setIsSigned(NewSign); 5174 ECD->setInitVal(InitVal); 5175 5176 // Adjust the Expr initializer and type. 5177 if (ECD->getInitExpr()) 5178 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, ECD->getInitExpr(), 5179 /*isLvalue=*/false)); 5180 if (getLangOptions().CPlusPlus) 5181 // C++ [dcl.enum]p4: Following the closing brace of an 5182 // enum-specifier, each enumerator has the type of its 5183 // enumeration. 5184 ECD->setType(EnumType); 5185 else 5186 ECD->setType(NewTy); 5187 } 5188 5189 Enum->completeDefinition(Context, BestType); 5190} 5191 5192Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 5193 ExprArg expr) { 5194 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 5195 5196 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 5197 Loc, AsmString); 5198 CurContext->addDecl(New); 5199 return DeclPtrTy::make(New); 5200} 5201 5202void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 5203 SourceLocation PragmaLoc, 5204 SourceLocation NameLoc) { 5205 Decl *PrevDecl = LookupName(TUScope, Name, LookupOrdinaryName); 5206 5207 // FIXME: This implementation is an ugly hack! 5208 if (PrevDecl) { 5209 PrevDecl->addAttr(::new (Context) WeakAttr()); 5210 return; 5211 } 5212 Diag(PragmaLoc, diag::err_unsupported_pragma_weak); 5213 return; 5214} 5215 5216void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 5217 IdentifierInfo* AliasName, 5218 SourceLocation PragmaLoc, 5219 SourceLocation NameLoc, 5220 SourceLocation AliasNameLoc) { 5221 Decl *PrevDecl = LookupName(TUScope, Name, LookupOrdinaryName); 5222 5223 // FIXME: This implementation is an ugly hack! 5224 if (PrevDecl) { 5225 PrevDecl->addAttr(::new (Context) AliasAttr(AliasName->getName())); 5226 PrevDecl->addAttr(::new (Context) WeakAttr()); 5227 return; 5228 } 5229 Diag(PragmaLoc, diag::err_unsupported_pragma_weak); 5230 return; 5231} 5232