SemaDecl.cpp revision 9e2b9e01aeaf38e474da3acce29f2f751b727ad7
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// Determines the context to return to after temporarily entering a 186// context. This depends in an unnecessarily complicated way on the 187// exact ordering of callbacks from the parser. 188DeclContext *Sema::getContainingDC(DeclContext *DC) { 189 190 // Functions defined inline within classes aren't parsed until we've 191 // finished parsing the top-level class, so the top-level class is 192 // the context we'll need to return to. 193 if (isa<FunctionDecl>(DC)) { 194 DC = DC->getLexicalParent(); 195 196 // A function not defined within a class will always return to its 197 // lexical context. 198 if (!isa<CXXRecordDecl>(DC)) 199 return DC; 200 201 // A C++ inline method/friend is parsed *after* the topmost class 202 // it was declared in is fully parsed ("complete"); the topmost 203 // class is the context we need to return to. 204 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 205 DC = RD; 206 207 // Return the declaration context of the topmost class the inline method is 208 // declared in. 209 return DC; 210 } 211 212 if (isa<ObjCMethodDecl>(DC)) 213 return Context.getTranslationUnitDecl(); 214 215 return DC->getLexicalParent(); 216} 217 218void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 219 assert(getContainingDC(DC) == CurContext && 220 "The next DeclContext should be lexically contained in the current one."); 221 CurContext = DC; 222 S->setEntity(DC); 223} 224 225void Sema::PopDeclContext() { 226 assert(CurContext && "DeclContext imbalance!"); 227 228 CurContext = getContainingDC(CurContext); 229} 230 231/// EnterDeclaratorContext - Used when we must lookup names in the context 232/// of a declarator's nested name specifier. 233void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { 234 assert(PreDeclaratorDC == 0 && "Previous declarator context not popped?"); 235 PreDeclaratorDC = static_cast<DeclContext*>(S->getEntity()); 236 CurContext = DC; 237 assert(CurContext && "No context?"); 238 S->setEntity(CurContext); 239} 240 241void Sema::ExitDeclaratorContext(Scope *S) { 242 S->setEntity(PreDeclaratorDC); 243 PreDeclaratorDC = 0; 244 245 // Reset CurContext to the nearest enclosing context. 246 while (!S->getEntity() && S->getParent()) 247 S = S->getParent(); 248 CurContext = static_cast<DeclContext*>(S->getEntity()); 249 assert(CurContext && "No context?"); 250} 251 252/// \brief Determine whether we allow overloading of the function 253/// PrevDecl with another declaration. 254/// 255/// This routine determines whether overloading is possible, not 256/// whether some new function is actually an overload. It will return 257/// true in C++ (where we can always provide overloads) or, as an 258/// extension, in C when the previous function is already an 259/// overloaded function declaration or has the "overloadable" 260/// attribute. 261static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) { 262 if (Context.getLangOptions().CPlusPlus) 263 return true; 264 265 if (isa<OverloadedFunctionDecl>(PrevDecl)) 266 return true; 267 268 return PrevDecl->getAttr<OverloadableAttr>() != 0; 269} 270 271/// Add this decl to the scope shadowed decl chains. 272void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 273 // Move up the scope chain until we find the nearest enclosing 274 // non-transparent context. The declaration will be introduced into this 275 // scope. 276 while (S->getEntity() && 277 ((DeclContext *)S->getEntity())->isTransparentContext()) 278 S = S->getParent(); 279 280 S->AddDecl(DeclPtrTy::make(D)); 281 282 // Add scoped declarations into their context, so that they can be 283 // found later. Declarations without a context won't be inserted 284 // into any context. 285 CurContext->addDecl(D); 286 287 // C++ [basic.scope]p4: 288 // -- exactly one declaration shall declare a class name or 289 // enumeration name that is not a typedef name and the other 290 // declarations shall all refer to the same object or 291 // enumerator, or all refer to functions and function templates; 292 // in this case the class name or enumeration name is hidden. 293 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 294 // We are pushing the name of a tag (enum or class). 295 if (CurContext->getLookupContext() 296 == TD->getDeclContext()->getLookupContext()) { 297 // We're pushing the tag into the current context, which might 298 // require some reshuffling in the identifier resolver. 299 IdentifierResolver::iterator 300 I = IdResolver.begin(TD->getDeclName()), 301 IEnd = IdResolver.end(); 302 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 303 NamedDecl *PrevDecl = *I; 304 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 305 PrevDecl = *I, ++I) { 306 if (TD->declarationReplaces(*I)) { 307 // This is a redeclaration. Remove it from the chain and 308 // break out, so that we'll add in the shadowed 309 // declaration. 310 S->RemoveDecl(DeclPtrTy::make(*I)); 311 if (PrevDecl == *I) { 312 IdResolver.RemoveDecl(*I); 313 IdResolver.AddDecl(TD); 314 return; 315 } else { 316 IdResolver.RemoveDecl(*I); 317 break; 318 } 319 } 320 } 321 322 // There is already a declaration with the same name in the same 323 // scope, which is not a tag declaration. It must be found 324 // before we find the new declaration, so insert the new 325 // declaration at the end of the chain. 326 IdResolver.AddShadowedDecl(TD, PrevDecl); 327 328 return; 329 } 330 } 331 } else if ((isa<FunctionDecl>(D) && 332 AllowOverloadingOfFunction(D, Context)) || 333 isa<FunctionTemplateDecl>(D)) { 334 // We are pushing the name of a function or function template, 335 // which might be an overloaded name. 336 IdentifierResolver::iterator Redecl 337 = std::find_if(IdResolver.begin(D->getDeclName()), 338 IdResolver.end(), 339 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 340 D)); 341 if (Redecl != IdResolver.end() && 342 S->isDeclScope(DeclPtrTy::make(*Redecl))) { 343 // There is already a declaration of a function on our 344 // IdResolver chain. Replace it with this declaration. 345 S->RemoveDecl(DeclPtrTy::make(*Redecl)); 346 IdResolver.RemoveDecl(*Redecl); 347 } 348 } else if (isa<ObjCInterfaceDecl>(D)) { 349 // We're pushing an Objective-C interface into the current 350 // context. If there is already an alias declaration, remove it first. 351 for (IdentifierResolver::iterator 352 I = IdResolver.begin(D->getDeclName()), IEnd = IdResolver.end(); 353 I != IEnd; ++I) { 354 if (isa<ObjCCompatibleAliasDecl>(*I)) { 355 S->RemoveDecl(DeclPtrTy::make(*I)); 356 IdResolver.RemoveDecl(*I); 357 break; 358 } 359 } 360 } 361 362 IdResolver.AddDecl(D); 363} 364 365void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 366 if (S->decl_empty()) return; 367 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 368 "Scope shouldn't contain decls!"); 369 370 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 371 I != E; ++I) { 372 Decl *TmpD = (*I).getAs<Decl>(); 373 assert(TmpD && "This decl didn't get pushed??"); 374 375 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 376 NamedDecl *D = cast<NamedDecl>(TmpD); 377 378 if (!D->getDeclName()) continue; 379 380 // Remove this name from our lexical scope. 381 IdResolver.RemoveDecl(D); 382 } 383} 384 385/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 386/// return 0 if one not found. 387ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 388 // The third "scope" argument is 0 since we aren't enabling lazy built-in 389 // creation from this context. 390 NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName); 391 392 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 393} 394 395/// getNonFieldDeclScope - Retrieves the innermost scope, starting 396/// from S, where a non-field would be declared. This routine copes 397/// with the difference between C and C++ scoping rules in structs and 398/// unions. For example, the following code is well-formed in C but 399/// ill-formed in C++: 400/// @code 401/// struct S6 { 402/// enum { BAR } e; 403/// }; 404/// 405/// void test_S6() { 406/// struct S6 a; 407/// a.e = BAR; 408/// } 409/// @endcode 410/// For the declaration of BAR, this routine will return a different 411/// scope. The scope S will be the scope of the unnamed enumeration 412/// within S6. In C++, this routine will return the scope associated 413/// with S6, because the enumeration's scope is a transparent 414/// context but structures can contain non-field names. In C, this 415/// routine will return the translation unit scope, since the 416/// enumeration's scope is a transparent context and structures cannot 417/// contain non-field names. 418Scope *Sema::getNonFieldDeclScope(Scope *S) { 419 while (((S->getFlags() & Scope::DeclScope) == 0) || 420 (S->getEntity() && 421 ((DeclContext *)S->getEntity())->isTransparentContext()) || 422 (S->isClassScope() && !getLangOptions().CPlusPlus)) 423 S = S->getParent(); 424 return S; 425} 426 427void Sema::InitBuiltinVaListType() { 428 if (!Context.getBuiltinVaListType().isNull()) 429 return; 430 431 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 432 NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName); 433 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 434 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 435} 436 437/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 438/// file scope. lazily create a decl for it. ForRedeclaration is true 439/// if we're creating this built-in in anticipation of redeclaring the 440/// built-in. 441NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 442 Scope *S, bool ForRedeclaration, 443 SourceLocation Loc) { 444 Builtin::ID BID = (Builtin::ID)bid; 445 446 if (Context.BuiltinInfo.hasVAListUse(BID)) 447 InitBuiltinVaListType(); 448 449 ASTContext::GetBuiltinTypeError Error; 450 QualType R = Context.GetBuiltinType(BID, Error); 451 switch (Error) { 452 case ASTContext::GE_None: 453 // Okay 454 break; 455 456 case ASTContext::GE_Missing_stdio: 457 if (ForRedeclaration) 458 Diag(Loc, diag::err_implicit_decl_requires_stdio) 459 << Context.BuiltinInfo.GetName(BID); 460 return 0; 461 462 case ASTContext::GE_Missing_setjmp: 463 if (ForRedeclaration) 464 Diag(Loc, diag::err_implicit_decl_requires_setjmp) 465 << Context.BuiltinInfo.GetName(BID); 466 return 0; 467 } 468 469 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 470 Diag(Loc, diag::ext_implicit_lib_function_decl) 471 << Context.BuiltinInfo.GetName(BID) 472 << R; 473 if (Context.BuiltinInfo.getHeaderName(BID) && 474 Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl) 475 != Diagnostic::Ignored) 476 Diag(Loc, diag::note_please_include_header) 477 << Context.BuiltinInfo.getHeaderName(BID) 478 << Context.BuiltinInfo.GetName(BID); 479 } 480 481 FunctionDecl *New = FunctionDecl::Create(Context, 482 Context.getTranslationUnitDecl(), 483 Loc, II, R, /*DInfo=*/0, 484 FunctionDecl::Extern, false, 485 /*hasPrototype=*/true); 486 New->setImplicit(); 487 488 // Create Decl objects for each parameter, adding them to the 489 // FunctionDecl. 490 if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) { 491 llvm::SmallVector<ParmVarDecl*, 16> Params; 492 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 493 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 494 FT->getArgType(i), /*DInfo=*/0, 495 VarDecl::None, 0)); 496 New->setParams(Context, Params.data(), Params.size()); 497 } 498 499 AddKnownFunctionAttributes(New); 500 501 // TUScope is the translation-unit scope to insert this function into. 502 // FIXME: This is hideous. We need to teach PushOnScopeChains to 503 // relate Scopes to DeclContexts, and probably eliminate CurContext 504 // entirely, but we're not there yet. 505 DeclContext *SavedContext = CurContext; 506 CurContext = Context.getTranslationUnitDecl(); 507 PushOnScopeChains(New, TUScope); 508 CurContext = SavedContext; 509 return New; 510} 511 512/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 513/// everything from the standard library is defined. 514NamespaceDecl *Sema::GetStdNamespace() { 515 if (!StdNamespace) { 516 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 517 DeclContext *Global = Context.getTranslationUnitDecl(); 518 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 519 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 520 } 521 return StdNamespace; 522} 523 524/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 525/// same name and scope as a previous declaration 'Old'. Figure out 526/// how to resolve this situation, merging decls or emitting 527/// diagnostics as appropriate. If there was an error, set New to be invalid. 528/// 529void Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 530 // If either decl is known invalid already, set the new one to be invalid and 531 // don't bother doing any merging checks. 532 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 533 return New->setInvalidDecl(); 534 535 // Allow multiple definitions for ObjC built-in typedefs. 536 // FIXME: Verify the underlying types are equivalent! 537 if (getLangOptions().ObjC1) { 538 const IdentifierInfo *TypeID = New->getIdentifier(); 539 switch (TypeID->getLength()) { 540 default: break; 541 case 2: 542 if (!TypeID->isStr("id")) 543 break; 544 Context.ObjCIdRedefinitionType = New->getUnderlyingType(); 545 // Install the built-in type for 'id', ignoring the current definition. 546 New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); 547 return; 548 case 5: 549 if (!TypeID->isStr("Class")) 550 break; 551 Context.ObjCClassRedefinitionType = New->getUnderlyingType(); 552 // Install the built-in type for 'Class', ignoring the current definition. 553 New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); 554 return; 555 case 3: 556 if (!TypeID->isStr("SEL")) 557 break; 558 Context.setObjCSelType(Context.getTypeDeclType(New)); 559 return; 560 case 8: 561 if (!TypeID->isStr("Protocol")) 562 break; 563 Context.setObjCProtoType(New->getUnderlyingType()); 564 return; 565 } 566 // Fall through - the typedef name was not a builtin type. 567 } 568 // Verify the old decl was also a type. 569 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 570 if (!Old) { 571 Diag(New->getLocation(), diag::err_redefinition_different_kind) 572 << New->getDeclName(); 573 if (OldD->getLocation().isValid()) 574 Diag(OldD->getLocation(), diag::note_previous_definition); 575 return New->setInvalidDecl(); 576 } 577 578 // Determine the "old" type we'll use for checking and diagnostics. 579 QualType OldType; 580 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 581 OldType = OldTypedef->getUnderlyingType(); 582 else 583 OldType = Context.getTypeDeclType(Old); 584 585 // If the typedef types are not identical, reject them in all languages and 586 // with any extensions enabled. 587 588 if (OldType != New->getUnderlyingType() && 589 Context.getCanonicalType(OldType) != 590 Context.getCanonicalType(New->getUnderlyingType())) { 591 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 592 << New->getUnderlyingType() << OldType; 593 if (Old->getLocation().isValid()) 594 Diag(Old->getLocation(), diag::note_previous_definition); 595 return New->setInvalidDecl(); 596 } 597 598 if (getLangOptions().Microsoft) 599 return; 600 601 // C++ [dcl.typedef]p2: 602 // In a given non-class scope, a typedef specifier can be used to 603 // redefine the name of any type declared in that scope to refer 604 // to the type to which it already refers. 605 if (getLangOptions().CPlusPlus) { 606 if (!isa<CXXRecordDecl>(CurContext)) 607 return; 608 Diag(New->getLocation(), diag::err_redefinition) 609 << New->getDeclName(); 610 Diag(Old->getLocation(), diag::note_previous_definition); 611 return New->setInvalidDecl(); 612 } 613 614 // If we have a redefinition of a typedef in C, emit a warning. This warning 615 // is normally mapped to an error, but can be controlled with 616 // -Wtypedef-redefinition. If either the original or the redefinition is 617 // in a system header, don't emit this for compatibility with GCC. 618 if (PP.getDiagnostics().getSuppressSystemWarnings() && 619 (Context.getSourceManager().isInSystemHeader(Old->getLocation()) || 620 Context.getSourceManager().isInSystemHeader(New->getLocation()))) 621 return; 622 623 Diag(New->getLocation(), diag::warn_redefinition_of_typedef) 624 << New->getDeclName(); 625 Diag(Old->getLocation(), diag::note_previous_definition); 626 return; 627} 628 629/// DeclhasAttr - returns true if decl Declaration already has the target 630/// attribute. 631static bool 632DeclHasAttr(const Decl *decl, const Attr *target) { 633 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 634 if (attr->getKind() == target->getKind()) 635 return true; 636 637 return false; 638} 639 640/// MergeAttributes - append attributes from the Old decl to the New one. 641static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) { 642 for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) { 643 if (!DeclHasAttr(New, attr) && attr->isMerged()) { 644 Attr *NewAttr = attr->clone(C); 645 NewAttr->setInherited(true); 646 New->addAttr(NewAttr); 647 } 648 } 649} 650 651/// Used in MergeFunctionDecl to keep track of function parameters in 652/// C. 653struct GNUCompatibleParamWarning { 654 ParmVarDecl *OldParm; 655 ParmVarDecl *NewParm; 656 QualType PromotedType; 657}; 658 659/// MergeFunctionDecl - We just parsed a function 'New' from 660/// declarator D which has the same name and scope as a previous 661/// declaration 'Old'. Figure out how to resolve this situation, 662/// merging decls or emitting diagnostics as appropriate. 663/// 664/// In C++, New and Old must be declarations that are not 665/// overloaded. Use IsOverload to determine whether New and Old are 666/// overloaded, and to select the Old declaration that New should be 667/// merged with. 668/// 669/// Returns true if there was an error, false otherwise. 670bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 671 assert(!isa<OverloadedFunctionDecl>(OldD) && 672 "Cannot merge with an overloaded function declaration"); 673 674 // Verify the old decl was also a function. 675 FunctionDecl *Old = 0; 676 if (FunctionTemplateDecl *OldFunctionTemplate 677 = dyn_cast<FunctionTemplateDecl>(OldD)) 678 Old = OldFunctionTemplate->getTemplatedDecl(); 679 else 680 Old = dyn_cast<FunctionDecl>(OldD); 681 if (!Old) { 682 Diag(New->getLocation(), diag::err_redefinition_different_kind) 683 << New->getDeclName(); 684 Diag(OldD->getLocation(), diag::note_previous_definition); 685 return true; 686 } 687 688 // Determine whether the previous declaration was a definition, 689 // implicit declaration, or a declaration. 690 diag::kind PrevDiag; 691 if (Old->isThisDeclarationADefinition()) 692 PrevDiag = diag::note_previous_definition; 693 else if (Old->isImplicit()) 694 PrevDiag = diag::note_previous_implicit_declaration; 695 else 696 PrevDiag = diag::note_previous_declaration; 697 698 QualType OldQType = Context.getCanonicalType(Old->getType()); 699 QualType NewQType = Context.getCanonicalType(New->getType()); 700 701 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 702 New->getStorageClass() == FunctionDecl::Static && 703 Old->getStorageClass() != FunctionDecl::Static) { 704 Diag(New->getLocation(), diag::err_static_non_static) 705 << New; 706 Diag(Old->getLocation(), PrevDiag); 707 return true; 708 } 709 710 if (getLangOptions().CPlusPlus) { 711 // (C++98 13.1p2): 712 // Certain function declarations cannot be overloaded: 713 // -- Function declarations that differ only in the return type 714 // cannot be overloaded. 715 QualType OldReturnType 716 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 717 QualType NewReturnType 718 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 719 if (OldReturnType != NewReturnType) { 720 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 721 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 722 return true; 723 } 724 725 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 726 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 727 if (OldMethod && NewMethod && 728 NewMethod->getLexicalDeclContext()->isRecord()) { 729 // -- Member function declarations with the same name and the 730 // same parameter types cannot be overloaded if any of them 731 // is a static member function declaration. 732 if (OldMethod->isStatic() || NewMethod->isStatic()) { 733 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 734 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 735 return true; 736 } 737 738 // C++ [class.mem]p1: 739 // [...] A member shall not be declared twice in the 740 // member-specification, except that a nested class or member 741 // class template can be declared and then later defined. 742 unsigned NewDiag; 743 if (isa<CXXConstructorDecl>(OldMethod)) 744 NewDiag = diag::err_constructor_redeclared; 745 else if (isa<CXXDestructorDecl>(NewMethod)) 746 NewDiag = diag::err_destructor_redeclared; 747 else if (isa<CXXConversionDecl>(NewMethod)) 748 NewDiag = diag::err_conv_function_redeclared; 749 else 750 NewDiag = diag::err_member_redeclared; 751 752 Diag(New->getLocation(), NewDiag); 753 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 754 } 755 756 // (C++98 8.3.5p3): 757 // All declarations for a function shall agree exactly in both the 758 // return type and the parameter-type-list. 759 if (OldQType == NewQType) 760 return MergeCompatibleFunctionDecls(New, Old); 761 762 // Fall through for conflicting redeclarations and redefinitions. 763 } 764 765 // C: Function types need to be compatible, not identical. This handles 766 // duplicate function decls like "void f(int); void f(enum X);" properly. 767 if (!getLangOptions().CPlusPlus && 768 Context.typesAreCompatible(OldQType, NewQType)) { 769 const FunctionType *OldFuncType = OldQType->getAsFunctionType(); 770 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 771 const FunctionProtoType *OldProto = 0; 772 if (isa<FunctionNoProtoType>(NewFuncType) && 773 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) { 774 // The old declaration provided a function prototype, but the 775 // new declaration does not. Merge in the prototype. 776 assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); 777 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 778 OldProto->arg_type_end()); 779 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 780 ParamTypes.data(), ParamTypes.size(), 781 OldProto->isVariadic(), 782 OldProto->getTypeQuals()); 783 New->setType(NewQType); 784 New->setHasInheritedPrototype(); 785 786 // Synthesize a parameter for each argument type. 787 llvm::SmallVector<ParmVarDecl*, 16> Params; 788 for (FunctionProtoType::arg_type_iterator 789 ParamType = OldProto->arg_type_begin(), 790 ParamEnd = OldProto->arg_type_end(); 791 ParamType != ParamEnd; ++ParamType) { 792 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 793 SourceLocation(), 0, 794 *ParamType, /*DInfo=*/0, 795 VarDecl::None, 0); 796 Param->setImplicit(); 797 Params.push_back(Param); 798 } 799 800 New->setParams(Context, Params.data(), Params.size()); 801 } 802 803 return MergeCompatibleFunctionDecls(New, Old); 804 } 805 806 // GNU C permits a K&R definition to follow a prototype declaration 807 // if the declared types of the parameters in the K&R definition 808 // match the types in the prototype declaration, even when the 809 // promoted types of the parameters from the K&R definition differ 810 // from the types in the prototype. GCC then keeps the types from 811 // the prototype. 812 // 813 // If a variadic prototype is followed by a non-variadic K&R definition, 814 // the K&R definition becomes variadic. This is sort of an edge case, but 815 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and 816 // C99 6.9.1p8. 817 if (!getLangOptions().CPlusPlus && 818 Old->hasPrototype() && !New->hasPrototype() && 819 New->getType()->getAsFunctionProtoType() && 820 Old->getNumParams() == New->getNumParams()) { 821 llvm::SmallVector<QualType, 16> ArgTypes; 822 llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings; 823 const FunctionProtoType *OldProto 824 = Old->getType()->getAsFunctionProtoType(); 825 const FunctionProtoType *NewProto 826 = New->getType()->getAsFunctionProtoType(); 827 828 // Determine whether this is the GNU C extension. 