SemaDecl.cpp revision 11b3a95d1698c033691fce6cd444201668ba3e0a
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/AST/APValue.h" 17#include "clang/AST/ASTConsumer.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/Analysis/CFG.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/StmtCXX.h" 24#include "clang/AST/StmtObjC.h" 25#include "clang/Parse/DeclSpec.h" 26#include "clang/Basic/TargetInfo.h" 27#include "clang/Basic/SourceManager.h" 28// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 29#include "clang/Lex/Preprocessor.h" 30#include "clang/Lex/HeaderSearch.h" 31#include "llvm/ADT/BitVector.h" 32#include "llvm/ADT/STLExtras.h" 33#include <algorithm> 34#include <functional> 35#include <queue> 36using namespace clang; 37 38/// getDeclName - Return a pretty name for the specified decl if possible, or 39/// an empty string if not. This is used for pretty crash reporting. 40std::string Sema::getDeclName(DeclPtrTy d) { 41 Decl *D = d.getAs<Decl>(); 42 if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D)) 43 return DN->getQualifiedNameAsString(); 44 return ""; 45} 46 47Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) { 48 return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>())); 49} 50 51/// \brief If the identifier refers to a type name within this scope, 52/// return the declaration of that type. 53/// 54/// This routine performs ordinary name lookup of the identifier II 55/// within the given scope, with optional C++ scope specifier SS, to 56/// determine whether the name refers to a type. If so, returns an 57/// opaque pointer (actually a QualType) corresponding to that 58/// type. Otherwise, returns NULL. 59/// 60/// If name lookup results in an ambiguity, this routine will complain 61/// and then return NULL. 62Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 63 Scope *S, const CXXScopeSpec *SS) { 64 // C++ [temp.res]p3: 65 // A qualified-id that refers to a type and in which the 66 // nested-name-specifier depends on a template-parameter (14.6.2) 67 // shall be prefixed by the keyword typename to indicate that the 68 // qualified-id denotes a type, forming an 69 // elaborated-type-specifier (7.1.5.3). 70 // 71 // We therefore do not perform any name lookup if the result would 72 // refer to a member of an unknown specialization. 73 if (SS && isUnknownSpecialization(*SS)) 74 return 0; 75 76 LookupResult Result 77 = LookupParsedName(S, SS, &II, LookupOrdinaryName, false, false); 78 79 NamedDecl *IIDecl = 0; 80 switch (Result.getKind()) { 81 case LookupResult::NotFound: 82 case LookupResult::FoundOverloaded: 83 return 0; 84 85 case LookupResult::AmbiguousBaseSubobjectTypes: 86 case LookupResult::AmbiguousBaseSubobjects: 87 case LookupResult::AmbiguousReference: { 88 // Look to see if we have a type anywhere in the list of results. 89 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); 90 Res != ResEnd; ++Res) { 91 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) { 92 if (!IIDecl || 93 (*Res)->getLocation().getRawEncoding() < 94 IIDecl->getLocation().getRawEncoding()) 95 IIDecl = *Res; 96 } 97 } 98 99 if (!IIDecl) { 100 // None of the entities we found is a type, so there is no way 101 // to even assume that the result is a type. In this case, don't 102 // complain about the ambiguity. The parser will either try to 103 // perform this lookup again (e.g., as an object name), which 104 // will produce the ambiguity, or will complain that it expected 105 // a type name. 106 Result.Destroy(); 107 return 0; 108 } 109 110 // We found a type within the ambiguous lookup; diagnose the 111 // ambiguity and then return that type. This might be the right 112 // answer, or it might not be, but it suppresses any attempt to 113 // perform the name lookup again. 114 DiagnoseAmbiguousLookup(Result, DeclarationName(&II), NameLoc); 115 break; 116 } 117 118 case LookupResult::Found: 119 IIDecl = Result.getAsDecl(); 120 break; 121 } 122 123 if (IIDecl) { 124 QualType T; 125 126 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 127 // Check whether we can use this type 128 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 129 130 if (getLangOptions().CPlusPlus) { 131 // C++ [temp.local]p2: 132 // Within the scope of a class template specialization or 133 // partial specialization, when the injected-class-name is 134 // not followed by a <, it is equivalent to the 135 // injected-class-name followed by the template-argument s 136 // of the class template specialization or partial 137 // specialization enclosed in <>. 138 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) 139 if (RD->isInjectedClassName()) 140 if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate()) 141 T = Template->getInjectedClassNameType(Context); 142 } 143 144 if (T.isNull()) 145 T = Context.getTypeDeclType(TD); 146 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 147 // Check whether we can use this interface. 148 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 149 150 T = Context.getObjCInterfaceType(IDecl); 151 } else 152 return 0; 153 154 if (SS) 155 T = getQualifiedNameType(*SS, T); 156 157 return T.getAsOpaquePtr(); 158 } 159 160 return 0; 161} 162 163/// isTagName() - This method is called *for error recovery purposes only* 164/// to determine if the specified name is a valid tag name ("struct foo"). If 165/// so, this returns the TST for the tag corresponding to it (TST_enum, 166/// TST_union, TST_struct, TST_class). This is used to diagnose cases in C 167/// where the user forgot to specify the tag. 168DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { 169 // Do a tag name lookup in this scope. 170 LookupResult R = LookupName(S, &II, LookupTagName, false, false); 171 if (R.getKind() == LookupResult::Found) 172 if (const TagDecl *TD = dyn_cast<TagDecl>(R.getAsDecl())) { 173 switch (TD->getTagKind()) { 174 case TagDecl::TK_struct: return DeclSpec::TST_struct; 175 case TagDecl::TK_union: return DeclSpec::TST_union; 176 case TagDecl::TK_class: return DeclSpec::TST_class; 177 case TagDecl::TK_enum: return DeclSpec::TST_enum; 178 } 179 } 180 181 return DeclSpec::TST_unspecified; 182} 183 184 185 186DeclContext *Sema::getContainingDC(DeclContext *DC) { 187 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 188 // A C++ out-of-line method will return to the file declaration context. 189 if (MD->isOutOfLine()) 190 return MD->getLexicalDeclContext(); 191 192 // A C++ inline method is parsed *after* the topmost class it was declared 193 // in is fully parsed (it's "complete"). 194 // The parsing of a C++ inline method happens at the declaration context of 195 // the topmost (non-nested) class it is lexically declared in. 196 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 197 DC = MD->getParent(); 198 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 199 DC = RD; 200 201 // Return the declaration context of the topmost class the inline method is 202 // declared in. 203 return DC; 204 } 205 206 if (isa<ObjCMethodDecl>(DC)) 207 return Context.getTranslationUnitDecl(); 208 209 return DC->getLexicalParent(); 210} 211 212void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 213 assert(getContainingDC(DC) == CurContext && 214 "The next DeclContext should be lexically contained in the current one."); 215 CurContext = DC; 216 S->setEntity(DC); 217} 218 219void Sema::PopDeclContext() { 220 assert(CurContext && "DeclContext imbalance!"); 221 222 CurContext = getContainingDC(CurContext); 223} 224 225/// EnterDeclaratorContext - Used when we must lookup names in the context 226/// of a declarator's nested name specifier. 227void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { 228 assert(PreDeclaratorDC == 0 && "Previous declarator context not popped?"); 229 PreDeclaratorDC = static_cast<DeclContext*>(S->getEntity()); 230 CurContext = DC; 231 assert(CurContext && "No context?"); 232 S->setEntity(CurContext); 233} 234 235void Sema::ExitDeclaratorContext(Scope *S) { 236 S->setEntity(PreDeclaratorDC); 237 PreDeclaratorDC = 0; 238 239 // Reset CurContext to the nearest enclosing context. 240 while (!S->getEntity() && S->getParent()) 241 S = S->getParent(); 242 CurContext = static_cast<DeclContext*>(S->getEntity()); 243 assert(CurContext && "No context?"); 244} 245 246/// \brief Determine whether we allow overloading of the function 247/// PrevDecl with another declaration. 248/// 249/// This routine determines whether overloading is possible, not 250/// whether some new function is actually an overload. It will return 251/// true in C++ (where we can always provide overloads) or, as an 252/// extension, in C when the previous function is already an 253/// overloaded function declaration or has the "overloadable" 254/// attribute. 255static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) { 256 if (Context.getLangOptions().CPlusPlus) 257 return true; 258 259 if (isa<OverloadedFunctionDecl>(PrevDecl)) 260 return true; 261 262 return PrevDecl->getAttr<OverloadableAttr>() != 0; 263} 264 265/// Add this decl to the scope shadowed decl chains. 266void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 267 // Move up the scope chain until we find the nearest enclosing 268 // non-transparent context. The declaration will be introduced into this 269 // scope. 270 while (S->getEntity() && 271 ((DeclContext *)S->getEntity())->isTransparentContext()) 272 S = S->getParent(); 273 274 S->AddDecl(DeclPtrTy::make(D)); 275 276 // Add scoped declarations into their context, so that they can be 277 // found later. Declarations without a context won't be inserted 278 // into any context. 279 CurContext->addDecl(D); 280 281 // C++ [basic.scope]p4: 282 // -- exactly one declaration shall declare a class name or 283 // enumeration name that is not a typedef name and the other 284 // declarations shall all refer to the same object or 285 // enumerator, or all refer to functions and function templates; 286 // in this case the class name or enumeration name is hidden. 287 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 288 // We are pushing the name of a tag (enum or class). 289 if (CurContext->getLookupContext() 290 == TD->getDeclContext()->getLookupContext()) { 291 // We're pushing the tag into the current context, which might 292 // require some reshuffling in the identifier resolver. 293 IdentifierResolver::iterator 294 I = IdResolver.begin(TD->getDeclName()), 295 IEnd = IdResolver.end(); 296 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 297 NamedDecl *PrevDecl = *I; 298 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 299 PrevDecl = *I, ++I) { 300 if (TD->declarationReplaces(*I)) { 301 // This is a redeclaration. Remove it from the chain and 302 // break out, so that we'll add in the shadowed 303 // declaration. 304 S->RemoveDecl(DeclPtrTy::make(*I)); 305 if (PrevDecl == *I) { 306 IdResolver.RemoveDecl(*I); 307 IdResolver.AddDecl(TD); 308 return; 309 } else { 310 IdResolver.RemoveDecl(*I); 311 break; 312 } 313 } 314 } 315 316 // There is already a declaration with the same name in the same 317 // scope, which is not a tag declaration. It must be found 318 // before we find the new declaration, so insert the new 319 // declaration at the end of the chain. 320 IdResolver.AddShadowedDecl(TD, PrevDecl); 321 322 return; 323 } 324 } 325 } else if ((isa<FunctionDecl>(D) && 326 AllowOverloadingOfFunction(D, Context)) || 327 isa<FunctionTemplateDecl>(D)) { 328 // We are pushing the name of a function or function template, 329 // which might be an overloaded name. 330 IdentifierResolver::iterator Redecl 331 = std::find_if(IdResolver.begin(D->getDeclName()), 332 IdResolver.end(), 333 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 334 D)); 335 if (Redecl != IdResolver.end() && 336 S->isDeclScope(DeclPtrTy::make(*Redecl))) { 337 // There is already a declaration of a function on our 338 // IdResolver chain. Replace it with this declaration. 339 S->RemoveDecl(DeclPtrTy::make(*Redecl)); 340 IdResolver.RemoveDecl(*Redecl); 341 } 342 } else if (isa<ObjCInterfaceDecl>(D)) { 343 // We're pushing an Objective-C interface into the current 344 // context. If there is already an alias declaration, remove it first. 345 for (IdentifierResolver::iterator 346 I = IdResolver.begin(D->getDeclName()), IEnd = IdResolver.end(); 347 I != IEnd; ++I) { 348 if (isa<ObjCCompatibleAliasDecl>(*I)) { 349 S->RemoveDecl(DeclPtrTy::make(*I)); 350 IdResolver.RemoveDecl(*I); 351 break; 352 } 353 } 354 } 355 356 IdResolver.AddDecl(D); 357} 358 359void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 360 if (S->decl_empty()) return; 361 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 362 "Scope shouldn't contain decls!"); 363 364 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 365 I != E; ++I) { 366 Decl *TmpD = (*I).getAs<Decl>(); 367 assert(TmpD && "This decl didn't get pushed??"); 368 369 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 370 NamedDecl *D = cast<NamedDecl>(TmpD); 371 372 if (!D->getDeclName()) continue; 373 374 // Remove this name from our lexical scope. 375 IdResolver.RemoveDecl(D); 376 } 377} 378 379/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 380/// return 0 if one not found. 381ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 382 // The third "scope" argument is 0 since we aren't enabling lazy built-in 383 // creation from this context. 384 NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName); 385 386 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 387} 388 389/// getNonFieldDeclScope - Retrieves the innermost scope, starting 390/// from S, where a non-field would be declared. This routine copes 391/// with the difference between C and C++ scoping rules in structs and 392/// unions. For example, the following code is well-formed in C but 393/// ill-formed in C++: 394/// @code 395/// struct S6 { 396/// enum { BAR } e; 397/// }; 398/// 399/// void test_S6() { 400/// struct S6 a; 401/// a.e = BAR; 402/// } 403/// @endcode 404/// For the declaration of BAR, this routine will return a different 405/// scope. The scope S will be the scope of the unnamed enumeration 406/// within S6. In C++, this routine will return the scope associated 407/// with S6, because the enumeration's scope is a transparent 408/// context but structures can contain non-field names. In C, this 409/// routine will return the translation unit scope, since the 410/// enumeration's scope is a transparent context and structures cannot 411/// contain non-field names. 412Scope *Sema::getNonFieldDeclScope(Scope *S) { 413 while (((S->getFlags() & Scope::DeclScope) == 0) || 414 (S->getEntity() && 415 ((DeclContext *)S->getEntity())->isTransparentContext()) || 416 (S->isClassScope() && !getLangOptions().CPlusPlus)) 417 S = S->getParent(); 418 return S; 419} 420 421void Sema::InitBuiltinVaListType() { 422 if (!Context.getBuiltinVaListType().isNull()) 423 return; 424 425 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 426 NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName); 427 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 428 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 429} 430 431/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 432/// file scope. lazily create a decl for it. ForRedeclaration is true 433/// if we're creating this built-in in anticipation of redeclaring the 434/// built-in. 435NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 436 Scope *S, bool ForRedeclaration, 437 SourceLocation Loc) { 438 Builtin::ID BID = (Builtin::ID)bid; 439 440 if (Context.BuiltinInfo.hasVAListUse(BID)) 441 InitBuiltinVaListType(); 442 443 ASTContext::GetBuiltinTypeError Error; 444 QualType R = Context.GetBuiltinType(BID, Error); 445 switch (Error) { 446 case ASTContext::GE_None: 447 // Okay 448 break; 449 450 case ASTContext::GE_Missing_stdio: 451 if (ForRedeclaration) 452 Diag(Loc, diag::err_implicit_decl_requires_stdio) 453 << Context.BuiltinInfo.GetName(BID); 454 return 0; 455 456 case ASTContext::GE_Missing_setjmp: 457 if (ForRedeclaration) 458 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 459 << Context.BuiltinInfo.GetName(BID); 460 return 0; 461 } 462 463 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 464 Diag(Loc, diag::ext_implicit_lib_function_decl) 465 << Context.BuiltinInfo.GetName(BID) 466 << R; 467 if (Context.BuiltinInfo.getHeaderName(BID) && 468 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 469 != Diagnostic::Ignored) 470 Diag(Loc, diag::note_please_include_header) 471 << Context.BuiltinInfo.getHeaderName(BID) 472 << Context.BuiltinInfo.GetName(BID); 473 } 474 475 FunctionDecl *New = FunctionDecl::Create(Context, 476 Context.getTranslationUnitDecl(), 477 Loc, II, R, 478 FunctionDecl::Extern, false, 479 /*hasPrototype=*/true); 480 New->setImplicit(); 481 482 // Create Decl objects for each parameter, adding them to the 483 // FunctionDecl. 484 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 485 llvm::SmallVector<ParmVarDecl*, 16> Params; 486 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 487 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 488 FT->getArgType(i), VarDecl::None, 0)); 489 New->setParams(Context, Params.data(), Params.size()); 490 } 491 492 AddKnownFunctionAttributes(New); 493 494 // TUScope is the translation-unit scope to insert this function into. 495 // FIXME: This is hideous. We need to teach PushOnScopeChains to 496 // relate Scopes to DeclContexts, and probably eliminate CurContext 497 // entirely, but we're not there yet. 498 DeclContext *SavedContext = CurContext; 499 CurContext = Context.getTranslationUnitDecl(); 500 PushOnScopeChains(New, TUScope); 501 CurContext = SavedContext; 502 return New; 503} 504 505/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 506/// everything from the standard library is defined. 507NamespaceDecl *Sema::GetStdNamespace() { 508 if (!StdNamespace) { 509 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 510 DeclContext *Global = Context.getTranslationUnitDecl(); 511 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 512 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 513 } 514 return StdNamespace; 515} 516 517/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 518/// same name and scope as a previous declaration 'Old'. Figure out 519/// how to resolve this situation, merging decls or emitting 520/// diagnostics as appropriate. If there was an error, set New to be invalid. 521/// 522void Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 523 // If either decl is known invalid already, set the new one to be invalid and 524 // don't bother doing any merging checks. 525 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 526 return New->setInvalidDecl(); 527 528 // Allow multiple definitions for ObjC built-in typedefs. 529 // FIXME: Verify the underlying types are equivalent! 530 if (getLangOptions().ObjC1) { 531 const IdentifierInfo *TypeID = New->getIdentifier(); 532 switch (TypeID->getLength()) { 533 default: break; 534 case 2: 535 if (!TypeID->isStr("id")) 536 break; 537 // Install the built-in type for 'id', ignoring the current definition. 538 New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); 539 return; 540 case 5: 541 if (!TypeID->isStr("Class")) 542 break; 543 // Install the built-in type for 'Class', ignoring the current definition. 544 New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); 545 return; 546 case 3: 547 if (!TypeID->isStr("SEL")) 548 break; 549 Context.setObjCSelType(Context.getTypeDeclType(New)); 550 return; 551 case 8: 552 if (!TypeID->isStr("Protocol")) 553 break; 554 Context.setObjCProtoType(New->getUnderlyingType()); 555 return; 556 } 557 // Fall through - the typedef name was not a builtin type. 558 } 559 // Verify the old decl was also a type. 560 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 561 if (!Old) { 562 Diag(New->getLocation(), diag::err_redefinition_different_kind) 563 << New->getDeclName(); 564 if (OldD->getLocation().isValid()) 565 Diag(OldD->getLocation(), diag::note_previous_definition); 566 return New->setInvalidDecl(); 567 } 568 569 // Determine the "old" type we'll use for checking and diagnostics. 570 QualType OldType; 571 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 572 OldType = OldTypedef->getUnderlyingType(); 573 else 574 OldType = Context.getTypeDeclType(Old); 575 576 // If the typedef types are not identical, reject them in all languages and 577 // with any extensions enabled. 578 579 if (OldType != New->getUnderlyingType() && 580 Context.getCanonicalType(OldType) != 581 Context.getCanonicalType(New->getUnderlyingType())) { 582 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 583 << New->getUnderlyingType() << OldType; 584 if (Old->getLocation().isValid()) 585 Diag(Old->getLocation(), diag::note_previous_definition); 586 return New->setInvalidDecl(); 587 } 588 589 if (getLangOptions().Microsoft) 590 return; 591 592 // C++ [dcl.typedef]p2: 593 // In a given non-class scope, a typedef specifier can be used to 594 // redefine the name of any type declared in that scope to refer 595 // to the type to which it already refers. 596 if (getLangOptions().CPlusPlus) { 597 if (!isa<CXXRecordDecl>(CurContext)) 598 return; 599 Diag(New->getLocation(), diag::err_redefinition) 600 << New->getDeclName(); 601 Diag(Old->getLocation(), diag::note_previous_definition); 602 return New->setInvalidDecl(); 603 } 604 605 // If we have a redefinition of a typedef in C, emit a warning. This warning 606 // is normally mapped to an error, but can be controlled with 607 // -Wtypedef-redefinition. If either the original or the redefinition is 608 // in a system header, don't emit this for compatibility with GCC. 609 if (PP.getDiagnostics().getSuppressSystemWarnings() && 610 (Context.getSourceManager().isInSystemHeader(Old->getLocation()) || 611 Context.getSourceManager().isInSystemHeader(New->getLocation()))) 612 return; 613 614 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 615 << New->getDeclName(); 616 Diag(Old->getLocation(), diag::note_previous_definition); 617 return; 618} 619 620/// DeclhasAttr - returns true if decl Declaration already has the target 621/// attribute. 622static bool 623DeclHasAttr(const Decl *decl, const Attr *target) { 624 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 625 if (attr->getKind() == target->getKind()) 626 return true; 627 628 return false; 629} 630 631/// MergeAttributes - append attributes from the Old decl to the New one. 632static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 633 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 634 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 635 Attr *NewAttr = attr->clone(C); 636 NewAttr->setInherited(true); 637 New->addAttr(NewAttr); 638 } 639 } 640} 641 642/// Used in MergeFunctionDecl to keep track of function parameters in 643/// C. 644struct GNUCompatibleParamWarning { 645 ParmVarDecl *OldParm; 646 ParmVarDecl *NewParm; 647 QualType PromotedType; 648}; 649 650/// MergeFunctionDecl - We just parsed a function 'New' from 651/// declarator D which has the same name and scope as a previous 652/// declaration 'Old'. Figure out how to resolve this situation, 653/// merging decls or emitting diagnostics as appropriate. 654/// 655/// In C++, New and Old must be declarations that are not 656/// overloaded. Use IsOverload to determine whether New and Old are 657/// overloaded, and to select the Old declaration that New should be 658/// merged with. 659/// 660/// Returns true if there was an error, false otherwise. 661bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 662 assert(!isa<OverloadedFunctionDecl>(OldD) && 663 "Cannot merge with an overloaded function declaration"); 664 665 // Verify the old decl was also a function. 666 FunctionDecl *Old = 0; 667 if (FunctionTemplateDecl *OldFunctionTemplate 668 = dyn_cast<FunctionTemplateDecl>(OldD)) 669 Old = OldFunctionTemplate->getTemplatedDecl(); 670 else 671 Old = dyn_cast<FunctionDecl>(OldD); 672 if (!Old) { 673 Diag(New->getLocation(), diag::err_redefinition_different_kind) 674 << New->getDeclName(); 675 Diag(OldD->getLocation(), diag::note_previous_definition); 676 return true; 677 } 678 679 // Determine whether the previous declaration was a definition, 680 // implicit declaration, or a declaration. 