SemaDecl.cpp revision 8260d5de5a366b0b4da0bed1bf6c85c5f215f423
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 (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC)) 92 return SD->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 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(D)) 125 CurContext->addDecl(SD); 126 127 // C++ [basic.scope]p4: 128 // -- exactly one declaration shall declare a class name or 129 // enumeration name that is not a typedef name and the other 130 // declarations shall all refer to the same object or 131 // enumerator, or all refer to functions and function templates; 132 // in this case the class name or enumeration name is hidden. 133 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 134 // We are pushing the name of a tag (enum or class). 135 if (CurContext->getLookupContext() 136 == TD->getDeclContext()->getLookupContext()) { 137 // We're pushing the tag into the current context, which might 138 // require some reshuffling in the identifier resolver. 139 IdentifierResolver::iterator 140 I = IdResolver.begin(TD->getDeclName(), CurContext, 141 false/*LookInParentCtx*/), 142 IEnd = IdResolver.end(); 143 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 144 NamedDecl *PrevDecl = *I; 145 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 146 PrevDecl = *I, ++I) { 147 if (TD->declarationReplaces(*I)) { 148 // This is a redeclaration. Remove it from the chain and 149 // break out, so that we'll add in the shadowed 150 // declaration. 151 S->RemoveDecl(*I); 152 if (PrevDecl == *I) { 153 IdResolver.RemoveDecl(*I); 154 IdResolver.AddDecl(TD); 155 return; 156 } else { 157 IdResolver.RemoveDecl(*I); 158 break; 159 } 160 } 161 } 162 163 // There is already a declaration with the same name in the same 164 // scope, which is not a tag declaration. It must be found 165 // before we find the new declaration, so insert the new 166 // declaration at the end of the chain. 167 IdResolver.AddShadowedDecl(TD, PrevDecl); 168 169 return; 170 } 171 } 172 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 173 // We are pushing the name of a function, which might be an 174 // overloaded name. 175 FunctionDecl *FD = cast<FunctionDecl>(D); 176 DeclContext *DC = FD->getDeclContext()->getLookupContext(); 177 IdentifierResolver::iterator Redecl 178 = std::find_if(IdResolver.begin(FD->getDeclName(), DC, 179 false/*LookInParentCtx*/), 180 IdResolver.end(), 181 std::bind1st(std::mem_fun(&ScopedDecl::declarationReplaces), 182 FD)); 183 if (Redecl != IdResolver.end()) { 184 // There is already a declaration of a function on our 185 // IdResolver chain. Replace it with this declaration. 186 S->RemoveDecl(*Redecl); 187 IdResolver.RemoveDecl(*Redecl); 188 } 189 } 190 191 IdResolver.AddDecl(D); 192} 193 194void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 195 if (S->decl_empty()) return; 196 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 197 "Scope shouldn't contain decls!"); 198 199 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 200 I != E; ++I) { 201 Decl *TmpD = static_cast<Decl*>(*I); 202 assert(TmpD && "This decl didn't get pushed??"); 203 204 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 205 NamedDecl *D = cast<NamedDecl>(TmpD); 206 207 if (!D->getDeclName()) continue; 208 209 // Remove this name from our lexical scope. 210 IdResolver.RemoveDecl(D); 211 } 212} 213 214/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 215/// return 0 if one not found. 216ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 217 // The third "scope" argument is 0 since we aren't enabling lazy built-in 218 // creation from this context. 219 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 220 221 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 222} 223 224/// getNonFieldDeclScope - Retrieves the innermost scope, starting 225/// from S, where a non-field would be declared. This routine copes 226/// with the difference between C and C++ scoping rules in structs and 227/// unions. For example, the following code is well-formed in C but 228/// ill-formed in C++: 229/// @code 230/// struct S6 { 231/// enum { BAR } e; 232/// }; 233/// 234/// void test_S6() { 235/// struct S6 a; 236/// a.e = BAR; 237/// } 238/// @endcode 239/// For the declaration of BAR, this routine will return a different 240/// scope. The scope S will be the scope of the unnamed enumeration 241/// within S6. In C++, this routine will return the scope associated 242/// with S6, because the enumeration's scope is a transparent 243/// context but structures can contain non-field names. In C, this 244/// routine will return the translation unit scope, since the 245/// enumeration's scope is a transparent context and structures cannot 246/// contain non-field names. 247Scope *Sema::getNonFieldDeclScope(Scope *S) { 248 while (((S->getFlags() & Scope::DeclScope) == 0) || 249 (S->getEntity() && 250 ((DeclContext *)S->getEntity())->isTransparentContext()) || 251 (S->isClassScope() && !getLangOptions().CPlusPlus)) 252 S = S->getParent(); 253 return S; 254} 255 256/// LookupDecl - Look up the inner-most declaration in the specified 257/// namespace. NamespaceNameOnly - during lookup only namespace names 258/// are considered as required in C++ [basic.lookup.udir] 3.4.6.p1 259/// 'When looking up a namespace-name in a using-directive or 260/// namespace-alias-definition, only namespace names are considered.' 261/// 262/// Note: The use of this routine is deprecated. Please use 263/// LookupName, LookupQualifiedName, or LookupParsedName instead. 264Sema::LookupResult 265Sema::LookupDecl(DeclarationName Name, unsigned NSI, Scope *S, 266 const DeclContext *LookupCtx, 267 bool enableLazyBuiltinCreation, 268 bool LookInParent, 269 bool NamespaceNameOnly) { 270 LookupCriteria::NameKind Kind; 271 if (NSI == Decl::IDNS_Ordinary) { 272 if (NamespaceNameOnly) 273 Kind = LookupCriteria::Namespace; 274 else 275 Kind = LookupCriteria::Ordinary; 276 } else if (NSI == Decl::IDNS_Tag) 277 Kind = LookupCriteria::Tag; 278 else if (NSI == Decl::IDNS_Member) 279 Kind = LookupCriteria::Member; 280 else 281 assert(false && "Unable to grok LookupDecl NSI argument"); 282 283 if (LookupCtx) 284 return LookupQualifiedName(const_cast<DeclContext *>(LookupCtx), Name, 285 LookupCriteria(Kind, !LookInParent, 286 getLangOptions().CPlusPlus)); 287 288 // Unqualified lookup 289 return LookupName(S, Name, 290 LookupCriteria(Kind, !LookInParent, 291 getLangOptions().CPlusPlus)); 292} 293 294void Sema::InitBuiltinVaListType() { 295 if (!Context.getBuiltinVaListType().isNull()) 296 return; 297 298 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 299 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 300 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 301 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 302} 303 304/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 305/// lazily create a decl for it. 306ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 307 Scope *S) { 308 Builtin::ID BID = (Builtin::ID)bid; 309 310 if (Context.BuiltinInfo.hasVAListUse(BID)) 311 InitBuiltinVaListType(); 312 313 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 314 FunctionDecl *New = FunctionDecl::Create(Context, 315 Context.getTranslationUnitDecl(), 316 SourceLocation(), II, R, 317 FunctionDecl::Extern, false, 0); 318 319 // Create Decl objects for each parameter, adding them to the 320 // FunctionDecl. 321 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 322 llvm::SmallVector<ParmVarDecl*, 16> Params; 323 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 324 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 325 FT->getArgType(i), VarDecl::None, 0, 326 0)); 327 New->setParams(Context, &Params[0], Params.size()); 328 } 329 330 331 332 // TUScope is the translation-unit scope to insert this function into. 333 // FIXME: This is hideous. We need to teach PushOnScopeChains to 334 // relate Scopes to DeclContexts, and probably eliminate CurContext 335 // entirely, but we're not there yet. 336 DeclContext *SavedContext = CurContext; 337 CurContext = Context.getTranslationUnitDecl(); 338 PushOnScopeChains(New, TUScope); 339 CurContext = SavedContext; 340 return New; 341} 342 343/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 344/// everything from the standard library is defined. 345NamespaceDecl *Sema::GetStdNamespace() { 346 if (!StdNamespace) { 347 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 348 DeclContext *Global = Context.getTranslationUnitDecl(); 349 Decl *Std = LookupDecl(StdIdent, Decl::IDNS_Ordinary, 350 0, Global, /*enableLazyBuiltinCreation=*/false); 351 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 352 } 353 return StdNamespace; 354} 355 356/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 357/// and scope as a previous declaration 'Old'. Figure out how to resolve this 358/// situation, merging decls or emitting diagnostics as appropriate. 359/// 360TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 361 // Allow multiple definitions for ObjC built-in typedefs. 362 // FIXME: Verify the underlying types are equivalent! 363 if (getLangOptions().ObjC1) { 364 const IdentifierInfo *TypeID = New->getIdentifier(); 365 switch (TypeID->getLength()) { 366 default: break; 367 case 2: 368 if (!TypeID->isStr("id")) 369 break; 370 Context.setObjCIdType(New); 371 return New; 372 case 5: 373 if (!TypeID->isStr("Class")) 374 break; 375 Context.setObjCClassType(New); 376 return New; 377 case 3: 378 if (!TypeID->isStr("SEL")) 379 break; 380 Context.setObjCSelType(New); 381 return New; 382 case 8: 383 if (!TypeID->isStr("Protocol")) 384 break; 385 Context.setObjCProtoType(New->getUnderlyingType()); 386 return New; 387 } 388 // Fall through - the typedef name was not a builtin type. 389 } 390 // Verify the old decl was also a typedef. 391 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 392 if (!Old) { 393 Diag(New->getLocation(), diag::err_redefinition_different_kind) 394 << New->getDeclName(); 395 Diag(OldD->getLocation(), diag::note_previous_definition); 396 return New; 397 } 398 399 // If the typedef types are not identical, reject them in all languages and 400 // with any extensions enabled. 401 if (Old->getUnderlyingType() != New->getUnderlyingType() && 402 Context.getCanonicalType(Old->getUnderlyingType()) != 403 Context.getCanonicalType(New->getUnderlyingType())) { 404 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 405 << New->getUnderlyingType() << Old->getUnderlyingType(); 406 Diag(Old->getLocation(), diag::note_previous_definition); 407 return New; 408 } 409 410 if (getLangOptions().Microsoft) return New; 411 412 // C++ [dcl.typedef]p2: 413 // In a given non-class scope, a typedef specifier can be used to 414 // redefine the name of any type declared in that scope to refer 415 // to the type to which it already refers. 416 if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext)) 417 return New; 418 419 // In C, redeclaration of a type is a constraint violation (6.7.2.3p1). 420 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 421 // *either* declaration is in a system header. The code below implements 422 // this adhoc compatibility rule. FIXME: The following code will not 423 // work properly when compiling ".i" files (containing preprocessed output). 424 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 425 SourceManager &SrcMgr = Context.getSourceManager(); 426 if (SrcMgr.isInSystemHeader(Old->getLocation())) 427 return New; 428 if (SrcMgr.isInSystemHeader(New->getLocation())) 429 return New; 430 } 431 432 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 433 Diag(Old->getLocation(), diag::note_previous_definition); 434 return New; 435} 436 437/// DeclhasAttr - returns true if decl Declaration already has the target 438/// attribute. 439static bool DeclHasAttr(const Decl *decl, const Attr *target) { 440 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 441 if (attr->getKind() == target->getKind()) 442 return true; 443 444 return false; 445} 446 447/// MergeAttributes - append attributes from the Old decl to the New one. 448static void MergeAttributes(Decl *New, Decl *Old) { 449 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 450 451 while (attr) { 452 tmp = attr; 453 attr = attr->getNext(); 454 455 if (!DeclHasAttr(New, tmp)) { 456 tmp->setInherited(true); 457 New->addAttr(tmp); 458 } else { 459 tmp->setNext(0); 460 delete(tmp); 461 } 462 } 463 464 Old->invalidateAttrs(); 465} 466 467/// MergeFunctionDecl - We just parsed a function 'New' from 468/// declarator D which has the same name and scope as a previous 469/// declaration 'Old'. Figure out how to resolve this situation, 470/// merging decls or emitting diagnostics as appropriate. 471/// Redeclaration will be set true if this New is a redeclaration OldD. 472/// 473/// In C++, New and Old must be declarations that are not 474/// overloaded. Use IsOverload to determine whether New and Old are 475/// overloaded, and to select the Old declaration that New should be 476/// merged with. 477FunctionDecl * 478Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 479 assert(!isa<OverloadedFunctionDecl>(OldD) && 480 "Cannot merge with an overloaded function declaration"); 481 482 Redeclaration = false; 483 // Verify the old decl was also a function. 484 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 485 if (!Old) { 486 Diag(New->getLocation(), diag::err_redefinition_different_kind) 487 << New->getDeclName(); 488 Diag(OldD->getLocation(), diag::note_previous_definition); 489 return New; 490 } 491 492 // Determine whether the previous declaration was a definition, 493 // implicit declaration, or a declaration. 494 diag::kind PrevDiag; 495 if (Old->isThisDeclarationADefinition()) 496 PrevDiag = diag::note_previous_definition; 497 else if (Old->isImplicit()) 498 PrevDiag = diag::note_previous_implicit_declaration; 499 else 500 PrevDiag = diag::note_previous_declaration; 501 502 QualType OldQType = Context.getCanonicalType(Old->getType()); 503 QualType NewQType = Context.getCanonicalType(New->getType()); 504 505 if (getLangOptions().CPlusPlus) { 506 // (C++98 13.1p2): 507 // Certain function declarations cannot be overloaded: 508 // -- Function declarations that differ only in the return type 509 // cannot be overloaded. 510 QualType OldReturnType 511 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 512 QualType NewReturnType 513 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 514 if (OldReturnType != NewReturnType) { 515 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 516 Diag(Old->getLocation(), PrevDiag); 517 Redeclaration = true; 518 return New; 519 } 520 521 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 522 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 523 if (OldMethod && NewMethod) { 524 // -- Member function declarations with the same name and the 525 // same parameter types cannot be overloaded if any of them 526 // is a static member function declaration. 527 if (OldMethod->isStatic() || NewMethod->isStatic()) { 528 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 529 Diag(Old->getLocation(), PrevDiag); 530 return New; 531 } 532 533 // C++ [class.mem]p1: 534 // [...] A member shall not be declared twice in the 535 // member-specification, except that a nested class or member 536 // class template can be declared and then later defined. 537 if (OldMethod->getLexicalDeclContext() == 538 NewMethod->getLexicalDeclContext()) { 539 unsigned NewDiag; 540 if (isa<CXXConstructorDecl>(OldMethod)) 541 NewDiag = diag::err_constructor_redeclared; 542 else if (isa<CXXDestructorDecl>(NewMethod)) 543 NewDiag = diag::err_destructor_redeclared; 544 else if (isa<CXXConversionDecl>(NewMethod)) 545 NewDiag = diag::err_conv_function_redeclared; 546 else 547 NewDiag = diag::err_member_redeclared; 548 549 Diag(New->getLocation(), NewDiag); 550 Diag(Old->getLocation(), PrevDiag); 551 } 552 } 553 554 // (C++98 8.3.5p3): 555 // All declarations for a function shall agree exactly in both the 556 // return type and the parameter-type-list. 557 if (OldQType == NewQType) { 558 // We have a redeclaration. 559 MergeAttributes(New, Old); 560 Redeclaration = true; 561 return MergeCXXFunctionDecl(New, Old); 562 } 563 564 // Fall through for conflicting redeclarations and redefinitions. 565 } 566 567 // C: Function types need to be compatible, not identical. This handles 568 // duplicate function decls like "void f(int); void f(enum X);" properly. 569 if (!getLangOptions().CPlusPlus && 570 Context.typesAreCompatible(OldQType, NewQType)) { 571 MergeAttributes(New, Old); 572 Redeclaration = true; 573 return New; 574 } 575 576 // A function that has already been declared has been redeclared or defined 577 // with a different type- show appropriate diagnostic 578 579 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 580 // TODO: This is totally simplistic. It should handle merging functions 581 // together etc, merging extern int X; int X; ... 