829 QualType MergedReturn = Context.mergeTypes(OldProto->getResultType(), 830 NewProto->getResultType()); 831 bool LooseCompatible = !MergedReturn.isNull(); 832 for (unsigned Idx = 0, End = Old->getNumParams(); 833 LooseCompatible && Idx != End; ++Idx) { 834 ParmVarDecl *OldParm = Old->getParamDecl(Idx); 835 ParmVarDecl *NewParm = New->getParamDecl(Idx); 836 if (Context.typesAreCompatible(OldParm->getType(), 837 NewProto->getArgType(Idx))) { 838 ArgTypes.push_back(NewParm->getType()); 839 } else if (Context.typesAreCompatible(OldParm->getType(), 840 NewParm->getType())) { 841 GNUCompatibleParamWarning Warn 842 = { OldParm, NewParm, NewProto->getArgType(Idx) }; 843 Warnings.push_back(Warn); 844 ArgTypes.push_back(NewParm->getType()); 845 } else 846 LooseCompatible = false; 847 } 848 849 if (LooseCompatible) { 850 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { 851 Diag(Warnings[Warn].NewParm->getLocation(), 852 diag::ext_param_promoted_not_compatible_with_prototype) 853 << Warnings[Warn].PromotedType 854 << Warnings[Warn].OldParm->getType(); 855 Diag(Warnings[Warn].OldParm->getLocation(), 856 diag::note_previous_declaration); 857 } 858 859 New->setType(Context.getFunctionType(MergedReturn, &ArgTypes[0], 860 ArgTypes.size(), 861 OldProto->isVariadic(), 0)); 862 return MergeCompatibleFunctionDecls(New, Old); 863 } 864 865 // Fall through to diagnose conflicting types. 866 } 867 868 // A function that has already been declared has been redeclared or defined 869 // with a different type- show appropriate diagnostic 870 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 871 // The user has declared a builtin function with an incompatible 872 // signature. 873 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 874 // The function the user is redeclaring is a library-defined 875 // function like 'malloc' or 'printf'. Warn about the 876 // redeclaration, then pretend that we don't know about this 877 // library built-in. 878 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 879 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 880 << Old << Old->getType(); 881 New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin); 882 Old->setInvalidDecl(); 883 return false; 884 } 885 886 PrevDiag = diag::note_previous_builtin_declaration; 887 } 888 889 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 890 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 891 return true; 892} 893 894/// \brief Completes the merge of two function declarations that are 895/// known to be compatible. 896/// 897/// This routine handles the merging of attributes and other 898/// properties of function declarations form the old declaration to 899/// the new declaration, once we know that New is in fact a 900/// redeclaration of Old. 901/// 902/// \returns false 903bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 904 // Merge the attributes 905 MergeAttributes(New, Old, Context); 906 907 // Merge the storage class. 908 if (Old->getStorageClass() != FunctionDecl::Extern) 909 New->setStorageClass(Old->getStorageClass()); 910 911 // Merge "inline" 912 if (Old->isInline()) 913 New->setInline(true); 914 915 // If this function declaration by itself qualifies as a C99 inline 916 // definition (C99 6.7.4p6), but the previous definition did not, 917 // then the function is not a C99 inline definition. 918 if (New->isC99InlineDefinition() && !Old->isC99InlineDefinition()) 919 New->setC99InlineDefinition(false); 920 else if (Old->isC99InlineDefinition() && !New->isC99InlineDefinition()) { 921 // Mark all preceding definitions as not being C99 inline definitions. 922 for (const FunctionDecl *Prev = Old; Prev; 923 Prev = Prev->getPreviousDeclaration()) 924 const_cast<FunctionDecl *>(Prev)->setC99InlineDefinition(false); 925 } 926 927 // Merge "pure" flag. 928 if (Old->isPure()) 929 New->setPure(); 930 931 // Merge the "deleted" flag. 932 if (Old->isDeleted()) 933 New->setDeleted(); 934 935 if (getLangOptions().CPlusPlus) 936 return MergeCXXFunctionDecl(New, Old); 937 938 return false; 939} 940 941/// MergeVarDecl - We just parsed a variable 'New' which has the same name 942/// and scope as a previous declaration 'Old'. Figure out how to resolve this 943/// situation, merging decls or emitting diagnostics as appropriate. 944/// 945/// Tentative definition rules (C99 6.9.2p2) are checked by 946/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 947/// definitions here, since the initializer hasn't been attached. 948/// 949void Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 950 // If either decl is invalid, make sure the new one is marked invalid and 951 // don't do any other checking. 952 if (New->isInvalidDecl() || OldD->isInvalidDecl()) 953 return New->setInvalidDecl(); 954 955 // Verify the old decl was also a variable. 956 VarDecl *Old = dyn_cast<VarDecl>(OldD); 957 if (!Old) { 958 Diag(New->getLocation(), diag::err_redefinition_different_kind) 959 << New->getDeclName(); 960 Diag(OldD->getLocation(), diag::note_previous_definition); 961 return New->setInvalidDecl(); 962 } 963 964 MergeAttributes(New, Old, Context); 965 966 // Merge the types 967 QualType MergedT; 968 if (getLangOptions().CPlusPlus) { 969 if (Context.hasSameType(New->getType(), Old->getType())) 970 MergedT = New->getType(); 971 } else { 972 MergedT = Context.mergeTypes(New->getType(), Old->getType()); 973 } 974 if (MergedT.isNull()) { 975 Diag(New->getLocation(), diag::err_redefinition_different_type) 976 << New->getDeclName(); 977 Diag(Old->getLocation(), diag::note_previous_definition); 978 return New->setInvalidDecl(); 979 } 980 New->setType(MergedT); 981 982 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 983 if (New->getStorageClass() == VarDecl::Static && 984 (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) { 985 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 986 Diag(Old->getLocation(), diag::note_previous_definition); 987 return New->setInvalidDecl(); 988 } 989 // C99 6.2.2p4: 990 // For an identifier declared with the storage-class specifier 991 // extern in a scope in which a prior declaration of that 992 // identifier is visible,23) if the prior declaration specifies 993 // internal or external linkage, the linkage of the identifier at 994 // the later declaration is the same as the linkage specified at 995 // the prior declaration. If no prior declaration is visible, or 996 // if the prior declaration specifies no linkage, then the 997 // identifier has external linkage. 998 if (New->hasExternalStorage() && Old->hasLinkage()) 999 /* Okay */; 1000 else if (New->getStorageClass() != VarDecl::Static && 1001 Old->getStorageClass() == VarDecl::Static) { 1002 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 1003 Diag(Old->getLocation(), diag::note_previous_definition); 1004 return New->setInvalidDecl(); 1005 } 1006 1007 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 1008 1009 // FIXME: The test for external storage here seems wrong? We still 1010 // need to check for mismatches. 1011 if (!New->hasExternalStorage() && !New->isFileVarDecl() && 1012 // Don't complain about out-of-line definitions of static members. 1013 !(Old->getLexicalDeclContext()->isRecord() && 1014 !New->getLexicalDeclContext()->isRecord())) { 1015 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 1016 Diag(Old->getLocation(), diag::note_previous_definition); 1017 return New->setInvalidDecl(); 1018 } 1019 1020 if (New->isThreadSpecified() && !Old->isThreadSpecified()) { 1021 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); 1022 Diag(Old->getLocation(), diag::note_previous_definition); 1023 } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) { 1024 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); 1025 Diag(Old->getLocation(), diag::note_previous_definition); 1026 } 1027 1028 // Keep a chain of previous declarations. 1029 New->setPreviousDeclaration(Old); 1030} 1031 1032/// CheckFallThrough - Check that we don't fall off the end of a 1033/// Statement that should return a value. 1034/// 1035/// \returns AlwaysFallThrough iff we always fall off the end of the statement, 1036/// MaybeFallThrough iff we might or might not fall off the end and 1037/// NeverFallThrough iff we never fall off the end of the statement. We assume 1038/// that functions not marked noreturn will return. 1039Sema::ControlFlowKind Sema::CheckFallThrough(Stmt *Root) { 1040 llvm::OwningPtr<CFG> cfg (CFG::buildCFG(Root, &Context)); 1041 1042 // FIXME: They should never return 0, fix that, delete this code. 1043 if (cfg == 0) 1044 return NeverFallThrough; 1045 // The CFG leaves in dead things, and we don't want to dead code paths to 1046 // confuse us, so we mark all live things first. 1047 std::queue<CFGBlock*> workq; 1048 llvm::BitVector live(cfg->getNumBlockIDs()); 1049 // Prep work queue 1050 workq.push(&cfg->getEntry()); 1051 // Solve 1052 while (!workq.empty()) { 1053 CFGBlock *item = workq.front(); 1054 workq.pop(); 1055 live.set(item->getBlockID()); 1056 for (CFGBlock::succ_iterator I=item->succ_begin(), 1057 E=item->succ_end(); 1058 I != E; 1059 ++I) { 1060 if ((*I) && !live[(*I)->getBlockID()]) { 1061 live.set((*I)->getBlockID()); 1062 workq.push(*I); 1063 } 1064 } 1065 } 1066 1067 // Now we know what is live, we check the live precessors of the exit block 1068 // and look for fall through paths, being careful to ignore normal returns, 1069 // and exceptional paths. 1070 bool HasLiveReturn = false; 1071 bool HasFakeEdge = false; 1072 bool HasPlainEdge = false; 1073 for (CFGBlock::succ_iterator I=cfg->getExit().pred_begin(), 1074 E = cfg->getExit().pred_end(); 1075 I != E; 1076 ++I) { 1077 CFGBlock& B = **I; 1078 if (!live[B.getBlockID()]) 1079 continue; 1080 if (B.size() == 0) { 1081 // A labeled empty statement, or the entry block... 1082 HasPlainEdge = true; 1083 continue; 1084 } 1085 Stmt *S = B[B.size()-1]; 1086 if (isa<ReturnStmt>(S)) { 1087 HasLiveReturn = true; 1088 continue; 1089 } 1090 if (isa<ObjCAtThrowStmt>(S)) { 1091 HasFakeEdge = true; 1092 continue; 1093 } 1094 if (isa<CXXThrowExpr>(S)) { 1095 HasFakeEdge = true; 1096 continue; 1097 } 1098 bool NoReturnEdge = false; 1099 if (CallExpr *C = dyn_cast<CallExpr>(S)) { 1100 Expr *CEE = C->getCallee()->IgnoreParenCasts(); 1101 if (CEE->getType().getNoReturnAttr()) { 1102 NoReturnEdge = true; 1103 HasFakeEdge = true; 1104 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) { 1105 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 1106 if (FD->hasAttr<NoReturnAttr>()) { 1107 NoReturnEdge = true; 1108 HasFakeEdge = true; 1109 } 1110 } 1111 } 1112 } 1113 // FIXME: Add noreturn message sends. 1114 if (NoReturnEdge == false) 1115 HasPlainEdge = true; 1116 } 1117 if (!HasPlainEdge) 1118 return NeverFallThrough; 1119 if (HasFakeEdge || HasLiveReturn) 1120 return MaybeFallThrough; 1121 // This says AlwaysFallThrough for calls to functions that are not marked 1122 // noreturn, that don't return. If people would like this warning to be more 1123 // accurate, such functions should be marked as noreturn. 1124 return AlwaysFallThrough; 1125} 1126 1127/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a 1128/// function that should return a value. Check that we don't fall off the end 1129/// of a noreturn function. We assume that functions and blocks not marked 1130/// noreturn will return. 1131void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body) { 1132 // FIXME: Would be nice if we had a better way to control cascading errors, 1133 // but for now, avoid them. The problem is that when Parse sees: 1134 // int foo() { return a; } 1135 // The return is eaten and the Sema code sees just: 1136 // int foo() { } 1137 // which this code would then warn about. 1138 if (getDiagnostics().hasErrorOccurred()) 1139 return; 1140 bool ReturnsVoid = false; 1141 bool HasNoReturn = false; 1142 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1143 if (FD->getResultType()->isVoidType()) 1144 ReturnsVoid = true; 1145 if (FD->hasAttr<NoReturnAttr>()) 1146 HasNoReturn = true; 1147 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 1148 if (MD->getResultType()->isVoidType()) 1149 ReturnsVoid = true; 1150 if (MD->hasAttr<NoReturnAttr>()) 1151 HasNoReturn = true; 1152 } 1153 1154 // Short circuit for compilation speed. 1155 if ((Diags.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function) 1156 == Diagnostic::Ignored || ReturnsVoid) 1157 && (Diags.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr) 1158 == Diagnostic::Ignored || !HasNoReturn) 1159 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1160 == Diagnostic::Ignored || !ReturnsVoid)) 1161 return; 1162 // FIXME: Funtion try block 1163 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1164 switch (CheckFallThrough(Body)) { 1165 case MaybeFallThrough: 1166 if (HasNoReturn) 1167 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1168 else if (!ReturnsVoid) 1169 Diag(Compound->getRBracLoc(),diag::warn_maybe_falloff_nonvoid_function); 1170 break; 1171 case AlwaysFallThrough: 1172 if (HasNoReturn) 1173 Diag(Compound->getRBracLoc(), diag::warn_falloff_noreturn_function); 1174 else if (!ReturnsVoid) 1175 Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function); 1176 break; 1177 case NeverFallThrough: 1178 if (ReturnsVoid) 1179 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function); 1180 break; 1181 } 1182 } 1183} 1184 1185/// CheckFallThroughForBlock - Check that we don't fall off the end of a block 1186/// that should return a value. Check that we don't fall off the end of a 1187/// noreturn block. We assume that functions and blocks not marked noreturn 1188/// will return. 1189void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body) { 1190 // FIXME: Would be nice if we had a better way to control cascading errors, 1191 // but for now, avoid them. The problem is that when Parse sees: 1192 // int foo() { return a; } 1193 // The return is eaten and the Sema code sees just: 1194 // int foo() { } 1195 // which this code would then warn about. 1196 if (getDiagnostics().hasErrorOccurred()) 1197 return; 1198 bool ReturnsVoid = false; 1199 bool HasNoReturn = false; 1200 if (const FunctionType *FT = BlockTy->getPointeeType()->getAsFunctionType()) { 1201 if (FT->getResultType()->isVoidType()) 1202 ReturnsVoid = true; 1203 if (FT->getNoReturnAttr()) 1204 HasNoReturn = true; 1205 } 1206 1207 // Short circuit for compilation speed. 1208 if (ReturnsVoid 1209 && !HasNoReturn 1210 && (Diags.getDiagnosticLevel(diag::warn_suggest_noreturn_block) 1211 == Diagnostic::Ignored || !ReturnsVoid)) 1212 return; 1213 // FIXME: Funtion try block 1214 if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { 1215 switch (CheckFallThrough(Body)) { 1216 case MaybeFallThrough: 1217 if (HasNoReturn) 1218 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1219 else if (!ReturnsVoid) 1220 Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block); 1221 break; 1222 case AlwaysFallThrough: 1223 if (HasNoReturn) 1224 Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr); 1225 else if (!ReturnsVoid) 1226 Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block); 1227 break; 1228 case NeverFallThrough: 1229 if (ReturnsVoid) 1230 Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block); 1231 break; 1232 } 1233 } 1234} 1235 1236/// CheckParmsForFunctionDef - Check that the parameters of the given 1237/// function are appropriate for the definition of a function. This 1238/// takes care of any checks that cannot be performed on the 1239/// declaration itself, e.g., that the types of each of the function 1240/// parameters are complete. 1241bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 1242 bool HasInvalidParm = false; 1243 1244 // PIC16 uses section string to encode the info about ISR. 1245 // Flash error if ISR has arguments. 1246 const char *TargetPrefix = Context.Target.getTargetPrefix(); 1247 if (strcmp(TargetPrefix, "pic16") == 0) { 1248 unsigned ParamCount = FD->getNumParams(); 1249 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) { 1250 const std::string &SecString = SA->getName(); 1251 if (SecString.find("interrupt") != std::string::npos 1252 && ParamCount > 0) { 1253 Diag(FD->getLocation(), diag::warn_ISR_has_arguments) 1254 << FD->getNameAsString(); 1255 } 1256 } 1257 } 1258 1259 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1260 ParmVarDecl *Param = FD->getParamDecl(p); 1261 1262 // C99 6.7.5.3p4: the parameters in a parameter type list in a 1263 // function declarator that is part of a function definition of 1264 // that function shall not have incomplete type. 1265 // 1266 // This is also C++ [dcl.fct]p6. 1267 if (!Param->isInvalidDecl() && 1268 RequireCompleteType(Param->getLocation(), Param->getType(), 1269 diag::err_typecheck_decl_incomplete_type)) { 1270 Param->setInvalidDecl(); 1271 HasInvalidParm = true; 1272 } 1273 1274 // C99 6.9.1p5: If the declarator includes a parameter type list, the 1275 // declaration of each parameter shall include an identifier. 1276 if (Param->getIdentifier() == 0 && 1277 !Param->isImplicit() && 1278 !getLangOptions().CPlusPlus) 1279 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 1280 } 1281 1282 return HasInvalidParm; 1283} 1284 1285/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 1286/// no declarator (e.g. "struct foo;") is parsed. 1287Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 1288 // FIXME: Error on auto/register at file scope 1289 // FIXME: Error on inline/virtual/explicit 1290 // FIXME: Error on invalid restrict 1291 // FIXME: Warn on useless __thread 1292 // FIXME: Warn on useless const/volatile 1293 // FIXME: Warn on useless static/extern/typedef/private_extern/mutable 1294 // FIXME: Warn on useless attributes 1295 TagDecl *Tag = 0; 1296 if (DS.getTypeSpecType() == DeclSpec::TST_class || 1297 DS.getTypeSpecType() == DeclSpec::TST_struct || 1298 DS.getTypeSpecType() == DeclSpec::TST_union || 1299 DS.getTypeSpecType() == DeclSpec::TST_enum) { 1300 if (!DS.getTypeRep()) // We probably had an error 1301 return DeclPtrTy(); 1302 1303 // Note that the above type specs guarantee that the 1304 // type rep is a Decl, whereas in many of the others 1305 // it's a Type. 1306 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 1307 } 1308 1309 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 1310 if (!Record->getDeclName() && Record->isDefinition() && 1311 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { 1312 if (getLangOptions().CPlusPlus || 1313 Record->getDeclContext()->isRecord()) 1314 return BuildAnonymousStructOrUnion(S, DS, Record); 1315 1316 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1317 << DS.getSourceRange(); 1318 } 1319 1320 // Microsoft allows unnamed struct/union fields. Don't complain 1321 // about them. 1322 // FIXME: Should we support Microsoft's extensions in this area? 1323 if (Record->getDeclName() && getLangOptions().Microsoft) 1324 return DeclPtrTy::make(Tag); 1325 } 1326 1327 if (!DS.isMissingDeclaratorOk() && 1328 DS.getTypeSpecType() != DeclSpec::TST_error) { 1329 // Warn about typedefs of enums without names, since this is an 1330 // extension in both Microsoft an GNU. 1331 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 1332 Tag && isa<EnumDecl>(Tag)) { 1333 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 1334 << DS.getSourceRange(); 1335 return DeclPtrTy::make(Tag); 1336 } 1337 1338 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 1339 << DS.getSourceRange(); 1340 return DeclPtrTy(); 1341 } 1342 1343 return DeclPtrTy::make(Tag); 1344} 1345 1346/// InjectAnonymousStructOrUnionMembers - Inject the members of the 1347/// anonymous struct or union AnonRecord into the owning context Owner 1348/// and scope S. This routine will be invoked just after we realize 1349/// that an unnamed union or struct is actually an anonymous union or 1350/// struct, e.g., 1351/// 1352/// @code 1353/// union { 1354/// int i; 1355/// float f; 1356/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 1357/// // f into the surrounding scope.x 1358/// @endcode 1359/// 1360/// This routine is recursive, injecting the names of nested anonymous 1361/// structs/unions into the owning context and scope as well. 1362bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 1363 RecordDecl *AnonRecord) { 1364 bool Invalid = false; 1365 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 1366 FEnd = AnonRecord->field_end(); 1367 F != FEnd; ++F) { 1368 if ((*F)->getDeclName()) { 1369 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 1370 LookupOrdinaryName, true); 1371 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 1372 // C++ [class.union]p2: 1373 // The names of the members of an anonymous union shall be 1374 // distinct from the names of any other entity in the 1375 // scope in which the anonymous union is declared. 1376 unsigned diagKind 1377 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 1378 : diag::err_anonymous_struct_member_redecl; 1379 Diag((*F)->getLocation(), diagKind) 1380 << (*F)->getDeclName(); 1381 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 1382 Invalid = true; 1383 } else { 1384 // C++ [class.union]p2: 1385 // For the purpose of name lookup, after the anonymous union 1386 // definition, the members of the anonymous union are 1387 // considered to have been defined in the scope in which the 1388 // anonymous union is declared. 1389 Owner->makeDeclVisibleInContext(*F); 1390 S->AddDecl(DeclPtrTy::make(*F)); 1391 IdResolver.AddDecl(*F); 1392 } 1393 } else if (const RecordType *InnerRecordType 1394 = (*F)->getType()->getAs<RecordType>()) { 1395 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 1396 if (InnerRecord->isAnonymousStructOrUnion()) 1397 Invalid = Invalid || 1398 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 1399 } 1400 } 1401 1402 return Invalid; 1403} 1404 1405/// ActOnAnonymousStructOrUnion - Handle the declaration of an 1406/// anonymous structure or union. Anonymous unions are a C++ feature 1407/// (C++ [class.union]) and a GNU C extension; anonymous structures 1408/// are a GNU C and GNU C++ extension. 1409Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 1410 RecordDecl *Record) { 1411 DeclContext *Owner = Record->getDeclContext(); 1412 1413 // Diagnose whether this anonymous struct/union is an extension. 1414 if (Record->isUnion() && !getLangOptions().CPlusPlus) 1415 Diag(Record->getLocation(), diag::ext_anonymous_union); 1416 else if (!Record->isUnion()) 1417 Diag(Record->getLocation(), diag::ext_anonymous_struct); 1418 1419 // C and C++ require different kinds of checks for anonymous 1420 // structs/unions. 1421 bool Invalid = false; 1422 if (getLangOptions().CPlusPlus) { 1423 const char* PrevSpec = 0; 1424 unsigned DiagID; 1425 // C++ [class.union]p3: 1426 // Anonymous unions declared in a named namespace or in the 1427 // global namespace shall be declared static. 1428 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 1429 (isa<TranslationUnitDecl>(Owner) || 1430 (isa<NamespaceDecl>(Owner) && 1431 cast<NamespaceDecl>(Owner)->getDeclName()))) { 1432 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 1433 Invalid = true; 1434 1435 // Recover by adding 'static'. 1436 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), 1437 PrevSpec, DiagID); 1438 } 1439 // C++ [class.union]p3: 1440 // A storage class is not allowed in a declaration of an 1441 // anonymous union in a class scope. 1442 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1443 isa<RecordDecl>(Owner)) { 1444 Diag(DS.getStorageClassSpecLoc(), 1445 diag::err_anonymous_union_with_storage_spec); 1446 Invalid = true; 1447 1448 // Recover by removing the storage specifier. 1449 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 1450 PrevSpec, DiagID); 1451 } 1452 1453 // C++ [class.union]p2: 1454 // The member-specification of an anonymous union shall only 1455 // define non-static data members. [Note: nested types and 1456 // functions cannot be declared within an anonymous union. ] 1457 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 1458 MemEnd = Record->decls_end(); 1459 Mem != MemEnd; ++Mem) { 1460 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 1461 // C++ [class.union]p3: 1462 // An anonymous union shall not have private or protected 1463 // members (clause 11). 