SemaDecl.cpp revision cf79b011e849a4455cb7b0de6dc4fb3b83308f39
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 "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/Parse/DeclSpec.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/SourceManager.h" 24// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/HeaderSearch.h" 27#include "llvm/ADT/SmallSet.h" 28#include "llvm/ADT/STLExtras.h" 29#include <algorithm> 30#include <functional> 31 32using namespace clang; 33 34Sema::TypeTy *Sema::isTypeName(IdentifierInfo &II, Scope *S, 35 const CXXScopeSpec *SS) { 36 DeclContext *DC = 0; 37 if (SS) { 38 if (SS->isInvalid()) 39 return 0; 40 DC = static_cast<DeclContext*>(SS->getScopeRep()); 41 } 42 LookupResult Result = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 43 44 Decl *IIDecl = 0; 45 switch (Result.getKind()) { 46 case LookupResult::NotFound: 47 case LookupResult::FoundOverloaded: 48 case LookupResult::AmbiguousBaseSubobjectTypes: 49 case LookupResult::AmbiguousBaseSubobjects: 50 // FIXME: In the event of an ambiguous lookup, we could visit all of 51 // the entities found to determine whether they are all types. This 52 // might provide better diagnostics. 53 return 0; 54 55 case LookupResult::Found: 56 IIDecl = Result.getAsDecl(); 57 break; 58 } 59 60 if (isa<TypedefDecl>(IIDecl) || 61 isa<ObjCInterfaceDecl>(IIDecl) || 62 isa<TagDecl>(IIDecl) || 63 isa<TemplateTypeParmDecl>(IIDecl)) 64 return IIDecl; 65 return 0; 66} 67 68DeclContext *Sema::getContainingDC(DeclContext *DC) { 69 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 70 // A C++ out-of-line method will return to the file declaration context. 71 if (MD->isOutOfLineDefinition()) 72 return MD->getLexicalDeclContext(); 73 74 // A C++ inline method is parsed *after* the topmost class it was declared in 75 // is fully parsed (it's "complete"). 76 // The parsing of a C++ inline method happens at the declaration context of 77 // the topmost (non-nested) class it is lexically declared in. 78 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 79 DC = MD->getParent(); 80 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 81 DC = RD; 82 83 // Return the declaration context of the topmost class the inline method is 84 // declared in. 85 return DC; 86 } 87 88 if (isa<ObjCMethodDecl>(DC)) 89 return Context.getTranslationUnitDecl(); 90 91 if (Decl *D = dyn_cast<Decl>(DC)) 92 return D->getLexicalDeclContext(); 93 94 return DC->getLexicalParent(); 95} 96 97void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 98 assert(getContainingDC(DC) == CurContext && 99 "The next DeclContext should be lexically contained in the current one."); 100 CurContext = DC; 101 S->setEntity(DC); 102} 103 104void Sema::PopDeclContext() { 105 assert(CurContext && "DeclContext imbalance!"); 106 107 CurContext = getContainingDC(CurContext); 108} 109 110/// Add this decl to the scope shadowed decl chains. 111void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 112 // Move up the scope chain until we find the nearest enclosing 113 // non-transparent context. The declaration will be introduced into this 114 // scope. 115 while (S->getEntity() && 116 ((DeclContext *)S->getEntity())->isTransparentContext()) 117 S = S->getParent(); 118 119 S->AddDecl(D); 120 121 // Add scoped declarations into their context, so that they can be 122 // found later. Declarations without a context won't be inserted 123 // into any context. 124 CurContext->addDecl(D); 125 126 // C++ [basic.scope]p4: 127 // -- exactly one declaration shall declare a class name or 128 // enumeration name that is not a typedef name and the other 129 // declarations shall all refer to the same object or 130 // enumerator, or all refer to functions and function templates; 131 // in this case the class name or enumeration name is hidden. 132 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 133 // We are pushing the name of a tag (enum or class). 134 if (CurContext->getLookupContext() 135 == TD->getDeclContext()->getLookupContext()) { 136 // We're pushing the tag into the current context, which might 137 // require some reshuffling in the identifier resolver. 138 IdentifierResolver::iterator 139 I = IdResolver.begin(TD->getDeclName(), CurContext, 140 false/*LookInParentCtx*/), 141 IEnd = IdResolver.end(); 142 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 143 NamedDecl *PrevDecl = *I; 144 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 145 PrevDecl = *I, ++I) { 146 if (TD->declarationReplaces(*I)) { 147 // This is a redeclaration. Remove it from the chain and 148 // break out, so that we'll add in the shadowed 149 // declaration. 150 S->RemoveDecl(*I); 151 if (PrevDecl == *I) { 152 IdResolver.RemoveDecl(*I); 153 IdResolver.AddDecl(TD); 154 return; 155 } else { 156 IdResolver.RemoveDecl(*I); 157 break; 158 } 159 } 160 } 161 162 // There is already a declaration with the same name in the same 163 // scope, which is not a tag declaration. It must be found 164 // before we find the new declaration, so insert the new 165 // declaration at the end of the chain. 166 IdResolver.AddShadowedDecl(TD, PrevDecl); 167 168 return; 169 } 170 } 171 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 172 // We are pushing the name of a function, which might be an 173 // overloaded name. 174 FunctionDecl *FD = cast<FunctionDecl>(D); 175 DeclContext *DC = FD->getDeclContext()->getLookupContext(); 176 IdentifierResolver::iterator Redecl 177 = std::find_if(IdResolver.begin(FD->getDeclName(), DC, 178 false/*LookInParentCtx*/), 179 IdResolver.end(), 180 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 181 FD)); 182 if (Redecl != IdResolver.end()) { 183 // There is already a declaration of a function on our 184 // IdResolver chain. Replace it with this declaration. 185 S->RemoveDecl(*Redecl); 186 IdResolver.RemoveDecl(*Redecl); 187 } 188 } 189 190 IdResolver.AddDecl(D); 191} 192 193void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 194 if (S->decl_empty()) return; 195 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 196 "Scope shouldn't contain decls!"); 197 198 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 199 I != E; ++I) { 200 Decl *TmpD = static_cast<Decl*>(*I); 201 assert(TmpD && "This decl didn't get pushed??"); 202 203 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 204 NamedDecl *D = cast<NamedDecl>(TmpD); 205 206 if (!D->getDeclName()) continue; 207 208 // Remove this name from our lexical scope. 209 IdResolver.RemoveDecl(D); 210 } 211} 212 213/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 214/// return 0 if one not found. 215ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 216 // The third "scope" argument is 0 since we aren't enabling lazy built-in 217 // creation from this context. 218 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 219 220 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 221} 222 223/// getNonFieldDeclScope - Retrieves the innermost scope, starting 224/// from S, where a non-field would be declared. This routine copes 225/// with the difference between C and C++ scoping rules in structs and 226/// unions. For example, the following code is well-formed in C but 227/// ill-formed in C++: 228/// @code 229/// struct S6 { 230/// enum { BAR } e; 231/// }; 232/// 233/// void test_S6() { 234/// struct S6 a; 235/// a.e = BAR; 236/// } 237/// @endcode 238/// For the declaration of BAR, this routine will return a different 239/// scope. The scope S will be the scope of the unnamed enumeration 240/// within S6. In C++, this routine will return the scope associated 241/// with S6, because the enumeration's scope is a transparent 242/// context but structures can contain non-field names. In C, this 243/// routine will return the translation unit scope, since the 244/// enumeration's scope is a transparent context and structures cannot 245/// contain non-field names. 246Scope *Sema::getNonFieldDeclScope(Scope *S) { 247 while (((S->getFlags() & Scope::DeclScope) == 0) || 248 (S->getEntity() && 249 ((DeclContext *)S->getEntity())->isTransparentContext()) || 250 (S->isClassScope() && !getLangOptions().CPlusPlus)) 251 S = S->getParent(); 252 return S; 253} 254 255/// LookupDecl - Look up the inner-most declaration in the specified 256/// namespace. NamespaceNameOnly - during lookup only namespace names 257/// are considered as required in C++ [basic.lookup.udir] 3.4.6.p1 258/// 'When looking up a namespace-name in a using-directive or 259/// namespace-alias-definition, only namespace names are considered.' 260/// 261/// Note: The use of this routine is deprecated. Please use 262/// LookupName, LookupQualifiedName, or LookupParsedName instead. 263Sema::LookupResult 264Sema::LookupDecl(DeclarationName Name, unsigned NSI, Scope *S, 265 const DeclContext *LookupCtx, 266 bool enableLazyBuiltinCreation, 267 bool LookInParent, 268 bool NamespaceNameOnly) { 269 LookupCriteria::NameKind Kind; 270 if (NSI == Decl::IDNS_Ordinary) { 271 if (NamespaceNameOnly) 272 Kind = LookupCriteria::Namespace; 273 else 274 Kind = LookupCriteria::Ordinary; 275 } else if (NSI == Decl::IDNS_Tag) 276 Kind = LookupCriteria::Tag; 277 else { 278 assert(NSI == Decl::IDNS_Member &&"Unable to grok LookupDecl NSI argument"); 279 Kind = LookupCriteria::Member; 280 } 281 282 if (LookupCtx) 283 return LookupQualifiedName(const_cast<DeclContext *>(LookupCtx), Name, 284 LookupCriteria(Kind, !LookInParent, 285 getLangOptions().CPlusPlus)); 286 287 // Unqualified lookup 288 return LookupName(S, Name, 289 LookupCriteria(Kind, !LookInParent, 290 getLangOptions().CPlusPlus)); 291} 292 293void Sema::InitBuiltinVaListType() { 294 if (!Context.getBuiltinVaListType().isNull()) 295 return; 296 297 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 298 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 299 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 300 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 301} 302 303/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 304/// lazily create a decl for it. 305NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 306 Scope *S) { 307 Builtin::ID BID = (Builtin::ID)bid; 308 309 if (Context.BuiltinInfo.hasVAListUse(BID)) 310 InitBuiltinVaListType(); 311 312 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 313 FunctionDecl *New = FunctionDecl::Create(Context, 314 Context.getTranslationUnitDecl(), 315 SourceLocation(), II, R, 316 FunctionDecl::Extern, false); 317 318 // Create Decl objects for each parameter, adding them to the 319 // FunctionDecl. 320 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 321 llvm::SmallVector<ParmVarDecl*, 16> Params; 322 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 323 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 324 FT->getArgType(i), VarDecl::None, 0)); 325 New->setParams(Context, &Params[0], Params.size()); 326 } 327 328 329 330 // TUScope is the translation-unit scope to insert this function into. 331 // FIXME: This is hideous. We need to teach PushOnScopeChains to 332 // relate Scopes to DeclContexts, and probably eliminate CurContext 333 // entirely, but we're not there yet. 334 DeclContext *SavedContext = CurContext; 335 CurContext = Context.getTranslationUnitDecl(); 336 PushOnScopeChains(New, TUScope); 337 CurContext = SavedContext; 338 return New; 339} 340 341/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 342/// everything from the standard library is defined. 343NamespaceDecl *Sema::GetStdNamespace() { 344 if (!StdNamespace) { 345 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 346 DeclContext *Global = Context.getTranslationUnitDecl(); 347 Decl *Std = LookupDecl(StdIdent, Decl::IDNS_Ordinary, 348 0, Global, /*enableLazyBuiltinCreation=*/false); 349 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 350 } 351 return StdNamespace; 352} 353 354/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 355/// and scope as a previous declaration 'Old'. Figure out how to resolve this 356/// situation, merging decls or emitting diagnostics as appropriate. 357/// 358TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 359 bool objc_types = false; 360 // Allow multiple definitions for ObjC built-in typedefs. 361 // FIXME: Verify the underlying types are equivalent! 362 if (getLangOptions().ObjC1) { 363 const IdentifierInfo *TypeID = New->getIdentifier(); 364 switch (TypeID->getLength()) { 365 default: break; 366 case 2: 367 if (!TypeID->isStr("id")) 368 break; 369 Context.setObjCIdType(New); 370 objc_types = true; 371 break; 372 case 5: 373 if (!TypeID->isStr("Class")) 374 break; 375 Context.setObjCClassType(New); 376 objc_types = true; 377 return New; 378 case 3: 379 if (!TypeID->isStr("SEL")) 380 break; 381 Context.setObjCSelType(New); 382 objc_types = true; 383 return New; 384 case 8: 385 if (!TypeID->isStr("Protocol")) 386 break; 387 Context.setObjCProtoType(New->getUnderlyingType()); 388 objc_types = true; 389 return New; 390 } 391 // Fall through - the typedef name was not a builtin type. 392 } 393 // Verify the old decl was also a typedef. 394 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 395 if (!Old) { 396 Diag(New->getLocation(), diag::err_redefinition_different_kind) 397 << New->getDeclName(); 398 if (!objc_types) 399 Diag(OldD->getLocation(), diag::note_previous_definition); 400 return New; 401 } 402 403 // If the typedef types are not identical, reject them in all languages and 404 // with any extensions enabled. 405 if (Old->getUnderlyingType() != New->getUnderlyingType() && 406 Context.getCanonicalType(Old->getUnderlyingType()) != 407 Context.getCanonicalType(New->getUnderlyingType())) { 408 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 409 << New->getUnderlyingType() << Old->getUnderlyingType(); 410 if (!objc_types) 411 Diag(Old->getLocation(), diag::note_previous_definition); 412 return New; 413 } 414 if (objc_types) return New; 415 if (getLangOptions().Microsoft) return New; 416 417 // C++ [dcl.typedef]p2: 418 // In a given non-class scope, a typedef specifier can be used to 419 // redefine the name of any type declared in that scope to refer 420 // to the type to which it already refers. 421 if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext)) 422 return New; 423 424 // In C, redeclaration of a type is a constraint violation (6.7.2.3p1). 425 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 426 // *either* declaration is in a system header. The code below implements 427 // this adhoc compatibility rule. FIXME: The following code will not 428 // work properly when compiling ".i" files (containing preprocessed output). 429 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 430 SourceManager &SrcMgr = Context.getSourceManager(); 431 if (SrcMgr.isInSystemHeader(Old->getLocation())) 432 return New; 433 if (SrcMgr.isInSystemHeader(New->getLocation())) 434 return New; 435 } 436 437 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 438 Diag(Old->getLocation(), diag::note_previous_definition); 439 return New; 440} 441 442/// DeclhasAttr - returns true if decl Declaration already has the target 443/// attribute. 444static bool DeclHasAttr(const Decl *decl, const Attr *target) { 445 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 446 if (attr->getKind() == target->getKind()) 447 return true; 448 449 return false; 450} 451 452/// MergeAttributes - append attributes from the Old decl to the New one. 453static void MergeAttributes(Decl *New, Decl *Old) { 454 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 455 456 while (attr) { 457 tmp = attr; 458 attr = attr->getNext(); 459 460 if (!DeclHasAttr(New, tmp)) { 461 tmp->setInherited(true); 462 New->addAttr(tmp); 463 } else { 464 tmp->setNext(0); 465 delete(tmp); 466 } 467 } 468 469 Old->invalidateAttrs(); 470} 471 472/// MergeFunctionDecl - We just parsed a function 'New' from 473/// declarator D which has the same name and scope as a previous 474/// declaration 'Old'. Figure out how to resolve this situation, 475/// merging decls or emitting diagnostics as appropriate. 476/// Redeclaration will be set true if this New is a redeclaration OldD. 477/// 478/// In C++, New and Old must be declarations that are not 479/// overloaded. Use IsOverload to determine whether New and Old are 480/// overloaded, and to select the Old declaration that New should be 481/// merged with. 482FunctionDecl * 483Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 484 assert(!isa<OverloadedFunctionDecl>(OldD) && 485 "Cannot merge with an overloaded function declaration"); 486 487 Redeclaration = false; 488 // Verify the old decl was also a function. 489 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 490 if (!Old) { 491 Diag(New->getLocation(), diag::err_redefinition_different_kind) 492 << New->getDeclName(); 493 Diag(OldD->getLocation(), diag::note_previous_definition); 494 return New; 495 } 496 497 // Determine whether the previous declaration was a definition, 498 // implicit declaration, or a declaration. 499 diag::kind PrevDiag; 500 if (Old->isThisDeclarationADefinition()) 501 PrevDiag = diag::note_previous_definition; 502 else if (Old->isImplicit()) 503 PrevDiag = diag::note_previous_implicit_declaration; 504 else 505 PrevDiag = diag::note_previous_declaration; 506 507 QualType OldQType = Context.getCanonicalType(Old->getType()); 508 QualType NewQType = Context.getCanonicalType(New->getType()); 509 510 if (getLangOptions().CPlusPlus) { 511 // (C++98 13.1p2): 512 // Certain function declarations cannot be overloaded: 513 // -- Function declarations that differ only in the return type 514 // cannot be overloaded. 