SemaDecl.cpp revision 25d944af5d8d665611e09956954f10896c1071f6
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/DeclTemplate.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/Parse/DeclSpec.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> 31using namespace clang; 32 33/// \brief If the identifier refers to a type name within this scope, 34/// return the declaration of that type. 35/// 36/// This routine performs ordinary name lookup of the identifier II 37/// within the given scope, with optional C++ scope specifier SS, to 38/// determine whether the name refers to a type. If so, returns an 39/// opaque pointer (actually a QualType) corresponding to that 40/// type. Otherwise, returns NULL. 41/// 42/// If name lookup results in an ambiguity, this routine will complain 43/// and then return NULL. 44Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc, 45 Scope *S, const CXXScopeSpec *SS) { 46 NamedDecl *IIDecl = 0; 47 LookupResult Result = LookupParsedName(S, SS, &II, LookupOrdinaryName, 48 false, false); 49 switch (Result.getKind()) { 50 case LookupResult::NotFound: 51 case LookupResult::FoundOverloaded: 52 return 0; 53 54 case LookupResult::AmbiguousBaseSubobjectTypes: 55 case LookupResult::AmbiguousBaseSubobjects: 56 case LookupResult::AmbiguousReference: 57 DiagnoseAmbiguousLookup(Result, DeclarationName(&II), NameLoc); 58 return 0; 59 60 case LookupResult::Found: 61 IIDecl = Result.getAsDecl(); 62 break; 63 } 64 65 if (IIDecl) { 66 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) { 67 // Check whether we can use this type 68 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 69 70 return Context.getTypeDeclType(TD).getAsOpaquePtr(); 71 } 72 73 if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) { 74 // Check whether we can use this interface. 75 (void)DiagnoseUseOfDecl(IIDecl, NameLoc); 76 77 return Context.getObjCInterfaceType(IDecl).getAsOpaquePtr(); 78 } 79 80 // Otherwise, could be a variable, function etc. 81 } 82 return 0; 83} 84 85DeclContext *Sema::getContainingDC(DeclContext *DC) { 86 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 87 // A C++ out-of-line method will return to the file declaration context. 88 if (MD->isOutOfLineDefinition()) 89 return MD->getLexicalDeclContext(); 90 91 // A C++ inline method is parsed *after* the topmost class it was declared 92 // in is fully parsed (it's "complete"). 93 // The parsing of a C++ inline method happens at the declaration context of 94 // the topmost (non-nested) class it is lexically declared in. 95 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 96 DC = MD->getParent(); 97 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 98 DC = RD; 99 100 // Return the declaration context of the topmost class the inline method is 101 // declared in. 102 return DC; 103 } 104 105 if (isa<ObjCMethodDecl>(DC)) 106 return Context.getTranslationUnitDecl(); 107 108 return DC->getLexicalParent(); 109} 110 111void Sema::PushDeclContext(Scope *S, DeclContext *DC) { 112 assert(getContainingDC(DC) == CurContext && 113 "The next DeclContext should be lexically contained in the current one."); 114 CurContext = DC; 115 S->setEntity(DC); 116} 117 118void Sema::PopDeclContext() { 119 assert(CurContext && "DeclContext imbalance!"); 120 121 CurContext = getContainingDC(CurContext); 122} 123 124/// \brief Determine whether we allow overloading of the function 125/// PrevDecl with another declaration. 126/// 127/// This routine determines whether overloading is possible, not 128/// whether some new function is actually an overload. It will return 129/// true in C++ (where we can always provide overloads) or, as an 130/// extension, in C when the previous function is already an 131/// overloaded function declaration or has the "overloadable" 132/// attribute. 133static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) { 134 if (Context.getLangOptions().CPlusPlus) 135 return true; 136 137 if (isa<OverloadedFunctionDecl>(PrevDecl)) 138 return true; 139 140 return PrevDecl->getAttr<OverloadableAttr>() != 0; 141} 142 143/// Add this decl to the scope shadowed decl chains. 144void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 145 // Move up the scope chain until we find the nearest enclosing 146 // non-transparent context. The declaration will be introduced into this 147 // scope. 148 while (S->getEntity() && 149 ((DeclContext *)S->getEntity())->isTransparentContext()) 150 S = S->getParent(); 151 152 S->AddDecl(D); 153 154 // Add scoped declarations into their context, so that they can be 155 // found later. Declarations without a context won't be inserted 156 // into any context. 157 CurContext->addDecl(D); 158 159 // C++ [basic.scope]p4: 160 // -- exactly one declaration shall declare a class name or 161 // enumeration name that is not a typedef name and the other 162 // declarations shall all refer to the same object or 163 // enumerator, or all refer to functions and function templates; 164 // in this case the class name or enumeration name is hidden. 165 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 166 // We are pushing the name of a tag (enum or class). 167 if (CurContext->getLookupContext() 168 == TD->getDeclContext()->getLookupContext()) { 169 // We're pushing the tag into the current context, which might 170 // require some reshuffling in the identifier resolver. 171 IdentifierResolver::iterator 172 I = IdResolver.begin(TD->getDeclName()), 173 IEnd = IdResolver.end(); 174 if (I != IEnd && isDeclInScope(*I, CurContext, S)) { 175 NamedDecl *PrevDecl = *I; 176 for (; I != IEnd && isDeclInScope(*I, CurContext, S); 177 PrevDecl = *I, ++I) { 178 if (TD->declarationReplaces(*I)) { 179 // This is a redeclaration. Remove it from the chain and 180 // break out, so that we'll add in the shadowed 181 // declaration. 182 S->RemoveDecl(*I); 183 if (PrevDecl == *I) { 184 IdResolver.RemoveDecl(*I); 185 IdResolver.AddDecl(TD); 186 return; 187 } else { 188 IdResolver.RemoveDecl(*I); 189 break; 190 } 191 } 192 } 193 194 // There is already a declaration with the same name in the same 195 // scope, which is not a tag declaration. It must be found 196 // before we find the new declaration, so insert the new 197 // declaration at the end of the chain. 198 IdResolver.AddShadowedDecl(TD, PrevDecl); 199 200 return; 201 } 202 } 203 } else if (isa<FunctionDecl>(D) && 204 AllowOverloadingOfFunction(D, Context)) { 205 // We are pushing the name of a function, which might be an 206 // overloaded name. 207 FunctionDecl *FD = cast<FunctionDecl>(D); 208 IdentifierResolver::iterator Redecl 209 = std::find_if(IdResolver.begin(FD->getDeclName()), 210 IdResolver.end(), 211 std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), 212 FD)); 213 if (Redecl != IdResolver.end() && S->isDeclScope(*Redecl)) { 214 // There is already a declaration of a function on our 215 // IdResolver chain. Replace it with this declaration. 216 S->RemoveDecl(*Redecl); 217 IdResolver.RemoveDecl(*Redecl); 218 } 219 } 220 221 IdResolver.AddDecl(D); 222} 223 224void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 225 if (S->decl_empty()) return; 226 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 227 "Scope shouldn't contain decls!"); 228 229 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 230 I != E; ++I) { 231 Decl *TmpD = static_cast<Decl*>(*I); 232 assert(TmpD && "This decl didn't get pushed??"); 233 234 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"); 235 NamedDecl *D = cast<NamedDecl>(TmpD); 236 237 if (!D->getDeclName()) continue; 238 239 // Remove this name from our lexical scope. 240 IdResolver.RemoveDecl(D); 241 } 242} 243 244/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 245/// return 0 if one not found. 246ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 247 // The third "scope" argument is 0 since we aren't enabling lazy built-in 248 // creation from this context. 249 NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName); 250 251 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 252} 253 254/// getNonFieldDeclScope - Retrieves the innermost scope, starting 255/// from S, where a non-field would be declared. This routine copes 256/// with the difference between C and C++ scoping rules in structs and 257/// unions. For example, the following code is well-formed in C but 258/// ill-formed in C++: 259/// @code 260/// struct S6 { 261/// enum { BAR } e; 262/// }; 263/// 264/// void test_S6() { 265/// struct S6 a; 266/// a.e = BAR; 267/// } 268/// @endcode 269/// For the declaration of BAR, this routine will return a different 270/// scope. The scope S will be the scope of the unnamed enumeration 271/// within S6. In C++, this routine will return the scope associated 272/// with S6, because the enumeration's scope is a transparent 273/// context but structures can contain non-field names. In C, this 274/// routine will return the translation unit scope, since the 275/// enumeration's scope is a transparent context and structures cannot 276/// contain non-field names. 277Scope *Sema::getNonFieldDeclScope(Scope *S) { 278 while (((S->getFlags() & Scope::DeclScope) == 0) || 279 (S->getEntity() && 280 ((DeclContext *)S->getEntity())->isTransparentContext()) || 281 (S->isClassScope() && !getLangOptions().CPlusPlus)) 282 S = S->getParent(); 283 return S; 284} 285 286void Sema::InitBuiltinVaListType() { 287 if (!Context.getBuiltinVaListType().isNull()) 288 return; 289 290 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 291 NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName); 292 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 293 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 294} 295 296/// LazilyCreateBuiltin - The specified Builtin-ID was first used at 297/// file scope. lazily create a decl for it. ForRedeclaration is true 298/// if we're creating this built-in in anticipation of redeclaring the 299/// built-in. 300NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 301 Scope *S, bool ForRedeclaration, 302 SourceLocation Loc) { 303 Builtin::ID BID = (Builtin::ID)bid; 304 305 if (Context.BuiltinInfo.hasVAListUse(BID)) 306 InitBuiltinVaListType(); 307 308 Builtin::Context::GetBuiltinTypeError Error; 309 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context, Error); 310 switch (Error) { 311 case Builtin::Context::GE_None: 312 // Okay 313 break; 314 315 case Builtin::Context::GE_Missing_FILE: 316 if (ForRedeclaration) 317 Diag(Loc, diag::err_implicit_decl_requires_stdio) 318 << Context.BuiltinInfo.GetName(BID); 319 return 0; 320 } 321 322 if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) { 323 Diag(Loc, diag::ext_implicit_lib_function_decl) 324 << Context.BuiltinInfo.GetName(BID) 325 << R; 326 if (Context.BuiltinInfo.getHeaderName(BID) && 327 Diags.getDiagnosticMapping(diag::ext_implicit_lib_function_decl) 328 != diag::MAP_IGNORE) 329 Diag(Loc, diag::note_please_include_header) 330 << Context.BuiltinInfo.getHeaderName(BID) 331 << Context.BuiltinInfo.GetName(BID); 332 } 333 334 FunctionDecl *New = FunctionDecl::Create(Context, 335 Context.getTranslationUnitDecl(), 336 Loc, II, R, 337 FunctionDecl::Extern, false); 338 New->setImplicit(); 339 340 // Create Decl objects for each parameter, adding them to the 341 // FunctionDecl. 342 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 343 llvm::SmallVector<ParmVarDecl*, 16> Params; 344 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 345 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 346 FT->getArgType(i), VarDecl::None, 0)); 347 New->setParams(Context, &Params[0], Params.size()); 348 } 349 350 AddKnownFunctionAttributes(New); 351 352 // TUScope is the translation-unit scope to insert this function into. 353 // FIXME: This is hideous. We need to teach PushOnScopeChains to 354 // relate Scopes to DeclContexts, and probably eliminate CurContext 355 // entirely, but we're not there yet. 356 DeclContext *SavedContext = CurContext; 357 CurContext = Context.getTranslationUnitDecl(); 358 PushOnScopeChains(New, TUScope); 359 CurContext = SavedContext; 360 return New; 361} 362 363/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 364/// everything from the standard library is defined. 365NamespaceDecl *Sema::GetStdNamespace() { 366 if (!StdNamespace) { 367 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 368 DeclContext *Global = Context.getTranslationUnitDecl(); 369 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 370 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 371 } 372 return StdNamespace; 373} 374 375/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 376/// same name and scope as a previous declaration 'Old'. Figure out 377/// how to resolve this situation, merging decls or emitting 378/// diagnostics as appropriate. Returns true if there was an error, 379/// false otherwise. 380/// 381bool Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 382 bool objc_types = false; 383 // Allow multiple definitions for ObjC built-in typedefs. 384 // FIXME: Verify the underlying types are equivalent! 385 if (getLangOptions().ObjC1) { 386 const IdentifierInfo *TypeID = New->getIdentifier(); 387 switch (TypeID->getLength()) { 388 default: break; 389 case 2: 390 if (!TypeID->isStr("id")) 391 break; 392 Context.setObjCIdType(New); 393 objc_types = true; 394 break; 395 case 5: 396 if (!TypeID->isStr("Class")) 397 break; 398 Context.setObjCClassType(New); 399 objc_types = true; 400 return false; 401 case 3: 402 if (!TypeID->isStr("SEL")) 403 break; 404 Context.setObjCSelType(New); 405 objc_types = true; 406 return false; 407 case 8: 408 if (!TypeID->isStr("Protocol")) 409 break; 410 Context.setObjCProtoType(New->getUnderlyingType()); 411 objc_types = true; 412 return false; 413 } 414 // Fall through - the typedef name was not a builtin type. 415 } 416 // Verify the old decl was also a type. 417 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 418 if (!Old) { 419 Diag(New->getLocation(), diag::err_redefinition_different_kind) 420 << New->getDeclName(); 421 if (!objc_types) 422 Diag(OldD->getLocation(), diag::note_previous_definition); 423 return true; 424 } 425 426 // Determine the "old" type we'll use for checking and diagnostics. 427 QualType OldType; 428 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 429 OldType = OldTypedef->getUnderlyingType(); 430 else 431 OldType = Context.getTypeDeclType(Old); 432 433 // If the typedef types are not identical, reject them in all languages and 434 // with any extensions enabled. 435 436 if (OldType != New->getUnderlyingType() && 437 Context.getCanonicalType(OldType) != 438 Context.getCanonicalType(New->getUnderlyingType())) { 439 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 440 << New->getUnderlyingType() << OldType; 441 if (!objc_types) 442 Diag(Old->getLocation(), diag::note_previous_definition); 443 return true; 444 } 445 if (objc_types) return false; 446 if (getLangOptions().Microsoft) return false; 447 448 // C++ [dcl.typedef]p2: 449 // In a given non-class scope, a typedef specifier can be used to 450 // redefine the name of any type declared in that scope to refer 451 // to the type to which it already refers. 452 if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext)) 453 return false; 454 455 // In C, redeclaration of a type is a constraint violation (6.7.2.3p1). 456 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 457 // *either* declaration is in a system header. The code below implements 458 // this adhoc compatibility rule. FIXME: The following code will not 459 // work properly when compiling ".i" files (containing preprocessed output). 460 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 461 SourceManager &SrcMgr = Context.getSourceManager(); 462 if (SrcMgr.isInSystemHeader(Old->getLocation())) 463 return false; 464 if (SrcMgr.isInSystemHeader(New->getLocation())) 465 return false; 466 } 467 468 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 469 Diag(Old->getLocation(), diag::note_previous_definition); 470 return true; 471} 472 473/// DeclhasAttr - returns true if decl Declaration already has the target 474/// attribute. 475static bool DeclHasAttr(const Decl *decl, const Attr *target) { 476 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 477 if (attr->getKind() == target->getKind()) 478 return true; 479 480 return false; 481} 482 483/// MergeAttributes - append attributes from the Old decl to the New one. 484static void MergeAttributes(Decl *New, Decl *Old) { 485 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 486 487 while (attr) { 488 tmp = attr; 489 attr = attr->getNext(); 490 491 if (!DeclHasAttr(New, tmp) && tmp->isMerged()) { 492 tmp->setInherited(true); 493 New->addAttr(tmp); 494 } else { 495 tmp->setNext(0); 496 delete(tmp); 497 } 498 } 499 500 Old->invalidateAttrs(); 501} 502 503/// MergeFunctionDecl - We just parsed a function 'New' from 504/// declarator D which has the same name and scope as a previous 505/// declaration 'Old'. Figure out how to resolve this situation, 506/// merging decls or emitting diagnostics as appropriate. 507/// 508/// In C++, New and Old must be declarations that are not 509/// overloaded. Use IsOverload to determine whether New and Old are 510/// overloaded, and to select the Old declaration that New should be 511/// merged with. 512/// 513/// Returns true if there was an error, false otherwise. 514bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 515 assert(!isa<OverloadedFunctionDecl>(OldD) && 516 "Cannot merge with an overloaded function declaration"); 517 518 // Verify the old decl was also a function. 519 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 520 if (!Old) { 521 Diag(New->getLocation(), diag::err_redefinition_different_kind) 522 << New->getDeclName(); 523 Diag(OldD->getLocation(), diag::note_previous_definition); 524 return true; 525 } 526 527 // Determine whether the previous declaration was a definition, 528 // implicit declaration, or a declaration. 529 diag::kind PrevDiag; 530 if (Old->isThisDeclarationADefinition()) 531 PrevDiag = diag::note_previous_definition; 532 else if (Old->isImplicit()) 533 PrevDiag = diag::note_previous_implicit_declaration; 534 else 535 PrevDiag = diag::note_previous_declaration; 536 537 QualType OldQType = Context.getCanonicalType(Old->getType()); 538 QualType NewQType = Context.getCanonicalType(New->getType()); 539 540 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 541 New->getStorageClass() == FunctionDecl::Static && 542 Old->getStorageClass() != FunctionDecl::Static) { 543 Diag(New->getLocation(), diag::err_static_non_static) 544 << New; 545 Diag(Old->getLocation(), PrevDiag); 546 return true; 547 } 548 549 if (getLangOptions().CPlusPlus) { 550 // (C++98 13.1p2): 551 // Certain function declarations cannot be overloaded: 552 // -- Function declarations that differ only in the return type 553 // cannot be overloaded. 