681 diag::kind PrevDiag; 682 if (Old->isThisDeclarationADefinition()) 683 PrevDiag = diag::note_previous_definition; 684 else if (Old->isImplicit()) 685 PrevDiag = diag::note_previous_implicit_declaration; 686 else 687 PrevDiag = diag::note_previous_declaration; 688 689 QualType OldQType = Context.getCanonicalType(Old->getType()); 690 QualType NewQType = Context.getCanonicalType(New->getType()); 691 692 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 693 New->getStorageClass() == FunctionDecl::Static && 694 Old->getStorageClass() != FunctionDecl::Static) { 695 Diag(New->getLocation(), diag::err_static_non_static) 696 << New; 697 Diag(Old->getLocation(), PrevDiag); 698 return true; 699 } 700 701 if (getLangOptions().CPlusPlus) { 702 // (C++98 13.1p2): 703 // Certain function declarations cannot be overloaded: 704 // -- Function declarations that differ only in the return type 705 // cannot be overloaded. 706 QualType OldReturnType 707 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 708 QualType NewReturnType 709 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 710 if (OldReturnType != NewReturnType) { 711 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 712 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 713 return true; 714 } 715 716 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 717 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 718 if (OldMethod && NewMethod && 719 NewMethod->getLexicalDeclContext()->isRecord()) { 720 // -- Member function declarations with the same name and the 721 // same parameter types cannot be overloaded if any of them 722 // is a static member function declaration. 723 if (OldMethod->isStatic() || NewMethod->isStatic()) { 724 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 725 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 726 return true; 727 } 728 729 // C++ [class.mem]p1: 730 // [...] A member shall not be declared twice in the 731 // member-specification, except that a nested class or member 732 // class template can be declared and then later defined. 733 unsigned NewDiag; 734 if (isa<CXXConstructorDecl>(OldMethod)) 735 NewDiag = diag::err_constructor_redeclared; 736 else if (isa<CXXDestructorDecl>(NewMethod)) 737 NewDiag = diag::err_destructor_redeclared; 738 else if (isa<CXXConversionDecl>(NewMethod)) 739 NewDiag = diag::err_conv_function_redeclared; 740 else 741 NewDiag = diag::err_member_redeclared; 742 743 Diag(New->getLocation(), NewDiag); 744 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 745 } 746 747 // (C++98 8.3.5p3): 748 // All declarations for a function shall agree exactly in both the 749 // return type and the parameter-type-list. 750 if (OldQType == NewQType) 751 return MergeCompatibleFunctionDecls(New, Old); 752 753 // Fall through for conflicting redeclarations and redefinitions. 754 } 755 756 // C: Function types need to be compatible, not identical. This handles 757 // duplicate function decls like "void f(int); void f(enum X);" properly. 758 if (!getLangOptions().CPlusPlus && 759 Context.typesAreCompatible(OldQType, NewQType)) { 760 const FunctionType *OldFuncType = OldQType->getAsFunctionType(); 761 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 762 const FunctionProtoType *OldProto = 0; 763 if (isa<FunctionNoProtoType>(NewFuncType) && 764 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 765 // The old declaration provided a function prototype, but the 766 // new declaration does not. Merge in the prototype. 767 assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); 768 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 769 OldProto->arg_type_end()); 770 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 771 ParamTypes.data(), ParamTypes.size(), 772 OldProto->isVariadic(), 773 OldProto->getTypeQuals()); 774 New->setType(NewQType); 775 New->setHasInheritedPrototype(); 776 777 // Synthesize a parameter for each argument type. 778 llvm::SmallVector<ParmVarDecl*, 16> Params; 779 for (FunctionProtoType::arg_type_iterator 780 ParamType = OldProto->arg_type_begin(), 781 ParamEnd = OldProto->arg_type_end(); 782 ParamType != ParamEnd; ++ParamType) { 783 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 784 SourceLocation(), 0, 785 *ParamType, VarDecl::None, 786 0); 787 Param->setImplicit(); 788 Params.push_back(Param); 789 } 790 791 New->setParams(Context, Params.data(), Params.size()); 792 } 793 794 return MergeCompatibleFunctionDecls(New, Old); 795 } 796 797 // GNU C permits a K&R definition to follow a prototype declaration 798 // if the declared types of the parameters in the K&R definition 799 // match the types in the prototype declaration, even when the 800 // promoted types of the parameters from the K&R definition differ 801 // from the types in the prototype. GCC then keeps the types from 802 // the prototype. 803 // 804 // If a variadic prototype is followed by a non-variadic K&R definition, 805 // the K&R definition becomes variadic. This is sort of an edge case, but 806 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and 807 // C99 6.9.1p8. 808 if (!getLangOptions().CPlusPlus && 809 Old->hasPrototype() && !New->hasPrototype() && 810 New->getType()->getAsFunctionProtoType() && 811 Old->getNumParams() == New->getNumParams()) { 812 llvm::SmallVector<QualType, 16> ArgTypes; 813 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 814 const FunctionProtoType *OldProto 815 = Old->getType()->getAsFunctionProtoType(); 816 const FunctionProtoType *NewProto 817 = New->getType()->getAsFunctionProtoType(); 818 819 // Determine whether this is the GNU C extension. 820 QualType MergedReturn = Context.mergeTypes(OldProto->getResultType(), 821 NewProto->getResultType()); 822 bool LooseCompatible = !MergedReturn.isNull(); 823 for (unsigned Idx = 0, End = Old->getNumParams(); 824 LooseCompatible && Idx != End; ++Idx) { 825 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 826 ParmVarDecl *NewParm = New->getParamDecl(Idx); 827 if (Context.typesAreCompatible(OldParm->getType(), 828 NewProto->getArgType(Idx))) { 829 ArgTypes.push_back(NewParm->getType()); 830 } else if (Context.typesAreCompatible(OldParm->getType(), 831 NewParm->getType())) { 832 GNUCompatibleParamWarning Warn 833 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 834 Warnings.push_back(Warn); 835 ArgTypes.push_back(NewParm->getType()); 836 } else 837 LooseCompatible = false; 838 } 839 840 if (LooseCompatible) { 841 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 842 Diag(Warnings[Warn].NewParm->getLocation(), 843 diag::ext_param_promoted_not_compatible_with_prototype) 844 << Warnings[Warn].PromotedType 845 << Warnings[Warn].OldParm->getType(); 846 Diag(Warnings[Warn].OldParm->getLocation(), 847 diag::note_previous_declaration); 848 } 849 850 New->setType(Context.getFunctionType(MergedReturn, &ArgTypes[0], 851 ArgTypes.size(), 852 OldProto->isVariadic(), 0)); 853 return MergeCompatibleFunctionDecls(New, Old); 854 } 855 856 // Fall through to diagnose conflicting types. 857 } 858 859 // A function that has already been declared has been redeclared or defined 860 // with a different type- show appropriate diagnostic 861 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 862 // The user has declared a builtin function with an incompatible 863 // signature. 864 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 865 // The function the user is redeclaring is a library-defined 866 // function like 'malloc' or 'printf'. Warn about the 867 // redeclaration, then pretend that we don't know about this 868 // library built-in. 869 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 870 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 871 << Old << Old->getType(); 872 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 873 Old->setInvalidDecl(); 874 return false; 875 } 876 877 PrevDiag = diag::note_previous_builtin_declaration; 878 } 879 880 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 881 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 882 return true; 883} 884 885/// \brief Completes the merge of two function declarations that are 886/// known to be compatible. 887/// 888/// This routine handles the merging of attributes and other 889/// properties of function declarations form the old declaration to 890/// the new declaration, once we know that New is in fact a 891/// redeclaration of Old. 892/// 893/// \returns false 894bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 895 // Merge the attributes 896 MergeAttributes(New, Old, Context); 897 898 // Merge the storage class. 899 if (Old->getStorageClass() != FunctionDecl::Extern) 900 New->setStorageClass(Old->getStorageClass()); 901 902 // Merge "inline" 903 if (Old->isInline()) 904 New->setInline(true); 905 906 // If this function declaration by itself qualifies as a C99 inline 907 // definition (C99 6.7.4p6), but the previous definition did not, 908 // then the function is not a C99 inline definition. 909 if (New->isC99InlineDefinition() && !Old->isC99InlineDefinition()) 910 New->setC99InlineDefinition(false); 911 else if (Old->isC99InlineDefinition() && !New->isC99InlineDefinition()) { 912 // Mark all preceding definitions as not being C99 inline definitions. 913 for (const FunctionDecl *Prev = Old; Prev; 914 Prev = Prev->getPreviousDeclaration()) 915 const_cast<FunctionDecl *>(Prev)->setC99InlineDefinition(false); 916 } 917 918 // Merge "pure" flag. 919 if (Old->isPure()) 920 New->setPure(); 921 922 // Merge the "deleted" flag. 923 if (Old->isDeleted()) 924 New->setDeleted(); 925 926 if (getLangOptions().CPlusPlus) 927 return MergeCXXFunctionDecl(New, Old); 928 929 return false; 930} 931 932/// MergeVarDecl - We just parsed a variable 'New' which has the same name 933/// and scope as a previous declaration 'Old'. Figure out how to resolve this 934/// situation, merging decls or emitting diagnostics as appropriate. 935/// 936/// Tentative definition rules (C99 6.9.2p2) are checked by 937/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 938/// definitions here, since the initializer hasn't been attached. 939/// 940void Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 941 // If either decl is invalid, make sure the new one is marked invalid and 942 // don't do any other checking. 943 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 944 return New->setInvalidDecl(); 945 946 // Verify the old decl was also a variable. 947 VarDecl *Old = dyn_cast<VarDecl>(OldD); 948 if (!Old) { 949 Diag(New->getLocation(), diag::err_redefinition_different_kind) 950 << New->getDeclName(); 951 Diag(OldD->getLocation(), diag::note_previous_definition); 952 return New->setInvalidDecl(); 953 } 954 955 MergeAttributes(New, Old, Context); 956 957 // Merge the types 958 QualType MergedT; 959 if (getLangOptions().CPlusPlus) { 960 if (Context.hasSameType(New->getType(), Old->getType())) 961 MergedT = New->getType(); 962 } else { 963 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 964 } 965 if (MergedT.isNull()) { 966 Diag(New->getLocation(), diag::err_redefinition_different_type) 967 << New->getDeclName(); 968 Diag(Old->getLocation(), diag::note_previous_definition); 969 return New->setInvalidDecl(); 970 } 971 New->setType(MergedT); 972 973 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 974 if (New->getStorageClass() == VarDecl::Static && 975 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 976 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 977 Diag(Old->getLocation(), diag::note_previous_definition); 978 return New->setInvalidDecl(); 979 } 980 // C99 6.2.2p4: 981 // For an identifier declared with the storage-class specifier 982 // extern in a scope in which a prior declaration of that 983 // identifier is visible,23) if the prior declaration specifies 984 // internal or external linkage, the linkage of the identifier at 985 // the later declaration is the same as the linkage specified at 986 // the prior declaration. If no prior declaration is visible, or 987 // if the prior declaration specifies no linkage, then the 988 // identifier has external linkage. 989 if (New->hasExternalStorage() && Old->hasLinkage()) 990 /* Okay */; 991 else if (New->getStorageClass() != VarDecl::Static && 992 Old->getStorageClass() == VarDecl::Static) { 993 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 994 Diag(Old->getLocation(), diag::note_previous_definition); 995 return New->setInvalidDecl(); 996 } 997 998 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 999 1000 // FIXME: The test for external storage here seems wrong? We still 1001 // need to check for mismatches. 1002 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 1003 // Don't complain about out-of-line definitions of static members. 1004 !(Old->getLexicalDeclContext()->isRecord() && 1005 !New->getLexicalDeclContext()->isRecord())) { 1006 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 1007 Diag(Old->getLocation(), diag::note_previous_definition); 1008 return New->setInvalidDecl(); 1009 } 1010 1011 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 1012 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 1013 Diag(Old->getLocation(), diag::note_previous_definition); 1014 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 1015 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 1016 Diag(Old->getLocation(), diag::note_previous_definition); 1017 } 1018 1019 // Keep a chain of previous declarations. 1020 New->setPreviousDeclaration(Old); 1021} 1022 1023/// CheckFallThrough - Check that we don't fall off the end of a 1024/// Statement that should return a value. 1025/// 1026/// \returns AlwaysFallThrough iff we always fall off the end of the statement, 1027/// MaybeFallThrough iff we might or might not fall off the end and 1028/// NeverFallThrough iff we never fall off the end of the statement. We assume 1029/// that functions not marked noreturn will return. 1030Sema::ControlFlowKind Sema::CheckFallThrough(Stmt *Root) { 1031 llvm::OwningPtr<CFG> cfg (CFG::buildCFG(Root, &Context)); 1032 1033 // FIXME: They should never return 0, fix that, delete this code. 1034 if (cfg == 0) 1035 return NeverFallThrough; 1036 // The CFG leaves in dead things, and we don't want to dead code paths to 1037 // confuse us, so we mark all live things first. 1038 std::queue<CFGBlock*> workq; 1039 llvm::BitVector live(cfg->getNumBlockIDs()); 1040 // Prep work queue 1041 workq.push(&cfg->getEntry()); 1042 // Solve 1043 while (!workq.empty()) { 1044 CFGBlock *item = workq.front(); 1045 workq.pop(); 1046 live.set(item->getBlockID()); 1047 for (CFGBlock::succ_iterator I=item->succ_begin(), 1048 E=item->succ_end(); 1049 I != E; 1050 ++I) { 1051 if ((*I) && !live[(*I)->getBlockID()]) { 1052 live.set((*I)->getBlockID()); 1053 workq.push(*I); 1054 } 1055 } 1056 } 1057 1058 // Now we know what is live, we check the live precessors of the exit block 1059 // and look for fall through paths, being careful to ignore normal returns, 1060 // and exceptional paths. 1061 bool HasLiveReturn = false; 1062 bool HasFakeEdge = false; 1063 bool HasPlainEdge = false; 1064 for (CFGBlock::succ_iterator I=cfg->getExit().pred_begin(), 1065 E = cfg->getExit().pred_end(); 1066 I != E; 1067 ++I) { 1068 CFGBlock& B = **I; 1069 if (!live[B.getBlockID()]) 1070 continue; 1071 if (B.size() == 0) { 1072 // A labeled empty statement, or the entry block... 1073 HasPlainEdge = true; 1074 continue; 1075 } 1076 Stmt *S = B[B.size()-1]; 1077 if (isa<ReturnStmt>(S)) { 1078 HasLiveReturn = true; 1079 continue; 1080 } 1081 if (isa<ObjCAtThrowStmt>(S)) { 1082 HasFakeEdge = true; 1083 continue; 1084 } 1085 if (isa<CXXThrowExpr>(S)) { 1086 HasFakeEdge = true; 1087 continue; 1088 } 1089 bool NoReturnEdge = false; 1090 if (CallExpr *C = dyn_cast<CallExpr>(S)) { 1091 Expr *CEE = C->getCallee()->IgnoreParenCasts(); 1092 if (CEE->getType().getNoReturnAttr()) { 1093 NoReturnEdge = true; 1094 HasFakeEdge = true; 1095 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) { 1096 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 1097 if (FD->hasAttr<NoReturnAttr>()) { 1098 NoReturnEdge = true; 1099 HasFakeEdge = true; 1100 } 1101 } 1102 } 1103 } 1104 // FIXME: Add noreturn message sends. 1105 if (NoReturnEdge == false) 1106 HasPlainEdge = true; 1107 } 1108 if (!HasPlainEdge) 1109 return NeverFallThrough; 1110 if (HasFakeEdge || HasLiveReturn) 1111 return MaybeFallThrough; 1112 // This says AlwaysFallThrough for calls to functions that are not marked 1113 // noreturn, that don't return. If people would like this warning to be more 1114 // accurate, such functions should be marked as noreturn. 1115 return AlwaysFallThrough; 1116} 1117 1118/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a 1119/// function that should return a value. Check that we don't fall off the end 1120/// of a noreturn function. We assume that functions and blocks not marked 1121/// noreturn will return. 1122void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body) { 1123 // FIXME: Would be nice if we had a better way to control cascading errors, 1124 // but for now, avoid them. The problem is that when Parse sees: 1125 // int foo() { return a; } 1126 // The return is eaten and the Sema code sees just: 1127 // int foo() { } 1128 // which this code would then warn about. 1129 if (getDiagnostics().hasErrorOccurred()) 1130 return; 1131 bool ReturnsVoid = false; 1132 bool HasNoReturn = false; 1133 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1134 if (FD->getResultType()->isVoidType()) 1135 ReturnsVoid = true; 1136 if (FD->hasAttr<NoReturnAttr>()) 1137 HasNoReturn = true; 1138 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 1139 if (MD->getResultType()->isVoidType()) 1140 ReturnsVoid = true; 1141 if (MD->hasAttr<NoReturnAttr>()) 1142 HasNoReturn = true; 1143 } 1144 1145 // Short circuit for compilation speed. 1146 if ((Diags.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function) 1147 == Diagnostic::Ignored || ReturnsVoid) 1148 && (Diags.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr) 1149 == Diagnostic::Ignored || !HasNoReturn) 1150 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1151 == Diagnostic::Ignored || !ReturnsVoid)) 1152 return; 1153 // FIXME: Funtion try block 1154 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1155 switch (CheckFallThrough(Body)) { 1156 case MaybeFallThrough: 1157 if (HasNoReturn) 1158 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1159 else if (!ReturnsVoid) 1160 Diag(Compound->getRBracLoc(),diag::warn_maybe_falloff_nonvoid_function); 1161 break; 1162 case AlwaysFallThrough: 1163 if (HasNoReturn) 1164 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1165 else if (!ReturnsVoid) 1166 Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function); 1167 break; 1168 case NeverFallThrough: 1169 if (ReturnsVoid) 1170 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function); 1171 break; 1172 } 1173 } 1174} 1175 1176/// CheckFallThroughForBlock - Check that we don't fall off the end of a block 1177/// that should return a value. Check that we don't fall off the end of a 1178/// noreturn block. We assume that functions and blocks not marked noreturn 1179/// will return. 1180void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body) { 1181 // FIXME: Would be nice if we had a better way to control cascading errors, 1182 // but for now, avoid them. The problem is that when Parse sees: 1183 // int foo() { return a; } 1184 // The return is eaten and the Sema code sees just: 1185 // int foo() { } 1186 // which this code would then warn about. 1187 if (getDiagnostics().hasErrorOccurred()) 1188 return; 1189 bool ReturnsVoid = false; 1190 bool HasNoReturn = false; 1191 if (const FunctionType *FT = BlockTy->getPointeeType()->getAsFunctionType()) { 1192 if (FT->getResultType()->isVoidType()) 1193 ReturnsVoid = true; 1194 if (FT->getNoReturnAttr()) 1195 HasNoReturn = true; 1196 } 1197 1198 // Short circuit for compilation speed. 1199 if (ReturnsVoid 1200 && !HasNoReturn 1201 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1202 == Diagnostic::Ignored || !ReturnsVoid)) 1203 return; 1204 // FIXME: Funtion try block 1205 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1206 switch (CheckFallThrough(Body)) { 1207 case MaybeFallThrough: 1208 if (HasNoReturn) 1209 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1210 else if (!ReturnsVoid) 1211 Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block); 1212 break; 1213 case AlwaysFallThrough: 1214 if (HasNoReturn) 1215 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1216 else if (!ReturnsVoid) 1217 Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block); 1218 break; 1219 case NeverFallThrough: 1220 if (ReturnsVoid) 1221 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block); 1222 break; 1223 } 1224 } 1225} 1226 1227/// CheckParmsForFunctionDef - Check that the parameters of the given 1228/// function are appropriate for the definition of a function. This 1229/// takes care of any checks that cannot be performed on the 1230/// declaration itself, e.g., that the types of each of the function 1231/// parameters are complete. 1232bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 1233 bool HasInvalidParm = false; 1234 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1235 ParmVarDecl *Param = FD->getParamDecl(p); 1236 1237 // C99 6.7.5.3p4: the parameters in a parameter type list in a 1238 // function declarator that is part of a function definition of 1239 // that function shall not have incomplete type. 1240 // 1241 // This is also C++ [dcl.fct]p6. 1242 if (!Param->isInvalidDecl() && 1243 RequireCompleteType(Param->getLocation(), Param->getType(), 1244 diag::err_typecheck_decl_incomplete_type)) { 1245 Param->setInvalidDecl(); 1246 HasInvalidParm = true; 1247 } 1248 1249 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1250 // declaration of each parameter shall include an identifier. 1251 if (Param->getIdentifier() == 0 && 1252 !Param->isImplicit() && 1253 !getLangOptions().CPlusPlus) 1254 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1255 } 1256 1257 return HasInvalidParm; 1258} 1259 1260/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1261/// no declarator (e.g. "struct foo;") is parsed. 1262Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1263 // FIXME: Error on auto/register at file scope 1264 // FIXME: Error on inline/virtual/explicit 1265 // FIXME: Error on invalid restrict 1266 // FIXME: Warn on useless __thread 1267 // FIXME: Warn on useless const/volatile 1268 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1269 // FIXME: Warn on useless attributes 1270 TagDecl *Tag = 0; 1271 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1272 DS.getTypeSpecType() == DeclSpec::TST_struct || 1273 DS.getTypeSpecType() == DeclSpec::TST_union || 1274 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1275 if (!DS.getTypeRep()) // We probably had an error 1276 return DeclPtrTy(); 1277 1278 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 1279 } 1280 1281 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1282 if (!Record->getDeclName() && Record->isDefinition() && 1283 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1284 if (getLangOptions().CPlusPlus || 1285 Record->getDeclContext()->isRecord()) 1286 return BuildAnonymousStructOrUnion(S, DS, Record); 1287 1288 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1289 << DS.getSourceRange(); 1290 } 1291 1292 // Microsoft allows unnamed struct/union fields. Don't complain 1293 // about them. 1294 // FIXME: Should we support Microsoft's extensions in this area? 1295 if (Record->getDeclName() && getLangOptions().Microsoft) 1296 return DeclPtrTy::make(Tag); 1297 } 1298 1299 if (!DS.isMissingDeclaratorOk() && 1300 DS.getTypeSpecType() != DeclSpec::TST_error) { 1301 // Warn about typedefs of enums without names, since this is an 1302 // extension in both Microsoft an GNU. 1303 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1304 Tag && isa<EnumDecl>(Tag)) { 1305 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1306 << DS.getSourceRange(); 1307 return DeclPtrTy::make(Tag); 1308 } 1309 1310 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1311 << DS.getSourceRange(); 1312 return DeclPtrTy(); 1313 } 1314 1315 return DeclPtrTy::make(Tag); 1316} 1317 1318/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1319/// anonymous struct or union AnonRecord into the owning context Owner 1320/// and scope S. This routine will be invoked just after we realize 1321/// that an unnamed union or struct is actually an anonymous union or 1322/// struct, e.g., 1323/// 1324/// @code 1325/// union { 1326/// int i; 1327/// float f; 1328/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1329/// // f into the surrounding scope.x 1330/// @endcode 1331/// 1332/// This routine is recursive, injecting the names of nested anonymous 1333/// structs/unions into the owning context and scope as well. 1334bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1335 RecordDecl *AnonRecord) { 1336 bool Invalid = false; 1337 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 1338 FEnd = AnonRecord->field_end(); 1339 F != FEnd; ++F) { 1340 if ((*F)->getDeclName()) { 1341 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 1342 LookupOrdinaryName, true); 1343 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 1344 // C++ [class.union]p2: 1345 // The names of the members of an anonymous union shall be 1346 // distinct from the names of any other entity in the 1347 // scope in which the anonymous union is declared. 