515 QualType OldReturnType 516 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 517 QualType NewReturnType 518 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 519 if (OldReturnType != NewReturnType) { 520 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 521 Diag(Old->getLocation(), PrevDiag); 522 Redeclaration = true; 523 return New; 524 } 525 526 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 527 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 528 if (OldMethod && NewMethod) { 529 // -- Member function declarations with the same name and the 530 // same parameter types cannot be overloaded if any of them 531 // is a static member function declaration. 532 if (OldMethod->isStatic() || NewMethod->isStatic()) { 533 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 534 Diag(Old->getLocation(), PrevDiag); 535 return New; 536 } 537 538 // C++ [class.mem]p1: 539 // [...] A member shall not be declared twice in the 540 // member-specification, except that a nested class or member 541 // class template can be declared and then later defined. 542 if (OldMethod->getLexicalDeclContext() == 543 NewMethod->getLexicalDeclContext()) { 544 unsigned NewDiag; 545 if (isa<CXXConstructorDecl>(OldMethod)) 546 NewDiag = diag::err_constructor_redeclared; 547 else if (isa<CXXDestructorDecl>(NewMethod)) 548 NewDiag = diag::err_destructor_redeclared; 549 else if (isa<CXXConversionDecl>(NewMethod)) 550 NewDiag = diag::err_conv_function_redeclared; 551 else 552 NewDiag = diag::err_member_redeclared; 553 554 Diag(New->getLocation(), NewDiag); 555 Diag(Old->getLocation(), PrevDiag); 556 } 557 } 558 559 // (C++98 8.3.5p3): 560 // All declarations for a function shall agree exactly in both the 561 // return type and the parameter-type-list. 562 if (OldQType == NewQType) { 563 // We have a redeclaration. 564 MergeAttributes(New, Old); 565 Redeclaration = true; 566 return MergeCXXFunctionDecl(New, Old); 567 } 568 569 // Fall through for conflicting redeclarations and redefinitions. 570 } 571 572 // C: Function types need to be compatible, not identical. This handles 573 // duplicate function decls like "void f(int); void f(enum X);" properly. 574 if (!getLangOptions().CPlusPlus && 575 Context.typesAreCompatible(OldQType, NewQType)) { 576 MergeAttributes(New, Old); 577 Redeclaration = true; 578 return New; 579 } 580 581 // A function that has already been declared has been redeclared or defined 582 // with a different type- show appropriate diagnostic 583 584 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 585 // TODO: This is totally simplistic. It should handle merging functions 586 // together etc, merging extern int X; int X; ... 587 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 588 Diag(Old->getLocation(), PrevDiag); 589 return New; 590} 591 592/// Predicate for C "tentative" external object definitions (C99 6.9.2). 593static bool isTentativeDefinition(VarDecl *VD) { 594 if (VD->isFileVarDecl()) 595 return (!VD->getInit() && 596 (VD->getStorageClass() == VarDecl::None || 597 VD->getStorageClass() == VarDecl::Static)); 598 return false; 599} 600 601/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 602/// when dealing with C "tentative" external object definitions (C99 6.9.2). 603void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 604 bool VDIsTentative = isTentativeDefinition(VD); 605 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 606 607 // FIXME: I don't think this will actually see all of the 608 // redefinitions. Can't we check this property on-the-fly? 609 for (IdentifierResolver::iterator 610 I = IdResolver.begin(VD->getIdentifier(), 611 VD->getDeclContext(), false/*LookInParentCtx*/), 612 E = IdResolver.end(); I != E; ++I) { 613 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 614 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 615 616 // Handle the following case: 617 // int a[10]; 618 // int a[]; - the code below makes sure we set the correct type. 619 // int a[11]; - this is an error, size isn't 10. 620 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 621 OldDecl->getType()->isConstantArrayType()) 622 VD->setType(OldDecl->getType()); 623 624 // Check for "tentative" definitions. We can't accomplish this in 625 // MergeVarDecl since the initializer hasn't been attached. 626 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 627 continue; 628 629 // Handle __private_extern__ just like extern. 630 if (OldDecl->getStorageClass() != VarDecl::Extern && 631 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 632 VD->getStorageClass() != VarDecl::Extern && 633 VD->getStorageClass() != VarDecl::PrivateExtern) { 634 Diag(VD->getLocation(), diag::err_redefinition) << VD->getDeclName(); 635 Diag(OldDecl->getLocation(), diag::note_previous_definition); 636 } 637 } 638 } 639} 640 641/// MergeVarDecl - We just parsed a variable 'New' which has the same name 642/// and scope as a previous declaration 'Old'. Figure out how to resolve this 643/// situation, merging decls or emitting diagnostics as appropriate. 644/// 645/// Tentative definition rules (C99 6.9.2p2) are checked by 646/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 647/// definitions here, since the initializer hasn't been attached. 648/// 649VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 650 // Verify the old decl was also a variable. 651 VarDecl *Old = dyn_cast<VarDecl>(OldD); 652 if (!Old) { 653 Diag(New->getLocation(), diag::err_redefinition_different_kind) 654 << New->getDeclName(); 655 Diag(OldD->getLocation(), diag::note_previous_definition); 656 return New; 657 } 658 659 MergeAttributes(New, Old); 660 661 // Verify the types match. 662 QualType OldCType = Context.getCanonicalType(Old->getType()); 663 QualType NewCType = Context.getCanonicalType(New->getType()); 664 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 665 Diag(New->getLocation(), diag::err_redefinition_different_type) 666 << New->getDeclName(); 667 Diag(Old->getLocation(), diag::note_previous_definition); 668 return New; 669 } 670 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 671 if (New->getStorageClass() == VarDecl::Static && 672 (Old->getStorageClass() == VarDecl::None || 673 Old->getStorageClass() == VarDecl::Extern)) { 674 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 675 Diag(Old->getLocation(), diag::note_previous_definition); 676 return New; 677 } 678 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 679 if (New->getStorageClass() != VarDecl::Static && 680 Old->getStorageClass() == VarDecl::Static) { 681 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 682 Diag(Old->getLocation(), diag::note_previous_definition); 683 return New; 684 } 685 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 686 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 687 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 688 Diag(Old->getLocation(), diag::note_previous_definition); 689 } 690 return New; 691} 692 693/// CheckParmsForFunctionDef - Check that the parameters of the given 694/// function are appropriate for the definition of a function. This 695/// takes care of any checks that cannot be performed on the 696/// declaration itself, e.g., that the types of each of the function 697/// parameters are complete. 698bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 699 bool HasInvalidParm = false; 700 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 701 ParmVarDecl *Param = FD->getParamDecl(p); 702 703 // C99 6.7.5.3p4: the parameters in a parameter type list in a 704 // function declarator that is part of a function definition of 705 // that function shall not have incomplete type. 706 if (!Param->isInvalidDecl() && 707 DiagnoseIncompleteType(Param->getLocation(), Param->getType(), 708 diag::err_typecheck_decl_incomplete_type)) { 709 Param->setInvalidDecl(); 710 HasInvalidParm = true; 711 } 712 713 // C99 6.9.1p5: If the declarator includes a parameter type list, the 714 // declaration of each parameter shall include an identifier. 715 if (Param->getIdentifier() == 0 && !getLangOptions().CPlusPlus) 716 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 717 } 718 719 return HasInvalidParm; 720} 721 722/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 723/// no declarator (e.g. "struct foo;") is parsed. 724Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 725 TagDecl *Tag 726 = dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 727 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 728 if (!Record->getDeclName() && Record->isDefinition() && 729 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) 730 return BuildAnonymousStructOrUnion(S, DS, Record); 731 732 // Microsoft allows unnamed struct/union fields. Don't complain 733 // about them. 734 // FIXME: Should we support Microsoft's extensions in this area? 735 if (Record->getDeclName() && getLangOptions().Microsoft) 736 return Tag; 737 } 738 739 // Permit typedefs without declarators as a Microsoft extension. 740 if (!DS.isMissingDeclaratorOk()) { 741 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 742 Tag && isa<EnumDecl>(Tag)) { 743 Diag(DS.getSourceRange().getBegin(), diag::warn_no_declarators) 744 << DS.getSourceRange(); 745 return Tag; 746 } 747 748 // FIXME: This diagnostic is emitted even when various previous 749 // errors occurred (see e.g. test/Sema/decl-invalid.c). However, 750 // DeclSpec has no means of communicating this information, and the 751 // responsible parser functions are quite far apart. 752 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 753 << DS.getSourceRange(); 754 return 0; 755 } 756 757 return Tag; 758} 759 760/// InjectAnonymousStructOrUnionMembers - Inject the members of the 761/// anonymous struct or union AnonRecord into the owning context Owner 762/// and scope S. This routine will be invoked just after we realize 763/// that an unnamed union or struct is actually an anonymous union or 764/// struct, e.g., 765/// 766/// @code 767/// union { 768/// int i; 769/// float f; 770/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 771/// // f into the surrounding scope.x 772/// @endcode 773/// 774/// This routine is recursive, injecting the names of nested anonymous 775/// structs/unions into the owning context and scope as well. 776bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 777 RecordDecl *AnonRecord) { 778 bool Invalid = false; 779 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 780 FEnd = AnonRecord->field_end(); 781 F != FEnd; ++F) { 782 if ((*F)->getDeclName()) { 783 Decl *PrevDecl = LookupDecl((*F)->getDeclName(), Decl::IDNS_Ordinary, 784 S, Owner, false, false, false); 785 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 786 // C++ [class.union]p2: 787 // The names of the members of an anonymous union shall be 788 // distinct from the names of any other entity in the 789 // scope in which the anonymous union is declared. 790 unsigned diagKind 791 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 792 : diag::err_anonymous_struct_member_redecl; 793 Diag((*F)->getLocation(), diagKind) 794 << (*F)->getDeclName(); 795 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 796 Invalid = true; 797 } else { 798 // C++ [class.union]p2: 799 // For the purpose of name lookup, after the anonymous union 800 // definition, the members of the anonymous union are 801 // considered to have been defined in the scope in which the 802 // anonymous union is declared. 803 Owner->makeDeclVisibleInContext(*F); 804 S->AddDecl(*F); 805 IdResolver.AddDecl(*F); 806 } 807 } else if (const RecordType *InnerRecordType 808 = (*F)->getType()->getAsRecordType()) { 809 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 810 if (InnerRecord->isAnonymousStructOrUnion()) 811 Invalid = Invalid || 812 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 813 } 814 } 815 816 return Invalid; 817} 818 819/// ActOnAnonymousStructOrUnion - Handle the declaration of an 820/// anonymous structure or union. Anonymous unions are a C++ feature 821/// (C++ [class.union]) and a GNU C extension; anonymous structures 822/// are a GNU C and GNU C++ extension. 823Sema::DeclTy *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 824 RecordDecl *Record) { 825 DeclContext *Owner = Record->getDeclContext(); 826 827 // Diagnose whether this anonymous struct/union is an extension. 828 if (Record->isUnion() && !getLangOptions().CPlusPlus) 829 Diag(Record->getLocation(), diag::ext_anonymous_union); 830 else if (!Record->isUnion()) 831 Diag(Record->getLocation(), diag::ext_anonymous_struct); 832 833 // C and C++ require different kinds of checks for anonymous 834 // structs/unions. 835 bool Invalid = false; 836 if (getLangOptions().CPlusPlus) { 837 const char* PrevSpec = 0; 838 // C++ [class.union]p3: 839 // Anonymous unions declared in a named namespace or in the 840 // global namespace shall be declared static. 841 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 842 (isa<TranslationUnitDecl>(Owner) || 843 (isa<NamespaceDecl>(Owner) && 844 cast<NamespaceDecl>(Owner)->getDeclName()))) { 845 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 846 Invalid = true; 847 848 // Recover by adding 'static'. 849 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec); 850 } 851 // C++ [class.union]p3: 852 // A storage class is not allowed in a declaration of an 853 // anonymous union in a class scope. 854 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 855 isa<RecordDecl>(Owner)) { 856 Diag(DS.getStorageClassSpecLoc(), 857 diag::err_anonymous_union_with_storage_spec); 858 Invalid = true; 859 860 // Recover by removing the storage specifier. 861 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 862 PrevSpec); 863 } 864 865 // C++ [class.union]p2: 866 // The member-specification of an anonymous union shall only 867 // define non-static data members. [Note: nested types and 868 // functions cannot be declared within an anonymous union. ] 869 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 870 MemEnd = Record->decls_end(); 871 Mem != MemEnd; ++Mem) { 872 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 873 // C++ [class.union]p3: 874 // An anonymous union shall not have private or protected 875 // members (clause 11). 876 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 877 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 878 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 879 Invalid = true; 880 } 881 } else if ((*Mem)->isImplicit()) { 882 // Any implicit members are fine. 883 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 884 if (!MemRecord->isAnonymousStructOrUnion() && 885 MemRecord->getDeclName()) { 886 // This is a nested type declaration. 887 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 888 << (int)Record->isUnion(); 889 Invalid = true; 890 } 891 } else { 892 // We have something that isn't a non-static data 893 // member. Complain about it. 894 unsigned DK = diag::err_anonymous_record_bad_member; 895 if (isa<TypeDecl>(*Mem)) 896 DK = diag::err_anonymous_record_with_type; 897 else if (isa<FunctionDecl>(*Mem)) 898 DK = diag::err_anonymous_record_with_function; 899 else if (isa<VarDecl>(*Mem)) 900 DK = diag::err_anonymous_record_with_static; 901 Diag((*Mem)->getLocation(), DK) 902 << (int)Record->isUnion(); 903 Invalid = true; 904 } 905 } 906 } else { 907 // FIXME: Check GNU C semantics 908 if (Record->isUnion() && !Owner->isRecord()) { 909 Diag(Record->getLocation(), diag::err_anonymous_union_not_member) 910 << (int)getLangOptions().CPlusPlus; 911 Invalid = true; 912 } 913 } 914 915 if (!Record->isUnion() && !Owner->isRecord()) { 916 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 917 << (int)getLangOptions().CPlusPlus; 918 Invalid = true; 919 } 920 921 // Create a declaration for this anonymous struct/union. 922 NamedDecl *Anon = 0; 923 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 924 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 925 /*IdentifierInfo=*/0, 926 Context.getTypeDeclType(Record), 927 /*BitWidth=*/0, /*Mutable=*/false); 928 Anon->setAccess(AS_public); 929 if (getLangOptions().CPlusPlus) 930 FieldCollector->Add(cast<FieldDecl>(Anon)); 931 } else { 932 VarDecl::StorageClass SC; 933 switch (DS.getStorageClassSpec()) { 934 default: assert(0 && "Unknown storage class!"); 935 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 936 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 937 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 938 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 939 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 940 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 941 case DeclSpec::SCS_mutable: 942 // mutable can only appear on non-static class members, so it's always 943 // an error here 944 Diag(Record->getLocation(), diag::err_mutable_nonmember); 945 Invalid = true; 946 SC = VarDecl::None; 947 break; 948 } 949 950 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 951 /*IdentifierInfo=*/0, 952 Context.getTypeDeclType(Record), 953 SC, DS.getSourceRange().getBegin()); 954 } 955 Anon->setImplicit(); 956 957 // Add the anonymous struct/union object to the current 958 // context. We'll be referencing this object when we refer to one of 959 // its members. 