554 QualType OldReturnType 555 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 556 QualType NewReturnType 557 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 558 if (OldReturnType != NewReturnType) { 559 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 560 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 561 return true; 562 } 563 564 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 565 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 566 if (OldMethod && NewMethod) { 567 // -- Member function declarations with the same name and the 568 // same parameter types cannot be overloaded if any of them 569 // is a static member function declaration. 570 if (OldMethod->isStatic() || NewMethod->isStatic()) { 571 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 572 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 573 return true; 574 } 575 576 // C++ [class.mem]p1: 577 // [...] A member shall not be declared twice in the 578 // member-specification, except that a nested class or member 579 // class template can be declared and then later defined. 580 if (OldMethod->getLexicalDeclContext() == 581 NewMethod->getLexicalDeclContext()) { 582 unsigned NewDiag; 583 if (isa<CXXConstructorDecl>(OldMethod)) 584 NewDiag = diag::err_constructor_redeclared; 585 else if (isa<CXXDestructorDecl>(NewMethod)) 586 NewDiag = diag::err_destructor_redeclared; 587 else if (isa<CXXConversionDecl>(NewMethod)) 588 NewDiag = diag::err_conv_function_redeclared; 589 else 590 NewDiag = diag::err_member_redeclared; 591 592 Diag(New->getLocation(), NewDiag); 593 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 594 } 595 } 596 597 // (C++98 8.3.5p3): 598 // All declarations for a function shall agree exactly in both the 599 // return type and the parameter-type-list. 600 if (OldQType == NewQType) 601 return MergeCompatibleFunctionDecls(New, Old); 602 603 // Fall through for conflicting redeclarations and redefinitions. 604 } 605 606 // C: Function types need to be compatible, not identical. This handles 607 // duplicate function decls like "void f(int); void f(enum X);" properly. 608 if (!getLangOptions().CPlusPlus && 609 Context.typesAreCompatible(OldQType, NewQType)) { 610 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 611 const FunctionTypeProto *OldProto = 0; 612 if (isa<FunctionTypeNoProto>(NewFuncType) && 613 (OldProto = OldQType->getAsFunctionTypeProto())) { 614 // The old declaration provided a function prototype, but the 615 // new declaration does not. Merge in the prototype. 616 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 617 OldProto->arg_type_end()); 618 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 619 &ParamTypes[0], ParamTypes.size(), 620 OldProto->isVariadic(), 621 OldProto->getTypeQuals()); 622 New->setType(NewQType); 623 New->setInheritedPrototype(); 624 625 // Synthesize a parameter for each argument type. 626 llvm::SmallVector<ParmVarDecl*, 16> Params; 627 for (FunctionTypeProto::arg_type_iterator 628 ParamType = OldProto->arg_type_begin(), 629 ParamEnd = OldProto->arg_type_end(); 630 ParamType != ParamEnd; ++ParamType) { 631 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 632 SourceLocation(), 0, 633 *ParamType, VarDecl::None, 634 0); 635 Param->setImplicit(); 636 Params.push_back(Param); 637 } 638 639 New->setParams(Context, &Params[0], Params.size()); 640 641 } 642 643 return MergeCompatibleFunctionDecls(New, Old); 644 } 645 646 // A function that has already been declared has been redeclared or defined 647 // with a different type- show appropriate diagnostic 648 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 649 // The user has declared a builtin function with an incompatible 650 // signature. 651 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 652 // The function the user is redeclaring is a library-defined 653 // function like 'malloc' or 'printf'. Warn about the 654 // redeclaration, then ignore it. 655 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 656 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 657 << Old << Old->getType(); 658 return true; 659 } 660 661 PrevDiag = diag::note_previous_builtin_declaration; 662 } 663 664 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 665 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 666 return true; 667} 668 669/// \brief Completes the merge of two function declarations that are 670/// known to be compatible. 671/// 672/// This routine handles the merging of attributes and other 673/// properties of function declarations form the old declaration to 674/// the new declaration, once we know that New is in fact a 675/// redeclaration of Old. 676/// 677/// \returns false 678bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 679 // Merge the attributes 680 MergeAttributes(New, Old); 681 682 // Merge the storage class. 683 New->setStorageClass(Old->getStorageClass()); 684 685 // FIXME: need to implement inline semantics 686 687 // Merge "pure" flag. 688 if (Old->isPure()) 689 New->setPure(); 690 691 // Merge the "deleted" flag. 692 if (Old->isDeleted()) 693 New->setDeleted(); 694 695 if (getLangOptions().CPlusPlus) 696 return MergeCXXFunctionDecl(New, Old); 697 698 return false; 699} 700 701/// Predicate for C "tentative" external object definitions (C99 6.9.2). 702static bool isTentativeDefinition(VarDecl *VD) { 703 if (VD->isFileVarDecl()) 704 return (!VD->getInit() && 705 (VD->getStorageClass() == VarDecl::None || 706 VD->getStorageClass() == VarDecl::Static)); 707 return false; 708} 709 710/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 711/// when dealing with C "tentative" external object definitions (C99 6.9.2). 712void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 713 bool VDIsTentative = isTentativeDefinition(VD); 714 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 715 716 // FIXME: I don't think this will actually see all of the 717 // redefinitions. Can't we check this property on-the-fly? 718 for (IdentifierResolver::iterator I = IdResolver.begin(VD->getIdentifier()), 719 E = IdResolver.end(); 720 I != E; ++I) { 721 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 722 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 723 724 // Handle the following case: 725 // int a[10]; 726 // int a[]; - the code below makes sure we set the correct type. 727 // int a[11]; - this is an error, size isn't 10. 728 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 729 OldDecl->getType()->isConstantArrayType()) 730 VD->setType(OldDecl->getType()); 731 732 // Check for "tentative" definitions. We can't accomplish this in 733 // MergeVarDecl since the initializer hasn't been attached. 734 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 735 continue; 736 737 // Handle __private_extern__ just like extern. 738 if (OldDecl->getStorageClass() != VarDecl::Extern && 739 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 740 VD->getStorageClass() != VarDecl::Extern && 741 VD->getStorageClass() != VarDecl::PrivateExtern) { 742 Diag(VD->getLocation(), diag::err_redefinition) << VD->getDeclName(); 743 Diag(OldDecl->getLocation(), diag::note_previous_definition); 744 // One redefinition error is enough. 745 break; 746 } 747 } 748 } 749} 750 751/// MergeVarDecl - We just parsed a variable 'New' which has the same name 752/// and scope as a previous declaration 'Old'. Figure out how to resolve this 753/// situation, merging decls or emitting diagnostics as appropriate. 754/// 755/// Tentative definition rules (C99 6.9.2p2) are checked by 756/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 757/// definitions here, since the initializer hasn't been attached. 758/// 759bool Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 760 // Verify the old decl was also a variable. 761 VarDecl *Old = dyn_cast<VarDecl>(OldD); 762 if (!Old) { 763 Diag(New->getLocation(), diag::err_redefinition_different_kind) 764 << New->getDeclName(); 765 Diag(OldD->getLocation(), diag::note_previous_definition); 766 return true; 767 } 768 769 MergeAttributes(New, Old); 770 771 // Merge the types 772 QualType MergedT = Context.mergeTypes(New->getType(), Old->getType()); 773 if (MergedT.isNull()) { 774 Diag(New->getLocation(), diag::err_redefinition_different_type) 775 << New->getDeclName(); 776 Diag(Old->getLocation(), diag::note_previous_definition); 777 return true; 778 } 779 New->setType(MergedT); 780 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 781 if (New->getStorageClass() == VarDecl::Static && 782 (Old->getStorageClass() == VarDecl::None || 783 Old->getStorageClass() == VarDecl::Extern)) { 784 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 785 Diag(Old->getLocation(), diag::note_previous_definition); 786 return true; 787 } 788 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 789 if (New->getStorageClass() != VarDecl::Static && 790 Old->getStorageClass() == VarDecl::Static) { 791 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 792 Diag(Old->getLocation(), diag::note_previous_definition); 793 return true; 794 } 795 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 796 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 797 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 798 Diag(Old->getLocation(), diag::note_previous_definition); 799 return true; 800 } 801 return false; 802} 803 804/// CheckParmsForFunctionDef - Check that the parameters of the given 805/// function are appropriate for the definition of a function. This 806/// takes care of any checks that cannot be performed on the 807/// declaration itself, e.g., that the types of each of the function 808/// parameters are complete. 809bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 810 bool HasInvalidParm = false; 811 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 812 ParmVarDecl *Param = FD->getParamDecl(p); 813 814 // C99 6.7.5.3p4: the parameters in a parameter type list in a 815 // function declarator that is part of a function definition of 816 // that function shall not have incomplete type. 817 if (!Param->isInvalidDecl() && 818 DiagnoseIncompleteType(Param->getLocation(), Param->getType(), 819 diag::err_typecheck_decl_incomplete_type)) { 820 Param->setInvalidDecl(); 821 HasInvalidParm = true; 822 } 823 824 // C99 6.9.1p5: If the declarator includes a parameter type list, the 825 // declaration of each parameter shall include an identifier. 826 if (Param->getIdentifier() == 0 && 827 !Param->isImplicit() && 828 !getLangOptions().CPlusPlus) 829 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 830 } 831 832 return HasInvalidParm; 833} 834 835/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 836/// no declarator (e.g. "struct foo;") is parsed. 837Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 838 TagDecl *Tag = 0; 839 if (DS.getTypeSpecType() == DeclSpec::TST_class || 840 DS.getTypeSpecType() == DeclSpec::TST_struct || 841 DS.getTypeSpecType() == DeclSpec::TST_union || 842 DS.getTypeSpecType() == DeclSpec::TST_enum) 843 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 844 845 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 846 if (!Record->getDeclName() && Record->isDefinition() && 847 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) 848 return BuildAnonymousStructOrUnion(S, DS, Record); 849 850 // Microsoft allows unnamed struct/union fields. Don't complain 851 // about them. 852 // FIXME: Should we support Microsoft's extensions in this area? 853 if (Record->getDeclName() && getLangOptions().Microsoft) 854 return Tag; 855 } 856 857 if (!DS.isMissingDeclaratorOk() && 858 DS.getTypeSpecType() != DeclSpec::TST_error) { 859 // Warn about typedefs of enums without names, since this is an 860 // extension in both Microsoft an GNU. 861 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 862 Tag && isa<EnumDecl>(Tag)) { 863 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 864 << DS.getSourceRange(); 865 return Tag; 866 } 867 868 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 869 << DS.getSourceRange(); 870 return 0; 871 } 872 873 return Tag; 874} 875 876/// InjectAnonymousStructOrUnionMembers - Inject the members of the 877/// anonymous struct or union AnonRecord into the owning context Owner 878/// and scope S. This routine will be invoked just after we realize 879/// that an unnamed union or struct is actually an anonymous union or 880/// struct, e.g., 881/// 882/// @code 883/// union { 884/// int i; 885/// float f; 886/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 887/// // f into the surrounding scope.x 888/// @endcode 889/// 890/// This routine is recursive, injecting the names of nested anonymous 891/// structs/unions into the owning context and scope as well. 892bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 893 RecordDecl *AnonRecord) { 894 bool Invalid = false; 895 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 896 FEnd = AnonRecord->field_end(); 897 F != FEnd; ++F) { 898 if ((*F)->getDeclName()) { 899 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 900 LookupOrdinaryName, true); 901 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 902 // C++ [class.union]p2: 903 // The names of the members of an anonymous union shall be 904 // distinct from the names of any other entity in the 905 // scope in which the anonymous union is declared. 906 unsigned diagKind 907 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 908 : diag::err_anonymous_struct_member_redecl; 909 Diag((*F)->getLocation(), diagKind) 910 << (*F)->getDeclName(); 911 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 912 Invalid = true; 913 } else { 914 // C++ [class.union]p2: 915 // For the purpose of name lookup, after the anonymous union 916 // definition, the members of the anonymous union are 917 // considered to have been defined in the scope in which the 918 // anonymous union is declared. 919 Owner->makeDeclVisibleInContext(*F); 920 S->AddDecl(*F); 921 IdResolver.AddDecl(*F); 922 } 923 } else if (const RecordType *InnerRecordType 924 = (*F)->getType()->getAsRecordType()) { 925 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 926 if (InnerRecord->isAnonymousStructOrUnion()) 927 Invalid = Invalid || 928 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 929 } 930 } 931 932 return Invalid; 933} 934 935/// ActOnAnonymousStructOrUnion - Handle the declaration of an 936/// anonymous structure or union. Anonymous unions are a C++ feature 937/// (C++ [class.union]) and a GNU C extension; anonymous structures 938/// are a GNU C and GNU C++ extension. 939Sema::DeclTy *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 940 RecordDecl *Record) { 941 DeclContext *Owner = Record->getDeclContext(); 942 943 // Diagnose whether this anonymous struct/union is an extension. 944 if (Record->isUnion() && !getLangOptions().CPlusPlus) 945 Diag(Record->getLocation(), diag::ext_anonymous_union); 946 else if (!Record->isUnion()) 947 Diag(Record->getLocation(), diag::ext_anonymous_struct); 948 949 // C and C++ require different kinds of checks for anonymous 950 // structs/unions. 951 bool Invalid = false; 952 if (getLangOptions().CPlusPlus) { 953 const char* PrevSpec = 0; 954 // C++ [class.union]p3: 955 // Anonymous unions declared in a named namespace or in the 956 // global namespace shall be declared static. 957 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 958 (isa<TranslationUnitDecl>(Owner) || 959 (isa<NamespaceDecl>(Owner) && 960 cast<NamespaceDecl>(Owner)->getDeclName()))) { 961 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 962 Invalid = true; 963 964 // Recover by adding 'static'. 965 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec); 966 } 967 // C++ [class.union]p3: 968 // A storage class is not allowed in a declaration of an 969 // anonymous union in a class scope. 970 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 971 isa<RecordDecl>(Owner)) { 972 Diag(DS.getStorageClassSpecLoc(), 973 diag::err_anonymous_union_with_storage_spec); 974 Invalid = true; 975 976 // Recover by removing the storage specifier. 977 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 978 PrevSpec); 979 } 980 981 // C++ [class.union]p2: 982 // The member-specification of an anonymous union shall only 983 // define non-static data members. [Note: nested types and 984 // functions cannot be declared within an anonymous union. ] 985 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 986 MemEnd = Record->decls_end(); 987 Mem != MemEnd; ++Mem) { 988 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 989 // C++ [class.union]p3: 990 // An anonymous union shall not have private or protected 991 // members (clause 11). 992 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 993 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 994 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 995 Invalid = true; 996 } 997 } else if ((*Mem)->isImplicit()) { 998 // Any implicit members are fine. 999 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1000 // This is a type that showed up in an 1001 // elaborated-type-specifier inside the anonymous struct or 1002 // union, but which actually declares a type outside of the 1003 // anonymous struct or union. It's okay. 1004 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1005 if (!MemRecord->isAnonymousStructOrUnion() && 1006 MemRecord->getDeclName()) { 1007 // This is a nested type declaration. 1008 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1009 << (int)Record->isUnion(); 1010 Invalid = true; 1011 } 1012 } else { 1013 // We have something that isn't a non-static data 1014 // member. Complain about it. 1015 unsigned DK = diag::err_anonymous_record_bad_member; 1016 if (isa<TypeDecl>(*Mem)) 1017 DK = diag::err_anonymous_record_with_type; 1018 else if (isa<FunctionDecl>(*Mem)) 1019 DK = diag::err_anonymous_record_with_function; 1020 else if (isa<VarDecl>(*Mem)) 1021 DK = diag::err_anonymous_record_with_static; 1022 Diag((*Mem)->getLocation(), DK) 1023 << (int)Record->isUnion(); 1024 Invalid = true; 1025 } 1026 } 1027 } else { 1028 // FIXME: Check GNU C semantics 1029 if (Record->isUnion() && !Owner->isRecord()) { 1030 Diag(Record->getLocation(), diag::err_anonymous_union_not_member) 1031 << (int)getLangOptions().CPlusPlus; 1032 Invalid = true; 1033 } 1034 } 1035 1036 if (!Record->isUnion() && !Owner->isRecord()) { 1037 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1038 << (int)getLangOptions().CPlusPlus; 1039 Invalid = true; 1040 } 1041 1042 // Create a declaration for this anonymous struct/union. 1043 NamedDecl *Anon = 0; 1044 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1045 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1046 /*IdentifierInfo=*/0, 1047 Context.getTypeDeclType(Record), 1048 /*BitWidth=*/0, /*Mutable=*/false); 1049 Anon->setAccess(AS_public); 1050 if (getLangOptions().CPlusPlus) 1051 FieldCollector->Add(cast<FieldDecl>(Anon)); 1052 } else { 1053 VarDecl::StorageClass SC; 1054 switch (DS.getStorageClassSpec()) { 1055 default: assert(0 && "Unknown storage class!"); 1056 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1057 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1058 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1059 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1060 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1061 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1062 case DeclSpec::SCS_mutable: 1063 // mutable can only appear on non-static class members, so it's always 1064 // an error here 1065 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1066 Invalid = true; 1067 SC = VarDecl::None; 1068 break; 1069 } 1070 1071 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1072 /*IdentifierInfo=*/0, 1073 Context.getTypeDeclType(Record), 1074 SC, DS.getSourceRange().getBegin()); 1075 } 1076 Anon->setImplicit(); 1077 1078 // Add the anonymous struct/union object to the current 1079 // context. We'll be referencing this object when we refer to one of 1080 // its members. 