1348 unsigned diagKind 1349 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 1350 : diag::err_anonymous_struct_member_redecl; 1351 Diag((*F)->getLocation(), diagKind) 1352 << (*F)->getDeclName(); 1353 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1354 Invalid = true; 1355 } else { 1356 // C++ [class.union]p2: 1357 // For the purpose of name lookup, after the anonymous union 1358 // definition, the members of the anonymous union are 1359 // considered to have been defined in the scope in which the 1360 // anonymous union is declared. 1361 Owner->makeDeclVisibleInContext(*F); 1362 S->AddDecl(DeclPtrTy::make(*F)); 1363 IdResolver.AddDecl(*F); 1364 } 1365 } else if (const RecordType *InnerRecordType 1366 = (*F)->getType()->getAs<RecordType>()) { 1367 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1368 if (InnerRecord->isAnonymousStructOrUnion()) 1369 Invalid = Invalid || 1370 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1371 } 1372 } 1373 1374 return Invalid; 1375} 1376 1377/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1378/// anonymous structure or union. Anonymous unions are a C++ feature 1379/// (C++ [class.union]) and a GNU C extension; anonymous structures 1380/// are a GNU C and GNU C++ extension. 1381Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1382 RecordDecl *Record) { 1383 DeclContext *Owner = Record->getDeclContext(); 1384 1385 // Diagnose whether this anonymous struct/union is an extension. 1386 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1387 Diag(Record->getLocation(), diag::ext_anonymous_union); 1388 else if (!Record->isUnion()) 1389 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1390 1391 // C and C++ require different kinds of checks for anonymous 1392 // structs/unions. 1393 bool Invalid = false; 1394 if (getLangOptions().CPlusPlus) { 1395 const char* PrevSpec = 0; 1396 unsigned DiagID; 1397 // C++ [class.union]p3: 1398 // Anonymous unions declared in a named namespace or in the 1399 // global namespace shall be declared static. 1400 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1401 (isa<TranslationUnitDecl>(Owner) || 1402 (isa<NamespaceDecl>(Owner) && 1403 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1404 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1405 Invalid = true; 1406 1407 // Recover by adding 'static'. 1408 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), 1409 PrevSpec, DiagID); 1410 } 1411 // C++ [class.union]p3: 1412 // A storage class is not allowed in a declaration of an 1413 // anonymous union in a class scope. 1414 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1415 isa<RecordDecl>(Owner)) { 1416 Diag(DS.getStorageClassSpecLoc(), 1417 diag::err_anonymous_union_with_storage_spec); 1418 Invalid = true; 1419 1420 // Recover by removing the storage specifier. 1421 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1422 PrevSpec, DiagID); 1423 } 1424 1425 // C++ [class.union]p2: 1426 // The member-specification of an anonymous union shall only 1427 // define non-static data members. [Note: nested types and 1428 // functions cannot be declared within an anonymous union. ] 1429 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 1430 MemEnd = Record->decls_end(); 1431 Mem != MemEnd; ++Mem) { 1432 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1433 // C++ [class.union]p3: 1434 // An anonymous union shall not have private or protected 1435 // members (clause 11). 1436 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1437 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1438 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1439 Invalid = true; 1440 } 1441 } else if ((*Mem)->isImplicit()) { 1442 // Any implicit members are fine. 1443 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1444 // This is a type that showed up in an 1445 // elaborated-type-specifier inside the anonymous struct or 1446 // union, but which actually declares a type outside of the 1447 // anonymous struct or union. It's okay. 1448 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1449 if (!MemRecord->isAnonymousStructOrUnion() && 1450 MemRecord->getDeclName()) { 1451 // This is a nested type declaration. 1452 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1453 << (int)Record->isUnion(); 1454 Invalid = true; 1455 } 1456 } else { 1457 // We have something that isn't a non-static data 1458 // member. Complain about it. 1459 unsigned DK = diag::err_anonymous_record_bad_member; 1460 if (isa<TypeDecl>(*Mem)) 1461 DK = diag::err_anonymous_record_with_type; 1462 else if (isa<FunctionDecl>(*Mem)) 1463 DK = diag::err_anonymous_record_with_function; 1464 else if (isa<VarDecl>(*Mem)) 1465 DK = diag::err_anonymous_record_with_static; 1466 Diag((*Mem)->getLocation(), DK) 1467 << (int)Record->isUnion(); 1468 Invalid = true; 1469 } 1470 } 1471 } 1472 1473 if (!Record->isUnion() && !Owner->isRecord()) { 1474 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1475 << (int)getLangOptions().CPlusPlus; 1476 Invalid = true; 1477 } 1478 1479 // Create a declaration for this anonymous struct/union. 1480 NamedDecl *Anon = 0; 1481 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1482 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1483 /*IdentifierInfo=*/0, 1484 Context.getTypeDeclType(Record), 1485 /*BitWidth=*/0, /*Mutable=*/false, 1486 DS.getSourceRange().getBegin()); 1487 Anon->setAccess(AS_public); 1488 if (getLangOptions().CPlusPlus) 1489 FieldCollector->Add(cast<FieldDecl>(Anon)); 1490 } else { 1491 VarDecl::StorageClass SC; 1492 switch (DS.getStorageClassSpec()) { 1493 default: assert(0 && "Unknown storage class!"); 1494 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1495 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1496 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1497 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1498 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1499 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1500 case DeclSpec::SCS_mutable: 1501 // mutable can only appear on non-static class members, so it's always 1502 // an error here 1503 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1504 Invalid = true; 1505 SC = VarDecl::None; 1506 break; 1507 } 1508 1509 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1510 /*IdentifierInfo=*/0, 1511 Context.getTypeDeclType(Record), 1512 SC, DS.getSourceRange().getBegin()); 1513 } 1514 Anon->setImplicit(); 1515 1516 // Add the anonymous struct/union object to the current 1517 // context. We'll be referencing this object when we refer to one of 1518 // its members. 1519 Owner->addDecl(Anon); 1520 1521 // Inject the members of the anonymous struct/union into the owning 1522 // context and into the identifier resolver chain for name lookup 1523 // purposes. 1524 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1525 Invalid = true; 1526 1527 // Mark this as an anonymous struct/union type. Note that we do not 1528 // do this until after we have already checked and injected the 1529 // members of this anonymous struct/union type, because otherwise 1530 // the members could be injected twice: once by DeclContext when it 1531 // builds its lookup table, and once by 1532 // InjectAnonymousStructOrUnionMembers. 1533 Record->setAnonymousStructOrUnion(true); 1534 1535 if (Invalid) 1536 Anon->setInvalidDecl(); 1537 1538 return DeclPtrTy::make(Anon); 1539} 1540 1541 1542/// GetNameForDeclarator - Determine the full declaration name for the 1543/// given Declarator. 1544DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1545 switch (D.getKind()) { 1546 case Declarator::DK_Abstract: 1547 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1548 return DeclarationName(); 1549 1550 case Declarator::DK_Normal: 1551 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1552 return DeclarationName(D.getIdentifier()); 1553 1554 case Declarator::DK_Constructor: { 1555 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1556 Ty = Context.getCanonicalType(Ty); 1557 return Context.DeclarationNames.getCXXConstructorName(Ty); 1558 } 1559 1560 case Declarator::DK_Destructor: { 1561 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1562 Ty = Context.getCanonicalType(Ty); 1563 return Context.DeclarationNames.getCXXDestructorName(Ty); 1564 } 1565 1566 case Declarator::DK_Conversion: { 1567 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1568 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1569 Ty = Context.getCanonicalType(Ty); 1570 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1571 } 1572 1573 case Declarator::DK_Operator: 1574 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1575 return Context.DeclarationNames.getCXXOperatorName( 1576 D.getOverloadedOperator()); 1577 } 1578 1579 assert(false && "Unknown name kind"); 1580 return DeclarationName(); 1581} 1582 1583/// isNearlyMatchingFunction - Determine whether the C++ functions 1584/// Declaration and Definition are "nearly" matching. This heuristic 1585/// is used to improve diagnostics in the case where an out-of-line 1586/// function definition doesn't match any declaration within 1587/// the class or namespace. 1588static bool isNearlyMatchingFunction(ASTContext &Context, 1589 FunctionDecl *Declaration, 1590 FunctionDecl *Definition) { 1591 if (Declaration->param_size() != Definition->param_size()) 1592 return false; 1593 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1594 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1595 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1596 1597 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1598 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1599 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1600 return false; 1601 } 1602 1603 return true; 1604} 1605 1606Sema::DeclPtrTy 1607Sema::HandleDeclarator(Scope *S, Declarator &D, 1608 MultiTemplateParamsArg TemplateParamLists, 1609 bool IsFunctionDefinition) { 1610 DeclarationName Name = GetNameForDeclarator(D); 1611 1612 // All of these full declarators require an identifier. If it doesn't have 1613 // one, the ParsedFreeStandingDeclSpec action should be used. 1614 if (!Name) { 1615 if (!D.isInvalidType()) // Reject this if we think it is valid. 1616 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1617 diag::err_declarator_need_ident) 1618 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1619 return DeclPtrTy(); 1620 } 1621 1622 // The scope passed in may not be a decl scope. Zip up the scope tree until 1623 // we find one that is. 1624 while ((S->getFlags() & Scope::DeclScope) == 0 || 1625 (S->getFlags() & Scope::TemplateParamScope) != 0) 1626 S = S->getParent(); 1627 1628 DeclContext *DC; 1629 NamedDecl *PrevDecl; 1630 NamedDecl *New; 1631 1632 QualType R = GetTypeForDeclarator(D, S); 1633 1634 // See if this is a redefinition of a variable in the same scope. 1635 if (D.getCXXScopeSpec().isInvalid()) { 1636 DC = CurContext; 1637 PrevDecl = 0; 1638 D.setInvalidType(); 1639 } else if (!D.getCXXScopeSpec().isSet()) { 1640 LookupNameKind NameKind = LookupOrdinaryName; 1641 1642 // If the declaration we're planning to build will be a function 1643 // or object with linkage, then look for another declaration with 1644 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1645 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1646 /* Do nothing*/; 1647 else if (R->isFunctionType()) { 1648 if (CurContext->isFunctionOrMethod() || 1649 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1650 NameKind = LookupRedeclarationWithLinkage; 1651 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1652 NameKind = LookupRedeclarationWithLinkage; 1653 else if (CurContext->getLookupContext()->isTranslationUnit() && 1654 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1655 NameKind = LookupRedeclarationWithLinkage; 1656 1657 DC = CurContext; 1658 PrevDecl = LookupName(S, Name, NameKind, true, 1659 NameKind == LookupRedeclarationWithLinkage, 1660 D.getIdentifierLoc()); 1661 } else { // Something like "int foo::x;" 1662 DC = computeDeclContext(D.getCXXScopeSpec(), true); 1663 // FIXME: RequireCompleteDeclContext(D.getCXXScopeSpec()); ? 1664 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1665 1666 // C++ 7.3.1.2p2: 1667 // Members (including explicit specializations of templates) of a named 1668 // namespace can also be defined outside that namespace by explicit 1669 // qualification of the name being defined, provided that the entity being 1670 // defined was already declared in the namespace and the definition appears 1671 // after the point of declaration in a namespace that encloses the 1672 // declarations namespace. 1673 // 1674 // Note that we only check the context at this point. We don't yet 1675 // have enough information to make sure that PrevDecl is actually 1676 // the declaration we want to match. For example, given: 1677 // 1678 // class X { 1679 // void f(); 1680 // void f(float); 1681 // }; 1682 // 1683 // void X::f(int) { } // ill-formed 1684 // 1685 // In this case, PrevDecl will point to the overload set 1686 // containing the two f's declared in X, but neither of them 1687 // matches. 1688 1689 // First check whether we named the global scope. 1690 if (isa<TranslationUnitDecl>(DC)) { 1691 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1692 << Name << D.getCXXScopeSpec().getRange(); 1693 } else if (!CurContext->Encloses(DC)) { 1694 // The qualifying scope doesn't enclose the original declaration. 1695 // Emit diagnostic based on current scope. 1696 SourceLocation L = D.getIdentifierLoc(); 1697 SourceRange R = D.getCXXScopeSpec().getRange(); 1698 if (isa<FunctionDecl>(CurContext)) 1699 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1700 else 1701 Diag(L, diag::err_invalid_declarator_scope) 1702 << Name << cast<NamedDecl>(DC) << R; 1703 D.setInvalidType(); 1704 } 1705 } 1706 1707 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1708 // Maybe we will complain about the shadowed template parameter. 1709 if (!D.isInvalidType()) 1710 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl)) 1711 D.setInvalidType(); 1712 1713 // Just pretend that we didn't see the previous declaration. 1714 PrevDecl = 0; 1715 } 1716 1717 // In C++, the previous declaration we find might be a tag type 1718 // (class or enum). In this case, the new declaration will hide the 1719 // tag type. Note that this does does not apply if we're declaring a 1720 // typedef (C++ [dcl.typedef]p4). 1721 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1722 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1723 PrevDecl = 0; 1724 1725 bool Redeclaration = false; 1726 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1727 if (TemplateParamLists.size()) { 1728 Diag(D.getIdentifierLoc(), diag::err_template_typedef); 1729 return DeclPtrTy(); 1730 } 1731 1732 New = ActOnTypedefDeclarator(S, D, DC, R, PrevDecl, Redeclaration); 1733 } else if (R->isFunctionType()) { 1734 New = ActOnFunctionDeclarator(S, D, DC, R, PrevDecl, 1735 move(TemplateParamLists), 1736 IsFunctionDefinition, Redeclaration); 1737 } else { 1738 New = ActOnVariableDeclarator(S, D, DC, R, PrevDecl, 1739 move(TemplateParamLists), 1740 Redeclaration); 1741 } 1742 1743 if (New == 0) 1744 return DeclPtrTy(); 1745 1746 // If this has an identifier and is not an invalid redeclaration, 1747 // add it to the scope stack. 1748 if (Name && !(Redeclaration && New->isInvalidDecl())) 1749 PushOnScopeChains(New, S); 1750 1751 return DeclPtrTy::make(New); 1752} 1753 1754/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1755/// types into constant array types in certain situations which would otherwise 1756/// be errors (for GCC compatibility). 1757static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1758 ASTContext &Context, 1759 bool &SizeIsNegative) { 1760 // This method tries to turn a variable array into a constant 1761 // array even when the size isn't an ICE. This is necessary 1762 // for compatibility with code that depends on gcc's buggy 1763 // constant expression folding, like struct {char x[(int)(char*)2];} 1764 SizeIsNegative = false; 1765 1766 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1767 QualType Pointee = PTy->getPointeeType(); 1768 QualType FixedType = 1769 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1770 if (FixedType.isNull()) return FixedType; 1771 FixedType = Context.getPointerType(FixedType); 1772 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1773 return FixedType; 1774 } 1775 1776 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1777 if (!VLATy) 1778 return QualType(); 1779 // FIXME: We should probably handle this case 1780 if (VLATy->getElementType()->isVariablyModifiedType()) 1781 return QualType(); 1782 1783 Expr::EvalResult EvalResult; 1784 if (!VLATy->getSizeExpr() || 1785 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 1786 !EvalResult.Val.isInt()) 1787 return QualType(); 1788 1789 llvm::APSInt &Res = EvalResult.Val.getInt(); 1790 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) { 1791 Expr* ArySizeExpr = VLATy->getSizeExpr(); 1792 // FIXME: here we could "steal" (how?) ArySizeExpr from the VLA, 1793 // so as to transfer ownership to the ConstantArrayWithExpr. 1794 // Alternatively, we could "clone" it (how?). 1795 // Since we don't know how to do things above, we just use the 1796 // very same Expr*. 1797 return Context.getConstantArrayWithExprType(VLATy->getElementType(), 1798 Res, ArySizeExpr, 1799 ArrayType::Normal, 0, 1800 VLATy->getBracketsRange()); 1801 } 1802 1803 SizeIsNegative = true; 1804 return QualType(); 1805} 1806 1807/// \brief Register the given locally-scoped external C declaration so 1808/// that it can be found later for redeclarations 1809void 1810Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, NamedDecl *PrevDecl, 1811 Scope *S) { 1812 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 1813 "Decl is not a locally-scoped decl!"); 1814 // Note that we have a locally-scoped external with this name. 1815 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 1816 1817 if (!PrevDecl) 1818 return; 1819 1820 // If there was a previous declaration of this variable, it may be 1821 // in our identifier chain. Update the identifier chain with the new 1822 // declaration. 1823 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 1824 // The previous declaration was found on the identifer resolver 1825 // chain, so remove it from its scope. 1826 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 1827 S = S->getParent(); 1828 1829 if (S) 1830 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 1831 } 1832} 1833 1834/// \brief Diagnose function specifiers on a declaration of an identifier that 1835/// does not identify a function. 1836void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 1837 // FIXME: We should probably indicate the identifier in question to avoid 1838 // confusion for constructs like "inline int a(), b;" 1839 if (D.getDeclSpec().isInlineSpecified()) 1840 Diag(D.getDeclSpec().getInlineSpecLoc(), 1841 diag::err_inline_non_function); 1842 1843 if (D.getDeclSpec().isVirtualSpecified()) 1844 Diag(D.getDeclSpec().getVirtualSpecLoc(), 1845 diag::err_virtual_non_function); 1846 1847 if (D.getDeclSpec().isExplicitSpecified()) 1848 Diag(D.getDeclSpec().getExplicitSpecLoc(), 1849 diag::err_explicit_non_function); 1850} 1851 1852NamedDecl* 1853Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1854 QualType R, Decl* PrevDecl, bool &Redeclaration) { 1855 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1856 if (D.getCXXScopeSpec().isSet()) { 1857 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1858 << D.getCXXScopeSpec().getRange(); 1859 D.setInvalidType(); 1860 // Pretend we didn't see the scope specifier. 1861 DC = 0; 1862 } 1863 1864 if (getLangOptions().CPlusPlus) { 1865 // Check that there are no default arguments (C++ only). 1866 CheckExtraCXXDefaultArguments(D); 1867 } 1868 1869 DiagnoseFunctionSpecifiers(D); 1870 1871 if (D.getDeclSpec().isThreadSpecified()) 1872 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 1873 1874 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R); 1875 if (!NewTD) return 0; 1876 1877 if (D.isInvalidType()) 1878 NewTD->setInvalidDecl(); 1879 1880 // Handle attributes prior to checking for duplicates in MergeVarDecl 1881 ProcessDeclAttributes(S, NewTD, D); 1882 // Merge the decl with the existing one if appropriate. If the decl is 1883 // in an outer scope, it isn't the same thing. 1884 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1885 Redeclaration = true; 1886 MergeTypeDefDecl(NewTD, PrevDecl); 1887 } 1888 1889 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1890 // then it shall have block scope. 1891 QualType T = NewTD->getUnderlyingType(); 1892 if (T->isVariablyModifiedType()) { 1893 CurFunctionNeedsScopeChecking = true; 1894 1895 if (S->getFnParent() == 0) { 1896 bool SizeIsNegative; 1897 QualType FixedTy = 1898 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1899 if (!FixedTy.isNull()) { 1900 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1901 NewTD->setUnderlyingType(FixedTy); 1902 } else { 1903 if (SizeIsNegative) 1904 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1905 else if (T->isVariableArrayType()) 1906 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1907 else 1908 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1909 NewTD->setInvalidDecl(); 1910 } 1911 } 1912 } 1913 1914 // If this is the C FILE type, notify the AST context. 1915 if (IdentifierInfo *II = NewTD->getIdentifier()) 1916 if (!NewTD->isInvalidDecl() && 1917 NewTD->getDeclContext()->getLookupContext()->isTranslationUnit()) { 1918 if (II->isStr("FILE")) 1919 Context.setFILEDecl(NewTD); 1920 else if (II->isStr("jmp_buf")) 1921 Context.setjmp_bufDecl(NewTD); 1922 else if (II->isStr("sigjmp_buf")) 1923 Context.setsigjmp_bufDecl(NewTD); 1924 } 1925 1926 return NewTD; 1927} 1928 1929/// \brief Determines whether the given declaration is an out-of-scope 1930/// previous declaration. 1931/// 1932/// This routine should be invoked when name lookup has found a 1933/// previous declaration (PrevDecl) that is not in the scope where a 1934/// new declaration by the same name is being introduced. If the new 1935/// declaration occurs in a local scope, previous declarations with 1936/// linkage may still be considered previous declarations (C99 1937/// 6.2.2p4-5, C++ [basic.link]p6). 1938/// 1939/// \param PrevDecl the previous declaration found by name 1940/// lookup 1941/// 1942/// \param DC the context in which the new declaration is being 1943/// declared. 1944/// 1945/// \returns true if PrevDecl is an out-of-scope previous declaration 1946/// for a new delcaration with the same name. 1947static bool 1948isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 1949 ASTContext &Context) { 1950 if (!PrevDecl) 1951 return 0; 1952 1953 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 1954 // case we need to check each of the overloaded functions. 