1464 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 1465 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 1466 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 1467 Invalid = true; 1468 } 1469 } else if ((*Mem)->isImplicit()) { 1470 // Any implicit members are fine. 1471 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1472 // This is a type that showed up in an 1473 // elaborated-type-specifier inside the anonymous struct or 1474 // union, but which actually declares a type outside of the 1475 // anonymous struct or union. It's okay. 1476 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1477 if (!MemRecord->isAnonymousStructOrUnion() && 1478 MemRecord->getDeclName()) { 1479 // This is a nested type declaration. 1480 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1481 << (int)Record->isUnion(); 1482 Invalid = true; 1483 } 1484 } else { 1485 // We have something that isn't a non-static data 1486 // member. Complain about it. 1487 unsigned DK = diag::err_anonymous_record_bad_member; 1488 if (isa<TypeDecl>(*Mem)) 1489 DK = diag::err_anonymous_record_with_type; 1490 else if (isa<FunctionDecl>(*Mem)) 1491 DK = diag::err_anonymous_record_with_function; 1492 else if (isa<VarDecl>(*Mem)) 1493 DK = diag::err_anonymous_record_with_static; 1494 Diag((*Mem)->getLocation(), DK) 1495 << (int)Record->isUnion(); 1496 Invalid = true; 1497 } 1498 } 1499 } 1500 1501 if (!Record->isUnion() && !Owner->isRecord()) { 1502 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1503 << (int)getLangOptions().CPlusPlus; 1504 Invalid = true; 1505 } 1506 1507 // Create a declaration for this anonymous struct/union. 1508 NamedDecl *Anon = 0; 1509 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1510 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1511 /*IdentifierInfo=*/0, 1512 Context.getTypeDeclType(Record), /*DInfo=*/0, 1513 /*BitWidth=*/0, /*Mutable=*/false, 1514 DS.getSourceRange().getBegin()); 1515 Anon->setAccess(AS_public); 1516 if (getLangOptions().CPlusPlus) 1517 FieldCollector->Add(cast<FieldDecl>(Anon)); 1518 } else { 1519 VarDecl::StorageClass SC; 1520 switch (DS.getStorageClassSpec()) { 1521 default: assert(0 && "Unknown storage class!"); 1522 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1523 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1524 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1525 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1526 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1527 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1528 case DeclSpec::SCS_mutable: 1529 // mutable can only appear on non-static class members, so it's always 1530 // an error here 1531 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1532 Invalid = true; 1533 SC = VarDecl::None; 1534 break; 1535 } 1536 1537 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1538 /*IdentifierInfo=*/0, 1539 Context.getTypeDeclType(Record), /*DInfo=*/0, 1540 SC, DS.getSourceRange().getBegin()); 1541 } 1542 Anon->setImplicit(); 1543 1544 // Add the anonymous struct/union object to the current 1545 // context. We'll be referencing this object when we refer to one of 1546 // its members. 1547 Owner->addDecl(Anon); 1548 1549 // Inject the members of the anonymous struct/union into the owning 1550 // context and into the identifier resolver chain for name lookup 1551 // purposes. 1552 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1553 Invalid = true; 1554 1555 // Mark this as an anonymous struct/union type. Note that we do not 1556 // do this until after we have already checked and injected the 1557 // members of this anonymous struct/union type, because otherwise 1558 // the members could be injected twice: once by DeclContext when it 1559 // builds its lookup table, and once by 1560 // InjectAnonymousStructOrUnionMembers. 1561 Record->setAnonymousStructOrUnion(true); 1562 1563 if (Invalid) 1564 Anon->setInvalidDecl(); 1565 1566 return DeclPtrTy::make(Anon); 1567} 1568 1569 1570/// GetNameForDeclarator - Determine the full declaration name for the 1571/// given Declarator. 1572DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1573 switch (D.getKind()) { 1574 case Declarator::DK_Abstract: 1575 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1576 return DeclarationName(); 1577 1578 case Declarator::DK_Normal: 1579 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1580 return DeclarationName(D.getIdentifier()); 1581 1582 case Declarator::DK_Constructor: { 1583 QualType Ty = GetTypeFromParser(D.getDeclaratorIdType()); 1584 return Context.DeclarationNames.getCXXConstructorName( 1585 Context.getCanonicalType(Ty)); 1586 } 1587 1588 case Declarator::DK_Destructor: { 1589 QualType Ty = GetTypeFromParser(D.getDeclaratorIdType()); 1590 return Context.DeclarationNames.getCXXDestructorName( 1591 Context.getCanonicalType(Ty)); 1592 } 1593 1594 case Declarator::DK_Conversion: { 1595 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1596 QualType Ty = GetTypeFromParser(D.getDeclaratorIdType()); 1597 return Context.DeclarationNames.getCXXConversionFunctionName( 1598 Context.getCanonicalType(Ty)); 1599 } 1600 1601 case Declarator::DK_Operator: 1602 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1603 return Context.DeclarationNames.getCXXOperatorName( 1604 D.getOverloadedOperator()); 1605 } 1606 1607 assert(false && "Unknown name kind"); 1608 return DeclarationName(); 1609} 1610 1611/// isNearlyMatchingFunction - Determine whether the C++ functions 1612/// Declaration and Definition are "nearly" matching. This heuristic 1613/// is used to improve diagnostics in the case where an out-of-line 1614/// function definition doesn't match any declaration within 1615/// the class or namespace. 1616static bool isNearlyMatchingFunction(ASTContext &Context, 1617 FunctionDecl *Declaration, 1618 FunctionDecl *Definition) { 1619 if (Declaration->param_size() != Definition->param_size()) 1620 return false; 1621 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1622 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1623 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1624 1625 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1626 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1627 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1628 return false; 1629 } 1630 1631 return true; 1632} 1633 1634Sema::DeclPtrTy 1635Sema::HandleDeclarator(Scope *S, Declarator &D, 1636 MultiTemplateParamsArg TemplateParamLists, 1637 bool IsFunctionDefinition) { 1638 DeclarationName Name = GetNameForDeclarator(D); 1639 1640 // All of these full declarators require an identifier. If it doesn't have 1641 // one, the ParsedFreeStandingDeclSpec action should be used. 1642 if (!Name) { 1643 if (!D.isInvalidType()) // Reject this if we think it is valid. 1644 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1645 diag::err_declarator_need_ident) 1646 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1647 return DeclPtrTy(); 1648 } 1649 1650 // The scope passed in may not be a decl scope. Zip up the scope tree until 1651 // we find one that is. 1652 while ((S->getFlags() & Scope::DeclScope) == 0 || 1653 (S->getFlags() & Scope::TemplateParamScope) != 0) 1654 S = S->getParent(); 1655 1656 // If this is an out-of-line definition of a member of a class template 1657 // or class template partial specialization, we may need to rebuild the 1658 // type specifier in the declarator. See RebuildTypeInCurrentInstantiation() 1659 // for more information. 1660 // FIXME: cope with decltype(expr) and typeof(expr) once the rebuilder can 1661 // handle expressions properly. 1662 DeclSpec &DS = const_cast<DeclSpec&>(D.getDeclSpec()); 1663 if (D.getCXXScopeSpec().isSet() && !D.getCXXScopeSpec().isInvalid() && 1664 isDependentScopeSpecifier(D.getCXXScopeSpec()) && 1665 (DS.getTypeSpecType() == DeclSpec::TST_typename || 1666 DS.getTypeSpecType() == DeclSpec::TST_typeofType || 1667 DS.getTypeSpecType() == DeclSpec::TST_typeofExpr || 1668 DS.getTypeSpecType() == DeclSpec::TST_decltype)) { 1669 if (DeclContext *DC = computeDeclContext(D.getCXXScopeSpec(), true)) { 1670 // FIXME: Preserve type source info. 1671 QualType T = GetTypeFromParser(DS.getTypeRep()); 1672 EnterDeclaratorContext(S, DC); 1673 T = RebuildTypeInCurrentInstantiation(T, D.getIdentifierLoc(), Name); 1674 ExitDeclaratorContext(S); 1675 if (T.isNull()) 1676 return DeclPtrTy(); 1677 DS.UpdateTypeRep(T.getAsOpaquePtr()); 1678 } 1679 } 1680 1681 DeclContext *DC; 1682 NamedDecl *PrevDecl; 1683 NamedDecl *New; 1684 1685 DeclaratorInfo *DInfo = 0; 1686 QualType R = GetTypeForDeclarator(D, S, &DInfo); 1687 1688 // See if this is a redefinition of a variable in the same scope. 1689 if (D.getCXXScopeSpec().isInvalid()) { 1690 DC = CurContext; 1691 PrevDecl = 0; 1692 D.setInvalidType(); 1693 } else if (!D.getCXXScopeSpec().isSet()) { 1694 LookupNameKind NameKind = LookupOrdinaryName; 1695 1696 // If the declaration we're planning to build will be a function 1697 // or object with linkage, then look for another declaration with 1698 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1699 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1700 /* Do nothing*/; 1701 else if (R->isFunctionType()) { 1702 if (CurContext->isFunctionOrMethod() || 1703 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1704 NameKind = LookupRedeclarationWithLinkage; 1705 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1706 NameKind = LookupRedeclarationWithLinkage; 1707 else if (CurContext->getLookupContext()->isTranslationUnit() && 1708 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) 1709 NameKind = LookupRedeclarationWithLinkage; 1710 1711 DC = CurContext; 1712 PrevDecl = LookupName(S, Name, NameKind, true, 1713 NameKind == LookupRedeclarationWithLinkage, 1714 D.getIdentifierLoc()); 1715 } else { // Something like "int foo::x;" 1716 DC = computeDeclContext(D.getCXXScopeSpec(), true); 1717 // FIXME: RequireCompleteDeclContext(D.getCXXScopeSpec()); ? 1718 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1719 1720 // C++ 7.3.1.2p2: 1721 // Members (including explicit specializations of templates) of a named 1722 // namespace can also be defined outside that namespace by explicit 1723 // qualification of the name being defined, provided that the entity being 1724 // defined was already declared in the namespace and the definition appears 1725 // after the point of declaration in a namespace that encloses the 1726 // declarations namespace. 1727 // 1728 // Note that we only check the context at this point. We don't yet 1729 // have enough information to make sure that PrevDecl is actually 1730 // the declaration we want to match. For example, given: 1731 // 1732 // class X { 1733 // void f(); 1734 // void f(float); 1735 // }; 1736 // 1737 // void X::f(int) { } // ill-formed 1738 // 1739 // In this case, PrevDecl will point to the overload set 1740 // containing the two f's declared in X, but neither of them 1741 // matches. 1742 1743 // First check whether we named the global scope. 1744 if (isa<TranslationUnitDecl>(DC)) { 1745 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1746 << Name << D.getCXXScopeSpec().getRange(); 1747 } else if (!CurContext->Encloses(DC)) { 1748 // The qualifying scope doesn't enclose the original declaration. 1749 // Emit diagnostic based on current scope. 1750 SourceLocation L = D.getIdentifierLoc(); 1751 SourceRange R = D.getCXXScopeSpec().getRange(); 1752 if (isa<FunctionDecl>(CurContext)) 1753 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1754 else 1755 Diag(L, diag::err_invalid_declarator_scope) 1756 << Name << cast<NamedDecl>(DC) << R; 1757 D.setInvalidType(); 1758 } 1759 } 1760 1761 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1762 // Maybe we will complain about the shadowed template parameter. 1763 if (!D.isInvalidType()) 1764 if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl)) 1765 D.setInvalidType(); 1766 1767 // Just pretend that we didn't see the previous declaration. 1768 PrevDecl = 0; 1769 } 1770 1771 // In C++, the previous declaration we find might be a tag type 1772 // (class or enum). In this case, the new declaration will hide the 1773 // tag type. Note that this does does not apply if we're declaring a 1774 // typedef (C++ [dcl.typedef]p4). 1775 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1776 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1777 PrevDecl = 0; 1778 1779 bool Redeclaration = false; 1780 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1781 if (TemplateParamLists.size()) { 1782 Diag(D.getIdentifierLoc(), diag::err_template_typedef); 1783 return DeclPtrTy(); 1784 } 1785 1786 New = ActOnTypedefDeclarator(S, D, DC, R, DInfo, PrevDecl, Redeclaration); 1787 } else if (R->isFunctionType()) { 1788 New = ActOnFunctionDeclarator(S, D, DC, R, DInfo, PrevDecl, 1789 move(TemplateParamLists), 1790 IsFunctionDefinition, Redeclaration); 1791 } else { 1792 New = ActOnVariableDeclarator(S, D, DC, R, DInfo, PrevDecl, 1793 move(TemplateParamLists), 1794 Redeclaration); 1795 } 1796 1797 if (New == 0) 1798 return DeclPtrTy(); 1799 1800 // If this has an identifier and is not an invalid redeclaration, 1801 // add it to the scope stack. 1802 if (Name && !(Redeclaration && New->isInvalidDecl())) 1803 PushOnScopeChains(New, S); 1804 1805 return DeclPtrTy::make(New); 1806} 1807 1808/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1809/// types into constant array types in certain situations which would otherwise 1810/// be errors (for GCC compatibility). 1811static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1812 ASTContext &Context, 1813 bool &SizeIsNegative) { 1814 // This method tries to turn a variable array into a constant 1815 // array even when the size isn't an ICE. This is necessary 1816 // for compatibility with code that depends on gcc's buggy 1817 // constant expression folding, like struct {char x[(int)(char*)2];} 1818 SizeIsNegative = false; 1819 1820 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1821 QualType Pointee = PTy->getPointeeType(); 1822 QualType FixedType = 1823 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1824 if (FixedType.isNull()) return FixedType; 1825 FixedType = Context.getPointerType(FixedType); 1826 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1827 return FixedType; 1828 } 1829 1830 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1831 if (!VLATy) 1832 return QualType(); 1833 // FIXME: We should probably handle this case 1834 if (VLATy->getElementType()->isVariablyModifiedType()) 1835 return QualType(); 1836 1837 Expr::EvalResult EvalResult; 1838 if (!VLATy->getSizeExpr() || 1839 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) || 1840 !EvalResult.Val.isInt()) 1841 return QualType(); 1842 1843 llvm::APSInt &Res = EvalResult.Val.getInt(); 1844 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) { 1845 Expr* ArySizeExpr = VLATy->getSizeExpr(); 1846 // FIXME: here we could "steal" (how?) ArySizeExpr from the VLA, 1847 // so as to transfer ownership to the ConstantArrayWithExpr. 1848 // Alternatively, we could "clone" it (how?). 1849 // Since we don't know how to do things above, we just use the 1850 // very same Expr*. 1851 return Context.getConstantArrayWithExprType(VLATy->getElementType(), 1852 Res, ArySizeExpr, 1853 ArrayType::Normal, 0, 1854 VLATy->getBracketsRange()); 1855 } 1856 1857 SizeIsNegative = true; 1858 return QualType(); 1859} 1860 1861/// \brief Register the given locally-scoped external C declaration so 1862/// that it can be found later for redeclarations 1863void 1864Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, NamedDecl *PrevDecl, 1865 Scope *S) { 1866 assert(ND->getLexicalDeclContext()->isFunctionOrMethod() && 1867 "Decl is not a locally-scoped decl!"); 1868 // Note that we have a locally-scoped external with this name. 1869 LocallyScopedExternalDecls[ND->getDeclName()] = ND; 1870 1871 if (!PrevDecl) 1872 return; 1873 1874 // If there was a previous declaration of this variable, it may be 1875 // in our identifier chain. Update the identifier chain with the new 1876 // declaration. 1877 if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) { 1878 // The previous declaration was found on the identifer resolver 1879 // chain, so remove it from its scope. 1880 while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl))) 1881 S = S->getParent(); 1882 1883 if (S) 1884 S->RemoveDecl(DeclPtrTy::make(PrevDecl)); 1885 } 1886} 1887 1888/// \brief Diagnose function specifiers on a declaration of an identifier that 1889/// does not identify a function. 1890void Sema::DiagnoseFunctionSpecifiers(Declarator& D) { 1891 // FIXME: We should probably indicate the identifier in question to avoid 1892 // confusion for constructs like "inline int a(), b;" 1893 if (D.getDeclSpec().isInlineSpecified()) 1894 Diag(D.getDeclSpec().getInlineSpecLoc(), 1895 diag::err_inline_non_function); 1896 1897 if (D.getDeclSpec().isVirtualSpecified()) 1898 Diag(D.getDeclSpec().getVirtualSpecLoc(), 1899 diag::err_virtual_non_function); 1900 1901 if (D.getDeclSpec().isExplicitSpecified()) 1902 Diag(D.getDeclSpec().getExplicitSpecLoc(), 1903 diag::err_explicit_non_function); 1904} 1905 1906NamedDecl* 1907Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1908 QualType R, DeclaratorInfo *DInfo, 1909 Decl* PrevDecl, bool &Redeclaration) { 1910 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1911 if (D.getCXXScopeSpec().isSet()) { 1912 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1913 << D.getCXXScopeSpec().getRange(); 1914 D.setInvalidType(); 1915 // Pretend we didn't see the scope specifier. 1916 DC = 0; 1917 } 1918 1919 if (getLangOptions().CPlusPlus) { 1920 // Check that there are no default arguments (C++ only). 1921 CheckExtraCXXDefaultArguments(D); 1922 } 1923 1924 DiagnoseFunctionSpecifiers(D); 1925 1926 if (D.getDeclSpec().isThreadSpecified()) 1927 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 1928 1929 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R); 1930 if (!NewTD) return 0; 1931 1932 if (D.isInvalidType()) 1933 NewTD->setInvalidDecl(); 1934 1935 // Handle attributes prior to checking for duplicates in MergeVarDecl 1936 ProcessDeclAttributes(S, NewTD, D); 1937 // Merge the decl with the existing one if appropriate. If the decl is 1938 // in an outer scope, it isn't the same thing. 1939 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1940 Redeclaration = true; 1941 MergeTypeDefDecl(NewTD, PrevDecl); 1942 } 1943 1944 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1945 // then it shall have block scope. 1946 QualType T = NewTD->getUnderlyingType(); 1947 if (T->isVariablyModifiedType()) { 1948 CurFunctionNeedsScopeChecking = true; 1949 1950 if (S->getFnParent() == 0) { 1951 bool SizeIsNegative; 1952 QualType FixedTy = 1953 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1954 if (!FixedTy.isNull()) { 1955 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1956 NewTD->setUnderlyingType(FixedTy); 1957 } else { 1958 if (SizeIsNegative) 1959 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1960 else if (T->isVariableArrayType()) 1961 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1962 else 1963 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1964 NewTD->setInvalidDecl(); 1965 } 1966 } 1967 } 1968 1969 // If this is the C FILE type, notify the AST context. 1970 if (IdentifierInfo *II = NewTD->getIdentifier()) 1971 if (!NewTD->isInvalidDecl() && 1972 NewTD->getDeclContext()->getLookupContext()->isTranslationUnit()) { 1973 if (II->isStr("FILE")) 1974 Context.setFILEDecl(NewTD); 1975 else if (II->isStr("jmp_buf")) 1976 Context.setjmp_bufDecl(NewTD); 1977 else if (II->isStr("sigjmp_buf")) 1978 Context.setsigjmp_bufDecl(NewTD); 1979 } 1980 1981 return NewTD; 1982} 1983 1984/// \brief Determines whether the given declaration is an out-of-scope 1985/// previous declaration. 1986/// 1987/// This routine should be invoked when name lookup has found a 1988/// previous declaration (PrevDecl) that is not in the scope where a 1989/// new declaration by the same name is being introduced. If the new 1990/// declaration occurs in a local scope, previous declarations with 1991/// linkage may still be considered previous declarations (C99 1992/// 6.2.2p4-5, C++ [basic.link]p6). 1993/// 1994/// \param PrevDecl the previous declaration found by name 1995/// lookup 1996/// 1997/// \param DC the context in which the new declaration is being 1998/// declared. 1999/// 2000/// \returns true if PrevDecl is an out-of-scope previous declaration 2001/// for a new delcaration with the same name. 2002static bool 2003isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 2004 ASTContext &Context) { 2005 if (!PrevDecl) 2006 return 0; 2007 2008 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 2009 // case we need to check each of the overloaded functions. 2010 if (!PrevDecl->hasLinkage()) 2011 return false; 2012 2013 if (Context.getLangOptions().CPlusPlus) { 2014 // C++ [basic.link]p6: 2015 // If there is a visible declaration of an entity with linkage 2016 // having the same name and type, ignoring entities declared 2017 // outside the innermost enclosing namespace scope, the block 2018 // scope declaration declares that same entity and receives the 2019 // linkage of the previous declaration. 2020 DeclContext *OuterContext = DC->getLookupContext(); 2021 if (!OuterContext->isFunctionOrMethod()) 2022 // This rule only applies to block-scope declarations. 2023 return false; 2024 else { 2025 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 2026 if (PrevOuterContext->isRecord()) 2027 // We found a member function: ignore it. 2028 return false; 2029 else { 2030 // Find the innermost enclosing namespace for the new and 2031 // previous declarations. 2032 while (!OuterContext->isFileContext()) 2033 OuterContext = OuterContext->getParent(); 2034 while (!PrevOuterContext->isFileContext()) 2035 PrevOuterContext = PrevOuterContext->getParent(); 2036 2037 // The previous declaration is in a different namespace, so it 2038 // isn't the same function. 2039 if (OuterContext->getPrimaryContext() != 2040 PrevOuterContext->getPrimaryContext()) 2041 return false; 2042 } 2043 } 2044 } 2045 2046 return true; 2047} 2048 2049NamedDecl* 2050Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2051 QualType R, DeclaratorInfo *DInfo, 2052 NamedDecl* PrevDecl, 2053 MultiTemplateParamsArg TemplateParamLists, 2054 bool &Redeclaration) { 2055 DeclarationName Name = GetNameForDeclarator(D); 2056 2057 // Check that there are no default arguments (C++ only). 2058 if (getLangOptions().CPlusPlus) 2059 CheckExtraCXXDefaultArguments(D); 2060 2061 VarDecl *NewVD; 2062 VarDecl::StorageClass SC; 2063 switch (D.getDeclSpec().getStorageClassSpec()) { 2064 default: assert(0 && "Unknown storage class!"); 2065 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 2066 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 2067 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 2068 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 2069 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 2070 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 2071 case DeclSpec::SCS_mutable: 2072 // mutable can only appear on non-static class members, so it's always 2073 // an error here 2074 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 2075 D.setInvalidType(); 2076 SC = VarDecl::None; 2077 break; 2078 } 2079 2080 IdentifierInfo *II = Name.getAsIdentifierInfo(); 2081 if (!II) { 2082 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 2083 << Name.getAsString(); 2084 return 0; 2085 } 2086 2087 DiagnoseFunctionSpecifiers(D); 2088 2089 if (!DC->isRecord() && S->getFnParent() == 0) { 2090 // C99 6.9p2: The storage-class specifiers auto and register shall not 2091 // appear in the declaration specifiers in an external declaration. 2092 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 2093 2094 // If this is a register variable with an asm label specified, then this 2095 // is a GNU extension. 2096 if (SC == VarDecl::Register && D.getAsmLabel()) 2097 Diag(D.getIdentifierLoc(), diag::err_unsupported_global_register); 2098 else 2099 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 2100 D.setInvalidType(); 2101 } 2102 } 2103 if (DC->isRecord() && !CurContext->isRecord()) { 2104 // This is an out-of-line definition of a static data member. 