1081 Owner->addDecl(Anon); 1082 1083 // Inject the members of the anonymous struct/union into the owning 1084 // context and into the identifier resolver chain for name lookup 1085 // purposes. 1086 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1087 Invalid = true; 1088 1089 // Mark this as an anonymous struct/union type. Note that we do not 1090 // do this until after we have already checked and injected the 1091 // members of this anonymous struct/union type, because otherwise 1092 // the members could be injected twice: once by DeclContext when it 1093 // builds its lookup table, and once by 1094 // InjectAnonymousStructOrUnionMembers. 1095 Record->setAnonymousStructOrUnion(true); 1096 1097 if (Invalid) 1098 Anon->setInvalidDecl(); 1099 1100 return Anon; 1101} 1102 1103bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType, 1104 bool DirectInit) { 1105 // Get the type before calling CheckSingleAssignmentConstraints(), since 1106 // it can promote the expression. 1107 QualType InitType = Init->getType(); 1108 1109 if (getLangOptions().CPlusPlus) { 1110 // FIXME: I dislike this error message. A lot. 1111 if (PerformImplicitConversion(Init, DeclType, "initializing", DirectInit)) 1112 return Diag(Init->getSourceRange().getBegin(), 1113 diag::err_typecheck_convert_incompatible) 1114 << DeclType << Init->getType() << "initializing" 1115 << Init->getSourceRange(); 1116 1117 return false; 1118 } 1119 1120 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 1121 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 1122 InitType, Init, "initializing"); 1123} 1124 1125bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 1126 const ArrayType *AT = Context.getAsArrayType(DeclT); 1127 1128 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 1129 // C99 6.7.8p14. We have an array of character type with unknown size 1130 // being initialized to a string literal. 1131 llvm::APSInt ConstVal(32); 1132 ConstVal = strLiteral->getByteLength() + 1; 1133 // Return a new array type (C99 6.7.8p22). 1134 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 1135 ArrayType::Normal, 0); 1136 } else { 1137 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 1138 // C99 6.7.8p14. We have an array of character type with known size. 1139 // FIXME: Avoid truncation for 64-bit length strings. 1140 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 1141 Diag(strLiteral->getSourceRange().getBegin(), 1142 diag::warn_initializer_string_for_char_array_too_long) 1143 << strLiteral->getSourceRange(); 1144 } 1145 // Set type from "char *" to "constant array of char". 1146 strLiteral->setType(DeclT); 1147 // For now, we always return false (meaning success). 1148 return false; 1149} 1150 1151StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 1152 const ArrayType *AT = Context.getAsArrayType(DeclType); 1153 if (AT && AT->getElementType()->isCharType()) { 1154 return dyn_cast<StringLiteral>(Init->IgnoreParens()); 1155 } 1156 return 0; 1157} 1158 1159bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 1160 SourceLocation InitLoc, 1161 DeclarationName InitEntity, 1162 bool DirectInit) { 1163 if (DeclType->isDependentType() || Init->isTypeDependent()) 1164 return false; 1165 1166 // C++ [dcl.init.ref]p1: 1167 // A variable declared to be a T&, that is "reference to type T" 1168 // (8.3.2), shall be initialized by an object, or function, of 1169 // type T or by an object that can be converted into a T. 1170 if (DeclType->isReferenceType()) 1171 return CheckReferenceInit(Init, DeclType, 0, false, DirectInit); 1172 1173 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 1174 // of unknown size ("[]") or an object type that is not a variable array type. 1175 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 1176 return Diag(InitLoc, diag::err_variable_object_no_init) 1177 << VAT->getSizeExpr()->getSourceRange(); 1178 1179 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 1180 if (!InitList) { 1181 // FIXME: Handle wide strings 1182 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 1183 return CheckStringLiteralInit(strLiteral, DeclType); 1184 1185 // C++ [dcl.init]p14: 1186 // -- If the destination type is a (possibly cv-qualified) class 1187 // type: 1188 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 1189 QualType DeclTypeC = Context.getCanonicalType(DeclType); 1190 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 1191 1192 // -- If the initialization is direct-initialization, or if it is 1193 // copy-initialization where the cv-unqualified version of the 1194 // source type is the same class as, or a derived class of, the 1195 // class of the destination, constructors are considered. 1196 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 1197 IsDerivedFrom(InitTypeC, DeclTypeC)) { 1198 CXXConstructorDecl *Constructor 1199 = PerformInitializationByConstructor(DeclType, &Init, 1, 1200 InitLoc, Init->getSourceRange(), 1201 InitEntity, 1202 DirectInit? IK_Direct : IK_Copy); 1203 return Constructor == 0; 1204 } 1205 1206 // -- Otherwise (i.e., for the remaining copy-initialization 1207 // cases), user-defined conversion sequences that can 1208 // convert from the source type to the destination type or 1209 // (when a conversion function is used) to a derived class 1210 // thereof are enumerated as described in 13.3.1.4, and the 1211 // best one is chosen through overload resolution 1212 // (13.3). If the conversion cannot be done or is 1213 // ambiguous, the initialization is ill-formed. The 1214 // function selected is called with the initializer 1215 // expression as its argument; if the function is a 1216 // constructor, the call initializes a temporary of the 1217 // destination type. 1218 // FIXME: We're pretending to do copy elision here; return to 1219 // this when we have ASTs for such things. 1220 if (!PerformImplicitConversion(Init, DeclType, "initializing")) 1221 return false; 1222 1223 if (InitEntity) 1224 return Diag(InitLoc, diag::err_cannot_initialize_decl) 1225 << InitEntity << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 1226 << Init->getType() << Init->getSourceRange(); 1227 else 1228 return Diag(InitLoc, diag::err_cannot_initialize_decl_noname) 1229 << DeclType << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 1230 << Init->getType() << Init->getSourceRange(); 1231 } 1232 1233 // C99 6.7.8p16. 1234 if (DeclType->isArrayType()) 1235 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 1236 << Init->getSourceRange(); 1237 1238 return CheckSingleInitializer(Init, DeclType, DirectInit); 1239 } 1240 1241 bool hadError = CheckInitList(InitList, DeclType); 1242 Init = InitList; 1243 return hadError; 1244} 1245 1246/// GetNameForDeclarator - Determine the full declaration name for the 1247/// given Declarator. 1248DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1249 switch (D.getKind()) { 1250 case Declarator::DK_Abstract: 1251 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1252 return DeclarationName(); 1253 1254 case Declarator::DK_Normal: 1255 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1256 return DeclarationName(D.getIdentifier()); 1257 1258 case Declarator::DK_Constructor: { 1259 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1260 Ty = Context.getCanonicalType(Ty); 1261 return Context.DeclarationNames.getCXXConstructorName(Ty); 1262 } 1263 1264 case Declarator::DK_Destructor: { 1265 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1266 Ty = Context.getCanonicalType(Ty); 1267 return Context.DeclarationNames.getCXXDestructorName(Ty); 1268 } 1269 1270 case Declarator::DK_Conversion: { 1271 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1272 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1273 Ty = Context.getCanonicalType(Ty); 1274 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1275 } 1276 1277 case Declarator::DK_Operator: 1278 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1279 return Context.DeclarationNames.getCXXOperatorName( 1280 D.getOverloadedOperator()); 1281 } 1282 1283 assert(false && "Unknown name kind"); 1284 return DeclarationName(); 1285} 1286 1287/// isNearlyMatchingFunction - Determine whether the C++ functions 1288/// Declaration and Definition are "nearly" matching. This heuristic 1289/// is used to improve diagnostics in the case where an out-of-line 1290/// function definition doesn't match any declaration within 1291/// the class or namespace. 1292static bool isNearlyMatchingFunction(ASTContext &Context, 1293 FunctionDecl *Declaration, 1294 FunctionDecl *Definition) { 1295 if (Declaration->param_size() != Definition->param_size()) 1296 return false; 1297 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1298 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1299 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1300 1301 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1302 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1303 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1304 return false; 1305 } 1306 1307 return true; 1308} 1309 1310Sema::DeclTy * 1311Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl, 1312 bool IsFunctionDefinition) { 1313 NamedDecl *LastDeclarator = dyn_cast_or_null<NamedDecl>((Decl *)lastDecl); 1314 DeclarationName Name = GetNameForDeclarator(D); 1315 1316 // All of these full declarators require an identifier. If it doesn't have 1317 // one, the ParsedFreeStandingDeclSpec action should be used. 1318 if (!Name) { 1319 if (!D.getInvalidType()) // Reject this if we think it is valid. 1320 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1321 diag::err_declarator_need_ident) 1322 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1323 return 0; 1324 } 1325 1326 // The scope passed in may not be a decl scope. Zip up the scope tree until 1327 // we find one that is. 1328 while ((S->getFlags() & Scope::DeclScope) == 0 || 1329 (S->getFlags() & Scope::TemplateParamScope) != 0) 1330 S = S->getParent(); 1331 1332 DeclContext *DC; 1333 NamedDecl *PrevDecl; 1334 NamedDecl *New; 1335 bool InvalidDecl = false; 1336 1337 // See if this is a redefinition of a variable in the same scope. 1338 if (!D.getCXXScopeSpec().isSet() && !D.getCXXScopeSpec().isInvalid()) { 1339 DC = CurContext; 1340 PrevDecl = LookupName(S, Name, LookupOrdinaryName, true, 1341 D.getDeclSpec().getStorageClassSpec() != 1342 DeclSpec::SCS_static, 1343 D.getIdentifierLoc()); 1344 } else { // Something like "int foo::x;" 1345 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 1346 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1347 1348 // C++ 7.3.1.2p2: 1349 // Members (including explicit specializations of templates) of a named 1350 // namespace can also be defined outside that namespace by explicit 1351 // qualification of the name being defined, provided that the entity being 1352 // defined was already declared in the namespace and the definition appears 1353 // after the point of declaration in a namespace that encloses the 1354 // declarations namespace. 1355 // 1356 // Note that we only check the context at this point. We don't yet 1357 // have enough information to make sure that PrevDecl is actually 1358 // the declaration we want to match. For example, given: 1359 // 1360 // class X { 1361 // void f(); 1362 // void f(float); 1363 // }; 1364 // 1365 // void X::f(int) { } // ill-formed 1366 // 1367 // In this case, PrevDecl will point to the overload set 1368 // containing the two f's declared in X, but neither of them 1369 // matches. 1370 1371 // First check whether we named the global scope. 1372 if (isa<TranslationUnitDecl>(DC)) { 1373 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1374 << Name << D.getCXXScopeSpec().getRange(); 1375 } else if (!CurContext->Encloses(DC)) { 1376 // The qualifying scope doesn't enclose the original declaration. 1377 // Emit diagnostic based on current scope. 1378 SourceLocation L = D.getIdentifierLoc(); 1379 SourceRange R = D.getCXXScopeSpec().getRange(); 1380 if (isa<FunctionDecl>(CurContext)) 1381 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1382 else 1383 Diag(L, diag::err_invalid_declarator_scope) 1384 << Name << cast<NamedDecl>(DC) << R; 1385 InvalidDecl = true; 1386 } 1387 } 1388 1389 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1390 // Maybe we will complain about the shadowed template parameter. 1391 InvalidDecl = InvalidDecl 1392 || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 1393 // Just pretend that we didn't see the previous declaration. 1394 PrevDecl = 0; 1395 } 1396 1397 // In C++, the previous declaration we find might be a tag type 1398 // (class or enum). In this case, the new declaration will hide the 1399 // tag type. Note that this does does not apply if we're declaring a 1400 // typedef (C++ [dcl.typedef]p4). 1401 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1402 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1403 PrevDecl = 0; 1404 1405 QualType R = GetTypeForDeclarator(D, S); 1406 if (R.isNull()) { 1407 InvalidDecl = true; 1408 R = Context.IntTy; 1409 } 1410 1411 bool Redeclaration = false; 1412 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1413 New = ActOnTypedefDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1414 InvalidDecl, Redeclaration); 1415 } else if (R.getTypePtr()->isFunctionType()) { 1416 New = ActOnFunctionDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1417 IsFunctionDefinition, InvalidDecl, 1418 Redeclaration); 1419 } else { 1420 New = ActOnVariableDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1421 InvalidDecl, Redeclaration); 1422 } 1423 1424 if (New == 0) 1425 return 0; 1426 1427 // Set the lexical context. If the declarator has a C++ scope specifier, the 1428 // lexical context will be different from the semantic context. 1429 New->setLexicalDeclContext(CurContext); 1430 1431 // If this has an identifier and is not an invalid redeclaration, 1432 // add it to the scope stack. 1433 if (Name && !(Redeclaration && InvalidDecl)) 1434 PushOnScopeChains(New, S); 1435 // If any semantic error occurred, mark the decl as invalid. 1436 if (D.getInvalidType() || InvalidDecl) 1437 New->setInvalidDecl(); 1438 1439 return New; 1440} 1441 1442/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1443/// types into constant array types in certain situations which would otherwise 1444/// be errors (for GCC compatibility). 1445static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1446 ASTContext &Context, 1447 bool &SizeIsNegative) { 1448 // This method tries to turn a variable array into a constant 1449 // array even when the size isn't an ICE. This is necessary 1450 // for compatibility with code that depends on gcc's buggy 1451 // constant expression folding, like struct {char x[(int)(char*)2];} 1452 SizeIsNegative = false; 1453 1454 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1455 QualType Pointee = PTy->getPointeeType(); 1456 QualType FixedType = 1457 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1458 if (FixedType.isNull()) return FixedType; 1459 FixedType = Context.getPointerType(FixedType); 1460 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1461 return FixedType; 1462 } 1463 1464 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1465 if (!VLATy) return QualType(); 1466 1467 Expr::EvalResult EvalResult; 1468 if (!VLATy->getSizeExpr() || 1469 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context)) 1470 return QualType(); 1471 1472 assert(EvalResult.Val.isInt() && "Size expressions must be integers!"); 1473 llvm::APSInt &Res = EvalResult.Val.getInt(); 1474 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1475 return Context.getConstantArrayType(VLATy->getElementType(), 1476 Res, ArrayType::Normal, 0); 1477 1478 SizeIsNegative = true; 1479 return QualType(); 1480} 1481 1482NamedDecl* 1483Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1484 QualType R, Decl* LastDeclarator, 1485 Decl* PrevDecl, bool& InvalidDecl, 1486 bool &Redeclaration) { 1487 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1488 if (D.getCXXScopeSpec().isSet()) { 1489 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1490 << D.getCXXScopeSpec().getRange(); 1491 InvalidDecl = true; 1492 // Pretend we didn't see the scope specifier. 1493 DC = 0; 1494 } 1495 1496 // Check that there are no default arguments (C++ only). 1497 if (getLangOptions().CPlusPlus) 1498 CheckExtraCXXDefaultArguments(D); 1499 1500 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 1501 if (!NewTD) return 0; 1502 1503 // Handle attributes prior to checking for duplicates in MergeVarDecl 1504 ProcessDeclAttributes(NewTD, D); 1505 // Merge the decl with the existing one if appropriate. If the decl is 1506 // in an outer scope, it isn't the same thing. 1507 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1508 Redeclaration = true; 1509 if (MergeTypeDefDecl(NewTD, PrevDecl)) 1510 InvalidDecl = true; 1511 } 1512 1513 if (S->getFnParent() == 0) { 1514 QualType T = NewTD->getUnderlyingType(); 1515 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1516 // then it shall have block scope. 1517 if (T->isVariablyModifiedType()) { 1518 bool SizeIsNegative; 1519 QualType FixedTy = 1520 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1521 if (!FixedTy.isNull()) { 1522 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1523 NewTD->setUnderlyingType(FixedTy); 1524 } else { 1525 if (SizeIsNegative) 1526 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1527 else if (T->isVariableArrayType()) 1528 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1529 else 1530 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1531 InvalidDecl = true; 1532 } 1533 } 1534 } 1535 return NewTD; 1536} 1537 1538NamedDecl* 1539Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1540 QualType R, Decl* LastDeclarator, 1541 Decl* PrevDecl, bool& InvalidDecl, 1542 bool &Redeclaration) { 1543 DeclarationName Name = GetNameForDeclarator(D); 1544 1545 // Check that there are no default arguments (C++ only). 