582 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 583 Diag(Old->getLocation(), PrevDiag); 584 return New; 585} 586 587/// Predicate for C "tentative" external object definitions (C99 6.9.2). 588static bool isTentativeDefinition(VarDecl *VD) { 589 if (VD->isFileVarDecl()) 590 return (!VD->getInit() && 591 (VD->getStorageClass() == VarDecl::None || 592 VD->getStorageClass() == VarDecl::Static)); 593 return false; 594} 595 596/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 597/// when dealing with C "tentative" external object definitions (C99 6.9.2). 598void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 599 bool VDIsTentative = isTentativeDefinition(VD); 600 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 601 602 // FIXME: I don't think this will actually see all of the 603 // redefinitions. Can't we check this property on-the-fly? 604 for (IdentifierResolver::iterator 605 I = IdResolver.begin(VD->getIdentifier(), 606 VD->getDeclContext(), false/*LookInParentCtx*/), 607 E = IdResolver.end(); I != E; ++I) { 608 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 609 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 610 611 // Handle the following case: 612 // int a[10]; 613 // int a[]; - the code below makes sure we set the correct type. 614 // int a[11]; - this is an error, size isn't 10. 615 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 616 OldDecl->getType()->isConstantArrayType()) 617 VD->setType(OldDecl->getType()); 618 619 // Check for "tentative" definitions. We can't accomplish this in 620 // MergeVarDecl since the initializer hasn't been attached. 621 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 622 continue; 623 624 // Handle __private_extern__ just like extern. 625 if (OldDecl->getStorageClass() != VarDecl::Extern && 626 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 627 VD->getStorageClass() != VarDecl::Extern && 628 VD->getStorageClass() != VarDecl::PrivateExtern) { 629 Diag(VD->getLocation(), diag::err_redefinition) << VD->getDeclName(); 630 Diag(OldDecl->getLocation(), diag::note_previous_definition); 631 } 632 } 633 } 634} 635 636/// MergeVarDecl - We just parsed a variable 'New' which has the same name 637/// and scope as a previous declaration 'Old'. Figure out how to resolve this 638/// situation, merging decls or emitting diagnostics as appropriate. 639/// 640/// Tentative definition rules (C99 6.9.2p2) are checked by 641/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 642/// definitions here, since the initializer hasn't been attached. 643/// 644VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 645 // Verify the old decl was also a variable. 646 VarDecl *Old = dyn_cast<VarDecl>(OldD); 647 if (!Old) { 648 Diag(New->getLocation(), diag::err_redefinition_different_kind) 649 << New->getDeclName(); 650 Diag(OldD->getLocation(), diag::note_previous_definition); 651 return New; 652 } 653 654 MergeAttributes(New, Old); 655 656 // Verify the types match. 657 QualType OldCType = Context.getCanonicalType(Old->getType()); 658 QualType NewCType = Context.getCanonicalType(New->getType()); 659 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 660 Diag(New->getLocation(), diag::err_redefinition_different_type) 661 << New->getDeclName(); 662 Diag(Old->getLocation(), diag::note_previous_definition); 663 return New; 664 } 665 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 666 if (New->getStorageClass() == VarDecl::Static && 667 (Old->getStorageClass() == VarDecl::None || 668 Old->getStorageClass() == VarDecl::Extern)) { 669 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 670 Diag(Old->getLocation(), diag::note_previous_definition); 671 return New; 672 } 673 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 674 if (New->getStorageClass() != VarDecl::Static && 675 Old->getStorageClass() == VarDecl::Static) { 676 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 677 Diag(Old->getLocation(), diag::note_previous_definition); 678 return New; 679 } 680 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 681 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 682 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 683 Diag(Old->getLocation(), diag::note_previous_definition); 684 } 685 return New; 686} 687 688/// CheckParmsForFunctionDef - Check that the parameters of the given 689/// function are appropriate for the definition of a function. This 690/// takes care of any checks that cannot be performed on the 691/// declaration itself, e.g., that the types of each of the function 692/// parameters are complete. 693bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 694 bool HasInvalidParm = false; 695 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 696 ParmVarDecl *Param = FD->getParamDecl(p); 697 698 // C99 6.7.5.3p4: the parameters in a parameter type list in a 699 // function declarator that is part of a function definition of 700 // that function shall not have incomplete type. 701 if (Param->getType()->isIncompleteType() && 702 !Param->isInvalidDecl()) { 703 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type) 704 << Param->getType(); 705 Param->setInvalidDecl(); 706 HasInvalidParm = true; 707 } 708 709 // C99 6.9.1p5: If the declarator includes a parameter type list, the 710 // declaration of each parameter shall include an identifier. 711 if (Param->getIdentifier() == 0 && !getLangOptions().CPlusPlus) 712 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 713 } 714 715 return HasInvalidParm; 716} 717 718/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 719/// no declarator (e.g. "struct foo;") is parsed. 720Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 721 TagDecl *Tag 722 = dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 723 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 724 if (!Record->getDeclName() && Record->isDefinition() && 725 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) 726 return BuildAnonymousStructOrUnion(S, DS, Record); 727 728 // Microsoft allows unnamed struct/union fields. Don't complain 729 // about them. 730 // FIXME: Should we support Microsoft's extensions in this area? 731 if (Record->getDeclName() && getLangOptions().Microsoft) 732 return Tag; 733 } 734 735 // Permit typedefs without declarators as a Microsoft extension. 736 if (!DS.isMissingDeclaratorOk()) { 737 if (getLangOptions().Microsoft && 738 DS.getStorageClassSpec() == DeclSpec::SCS_typedef) { 739 Diag(DS.getSourceRange().getBegin(), diag::ext_no_declarators) 740 << DS.getSourceRange(); 741 return Tag; 742 } 743 744 // FIXME: This diagnostic is emitted even when various previous 745 // errors occurred (see e.g. test/Sema/decl-invalid.c). However, 746 // DeclSpec has no means of communicating this information, and the 747 // responsible parser functions are quite far apart. 748 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 749 << DS.getSourceRange(); 750 return 0; 751 } 752 753 return Tag; 754} 755 756/// InjectAnonymousStructOrUnionMembers - Inject the members of the 757/// anonymous struct or union AnonRecord into the owning context Owner 758/// and scope S. This routine will be invoked just after we realize 759/// that an unnamed union or struct is actually an anonymous union or 760/// struct, e.g., 761/// 762/// @code 763/// union { 764/// int i; 765/// float f; 766/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 767/// // f into the surrounding scope.x 768/// @endcode 769/// 770/// This routine is recursive, injecting the names of nested anonymous 771/// structs/unions into the owning context and scope as well. 772bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 773 RecordDecl *AnonRecord) { 774 bool Invalid = false; 775 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 776 FEnd = AnonRecord->field_end(); 777 F != FEnd; ++F) { 778 if ((*F)->getDeclName()) { 779 Decl *PrevDecl = LookupDecl((*F)->getDeclName(), Decl::IDNS_Ordinary, 780 S, Owner, false, false, false); 781 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 782 // C++ [class.union]p2: 783 // The names of the members of an anonymous union shall be 784 // distinct from the names of any other entity in the 785 // scope in which the anonymous union is declared. 786 unsigned diagKind 787 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 788 : diag::err_anonymous_struct_member_redecl; 789 Diag((*F)->getLocation(), diagKind) 790 << (*F)->getDeclName(); 791 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 792 Invalid = true; 793 } else { 794 // C++ [class.union]p2: 795 // For the purpose of name lookup, after the anonymous union 796 // definition, the members of the anonymous union are 797 // considered to have been defined in the scope in which the 798 // anonymous union is declared. 799 Owner->insert(*F); 800 S->AddDecl(*F); 801 IdResolver.AddDecl(*F); 802 } 803 } else if (const RecordType *InnerRecordType 804 = (*F)->getType()->getAsRecordType()) { 805 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 806 if (InnerRecord->isAnonymousStructOrUnion()) 807 Invalid = Invalid || 808 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 809 } 810 } 811 812 return Invalid; 813} 814 815/// ActOnAnonymousStructOrUnion - Handle the declaration of an 816/// anonymous structure or union. Anonymous unions are a C++ feature 817/// (C++ [class.union]) and a GNU C extension; anonymous structures 818/// are a GNU C and GNU C++ extension. 819Sema::DeclTy *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 820 RecordDecl *Record) { 821 DeclContext *Owner = Record->getDeclContext(); 822 823 // Diagnose whether this anonymous struct/union is an extension. 824 if (Record->isUnion() && !getLangOptions().CPlusPlus) 825 Diag(Record->getLocation(), diag::ext_anonymous_union); 826 else if (!Record->isUnion()) 827 Diag(Record->getLocation(), diag::ext_anonymous_struct); 828 829 // C and C++ require different kinds of checks for anonymous 830 // structs/unions. 831 bool Invalid = false; 832 if (getLangOptions().CPlusPlus) { 833 const char* PrevSpec = 0; 834 // C++ [class.union]p3: 835 // Anonymous unions declared in a named namespace or in the 836 // global namespace shall be declared static. 837 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 838 (isa<TranslationUnitDecl>(Owner) || 839 (isa<NamespaceDecl>(Owner) && 840 cast<NamespaceDecl>(Owner)->getDeclName()))) { 841 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 842 Invalid = true; 843 844 // Recover by adding 'static'. 845 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec); 846 } 847 // C++ [class.union]p3: 848 // A storage class is not allowed in a declaration of an 849 // anonymous union in a class scope. 850 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 851 isa<RecordDecl>(Owner)) { 852 Diag(DS.getStorageClassSpecLoc(), 853 diag::err_anonymous_union_with_storage_spec); 854 Invalid = true; 855 856 // Recover by removing the storage specifier. 857 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 858 PrevSpec); 859 } 860 861 // C++ [class.union]p2: 862 // The member-specification of an anonymous union shall only 863 // define non-static data members. [Note: nested types and 864 // functions cannot be declared within an anonymous union. ] 865 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 866 MemEnd = Record->decls_end(); 867 Mem != MemEnd; ++Mem) { 868 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 869 // C++ [class.union]p3: 870 // An anonymous union shall not have private or protected 871 // members (clause 11). 872 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 873 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 874 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 875 Invalid = true; 876 } 877 } else if ((*Mem)->isImplicit()) { 878 // Any implicit members are fine. 879 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 880 if (!MemRecord->isAnonymousStructOrUnion() && 881 MemRecord->getDeclName()) { 882 // This is a nested type declaration. 883 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 884 << (int)Record->isUnion(); 885 Invalid = true; 886 } 887 } else { 888 // We have something that isn't a non-static data 889 // member. Complain about it. 890 unsigned DK = diag::err_anonymous_record_bad_member; 891 if (isa<TypeDecl>(*Mem)) 892 DK = diag::err_anonymous_record_with_type; 893 else if (isa<FunctionDecl>(*Mem)) 894 DK = diag::err_anonymous_record_with_function; 895 else if (isa<VarDecl>(*Mem)) 896 DK = diag::err_anonymous_record_with_static; 897 Diag((*Mem)->getLocation(), DK) 898 << (int)Record->isUnion(); 899 Invalid = true; 900 } 901 } 902 } else { 903 // FIXME: Check GNU C semantics 904 if (Record->isUnion() && !Owner->isRecord()) { 905 Diag(Record->getLocation(), diag::err_anonymous_union_not_member) 906 << (int)getLangOptions().CPlusPlus; 907 Invalid = true; 908 } 909 } 910 911 if (!Record->isUnion() && !Owner->isRecord()) { 912 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 913 << (int)getLangOptions().CPlusPlus; 914 Invalid = true; 915 } 916 917 // Create a declaration for this anonymous struct/union. 918 ScopedDecl *Anon = 0; 919 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 920 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 921 /*IdentifierInfo=*/0, 922 Context.getTypeDeclType(Record), 923 /*BitWidth=*/0, /*Mutable=*/false, 924 /*PrevDecl=*/0); 925 Anon->setAccess(AS_public); 926 if (getLangOptions().CPlusPlus) 927 FieldCollector->Add(cast<FieldDecl>(Anon)); 928 } else { 929 VarDecl::StorageClass SC; 930 switch (DS.getStorageClassSpec()) { 931 default: assert(0 && "Unknown storage class!"); 932 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 933 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 934 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 935 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 936 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 937 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 938 case DeclSpec::SCS_mutable: 939 // mutable can only appear on non-static class members, so it's always 940 // an error here 941 Diag(Record->getLocation(), diag::err_mutable_nonmember); 942 Invalid = true; 943 SC = VarDecl::None; 944 break; 945 } 946 947 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 948 /*IdentifierInfo=*/0, 949 Context.getTypeDeclType(Record), 950 SC, /*FIXME:LastDeclarator=*/0, 951 DS.getSourceRange().getBegin()); 952 } 953 Anon->setImplicit(); 954 955 // Add the anonymous struct/union object to the current 956 // context. We'll be referencing this object when we refer to one of 957 // its members. 958 Owner->addDecl(Anon); 959 960 // Inject the members of the anonymous struct/union into the owning 961 // context and into the identifier resolver chain for name lookup 962 // purposes. 963 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 964 Invalid = true; 965 966 // Mark this as an anonymous struct/union type. Note that we do not 967 // do this until after we have already checked and injected the 968 // members of this anonymous struct/union type, because otherwise 969 // the members could be injected twice: once by DeclContext when it 970 // builds its lookup table, and once by 971 // InjectAnonymousStructOrUnionMembers. 972 Record->setAnonymousStructOrUnion(true); 973 974 if (Invalid) 975 Anon->setInvalidDecl(); 976 977 return Anon; 978} 979 980bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType, 981 bool DirectInit) { 982 // Get the type before calling CheckSingleAssignmentConstraints(), since 983 // it can promote the expression. 984 QualType InitType = Init->getType(); 985 986 if (getLangOptions().CPlusPlus) { 987 // FIXME: I dislike this error message. A lot. 988 if (PerformImplicitConversion(Init, DeclType, "initializing", DirectInit)) 989 return Diag(Init->getSourceRange().getBegin(), 990 diag::err_typecheck_convert_incompatible) 991 << DeclType << Init->getType() << "initializing" 992 << Init->getSourceRange(); 993 994 return false; 995 } 996 997 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 998 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 999 InitType, Init, "initializing"); 1000} 1001 1002bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 1003 const ArrayType *AT = Context.getAsArrayType(DeclT); 1004 1005 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 1006 // C99 6.7.8p14. We have an array of character type with unknown size 1007 // being initialized to a string literal. 1008 llvm::APSInt ConstVal(32); 1009 ConstVal = strLiteral->getByteLength() + 1; 1010 // Return a new array type (C99 6.7.8p22). 1011 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 1012 ArrayType::Normal, 0); 1013 } else { 1014 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 1015 // C99 6.7.8p14. We have an array of character type with known size. 1016 // FIXME: Avoid truncation for 64-bit length strings. 