2105 if (SC == VarDecl::Static) { 2106 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2107 diag::err_static_out_of_line) 2108 << CodeModificationHint::CreateRemoval( 2109 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2110 } else if (SC == VarDecl::None) 2111 SC = VarDecl::Static; 2112 } 2113 if (SC == VarDecl::Static) { 2114 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 2115 if (RD->isLocalClass()) 2116 Diag(D.getIdentifierLoc(), 2117 diag::err_static_data_member_not_allowed_in_local_class) 2118 << Name << RD->getDeclName(); 2119 } 2120 } 2121 2122 // Check that we can declare a template here. 2123 if (TemplateParamLists.size() && 2124 CheckTemplateDeclScope(S, TemplateParamLists)) 2125 return 0; 2126 2127 // Match up the template parameter lists with the scope specifier, then 2128 // determine whether we have a template or a template specialization. 2129 if (TemplateParameterList *TemplateParams 2130 = MatchTemplateParametersToScopeSpecifier( 2131 D.getDeclSpec().getSourceRange().getBegin(), 2132 D.getCXXScopeSpec(), 2133 (TemplateParameterList**)TemplateParamLists.get(), 2134 TemplateParamLists.size())) { 2135 if (TemplateParams->size() > 0) { 2136 // There is no such thing as a variable template. 2137 Diag(D.getIdentifierLoc(), diag::err_template_variable) 2138 << II 2139 << SourceRange(TemplateParams->getTemplateLoc(), 2140 TemplateParams->getRAngleLoc()); 2141 return 0; 2142 } else { 2143 // There is an extraneous 'template<>' for this variable. Complain 2144 // about it, but allow the declaration of the variable. 2145 Diag(TemplateParams->getTemplateLoc(), 2146 diag::err_template_variable_noparams) 2147 << II 2148 << SourceRange(TemplateParams->getTemplateLoc(), 2149 TemplateParams->getRAngleLoc()); 2150 } 2151 } 2152 2153 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 2154 II, R, DInfo, SC, 2155 // FIXME: Move to DeclGroup... 2156 D.getDeclSpec().getSourceRange().getBegin()); 2157 2158 if (D.isInvalidType()) 2159 NewVD->setInvalidDecl(); 2160 2161 if (D.getDeclSpec().isThreadSpecified()) { 2162 if (NewVD->hasLocalStorage()) 2163 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global); 2164 else if (!Context.Target.isTLSSupported()) 2165 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported); 2166 else 2167 NewVD->setThreadSpecified(true); 2168 } 2169 2170 // Set the lexical context. If the declarator has a C++ scope specifier, the 2171 // lexical context will be different from the semantic context. 2172 NewVD->setLexicalDeclContext(CurContext); 2173 2174 // Handle attributes prior to checking for duplicates in MergeVarDecl 2175 ProcessDeclAttributes(S, NewVD, D); 2176 2177 // Handle GNU asm-label extension (encoded as an attribute). 2178 if (Expr *E = (Expr*) D.getAsmLabel()) { 2179 // The parser guarantees this is a string. 2180 StringLiteral *SE = cast<StringLiteral>(E); 2181 NewVD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2182 SE->getByteLength()))); 2183 } 2184 2185 // If name lookup finds a previous declaration that is not in the 2186 // same scope as the new declaration, this may still be an 2187 // acceptable redeclaration. 2188 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2189 !(NewVD->hasLinkage() && 2190 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2191 PrevDecl = 0; 2192 2193 // Merge the decl with the existing one if appropriate. 2194 if (PrevDecl) { 2195 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 2196 // The user tried to define a non-static data member 2197 // out-of-line (C++ [dcl.meaning]p1). 2198 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 2199 << D.getCXXScopeSpec().getRange(); 2200 PrevDecl = 0; 2201 NewVD->setInvalidDecl(); 2202 } 2203 } else if (D.getCXXScopeSpec().isSet()) { 2204 // No previous declaration in the qualifying scope. 2205 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 2206 << Name << D.getCXXScopeSpec().getRange(); 2207 NewVD->setInvalidDecl(); 2208 } 2209 2210 CheckVariableDeclaration(NewVD, PrevDecl, Redeclaration); 2211 2212 // attributes declared post-definition are currently ignored 2213 if (PrevDecl) { 2214 const VarDecl *Def = 0, *PrevVD = dyn_cast<VarDecl>(PrevDecl); 2215 if (PrevVD->getDefinition(Def) && D.hasAttributes()) { 2216 Diag(NewVD->getLocation(), diag::warn_attribute_precede_definition); 2217 Diag(Def->getLocation(), diag::note_previous_definition); 2218 } 2219 } 2220 2221 // If this is a locally-scoped extern C variable, update the map of 2222 // such variables. 2223 if (CurContext->isFunctionOrMethod() && NewVD->isExternC(Context) && 2224 !NewVD->isInvalidDecl()) 2225 RegisterLocallyScopedExternCDecl(NewVD, PrevDecl, S); 2226 2227 return NewVD; 2228} 2229 2230/// \brief Perform semantic checking on a newly-created variable 2231/// declaration. 2232/// 2233/// This routine performs all of the type-checking required for a 2234/// variable declaration once it has been built. It is used both to 2235/// check variables after they have been parsed and their declarators 2236/// have been translated into a declaration, and to check variables 2237/// that have been instantiated from a template. 2238/// 2239/// Sets NewVD->isInvalidDecl() if an error was encountered. 2240void Sema::CheckVariableDeclaration(VarDecl *NewVD, NamedDecl *PrevDecl, 2241 bool &Redeclaration) { 2242 // If the decl is already known invalid, don't check it. 2243 if (NewVD->isInvalidDecl()) 2244 return; 2245 2246 QualType T = NewVD->getType(); 2247 2248 if (T->isObjCInterfaceType()) { 2249 Diag(NewVD->getLocation(), diag::err_statically_allocated_object); 2250 return NewVD->setInvalidDecl(); 2251 } 2252 2253 // The variable can not have an abstract class type. 2254 if (RequireNonAbstractType(NewVD->getLocation(), T, 2255 diag::err_abstract_type_in_decl, 2256 AbstractVariableType)) 2257 return NewVD->setInvalidDecl(); 2258 2259 // Emit an error if an address space was applied to decl with local storage. 2260 // This includes arrays of objects with address space qualifiers, but not 2261 // automatic variables that point to other address spaces. 2262 // ISO/IEC TR 18037 S5.1.2 2263 if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) { 2264 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl); 2265 return NewVD->setInvalidDecl(); 2266 } 2267 2268 if (NewVD->hasLocalStorage() && T.isObjCGCWeak() 2269 && !NewVD->hasAttr<BlocksAttr>()) 2270 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); 2271 2272 bool isVM = T->isVariablyModifiedType(); 2273 if (isVM || NewVD->hasAttr<CleanupAttr>() || 2274 NewVD->hasAttr<BlocksAttr>()) 2275 CurFunctionNeedsScopeChecking = true; 2276 2277 if ((isVM && NewVD->hasLinkage()) || 2278 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { 2279 bool SizeIsNegative; 2280 QualType FixedTy = 2281 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 2282 2283 if (FixedTy.isNull() && T->isVariableArrayType()) { 2284 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2285 // FIXME: This won't give the correct result for 2286 // int a[10][n]; 2287 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2288 2289 if (NewVD->isFileVarDecl()) 2290 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) 2291 << SizeRange; 2292 else if (NewVD->getStorageClass() == VarDecl::Static) 2293 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) 2294 << SizeRange; 2295 else 2296 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) 2297 << SizeRange; 2298 return NewVD->setInvalidDecl(); 2299 } 2300 2301 if (FixedTy.isNull()) { 2302 if (NewVD->isFileVarDecl()) 2303 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); 2304 else 2305 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); 2306 return NewVD->setInvalidDecl(); 2307 } 2308 2309 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); 2310 NewVD->setType(FixedTy); 2311 } 2312 2313 if (!PrevDecl && NewVD->isExternC(Context)) { 2314 // Since we did not find anything by this name and we're declaring 2315 // an extern "C" variable, look for a non-visible extern "C" 2316 // declaration with the same name. 2317 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2318 = LocallyScopedExternalDecls.find(NewVD->getDeclName()); 2319 if (Pos != LocallyScopedExternalDecls.end()) 2320 PrevDecl = Pos->second; 2321 } 2322 2323 if (T->isVoidType() && !NewVD->hasExternalStorage()) { 2324 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) 2325 << T; 2326 return NewVD->setInvalidDecl(); 2327 } 2328 2329 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) { 2330 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); 2331 return NewVD->setInvalidDecl(); 2332 } 2333 2334 if (isVM && NewVD->hasAttr<BlocksAttr>()) { 2335 Diag(NewVD->getLocation(), diag::err_block_on_vm); 2336 return NewVD->setInvalidDecl(); 2337 } 2338 2339 if (PrevDecl) { 2340 Redeclaration = true; 2341 MergeVarDecl(NewVD, PrevDecl); 2342 } 2343} 2344 2345NamedDecl* 2346Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 2347 QualType R, DeclaratorInfo *DInfo, 2348 NamedDecl* PrevDecl, 2349 MultiTemplateParamsArg TemplateParamLists, 2350 bool IsFunctionDefinition, bool &Redeclaration) { 2351 assert(R.getTypePtr()->isFunctionType()); 2352 2353 DeclarationName Name = GetNameForDeclarator(D); 2354 FunctionDecl::StorageClass SC = FunctionDecl::None; 2355 switch (D.getDeclSpec().getStorageClassSpec()) { 2356 default: assert(0 && "Unknown storage class!"); 2357 case DeclSpec::SCS_auto: 2358 case DeclSpec::SCS_register: 2359 case DeclSpec::SCS_mutable: 2360 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2361 diag::err_typecheck_sclass_func); 2362 D.setInvalidType(); 2363 break; 2364 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 2365 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 2366 case DeclSpec::SCS_static: { 2367 if (CurContext->getLookupContext()->isFunctionOrMethod()) { 2368 // C99 6.7.1p5: 2369 // The declaration of an identifier for a function that has 2370 // block scope shall have no explicit storage-class specifier 2371 // other than extern 2372 // See also (C++ [dcl.stc]p4). 2373 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2374 diag::err_static_block_func); 2375 SC = FunctionDecl::None; 2376 } else 2377 SC = FunctionDecl::Static; 2378 break; 2379 } 2380 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 2381 } 2382 2383 if (D.getDeclSpec().isThreadSpecified()) 2384 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 2385 2386 bool isFriend = D.getDeclSpec().isFriendSpecified(); 2387 bool isInline = D.getDeclSpec().isInlineSpecified(); 2388 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 2389 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 2390 2391 // Check that the return type is not an abstract class type. 2392 // For record types, this is done by the AbstractClassUsageDiagnoser once 2393 // the class has been completely parsed. 2394 if (!DC->isRecord() && 2395 RequireNonAbstractType(D.getIdentifierLoc(), 2396 R->getAsFunctionType()->getResultType(), 2397 diag::err_abstract_type_in_decl, 2398 AbstractReturnType)) 2399 D.setInvalidType(); 2400 2401 // Do not allow returning a objc interface by-value. 2402 if (R->getAsFunctionType()->getResultType()->isObjCInterfaceType()) { 2403 Diag(D.getIdentifierLoc(), 2404 diag::err_object_cannot_be_passed_returned_by_value) << 0 2405 << R->getAsFunctionType()->getResultType(); 2406 D.setInvalidType(); 2407 } 2408 2409 // Check that we can declare a template here. 2410 if (TemplateParamLists.size() && 2411 CheckTemplateDeclScope(S, TemplateParamLists)) 2412 return 0; 2413 2414 bool isVirtualOkay = false; 2415 FunctionDecl *NewFD; 2416 if (isFriend) { 2417 // DC is the namespace in which the function is being declared. 2418 assert(DC->isFileContext() || D.getCXXScopeSpec().isSet()); 2419 2420 // C++ [class.friend]p5 2421 // A function can be defined in a friend declaration of a 2422 // class . . . . Such a function is implicitly inline. 2423 isInline |= IsFunctionDefinition; 2424 2425 NewFD = FriendFunctionDecl::Create(Context, DC, 2426 D.getIdentifierLoc(), Name, R, DInfo, 2427 isInline, 2428 D.getDeclSpec().getFriendSpecLoc()); 2429 2430 } else if (D.getKind() == Declarator::DK_Constructor) { 2431 // This is a C++ constructor declaration. 2432 assert(DC->isRecord() && 2433 "Constructors can only be declared in a member context"); 2434 2435 R = CheckConstructorDeclarator(D, R, SC); 2436 2437 // Create the new declaration 2438 NewFD = CXXConstructorDecl::Create(Context, 2439 cast<CXXRecordDecl>(DC), 2440 D.getIdentifierLoc(), Name, R, DInfo, 2441 isExplicit, isInline, 2442 /*isImplicitlyDeclared=*/false); 2443 } else if (D.getKind() == Declarator::DK_Destructor) { 2444 // This is a C++ destructor declaration. 2445 if (DC->isRecord()) { 2446 R = CheckDestructorDeclarator(D, SC); 2447 2448 NewFD = CXXDestructorDecl::Create(Context, 2449 cast<CXXRecordDecl>(DC), 2450 D.getIdentifierLoc(), Name, R, 2451 isInline, 2452 /*isImplicitlyDeclared=*/false); 2453 2454 isVirtualOkay = true; 2455 } else { 2456 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 2457 2458 // Create a FunctionDecl to satisfy the function definition parsing 2459 // code path. 2460 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 2461 Name, R, DInfo, SC, isInline, 2462 /*hasPrototype=*/true, 2463 // FIXME: Move to DeclGroup... 2464 D.getDeclSpec().getSourceRange().getBegin()); 2465 D.setInvalidType(); 2466 } 2467 } else if (D.getKind() == Declarator::DK_Conversion) { 2468 if (!DC->isRecord()) { 2469 Diag(D.getIdentifierLoc(), 2470 diag::err_conv_function_not_member); 2471 return 0; 2472 } 2473 2474 CheckConversionDeclarator(D, R, SC); 2475 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 2476 D.getIdentifierLoc(), Name, R, DInfo, 2477 isInline, isExplicit); 2478 2479 isVirtualOkay = true; 2480 } else if (DC->isRecord()) { 2481 // If the of the function is the same as the name of the record, then this 2482 // must be an invalid constructor that has a return type. 2483 // (The parser checks for a return type and makes the declarator a 2484 // constructor if it has no return type). 2485 // must have an invalid constructor that has a return type 2486 if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){ 2487 Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) 2488 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 2489 << SourceRange(D.getIdentifierLoc()); 2490 return 0; 2491 } 2492 2493 // This is a C++ method declaration. 2494 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 2495 D.getIdentifierLoc(), Name, R, DInfo, 2496 (SC == FunctionDecl::Static), isInline); 2497 2498 isVirtualOkay = (SC != FunctionDecl::Static); 2499 } else { 2500 // Determine whether the function was written with a 2501 // prototype. This true when: 2502 // - we're in C++ (where every function has a prototype), 2503 // - there is a prototype in the declarator, or 2504 // - the type R of the function is some kind of typedef or other reference 2505 // to a type name (which eventually refers to a function type). 2506 bool HasPrototype = 2507 getLangOptions().CPlusPlus || 2508 (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) || 2509 (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType()); 2510 2511 NewFD = FunctionDecl::Create(Context, DC, 2512 D.getIdentifierLoc(), 2513 Name, R, DInfo, SC, isInline, HasPrototype, 2514 // FIXME: Move to DeclGroup... 2515 D.getDeclSpec().getSourceRange().getBegin()); 2516 } 2517 2518 if (D.isInvalidType()) 2519 NewFD->setInvalidDecl(); 2520 2521 // Set the lexical context. If the declarator has a C++ 2522 // scope specifier, the lexical context will be different 2523 // from the semantic context. 2524 NewFD->setLexicalDeclContext(CurContext); 2525 2526 // Match up the template parameter lists with the scope specifier, then 2527 // determine whether we have a template or a template specialization. 2528 FunctionTemplateDecl *FunctionTemplate = 0; 2529 if (TemplateParameterList *TemplateParams 2530 = MatchTemplateParametersToScopeSpecifier( 2531 D.getDeclSpec().getSourceRange().getBegin(), 2532 D.getCXXScopeSpec(), 2533 (TemplateParameterList**)TemplateParamLists.get(), 2534 TemplateParamLists.size())) { 2535 if (TemplateParams->size() > 0) { 2536 // This is a function template 2537 FunctionTemplate = FunctionTemplateDecl::Create(Context, CurContext, 2538 NewFD->getLocation(), 2539 Name, TemplateParams, 2540 NewFD); 2541 NewFD->setDescribedFunctionTemplate(FunctionTemplate); 2542 } else { 2543 // FIXME: Handle function template specializations 2544 } 2545 2546 // FIXME: Free this memory properly. 2547 TemplateParamLists.release(); 2548 } 2549 2550 // C++ [dcl.fct.spec]p5: 2551 // The virtual specifier shall only be used in declarations of 2552 // nonstatic class member functions that appear within a 2553 // member-specification of a class declaration; see 10.3. 2554 // 2555 if (isVirtual && !NewFD->isInvalidDecl()) { 2556 if (!isVirtualOkay) { 2557 Diag(D.getDeclSpec().getVirtualSpecLoc(), 2558 diag::err_virtual_non_function); 2559 } else if (!CurContext->isRecord()) { 2560 // 'virtual' was specified outside of the class. 2561 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class) 2562 << CodeModificationHint::CreateRemoval( 2563 SourceRange(D.getDeclSpec().getVirtualSpecLoc())); 2564 } else { 2565 // Okay: Add virtual to the method. 2566 cast<CXXMethodDecl>(NewFD)->setVirtualAsWritten(true); 2567 CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC); 2568 CurClass->setAggregate(false); 2569 CurClass->setPOD(false); 2570 CurClass->setEmpty(false); 2571 CurClass->setPolymorphic(true); 2572 CurClass->setHasTrivialConstructor(false); 2573 CurClass->setHasTrivialCopyConstructor(false); 2574 CurClass->setHasTrivialCopyAssignment(false); 2575 } 2576 } 2577 2578 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD)) { 2579 // Look for virtual methods in base classes that this method might override. 2580 2581 BasePaths Paths; 2582 if (LookupInBases(cast<CXXRecordDecl>(DC), 2583 MemberLookupCriteria(NewMD), Paths)) { 2584 for (BasePaths::decl_iterator I = Paths.found_decls_begin(), 2585 E = Paths.found_decls_end(); I != E; ++I) { 2586 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(*I)) { 2587 if (!CheckOverridingFunctionReturnType(NewMD, OldMD) && 2588 !CheckOverridingFunctionExceptionSpec(NewMD, OldMD)) 2589 NewMD->addOverriddenMethod(OldMD); 2590 } 2591 } 2592 } 2593 } 2594 2595 if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) && 2596 !CurContext->isRecord()) { 2597 // C++ [class.static]p1: 2598 // A data or function member of a class may be declared static 2599 // in a class definition, in which case it is a static member of 2600 // the class. 2601 2602 // Complain about the 'static' specifier if it's on an out-of-line 2603 // member function definition. 2604 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 2605 diag::err_static_out_of_line) 2606 << CodeModificationHint::CreateRemoval( 2607 SourceRange(D.getDeclSpec().getStorageClassSpecLoc())); 2608 } 2609 2610 // Handle GNU asm-label extension (encoded as an attribute). 2611 if (Expr *E = (Expr*) D.getAsmLabel()) { 2612 // The parser guarantees this is a string. 2613 StringLiteral *SE = cast<StringLiteral>(E); 2614 NewFD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(), 2615 SE->getByteLength()))); 2616 } 2617 2618 // Copy the parameter declarations from the declarator D to the function 2619 // declaration NewFD, if they are available. First scavenge them into Params. 2620 llvm::SmallVector<ParmVarDecl*, 16> Params; 2621 if (D.getNumTypeObjects() > 0) { 2622 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2623 2624 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 2625 // function that takes no arguments, not a function that takes a 2626 // single void argument. 2627 // We let through "const void" here because Sema::GetTypeForDeclarator 2628 // already checks for that case. 2629 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 2630 FTI.ArgInfo[0].Param && 2631 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) { 2632 // Empty arg list, don't push any params. 2633 ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>(); 2634 2635 // In C++, the empty parameter-type-list must be spelled "void"; a 2636 // typedef of void is not permitted. 2637 if (getLangOptions().CPlusPlus && 2638 Param->getType().getUnqualifiedType() != Context.VoidTy) 2639 Diag(Param->getLocation(), diag::err_param_typedef_of_void); 2640 // FIXME: Leaks decl? 2641 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 2642 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2643 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 2644 assert(Param->getDeclContext() != NewFD && "Was set before ?"); 2645 Param->setDeclContext(NewFD); 2646 Params.push_back(Param); 2647 } 2648 } 2649 2650 } else if (const FunctionProtoType *FT = R->getAsFunctionProtoType()) { 2651 // When we're declaring a function with a typedef, typeof, etc as in the 2652 // following example, we'll need to synthesize (unnamed) 2653 // parameters for use in the declaration. 2654 // 2655 // @code 2656 // typedef void fn(int); 2657 // fn f; 2658 // @endcode 2659 2660 // Synthesize a parameter for each argument type. 2661 for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(), 2662 AE = FT->arg_type_end(); AI != AE; ++AI) { 2663 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 2664 SourceLocation(), 0, 2665 *AI, /*DInfo=*/0, 2666 VarDecl::None, 0); 2667 Param->setImplicit(); 2668 Params.push_back(Param); 2669 } 2670 } else { 2671 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && 2672 "Should not need args for typedef of non-prototype fn"); 2673 } 2674 // Finally, we know we have the right number of parameters, install them. 2675 NewFD->setParams(Context, Params.data(), Params.size()); 2676 2677 // If name lookup finds a previous declaration that is not in the 2678 // same scope as the new declaration, this may still be an 2679 // acceptable redeclaration. 2680 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 2681 !(NewFD->hasLinkage() && 2682 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 2683 PrevDecl = 0; 2684 2685 // Perform semantic checking on the function declaration. 2686 bool OverloadableAttrRequired = false; // FIXME: HACK! 2687 CheckFunctionDeclaration(NewFD, PrevDecl, Redeclaration, 2688 /*FIXME:*/OverloadableAttrRequired); 2689 2690 if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) { 2691 // An out-of-line member function declaration must also be a 2692 // definition (C++ [dcl.meaning]p1). 2693 if (!IsFunctionDefinition && !isFriend) { 2694 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2695 << D.getCXXScopeSpec().getRange(); 2696 NewFD->setInvalidDecl(); 2697 } else if (!Redeclaration && (!PrevDecl || !isa<UsingDecl>(PrevDecl))) { 2698 // The user tried to provide an out-of-line definition for a 2699 // function that is a member of a class or namespace, but there 2700 // was no such member function declared (C++ [class.mfct]p2, 2701 // C++ [namespace.memdef]p2). For example: 2702 // 2703 // class X { 2704 // void f() const; 2705 // }; 2706 // 2707 // void X::f() { } // ill-formed 2708 // 2709 // Complain about this problem, and attempt to suggest close 2710 // matches (e.g., those that differ only in cv-qualifiers and 2711 // whether the parameter types are references). 2712 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 2713 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 2714 NewFD->setInvalidDecl(); 2715 2716 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 2717 true); 2718 assert(!Prev.isAmbiguous() && 2719 "Cannot have an ambiguity in previous-declaration lookup"); 2720 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 2721 Func != FuncEnd; ++Func) { 2722 if (isa<FunctionDecl>(*Func) && 2723 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 2724 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 2725 } 2726 2727 PrevDecl = 0; 2728 } 2729 } 2730 2731 // Handle attributes. We need to have merged decls when handling attributes 2732 // (for example to check for conflicts, etc). 2733 // FIXME: This needs to happen before we merge declarations. Then, 2734 // let attribute merging cope with attribute conflicts. 