1546 if (getLangOptions().CPlusPlus) 1547 CheckExtraCXXDefaultArguments(D); 1548 1549 if (R.getTypePtr()->isObjCInterfaceType()) { 1550 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object); 1551 InvalidDecl = true; 1552 } 1553 1554 VarDecl *NewVD; 1555 VarDecl::StorageClass SC; 1556 switch (D.getDeclSpec().getStorageClassSpec()) { 1557 default: assert(0 && "Unknown storage class!"); 1558 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1559 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1560 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1561 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1562 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1563 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1564 case DeclSpec::SCS_mutable: 1565 // mutable can only appear on non-static class members, so it's always 1566 // an error here 1567 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1568 InvalidDecl = true; 1569 SC = VarDecl::None; 1570 break; 1571 } 1572 1573 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1574 if (!II) { 1575 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1576 << Name.getAsString(); 1577 return 0; 1578 } 1579 1580 if (DC->isRecord()) { 1581 // This is a static data member for a C++ class. 1582 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1583 D.getIdentifierLoc(), II, 1584 R); 1585 } else { 1586 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1587 if (S->getFnParent() == 0) { 1588 // C99 6.9p2: The storage-class specifiers auto and register shall not 1589 // appear in the declaration specifiers in an external declaration. 1590 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1591 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 1592 InvalidDecl = true; 1593 } 1594 } 1595 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1596 II, R, SC, 1597 // FIXME: Move to DeclGroup... 1598 D.getDeclSpec().getSourceRange().getBegin()); 1599 NewVD->setThreadSpecified(ThreadSpecified); 1600 } 1601 NewVD->setNextDeclarator(LastDeclarator); 1602 1603 // Handle attributes prior to checking for duplicates in MergeVarDecl 1604 ProcessDeclAttributes(NewVD, D); 1605 1606 // Handle GNU asm-label extension (encoded as an attribute). 1607 if (Expr *E = (Expr*) D.getAsmLabel()) { 1608 // The parser guarantees this is a string. 1609 StringLiteral *SE = cast<StringLiteral>(E); 1610 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1611 SE->getByteLength()))); 1612 } 1613 1614 // Emit an error if an address space was applied to decl with local storage. 1615 // This includes arrays of objects with address space qualifiers, but not 1616 // automatic variables that point to other address spaces. 1617 // ISO/IEC TR 18037 S5.1.2 1618 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1619 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1620 InvalidDecl = true; 1621 } 1622 1623 if (NewVD->hasLocalStorage() && NewVD->getType().isObjCGCWeak()) { 1624 Diag(D.getIdentifierLoc(), diag::warn_attribute_weak_on_local); 1625 } 1626 1627 // Merge the decl with the existing one if appropriate. If the decl is 1628 // in an outer scope, it isn't the same thing. 1629 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1630 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 1631 // The user tried to define a non-static data member 1632 // out-of-line (C++ [dcl.meaning]p1). 1633 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 1634 << D.getCXXScopeSpec().getRange(); 1635 NewVD->Destroy(Context); 1636 return 0; 1637 } 1638 1639 Redeclaration = true; 1640 if (MergeVarDecl(NewVD, PrevDecl)) 1641 InvalidDecl = true; 1642 1643 if (D.getCXXScopeSpec().isSet()) { 1644 // No previous declaration in the qualifying scope. 1645 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 1646 << Name << D.getCXXScopeSpec().getRange(); 1647 InvalidDecl = true; 1648 } 1649 } 1650 return NewVD; 1651} 1652 1653NamedDecl* 1654Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1655 QualType R, Decl *LastDeclarator, 1656 NamedDecl* PrevDecl, bool IsFunctionDefinition, 1657 bool& InvalidDecl, bool &Redeclaration) { 1658 assert(R.getTypePtr()->isFunctionType()); 1659 1660 DeclarationName Name = GetNameForDeclarator(D); 1661 FunctionDecl::StorageClass SC = FunctionDecl::None; 1662 switch (D.getDeclSpec().getStorageClassSpec()) { 1663 default: assert(0 && "Unknown storage class!"); 1664 case DeclSpec::SCS_auto: 1665 case DeclSpec::SCS_register: 1666 case DeclSpec::SCS_mutable: 1667 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1668 diag::err_typecheck_sclass_func); 1669 InvalidDecl = true; 1670 break; 1671 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 1672 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 1673 case DeclSpec::SCS_static: { 1674 if (DC->getLookupContext()->isFunctionOrMethod()) { 1675 // C99 6.7.1p5: 1676 // The declaration of an identifier for a function that has 1677 // block scope shall have no explicit storage-class specifier 1678 // other than extern 1679 // See also (C++ [dcl.stc]p4). 1680 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1681 diag::err_static_block_func); 1682 SC = FunctionDecl::None; 1683 } else 1684 SC = FunctionDecl::Static; 1685 break; 1686 } 1687 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 1688 } 1689 1690 bool isInline = D.getDeclSpec().isInlineSpecified(); 1691 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 1692 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 1693 1694 FunctionDecl *NewFD; 1695 if (D.getKind() == Declarator::DK_Constructor) { 1696 // This is a C++ constructor declaration. 1697 assert(DC->isRecord() && 1698 "Constructors can only be declared in a member context"); 1699 1700 InvalidDecl = InvalidDecl || CheckConstructorDeclarator(D, R, SC); 1701 1702 // Create the new declaration 1703 NewFD = CXXConstructorDecl::Create(Context, 1704 cast<CXXRecordDecl>(DC), 1705 D.getIdentifierLoc(), Name, R, 1706 isExplicit, isInline, 1707 /*isImplicitlyDeclared=*/false); 1708 1709 if (InvalidDecl) 1710 NewFD->setInvalidDecl(); 1711 } else if (D.getKind() == Declarator::DK_Destructor) { 1712 // This is a C++ destructor declaration. 1713 if (DC->isRecord()) { 1714 InvalidDecl = InvalidDecl || CheckDestructorDeclarator(D, R, SC); 1715 1716 NewFD = CXXDestructorDecl::Create(Context, 1717 cast<CXXRecordDecl>(DC), 1718 D.getIdentifierLoc(), Name, R, 1719 isInline, 1720 /*isImplicitlyDeclared=*/false); 1721 1722 if (InvalidDecl) 1723 NewFD->setInvalidDecl(); 1724 } else { 1725 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 1726 1727 // Create a FunctionDecl to satisfy the function definition parsing 1728 // code path. 1729 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 1730 Name, R, SC, isInline, 1731 // FIXME: Move to DeclGroup... 1732 D.getDeclSpec().getSourceRange().getBegin()); 1733 InvalidDecl = true; 1734 NewFD->setInvalidDecl(); 1735 } 1736 } else if (D.getKind() == Declarator::DK_Conversion) { 1737 if (!DC->isRecord()) { 1738 Diag(D.getIdentifierLoc(), 1739 diag::err_conv_function_not_member); 1740 return 0; 1741 } else { 1742 InvalidDecl = InvalidDecl || CheckConversionDeclarator(D, R, SC); 1743 1744 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 1745 D.getIdentifierLoc(), Name, R, 1746 isInline, isExplicit); 1747 1748 if (InvalidDecl) 1749 NewFD->setInvalidDecl(); 1750 } 1751 } else if (DC->isRecord()) { 1752 // This is a C++ method declaration. 1753 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 1754 D.getIdentifierLoc(), Name, R, 1755 (SC == FunctionDecl::Static), isInline); 1756 } else { 1757 NewFD = FunctionDecl::Create(Context, DC, 1758 D.getIdentifierLoc(), 1759 Name, R, SC, isInline, 1760 // FIXME: Move to DeclGroup... 1761 D.getDeclSpec().getSourceRange().getBegin()); 1762 } 1763 NewFD->setNextDeclarator(LastDeclarator); 1764 1765 // Set the lexical context. If the declarator has a C++ 1766 // scope specifier, the lexical context will be different 1767 // from the semantic context. 1768 NewFD->setLexicalDeclContext(CurContext); 1769 1770 // Handle GNU asm-label extension (encoded as an attribute). 1771 if (Expr *E = (Expr*) D.getAsmLabel()) { 1772 // The parser guarantees this is a string. 1773 StringLiteral *SE = cast<StringLiteral>(E); 1774 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1775 SE->getByteLength()))); 1776 } 1777 1778 // Copy the parameter declarations from the declarator D to 1779 // the function declaration NewFD, if they are available. 1780 if (D.getNumTypeObjects() > 0) { 1781 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1782 1783 // Create Decl objects for each parameter, adding them to the 1784 // FunctionDecl. 1785 llvm::SmallVector<ParmVarDecl*, 16> Params; 1786 1787 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1788 // function that takes no arguments, not a function that takes a 1789 // single void argument. 1790 // We let through "const void" here because Sema::GetTypeForDeclarator 1791 // already checks for that case. 1792 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1793 FTI.ArgInfo[0].Param && 1794 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1795 // empty arg list, don't push any params. 1796 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1797 1798 // In C++, the empty parameter-type-list must be spelled "void"; a 1799 // typedef of void is not permitted. 1800 if (getLangOptions().CPlusPlus && 1801 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1802 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1803 } 1804 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1805 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1806 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1807 } 1808 1809 NewFD->setParams(Context, &Params[0], Params.size()); 1810 } else if (R->getAsTypedefType()) { 1811 // When we're declaring a function with a typedef, as in the 1812 // following example, we'll need to synthesize (unnamed) 1813 // parameters for use in the declaration. 1814 // 1815 // @code 1816 // typedef void fn(int); 1817 // fn f; 1818 // @endcode 1819 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1820 if (!FT) { 1821 // This is a typedef of a function with no prototype, so we 1822 // don't need to do anything. 1823 } else if ((FT->getNumArgs() == 0) || 1824 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1825 FT->getArgType(0)->isVoidType())) { 1826 // This is a zero-argument function. We don't need to do anything. 1827 } else { 1828 // Synthesize a parameter for each argument type. 1829 llvm::SmallVector<ParmVarDecl*, 16> Params; 1830 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1831 ArgType != FT->arg_type_end(); ++ArgType) { 1832 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 1833 SourceLocation(), 0, 1834 *ArgType, VarDecl::None, 1835 0); 1836 Param->setImplicit(); 1837 Params.push_back(Param); 1838 } 1839 1840 NewFD->setParams(Context, &Params[0], Params.size()); 1841 } 1842 } 1843 1844 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1845 InvalidDecl = InvalidDecl || CheckConstructor(Constructor); 1846 else if (isa<CXXDestructorDecl>(NewFD)) { 1847 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 1848 Record->setUserDeclaredDestructor(true); 1849 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 1850 // user-defined destructor. 1851 Record->setPOD(false); 1852 } else if (CXXConversionDecl *Conversion = 1853 dyn_cast<CXXConversionDecl>(NewFD)) 1854 ActOnConversionDeclarator(Conversion); 1855 1856 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1857 if (NewFD->isOverloadedOperator() && 1858 CheckOverloadedOperatorDeclaration(NewFD)) 1859 NewFD->setInvalidDecl(); 1860 1861 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S)) { 1862 // Name lookup has found a previous declaration that is not in the 1863 // same scope as the new declaration. However, these two 1864 // declarations might still declare the same thing (C99 6.2.2p3-4, 1865 // C++ [basic.link]p6). 1866 1867 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 1868 // case we need to check each of the overloaded functions. 1869 1870 if (getLangOptions().CPlusPlus) { 1871 // C++ [basic.link]p6: 1872 // If there is a visible declaration of an entity with linkage 1873 // having the same name and type, ignoring entities declared 1874 // outside the innermost enclosing namespace scope, the block 1875 // scope declaration declares that same entity and receives the 1876 // linkage of the previous declaration. 1877 DeclContext *OuterContext = DC->getLookupContext(); 1878 if (!OuterContext->isFunctionOrMethod()) 1879 // This rule only applies to block-scope declarations. 1880 PrevDecl = 0; 1881 else { 1882 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 1883 if (PrevOuterContext->isRecord()) 1884 // We found a member function: ignore it. 1885 PrevDecl = 0; 1886 else { 1887 // Find the innermost enclosing namespace for the new and 1888 // previous declarations. 1889 while (!OuterContext->isFileContext()) 1890 OuterContext = OuterContext->getParent(); 1891 while (!PrevOuterContext->isFileContext()) 1892 PrevOuterContext = PrevOuterContext->getParent(); 1893 1894 // The previous declaration is in a different namespace, so it 1895 // isn't the same function. 1896 if (OuterContext->getPrimaryContext() != 1897 PrevOuterContext->getPrimaryContext()) 1898 PrevDecl = 0; 1899 } 1900 } 1901 } 1902 1903 // If the declaration we've found has no linkage, ignore it. 1904 if (VarDecl *VD = dyn_cast_or_null<VarDecl>(PrevDecl)) { 1905 if (!VD->hasGlobalStorage()) 1906 PrevDecl = 0; 1907 } else if (PrevDecl && !isa<FunctionDecl>(PrevDecl)) 1908 PrevDecl = 0; 1909 } 1910 1911 // Merge or overload the declaration with an existing declaration of 1912 // the same name, if appropriate. 1913 bool OverloadableAttrRequired = false; 1914 if (PrevDecl) { 1915 // Determine whether NewFD is an overload of PrevDecl or 1916 // a declaration that requires merging. If it's an overload, 1917 // there's no more work to do here; we'll just add the new 1918 // function to the scope. 1919 OverloadedFunctionDecl::function_iterator MatchedDecl; 1920 1921 if (!getLangOptions().CPlusPlus && 1922 AllowOverloadingOfFunction(PrevDecl, Context)) { 1923 OverloadableAttrRequired = true; 1924 1925 // Functions marked "overloadable" must have a prototype (that 1926 // we can't get through declaration merging). 1927 if (!R->getAsFunctionTypeProto()) { 1928 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 1929 << NewFD; 1930 InvalidDecl = true; 1931 Redeclaration = true; 1932 1933 // Turn this into a variadic function with no parameters. 1934 R = Context.getFunctionType(R->getAsFunctionType()->getResultType(), 1935 0, 0, true, 0); 1936 NewFD->setType(R); 1937 } 1938 } 1939 1940 if (PrevDecl && 1941 (!AllowOverloadingOfFunction(PrevDecl, Context) || 1942 !IsOverload(NewFD, PrevDecl, MatchedDecl))) { 1943 Redeclaration = true; 1944 Decl *OldDecl = PrevDecl; 1945 1946 // If PrevDecl was an overloaded function, extract the 1947 // FunctionDecl that matched. 1948 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1949 OldDecl = *MatchedDecl; 1950 1951 // NewFD and PrevDecl represent declarations that need to be 1952 // merged. 1953 if (MergeFunctionDecl(NewFD, OldDecl)) 1954 InvalidDecl = true; 1955 1956 if (!InvalidDecl) { 1957 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1958 1959 // An out-of-line member function declaration must also be a 1960 // definition (C++ [dcl.meaning]p1). 1961 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && 1962 !InvalidDecl) { 1963 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 1964 << D.getCXXScopeSpec().getRange(); 1965 NewFD->setInvalidDecl(); 1966 } 1967 } 1968 } 1969 } 1970 1971 if (D.getCXXScopeSpec().isSet() && 1972 (!PrevDecl || !Redeclaration)) { 1973 // The user tried to provide an out-of-line definition for a 1974 // function that is a member of a class or namespace, but there 1975 // was no such member function declared (C++ [class.mfct]p2, 1976 // C++ [namespace.memdef]p2). For example: 1977 // 1978 // class X { 1979 // void f() const; 1980 // }; 1981 // 1982 // void X::f() { } // ill-formed 1983 // 1984 // Complain about this problem, and attempt to suggest close 1985 // matches (e.g., those that differ only in cv-qualifiers and 1986 // whether the parameter types are references). 1987 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 1988 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 1989 InvalidDecl = true; 1990 1991 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 1992 true); 1993 assert(!Prev.isAmbiguous() && 1994 "Cannot have an ambiguity in previous-declaration lookup"); 1995 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 1996 Func != FuncEnd; ++Func) { 1997 if (isa<FunctionDecl>(*Func) && 1998 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 1999 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 2000 } 2001 2002 PrevDecl = 0; 2003 } 2004 2005 // Handle attributes. We need to have merged decls when handling attributes 2006 // (for example to check for conflicts, etc). 2007 ProcessDeclAttributes(NewFD, D); 2008 AddKnownFunctionAttributes(NewFD); 2009 2010 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 2011 // If a function name is overloadable in C, then every function 2012 // with that name must be marked "overloadable". 2013 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 2014 << Redeclaration << NewFD; 2015 if (PrevDecl) 2016 Diag(PrevDecl->getLocation(), 2017 diag::note_attribute_overloadable_prev_overload); 2018 NewFD->addAttr(new OverloadableAttr); 2019 } 2020 2021 if (getLangOptions().CPlusPlus) { 2022 // In C++, check default arguments now that we have merged decls. Unless 2023 // the lexical context is the class, because in this case this is done 2024 // during delayed parsing anyway. 2025 if (!CurContext->isRecord()) 2026 CheckCXXDefaultArguments(NewFD); 2027 2028 // An out-of-line member function declaration must also be a 2029 // definition (C++ [dcl.meaning]p1). 2030 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && !InvalidDecl) { 2031 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2032 << D.getCXXScopeSpec().getRange(); 2033 InvalidDecl = true; 2034 } 2035 } 2036 2037 if (!getLangOptions().CPlusPlus && CurContext->isFunctionOrMethod()) { 2038 // If this is a function declaration in local scope, inject its 2039 // name into the top-level scope so that it will be visible to 2040 // later uses and declarations of the same function, since the 2041 // function is external. 2042 // FIXME: We don't do this in C++ because, although we would like 2043 // to get the extra checking that this operation implies, 2044 // the declaration itself is not visible according to C++'s rules. 2045 IdentifierResolver::iterator I = IdResolver.begin(Name), 2046 IEnd = IdResolver.end(); 2047 NamedDecl *PrevIdDecl = 0; 2048 while (I != IEnd && !isa<TranslationUnitDecl>((*I)->getDeclContext())) { 2049 PrevIdDecl = *I; 2050 ++I; 2051 } 2052 2053 if (I == IEnd) { 2054 // No name with this identifier has been declared at translation 2055 // unit scope. Add this name into the appropriate scope. 2056 if (PrevIdDecl) 2057 IdResolver.AddShadowedDecl(NewFD, PrevIdDecl); 2058 else 2059 IdResolver.AddDecl(NewFD); 2060 TUScope->AddDecl(NewFD); 2061 return NewFD; 2062 } 2063 2064 if (isa<TagDecl>(*I)) { 2065 // The first thing we found was a tag declaration, so insert 2066 // this function so that it will be found before the tag 2067 // declaration. 