960 Owner->addDecl(Anon); 961 962 // Inject the members of the anonymous struct/union into the owning 963 // context and into the identifier resolver chain for name lookup 964 // purposes. 965 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 966 Invalid = true; 967 968 // Mark this as an anonymous struct/union type. Note that we do not 969 // do this until after we have already checked and injected the 970 // members of this anonymous struct/union type, because otherwise 971 // the members could be injected twice: once by DeclContext when it 972 // builds its lookup table, and once by 973 // InjectAnonymousStructOrUnionMembers. 974 Record->setAnonymousStructOrUnion(true); 975 976 if (Invalid) 977 Anon->setInvalidDecl(); 978 979 return Anon; 980} 981 982bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType, 983 bool DirectInit) { 984 // Get the type before calling CheckSingleAssignmentConstraints(), since 985 // it can promote the expression. 986 QualType InitType = Init->getType(); 987 988 if (getLangOptions().CPlusPlus) { 989 // FIXME: I dislike this error message. A lot. 990 if (PerformImplicitConversion(Init, DeclType, "initializing", DirectInit)) 991 return Diag(Init->getSourceRange().getBegin(), 992 diag::err_typecheck_convert_incompatible) 993 << DeclType << Init->getType() << "initializing" 994 << Init->getSourceRange(); 995 996 return false; 997 } 998 999 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 1000 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 1001 InitType, Init, "initializing"); 1002} 1003 1004bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 1005 const ArrayType *AT = Context.getAsArrayType(DeclT); 1006 1007 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 1008 // C99 6.7.8p14. We have an array of character type with unknown size 1009 // being initialized to a string literal. 1010 llvm::APSInt ConstVal(32); 1011 ConstVal = strLiteral->getByteLength() + 1; 1012 // Return a new array type (C99 6.7.8p22). 1013 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 1014 ArrayType::Normal, 0); 1015 } else { 1016 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 1017 // C99 6.7.8p14. We have an array of character type with known size. 1018 // FIXME: Avoid truncation for 64-bit length strings. 1019 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 1020 Diag(strLiteral->getSourceRange().getBegin(), 1021 diag::warn_initializer_string_for_char_array_too_long) 1022 << strLiteral->getSourceRange(); 1023 } 1024 // Set type from "char *" to "constant array of char". 1025 strLiteral->setType(DeclT); 1026 // For now, we always return false (meaning success). 1027 return false; 1028} 1029 1030StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 1031 const ArrayType *AT = Context.getAsArrayType(DeclType); 1032 if (AT && AT->getElementType()->isCharType()) { 1033 return dyn_cast<StringLiteral>(Init); 1034 } 1035 return 0; 1036} 1037 1038bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 1039 SourceLocation InitLoc, 1040 DeclarationName InitEntity, 1041 bool DirectInit) { 1042 if (DeclType->isDependentType() || Init->isTypeDependent()) 1043 return false; 1044 1045 // C++ [dcl.init.ref]p1: 1046 // A variable declared to be a T&, that is "reference to type T" 1047 // (8.3.2), shall be initialized by an object, or function, of 1048 // type T or by an object that can be converted into a T. 1049 if (DeclType->isReferenceType()) 1050 return CheckReferenceInit(Init, DeclType, 0, false, DirectInit); 1051 1052 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 1053 // of unknown size ("[]") or an object type that is not a variable array type. 1054 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 1055 return Diag(InitLoc, diag::err_variable_object_no_init) 1056 << VAT->getSizeExpr()->getSourceRange(); 1057 1058 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 1059 if (!InitList) { 1060 // FIXME: Handle wide strings 1061 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 1062 return CheckStringLiteralInit(strLiteral, DeclType); 1063 1064 // C++ [dcl.init]p14: 1065 // -- If the destination type is a (possibly cv-qualified) class 1066 // type: 1067 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 1068 QualType DeclTypeC = Context.getCanonicalType(DeclType); 1069 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 1070 1071 // -- If the initialization is direct-initialization, or if it is 1072 // copy-initialization where the cv-unqualified version of the 1073 // source type is the same class as, or a derived class of, the 1074 // class of the destination, constructors are considered. 1075 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 1076 IsDerivedFrom(InitTypeC, DeclTypeC)) { 1077 CXXConstructorDecl *Constructor 1078 = PerformInitializationByConstructor(DeclType, &Init, 1, 1079 InitLoc, Init->getSourceRange(), 1080 InitEntity, 1081 DirectInit? IK_Direct : IK_Copy); 1082 return Constructor == 0; 1083 } 1084 1085 // -- Otherwise (i.e., for the remaining copy-initialization 1086 // cases), user-defined conversion sequences that can 1087 // convert from the source type to the destination type or 1088 // (when a conversion function is used) to a derived class 1089 // thereof are enumerated as described in 13.3.1.4, and the 1090 // best one is chosen through overload resolution 1091 // (13.3). If the conversion cannot be done or is 1092 // ambiguous, the initialization is ill-formed. The 1093 // function selected is called with the initializer 1094 // expression as its argument; if the function is a 1095 // constructor, the call initializes a temporary of the 1096 // destination type. 1097 // FIXME: We're pretending to do copy elision here; return to 1098 // this when we have ASTs for such things. 1099 if (!PerformImplicitConversion(Init, DeclType, "initializing")) 1100 return false; 1101 1102 if (InitEntity) 1103 return Diag(InitLoc, diag::err_cannot_initialize_decl) 1104 << InitEntity << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 1105 << Init->getType() << Init->getSourceRange(); 1106 else 1107 return Diag(InitLoc, diag::err_cannot_initialize_decl_noname) 1108 << DeclType << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 1109 << Init->getType() << Init->getSourceRange(); 1110 } 1111 1112 // C99 6.7.8p16. 1113 if (DeclType->isArrayType()) 1114 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 1115 << Init->getSourceRange(); 1116 1117 return CheckSingleInitializer(Init, DeclType, DirectInit); 1118 } else if (getLangOptions().CPlusPlus) { 1119 // C++ [dcl.init]p14: 1120 // [...] If the class is an aggregate (8.5.1), and the initializer 1121 // is a brace-enclosed list, see 8.5.1. 1122 // 1123 // Note: 8.5.1 is handled below; here, we diagnose the case where 1124 // we have an initializer list and a destination type that is not 1125 // an aggregate. 1126 // FIXME: In C++0x, this is yet another form of initialization. 1127 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 1128 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 1129 if (!ClassDecl->isAggregate()) 1130 return Diag(InitLoc, diag::err_init_non_aggr_init_list) 1131 << DeclType << Init->getSourceRange(); 1132 } 1133 } 1134 1135 InitListChecker CheckInitList(this, InitList, DeclType); 1136 return CheckInitList.HadError(); 1137} 1138 1139/// GetNameForDeclarator - Determine the full declaration name for the 1140/// given Declarator. 1141DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1142 switch (D.getKind()) { 1143 case Declarator::DK_Abstract: 1144 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1145 return DeclarationName(); 1146 1147 case Declarator::DK_Normal: 1148 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1149 return DeclarationName(D.getIdentifier()); 1150 1151 case Declarator::DK_Constructor: { 1152 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 1153 Ty = Context.getCanonicalType(Ty); 1154 return Context.DeclarationNames.getCXXConstructorName(Ty); 1155 } 1156 1157 case Declarator::DK_Destructor: { 1158 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 1159 Ty = Context.getCanonicalType(Ty); 1160 return Context.DeclarationNames.getCXXDestructorName(Ty); 1161 } 1162 1163 case Declarator::DK_Conversion: { 1164 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1165 Ty = Context.getCanonicalType(Ty); 1166 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1167 } 1168 1169 case Declarator::DK_Operator: 1170 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1171 return Context.DeclarationNames.getCXXOperatorName( 1172 D.getOverloadedOperator()); 1173 } 1174 1175 assert(false && "Unknown name kind"); 1176 return DeclarationName(); 1177} 1178 1179/// isNearlyMatchingMemberFunction - Determine whether the C++ member 1180/// functions Declaration and Definition are "nearly" matching. This 1181/// heuristic is used to improve diagnostics in the case where an 1182/// out-of-line member function definition doesn't match any 1183/// declaration within the class. 1184static bool isNearlyMatchingMemberFunction(ASTContext &Context, 1185 FunctionDecl *Declaration, 1186 FunctionDecl *Definition) { 1187 if (Declaration->param_size() != Definition->param_size()) 1188 return false; 1189 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1190 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1191 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1192 1193 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1194 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1195 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1196 return false; 1197 } 1198 1199 return true; 1200} 1201 1202Sema::DeclTy * 1203Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl, 1204 bool IsFunctionDefinition) { 1205 NamedDecl *LastDeclarator = dyn_cast_or_null<NamedDecl>((Decl *)lastDecl); 1206 DeclarationName Name = GetNameForDeclarator(D); 1207 1208 // All of these full declarators require an identifier. If it doesn't have 1209 // one, the ParsedFreeStandingDeclSpec action should be used. 1210 if (!Name) { 1211 if (!D.getInvalidType()) // Reject this if we think it is valid. 1212 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1213 diag::err_declarator_need_ident) 1214 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1215 return 0; 1216 } 1217 1218 // The scope passed in may not be a decl scope. Zip up the scope tree until 1219 // we find one that is. 1220 while ((S->getFlags() & Scope::DeclScope) == 0 || 1221 (S->getFlags() & Scope::TemplateParamScope) != 0) 1222 S = S->getParent(); 1223 1224 DeclContext *DC; 1225 Decl *PrevDecl; 1226 NamedDecl *New; 1227 bool InvalidDecl = false; 1228 1229 // See if this is a redefinition of a variable in the same scope. 1230 if (!D.getCXXScopeSpec().isSet()) { 1231 DC = CurContext; 1232 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S); 1233 } else { // Something like "int foo::x;" 1234 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 1235 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 1236 1237 // C++ 7.3.1.2p2: 1238 // Members (including explicit specializations of templates) of a named 1239 // namespace can also be defined outside that namespace by explicit 1240 // qualification of the name being defined, provided that the entity being 1241 // defined was already declared in the namespace and the definition appears 1242 // after the point of declaration in a namespace that encloses the 1243 // declarations namespace. 1244 // 1245 // Note that we only check the context at this point. We don't yet 1246 // have enough information to make sure that PrevDecl is actually 1247 // the declaration we want to match. For example, given: 1248 // 1249 // class X { 1250 // void f(); 1251 // void f(float); 1252 // }; 1253 // 1254 // void X::f(int) { } // ill-formed 1255 // 1256 // In this case, PrevDecl will point to the overload set 1257 // containing the two f's declared in X, but neither of them 1258 // matches. 1259 if (!CurContext->Encloses(DC)) { 1260 // The qualifying scope doesn't enclose the original declaration. 1261 // Emit diagnostic based on current scope. 1262 SourceLocation L = D.getIdentifierLoc(); 1263 SourceRange R = D.getCXXScopeSpec().getRange(); 1264 if (isa<FunctionDecl>(CurContext)) { 1265 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1266 } else { 1267 Diag(L, diag::err_invalid_declarator_scope) 1268 << Name << cast<NamedDecl>(DC)->getDeclName() << R; 1269 } 1270 InvalidDecl = true; 1271 } 1272 } 1273 1274 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1275 // Maybe we will complain about the shadowed template parameter. 1276 InvalidDecl = InvalidDecl 1277 || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 1278 // Just pretend that we didn't see the previous declaration. 1279 PrevDecl = 0; 1280 } 1281 1282 // In C++, the previous declaration we find might be a tag type 1283 // (class or enum). In this case, the new declaration will hide the 1284 // tag type. 1285 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 1286 PrevDecl = 0; 1287 1288 QualType R = GetTypeForDeclarator(D, S); 1289 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 1290 1291 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1292 New = ActOnTypedefDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1293 InvalidDecl); 1294 } else if (R.getTypePtr()->isFunctionType()) { 1295 New = ActOnFunctionDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1296 IsFunctionDefinition, InvalidDecl); 1297 } else { 1298 New = ActOnVariableDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1299 InvalidDecl); 1300 } 1301 1302 if (New == 0) 1303 return 0; 1304 1305 // Set the lexical context. If the declarator has a C++ scope specifier, the 1306 // lexical context will be different from the semantic context. 1307 New->setLexicalDeclContext(CurContext); 1308 1309 // If this has an identifier, add it to the scope stack. 1310 if (Name) 1311 PushOnScopeChains(New, S); 1312 // If any semantic error occurred, mark the decl as invalid. 1313 if (D.getInvalidType() || InvalidDecl) 1314 New->setInvalidDecl(); 1315 1316 return New; 1317} 1318 1319NamedDecl* 1320Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1321 QualType R, Decl* LastDeclarator, 1322 Decl* PrevDecl, bool& InvalidDecl) { 1323 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1324 if (D.getCXXScopeSpec().isSet()) { 1325 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1326 << D.getCXXScopeSpec().getRange(); 1327 InvalidDecl = true; 1328 // Pretend we didn't see the scope specifier. 1329 DC = 0; 1330 } 1331 1332 // Check that there are no default arguments (C++ only). 1333 if (getLangOptions().CPlusPlus) 1334 CheckExtraCXXDefaultArguments(D); 1335 1336 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 1337 if (!NewTD) return 0; 1338 1339 // Handle attributes prior to checking for duplicates in MergeVarDecl 1340 ProcessDeclAttributes(NewTD, D); 1341 // Merge the decl with the existing one if appropriate. If the decl is 1342 // in an outer scope, it isn't the same thing. 1343 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1344 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 1345 if (NewTD == 0) return 0; 1346 } 1347 1348 if (S->getFnParent() == 0) { 1349 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1350 // then it shall have block scope. 1351 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 1352 if (NewTD->getUnderlyingType()->isVariableArrayType()) 1353 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1354 else 1355 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1356 1357 InvalidDecl = true; 1358 } 1359 } 1360 return NewTD; 1361} 1362 1363NamedDecl* 1364Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1365 QualType R, Decl* LastDeclarator, 1366 Decl* PrevDecl, bool& InvalidDecl) { 1367 DeclarationName Name = GetNameForDeclarator(D); 1368 1369 // Check that there are no default arguments (C++ only). 1370 if (getLangOptions().CPlusPlus) 1371 CheckExtraCXXDefaultArguments(D); 1372 1373 if (R.getTypePtr()->isObjCInterfaceType()) { 1374 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object) 1375 << D.getIdentifier(); 1376 InvalidDecl = true; 1377 } 1378 1379 VarDecl *NewVD; 1380 VarDecl::StorageClass SC; 1381 switch (D.getDeclSpec().getStorageClassSpec()) { 1382 default: assert(0 && "Unknown storage class!"); 1383 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1384 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1385 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1386 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1387 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1388 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1389 case DeclSpec::SCS_mutable: 1390 // mutable can only appear on non-static class members, so it's always 1391 // an error here 1392 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1393 InvalidDecl = true; 1394 SC = VarDecl::None; 1395 break; 1396 } 1397 1398 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1399 if (!II) { 1400 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1401 << Name.getAsString(); 1402 return 0; 1403 } 1404 1405 if (DC->isRecord()) { 1406 // This is a static data member for a C++ class. 1407 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1408 D.getIdentifierLoc(), II, 1409 R); 1410 } else { 1411 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1412 if (S->getFnParent() == 0) { 1413 // C99 6.9p2: The storage-class specifiers auto and register shall not 1414 // appear in the declaration specifiers in an external declaration. 