1017 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 1018 Diag(strLiteral->getSourceRange().getBegin(), 1019 diag::warn_initializer_string_for_char_array_too_long) 1020 << strLiteral->getSourceRange(); 1021 } 1022 // Set type from "char *" to "constant array of char". 1023 strLiteral->setType(DeclT); 1024 // For now, we always return false (meaning success). 1025 return false; 1026} 1027 1028StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 1029 const ArrayType *AT = Context.getAsArrayType(DeclType); 1030 if (AT && AT->getElementType()->isCharType()) { 1031 return dyn_cast<StringLiteral>(Init); 1032 } 1033 return 0; 1034} 1035 1036bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 1037 SourceLocation InitLoc, 1038 DeclarationName InitEntity, 1039 bool DirectInit) { 1040 if (DeclType->isDependentType() || Init->isTypeDependent()) 1041 return false; 1042 1043 // C++ [dcl.init.ref]p1: 1044 // A variable declared to be a T&, that is "reference to type T" 1045 // (8.3.2), shall be initialized by an object, or function, of 1046 // type T or by an object that can be converted into a T. 1047 if (DeclType->isReferenceType()) 1048 return CheckReferenceInit(Init, DeclType, 0, false, DirectInit); 1049 1050 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 1051 // of unknown size ("[]") or an object type that is not a variable array type. 1052 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 1053 return Diag(InitLoc, diag::err_variable_object_no_init) 1054 << VAT->getSizeExpr()->getSourceRange(); 1055 1056 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 1057 if (!InitList) { 1058 // FIXME: Handle wide strings 1059 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 1060 return CheckStringLiteralInit(strLiteral, DeclType); 1061 1062 // C++ [dcl.init]p14: 1063 // -- If the destination type is a (possibly cv-qualified) class 1064 // type: 1065 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 1066 QualType DeclTypeC = Context.getCanonicalType(DeclType); 1067 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 1068 1069 // -- If the initialization is direct-initialization, or if it is 1070 // copy-initialization where the cv-unqualified version of the 1071 // source type is the same class as, or a derived class of, the 1072 // class of the destination, constructors are considered. 1073 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 1074 IsDerivedFrom(InitTypeC, DeclTypeC)) { 1075 CXXConstructorDecl *Constructor 1076 = PerformInitializationByConstructor(DeclType, &Init, 1, 1077 InitLoc, Init->getSourceRange(), 1078 InitEntity, 1079 DirectInit? IK_Direct : IK_Copy); 1080 return Constructor == 0; 1081 } 1082 1083 // -- Otherwise (i.e., for the remaining copy-initialization 1084 // cases), user-defined conversion sequences that can 1085 // convert from the source type to the destination type or 1086 // (when a conversion function is used) to a derived class 1087 // thereof are enumerated as described in 13.3.1.4, and the 1088 // best one is chosen through overload resolution 1089 // (13.3). If the conversion cannot be done or is 1090 // ambiguous, the initialization is ill-formed. The 1091 // function selected is called with the initializer 1092 // expression as its argument; if the function is a 1093 // constructor, the call initializes a temporary of the 1094 // destination type. 1095 // FIXME: We're pretending to do copy elision here; return to 1096 // this when we have ASTs for such things. 1097 if (!PerformImplicitConversion(Init, DeclType, "initializing")) 1098 return false; 1099 1100 if (InitEntity) 1101 return Diag(InitLoc, diag::err_cannot_initialize_decl) 1102 << InitEntity << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 1103 << Init->getType() << Init->getSourceRange(); 1104 else 1105 return Diag(InitLoc, diag::err_cannot_initialize_decl_noname) 1106 << DeclType << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 1107 << Init->getType() << Init->getSourceRange(); 1108 } 1109 1110 // C99 6.7.8p16. 1111 if (DeclType->isArrayType()) 1112 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 1113 << Init->getSourceRange(); 1114 1115 return CheckSingleInitializer(Init, DeclType, DirectInit); 1116 } else if (getLangOptions().CPlusPlus) { 1117 // C++ [dcl.init]p14: 1118 // [...] If the class is an aggregate (8.5.1), and the initializer 1119 // is a brace-enclosed list, see 8.5.1. 1120 // 1121 // Note: 8.5.1 is handled below; here, we diagnose the case where 1122 // we have an initializer list and a destination type that is not 1123 // an aggregate. 1124 // FIXME: In C++0x, this is yet another form of initialization. 1125 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 1126 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 1127 if (!ClassDecl->isAggregate()) 1128 return Diag(InitLoc, diag::err_init_non_aggr_init_list) 1129 << DeclType << Init->getSourceRange(); 1130 } 1131 } 1132 1133 InitListChecker CheckInitList(this, InitList, DeclType); 1134 return CheckInitList.HadError(); 1135} 1136 1137/// GetNameForDeclarator - Determine the full declaration name for the 1138/// given Declarator. 1139DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1140 switch (D.getKind()) { 1141 case Declarator::DK_Abstract: 1142 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1143 return DeclarationName(); 1144 1145 case Declarator::DK_Normal: 1146 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1147 return DeclarationName(D.getIdentifier()); 1148 1149 case Declarator::DK_Constructor: { 1150 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 1151 Ty = Context.getCanonicalType(Ty); 1152 return Context.DeclarationNames.getCXXConstructorName(Ty); 1153 } 1154 1155 case Declarator::DK_Destructor: { 1156 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 1157 Ty = Context.getCanonicalType(Ty); 1158 return Context.DeclarationNames.getCXXDestructorName(Ty); 1159 } 1160 1161 case Declarator::DK_Conversion: { 1162 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1163 Ty = Context.getCanonicalType(Ty); 1164 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1165 } 1166 1167 case Declarator::DK_Operator: 1168 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1169 return Context.DeclarationNames.getCXXOperatorName( 1170 D.getOverloadedOperator()); 1171 } 1172 1173 assert(false && "Unknown name kind"); 1174 return DeclarationName(); 1175} 1176 1177/// isNearlyMatchingMemberFunction - Determine whether the C++ member 1178/// functions Declaration and Definition are "nearly" matching. This 1179/// heuristic is used to improve diagnostics in the case where an 1180/// out-of-line member function definition doesn't match any 1181/// declaration within the class. 1182static bool isNearlyMatchingMemberFunction(ASTContext &Context, 1183 FunctionDecl *Declaration, 1184 FunctionDecl *Definition) { 1185 if (Declaration->param_size() != Definition->param_size()) 1186 return false; 1187 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1188 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1189 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1190 1191 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1192 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1193 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1194 return false; 1195 } 1196 1197 return true; 1198} 1199 1200Sema::DeclTy * 1201Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl, 1202 bool IsFunctionDefinition) { 1203 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 1204 DeclarationName Name = GetNameForDeclarator(D); 1205 1206 // All of these full declarators require an identifier. If it doesn't have 1207 // one, the ParsedFreeStandingDeclSpec action should be used. 1208 if (!Name) { 1209 if (!D.getInvalidType()) // Reject this if we think it is valid. 1210 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1211 diag::err_declarator_need_ident) 1212 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1213 return 0; 1214 } 1215 1216 // The scope passed in may not be a decl scope. Zip up the scope tree until 1217 // we find one that is. 1218 while ((S->getFlags() & Scope::DeclScope) == 0 || 1219 (S->getFlags() & Scope::TemplateParamScope) != 0) 1220 S = S->getParent(); 1221 1222 DeclContext *DC; 1223 Decl *PrevDecl; 1224 ScopedDecl *New; 1225 bool InvalidDecl = false; 1226 1227 // See if this is a redefinition of a variable in the same scope. 1228 if (!D.getCXXScopeSpec().isSet()) { 1229 DC = CurContext; 1230 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S); 1231 } else { // Something like "int foo::x;" 1232 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 1233 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 1234 1235 // C++ 7.3.1.2p2: 1236 // Members (including explicit specializations of templates) of a named 1237 // namespace can also be defined outside that namespace by explicit 1238 // qualification of the name being defined, provided that the entity being 1239 // defined was already declared in the namespace and the definition appears 1240 // after the point of declaration in a namespace that encloses the 1241 // declarations namespace. 1242 // 1243 // Note that we only check the context at this point. We don't yet 1244 // have enough information to make sure that PrevDecl is actually 1245 // the declaration we want to match. For example, given: 1246 // 1247 // class X { 1248 // void f(); 1249 // void f(float); 1250 // }; 1251 // 1252 // void X::f(int) { } // ill-formed 1253 // 1254 // In this case, PrevDecl will point to the overload set 1255 // containing the two f's declared in X, but neither of them 1256 // matches. 1257 if (!CurContext->Encloses(DC)) { 1258 // The qualifying scope doesn't enclose the original declaration. 1259 // Emit diagnostic based on current scope. 1260 SourceLocation L = D.getIdentifierLoc(); 1261 SourceRange R = D.getCXXScopeSpec().getRange(); 1262 if (isa<FunctionDecl>(CurContext)) { 1263 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1264 } else { 1265 Diag(L, diag::err_invalid_declarator_scope) 1266 << Name << cast<NamedDecl>(DC)->getDeclName() << R; 1267 } 1268 InvalidDecl = true; 1269 } 1270 } 1271 1272 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1273 // Maybe we will complain about the shadowed template parameter. 1274 InvalidDecl = InvalidDecl 1275 || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 1276 // Just pretend that we didn't see the previous declaration. 1277 PrevDecl = 0; 1278 } 1279 1280 // In C++, the previous declaration we find might be a tag type 1281 // (class or enum). In this case, the new declaration will hide the 1282 // tag type. 1283 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 1284 PrevDecl = 0; 1285 1286 QualType R = GetTypeForDeclarator(D, S); 1287 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 1288 1289 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1290 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1291 if (D.getCXXScopeSpec().isSet()) { 1292 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1293 << D.getCXXScopeSpec().getRange(); 1294 InvalidDecl = true; 1295 // Pretend we didn't see the scope specifier. 1296 DC = 0; 1297 } 1298 1299 // Check that there are no default arguments (C++ only). 1300 if (getLangOptions().CPlusPlus) 1301 CheckExtraCXXDefaultArguments(D); 1302 1303 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 1304 if (!NewTD) return 0; 1305 1306 // Handle attributes prior to checking for duplicates in MergeVarDecl 1307 ProcessDeclAttributes(NewTD, D); 1308 // Merge the decl with the existing one if appropriate. If the decl is 1309 // in an outer scope, it isn't the same thing. 1310 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1311 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 1312 if (NewTD == 0) return 0; 1313 } 1314 New = NewTD; 1315 if (S->getFnParent() == 0) { 1316 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1317 // then it shall have block scope. 1318 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 1319 if (NewTD->getUnderlyingType()->isVariableArrayType()) 1320 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1321 else 1322 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1323 1324 InvalidDecl = true; 1325 } 1326 } 1327 } else if (R.getTypePtr()->isFunctionType()) { 1328 FunctionDecl::StorageClass SC = FunctionDecl::None; 1329 switch (D.getDeclSpec().getStorageClassSpec()) { 1330 default: assert(0 && "Unknown storage class!"); 1331 case DeclSpec::SCS_auto: 1332 case DeclSpec::SCS_register: 1333 case DeclSpec::SCS_mutable: 1334 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func); 1335 InvalidDecl = true; 1336 break; 1337 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 1338 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 1339 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 1340 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 1341 } 1342 1343 bool isInline = D.getDeclSpec().isInlineSpecified(); 1344 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 1345 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 1346 1347 FunctionDecl *NewFD; 1348 if (D.getKind() == Declarator::DK_Constructor) { 1349 // This is a C++ constructor declaration. 1350 assert(DC->isRecord() && 1351 "Constructors can only be declared in a member context"); 1352 1353 InvalidDecl = InvalidDecl || CheckConstructorDeclarator(D, R, SC); 1354 1355 // Create the new declaration 1356 NewFD = CXXConstructorDecl::Create(Context, 1357 cast<CXXRecordDecl>(DC), 1358 D.getIdentifierLoc(), Name, R, 1359 isExplicit, isInline, 1360 /*isImplicitlyDeclared=*/false); 1361 1362 if (InvalidDecl) 1363 NewFD->setInvalidDecl(); 1364 } else if (D.getKind() == Declarator::DK_Destructor) { 1365 // This is a C++ destructor declaration. 1366 if (DC->isRecord()) { 1367 InvalidDecl = InvalidDecl || CheckDestructorDeclarator(D, R, SC); 1368 1369 NewFD = CXXDestructorDecl::Create(Context, 1370 cast<CXXRecordDecl>(DC), 1371 D.getIdentifierLoc(), Name, R, 1372 isInline, 1373 /*isImplicitlyDeclared=*/false); 1374 1375 if (InvalidDecl) 1376 NewFD->setInvalidDecl(); 1377 } else { 1378 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 1379 1380 // Create a FunctionDecl to satisfy the function definition parsing 1381 // code path. 1382 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 1383 Name, R, SC, isInline, LastDeclarator, 1384 // FIXME: Move to DeclGroup... 1385 D.getDeclSpec().getSourceRange().getBegin()); 1386 InvalidDecl = true; 1387 NewFD->setInvalidDecl(); 1388 } 1389 } else if (D.getKind() == Declarator::DK_Conversion) { 1390 if (!DC->isRecord()) { 1391 Diag(D.getIdentifierLoc(), 1392 diag::err_conv_function_not_member); 1393 return 0; 1394 } else { 1395 InvalidDecl = InvalidDecl || CheckConversionDeclarator(D, R, SC); 1396 1397 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 1398 D.getIdentifierLoc(), Name, R, 1399 isInline, isExplicit); 1400 1401 if (InvalidDecl) 1402 NewFD->setInvalidDecl(); 1403 } 1404 } else if (DC->isRecord()) { 1405 // This is a C++ method declaration. 1406 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 1407 D.getIdentifierLoc(), Name, R, 1408 (SC == FunctionDecl::Static), isInline, 1409 LastDeclarator); 1410 } else { 1411 NewFD = FunctionDecl::Create(Context, DC, 1412 D.getIdentifierLoc(), 1413 Name, R, SC, isInline, LastDeclarator, 1414 // FIXME: Move to DeclGroup... 1415 D.getDeclSpec().getSourceRange().getBegin()); 1416 } 1417 1418 // Set the lexical context. If the declarator has a C++ 1419 // scope specifier, the lexical context will be different 1420 // from the semantic context. 1421 NewFD->setLexicalDeclContext(CurContext); 1422 1423 // Handle GNU asm-label extension (encoded as an attribute). 1424 if (Expr *E = (Expr*) D.getAsmLabel()) { 1425 // The parser guarantees this is a string. 1426 StringLiteral *SE = cast<StringLiteral>(E); 1427 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1428 SE->getByteLength()))); 1429 } 1430 1431 // Copy the parameter declarations from the declarator D to 1432 // the function declaration NewFD, if they are available. 1433 if (D.getNumTypeObjects() > 0) { 1434 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1435 1436 // Create Decl objects for each parameter, adding them to the 1437 // FunctionDecl. 1438 llvm::SmallVector<ParmVarDecl*, 16> Params; 1439 1440 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1441 // function that takes no arguments, not a function that takes a 1442 // single void argument. 1443 // We let through "const void" here because Sema::GetTypeForDeclarator 1444 // already checks for that case. 1445 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1446 FTI.ArgInfo[0].Param && 1447 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1448 // empty arg list, don't push any params. 1449 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1450 1451 // In C++, the empty parameter-type-list must be spelled "void"; a 1452 // typedef of void is not permitted. 