SemaDecl.cpp revision 2224f84658fb9b3725a31f2680edb64ae73bf705
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 /*hasPrototype=*/true); 339 New->setImplicit(); 340 341 // Create Decl objects for each parameter, adding them to the 342 // FunctionDecl. 343 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 344 llvm::SmallVector<ParmVarDecl*, 16> Params; 345 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 346 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 347 FT->getArgType(i), VarDecl::None, 0)); 348 New->setParams(Context, &Params[0], Params.size()); 349 } 350 351 AddKnownFunctionAttributes(New); 352 353 // TUScope is the translation-unit scope to insert this function into. 354 // FIXME: This is hideous. We need to teach PushOnScopeChains to 355 // relate Scopes to DeclContexts, and probably eliminate CurContext 356 // entirely, but we're not there yet. 357 DeclContext *SavedContext = CurContext; 358 CurContext = Context.getTranslationUnitDecl(); 359 PushOnScopeChains(New, TUScope); 360 CurContext = SavedContext; 361 return New; 362} 363 364/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 365/// everything from the standard library is defined. 366NamespaceDecl *Sema::GetStdNamespace() { 367 if (!StdNamespace) { 368 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 369 DeclContext *Global = Context.getTranslationUnitDecl(); 370 Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName); 371 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 372 } 373 return StdNamespace; 374} 375 376/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the 377/// same name and scope as a previous declaration 'Old'. Figure out 378/// how to resolve this situation, merging decls or emitting 379/// diagnostics as appropriate. Returns true if there was an error, 380/// false otherwise. 381/// 382bool Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 383 bool objc_types = false; 384 // Allow multiple definitions for ObjC built-in typedefs. 385 // FIXME: Verify the underlying types are equivalent! 386 if (getLangOptions().ObjC1) { 387 const IdentifierInfo *TypeID = New->getIdentifier(); 388 switch (TypeID->getLength()) { 389 default: break; 390 case 2: 391 if (!TypeID->isStr("id")) 392 break; 393 Context.setObjCIdType(New); 394 objc_types = true; 395 break; 396 case 5: 397 if (!TypeID->isStr("Class")) 398 break; 399 Context.setObjCClassType(New); 400 objc_types = true; 401 return false; 402 case 3: 403 if (!TypeID->isStr("SEL")) 404 break; 405 Context.setObjCSelType(New); 406 objc_types = true; 407 return false; 408 case 8: 409 if (!TypeID->isStr("Protocol")) 410 break; 411 Context.setObjCProtoType(New->getUnderlyingType()); 412 objc_types = true; 413 return false; 414 } 415 // Fall through - the typedef name was not a builtin type. 416 } 417 // Verify the old decl was also a type. 418 TypeDecl *Old = dyn_cast<TypeDecl>(OldD); 419 if (!Old) { 420 Diag(New->getLocation(), diag::err_redefinition_different_kind) 421 << New->getDeclName(); 422 if (!objc_types) 423 Diag(OldD->getLocation(), diag::note_previous_definition); 424 return true; 425 } 426 427 // Determine the "old" type we'll use for checking and diagnostics. 428 QualType OldType; 429 if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old)) 430 OldType = OldTypedef->getUnderlyingType(); 431 else 432 OldType = Context.getTypeDeclType(Old); 433 434 // If the typedef types are not identical, reject them in all languages and 435 // with any extensions enabled. 436 437 if (OldType != New->getUnderlyingType() && 438 Context.getCanonicalType(OldType) != 439 Context.getCanonicalType(New->getUnderlyingType())) { 440 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 441 << New->getUnderlyingType() << OldType; 442 if (!objc_types) 443 Diag(Old->getLocation(), diag::note_previous_definition); 444 return true; 445 } 446 if (objc_types) return false; 447 if (getLangOptions().Microsoft) return false; 448 449 // C++ [dcl.typedef]p2: 450 // In a given non-class scope, a typedef specifier can be used to 451 // redefine the name of any type declared in that scope to refer 452 // to the type to which it already refers. 453 if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext)) 454 return false; 455 456 // In C, redeclaration of a type is a constraint violation (6.7.2.3p1). 457 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 458 // *either* declaration is in a system header. The code below implements 459 // this adhoc compatibility rule. FIXME: The following code will not 460 // work properly when compiling ".i" files (containing preprocessed output). 461 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 462 SourceManager &SrcMgr = Context.getSourceManager(); 463 if (SrcMgr.isInSystemHeader(Old->getLocation())) 464 return false; 465 if (SrcMgr.isInSystemHeader(New->getLocation())) 466 return false; 467 } 468 469 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 470 Diag(Old->getLocation(), diag::note_previous_definition); 471 return true; 472} 473 474/// DeclhasAttr - returns true if decl Declaration already has the target 475/// attribute. 