1415 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1416 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 1417 InvalidDecl = true; 1418 } 1419 } 1420 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1421 II, R, SC, 1422 // FIXME: Move to DeclGroup... 1423 D.getDeclSpec().getSourceRange().getBegin()); 1424 NewVD->setThreadSpecified(ThreadSpecified); 1425 } 1426 NewVD->setNextDeclarator(LastDeclarator); 1427 1428 // Handle attributes prior to checking for duplicates in MergeVarDecl 1429 ProcessDeclAttributes(NewVD, D); 1430 1431 // Handle GNU asm-label extension (encoded as an attribute). 1432 if (Expr *E = (Expr*) D.getAsmLabel()) { 1433 // The parser guarantees this is a string. 1434 StringLiteral *SE = cast<StringLiteral>(E); 1435 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1436 SE->getByteLength()))); 1437 } 1438 1439 // Emit an error if an address space was applied to decl with local storage. 1440 // This includes arrays of objects with address space qualifiers, but not 1441 // automatic variables that point to other address spaces. 1442 // ISO/IEC TR 18037 S5.1.2 1443 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1444 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1445 InvalidDecl = true; 1446 } 1447 // Merge the decl with the existing one if appropriate. If the decl is 1448 // in an outer scope, it isn't the same thing. 1449 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1450 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 1451 // The user tried to define a non-static data member 1452 // out-of-line (C++ [dcl.meaning]p1). 1453 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 1454 << D.getCXXScopeSpec().getRange(); 1455 NewVD->Destroy(Context); 1456 return 0; 1457 } 1458 1459 NewVD = MergeVarDecl(NewVD, PrevDecl); 1460 if (NewVD == 0) return 0; 1461 1462 if (D.getCXXScopeSpec().isSet()) { 1463 // No previous declaration in the qualifying scope. 1464 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 1465 << Name << D.getCXXScopeSpec().getRange(); 1466 InvalidDecl = true; 1467 } 1468 } 1469 return NewVD; 1470} 1471 1472NamedDecl* 1473Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1474 QualType R, Decl *LastDeclarator, 1475 Decl* PrevDecl, bool IsFunctionDefinition, 1476 bool& InvalidDecl) { 1477 assert(R.getTypePtr()->isFunctionType()); 1478 1479 DeclarationName Name = GetNameForDeclarator(D); 1480 FunctionDecl::StorageClass SC = FunctionDecl::None; 1481 switch (D.getDeclSpec().getStorageClassSpec()) { 1482 default: assert(0 && "Unknown storage class!"); 1483 case DeclSpec::SCS_auto: 1484 case DeclSpec::SCS_register: 1485 case DeclSpec::SCS_mutable: 1486 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func); 1487 InvalidDecl = true; 1488 break; 1489 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 1490 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 1491 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 1492 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 1493 } 1494 1495 bool isInline = D.getDeclSpec().isInlineSpecified(); 1496 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 1497 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 1498 1499 FunctionDecl *NewFD; 1500 if (D.getKind() == Declarator::DK_Constructor) { 1501 // This is a C++ constructor declaration. 1502 assert(DC->isRecord() && 1503 "Constructors can only be declared in a member context"); 1504 1505 InvalidDecl = InvalidDecl || CheckConstructorDeclarator(D, R, SC); 1506 1507 // Create the new declaration 1508 NewFD = CXXConstructorDecl::Create(Context, 1509 cast<CXXRecordDecl>(DC), 1510 D.getIdentifierLoc(), Name, R, 1511 isExplicit, isInline, 1512 /*isImplicitlyDeclared=*/false); 1513 1514 if (InvalidDecl) 1515 NewFD->setInvalidDecl(); 1516 } else if (D.getKind() == Declarator::DK_Destructor) { 1517 // This is a C++ destructor declaration. 1518 if (DC->isRecord()) { 1519 InvalidDecl = InvalidDecl || CheckDestructorDeclarator(D, R, SC); 1520 1521 NewFD = CXXDestructorDecl::Create(Context, 1522 cast<CXXRecordDecl>(DC), 1523 D.getIdentifierLoc(), Name, R, 1524 isInline, 1525 /*isImplicitlyDeclared=*/false); 1526 1527 if (InvalidDecl) 1528 NewFD->setInvalidDecl(); 1529 } else { 1530 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 1531 1532 // Create a FunctionDecl to satisfy the function definition parsing 1533 // code path. 1534 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 1535 Name, R, SC, isInline, 1536 // FIXME: Move to DeclGroup... 1537 D.getDeclSpec().getSourceRange().getBegin()); 1538 InvalidDecl = true; 1539 NewFD->setInvalidDecl(); 1540 } 1541 } else if (D.getKind() == Declarator::DK_Conversion) { 1542 if (!DC->isRecord()) { 1543 Diag(D.getIdentifierLoc(), 1544 diag::err_conv_function_not_member); 1545 return 0; 1546 } else { 1547 InvalidDecl = InvalidDecl || CheckConversionDeclarator(D, R, SC); 1548 1549 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 1550 D.getIdentifierLoc(), Name, R, 1551 isInline, isExplicit); 1552 1553 if (InvalidDecl) 1554 NewFD->setInvalidDecl(); 1555 } 1556 } else if (DC->isRecord()) { 1557 // This is a C++ method declaration. 1558 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 1559 D.getIdentifierLoc(), Name, R, 1560 (SC == FunctionDecl::Static), isInline); 1561 } else { 1562 NewFD = FunctionDecl::Create(Context, DC, 1563 D.getIdentifierLoc(), 1564 Name, R, SC, isInline, 1565 // FIXME: Move to DeclGroup... 1566 D.getDeclSpec().getSourceRange().getBegin()); 1567 } 1568 NewFD->setNextDeclarator(LastDeclarator); 1569 1570 // Set the lexical context. If the declarator has a C++ 1571 // scope specifier, the lexical context will be different 1572 // from the semantic context. 1573 NewFD->setLexicalDeclContext(CurContext); 1574 1575 // Handle GNU asm-label extension (encoded as an attribute). 1576 if (Expr *E = (Expr*) D.getAsmLabel()) { 1577 // The parser guarantees this is a string. 1578 StringLiteral *SE = cast<StringLiteral>(E); 1579 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1580 SE->getByteLength()))); 1581 } 1582 1583 // Copy the parameter declarations from the declarator D to 1584 // the function declaration NewFD, if they are available. 1585 if (D.getNumTypeObjects() > 0) { 1586 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1587 1588 // Create Decl objects for each parameter, adding them to the 1589 // FunctionDecl. 1590 llvm::SmallVector<ParmVarDecl*, 16> Params; 1591 1592 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1593 // function that takes no arguments, not a function that takes a 1594 // single void argument. 1595 // We let through "const void" here because Sema::GetTypeForDeclarator 1596 // already checks for that case. 1597 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1598 FTI.ArgInfo[0].Param && 1599 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1600 // empty arg list, don't push any params. 1601 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1602 1603 // In C++, the empty parameter-type-list must be spelled "void"; a 1604 // typedef of void is not permitted. 1605 if (getLangOptions().CPlusPlus && 1606 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1607 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1608 } 1609 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1610 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1611 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1612 } 1613 1614 NewFD->setParams(Context, &Params[0], Params.size()); 1615 } else if (R->getAsTypedefType()) { 1616 // When we're declaring a function with a typedef, as in the 1617 // following example, we'll need to synthesize (unnamed) 1618 // parameters for use in the declaration. 1619 // 1620 // @code 1621 // typedef void fn(int); 1622 // fn f; 1623 // @endcode 1624 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1625 if (!FT) { 1626 // This is a typedef of a function with no prototype, so we 1627 // don't need to do anything. 1628 } else if ((FT->getNumArgs() == 0) || 1629 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1630 FT->getArgType(0)->isVoidType())) { 1631 // This is a zero-argument function. We don't need to do anything. 1632 } else { 1633 // Synthesize a parameter for each argument type. 1634 llvm::SmallVector<ParmVarDecl*, 16> Params; 1635 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1636 ArgType != FT->arg_type_end(); ++ArgType) { 1637 Params.push_back(ParmVarDecl::Create(Context, DC, 1638 SourceLocation(), 0, 1639 *ArgType, VarDecl::None, 1640 0)); 1641 } 1642 1643 NewFD->setParams(Context, &Params[0], Params.size()); 1644 } 1645 } 1646 1647 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1648 InvalidDecl = InvalidDecl || CheckConstructor(Constructor); 1649 else if (isa<CXXDestructorDecl>(NewFD)) { 1650 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 1651 Record->setUserDeclaredDestructor(true); 1652 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 1653 // user-defined destructor. 1654 Record->setPOD(false); 1655 } else if (CXXConversionDecl *Conversion = 1656 dyn_cast<CXXConversionDecl>(NewFD)) 1657 ActOnConversionDeclarator(Conversion); 1658 1659 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1660 if (NewFD->isOverloadedOperator() && 1661 CheckOverloadedOperatorDeclaration(NewFD)) 1662 NewFD->setInvalidDecl(); 1663 1664 // Merge the decl with the existing one if appropriate. Since C functions 1665 // are in a flat namespace, make sure we consider decls in outer scopes. 1666 if (PrevDecl && 1667 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1668 bool Redeclaration = false; 1669 1670 // If C++, determine whether NewFD is an overload of PrevDecl or 1671 // a declaration that requires merging. If it's an overload, 1672 // there's no more work to do here; we'll just add the new 1673 // function to the scope. 1674 OverloadedFunctionDecl::function_iterator MatchedDecl; 1675 if (!getLangOptions().CPlusPlus || 1676 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1677 Decl *OldDecl = PrevDecl; 1678 1679 // If PrevDecl was an overloaded function, extract the 1680 // FunctionDecl that matched. 1681 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1682 OldDecl = *MatchedDecl; 1683 1684 // NewFD and PrevDecl represent declarations that need to be 1685 // merged. 1686 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1687 1688 if (NewFD == 0) return 0; 1689 if (Redeclaration) { 1690 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1691 1692 // An out-of-line member function declaration must also be a 1693 // definition (C++ [dcl.meaning]p1). 1694 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && 1695 !InvalidDecl) { 1696 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 1697 << D.getCXXScopeSpec().getRange(); 1698 NewFD->setInvalidDecl(); 1699 } 1700 } 1701 } 1702 1703 if (!Redeclaration && D.getCXXScopeSpec().isSet()) { 1704 // The user tried to provide an out-of-line definition for a 1705 // member function, but there was no such member function 1706 // declared (C++ [class.mfct]p2). For example: 1707 // 1708 // class X { 1709 // void f() const; 1710 // }; 1711 // 1712 // void X::f() { } // ill-formed 1713 // 1714 // Complain about this problem, and attempt to suggest close 1715 // matches (e.g., those that differ only in cv-qualifiers and 1716 // whether the parameter types are references). 1717 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 1718 << cast<CXXRecordDecl>(DC)->getDeclName() 1719 << D.getCXXScopeSpec().getRange(); 1720 InvalidDecl = true; 1721 1722 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 1723 if (!PrevDecl) { 1724 // Nothing to suggest. 1725 } else if (OverloadedFunctionDecl *Ovl 1726 = dyn_cast<OverloadedFunctionDecl>(PrevDecl)) { 1727 for (OverloadedFunctionDecl::function_iterator 1728 Func = Ovl->function_begin(), 1729 FuncEnd = Ovl->function_end(); 1730 Func != FuncEnd; ++Func) { 1731 if (isNearlyMatchingMemberFunction(Context, *Func, NewFD)) 1732 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 1733 1734 } 1735 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(PrevDecl)) { 1736 // Suggest this no matter how mismatched it is; it's the only 1737 // thing we have. 1738 unsigned diag; 1739 if (isNearlyMatchingMemberFunction(Context, Method, NewFD)) 1740 diag = diag::note_member_def_close_match; 1741 else if (Method->getBody()) 1742 diag = diag::note_previous_definition; 1743 else 1744 diag = diag::note_previous_declaration; 1745 Diag(Method->getLocation(), diag); 1746 } 1747 1748 PrevDecl = 0; 1749 } 1750 } 1751 // Handle attributes. We need to have merged decls when handling attributes 1752 // (for example to check for conflicts, etc). 1753 ProcessDeclAttributes(NewFD, D); 1754 1755 if (getLangOptions().CPlusPlus) { 1756 // In C++, check default arguments now that we have merged decls. 1757 CheckCXXDefaultArguments(NewFD); 1758 1759 // An out-of-line member function declaration must also be a 1760 // definition (C++ [dcl.meaning]p1). 1761 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && !InvalidDecl) { 1762 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 1763 << D.getCXXScopeSpec().getRange(); 1764 InvalidDecl = true; 1765 } 1766 } 1767 return NewFD; 1768} 1769 1770void Sema::InitializerElementNotConstant(const Expr *Init) { 1771 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 1772 << Init->getSourceRange(); 1773} 1774 1775bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1776 switch (Init->getStmtClass()) { 1777 default: 1778 InitializerElementNotConstant(Init); 1779 return true; 1780 case Expr::ParenExprClass: { 1781 const ParenExpr* PE = cast<ParenExpr>(Init); 1782 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1783 } 1784 case Expr::CompoundLiteralExprClass: 1785 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1786 case Expr::DeclRefExprClass: 1787 case Expr::QualifiedDeclRefExprClass: { 1788 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1789 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1790 if (VD->hasGlobalStorage()) 1791 return false; 1792 InitializerElementNotConstant(Init); 1793 return true; 1794 } 1795 if (isa<FunctionDecl>(D)) 1796 return false; 1797 InitializerElementNotConstant(Init); 1798 return true; 1799 } 1800 case Expr::MemberExprClass: { 1801 const MemberExpr *M = cast<MemberExpr>(Init); 1802 if (M->isArrow()) 1803 return CheckAddressConstantExpression(M->getBase()); 1804 return CheckAddressConstantExpressionLValue(M->getBase()); 1805 } 1806 case Expr::ArraySubscriptExprClass: { 1807 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1808 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1809 return CheckAddressConstantExpression(ASE->getBase()) || 1810 CheckArithmeticConstantExpression(ASE->getIdx()); 1811 } 1812 case Expr::StringLiteralClass: 1813 case Expr::PredefinedExprClass: 1814 return false; 1815 case Expr::UnaryOperatorClass: { 1816 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1817 1818 // C99 6.6p9 1819 if (Exp->getOpcode() == UnaryOperator::Deref) 1820 return CheckAddressConstantExpression(Exp->getSubExpr()); 1821 1822 InitializerElementNotConstant(Init); 1823 return true; 1824 } 1825 } 1826} 1827 1828bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1829 switch (Init->getStmtClass()) { 1830 default: 1831 InitializerElementNotConstant(Init); 1832 return true; 1833 case Expr::ParenExprClass: 1834 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1835 case Expr::StringLiteralClass: 1836 case Expr::ObjCStringLiteralClass: 1837 return false; 1838 case Expr::CallExprClass: 1839 case Expr::CXXOperatorCallExprClass: 1840 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1841 if (cast<CallExpr>(Init)->isBuiltinCall() == 1842 Builtin::BI__builtin___CFStringMakeConstantString) 1843 return false; 1844 1845 InitializerElementNotConstant(Init); 1846 return true; 1847 1848 case Expr::UnaryOperatorClass: { 1849 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1850 1851 // C99 6.6p9 1852 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1853 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1854 1855 if (Exp->getOpcode() == UnaryOperator::Extension) 1856 return CheckAddressConstantExpression(Exp->getSubExpr()); 1857 1858 InitializerElementNotConstant(Init); 1859 return true; 1860 } 1861 case Expr::BinaryOperatorClass: { 1862 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1863 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1864 1865 Expr *PExp = Exp->getLHS(); 1866 Expr *IExp = Exp->getRHS(); 1867 if (IExp->getType()->isPointerType()) 1868 std::swap(PExp, IExp); 1869 1870 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1871 return CheckAddressConstantExpression(PExp) || 1872 CheckArithmeticConstantExpression(IExp); 1873 } 1874 case Expr::ImplicitCastExprClass: 1875 case Expr::CStyleCastExprClass: { 1876 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1877 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1878 // Check for implicit promotion 1879 if (SubExpr->getType()->isFunctionType() || 1880 SubExpr->getType()->isArrayType()) 1881 return CheckAddressConstantExpressionLValue(SubExpr); 1882 } 1883 1884 // Check for pointer->pointer cast 1885 if (SubExpr->getType()->isPointerType()) 1886 return CheckAddressConstantExpression(SubExpr); 1887 1888 if (SubExpr->getType()->isIntegralType()) { 1889 // Check for the special-case of a pointer->int->pointer cast; 1890 // this isn't standard, but some code requires it. See 1891 // PR2720 for an example. 