2735 ProcessDeclAttributes(S, NewFD, D); 2736 2737 // attributes declared post-definition are currently ignored 2738 if (PrevDecl) { 2739 const FunctionDecl *Def, *PrevFD = dyn_cast<FunctionDecl>(PrevDecl); 2740 if (PrevFD && PrevFD->getBody(Def) && D.hasAttributes()) { 2741 Diag(NewFD->getLocation(), diag::warn_attribute_precede_definition); 2742 Diag(Def->getLocation(), diag::note_previous_definition); 2743 } 2744 } 2745 2746 AddKnownFunctionAttributes(NewFD); 2747 2748 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 2749 // If a function name is overloadable in C, then every function 2750 // with that name must be marked "overloadable". 2751 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 2752 << Redeclaration << NewFD; 2753 if (PrevDecl) 2754 Diag(PrevDecl->getLocation(), 2755 diag::note_attribute_overloadable_prev_overload); 2756 NewFD->addAttr(::new (Context) OverloadableAttr()); 2757 } 2758 2759 // If this is a locally-scoped extern C function, update the 2760 // map of such names. 2761 if (CurContext->isFunctionOrMethod() && NewFD->isExternC(Context) 2762 && !NewFD->isInvalidDecl()) 2763 RegisterLocallyScopedExternCDecl(NewFD, PrevDecl, S); 2764 2765 // Set this FunctionDecl's range up to the right paren. 2766 NewFD->setLocEnd(D.getSourceRange().getEnd()); 2767 2768 if (FunctionTemplate && NewFD->isInvalidDecl()) 2769 FunctionTemplate->setInvalidDecl(); 2770 2771 if (FunctionTemplate) 2772 return FunctionTemplate; 2773 2774 return NewFD; 2775} 2776 2777/// \brief Perform semantic checking of a new function declaration. 2778/// 2779/// Performs semantic analysis of the new function declaration 2780/// NewFD. This routine performs all semantic checking that does not 2781/// require the actual declarator involved in the declaration, and is 2782/// used both for the declaration of functions as they are parsed 2783/// (called via ActOnDeclarator) and for the declaration of functions 2784/// that have been instantiated via C++ template instantiation (called 2785/// via InstantiateDecl). 2786/// 2787/// This sets NewFD->isInvalidDecl() to true if there was an error. 2788void Sema::CheckFunctionDeclaration(FunctionDecl *NewFD, NamedDecl *&PrevDecl, 2789 bool &Redeclaration, 2790 bool &OverloadableAttrRequired) { 2791 // If NewFD is already known erroneous, don't do any of this checking. 2792 if (NewFD->isInvalidDecl()) 2793 return; 2794 2795 if (NewFD->getResultType()->isVariablyModifiedType()) { 2796 // Functions returning a variably modified type violate C99 6.7.5.2p2 2797 // because all functions have linkage. 2798 Diag(NewFD->getLocation(), diag::err_vm_func_decl); 2799 return NewFD->setInvalidDecl(); 2800 } 2801 2802 if (NewFD->isMain(Context)) CheckMain(NewFD); 2803 2804 // Semantic checking for this function declaration (in isolation). 2805 if (getLangOptions().CPlusPlus) { 2806 // C++-specific checks. 2807 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 2808 CheckConstructor(Constructor); 2809 } else if (isa<CXXDestructorDecl>(NewFD)) { 2810 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 2811 QualType ClassType = Context.getTypeDeclType(Record); 2812 if (!ClassType->isDependentType()) { 2813 DeclarationName Name 2814 = Context.DeclarationNames.getCXXDestructorName( 2815 Context.getCanonicalType(ClassType)); 2816 if (NewFD->getDeclName() != Name) { 2817 Diag(NewFD->getLocation(), diag::err_destructor_name); 2818 return NewFD->setInvalidDecl(); 2819 } 2820 } 2821 Record->setUserDeclaredDestructor(true); 2822 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 2823 // user-defined destructor. 2824 Record->setPOD(false); 2825 2826 // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly- 2827 // declared destructor. 2828 // FIXME: C++0x: don't do this for "= default" destructors 2829 Record->setHasTrivialDestructor(false); 2830 } else if (CXXConversionDecl *Conversion 2831 = dyn_cast<CXXConversionDecl>(NewFD)) 2832 ActOnConversionDeclarator(Conversion); 2833 2834 // Extra checking for C++ overloaded operators (C++ [over.oper]). 2835 if (NewFD->isOverloadedOperator() && 2836 CheckOverloadedOperatorDeclaration(NewFD)) 2837 return NewFD->setInvalidDecl(); 2838 } 2839 2840 // C99 6.7.4p6: 2841 // [... ] For a function with external linkage, the following 2842 // restrictions apply: [...] If all of the file scope declarations 2843 // for a function in a translation unit include the inline 2844 // function specifier without extern, then the definition in that 2845 // translation unit is an inline definition. An inline definition 2846 // does not provide an external definition for the function, and 2847 // does not forbid an external definition in another translation 2848 // unit. 2849 // 2850 // Here we determine whether this function, in isolation, would be a 2851 // C99 inline definition. MergeCompatibleFunctionDecls looks at 2852 // previous declarations. 2853 if (NewFD->isInline() && getLangOptions().C99 && 2854 NewFD->getStorageClass() == FunctionDecl::None && 2855 NewFD->getDeclContext()->getLookupContext()->isTranslationUnit()) 2856 NewFD->setC99InlineDefinition(true); 2857 2858 // Check for a previous declaration of this name. 2859 if (!PrevDecl && NewFD->isExternC(Context)) { 2860 // Since we did not find anything by this name and we're declaring 2861 // an extern "C" function, look for a non-visible extern "C" 2862 // declaration with the same name. 2863 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 2864 = LocallyScopedExternalDecls.find(NewFD->getDeclName()); 2865 if (Pos != LocallyScopedExternalDecls.end()) 2866 PrevDecl = Pos->second; 2867 } 2868 2869 // Merge or overload the declaration with an existing declaration of 2870 // the same name, if appropriate. 2871 if (PrevDecl) { 2872 // Determine whether NewFD is an overload of PrevDecl or 2873 // a declaration that requires merging. If it's an overload, 2874 // there's no more work to do here; we'll just add the new 2875 // function to the scope. 2876 OverloadedFunctionDecl::function_iterator MatchedDecl; 2877 2878 if (!getLangOptions().CPlusPlus && 2879 AllowOverloadingOfFunction(PrevDecl, Context)) { 2880 OverloadableAttrRequired = true; 2881 2882 // Functions marked "overloadable" must have a prototype (that 2883 // we can't get through declaration merging). 2884 if (!NewFD->getType()->getAsFunctionProtoType()) { 2885 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 2886 << NewFD; 2887 Redeclaration = true; 2888 2889 // Turn this into a variadic function with no parameters. 2890 QualType R = Context.getFunctionType( 2891 NewFD->getType()->getAsFunctionType()->getResultType(), 2892 0, 0, true, 0); 2893 NewFD->setType(R); 2894 return NewFD->setInvalidDecl(); 2895 } 2896 } 2897 2898 if (PrevDecl && 2899 (!AllowOverloadingOfFunction(PrevDecl, Context) || 2900 !IsOverload(NewFD, PrevDecl, MatchedDecl)) && 2901 !isa<UsingDecl>(PrevDecl)) { 2902 Redeclaration = true; 2903 Decl *OldDecl = PrevDecl; 2904 2905 // If PrevDecl was an overloaded function, extract the 2906 // FunctionDecl that matched. 2907 if (isa<OverloadedFunctionDecl>(PrevDecl)) 2908 OldDecl = *MatchedDecl; 2909 2910 // NewFD and OldDecl represent declarations that need to be 2911 // merged. 2912 if (MergeFunctionDecl(NewFD, OldDecl)) 2913 return NewFD->setInvalidDecl(); 2914 2915 if (FunctionTemplateDecl *OldTemplateDecl 2916 = dyn_cast<FunctionTemplateDecl>(OldDecl)) 2917 NewFD->setPreviousDeclaration(OldTemplateDecl->getTemplatedDecl()); 2918 else { 2919 if (isa<CXXMethodDecl>(NewFD)) // Set access for out-of-line definitions 2920 NewFD->setAccess(OldDecl->getAccess()); 2921 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 2922 } 2923 } 2924 } 2925 2926 // In C++, check default arguments now that we have merged decls. Unless 2927 // the lexical context is the class, because in this case this is done 2928 // during delayed parsing anyway. 2929 if (getLangOptions().CPlusPlus && !CurContext->isRecord()) 2930 CheckCXXDefaultArguments(NewFD); 2931} 2932 2933void Sema::CheckMain(FunctionDecl* FD) { 2934 // C++ [basic.start.main]p3: A program that declares main to be inline 2935 // or static is ill-formed. 2936 // C99 6.7.4p4: In a hosted environment, the inline function specifier 2937 // shall not appear in a declaration of main. 2938 // static main is not an error under C99, but we should warn about it. 2939 bool isInline = FD->isInline(); 2940 bool isStatic = FD->getStorageClass() == FunctionDecl::Static; 2941 if (isInline || isStatic) { 2942 unsigned diagID = diag::warn_unusual_main_decl; 2943 if (isInline || getLangOptions().CPlusPlus) 2944 diagID = diag::err_unusual_main_decl; 2945 2946 int which = isStatic + (isInline << 1) - 1; 2947 Diag(FD->getLocation(), diagID) << which; 2948 } 2949 2950 QualType T = FD->getType(); 2951 assert(T->isFunctionType() && "function decl is not of function type"); 2952 const FunctionType* FT = T->getAsFunctionType(); 2953 2954 if (!Context.hasSameUnqualifiedType(FT->getResultType(), Context.IntTy)) { 2955 // TODO: add a replacement fixit to turn the return type into 'int'. 2956 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint); 2957 FD->setInvalidDecl(true); 2958 } 2959 2960 // Treat protoless main() as nullary. 2961 if (isa<FunctionNoProtoType>(FT)) return; 2962 2963 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 2964 unsigned nparams = FTP->getNumArgs(); 2965 assert(FD->getNumParams() == nparams); 2966 2967 if (nparams > 3) { 2968 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 2969 FD->setInvalidDecl(true); 2970 nparams = 3; 2971 } 2972 2973 // FIXME: a lot of the following diagnostics would be improved 2974 // if we had some location information about types. 2975 2976 QualType CharPP = 2977 Context.getPointerType(Context.getPointerType(Context.CharTy)); 2978 QualType Expected[] = { Context.IntTy, CharPP, CharPP }; 2979 2980 for (unsigned i = 0; i < nparams; ++i) { 2981 QualType AT = FTP->getArgType(i); 2982 2983 bool mismatch = true; 2984 2985 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 2986 mismatch = false; 2987 else if (Expected[i] == CharPP) { 2988 // As an extension, the following forms are okay: 2989 // char const ** 2990 // char const * const * 2991 // char * const * 2992 2993 QualifierSet qs; 2994 const PointerType* PT; 2995 if ((PT = qs.strip(AT)->getAs<PointerType>()) && 2996 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) && 2997 (QualType(qs.strip(PT->getPointeeType()), 0) == Context.CharTy)) { 2998 qs.removeConst(); 2999 mismatch = !qs.empty(); 3000 } 3001 } 3002 3003 if (mismatch) { 3004 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 3005 // TODO: suggest replacing given type with expected type 3006 FD->setInvalidDecl(true); 3007 } 3008 } 3009 3010 if (nparams == 1 && !FD->isInvalidDecl()) { 3011 Diag(FD->getLocation(), diag::warn_main_one_arg); 3012 } 3013} 3014 3015bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 3016 // FIXME: Need strict checking. In C89, we need to check for 3017 // any assignment, increment, decrement, function-calls, or 3018 // commas outside of a sizeof. In C99, it's the same list, 3019 // except that the aforementioned are allowed in unevaluated 3020 // expressions. Everything else falls under the 3021 // "may accept other forms of constant expressions" exception. 3022 // (We never end up here for C++, so the constant expression 3023 // rules there don't matter.) 3024 if (Init->isConstantInitializer(Context)) 3025 return false; 3026 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 3027 << Init->getSourceRange(); 3028 return true; 3029} 3030 3031void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init) { 3032 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 3033} 3034 3035/// AddInitializerToDecl - Adds the initializer Init to the 3036/// declaration dcl. If DirectInit is true, this is C++ direct 3037/// initialization rather than copy initialization. 3038void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) { 3039 Decl *RealDecl = dcl.getAs<Decl>(); 3040 // If there is no declaration, there was an error parsing it. Just ignore 3041 // the initializer. 3042 if (RealDecl == 0) 3043 return; 3044 3045 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 3046 // With declarators parsed the way they are, the parser cannot 3047 // distinguish between a normal initializer and a pure-specifier. 3048 // Thus this grotesque test. 3049 IntegerLiteral *IL; 3050 Expr *Init = static_cast<Expr *>(init.get()); 3051 if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 && 3052 Context.getCanonicalType(IL->getType()) == Context.IntTy) { 3053 if (Method->isVirtualAsWritten()) { 3054 Method->setPure(); 3055 3056 // A class is abstract if at least one function is pure virtual. 3057 cast<CXXRecordDecl>(CurContext)->setAbstract(true); 3058 } else if (!Method->isInvalidDecl()) { 3059 Diag(Method->getLocation(), diag::err_non_virtual_pure) 3060 << Method->getDeclName() << Init->getSourceRange(); 3061 Method->setInvalidDecl(); 3062 } 3063 } else { 3064 Diag(Method->getLocation(), diag::err_member_function_initialization) 3065 << Method->getDeclName() << Init->getSourceRange(); 3066 Method->setInvalidDecl(); 3067 } 3068 return; 3069 } 3070 3071 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 3072 if (!VDecl) { 3073 if (getLangOptions().CPlusPlus && 3074 RealDecl->getLexicalDeclContext()->isRecord() && 3075 isa<NamedDecl>(RealDecl)) 3076 Diag(RealDecl->getLocation(), diag::err_member_initialization) 3077 << cast<NamedDecl>(RealDecl)->getDeclName(); 3078 else 3079 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 3080 RealDecl->setInvalidDecl(); 3081 return; 3082 } 3083 3084 if (!VDecl->getType()->isArrayType() && 3085 RequireCompleteType(VDecl->getLocation(), VDecl->getType(), 3086 diag::err_typecheck_decl_incomplete_type)) { 3087 RealDecl->setInvalidDecl(); 3088 return; 3089 } 3090 3091 const VarDecl *Def = 0; 3092 if (VDecl->getDefinition(Def)) { 3093 Diag(VDecl->getLocation(), diag::err_redefinition) 3094 << VDecl->getDeclName(); 3095 Diag(Def->getLocation(), diag::note_previous_definition); 3096 VDecl->setInvalidDecl(); 3097 return; 3098 } 3099 3100 // Take ownership of the expression, now that we're sure we have somewhere 3101 // to put it. 3102 Expr *Init = init.takeAs<Expr>(); 3103 assert(Init && "missing initializer"); 3104 3105 // Get the decls type and save a reference for later, since 3106 // CheckInitializerTypes may change it. 3107 QualType DclT = VDecl->getType(), SavT = DclT; 3108 if (VDecl->isBlockVarDecl()) { 3109 if (VDecl->hasExternalStorage()) { // C99 6.7.8p5 3110 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 3111 VDecl->setInvalidDecl(); 3112 } else if (!VDecl->isInvalidDecl()) { 3113 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3114 VDecl->getDeclName(), DirectInit)) 3115 VDecl->setInvalidDecl(); 3116 3117 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3118 // Don't check invalid declarations to avoid emitting useless diagnostics. 3119 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3120 if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4. 3121 CheckForConstantInitializer(Init, DclT); 3122 } 3123 } 3124 } else if (VDecl->isStaticDataMember() && 3125 VDecl->getLexicalDeclContext()->isRecord()) { 3126 // This is an in-class initialization for a static data member, e.g., 3127 // 3128 // struct S { 3129 // static const int value = 17; 3130 // }; 3131 3132 // Attach the initializer 3133 VDecl->setInit(Context, Init); 3134 3135 // C++ [class.mem]p4: 3136 // A member-declarator can contain a constant-initializer only 3137 // if it declares a static member (9.4) of const integral or 3138 // const enumeration type, see 9.4.2. 3139 QualType T = VDecl->getType(); 3140 if (!T->isDependentType() && 3141 (!Context.getCanonicalType(T).isConstQualified() || 3142 !T->isIntegralType())) { 3143 Diag(VDecl->getLocation(), diag::err_member_initialization) 3144 << VDecl->getDeclName() << Init->getSourceRange(); 3145 VDecl->setInvalidDecl(); 3146 } else { 3147 // C++ [class.static.data]p4: 3148 // If a static data member is of const integral or const 3149 // enumeration type, its declaration in the class definition 3150 // can specify a constant-initializer which shall be an 3151 // integral constant expression (5.19). 3152 if (!Init->isTypeDependent() && 3153 !Init->getType()->isIntegralType()) { 3154 // We have a non-dependent, non-integral or enumeration type. 3155 Diag(Init->getSourceRange().getBegin(), 3156 diag::err_in_class_initializer_non_integral_type) 3157 << Init->getType() << Init->getSourceRange(); 3158 VDecl->setInvalidDecl(); 3159 } else if (!Init->isTypeDependent() && !Init->isValueDependent()) { 3160 // Check whether the expression is a constant expression. 3161 llvm::APSInt Value; 3162 SourceLocation Loc; 3163 if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) { 3164 Diag(Loc, diag::err_in_class_initializer_non_constant) 3165 << Init->getSourceRange(); 3166 VDecl->setInvalidDecl(); 3167 } else if (!VDecl->getType()->isDependentType()) 3168 ImpCastExprToType(Init, VDecl->getType()); 3169 } 3170 } 3171 } else if (VDecl->isFileVarDecl()) { 3172 if (VDecl->getStorageClass() == VarDecl::Extern) 3173 Diag(VDecl->getLocation(), diag::warn_extern_init); 3174 if (!VDecl->isInvalidDecl()) 3175 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 3176 VDecl->getDeclName(), DirectInit)) 3177 VDecl->setInvalidDecl(); 3178 3179 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 3180 // Don't check invalid declarations to avoid emitting useless diagnostics. 3181 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 3182 // C99 6.7.8p4. All file scoped initializers need to be constant. 3183 CheckForConstantInitializer(Init, DclT); 3184 } 3185 } 3186 // If the type changed, it means we had an incomplete type that was 3187 // completed by the initializer. For example: 3188 // int ary[] = { 1, 3, 5 }; 3189 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 3190 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 3191 VDecl->setType(DclT); 3192 Init->setType(DclT); 3193 } 3194 3195 Init = MaybeCreateCXXExprWithTemporaries(Init, 3196 /*ShouldDestroyTemporaries=*/true); 3197 // Attach the initializer to the decl. 3198 VDecl->setInit(Context, Init); 3199 3200 // If the previous declaration of VDecl was a tentative definition, 3201 // remove it from the set of tentative definitions. 3202 if (VDecl->getPreviousDeclaration() && 3203 VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) { 3204 llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos 3205 = TentativeDefinitions.find(VDecl->getDeclName()); 3206 assert(Pos != TentativeDefinitions.end() && 3207 "Unrecorded tentative definition?"); 3208 TentativeDefinitions.erase(Pos); 3209 } 3210 3211 return; 3212} 3213 3214void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 3215 bool TypeContainsUndeducedAuto) { 3216 Decl *RealDecl = dcl.getAs<Decl>(); 3217 3218 // If there is no declaration, there was an error parsing it. Just ignore it. 3219 if (RealDecl == 0) 3220 return; 3221 3222 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 3223 QualType Type = Var->getType(); 3224 3225 // Record tentative definitions. 3226 if (Var->isTentativeDefinition(Context)) 3227 TentativeDefinitions[Var->getDeclName()] = Var; 3228 3229 // C++ [dcl.init.ref]p3: 3230 // The initializer can be omitted for a reference only in a 3231 // parameter declaration (8.3.5), in the declaration of a 3232 // function return type, in the declaration of a class member 3233 // within its class declaration (9.2), and where the extern 3234 // specifier is explicitly used. 3235 if (Type->isReferenceType() && !Var->hasExternalStorage()) { 3236 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 3237 << Var->getDeclName() 3238 << SourceRange(Var->getLocation(), Var->getLocation()); 3239 Var->setInvalidDecl(); 3240 return; 3241 } 3242 3243 // C++0x [dcl.spec.auto]p3 3244 if (TypeContainsUndeducedAuto) { 3245 Diag(Var->getLocation(), diag::err_auto_var_requires_init) 3246 << Var->getDeclName() << Type; 3247 Var->setInvalidDecl(); 3248 return; 3249 } 3250 3251 // C++ [dcl.init]p9: 3252 // 3253 // If no initializer is specified for an object, and the object 3254 // is of (possibly cv-qualified) non-POD class type (or array 3255 // thereof), the object shall be default-initialized; if the 3256 // object is of const-qualified type, the underlying class type 3257 // shall have a user-declared default constructor. 3258 if (getLangOptions().CPlusPlus) { 3259 QualType InitType = Type; 3260 if (const ArrayType *Array = Context.getAsArrayType(Type)) 3261 InitType = Array->getElementType(); 3262 if ((!Var->hasExternalStorage() && !Var->isExternC(Context)) && 3263 InitType->isRecordType() && !InitType->isDependentType()) { 3264 CXXRecordDecl *RD = 3265 cast<CXXRecordDecl>(InitType->getAs<RecordType>()->getDecl()); 3266 CXXConstructorDecl *Constructor = 0; 3267 if (!RequireCompleteType(Var->getLocation(), InitType, 3268 diag::err_invalid_incomplete_type_use)) 3269 Constructor 3270 = PerformInitializationByConstructor(InitType, 0, 0, 3271 Var->getLocation(), 3272 SourceRange(Var->getLocation(), 3273 Var->getLocation()), 3274 Var->getDeclName(), 3275 IK_Default); 3276 if (!Constructor) 3277 Var->setInvalidDecl(); 3278 else { 3279 if (!RD->hasTrivialConstructor() || !RD->hasTrivialDestructor()) 3280 InitializeVarWithConstructor(Var, Constructor, InitType, 0, 0); 3281 FinalizeVarWithDestructor(Var, InitType); 3282 } 3283 } 3284 } 3285 3286#if 0 3287 // FIXME: Temporarily disabled because we are not properly parsing 3288 // linkage specifications on declarations, e.g., 3289 // 3290 // extern "C" const CGPoint CGPointerZero; 3291 // 3292 // C++ [dcl.init]p9: 3293 // 3294 // If no initializer is specified for an object, and the 3295 // object is of (possibly cv-qualified) non-POD class type (or 3296 // array thereof), the object shall be default-initialized; if 3297 // the object is of const-qualified type, the underlying class 3298 // type shall have a user-declared default 3299 // constructor. Otherwise, if no initializer is specified for 3300 // an object, the object and its subobjects, if any, have an 3301 // indeterminate initial value; if the object or any of its 3302 // subobjects are of const-qualified type, the program is 3303 // ill-formed. 3304 // 3305 // This isn't technically an error in C, so we don't diagnose it. 3306 // 3307 // FIXME: Actually perform the POD/user-defined default 3308 // constructor check. 3309 if (getLangOptions().CPlusPlus && 3310 Context.getCanonicalType(Type).isConstQualified() && 3311 !Var->hasExternalStorage()) 3312 Diag(Var->getLocation(), diag::err_const_var_requires_init) 3313 << Var->getName() 3314 << SourceRange(Var->getLocation(), Var->getLocation()); 3315#endif 3316 } 3317} 3318 3319Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 3320 DeclPtrTy *Group, 3321 unsigned NumDecls) { 3322 llvm::SmallVector<Decl*, 8> Decls; 3323 3324 if (DS.isTypeSpecOwned()) 3325 Decls.push_back((Decl*)DS.getTypeRep()); 3326 3327 for (unsigned i = 0; i != NumDecls; ++i) 3328 if (Decl *D = Group[i].getAs<Decl>()) 3329 Decls.push_back(D); 3330 3331 // Perform semantic analysis that depends on having fully processed both 3332 // the declarator and initializer. 3333 for (unsigned i = 0, e = Decls.size(); i != e; ++i) { 3334 VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]); 3335 if (!IDecl) 3336 continue; 3337 QualType T = IDecl->getType(); 3338 3339 // Block scope. C99 6.7p7: If an identifier for an object is declared with 3340 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 3341 if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) { 3342 if (!IDecl->isInvalidDecl() && 3343 RequireCompleteType(IDecl->getLocation(), T, 3344 diag::err_typecheck_decl_incomplete_type)) 3345 IDecl->setInvalidDecl(); 3346 } 3347 // File scope. C99 6.9.2p2: A declaration of an identifier for an 3348 // object that has file scope without an initializer, and without a 3349 // storage-class specifier or with the storage-class specifier "static", 3350 // constitutes a tentative definition. Note: A tentative definition with 3351 // external linkage is valid (C99 6.2.2p5). 