1955 if (!PrevDecl->hasLinkage()) 1956 return false; 1957 1958 if (Context.getLangOptions().CPlusPlus) { 1959 // C++ [basic.link]p6: 1960 // If there is a visible declaration of an entity with linkage 1961 // having the same name and type, ignoring entities declared 1962 // outside the innermost enclosing namespace scope, the block 1963 // scope declaration declares that same entity and receives the 1964 // linkage of the previous declaration. 1965 DeclContext *OuterContext = DC->getLookupContext(); 1966 if (!OuterContext->isFunctionOrMethod()) 1967 // This rule only applies to block-scope declarations. 1968 return false; 1969 else { 1970 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 1971 if (PrevOuterContext->isRecord()) 1972 // We found a member function: ignore it. 1973 return false; 1974 else { 1975 // Find the innermost enclosing namespace for the new and 1976 // previous declarations. 1977 while (!OuterContext->isFileContext()) 1978 OuterContext = OuterContext->getParent(); 1979 while (!PrevOuterContext->isFileContext()) 1980 PrevOuterContext = PrevOuterContext->getParent(); 1981 1982 // The previous declaration is in a different namespace, so it 1983 // isn't the same function. 1984 if (OuterContext->getPrimaryContext() != 1985 PrevOuterContext->getPrimaryContext()) 1986 return false; 1987 } 1988 } 1989 } 1990 1991 return true; 1992} 1993 1994NamedDecl* 1995Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1996 QualType R,NamedDecl* PrevDecl, 1997 MultiTemplateParamsArg TemplateParamLists, 1998 bool &Redeclaration) { 1999 DeclarationName Name = GetNameForDeclarator(D); 2000 2001 // Check that there are no default arguments (C++ only). 2002 if (getLangOptions().CPlusPlus) 2003 CheckExtraCXXDefaultArguments(D); 2004 2005 VarDecl *NewVD; 2006 VarDecl::StorageClass SC; 2007 switch (D.getDeclSpec().getStorageClassSpec()) { 2008 default: assert(0 && "Unknown storage class!"); 2009 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2010 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2011 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2012 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2013 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2014 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2015 case DeclSpec::SCS_mutable: 2016 // mutable can only appear on non-static class members, so it's always 2017 // an error here 2018 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 2019 D.setInvalidType(); 2020 SC = VarDecl::None; 2021 break; 2022 } 2023 2024 IdentifierInfo *II = Name.getAsIdentifierInfo(); 2025 if (!II) { 2026 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 2027 << Name.getAsString(); 2028 return 0; 2029 } 2030 2031 DiagnoseFunctionSpecifiers(D); 2032 2033 if (!DC->isRecord() && S->getFnParent() == 0) { 2034 // C99 6.9p2: The storage-class specifiers auto and register shall not 2035 // appear in the declaration specifiers in an external declaration. 2036 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 2037 2038 // If this is a register variable with an asm label specified, then this 2039 // is a GNU extension. 2040 if (SC == VarDecl::Register && D.getAsmLabel()) 2041 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 2042 else 2043 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 2044 D.setInvalidType(); 2045 } 2046 } 2047 if (DC->isRecord() && !CurContext->isRecord()) { 2048 // This is an out-of-line definition of a static data member. 2049 if (SC == VarDecl::Static) { 2050 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2051 diag::err_static_out_of_line) 2052 << CodeModificationHint::CreateRemoval( 2053 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2054 } else if (SC == VarDecl::None) 2055 SC = VarDecl::Static; 2056 } 2057 if (SC == VarDecl::Static) { 2058 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 2059 if (RD->isLocalClass()) 2060 Diag(D.getIdentifierLoc(), 2061 diag::err_static_data_member_not_allowed_in_local_class) 2062 << Name << RD->getDeclName(); 2063 } 2064 } 2065 2066 // Check that we can declare a template here. 2067 if (TemplateParamLists.size() && 2068 CheckTemplateDeclScope(S, TemplateParamLists)) 2069 return 0; 2070 2071 // Match up the template parameter lists with the scope specifier, then 2072 // determine whether we have a template or a template specialization. 2073 if (TemplateParameterList *TemplateParams 2074 = MatchTemplateParametersToScopeSpecifier( 2075 D.getDeclSpec().getSourceRange().getBegin(), 2076 D.getCXXScopeSpec(), 2077 (TemplateParameterList**)TemplateParamLists.get(), 2078 TemplateParamLists.size())) { 2079 if (TemplateParams->size() > 0) { 2080 // There is no such thing as a variable template. 2081 Diag(D.getIdentifierLoc(), diag::err_template_variable) 2082 << II 2083 << SourceRange(TemplateParams->getTemplateLoc(), 2084 TemplateParams->getRAngleLoc()); 2085 return 0; 2086 } else { 2087 // There is an extraneous 'template<>' for this variable. Complain 2088 // about it, but allow the declaration of the variable. 2089 Diag(TemplateParams->getTemplateLoc(), 2090 diag::err_template_variable_noparams) 2091 << II 2092 << SourceRange(TemplateParams->getTemplateLoc(), 2093 TemplateParams->getRAngleLoc()); 2094 } 2095 } 2096 2097 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 2098 II, R, SC, 2099 // FIXME: Move to DeclGroup... 2100 D.getDeclSpec().getSourceRange().getBegin()); 2101 2102 if (D.isInvalidType()) 2103 NewVD->setInvalidDecl(); 2104 2105 if (D.getDeclSpec().isThreadSpecified()) { 2106 if (NewVD->hasLocalStorage()) 2107 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 2108 else if (!Context.Target.isTLSSupported()) 2109 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 2110 else 2111 NewVD->setThreadSpecified(true); 2112 } 2113 2114 // Set the lexical context. If the declarator has a C++ scope specifier, the 2115 // lexical context will be different from the semantic context. 2116 NewVD->setLexicalDeclContext(CurContext); 2117 2118 // Handle attributes prior to checking for duplicates in MergeVarDecl 2119 ProcessDeclAttributes(S, NewVD, D); 2120 2121 // Handle GNU asm-label extension (encoded as an attribute). 2122 if (Expr *E = (Expr*) D.getAsmLabel()) { 2123 // The parser guarantees this is a string. 2124 StringLiteral *SE = cast<StringLiteral>(E); 2125 NewVD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2126 SE->getByteLength()))); 2127 } 2128 2129 // If name lookup finds a previous declaration that is not in the 2130 // same scope as the new declaration, this may still be an 2131 // acceptable redeclaration. 2132 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2133 !(NewVD->hasLinkage() && 2134 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2135 PrevDecl = 0; 2136 2137 // Merge the decl with the existing one if appropriate. 2138 if (PrevDecl) { 2139 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 2140 // The user tried to define a non-static data member 2141 // out-of-line (C++ [dcl.meaning]p1). 2142 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 2143 << D.getCXXScopeSpec().getRange(); 2144 PrevDecl = 0; 2145 NewVD->setInvalidDecl(); 2146 } 2147 } else if (D.getCXXScopeSpec().isSet()) { 2148 // No previous declaration in the qualifying scope. 2149 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 2150 << Name << D.getCXXScopeSpec().getRange(); 2151 NewVD->setInvalidDecl(); 2152 } 2153 2154 CheckVariableDeclaration(NewVD, PrevDecl, Redeclaration); 2155 2156 // attributes declared post-definition are currently ignored 2157 if (PrevDecl) { 2158 const VarDecl *Def = 0, *PrevVD = dyn_cast<VarDecl>(PrevDecl); 2159 if (PrevVD->getDefinition(Def) && D.hasAttributes()) { 2160 Diag(NewVD->getLocation(), diag::warn_attribute_precede_definition); 2161 Diag(Def->getLocation(), diag::note_previous_definition); 2162 } 2163 } 2164 2165 // If this is a locally-scoped extern C variable, update the map of 2166 // such variables. 2167 if (CurContext->isFunctionOrMethod() && NewVD->isExternC(Context) && 2168 !NewVD->isInvalidDecl()) 2169 RegisterLocallyScopedExternCDecl(NewVD, PrevDecl, S); 2170 2171 return NewVD; 2172} 2173 2174/// \brief Perform semantic checking on a newly-created variable 2175/// declaration. 2176/// 2177/// This routine performs all of the type-checking required for a 2178/// variable declaration once it has been built. It is used both to 2179/// check variables after they have been parsed and their declarators 2180/// have been translated into a declaration, and to check variables 2181/// that have been instantiated from a template. 2182/// 2183/// Sets NewVD->isInvalidDecl() if an error was encountered. 2184void Sema::CheckVariableDeclaration(VarDecl *NewVD, NamedDecl *PrevDecl, 2185 bool &Redeclaration) { 2186 // If the decl is already known invalid, don't check it. 2187 if (NewVD->isInvalidDecl()) 2188 return; 2189 2190 QualType T = NewVD->getType(); 2191 2192 if (T->isObjCInterfaceType()) { 2193 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 2194 return NewVD->setInvalidDecl(); 2195 } 2196 2197 // The variable can not have an abstract class type. 2198 if (RequireNonAbstractType(NewVD->getLocation(), T, 2199 diag::err_abstract_type_in_decl, 2200 AbstractVariableType)) 2201 return NewVD->setInvalidDecl(); 2202 2203 // Emit an error if an address space was applied to decl with local storage. 2204 // This includes arrays of objects with address space qualifiers, but not 2205 // automatic variables that point to other address spaces. 2206 // ISO/IEC TR 18037 S5.1.2 2207 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 2208 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 2209 return NewVD->setInvalidDecl(); 2210 } 2211 2212 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 2213 && !NewVD->hasAttr<BlocksAttr>()) 2214 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 2215 2216 bool isVM = T->isVariablyModifiedType(); 2217 if (isVM || NewVD->hasAttr<CleanupAttr>() || 2218 NewVD->hasAttr<BlocksAttr>()) 2219 CurFunctionNeedsScopeChecking = true; 2220 2221 if ((isVM && NewVD->hasLinkage()) || 2222 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 2223 bool SizeIsNegative; 2224 QualType FixedTy = 2225 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2226 2227 if (FixedTy.isNull() && T->isVariableArrayType()) { 2228 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2229 // FIXME: This won't give the correct result for 2230 // int a[10][n]; 2231 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2232 2233 if (NewVD->isFileVarDecl()) 2234 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 2235 << SizeRange; 2236 else if (NewVD->getStorageClass() == VarDecl::Static) 2237 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 2238 << SizeRange; 2239 else 2240 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 2241 << SizeRange; 2242 return NewVD->setInvalidDecl(); 2243 } 2244 2245 if (FixedTy.isNull()) { 2246 if (NewVD->isFileVarDecl()) 2247 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 2248 else 2249 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 2250 return NewVD->setInvalidDecl(); 2251 } 2252 2253 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 2254 NewVD->setType(FixedTy); 2255 } 2256 2257 if (!PrevDecl && NewVD->isExternC(Context)) { 2258 // Since we did not find anything by this name and we're declaring 2259 // an extern "C" variable, look for a non-visible extern "C" 2260 // declaration with the same name. 2261 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2262 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 2263 if (Pos != LocallyScopedExternalDecls.end()) 2264 PrevDecl = Pos->second; 2265 } 2266 2267 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 2268 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 2269 << T; 2270 return NewVD->setInvalidDecl(); 2271 } 2272 2273 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 2274 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 2275 return NewVD->setInvalidDecl(); 2276 } 2277 2278 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 2279 Diag(NewVD->getLocation(), diag::err_block_on_vm); 2280 return NewVD->setInvalidDecl(); 2281 } 2282 2283 if (PrevDecl) { 2284 Redeclaration = true; 2285 MergeVarDecl(NewVD, PrevDecl); 2286 } 2287} 2288 2289NamedDecl* 2290Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2291 QualType R, NamedDecl* PrevDecl, 2292 MultiTemplateParamsArg TemplateParamLists, 2293 bool IsFunctionDefinition, bool &Redeclaration) { 2294 assert(R.getTypePtr()->isFunctionType()); 2295 2296 DeclarationName Name = GetNameForDeclarator(D); 2297 FunctionDecl::StorageClass SC = FunctionDecl::None; 2298 switch (D.getDeclSpec().getStorageClassSpec()) { 2299 default: assert(0 && "Unknown storage class!"); 2300 case DeclSpec::SCS_auto: 2301 case DeclSpec::SCS_register: 2302 case DeclSpec::SCS_mutable: 2303 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2304 diag::err_typecheck_sclass_func); 2305 D.setInvalidType(); 2306 break; 2307 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 2308 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 2309 case DeclSpec::SCS_static: { 2310 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 2311 // C99 6.7.1p5: 2312 // The declaration of an identifier for a function that has 2313 // block scope shall have no explicit storage-class specifier 2314 // other than extern 2315 // See also (C++ [dcl.stc]p4). 2316 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2317 diag::err_static_block_func); 2318 SC = FunctionDecl::None; 2319 } else 2320 SC = FunctionDecl::Static; 2321 break; 2322 } 2323 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 2324 } 2325 2326 if (D.getDeclSpec().isThreadSpecified()) 2327 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2328 2329 bool isInline = D.getDeclSpec().isInlineSpecified(); 2330 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 2331 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 2332 2333 // Check that the return type is not an abstract class type. 2334 // For record types, this is done by the AbstractClassUsageDiagnoser once 2335 // the class has been completely parsed. 2336 if (!DC->isRecord() && 2337 RequireNonAbstractType(D.getIdentifierLoc(), 2338 R->getAsFunctionType()->getResultType(), 2339 diag::err_abstract_type_in_decl, 2340 AbstractReturnType)) 2341 D.setInvalidType(); 2342 2343 // Do not allow returning a objc interface by-value. 2344 if (R->getAsFunctionType()->getResultType()->isObjCInterfaceType()) { 2345 Diag(D.getIdentifierLoc(), 2346 diag::err_object_cannot_be_passed_returned_by_value) << 0 2347 << R->getAsFunctionType()->getResultType(); 2348 D.setInvalidType(); 2349 } 2350 2351 // Check that we can declare a template here. 2352 if (TemplateParamLists.size() && 2353 CheckTemplateDeclScope(S, TemplateParamLists)) 2354 return 0; 2355 2356 bool isVirtualOkay = false; 2357 FunctionDecl *NewFD; 2358 if (D.getKind() == Declarator::DK_Constructor) { 2359 // This is a C++ constructor declaration. 2360 assert(DC->isRecord() && 2361 "Constructors can only be declared in a member context"); 2362 2363 R = CheckConstructorDeclarator(D, R, SC); 2364 2365 // Create the new declaration 2366 NewFD = CXXConstructorDecl::Create(Context, 2367 cast<CXXRecordDecl>(DC), 2368 D.getIdentifierLoc(), Name, R, 2369 isExplicit, isInline, 2370 /*isImplicitlyDeclared=*/false); 2371 } else if (D.getKind() == Declarator::DK_Destructor) { 2372 // This is a C++ destructor declaration. 2373 if (DC->isRecord()) { 2374 R = CheckDestructorDeclarator(D, SC); 2375 2376 NewFD = CXXDestructorDecl::Create(Context, 2377 cast<CXXRecordDecl>(DC), 2378 D.getIdentifierLoc(), Name, R, 2379 isInline, 2380 /*isImplicitlyDeclared=*/false); 2381 2382 isVirtualOkay = true; 2383 } else { 2384 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 2385 2386 // Create a FunctionDecl to satisfy the function definition parsing 2387 // code path. 2388 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 2389 Name, R, SC, isInline, 2390 /*hasPrototype=*/true, 2391 // FIXME: Move to DeclGroup... 2392 D.getDeclSpec().getSourceRange().getBegin()); 2393 D.setInvalidType(); 2394 } 2395 } else if (D.getKind() == Declarator::DK_Conversion) { 2396 if (!DC->isRecord()) { 2397 Diag(D.getIdentifierLoc(), 2398 diag::err_conv_function_not_member); 2399 return 0; 2400 } 2401 2402 CheckConversionDeclarator(D, R, SC); 2403 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 2404 D.getIdentifierLoc(), Name, R, 2405 isInline, isExplicit); 2406 2407 isVirtualOkay = true; 2408 } else if (DC->isRecord()) { 2409 // If the of the function is the same as the name of the record, then this 2410 // must be an invalid constructor that has a return type. 2411 // (The parser checks for a return type and makes the declarator a 2412 // constructor if it has no return type). 2413 // must have an invalid constructor that has a return type 2414 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 2415 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 2416 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 2417 << SourceRange(D.getIdentifierLoc()); 2418 return 0; 2419 } 2420 2421 // This is a C++ method declaration. 2422 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 2423 D.getIdentifierLoc(), Name, R, 2424 (SC == FunctionDecl::Static), isInline); 2425 2426 isVirtualOkay = (SC != FunctionDecl::Static); 2427 } else { 2428 // Determine whether the function was written with a 2429 // prototype. This true when: 2430 // - we're in C++ (where every function has a prototype), 2431 // - there is a prototype in the declarator, or 2432 // - the type R of the function is some kind of typedef or other reference 2433 // to a type name (which eventually refers to a function type). 2434 bool HasPrototype = 2435 getLangOptions().CPlusPlus || 2436 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 2437 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 2438 2439 NewFD = FunctionDecl::Create(Context, DC, 2440 D.getIdentifierLoc(), 2441 Name, R, SC, isInline, HasPrototype, 2442 // FIXME: Move to DeclGroup... 2443 D.getDeclSpec().getSourceRange().getBegin()); 2444 } 2445 2446 if (D.isInvalidType()) 2447 NewFD->setInvalidDecl(); 2448 2449 // Set the lexical context. If the declarator has a C++ 2450 // scope specifier, the lexical context will be different 2451 // from the semantic context. 2452 NewFD->setLexicalDeclContext(CurContext); 2453 2454 // Match up the template parameter lists with the scope specifier, then 2455 // determine whether we have a template or a template specialization. 2456 FunctionTemplateDecl *FunctionTemplate = 0; 2457 if (TemplateParameterList *TemplateParams 2458 = MatchTemplateParametersToScopeSpecifier( 2459 D.getDeclSpec().getSourceRange().getBegin(), 2460 D.getCXXScopeSpec(), 2461 (TemplateParameterList**)TemplateParamLists.get(), 2462 TemplateParamLists.size())) { 2463 if (TemplateParams->size() > 0) { 2464 // This is a function template 2465 FunctionTemplate = FunctionTemplateDecl::Create(Context, CurContext, 2466 NewFD->getLocation(), 2467 Name, TemplateParams, 2468 NewFD); 2469 NewFD->setDescribedFunctionTemplate(FunctionTemplate); 2470 } else { 2471 // FIXME: Handle function template specializations 2472 } 2473 2474 // FIXME: Free this memory properly. 2475 TemplateParamLists.release(); 2476 } 2477 2478 // C++ [dcl.fct.spec]p5: 2479 // The virtual specifier shall only be used in declarations of 2480 // nonstatic class member functions that appear within a 2481 // member-specification of a class declaration; see 10.3. 2482 // 2483 if (isVirtual && !NewFD->isInvalidDecl()) { 2484 if (!isVirtualOkay) { 2485 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2486 diag::err_virtual_non_function); 2487 } else if (!CurContext->isRecord()) { 2488 // 'virtual' was specified outside of the class. 2489 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 2490 << CodeModificationHint::CreateRemoval( 2491 SourceRange(D.getDeclSpec().getVirtualSpecLoc())); 2492 } else { 2493 // Okay: Add virtual to the method. 2494 cast<CXXMethodDecl>(NewFD)->setVirtualAsWritten(true); 2495 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 2496 CurClass->setAggregate(false); 2497 CurClass->setPOD(false); 2498 CurClass->setPolymorphic(true); 2499 CurClass->setHasTrivialConstructor(false); 2500 CurClass->setHasTrivialCopyConstructor(false); 2501 CurClass->setHasTrivialCopyAssignment(false); 2502 } 2503 } 2504 2505 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD)) { 2506 // Look for virtual methods in base classes that this method might override. 2507 2508 BasePaths Paths; 2509 if (LookupInBases(cast<CXXRecordDecl>(DC), 2510 MemberLookupCriteria(NewMD), Paths)) { 2511 for (BasePaths::decl_iterator I = Paths.found_decls_begin(), 2512 E = Paths.found_decls_end(); I != E; ++I) { 2513 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2514 if (!CheckOverridingFunctionReturnType(NewMD, OldMD) && 2515 !CheckOverridingFunctionExceptionSpec(NewMD, OldMD)) 2516 NewMD->addOverriddenMethod(OldMD); 2517 } 2518 } 2519 } 2520 } 2521 2522 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 2523 !CurContext->isRecord()) { 2524 // C++ [class.static]p1: 2525 // A data or function member of a class may be declared static 2526 // in a class definition, in which case it is a static member of 2527 // the class. 2528 2529 // Complain about the 'static' specifier if it's on an out-of-line 2530 // member function definition. 2531 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2532 diag::err_static_out_of_line) 2533 << CodeModificationHint::CreateRemoval( 2534 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2535 } 2536 2537 // Handle GNU asm-label extension (encoded as an attribute). 2538 if (Expr *E = (Expr*) D.getAsmLabel()) { 2539 // The parser guarantees this is a string. 2540 StringLiteral *SE = cast<StringLiteral>(E); 2541 NewFD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2542 SE->getByteLength()))); 2543 } 2544 2545 // Copy the parameter declarations from the declarator D to the function 2546 // declaration NewFD, if they are available. First scavenge them into Params. 2547 llvm::SmallVector<ParmVarDecl*, 16> Params; 2548 if (D.getNumTypeObjects() > 0) { 2549 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2550 2551 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 2552 // function that takes no arguments, not a function that takes a 2553 // single void argument. 2554 // We let through "const void" here because Sema::GetTypeForDeclarator 2555 // already checks for that case. 2556 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 2557 FTI.ArgInfo[0].Param && 2558 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 2559 // Empty arg list, don't push any params. 2560 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 2561 2562 // In C++, the empty parameter-type-list must be spelled "void"; a 2563 // typedef of void is not permitted. 2564 if (getLangOptions().CPlusPlus && 2565 Param->getType().getUnqualifiedType() != Context.VoidTy) 2566 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 2567 // FIXME: Leaks decl? 2568 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 2569 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2570 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 2571 assert(Param->getDeclContext() != NewFD && "Was set before ?"); 2572 Param->setDeclContext(NewFD); 2573 Params.push_back(Param); 2574 } 2575 } 2576 2577 } else if (const FunctionProtoType *FT = R->getAsFunctionProtoType()) { 2578 // When we're declaring a function with a typedef, typeof, etc as in the 2579 // following example, we'll need to synthesize (unnamed) 2580 // parameters for use in the declaration. 2581 // 2582 // @code 2583 // typedef void fn(int); 2584 // fn f; 2585 // @endcode 2586 2587 // Synthesize a parameter for each argument type. 2588 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 2589 AE = FT->arg_type_end(); AI != AE; ++AI) { 2590 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 2591 SourceLocation(), 0, 2592 *AI, VarDecl::None, 0); 2593 Param->setImplicit(); 2594 Params.push_back(Param); 2595 } 2596 } else { 2597 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 2598 "Should not need args for typedef of non-prototype fn"); 2599 } 2600 // Finally, we know we have the right number of parameters, install them. 2601 NewFD->setParams(Context, Params.data(), Params.size()); 2602 2603 // If name lookup finds a previous declaration that is not in the 2604 // same scope as the new declaration, this may still be an 2605 // acceptable redeclaration. 