476static bool DeclHasAttr(const Decl *decl, const Attr *target) { 477 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 478 if (attr->getKind() == target->getKind()) 479 return true; 480 481 return false; 482} 483 484/// MergeAttributes - append attributes from the Old decl to the New one. 485static void MergeAttributes(Decl *New, Decl *Old) { 486 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 487 488 while (attr) { 489 tmp = attr; 490 attr = attr->getNext(); 491 492 if (!DeclHasAttr(New, tmp) && tmp->isMerged()) { 493 tmp->setInherited(true); 494 New->addAttr(tmp); 495 } else { 496 tmp->setNext(0); 497 delete(tmp); 498 } 499 } 500 501 Old->invalidateAttrs(); 502} 503 504/// MergeFunctionDecl - We just parsed a function 'New' from 505/// declarator D which has the same name and scope as a previous 506/// declaration 'Old'. Figure out how to resolve this situation, 507/// merging decls or emitting diagnostics as appropriate. 508/// 509/// In C++, New and Old must be declarations that are not 510/// overloaded. Use IsOverload to determine whether New and Old are 511/// overloaded, and to select the Old declaration that New should be 512/// merged with. 513/// 514/// Returns true if there was an error, false otherwise. 515bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) { 516 assert(!isa<OverloadedFunctionDecl>(OldD) && 517 "Cannot merge with an overloaded function declaration"); 518 519 // Verify the old decl was also a function. 520 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 521 if (!Old) { 522 Diag(New->getLocation(), diag::err_redefinition_different_kind) 523 << New->getDeclName(); 524 Diag(OldD->getLocation(), diag::note_previous_definition); 525 return true; 526 } 527 528 // Determine whether the previous declaration was a definition, 529 // implicit declaration, or a declaration. 530 diag::kind PrevDiag; 531 if (Old->isThisDeclarationADefinition()) 532 PrevDiag = diag::note_previous_definition; 533 else if (Old->isImplicit()) 534 PrevDiag = diag::note_previous_implicit_declaration; 535 else 536 PrevDiag = diag::note_previous_declaration; 537 538 QualType OldQType = Context.getCanonicalType(Old->getType()); 539 QualType NewQType = Context.getCanonicalType(New->getType()); 540 541 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) && 542 New->getStorageClass() == FunctionDecl::Static && 543 Old->getStorageClass() != FunctionDecl::Static) { 544 Diag(New->getLocation(), diag::err_static_non_static) 545 << New; 546 Diag(Old->getLocation(), PrevDiag); 547 return true; 548 } 549 550 if (getLangOptions().CPlusPlus) { 551 // (C++98 13.1p2): 552 // Certain function declarations cannot be overloaded: 553 // -- Function declarations that differ only in the return type 554 // cannot be overloaded. 555 QualType OldReturnType 556 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 557 QualType NewReturnType 558 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 559 if (OldReturnType != NewReturnType) { 560 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 561 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 562 return true; 563 } 564 565 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 566 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 567 if (OldMethod && NewMethod) { 568 // -- Member function declarations with the same name and the 569 // same parameter types cannot be overloaded if any of them 570 // is a static member function declaration. 571 if (OldMethod->isStatic() || NewMethod->isStatic()) { 572 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 573 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 574 return true; 575 } 576 577 // C++ [class.mem]p1: 578 // [...] A member shall not be declared twice in the 579 // member-specification, except that a nested class or member 580 // class template can be declared and then later defined. 581 if (OldMethod->getLexicalDeclContext() == 582 NewMethod->getLexicalDeclContext()) { 583 unsigned NewDiag; 584 if (isa<CXXConstructorDecl>(OldMethod)) 585 NewDiag = diag::err_constructor_redeclared; 586 else if (isa<CXXDestructorDecl>(NewMethod)) 587 NewDiag = diag::err_destructor_redeclared; 588 else if (isa<CXXConversionDecl>(NewMethod)) 589 NewDiag = diag::err_conv_function_redeclared; 590 else 591 NewDiag = diag::err_member_redeclared; 592 593 Diag(New->getLocation(), NewDiag); 594 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 595 } 596 } 597 598 // (C++98 8.3.5p3): 599 // All declarations for a function shall agree exactly in both the 600 // return type and the parameter-type-list. 601 if (OldQType == NewQType) 602 return MergeCompatibleFunctionDecls(New, Old); 603 604 // Fall through for conflicting redeclarations and redefinitions. 605 } 606 607 // C: Function types need to be compatible, not identical. This handles 608 // duplicate function decls like "void f(int); void f(enum X);" properly. 