3352 if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) { 3353 if (const IncompleteArrayType *ArrayT 3354 = Context.getAsIncompleteArrayType(T)) { 3355 if (RequireCompleteType(IDecl->getLocation(), 3356 ArrayT->getElementType(), 3357 diag::err_illegal_decl_array_incomplete_type)) 3358 IDecl->setInvalidDecl(); 3359 } else if (IDecl->getStorageClass() == VarDecl::Static) { 3360 // C99 6.9.2p3: If the declaration of an identifier for an object is 3361 // a tentative definition and has internal linkage (C99 6.2.2p3), the 3362 // declared type shall not be an incomplete type. 3363 // NOTE: code such as the following 3364 // static struct s; 3365 // struct s { int a; }; 3366 // is accepted by gcc. Hence here we issue a warning instead of 3367 // an error and we do not invalidate the static declaration. 3368 // NOTE: to avoid multiple warnings, only check the first declaration. 3369 if (IDecl->getPreviousDeclaration() == 0) 3370 RequireCompleteType(IDecl->getLocation(), T, 3371 diag::ext_typecheck_decl_incomplete_type); 3372 } 3373 } 3374 } 3375 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, 3376 Decls.data(), Decls.size())); 3377} 3378 3379 3380/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 3381/// to introduce parameters into function prototype scope. 3382Sema::DeclPtrTy 3383Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 3384 const DeclSpec &DS = D.getDeclSpec(); 3385 3386 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 3387 VarDecl::StorageClass StorageClass = VarDecl::None; 3388 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 3389 StorageClass = VarDecl::Register; 3390 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 3391 Diag(DS.getStorageClassSpecLoc(), 3392 diag::err_invalid_storage_class_in_func_decl); 3393 D.getMutableDeclSpec().ClearStorageClassSpecs(); 3394 } 3395 3396 if (D.getDeclSpec().isThreadSpecified()) 3397 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 3398 3399 DiagnoseFunctionSpecifiers(D); 3400 3401 // Check that there are no default arguments inside the type of this 3402 // parameter (C++ only). 3403 if (getLangOptions().CPlusPlus) 3404 CheckExtraCXXDefaultArguments(D); 3405 3406 DeclaratorInfo *DInfo = 0; 3407 TagDecl *OwnedDecl = 0; 3408 QualType parmDeclType = GetTypeForDeclarator(D, S, &DInfo, /*Skip=*/0, 3409 &OwnedDecl); 3410 3411 if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) { 3412 // C++ [dcl.fct]p6: 3413 // Types shall not be defined in return or parameter types. 3414 Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type) 3415 << Context.getTypeDeclType(OwnedDecl); 3416 } 3417 3418 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 3419 // Can this happen for params? We already checked that they don't conflict 3420 // among each other. Here they can only shadow globals, which is ok. 3421 IdentifierInfo *II = D.getIdentifier(); 3422 if (II) { 3423 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 3424 if (PrevDecl->isTemplateParameter()) { 3425 // Maybe we will complain about the shadowed template parameter. 3426 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 3427 // Just pretend that we didn't see the previous declaration. 3428 PrevDecl = 0; 3429 } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) { 3430 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 3431 3432 // Recover by removing the name 3433 II = 0; 3434 D.SetIdentifier(0, D.getIdentifierLoc()); 3435 } 3436 } 3437 } 3438 3439 // Parameters can not be abstract class types. 3440 // For record types, this is done by the AbstractClassUsageDiagnoser once 3441 // the class has been completely parsed. 3442 if (!CurContext->isRecord() && 3443 RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType, 3444 diag::err_abstract_type_in_decl, 3445 AbstractParamType)) 3446 D.setInvalidType(true); 3447 3448 QualType T = adjustParameterType(parmDeclType); 3449 3450 ParmVarDecl *New; 3451 if (T == parmDeclType) // parameter type did not need adjustment 3452 New = ParmVarDecl::Create(Context, CurContext, 3453 D.getIdentifierLoc(), II, 3454 parmDeclType, DInfo, StorageClass, 3455 0); 3456 else // keep track of both the adjusted and unadjusted types 3457 New = OriginalParmVarDecl::Create(Context, CurContext, 3458 D.getIdentifierLoc(), II, T, DInfo, 3459 parmDeclType, StorageClass, 0); 3460 3461 if (D.isInvalidType()) 3462 New->setInvalidDecl(); 3463 3464 // Parameter declarators cannot be interface types. All ObjC objects are 3465 // passed by reference. 3466 if (T->isObjCInterfaceType()) { 3467 Diag(D.getIdentifierLoc(), 3468 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T; 3469 New->setInvalidDecl(); 3470 } 3471 3472 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 3473 if (D.getCXXScopeSpec().isSet()) { 3474 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 3475 << D.getCXXScopeSpec().getRange(); 3476 New->setInvalidDecl(); 3477 } 3478 3479 // Add the parameter declaration into this scope. 3480 S->AddDecl(DeclPtrTy::make(New)); 3481 if (II) 3482 IdResolver.AddDecl(New); 3483 3484 ProcessDeclAttributes(S, New, D); 3485 3486 if (New->hasAttr<BlocksAttr>()) { 3487 Diag(New->getLocation(), diag::err_block_on_nonlocal); 3488 } 3489 return DeclPtrTy::make(New); 3490} 3491 3492void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 3493 SourceLocation LocAfterDecls) { 3494 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3495 "Not a function declarator!"); 3496 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3497 3498 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 3499 // for a K&R function. 3500 if (!FTI.hasPrototype) { 3501 for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) { 3502 --i; 3503 if (FTI.ArgInfo[i].Param == 0) { 3504 std::string Code = " int "; 3505 Code += FTI.ArgInfo[i].Ident->getName(); 3506 Code += ";\n"; 3507 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 3508 << FTI.ArgInfo[i].Ident 3509 << CodeModificationHint::CreateInsertion(LocAfterDecls, Code); 3510 3511 // Implicitly declare the argument as type 'int' for lack of a better 3512 // type. 3513 DeclSpec DS; 3514 const char* PrevSpec; // unused 3515 unsigned DiagID; // unused 3516 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 3517 PrevSpec, DiagID); 3518 Declarator ParamD(DS, Declarator::KNRTypeListContext); 3519 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 3520 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 3521 } 3522 } 3523 } 3524} 3525 3526Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, 3527 Declarator &D) { 3528 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 3529 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3530 "Not a function declarator!"); 3531 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3532 3533 if (FTI.hasPrototype) { 3534 // FIXME: Diagnose arguments without names in C. 3535 } 3536 3537 Scope *ParentScope = FnBodyScope->getParent(); 3538 3539 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 3540 MultiTemplateParamsArg(*this), 3541 /*IsFunctionDefinition=*/true); 3542 return ActOnStartOfFunctionDef(FnBodyScope, DP); 3543} 3544 3545Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) { 3546 if (!D) 3547 return D; 3548 FunctionDecl *FD = cast<FunctionDecl>(D.getAs<Decl>()); 3549 3550 CurFunctionNeedsScopeChecking = false; 3551 3552 // See if this is a redefinition. 3553 const FunctionDecl *Definition; 3554 if (FD->getBody(Definition)) { 3555 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 3556 Diag(Definition->getLocation(), diag::note_previous_definition); 3557 } 3558 3559 // Builtin functions cannot be defined. 3560 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3561 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 3562 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 3563 FD->setInvalidDecl(); 3564 } 3565 } 3566 3567 // The return type of a function definition must be complete 3568 // (C99 6.9.1p3, C++ [dcl.fct]p6). 3569 QualType ResultType = FD->getResultType(); 3570 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 3571 !FD->isInvalidDecl() && 3572 RequireCompleteType(FD->getLocation(), ResultType, 3573 diag::err_func_def_incomplete_result)) 3574 FD->setInvalidDecl(); 3575 3576 // GNU warning -Wmissing-prototypes: 3577 // Warn if a global function is defined without a previous 3578 // prototype declaration. This warning is issued even if the 3579 // definition itself provides a prototype. The aim is to detect 3580 // global functions that fail to be declared in header files. 3581 if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) && 3582 !FD->isMain(Context)) { 3583 bool MissingPrototype = true; 3584 for (const FunctionDecl *Prev = FD->getPreviousDeclaration(); 3585 Prev; Prev = Prev->getPreviousDeclaration()) { 3586 // Ignore any declarations that occur in function or method 3587 // scope, because they aren't visible from the header. 3588 if (Prev->getDeclContext()->isFunctionOrMethod()) 3589 continue; 3590 3591 MissingPrototype = !Prev->getType()->isFunctionProtoType(); 3592 break; 3593 } 3594 3595 if (MissingPrototype) 3596 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 3597 } 3598 3599 if (FnBodyScope) 3600 PushDeclContext(FnBodyScope, FD); 3601 3602 // Check the validity of our function parameters 3603 CheckParmsForFunctionDef(FD); 3604 3605 // Introduce our parameters into the function scope 3606 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 3607 ParmVarDecl *Param = FD->getParamDecl(p); 3608 Param->setOwningFunction(FD); 3609 3610 // If this has an identifier, add it to the scope stack. 3611 if (Param->getIdentifier() && FnBodyScope) 3612 PushOnScopeChains(Param, FnBodyScope); 3613 } 3614 3615 // Checking attributes of current function definition 3616 // dllimport attribute. 3617 if (FD->getAttr<DLLImportAttr>() && 3618 (!FD->getAttr<DLLExportAttr>())) { 3619 // dllimport attribute cannot be applied to definition. 3620 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 3621 Diag(FD->getLocation(), 3622 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 3623 << "dllimport"; 3624 FD->setInvalidDecl(); 3625 return DeclPtrTy::make(FD); 3626 } else { 3627 // If a symbol previously declared dllimport is later defined, the 3628 // attribute is ignored in subsequent references, and a warning is 3629 // emitted. 3630 Diag(FD->getLocation(), 3631 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3632 << FD->getNameAsCString() << "dllimport"; 3633 } 3634 } 3635 return DeclPtrTy::make(FD); 3636} 3637 3638Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) { 3639 return ActOnFinishFunctionBody(D, move(BodyArg), false); 3640} 3641 3642Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg, 3643 bool IsInstantiation) { 3644 Decl *dcl = D.getAs<Decl>(); 3645 Stmt *Body = BodyArg.takeAs<Stmt>(); 3646 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3647 FD->setBody(Body); 3648 if (FD->isMain(Context)) 3649 // C and C++ allow for main to automagically return 0. 3650 // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3. 3651 FD->setHasImplicitReturnZero(true); 3652 else 3653 CheckFallThroughForFunctionDef(FD, Body); 3654 3655 if (!FD->isInvalidDecl()) 3656 DiagnoseUnusedParameters(FD->param_begin(), FD->param_end()); 3657 3658 // C++ [basic.def.odr]p2: 3659 // [...] A virtual member function is used if it is not pure. [...] 3660 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 3661 if (Method->isVirtual() && !Method->isPure()) 3662 MarkDeclarationReferenced(Method->getLocation(), Method); 3663 3664 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3665 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3666 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3667 MD->setBody(Body); 3668 CheckFallThroughForFunctionDef(MD, Body); 3669 MD->setEndLoc(Body->getLocEnd()); 3670 3671 if (!MD->isInvalidDecl()) 3672 DiagnoseUnusedParameters(MD->param_begin(), MD->param_end()); 3673 } else { 3674 Body->Destroy(Context); 3675 return DeclPtrTy(); 3676 } 3677 if (!IsInstantiation) 3678 PopDeclContext(); 3679 3680 // Verify and clean out per-function state. 3681 3682 assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?"); 3683 3684 // Check goto/label use. 3685 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3686 I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) { 3687 LabelStmt *L = I->second; 3688 3689 // Verify that we have no forward references left. If so, there was a goto 3690 // or address of a label taken, but no definition of it. Label fwd 3691 // definitions are indicated with a null substmt. 3692 if (L->getSubStmt() != 0) 3693 continue; 3694 3695 // Emit error. 3696 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3697 3698 // At this point, we have gotos that use the bogus label. Stitch it into 3699 // the function body so that they aren't leaked and that the AST is well 3700 // formed. 3701 if (Body == 0) { 3702 // The whole function wasn't parsed correctly, just delete this. 3703 L->Destroy(Context); 3704 continue; 3705 } 3706 3707 // Otherwise, the body is valid: we want to stitch the label decl into the 3708 // function somewhere so that it is properly owned and so that the goto 3709 // has a valid target. Do this by creating a new compound stmt with the 3710 // label in it. 3711 3712 // Give the label a sub-statement. 3713 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3714 3715 CompoundStmt *Compound = isa<CXXTryStmt>(Body) ? 3716 cast<CXXTryStmt>(Body)->getTryBlock() : 3717 cast<CompoundStmt>(Body); 3718 std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end()); 3719 Elements.push_back(L); 3720 Compound->setStmts(Context, &Elements[0], Elements.size()); 3721 } 3722 FunctionLabelMap.clear(); 3723 3724 if (!Body) return D; 3725 3726 // Verify that that gotos and switch cases don't jump into scopes illegally. 3727 if (CurFunctionNeedsScopeChecking) 3728 DiagnoseInvalidJumps(Body); 3729 3730 // C++ constructors that have function-try-blocks can't have return 3731 // statements in the handlers of that block. (C++ [except.handle]p14) 3732 // Verify this. 3733 if (isa<CXXConstructorDecl>(dcl) && isa<CXXTryStmt>(Body)) 3734 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 3735 3736 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) 3737 Destructor->computeBaseOrMembersToDestroy(Context); 3738 return D; 3739} 3740 3741/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3742/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3743NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3744 IdentifierInfo &II, Scope *S) { 3745 // Before we produce a declaration for an implicitly defined 3746 // function, see whether there was a locally-scoped declaration of 3747 // this name as a function or variable. If so, use that 3748 // (non-visible) declaration, and complain about it. 3749 llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos 3750 = LocallyScopedExternalDecls.find(&II); 3751 if (Pos != LocallyScopedExternalDecls.end()) { 3752 Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second; 3753 Diag(Pos->second->getLocation(), diag::note_previous_declaration); 3754 return Pos->second; 3755 } 3756 3757 // Extension in C99. Legal in C90, but warn about it. 3758 if (getLangOptions().C99) 3759 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3760 else 3761 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3762 3763 // FIXME: handle stuff like: 3764 // void foo() { extern float X(); } 3765 // void bar() { X(); } <-- implicit decl for X in another scope. 3766 3767 // Set a Declarator for the implicit definition: int foo(); 3768 const char *Dummy; 3769 DeclSpec DS; 3770 unsigned DiagID; 3771 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID); 3772 Error = Error; // Silence warning. 3773 assert(!Error && "Error setting up implicit decl!"); 3774 Declarator D(DS, Declarator::BlockContext); 3775 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0, 3776 0, 0, false, SourceLocation(), 3777 false, 0,0,0, Loc, Loc, D), 3778 SourceLocation()); 3779 D.SetIdentifier(&II, Loc); 3780 3781 // Insert this function into translation-unit scope. 3782 3783 DeclContext *PrevDC = CurContext; 3784 CurContext = Context.getTranslationUnitDecl(); 3785 3786 FunctionDecl *FD = 3787 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D).getAs<Decl>()); 3788 FD->setImplicit(); 3789 3790 CurContext = PrevDC; 3791 3792 AddKnownFunctionAttributes(FD); 3793 3794 return FD; 3795} 3796 3797/// \brief Adds any function attributes that we know a priori based on 3798/// the declaration of this function. 3799/// 3800/// These attributes can apply both to implicitly-declared builtins 3801/// (like __builtin___printf_chk) or to library-declared functions 3802/// like NSLog or printf. 3803void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3804 if (FD->isInvalidDecl()) 3805 return; 3806 3807 // If this is a built-in function, map its builtin attributes to 3808 // actual attributes. 3809 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3810 // Handle printf-formatting attributes. 3811 unsigned FormatIdx; 3812 bool HasVAListArg; 3813 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3814 if (!FD->getAttr<FormatAttr>()) 3815 FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1, 3816 HasVAListArg ? 0 : FormatIdx + 2)); 3817 } 3818 3819 // Mark const if we don't care about errno and that is the only 3820 // thing preventing the function from being const. This allows 3821 // IRgen to use LLVM intrinsics for such functions. 3822 if (!getLangOptions().MathErrno && 3823 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3824 if (!FD->getAttr<ConstAttr>()) 3825 FD->addAttr(::new (Context) ConstAttr()); 3826 } 3827 3828 if (Context.BuiltinInfo.isNoReturn(BuiltinID)) 3829 FD->addAttr(::new (Context) NoReturnAttr()); 3830 } 3831 3832 IdentifierInfo *Name = FD->getIdentifier(); 3833 if (!Name) 3834 return; 3835 if ((!getLangOptions().CPlusPlus && 3836 FD->getDeclContext()->isTranslationUnit()) || 3837 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3838 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3839 LinkageSpecDecl::lang_c)) { 3840 // Okay: this could be a libc/libm/Objective-C function we know 3841 // about. 3842 } else 3843 return; 3844 3845 if (Name->isStr("NSLog") || Name->isStr("NSLogv")) { 3846 // FIXME: NSLog and NSLogv should be target specific 3847 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3848 // FIXME: We known better than our headers. 3849 const_cast<FormatAttr *>(Format)->setType("printf"); 3850 } else 3851 FD->addAttr(::new (Context) FormatAttr("printf", 1, 3852 Name->isStr("NSLogv") ? 0 : 2)); 3853 } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 3854 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 3855 // target-specific builtins, perhaps? 3856 if (!FD->getAttr<FormatAttr>()) 3857 FD->addAttr(::new (Context) FormatAttr("printf", 2, 3858 Name->isStr("vasprintf") ? 0 : 3)); 3859 } 3860} 3861 3862TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T) { 3863 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3864 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3865 3866 // Scope manipulation handled by caller. 3867 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3868 D.getIdentifierLoc(), 3869 D.getIdentifier(), 3870 T); 3871 3872 if (TagType *TT = dyn_cast<TagType>(T)) { 3873 TagDecl *TD = TT->getDecl(); 3874 3875 // If the TagDecl that the TypedefDecl points to is an anonymous decl 3876 // keep track of the TypedefDecl. 3877 if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl()) 3878 TD->setTypedefForAnonDecl(NewTD); 3879 } 3880 3881 if (D.isInvalidType()) 3882 NewTD->setInvalidDecl(); 3883 return NewTD; 3884} 3885 3886 3887/// \brief Determine whether a tag with a given kind is acceptable 3888/// as a redeclaration of the given tag declaration. 3889/// 3890/// \returns true if the new tag kind is acceptable, false otherwise. 3891bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 3892 TagDecl::TagKind NewTag, 3893 SourceLocation NewTagLoc, 3894 const IdentifierInfo &Name) { 3895 // C++ [dcl.type.elab]p3: 3896 // The class-key or enum keyword present in the 3897 // elaborated-type-specifier shall agree in kind with the 3898 // declaration to which the name in theelaborated-type-specifier 3899 // refers. This rule also applies to the form of 3900 // elaborated-type-specifier that declares a class-name or 3901 // friend class since it can be construed as referring to the 3902 // definition of the class. Thus, in any 3903 // elaborated-type-specifier, the enum keyword shall be used to 3904 // refer to an enumeration (7.2), the union class-keyshall be 3905 // used to refer to a union (clause 9), and either the class or 3906 // struct class-key shall be used to refer to a class (clause 9) 3907 // declared using the class or struct class-key. 3908 TagDecl::TagKind OldTag = Previous->getTagKind(); 3909 if (OldTag == NewTag) 3910 return true; 3911 3912 if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) && 3913 (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) { 3914 // Warn about the struct/class tag mismatch. 3915 bool isTemplate = false; 3916 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 3917 isTemplate = Record->getDescribedClassTemplate(); 3918 3919 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 3920 << (NewTag == TagDecl::TK_class) 3921 << isTemplate << &Name 3922 << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc), 3923 OldTag == TagDecl::TK_class? "class" : "struct"); 3924 Diag(Previous->getLocation(), diag::note_previous_use); 3925 return true; 3926 } 3927 return false; 3928} 3929 3930/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3931/// former case, Name will be non-null. In the later case, Name will be null. 3932/// TagSpec indicates what kind of tag this is. TUK indicates whether this is a 3933/// reference/declaration/definition of a tag. 3934Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 3935 SourceLocation KWLoc, const CXXScopeSpec &SS, 3936 IdentifierInfo *Name, SourceLocation NameLoc, 3937 AttributeList *Attr, AccessSpecifier AS, 3938 MultiTemplateParamsArg TemplateParameterLists, 3939 bool &OwnedDecl) { 3940 // If this is not a definition, it must have a name. 3941 assert((Name != 0 || TUK == TUK_Definition) && 3942 "Nameless record must be a definition!"); 3943 3944 OwnedDecl = false; 3945 TagDecl::TagKind Kind; 3946 switch (TagSpec) { 3947 default: assert(0 && "Unknown tag type!"); 3948 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3949 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3950 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3951 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3952 } 3953 3954 if (TUK != TUK_Reference) { 3955 if (TemplateParameterList *TemplateParams 3956 = MatchTemplateParametersToScopeSpecifier(KWLoc, SS, 3957 (TemplateParameterList**)TemplateParameterLists.get(), 3958 TemplateParameterLists.size())) { 3959 if (TemplateParams->size() > 0) { 3960 // This is a declaration or definition of a class template (which may 3961 // be a member of another template). 3962 OwnedDecl = false; 3963 DeclResult Result = CheckClassTemplate(S, TagSpec, TUK, KWLoc, 3964 SS, Name, NameLoc, Attr, 3965 move(TemplateParameterLists), 3966 AS); 3967 return Result.get(); 3968 } else { 3969 // FIXME: diagnose the extraneous 'template<>', once we recover 3970 // slightly better in ParseTemplate.cpp from bogus template 3971 // parameters. 3972 } 3973 } 3974 } 3975 3976 DeclContext *SearchDC = CurContext; 3977 DeclContext *DC = CurContext; 3978 NamedDecl *PrevDecl = 0; 3979 3980 bool Invalid = false; 3981 3982 if (Name && SS.isNotEmpty()) { 3983 // We have a nested-name tag ('struct foo::bar'). 3984 3985 // Check for invalid 'foo::'. 3986 if (SS.isInvalid()) { 3987 Name = 0; 3988 goto CreateNewDecl; 3989 } 3990 3991 if (RequireCompleteDeclContext(SS)) 3992 return DeclPtrTy::make((Decl *)0); 3993 3994 DC = computeDeclContext(SS, true); 3995 SearchDC = DC; 3996 // Look-up name inside 'foo::'. 3997 PrevDecl 3998 = dyn_cast_or_null<TagDecl>( 3999 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 4000 4001 // A tag 'foo::bar' must already exist. 4002 if (PrevDecl == 0) { 4003 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 4004 Name = 0; 4005 Invalid = true; 4006 goto CreateNewDecl; 4007 } 4008 } else if (Name) { 4009 // If this is a named struct, check to see if there was a previous forward 4010 // declaration or definition. 