1453 if (getLangOptions().CPlusPlus && 1454 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1455 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1456 } 1457 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1458 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1459 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1460 } 1461 1462 NewFD->setParams(Context, &Params[0], Params.size()); 1463 } else if (R->getAsTypedefType()) { 1464 // When we're declaring a function with a typedef, as in the 1465 // following example, we'll need to synthesize (unnamed) 1466 // parameters for use in the declaration. 1467 // 1468 // @code 1469 // typedef void fn(int); 1470 // fn f; 1471 // @endcode 1472 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1473 if (!FT) { 1474 // This is a typedef of a function with no prototype, so we 1475 // don't need to do anything. 1476 } else if ((FT->getNumArgs() == 0) || 1477 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1478 FT->getArgType(0)->isVoidType())) { 1479 // This is a zero-argument function. We don't need to do anything. 1480 } else { 1481 // Synthesize a parameter for each argument type. 1482 llvm::SmallVector<ParmVarDecl*, 16> Params; 1483 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1484 ArgType != FT->arg_type_end(); ++ArgType) { 1485 Params.push_back(ParmVarDecl::Create(Context, DC, 1486 SourceLocation(), 0, 1487 *ArgType, VarDecl::None, 1488 0, 0)); 1489 } 1490 1491 NewFD->setParams(Context, &Params[0], Params.size()); 1492 } 1493 } 1494 1495 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1496 InvalidDecl = InvalidDecl || CheckConstructor(Constructor); 1497 else if (isa<CXXDestructorDecl>(NewFD)) { 1498 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 1499 Record->setUserDeclaredDestructor(true); 1500 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 1501 // user-defined destructor. 1502 Record->setPOD(false); 1503 } else if (CXXConversionDecl *Conversion = 1504 dyn_cast<CXXConversionDecl>(NewFD)) 1505 ActOnConversionDeclarator(Conversion); 1506 1507 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1508 if (NewFD->isOverloadedOperator() && 1509 CheckOverloadedOperatorDeclaration(NewFD)) 1510 NewFD->setInvalidDecl(); 1511 1512 // Merge the decl with the existing one if appropriate. Since C functions 1513 // are in a flat namespace, make sure we consider decls in outer scopes. 1514 if (PrevDecl && 1515 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1516 bool Redeclaration = false; 1517 1518 // If C++, determine whether NewFD is an overload of PrevDecl or 1519 // a declaration that requires merging. If it's an overload, 1520 // there's no more work to do here; we'll just add the new 1521 // function to the scope. 1522 OverloadedFunctionDecl::function_iterator MatchedDecl; 1523 if (!getLangOptions().CPlusPlus || 1524 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1525 Decl *OldDecl = PrevDecl; 1526 1527 // If PrevDecl was an overloaded function, extract the 1528 // FunctionDecl that matched. 1529 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1530 OldDecl = *MatchedDecl; 1531 1532 // NewFD and PrevDecl represent declarations that need to be 1533 // merged. 1534 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1535 1536 if (NewFD == 0) return 0; 1537 if (Redeclaration) { 1538 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1539 1540 // An out-of-line member function declaration must also be a 1541 // definition (C++ [dcl.meaning]p1). 1542 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && 1543 !InvalidDecl) { 1544 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 1545 << D.getCXXScopeSpec().getRange(); 1546 NewFD->setInvalidDecl(); 1547 } 1548 } 1549 } 1550 1551 if (!Redeclaration && D.getCXXScopeSpec().isSet()) { 1552 // The user tried to provide an out-of-line definition for a 1553 // member function, but there was no such member function 1554 // declared (C++ [class.mfct]p2). For example: 1555 // 1556 // class X { 1557 // void f() const; 1558 // }; 1559 // 1560 // void X::f() { } // ill-formed 1561 // 1562 // Complain about this problem, and attempt to suggest close 1563 // matches (e.g., those that differ only in cv-qualifiers and 1564 // whether the parameter types are references). 1565 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 1566 << cast<CXXRecordDecl>(DC)->getDeclName() 1567 << D.getCXXScopeSpec().getRange(); 1568 InvalidDecl = true; 1569 1570 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 1571 if (!PrevDecl) { 1572 // Nothing to suggest. 1573 } else if (OverloadedFunctionDecl *Ovl 1574 = dyn_cast<OverloadedFunctionDecl>(PrevDecl)) { 1575 for (OverloadedFunctionDecl::function_iterator 1576 Func = Ovl->function_begin(), 1577 FuncEnd = Ovl->function_end(); 1578 Func != FuncEnd; ++Func) { 1579 if (isNearlyMatchingMemberFunction(Context, *Func, NewFD)) 1580 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 1581 1582 } 1583 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(PrevDecl)) { 1584 // Suggest this no matter how mismatched it is; it's the only 1585 // thing we have. 1586 unsigned diag; 1587 if (isNearlyMatchingMemberFunction(Context, Method, NewFD)) 1588 diag = diag::note_member_def_close_match; 1589 else if (Method->getBody()) 1590 diag = diag::note_previous_definition; 1591 else 1592 diag = diag::note_previous_declaration; 1593 Diag(Method->getLocation(), diag); 1594 } 1595 1596 PrevDecl = 0; 1597 } 1598 } 1599 // Handle attributes. We need to have merged decls when handling attributes 1600 // (for example to check for conflicts, etc). 1601 ProcessDeclAttributes(NewFD, D); 1602 New = NewFD; 1603 1604 if (getLangOptions().CPlusPlus) { 1605 // In C++, check default arguments now that we have merged decls. 1606 CheckCXXDefaultArguments(NewFD); 1607 1608 // An out-of-line member function declaration must also be a 1609 // definition (C++ [dcl.meaning]p1). 1610 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && !InvalidDecl) { 1611 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 1612 << D.getCXXScopeSpec().getRange(); 1613 InvalidDecl = true; 1614 } 1615 } 1616 } else { 1617 // Check that there are no default arguments (C++ only). 1618 if (getLangOptions().CPlusPlus) 1619 CheckExtraCXXDefaultArguments(D); 1620 1621 if (R.getTypePtr()->isObjCInterfaceType()) { 1622 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object) 1623 << D.getIdentifier(); 1624 InvalidDecl = true; 1625 } 1626 1627 VarDecl *NewVD; 1628 VarDecl::StorageClass SC; 1629 switch (D.getDeclSpec().getStorageClassSpec()) { 1630 default: assert(0 && "Unknown storage class!"); 1631 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1632 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1633 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1634 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1635 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1636 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1637 case DeclSpec::SCS_mutable: 1638 // mutable can only appear on non-static class members, so it's always 1639 // an error here 1640 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1641 InvalidDecl = true; 1642 SC = VarDecl::None; 1643 break; 1644 } 1645 1646 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1647 if (!II) { 1648 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1649 << Name.getAsString(); 1650 return 0; 1651 } 1652 1653 if (DC->isRecord()) { 1654 // This is a static data member for a C++ class. 1655 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1656 D.getIdentifierLoc(), II, 1657 R, LastDeclarator); 1658 } else { 1659 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1660 if (S->getFnParent() == 0) { 1661 // C99 6.9p2: The storage-class specifiers auto and register shall not 1662 // appear in the declaration specifiers in an external declaration. 1663 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1664 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 1665 InvalidDecl = true; 1666 } 1667 } 1668 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1669 II, R, SC, LastDeclarator, 1670 // FIXME: Move to DeclGroup... 1671 D.getDeclSpec().getSourceRange().getBegin()); 1672 NewVD->setThreadSpecified(ThreadSpecified); 1673 } 1674 // Handle attributes prior to checking for duplicates in MergeVarDecl 1675 ProcessDeclAttributes(NewVD, D); 1676 1677 // Handle GNU asm-label extension (encoded as an attribute). 1678 if (Expr *E = (Expr*) D.getAsmLabel()) { 1679 // The parser guarantees this is a string. 1680 StringLiteral *SE = cast<StringLiteral>(E); 1681 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1682 SE->getByteLength()))); 1683 } 1684 1685 // Emit an error if an address space was applied to decl with local storage. 1686 // This includes arrays of objects with address space qualifiers, but not 1687 // automatic variables that point to other address spaces. 1688 // ISO/IEC TR 18037 S5.1.2 1689 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1690 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1691 InvalidDecl = true; 1692 } 1693 // Merge the decl with the existing one if appropriate. If the decl is 1694 // in an outer scope, it isn't the same thing. 1695 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1696 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 1697 // The user tried to define a non-static data member 1698 // out-of-line (C++ [dcl.meaning]p1). 1699 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 1700 << D.getCXXScopeSpec().getRange(); 1701 NewVD->Destroy(Context); 1702 return 0; 1703 } 1704 1705 NewVD = MergeVarDecl(NewVD, PrevDecl); 1706 if (NewVD == 0) return 0; 1707 1708 if (D.getCXXScopeSpec().isSet()) { 1709 // No previous declaration in the qualifying scope. 1710 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 1711 << Name << D.getCXXScopeSpec().getRange(); 1712 InvalidDecl = true; 1713 } 1714 } 1715 New = NewVD; 1716 } 1717 1718 // Set the lexical context. If the declarator has a C++ scope specifier, the 1719 // lexical context will be different from the semantic context. 1720 New->setLexicalDeclContext(CurContext); 1721 1722 // If this has an identifier, add it to the scope stack. 1723 if (Name) 1724 PushOnScopeChains(New, S); 1725 // If any semantic error occurred, mark the decl as invalid. 1726 if (D.getInvalidType() || InvalidDecl) 1727 New->setInvalidDecl(); 1728 1729 return New; 1730} 1731 1732void Sema::InitializerElementNotConstant(const Expr *Init) { 1733 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 1734 << Init->getSourceRange(); 1735} 1736 1737bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1738 switch (Init->getStmtClass()) { 1739 default: 1740 InitializerElementNotConstant(Init); 1741 return true; 1742 case Expr::ParenExprClass: { 1743 const ParenExpr* PE = cast<ParenExpr>(Init); 1744 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1745 } 1746 case Expr::CompoundLiteralExprClass: 1747 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1748 case Expr::DeclRefExprClass: 1749 case Expr::QualifiedDeclRefExprClass: { 1750 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1751 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1752 if (VD->hasGlobalStorage()) 1753 return false; 1754 InitializerElementNotConstant(Init); 1755 return true; 1756 } 1757 if (isa<FunctionDecl>(D)) 1758 return false; 1759 InitializerElementNotConstant(Init); 1760 return true; 1761 } 1762 case Expr::MemberExprClass: { 1763 const MemberExpr *M = cast<MemberExpr>(Init); 1764 if (M->isArrow()) 1765 return CheckAddressConstantExpression(M->getBase()); 1766 return CheckAddressConstantExpressionLValue(M->getBase()); 1767 } 1768 case Expr::ArraySubscriptExprClass: { 1769 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1770 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1771 return CheckAddressConstantExpression(ASE->getBase()) || 1772 CheckArithmeticConstantExpression(ASE->getIdx()); 1773 } 1774 case Expr::StringLiteralClass: 1775 case Expr::PredefinedExprClass: 1776 return false; 1777 case Expr::UnaryOperatorClass: { 1778 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1779 1780 // C99 6.6p9 1781 if (Exp->getOpcode() == UnaryOperator::Deref) 1782 return CheckAddressConstantExpression(Exp->getSubExpr()); 1783 1784 InitializerElementNotConstant(Init); 1785 return true; 1786 } 1787 } 1788} 1789 1790bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1791 switch (Init->getStmtClass()) { 1792 default: 1793 InitializerElementNotConstant(Init); 1794 return true; 1795 case Expr::ParenExprClass: 1796 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1797 case Expr::StringLiteralClass: 1798 case Expr::ObjCStringLiteralClass: 1799 return false; 1800 case Expr::CallExprClass: 1801 case Expr::CXXOperatorCallExprClass: 1802 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1803 if (cast<CallExpr>(Init)->isBuiltinCall() == 1804 Builtin::BI__builtin___CFStringMakeConstantString) 1805 return false; 1806 1807 InitializerElementNotConstant(Init); 1808 return true; 1809 1810 case Expr::UnaryOperatorClass: { 1811 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1812 1813 // C99 6.6p9 1814 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1815 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1816 1817 if (Exp->getOpcode() == UnaryOperator::Extension) 1818 return CheckAddressConstantExpression(Exp->getSubExpr()); 1819 1820 InitializerElementNotConstant(Init); 1821 return true; 1822 } 1823 case Expr::BinaryOperatorClass: { 1824 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1825 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1826 1827 Expr *PExp = Exp->getLHS(); 1828 Expr *IExp = Exp->getRHS(); 1829 if (IExp->getType()->isPointerType()) 1830 std::swap(PExp, IExp); 1831 1832 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1833 return CheckAddressConstantExpression(PExp) || 1834 CheckArithmeticConstantExpression(IExp); 1835 } 1836 case Expr::ImplicitCastExprClass: 1837 case Expr::CStyleCastExprClass: { 1838 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1839 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1840 // Check for implicit promotion 1841 if (SubExpr->getType()->isFunctionType() || 1842 SubExpr->getType()->isArrayType()) 1843 return CheckAddressConstantExpressionLValue(SubExpr); 1844 } 1845 1846 // Check for pointer->pointer cast 1847 if (SubExpr->getType()->isPointerType()) 1848 return CheckAddressConstantExpression(SubExpr); 1849 1850 if (SubExpr->getType()->isIntegralType()) { 1851 // Check for the special-case of a pointer->int->pointer cast; 1852 // this isn't standard, but some code requires it. See 1853 // PR2720 for an example. 