2606 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2607 !(NewFD->hasLinkage() && 2608 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2609 PrevDecl = 0; 2610 2611 // Perform semantic checking on the function declaration. 2612 bool OverloadableAttrRequired = false; // FIXME: HACK! 2613 CheckFunctionDeclaration(NewFD, PrevDecl, Redeclaration, 2614 /*FIXME:*/OverloadableAttrRequired); 2615 2616 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 2617 // An out-of-line member function declaration must also be a 2618 // definition (C++ [dcl.meaning]p1). 2619 if (!IsFunctionDefinition) { 2620 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2621 << D.getCXXScopeSpec().getRange(); 2622 NewFD->setInvalidDecl(); 2623 } else if (!Redeclaration && (!PrevDecl || !isa<UsingDecl>(PrevDecl))) { 2624 // The user tried to provide an out-of-line definition for a 2625 // function that is a member of a class or namespace, but there 2626 // was no such member function declared (C++ [class.mfct]p2, 2627 // C++ [namespace.memdef]p2). For example: 2628 // 2629 // class X { 2630 // void f() const; 2631 // }; 2632 // 2633 // void X::f() { } // ill-formed 2634 // 2635 // Complain about this problem, and attempt to suggest close 2636 // matches (e.g., those that differ only in cv-qualifiers and 2637 // whether the parameter types are references). 2638 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 2639 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 2640 NewFD->setInvalidDecl(); 2641 2642 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 2643 true); 2644 assert(!Prev.isAmbiguous() && 2645 "Cannot have an ambiguity in previous-declaration lookup"); 2646 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 2647 Func != FuncEnd; ++Func) { 2648 if (isa<FunctionDecl>(*Func) && 2649 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 2650 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 2651 } 2652 2653 PrevDecl = 0; 2654 } 2655 } 2656 2657 // Handle attributes. We need to have merged decls when handling attributes 2658 // (for example to check for conflicts, etc). 2659 // FIXME: This needs to happen before we merge declarations. Then, 2660 // let attribute merging cope with attribute conflicts. 2661 ProcessDeclAttributes(S, NewFD, D); 2662 2663 // attributes declared post-definition are currently ignored 2664 if (PrevDecl) { 2665 const FunctionDecl *Def, *PrevFD = dyn_cast<FunctionDecl>(PrevDecl); 2666 if (PrevFD && PrevFD->getBody(Def) && D.hasAttributes()) { 2667 Diag(NewFD->getLocation(), diag::warn_attribute_precede_definition); 2668 Diag(Def->getLocation(), diag::note_previous_definition); 2669 } 2670 } 2671 2672 AddKnownFunctionAttributes(NewFD); 2673 2674 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 2675 // If a function name is overloadable in C, then every function 2676 // with that name must be marked "overloadable". 2677 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 2678 << Redeclaration << NewFD; 2679 if (PrevDecl) 2680 Diag(PrevDecl->getLocation(), 2681 diag::note_attribute_overloadable_prev_overload); 2682 NewFD->addAttr(::new (Context) OverloadableAttr()); 2683 } 2684 2685 // If this is a locally-scoped extern C function, update the 2686 // map of such names. 2687 if (CurContext->isFunctionOrMethod() && NewFD->isExternC(Context) 2688 && !NewFD->isInvalidDecl()) 2689 RegisterLocallyScopedExternCDecl(NewFD, PrevDecl, S); 2690 2691 // Set this FunctionDecl's range up to the right paren. 2692 NewFD->setLocEnd(D.getSourceRange().getEnd()); 2693 2694 if (FunctionTemplate && NewFD->isInvalidDecl()) 2695 FunctionTemplate->setInvalidDecl(); 2696 2697 if (FunctionTemplate) 2698 return FunctionTemplate; 2699 2700 return NewFD; 2701} 2702 2703/// \brief Perform semantic checking of a new function declaration. 2704/// 2705/// Performs semantic analysis of the new function declaration 2706/// NewFD. This routine performs all semantic checking that does not 2707/// require the actual declarator involved in the declaration, and is 2708/// used both for the declaration of functions as they are parsed 2709/// (called via ActOnDeclarator) and for the declaration of functions 2710/// that have been instantiated via C++ template instantiation (called 2711/// via InstantiateDecl). 2712/// 2713/// This sets NewFD->isInvalidDecl() to true if there was an error. 2714void Sema::CheckFunctionDeclaration(FunctionDecl *NewFD, NamedDecl *&PrevDecl, 2715 bool &Redeclaration, 2716 bool &OverloadableAttrRequired) { 2717 // If NewFD is already known erroneous, don't do any of this checking. 2718 if (NewFD->isInvalidDecl()) 2719 return; 2720 2721 if (NewFD->getResultType()->isVariablyModifiedType()) { 2722 // Functions returning a variably modified type violate C99 6.7.5.2p2 2723 // because all functions have linkage. 2724 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 2725 return NewFD->setInvalidDecl(); 2726 } 2727 2728 if (NewFD->isMain()) CheckMain(NewFD); 2729 2730 // Semantic checking for this function declaration (in isolation). 2731 if (getLangOptions().CPlusPlus) { 2732 // C++-specific checks. 2733 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 2734 CheckConstructor(Constructor); 2735 } else if (isa<CXXDestructorDecl>(NewFD)) { 2736 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 2737 QualType ClassType = Context.getTypeDeclType(Record); 2738 if (!ClassType->isDependentType()) { 2739 ClassType = Context.getCanonicalType(ClassType); 2740 DeclarationName Name 2741 = Context.DeclarationNames.getCXXDestructorName(ClassType); 2742 if (NewFD->getDeclName() != Name) { 2743 Diag(NewFD->getLocation(), diag::err_destructor_name); 2744 return NewFD->setInvalidDecl(); 2745 } 2746 } 2747 Record->setUserDeclaredDestructor(true); 2748 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 2749 // user-defined destructor. 2750 Record->setPOD(false); 2751 2752 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 2753 // declared destructor. 2754 // FIXME: C++0x: don't do this for "= default" destructors 2755 Record->setHasTrivialDestructor(false); 2756 } else if (CXXConversionDecl *Conversion 2757 = dyn_cast<CXXConversionDecl>(NewFD)) 2758 ActOnConversionDeclarator(Conversion); 2759 2760 // Extra checking for C++ overloaded operators (C++ [over.oper]). 2761 if (NewFD->isOverloadedOperator() && 2762 CheckOverloadedOperatorDeclaration(NewFD)) 2763 return NewFD->setInvalidDecl(); 2764 } 2765 2766 // C99 6.7.4p6: 2767 // [... ] For a function with external linkage, the following 2768 // restrictions apply: [...] If all of the file scope declarations 2769 // for a function in a translation unit include the inline 2770 // function specifier without extern, then the definition in that 2771 // translation unit is an inline definition. An inline definition 2772 // does not provide an external definition for the function, and 2773 // does not forbid an external definition in another translation 2774 // unit. 2775 // 2776 // Here we determine whether this function, in isolation, would be a 2777 // C99 inline definition. MergeCompatibleFunctionDecls looks at 2778 // previous declarations. 2779 if (NewFD->isInline() && getLangOptions().C99 && 2780 NewFD->getStorageClass() == FunctionDecl::None && 2781 NewFD->getDeclContext()->getLookupContext()->isTranslationUnit()) 2782 NewFD->setC99InlineDefinition(true); 2783 2784 // Check for a previous declaration of this name. 2785 if (!PrevDecl && NewFD->isExternC(Context)) { 2786 // Since we did not find anything by this name and we're declaring 2787 // an extern "C" function, look for a non-visible extern "C" 2788 // declaration with the same name. 2789 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2790 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 2791 if (Pos != LocallyScopedExternalDecls.end()) 2792 PrevDecl = Pos->second; 2793 } 2794 2795 // Merge or overload the declaration with an existing declaration of 2796 // the same name, if appropriate. 2797 if (PrevDecl) { 2798 // Determine whether NewFD is an overload of PrevDecl or 2799 // a declaration that requires merging. If it's an overload, 2800 // there's no more work to do here; we'll just add the new 2801 // function to the scope. 2802 OverloadedFunctionDecl::function_iterator MatchedDecl; 2803 2804 if (!getLangOptions().CPlusPlus && 2805 AllowOverloadingOfFunction(PrevDecl, Context)) { 2806 OverloadableAttrRequired = true; 2807 2808 // Functions marked "overloadable" must have a prototype (that 2809 // we can't get through declaration merging). 2810 if (!NewFD->getType()->getAsFunctionProtoType()) { 2811 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 2812 << NewFD; 2813 Redeclaration = true; 2814 2815 // Turn this into a variadic function with no parameters. 2816 QualType R = Context.getFunctionType( 2817 NewFD->getType()->getAsFunctionType()->getResultType(), 2818 0, 0, true, 0); 2819 NewFD->setType(R); 2820 return NewFD->setInvalidDecl(); 2821 } 2822 } 2823 2824 if (PrevDecl && 2825 (!AllowOverloadingOfFunction(PrevDecl, Context) || 2826 !IsOverload(NewFD, PrevDecl, MatchedDecl)) && 2827 !isa<UsingDecl>(PrevDecl)) { 2828 Redeclaration = true; 2829 Decl *OldDecl = PrevDecl; 2830 2831 // If PrevDecl was an overloaded function, extract the 2832 // FunctionDecl that matched. 2833 if (isa<OverloadedFunctionDecl>(PrevDecl)) 2834 OldDecl = *MatchedDecl; 2835 2836 // NewFD and OldDecl represent declarations that need to be 2837 // merged. 2838 if (MergeFunctionDecl(NewFD, OldDecl)) 2839 return NewFD->setInvalidDecl(); 2840 2841 if (FunctionTemplateDecl *OldTemplateDecl 2842 = dyn_cast<FunctionTemplateDecl>(OldDecl)) 2843 NewFD->setPreviousDeclaration(OldTemplateDecl->getTemplatedDecl()); 2844 else { 2845 if (isa<CXXMethodDecl>(NewFD)) // Set access for out-of-line definitions 2846 NewFD->setAccess(OldDecl->getAccess()); 2847 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 2848 } 2849 } 2850 } 2851 2852 // In C++, check default arguments now that we have merged decls. Unless 2853 // the lexical context is the class, because in this case this is done 2854 // during delayed parsing anyway. 2855 if (getLangOptions().CPlusPlus && !CurContext->isRecord()) 2856 CheckCXXDefaultArguments(NewFD); 2857} 2858 2859void Sema::CheckMain(FunctionDecl* FD) { 2860 // C++ [basic.start.main]p3: A program that declares main to be inline 2861 // or static is ill-formed. 2862 // C99 6.7.4p4: In a hosted environment, the inline function specifier 2863 // shall not appear in a declaration of main. 2864 // static main is not an error under C99, but we should warn about it. 2865 bool isInline = FD->isInline(); 2866 bool isStatic = FD->getStorageClass() == FunctionDecl::Static; 2867 if (isInline || isStatic) { 2868 unsigned diagID = diag::warn_unusual_main_decl; 2869 if (isInline || getLangOptions().CPlusPlus) 2870 diagID = diag::err_unusual_main_decl; 2871 2872 int which = isStatic + (isInline << 1) - 1; 2873 Diag(FD->getLocation(), diagID) << which; 2874 } 2875 2876 QualType T = FD->getType(); 2877 assert(T->isFunctionType() && "function decl is not of function type"); 2878 const FunctionType* FT = T->getAsFunctionType(); 2879 2880 if (!Context.hasSameUnqualifiedType(FT->getResultType(), Context.IntTy)) { 2881 // TODO: add a replacement fixit to turn the return type into 'int'. 2882 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint); 2883 FD->setInvalidDecl(true); 2884 } 2885 2886 // Treat protoless main() as nullary. 2887 if (isa<FunctionNoProtoType>(FT)) return; 2888 2889 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 2890 unsigned nparams = FTP->getNumArgs(); 2891 assert(FD->getNumParams() == nparams); 2892 2893 if (nparams > 3) { 2894 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 2895 FD->setInvalidDecl(true); 2896 nparams = 3; 2897 } 2898 2899 // FIXME: a lot of the following diagnostics would be improved 2900 // if we had some location information about types. 2901 2902 QualType CharPP = 2903 Context.getPointerType(Context.getPointerType(Context.CharTy)); 2904 QualType Expected[] = { Context.IntTy, CharPP, CharPP }; 2905 2906 for (unsigned i = 0; i < nparams; ++i) { 2907 QualType AT = FTP->getArgType(i); 2908 2909 bool mismatch = true; 2910 2911 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 2912 mismatch = false; 2913 else if (Expected[i] == CharPP) { 2914 // As an extension, the following forms are okay: 2915 // char const ** 2916 // char const * const * 2917 // char * const * 2918 2919 QualifierSet qs; 2920 const PointerType* PT; 2921 if ((PT = qs.strip(AT)->getAs<PointerType>()) && 2922 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) && 2923 (QualType(qs.strip(PT->getPointeeType()), 0) == Context.CharTy)) { 2924 qs.removeConst(); 2925 mismatch = !qs.empty(); 2926 } 2927 } 2928 2929 if (mismatch) { 2930 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 2931 // TODO: suggest replacing given type with expected type 2932 FD->setInvalidDecl(true); 2933 } 2934 } 2935 2936 if (nparams == 1 && !FD->isInvalidDecl()) { 2937 Diag(FD->getLocation(), diag::warn_main_one_arg); 2938 } 2939} 2940 2941bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2942 // FIXME: Need strict checking. In C89, we need to check for 2943 // any assignment, increment, decrement, function-calls, or 2944 // commas outside of a sizeof. In C99, it's the same list, 2945 // except that the aforementioned are allowed in unevaluated 2946 // expressions. Everything else falls under the 2947 // "may accept other forms of constant expressions" exception. 2948 // (We never end up here for C++, so the constant expression 2949 // rules there don't matter.) 2950 if (Init->isConstantInitializer(Context)) 2951 return false; 2952 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 2953 << Init->getSourceRange(); 2954 return true; 2955} 2956 2957void Sema::AddInitializerToDecl(DeclPtrTy dcl, FullExprArg init) { 2958 AddInitializerToDecl(dcl, init.release(), /*DirectInit=*/false); 2959} 2960 2961/// AddInitializerToDecl - Adds the initializer Init to the 2962/// declaration dcl. If DirectInit is true, this is C++ direct 2963/// initialization rather than copy initialization. 2964void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 2965 Decl *RealDecl = dcl.getAs<Decl>(); 2966 // If there is no declaration, there was an error parsing it. Just ignore 2967 // the initializer. 2968 if (RealDecl == 0) 2969 return; 2970 2971 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 2972 // With declarators parsed the way they are, the parser cannot 2973 // distinguish between a normal initializer and a pure-specifier. 2974 // Thus this grotesque test. 2975 IntegerLiteral *IL; 2976 Expr *Init = static_cast<Expr *>(init.get()); 2977 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 2978 Context.getCanonicalType(IL->getType()) == Context.IntTy) { 2979 if (Method->isVirtualAsWritten()) { 2980 Method->setPure(); 2981 2982 // A class is abstract if at least one function is pure virtual. 2983 cast<CXXRecordDecl>(CurContext)->setAbstract(true); 2984 } else if (!Method->isInvalidDecl()) { 2985 Diag(Method->getLocation(), diag::err_non_virtual_pure) 2986 << Method->getDeclName() << Init->getSourceRange(); 2987 Method->setInvalidDecl(); 2988 } 2989 } else { 2990 Diag(Method->getLocation(), diag::err_member_function_initialization) 2991 << Method->getDeclName() << Init->getSourceRange(); 2992 Method->setInvalidDecl(); 2993 } 2994 return; 2995 } 2996 2997 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 2998 if (!VDecl) { 2999 if (getLangOptions().CPlusPlus && 3000 RealDecl->getLexicalDeclContext()->isRecord() && 3001 isa<NamedDecl>(RealDecl)) 3002 Diag(RealDecl->getLocation(), diag::err_member_initialization) 3003 << cast<NamedDecl>(RealDecl)->getDeclName(); 3004 else 3005 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 3006 RealDecl->setInvalidDecl(); 3007 return; 3008 } 3009 3010 if (!VDecl->getType()->isArrayType() && 3011 RequireCompleteType(VDecl->getLocation(), VDecl->getType(), 3012 diag::err_typecheck_decl_incomplete_type)) { 3013 RealDecl->setInvalidDecl(); 3014 return; 3015 } 3016 3017 const VarDecl *Def = 0; 3018 if (VDecl->getDefinition(Def)) { 3019 Diag(VDecl->getLocation(), diag::err_redefinition) 3020 << VDecl->getDeclName(); 3021 Diag(Def->getLocation(), diag::note_previous_definition); 3022 VDecl->setInvalidDecl(); 3023 return; 3024 } 3025 3026 // Take ownership of the expression, now that we're sure we have somewhere 3027 // to put it. 3028 Expr *Init = init.takeAs<Expr>(); 3029 assert(Init && "missing initializer"); 3030 3031 // Get the decls type and save a reference for later, since 3032 // CheckInitializerTypes may change it. 3033 QualType DclT = VDecl->getType(), SavT = DclT; 3034 if (VDecl->isBlockVarDecl()) { 3035 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 3036 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 3037 VDecl->setInvalidDecl(); 3038 } else if (!VDecl->isInvalidDecl()) { 3039 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3040 VDecl->getDeclName(), DirectInit)) 3041 VDecl->setInvalidDecl(); 3042 3043 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3044 // Don't check invalid declarations to avoid emitting useless diagnostics. 3045 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3046 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 3047 CheckForConstantInitializer(Init, DclT); 3048 } 3049 } 3050 } else if (VDecl->isStaticDataMember() && 3051 VDecl->getLexicalDeclContext()->isRecord()) { 3052 // This is an in-class initialization for a static data member, e.g., 3053 // 3054 // struct S { 3055 // static const int value = 17; 3056 // }; 3057 3058 // Attach the initializer 3059 VDecl->setInit(Context, Init); 3060 3061 // C++ [class.mem]p4: 3062 // A member-declarator can contain a constant-initializer only 3063 // if it declares a static member (9.4) of const integral or 3064 // const enumeration type, see 9.4.2. 3065 QualType T = VDecl->getType(); 3066 if (!T->isDependentType() && 3067 (!Context.getCanonicalType(T).isConstQualified() || 3068 !T->isIntegralType())) { 3069 Diag(VDecl->getLocation(), diag::err_member_initialization) 3070 << VDecl->getDeclName() << Init->getSourceRange(); 3071 VDecl->setInvalidDecl(); 3072 } else { 3073 // C++ [class.static.data]p4: 3074 // If a static data member is of const integral or const 3075 // enumeration type, its declaration in the class definition 3076 // can specify a constant-initializer which shall be an 3077 // integral constant expression (5.19). 3078 if (!Init->isTypeDependent() && 3079 !Init->getType()->isIntegralType()) { 3080 // We have a non-dependent, non-integral or enumeration type. 3081 Diag(Init->getSourceRange().getBegin(), 3082 diag::err_in_class_initializer_non_integral_type) 3083 << Init->getType() << Init->getSourceRange(); 3084 VDecl->setInvalidDecl(); 3085 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 3086 // Check whether the expression is a constant expression. 3087 llvm::APSInt Value; 3088 SourceLocation Loc; 3089 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 3090 Diag(Loc, diag::err_in_class_initializer_non_constant) 3091 << Init->getSourceRange(); 3092 VDecl->setInvalidDecl(); 3093 } else if (!VDecl->getType()->isDependentType()) 3094 ImpCastExprToType(Init, VDecl->getType()); 3095 } 3096 } 3097 } else if (VDecl->isFileVarDecl()) { 3098 if (VDecl->getStorageClass() == VarDecl::Extern) 3099 Diag(VDecl->getLocation(), diag::warn_extern_init); 3100 if (!VDecl->isInvalidDecl()) 3101 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3102 VDecl->getDeclName(), DirectInit)) 3103 VDecl->setInvalidDecl(); 3104 3105 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3106 // Don't check invalid declarations to avoid emitting useless diagnostics. 3107 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3108 // C99 6.7.8p4. All file scoped initializers need to be constant. 3109 CheckForConstantInitializer(Init, DclT); 3110 } 3111 } 3112 // If the type changed, it means we had an incomplete type that was 3113 // completed by the initializer. For example: 3114 // int ary[] = { 1, 3, 5 }; 3115 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 3116 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 3117 VDecl->setType(DclT); 3118 Init->setType(DclT); 3119 } 3120 3121 // Attach the initializer to the decl. 3122 VDecl->setInit(Context, Init); 3123 3124 // If the previous declaration of VDecl was a tentative definition, 3125 // remove it from the set of tentative definitions. 3126 if (VDecl->getPreviousDeclaration() && 3127 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 3128 llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos 3129 = TentativeDefinitions.find(VDecl->getDeclName()); 3130 assert(Pos != TentativeDefinitions.end() && 3131 "Unrecorded tentative definition?"); 3132 TentativeDefinitions.erase(Pos); 3133 } 3134 3135 return; 3136} 3137 3138void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 3139 bool TypeContainsUndeducedAuto) { 3140 Decl *RealDecl = dcl.getAs<Decl>(); 3141 3142 // If there is no declaration, there was an error parsing it. Just ignore it. 3143 if (RealDecl == 0) 3144 return; 3145 3146 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 3147 QualType Type = Var->getType(); 3148 3149 // Record tentative definitions. 3150 if (Var->isTentativeDefinition(Context)) 3151 TentativeDefinitions[Var->getDeclName()] = Var; 3152 3153 // C++ [dcl.init.ref]p3: 3154 // The initializer can be omitted for a reference only in a 3155 // parameter declaration (8.3.5), in the declaration of a 3156 // function return type, in the declaration of a class member 3157 // within its class declaration (9.2), and where the extern 3158 // specifier is explicitly used. 3159 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 3160 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 3161 << Var->getDeclName() 3162 << SourceRange(Var->getLocation(), Var->getLocation()); 3163 Var->setInvalidDecl(); 3164 return; 3165 } 3166 3167 // C++0x [dcl.spec.auto]p3 3168 if (TypeContainsUndeducedAuto) { 3169 Diag(Var->getLocation(), diag::err_auto_var_requires_init) 3170 << Var->getDeclName() << Type; 3171 Var->setInvalidDecl(); 3172 return; 3173 } 3174 3175 // C++ [dcl.init]p9: 3176 // 3177 // If no initializer is specified for an object, and the object 3178 // is of (possibly cv-qualified) non-POD class type (or array 3179 // thereof), the object shall be default-initialized; if the 3180 // object is of const-qualified type, the underlying class type 3181 // shall have a user-declared default constructor. 3182 if (getLangOptions().CPlusPlus) { 3183 QualType InitType = Type; 3184 if (const ArrayType *Array = Context.getAsArrayType(Type)) 3185 InitType = Array->getElementType(); 3186 if ((!Var->hasExternalStorage() && !Var->isExternC(Context)) && 3187 InitType->isRecordType() && !InitType->isDependentType()) { 3188 CXXRecordDecl *RD = 3189 cast<CXXRecordDecl>(InitType->getAs<RecordType>()->getDecl()); 3190 CXXConstructorDecl *Constructor = 0; 3191 if (!RequireCompleteType(Var->getLocation(), InitType, 3192 diag::err_invalid_incomplete_type_use)) 3193 Constructor 3194 = PerformInitializationByConstructor(InitType, 0, 0, 3195 Var->getLocation(), 3196 SourceRange(Var->getLocation(), 3197 Var->getLocation()), 3198 Var->getDeclName(), 3199 IK_Default); 3200 if (!Constructor) 3201 Var->setInvalidDecl(); 3202 else { 3203 if (!RD->hasTrivialConstructor()) 3204 InitializeVarWithConstructor(Var, Constructor, InitType, 0, 0); 3205 FinalizeVarWithDestructor(Var, InitType); 3206 } 3207 } 3208 } 3209 3210#if 0 3211 // FIXME: Temporarily disabled because we are not properly parsing 3212 // linkage specifications on declarations, e.g., 3213 // 3214 // extern "C" const CGPoint CGPointerZero; 3215 // 3216 // C++ [dcl.init]p9: 3217 // 3218 // If no initializer is specified for an object, and the 3219 // object is of (possibly cv-qualified) non-POD class type (or 3220 // array thereof), the object shall be default-initialized; if 3221 // the object is of const-qualified type, the underlying class 3222 // type shall have a user-declared default 3223 // constructor. Otherwise, if no initializer is specified for 3224 // an object, the object and its subobjects, if any, have an 3225 // indeterminate initial value; if the object or any of its 3226 // subobjects are of const-qualified type, the program is 3227 // ill-formed. 