609 if (!getLangOptions().CPlusPlus && 610 Context.typesAreCompatible(OldQType, NewQType)) { 611 const FunctionType *NewFuncType = NewQType->getAsFunctionType(); 612 const FunctionTypeProto *OldProto = 0; 613 if (isa<FunctionTypeNoProto>(NewFuncType) && 614 (OldProto = OldQType->getAsFunctionTypeProto())) { 615 // The old declaration provided a function prototype, but the 616 // new declaration does not. Merge in the prototype. 617 llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(), 618 OldProto->arg_type_end()); 619 NewQType = Context.getFunctionType(NewFuncType->getResultType(), 620 &ParamTypes[0], ParamTypes.size(), 621 OldProto->isVariadic(), 622 OldProto->getTypeQuals()); 623 New->setType(NewQType); 624 New->setInheritedPrototype(); 625 626 // Synthesize a parameter for each argument type. 627 llvm::SmallVector<ParmVarDecl*, 16> Params; 628 for (FunctionTypeProto::arg_type_iterator 629 ParamType = OldProto->arg_type_begin(), 630 ParamEnd = OldProto->arg_type_end(); 631 ParamType != ParamEnd; ++ParamType) { 632 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, 633 SourceLocation(), 0, 634 *ParamType, VarDecl::None, 635 0); 636 Param->setImplicit(); 637 Params.push_back(Param); 638 } 639 640 New->setParams(Context, &Params[0], Params.size()); 641 642 } 643 644 return MergeCompatibleFunctionDecls(New, Old); 645 } 646 647 // A function that has already been declared has been redeclared or defined 648 // with a different type- show appropriate diagnostic 649 if (unsigned BuiltinID = Old->getBuiltinID(Context)) { 650 // The user has declared a builtin function with an incompatible 651 // signature. 652 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 653 // The function the user is redeclaring is a library-defined 654 // function like 'malloc' or 'printf'. Warn about the 655 // redeclaration, then ignore it. 656 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; 657 Diag(Old->getLocation(), diag::note_previous_builtin_declaration) 658 << Old << Old->getType(); 659 return true; 660 } 661 662 PrevDiag = diag::note_previous_builtin_declaration; 663 } 664 665 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 666 Diag(Old->getLocation(), PrevDiag) << Old << Old->getType(); 667 return true; 668} 669 670/// \brief Completes the merge of two function declarations that are 671/// known to be compatible. 672/// 673/// This routine handles the merging of attributes and other 674/// properties of function declarations form the old declaration to 675/// the new declaration, once we know that New is in fact a 676/// redeclaration of Old. 677/// 678/// \returns false 679bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) { 680 // Merge the attributes 681 MergeAttributes(New, Old); 682 683 // Merge the storage class. 684 New->setStorageClass(Old->getStorageClass()); 685 686 // FIXME: need to implement inline semantics 687 688 // Merge "pure" flag. 689 if (Old->isPure()) 690 New->setPure(); 691 692 // Merge the "deleted" flag. 693 if (Old->isDeleted()) 694 New->setDeleted(); 695 696 if (getLangOptions().CPlusPlus) 697 return MergeCXXFunctionDecl(New, Old); 698 699 return false; 700} 701 702/// Predicate for C "tentative" external object definitions (C99 6.9.2). 703static bool isTentativeDefinition(VarDecl *VD) { 704 if (VD->isFileVarDecl()) 705 return (!VD->getInit() && 706 (VD->getStorageClass() == VarDecl::None || 707 VD->getStorageClass() == VarDecl::Static)); 708 return false; 709} 710 711/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 712/// when dealing with C "tentative" external object definitions (C99 6.9.2). 713void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 714 bool VDIsTentative = isTentativeDefinition(VD); 715 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 716 717 // FIXME: I don't think this will actually see all of the 718 // redefinitions. Can't we check this property on-the-fly? 719 for (IdentifierResolver::iterator I = IdResolver.begin(VD->getIdentifier()), 720 E = IdResolver.end(); 721 I != E; ++I) { 722 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 723 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 724 725 // Handle the following case: 726 // int a[10]; 727 // int a[]; - the code below makes sure we set the correct type. 728 // int a[11]; - this is an error, size isn't 10. 729 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 730 OldDecl->getType()->isConstantArrayType()) 731 VD->setType(OldDecl->getType()); 732 733 // Check for "tentative" definitions. We can't accomplish this in 734 // MergeVarDecl since the initializer hasn't been attached. 735 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 736 continue; 737 738 // Handle __private_extern__ just like extern. 739 if (OldDecl->getStorageClass() != VarDecl::Extern && 740 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 741 VD->getStorageClass() != VarDecl::Extern && 742 VD->getStorageClass() != VarDecl::PrivateExtern) { 743 Diag(VD->getLocation(), diag::err_redefinition) << VD->getDeclName(); 744 Diag(OldDecl->getLocation(), diag::note_previous_definition); 745 // One redefinition error is enough. 