1854 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1855 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1856 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1857 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1858 if (IntWidth >= PointerWidth) { 1859 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1860 } 1861 } 1862 } 1863 } 1864 if (SubExpr->getType()->isArithmeticType()) { 1865 return CheckArithmeticConstantExpression(SubExpr); 1866 } 1867 1868 InitializerElementNotConstant(Init); 1869 return true; 1870 } 1871 case Expr::ConditionalOperatorClass: { 1872 // FIXME: Should we pedwarn here? 1873 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1874 if (!Exp->getCond()->getType()->isArithmeticType()) { 1875 InitializerElementNotConstant(Init); 1876 return true; 1877 } 1878 if (CheckArithmeticConstantExpression(Exp->getCond())) 1879 return true; 1880 if (Exp->getLHS() && 1881 CheckAddressConstantExpression(Exp->getLHS())) 1882 return true; 1883 return CheckAddressConstantExpression(Exp->getRHS()); 1884 } 1885 case Expr::AddrLabelExprClass: 1886 return false; 1887 } 1888} 1889 1890static const Expr* FindExpressionBaseAddress(const Expr* E); 1891 1892static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1893 switch (E->getStmtClass()) { 1894 default: 1895 return E; 1896 case Expr::ParenExprClass: { 1897 const ParenExpr* PE = cast<ParenExpr>(E); 1898 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1899 } 1900 case Expr::MemberExprClass: { 1901 const MemberExpr *M = cast<MemberExpr>(E); 1902 if (M->isArrow()) 1903 return FindExpressionBaseAddress(M->getBase()); 1904 return FindExpressionBaseAddressLValue(M->getBase()); 1905 } 1906 case Expr::ArraySubscriptExprClass: { 1907 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1908 return FindExpressionBaseAddress(ASE->getBase()); 1909 } 1910 case Expr::UnaryOperatorClass: { 1911 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1912 1913 if (Exp->getOpcode() == UnaryOperator::Deref) 1914 return FindExpressionBaseAddress(Exp->getSubExpr()); 1915 1916 return E; 1917 } 1918 } 1919} 1920 1921static const Expr* FindExpressionBaseAddress(const Expr* E) { 1922 switch (E->getStmtClass()) { 1923 default: 1924 return E; 1925 case Expr::ParenExprClass: { 1926 const ParenExpr* PE = cast<ParenExpr>(E); 1927 return FindExpressionBaseAddress(PE->getSubExpr()); 1928 } 1929 case Expr::UnaryOperatorClass: { 1930 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1931 1932 // C99 6.6p9 1933 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1934 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1935 1936 if (Exp->getOpcode() == UnaryOperator::Extension) 1937 return FindExpressionBaseAddress(Exp->getSubExpr()); 1938 1939 return E; 1940 } 1941 case Expr::BinaryOperatorClass: { 1942 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1943 1944 Expr *PExp = Exp->getLHS(); 1945 Expr *IExp = Exp->getRHS(); 1946 if (IExp->getType()->isPointerType()) 1947 std::swap(PExp, IExp); 1948 1949 return FindExpressionBaseAddress(PExp); 1950 } 1951 case Expr::ImplicitCastExprClass: { 1952 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1953 1954 // Check for implicit promotion 1955 if (SubExpr->getType()->isFunctionType() || 1956 SubExpr->getType()->isArrayType()) 1957 return FindExpressionBaseAddressLValue(SubExpr); 1958 1959 // Check for pointer->pointer cast 1960 if (SubExpr->getType()->isPointerType()) 1961 return FindExpressionBaseAddress(SubExpr); 1962 1963 // We assume that we have an arithmetic expression here; 1964 // if we don't, we'll figure it out later 1965 return 0; 1966 } 1967 case Expr::CStyleCastExprClass: { 1968 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1969 1970 // Check for pointer->pointer cast 1971 if (SubExpr->getType()->isPointerType()) 1972 return FindExpressionBaseAddress(SubExpr); 1973 1974 // We assume that we have an arithmetic expression here; 1975 // if we don't, we'll figure it out later 1976 return 0; 1977 } 1978 } 1979} 1980 1981bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1982 switch (Init->getStmtClass()) { 1983 default: 1984 InitializerElementNotConstant(Init); 1985 return true; 1986 case Expr::ParenExprClass: { 1987 const ParenExpr* PE = cast<ParenExpr>(Init); 1988 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1989 } 1990 case Expr::FloatingLiteralClass: 1991 case Expr::IntegerLiteralClass: 1992 case Expr::CharacterLiteralClass: 1993 case Expr::ImaginaryLiteralClass: 1994 case Expr::TypesCompatibleExprClass: 1995 case Expr::CXXBoolLiteralExprClass: 1996 return false; 1997 case Expr::CallExprClass: 1998 case Expr::CXXOperatorCallExprClass: { 1999 const CallExpr *CE = cast<CallExpr>(Init); 2000 2001 // Allow any constant foldable calls to builtins. 2002 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 2003 return false; 2004 2005 InitializerElementNotConstant(Init); 2006 return true; 2007 } 2008 case Expr::DeclRefExprClass: 2009 case Expr::QualifiedDeclRefExprClass: { 2010 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 2011 if (isa<EnumConstantDecl>(D)) 2012 return false; 2013 InitializerElementNotConstant(Init); 2014 return true; 2015 } 2016 case Expr::CompoundLiteralExprClass: 2017 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 2018 // but vectors are allowed to be magic. 2019 if (Init->getType()->isVectorType()) 2020 return false; 2021 InitializerElementNotConstant(Init); 2022 return true; 2023 case Expr::UnaryOperatorClass: { 2024 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2025 2026 switch (Exp->getOpcode()) { 2027 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 2028 // See C99 6.6p3. 2029 default: 2030 InitializerElementNotConstant(Init); 2031 return true; 2032 case UnaryOperator::OffsetOf: 2033 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 2034 return false; 2035 InitializerElementNotConstant(Init); 2036 return true; 2037 case UnaryOperator::Extension: 2038 case UnaryOperator::LNot: 2039 case UnaryOperator::Plus: 2040 case UnaryOperator::Minus: 2041 case UnaryOperator::Not: 2042 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 2043 } 2044 } 2045 case Expr::SizeOfAlignOfExprClass: { 2046 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 2047 // Special check for void types, which are allowed as an extension 2048 if (Exp->getTypeOfArgument()->isVoidType()) 2049 return false; 2050 // alignof always evaluates to a constant. 2051 // FIXME: is sizeof(int[3.0]) a constant expression? 2052 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 2053 InitializerElementNotConstant(Init); 2054 return true; 2055 } 2056 return false; 2057 } 2058 case Expr::BinaryOperatorClass: { 2059 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 2060 2061 if (Exp->getLHS()->getType()->isArithmeticType() && 2062 Exp->getRHS()->getType()->isArithmeticType()) { 2063 return CheckArithmeticConstantExpression(Exp->getLHS()) || 2064 CheckArithmeticConstantExpression(Exp->getRHS()); 2065 } 2066 2067 if (Exp->getLHS()->getType()->isPointerType() && 2068 Exp->getRHS()->getType()->isPointerType()) { 2069 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 2070 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 2071 2072 // Only allow a null (constant integer) base; we could 2073 // allow some additional cases if necessary, but this 2074 // is sufficient to cover offsetof-like constructs. 2075 if (!LHSBase && !RHSBase) { 2076 return CheckAddressConstantExpression(Exp->getLHS()) || 2077 CheckAddressConstantExpression(Exp->getRHS()); 2078 } 2079 } 2080 2081 InitializerElementNotConstant(Init); 2082 return true; 2083 } 2084 case Expr::ImplicitCastExprClass: 2085 case Expr::CStyleCastExprClass: { 2086 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 2087 if (SubExpr->getType()->isArithmeticType()) 2088 return CheckArithmeticConstantExpression(SubExpr); 2089 2090 if (SubExpr->getType()->isPointerType()) { 2091 const Expr* Base = FindExpressionBaseAddress(SubExpr); 2092 // If the pointer has a null base, this is an offsetof-like construct 2093 if (!Base) 2094 return CheckAddressConstantExpression(SubExpr); 2095 } 2096 2097 InitializerElementNotConstant(Init); 2098 return true; 2099 } 2100 case Expr::ConditionalOperatorClass: { 2101 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 2102 2103 // If GNU extensions are disabled, we require all operands to be arithmetic 2104 // constant expressions. 2105 if (getLangOptions().NoExtensions) { 2106 return CheckArithmeticConstantExpression(Exp->getCond()) || 2107 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 2108 CheckArithmeticConstantExpression(Exp->getRHS()); 2109 } 2110 2111 // Otherwise, we have to emulate some of the behavior of fold here. 2112 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 2113 // because it can constant fold things away. To retain compatibility with 2114 // GCC code, we see if we can fold the condition to a constant (which we 2115 // should always be able to do in theory). If so, we only require the 2116 // specified arm of the conditional to be a constant. This is a horrible 2117 // hack, but is require by real world code that uses __builtin_constant_p. 2118 Expr::EvalResult EvalResult; 2119 if (!Exp->getCond()->Evaluate(EvalResult, Context) || 2120 EvalResult.HasSideEffects) { 2121 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 2122 // won't be able to either. Use it to emit the diagnostic though. 2123 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 2124 assert(Res && "Evaluate couldn't evaluate this constant?"); 2125 return Res; 2126 } 2127 2128 // Verify that the side following the condition is also a constant. 2129 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 2130 if (EvalResult.Val.getInt() == 0) 2131 std::swap(TrueSide, FalseSide); 2132 2133 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 2134 return true; 2135 2136 // Okay, the evaluated side evaluates to a constant, so we accept this. 2137 // Check to see if the other side is obviously not a constant. If so, 2138 // emit a warning that this is a GNU extension. 2139 if (FalseSide && !FalseSide->isEvaluatable(Context)) 2140 Diag(Init->getExprLoc(), 2141 diag::ext_typecheck_expression_not_constant_but_accepted) 2142 << FalseSide->getSourceRange(); 2143 return false; 2144 } 2145 } 2146} 2147 2148bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2149 Expr::EvalResult Result; 2150 2151 Init = Init->IgnoreParens(); 2152 2153 if (Init->Evaluate(Result, Context) && !Result.HasSideEffects) 2154 return false; 2155 2156 // Look through CXXDefaultArgExprs; they have no meaning in this context. 2157 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 2158 return CheckForConstantInitializer(DAE->getExpr(), DclT); 2159 2160 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 2161 return CheckForConstantInitializer(e->getInitializer(), DclT); 2162 2163 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 2164 unsigned numInits = Exp->getNumInits(); 2165 for (unsigned i = 0; i < numInits; i++) { 2166 // FIXME: Need to get the type of the declaration for C++, 2167 // because it could be a reference? 2168 if (CheckForConstantInitializer(Exp->getInit(i), 2169 Exp->getInit(i)->getType())) 2170 return true; 2171 } 2172 return false; 2173 } 2174 2175 // FIXME: We can probably remove some of this code below, now that 2176 // Expr::Evaluate is doing the heavy lifting for scalars. 2177 2178 if (Init->isNullPointerConstant(Context)) 2179 return false; 2180 if (Init->getType()->isArithmeticType()) { 2181 QualType InitTy = Context.getCanonicalType(Init->getType()) 2182 .getUnqualifiedType(); 2183 if (InitTy == Context.BoolTy) { 2184 // Special handling for pointers implicitly cast to bool; 2185 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 2186 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 2187 Expr* SubE = ICE->getSubExpr(); 2188 if (SubE->getType()->isPointerType() || 2189 SubE->getType()->isArrayType() || 2190 SubE->getType()->isFunctionType()) { 2191 return CheckAddressConstantExpression(Init); 2192 } 2193 } 2194 } else if (InitTy->isIntegralType()) { 2195 Expr* SubE = 0; 2196 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 2197 SubE = CE->getSubExpr(); 2198 // Special check for pointer cast to int; we allow as an extension 2199 // an address constant cast to an integer if the integer 2200 // is of an appropriate width (this sort of code is apparently used 2201 // in some places). 2202 // FIXME: Add pedwarn? 2203 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 2204 if (SubE && (SubE->getType()->isPointerType() || 2205 SubE->getType()->isArrayType() || 2206 SubE->getType()->isFunctionType())) { 2207 unsigned IntWidth = Context.getTypeSize(Init->getType()); 2208 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 2209 if (IntWidth >= PointerWidth) 2210 return CheckAddressConstantExpression(Init); 2211 } 2212 } 2213 2214 return CheckArithmeticConstantExpression(Init); 2215 } 2216 2217 if (Init->getType()->isPointerType()) 2218 return CheckAddressConstantExpression(Init); 2219 2220 // An array type at the top level that isn't an init-list must 2221 // be a string literal 2222 if (Init->getType()->isArrayType()) 2223 return false; 2224 2225 if (Init->getType()->isFunctionType()) 2226 return false; 2227 2228 // Allow block exprs at top level. 2229 if (Init->getType()->isBlockPointerType()) 2230 return false; 2231 2232 // GCC cast to union extension 2233 // note: the validity of the cast expr is checked by CheckCastTypes() 2234 if (CastExpr *C = dyn_cast<CastExpr>(Init)) { 2235 QualType T = C->getType(); 2236 return T->isUnionType() && CheckForConstantInitializer(C->getSubExpr(), T); 2237 } 2238 2239 InitializerElementNotConstant(Init); 2240 return true; 2241} 2242 2243void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init) { 2244 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 2245} 2246 2247/// AddInitializerToDecl - Adds the initializer Init to the 2248/// declaration dcl. If DirectInit is true, this is C++ direct 2249/// initialization rather than copy initialization. 2250void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init, bool DirectInit) { 2251 Decl *RealDecl = static_cast<Decl *>(dcl); 2252 Expr *Init = static_cast<Expr *>(init.release()); 2253 assert(Init && "missing initializer"); 2254 2255 // If there is no declaration, there was an error parsing it. Just ignore 2256 // the initializer. 2257 if (RealDecl == 0) { 2258 delete Init; 2259 return; 2260 } 2261 2262 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 2263 if (!VDecl) { 2264 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 2265 diag::err_illegal_initializer); 2266 RealDecl->setInvalidDecl(); 2267 return; 2268 } 2269 // Get the decls type and save a reference for later, since 2270 // CheckInitializerTypes may change it. 2271 QualType DclT = VDecl->getType(), SavT = DclT; 2272 if (VDecl->isBlockVarDecl()) { 2273 VarDecl::StorageClass SC = VDecl->getStorageClass(); 2274 if (SC == VarDecl::Extern) { // C99 6.7.8p5 2275 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 2276 VDecl->setInvalidDecl(); 2277 } else if (!VDecl->isInvalidDecl()) { 2278 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2279 VDecl->getDeclName(), DirectInit)) 2280 VDecl->setInvalidDecl(); 2281 2282 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2283 if (!getLangOptions().CPlusPlus) { 2284 if (SC == VarDecl::Static) // C99 6.7.8p4. 2285 CheckForConstantInitializer(Init, DclT); 2286 } 2287 } 2288 } else if (VDecl->isFileVarDecl()) { 2289 if (VDecl->getStorageClass() == VarDecl::Extern) 2290 Diag(VDecl->getLocation(), diag::warn_extern_init); 2291 if (!VDecl->isInvalidDecl()) 2292 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2293 VDecl->getDeclName(), DirectInit)) 2294 VDecl->setInvalidDecl(); 2295 2296 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2297 if (!getLangOptions().CPlusPlus) { 2298 // C99 6.7.8p4. All file scoped initializers need to be constant. 2299 CheckForConstantInitializer(Init, DclT); 2300 } 2301 } 2302 // If the type changed, it means we had an incomplete type that was 2303 // completed by the initializer. For example: 2304 // int ary[] = { 1, 3, 5 }; 2305 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 2306 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 2307 VDecl->setType(DclT); 2308 Init->setType(DclT); 2309 } 2310 2311 // Attach the initializer to the decl. 2312 VDecl->setInit(Init); 2313 return; 2314} 2315 2316void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 2317 Decl *RealDecl = static_cast<Decl *>(dcl); 2318 2319 // If there is no declaration, there was an error parsing it. Just ignore it. 2320 if (RealDecl == 0) 2321 return; 2322 2323 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 2324 QualType Type = Var->getType(); 2325 // C++ [dcl.init.ref]p3: 2326 // The initializer can be omitted for a reference only in a 2327 // parameter declaration (8.3.5), in the declaration of a 2328 // function return type, in the declaration of a class member 2329 // within its class declaration (9.2), and where the extern 2330 // specifier is explicitly used. 2331 if (Type->isReferenceType() && 2332 Var->getStorageClass() != VarDecl::Extern && 2333 Var->getStorageClass() != VarDecl::PrivateExtern) { 2334 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 2335 << Var->getDeclName() 2336 << SourceRange(Var->getLocation(), Var->getLocation()); 2337 Var->setInvalidDecl(); 2338 return; 2339 } 2340 2341 // C++ [dcl.init]p9: 2342 // 2343 // If no initializer is specified for an object, and the object 2344 // is of (possibly cv-qualified) non-POD class type (or array 2345 // thereof), the object shall be default-initialized; if the 2346 // object is of const-qualified type, the underlying class type 2347 // shall have a user-declared default constructor. 2348 if (getLangOptions().CPlusPlus) { 2349 QualType InitType = Type; 2350 if (const ArrayType *Array = Context.getAsArrayType(Type)) 2351 InitType = Array->getElementType(); 2352 if (Var->getStorageClass() != VarDecl::Extern && 2353 Var->getStorageClass() != VarDecl::PrivateExtern && 2354 InitType->isRecordType()) { 2355 const CXXConstructorDecl *Constructor 2356 = PerformInitializationByConstructor(InitType, 0, 0, 2357 Var->getLocation(), 2358 SourceRange(Var->getLocation(), 2359 Var->getLocation()), 2360 Var->getDeclName(), 2361 IK_Default); 2362 if (!Constructor) 2363 Var->setInvalidDecl(); 2364 } 2365 } 2366 2367#if 0 2368 // FIXME: Temporarily disabled because we are not properly parsing 2369 // linkage specifications on declarations, e.g., 2370 // 2371 // extern "C" const CGPoint CGPointerZero; 2372 // 2373 // C++ [dcl.init]p9: 2374 // 2375 // If no initializer is specified for an object, and the 2376 // object is of (possibly cv-qualified) non-POD class type (or 2377 // array thereof), the object shall be default-initialized; if 2378 // the object is of const-qualified type, the underlying class 2379 // type shall have a user-declared default 2380 // constructor. Otherwise, if no initializer is specified for 2381 // an object, the object and its subobjects, if any, have an 2382 // indeterminate initial value; if the object or any of its 2383 // subobjects are of const-qualified type, the program is 2384 // ill-formed. 