3228 // 3229 // This isn't technically an error in C, so we don't diagnose it. 3230 // 3231 // FIXME: Actually perform the POD/user-defined default 3232 // constructor check. 3233 if (getLangOptions().CPlusPlus && 3234 Context.getCanonicalType(Type).isConstQualified() && 3235 !Var->hasExternalStorage()) 3236 Diag(Var->getLocation(), diag::err_const_var_requires_init) 3237 << Var->getName() 3238 << SourceRange(Var->getLocation(), Var->getLocation()); 3239#endif 3240 } 3241} 3242 3243Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 3244 DeclPtrTy *Group, 3245 unsigned NumDecls) { 3246 llvm::SmallVector<Decl*, 8> Decls; 3247 3248 if (DS.isTypeSpecOwned()) 3249 Decls.push_back((Decl*)DS.getTypeRep()); 3250 3251 for (unsigned i = 0; i != NumDecls; ++i) 3252 if (Decl *D = Group[i].getAs<Decl>()) 3253 Decls.push_back(D); 3254 3255 // Perform semantic analysis that depends on having fully processed both 3256 // the declarator and initializer. 3257 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 3258 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 3259 if (!IDecl) 3260 continue; 3261 QualType T = IDecl->getType(); 3262 3263 // Block scope. C99 6.7p7: If an identifier for an object is declared with 3264 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 3265 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 3266 if (!IDecl->isInvalidDecl() && 3267 RequireCompleteType(IDecl->getLocation(), T, 3268 diag::err_typecheck_decl_incomplete_type)) 3269 IDecl->setInvalidDecl(); 3270 } 3271 // File scope. C99 6.9.2p2: A declaration of an identifier for an 3272 // object that has file scope without an initializer, and without a 3273 // storage-class specifier or with the storage-class specifier "static", 3274 // constitutes a tentative definition. Note: A tentative definition with 3275 // external linkage is valid (C99 6.2.2p5). 3276 if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) { 3277 if (const IncompleteArrayType *ArrayT 3278 = Context.getAsIncompleteArrayType(T)) { 3279 if (RequireCompleteType(IDecl->getLocation(), 3280 ArrayT->getElementType(), 3281 diag::err_illegal_decl_array_incomplete_type)) 3282 IDecl->setInvalidDecl(); 3283 } else if (IDecl->getStorageClass() == VarDecl::Static) { 3284 // C99 6.9.2p3: If the declaration of an identifier for an object is 3285 // a tentative definition and has internal linkage (C99 6.2.2p3), the 3286 // declared type shall not be an incomplete type. 3287 // NOTE: code such as the following 3288 // static struct s; 3289 // struct s { int a; }; 3290 // is accepted by gcc. Hence here we issue a warning instead of 3291 // an error and we do not invalidate the static declaration. 3292 // NOTE: to avoid multiple warnings, only check the first declaration. 3293 if (IDecl->getPreviousDeclaration() == 0) 3294 RequireCompleteType(IDecl->getLocation(), T, 3295 diag::ext_typecheck_decl_incomplete_type); 3296 } 3297 } 3298 } 3299 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 3300 Decls.data(), Decls.size())); 3301} 3302 3303 3304/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 3305/// to introduce parameters into function prototype scope. 3306Sema::DeclPtrTy 3307Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 3308 const DeclSpec &DS = D.getDeclSpec(); 3309 3310 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 3311 VarDecl::StorageClass StorageClass = VarDecl::None; 3312 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 3313 StorageClass = VarDecl::Register; 3314 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 3315 Diag(DS.getStorageClassSpecLoc(), 3316 diag::err_invalid_storage_class_in_func_decl); 3317 D.getMutableDeclSpec().ClearStorageClassSpecs(); 3318 } 3319 3320 if (D.getDeclSpec().isThreadSpecified()) 3321 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3322 3323 DiagnoseFunctionSpecifiers(D); 3324 3325 // Check that there are no default arguments inside the type of this 3326 // parameter (C++ only). 3327 if (getLangOptions().CPlusPlus) 3328 CheckExtraCXXDefaultArguments(D); 3329 3330 TagDecl *OwnedDecl = 0; 3331 QualType parmDeclType = GetTypeForDeclarator(D, S, /*Skip=*/0, &OwnedDecl); 3332 3333 if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) { 3334 // C++ [dcl.fct]p6: 3335 // Types shall not be defined in return or parameter types. 3336 Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type) 3337 << Context.getTypeDeclType(OwnedDecl); 3338 } 3339 3340 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 3341 // Can this happen for params? We already checked that they don't conflict 3342 // among each other. Here they can only shadow globals, which is ok. 3343 IdentifierInfo *II = D.getIdentifier(); 3344 if (II) { 3345 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 3346 if (PrevDecl->isTemplateParameter()) { 3347 // Maybe we will complain about the shadowed template parameter. 3348 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 3349 // Just pretend that we didn't see the previous declaration. 3350 PrevDecl = 0; 3351 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 3352 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 3353 3354 // Recover by removing the name 3355 II = 0; 3356 D.SetIdentifier(0, D.getIdentifierLoc()); 3357 } 3358 } 3359 } 3360 3361 // Parameters can not be abstract class types. 3362 // For record types, this is done by the AbstractClassUsageDiagnoser once 3363 // the class has been completely parsed. 3364 if (!CurContext->isRecord() && 3365 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 3366 diag::err_abstract_type_in_decl, 3367 AbstractParamType)) 3368 D.setInvalidType(true); 3369 3370 QualType T = adjustParameterType(parmDeclType); 3371 3372 ParmVarDecl *New; 3373 if (T == parmDeclType) // parameter type did not need adjustment 3374 New = ParmVarDecl::Create(Context, CurContext, 3375 D.getIdentifierLoc(), II, 3376 parmDeclType, StorageClass, 3377 0); 3378 else // keep track of both the adjusted and unadjusted types 3379 New = OriginalParmVarDecl::Create(Context, CurContext, 3380 D.getIdentifierLoc(), II, T, 3381 parmDeclType, StorageClass, 0); 3382 3383 if (D.isInvalidType()) 3384 New->setInvalidDecl(); 3385 3386 // Parameter declarators cannot be interface types. All ObjC objects are 3387 // passed by reference. 3388 if (T->isObjCInterfaceType()) { 3389 Diag(D.getIdentifierLoc(), 3390 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 3391 New->setInvalidDecl(); 3392 } 3393 3394 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 3395 if (D.getCXXScopeSpec().isSet()) { 3396 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 3397 << D.getCXXScopeSpec().getRange(); 3398 New->setInvalidDecl(); 3399 } 3400 3401 // Add the parameter declaration into this scope. 3402 S->AddDecl(DeclPtrTy::make(New)); 3403 if (II) 3404 IdResolver.AddDecl(New); 3405 3406 ProcessDeclAttributes(S, New, D); 3407 3408 if (New->hasAttr<BlocksAttr>()) { 3409 Diag(New->getLocation(), diag::err_block_on_nonlocal); 3410 } 3411 return DeclPtrTy::make(New); 3412} 3413 3414void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 3415 SourceLocation LocAfterDecls) { 3416 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3417 "Not a function declarator!"); 3418 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3419 3420 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 3421 // for a K&R function. 3422 if (!FTI.hasPrototype) { 3423 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 3424 --i; 3425 if (FTI.ArgInfo[i].Param == 0) { 3426 std::string Code = " int "; 3427 Code += FTI.ArgInfo[i].Ident->getName(); 3428 Code += ";\n"; 3429 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 3430 << FTI.ArgInfo[i].Ident 3431 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code); 3432 3433 // Implicitly declare the argument as type 'int' for lack of a better 3434 // type. 3435 DeclSpec DS; 3436 const char* PrevSpec; // unused 3437 unsigned DiagID; // unused 3438 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 3439 PrevSpec, DiagID); 3440 Declarator ParamD(DS, Declarator::KNRTypeListContext); 3441 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 3442 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 3443 } 3444 } 3445 } 3446} 3447 3448Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 3449 Declarator &D) { 3450 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 3451 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3452 "Not a function declarator!"); 3453 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3454 3455 if (FTI.hasPrototype) { 3456 // FIXME: Diagnose arguments without names in C. 3457 } 3458 3459 Scope *ParentScope = FnBodyScope->getParent(); 3460 3461 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 3462 MultiTemplateParamsArg(*this), 3463 /*IsFunctionDefinition=*/true); 3464 return ActOnStartOfFunctionDef(FnBodyScope, DP); 3465} 3466 3467Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 3468 if (!D) 3469 return D; 3470 FunctionDecl *FD = cast<FunctionDecl>(D.getAs<Decl>()); 3471 3472 CurFunctionNeedsScopeChecking = false; 3473 3474 // See if this is a redefinition. 3475 const FunctionDecl *Definition; 3476 if (FD->getBody(Definition)) { 3477 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 3478 Diag(Definition->getLocation(), diag::note_previous_definition); 3479 } 3480 3481 // Builtin functions cannot be defined. 3482 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3483 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 3484 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 3485 FD->setInvalidDecl(); 3486 } 3487 } 3488 3489 // The return type of a function definition must be complete 3490 // (C99 6.9.1p3, C++ [dcl.fct]p6). 3491 QualType ResultType = FD->getResultType(); 3492 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 3493 !FD->isInvalidDecl() && 3494 RequireCompleteType(FD->getLocation(), ResultType, 3495 diag::err_func_def_incomplete_result)) 3496 FD->setInvalidDecl(); 3497 3498 // GNU warning -Wmissing-prototypes: 3499 // Warn if a global function is defined without a previous 3500 // prototype declaration. This warning is issued even if the 3501 // definition itself provides a prototype. The aim is to detect 3502 // global functions that fail to be declared in header files. 3503 if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) && 3504 !FD->isMain()) { 3505 bool MissingPrototype = true; 3506 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 3507 Prev; Prev = Prev->getPreviousDeclaration()) { 3508 // Ignore any declarations that occur in function or method 3509 // scope, because they aren't visible from the header. 3510 if (Prev->getDeclContext()->isFunctionOrMethod()) 3511 continue; 3512 3513 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 3514 break; 3515 } 3516 3517 if (MissingPrototype) 3518 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 3519 } 3520 3521 if (FnBodyScope) 3522 PushDeclContext(FnBodyScope, FD); 3523 3524 // Check the validity of our function parameters 3525 CheckParmsForFunctionDef(FD); 3526 3527 // Introduce our parameters into the function scope 3528 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 3529 ParmVarDecl *Param = FD->getParamDecl(p); 3530 Param->setOwningFunction(FD); 3531 3532 // If this has an identifier, add it to the scope stack. 3533 if (Param->getIdentifier() && FnBodyScope) 3534 PushOnScopeChains(Param, FnBodyScope); 3535 } 3536 3537 // Checking attributes of current function definition 3538 // dllimport attribute. 3539 if (FD->getAttr<DLLImportAttr>() && 3540 (!FD->getAttr<DLLExportAttr>())) { 3541 // dllimport attribute cannot be applied to definition. 3542 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 3543 Diag(FD->getLocation(), 3544 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 3545 << "dllimport"; 3546 FD->setInvalidDecl(); 3547 return DeclPtrTy::make(FD); 3548 } else { 3549 // If a symbol previously declared dllimport is later defined, the 3550 // attribute is ignored in subsequent references, and a warning is 3551 // emitted. 3552 Diag(FD->getLocation(), 3553 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3554 << FD->getNameAsCString() << "dllimport"; 3555 } 3556 } 3557 return DeclPtrTy::make(FD); 3558} 3559 3560Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 3561 return ActOnFinishFunctionBody(D, move(BodyArg), false); 3562} 3563 3564Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 3565 bool IsInstantiation) { 3566 Decl *dcl = D.getAs<Decl>(); 3567 Stmt *Body = BodyArg.takeAs<Stmt>(); 3568 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3569 FD->setBody(Body); 3570 if (FD->isMain()) 3571 // C and C++ allow for main to automagically return 0. 3572 // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3. 3573 FD->setHasImplicitReturnZero(true); 3574 else 3575 CheckFallThroughForFunctionDef(FD, Body); 3576 3577 if (!FD->isInvalidDecl()) 3578 DiagnoseUnusedParameters(FD->param_begin(), FD->param_end()); 3579 3580 // C++ [basic.def.odr]p2: 3581 // [...] A virtual member function is used if it is not pure. [...] 3582 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 3583 if (Method->isVirtual() && !Method->isPure()) 3584 MarkDeclarationReferenced(Method->getLocation(), Method); 3585 3586 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3587 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3588 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3589 MD->setBody(Body); 3590 CheckFallThroughForFunctionDef(MD, Body); 3591 MD->setEndLoc(Body->getLocEnd()); 3592 3593 if (!MD->isInvalidDecl()) 3594 DiagnoseUnusedParameters(MD->param_begin(), MD->param_end()); 3595 } else { 3596 Body->Destroy(Context); 3597 return DeclPtrTy(); 3598 } 3599 if (!IsInstantiation) 3600 PopDeclContext(); 3601 3602 // Verify and clean out per-function state. 3603 3604 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 3605 3606 // Check goto/label use. 3607 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3608 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 3609 LabelStmt *L = I->second; 3610 3611 // Verify that we have no forward references left. If so, there was a goto 3612 // or address of a label taken, but no definition of it. Label fwd 3613 // definitions are indicated with a null substmt. 3614 if (L->getSubStmt() != 0) 3615 continue; 3616 3617 // Emit error. 3618 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3619 3620 // At this point, we have gotos that use the bogus label. Stitch it into 3621 // the function body so that they aren't leaked and that the AST is well 3622 // formed. 3623 if (Body == 0) { 3624 // The whole function wasn't parsed correctly, just delete this. 3625 L->Destroy(Context); 3626 continue; 3627 } 3628 3629 // Otherwise, the body is valid: we want to stitch the label decl into the 3630 // function somewhere so that it is properly owned and so that the goto 3631 // has a valid target. Do this by creating a new compound stmt with the 3632 // label in it. 3633 3634 // Give the label a sub-statement. 3635 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3636 3637 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 3638 cast<CXXTryStmt>(Body)->getTryBlock() : 3639 cast<CompoundStmt>(Body); 3640 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 3641 Elements.push_back(L); 3642 Compound->setStmts(Context, &Elements[0], Elements.size()); 3643 } 3644 FunctionLabelMap.clear(); 3645 3646 if (!Body) return D; 3647 3648 // Verify that that gotos and switch cases don't jump into scopes illegally. 3649 if (CurFunctionNeedsScopeChecking) 3650 DiagnoseInvalidJumps(Body); 3651 3652 // C++ constructors that have function-try-blocks can't have return 3653 // statements in the handlers of that block. (C++ [except.handle]p14) 3654 // Verify this. 3655 if (isa<CXXConstructorDecl>(dcl) && isa<CXXTryStmt>(Body)) 3656 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 3657 3658 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) 3659 Destructor->computeBaseOrMembersToDestroy(Context); 3660 return D; 3661} 3662 3663/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3664/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3665NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3666 IdentifierInfo &II, Scope *S) { 3667 // Before we produce a declaration for an implicitly defined 3668 // function, see whether there was a locally-scoped declaration of 3669 // this name as a function or variable. If so, use that 3670 // (non-visible) declaration, and complain about it. 3671 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3672 = LocallyScopedExternalDecls.find(&II); 3673 if (Pos != LocallyScopedExternalDecls.end()) { 3674 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 3675 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 3676 return Pos->second; 3677 } 3678 3679 // Extension in C99. Legal in C90, but warn about it. 3680 if (getLangOptions().C99) 3681 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3682 else 3683 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3684 3685 // FIXME: handle stuff like: 3686 // void foo() { extern float X(); } 3687 // void bar() { X(); } <-- implicit decl for X in another scope. 3688 3689 // Set a Declarator for the implicit definition: int foo(); 3690 const char *Dummy; 3691 DeclSpec DS; 3692 unsigned DiagID; 3693 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID); 3694 Error = Error; // Silence warning. 3695 assert(!Error && "Error setting up implicit decl!"); 3696 Declarator D(DS, Declarator::BlockContext); 3697 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 3698 0, 0, false, SourceLocation(), 3699 false, 0,0,0, Loc, D), 3700 SourceLocation()); 3701 D.SetIdentifier(&II, Loc); 3702 3703 // Insert this function into translation-unit scope. 3704 3705 DeclContext *PrevDC = CurContext; 3706 CurContext = Context.getTranslationUnitDecl(); 3707 3708 FunctionDecl *FD = 3709 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D).getAs<Decl>()); 3710 FD->setImplicit(); 3711 3712 CurContext = PrevDC; 3713 3714 AddKnownFunctionAttributes(FD); 3715 3716 return FD; 3717} 3718 3719/// \brief Adds any function attributes that we know a priori based on 3720/// the declaration of this function. 3721/// 3722/// These attributes can apply both to implicitly-declared builtins 3723/// (like __builtin___printf_chk) or to library-declared functions 3724/// like NSLog or printf. 3725void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3726 if (FD->isInvalidDecl()) 3727 return; 3728 3729 // If this is a built-in function, map its builtin attributes to 3730 // actual attributes. 3731 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3732 // Handle printf-formatting attributes. 3733 unsigned FormatIdx; 3734 bool HasVAListArg; 3735 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3736 if (!FD->getAttr<FormatAttr>()) 3737 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 3738 HasVAListArg ? 0 : FormatIdx + 2)); 3739 } 3740 3741 // Mark const if we don't care about errno and that is the only 3742 // thing preventing the function from being const. This allows 3743 // IRgen to use LLVM intrinsics for such functions. 3744 if (!getLangOptions().MathErrno && 3745 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3746 if (!FD->getAttr<ConstAttr>()) 3747 FD->addAttr(::new (Context) ConstAttr()); 3748 } 3749 3750 if (Context.BuiltinInfo.isNoReturn(BuiltinID)) 3751 FD->addAttr(::new (Context) NoReturnAttr()); 3752 } 3753 3754 IdentifierInfo *Name = FD->getIdentifier(); 3755 if (!Name) 3756 return; 3757 if ((!getLangOptions().CPlusPlus && 3758 FD->getDeclContext()->isTranslationUnit()) || 3759 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3760 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3761 LinkageSpecDecl::lang_c)) { 3762 // Okay: this could be a libc/libm/Objective-C function we know 3763 // about. 3764 } else 3765 return; 3766 3767 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 3768 // FIXME: NSLog and NSLogv should be target specific 3769 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3770 // FIXME: We known better than our headers. 3771 const_cast<FormatAttr *>(Format)->setType("printf"); 3772 } else 3773 FD->addAttr(::new (Context) FormatAttr("printf", 1, 3774 Name->isStr("NSLogv") ? 0 : 2)); 3775 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 3776 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 3777 // target-specific builtins, perhaps? 3778 if (!FD->getAttr<FormatAttr>()) 3779 FD->addAttr(::new (Context) FormatAttr("printf", 2, 3780 Name->isStr("vasprintf") ? 0 : 3)); 3781 } 3782} 3783 3784TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T) { 3785 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3786 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3787 3788 // Scope manipulation handled by caller. 3789 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3790 D.getIdentifierLoc(), 3791 D.getIdentifier(), 3792 T); 3793 3794 if (TagType *TT = dyn_cast<TagType>(T)) { 3795 TagDecl *TD = TT->getDecl(); 3796 3797 // If the TagDecl that the TypedefDecl points to is an anonymous decl 3798 // keep track of the TypedefDecl. 3799 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 3800 TD->setTypedefForAnonDecl(NewTD); 3801 } 3802 3803 if (D.isInvalidType()) 3804 NewTD->setInvalidDecl(); 3805 return NewTD; 3806} 3807 3808 3809/// \brief Determine whether a tag with a given kind is acceptable 3810/// as a redeclaration of the given tag declaration. 3811/// 3812/// \returns true if the new tag kind is acceptable, false otherwise. 3813bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 3814 TagDecl::TagKind NewTag, 3815 SourceLocation NewTagLoc, 3816 const IdentifierInfo &Name) { 3817 // C++ [dcl.type.elab]p3: 3818 // The class-key or enum keyword present in the 3819 // elaborated-type-specifier shall agree in kind with the 3820 // declaration to which the name in theelaborated-type-specifier 3821 // refers. This rule also applies to the form of 3822 // elaborated-type-specifier that declares a class-name or 3823 // friend class since it can be construed as referring to the 3824 // definition of the class. Thus, in any 3825 // elaborated-type-specifier, the enum keyword shall be used to 3826 // refer to an enumeration (7.2), the union class-keyshall be 3827 // used to refer to a union (clause 9), and either the class or 3828 // struct class-key shall be used to refer to a class (clause 9) 3829 // declared using the class or struct class-key. 3830 TagDecl::TagKind OldTag = Previous->getTagKind(); 3831 if (OldTag == NewTag) 3832 return true; 3833 3834 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 3835 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 3836 // Warn about the struct/class tag mismatch. 3837 bool isTemplate = false; 3838 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 3839 isTemplate = Record->getDescribedClassTemplate(); 3840 3841 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 3842 << (NewTag == TagDecl::TK_class) 3843 << isTemplate << &Name 3844 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 3845 OldTag == TagDecl::TK_class? "class" : "struct"); 3846 Diag(Previous->getLocation(), diag::note_previous_use); 3847 return true; 3848 } 3849 return false; 3850} 3851 3852/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3853/// former case, Name will be non-null. In the later case, Name will be null. 3854/// TagSpec indicates what kind of tag this is. TUK indicates whether this is a 3855/// reference/declaration/definition of a tag. 3856Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 3857 SourceLocation KWLoc, const CXXScopeSpec &SS, 3858 IdentifierInfo *Name, SourceLocation NameLoc, 3859 AttributeList *Attr, AccessSpecifier AS, 3860 MultiTemplateParamsArg TemplateParameterLists, 3861 bool &OwnedDecl) { 3862 // If this is not a definition, it must have a name. 3863 assert((Name != 0 || TUK == TUK_Definition) && 3864 "Nameless record must be a definition!"); 3865 3866 OwnedDecl = false; 3867 TagDecl::TagKind Kind; 3868 switch (TagSpec) { 3869 default: assert(0 && "Unknown tag type!"); 3870 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3871 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3872 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3873 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3874 } 3875 3876 if (TUK != TUK_Reference) { 3877 if (TemplateParameterList *TemplateParams 3878 = MatchTemplateParametersToScopeSpecifier(KWLoc, SS, 3879 (TemplateParameterList**)TemplateParameterLists.get(), 3880 TemplateParameterLists.size())) { 3881 if (TemplateParams->size() > 0) { 3882 // This is a declaration or definition of a class template (which may 3883 // be a member of another template). 