4011 // FIXME: We're looking into outer scopes here, even when we 4012 // shouldn't be. Doing so can result in ambiguities that we 4013 // shouldn't be diagnosing. 4014 LookupResult R = LookupName(S, Name, LookupTagName, 4015 /*RedeclarationOnly=*/(TUK != TUK_Reference)); 4016 if (R.isAmbiguous()) { 4017 DiagnoseAmbiguousLookup(R, Name, NameLoc); 4018 // FIXME: This is not best way to recover from case like: 4019 // 4020 // struct S s; 4021 // 4022 // causes needless "incomplete type" error later. 4023 Name = 0; 4024 PrevDecl = 0; 4025 Invalid = true; 4026 } else 4027 PrevDecl = R; 4028 4029 if (!getLangOptions().CPlusPlus && TUK != TUK_Reference) { 4030 // FIXME: This makes sure that we ignore the contexts associated 4031 // with C structs, unions, and enums when looking for a matching 4032 // tag declaration or definition. See the similar lookup tweak 4033 // in Sema::LookupName; is there a better way to deal with this? 4034 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 4035 SearchDC = SearchDC->getParent(); 4036 } 4037 } 4038 4039 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4040 // Maybe we will complain about the shadowed template parameter. 4041 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 4042 // Just pretend that we didn't see the previous declaration. 4043 PrevDecl = 0; 4044 } 4045 4046 if (PrevDecl) { 4047 // Check whether the previous declaration is usable. 4048 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 4049 4050 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 4051 // If this is a use of a previous tag, or if the tag is already declared 4052 // in the same scope (so that the definition/declaration completes or 4053 // rementions the tag), reuse the decl. 4054 if (TUK == TUK_Reference || TUK == TUK_Friend || 4055 isDeclInScope(PrevDecl, SearchDC, S)) { 4056 // Make sure that this wasn't declared as an enum and now used as a 4057 // struct or something similar. 4058 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) { 4059 bool SafeToContinue 4060 = (PrevTagDecl->getTagKind() != TagDecl::TK_enum && 4061 Kind != TagDecl::TK_enum); 4062 if (SafeToContinue) 4063 Diag(KWLoc, diag::err_use_with_wrong_tag) 4064 << Name 4065 << CodeModificationHint::CreateReplacement(SourceRange(KWLoc), 4066 PrevTagDecl->getKindName()); 4067 else 4068 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 4069 Diag(PrevDecl->getLocation(), diag::note_previous_use); 4070 4071 if (SafeToContinue) 4072 Kind = PrevTagDecl->getTagKind(); 4073 else { 4074 // Recover by making this an anonymous redefinition. 4075 Name = 0; 4076 PrevDecl = 0; 4077 Invalid = true; 4078 } 4079 } 4080 4081 if (!Invalid) { 4082 // If this is a use, just return the declaration we found. 4083 4084 // FIXME: In the future, return a variant or some other clue 4085 // for the consumer of this Decl to know it doesn't own it. 4086 // For our current ASTs this shouldn't be a problem, but will 4087 // need to be changed with DeclGroups. 4088 if (TUK == TUK_Reference) 4089 return DeclPtrTy::make(PrevDecl); 4090 4091 // If this is a friend, make sure we create the new 4092 // declaration in the appropriate semantic context. 4093 if (TUK == TUK_Friend) 4094 SearchDC = PrevDecl->getDeclContext(); 4095 4096 // Diagnose attempts to redefine a tag. 4097 if (TUK == TUK_Definition) { 4098 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 4099 Diag(NameLoc, diag::err_redefinition) << Name; 4100 Diag(Def->getLocation(), diag::note_previous_definition); 4101 // If this is a redefinition, recover by making this 4102 // struct be anonymous, which will make any later 4103 // references get the previous definition. 4104 Name = 0; 4105 PrevDecl = 0; 4106 Invalid = true; 4107 } else { 4108 // If the type is currently being defined, complain 4109 // about a nested redefinition. 4110 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 4111 if (Tag->isBeingDefined()) { 4112 Diag(NameLoc, diag::err_nested_redefinition) << Name; 4113 Diag(PrevTagDecl->getLocation(), 4114 diag::note_previous_definition); 4115 Name = 0; 4116 PrevDecl = 0; 4117 Invalid = true; 4118 } 4119 } 4120 4121 // Okay, this is definition of a previously declared or referenced 4122 // tag PrevDecl. We're going to create a new Decl for it. 4123 } 4124 } 4125 // If we get here we have (another) forward declaration or we 4126 // have a definition. Just create a new decl. 4127 4128 } else { 4129 // If we get here, this is a definition of a new tag type in a nested 4130 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 4131 // new decl/type. We set PrevDecl to NULL so that the entities 4132 // have distinct types. 4133 PrevDecl = 0; 4134 } 4135 // If we get here, we're going to create a new Decl. If PrevDecl 4136 // is non-NULL, it's a definition of the tag declared by 4137 // PrevDecl. If it's NULL, we have a new definition. 4138 } else { 4139 // PrevDecl is a namespace, template, or anything else 4140 // that lives in the IDNS_Tag identifier namespace. 4141 if (isDeclInScope(PrevDecl, SearchDC, S)) { 4142 // The tag name clashes with a namespace name, issue an error and 4143 // recover by making this tag be anonymous. 4144 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 4145 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 4146 Name = 0; 4147 PrevDecl = 0; 4148 Invalid = true; 4149 } else { 4150 // The existing declaration isn't relevant to us; we're in a 4151 // new scope, so clear out the previous declaration. 4152 PrevDecl = 0; 4153 } 4154 } 4155 } else if (TUK == TUK_Reference && SS.isEmpty() && Name && 4156 (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) { 4157 // C++ [basic.scope.pdecl]p5: 4158 // -- for an elaborated-type-specifier of the form 4159 // 4160 // class-key identifier 4161 // 4162 // if the elaborated-type-specifier is used in the 4163 // decl-specifier-seq or parameter-declaration-clause of a 4164 // function defined in namespace scope, the identifier is 4165 // declared as a class-name in the namespace that contains 4166 // the declaration; otherwise, except as a friend 4167 // declaration, the identifier is declared in the smallest 4168 // non-class, non-function-prototype scope that contains the 4169 // declaration. 4170 // 4171 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 4172 // C structs and unions. 4173 // 4174 // GNU C also supports this behavior as part of its incomplete 4175 // enum types extension, while GNU C++ does not. 4176 // 4177 // Find the context where we'll be declaring the tag. 4178 // FIXME: We would like to maintain the current DeclContext as the 4179 // lexical context, 4180 while (SearchDC->isRecord()) 4181 SearchDC = SearchDC->getParent(); 4182 4183 // Find the scope where we'll be declaring the tag. 4184 while (S->isClassScope() || 4185 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 4186 ((S->getFlags() & Scope::DeclScope) == 0) || 4187 (S->getEntity() && 4188 ((DeclContext *)S->getEntity())->isTransparentContext())) 4189 S = S->getParent(); 4190 4191 } else if (TUK == TUK_Friend && SS.isEmpty() && Name) { 4192 // C++ [namespace.memdef]p3: 4193 // If a friend declaration in a non-local class first declares a 4194 // class or function, the friend class or function is a member of 4195 // the innermost enclosing namespace. 4196 while (!SearchDC->isFileContext()) 4197 SearchDC = SearchDC->getParent(); 4198 4199 // The entity of a decl scope is a DeclContext; see PushDeclContext. 4200 while (S->getEntity() != SearchDC) 4201 S = S->getParent(); 4202 } 4203 4204CreateNewDecl: 4205 4206 // If there is an identifier, use the location of the identifier as the 4207 // location of the decl, otherwise use the location of the struct/union 4208 // keyword. 4209 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 4210 4211 // Otherwise, create a new declaration. If there is a previous 4212 // declaration of the same entity, the two will be linked via 4213 // PrevDecl. 4214 TagDecl *New; 4215 4216 if (Kind == TagDecl::TK_enum) { 4217 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4218 // enum X { A, B, C } D; D should chain to X. 4219 New = EnumDecl::Create(Context, SearchDC, Loc, Name, KWLoc, 4220 cast_or_null<EnumDecl>(PrevDecl)); 4221 // If this is an undefined enum, warn. 4222 if (TUK != TUK_Definition && !Invalid) { 4223 unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum 4224 : diag::ext_forward_ref_enum; 4225 Diag(Loc, DK); 4226 } 4227 } else { 4228 // struct/union/class 4229 4230 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 4231 // struct X { int A; } D; D should chain to X. 4232 if (getLangOptions().CPlusPlus) 4233 // FIXME: Look for a way to use RecordDecl for simple structs. 4234 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4235 cast_or_null<CXXRecordDecl>(PrevDecl)); 4236 else 4237 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, KWLoc, 4238 cast_or_null<RecordDecl>(PrevDecl)); 4239 } 4240 4241 if (Kind != TagDecl::TK_enum) { 4242 // Handle #pragma pack: if the #pragma pack stack has non-default 4243 // alignment, make up a packed attribute for this decl. These 4244 // attributes are checked when the ASTContext lays out the 4245 // structure. 4246 // 4247 // It is important for implementing the correct semantics that this 4248 // happen here (in act on tag decl). The #pragma pack stack is 4249 // maintained as a result of parser callbacks which can occur at 4250 // many points during the parsing of a struct declaration (because 4251 // the #pragma tokens are effectively skipped over during the 4252 // parsing of the struct). 4253 if (unsigned Alignment = getPragmaPackAlignment()) 4254 New->addAttr(::new (Context) PragmaPackAttr(Alignment * 8)); 4255 } 4256 4257 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 4258 // C++ [dcl.typedef]p3: 4259 // [...] Similarly, in a given scope, a class or enumeration 4260 // shall not be declared with the same name as a typedef-name 4261 // that is declared in that scope and refers to a type other 4262 // than the class or enumeration itself. 4263 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 4264 TypedefDecl *PrevTypedef = 0; 4265 if (Lookup.getKind() == LookupResult::Found) 4266 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 4267 4268 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 4269 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 4270 Context.getCanonicalType(Context.getTypeDeclType(New))) { 4271 Diag(Loc, diag::err_tag_definition_of_typedef) 4272 << Context.getTypeDeclType(New) 4273 << PrevTypedef->getUnderlyingType(); 4274 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 4275 Invalid = true; 4276 } 4277 } 4278 4279 if (Invalid) 4280 New->setInvalidDecl(); 4281 4282 if (Attr) 4283 ProcessDeclAttributeList(S, New, Attr); 4284 4285 // If we're declaring or defining a tag in function prototype scope 4286 // in C, note that this type can only be used within the function. 4287 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 4288 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 4289 4290 // Set the lexical context. If the tag has a C++ scope specifier, the 4291 // lexical context will be different from the semantic context. 4292 New->setLexicalDeclContext(CurContext); 4293 4294 // Set the access specifier. 4295 if (!Invalid && TUK != TUK_Friend) 4296 SetMemberAccessSpecifier(New, PrevDecl, AS); 4297 4298 if (TUK == TUK_Definition) 4299 New->startDefinition(); 4300 4301 // If this has an identifier, add it to the scope stack. 4302 if (Name && TUK != TUK_Friend) { 4303 S = getNonFieldDeclScope(S); 4304 PushOnScopeChains(New, S); 4305 } else { 4306 CurContext->addDecl(New); 4307 } 4308 4309 // If this is the C FILE type, notify the AST context. 4310 if (IdentifierInfo *II = New->getIdentifier()) 4311 if (!New->isInvalidDecl() && 4312 New->getDeclContext()->getLookupContext()->isTranslationUnit() && 4313 II->isStr("FILE")) 4314 Context.setFILEDecl(New); 4315 4316 OwnedDecl = true; 4317 return DeclPtrTy::make(New); 4318} 4319 4320void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) { 4321 AdjustDeclIfTemplate(TagD); 4322 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4323 4324 // Enter the tag context. 4325 PushDeclContext(S, Tag); 4326 4327 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 4328 FieldCollector->StartClass(); 4329 4330 if (Record->getIdentifier()) { 4331 // C++ [class]p2: 4332 // [...] The class-name is also inserted into the scope of the 4333 // class itself; this is known as the injected-class-name. For 4334 // purposes of access checking, the injected-class-name is treated 4335 // as if it were a public member name. 4336 CXXRecordDecl *InjectedClassName 4337 = CXXRecordDecl::Create(Context, Record->getTagKind(), 4338 CurContext, Record->getLocation(), 4339 Record->getIdentifier(), 4340 Record->getTagKeywordLoc(), 4341 Record); 4342 InjectedClassName->setImplicit(); 4343 InjectedClassName->setAccess(AS_public); 4344 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 4345 InjectedClassName->setDescribedClassTemplate(Template); 4346 PushOnScopeChains(InjectedClassName, S); 4347 assert(InjectedClassName->isInjectedClassName() && 4348 "Broken injected-class-name"); 4349 } 4350 } 4351} 4352 4353void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD, 4354 SourceLocation RBraceLoc) { 4355 AdjustDeclIfTemplate(TagD); 4356 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4357 Tag->setRBraceLoc(RBraceLoc); 4358 4359 if (isa<CXXRecordDecl>(Tag)) 4360 FieldCollector->FinishClass(); 4361 4362 // Exit this scope of this tag's definition. 4363 PopDeclContext(); 4364 4365 // Notify the consumer that we've defined a tag. 4366 Consumer.HandleTagDeclDefinition(Tag); 4367} 4368 4369// Note that FieldName may be null for anonymous bitfields. 4370bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 4371 QualType FieldTy, const Expr *BitWidth, 4372 bool *ZeroWidth) { 4373 // Default to true; that shouldn't confuse checks for emptiness 4374 if (ZeroWidth) 4375 *ZeroWidth = true; 4376 4377 // C99 6.7.2.1p4 - verify the field type. 4378 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 4379 if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) { 4380 // Handle incomplete types with specific error. 4381 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) 4382 return true; 4383 if (FieldName) 4384 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 4385 << FieldName << FieldTy << BitWidth->getSourceRange(); 4386 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 4387 << FieldTy << BitWidth->getSourceRange(); 4388 } 4389 4390 // If the bit-width is type- or value-dependent, don't try to check 4391 // it now. 4392 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 4393 return false; 4394 4395 llvm::APSInt Value; 4396 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 4397 return true; 4398 4399 if (Value != 0 && ZeroWidth) 4400 *ZeroWidth = false; 4401 4402 // Zero-width bitfield is ok for anonymous field. 4403 if (Value == 0 && FieldName) 4404 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 4405 4406 if (Value.isSigned() && Value.isNegative()) { 4407 if (FieldName) 4408 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 4409 << FieldName << Value.toString(10); 4410 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 4411 << Value.toString(10); 4412 } 4413 4414 if (!FieldTy->isDependentType()) { 4415 uint64_t TypeSize = Context.getTypeSize(FieldTy); 4416 if (Value.getZExtValue() > TypeSize) { 4417 if (FieldName) 4418 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 4419 << FieldName << (unsigned)TypeSize; 4420 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size) 4421 << (unsigned)TypeSize; 4422 } 4423 } 4424 4425 return false; 4426} 4427 4428/// ActOnField - Each field of a struct/union/class is passed into this in order 4429/// to create a FieldDecl object for it. 4430Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD, 4431 SourceLocation DeclStart, 4432 Declarator &D, ExprTy *BitfieldWidth) { 4433 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()), 4434 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 4435 AS_public); 4436 return DeclPtrTy::make(Res); 4437} 4438 4439/// HandleField - Analyze a field of a C struct or a C++ data member. 4440/// 4441FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 4442 SourceLocation DeclStart, 4443 Declarator &D, Expr *BitWidth, 4444 AccessSpecifier AS) { 4445 IdentifierInfo *II = D.getIdentifier(); 4446 SourceLocation Loc = DeclStart; 4447 if (II) Loc = D.getIdentifierLoc(); 4448 4449 DeclaratorInfo *DInfo = 0; 4450 QualType T = GetTypeForDeclarator(D, S, &DInfo); 4451 if (getLangOptions().CPlusPlus) 4452 CheckExtraCXXDefaultArguments(D); 4453 4454 DiagnoseFunctionSpecifiers(D); 4455 4456 if (D.getDeclSpec().isThreadSpecified()) 4457 Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread); 4458 4459 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4460 4461 if (PrevDecl && PrevDecl->isTemplateParameter()) { 4462 // Maybe we will complain about the shadowed template parameter. 4463 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 4464 // Just pretend that we didn't see the previous declaration. 4465 PrevDecl = 0; 4466 } 4467 4468 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 4469 PrevDecl = 0; 4470 4471 bool Mutable 4472 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 4473 SourceLocation TSSL = D.getSourceRange().getBegin(); 4474 FieldDecl *NewFD 4475 = CheckFieldDecl(II, T, DInfo, Record, Loc, Mutable, BitWidth, TSSL, 4476 AS, PrevDecl, &D); 4477 if (NewFD->isInvalidDecl() && PrevDecl) { 4478 // Don't introduce NewFD into scope; there's already something 4479 // with the same name in the same scope. 4480 } else if (II) { 4481 PushOnScopeChains(NewFD, S); 4482 } else 4483 Record->addDecl(NewFD); 4484 4485 return NewFD; 4486} 4487 4488/// \brief Build a new FieldDecl and check its well-formedness. 4489/// 4490/// This routine builds a new FieldDecl given the fields name, type, 4491/// record, etc. \p PrevDecl should refer to any previous declaration 4492/// with the same name and in the same scope as the field to be 4493/// created. 4494/// 4495/// \returns a new FieldDecl. 4496/// 4497/// \todo The Declarator argument is a hack. It will be removed once 4498FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 4499 DeclaratorInfo *DInfo, 4500 RecordDecl *Record, SourceLocation Loc, 4501 bool Mutable, Expr *BitWidth, 4502 SourceLocation TSSL, 4503 AccessSpecifier AS, NamedDecl *PrevDecl, 4504 Declarator *D) { 4505 IdentifierInfo *II = Name.getAsIdentifierInfo(); 4506 bool InvalidDecl = false; 4507 if (D) InvalidDecl = D->isInvalidType(); 4508 4509 // If we receive a broken type, recover by assuming 'int' and 4510 // marking this declaration as invalid. 4511 if (T.isNull()) { 4512 InvalidDecl = true; 4513 T = Context.IntTy; 4514 } 4515 4516 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4517 // than a variably modified type. 4518 if (T->isVariablyModifiedType()) { 4519 bool SizeIsNegative; 4520 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 4521 SizeIsNegative); 4522 if (!FixedTy.isNull()) { 4523 Diag(Loc, diag::warn_illegal_constant_array_size); 4524 T = FixedTy; 4525 } else { 4526 if (SizeIsNegative) 4527 Diag(Loc, diag::err_typecheck_negative_array_size); 4528 else 4529 Diag(Loc, diag::err_typecheck_field_variable_size); 4530 InvalidDecl = true; 4531 } 4532 } 4533 4534 // Fields can not have abstract class types 4535 if (RequireNonAbstractType(Loc, T, diag::err_abstract_type_in_decl, 4536 AbstractFieldType)) 4537 InvalidDecl = true; 4538 4539 bool ZeroWidth = false; 4540 // If this is declared as a bit-field, check the bit-field. 4541 if (BitWidth && VerifyBitField(Loc, II, T, BitWidth, &ZeroWidth)) { 4542 InvalidDecl = true; 4543 DeleteExpr(BitWidth); 4544 BitWidth = 0; 4545 ZeroWidth = false; 4546 } 4547 4548 FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, DInfo, 4549 BitWidth, Mutable, TSSL); 4550 if (InvalidDecl) 4551 NewFD->setInvalidDecl(); 4552 4553 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 4554 Diag(Loc, diag::err_duplicate_member) << II; 4555 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4556 NewFD->setInvalidDecl(); 4557 } 4558 4559 if (getLangOptions().CPlusPlus) { 4560 QualType EltTy = Context.getBaseElementType(T); 4561 4562 CXXRecordDecl* CXXRecord = cast<CXXRecordDecl>(Record); 4563 4564 if (!T->isPODType()) 4565 CXXRecord->setPOD(false); 4566 if (!ZeroWidth) 4567 CXXRecord->setEmpty(false); 4568 4569 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 4570 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 4571 4572 if (!RDecl->hasTrivialConstructor()) 4573 CXXRecord->setHasTrivialConstructor(false); 4574 if (!RDecl->hasTrivialCopyConstructor()) 4575 CXXRecord->setHasTrivialCopyConstructor(false); 4576 if (!RDecl->hasTrivialCopyAssignment()) 4577 CXXRecord->setHasTrivialCopyAssignment(false); 4578 if (!RDecl->hasTrivialDestructor()) 4579 CXXRecord->setHasTrivialDestructor(false); 4580 4581 // C++ 9.5p1: An object of a class with a non-trivial 4582 // constructor, a non-trivial copy constructor, a non-trivial 4583 // destructor, or a non-trivial copy assignment operator 4584 // cannot be a member of a union, nor can an array of such 4585 // objects. 4586 // TODO: C++0x alters this restriction significantly. 4587 if (Record->isUnion()) { 4588 // We check for copy constructors before constructors 4589 // because otherwise we'll never get complaints about 4590 // copy constructors. 4591 4592 const CXXSpecialMember invalid = (CXXSpecialMember) -1; 4593 4594 CXXSpecialMember member; 4595 if (!RDecl->hasTrivialCopyConstructor()) 4596 member = CXXCopyConstructor; 4597 else if (!RDecl->hasTrivialConstructor()) 4598 member = CXXDefaultConstructor; 4599 else if (!RDecl->hasTrivialCopyAssignment()) 4600 member = CXXCopyAssignment; 4601 else if (!RDecl->hasTrivialDestructor()) 4602 member = CXXDestructor; 4603 else 4604 member = invalid; 4605 4606 if (member != invalid) { 4607 Diag(Loc, diag::err_illegal_union_member) << Name << member; 4608 DiagnoseNontrivial(RT, member); 4609 NewFD->setInvalidDecl(); 4610 } 4611 } 4612 } 4613 } 4614 4615 // FIXME: We need to pass in the attributes given an AST 4616 // representation, not a parser representation. 4617 if (D) 4618 // FIXME: What to pass instead of TUScope? 4619 ProcessDeclAttributes(TUScope, NewFD, *D); 4620 4621 if (T.isObjCGCWeak()) 4622 Diag(Loc, diag::warn_attribute_weak_on_field); 4623 4624 NewFD->setAccess(AS); 4625 4626 // C++ [dcl.init.aggr]p1: 4627 // An aggregate is an array or a class (clause 9) with [...] no 4628 // private or protected non-static data members (clause 11). 4629 // A POD must be an aggregate. 4630 if (getLangOptions().CPlusPlus && 4631 (AS == AS_private || AS == AS_protected)) { 4632 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 4633 CXXRecord->setAggregate(false); 4634 CXXRecord->setPOD(false); 4635 } 4636 4637 return NewFD; 4638} 4639 4640/// DiagnoseNontrivial - Given that a class has a non-trivial 4641/// special member, figure out why. 4642void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) { 4643 QualType QT(T, 0U); 4644 CXXRecordDecl* RD = cast<CXXRecordDecl>(T->getDecl()); 4645 4646 // Check whether the member was user-declared. 4647 switch (member) { 4648 case CXXDefaultConstructor: 4649 if (RD->hasUserDeclaredConstructor()) { 4650 typedef CXXRecordDecl::ctor_iterator ctor_iter; 4651 for (ctor_iter ci = RD->ctor_begin(), ce = RD->ctor_end(); ci != ce; ++ci) 4652 if (!ci->isImplicitlyDefined(Context)) { 4653 SourceLocation CtorLoc = ci->getLocation(); 4654 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4655 return; 4656 } 4657 4658 assert(0 && "found no user-declared constructors"); 4659 return; 4660 } 4661 break; 4662 4663 case CXXCopyConstructor: 4664 if (RD->hasUserDeclaredCopyConstructor()) { 4665 SourceLocation CtorLoc = 4666 RD->getCopyConstructor(Context, 0)->getLocation(); 4667 Diag(CtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4668 return; 4669 } 4670 break; 4671 4672 case CXXCopyAssignment: 4673 if (RD->hasUserDeclaredCopyAssignment()) { 4674 // FIXME: this should use the location of the copy 4675 // assignment, not the type. 4676 SourceLocation TyLoc = RD->getSourceRange().getBegin(); 4677 Diag(TyLoc, diag::note_nontrivial_user_defined) << QT << member; 4678 return; 4679 } 4680 break; 4681 4682 case CXXDestructor: 4683 if (RD->hasUserDeclaredDestructor()) { 4684 SourceLocation DtorLoc = RD->getDestructor(Context)->getLocation(); 4685 Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member; 4686 return; 4687 } 4688 break; 4689 } 4690 4691 typedef CXXRecordDecl::base_class_iterator base_iter; 4692 4693 // Virtual bases and members inhibit trivial copying/construction, 4694 // but not trivial destruction. 