2068 if (PrevIdDecl) 2069 IdResolver.AddShadowedDecl(NewFD, PrevIdDecl); 2070 else 2071 IdResolver.AddDecl(NewFD); 2072 TUScope->AddDecl(NewFD); 2073 } else if (isa<FunctionDecl>(*I) && NewFD->declarationReplaces(*I)) { 2074 // We found a previous declaration of the same function. Replace 2075 // that declaration with this one. 2076 TUScope->RemoveDecl(*I); 2077 TUScope->AddDecl(NewFD); 2078 IdResolver.RemoveDecl(*I); 2079 if (PrevIdDecl) 2080 IdResolver.AddShadowedDecl(NewFD, PrevIdDecl); 2081 else 2082 IdResolver.AddDecl(NewFD); 2083 } 2084 2085 return NewFD; 2086 } 2087 2088 return NewFD; 2089} 2090 2091void Sema::InitializerElementNotConstant(const Expr *Init) { 2092 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 2093 << Init->getSourceRange(); 2094} 2095 2096bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 2097 switch (Init->getStmtClass()) { 2098 default: 2099 InitializerElementNotConstant(Init); 2100 return true; 2101 case Expr::ParenExprClass: { 2102 const ParenExpr* PE = cast<ParenExpr>(Init); 2103 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 2104 } 2105 case Expr::CompoundLiteralExprClass: 2106 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 2107 case Expr::DeclRefExprClass: 2108 case Expr::QualifiedDeclRefExprClass: { 2109 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 2110 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 2111 if (VD->hasGlobalStorage()) 2112 return false; 2113 InitializerElementNotConstant(Init); 2114 return true; 2115 } 2116 if (isa<FunctionDecl>(D)) 2117 return false; 2118 InitializerElementNotConstant(Init); 2119 return true; 2120 } 2121 case Expr::MemberExprClass: { 2122 const MemberExpr *M = cast<MemberExpr>(Init); 2123 if (M->isArrow()) 2124 return CheckAddressConstantExpression(M->getBase()); 2125 return CheckAddressConstantExpressionLValue(M->getBase()); 2126 } 2127 case Expr::ArraySubscriptExprClass: { 2128 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 2129 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 2130 return CheckAddressConstantExpression(ASE->getBase()) || 2131 CheckArithmeticConstantExpression(ASE->getIdx()); 2132 } 2133 case Expr::StringLiteralClass: 2134 case Expr::PredefinedExprClass: 2135 return false; 2136 case Expr::UnaryOperatorClass: { 2137 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2138 2139 // C99 6.6p9 2140 if (Exp->getOpcode() == UnaryOperator::Deref) 2141 return CheckAddressConstantExpression(Exp->getSubExpr()); 2142 2143 InitializerElementNotConstant(Init); 2144 return true; 2145 } 2146 } 2147} 2148 2149bool Sema::CheckAddressConstantExpression(const Expr* Init) { 2150 switch (Init->getStmtClass()) { 2151 default: 2152 InitializerElementNotConstant(Init); 2153 return true; 2154 case Expr::ParenExprClass: 2155 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 2156 case Expr::StringLiteralClass: 2157 case Expr::ObjCStringLiteralClass: 2158 return false; 2159 case Expr::CallExprClass: 2160 case Expr::CXXOperatorCallExprClass: 2161 // __builtin___CFStringMakeConstantString is a valid constant l-value. 2162 if (cast<CallExpr>(Init)->isBuiltinCall(Context) == 2163 Builtin::BI__builtin___CFStringMakeConstantString) 2164 return false; 2165 2166 InitializerElementNotConstant(Init); 2167 return true; 2168 2169 case Expr::UnaryOperatorClass: { 2170 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2171 2172 // C99 6.6p9 2173 if (Exp->getOpcode() == UnaryOperator::AddrOf) 2174 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 2175 2176 if (Exp->getOpcode() == UnaryOperator::Extension) 2177 return CheckAddressConstantExpression(Exp->getSubExpr()); 2178 2179 InitializerElementNotConstant(Init); 2180 return true; 2181 } 2182 case Expr::BinaryOperatorClass: { 2183 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 2184 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 2185 2186 Expr *PExp = Exp->getLHS(); 2187 Expr *IExp = Exp->getRHS(); 2188 if (IExp->getType()->isPointerType()) 2189 std::swap(PExp, IExp); 2190 2191 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 2192 return CheckAddressConstantExpression(PExp) || 2193 CheckArithmeticConstantExpression(IExp); 2194 } 2195 case Expr::ImplicitCastExprClass: 2196 case Expr::CStyleCastExprClass: { 2197 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 2198 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 2199 // Check for implicit promotion 2200 if (SubExpr->getType()->isFunctionType() || 2201 SubExpr->getType()->isArrayType()) 2202 return CheckAddressConstantExpressionLValue(SubExpr); 2203 } 2204 2205 // Check for pointer->pointer cast 2206 if (SubExpr->getType()->isPointerType()) 2207 return CheckAddressConstantExpression(SubExpr); 2208 2209 if (SubExpr->getType()->isIntegralType()) { 2210 // Check for the special-case of a pointer->int->pointer cast; 2211 // this isn't standard, but some code requires it. See 2212 // PR2720 for an example. 2213 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 2214 if (SubCast->getSubExpr()->getType()->isPointerType()) { 2215 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 2216 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 2217 if (IntWidth >= PointerWidth) { 2218 return CheckAddressConstantExpression(SubCast->getSubExpr()); 2219 } 2220 } 2221 } 2222 } 2223 if (SubExpr->getType()->isArithmeticType()) { 2224 return CheckArithmeticConstantExpression(SubExpr); 2225 } 2226 2227 InitializerElementNotConstant(Init); 2228 return true; 2229 } 2230 case Expr::ConditionalOperatorClass: { 2231 // FIXME: Should we pedwarn here? 2232 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 2233 if (!Exp->getCond()->getType()->isArithmeticType()) { 2234 InitializerElementNotConstant(Init); 2235 return true; 2236 } 2237 if (CheckArithmeticConstantExpression(Exp->getCond())) 2238 return true; 2239 if (Exp->getLHS() && 2240 CheckAddressConstantExpression(Exp->getLHS())) 2241 return true; 2242 return CheckAddressConstantExpression(Exp->getRHS()); 2243 } 2244 case Expr::AddrLabelExprClass: 2245 return false; 2246 } 2247} 2248 2249static const Expr* FindExpressionBaseAddress(const Expr* E); 2250 2251static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 2252 switch (E->getStmtClass()) { 2253 default: 2254 return E; 2255 case Expr::ParenExprClass: { 2256 const ParenExpr* PE = cast<ParenExpr>(E); 2257 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 2258 } 2259 case Expr::MemberExprClass: { 2260 const MemberExpr *M = cast<MemberExpr>(E); 2261 if (M->isArrow()) 2262 return FindExpressionBaseAddress(M->getBase()); 2263 return FindExpressionBaseAddressLValue(M->getBase()); 2264 } 2265 case Expr::ArraySubscriptExprClass: { 2266 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 2267 return FindExpressionBaseAddress(ASE->getBase()); 2268 } 2269 case Expr::UnaryOperatorClass: { 2270 const UnaryOperator *Exp = cast<UnaryOperator>(E); 2271 2272 if (Exp->getOpcode() == UnaryOperator::Deref) 2273 return FindExpressionBaseAddress(Exp->getSubExpr()); 2274 2275 return E; 2276 } 2277 } 2278} 2279 2280static const Expr* FindExpressionBaseAddress(const Expr* E) { 2281 switch (E->getStmtClass()) { 2282 default: 2283 return E; 2284 case Expr::ParenExprClass: { 2285 const ParenExpr* PE = cast<ParenExpr>(E); 2286 return FindExpressionBaseAddress(PE->getSubExpr()); 2287 } 2288 case Expr::UnaryOperatorClass: { 2289 const UnaryOperator *Exp = cast<UnaryOperator>(E); 2290 2291 // C99 6.6p9 2292 if (Exp->getOpcode() == UnaryOperator::AddrOf) 2293 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 2294 2295 if (Exp->getOpcode() == UnaryOperator::Extension) 2296 return FindExpressionBaseAddress(Exp->getSubExpr()); 2297 2298 return E; 2299 } 2300 case Expr::BinaryOperatorClass: { 2301 const BinaryOperator *Exp = cast<BinaryOperator>(E); 2302 2303 Expr *PExp = Exp->getLHS(); 2304 Expr *IExp = Exp->getRHS(); 2305 if (IExp->getType()->isPointerType()) 2306 std::swap(PExp, IExp); 2307 2308 return FindExpressionBaseAddress(PExp); 2309 } 2310 case Expr::ImplicitCastExprClass: { 2311 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 2312 2313 // Check for implicit promotion 2314 if (SubExpr->getType()->isFunctionType() || 2315 SubExpr->getType()->isArrayType()) 2316 return FindExpressionBaseAddressLValue(SubExpr); 2317 2318 // Check for pointer->pointer cast 2319 if (SubExpr->getType()->isPointerType()) 2320 return FindExpressionBaseAddress(SubExpr); 2321 2322 // We assume that we have an arithmetic expression here; 2323 // if we don't, we'll figure it out later 2324 return 0; 2325 } 2326 case Expr::CStyleCastExprClass: { 2327 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 2328 2329 // Check for pointer->pointer cast 2330 if (SubExpr->getType()->isPointerType()) 2331 return FindExpressionBaseAddress(SubExpr); 2332 2333 // We assume that we have an arithmetic expression here; 2334 // if we don't, we'll figure it out later 2335 return 0; 2336 } 2337 } 2338} 2339 2340bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 2341 switch (Init->getStmtClass()) { 2342 default: 2343 InitializerElementNotConstant(Init); 2344 return true; 2345 case Expr::ParenExprClass: { 2346 const ParenExpr* PE = cast<ParenExpr>(Init); 2347 return CheckArithmeticConstantExpression(PE->getSubExpr()); 2348 } 2349 case Expr::FloatingLiteralClass: 2350 case Expr::IntegerLiteralClass: 2351 case Expr::CharacterLiteralClass: 2352 case Expr::ImaginaryLiteralClass: 2353 case Expr::TypesCompatibleExprClass: 2354 case Expr::CXXBoolLiteralExprClass: 2355 return false; 2356 case Expr::CallExprClass: 2357 case Expr::CXXOperatorCallExprClass: { 2358 const CallExpr *CE = cast<CallExpr>(Init); 2359 2360 // Allow any constant foldable calls to builtins. 2361 if (CE->isBuiltinCall(Context) && CE->isEvaluatable(Context)) 2362 return false; 2363 2364 InitializerElementNotConstant(Init); 2365 return true; 2366 } 2367 case Expr::DeclRefExprClass: 2368 case Expr::QualifiedDeclRefExprClass: { 2369 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 2370 if (isa<EnumConstantDecl>(D)) 2371 return false; 2372 InitializerElementNotConstant(Init); 2373 return true; 2374 } 2375 case Expr::CompoundLiteralExprClass: 2376 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 2377 // but vectors are allowed to be magic. 2378 if (Init->getType()->isVectorType()) 2379 return false; 2380 InitializerElementNotConstant(Init); 2381 return true; 2382 case Expr::UnaryOperatorClass: { 2383 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2384 2385 switch (Exp->getOpcode()) { 2386 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 2387 // See C99 6.6p3. 2388 default: 2389 InitializerElementNotConstant(Init); 2390 return true; 2391 case UnaryOperator::OffsetOf: 2392 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 2393 return false; 2394 InitializerElementNotConstant(Init); 2395 return true; 2396 case UnaryOperator::Extension: 2397 case UnaryOperator::LNot: 2398 case UnaryOperator::Plus: 2399 case UnaryOperator::Minus: 2400 case UnaryOperator::Not: 2401 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 2402 } 2403 } 2404 case Expr::SizeOfAlignOfExprClass: { 2405 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 2406 // Special check for void types, which are allowed as an extension 2407 if (Exp->getTypeOfArgument()->isVoidType()) 2408 return false; 2409 // alignof always evaluates to a constant. 2410 // FIXME: is sizeof(int[3.0]) a constant expression? 2411 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 2412 InitializerElementNotConstant(Init); 2413 return true; 2414 } 2415 return false; 2416 } 2417 case Expr::BinaryOperatorClass: { 2418 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 2419 2420 if (Exp->getLHS()->getType()->isArithmeticType() && 2421 Exp->getRHS()->getType()->isArithmeticType()) { 2422 return CheckArithmeticConstantExpression(Exp->getLHS()) || 2423 CheckArithmeticConstantExpression(Exp->getRHS()); 2424 } 2425 2426 if (Exp->getLHS()->getType()->isPointerType() && 2427 Exp->getRHS()->getType()->isPointerType()) { 2428 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 2429 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 2430 2431 // Only allow a null (constant integer) base; we could 2432 // allow some additional cases if necessary, but this 2433 // is sufficient to cover offsetof-like constructs. 2434 if (!LHSBase && !RHSBase) { 2435 return CheckAddressConstantExpression(Exp->getLHS()) || 2436 CheckAddressConstantExpression(Exp->getRHS()); 2437 } 2438 } 2439 2440 InitializerElementNotConstant(Init); 2441 return true; 2442 } 2443 case Expr::ImplicitCastExprClass: 2444 case Expr::CStyleCastExprClass: { 2445 const CastExpr *CE = cast<CastExpr>(Init); 2446 const Expr *SubExpr = CE->getSubExpr(); 2447 2448 if (SubExpr->getType()->isArithmeticType()) 2449 return CheckArithmeticConstantExpression(SubExpr); 2450 2451 if (SubExpr->getType()->isPointerType()) { 2452 const Expr* Base = FindExpressionBaseAddress(SubExpr); 2453 if (Base) { 2454 // the cast is only valid if done to a wide enough type 2455 if (Context.getTypeSize(CE->getType()) >= 2456 Context.getTypeSize(SubExpr->getType())) 2457 return false; 2458 } else { 2459 // If the pointer has a null base, this is an offsetof-like construct 2460 return CheckAddressConstantExpression(SubExpr); 2461 } 2462 } 2463 2464 InitializerElementNotConstant(Init); 2465 return true; 2466 } 2467 case Expr::ConditionalOperatorClass: { 2468 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 2469 2470 // If GNU extensions are disabled, we require all operands to be arithmetic 2471 // constant expressions. 2472 if (getLangOptions().NoExtensions) { 2473 return CheckArithmeticConstantExpression(Exp->getCond()) || 2474 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 2475 CheckArithmeticConstantExpression(Exp->getRHS()); 2476 } 2477 2478 // Otherwise, we have to emulate some of the behavior of fold here. 2479 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 2480 // because it can constant fold things away. To retain compatibility with 2481 // GCC code, we see if we can fold the condition to a constant (which we 2482 // should always be able to do in theory). If so, we only require the 2483 // specified arm of the conditional to be a constant. This is a horrible 2484 // hack, but is require by real world code that uses __builtin_constant_p. 2485 Expr::EvalResult EvalResult; 2486 if (!Exp->getCond()->Evaluate(EvalResult, Context) || 2487 EvalResult.HasSideEffects) { 2488 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 2489 // won't be able to either. Use it to emit the diagnostic though. 2490 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 2491 assert(Res && "Evaluate couldn't evaluate this constant?"); 2492 return Res; 2493 } 2494 2495 // Verify that the side following the condition is also a constant. 2496 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 2497 if (EvalResult.Val.getInt() == 0) 2498 std::swap(TrueSide, FalseSide); 2499 2500 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 2501 return true; 2502 2503 // Okay, the evaluated side evaluates to a constant, so we accept this. 2504 // Check to see if the other side is obviously not a constant. If so, 2505 // emit a warning that this is a GNU extension. 2506 if (FalseSide && !FalseSide->isEvaluatable(Context)) 2507 Diag(Init->getExprLoc(), 2508 diag::ext_typecheck_expression_not_constant_but_accepted) 2509 << FalseSide->getSourceRange(); 2510 return false; 2511 } 2512 } 2513} 2514 2515bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2516 if (Init->isConstantInitializer(Context)) { 2517 return false; 2518 } 2519 InitializerElementNotConstant(Init); 2520 return true; 2521 2522 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) 2523 Init = DIE->getInit(); 2524 2525 Init = Init->IgnoreParens(); 2526 2527 if (Init->isEvaluatable(Context)) 2528 return false; 2529 2530 // Look through CXXDefaultArgExprs; they have no meaning in this context. 2531 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 2532 return CheckForConstantInitializer(DAE->getExpr(), DclT); 2533 2534 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 2535 return CheckForConstantInitializer(e->getInitializer(), DclT); 2536 2537 if (isa<ImplicitValueInitExpr>(Init)) { 2538 // FIXME: In C++, check for non-POD types. 2539 return false; 2540 } 2541 2542 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 2543 unsigned numInits = Exp->getNumInits(); 2544 for (unsigned i = 0; i < numInits; i++) { 2545 // FIXME: Need to get the type of the declaration for C++, 2546 // because it could be a reference? 2547 2548 if (CheckForConstantInitializer(Exp->getInit(i), 2549 Exp->getInit(i)->getType())) 2550 return true; 2551 } 2552 return false; 2553 } 2554 2555 // FIXME: We can probably remove some of this code below, now that 2556 // Expr::Evaluate is doing the heavy lifting for scalars. 2557 2558 if (Init->isNullPointerConstant(Context)) 2559 return false; 2560 if (Init->getType()->isArithmeticType()) { 2561 QualType InitTy = Context.getCanonicalType(Init->getType()) 2562 .getUnqualifiedType(); 2563 if (InitTy == Context.BoolTy) { 2564 // Special handling for pointers implicitly cast to bool; 2565 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 2566 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 2567 Expr* SubE = ICE->getSubExpr(); 2568 if (SubE->getType()->isPointerType() || 2569 SubE->getType()->isArrayType() || 2570 SubE->getType()->isFunctionType()) { 2571 return CheckAddressConstantExpression(Init); 2572 } 2573 } 2574 } else if (InitTy->isIntegralType()) { 2575 Expr* SubE = 0; 2576 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 2577 SubE = CE->getSubExpr(); 2578 // Special check for pointer cast to int; we allow as an extension 2579 // an address constant cast to an integer if the integer 2580 // is of an appropriate width (this sort of code is apparently used 2581 // in some places). 2582 // FIXME: Add pedwarn? 2583 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 2584 if (SubE && (SubE->getType()->isPointerType() || 2585 SubE->getType()->isArrayType() || 2586 SubE->getType()->isFunctionType())) { 2587 unsigned IntWidth = Context.getTypeSize(Init->getType()); 2588 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 2589 if (IntWidth >= PointerWidth) 2590 return CheckAddressConstantExpression(Init); 2591 } 2592 } 2593 2594 return CheckArithmeticConstantExpression(Init); 2595 } 2596 2597 if (Init->getType()->isPointerType()) 2598 return CheckAddressConstantExpression(Init); 2599 2600 // An array type at the top level that isn't an init-list must 2601 // be a string literal 2602 if (Init->getType()->isArrayType()) 2603 return false; 2604 2605 if (Init->getType()->isFunctionType()) 2606 return false; 2607 2608 // Allow block exprs at top level. 2609 if (Init->getType()->isBlockPointerType()) 2610 return false; 2611 2612 // GCC cast to union extension 2613 // note: the validity of the cast expr is checked by CheckCastTypes() 2614 if (CastExpr *C = dyn_cast<CastExpr>(Init)) { 2615 QualType T = C->getType(); 2616 return T->isUnionType() && CheckForConstantInitializer(C->getSubExpr(), T); 2617 } 2618 2619 InitializerElementNotConstant(Init); 2620 return true; 2621} 2622 2623void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init) { 2624 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 2625} 2626 2627/// AddInitializerToDecl - Adds the initializer Init to the 2628/// declaration dcl. If DirectInit is true, this is C++ direct 2629/// initialization rather than copy initialization. 