1892 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1893 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1894 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1895 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1896 if (IntWidth >= PointerWidth) { 1897 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1898 } 1899 } 1900 } 1901 } 1902 if (SubExpr->getType()->isArithmeticType()) { 1903 return CheckArithmeticConstantExpression(SubExpr); 1904 } 1905 1906 InitializerElementNotConstant(Init); 1907 return true; 1908 } 1909 case Expr::ConditionalOperatorClass: { 1910 // FIXME: Should we pedwarn here? 1911 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1912 if (!Exp->getCond()->getType()->isArithmeticType()) { 1913 InitializerElementNotConstant(Init); 1914 return true; 1915 } 1916 if (CheckArithmeticConstantExpression(Exp->getCond())) 1917 return true; 1918 if (Exp->getLHS() && 1919 CheckAddressConstantExpression(Exp->getLHS())) 1920 return true; 1921 return CheckAddressConstantExpression(Exp->getRHS()); 1922 } 1923 case Expr::AddrLabelExprClass: 1924 return false; 1925 } 1926} 1927 1928static const Expr* FindExpressionBaseAddress(const Expr* E); 1929 1930static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1931 switch (E->getStmtClass()) { 1932 default: 1933 return E; 1934 case Expr::ParenExprClass: { 1935 const ParenExpr* PE = cast<ParenExpr>(E); 1936 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1937 } 1938 case Expr::MemberExprClass: { 1939 const MemberExpr *M = cast<MemberExpr>(E); 1940 if (M->isArrow()) 1941 return FindExpressionBaseAddress(M->getBase()); 1942 return FindExpressionBaseAddressLValue(M->getBase()); 1943 } 1944 case Expr::ArraySubscriptExprClass: { 1945 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1946 return FindExpressionBaseAddress(ASE->getBase()); 1947 } 1948 case Expr::UnaryOperatorClass: { 1949 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1950 1951 if (Exp->getOpcode() == UnaryOperator::Deref) 1952 return FindExpressionBaseAddress(Exp->getSubExpr()); 1953 1954 return E; 1955 } 1956 } 1957} 1958 1959static const Expr* FindExpressionBaseAddress(const Expr* E) { 1960 switch (E->getStmtClass()) { 1961 default: 1962 return E; 1963 case Expr::ParenExprClass: { 1964 const ParenExpr* PE = cast<ParenExpr>(E); 1965 return FindExpressionBaseAddress(PE->getSubExpr()); 1966 } 1967 case Expr::UnaryOperatorClass: { 1968 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1969 1970 // C99 6.6p9 1971 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1972 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1973 1974 if (Exp->getOpcode() == UnaryOperator::Extension) 1975 return FindExpressionBaseAddress(Exp->getSubExpr()); 1976 1977 return E; 1978 } 1979 case Expr::BinaryOperatorClass: { 1980 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1981 1982 Expr *PExp = Exp->getLHS(); 1983 Expr *IExp = Exp->getRHS(); 1984 if (IExp->getType()->isPointerType()) 1985 std::swap(PExp, IExp); 1986 1987 return FindExpressionBaseAddress(PExp); 1988 } 1989 case Expr::ImplicitCastExprClass: { 1990 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1991 1992 // Check for implicit promotion 1993 if (SubExpr->getType()->isFunctionType() || 1994 SubExpr->getType()->isArrayType()) 1995 return FindExpressionBaseAddressLValue(SubExpr); 1996 1997 // Check for pointer->pointer cast 1998 if (SubExpr->getType()->isPointerType()) 1999 return FindExpressionBaseAddress(SubExpr); 2000 2001 // We assume that we have an arithmetic expression here; 2002 // if we don't, we'll figure it out later 2003 return 0; 2004 } 2005 case Expr::CStyleCastExprClass: { 2006 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 2007 2008 // Check for pointer->pointer cast 2009 if (SubExpr->getType()->isPointerType()) 2010 return FindExpressionBaseAddress(SubExpr); 2011 2012 // We assume that we have an arithmetic expression here; 2013 // if we don't, we'll figure it out later 2014 return 0; 2015 } 2016 } 2017} 2018 2019bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 2020 switch (Init->getStmtClass()) { 2021 default: 2022 InitializerElementNotConstant(Init); 2023 return true; 2024 case Expr::ParenExprClass: { 2025 const ParenExpr* PE = cast<ParenExpr>(Init); 2026 return CheckArithmeticConstantExpression(PE->getSubExpr()); 2027 } 2028 case Expr::FloatingLiteralClass: 2029 case Expr::IntegerLiteralClass: 2030 case Expr::CharacterLiteralClass: 2031 case Expr::ImaginaryLiteralClass: 2032 case Expr::TypesCompatibleExprClass: 2033 case Expr::CXXBoolLiteralExprClass: 2034 return false; 2035 case Expr::CallExprClass: 2036 case Expr::CXXOperatorCallExprClass: { 2037 const CallExpr *CE = cast<CallExpr>(Init); 2038 2039 // Allow any constant foldable calls to builtins. 2040 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 2041 return false; 2042 2043 InitializerElementNotConstant(Init); 2044 return true; 2045 } 2046 case Expr::DeclRefExprClass: 2047 case Expr::QualifiedDeclRefExprClass: { 2048 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 2049 if (isa<EnumConstantDecl>(D)) 2050 return false; 2051 InitializerElementNotConstant(Init); 2052 return true; 2053 } 2054 case Expr::CompoundLiteralExprClass: 2055 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 2056 // but vectors are allowed to be magic. 2057 if (Init->getType()->isVectorType()) 2058 return false; 2059 InitializerElementNotConstant(Init); 2060 return true; 2061 case Expr::UnaryOperatorClass: { 2062 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2063 2064 switch (Exp->getOpcode()) { 2065 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 2066 // See C99 6.6p3. 2067 default: 2068 InitializerElementNotConstant(Init); 2069 return true; 2070 case UnaryOperator::OffsetOf: 2071 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 2072 return false; 2073 InitializerElementNotConstant(Init); 2074 return true; 2075 case UnaryOperator::Extension: 2076 case UnaryOperator::LNot: 2077 case UnaryOperator::Plus: 2078 case UnaryOperator::Minus: 2079 case UnaryOperator::Not: 2080 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 2081 } 2082 } 2083 case Expr::SizeOfAlignOfExprClass: { 2084 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 2085 // Special check for void types, which are allowed as an extension 2086 if (Exp->getTypeOfArgument()->isVoidType()) 2087 return false; 2088 // alignof always evaluates to a constant. 2089 // FIXME: is sizeof(int[3.0]) a constant expression? 2090 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 2091 InitializerElementNotConstant(Init); 2092 return true; 2093 } 2094 return false; 2095 } 2096 case Expr::BinaryOperatorClass: { 2097 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 2098 2099 if (Exp->getLHS()->getType()->isArithmeticType() && 2100 Exp->getRHS()->getType()->isArithmeticType()) { 2101 return CheckArithmeticConstantExpression(Exp->getLHS()) || 2102 CheckArithmeticConstantExpression(Exp->getRHS()); 2103 } 2104 2105 if (Exp->getLHS()->getType()->isPointerType() && 2106 Exp->getRHS()->getType()->isPointerType()) { 2107 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 2108 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 2109 2110 // Only allow a null (constant integer) base; we could 2111 // allow some additional cases if necessary, but this 2112 // is sufficient to cover offsetof-like constructs. 2113 if (!LHSBase && !RHSBase) { 2114 return CheckAddressConstantExpression(Exp->getLHS()) || 2115 CheckAddressConstantExpression(Exp->getRHS()); 2116 } 2117 } 2118 2119 InitializerElementNotConstant(Init); 2120 return true; 2121 } 2122 case Expr::ImplicitCastExprClass: 2123 case Expr::CStyleCastExprClass: { 2124 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 2125 if (SubExpr->getType()->isArithmeticType()) 2126 return CheckArithmeticConstantExpression(SubExpr); 2127 2128 if (SubExpr->getType()->isPointerType()) { 2129 const Expr* Base = FindExpressionBaseAddress(SubExpr); 2130 // If the pointer has a null base, this is an offsetof-like construct 2131 if (!Base) 2132 return CheckAddressConstantExpression(SubExpr); 2133 } 2134 2135 InitializerElementNotConstant(Init); 2136 return true; 2137 } 2138 case Expr::ConditionalOperatorClass: { 2139 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 2140 2141 // If GNU extensions are disabled, we require all operands to be arithmetic 2142 // constant expressions. 2143 if (getLangOptions().NoExtensions) { 2144 return CheckArithmeticConstantExpression(Exp->getCond()) || 2145 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 2146 CheckArithmeticConstantExpression(Exp->getRHS()); 2147 } 2148 2149 // Otherwise, we have to emulate some of the behavior of fold here. 2150 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 2151 // because it can constant fold things away. To retain compatibility with 2152 // GCC code, we see if we can fold the condition to a constant (which we 2153 // should always be able to do in theory). If so, we only require the 2154 // specified arm of the conditional to be a constant. This is a horrible 2155 // hack, but is require by real world code that uses __builtin_constant_p. 2156 Expr::EvalResult EvalResult; 2157 if (!Exp->getCond()->Evaluate(EvalResult, Context) || 2158 EvalResult.HasSideEffects) { 2159 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 2160 // won't be able to either. Use it to emit the diagnostic though. 2161 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 2162 assert(Res && "Evaluate couldn't evaluate this constant?"); 2163 return Res; 2164 } 2165 2166 // Verify that the side following the condition is also a constant. 2167 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 2168 if (EvalResult.Val.getInt() == 0) 2169 std::swap(TrueSide, FalseSide); 2170 2171 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 2172 return true; 2173 2174 // Okay, the evaluated side evaluates to a constant, so we accept this. 2175 // Check to see if the other side is obviously not a constant. If so, 2176 // emit a warning that this is a GNU extension. 2177 if (FalseSide && !FalseSide->isEvaluatable(Context)) 2178 Diag(Init->getExprLoc(), 2179 diag::ext_typecheck_expression_not_constant_but_accepted) 2180 << FalseSide->getSourceRange(); 2181 return false; 2182 } 2183 } 2184} 2185 2186bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2187 Init = Init->IgnoreParens(); 2188 2189 if (Init->isEvaluatable(Context)) 2190 return false; 2191 2192 // Look through CXXDefaultArgExprs; they have no meaning in this context. 2193 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 2194 return CheckForConstantInitializer(DAE->getExpr(), DclT); 2195 2196 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 2197 return CheckForConstantInitializer(e->getInitializer(), DclT); 2198 2199 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 2200 unsigned numInits = Exp->getNumInits(); 2201 for (unsigned i = 0; i < numInits; i++) { 2202 // FIXME: Need to get the type of the declaration for C++, 2203 // because it could be a reference? 2204 if (CheckForConstantInitializer(Exp->getInit(i), 2205 Exp->getInit(i)->getType())) 2206 return true; 2207 } 2208 return false; 2209 } 2210 2211 // FIXME: We can probably remove some of this code below, now that 2212 // Expr::Evaluate is doing the heavy lifting for scalars. 2213 2214 if (Init->isNullPointerConstant(Context)) 2215 return false; 2216 if (Init->getType()->isArithmeticType()) { 2217 QualType InitTy = Context.getCanonicalType(Init->getType()) 2218 .getUnqualifiedType(); 2219 if (InitTy == Context.BoolTy) { 2220 // Special handling for pointers implicitly cast to bool; 2221 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 2222 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 2223 Expr* SubE = ICE->getSubExpr(); 2224 if (SubE->getType()->isPointerType() || 2225 SubE->getType()->isArrayType() || 2226 SubE->getType()->isFunctionType()) { 2227 return CheckAddressConstantExpression(Init); 2228 } 2229 } 2230 } else if (InitTy->isIntegralType()) { 2231 Expr* SubE = 0; 2232 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 2233 SubE = CE->getSubExpr(); 2234 // Special check for pointer cast to int; we allow as an extension 2235 // an address constant cast to an integer if the integer 2236 // is of an appropriate width (this sort of code is apparently used 2237 // in some places). 2238 // FIXME: Add pedwarn? 2239 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 2240 if (SubE && (SubE->getType()->isPointerType() || 2241 SubE->getType()->isArrayType() || 2242 SubE->getType()->isFunctionType())) { 2243 unsigned IntWidth = Context.getTypeSize(Init->getType()); 2244 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 2245 if (IntWidth >= PointerWidth) 2246 return CheckAddressConstantExpression(Init); 2247 } 2248 } 2249 2250 return CheckArithmeticConstantExpression(Init); 2251 } 2252 2253 if (Init->getType()->isPointerType()) 2254 return CheckAddressConstantExpression(Init); 2255 2256 // An array type at the top level that isn't an init-list must 2257 // be a string literal 2258 if (Init->getType()->isArrayType()) 2259 return false; 2260 2261 if (Init->getType()->isFunctionType()) 2262 return false; 2263 2264 // Allow block exprs at top level. 2265 if (Init->getType()->isBlockPointerType()) 2266 return false; 2267 2268 // GCC cast to union extension 2269 // note: the validity of the cast expr is checked by CheckCastTypes() 2270 if (CastExpr *C = dyn_cast<CastExpr>(Init)) { 2271 QualType T = C->getType(); 2272 return T->isUnionType() && CheckForConstantInitializer(C->getSubExpr(), T); 2273 } 2274 2275 InitializerElementNotConstant(Init); 2276 return true; 2277} 2278 2279void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init) { 2280 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 2281} 2282 2283/// AddInitializerToDecl - Adds the initializer Init to the 2284/// declaration dcl. If DirectInit is true, this is C++ direct 2285/// initialization rather than copy initialization. 2286void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init, bool DirectInit) { 2287 Decl *RealDecl = static_cast<Decl *>(dcl); 2288 Expr *Init = static_cast<Expr *>(init.release()); 2289 assert(Init && "missing initializer"); 2290 2291 // If there is no declaration, there was an error parsing it. Just ignore 2292 // the initializer. 2293 if (RealDecl == 0) { 2294 delete Init; 2295 return; 2296 } 2297 2298 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 2299 if (!VDecl) { 2300 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 2301 RealDecl->setInvalidDecl(); 2302 return; 2303 } 2304 // Get the decls type and save a reference for later, since 2305 // CheckInitializerTypes may change it. 2306 QualType DclT = VDecl->getType(), SavT = DclT; 2307 if (VDecl->isBlockVarDecl()) { 2308 VarDecl::StorageClass SC = VDecl->getStorageClass(); 2309 if (SC == VarDecl::Extern) { // C99 6.7.8p5 2310 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 2311 VDecl->setInvalidDecl(); 2312 } else if (!VDecl->isInvalidDecl()) { 2313 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2314 VDecl->getDeclName(), DirectInit)) 2315 VDecl->setInvalidDecl(); 2316 2317 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2318 if (!getLangOptions().CPlusPlus) { 2319 if (SC == VarDecl::Static) // C99 6.7.8p4. 2320 CheckForConstantInitializer(Init, DclT); 2321 } 2322 } 2323 } else if (VDecl->isFileVarDecl()) { 2324 if (VDecl->getStorageClass() == VarDecl::Extern) 2325 Diag(VDecl->getLocation(), diag::warn_extern_init); 2326 if (!VDecl->isInvalidDecl()) 2327 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2328 VDecl->getDeclName(), DirectInit)) 2329 VDecl->setInvalidDecl(); 2330 2331 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2332 if (!getLangOptions().CPlusPlus) { 2333 // C99 6.7.8p4. All file scoped initializers need to be constant. 2334 CheckForConstantInitializer(Init, DclT); 2335 } 2336 } 2337 // If the type changed, it means we had an incomplete type that was 2338 // completed by the initializer. For example: 2339 // int ary[] = { 1, 3, 5 }; 2340 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 2341 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 2342 VDecl->setType(DclT); 2343 Init->setType(DclT); 2344 } 2345 2346 // Attach the initializer to the decl. 2347 VDecl->setInit(Init); 2348 return; 2349} 2350 2351void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 2352 Decl *RealDecl = static_cast<Decl *>(dcl); 2353 2354 // If there is no declaration, there was an error parsing it. Just ignore it. 2355 if (RealDecl == 0) 2356 return; 2357 2358 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 2359 QualType Type = Var->getType(); 2360 // C++ [dcl.init.ref]p3: 2361 // The initializer can be omitted for a reference only in a 2362 // parameter declaration (8.3.5), in the declaration of a 2363 // function return type, in the declaration of a class member 2364 // within its class declaration (9.2), and where the extern 2365 // specifier is explicitly used. 2366 if (Type->isReferenceType() && 2367 Var->getStorageClass() != VarDecl::Extern && 2368 Var->getStorageClass() != VarDecl::PrivateExtern) { 2369 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 2370 << Var->getDeclName() 2371 << SourceRange(Var->getLocation(), Var->getLocation()); 2372 Var->setInvalidDecl(); 2373 return; 2374 } 2375 2376 // C++ [dcl.init]p9: 2377 // 2378 // If no initializer is specified for an object, and the object 2379 // is of (possibly cv-qualified) non-POD class type (or array 2380 // thereof), the object shall be default-initialized; if the 2381 // object is of const-qualified type, the underlying class type 2382 // shall have a user-declared default constructor. 