746 break; 747 } 748 } 749 } 750} 751 752/// MergeVarDecl - We just parsed a variable 'New' which has the same name 753/// and scope as a previous declaration 'Old'. Figure out how to resolve this 754/// situation, merging decls or emitting diagnostics as appropriate. 755/// 756/// Tentative definition rules (C99 6.9.2p2) are checked by 757/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 758/// definitions here, since the initializer hasn't been attached. 759/// 760bool Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 761 // Verify the old decl was also a variable. 762 VarDecl *Old = dyn_cast<VarDecl>(OldD); 763 if (!Old) { 764 Diag(New->getLocation(), diag::err_redefinition_different_kind) 765 << New->getDeclName(); 766 Diag(OldD->getLocation(), diag::note_previous_definition); 767 return true; 768 } 769 770 MergeAttributes(New, Old); 771 772 // Merge the types 773 QualType MergedT = Context.mergeTypes(New->getType(), Old->getType()); 774 if (MergedT.isNull()) { 775 Diag(New->getLocation(), diag::err_redefinition_different_type) 776 << New->getDeclName(); 777 Diag(Old->getLocation(), diag::note_previous_definition); 778 return true; 779 } 780 New->setType(MergedT); 781 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 782 if (New->getStorageClass() == VarDecl::Static && 783 (Old->getStorageClass() == VarDecl::None || 784 Old->getStorageClass() == VarDecl::Extern)) { 785 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 786 Diag(Old->getLocation(), diag::note_previous_definition); 787 return true; 788 } 789 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 790 if (New->getStorageClass() != VarDecl::Static && 791 Old->getStorageClass() == VarDecl::Static) { 792 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 793 Diag(Old->getLocation(), diag::note_previous_definition); 794 return true; 795 } 796 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 797 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 798 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 799 Diag(Old->getLocation(), diag::note_previous_definition); 800 return true; 801 } 802 return false; 803} 804 805/// CheckParmsForFunctionDef - Check that the parameters of the given 806/// function are appropriate for the definition of a function. This 807/// takes care of any checks that cannot be performed on the 808/// declaration itself, e.g., that the types of each of the function 809/// parameters are complete. 810bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 811 bool HasInvalidParm = false; 812 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 813 ParmVarDecl *Param = FD->getParamDecl(p); 814 815 // C99 6.7.5.3p4: the parameters in a parameter type list in a 816 // function declarator that is part of a function definition of 817 // that function shall not have incomplete type. 818 if (!Param->isInvalidDecl() && 819 DiagnoseIncompleteType(Param->getLocation(), Param->getType(), 820 diag::err_typecheck_decl_incomplete_type)) { 821 Param->setInvalidDecl(); 822 HasInvalidParm = true; 823 } 824 825 // C99 6.9.1p5: If the declarator includes a parameter type list, the 826 // declaration of each parameter shall include an identifier. 827 if (Param->getIdentifier() == 0 && 828 !Param->isImplicit() && 829 !getLangOptions().CPlusPlus) 830 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 831 } 832 833 return HasInvalidParm; 834} 835 836/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 837/// no declarator (e.g. "struct foo;") is parsed. 838Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 839 TagDecl *Tag = 0; 840 if (DS.getTypeSpecType() == DeclSpec::TST_class || 841 DS.getTypeSpecType() == DeclSpec::TST_struct || 842 DS.getTypeSpecType() == DeclSpec::TST_union || 843 DS.getTypeSpecType() == DeclSpec::TST_enum) 844 Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 845 846 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) { 847 if (!Record->getDeclName() && Record->isDefinition() && 848 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) 849 return BuildAnonymousStructOrUnion(S, DS, Record); 850 851 // Microsoft allows unnamed struct/union fields. Don't complain 852 // about them. 853 // FIXME: Should we support Microsoft's extensions in this area? 854 if (Record->getDeclName() && getLangOptions().Microsoft) 855 return Tag; 856 } 857 858 if (!DS.isMissingDeclaratorOk() && 859 DS.getTypeSpecType() != DeclSpec::TST_error) { 860 // Warn about typedefs of enums without names, since this is an 861 // extension in both Microsoft an GNU. 862 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef && 863 Tag && isa<EnumDecl>(Tag)) { 864 Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name) 865 << DS.getSourceRange(); 866 return Tag; 867 } 868 869 Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators) 870 << DS.getSourceRange(); 