4695 if (member != CXXDestructor) { 4696 // Check for virtual bases. vbases includes indirect virtual bases, 4697 // so we just iterate through the direct bases. 4698 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) 4699 if (bi->isVirtual()) { 4700 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4701 Diag(BaseLoc, diag::note_nontrivial_has_virtual) << QT << 1; 4702 return; 4703 } 4704 4705 // Check for virtual methods. 4706 typedef CXXRecordDecl::method_iterator meth_iter; 4707 for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; 4708 ++mi) { 4709 if (mi->isVirtual()) { 4710 SourceLocation MLoc = mi->getSourceRange().getBegin(); 4711 Diag(MLoc, diag::note_nontrivial_has_virtual) << QT << 0; 4712 return; 4713 } 4714 } 4715 } 4716 4717 bool (CXXRecordDecl::*hasTrivial)() const; 4718 switch (member) { 4719 case CXXDefaultConstructor: 4720 hasTrivial = &CXXRecordDecl::hasTrivialConstructor; break; 4721 case CXXCopyConstructor: 4722 hasTrivial = &CXXRecordDecl::hasTrivialCopyConstructor; break; 4723 case CXXCopyAssignment: 4724 hasTrivial = &CXXRecordDecl::hasTrivialCopyAssignment; break; 4725 case CXXDestructor: 4726 hasTrivial = &CXXRecordDecl::hasTrivialDestructor; break; 4727 default: 4728 assert(0 && "unexpected special member"); return; 4729 } 4730 4731 // Check for nontrivial bases (and recurse). 4732 for (base_iter bi = RD->bases_begin(), be = RD->bases_end(); bi != be; ++bi) { 4733 const RecordType *BaseRT = bi->getType()->getAs<RecordType>(); 4734 assert(BaseRT); 4735 CXXRecordDecl *BaseRecTy = cast<CXXRecordDecl>(BaseRT->getDecl()); 4736 if (!(BaseRecTy->*hasTrivial)()) { 4737 SourceLocation BaseLoc = bi->getSourceRange().getBegin(); 4738 Diag(BaseLoc, diag::note_nontrivial_has_nontrivial) << QT << 1 << member; 4739 DiagnoseNontrivial(BaseRT, member); 4740 return; 4741 } 4742 } 4743 4744 // Check for nontrivial members (and recurse). 4745 typedef RecordDecl::field_iterator field_iter; 4746 for (field_iter fi = RD->field_begin(), fe = RD->field_end(); fi != fe; 4747 ++fi) { 4748 QualType EltTy = Context.getBaseElementType((*fi)->getType()); 4749 if (const RecordType *EltRT = EltTy->getAs<RecordType>()) { 4750 CXXRecordDecl* EltRD = cast<CXXRecordDecl>(EltRT->getDecl()); 4751 4752 if (!(EltRD->*hasTrivial)()) { 4753 SourceLocation FLoc = (*fi)->getLocation(); 4754 Diag(FLoc, diag::note_nontrivial_has_nontrivial) << QT << 0 << member; 4755 DiagnoseNontrivial(EltRT, member); 4756 return; 4757 } 4758 } 4759 } 4760 4761 assert(0 && "found no explanation for non-trivial member"); 4762} 4763 4764/// TranslateIvarVisibility - Translate visibility from a token ID to an 4765/// AST enum value. 4766static ObjCIvarDecl::AccessControl 4767TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 4768 switch (ivarVisibility) { 4769 default: assert(0 && "Unknown visitibility kind"); 4770 case tok::objc_private: return ObjCIvarDecl::Private; 4771 case tok::objc_public: return ObjCIvarDecl::Public; 4772 case tok::objc_protected: return ObjCIvarDecl::Protected; 4773 case tok::objc_package: return ObjCIvarDecl::Package; 4774 } 4775} 4776 4777/// ActOnIvar - Each ivar field of an objective-c class is passed into this 4778/// in order to create an IvarDecl object for it. 4779Sema::DeclPtrTy Sema::ActOnIvar(Scope *S, 4780 SourceLocation DeclStart, 4781 DeclPtrTy IntfDecl, 4782 Declarator &D, ExprTy *BitfieldWidth, 4783 tok::ObjCKeywordKind Visibility) { 4784 4785 IdentifierInfo *II = D.getIdentifier(); 4786 Expr *BitWidth = (Expr*)BitfieldWidth; 4787 SourceLocation Loc = DeclStart; 4788 if (II) Loc = D.getIdentifierLoc(); 4789 4790 // FIXME: Unnamed fields can be handled in various different ways, for 4791 // example, unnamed unions inject all members into the struct namespace! 4792 4793 DeclaratorInfo *DInfo = 0; 4794 QualType T = GetTypeForDeclarator(D, S, &DInfo); 4795 4796 if (BitWidth) { 4797 // 6.7.2.1p3, 6.7.2.1p4 4798 if (VerifyBitField(Loc, II, T, BitWidth)) { 4799 D.setInvalidType(); 4800 DeleteExpr(BitWidth); 4801 BitWidth = 0; 4802 } 4803 } else { 4804 // Not a bitfield. 4805 4806 // validate II. 4807 4808 } 4809 4810 // C99 6.7.2.1p8: A member of a structure or union may have any type other 4811 // than a variably modified type. 4812 if (T->isVariablyModifiedType()) { 4813 Diag(Loc, diag::err_typecheck_ivar_variable_size); 4814 D.setInvalidType(); 4815 } 4816 4817 // Get the visibility (access control) for this ivar. 4818 ObjCIvarDecl::AccessControl ac = 4819 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 4820 : ObjCIvarDecl::None; 4821 // Must set ivar's DeclContext to its enclosing interface. 4822 Decl *EnclosingDecl = IntfDecl.getAs<Decl>(); 4823 DeclContext *EnclosingContext; 4824 if (ObjCImplementationDecl *IMPDecl = 4825 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 4826 // Case of ivar declared in an implementation. Context is that of its class. 4827 ObjCInterfaceDecl* IDecl = IMPDecl->getClassInterface(); 4828 assert(IDecl && "No class- ActOnIvar"); 4829 EnclosingContext = cast_or_null<DeclContext>(IDecl); 4830 } else 4831 EnclosingContext = dyn_cast<DeclContext>(EnclosingDecl); 4832 assert(EnclosingContext && "null DeclContext for ivar - ActOnIvar"); 4833 4834 // Construct the decl. 4835 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, 4836 EnclosingContext, Loc, II, T, 4837 DInfo, ac, (Expr *)BitfieldWidth); 4838 4839 if (II) { 4840 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 4841 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 4842 && !isa<TagDecl>(PrevDecl)) { 4843 Diag(Loc, diag::err_duplicate_member) << II; 4844 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 4845 NewID->setInvalidDecl(); 4846 } 4847 } 4848 4849 // Process attributes attached to the ivar. 4850 ProcessDeclAttributes(S, NewID, D); 4851 4852 if (D.isInvalidType()) 4853 NewID->setInvalidDecl(); 4854 4855 if (II) { 4856 // FIXME: When interfaces are DeclContexts, we'll need to add 4857 // these to the interface. 4858 S->AddDecl(DeclPtrTy::make(NewID)); 4859 IdResolver.AddDecl(NewID); 4860 } 4861 4862 return DeclPtrTy::make(NewID); 4863} 4864 4865void Sema::ActOnFields(Scope* S, 4866 SourceLocation RecLoc, DeclPtrTy RecDecl, 4867 DeclPtrTy *Fields, unsigned NumFields, 4868 SourceLocation LBrac, SourceLocation RBrac, 4869 AttributeList *Attr) { 4870 Decl *EnclosingDecl = RecDecl.getAs<Decl>(); 4871 assert(EnclosingDecl && "missing record or interface decl"); 4872 4873 // If the decl this is being inserted into is invalid, then it may be a 4874 // redeclaration or some other bogus case. Don't try to add fields to it. 4875 if (EnclosingDecl->isInvalidDecl()) { 4876 // FIXME: Deallocate fields? 4877 return; 4878 } 4879 4880 4881 // Verify that all the fields are okay. 4882 unsigned NumNamedMembers = 0; 4883 llvm::SmallVector<FieldDecl*, 32> RecFields; 4884 4885 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 4886 for (unsigned i = 0; i != NumFields; ++i) { 4887 FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>()); 4888 4889 // Get the type for the field. 4890 Type *FDTy = FD->getType().getTypePtr(); 4891 4892 if (!FD->isAnonymousStructOrUnion()) { 4893 // Remember all fields written by the user. 4894 RecFields.push_back(FD); 4895 } 4896 4897 // If the field is already invalid for some reason, don't emit more 4898 // diagnostics about it. 4899 if (FD->isInvalidDecl()) 4900 continue; 4901 4902 // C99 6.7.2.1p2: 4903 // A structure or union shall not contain a member with 4904 // incomplete or function type (hence, a structure shall not 4905 // contain an instance of itself, but may contain a pointer to 4906 // an instance of itself), except that the last member of a 4907 // structure with more than one named member may have incomplete 4908 // array type; such a structure (and any union containing, 4909 // possibly recursively, a member that is such a structure) 4910 // shall not be a member of a structure or an element of an 4911 // array. 4912 if (FDTy->isFunctionType()) { 4913 // Field declared as a function. 4914 Diag(FD->getLocation(), diag::err_field_declared_as_function) 4915 << FD->getDeclName(); 4916 FD->setInvalidDecl(); 4917 EnclosingDecl->setInvalidDecl(); 4918 continue; 4919 } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 && 4920 Record && Record->isStruct()) { 4921 // Flexible array member. 4922 if (NumNamedMembers < 1) { 4923 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 4924 << FD->getDeclName(); 4925 FD->setInvalidDecl(); 4926 EnclosingDecl->setInvalidDecl(); 4927 continue; 4928 } 4929 // Okay, we have a legal flexible array member at the end of the struct. 4930 if (Record) 4931 Record->setHasFlexibleArrayMember(true); 4932 } else if (!FDTy->isDependentType() && 4933 RequireCompleteType(FD->getLocation(), FD->getType(), 4934 diag::err_field_incomplete)) { 4935 // Incomplete type 4936 FD->setInvalidDecl(); 4937 EnclosingDecl->setInvalidDecl(); 4938 continue; 4939 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) { 4940 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 4941 // If this is a member of a union, then entire union becomes "flexible". 4942 if (Record && Record->isUnion()) { 4943 Record->setHasFlexibleArrayMember(true); 4944 } else { 4945 // If this is a struct/class and this is not the last element, reject 4946 // it. Note that GCC supports variable sized arrays in the middle of 4947 // structures. 4948 if (i != NumFields-1) 4949 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 4950 << FD->getDeclName() << FD->getType(); 4951 else { 4952 // We support flexible arrays at the end of structs in 4953 // other structs as an extension. 4954 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 4955 << FD->getDeclName(); 4956 if (Record) 4957 Record->setHasFlexibleArrayMember(true); 4958 } 4959 } 4960 } 4961 if (Record && FDTTy->getDecl()->hasObjectMember()) 4962 Record->setHasObjectMember(true); 4963 } else if (FDTy->isObjCInterfaceType()) { 4964 /// A field cannot be an Objective-c object 4965 Diag(FD->getLocation(), diag::err_statically_allocated_object); 4966 FD->setInvalidDecl(); 4967 EnclosingDecl->setInvalidDecl(); 4968 continue; 4969 } else if (getLangOptions().ObjC1 && 4970 getLangOptions().getGCMode() != LangOptions::NonGC && 4971 Record && 4972 (FD->getType()->isObjCObjectPointerType() || 4973 FD->getType().isObjCGCStrong())) 4974 Record->setHasObjectMember(true); 4975 // Keep track of the number of named members. 4976 if (FD->getIdentifier()) 4977 ++NumNamedMembers; 4978 } 4979 4980 // Okay, we successfully defined 'Record'. 4981 if (Record) { 4982 Record->completeDefinition(Context); 4983 } else { 4984 ObjCIvarDecl **ClsFields = 4985 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 4986 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 4987 ID->setIVarList(ClsFields, RecFields.size(), Context); 4988 ID->setLocEnd(RBrac); 4989 // Add ivar's to class's DeclContext. 4990 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 4991 ClsFields[i]->setLexicalDeclContext(ID); 4992 ID->addDecl(ClsFields[i]); 4993 } 4994 // Must enforce the rule that ivars in the base classes may not be 4995 // duplicates. 4996 if (ID->getSuperClass()) { 4997 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 4998 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 4999 ObjCIvarDecl* Ivar = (*IVI); 5000 5001 if (IdentifierInfo *II = Ivar->getIdentifier()) { 5002 ObjCIvarDecl* prevIvar = 5003 ID->getSuperClass()->lookupInstanceVariable(II); 5004 if (prevIvar) { 5005 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 5006 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 5007 } 5008 } 5009 } 5010 } 5011 } else if (ObjCImplementationDecl *IMPDecl = 5012 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 5013 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 5014 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 5015 // Ivar declared in @implementation never belongs to the implementation. 5016 // Only it is in implementation's lexical context. 5017 ClsFields[I]->setLexicalDeclContext(IMPDecl); 5018 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 5019 } 5020 } 5021 5022 if (Attr) 5023 ProcessDeclAttributeList(S, Record, Attr); 5024} 5025 5026EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 5027 EnumConstantDecl *LastEnumConst, 5028 SourceLocation IdLoc, 5029 IdentifierInfo *Id, 5030 ExprArg val) { 5031 Expr *Val = (Expr *)val.get(); 5032 5033 llvm::APSInt EnumVal(32); 5034 QualType EltTy; 5035 if (Val && !Val->isTypeDependent()) { 5036 // Make sure to promote the operand type to int. 5037 UsualUnaryConversions(Val); 5038 if (Val != val.get()) { 5039 val.release(); 5040 val = Val; 5041 } 5042 5043 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 5044 SourceLocation ExpLoc; 5045 if (!Val->isValueDependent() && 5046 VerifyIntegerConstantExpression(Val, &EnumVal)) { 5047 Val = 0; 5048 } else { 5049 EltTy = Val->getType(); 5050 } 5051 } 5052 5053 if (!Val) { 5054 if (LastEnumConst) { 5055 // Assign the last value + 1. 5056 EnumVal = LastEnumConst->getInitVal(); 5057 ++EnumVal; 5058 5059 // Check for overflow on increment. 5060 if (EnumVal < LastEnumConst->getInitVal()) 5061 Diag(IdLoc, diag::warn_enum_value_overflow); 5062 5063 EltTy = LastEnumConst->getType(); 5064 } else { 5065 // First value, set to zero. 5066 EltTy = Context.IntTy; 5067 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 5068 } 5069 } 5070 5071 val.release(); 5072 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 5073 Val, EnumVal); 5074} 5075 5076 5077Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl, 5078 DeclPtrTy lastEnumConst, 5079 SourceLocation IdLoc, 5080 IdentifierInfo *Id, 5081 SourceLocation EqualLoc, ExprTy *val) { 5082 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>()); 5083 EnumConstantDecl *LastEnumConst = 5084 cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>()); 5085 Expr *Val = static_cast<Expr*>(val); 5086 5087 // The scope passed in may not be a decl scope. Zip up the scope tree until 5088 // we find one that is. 5089 S = getNonFieldDeclScope(S); 5090 5091 // Verify that there isn't already something declared with this name in this 5092 // scope. 5093 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 5094 if (PrevDecl && PrevDecl->isTemplateParameter()) { 5095 // Maybe we will complain about the shadowed template parameter. 5096 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 5097 // Just pretend that we didn't see the previous declaration. 5098 PrevDecl = 0; 5099 } 5100 5101 if (PrevDecl) { 5102 // When in C++, we may get a TagDecl with the same name; in this case the 5103 // enum constant will 'hide' the tag. 5104 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 5105 "Received TagDecl when not in C++!"); 5106 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 5107 if (isa<EnumConstantDecl>(PrevDecl)) 5108 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 5109 else 5110 Diag(IdLoc, diag::err_redefinition) << Id; 5111 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 5112 if (Val) Val->Destroy(Context); 5113 return DeclPtrTy(); 5114 } 5115 } 5116 5117 EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst, 5118 IdLoc, Id, Owned(Val)); 5119 5120 // Register this decl in the current scope stack. 5121 if (New) 5122 PushOnScopeChains(New, S); 5123 5124 return DeclPtrTy::make(New); 5125} 5126 5127void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc, 5128 SourceLocation RBraceLoc, DeclPtrTy EnumDeclX, 5129 DeclPtrTy *Elements, unsigned NumElements, 5130 Scope *S, AttributeList *Attr) { 5131 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>()); 5132 QualType EnumType = Context.getTypeDeclType(Enum); 5133 5134 if (Attr) 5135 ProcessDeclAttributeList(S, Enum, Attr); 5136 5137 // TODO: If the result value doesn't fit in an int, it must be a long or long 5138 // long value. ISO C does not support this, but GCC does as an extension, 5139 // emit a warning. 5140 unsigned IntWidth = Context.Target.getIntWidth(); 5141 unsigned CharWidth = Context.Target.getCharWidth(); 5142 unsigned ShortWidth = Context.Target.getShortWidth(); 5143 5144 // Verify that all the values are okay, compute the size of the values, and 5145 // reverse the list. 5146 unsigned NumNegativeBits = 0; 5147 unsigned NumPositiveBits = 0; 5148 5149 // Keep track of whether all elements have type int. 5150 bool AllElementsInt = true; 5151 5152 for (unsigned i = 0; i != NumElements; ++i) { 5153 EnumConstantDecl *ECD = 5154 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5155 if (!ECD) continue; // Already issued a diagnostic. 5156 5157 // If the enum value doesn't fit in an int, emit an extension warning. 5158 const llvm::APSInt &InitVal = ECD->getInitVal(); 5159 assert(InitVal.getBitWidth() >= IntWidth && 5160 "Should have promoted value to int"); 5161 if (InitVal.getBitWidth() > IntWidth) { 5162 llvm::APSInt V(InitVal); 5163 V.trunc(IntWidth); 5164 V.extend(InitVal.getBitWidth()); 5165 if (V != InitVal) 5166 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 5167 << InitVal.toString(10); 5168 } 5169 5170 // Keep track of the size of positive and negative values. 5171 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 5172 NumPositiveBits = std::max(NumPositiveBits, 5173 (unsigned)InitVal.getActiveBits()); 5174 else 5175 NumNegativeBits = std::max(NumNegativeBits, 5176 (unsigned)InitVal.getMinSignedBits()); 5177 5178 // Keep track of whether every enum element has type int (very commmon). 5179 if (AllElementsInt) 5180 AllElementsInt = ECD->getType() == Context.IntTy; 5181 } 5182 5183 // Figure out the type that should be used for this enum. 5184 // FIXME: Support -fshort-enums. 5185 QualType BestType; 5186 unsigned BestWidth; 5187 5188 bool Packed = Enum->getAttr<PackedAttr>() ? true : false; 5189 5190 if (NumNegativeBits) { 5191 // If there is a negative value, figure out the smallest integer type (of 5192 // int/long/longlong) that fits. 5193 // If it's packed, check also if it fits a char or a short. 5194 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) { 5195 BestType = Context.SignedCharTy; 5196 BestWidth = CharWidth; 5197 } else if (Packed && NumNegativeBits <= ShortWidth && 5198 NumPositiveBits < ShortWidth) { 5199 BestType = Context.ShortTy; 5200 BestWidth = ShortWidth; 5201 } 5202 else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 5203 BestType = Context.IntTy; 5204 BestWidth = IntWidth; 5205 } else { 5206 BestWidth = Context.Target.getLongWidth(); 5207 5208 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 5209 BestType = Context.LongTy; 5210 else { 5211 BestWidth = Context.Target.getLongLongWidth(); 5212 5213 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 5214 Diag(Enum->getLocation(), diag::warn_enum_too_large); 5215 BestType = Context.LongLongTy; 5216 } 5217 } 5218 } else { 5219 // If there is no negative value, figure out which of uint, ulong, ulonglong 5220 // fits. 5221 // If it's packed, check also if it fits a char or a short. 5222 if (Packed && NumPositiveBits <= CharWidth) { 5223 BestType = Context.UnsignedCharTy; 5224 BestWidth = CharWidth; 5225 } else if (Packed && NumPositiveBits <= ShortWidth) { 5226 BestType = Context.UnsignedShortTy; 5227 BestWidth = ShortWidth; 5228 } 5229 else if (NumPositiveBits <= IntWidth) { 5230 BestType = Context.UnsignedIntTy; 5231 BestWidth = IntWidth; 5232 } else if (NumPositiveBits <= 5233 (BestWidth = Context.Target.getLongWidth())) { 5234 BestType = Context.UnsignedLongTy; 5235 } else { 5236 BestWidth = Context.Target.getLongLongWidth(); 5237 assert(NumPositiveBits <= BestWidth && 5238 "How could an initializer get larger than ULL?"); 5239 BestType = Context.UnsignedLongLongTy; 5240 } 5241 } 5242 5243 // Loop over all of the enumerator constants, changing their types to match 5244 // the type of the enum if needed. 5245 for (unsigned i = 0; i != NumElements; ++i) { 5246 EnumConstantDecl *ECD = 5247 cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>()); 5248 if (!ECD) continue; // Already issued a diagnostic. 5249 5250 // Standard C says the enumerators have int type, but we allow, as an 5251 // extension, the enumerators to be larger than int size. If each 5252 // enumerator value fits in an int, type it as an int, otherwise type it the 5253 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 5254 // that X has type 'int', not 'unsigned'. 5255 if (ECD->getType() == Context.IntTy) { 5256 // Make sure the init value is signed. 5257 llvm::APSInt IV = ECD->getInitVal(); 5258 IV.setIsSigned(true); 5259 ECD->setInitVal(IV); 5260 5261 if (getLangOptions().CPlusPlus) 5262 // C++ [dcl.enum]p4: Following the closing brace of an 5263 // enum-specifier, each enumerator has the type of its 5264 // enumeration. 5265 ECD->setType(EnumType); 5266 continue; // Already int type. 5267 } 5268 5269 // Determine whether the value fits into an int. 5270 llvm::APSInt InitVal = ECD->getInitVal(); 5271 bool FitsInInt; 5272 if (InitVal.isUnsigned() || !InitVal.isNegative()) 5273 FitsInInt = InitVal.getActiveBits() < IntWidth; 5274 else 5275 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 5276 5277 // If it fits into an integer type, force it. Otherwise force it to match 5278 // the enum decl type. 5279 QualType NewTy; 5280 unsigned NewWidth; 5281 bool NewSign; 5282 if (FitsInInt) { 5283 NewTy = Context.IntTy; 5284 NewWidth = IntWidth; 5285 NewSign = true; 5286 } else if (ECD->getType() == BestType) { 5287 // Already the right type! 5288 if (getLangOptions().CPlusPlus) 5289 // C++ [dcl.enum]p4: Following the closing brace of an 5290 // enum-specifier, each enumerator has the type of its 5291 // enumeration. 5292 ECD->setType(EnumType); 5293 continue; 5294 } else { 5295 NewTy = BestType; 5296 NewWidth = BestWidth; 5297 NewSign = BestType->isSignedIntegerType(); 5298 } 5299 5300 // Adjust the APSInt value. 5301 InitVal.extOrTrunc(NewWidth); 5302 InitVal.setIsSigned(NewSign); 5303 ECD->setInitVal(InitVal); 5304 5305 // Adjust the Expr initializer and type. 5306 if (ECD->getInitExpr()) 5307 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, 5308 CastExpr::CK_Unknown, 5309 ECD->getInitExpr(), 5310 /*isLvalue=*/false)); 5311 if (getLangOptions().CPlusPlus) 5312 // C++ [dcl.enum]p4: Following the closing brace of an 5313 // enum-specifier, each enumerator has the type of its 5314 // enumeration. 5315 ECD->setType(EnumType); 5316 else 5317 ECD->setType(NewTy); 5318 } 5319 5320 Enum->completeDefinition(Context, BestType); 5321} 5322 5323Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 5324 ExprArg expr) { 5325 StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>()); 5326 5327 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 5328 Loc, AsmString); 5329 CurContext->addDecl(New); 5330 return DeclPtrTy::make(New); 5331} 5332 5333void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 5334 SourceLocation PragmaLoc, 5335 SourceLocation NameLoc) { 5336 Decl *PrevDecl = LookupName(TUScope, Name, LookupOrdinaryName); 5337 5338 if (PrevDecl) { 5339 PrevDecl->addAttr(::new (Context) WeakAttr()); 5340 } else { 5341 (void)WeakUndeclaredIdentifiers.insert( 5342 std::pair<IdentifierInfo*,WeakInfo> 5343 (Name, WeakInfo((IdentifierInfo*)0, NameLoc))); 5344 } 5345} 5346 5347void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 5348 IdentifierInfo* AliasName, 5349 SourceLocation PragmaLoc, 5350 SourceLocation NameLoc, 5351 SourceLocation AliasNameLoc) { 5352 Decl *PrevDecl = LookupName(TUScope, AliasName, LookupOrdinaryName); 5353 WeakInfo W = WeakInfo(Name, NameLoc); 5354 5355 if (PrevDecl) { 5356 if (!PrevDecl->hasAttr<AliasAttr>()) 5357 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl)) 5358 DeclApplyPragmaWeak(TUScope, ND, W); 5359 } else { 5360 (void)WeakUndeclaredIdentifiers.insert( 5361 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W)); 5362 } 5363} 5364