2383 if (getLangOptions().CPlusPlus) { 2384 QualType InitType = Type; 2385 if (const ArrayType *Array = Context.getAsArrayType(Type)) 2386 InitType = Array->getElementType(); 2387 if (Var->getStorageClass() != VarDecl::Extern && 2388 Var->getStorageClass() != VarDecl::PrivateExtern && 2389 InitType->isRecordType()) { 2390 const CXXConstructorDecl *Constructor 2391 = PerformInitializationByConstructor(InitType, 0, 0, 2392 Var->getLocation(), 2393 SourceRange(Var->getLocation(), 2394 Var->getLocation()), 2395 Var->getDeclName(), 2396 IK_Default); 2397 if (!Constructor) 2398 Var->setInvalidDecl(); 2399 } 2400 } 2401 2402#if 0 2403 // FIXME: Temporarily disabled because we are not properly parsing 2404 // linkage specifications on declarations, e.g., 2405 // 2406 // extern "C" const CGPoint CGPointerZero; 2407 // 2408 // C++ [dcl.init]p9: 2409 // 2410 // If no initializer is specified for an object, and the 2411 // object is of (possibly cv-qualified) non-POD class type (or 2412 // array thereof), the object shall be default-initialized; if 2413 // the object is of const-qualified type, the underlying class 2414 // type shall have a user-declared default 2415 // constructor. Otherwise, if no initializer is specified for 2416 // an object, the object and its subobjects, if any, have an 2417 // indeterminate initial value; if the object or any of its 2418 // subobjects are of const-qualified type, the program is 2419 // ill-formed. 2420 // 2421 // This isn't technically an error in C, so we don't diagnose it. 2422 // 2423 // FIXME: Actually perform the POD/user-defined default 2424 // constructor check. 2425 if (getLangOptions().CPlusPlus && 2426 Context.getCanonicalType(Type).isConstQualified() && 2427 Var->getStorageClass() != VarDecl::Extern) 2428 Diag(Var->getLocation(), diag::err_const_var_requires_init) 2429 << Var->getName() 2430 << SourceRange(Var->getLocation(), Var->getLocation()); 2431#endif 2432 } 2433} 2434 2435/// The declarators are chained together backwards, reverse the list. 2436Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 2437 // Often we have single declarators, handle them quickly. 2438 Decl *GroupDecl = static_cast<Decl*>(group); 2439 if (GroupDecl == 0) 2440 return 0; 2441 2442 Decl *Group = dyn_cast<Decl>(GroupDecl); 2443 Decl *NewGroup = 0; 2444 if (Group->getNextDeclarator() == 0) 2445 NewGroup = Group; 2446 else { // reverse the list. 2447 while (Group) { 2448 Decl *Next = Group->getNextDeclarator(); 2449 Group->setNextDeclarator(NewGroup); 2450 NewGroup = Group; 2451 Group = Next; 2452 } 2453 } 2454 // Perform semantic analysis that depends on having fully processed both 2455 // the declarator and initializer. 2456 for (Decl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 2457 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 2458 if (!IDecl) 2459 continue; 2460 QualType T = IDecl->getType(); 2461 2462 if (T->isVariableArrayType()) { 2463 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2464 2465 // FIXME: This won't give the correct result for 2466 // int a[10][n]; 2467 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2468 if (IDecl->isFileVarDecl()) { 2469 Diag(IDecl->getLocation(), diag::err_vla_decl_in_file_scope) << 2470 SizeRange; 2471 2472 IDecl->setInvalidDecl(); 2473 } else { 2474 // C99 6.7.5.2p2: If an identifier is declared to be an object with 2475 // static storage duration, it shall not have a variable length array. 2476 if (IDecl->getStorageClass() == VarDecl::Static) { 2477 Diag(IDecl->getLocation(), diag::err_vla_decl_has_static_storage) 2478 << SizeRange; 2479 IDecl->setInvalidDecl(); 2480 } else if (IDecl->getStorageClass() == VarDecl::Extern) { 2481 Diag(IDecl->getLocation(), diag::err_vla_decl_has_extern_linkage) 2482 << SizeRange; 2483 IDecl->setInvalidDecl(); 2484 } 2485 } 2486 } else if (T->isVariablyModifiedType()) { 2487 if (IDecl->isFileVarDecl()) { 2488 Diag(IDecl->getLocation(), diag::err_vm_decl_in_file_scope); 2489 IDecl->setInvalidDecl(); 2490 } else { 2491 if (IDecl->getStorageClass() == VarDecl::Extern) { 2492 Diag(IDecl->getLocation(), diag::err_vm_decl_has_extern_linkage); 2493 IDecl->setInvalidDecl(); 2494 } 2495 } 2496 } 2497 2498 // Block scope. C99 6.7p7: If an identifier for an object is declared with 2499 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 2500 if (IDecl->isBlockVarDecl() && 2501 IDecl->getStorageClass() != VarDecl::Extern) { 2502 if (!IDecl->isInvalidDecl() && 2503 DiagnoseIncompleteType(IDecl->getLocation(), T, 2504 diag::err_typecheck_decl_incomplete_type)) 2505 IDecl->setInvalidDecl(); 2506 } 2507 // File scope. C99 6.9.2p2: A declaration of an identifier for and 2508 // object that has file scope without an initializer, and without a 2509 // storage-class specifier or with the storage-class specifier "static", 2510 // constitutes a tentative definition. Note: A tentative definition with 2511 // external linkage is valid (C99 6.2.2p5). 2512 if (isTentativeDefinition(IDecl)) { 2513 if (T->isIncompleteArrayType()) { 2514 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 2515 // array to be completed. Don't issue a diagnostic. 2516 } else if (!IDecl->isInvalidDecl() && 2517 DiagnoseIncompleteType(IDecl->getLocation(), T, 2518 diag::err_typecheck_decl_incomplete_type)) 2519 // C99 6.9.2p3: If the declaration of an identifier for an object is 2520 // a tentative definition and has internal linkage (C99 6.2.2p3), the 2521 // declared type shall not be an incomplete type. 2522 IDecl->setInvalidDecl(); 2523 } 2524 if (IDecl->isFileVarDecl()) 2525 CheckForFileScopedRedefinitions(S, IDecl); 2526 } 2527 return NewGroup; 2528} 2529 2530/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 2531/// to introduce parameters into function prototype scope. 2532Sema::DeclTy * 2533Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 2534 const DeclSpec &DS = D.getDeclSpec(); 2535 2536 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 2537 VarDecl::StorageClass StorageClass = VarDecl::None; 2538 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 2539 StorageClass = VarDecl::Register; 2540 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 2541 Diag(DS.getStorageClassSpecLoc(), 2542 diag::err_invalid_storage_class_in_func_decl); 2543 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2544 } 2545 if (DS.isThreadSpecified()) { 2546 Diag(DS.getThreadSpecLoc(), 2547 diag::err_invalid_storage_class_in_func_decl); 2548 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2549 } 2550 2551 // Check that there are no default arguments inside the type of this 2552 // parameter (C++ only). 2553 if (getLangOptions().CPlusPlus) 2554 CheckExtraCXXDefaultArguments(D); 2555 2556 // In this context, we *do not* check D.getInvalidType(). If the declarator 2557 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 2558 // though it will not reflect the user specified type. 2559 QualType parmDeclType = GetTypeForDeclarator(D, S); 2560 2561 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 2562 2563 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 2564 // Can this happen for params? We already checked that they don't conflict 2565 // among each other. Here they can only shadow globals, which is ok. 2566 IdentifierInfo *II = D.getIdentifier(); 2567 if (II) { 2568 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 2569 if (PrevDecl->isTemplateParameter()) { 2570 // Maybe we will complain about the shadowed template parameter. 2571 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 2572 // Just pretend that we didn't see the previous declaration. 2573 PrevDecl = 0; 2574 } else if (S->isDeclScope(PrevDecl)) { 2575 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 2576 2577 // Recover by removing the name 2578 II = 0; 2579 D.SetIdentifier(0, D.getIdentifierLoc()); 2580 } 2581 } 2582 } 2583 2584 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 2585 // Doing the promotion here has a win and a loss. The win is the type for 2586 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 2587 // code generator). The loss is the orginal type isn't preserved. For example: 2588 // 2589 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2590 // int blockvardecl[5]; 2591 // sizeof(parmvardecl); // size == 4 2592 // sizeof(blockvardecl); // size == 20 2593 // } 2594 // 2595 // For expressions, all implicit conversions are captured using the 2596 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2597 // 2598 // FIXME: If a source translation tool needs to see the original type, then 2599 // we need to consider storing both types (in ParmVarDecl)... 2600 // 2601 if (parmDeclType->isArrayType()) { 2602 // int x[restrict 4] -> int *restrict 2603 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2604 } else if (parmDeclType->isFunctionType()) 2605 parmDeclType = Context.getPointerType(parmDeclType); 2606 2607 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2608 D.getIdentifierLoc(), II, 2609 parmDeclType, StorageClass, 2610 0); 2611 2612 if (D.getInvalidType()) 2613 New->setInvalidDecl(); 2614 2615 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 2616 if (D.getCXXScopeSpec().isSet()) { 2617 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 2618 << D.getCXXScopeSpec().getRange(); 2619 New->setInvalidDecl(); 2620 } 2621 2622 // Add the parameter declaration into this scope. 2623 S->AddDecl(New); 2624 if (II) 2625 IdResolver.AddDecl(New); 2626 2627 ProcessDeclAttributes(New, D); 2628 return New; 2629 2630} 2631 2632Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2633 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2634 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2635 "Not a function declarator!"); 2636 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2637 2638 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2639 // for a K&R function. 2640 if (!FTI.hasPrototype) { 2641 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2642 if (FTI.ArgInfo[i].Param == 0) { 2643 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2644 << FTI.ArgInfo[i].Ident; 2645 // Implicitly declare the argument as type 'int' for lack of a better 2646 // type. 2647 DeclSpec DS; 2648 const char* PrevSpec; // unused 2649 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2650 PrevSpec); 2651 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2652 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2653 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2654 } 2655 } 2656 } else { 2657 // FIXME: Diagnose arguments without names in C. 2658 } 2659 2660 Scope *ParentScope = FnBodyScope->getParent(); 2661 2662 return ActOnStartOfFunctionDef(FnBodyScope, 2663 ActOnDeclarator(ParentScope, D, 0, 2664 /*IsFunctionDefinition=*/true)); 2665} 2666 2667Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2668 Decl *decl = static_cast<Decl*>(D); 2669 FunctionDecl *FD = cast<FunctionDecl>(decl); 2670 2671 // See if this is a redefinition. 2672 const FunctionDecl *Definition; 2673 if (FD->getBody(Definition)) { 2674 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 2675 Diag(Definition->getLocation(), diag::note_previous_definition); 2676 } 2677 2678 PushDeclContext(FnBodyScope, FD); 2679 2680 // Check the validity of our function parameters 2681 CheckParmsForFunctionDef(FD); 2682 2683 // Introduce our parameters into the function scope 2684 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2685 ParmVarDecl *Param = FD->getParamDecl(p); 2686 Param->setOwningFunction(FD); 2687 2688 // If this has an identifier, add it to the scope stack. 2689 if (Param->getIdentifier()) 2690 PushOnScopeChains(Param, FnBodyScope); 2691 } 2692 2693 // Checking attributes of current function definition 2694 // dllimport attribute. 2695 if (FD->getAttr<DLLImportAttr>() && (!FD->getAttr<DLLExportAttr>())) { 2696 // dllimport attribute cannot be applied to definition. 2697 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 2698 Diag(FD->getLocation(), 2699 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 2700 << "dllimport"; 2701 FD->setInvalidDecl(); 2702 return FD; 2703 } else { 2704 // If a symbol previously declared dllimport is later defined, the 2705 // attribute is ignored in subsequent references, and a warning is 2706 // emitted. 2707 Diag(FD->getLocation(), 2708 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 2709 << FD->getNameAsCString() << "dllimport"; 2710 } 2711 } 2712 return FD; 2713} 2714 2715Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtArg BodyArg) { 2716 Decl *dcl = static_cast<Decl *>(D); 2717 Stmt *Body = static_cast<Stmt*>(BodyArg.release()); 2718 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2719 FD->setBody(Body); 2720 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2721 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2722 MD->setBody((Stmt*)Body); 2723 } else 2724 return 0; 2725 PopDeclContext(); 2726 // Verify and clean out per-function state. 2727 2728 // Check goto/label use. 2729 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2730 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2731 // Verify that we have no forward references left. If so, there was a goto 2732 // or address of a label taken, but no definition of it. Label fwd 2733 // definitions are indicated with a null substmt. 2734 if (I->second->getSubStmt() == 0) { 2735 LabelStmt *L = I->second; 2736 // Emit error. 2737 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 2738 2739 // At this point, we have gotos that use the bogus label. Stitch it into 2740 // the function body so that they aren't leaked and that the AST is well 2741 // formed. 2742 if (Body) { 2743 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2744 cast<CompoundStmt>(Body)->push_back(L); 2745 } else { 2746 // The whole function wasn't parsed correctly, just delete this. 2747 delete L; 2748 } 2749 } 2750 } 2751 LabelMap.clear(); 2752 2753 return D; 2754} 2755 2756/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2757/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2758NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2759 IdentifierInfo &II, Scope *S) { 2760 // Extension in C99. Legal in C90, but warn about it. 2761 if (getLangOptions().C99) 2762 Diag(Loc, diag::ext_implicit_function_decl) << &II; 2763 else 2764 Diag(Loc, diag::warn_implicit_function_decl) << &II; 2765 2766 // FIXME: handle stuff like: 2767 // void foo() { extern float X(); } 2768 // void bar() { X(); } <-- implicit decl for X in another scope. 2769 2770 // Set a Declarator for the implicit definition: int foo(); 2771 const char *Dummy; 2772 DeclSpec DS; 2773 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2774 Error = Error; // Silence warning. 2775 assert(!Error && "Error setting up implicit decl!"); 2776 Declarator D(DS, Declarator::BlockContext); 2777 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc, D)); 2778 D.SetIdentifier(&II, Loc); 2779 2780 // Insert this function into translation-unit scope. 2781 2782 DeclContext *PrevDC = CurContext; 2783 CurContext = Context.getTranslationUnitDecl(); 2784 2785 FunctionDecl *FD = 2786 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2787 FD->setImplicit(); 2788 2789 CurContext = PrevDC; 2790 2791 return FD; 2792} 2793 2794 2795TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2796 Decl *LastDeclarator) { 2797 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2798 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2799 2800 // Scope manipulation handled by caller. 2801 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2802 D.getIdentifierLoc(), 2803 D.getIdentifier(), 2804 T); 2805 NewTD->setNextDeclarator(LastDeclarator); 2806 if (D.getInvalidType()) 2807 NewTD->setInvalidDecl(); 2808 return NewTD; 2809} 2810 2811/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2812/// former case, Name will be non-null. In the later case, Name will be null. 2813/// TagSpec indicates what kind of tag this is. TK indicates whether this is a 2814/// reference/declaration/definition of a tag. 2815Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK, 2816 SourceLocation KWLoc, const CXXScopeSpec &SS, 2817 IdentifierInfo *Name, SourceLocation NameLoc, 2818 AttributeList *Attr, 2819 MultiTemplateParamsArg TemplateParameterLists) { 2820 // If this is not a definition, it must have a name. 2821 assert((Name != 0 || TK == TK_Definition) && 2822 "Nameless record must be a definition!"); 2823 2824 TagDecl::TagKind Kind; 2825 switch (TagSpec) { 2826 default: assert(0 && "Unknown tag type!"); 2827 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2828 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2829 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2830 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2831 } 2832 2833 DeclContext *SearchDC = CurContext; 2834 DeclContext *DC = CurContext; 2835 DeclContext *LexicalContext = CurContext; 2836 Decl *PrevDecl = 0; 2837 2838 bool Invalid = false; 2839 2840 if (Name && SS.isNotEmpty()) { 2841 // We have a nested-name tag ('struct foo::bar'). 