871 return 0; 872 } 873 874 return Tag; 875} 876 877/// InjectAnonymousStructOrUnionMembers - Inject the members of the 878/// anonymous struct or union AnonRecord into the owning context Owner 879/// and scope S. This routine will be invoked just after we realize 880/// that an unnamed union or struct is actually an anonymous union or 881/// struct, e.g., 882/// 883/// @code 884/// union { 885/// int i; 886/// float f; 887/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and 888/// // f into the surrounding scope.x 889/// @endcode 890/// 891/// This routine is recursive, injecting the names of nested anonymous 892/// structs/unions into the owning context and scope as well. 893bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner, 894 RecordDecl *AnonRecord) { 895 bool Invalid = false; 896 for (RecordDecl::field_iterator F = AnonRecord->field_begin(), 897 FEnd = AnonRecord->field_end(); 898 F != FEnd; ++F) { 899 if ((*F)->getDeclName()) { 900 NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(), 901 LookupOrdinaryName, true); 902 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 903 // C++ [class.union]p2: 904 // The names of the members of an anonymous union shall be 905 // distinct from the names of any other entity in the 906 // scope in which the anonymous union is declared. 907 unsigned diagKind 908 = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl 909 : diag::err_anonymous_struct_member_redecl; 910 Diag((*F)->getLocation(), diagKind) 911 << (*F)->getDeclName(); 912 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 913 Invalid = true; 914 } else { 915 // C++ [class.union]p2: 916 // For the purpose of name lookup, after the anonymous union 917 // definition, the members of the anonymous union are 918 // considered to have been defined in the scope in which the 919 // anonymous union is declared. 920 Owner->makeDeclVisibleInContext(*F); 921 S->AddDecl(*F); 922 IdResolver.AddDecl(*F); 923 } 924 } else if (const RecordType *InnerRecordType 925 = (*F)->getType()->getAsRecordType()) { 926 RecordDecl *InnerRecord = InnerRecordType->getDecl(); 927 if (InnerRecord->isAnonymousStructOrUnion()) 928 Invalid = Invalid || 929 InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord); 930 } 931 } 932 933 return Invalid; 934} 935 936/// ActOnAnonymousStructOrUnion - Handle the declaration of an 937/// anonymous structure or union. Anonymous unions are a C++ feature 938/// (C++ [class.union]) and a GNU C extension; anonymous structures 939/// are a GNU C and GNU C++ extension. 940Sema::DeclTy *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, 941 RecordDecl *Record) { 942 DeclContext *Owner = Record->getDeclContext(); 943 944 // Diagnose whether this anonymous struct/union is an extension. 945 if (Record->isUnion() && !getLangOptions().CPlusPlus) 946 Diag(Record->getLocation(), diag::ext_anonymous_union); 947 else if (!Record->isUnion()) 948 Diag(Record->getLocation(), diag::ext_anonymous_struct); 949 950 // C and C++ require different kinds of checks for anonymous 951 // structs/unions. 952 bool Invalid = false; 953 if (getLangOptions().CPlusPlus) { 954 const char* PrevSpec = 0; 955 // C++ [class.union]p3: 956 // Anonymous unions declared in a named namespace or in the 957 // global namespace shall be declared static. 958 if (DS.getStorageClassSpec() != DeclSpec::SCS_static && 959 (isa<TranslationUnitDecl>(Owner) || 960 (isa<NamespaceDecl>(Owner) && 961 cast<NamespaceDecl>(Owner)->getDeclName()))) { 962 Diag(Record->getLocation(), diag::err_anonymous_union_not_static); 963 Invalid = true; 964 965 // Recover by adding 'static'. 966 DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec); 967 } 968 // C++ [class.union]p3: 969 // A storage class is not allowed in a declaration of an 970 // anonymous union in a class scope. 971 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 972 isa<RecordDecl>(Owner)) { 973 Diag(DS.getStorageClassSpecLoc(), 974 diag::err_anonymous_union_with_storage_spec); 975 Invalid = true; 976 977 // Recover by removing the storage specifier. 978 DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(), 979 PrevSpec); 980 } 981 982 // C++ [class.union]p2: 983 // The member-specification of an anonymous union shall only 984 // define non-static data members. [Note: nested types and 985 // functions cannot be declared within an anonymous union. ] 986 for (DeclContext::decl_iterator Mem = Record->decls_begin(), 987 MemEnd = Record->decls_end(); 988 Mem != MemEnd; ++Mem) { 989 if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) { 990 // C++ [class.union]p3: 991 // An anonymous union shall not have private or protected 992 // members (clause 11). 