2385 // 2386 // This isn't technically an error in C, so we don't diagnose it. 2387 // 2388 // FIXME: Actually perform the POD/user-defined default 2389 // constructor check. 2390 if (getLangOptions().CPlusPlus && 2391 Context.getCanonicalType(Type).isConstQualified() && 2392 Var->getStorageClass() != VarDecl::Extern) 2393 Diag(Var->getLocation(), diag::err_const_var_requires_init) 2394 << Var->getName() 2395 << SourceRange(Var->getLocation(), Var->getLocation()); 2396#endif 2397 } 2398} 2399 2400/// The declarators are chained together backwards, reverse the list. 2401Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 2402 // Often we have single declarators, handle them quickly. 2403 Decl *GroupDecl = static_cast<Decl*>(group); 2404 if (GroupDecl == 0) 2405 return 0; 2406 2407 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 2408 ScopedDecl *NewGroup = 0; 2409 if (Group->getNextDeclarator() == 0) 2410 NewGroup = Group; 2411 else { // reverse the list. 2412 while (Group) { 2413 ScopedDecl *Next = Group->getNextDeclarator(); 2414 Group->setNextDeclarator(NewGroup); 2415 NewGroup = Group; 2416 Group = Next; 2417 } 2418 } 2419 // Perform semantic analysis that depends on having fully processed both 2420 // the declarator and initializer. 2421 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 2422 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 2423 if (!IDecl) 2424 continue; 2425 QualType T = IDecl->getType(); 2426 2427 if (T->isVariableArrayType()) { 2428 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2429 2430 // FIXME: This won't give the correct result for 2431 // int a[10][n]; 2432 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2433 if (IDecl->isFileVarDecl()) { 2434 Diag(IDecl->getLocation(), diag::err_vla_decl_in_file_scope) << 2435 SizeRange; 2436 2437 IDecl->setInvalidDecl(); 2438 } else { 2439 // C99 6.7.5.2p2: If an identifier is declared to be an object with 2440 // static storage duration, it shall not have a variable length array. 2441 if (IDecl->getStorageClass() == VarDecl::Static) { 2442 Diag(IDecl->getLocation(), diag::err_vla_decl_has_static_storage) 2443 << SizeRange; 2444 IDecl->setInvalidDecl(); 2445 } else if (IDecl->getStorageClass() == VarDecl::Extern) { 2446 Diag(IDecl->getLocation(), diag::err_vla_decl_has_extern_linkage) 2447 << SizeRange; 2448 IDecl->setInvalidDecl(); 2449 } 2450 } 2451 } else if (T->isVariablyModifiedType()) { 2452 if (IDecl->isFileVarDecl()) { 2453 Diag(IDecl->getLocation(), diag::err_vm_decl_in_file_scope); 2454 IDecl->setInvalidDecl(); 2455 } else { 2456 if (IDecl->getStorageClass() == VarDecl::Extern) { 2457 Diag(IDecl->getLocation(), diag::err_vm_decl_has_extern_linkage); 2458 IDecl->setInvalidDecl(); 2459 } 2460 } 2461 } 2462 2463 // Block scope. C99 6.7p7: If an identifier for an object is declared with 2464 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 2465 if (IDecl->isBlockVarDecl() && 2466 IDecl->getStorageClass() != VarDecl::Extern) { 2467 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 2468 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type)<<T; 2469 IDecl->setInvalidDecl(); 2470 } 2471 } 2472 // File scope. C99 6.9.2p2: A declaration of an identifier for and 2473 // object that has file scope without an initializer, and without a 2474 // storage-class specifier or with the storage-class specifier "static", 2475 // constitutes a tentative definition. Note: A tentative definition with 2476 // external linkage is valid (C99 6.2.2p5). 2477 if (isTentativeDefinition(IDecl)) { 2478 if (T->isIncompleteArrayType()) { 2479 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 2480 // array to be completed. Don't issue a diagnostic. 2481 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 2482 // C99 6.9.2p3: If the declaration of an identifier for an object is 2483 // a tentative definition and has internal linkage (C99 6.2.2p3), the 2484 // declared type shall not be an incomplete type. 2485 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type)<<T; 2486 IDecl->setInvalidDecl(); 2487 } 2488 } 2489 if (IDecl->isFileVarDecl()) 2490 CheckForFileScopedRedefinitions(S, IDecl); 2491 } 2492 return NewGroup; 2493} 2494 2495/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 2496/// to introduce parameters into function prototype scope. 2497Sema::DeclTy * 2498Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 2499 const DeclSpec &DS = D.getDeclSpec(); 2500 2501 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 2502 VarDecl::StorageClass StorageClass = VarDecl::None; 2503 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 2504 StorageClass = VarDecl::Register; 2505 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 2506 Diag(DS.getStorageClassSpecLoc(), 2507 diag::err_invalid_storage_class_in_func_decl); 2508 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2509 } 2510 if (DS.isThreadSpecified()) { 2511 Diag(DS.getThreadSpecLoc(), 2512 diag::err_invalid_storage_class_in_func_decl); 2513 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2514 } 2515 2516 // Check that there are no default arguments inside the type of this 2517 // parameter (C++ only). 2518 if (getLangOptions().CPlusPlus) 2519 CheckExtraCXXDefaultArguments(D); 2520 2521 // In this context, we *do not* check D.getInvalidType(). If the declarator 2522 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 2523 // though it will not reflect the user specified type. 2524 QualType parmDeclType = GetTypeForDeclarator(D, S); 2525 2526 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 2527 2528 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 2529 // Can this happen for params? We already checked that they don't conflict 2530 // among each other. Here they can only shadow globals, which is ok. 2531 IdentifierInfo *II = D.getIdentifier(); 2532 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 2533 if (PrevDecl->isTemplateParameter()) { 2534 // Maybe we will complain about the shadowed template parameter. 2535 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 2536 // Just pretend that we didn't see the previous declaration. 2537 PrevDecl = 0; 2538 } else if (S->isDeclScope(PrevDecl)) { 2539 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 2540 2541 // Recover by removing the name 2542 II = 0; 2543 D.SetIdentifier(0, D.getIdentifierLoc()); 2544 } 2545 } 2546 2547 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 2548 // Doing the promotion here has a win and a loss. The win is the type for 2549 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 2550 // code generator). The loss is the orginal type isn't preserved. For example: 2551 // 2552 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2553 // int blockvardecl[5]; 2554 // sizeof(parmvardecl); // size == 4 2555 // sizeof(blockvardecl); // size == 20 2556 // } 2557 // 2558 // For expressions, all implicit conversions are captured using the 2559 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2560 // 2561 // FIXME: If a source translation tool needs to see the original type, then 2562 // we need to consider storing both types (in ParmVarDecl)... 2563 // 2564 if (parmDeclType->isArrayType()) { 2565 // int x[restrict 4] -> int *restrict 2566 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2567 } else if (parmDeclType->isFunctionType()) 2568 parmDeclType = Context.getPointerType(parmDeclType); 2569 2570 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2571 D.getIdentifierLoc(), II, 2572 parmDeclType, StorageClass, 2573 0, 0); 2574 2575 if (D.getInvalidType()) 2576 New->setInvalidDecl(); 2577 2578 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 2579 if (D.getCXXScopeSpec().isSet()) { 2580 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 2581 << D.getCXXScopeSpec().getRange(); 2582 New->setInvalidDecl(); 2583 } 2584 2585 // Add the parameter declaration into this scope. 2586 S->AddDecl(New); 2587 if (II) 2588 IdResolver.AddDecl(New); 2589 2590 ProcessDeclAttributes(New, D); 2591 return New; 2592 2593} 2594 2595Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2596 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2597 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2598 "Not a function declarator!"); 2599 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2600 2601 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2602 // for a K&R function. 2603 if (!FTI.hasPrototype) { 2604 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2605 if (FTI.ArgInfo[i].Param == 0) { 2606 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2607 << FTI.ArgInfo[i].Ident; 2608 // Implicitly declare the argument as type 'int' for lack of a better 2609 // type. 2610 DeclSpec DS; 2611 const char* PrevSpec; // unused 2612 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2613 PrevSpec); 2614 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2615 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2616 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2617 } 2618 } 2619 } else { 2620 // FIXME: Diagnose arguments without names in C. 2621 } 2622 2623 Scope *ParentScope = FnBodyScope->getParent(); 2624 2625 return ActOnStartOfFunctionDef(FnBodyScope, 2626 ActOnDeclarator(ParentScope, D, 0, 2627 /*IsFunctionDefinition=*/true)); 2628} 2629 2630Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2631 Decl *decl = static_cast<Decl*>(D); 2632 FunctionDecl *FD = cast<FunctionDecl>(decl); 2633 2634 // See if this is a redefinition. 2635 const FunctionDecl *Definition; 2636 if (FD->getBody(Definition)) { 2637 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 2638 Diag(Definition->getLocation(), diag::note_previous_definition); 2639 } 2640 2641 PushDeclContext(FnBodyScope, FD); 2642 2643 // Check the validity of our function parameters 2644 CheckParmsForFunctionDef(FD); 2645 2646 // Introduce our parameters into the function scope 2647 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2648 ParmVarDecl *Param = FD->getParamDecl(p); 2649 Param->setOwningFunction(FD); 2650 2651 // If this has an identifier, add it to the scope stack. 2652 if (Param->getIdentifier()) 2653 PushOnScopeChains(Param, FnBodyScope); 2654 } 2655 2656 // Checking attributes of current function definition 2657 // dllimport attribute. 2658 if (FD->getAttr<DLLImportAttr>() && (!FD->getAttr<DLLExportAttr>())) { 2659 // dllimport attribute cannot be applied to definition. 2660 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 2661 Diag(FD->getLocation(), 2662 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 2663 << "dllimport"; 2664 FD->setInvalidDecl(); 2665 return FD; 2666 } else { 2667 // If a symbol previously declared dllimport is later defined, the 2668 // attribute is ignored in subsequent references, and a warning is 2669 // emitted. 2670 Diag(FD->getLocation(), 2671 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 2672 << FD->getNameAsCString() << "dllimport"; 2673 } 2674 } 2675 return FD; 2676} 2677 2678Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtArg BodyArg) { 2679 Decl *dcl = static_cast<Decl *>(D); 2680 Stmt *Body = static_cast<Stmt*>(BodyArg.release()); 2681 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2682 FD->setBody(Body); 2683 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2684 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2685 MD->setBody((Stmt*)Body); 2686 } else 2687 return 0; 2688 PopDeclContext(); 2689 // Verify and clean out per-function state. 2690 2691 // Check goto/label use. 2692 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2693 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2694 // Verify that we have no forward references left. If so, there was a goto 2695 // or address of a label taken, but no definition of it. Label fwd 2696 // definitions are indicated with a null substmt. 2697 if (I->second->getSubStmt() == 0) { 2698 LabelStmt *L = I->second; 2699 // Emit error. 2700 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 2701 2702 // At this point, we have gotos that use the bogus label. Stitch it into 2703 // the function body so that they aren't leaked and that the AST is well 2704 // formed. 2705 if (Body) { 2706 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2707 cast<CompoundStmt>(Body)->push_back(L); 2708 } else { 2709 // The whole function wasn't parsed correctly, just delete this. 2710 delete L; 2711 } 2712 } 2713 } 2714 LabelMap.clear(); 2715 2716 return D; 2717} 2718 2719/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2720/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2721ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2722 IdentifierInfo &II, Scope *S) { 2723 // Extension in C99. Legal in C90, but warn about it. 2724 if (getLangOptions().C99) 2725 Diag(Loc, diag::ext_implicit_function_decl) << &II; 2726 else 2727 Diag(Loc, diag::warn_implicit_function_decl) << &II; 2728 2729 // FIXME: handle stuff like: 2730 // void foo() { extern float X(); } 2731 // void bar() { X(); } <-- implicit decl for X in another scope. 2732 2733 // Set a Declarator for the implicit definition: int foo(); 2734 const char *Dummy; 2735 DeclSpec DS; 2736 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2737 Error = Error; // Silence warning. 2738 assert(!Error && "Error setting up implicit decl!"); 2739 Declarator D(DS, Declarator::BlockContext); 2740 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2741 D.SetIdentifier(&II, Loc); 2742 2743 // Insert this function into translation-unit scope. 2744 2745 DeclContext *PrevDC = CurContext; 2746 CurContext = Context.getTranslationUnitDecl(); 2747 2748 FunctionDecl *FD = 2749 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2750 FD->setImplicit(); 2751 2752 CurContext = PrevDC; 2753 2754 return FD; 2755} 2756 2757 2758TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2759 ScopedDecl *LastDeclarator) { 2760 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2761 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2762 2763 // Scope manipulation handled by caller. 2764 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2765 D.getIdentifierLoc(), 2766 D.getIdentifier(), 2767 T, LastDeclarator); 2768 if (D.getInvalidType()) 2769 NewTD->setInvalidDecl(); 2770 return NewTD; 2771} 2772 2773/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2774/// former case, Name will be non-null. In the later case, Name will be null. 2775/// TagType indicates what kind of tag this is. TK indicates whether this is a 2776/// reference/declaration/definition of a tag. 2777Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2778 SourceLocation KWLoc, const CXXScopeSpec &SS, 2779 IdentifierInfo *Name, SourceLocation NameLoc, 2780 AttributeList *Attr, 2781 MultiTemplateParamsArg TemplateParameterLists) { 2782 // If this is not a definition, it must have a name. 2783 assert((Name != 0 || TK == TK_Definition) && 2784 "Nameless record must be a definition!"); 2785 2786 TagDecl::TagKind Kind; 2787 switch (TagType) { 2788 default: assert(0 && "Unknown tag type!"); 2789 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2790 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2791 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2792 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2793 } 2794 2795 DeclContext *SearchDC = CurContext; 2796 DeclContext *DC = CurContext; 2797 DeclContext *LexicalContext = CurContext; 2798 ScopedDecl *PrevDecl = 0; 2799 2800 if (Name && SS.isNotEmpty()) { 2801 // We have a nested-name tag ('struct foo::bar'). 2802 2803 // Check for invalid 'foo::'. 2804 if (SS.isInvalid()) { 2805 Name = 0; 2806 goto CreateNewDecl; 2807 } 2808 2809 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2810 // Look-up name inside 'foo::'. 2811 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC) 2812 .getAsDecl()); 2813 2814 // A tag 'foo::bar' must already exist. 2815 if (PrevDecl == 0) { 2816 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2817 Name = 0; 2818 goto CreateNewDecl; 2819 } 2820 } else { 2821 // If this is a named struct, check to see if there was a previous forward 2822 // declaration or definition. 2823 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2824 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S) 2825 .getAsDecl()); 2826 2827 if (!getLangOptions().CPlusPlus && TK != TK_Reference) { 2828 // FIXME: This makes sure that we ignore the contexts associated 2829 // with C structs, unions, and enums when looking for a matching 2830 // tag declaration or definition. See the similar lookup tweak 2831 // in Sema::LookupDecl; is there a better way to deal with this? 2832 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 2833 SearchDC = SearchDC->getParent(); 2834 } 2835 } 2836 2837 if (PrevDecl && PrevDecl->isTemplateParameter()) { 2838 // Maybe we will complain about the shadowed template parameter. 