2842 2843 // Check for invalid 'foo::'. 2844 if (SS.isInvalid()) { 2845 Name = 0; 2846 goto CreateNewDecl; 2847 } 2848 2849 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2850 // Look-up name inside 'foo::'. 2851 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC) 2852 .getAsDecl()); 2853 2854 // A tag 'foo::bar' must already exist. 2855 if (PrevDecl == 0) { 2856 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2857 Name = 0; 2858 goto CreateNewDecl; 2859 } 2860 } else if (Name) { 2861 // If this is a named struct, check to see if there was a previous forward 2862 // declaration or definition. 2863 PrevDecl = dyn_cast_or_null<NamedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S) 2864 .getAsDecl()); 2865 2866 if (!getLangOptions().CPlusPlus && TK != TK_Reference) { 2867 // FIXME: This makes sure that we ignore the contexts associated 2868 // with C structs, unions, and enums when looking for a matching 2869 // tag declaration or definition. See the similar lookup tweak 2870 // in Sema::LookupDecl; is there a better way to deal with this? 2871 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 2872 SearchDC = SearchDC->getParent(); 2873 } 2874 } 2875 2876 if (PrevDecl && PrevDecl->isTemplateParameter()) { 2877 // Maybe we will complain about the shadowed template parameter. 2878 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 2879 // Just pretend that we didn't see the previous declaration. 2880 PrevDecl = 0; 2881 } 2882 2883 if (PrevDecl) { 2884 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2885 "unexpected Decl type"); 2886 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2887 // If this is a use of a previous tag, or if the tag is already declared 2888 // in the same scope (so that the definition/declaration completes or 2889 // rementions the tag), reuse the decl. 2890 if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 2891 // Make sure that this wasn't declared as an enum and now used as a 2892 // struct or something similar. 2893 if (PrevTagDecl->getTagKind() != Kind) { 2894 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2895 Diag(PrevDecl->getLocation(), diag::note_previous_use); 2896 // Recover by making this an anonymous redefinition. 2897 Name = 0; 2898 PrevDecl = 0; 2899 Invalid = true; 2900 } else { 2901 // If this is a use, just return the declaration we found. 2902 2903 // FIXME: In the future, return a variant or some other clue 2904 // for the consumer of this Decl to know it doesn't own it. 2905 // For our current ASTs this shouldn't be a problem, but will 2906 // need to be changed with DeclGroups. 2907 if (TK == TK_Reference) 2908 return PrevDecl; 2909 2910 // Diagnose attempts to redefine a tag. 2911 if (TK == TK_Definition) { 2912 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 2913 Diag(NameLoc, diag::err_redefinition) << Name; 2914 Diag(Def->getLocation(), diag::note_previous_definition); 2915 // If this is a redefinition, recover by making this 2916 // struct be anonymous, which will make any later 2917 // references get the previous definition. 2918 Name = 0; 2919 PrevDecl = 0; 2920 Invalid = true; 2921 } else { 2922 // If the type is currently being defined, complain 2923 // about a nested redefinition. 2924 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 2925 if (Tag->isBeingDefined()) { 2926 Diag(NameLoc, diag::err_nested_redefinition) << Name; 2927 Diag(PrevTagDecl->getLocation(), 2928 diag::note_previous_definition); 2929 Name = 0; 2930 PrevDecl = 0; 2931 Invalid = true; 2932 } 2933 } 2934 2935 // Okay, this is definition of a previously declared or referenced 2936 // tag PrevDecl. We're going to create a new Decl for it. 2937 } 2938 } 2939 // If we get here we have (another) forward declaration or we 2940 // have a definition. Just create a new decl. 2941 } else { 2942 // If we get here, this is a definition of a new tag type in a nested 2943 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2944 // new decl/type. We set PrevDecl to NULL so that the entities 2945 // have distinct types. 2946 PrevDecl = 0; 2947 } 2948 // If we get here, we're going to create a new Decl. If PrevDecl 2949 // is non-NULL, it's a definition of the tag declared by 2950 // PrevDecl. If it's NULL, we have a new definition. 2951 } else { 2952 // PrevDecl is a namespace. 2953 if (isDeclInScope(PrevDecl, SearchDC, S)) { 2954 // The tag name clashes with a namespace name, issue an error and 2955 // recover by making this tag be anonymous. 2956 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2957 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 2958 Name = 0; 2959 PrevDecl = 0; 2960 Invalid = true; 2961 } else { 2962 // The existing declaration isn't relevant to us; we're in a 2963 // new scope, so clear out the previous declaration. 2964 PrevDecl = 0; 2965 } 2966 } 2967 } else if (TK == TK_Reference && SS.isEmpty() && Name && 2968 (Kind != TagDecl::TK_enum)) { 2969 // C++ [basic.scope.pdecl]p5: 2970 // -- for an elaborated-type-specifier of the form 2971 // 2972 // class-key identifier 2973 // 2974 // if the elaborated-type-specifier is used in the 2975 // decl-specifier-seq or parameter-declaration-clause of a 2976 // function defined in namespace scope, the identifier is 2977 // declared as a class-name in the namespace that contains 2978 // the declaration; otherwise, except as a friend 2979 // declaration, the identifier is declared in the smallest 2980 // non-class, non-function-prototype scope that contains the 2981 // declaration. 2982 // 2983 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 2984 // C structs and unions. 2985 2986 // Find the context where we'll be declaring the tag. 2987 // FIXME: We would like to maintain the current DeclContext as the 2988 // lexical context, 2989 while (DC->isRecord()) 2990 DC = DC->getParent(); 2991 LexicalContext = DC; 2992 2993 // Find the scope where we'll be declaring the tag. 2994 while (S->isClassScope() || 2995 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 2996 ((S->getFlags() & Scope::DeclScope) == 0) || 2997 (S->getEntity() && 2998 ((DeclContext *)S->getEntity())->isTransparentContext())) 2999 S = S->getParent(); 3000 } 3001 3002CreateNewDecl: 3003 3004 // If there is an identifier, use the location of the identifier as the 3005 // location of the decl, otherwise use the location of the struct/union 3006 // keyword. 3007 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 3008 3009 // Otherwise, create a new declaration. If there is a previous 3010 // declaration of the same entity, the two will be linked via 3011 // PrevDecl. 3012 TagDecl *New; 3013 3014 if (Kind == TagDecl::TK_enum) { 3015 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3016 // enum X { A, B, C } D; D should chain to X. 3017 New = EnumDecl::Create(Context, DC, Loc, Name, 3018 cast_or_null<EnumDecl>(PrevDecl)); 3019 // If this is an undefined enum, warn. 3020 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 3021 } else { 3022 // struct/union/class 3023 3024 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3025 // struct X { int A; } D; D should chain to X. 3026 if (getLangOptions().CPlusPlus) 3027 // FIXME: Look for a way to use RecordDecl for simple structs. 3028 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 3029 cast_or_null<CXXRecordDecl>(PrevDecl)); 3030 else 3031 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 3032 cast_or_null<RecordDecl>(PrevDecl)); 3033 } 3034 3035 if (Kind != TagDecl::TK_enum) { 3036 // Handle #pragma pack: if the #pragma pack stack has non-default 3037 // alignment, make up a packed attribute for this decl. These 3038 // attributes are checked when the ASTContext lays out the 3039 // structure. 3040 // 3041 // It is important for implementing the correct semantics that this 3042 // happen here (in act on tag decl). The #pragma pack stack is 3043 // maintained as a result of parser callbacks which can occur at 3044 // many points during the parsing of a struct declaration (because 3045 // the #pragma tokens are effectively skipped over during the 3046 // parsing of the struct). 3047 if (unsigned Alignment = PackContext.getAlignment()) 3048 New->addAttr(new PackedAttr(Alignment * 8)); 3049 } 3050 3051 if (Invalid) 3052 New->setInvalidDecl(); 3053 3054 if (Attr) 3055 ProcessDeclAttributeList(New, Attr); 3056 3057 // If we're declaring or defining a tag in function prototype scope 3058 // in C, note that this type can only be used within the function. 3059 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 3060 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 3061 3062 // Set the lexical context. If the tag has a C++ scope specifier, the 3063 // lexical context will be different from the semantic context. 3064 New->setLexicalDeclContext(LexicalContext); 3065 3066 if (TK == TK_Definition) 3067 New->startDefinition(); 3068 3069 // If this has an identifier, add it to the scope stack. 3070 if (Name) { 3071 S = getNonFieldDeclScope(S); 3072 3073 // Add it to the decl chain. 3074 if (LexicalContext != CurContext) { 3075 // FIXME: PushOnScopeChains should not rely on CurContext! 3076 DeclContext *OldContext = CurContext; 3077 CurContext = LexicalContext; 3078 PushOnScopeChains(New, S); 3079 CurContext = OldContext; 3080 } else 3081 PushOnScopeChains(New, S); 3082 } else { 3083 LexicalContext->addDecl(New); 3084 } 3085 3086 return New; 3087} 3088 3089void Sema::ActOnTagStartDefinition(Scope *S, DeclTy *TagD) { 3090 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3091 3092 // Enter the tag context. 3093 PushDeclContext(S, Tag); 3094 3095 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 3096 FieldCollector->StartClass(); 3097 3098 if (Record->getIdentifier()) { 3099 // C++ [class]p2: 3100 // [...] The class-name is also inserted into the scope of the 3101 // class itself; this is known as the injected-class-name. For 3102 // purposes of access checking, the injected-class-name is treated 3103 // as if it were a public member name. 3104 RecordDecl *InjectedClassName 3105 = CXXRecordDecl::Create(Context, Record->getTagKind(), 3106 CurContext, Record->getLocation(), 3107 Record->getIdentifier(), Record); 3108 InjectedClassName->setImplicit(); 3109 PushOnScopeChains(InjectedClassName, S); 3110 } 3111 } 3112} 3113 3114void Sema::ActOnTagFinishDefinition(Scope *S, DeclTy *TagD) { 3115 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3116 3117 if (isa<CXXRecordDecl>(Tag)) 3118 FieldCollector->FinishClass(); 3119 3120 // Exit this scope of this tag's definition. 3121 PopDeclContext(); 3122 3123 // Notify the consumer that we've defined a tag. 3124 Consumer.HandleTagDeclDefinition(Tag); 3125} 3126 3127/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 3128/// types into constant array types in certain situations which would otherwise 3129/// be errors (for GCC compatibility). 3130static QualType TryToFixInvalidVariablyModifiedType(QualType T, 3131 ASTContext &Context) { 3132 // This method tries to turn a variable array into a constant 3133 // array even when the size isn't an ICE. This is necessary 3134 // for compatibility with code that depends on gcc's buggy 3135 // constant expression folding, like struct {char x[(int)(char*)2];} 3136 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 3137 if (!VLATy) return QualType(); 3138 3139 Expr::EvalResult EvalResult; 3140 if (!VLATy->getSizeExpr() || 3141 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context)) 3142 return QualType(); 3143 3144 assert(EvalResult.Val.isInt() && "Size expressions must be integers!"); 3145 llvm::APSInt &Res = EvalResult.Val.getInt(); 3146 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 3147 return Context.getConstantArrayType(VLATy->getElementType(), 3148 Res, ArrayType::Normal, 0); 3149 return QualType(); 3150} 3151 3152bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 3153 QualType FieldTy, const Expr *BitWidth) { 3154 // FIXME: 6.7.2.1p4 - verify the field type. 3155 3156 llvm::APSInt Value; 3157 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 3158 return true; 3159 3160 // Zero-width bitfield is ok for anonymous field. 3161 if (Value == 0 && FieldName) 3162 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 3163 3164 if (Value.isNegative()) 3165 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) << FieldName; 3166 3167 uint64_t TypeSize = Context.getTypeSize(FieldTy); 3168 // FIXME: We won't need the 0 size once we check that the field type is valid. 3169 if (TypeSize && Value.getZExtValue() > TypeSize) 3170 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 3171 << FieldName << (unsigned)TypeSize; 3172 3173 return false; 3174} 3175 3176/// ActOnField - Each field of a struct/union/class is passed into this in order 3177/// to create a FieldDecl object for it. 3178Sema::DeclTy *Sema::ActOnField(Scope *S, DeclTy *TagD, 3179 SourceLocation DeclStart, 3180 Declarator &D, ExprTy *BitfieldWidth) { 3181 IdentifierInfo *II = D.getIdentifier(); 3182 Expr *BitWidth = (Expr*)BitfieldWidth; 3183 SourceLocation Loc = DeclStart; 3184 RecordDecl *Record = (RecordDecl *)TagD; 3185 if (II) Loc = D.getIdentifierLoc(); 3186 3187 // FIXME: Unnamed fields can be handled in various different ways, for 3188 // example, unnamed unions inject all members into the struct namespace! 3189 3190 QualType T = GetTypeForDeclarator(D, S); 3191 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3192 bool InvalidDecl = false; 3193 3194 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3195 // than a variably modified type. 3196 if (T->isVariablyModifiedType()) { 3197 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 3198 if (!FixedTy.isNull()) { 3199 Diag(Loc, diag::warn_illegal_constant_array_size); 3200 T = FixedTy; 3201 } else { 3202 Diag(Loc, diag::err_typecheck_field_variable_size); 3203 T = Context.IntTy; 3204 InvalidDecl = true; 3205 } 3206 } 3207 3208 if (BitWidth) { 3209 if (VerifyBitField(Loc, II, T, BitWidth)) 3210 InvalidDecl = true; 3211 } else { 3212 // Not a bitfield. 3213 3214 // validate II. 3215 3216 } 3217 3218 // FIXME: Chain fielddecls together. 3219 FieldDecl *NewFD; 3220 3221 NewFD = FieldDecl::Create(Context, Record, 3222 Loc, II, T, BitWidth, 3223 D.getDeclSpec().getStorageClassSpec() == 3224 DeclSpec::SCS_mutable); 3225 3226 if (II) { 3227 Decl *PrevDecl 3228 = LookupDecl(II, Decl::IDNS_Member, S, 0, false, false, false); 3229 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3230 && !isa<TagDecl>(PrevDecl)) { 3231 Diag(Loc, diag::err_duplicate_member) << II; 3232 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3233 NewFD->setInvalidDecl(); 3234 Record->setInvalidDecl(); 3235 } 3236 } 3237 3238 if (getLangOptions().CPlusPlus) { 3239 CheckExtraCXXDefaultArguments(D); 3240 if (!T->isPODType()) 3241 cast<CXXRecordDecl>(Record)->setPOD(false); 3242 } 3243 3244 ProcessDeclAttributes(NewFD, D); 3245 3246 if (D.getInvalidType() || InvalidDecl) 3247 NewFD->setInvalidDecl(); 3248 3249 if (II) { 3250 PushOnScopeChains(NewFD, S); 3251 } else 3252 Record->addDecl(NewFD); 3253 3254 return NewFD; 3255} 3256 3257/// TranslateIvarVisibility - Translate visibility from a token ID to an 3258/// AST enum value. 3259static ObjCIvarDecl::AccessControl 3260TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 3261 switch (ivarVisibility) { 3262 default: assert(0 && "Unknown visitibility kind"); 3263 case tok::objc_private: return ObjCIvarDecl::Private; 3264 case tok::objc_public: return ObjCIvarDecl::Public; 3265 case tok::objc_protected: return ObjCIvarDecl::Protected; 3266 case tok::objc_package: return ObjCIvarDecl::Package; 3267 } 3268} 3269 3270/// ActOnIvar - Each ivar field of an objective-c class is passed into this 3271/// in order to create an IvarDecl object for it. 3272Sema::DeclTy *Sema::ActOnIvar(Scope *S, 3273 SourceLocation DeclStart, 3274 Declarator &D, ExprTy *BitfieldWidth, 3275 tok::ObjCKeywordKind Visibility) { 3276 3277 IdentifierInfo *II = D.getIdentifier(); 3278 Expr *BitWidth = (Expr*)BitfieldWidth; 3279 SourceLocation Loc = DeclStart; 3280 if (II) Loc = D.getIdentifierLoc(); 3281 3282 // FIXME: Unnamed fields can be handled in various different ways, for 3283 // example, unnamed unions inject all members into the struct namespace! 3284 3285 QualType T = GetTypeForDeclarator(D, S); 3286 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3287 bool InvalidDecl = false; 3288 3289 if (BitWidth) { 3290 // TODO: Validate. 3291 //printf("WARNING: BITFIELDS IGNORED!\n"); 3292 3293 // 6.7.2.1p3 3294 // 6.7.2.1p4 3295 3296 } else { 3297 // Not a bitfield. 3298 3299 // validate II. 3300 3301 } 3302 3303 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3304 // than a variably modified type. 3305 if (T->isVariablyModifiedType()) { 3306 Diag(Loc, diag::err_typecheck_ivar_variable_size); 3307 InvalidDecl = true; 3308 } 3309 3310 // Get the visibility (access control) for this ivar. 3311 ObjCIvarDecl::AccessControl ac = 3312 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 3313 : ObjCIvarDecl::None; 3314 3315 // Construct the decl. 3316 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 3317 (Expr *)BitfieldWidth); 3318 3319 if (II) { 3320 Decl *PrevDecl 3321 = LookupDecl(II, Decl::IDNS_Member, S, 0, false, false, false); 3322 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3323 && !isa<TagDecl>(PrevDecl)) { 3324 Diag(Loc, diag::err_duplicate_member) << II; 3325 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3326 NewID->setInvalidDecl(); 3327 } 3328 } 3329 3330 // Process attributes attached to the ivar. 3331 ProcessDeclAttributes(NewID, D); 3332 3333 if (D.getInvalidType() || InvalidDecl) 3334 NewID->setInvalidDecl(); 3335 3336 if (II) { 3337 // FIXME: When interfaces are DeclContexts, we'll need to add 3338 // these to the interface. 