993 if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) { 994 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) 995 << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected); 996 Invalid = true; 997 } 998 } else if ((*Mem)->isImplicit()) { 999 // Any implicit members are fine. 1000 } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) { 1001 // This is a type that showed up in an 1002 // elaborated-type-specifier inside the anonymous struct or 1003 // union, but which actually declares a type outside of the 1004 // anonymous struct or union. It's okay. 1005 } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) { 1006 if (!MemRecord->isAnonymousStructOrUnion() && 1007 MemRecord->getDeclName()) { 1008 // This is a nested type declaration. 1009 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) 1010 << (int)Record->isUnion(); 1011 Invalid = true; 1012 } 1013 } else { 1014 // We have something that isn't a non-static data 1015 // member. Complain about it. 1016 unsigned DK = diag::err_anonymous_record_bad_member; 1017 if (isa<TypeDecl>(*Mem)) 1018 DK = diag::err_anonymous_record_with_type; 1019 else if (isa<FunctionDecl>(*Mem)) 1020 DK = diag::err_anonymous_record_with_function; 1021 else if (isa<VarDecl>(*Mem)) 1022 DK = diag::err_anonymous_record_with_static; 1023 Diag((*Mem)->getLocation(), DK) 1024 << (int)Record->isUnion(); 1025 Invalid = true; 1026 } 1027 } 1028 } else { 1029 // FIXME: Check GNU C semantics 1030 if (Record->isUnion() && !Owner->isRecord()) { 1031 Diag(Record->getLocation(), diag::err_anonymous_union_not_member) 1032 << (int)getLangOptions().CPlusPlus; 1033 Invalid = true; 1034 } 1035 } 1036 1037 if (!Record->isUnion() && !Owner->isRecord()) { 1038 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) 1039 << (int)getLangOptions().CPlusPlus; 1040 Invalid = true; 1041 } 1042 1043 // Create a declaration for this anonymous struct/union. 1044 NamedDecl *Anon = 0; 1045 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) { 1046 Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(), 1047 /*IdentifierInfo=*/0, 1048 Context.getTypeDeclType(Record), 1049 /*BitWidth=*/0, /*Mutable=*/false); 1050 Anon->setAccess(AS_public); 1051 if (getLangOptions().CPlusPlus) 1052 FieldCollector->Add(cast<FieldDecl>(Anon)); 1053 } else { 1054 VarDecl::StorageClass SC; 1055 switch (DS.getStorageClassSpec()) { 1056 default: assert(0 && "Unknown storage class!"); 1057 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1058 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1059 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1060 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1061 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1062 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1063 case DeclSpec::SCS_mutable: 1064 // mutable can only appear on non-static class members, so it's always 1065 // an error here 1066 Diag(Record->getLocation(), diag::err_mutable_nonmember); 1067 Invalid = true; 1068 SC = VarDecl::None; 1069 break; 1070 } 1071 1072 Anon = VarDecl::Create(Context, Owner, Record->getLocation(), 1073 /*IdentifierInfo=*/0, 1074 Context.getTypeDeclType(Record), 1075 SC, DS.getSourceRange().getBegin()); 1076 } 1077 Anon->setImplicit(); 1078 1079 // Add the anonymous struct/union object to the current 1080 // context. We'll be referencing this object when we refer to one of 1081 // its members. 1082 Owner->addDecl(Anon); 1083 1084 // Inject the members of the anonymous struct/union into the owning 1085 // context and into the identifier resolver chain for name lookup 1086 // purposes. 1087 if (InjectAnonymousStructOrUnionMembers(S, Owner, Record)) 1088 Invalid = true; 1089 1090 // Mark this as an anonymous struct/union type. Note that we do not 1091 // do this until after we have already checked and injected the 1092 // members of this anonymous struct/union type, because otherwise 1093 // the members could be injected twice: once by DeclContext when it 1094 // builds its lookup table, and once by 1095 // InjectAnonymousStructOrUnionMembers. 1096 Record->setAnonymousStructOrUnion(true); 1097 1098 if (Invalid) 1099 Anon->setInvalidDecl(); 1100 1101 return Anon; 1102} 1103 1104 1105/// GetNameForDeclarator - Determine the full declaration name for the 1106/// given Declarator. 1107DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 1108 switch (D.getKind()) { 1109 case Declarator::DK_Abstract: 1110 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 1111 return DeclarationName(); 1112 1113 case Declarator::DK_Normal: 1114 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 1115 return DeclarationName(D.getIdentifier()); 1116 1117 case Declarator::DK_Constructor: { 1118 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1119 Ty = Context.getCanonicalType(Ty); 1120 return Context.DeclarationNames.getCXXConstructorName(Ty); 1121 } 1122 1123 case Declarator::DK_Destructor: { 1124 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1125 Ty = Context.getCanonicalType(Ty); 1126 return Context.DeclarationNames.getCXXDestructorName(Ty); 1127 } 1128 1129 case Declarator::DK_Conversion: { 1130 // FIXME: We'd like to keep the non-canonical type for diagnostics! 