2630void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init, bool DirectInit) { 2631 Decl *RealDecl = static_cast<Decl *>(dcl); 2632 Expr *Init = static_cast<Expr *>(init.release()); 2633 assert(Init && "missing initializer"); 2634 2635 // If there is no declaration, there was an error parsing it. Just ignore 2636 // the initializer. 2637 if (RealDecl == 0) { 2638 Init->Destroy(Context); 2639 return; 2640 } 2641 2642 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 2643 if (!VDecl) { 2644 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 2645 RealDecl->setInvalidDecl(); 2646 return; 2647 } 2648 // Get the decls type and save a reference for later, since 2649 // CheckInitializerTypes may change it. 2650 QualType DclT = VDecl->getType(), SavT = DclT; 2651 if (VDecl->isBlockVarDecl()) { 2652 VarDecl::StorageClass SC = VDecl->getStorageClass(); 2653 if (SC == VarDecl::Extern) { // C99 6.7.8p5 2654 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 2655 VDecl->setInvalidDecl(); 2656 } else if (!VDecl->isInvalidDecl()) { 2657 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2658 VDecl->getDeclName(), DirectInit)) 2659 VDecl->setInvalidDecl(); 2660 2661 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2662 // Don't check invalid declarations to avoid emitting useless diagnostics. 2663 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 2664 if (SC == VarDecl::Static) // C99 6.7.8p4. 2665 CheckForConstantInitializer(Init, DclT); 2666 } 2667 } 2668 } else if (VDecl->isFileVarDecl()) { 2669 if (VDecl->getStorageClass() == VarDecl::Extern) 2670 Diag(VDecl->getLocation(), diag::warn_extern_init); 2671 if (!VDecl->isInvalidDecl()) 2672 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2673 VDecl->getDeclName(), DirectInit)) 2674 VDecl->setInvalidDecl(); 2675 2676 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2677 // Don't check invalid declarations to avoid emitting useless diagnostics. 2678 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 2679 // C99 6.7.8p4. All file scoped initializers need to be constant. 2680 CheckForConstantInitializer(Init, DclT); 2681 } 2682 } 2683 // If the type changed, it means we had an incomplete type that was 2684 // completed by the initializer. For example: 2685 // int ary[] = { 1, 3, 5 }; 2686 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 2687 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 2688 VDecl->setType(DclT); 2689 Init->setType(DclT); 2690 } 2691 2692 // Attach the initializer to the decl. 2693 VDecl->setInit(Init); 2694 return; 2695} 2696 2697void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 2698 Decl *RealDecl = static_cast<Decl *>(dcl); 2699 2700 // If there is no declaration, there was an error parsing it. Just ignore it. 2701 if (RealDecl == 0) 2702 return; 2703 2704 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 2705 QualType Type = Var->getType(); 2706 // C++ [dcl.init.ref]p3: 2707 // The initializer can be omitted for a reference only in a 2708 // parameter declaration (8.3.5), in the declaration of a 2709 // function return type, in the declaration of a class member 2710 // within its class declaration (9.2), and where the extern 2711 // specifier is explicitly used. 2712 if (Type->isReferenceType() && 2713 Var->getStorageClass() != VarDecl::Extern && 2714 Var->getStorageClass() != VarDecl::PrivateExtern) { 2715 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 2716 << Var->getDeclName() 2717 << SourceRange(Var->getLocation(), Var->getLocation()); 2718 Var->setInvalidDecl(); 2719 return; 2720 } 2721 2722 // C++ [dcl.init]p9: 2723 // 2724 // If no initializer is specified for an object, and the object 2725 // is of (possibly cv-qualified) non-POD class type (or array 2726 // thereof), the object shall be default-initialized; if the 2727 // object is of const-qualified type, the underlying class type 2728 // shall have a user-declared default constructor. 2729 if (getLangOptions().CPlusPlus) { 2730 QualType InitType = Type; 2731 if (const ArrayType *Array = Context.getAsArrayType(Type)) 2732 InitType = Array->getElementType(); 2733 if (Var->getStorageClass() != VarDecl::Extern && 2734 Var->getStorageClass() != VarDecl::PrivateExtern && 2735 InitType->isRecordType()) { 2736 const CXXConstructorDecl *Constructor 2737 = PerformInitializationByConstructor(InitType, 0, 0, 2738 Var->getLocation(), 2739 SourceRange(Var->getLocation(), 2740 Var->getLocation()), 2741 Var->getDeclName(), 2742 IK_Default); 2743 if (!Constructor) 2744 Var->setInvalidDecl(); 2745 } 2746 } 2747 2748#if 0 2749 // FIXME: Temporarily disabled because we are not properly parsing 2750 // linkage specifications on declarations, e.g., 2751 // 2752 // extern "C" const CGPoint CGPointerZero; 2753 // 2754 // C++ [dcl.init]p9: 2755 // 2756 // If no initializer is specified for an object, and the 2757 // object is of (possibly cv-qualified) non-POD class type (or 2758 // array thereof), the object shall be default-initialized; if 2759 // the object is of const-qualified type, the underlying class 2760 // type shall have a user-declared default 2761 // constructor. Otherwise, if no initializer is specified for 2762 // an object, the object and its subobjects, if any, have an 2763 // indeterminate initial value; if the object or any of its 2764 // subobjects are of const-qualified type, the program is 2765 // ill-formed. 2766 // 2767 // This isn't technically an error in C, so we don't diagnose it. 2768 // 2769 // FIXME: Actually perform the POD/user-defined default 2770 // constructor check. 2771 if (getLangOptions().CPlusPlus && 2772 Context.getCanonicalType(Type).isConstQualified() && 2773 Var->getStorageClass() != VarDecl::Extern) 2774 Diag(Var->getLocation(), diag::err_const_var_requires_init) 2775 << Var->getName() 2776 << SourceRange(Var->getLocation(), Var->getLocation()); 2777#endif 2778 } 2779} 2780 2781/// The declarators are chained together backwards, reverse the list. 2782Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 2783 // Often we have single declarators, handle them quickly. 2784 Decl *Group = static_cast<Decl*>(group); 2785 if (Group == 0) 2786 return 0; 2787 2788 Decl *NewGroup = 0; 2789 if (Group->getNextDeclarator() == 0) 2790 NewGroup = Group; 2791 else { // reverse the list. 2792 while (Group) { 2793 Decl *Next = Group->getNextDeclarator(); 2794 Group->setNextDeclarator(NewGroup); 2795 NewGroup = Group; 2796 Group = Next; 2797 } 2798 } 2799 // Perform semantic analysis that depends on having fully processed both 2800 // the declarator and initializer. 2801 for (Decl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 2802 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 2803 if (!IDecl) 2804 continue; 2805 QualType T = IDecl->getType(); 2806 2807 if (T->isVariableArrayType()) { 2808 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2809 2810 // FIXME: This won't give the correct result for 2811 // int a[10][n]; 2812 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2813 if (IDecl->isFileVarDecl()) { 2814 Diag(IDecl->getLocation(), diag::err_vla_decl_in_file_scope) << 2815 SizeRange; 2816 2817 IDecl->setInvalidDecl(); 2818 } else { 2819 // C99 6.7.5.2p2: If an identifier is declared to be an object with 2820 // static storage duration, it shall not have a variable length array. 2821 if (IDecl->getStorageClass() == VarDecl::Static) { 2822 Diag(IDecl->getLocation(), diag::err_vla_decl_has_static_storage) 2823 << SizeRange; 2824 IDecl->setInvalidDecl(); 2825 } else if (IDecl->getStorageClass() == VarDecl::Extern) { 2826 Diag(IDecl->getLocation(), diag::err_vla_decl_has_extern_linkage) 2827 << SizeRange; 2828 IDecl->setInvalidDecl(); 2829 } 2830 } 2831 } else if (T->isVariablyModifiedType()) { 2832 if (IDecl->isFileVarDecl()) { 2833 Diag(IDecl->getLocation(), diag::err_vm_decl_in_file_scope); 2834 IDecl->setInvalidDecl(); 2835 } else { 2836 if (IDecl->getStorageClass() == VarDecl::Extern) { 2837 Diag(IDecl->getLocation(), diag::err_vm_decl_has_extern_linkage); 2838 IDecl->setInvalidDecl(); 2839 } 2840 } 2841 } 2842 2843 // Block scope. C99 6.7p7: If an identifier for an object is declared with 2844 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 2845 if (IDecl->isBlockVarDecl() && 2846 IDecl->getStorageClass() != VarDecl::Extern) { 2847 if (!IDecl->isInvalidDecl() && 2848 DiagnoseIncompleteType(IDecl->getLocation(), T, 2849 diag::err_typecheck_decl_incomplete_type)) 2850 IDecl->setInvalidDecl(); 2851 } 2852 // File scope. C99 6.9.2p2: A declaration of an identifier for and 2853 // object that has file scope without an initializer, and without a 2854 // storage-class specifier or with the storage-class specifier "static", 2855 // constitutes a tentative definition. Note: A tentative definition with 2856 // external linkage is valid (C99 6.2.2p5). 2857 if (isTentativeDefinition(IDecl)) { 2858 if (T->isIncompleteArrayType()) { 2859 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 2860 // array to be completed. Don't issue a diagnostic. 2861 } else if (!IDecl->isInvalidDecl() && 2862 DiagnoseIncompleteType(IDecl->getLocation(), T, 2863 diag::err_typecheck_decl_incomplete_type)) 2864 // C99 6.9.2p3: If the declaration of an identifier for an object is 2865 // a tentative definition and has internal linkage (C99 6.2.2p3), the 2866 // declared type shall not be an incomplete type. 2867 IDecl->setInvalidDecl(); 2868 } 2869 if (IDecl->isFileVarDecl()) 2870 CheckForFileScopedRedefinitions(S, IDecl); 2871 } 2872 return NewGroup; 2873} 2874 2875/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 2876/// to introduce parameters into function prototype scope. 2877Sema::DeclTy * 2878Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 2879 const DeclSpec &DS = D.getDeclSpec(); 2880 2881 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 2882 VarDecl::StorageClass StorageClass = VarDecl::None; 2883 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 2884 StorageClass = VarDecl::Register; 2885 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 2886 Diag(DS.getStorageClassSpecLoc(), 2887 diag::err_invalid_storage_class_in_func_decl); 2888 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2889 } 2890 if (DS.isThreadSpecified()) { 2891 Diag(DS.getThreadSpecLoc(), 2892 diag::err_invalid_storage_class_in_func_decl); 2893 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2894 } 2895 2896 // Check that there are no default arguments inside the type of this 2897 // parameter (C++ only). 2898 if (getLangOptions().CPlusPlus) 2899 CheckExtraCXXDefaultArguments(D); 2900 2901 // In this context, we *do not* check D.getInvalidType(). If the declarator 2902 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 2903 // though it will not reflect the user specified type. 2904 QualType parmDeclType = GetTypeForDeclarator(D, S); 2905 2906 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 2907 2908 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 2909 // Can this happen for params? We already checked that they don't conflict 2910 // among each other. Here they can only shadow globals, which is ok. 2911 IdentifierInfo *II = D.getIdentifier(); 2912 if (II) { 2913 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 2914 if (PrevDecl->isTemplateParameter()) { 2915 // Maybe we will complain about the shadowed template parameter. 2916 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 2917 // Just pretend that we didn't see the previous declaration. 2918 PrevDecl = 0; 2919 } else if (S->isDeclScope(PrevDecl)) { 2920 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 2921 2922 // Recover by removing the name 2923 II = 0; 2924 D.SetIdentifier(0, D.getIdentifierLoc()); 2925 } 2926 } 2927 } 2928 2929 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 2930 // Doing the promotion here has a win and a loss. The win is the type for 2931 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 2932 // code generator). The loss is the orginal type isn't preserved. For example: 2933 // 2934 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2935 // int blockvardecl[5]; 2936 // sizeof(parmvardecl); // size == 4 2937 // sizeof(blockvardecl); // size == 20 2938 // } 2939 // 2940 // For expressions, all implicit conversions are captured using the 2941 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2942 // 2943 // FIXME: If a source translation tool needs to see the original type, then 2944 // we need to consider storing both types (in ParmVarDecl)... 2945 // 2946 if (parmDeclType->isArrayType()) { 2947 // int x[restrict 4] -> int *restrict 2948 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2949 } else if (parmDeclType->isFunctionType()) 2950 parmDeclType = Context.getPointerType(parmDeclType); 2951 2952 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2953 D.getIdentifierLoc(), II, 2954 parmDeclType, StorageClass, 2955 0); 2956 2957 if (D.getInvalidType()) 2958 New->setInvalidDecl(); 2959 2960 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 2961 if (D.getCXXScopeSpec().isSet()) { 2962 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 2963 << D.getCXXScopeSpec().getRange(); 2964 New->setInvalidDecl(); 2965 } 2966 // Parameter declarators cannot be interface types. All ObjC objects are 2967 // passed by reference. 2968 if (parmDeclType->isObjCInterfaceType()) { 2969 Diag(D.getIdentifierLoc(), diag::err_object_cannot_be_by_value) 2970 << "passed"; 2971 New->setInvalidDecl(); 2972 } 2973 2974 // Add the parameter declaration into this scope. 2975 S->AddDecl(New); 2976 if (II) 2977 IdResolver.AddDecl(New); 2978 2979 ProcessDeclAttributes(New, D); 2980 return New; 2981 2982} 2983 2984void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D) { 2985 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2986 "Not a function declarator!"); 2987 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2988 2989 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2990 // for a K&R function. 2991 if (!FTI.hasPrototype) { 2992 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2993 if (FTI.ArgInfo[i].Param == 0) { 2994 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2995 << FTI.ArgInfo[i].Ident; 2996 // Implicitly declare the argument as type 'int' for lack of a better 2997 // type. 2998 DeclSpec DS; 2999 const char* PrevSpec; // unused 3000 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 3001 PrevSpec); 3002 Declarator ParamD(DS, Declarator::KNRTypeListContext); 3003 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 3004 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 3005 } 3006 } 3007 } 3008} 3009 3010Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 3011 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 3012 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3013 "Not a function declarator!"); 3014 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3015 3016 if (FTI.hasPrototype) { 3017 // FIXME: Diagnose arguments without names in C. 3018 } 3019 3020 Scope *ParentScope = FnBodyScope->getParent(); 3021 3022 return ActOnStartOfFunctionDef(FnBodyScope, 3023 ActOnDeclarator(ParentScope, D, 0, 3024 /*IsFunctionDefinition=*/true)); 3025} 3026 3027Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 3028 Decl *decl = static_cast<Decl*>(D); 3029 FunctionDecl *FD = cast<FunctionDecl>(decl); 3030 3031 // See if this is a redefinition. 3032 const FunctionDecl *Definition; 3033 if (FD->getBody(Definition)) { 3034 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 3035 Diag(Definition->getLocation(), diag::note_previous_definition); 3036 } 3037 3038 // Builtin functions cannot be defined. 3039 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3040 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 3041 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 3042 FD->setInvalidDecl(); 3043 } 3044 } 3045 3046 PushDeclContext(FnBodyScope, FD); 3047 3048 // Check the validity of our function parameters 3049 CheckParmsForFunctionDef(FD); 3050 3051 // Introduce our parameters into the function scope 3052 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 3053 ParmVarDecl *Param = FD->getParamDecl(p); 3054 Param->setOwningFunction(FD); 3055 3056 // If this has an identifier, add it to the scope stack. 3057 if (Param->getIdentifier()) 3058 PushOnScopeChains(Param, FnBodyScope); 3059 } 3060 3061 // Checking attributes of current function definition 3062 // dllimport attribute. 3063 if (FD->getAttr<DLLImportAttr>() && (!FD->getAttr<DLLExportAttr>())) { 3064 // dllimport attribute cannot be applied to definition. 3065 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 3066 Diag(FD->getLocation(), 3067 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 3068 << "dllimport"; 3069 FD->setInvalidDecl(); 3070 return FD; 3071 } else { 3072 // If a symbol previously declared dllimport is later defined, the 3073 // attribute is ignored in subsequent references, and a warning is 3074 // emitted. 3075 Diag(FD->getLocation(), 3076 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3077 << FD->getNameAsCString() << "dllimport"; 3078 } 3079 } 3080 return FD; 3081} 3082 3083Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtArg BodyArg) { 3084 Decl *dcl = static_cast<Decl *>(D); 3085 Stmt *Body = static_cast<Stmt*>(BodyArg.release()); 3086 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3087 FD->setBody(Body); 3088 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3089 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3090 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3091 MD->setBody((Stmt*)Body); 3092 } else { 3093 Body->Destroy(Context); 3094 return 0; 3095 } 3096 PopDeclContext(); 3097 // Verify and clean out per-function state. 3098 3099 // Check goto/label use. 3100 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3101 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 3102 // Verify that we have no forward references left. If so, there was a goto 3103 // or address of a label taken, but no definition of it. Label fwd 3104 // definitions are indicated with a null substmt. 3105 if (I->second->getSubStmt() == 0) { 3106 LabelStmt *L = I->second; 3107 // Emit error. 3108 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3109 3110 // At this point, we have gotos that use the bogus label. Stitch it into 3111 // the function body so that they aren't leaked and that the AST is well 3112 // formed. 3113 if (Body) { 3114#if 0 3115 // FIXME: Why do this? Having a 'push_back' in CompoundStmt is ugly, 3116 // and the AST is malformed anyway. We should just blow away 'L'. 