3339 S->AddDecl(NewID); 3340 IdResolver.AddDecl(NewID); 3341 } 3342 3343 return NewID; 3344} 3345 3346void Sema::ActOnFields(Scope* S, 3347 SourceLocation RecLoc, DeclTy *RecDecl, 3348 DeclTy **Fields, unsigned NumFields, 3349 SourceLocation LBrac, SourceLocation RBrac, 3350 AttributeList *Attr) { 3351 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 3352 assert(EnclosingDecl && "missing record or interface decl"); 3353 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 3354 3355 // Verify that all the fields are okay. 3356 unsigned NumNamedMembers = 0; 3357 llvm::SmallVector<FieldDecl*, 32> RecFields; 3358 3359 for (unsigned i = 0; i != NumFields; ++i) { 3360 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 3361 assert(FD && "missing field decl"); 3362 3363 // Get the type for the field. 3364 Type *FDTy = FD->getType().getTypePtr(); 3365 3366 if (!FD->isAnonymousStructOrUnion()) { 3367 // Remember all fields written by the user. 3368 RecFields.push_back(FD); 3369 } 3370 3371 // C99 6.7.2.1p2 - A field may not be a function type. 3372 if (FDTy->isFunctionType()) { 3373 Diag(FD->getLocation(), diag::err_field_declared_as_function) 3374 << FD->getDeclName(); 3375 FD->setInvalidDecl(); 3376 EnclosingDecl->setInvalidDecl(); 3377 continue; 3378 } 3379 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 3380 if (FDTy->isIncompleteType()) { 3381 if (!Record) { // Incomplete ivar type is always an error. 3382 DiagnoseIncompleteType(FD->getLocation(), FD->getType(), 3383 diag::err_field_incomplete); 3384 FD->setInvalidDecl(); 3385 EnclosingDecl->setInvalidDecl(); 3386 continue; 3387 } 3388 if (i != NumFields-1 || // ... that the last member ... 3389 !Record->isStruct() || // ... of a structure ... 3390 !FDTy->isArrayType()) { //... may have incomplete array type. 3391 DiagnoseIncompleteType(FD->getLocation(), FD->getType(), 3392 diag::err_field_incomplete); 3393 FD->setInvalidDecl(); 3394 EnclosingDecl->setInvalidDecl(); 3395 continue; 3396 } 3397 if (NumNamedMembers < 1) { //... must have more than named member ... 3398 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 3399 << FD->getDeclName(); 3400 FD->setInvalidDecl(); 3401 EnclosingDecl->setInvalidDecl(); 3402 continue; 3403 } 3404 // Okay, we have a legal flexible array member at the end of the struct. 3405 if (Record) 3406 Record->setHasFlexibleArrayMember(true); 3407 } 3408 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 3409 /// field of another structure or the element of an array. 3410 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 3411 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 3412 // If this is a member of a union, then entire union becomes "flexible". 3413 if (Record && Record->isUnion()) { 3414 Record->setHasFlexibleArrayMember(true); 3415 } else { 3416 // If this is a struct/class and this is not the last element, reject 3417 // it. Note that GCC supports variable sized arrays in the middle of 3418 // structures. 3419 if (i != NumFields-1) { 3420 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct) 3421 << FD->getDeclName(); 3422 FD->setInvalidDecl(); 3423 EnclosingDecl->setInvalidDecl(); 3424 continue; 3425 } 3426 // We support flexible arrays at the end of structs in other structs 3427 // as an extension. 3428 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 3429 << FD->getDeclName(); 3430 if (Record) 3431 Record->setHasFlexibleArrayMember(true); 3432 } 3433 } 3434 } 3435 /// A field cannot be an Objective-c object 3436 if (FDTy->isObjCInterfaceType()) { 3437 Diag(FD->getLocation(), diag::err_statically_allocated_object) 3438 << FD->getDeclName(); 3439 FD->setInvalidDecl(); 3440 EnclosingDecl->setInvalidDecl(); 3441 continue; 3442 } 3443 // Keep track of the number of named members. 3444 if (FD->getIdentifier()) 3445 ++NumNamedMembers; 3446 } 3447 3448 // Okay, we successfully defined 'Record'. 3449 if (Record) { 3450 Record->completeDefinition(Context); 3451 } else { 3452 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 3453 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 3454 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 3455 // Must enforce the rule that ivars in the base classes may not be 3456 // duplicates. 3457 if (ID->getSuperClass()) { 3458 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 3459 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 3460 ObjCIvarDecl* Ivar = (*IVI); 3461 IdentifierInfo *II = Ivar->getIdentifier(); 3462 ObjCIvarDecl* prevIvar = ID->getSuperClass()->FindIvarDeclaration(II); 3463 if (prevIvar) { 3464 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 3465 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 3466 } 3467 } 3468 } 3469 } 3470 else if (ObjCImplementationDecl *IMPDecl = 3471 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 3472 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 3473 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 3474 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 3475 } 3476 } 3477 3478 if (Attr) 3479 ProcessDeclAttributeList(Record, Attr); 3480} 3481 3482Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 3483 DeclTy *lastEnumConst, 3484 SourceLocation IdLoc, IdentifierInfo *Id, 3485 SourceLocation EqualLoc, ExprTy *val) { 3486 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 3487 EnumConstantDecl *LastEnumConst = 3488 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 3489 Expr *Val = static_cast<Expr*>(val); 3490 3491 // The scope passed in may not be a decl scope. Zip up the scope tree until 3492 // we find one that is. 3493 S = getNonFieldDeclScope(S); 3494 3495 // Verify that there isn't already something declared with this name in this 3496 // scope. 3497 Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S); 3498 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3499 // Maybe we will complain about the shadowed template parameter. 3500 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 3501 // Just pretend that we didn't see the previous declaration. 3502 PrevDecl = 0; 3503 } 3504 3505 if (PrevDecl) { 3506 // When in C++, we may get a TagDecl with the same name; in this case the 3507 // enum constant will 'hide' the tag. 3508 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 3509 "Received TagDecl when not in C++!"); 3510 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 3511 if (isa<EnumConstantDecl>(PrevDecl)) 3512 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 3513 else 3514 Diag(IdLoc, diag::err_redefinition) << Id; 3515 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3516 delete Val; 3517 return 0; 3518 } 3519 } 3520 3521 llvm::APSInt EnumVal(32); 3522 QualType EltTy; 3523 if (Val) { 3524 // Make sure to promote the operand type to int. 3525 UsualUnaryConversions(Val); 3526 3527 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 3528 SourceLocation ExpLoc; 3529 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 3530 delete Val; 3531 Val = 0; // Just forget about it. 3532 } else { 3533 EltTy = Val->getType(); 3534 } 3535 } 3536 3537 if (!Val) { 3538 if (LastEnumConst) { 3539 // Assign the last value + 1. 3540 EnumVal = LastEnumConst->getInitVal(); 3541 ++EnumVal; 3542 3543 // Check for overflow on increment. 3544 if (EnumVal < LastEnumConst->getInitVal()) 3545 Diag(IdLoc, diag::warn_enum_value_overflow); 3546 3547 EltTy = LastEnumConst->getType(); 3548 } else { 3549 // First value, set to zero. 3550 EltTy = Context.IntTy; 3551 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 3552 } 3553 } 3554 3555 EnumConstantDecl *New = 3556 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 3557 Val, EnumVal); 3558 3559 // Register this decl in the current scope stack. 3560 PushOnScopeChains(New, S); 3561 3562 return New; 3563} 3564 3565// FIXME: For consistency with ActOnFields(), we should have the parser 3566// pass in the source location for the left/right braces. 3567void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 3568 DeclTy **Elements, unsigned NumElements) { 3569 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 3570 QualType EnumType = Context.getTypeDeclType(Enum); 3571 3572 // TODO: If the result value doesn't fit in an int, it must be a long or long 3573 // long value. ISO C does not support this, but GCC does as an extension, 3574 // emit a warning. 3575 unsigned IntWidth = Context.Target.getIntWidth(); 3576 3577 // Verify that all the values are okay, compute the size of the values, and 3578 // reverse the list. 3579 unsigned NumNegativeBits = 0; 3580 unsigned NumPositiveBits = 0; 3581 3582 // Keep track of whether all elements have type int. 3583 bool AllElementsInt = true; 3584 3585 for (unsigned i = 0; i != NumElements; ++i) { 3586 EnumConstantDecl *ECD = 3587 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3588 if (!ECD) continue; // Already issued a diagnostic. 3589 3590 // If the enum value doesn't fit in an int, emit an extension warning. 3591 const llvm::APSInt &InitVal = ECD->getInitVal(); 3592 assert(InitVal.getBitWidth() >= IntWidth && 3593 "Should have promoted value to int"); 3594 if (InitVal.getBitWidth() > IntWidth) { 3595 llvm::APSInt V(InitVal); 3596 V.trunc(IntWidth); 3597 V.extend(InitVal.getBitWidth()); 3598 if (V != InitVal) 3599 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 3600 << InitVal.toString(10); 3601 } 3602 3603 // Keep track of the size of positive and negative values. 3604 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 3605 NumPositiveBits = std::max(NumPositiveBits, 3606 (unsigned)InitVal.getActiveBits()); 3607 else 3608 NumNegativeBits = std::max(NumNegativeBits, 3609 (unsigned)InitVal.getMinSignedBits()); 3610 3611 // Keep track of whether every enum element has type int (very commmon). 3612 if (AllElementsInt) 3613 AllElementsInt = ECD->getType() == Context.IntTy; 3614 } 3615 3616 // Figure out the type that should be used for this enum. 3617 // FIXME: Support attribute(packed) on enums and -fshort-enums. 3618 QualType BestType; 3619 unsigned BestWidth; 3620 3621 if (NumNegativeBits) { 3622 // If there is a negative value, figure out the smallest integer type (of 3623 // int/long/longlong) that fits. 3624 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 3625 BestType = Context.IntTy; 3626 BestWidth = IntWidth; 3627 } else { 3628 BestWidth = Context.Target.getLongWidth(); 3629 3630 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 3631 BestType = Context.LongTy; 3632 else { 3633 BestWidth = Context.Target.getLongLongWidth(); 3634 3635 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 3636 Diag(Enum->getLocation(), diag::warn_enum_too_large); 3637 BestType = Context.LongLongTy; 3638 } 3639 } 3640 } else { 3641 // If there is no negative value, figure out which of uint, ulong, ulonglong 3642 // fits. 3643 if (NumPositiveBits <= IntWidth) { 3644 BestType = Context.UnsignedIntTy; 3645 BestWidth = IntWidth; 3646 } else if (NumPositiveBits <= 3647 (BestWidth = Context.Target.getLongWidth())) { 3648 BestType = Context.UnsignedLongTy; 3649 } else { 3650 BestWidth = Context.Target.getLongLongWidth(); 3651 assert(NumPositiveBits <= BestWidth && 3652 "How could an initializer get larger than ULL?"); 3653 BestType = Context.UnsignedLongLongTy; 3654 } 3655 } 3656 3657 // Loop over all of the enumerator constants, changing their types to match 3658 // the type of the enum if needed. 3659 for (unsigned i = 0; i != NumElements; ++i) { 3660 EnumConstantDecl *ECD = 3661 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3662 if (!ECD) continue; // Already issued a diagnostic. 3663 3664 // Standard C says the enumerators have int type, but we allow, as an 3665 // extension, the enumerators to be larger than int size. If each 3666 // enumerator value fits in an int, type it as an int, otherwise type it the 3667 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 3668 // that X has type 'int', not 'unsigned'. 3669 if (ECD->getType() == Context.IntTy) { 3670 // Make sure the init value is signed. 3671 llvm::APSInt IV = ECD->getInitVal(); 3672 IV.setIsSigned(true); 3673 ECD->setInitVal(IV); 3674 3675 if (getLangOptions().CPlusPlus) 3676 // C++ [dcl.enum]p4: Following the closing brace of an 3677 // enum-specifier, each enumerator has the type of its 3678 // enumeration. 3679 ECD->setType(EnumType); 3680 continue; // Already int type. 3681 } 3682 3683 // Determine whether the value fits into an int. 3684 llvm::APSInt InitVal = ECD->getInitVal(); 3685 bool FitsInInt; 3686 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3687 FitsInInt = InitVal.getActiveBits() < IntWidth; 3688 else 3689 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3690 3691 // If it fits into an integer type, force it. Otherwise force it to match 3692 // the enum decl type. 3693 QualType NewTy; 3694 unsigned NewWidth; 3695 bool NewSign; 3696 if (FitsInInt) { 3697 NewTy = Context.IntTy; 3698 NewWidth = IntWidth; 3699 NewSign = true; 3700 } else if (ECD->getType() == BestType) { 3701 // Already the right type! 3702 if (getLangOptions().CPlusPlus) 3703 // C++ [dcl.enum]p4: Following the closing brace of an 3704 // enum-specifier, each enumerator has the type of its 3705 // enumeration. 3706 ECD->setType(EnumType); 3707 continue; 3708 } else { 3709 NewTy = BestType; 3710 NewWidth = BestWidth; 3711 NewSign = BestType->isSignedIntegerType(); 3712 } 3713 3714 // Adjust the APSInt value. 3715 InitVal.extOrTrunc(NewWidth); 3716 InitVal.setIsSigned(NewSign); 3717 ECD->setInitVal(InitVal); 3718 3719 // Adjust the Expr initializer and type. 3720 if (ECD->getInitExpr()) 3721 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3722 /*isLvalue=*/false)); 3723 if (getLangOptions().CPlusPlus) 3724 // C++ [dcl.enum]p4: Following the closing brace of an 3725 // enum-specifier, each enumerator has the type of its 3726 // enumeration. 3727 ECD->setType(EnumType); 3728 else 3729 ECD->setType(NewTy); 3730 } 3731 3732 Enum->completeDefinition(Context, BestType); 3733} 3734 3735Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3736 ExprArg expr) { 3737 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr.release()); 3738 3739 return FileScopeAsmDecl::Create(Context, CurContext, Loc, AsmString); 3740} 3741 3742 3743void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3744 ExprTy *alignment, SourceLocation PragmaLoc, 3745 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3746 Expr *Alignment = static_cast<Expr *>(alignment); 3747 3748 // If specified then alignment must be a "small" power of two. 3749 unsigned AlignmentVal = 0; 3750 if (Alignment) { 3751 llvm::APSInt Val; 3752 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3753 !Val.isPowerOf2() || 3754 Val.getZExtValue() > 16) { 3755 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3756 delete Alignment; 3757 return; // Ignore 3758 } 3759 3760 AlignmentVal = (unsigned) Val.getZExtValue(); 3761 } 3762 3763 switch (Kind) { 3764 case Action::PPK_Default: // pack([n]) 3765 PackContext.setAlignment(AlignmentVal); 3766 break; 3767 3768 case Action::PPK_Show: // pack(show) 3769 // Show the current alignment, making sure to show the right value 3770 // for the default. 3771 AlignmentVal = PackContext.getAlignment(); 3772 // FIXME: This should come from the target. 3773 if (AlignmentVal == 0) 3774 AlignmentVal = 8; 3775 Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 3776 break; 3777 3778 case Action::PPK_Push: // pack(push [, id] [, [n]) 3779 PackContext.push(Name); 3780 // Set the new alignment if specified. 3781 if (Alignment) 3782 PackContext.setAlignment(AlignmentVal); 3783 break; 3784 3785 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3786 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3787 // "#pragma pack(pop, identifier, n) is undefined" 3788 if (Alignment && Name) 3789 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3790 3791 // Do the pop. 3792 if (!PackContext.pop(Name)) { 3793 // If a name was specified then failure indicates the name 3794 // wasn't found. Otherwise failure indicates the stack was 3795 // empty. 3796 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed) 3797 << (Name ? "no record matching name" : "stack empty"); 3798 3799 // FIXME: Warn about popping named records as MSVC does. 3800 } else { 3801 // Pop succeeded, set the new alignment if specified. 3802 if (Alignment) 3803 PackContext.setAlignment(AlignmentVal); 3804 } 3805 break; 3806 3807 default: 3808 assert(0 && "Invalid #pragma pack kind."); 3809 } 3810} 3811 3812bool PragmaPackStack::pop(IdentifierInfo *Name) { 3813 if (Stack.empty()) 3814 return false; 3815 3816 // If name is empty just pop top. 3817 if (!Name) { 3818 Alignment = Stack.back().first; 3819 Stack.pop_back(); 3820 return true; 3821 } 3822 3823 // Otherwise, find the named record. 3824 for (unsigned i = Stack.size(); i != 0; ) { 3825 --i; 3826 if (Stack[i].second == Name) { 3827 // Found it, pop up to and including this record. 3828 Alignment = Stack[i].first; 3829 Stack.erase(Stack.begin() + i, Stack.end()); 3830 return true; 3831 } 3832 } 3833 3834 return false; 3835} 3836