1131 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 1132 Ty = Context.getCanonicalType(Ty); 1133 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 1134 } 1135 1136 case Declarator::DK_Operator: 1137 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 1138 return Context.DeclarationNames.getCXXOperatorName( 1139 D.getOverloadedOperator()); 1140 } 1141 1142 assert(false && "Unknown name kind"); 1143 return DeclarationName(); 1144} 1145 1146/// isNearlyMatchingFunction - Determine whether the C++ functions 1147/// Declaration and Definition are "nearly" matching. This heuristic 1148/// is used to improve diagnostics in the case where an out-of-line 1149/// function definition doesn't match any declaration within 1150/// the class or namespace. 1151static bool isNearlyMatchingFunction(ASTContext &Context, 1152 FunctionDecl *Declaration, 1153 FunctionDecl *Definition) { 1154 if (Declaration->param_size() != Definition->param_size()) 1155 return false; 1156 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { 1157 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); 1158 QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); 1159 1160 DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType()); 1161 DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType()); 1162 if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType()) 1163 return false; 1164 } 1165 1166 return true; 1167} 1168 1169Sema::DeclTy * 1170Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl, 1171 bool IsFunctionDefinition) { 1172 NamedDecl *LastDeclarator = dyn_cast_or_null<NamedDecl>((Decl *)lastDecl); 1173 DeclarationName Name = GetNameForDeclarator(D); 1174 1175 // All of these full declarators require an identifier. If it doesn't have 1176 // one, the ParsedFreeStandingDeclSpec action should be used. 1177 if (!Name) { 1178 if (!D.getInvalidType()) // Reject this if we think it is valid. 1179 Diag(D.getDeclSpec().getSourceRange().getBegin(), 1180 diag::err_declarator_need_ident) 1181 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 1182 return 0; 1183 } 1184 1185 // The scope passed in may not be a decl scope. Zip up the scope tree until 1186 // we find one that is. 1187 while ((S->getFlags() & Scope::DeclScope) == 0 || 1188 (S->getFlags() & Scope::TemplateParamScope) != 0) 1189 S = S->getParent(); 1190 1191 DeclContext *DC; 1192 NamedDecl *PrevDecl; 1193 NamedDecl *New; 1194 bool InvalidDecl = false; 1195 1196 QualType R = GetTypeForDeclarator(D, S); 1197 if (R.isNull()) { 1198 InvalidDecl = true; 1199 R = Context.IntTy; 1200 } 1201 1202 // See if this is a redefinition of a variable in the same scope. 1203 if (!D.getCXXScopeSpec().isSet() && !D.getCXXScopeSpec().isInvalid()) { 1204 LookupNameKind NameKind = LookupOrdinaryName; 1205 1206 // If the declaration we're planning to build will be a function 1207 // or object with linkage, then look for another declaration with 1208 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). 1209 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) 1210 /* Do nothing*/; 1211 else if (R->isFunctionType()) { 1212 if (CurContext->isFunctionOrMethod()) 1213 NameKind = LookupRedeclarationWithLinkage; 1214 } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern) 1215 NameKind = LookupRedeclarationWithLinkage; 1216 1217 DC = CurContext; 1218 PrevDecl = LookupName(S, Name, NameKind, true, 1219 D.getDeclSpec().getStorageClassSpec() != 1220 DeclSpec::SCS_static, 1221 D.getIdentifierLoc()); 1222 } else { // Something like "int foo::x;" 1223 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 1224 PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1225 1226 // C++ 7.3.1.2p2: 1227 // Members (including explicit specializations of templates) of a named 1228 // namespace can also be defined outside that namespace by explicit 1229 // qualification of the name being defined, provided that the entity being 1230 // defined was already declared in the namespace and the definition appears 1231 // after the point of declaration in a namespace that encloses the 1232 // declarations namespace. 1233 // 1234 // Note that we only check the context at this point. We don't yet 1235 // have enough information to make sure that PrevDecl is actually 1236 // the declaration we want to match. For example, given: 1237 // 1238 // class X { 1239 // void f(); 1240 // void f(float); 1241 // }; 1242 // 1243 // void X::f(int) { } // ill-formed 1244 // 1245 // In this case, PrevDecl will point to the overload set 1246 // containing the two f's declared in X, but neither of them 1247 // matches. 1248 1249 // First check whether we named the global scope. 1250 if (isa<TranslationUnitDecl>(DC)) { 1251 Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope) 1252 << Name << D.getCXXScopeSpec().getRange(); 1253 } else if (!CurContext->Encloses(DC)) { 1254 // The qualifying scope doesn't enclose the original declaration. 1255 // Emit diagnostic based on current scope. 