2839 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 2840 // Just pretend that we didn't see the previous declaration. 2841 PrevDecl = 0; 2842 } 2843 2844 if (PrevDecl) { 2845 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2846 "unexpected Decl type"); 2847 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2848 // If this is a use of a previous tag, or if the tag is already declared 2849 // in the same scope (so that the definition/declaration completes or 2850 // rementions the tag), reuse the decl. 2851 if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 2852 // Make sure that this wasn't declared as an enum and now used as a 2853 // struct or something similar. 2854 if (PrevTagDecl->getTagKind() != Kind) { 2855 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2856 Diag(PrevDecl->getLocation(), diag::note_previous_use); 2857 // Recover by making this an anonymous redefinition. 2858 Name = 0; 2859 PrevDecl = 0; 2860 } else { 2861 // If this is a use, just return the declaration we found. 2862 2863 // FIXME: In the future, return a variant or some other clue 2864 // for the consumer of this Decl to know it doesn't own it. 2865 // For our current ASTs this shouldn't be a problem, but will 2866 // need to be changed with DeclGroups. 2867 if (TK == TK_Reference) 2868 return PrevDecl; 2869 2870 // Diagnose attempts to redefine a tag. 2871 if (TK == TK_Definition) { 2872 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 2873 Diag(NameLoc, diag::err_redefinition) << Name; 2874 Diag(Def->getLocation(), diag::note_previous_definition); 2875 // If this is a redefinition, recover by making this struct be 2876 // anonymous, which will make any later references get the previous 2877 // definition. 2878 Name = 0; 2879 PrevDecl = 0; 2880 } 2881 // Okay, this is definition of a previously declared or referenced 2882 // tag PrevDecl. We're going to create a new Decl for it. 2883 } 2884 } 2885 // If we get here we have (another) forward declaration or we 2886 // have a definition. Just create a new decl. 2887 } else { 2888 // If we get here, this is a definition of a new tag type in a nested 2889 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2890 // new decl/type. We set PrevDecl to NULL so that the entities 2891 // have distinct types. 2892 PrevDecl = 0; 2893 } 2894 // If we get here, we're going to create a new Decl. If PrevDecl 2895 // is non-NULL, it's a definition of the tag declared by 2896 // PrevDecl. If it's NULL, we have a new definition. 2897 } else { 2898 // PrevDecl is a namespace. 2899 if (isDeclInScope(PrevDecl, SearchDC, S)) { 2900 // The tag name clashes with a namespace name, issue an error and 2901 // recover by making this tag be anonymous. 2902 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2903 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 2904 Name = 0; 2905 PrevDecl = 0; 2906 } else { 2907 // The existing declaration isn't relevant to us; we're in a 2908 // new scope, so clear out the previous declaration. 2909 PrevDecl = 0; 2910 } 2911 } 2912 } else if (TK == TK_Reference && SS.isEmpty() && Name && 2913 (Kind != TagDecl::TK_enum)) { 2914 // C++ [basic.scope.pdecl]p5: 2915 // -- for an elaborated-type-specifier of the form 2916 // 2917 // class-key identifier 2918 // 2919 // if the elaborated-type-specifier is used in the 2920 // decl-specifier-seq or parameter-declaration-clause of a 2921 // function defined in namespace scope, the identifier is 2922 // declared as a class-name in the namespace that contains 2923 // the declaration; otherwise, except as a friend 2924 // declaration, the identifier is declared in the smallest 2925 // non-class, non-function-prototype scope that contains the 2926 // declaration. 2927 // 2928 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 2929 // C structs and unions. 2930 2931 // Find the context where we'll be declaring the tag. 2932 // FIXME: We would like to maintain the current DeclContext as the 2933 // lexical context, 2934 while (DC->isRecord()) 2935 DC = DC->getParent(); 2936 LexicalContext = DC; 2937 2938 // Find the scope where we'll be declaring the tag. 2939 while (S->isClassScope() || 2940 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 2941 ((S->getFlags() & Scope::DeclScope) == 0) || 2942 (S->getEntity() && 2943 ((DeclContext *)S->getEntity())->isTransparentContext())) 2944 S = S->getParent(); 2945 } 2946 2947CreateNewDecl: 2948 2949 // If there is an identifier, use the location of the identifier as the 2950 // location of the decl, otherwise use the location of the struct/union 2951 // keyword. 2952 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2953 2954 // Otherwise, create a new declaration. If there is a previous 2955 // declaration of the same entity, the two will be linked via 2956 // PrevDecl. 2957 TagDecl *New; 2958 2959 if (Kind == TagDecl::TK_enum) { 2960 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2961 // enum X { A, B, C } D; D should chain to X. 2962 New = EnumDecl::Create(Context, DC, Loc, Name, 2963 cast_or_null<EnumDecl>(PrevDecl)); 2964 // If this is an undefined enum, warn. 2965 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2966 } else { 2967 // struct/union/class 2968 2969 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2970 // struct X { int A; } D; D should chain to X. 2971 if (getLangOptions().CPlusPlus) 2972 // FIXME: Look for a way to use RecordDecl for simple structs. 2973 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2974 cast_or_null<CXXRecordDecl>(PrevDecl)); 2975 else 2976 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2977 cast_or_null<RecordDecl>(PrevDecl)); 2978 } 2979 2980 if (Kind != TagDecl::TK_enum) { 2981 // Handle #pragma pack: if the #pragma pack stack has non-default 2982 // alignment, make up a packed attribute for this decl. These 2983 // attributes are checked when the ASTContext lays out the 2984 // structure. 2985 // 2986 // It is important for implementing the correct semantics that this 2987 // happen here (in act on tag decl). The #pragma pack stack is 2988 // maintained as a result of parser callbacks which can occur at 2989 // many points during the parsing of a struct declaration (because 2990 // the #pragma tokens are effectively skipped over during the 2991 // parsing of the struct). 2992 if (unsigned Alignment = PackContext.getAlignment()) 2993 New->addAttr(new PackedAttr(Alignment * 8)); 2994 } 2995 2996 if (Attr) 2997 ProcessDeclAttributeList(New, Attr); 2998 2999 // If we're declaring or defining 3000 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 3001 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 3002 3003 // Set the lexical context. If the tag has a C++ scope specifier, the 3004 // lexical context will be different from the semantic context. 3005 New->setLexicalDeclContext(LexicalContext); 3006 3007 // If this has an identifier, add it to the scope stack. 3008 if (Name) { 3009 S = getNonFieldDeclScope(S); 3010 3011 // Add it to the decl chain. 3012 if (LexicalContext != CurContext) { 3013 // FIXME: PushOnScopeChains should not rely on CurContext! 3014 DeclContext *OldContext = CurContext; 3015 CurContext = LexicalContext; 3016 PushOnScopeChains(New, S); 3017 CurContext = OldContext; 3018 } else 3019 PushOnScopeChains(New, S); 3020 } else { 3021 LexicalContext->addDecl(New); 3022 } 3023 3024 return New; 3025} 3026 3027void Sema::ActOnTagStartDefinition(Scope *S, DeclTy *TagD) { 3028 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3029 3030 // Enter the tag context. 3031 PushDeclContext(S, Tag); 3032 3033 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 3034 FieldCollector->StartClass(); 3035 3036 if (Record->getIdentifier()) { 3037 // C++ [class]p2: 3038 // [...] The class-name is also inserted into the scope of the 3039 // class itself; this is known as the injected-class-name. For 3040 // purposes of access checking, the injected-class-name is treated 3041 // as if it were a public member name. 3042 RecordDecl *InjectedClassName 3043 = CXXRecordDecl::Create(Context, Record->getTagKind(), 3044 CurContext, Record->getLocation(), 3045 Record->getIdentifier(), Record); 3046 InjectedClassName->setImplicit(); 3047 PushOnScopeChains(InjectedClassName, S); 3048 } 3049 } 3050} 3051 3052void Sema::ActOnTagFinishDefinition(Scope *S, DeclTy *TagD) { 3053 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3054 3055 if (isa<CXXRecordDecl>(Tag)) 3056 FieldCollector->FinishClass(); 3057 3058 // Exit this scope of this tag's definition. 3059 PopDeclContext(); 3060 3061 // Notify the consumer that we've defined a tag. 3062 Consumer.HandleTagDeclDefinition(Tag); 3063} 3064 3065/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 3066/// types into constant array types in certain situations which would otherwise 3067/// be errors (for GCC compatibility). 3068static QualType TryToFixInvalidVariablyModifiedType(QualType T, 3069 ASTContext &Context) { 3070 // This method tries to turn a variable array into a constant 3071 // array even when the size isn't an ICE. This is necessary 3072 // for compatibility with code that depends on gcc's buggy 3073 // constant expression folding, like struct {char x[(int)(char*)2];} 3074 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 3075 if (!VLATy) return QualType(); 3076 3077 Expr::EvalResult EvalResult; 3078 if (!VLATy->getSizeExpr() || 3079 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context)) 3080 return QualType(); 3081 3082 assert(EvalResult.Val.isInt() && "Size expressions must be integers!"); 3083 llvm::APSInt &Res = EvalResult.Val.getInt(); 3084 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 3085 return Context.getConstantArrayType(VLATy->getElementType(), 3086 Res, ArrayType::Normal, 0); 3087 return QualType(); 3088} 3089 3090bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 3091 QualType FieldTy, const Expr *BitWidth) { 3092 // FIXME: 6.7.2.1p4 - verify the field type. 3093 3094 llvm::APSInt Value; 3095 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 3096 return true; 3097 3098 // Zero-width bitfield is ok for anonymous field. 3099 if (Value == 0 && FieldName) 3100 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 3101 3102 if (Value.isNegative()) 3103 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) << FieldName; 3104 3105 uint64_t TypeSize = Context.getTypeSize(FieldTy); 3106 // FIXME: We won't need the 0 size once we check that the field type is valid. 3107 if (TypeSize && Value.getZExtValue() > TypeSize) 3108 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 3109 << FieldName << (unsigned)TypeSize; 3110 3111 return false; 3112} 3113 3114/// ActOnField - Each field of a struct/union/class is passed into this in order 3115/// to create a FieldDecl object for it. 3116Sema::DeclTy *Sema::ActOnField(Scope *S, DeclTy *TagD, 3117 SourceLocation DeclStart, 3118 Declarator &D, ExprTy *BitfieldWidth) { 3119 IdentifierInfo *II = D.getIdentifier(); 3120 Expr *BitWidth = (Expr*)BitfieldWidth; 3121 SourceLocation Loc = DeclStart; 3122 RecordDecl *Record = (RecordDecl *)TagD; 3123 if (II) Loc = D.getIdentifierLoc(); 3124 3125 // FIXME: Unnamed fields can be handled in various different ways, for 3126 // example, unnamed unions inject all members into the struct namespace! 3127 3128 QualType T = GetTypeForDeclarator(D, S); 3129 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3130 bool InvalidDecl = false; 3131 3132 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3133 // than a variably modified type. 3134 if (T->isVariablyModifiedType()) { 3135 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 3136 if (!FixedTy.isNull()) { 3137 Diag(Loc, diag::warn_illegal_constant_array_size); 3138 T = FixedTy; 3139 } else { 3140 Diag(Loc, diag::err_typecheck_field_variable_size); 3141 T = Context.IntTy; 3142 InvalidDecl = true; 3143 } 3144 } 3145 3146 if (BitWidth) { 3147 if (VerifyBitField(Loc, II, T, BitWidth)) 3148 InvalidDecl = true; 3149 } else { 3150 // Not a bitfield. 3151 3152 // validate II. 3153 3154 } 3155 3156 // FIXME: Chain fielddecls together. 3157 FieldDecl *NewFD; 3158 3159 NewFD = FieldDecl::Create(Context, Record, 3160 Loc, II, T, BitWidth, 3161 D.getDeclSpec().getStorageClassSpec() == 3162 DeclSpec::SCS_mutable, 3163 /*PrevDecl=*/0); 3164 3165 if (II) { 3166 Decl *PrevDecl 3167 = LookupDecl(II, Decl::IDNS_Member, S, 0, false, false, false); 3168 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3169 && !isa<TagDecl>(PrevDecl)) { 3170 Diag(Loc, diag::err_duplicate_member) << II; 3171 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3172 NewFD->setInvalidDecl(); 3173 Record->setInvalidDecl(); 3174 } 3175 } 3176 3177 if (getLangOptions().CPlusPlus) { 3178 CheckExtraCXXDefaultArguments(D); 3179 if (!T->isPODType()) 3180 cast<CXXRecordDecl>(Record)->setPOD(false); 3181 } 3182 3183 ProcessDeclAttributes(NewFD, D); 3184 3185 if (D.getInvalidType() || InvalidDecl) 3186 NewFD->setInvalidDecl(); 3187 3188 if (II) { 3189 PushOnScopeChains(NewFD, S); 3190 } else 3191 Record->addDecl(NewFD); 3192 3193 return NewFD; 3194} 3195 3196/// TranslateIvarVisibility - Translate visibility from a token ID to an 3197/// AST enum value. 3198static ObjCIvarDecl::AccessControl 3199TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 3200 switch (ivarVisibility) { 3201 default: assert(0 && "Unknown visitibility kind"); 3202 case tok::objc_private: return ObjCIvarDecl::Private; 3203 case tok::objc_public: return ObjCIvarDecl::Public; 3204 case tok::objc_protected: return ObjCIvarDecl::Protected; 3205 case tok::objc_package: return ObjCIvarDecl::Package; 3206 } 3207} 3208 3209/// ActOnIvar - Each ivar field of an objective-c class is passed into this 3210/// in order to create an IvarDecl object for it. 3211Sema::DeclTy *Sema::ActOnIvar(Scope *S, 3212 SourceLocation DeclStart, 3213 Declarator &D, ExprTy *BitfieldWidth, 3214 tok::ObjCKeywordKind Visibility) { 3215 3216 IdentifierInfo *II = D.getIdentifier(); 3217 Expr *BitWidth = (Expr*)BitfieldWidth; 3218 SourceLocation Loc = DeclStart; 3219 if (II) Loc = D.getIdentifierLoc(); 3220 3221 // FIXME: Unnamed fields can be handled in various different ways, for 3222 // example, unnamed unions inject all members into the struct namespace! 3223 3224 QualType T = GetTypeForDeclarator(D, S); 3225 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3226 bool InvalidDecl = false; 3227 3228 if (BitWidth) { 3229 // TODO: Validate. 3230 //printf("WARNING: BITFIELDS IGNORED!\n"); 3231 3232 // 6.7.2.1p3 3233 // 6.7.2.1p4 3234 3235 } else { 3236 // Not a bitfield. 3237 3238 // validate II. 3239 3240 } 3241 3242 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3243 // than a variably modified type. 3244 if (T->isVariablyModifiedType()) { 3245 Diag(Loc, diag::err_typecheck_ivar_variable_size); 3246 InvalidDecl = true; 3247 } 3248 3249 // Get the visibility (access control) for this ivar. 3250 ObjCIvarDecl::AccessControl ac = 3251 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 3252 : ObjCIvarDecl::None; 3253 3254 // Construct the decl. 3255 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 3256 (Expr *)BitfieldWidth); 3257 3258 if (II) { 3259 Decl *PrevDecl 3260 = LookupDecl(II, Decl::IDNS_Member, S, 0, false, false, false); 3261 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3262 && !isa<TagDecl>(PrevDecl)) { 3263 Diag(Loc, diag::err_duplicate_member) << II; 3264 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3265 NewID->setInvalidDecl(); 3266 } 3267 } 3268 3269 // Process attributes attached to the ivar. 3270 ProcessDeclAttributes(NewID, D); 3271 3272 if (D.getInvalidType() || InvalidDecl) 3273 NewID->setInvalidDecl(); 3274 3275 if (II) { 3276 // FIXME: When interfaces are DeclContexts, we'll need to add 3277 // these to the interface. 3278 S->AddDecl(NewID); 3279 IdResolver.AddDecl(NewID); 3280 } 3281 3282 return NewID; 3283} 3284 3285void Sema::ActOnFields(Scope* S, 3286 SourceLocation RecLoc, DeclTy *RecDecl, 3287 DeclTy **Fields, unsigned NumFields, 3288 SourceLocation LBrac, SourceLocation RBrac, 3289 AttributeList *Attr) { 3290 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 3291 assert(EnclosingDecl && "missing record or interface decl"); 3292 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 3293 3294 if (Record) { 3295 QualType RecordType = Context.getTypeDeclType(Record); 3296 if (RecordType->getAsRecordType()->getDecl()->isDefinition()) { 3297 RecordDecl *Def = RecordType->getAsRecordType()->getDecl(); 3298 // Diagnose code like: 3299 // struct S { struct S {} X; }; 3300 // We discover this when we complete the outer S. Reject and ignore the 3301 // outer S. 3302 Diag(Def->getLocation(), diag::err_nested_redefinition) 3303 << Def->getDeclName(); 3304 Diag(RecLoc, diag::note_previous_definition); 3305 Record->setInvalidDecl(); 3306 return; 3307 } 3308 } 3309 3310 // Verify that all the fields are okay. 3311 unsigned NumNamedMembers = 0; 3312 llvm::SmallVector<FieldDecl*, 32> RecFields; 3313 3314 for (unsigned i = 0; i != NumFields; ++i) { 3315 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 3316 assert(FD && "missing field decl"); 3317 3318 // Get the type for the field. 