3117 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3118 cast<CompoundStmt>(Body)->push_back(L); 3119#else 3120 L->Destroy(Context); 3121#endif 3122 } else { 3123 // The whole function wasn't parsed correctly, just delete this. 3124 L->Destroy(Context); 3125 } 3126 } 3127 } 3128 LabelMap.clear(); 3129 3130 return D; 3131} 3132 3133/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3134/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3135NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3136 IdentifierInfo &II, Scope *S) { 3137 // Extension in C99. Legal in C90, but warn about it. 3138 if (getLangOptions().C99) 3139 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3140 else 3141 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3142 3143 // FIXME: handle stuff like: 3144 // void foo() { extern float X(); } 3145 // void bar() { X(); } <-- implicit decl for X in another scope. 3146 3147 // Set a Declarator for the implicit definition: int foo(); 3148 const char *Dummy; 3149 DeclSpec DS; 3150 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 3151 Error = Error; // Silence warning. 3152 assert(!Error && "Error setting up implicit decl!"); 3153 Declarator D(DS, Declarator::BlockContext); 3154 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 3155 0, 0, 0, Loc, D), 3156 SourceLocation()); 3157 D.SetIdentifier(&II, Loc); 3158 3159 // Insert this function into translation-unit scope. 3160 3161 DeclContext *PrevDC = CurContext; 3162 CurContext = Context.getTranslationUnitDecl(); 3163 3164 FunctionDecl *FD = 3165 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 3166 FD->setImplicit(); 3167 3168 CurContext = PrevDC; 3169 3170 AddKnownFunctionAttributes(FD); 3171 3172 return FD; 3173} 3174 3175/// \brief Adds any function attributes that we know a priori based on 3176/// the declaration of this function. 3177/// 3178/// These attributes can apply both to implicitly-declared builtins 3179/// (like __builtin___printf_chk) or to library-declared functions 3180/// like NSLog or printf. 3181void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3182 if (FD->isInvalidDecl()) 3183 return; 3184 3185 // If this is a built-in function, map its builtin attributes to 3186 // actual attributes. 3187 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3188 // Handle printf-formatting attributes. 3189 unsigned FormatIdx; 3190 bool HasVAListArg; 3191 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3192 if (!FD->getAttr<FormatAttr>()) 3193 FD->addAttr(new FormatAttr("printf", FormatIdx + 1, FormatIdx + 2)); 3194 } 3195 3196 // Mark const if we don't care about errno and that is the only 3197 // thing preventing the function from being const. This allows 3198 // IRgen to use LLVM intrinsics for such functions. 3199 if (!getLangOptions().MathErrno && 3200 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3201 if (!FD->getAttr<ConstAttr>()) 3202 FD->addAttr(new ConstAttr()); 3203 } 3204 } 3205 3206 IdentifierInfo *Name = FD->getIdentifier(); 3207 if (!Name) 3208 return; 3209 if ((!getLangOptions().CPlusPlus && 3210 FD->getDeclContext()->isTranslationUnit()) || 3211 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3212 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3213 LinkageSpecDecl::lang_c)) { 3214 // Okay: this could be a libc/libm/Objective-C function we know 3215 // about. 3216 } else 3217 return; 3218 3219 unsigned KnownID; 3220 for (KnownID = 0; KnownID != id_num_known_functions; ++KnownID) 3221 if (KnownFunctionIDs[KnownID] == Name) 3222 break; 3223 3224 switch (KnownID) { 3225 case id_NSLog: 3226 case id_NSLogv: 3227 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3228 // FIXME: We known better than our headers. 3229 const_cast<FormatAttr *>(Format)->setType("printf"); 3230 } else 3231 FD->addAttr(new FormatAttr("printf", 1, 2)); 3232 break; 3233 3234 case id_asprintf: 3235 case id_vasprintf: 3236 if (!FD->getAttr<FormatAttr>()) 3237 FD->addAttr(new FormatAttr("printf", 2, 3)); 3238 break; 3239 3240 default: 3241 // Unknown function or known function without any attributes to 3242 // add. Do nothing. 3243 break; 3244 } 3245} 3246 3247TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 3248 Decl *LastDeclarator) { 3249 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3250 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3251 3252 // Scope manipulation handled by caller. 3253 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3254 D.getIdentifierLoc(), 3255 D.getIdentifier(), 3256 T); 3257 NewTD->setNextDeclarator(LastDeclarator); 3258 if (D.getInvalidType()) 3259 NewTD->setInvalidDecl(); 3260 return NewTD; 3261} 3262 3263/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3264/// former case, Name will be non-null. In the later case, Name will be null. 3265/// TagSpec indicates what kind of tag this is. TK indicates whether this is a 3266/// reference/declaration/definition of a tag. 3267Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK, 3268 SourceLocation KWLoc, const CXXScopeSpec &SS, 3269 IdentifierInfo *Name, SourceLocation NameLoc, 3270 AttributeList *Attr) { 3271 // If this is not a definition, it must have a name. 3272 assert((Name != 0 || TK == TK_Definition) && 3273 "Nameless record must be a definition!"); 3274 3275 TagDecl::TagKind Kind; 3276 switch (TagSpec) { 3277 default: assert(0 && "Unknown tag type!"); 3278 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3279 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3280 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3281 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3282 } 3283 3284 DeclContext *SearchDC = CurContext; 3285 DeclContext *DC = CurContext; 3286 NamedDecl *PrevDecl = 0; 3287 3288 bool Invalid = false; 3289 3290 if (Name && SS.isNotEmpty()) { 3291 // We have a nested-name tag ('struct foo::bar'). 3292 3293 // Check for invalid 'foo::'. 3294 if (SS.isInvalid()) { 3295 Name = 0; 3296 goto CreateNewDecl; 3297 } 3298 3299 DC = static_cast<DeclContext*>(SS.getScopeRep()); 3300 SearchDC = DC; 3301 // Look-up name inside 'foo::'. 3302 PrevDecl = dyn_cast_or_null<TagDecl>( 3303 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 3304 3305 // A tag 'foo::bar' must already exist. 3306 if (PrevDecl == 0) { 3307 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 3308 Name = 0; 3309 goto CreateNewDecl; 3310 } 3311 } else if (Name) { 3312 // If this is a named struct, check to see if there was a previous forward 3313 // declaration or definition. 3314 // FIXME: We're looking into outer scopes here, even when we 3315 // shouldn't be. Doing so can result in ambiguities that we 3316 // shouldn't be diagnosing. 3317 LookupResult R = LookupName(S, Name, LookupTagName, 3318 /*RedeclarationOnly=*/(TK != TK_Reference)); 3319 if (R.isAmbiguous()) { 3320 DiagnoseAmbiguousLookup(R, Name, NameLoc); 3321 // FIXME: This is not best way to recover from case like: 3322 // 3323 // struct S s; 3324 // 3325 // causes needless err_ovl_no_viable_function_in_init latter. 3326 Name = 0; 3327 PrevDecl = 0; 3328 Invalid = true; 3329 } 3330 else 3331 PrevDecl = R; 3332 3333 if (!getLangOptions().CPlusPlus && TK != TK_Reference) { 3334 // FIXME: This makes sure that we ignore the contexts associated 3335 // with C structs, unions, and enums when looking for a matching 3336 // tag declaration or definition. See the similar lookup tweak 3337 // in Sema::LookupName; is there a better way to deal with this? 3338 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 3339 SearchDC = SearchDC->getParent(); 3340 } 3341 } 3342 3343 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3344 // Maybe we will complain about the shadowed template parameter. 3345 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 3346 // Just pretend that we didn't see the previous declaration. 3347 PrevDecl = 0; 3348 } 3349 3350 if (PrevDecl) { 3351 // Check whether the previous declaration is usable. 3352 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 3353 3354 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 3355 // If this is a use of a previous tag, or if the tag is already declared 3356 // in the same scope (so that the definition/declaration completes or 3357 // rementions the tag), reuse the decl. 3358 if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 3359 // Make sure that this wasn't declared as an enum and now used as a 3360 // struct or something similar. 3361 if (PrevTagDecl->getTagKind() != Kind) { 3362 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 3363 Diag(PrevDecl->getLocation(), diag::note_previous_use); 3364 // Recover by making this an anonymous redefinition. 3365 Name = 0; 3366 PrevDecl = 0; 3367 Invalid = true; 3368 } else { 3369 // If this is a use, just return the declaration we found. 3370 3371 // FIXME: In the future, return a variant or some other clue 3372 // for the consumer of this Decl to know it doesn't own it. 3373 // For our current ASTs this shouldn't be a problem, but will 3374 // need to be changed with DeclGroups. 3375 if (TK == TK_Reference) 3376 return PrevDecl; 3377 3378 // Diagnose attempts to redefine a tag. 3379 if (TK == TK_Definition) { 3380 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 3381 Diag(NameLoc, diag::err_redefinition) << Name; 3382 Diag(Def->getLocation(), diag::note_previous_definition); 3383 // If this is a redefinition, recover by making this 3384 // struct be anonymous, which will make any later 3385 // references get the previous definition. 3386 Name = 0; 3387 PrevDecl = 0; 3388 Invalid = true; 3389 } else { 3390 // If the type is currently being defined, complain 3391 // about a nested redefinition. 3392 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 3393 if (Tag->isBeingDefined()) { 3394 Diag(NameLoc, diag::err_nested_redefinition) << Name; 3395 Diag(PrevTagDecl->getLocation(), 3396 diag::note_previous_definition); 3397 Name = 0; 3398 PrevDecl = 0; 3399 Invalid = true; 3400 } 3401 } 3402 3403 // Okay, this is definition of a previously declared or referenced 3404 // tag PrevDecl. We're going to create a new Decl for it. 3405 } 3406 } 3407 // If we get here we have (another) forward declaration or we 3408 // have a definition. Just create a new decl. 3409 } else { 3410 // If we get here, this is a definition of a new tag type in a nested 3411 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 3412 // new decl/type. We set PrevDecl to NULL so that the entities 3413 // have distinct types. 3414 PrevDecl = 0; 3415 } 3416 // If we get here, we're going to create a new Decl. If PrevDecl 3417 // is non-NULL, it's a definition of the tag declared by 3418 // PrevDecl. If it's NULL, we have a new definition. 3419 } else { 3420 // PrevDecl is a namespace, template, or anything else 3421 // that lives in the IDNS_Tag identifier namespace. 3422 if (isDeclInScope(PrevDecl, SearchDC, S)) { 3423 // The tag name clashes with a namespace name, issue an error and 3424 // recover by making this tag be anonymous. 3425 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 3426 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3427 Name = 0; 3428 PrevDecl = 0; 3429 Invalid = true; 3430 } else { 3431 // The existing declaration isn't relevant to us; we're in a 3432 // new scope, so clear out the previous declaration. 3433 PrevDecl = 0; 3434 } 3435 } 3436 } else if (TK == TK_Reference && SS.isEmpty() && Name && 3437 (Kind != TagDecl::TK_enum)) { 3438 // C++ [basic.scope.pdecl]p5: 3439 // -- for an elaborated-type-specifier of the form 3440 // 3441 // class-key identifier 3442 // 3443 // if the elaborated-type-specifier is used in the 3444 // decl-specifier-seq or parameter-declaration-clause of a 3445 // function defined in namespace scope, the identifier is 3446 // declared as a class-name in the namespace that contains 3447 // the declaration; otherwise, except as a friend 3448 // declaration, the identifier is declared in the smallest 3449 // non-class, non-function-prototype scope that contains the 3450 // declaration. 3451 // 3452 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 3453 // C structs and unions. 3454 3455 // Find the context where we'll be declaring the tag. 3456 // FIXME: We would like to maintain the current DeclContext as the 3457 // lexical context, 3458 while (SearchDC->isRecord()) 3459 SearchDC = SearchDC->getParent(); 3460 3461 // Find the scope where we'll be declaring the tag. 3462 while (S->isClassScope() || 3463 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 3464 ((S->getFlags() & Scope::DeclScope) == 0) || 3465 (S->getEntity() && 3466 ((DeclContext *)S->getEntity())->isTransparentContext())) 3467 S = S->getParent(); 3468 } 3469 3470CreateNewDecl: 3471 3472 // If there is an identifier, use the location of the identifier as the 3473 // location of the decl, otherwise use the location of the struct/union 3474 // keyword. 3475 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 3476 3477 // Otherwise, create a new declaration. If there is a previous 3478 // declaration of the same entity, the two will be linked via 3479 // PrevDecl. 3480 TagDecl *New; 3481 3482 if (Kind == TagDecl::TK_enum) { 3483 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3484 // enum X { A, B, C } D; D should chain to X. 3485 New = EnumDecl::Create(Context, SearchDC, Loc, Name, 3486 cast_or_null<EnumDecl>(PrevDecl)); 3487 // If this is an undefined enum, warn. 3488 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 3489 } else { 3490 // struct/union/class 3491 3492 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3493 // struct X { int A; } D; D should chain to X. 3494 if (getLangOptions().CPlusPlus) 3495 // FIXME: Look for a way to use RecordDecl for simple structs. 3496 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, 3497 cast_or_null<CXXRecordDecl>(PrevDecl)); 3498 else 3499 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, 3500 cast_or_null<RecordDecl>(PrevDecl)); 3501 } 3502 3503 if (Kind != TagDecl::TK_enum) { 3504 // Handle #pragma pack: if the #pragma pack stack has non-default 3505 // alignment, make up a packed attribute for this decl. These 3506 // attributes are checked when the ASTContext lays out the 3507 // structure. 3508 // 3509 // It is important for implementing the correct semantics that this 3510 // happen here (in act on tag decl). The #pragma pack stack is 3511 // maintained as a result of parser callbacks which can occur at 3512 // many points during the parsing of a struct declaration (because 3513 // the #pragma tokens are effectively skipped over during the 3514 // parsing of the struct). 3515 if (unsigned Alignment = getPragmaPackAlignment()) 3516 New->addAttr(new PackedAttr(Alignment * 8)); 3517 } 3518 3519 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 3520 // C++ [dcl.typedef]p3: 3521 // [...] Similarly, in a given scope, a class or enumeration 3522 // shall not be declared with the same name as a typedef-name 3523 // that is declared in that scope and refers to a type other 3524 // than the class or enumeration itself. 3525 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 3526 TypedefDecl *PrevTypedef = 0; 3527 if (Lookup.getKind() == LookupResult::Found) 3528 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 3529 3530 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 3531 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 3532 Context.getCanonicalType(Context.getTypeDeclType(New))) { 3533 Diag(Loc, diag::err_tag_definition_of_typedef) 3534 << Context.getTypeDeclType(New) 3535 << PrevTypedef->getUnderlyingType(); 3536 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 3537 Invalid = true; 3538 } 3539 } 3540 3541 if (Invalid) 3542 New->setInvalidDecl(); 3543 3544 if (Attr) 3545 ProcessDeclAttributeList(New, Attr); 3546 3547 // If we're declaring or defining a tag in function prototype scope 3548 // in C, note that this type can only be used within the function. 3549 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 3550 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 3551 3552 // Set the lexical context. If the tag has a C++ scope specifier, the 3553 // lexical context will be different from the semantic context. 3554 New->setLexicalDeclContext(CurContext); 3555 3556 if (TK == TK_Definition) 3557 New->startDefinition(); 3558 3559 // If this has an identifier, add it to the scope stack. 3560 if (Name) { 3561 S = getNonFieldDeclScope(S); 3562 PushOnScopeChains(New, S); 3563 } else { 3564 CurContext->addDecl(New); 3565 } 3566 3567 return New; 3568} 3569 3570void Sema::ActOnTagStartDefinition(Scope *S, DeclTy *TagD) { 3571 AdjustDeclIfTemplate(TagD); 3572 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3573 3574 // Enter the tag context. 3575 PushDeclContext(S, Tag); 3576 3577 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 3578 FieldCollector->StartClass(); 3579 3580 if (Record->getIdentifier()) { 3581 // C++ [class]p2: 3582 // [...] The class-name is also inserted into the scope of the 3583 // class itself; this is known as the injected-class-name. For 3584 // purposes of access checking, the injected-class-name is treated 3585 // as if it were a public member name. 3586 RecordDecl *InjectedClassName 3587 = CXXRecordDecl::Create(Context, Record->getTagKind(), 3588 CurContext, Record->getLocation(), 3589 Record->getIdentifier(), Record); 3590 InjectedClassName->setImplicit(); 3591 PushOnScopeChains(InjectedClassName, S); 3592 } 3593 } 3594} 3595 3596void Sema::ActOnTagFinishDefinition(Scope *S, DeclTy *TagD) { 3597 AdjustDeclIfTemplate(TagD); 3598 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3599 3600 if (isa<CXXRecordDecl>(Tag)) 3601 FieldCollector->FinishClass(); 3602 3603 // Exit this scope of this tag's definition. 3604 PopDeclContext(); 3605 3606 // Notify the consumer that we've defined a tag. 3607 Consumer.HandleTagDeclDefinition(Tag); 3608} 3609 3610bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 3611 QualType FieldTy, const Expr *BitWidth) { 3612 // FIXME: 6.7.2.1p4 - verify the field type. 3613 3614 llvm::APSInt Value; 3615 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 3616 return true; 3617 3618 // Zero-width bitfield is ok for anonymous field. 3619 if (Value == 0 && FieldName) 3620 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 3621 3622 if (Value.isNegative()) 3623 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) << FieldName; 3624 3625 uint64_t TypeSize = Context.getTypeSize(FieldTy); 3626 // FIXME: We won't need the 0 size once we check that the field type is valid. 3627 if (TypeSize && Value.getZExtValue() > TypeSize) 3628 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 3629 << FieldName << (unsigned)TypeSize; 3630 3631 return false; 3632} 3633 3634/// ActOnField - Each field of a struct/union/class is passed into this in order 3635/// to create a FieldDecl object for it. 3636Sema::DeclTy *Sema::ActOnField(Scope *S, DeclTy *TagD, 3637 SourceLocation DeclStart, 3638 Declarator &D, ExprTy *BitfieldWidth) { 3639 IdentifierInfo *II = D.getIdentifier(); 3640 Expr *BitWidth = (Expr*)BitfieldWidth; 3641 SourceLocation Loc = DeclStart; 3642 RecordDecl *Record = (RecordDecl *)TagD; 3643 if (II) Loc = D.getIdentifierLoc(); 3644 3645 // FIXME: Unnamed fields can be handled in various different ways, for 3646 // example, unnamed unions inject all members into the struct namespace! 