3884 OwnedDecl = false; 3885 DeclResult Result = CheckClassTemplate(S, TagSpec, TUK, KWLoc, 3886 SS, Name, NameLoc, Attr, 3887 move(TemplateParameterLists), 3888 AS); 3889 return Result.get(); 3890 } else { 3891 // FIXME: diagnose the extraneous 'template<>', once we recover 3892 // slightly better in ParseTemplate.cpp from bogus template 3893 // parameters. 3894 } 3895 } 3896 } 3897 3898 DeclContext *SearchDC = CurContext; 3899 DeclContext *DC = CurContext; 3900 NamedDecl *PrevDecl = 0; 3901 3902 bool Invalid = false; 3903 3904 if (Name && SS.isNotEmpty()) { 3905 // We have a nested-name tag ('struct foo::bar'). 3906 3907 // Check for invalid 'foo::'. 3908 if (SS.isInvalid()) { 3909 Name = 0; 3910 goto CreateNewDecl; 3911 } 3912 3913 if (RequireCompleteDeclContext(SS)) 3914 return DeclPtrTy::make((Decl *)0); 3915 3916 DC = computeDeclContext(SS, true); 3917 SearchDC = DC; 3918 // Look-up name inside 'foo::'. 3919 PrevDecl 3920 = dyn_cast_or_null<TagDecl>( 3921 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 3922 3923 // A tag 'foo::bar' must already exist. 3924 if (PrevDecl == 0) { 3925 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 3926 Name = 0; 3927 Invalid = true; 3928 goto CreateNewDecl; 3929 } 3930 } else if (Name) { 3931 // If this is a named struct, check to see if there was a previous forward 3932 // declaration or definition. 3933 // FIXME: We're looking into outer scopes here, even when we 3934 // shouldn't be. Doing so can result in ambiguities that we 3935 // shouldn't be diagnosing. 3936 LookupResult R = LookupName(S, Name, LookupTagName, 3937 /*RedeclarationOnly=*/(TUK != TUK_Reference)); 3938 if (R.isAmbiguous()) { 3939 DiagnoseAmbiguousLookup(R, Name, NameLoc); 3940 // FIXME: This is not best way to recover from case like: 3941 // 3942 // struct S s; 3943 // 3944 // causes needless "incomplete type" error later. 3945 Name = 0; 3946 PrevDecl = 0; 3947 Invalid = true; 3948 } else 3949 PrevDecl = R; 3950 3951 if (!getLangOptions().CPlusPlus && TUK != TUK_Reference) { 3952 // FIXME: This makes sure that we ignore the contexts associated 3953 // with C structs, unions, and enums when looking for a matching 3954 // tag declaration or definition. See the similar lookup tweak 3955 // in Sema::LookupName; is there a better way to deal with this? 3956 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 3957 SearchDC = SearchDC->getParent(); 3958 } 3959 } 3960 3961 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3962 // Maybe we will complain about the shadowed template parameter. 3963 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 3964 // Just pretend that we didn't see the previous declaration. 3965 PrevDecl = 0; 3966 } 3967 3968 if (PrevDecl) { 3969 // Check whether the previous declaration is usable. 3970 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 3971 3972 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 3973 // If this is a use of a previous tag, or if the tag is already declared 3974 // in the same scope (so that the definition/declaration completes or 3975 // rementions the tag), reuse the decl. 3976 if (TUK == TUK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 3977 // Make sure that this wasn't declared as an enum and now used as a 3978 // struct or something similar. 3979 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 3980 bool SafeToContinue 3981 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 3982 Kind != TagDecl::TK_enum); 3983 if (SafeToContinue) 3984 Diag(KWLoc, diag::err_use_with_wrong_tag) 3985 << Name 3986 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 3987 PrevTagDecl->getKindName()); 3988 else 3989 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 3990 Diag(PrevDecl->getLocation(), diag::note_previous_use); 3991 3992 if (SafeToContinue) 3993 Kind = PrevTagDecl->getTagKind(); 3994 else { 3995 // Recover by making this an anonymous redefinition. 3996 Name = 0; 3997 PrevDecl = 0; 3998 Invalid = true; 3999 } 4000 } 4001 4002 if (!Invalid) { 4003 // If this is a use, just return the declaration we found. 4004 4005 // FIXME: In the future, return a variant or some other clue 4006 // for the consumer of this Decl to know it doesn't own it. 4007 // For our current ASTs this shouldn't be a problem, but will 4008 // need to be changed with DeclGroups. 4009 if (TUK == TUK_Reference) 4010 return DeclPtrTy::make(PrevDecl); 4011 4012 // Diagnose attempts to redefine a tag. 4013 if (TUK == TUK_Definition) { 4014 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 4015 Diag(NameLoc, diag::err_redefinition) << Name; 4016 Diag(Def->getLocation(), diag::note_previous_definition); 4017 // If this is a redefinition, recover by making this 4018 // struct be anonymous, which will make any later 4019 // references get the previous definition. 4020 Name = 0; 4021 PrevDecl = 0; 4022 Invalid = true; 4023 } else { 4024 // If the type is currently being defined, complain 4025 // about a nested redefinition. 4026 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 4027 if (Tag->isBeingDefined()) { 4028 Diag(NameLoc, diag::err_nested_redefinition) << Name; 4029 Diag(PrevTagDecl->getLocation(), 4030 diag::note_previous_definition); 4031 Name = 0; 4032 PrevDecl = 0; 4033 Invalid = true; 4034 } 4035 } 4036 4037 // Okay, this is definition of a previously declared or referenced 4038 // tag PrevDecl. We're going to create a new Decl for it. 4039 } 4040 } 4041 // If we get here we have (another) forward declaration or we 4042 // have a definition. Just create a new decl. 4043 } else { 4044 // If we get here, this is a definition of a new tag type in a nested 4045 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 4046 // new decl/type. We set PrevDecl to NULL so that the entities 4047 // have distinct types. 4048 PrevDecl = 0; 4049 } 4050 // If we get here, we're going to create a new Decl. If PrevDecl 4051 // is non-NULL, it's a definition of the tag declared by 4052 // PrevDecl. If it's NULL, we have a new definition. 4053 } else { 4054 // PrevDecl is a namespace, template, or anything else 4055 // that lives in the IDNS_Tag identifier namespace. 4056 if (isDeclInScope(PrevDecl, SearchDC, S)) { 4057 // The tag name clashes with a namespace name, issue an error and 4058 // recover by making this tag be anonymous. 4059 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 4060 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4061 Name = 0; 4062 PrevDecl = 0; 4063 Invalid = true; 4064 } else { 4065 // The existing declaration isn't relevant to us; we're in a 4066 // new scope, so clear out the previous declaration. 4067 PrevDecl = 0; 4068 } 4069 } 4070 } else if (TUK == TUK_Reference && SS.isEmpty() && Name && 4071 (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) { 4072 // C++ [basic.scope.pdecl]p5: 4073 // -- for an elaborated-type-specifier of the form 4074 // 4075 // class-key identifier 4076 // 4077 // if the elaborated-type-specifier is used in the 4078 // decl-specifier-seq or parameter-declaration-clause of a 4079 // function defined in namespace scope, the identifier is 4080 // declared as a class-name in the namespace that contains 4081 // the declaration; otherwise, except as a friend 4082 // declaration, the identifier is declared in the smallest 4083 // non-class, non-function-prototype scope that contains the 4084 // declaration. 4085 // 4086 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 4087 // C structs and unions. 4088 // 4089 // GNU C also supports this behavior as part of its incomplete 4090 // enum types extension, while GNU C++ does not. 4091 // 4092 // Find the context where we'll be declaring the tag. 4093 // FIXME: We would like to maintain the current DeclContext as the 4094 // lexical context, 4095 while (SearchDC->isRecord()) 4096 SearchDC = SearchDC->getParent(); 4097 4098 // Find the scope where we'll be declaring the tag. 4099 while (S->isClassScope() || 4100 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 4101 ((S->getFlags() & Scope::DeclScope) == 0) || 4102 (S->getEntity() && 4103 ((DeclContext *)S->getEntity())->isTransparentContext())) 4104 S = S->getParent(); 4105 } 4106 4107CreateNewDecl: 4108 4109 // If there is an identifier, use the location of the identifier as the 4110 // location of the decl, otherwise use the location of the struct/union 4111 // keyword. 4112 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 4113 4114 // Otherwise, create a new declaration. If there is a previous 4115 // declaration of the same entity, the two will be linked via 4116 // PrevDecl. 4117 TagDecl *New; 4118 4119 if (Kind == TagDecl::TK_enum) { 4120 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4121 // enum X { A, B, C } D; D should chain to X. 4122 New = EnumDecl::Create(Context, SearchDC, Loc, Name, KWLoc, 4123 cast_or_null<EnumDecl>(PrevDecl)); 4124 // If this is an undefined enum, warn. 4125 if (TUK != TUK_Definition && !Invalid) { 4126 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 4127 : diag::ext_forward_ref_enum; 4128 Diag(Loc, DK); 4129 } 4130 } else { 4131 // struct/union/class 4132 4133 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4134 // struct X { int A; } D; D should chain to X. 4135 if (getLangOptions().CPlusPlus) 4136 // FIXME: Look for a way to use RecordDecl for simple structs. 4137 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4138 cast_or_null<CXXRecordDecl>(PrevDecl)); 4139 else 4140 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4141 cast_or_null<RecordDecl>(PrevDecl)); 4142 } 4143 4144 if (Kind != TagDecl::TK_enum) { 4145 // Handle #pragma pack: if the #pragma pack stack has non-default 4146 // alignment, make up a packed attribute for this decl. These 4147 // attributes are checked when the ASTContext lays out the 4148 // structure. 4149 // 4150 // It is important for implementing the correct semantics that this 4151 // happen here (in act on tag decl). The #pragma pack stack is 4152 // maintained as a result of parser callbacks which can occur at 4153 // many points during the parsing of a struct declaration (because 4154 // the #pragma tokens are effectively skipped over during the 4155 // parsing of the struct). 4156 if (unsigned Alignment = getPragmaPackAlignment()) 4157 New->addAttr(::new (Context) PackedAttr(Alignment * 8)); 4158 } 4159 4160 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 4161 // C++ [dcl.typedef]p3: 4162 // [...] Similarly, in a given scope, a class or enumeration 4163 // shall not be declared with the same name as a typedef-name 4164 // that is declared in that scope and refers to a type other 4165 // than the class or enumeration itself. 4166 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 4167 TypedefDecl *PrevTypedef = 0; 4168 if (Lookup.getKind() == LookupResult::Found) 4169 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 4170 4171 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 4172 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 4173 Context.getCanonicalType(Context.getTypeDeclType(New))) { 4174 Diag(Loc, diag::err_tag_definition_of_typedef) 4175 << Context.getTypeDeclType(New) 4176 << PrevTypedef->getUnderlyingType(); 4177 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 4178 Invalid = true; 4179 } 4180 } 4181 4182 if (Invalid) 4183 New->setInvalidDecl(); 4184 4185 if (Attr) 4186 ProcessDeclAttributeList(S, New, Attr); 4187 4188 // If we're declaring or defining a tag in function prototype scope 4189 // in C, note that this type can only be used within the function. 4190 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 4191 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 4192 4193 // Set the lexical context. If the tag has a C++ scope specifier, the 4194 // lexical context will be different from the semantic context. 4195 New->setLexicalDeclContext(CurContext); 4196 4197 // Set the access specifier. 4198 if (!Invalid) 4199 SetMemberAccessSpecifier(New, PrevDecl, AS); 4200 4201 if (TUK == TUK_Definition) 4202 New->startDefinition(); 4203 4204 // If this has an identifier, add it to the scope stack. 4205 if (Name) { 4206 S = getNonFieldDeclScope(S); 4207 PushOnScopeChains(New, S); 4208 } else { 4209 CurContext->addDecl(New); 4210 } 4211 4212 // If this is the C FILE type, notify the AST context. 4213 if (IdentifierInfo *II = New->getIdentifier()) 4214 if (!New->isInvalidDecl() && 4215 New->getDeclContext()->getLookupContext()->isTranslationUnit() && 4216 II->isStr("FILE")) 4217 Context.setFILEDecl(New); 4218 4219 OwnedDecl = true; 4220 return DeclPtrTy::make(New); 4221} 4222 4223void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 4224 AdjustDeclIfTemplate(TagD); 4225 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4226 4227 // Enter the tag context. 4228 PushDeclContext(S, Tag); 4229 4230 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 4231 FieldCollector->StartClass(); 4232 4233 if (Record->getIdentifier()) { 4234 // C++ [class]p2: 4235 // [...] The class-name is also inserted into the scope of the 4236 // class itself; this is known as the injected-class-name. For 4237 // purposes of access checking, the injected-class-name is treated 4238 // as if it were a public member name. 4239 CXXRecordDecl *InjectedClassName 4240 = CXXRecordDecl::Create(Context, Record->getTagKind(), 4241 CurContext, Record->getLocation(), 4242 Record->getIdentifier(), 4243 Record->getTagKeywordLoc(), 4244 Record); 4245 InjectedClassName->setImplicit(); 4246 InjectedClassName->setAccess(AS_public); 4247 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 4248 InjectedClassName->setDescribedClassTemplate(Template); 4249 PushOnScopeChains(InjectedClassName, S); 4250 assert(InjectedClassName->isInjectedClassName() && 4251 "Broken injected-class-name"); 4252 } 4253 } 4254} 4255 4256void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD, 4257 SourceLocation RBraceLoc) { 4258 AdjustDeclIfTemplate(TagD); 4259 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4260 Tag->setRBraceLoc(RBraceLoc); 4261 4262 if (isa<CXXRecordDecl>(Tag)) 4263 FieldCollector->FinishClass(); 4264 4265 // Exit this scope of this tag's definition. 4266 PopDeclContext(); 4267 4268 // Notify the consumer that we've defined a tag. 4269 Consumer.HandleTagDeclDefinition(Tag); 4270} 4271 4272// Note that FieldName may be null for anonymous bitfields. 4273bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 4274 QualType FieldTy, const Expr *BitWidth) { 4275 4276 // C99 6.7.2.1p4 - verify the field type. 4277 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 4278 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 4279 // Handle incomplete types with specific error. 4280 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 4281 return true; 4282 if (FieldName) 4283 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 4284 << FieldName << FieldTy << BitWidth->getSourceRange(); 4285 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 4286 << FieldTy << BitWidth->getSourceRange(); 4287 } 4288 4289 // If the bit-width is type- or value-dependent, don't try to check 4290 // it now. 4291 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 4292 return false; 4293 4294 llvm::APSInt Value; 4295 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 4296 return true; 4297 4298 // Zero-width bitfield is ok for anonymous field. 4299 if (Value == 0 && FieldName) 4300 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 4301 4302 if (Value.isSigned() && Value.isNegative()) { 4303 if (FieldName) 4304 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 4305 << FieldName << Value.toString(10); 4306 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 4307 << Value.toString(10); 4308 } 4309 4310 if (!FieldTy->isDependentType()) { 4311 uint64_t TypeSize = Context.getTypeSize(FieldTy); 4312 if (Value.getZExtValue() > TypeSize) { 4313 if (FieldName) 4314 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 4315 << FieldName << (unsigned)TypeSize; 4316 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 4317 << (unsigned)TypeSize; 4318 } 4319 } 4320 4321 return false; 4322} 4323 4324/// ActOnField - Each field of a struct/union/class is passed into this in order 4325/// to create a FieldDecl object for it. 4326Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 4327 SourceLocation DeclStart, 4328 Declarator &D, ExprTy *BitfieldWidth) { 4329 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 4330 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 4331 AS_public); 4332 return DeclPtrTy::make(Res); 4333} 4334 4335/// HandleField - Analyze a field of a C struct or a C++ data member. 4336/// 4337FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 4338 SourceLocation DeclStart, 4339 Declarator &D, Expr *BitWidth, 4340 AccessSpecifier AS) { 4341 IdentifierInfo *II = D.getIdentifier(); 4342 SourceLocation Loc = DeclStart; 4343 if (II) Loc = D.getIdentifierLoc(); 4344 4345 QualType T = GetTypeForDeclarator(D, S); 4346 if (getLangOptions().CPlusPlus) 4347 CheckExtraCXXDefaultArguments(D); 4348 4349 DiagnoseFunctionSpecifiers(D); 4350 4351 if (D.getDeclSpec().isThreadSpecified()) 4352 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 4353 4354 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4355 4356 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4357 // Maybe we will complain about the shadowed template parameter. 4358 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 4359 // Just pretend that we didn't see the previous declaration. 4360 PrevDecl = 0; 4361 } 4362 4363 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 4364 PrevDecl = 0; 4365 4366 bool Mutable 4367 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 4368 SourceLocation TSSL = D.getSourceRange().getBegin(); 4369 FieldDecl *NewFD 4370 = CheckFieldDecl(II, T, Record, Loc, Mutable, BitWidth, TSSL, 4371 AS, PrevDecl, &D); 4372 if (NewFD->isInvalidDecl() && PrevDecl) { 4373 // Don't introduce NewFD into scope; there's already something 4374 // with the same name in the same scope. 4375 } else if (II) { 4376 PushOnScopeChains(NewFD, S); 4377 } else 4378 Record->addDecl(NewFD); 4379 4380 return NewFD; 4381} 4382 4383/// \brief Build a new FieldDecl and check its well-formedness. 4384/// 4385/// This routine builds a new FieldDecl given the fields name, type, 4386/// record, etc. \p PrevDecl should refer to any previous declaration 4387/// with the same name and in the same scope as the field to be 4388/// created. 4389/// 4390/// \returns a new FieldDecl. 4391/// 4392/// \todo The Declarator argument is a hack. It will be removed once 4393FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 4394 RecordDecl *Record, SourceLocation Loc, 4395 bool Mutable, Expr *BitWidth, 4396 SourceLocation TSSL, 4397 AccessSpecifier AS, NamedDecl *PrevDecl, 4398 Declarator *D) { 4399 IdentifierInfo *II = Name.getAsIdentifierInfo(); 4400 bool InvalidDecl = false; 4401 if (D) InvalidDecl = D->isInvalidType(); 4402 4403 // If we receive a broken type, recover by assuming 'int' and 4404 // marking this declaration as invalid. 4405 if (T.isNull()) { 4406 InvalidDecl = true; 4407 T = Context.IntTy; 4408 } 4409 4410 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4411 // than a variably modified type. 4412 if (T->isVariablyModifiedType()) { 4413 bool SizeIsNegative; 4414 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 4415 SizeIsNegative); 4416 if (!FixedTy.isNull()) { 4417 Diag(Loc, diag::warn_illegal_constant_array_size); 4418 T = FixedTy; 4419 } else { 4420 if (SizeIsNegative) 4421 Diag(Loc, diag::err_typecheck_negative_array_size); 4422 else 4423 Diag(Loc, diag::err_typecheck_field_variable_size); 4424 InvalidDecl = true; 4425 } 4426 } 4427 4428 // Fields can not have abstract class types 4429 if (RequireNonAbstractType(Loc, T, diag::err_abstract_type_in_decl, 4430 AbstractFieldType)) 4431 InvalidDecl = true; 4432 4433 // If this is declared as a bit-field, check the bit-field. 4434 if (BitWidth && VerifyBitField(Loc, II, T, BitWidth)) { 4435 InvalidDecl = true; 4436 DeleteExpr(BitWidth); 4437 BitWidth = 0; 4438 } 4439 4440 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, BitWidth, 4441 Mutable, TSSL); 4442 if (InvalidDecl) 4443 NewFD->setInvalidDecl(); 4444 4445 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 4446 Diag(Loc, diag::err_duplicate_member) << II; 4447 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4448 NewFD->setInvalidDecl(); 4449 } 4450 4451 if (getLangOptions().CPlusPlus) { 4452 QualType EltTy = Context.getBaseElementType(T); 4453 4454 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 4455 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 4456 4457 if (!RDecl->hasTrivialConstructor()) 4458 cast<CXXRecordDecl>(Record)->setHasTrivialConstructor(false); 4459 if (!RDecl->hasTrivialCopyConstructor()) 4460 cast<CXXRecordDecl>(Record)->setHasTrivialCopyConstructor(false); 4461 if (!RDecl->hasTrivialCopyAssignment()) 4462 cast<CXXRecordDecl>(Record)->setHasTrivialCopyAssignment(false); 4463 if (!RDecl->hasTrivialDestructor()) 4464 cast<CXXRecordDecl>(Record)->setHasTrivialDestructor(false); 4465 4466 // C++ 9.5p1: An object of a class with a non-trivial 4467 // constructor, a non-trivial copy constructor, a non-trivial 4468 // destructor, or a non-trivial copy assignment operator 4469 // cannot be a member of a union, nor can an array of such 4470 // objects. 4471 // TODO: C++0x alters this restriction significantly. 4472 if (Record->isUnion()) { 4473 // We check for copy constructors before constructors 4474 // because otherwise we'll never get complaints about 4475 // copy constructors. 4476 4477 const CXXSpecialMember invalid = (CXXSpecialMember) -1; 4478 4479 CXXSpecialMember member; 4480 if (!RDecl->hasTrivialCopyConstructor()) 4481 member = CXXCopyConstructor; 4482 else if (!RDecl->hasTrivialConstructor()) 4483 member = CXXDefaultConstructor; 4484 else if (!RDecl->hasTrivialCopyAssignment()) 4485 member = CXXCopyAssignment; 4486 else if (!RDecl->hasTrivialDestructor()) 4487 member = CXXDestructor; 4488 else 4489 member = invalid; 4490 4491 if (member != invalid) { 4492 Diag(Loc, diag::err_illegal_union_member) << Name << member; 4493 DiagnoseNontrivial(RT, member); 4494 NewFD->setInvalidDecl(); 4495 } 4496 } 4497 } 4498 } 4499 4500 if (getLangOptions().CPlusPlus && !T->isPODType()) 4501 cast<CXXRecordDecl>(Record)->setPOD(false); 4502 4503 // FIXME: We need to pass in the attributes given an AST 4504 // representation, not a parser representation. 4505 if (D) 4506 // FIXME: What to pass instead of TUScope? 4507 ProcessDeclAttributes(TUScope, NewFD, *D); 4508 4509 if (T.isObjCGCWeak()) 4510 Diag(Loc, diag::warn_attribute_weak_on_field); 4511 4512 NewFD->setAccess(AS); 4513 4514 // C++ [dcl.init.aggr]p1: 4515 // An aggregate is an array or a class (clause 9) with [...] no 4516 // private or protected non-static data members (clause 11). 4517 // A POD must be an aggregate. 4518 if (getLangOptions().CPlusPlus && 4519 (AS == AS_private || AS == AS_protected)) { 4520 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 4521 CXXRecord->setAggregate(false); 4522 CXXRecord->setPOD(false); 4523 } 4524 4525 return NewFD; 4526} 4527 4528/// DiagnoseNontrivial - Given that a class has a non-trivial 4529/// special member, figure out why. 4530void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) { 4531 QualType QT(T, 0U); 4532 CXXRecordDecl* RD = cast<CXXRecordDecl>(T->getDecl()); 4533 4534 // Check whether the member was user-declared. 