3319 Type *FDTy = FD->getType().getTypePtr(); 3320 3321 if (!FD->isAnonymousStructOrUnion()) { 3322 // Remember all fields written by the user. 3323 RecFields.push_back(FD); 3324 } 3325 3326 // C99 6.7.2.1p2 - A field may not be a function type. 3327 if (FDTy->isFunctionType()) { 3328 Diag(FD->getLocation(), diag::err_field_declared_as_function) 3329 << FD->getDeclName(); 3330 FD->setInvalidDecl(); 3331 EnclosingDecl->setInvalidDecl(); 3332 continue; 3333 } 3334 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 3335 if (FDTy->isIncompleteType()) { 3336 if (!Record) { // Incomplete ivar type is always an error. 3337 Diag(FD->getLocation(), diag::err_field_incomplete) <<FD->getDeclName(); 3338 FD->setInvalidDecl(); 3339 EnclosingDecl->setInvalidDecl(); 3340 continue; 3341 } 3342 if (i != NumFields-1 || // ... that the last member ... 3343 !Record->isStruct() || // ... of a structure ... 3344 !FDTy->isArrayType()) { //... may have incomplete array type. 3345 Diag(FD->getLocation(), diag::err_field_incomplete) <<FD->getDeclName(); 3346 FD->setInvalidDecl(); 3347 EnclosingDecl->setInvalidDecl(); 3348 continue; 3349 } 3350 if (NumNamedMembers < 1) { //... must have more than named member ... 3351 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 3352 << FD->getDeclName(); 3353 FD->setInvalidDecl(); 3354 EnclosingDecl->setInvalidDecl(); 3355 continue; 3356 } 3357 // Okay, we have a legal flexible array member at the end of the struct. 3358 if (Record) 3359 Record->setHasFlexibleArrayMember(true); 3360 } 3361 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 3362 /// field of another structure or the element of an array. 3363 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 3364 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 3365 // If this is a member of a union, then entire union becomes "flexible". 3366 if (Record && Record->isUnion()) { 3367 Record->setHasFlexibleArrayMember(true); 3368 } else { 3369 // If this is a struct/class and this is not the last element, reject 3370 // it. Note that GCC supports variable sized arrays in the middle of 3371 // structures. 3372 if (i != NumFields-1) { 3373 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct) 3374 << FD->getDeclName(); 3375 FD->setInvalidDecl(); 3376 EnclosingDecl->setInvalidDecl(); 3377 continue; 3378 } 3379 // We support flexible arrays at the end of structs in other structs 3380 // as an extension. 3381 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 3382 << FD->getDeclName(); 3383 if (Record) 3384 Record->setHasFlexibleArrayMember(true); 3385 } 3386 } 3387 } 3388 /// A field cannot be an Objective-c object 3389 if (FDTy->isObjCInterfaceType()) { 3390 Diag(FD->getLocation(), diag::err_statically_allocated_object) 3391 << FD->getDeclName(); 3392 FD->setInvalidDecl(); 3393 EnclosingDecl->setInvalidDecl(); 3394 continue; 3395 } 3396 // Keep track of the number of named members. 3397 if (FD->getIdentifier()) 3398 ++NumNamedMembers; 3399 } 3400 3401 // Okay, we successfully defined 'Record'. 3402 if (Record) { 3403 Record->completeDefinition(Context); 3404 } else { 3405 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 3406 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 3407 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 3408 // Must enforce the rule that ivars in the base classes may not be 3409 // duplicates. 3410 if (ID->getSuperClass()) { 3411 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 3412 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 3413 ObjCIvarDecl* Ivar = (*IVI); 3414 IdentifierInfo *II = Ivar->getIdentifier(); 3415 ObjCIvarDecl* prevIvar = ID->getSuperClass()->FindIvarDeclaration(II); 3416 if (prevIvar) { 3417 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 3418 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 3419 } 3420 } 3421 } 3422 } 3423 else if (ObjCImplementationDecl *IMPDecl = 3424 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 3425 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 3426 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 3427 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 3428 } 3429 } 3430 3431 if (Attr) 3432 ProcessDeclAttributeList(Record, Attr); 3433} 3434 3435Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 3436 DeclTy *lastEnumConst, 3437 SourceLocation IdLoc, IdentifierInfo *Id, 3438 SourceLocation EqualLoc, ExprTy *val) { 3439 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 3440 EnumConstantDecl *LastEnumConst = 3441 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 3442 Expr *Val = static_cast<Expr*>(val); 3443 3444 // The scope passed in may not be a decl scope. Zip up the scope tree until 3445 // we find one that is. 3446 S = getNonFieldDeclScope(S); 3447 3448 // Verify that there isn't already something declared with this name in this 3449 // scope. 3450 Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S); 3451 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3452 // Maybe we will complain about the shadowed template parameter. 3453 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 3454 // Just pretend that we didn't see the previous declaration. 3455 PrevDecl = 0; 3456 } 3457 3458 if (PrevDecl) { 3459 // When in C++, we may get a TagDecl with the same name; in this case the 3460 // enum constant will 'hide' the tag. 3461 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 3462 "Received TagDecl when not in C++!"); 3463 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 3464 if (isa<EnumConstantDecl>(PrevDecl)) 3465 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 3466 else 3467 Diag(IdLoc, diag::err_redefinition) << Id; 3468 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3469 delete Val; 3470 return 0; 3471 } 3472 } 3473 3474 llvm::APSInt EnumVal(32); 3475 QualType EltTy; 3476 if (Val) { 3477 // Make sure to promote the operand type to int. 3478 UsualUnaryConversions(Val); 3479 3480 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 3481 SourceLocation ExpLoc; 3482 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 3483 delete Val; 3484 Val = 0; // Just forget about it. 3485 } else { 3486 EltTy = Val->getType(); 3487 } 3488 } 3489 3490 if (!Val) { 3491 if (LastEnumConst) { 3492 // Assign the last value + 1. 3493 EnumVal = LastEnumConst->getInitVal(); 3494 ++EnumVal; 3495 3496 // Check for overflow on increment. 3497 if (EnumVal < LastEnumConst->getInitVal()) 3498 Diag(IdLoc, diag::warn_enum_value_overflow); 3499 3500 EltTy = LastEnumConst->getType(); 3501 } else { 3502 // First value, set to zero. 3503 EltTy = Context.IntTy; 3504 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 3505 } 3506 } 3507 3508 EnumConstantDecl *New = 3509 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 3510 Val, EnumVal, 3511 LastEnumConst); 3512 3513 // Register this decl in the current scope stack. 3514 PushOnScopeChains(New, S); 3515 3516 return New; 3517} 3518 3519// FIXME: For consistency with ActOnFields(), we should have the parser 3520// pass in the source location for the left/right braces. 3521void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 3522 DeclTy **Elements, unsigned NumElements) { 3523 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 3524 QualType EnumType = Context.getTypeDeclType(Enum); 3525 3526 if (EnumType->getAsEnumType()->getDecl()->isDefinition()) { 3527 EnumDecl *Def = EnumType->getAsEnumType()->getDecl(); 3528 // Diagnose code like: 3529 // enum e0 { 3530 // E0 = sizeof(enum e0 { E1 }) 3531 // }; 3532 Diag(Def->getLocation(), diag::err_nested_redefinition) 3533 << Enum->getDeclName(); 3534 Diag(Enum->getLocation(), diag::note_previous_definition); 3535 Enum->setInvalidDecl(); 3536 return; 3537 } 3538 3539 // TODO: If the result value doesn't fit in an int, it must be a long or long 3540 // long value. ISO C does not support this, but GCC does as an extension, 3541 // emit a warning. 3542 unsigned IntWidth = Context.Target.getIntWidth(); 3543 3544 // Verify that all the values are okay, compute the size of the values, and 3545 // reverse the list. 3546 unsigned NumNegativeBits = 0; 3547 unsigned NumPositiveBits = 0; 3548 3549 // Keep track of whether all elements have type int. 3550 bool AllElementsInt = true; 3551 3552 for (unsigned i = 0; i != NumElements; ++i) { 3553 EnumConstantDecl *ECD = 3554 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3555 if (!ECD) continue; // Already issued a diagnostic. 3556 3557 // If the enum value doesn't fit in an int, emit an extension warning. 3558 const llvm::APSInt &InitVal = ECD->getInitVal(); 3559 assert(InitVal.getBitWidth() >= IntWidth && 3560 "Should have promoted value to int"); 3561 if (InitVal.getBitWidth() > IntWidth) { 3562 llvm::APSInt V(InitVal); 3563 V.trunc(IntWidth); 3564 V.extend(InitVal.getBitWidth()); 3565 if (V != InitVal) 3566 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 3567 << InitVal.toString(10); 3568 } 3569 3570 // Keep track of the size of positive and negative values. 3571 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 3572 NumPositiveBits = std::max(NumPositiveBits, 3573 (unsigned)InitVal.getActiveBits()); 3574 else 3575 NumNegativeBits = std::max(NumNegativeBits, 3576 (unsigned)InitVal.getMinSignedBits()); 3577 3578 // Keep track of whether every enum element has type int (very commmon). 3579 if (AllElementsInt) 3580 AllElementsInt = ECD->getType() == Context.IntTy; 3581 } 3582 3583 // Figure out the type that should be used for this enum. 3584 // FIXME: Support attribute(packed) on enums and -fshort-enums. 3585 QualType BestType; 3586 unsigned BestWidth; 3587 3588 if (NumNegativeBits) { 3589 // If there is a negative value, figure out the smallest integer type (of 3590 // int/long/longlong) that fits. 3591 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 3592 BestType = Context.IntTy; 3593 BestWidth = IntWidth; 3594 } else { 3595 BestWidth = Context.Target.getLongWidth(); 3596 3597 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 3598 BestType = Context.LongTy; 3599 else { 3600 BestWidth = Context.Target.getLongLongWidth(); 3601 3602 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 3603 Diag(Enum->getLocation(), diag::warn_enum_too_large); 3604 BestType = Context.LongLongTy; 3605 } 3606 } 3607 } else { 3608 // If there is no negative value, figure out which of uint, ulong, ulonglong 3609 // fits. 3610 if (NumPositiveBits <= IntWidth) { 3611 BestType = Context.UnsignedIntTy; 3612 BestWidth = IntWidth; 3613 } else if (NumPositiveBits <= 3614 (BestWidth = Context.Target.getLongWidth())) { 3615 BestType = Context.UnsignedLongTy; 3616 } else { 3617 BestWidth = Context.Target.getLongLongWidth(); 3618 assert(NumPositiveBits <= BestWidth && 3619 "How could an initializer get larger than ULL?"); 3620 BestType = Context.UnsignedLongLongTy; 3621 } 3622 } 3623 3624 // Loop over all of the enumerator constants, changing their types to match 3625 // the type of the enum if needed. 3626 for (unsigned i = 0; i != NumElements; ++i) { 3627 EnumConstantDecl *ECD = 3628 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3629 if (!ECD) continue; // Already issued a diagnostic. 3630 3631 // Standard C says the enumerators have int type, but we allow, as an 3632 // extension, the enumerators to be larger than int size. If each 3633 // enumerator value fits in an int, type it as an int, otherwise type it the 3634 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 3635 // that X has type 'int', not 'unsigned'. 3636 if (ECD->getType() == Context.IntTy) { 3637 // Make sure the init value is signed. 3638 llvm::APSInt IV = ECD->getInitVal(); 3639 IV.setIsSigned(true); 3640 ECD->setInitVal(IV); 3641 3642 if (getLangOptions().CPlusPlus) 3643 // C++ [dcl.enum]p4: Following the closing brace of an 3644 // enum-specifier, each enumerator has the type of its 3645 // enumeration. 3646 ECD->setType(EnumType); 3647 continue; // Already int type. 3648 } 3649 3650 // Determine whether the value fits into an int. 3651 llvm::APSInt InitVal = ECD->getInitVal(); 3652 bool FitsInInt; 3653 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3654 FitsInInt = InitVal.getActiveBits() < IntWidth; 3655 else 3656 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3657 3658 // If it fits into an integer type, force it. Otherwise force it to match 3659 // the enum decl type. 3660 QualType NewTy; 3661 unsigned NewWidth; 3662 bool NewSign; 3663 if (FitsInInt) { 3664 NewTy = Context.IntTy; 3665 NewWidth = IntWidth; 3666 NewSign = true; 3667 } else if (ECD->getType() == BestType) { 3668 // Already the right type! 3669 if (getLangOptions().CPlusPlus) 3670 // C++ [dcl.enum]p4: Following the closing brace of an 3671 // enum-specifier, each enumerator has the type of its 3672 // enumeration. 3673 ECD->setType(EnumType); 3674 continue; 3675 } else { 3676 NewTy = BestType; 3677 NewWidth = BestWidth; 3678 NewSign = BestType->isSignedIntegerType(); 3679 } 3680 3681 // Adjust the APSInt value. 3682 InitVal.extOrTrunc(NewWidth); 3683 InitVal.setIsSigned(NewSign); 3684 ECD->setInitVal(InitVal); 3685 3686 // Adjust the Expr initializer and type. 3687 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3688 /*isLvalue=*/false)); 3689 if (getLangOptions().CPlusPlus) 3690 // C++ [dcl.enum]p4: Following the closing brace of an 3691 // enum-specifier, each enumerator has the type of its 3692 // enumeration. 3693 ECD->setType(EnumType); 3694 else 3695 ECD->setType(NewTy); 3696 } 3697 3698 Enum->completeDefinition(Context, BestType); 3699} 3700 3701Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3702 ExprArg expr) { 3703 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr.release()); 3704 3705 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3706} 3707 3708 3709void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3710 ExprTy *alignment, SourceLocation PragmaLoc, 3711 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3712 Expr *Alignment = static_cast<Expr *>(alignment); 3713 3714 // If specified then alignment must be a "small" power of two. 3715 unsigned AlignmentVal = 0; 3716 if (Alignment) { 3717 llvm::APSInt Val; 3718 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3719 !Val.isPowerOf2() || 3720 Val.getZExtValue() > 16) { 3721 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3722 delete Alignment; 3723 return; // Ignore 3724 } 3725 3726 AlignmentVal = (unsigned) Val.getZExtValue(); 3727 } 3728 3729 switch (Kind) { 3730 case Action::PPK_Default: // pack([n]) 3731 PackContext.setAlignment(AlignmentVal); 3732 break; 3733 3734 case Action::PPK_Show: // pack(show) 3735 // Show the current alignment, making sure to show the right value 3736 // for the default. 3737 AlignmentVal = PackContext.getAlignment(); 3738 // FIXME: This should come from the target. 3739 if (AlignmentVal == 0) 3740 AlignmentVal = 8; 3741 Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 3742 break; 3743 3744 case Action::PPK_Push: // pack(push [, id] [, [n]) 3745 PackContext.push(Name); 3746 // Set the new alignment if specified. 3747 if (Alignment) 3748 PackContext.setAlignment(AlignmentVal); 3749 break; 3750 3751 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3752 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3753 // "#pragma pack(pop, identifier, n) is undefined" 3754 if (Alignment && Name) 3755 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3756 3757 // Do the pop. 3758 if (!PackContext.pop(Name)) { 3759 // If a name was specified then failure indicates the name 3760 // wasn't found. Otherwise failure indicates the stack was 3761 // empty. 3762 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed) 3763 << (Name ? "no record matching name" : "stack empty"); 3764 3765 // FIXME: Warn about popping named records as MSVC does. 3766 } else { 3767 // Pop succeeded, set the new alignment if specified. 3768 if (Alignment) 3769 PackContext.setAlignment(AlignmentVal); 3770 } 3771 break; 3772 3773 default: 3774 assert(0 && "Invalid #pragma pack kind."); 3775 } 3776} 3777 3778bool PragmaPackStack::pop(IdentifierInfo *Name) { 3779 if (Stack.empty()) 3780 return false; 3781 3782 // If name is empty just pop top. 3783 if (!Name) { 3784 Alignment = Stack.back().first; 3785 Stack.pop_back(); 3786 return true; 3787 } 3788 3789 // Otherwise, find the named record. 3790 for (unsigned i = Stack.size(); i != 0; ) { 3791 --i; 3792 if (Stack[i].second == Name) { 3793 // Found it, pop up to and including this record. 3794 Alignment = Stack[i].first; 3795 Stack.erase(Stack.begin() + i, Stack.end()); 3796 return true; 3797 } 3798 } 3799 3800 return false; 3801} 3802