3647 3648 QualType T = GetTypeForDeclarator(D, S); 3649 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3650 bool InvalidDecl = false; 3651 3652 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3653 // than a variably modified type. 3654 if (T->isVariablyModifiedType()) { 3655 bool SizeIsNegative; 3656 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 3657 SizeIsNegative); 3658 if (!FixedTy.isNull()) { 3659 Diag(Loc, diag::warn_illegal_constant_array_size); 3660 T = FixedTy; 3661 } else { 3662 if (SizeIsNegative) 3663 Diag(Loc, diag::err_typecheck_negative_array_size); 3664 else 3665 Diag(Loc, diag::err_typecheck_field_variable_size); 3666 T = Context.IntTy; 3667 InvalidDecl = true; 3668 } 3669 } 3670 3671 if (BitWidth) { 3672 if (VerifyBitField(Loc, II, T, BitWidth)) 3673 InvalidDecl = true; 3674 } else { 3675 // Not a bitfield. 3676 3677 // validate II. 3678 3679 } 3680 3681 FieldDecl *NewFD = FieldDecl::Create(Context, Record, 3682 Loc, II, T, BitWidth, 3683 D.getDeclSpec().getStorageClassSpec() == 3684 DeclSpec::SCS_mutable); 3685 3686 if (II) { 3687 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 3688 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3689 && !isa<TagDecl>(PrevDecl)) { 3690 Diag(Loc, diag::err_duplicate_member) << II; 3691 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3692 NewFD->setInvalidDecl(); 3693 Record->setInvalidDecl(); 3694 } 3695 } 3696 3697 if (getLangOptions().CPlusPlus) { 3698 CheckExtraCXXDefaultArguments(D); 3699 if (!T->isPODType()) 3700 cast<CXXRecordDecl>(Record)->setPOD(false); 3701 } 3702 3703 ProcessDeclAttributes(NewFD, D); 3704 if (T.isObjCGCWeak()) 3705 Diag(Loc, diag::warn_attribute_weak_on_field); 3706 3707 if (D.getInvalidType() || InvalidDecl) 3708 NewFD->setInvalidDecl(); 3709 3710 if (II) { 3711 PushOnScopeChains(NewFD, S); 3712 } else 3713 Record->addDecl(NewFD); 3714 3715 return NewFD; 3716} 3717 3718/// TranslateIvarVisibility - Translate visibility from a token ID to an 3719/// AST enum value. 3720static ObjCIvarDecl::AccessControl 3721TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 3722 switch (ivarVisibility) { 3723 default: assert(0 && "Unknown visitibility kind"); 3724 case tok::objc_private: return ObjCIvarDecl::Private; 3725 case tok::objc_public: return ObjCIvarDecl::Public; 3726 case tok::objc_protected: return ObjCIvarDecl::Protected; 3727 case tok::objc_package: return ObjCIvarDecl::Package; 3728 } 3729} 3730 3731/// ActOnIvar - Each ivar field of an objective-c class is passed into this 3732/// in order to create an IvarDecl object for it. 3733Sema::DeclTy *Sema::ActOnIvar(Scope *S, 3734 SourceLocation DeclStart, 3735 Declarator &D, ExprTy *BitfieldWidth, 3736 tok::ObjCKeywordKind Visibility) { 3737 3738 IdentifierInfo *II = D.getIdentifier(); 3739 Expr *BitWidth = (Expr*)BitfieldWidth; 3740 SourceLocation Loc = DeclStart; 3741 if (II) Loc = D.getIdentifierLoc(); 3742 3743 // FIXME: Unnamed fields can be handled in various different ways, for 3744 // example, unnamed unions inject all members into the struct namespace! 3745 3746 QualType T = GetTypeForDeclarator(D, S); 3747 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3748 bool InvalidDecl = false; 3749 3750 if (BitWidth) { 3751 // 6.7.2.1p3, 6.7.2.1p4 3752 if (VerifyBitField(Loc, II, T, BitWidth)) 3753 InvalidDecl = true; 3754 } else { 3755 // Not a bitfield. 3756 3757 // validate II. 3758 3759 } 3760 3761 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3762 // than a variably modified type. 3763 if (T->isVariablyModifiedType()) { 3764 Diag(Loc, diag::err_typecheck_ivar_variable_size); 3765 InvalidDecl = true; 3766 } 3767 3768 // Get the visibility (access control) for this ivar. 3769 ObjCIvarDecl::AccessControl ac = 3770 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 3771 : ObjCIvarDecl::None; 3772 3773 // Construct the decl. 3774 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, CurContext, Loc, II, T,ac, 3775 (Expr *)BitfieldWidth); 3776 3777 if (II) { 3778 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 3779 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3780 && !isa<TagDecl>(PrevDecl)) { 3781 Diag(Loc, diag::err_duplicate_member) << II; 3782 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3783 NewID->setInvalidDecl(); 3784 } 3785 } 3786 3787 // Process attributes attached to the ivar. 3788 ProcessDeclAttributes(NewID, D); 3789 3790 if (D.getInvalidType() || InvalidDecl) 3791 NewID->setInvalidDecl(); 3792 3793 if (II) { 3794 // FIXME: When interfaces are DeclContexts, we'll need to add 3795 // these to the interface. 3796 S->AddDecl(NewID); 3797 IdResolver.AddDecl(NewID); 3798 } 3799 3800 return NewID; 3801} 3802 3803void Sema::ActOnFields(Scope* S, 3804 SourceLocation RecLoc, DeclTy *RecDecl, 3805 DeclTy **Fields, unsigned NumFields, 3806 SourceLocation LBrac, SourceLocation RBrac, 3807 AttributeList *Attr) { 3808 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 3809 assert(EnclosingDecl && "missing record or interface decl"); 3810 3811 // If the decl this is being inserted into is invalid, then it may be a 3812 // redeclaration or some other bogus case. Don't try to add fields to it. 3813 if (EnclosingDecl->isInvalidDecl()) { 3814 // FIXME: Deallocate fields? 3815 return; 3816 } 3817 3818 3819 // Verify that all the fields are okay. 3820 unsigned NumNamedMembers = 0; 3821 llvm::SmallVector<FieldDecl*, 32> RecFields; 3822 3823 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 3824 for (unsigned i = 0; i != NumFields; ++i) { 3825 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 3826 assert(FD && "missing field decl"); 3827 3828 // Get the type for the field. 3829 Type *FDTy = FD->getType().getTypePtr(); 3830 3831 if (!FD->isAnonymousStructOrUnion()) { 3832 // Remember all fields written by the user. 3833 RecFields.push_back(FD); 3834 } 3835 3836 // C99 6.7.2.1p2 - A field may not be a function type. 3837 if (FDTy->isFunctionType()) { 3838 Diag(FD->getLocation(), diag::err_field_declared_as_function) 3839 << FD->getDeclName(); 3840 FD->setInvalidDecl(); 3841 EnclosingDecl->setInvalidDecl(); 3842 continue; 3843 } 3844 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 3845 if (FDTy->isIncompleteType()) { 3846 if (!Record) { // Incomplete ivar type is always an error. 3847 DiagnoseIncompleteType(FD->getLocation(), FD->getType(), 3848 diag::err_field_incomplete); 3849 FD->setInvalidDecl(); 3850 EnclosingDecl->setInvalidDecl(); 3851 continue; 3852 } 3853 if (i != NumFields-1 || // ... that the last member ... 3854 !Record->isStruct() || // ... of a structure ... 3855 !FDTy->isArrayType()) { //... may have incomplete array type. 3856 DiagnoseIncompleteType(FD->getLocation(), FD->getType(), 3857 diag::err_field_incomplete); 3858 FD->setInvalidDecl(); 3859 EnclosingDecl->setInvalidDecl(); 3860 continue; 3861 } 3862 if (NumNamedMembers < 1) { //... must have more than named member ... 3863 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 3864 << FD->getDeclName(); 3865 FD->setInvalidDecl(); 3866 EnclosingDecl->setInvalidDecl(); 3867 continue; 3868 } 3869 // Okay, we have a legal flexible array member at the end of the struct. 3870 if (Record) 3871 Record->setHasFlexibleArrayMember(true); 3872 } 3873 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 3874 /// field of another structure or the element of an array. 3875 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 3876 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 3877 // If this is a member of a union, then entire union becomes "flexible". 3878 if (Record && Record->isUnion()) { 3879 Record->setHasFlexibleArrayMember(true); 3880 } else { 3881 // If this is a struct/class and this is not the last element, reject 3882 // it. Note that GCC supports variable sized arrays in the middle of 3883 // structures. 3884 if (i != NumFields-1) { 3885 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct) 3886 << FD->getDeclName(); 3887 FD->setInvalidDecl(); 3888 EnclosingDecl->setInvalidDecl(); 3889 continue; 3890 } 3891 // We support flexible arrays at the end of structs in other structs 3892 // as an extension. 3893 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 3894 << FD->getDeclName(); 3895 if (Record) 3896 Record->setHasFlexibleArrayMember(true); 3897 } 3898 } 3899 } 3900 /// A field cannot be an Objective-c object 3901 if (FDTy->isObjCInterfaceType()) { 3902 Diag(FD->getLocation(), diag::err_statically_allocated_object); 3903 FD->setInvalidDecl(); 3904 EnclosingDecl->setInvalidDecl(); 3905 continue; 3906 } 3907 // Keep track of the number of named members. 3908 if (FD->getIdentifier()) 3909 ++NumNamedMembers; 3910 } 3911 3912 // Okay, we successfully defined 'Record'. 3913 if (Record) { 3914 Record->completeDefinition(Context); 3915 } else { 3916 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 3917 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 3918 ID->setIVarList(ClsFields, RecFields.size(), Context); 3919 ID->setLocEnd(RBrac); 3920 3921 // Must enforce the rule that ivars in the base classes may not be 3922 // duplicates. 3923 if (ID->getSuperClass()) { 3924 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 3925 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 3926 ObjCIvarDecl* Ivar = (*IVI); 3927 IdentifierInfo *II = Ivar->getIdentifier(); 3928 ObjCIvarDecl* prevIvar = ID->getSuperClass()->lookupInstanceVariable(II); 3929 if (prevIvar) { 3930 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 3931 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 3932 } 3933 } 3934 } 3935 } else if (ObjCImplementationDecl *IMPDecl = 3936 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 3937 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 3938 IMPDecl->setIVarList(ClsFields, RecFields.size(), Context); 3939 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 3940 } 3941 } 3942 3943 if (Attr) 3944 ProcessDeclAttributeList(Record, Attr); 3945} 3946 3947Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 3948 DeclTy *lastEnumConst, 3949 SourceLocation IdLoc, IdentifierInfo *Id, 3950 SourceLocation EqualLoc, ExprTy *val) { 3951 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 3952 EnumConstantDecl *LastEnumConst = 3953 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 3954 Expr *Val = static_cast<Expr*>(val); 3955 3956 // The scope passed in may not be a decl scope. Zip up the scope tree until 3957 // we find one that is. 3958 S = getNonFieldDeclScope(S); 3959 3960 // Verify that there isn't already something declared with this name in this 3961 // scope. 3962 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 3963 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3964 // Maybe we will complain about the shadowed template parameter. 3965 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 3966 // Just pretend that we didn't see the previous declaration. 3967 PrevDecl = 0; 3968 } 3969 3970 if (PrevDecl) { 3971 // When in C++, we may get a TagDecl with the same name; in this case the 3972 // enum constant will 'hide' the tag. 3973 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 3974 "Received TagDecl when not in C++!"); 3975 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 3976 if (isa<EnumConstantDecl>(PrevDecl)) 3977 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 3978 else 3979 Diag(IdLoc, diag::err_redefinition) << Id; 3980 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3981 Val->Destroy(Context); 3982 return 0; 3983 } 3984 } 3985 3986 llvm::APSInt EnumVal(32); 3987 QualType EltTy; 3988 if (Val) { 3989 // Make sure to promote the operand type to int. 3990 UsualUnaryConversions(Val); 3991 3992 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 3993 SourceLocation ExpLoc; 3994 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 3995 Val->Destroy(Context); 3996 Val = 0; // Just forget about it. 3997 } else { 3998 EltTy = Val->getType(); 3999 } 4000 } 4001 4002 if (!Val) { 4003 if (LastEnumConst) { 4004 // Assign the last value + 1. 4005 EnumVal = LastEnumConst->getInitVal(); 4006 ++EnumVal; 4007 4008 // Check for overflow on increment. 4009 if (EnumVal < LastEnumConst->getInitVal()) 4010 Diag(IdLoc, diag::warn_enum_value_overflow); 4011 4012 EltTy = LastEnumConst->getType(); 4013 } else { 4014 // First value, set to zero. 4015 EltTy = Context.IntTy; 4016 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 4017 } 4018 } 4019 4020 EnumConstantDecl *New = 4021 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 4022 Val, EnumVal); 4023 4024 // Register this decl in the current scope stack. 4025 PushOnScopeChains(New, S); 4026 4027 return New; 4028} 4029 4030// FIXME: For consistency with ActOnFields(), we should have the parser 4031// pass in the source location for the left/right braces. 4032void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 4033 DeclTy **Elements, unsigned NumElements) { 4034 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 4035 QualType EnumType = Context.getTypeDeclType(Enum); 4036 4037 // TODO: If the result value doesn't fit in an int, it must be a long or long 4038 // long value. ISO C does not support this, but GCC does as an extension, 4039 // emit a warning. 4040 unsigned IntWidth = Context.Target.getIntWidth(); 4041 4042 // Verify that all the values are okay, compute the size of the values, and 4043 // reverse the list. 4044 unsigned NumNegativeBits = 0; 4045 unsigned NumPositiveBits = 0; 4046 4047 // Keep track of whether all elements have type int. 4048 bool AllElementsInt = true; 4049 4050 for (unsigned i = 0; i != NumElements; ++i) { 4051 EnumConstantDecl *ECD = 4052 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 4053 if (!ECD) continue; // Already issued a diagnostic. 4054 4055 // If the enum value doesn't fit in an int, emit an extension warning. 4056 const llvm::APSInt &InitVal = ECD->getInitVal(); 4057 assert(InitVal.getBitWidth() >= IntWidth && 4058 "Should have promoted value to int"); 4059 if (InitVal.getBitWidth() > IntWidth) { 4060 llvm::APSInt V(InitVal); 4061 V.trunc(IntWidth); 4062 V.extend(InitVal.getBitWidth()); 4063 if (V != InitVal) 4064 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 4065 << InitVal.toString(10); 4066 } 4067 4068 // Keep track of the size of positive and negative values. 4069 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 4070 NumPositiveBits = std::max(NumPositiveBits, 4071 (unsigned)InitVal.getActiveBits()); 4072 else 4073 NumNegativeBits = std::max(NumNegativeBits, 4074 (unsigned)InitVal.getMinSignedBits()); 4075 4076 // Keep track of whether every enum element has type int (very commmon). 4077 if (AllElementsInt) 4078 AllElementsInt = ECD->getType() == Context.IntTy; 4079 } 4080 4081 // Figure out the type that should be used for this enum. 4082 // FIXME: Support attribute(packed) on enums and -fshort-enums. 4083 QualType BestType; 4084 unsigned BestWidth; 4085 4086 if (NumNegativeBits) { 4087 // If there is a negative value, figure out the smallest integer type (of 4088 // int/long/longlong) that fits. 4089 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 4090 BestType = Context.IntTy; 4091 BestWidth = IntWidth; 4092 } else { 4093 BestWidth = Context.Target.getLongWidth(); 4094 4095 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 4096 BestType = Context.LongTy; 4097 else { 4098 BestWidth = Context.Target.getLongLongWidth(); 4099 4100 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 4101 Diag(Enum->getLocation(), diag::warn_enum_too_large); 4102 BestType = Context.LongLongTy; 4103 } 4104 } 4105 } else { 4106 // If there is no negative value, figure out which of uint, ulong, ulonglong 4107 // fits. 4108 if (NumPositiveBits <= IntWidth) { 4109 BestType = Context.UnsignedIntTy; 4110 BestWidth = IntWidth; 4111 } else if (NumPositiveBits <= 4112 (BestWidth = Context.Target.getLongWidth())) { 4113 BestType = Context.UnsignedLongTy; 4114 } else { 4115 BestWidth = Context.Target.getLongLongWidth(); 4116 assert(NumPositiveBits <= BestWidth && 4117 "How could an initializer get larger than ULL?"); 4118 BestType = Context.UnsignedLongLongTy; 4119 } 4120 } 4121 4122 // Loop over all of the enumerator constants, changing their types to match 4123 // the type of the enum if needed. 4124 for (unsigned i = 0; i != NumElements; ++i) { 4125 EnumConstantDecl *ECD = 4126 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 4127 if (!ECD) continue; // Already issued a diagnostic. 4128 4129 // Standard C says the enumerators have int type, but we allow, as an 4130 // extension, the enumerators to be larger than int size. If each 4131 // enumerator value fits in an int, type it as an int, otherwise type it the 4132 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 4133 // that X has type 'int', not 'unsigned'. 4134 if (ECD->getType() == Context.IntTy) { 4135 // Make sure the init value is signed. 4136 llvm::APSInt IV = ECD->getInitVal(); 4137 IV.setIsSigned(true); 4138 ECD->setInitVal(IV); 4139 4140 if (getLangOptions().CPlusPlus) 4141 // C++ [dcl.enum]p4: Following the closing brace of an 4142 // enum-specifier, each enumerator has the type of its 4143 // enumeration. 4144 ECD->setType(EnumType); 4145 continue; // Already int type. 4146 } 4147 4148 // Determine whether the value fits into an int. 4149 llvm::APSInt InitVal = ECD->getInitVal(); 4150 bool FitsInInt; 4151 if (InitVal.isUnsigned() || !InitVal.isNegative()) 4152 FitsInInt = InitVal.getActiveBits() < IntWidth; 4153 else 4154 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 4155 4156 // If it fits into an integer type, force it. Otherwise force it to match 4157 // the enum decl type. 4158 QualType NewTy; 4159 unsigned NewWidth; 4160 bool NewSign; 4161 if (FitsInInt) { 4162 NewTy = Context.IntTy; 4163 NewWidth = IntWidth; 4164 NewSign = true; 4165 } else if (ECD->getType() == BestType) { 4166 // Already the right type! 4167 if (getLangOptions().CPlusPlus) 4168 // C++ [dcl.enum]p4: Following the closing brace of an 4169 // enum-specifier, each enumerator has the type of its 4170 // enumeration. 4171 ECD->setType(EnumType); 4172 continue; 4173 } else { 4174 NewTy = BestType; 4175 NewWidth = BestWidth; 4176 NewSign = BestType->isSignedIntegerType(); 4177 } 4178 4179 // Adjust the APSInt value. 4180 InitVal.extOrTrunc(NewWidth); 4181 InitVal.setIsSigned(NewSign); 4182 ECD->setInitVal(InitVal); 4183 4184 // Adjust the Expr initializer and type. 4185 if (ECD->getInitExpr()) 4186 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, ECD->getInitExpr(), 4187 /*isLvalue=*/false)); 4188 if (getLangOptions().CPlusPlus) 4189 // C++ [dcl.enum]p4: Following the closing brace of an 4190 // enum-specifier, each enumerator has the type of its 4191 // enumeration. 4192 ECD->setType(EnumType); 4193 else 4194 ECD->setType(NewTy); 4195 } 4196 4197 Enum->completeDefinition(Context, BestType); 4198} 4199 4200Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 4201 ExprArg expr) { 4202 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr.release()); 4203 4204 return FileScopeAsmDecl::Create(Context, CurContext, Loc, AsmString); 4205} 4206 4207