4535 switch (member) { 4536 case CXXDefaultConstructor: 4537 if (RD->hasUserDeclaredConstructor()) { 4538 typedef CXXRecordDecl::ctor_iterator ctor_iter; 4539 for (ctor_iter ci = RD->ctor_begin(), ce = RD->ctor_end(); ci != ce; ++ci) 4540 if (!ci->isImplicitlyDefined(Context)) { 4541 SourceLocation CtorLoc = ci->getLocation(); 4542 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4543 return; 4544 } 4545 4546 assert(0 && "found no user-declared constructors"); 4547 return; 4548 } 4549 break; 4550 4551 case CXXCopyConstructor: 4552 if (RD->hasUserDeclaredCopyConstructor()) { 4553 SourceLocation CtorLoc = 4554 RD->getCopyConstructor(Context, 0)->getLocation(); 4555 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4556 return; 4557 } 4558 break; 4559 4560 case CXXCopyAssignment: 4561 if (RD->hasUserDeclaredCopyAssignment()) { 4562 // FIXME: this should use the location of the copy 4563 // assignment, not the type. 4564 SourceLocation TyLoc = RD->getSourceRange().getBegin(); 4565 Diag(TyLoc, diag::note_nontrivial_user_defined) << QT << member; 4566 return; 4567 } 4568 break; 4569 4570 case CXXDestructor: 4571 if (RD->hasUserDeclaredDestructor()) { 4572 SourceLocation DtorLoc = RD->getDestructor(Context)->getLocation(); 4573 Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4574 return; 4575 } 4576 break; 4577 } 4578 4579 typedef CXXRecordDecl::base_class_iterator base_iter; 4580 4581 // Virtual bases and members inhibit trivial copying/construction, 4582 // but not trivial destruction. 4583 if (member != CXXDestructor) { 4584 // Check for virtual bases. vbases includes indirect virtual bases, 4585 // so we just iterate through the direct bases. 4586 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) 4587 if (bi->isVirtual()) { 4588 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4589 Diag(BaseLoc, diag::note_nontrivial_has_virtual) << QT << 1; 4590 return; 4591 } 4592 4593 // Check for virtual methods. 4594 typedef CXXRecordDecl::method_iterator meth_iter; 4595 for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; 4596 ++mi) { 4597 if (mi->isVirtual()) { 4598 SourceLocation MLoc = mi->getSourceRange().getBegin(); 4599 Diag(MLoc, diag::note_nontrivial_has_virtual) << QT << 0; 4600 return; 4601 } 4602 } 4603 } 4604 4605 bool (CXXRecordDecl::*hasTrivial)() const; 4606 switch (member) { 4607 case CXXDefaultConstructor: 4608 hasTrivial = &CXXRecordDecl::hasTrivialConstructor; break; 4609 case CXXCopyConstructor: 4610 hasTrivial = &CXXRecordDecl::hasTrivialCopyConstructor; break; 4611 case CXXCopyAssignment: 4612 hasTrivial = &CXXRecordDecl::hasTrivialCopyAssignment; break; 4613 case CXXDestructor: 4614 hasTrivial = &CXXRecordDecl::hasTrivialDestructor; break; 4615 default: 4616 assert(0 && "unexpected special member"); return; 4617 } 4618 4619 // Check for nontrivial bases (and recurse). 4620 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) { 4621 const RecordType *BaseRT = bi->getType()->getAs<RecordType>(); 4622 assert(BaseRT); 4623 CXXRecordDecl *BaseRecTy = cast<CXXRecordDecl>(BaseRT->getDecl()); 4624 if (!(BaseRecTy->*hasTrivial)()) { 4625 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4626 Diag(BaseLoc, diag::note_nontrivial_has_nontrivial) << QT << 1 << member; 4627 DiagnoseNontrivial(BaseRT, member); 4628 return; 4629 } 4630 } 4631 4632 // Check for nontrivial members (and recurse). 4633 typedef RecordDecl::field_iterator field_iter; 4634 for (field_iter fi = RD->field_begin(), fe = RD->field_end(); fi != fe; 4635 ++fi) { 4636 QualType EltTy = Context.getBaseElementType((*fi)->getType()); 4637 if (const RecordType *EltRT = EltTy->getAs<RecordType>()) { 4638 CXXRecordDecl* EltRD = cast<CXXRecordDecl>(EltRT->getDecl()); 4639 4640 if (!(EltRD->*hasTrivial)()) { 4641 SourceLocation FLoc = (*fi)->getLocation(); 4642 Diag(FLoc, diag::note_nontrivial_has_nontrivial) << QT << 0 << member; 4643 DiagnoseNontrivial(EltRT, member); 4644 return; 4645 } 4646 } 4647 } 4648 4649 assert(0 && "found no explanation for non-trivial member"); 4650} 4651 4652/// TranslateIvarVisibility - Translate visibility from a token ID to an 4653/// AST enum value. 4654static ObjCIvarDecl::AccessControl 4655TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 4656 switch (ivarVisibility) { 4657 default: assert(0 && "Unknown visitibility kind"); 4658 case tok::objc_private: return ObjCIvarDecl::Private; 4659 case tok::objc_public: return ObjCIvarDecl::Public; 4660 case tok::objc_protected: return ObjCIvarDecl::Protected; 4661 case tok::objc_package: return ObjCIvarDecl::Package; 4662 } 4663} 4664 4665/// ActOnIvar - Each ivar field of an objective-c class is passed into this 4666/// in order to create an IvarDecl object for it. 4667Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 4668 SourceLocation DeclStart, 4669 DeclPtrTy IntfDecl, 4670 Declarator &D, ExprTy *BitfieldWidth, 4671 tok::ObjCKeywordKind Visibility) { 4672 4673 IdentifierInfo *II = D.getIdentifier(); 4674 Expr *BitWidth = (Expr*)BitfieldWidth; 4675 SourceLocation Loc = DeclStart; 4676 if (II) Loc = D.getIdentifierLoc(); 4677 4678 // FIXME: Unnamed fields can be handled in various different ways, for 4679 // example, unnamed unions inject all members into the struct namespace! 4680 4681 QualType T = GetTypeForDeclarator(D, S); 4682 4683 if (BitWidth) { 4684 // 6.7.2.1p3, 6.7.2.1p4 4685 if (VerifyBitField(Loc, II, T, BitWidth)) { 4686 D.setInvalidType(); 4687 DeleteExpr(BitWidth); 4688 BitWidth = 0; 4689 } 4690 } else { 4691 // Not a bitfield. 4692 4693 // validate II. 4694 4695 } 4696 4697 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4698 // than a variably modified type. 4699 if (T->isVariablyModifiedType()) { 4700 Diag(Loc, diag::err_typecheck_ivar_variable_size); 4701 D.setInvalidType(); 4702 } 4703 4704 // Get the visibility (access control) for this ivar. 4705 ObjCIvarDecl::AccessControl ac = 4706 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 4707 : ObjCIvarDecl::None; 4708 // Must set ivar's DeclContext to its enclosing interface. 4709 Decl *EnclosingDecl = IntfDecl.getAs<Decl>(); 4710 DeclContext *EnclosingContext; 4711 if (ObjCImplementationDecl *IMPDecl = 4712 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4713 // Case of ivar declared in an implementation. Context is that of its class. 4714 ObjCInterfaceDecl* IDecl = IMPDecl->getClassInterface(); 4715 assert(IDecl && "No class- ActOnIvar"); 4716 EnclosingContext = cast_or_null<DeclContext>(IDecl); 4717 } else 4718 EnclosingContext = dyn_cast<DeclContext>(EnclosingDecl); 4719 assert(EnclosingContext && "null DeclContext for ivar - ActOnIvar"); 4720 4721 // Construct the decl. 4722 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, 4723 EnclosingContext, Loc, II, T,ac, 4724 (Expr *)BitfieldWidth); 4725 4726 if (II) { 4727 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4728 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 4729 && !isa<TagDecl>(PrevDecl)) { 4730 Diag(Loc, diag::err_duplicate_member) << II; 4731 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4732 NewID->setInvalidDecl(); 4733 } 4734 } 4735 4736 // Process attributes attached to the ivar. 4737 ProcessDeclAttributes(S, NewID, D); 4738 4739 if (D.isInvalidType()) 4740 NewID->setInvalidDecl(); 4741 4742 if (II) { 4743 // FIXME: When interfaces are DeclContexts, we'll need to add 4744 // these to the interface. 4745 S->AddDecl(DeclPtrTy::make(NewID)); 4746 IdResolver.AddDecl(NewID); 4747 } 4748 4749 return DeclPtrTy::make(NewID); 4750} 4751 4752void Sema::ActOnFields(Scope* S, 4753 SourceLocation RecLoc, DeclPtrTy RecDecl, 4754 DeclPtrTy *Fields, unsigned NumFields, 4755 SourceLocation LBrac, SourceLocation RBrac, 4756 AttributeList *Attr) { 4757 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 4758 assert(EnclosingDecl && "missing record or interface decl"); 4759 4760 // If the decl this is being inserted into is invalid, then it may be a 4761 // redeclaration or some other bogus case. Don't try to add fields to it. 4762 if (EnclosingDecl->isInvalidDecl()) { 4763 // FIXME: Deallocate fields? 4764 return; 4765 } 4766 4767 4768 // Verify that all the fields are okay. 4769 unsigned NumNamedMembers = 0; 4770 llvm::SmallVector<FieldDecl*, 32> RecFields; 4771 4772 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 4773 for (unsigned i = 0; i != NumFields; ++i) { 4774 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 4775 4776 // Get the type for the field. 4777 Type *FDTy = FD->getType().getTypePtr(); 4778 4779 if (!FD->isAnonymousStructOrUnion()) { 4780 // Remember all fields written by the user. 4781 RecFields.push_back(FD); 4782 } 4783 4784 // If the field is already invalid for some reason, don't emit more 4785 // diagnostics about it. 4786 if (FD->isInvalidDecl()) 4787 continue; 4788 4789 // C99 6.7.2.1p2: 4790 // A structure or union shall not contain a member with 4791 // incomplete or function type (hence, a structure shall not 4792 // contain an instance of itself, but may contain a pointer to 4793 // an instance of itself), except that the last member of a 4794 // structure with more than one named member may have incomplete 4795 // array type; such a structure (and any union containing, 4796 // possibly recursively, a member that is such a structure) 4797 // shall not be a member of a structure or an element of an 4798 // array. 4799 if (FDTy->isFunctionType()) { 4800 // Field declared as a function. 4801 Diag(FD->getLocation(), diag::err_field_declared_as_function) 4802 << FD->getDeclName(); 4803 FD->setInvalidDecl(); 4804 EnclosingDecl->setInvalidDecl(); 4805 continue; 4806 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 4807 Record && Record->isStruct()) { 4808 // Flexible array member. 4809 if (NumNamedMembers < 1) { 4810 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 4811 << FD->getDeclName(); 4812 FD->setInvalidDecl(); 4813 EnclosingDecl->setInvalidDecl(); 4814 continue; 4815 } 4816 // Okay, we have a legal flexible array member at the end of the struct. 4817 if (Record) 4818 Record->setHasFlexibleArrayMember(true); 4819 } else if (!FDTy->isDependentType() && 4820 RequireCompleteType(FD->getLocation(), FD->getType(), 4821 diag::err_field_incomplete)) { 4822 // Incomplete type 4823 FD->setInvalidDecl(); 4824 EnclosingDecl->setInvalidDecl(); 4825 continue; 4826 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) { 4827 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 4828 // If this is a member of a union, then entire union becomes "flexible". 4829 if (Record && Record->isUnion()) { 4830 Record->setHasFlexibleArrayMember(true); 4831 } else { 4832 // If this is a struct/class and this is not the last element, reject 4833 // it. Note that GCC supports variable sized arrays in the middle of 4834 // structures. 4835 if (i != NumFields-1) 4836 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 4837 << FD->getDeclName() << FD->getType(); 4838 else { 4839 // We support flexible arrays at the end of structs in 4840 // other structs as an extension. 4841 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 4842 << FD->getDeclName(); 4843 if (Record) 4844 Record->setHasFlexibleArrayMember(true); 4845 } 4846 } 4847 } 4848 if (Record && FDTTy->getDecl()->hasObjectMember()) 4849 Record->setHasObjectMember(true); 4850 } else if (FDTy->isObjCInterfaceType()) { 4851 /// A field cannot be an Objective-c object 4852 Diag(FD->getLocation(), diag::err_statically_allocated_object); 4853 FD->setInvalidDecl(); 4854 EnclosingDecl->setInvalidDecl(); 4855 continue; 4856 } else if (getLangOptions().ObjC1 && 4857 getLangOptions().getGCMode() != LangOptions::NonGC && 4858 Record && 4859 (FD->getType()->isObjCObjectPointerType() || 4860 FD->getType().isObjCGCStrong())) 4861 Record->setHasObjectMember(true); 4862 // Keep track of the number of named members. 4863 if (FD->getIdentifier()) 4864 ++NumNamedMembers; 4865 } 4866 4867 // Okay, we successfully defined 'Record'. 4868 if (Record) { 4869 Record->completeDefinition(Context); 4870 } else { 4871 ObjCIvarDecl **ClsFields = 4872 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 4873 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 4874 ID->setIVarList(ClsFields, RecFields.size(), Context); 4875 ID->setLocEnd(RBrac); 4876 // Add ivar's to class's DeclContext. 4877 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 4878 ClsFields[i]->setLexicalDeclContext(ID); 4879 ID->addDecl(ClsFields[i]); 4880 } 4881 // Must enforce the rule that ivars in the base classes may not be 4882 // duplicates. 4883 if (ID->getSuperClass()) { 4884 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 4885 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 4886 ObjCIvarDecl* Ivar = (*IVI); 4887 4888 if (IdentifierInfo *II = Ivar->getIdentifier()) { 4889 ObjCIvarDecl* prevIvar = 4890 ID->getSuperClass()->lookupInstanceVariable(II); 4891 if (prevIvar) { 4892 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 4893 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 4894 } 4895 } 4896 } 4897 } 4898 } else if (ObjCImplementationDecl *IMPDecl = 4899 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4900 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 4901 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 4902 // Ivar declared in @implementation never belongs to the implementation. 4903 // Only it is in implementation's lexical context. 4904 ClsFields[I]->setLexicalDeclContext(IMPDecl); 4905 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 4906 } 4907 } 4908 4909 if (Attr) 4910 ProcessDeclAttributeList(S, Record, Attr); 4911} 4912 4913EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 4914 EnumConstantDecl *LastEnumConst, 4915 SourceLocation IdLoc, 4916 IdentifierInfo *Id, 4917 ExprArg val) { 4918 Expr *Val = (Expr *)val.get(); 4919 4920 llvm::APSInt EnumVal(32); 4921 QualType EltTy; 4922 if (Val && !Val->isTypeDependent()) { 4923 // Make sure to promote the operand type to int. 4924 UsualUnaryConversions(Val); 4925 if (Val != val.get()) { 4926 val.release(); 4927 val = Val; 4928 } 4929 4930 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 4931 SourceLocation ExpLoc; 4932 if (!Val->isValueDependent() && 4933 VerifyIntegerConstantExpression(Val, &EnumVal)) { 4934 Val = 0; 4935 } else { 4936 EltTy = Val->getType(); 4937 } 4938 } 4939 4940 if (!Val) { 4941 if (LastEnumConst) { 4942 // Assign the last value + 1. 4943 EnumVal = LastEnumConst->getInitVal(); 4944 ++EnumVal; 4945 4946 // Check for overflow on increment. 4947 if (EnumVal < LastEnumConst->getInitVal()) 4948 Diag(IdLoc, diag::warn_enum_value_overflow); 4949 4950 EltTy = LastEnumConst->getType(); 4951 } else { 4952 // First value, set to zero. 4953 EltTy = Context.IntTy; 4954 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 4955 } 4956 } 4957 4958 val.release(); 4959 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 4960 Val, EnumVal); 4961} 4962 4963 4964Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 4965 DeclPtrTy lastEnumConst, 4966 SourceLocation IdLoc, 4967 IdentifierInfo *Id, 4968 SourceLocation EqualLoc, ExprTy *val) { 4969 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 4970 EnumConstantDecl *LastEnumConst = 4971 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 4972 Expr *Val = static_cast<Expr*>(val); 4973 4974 // The scope passed in may not be a decl scope. Zip up the scope tree until 4975 // we find one that is. 4976 S = getNonFieldDeclScope(S); 4977 4978 // Verify that there isn't already something declared with this name in this 4979 // scope. 4980 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 4981 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4982 // Maybe we will complain about the shadowed template parameter. 4983 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 4984 // Just pretend that we didn't see the previous declaration. 4985 PrevDecl = 0; 4986 } 4987 4988 if (PrevDecl) { 4989 // When in C++, we may get a TagDecl with the same name; in this case the 4990 // enum constant will 'hide' the tag. 4991 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 4992 "Received TagDecl when not in C++!"); 4993 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 4994 if (isa<EnumConstantDecl>(PrevDecl)) 4995 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 4996 else 4997 Diag(IdLoc, diag::err_redefinition) << Id; 4998 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4999 if (Val) Val->Destroy(Context); 5000 return DeclPtrTy(); 5001 } 5002 } 5003 5004 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 5005 IdLoc, Id, Owned(Val)); 5006 5007 // Register this decl in the current scope stack. 5008 if (New) 5009 PushOnScopeChains(New, S); 5010 5011 return DeclPtrTy::make(New); 5012} 5013 5014void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 5015 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 5016 DeclPtrTy *Elements, unsigned NumElements) { 5017 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 5018 QualType EnumType = Context.getTypeDeclType(Enum); 5019 5020 // TODO: If the result value doesn't fit in an int, it must be a long or long 5021 // long value. ISO C does not support this, but GCC does as an extension, 5022 // emit a warning. 5023 unsigned IntWidth = Context.Target.getIntWidth(); 5024 5025 // Verify that all the values are okay, compute the size of the values, and 5026 // reverse the list. 5027 unsigned NumNegativeBits = 0; 5028 unsigned NumPositiveBits = 0; 5029 5030 // Keep track of whether all elements have type int. 5031 bool AllElementsInt = true; 5032 5033 for (unsigned i = 0; i != NumElements; ++i) { 5034 EnumConstantDecl *ECD = 5035 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5036 if (!ECD) continue; // Already issued a diagnostic. 5037 5038 // If the enum value doesn't fit in an int, emit an extension warning. 5039 const llvm::APSInt &InitVal = ECD->getInitVal(); 5040 assert(InitVal.getBitWidth() >= IntWidth && 5041 "Should have promoted value to int"); 5042 if (InitVal.getBitWidth() > IntWidth) { 5043 llvm::APSInt V(InitVal); 5044 V.trunc(IntWidth); 5045 V.extend(InitVal.getBitWidth()); 5046 if (V != InitVal) 5047 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 5048 << InitVal.toString(10); 5049 } 5050 5051 // Keep track of the size of positive and negative values. 5052 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 5053 NumPositiveBits = std::max(NumPositiveBits, 5054 (unsigned)InitVal.getActiveBits()); 5055 else 5056 NumNegativeBits = std::max(NumNegativeBits, 5057 (unsigned)InitVal.getMinSignedBits()); 5058 5059 // Keep track of whether every enum element has type int (very commmon). 5060 if (AllElementsInt) 5061 AllElementsInt = ECD->getType() == Context.IntTy; 5062 } 5063 5064 // Figure out the type that should be used for this enum. 5065 // FIXME: Support attribute(packed) on enums and -fshort-enums. 5066 QualType BestType; 5067 unsigned BestWidth; 5068 5069 if (NumNegativeBits) { 5070 // If there is a negative value, figure out the smallest integer type (of 5071 // int/long/longlong) that fits. 5072 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 5073 BestType = Context.IntTy; 5074 BestWidth = IntWidth; 5075 } else { 5076 BestWidth = Context.Target.getLongWidth(); 5077 5078 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 5079 BestType = Context.LongTy; 5080 else { 5081 BestWidth = Context.Target.getLongLongWidth(); 5082 5083 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 5084 Diag(Enum->getLocation(), diag::warn_enum_too_large); 5085 BestType = Context.LongLongTy; 5086 } 5087 } 5088 } else { 5089 // If there is no negative value, figure out which of uint, ulong, ulonglong 5090 // fits. 5091 if (NumPositiveBits <= IntWidth) { 5092 BestType = Context.UnsignedIntTy; 5093 BestWidth = IntWidth; 5094 } else if (NumPositiveBits <= 5095 (BestWidth = Context.Target.getLongWidth())) { 5096 BestType = Context.UnsignedLongTy; 5097 } else { 5098 BestWidth = Context.Target.getLongLongWidth(); 5099 assert(NumPositiveBits <= BestWidth && 5100 "How could an initializer get larger than ULL?"); 5101 BestType = Context.UnsignedLongLongTy; 5102 } 5103 } 5104 5105 // Loop over all of the enumerator constants, changing their types to match 5106 // the type of the enum if needed. 5107 for (unsigned i = 0; i != NumElements; ++i) { 5108 EnumConstantDecl *ECD = 5109 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5110 if (!ECD) continue; // Already issued a diagnostic. 5111 5112 // Standard C says the enumerators have int type, but we allow, as an 5113 // extension, the enumerators to be larger than int size. If each 5114 // enumerator value fits in an int, type it as an int, otherwise type it the 5115 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 5116 // that X has type 'int', not 'unsigned'. 5117 if (ECD->getType() == Context.IntTy) { 5118 // Make sure the init value is signed. 5119 llvm::APSInt IV = ECD->getInitVal(); 5120 IV.setIsSigned(true); 5121 ECD->setInitVal(IV); 5122 5123 if (getLangOptions().CPlusPlus) 5124 // C++ [dcl.enum]p4: Following the closing brace of an 5125 // enum-specifier, each enumerator has the type of its 5126 // enumeration. 5127 ECD->setType(EnumType); 5128 continue; // Already int type. 5129 } 5130 5131 // Determine whether the value fits into an int. 5132 llvm::APSInt InitVal = ECD->getInitVal(); 5133 bool FitsInInt; 5134 if (InitVal.isUnsigned() || !InitVal.isNegative()) 5135 FitsInInt = InitVal.getActiveBits() < IntWidth; 5136 else 5137 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 5138 5139 // If it fits into an integer type, force it. Otherwise force it to match 5140 // the enum decl type. 5141 QualType NewTy; 5142 unsigned NewWidth; 5143 bool NewSign; 5144 if (FitsInInt) { 5145 NewTy = Context.IntTy; 5146 NewWidth = IntWidth; 5147 NewSign = true; 5148 } else if (ECD->getType() == BestType) { 5149 // Already the right type! 5150 if (getLangOptions().CPlusPlus) 5151 // C++ [dcl.enum]p4: Following the closing brace of an 5152 // enum-specifier, each enumerator has the type of its 5153 // enumeration. 5154 ECD->setType(EnumType); 5155 continue; 5156 } else { 5157 NewTy = BestType; 5158 NewWidth = BestWidth; 5159 NewSign = BestType->isSignedIntegerType(); 5160 } 5161 5162 // Adjust the APSInt value. 5163 InitVal.extOrTrunc(NewWidth); 5164 InitVal.setIsSigned(NewSign); 5165 ECD->setInitVal(InitVal); 5166 5167 // Adjust the Expr initializer and type. 5168 if (ECD->getInitExpr()) 5169 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, 5170 CastExpr::CK_Unknown, 5171 ECD->getInitExpr(), 5172 /*isLvalue=*/false)); 5173 if (getLangOptions().CPlusPlus) 5174 // C++ [dcl.enum]p4: Following the closing brace of an 5175 // enum-specifier, each enumerator has the type of its 5176 // enumeration. 5177 ECD->setType(EnumType); 5178 else 5179 ECD->setType(NewTy); 5180 } 5181 5182 Enum->completeDefinition(Context, BestType); 5183} 5184 5185Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 5186 ExprArg expr) { 5187 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 5188 5189 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 5190 Loc, AsmString); 5191 CurContext->addDecl(New); 5192 return DeclPtrTy::make(New); 5193} 5194 5195void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 5196 SourceLocation PragmaLoc, 5197 SourceLocation NameLoc) { 5198 Decl *PrevDecl = LookupName(TUScope, Name, LookupOrdinaryName); 5199 5200 if (PrevDecl) { 5201 PrevDecl->addAttr(::new (Context) WeakAttr()); 5202 } else { 5203 (void)WeakUndeclaredIdentifiers.insert( 5204 std::pair<IdentifierInfo*,WeakInfo> 5205 (Name, WeakInfo((IdentifierInfo*)0, NameLoc))); 5206 } 5207} 5208 5209void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 5210 IdentifierInfo* AliasName, 5211 SourceLocation PragmaLoc, 5212 SourceLocation NameLoc, 5213 SourceLocation AliasNameLoc) { 5214 Decl *PrevDecl = LookupName(TUScope, AliasName, LookupOrdinaryName); 5215 WeakInfo W = WeakInfo(Name, NameLoc); 5216 5217 if (PrevDecl) { 5218 if (!PrevDecl->hasAttr<AliasAttr>()) 5219 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl)) 5220 DeclApplyPragmaWeak(TUScope, ND, W); 5221 } else { 5222 (void)WeakUndeclaredIdentifiers.insert( 5223 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W)); 5224 } 5225} 5226