1256 SourceLocation L = D.getIdentifierLoc(); 1257 SourceRange R = D.getCXXScopeSpec().getRange(); 1258 if (isa<FunctionDecl>(CurContext)) 1259 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 1260 else 1261 Diag(L, diag::err_invalid_declarator_scope) 1262 << Name << cast<NamedDecl>(DC) << R; 1263 InvalidDecl = true; 1264 } 1265 } 1266 1267 if (PrevDecl && PrevDecl->isTemplateParameter()) { 1268 // Maybe we will complain about the shadowed template parameter. 1269 InvalidDecl = InvalidDecl 1270 || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 1271 // Just pretend that we didn't see the previous declaration. 1272 PrevDecl = 0; 1273 } 1274 1275 // In C++, the previous declaration we find might be a tag type 1276 // (class or enum). In this case, the new declaration will hide the 1277 // tag type. Note that this does does not apply if we're declaring a 1278 // typedef (C++ [dcl.typedef]p4). 1279 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag && 1280 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef) 1281 PrevDecl = 0; 1282 1283 bool Redeclaration = false; 1284 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 1285 New = ActOnTypedefDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1286 InvalidDecl, Redeclaration); 1287 } else if (R->isFunctionType()) { 1288 New = ActOnFunctionDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1289 IsFunctionDefinition, InvalidDecl, 1290 Redeclaration); 1291 } else { 1292 New = ActOnVariableDeclarator(S, D, DC, R, LastDeclarator, PrevDecl, 1293 InvalidDecl, Redeclaration); 1294 } 1295 1296 if (New == 0) 1297 return 0; 1298 1299 // Set the lexical context. If the declarator has a C++ scope specifier, the 1300 // lexical context will be different from the semantic context. 1301 New->setLexicalDeclContext(CurContext); 1302 1303 // If this has an identifier and is not an invalid redeclaration, 1304 // add it to the scope stack. 1305 if (Name && !(Redeclaration && InvalidDecl)) 1306 PushOnScopeChains(New, S); 1307 // If any semantic error occurred, mark the decl as invalid. 1308 if (D.getInvalidType() || InvalidDecl) 1309 New->setInvalidDecl(); 1310 1311 return New; 1312} 1313 1314/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 1315/// types into constant array types in certain situations which would otherwise 1316/// be errors (for GCC compatibility). 1317static QualType TryToFixInvalidVariablyModifiedType(QualType T, 1318 ASTContext &Context, 1319 bool &SizeIsNegative) { 1320 // This method tries to turn a variable array into a constant 1321 // array even when the size isn't an ICE. This is necessary 1322 // for compatibility with code that depends on gcc's buggy 1323 // constant expression folding, like struct {char x[(int)(char*)2];} 1324 SizeIsNegative = false; 1325 1326 if (const PointerType* PTy = dyn_cast<PointerType>(T)) { 1327 QualType Pointee = PTy->getPointeeType(); 1328 QualType FixedType = 1329 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative); 1330 if (FixedType.isNull()) return FixedType; 1331 FixedType = Context.getPointerType(FixedType); 1332 FixedType.setCVRQualifiers(T.getCVRQualifiers()); 1333 return FixedType; 1334 } 1335 1336 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 1337 if (!VLATy) return QualType(); 1338 1339 Expr::EvalResult EvalResult; 1340 if (!VLATy->getSizeExpr() || 1341 !VLATy->getSizeExpr()->Evaluate(EvalResult, Context)) 1342 return QualType(); 1343 1344 assert(EvalResult.Val.isInt() && "Size expressions must be integers!"); 1345 llvm::APSInt &Res = EvalResult.Val.getInt(); 1346 if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1347 return Context.getConstantArrayType(VLATy->getElementType(), 1348 Res, ArrayType::Normal, 0); 1349 1350 SizeIsNegative = true; 1351 return QualType(); 1352} 1353 1354NamedDecl* 1355Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1356 QualType R, Decl* LastDeclarator, 1357 Decl* PrevDecl, bool& InvalidDecl, 1358 bool &Redeclaration) { 1359 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). 1360 if (D.getCXXScopeSpec().isSet()) { 1361 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) 1362 << D.getCXXScopeSpec().getRange(); 1363 InvalidDecl = true; 1364 // Pretend we didn't see the scope specifier. 1365 DC = 0; 1366 } 1367 1368 // Check that there are no default arguments (C++ only). 1369 if (getLangOptions().CPlusPlus) 1370 CheckExtraCXXDefaultArguments(D); 1371 1372 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 1373 if (!NewTD) return 0; 1374 1375 // Handle attributes prior to checking for duplicates in MergeVarDecl 1376 ProcessDeclAttributes(NewTD, D); 1377 // Merge the decl with the existing one if appropriate. If the decl is 1378 // in an outer scope, it isn't the same thing. 1379 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1380 Redeclaration = true; 1381 if (MergeTypeDefDecl(NewTD, PrevDecl)) 1382 InvalidDecl = true; 1383 } 1384 1385 if (S->getFnParent() == 0) { 1386 QualType T = NewTD->getUnderlyingType(); 1387 // C99 6.7.7p2: If a typedef name specifies a variably modified type 1388 // then it shall have block scope. 1389 if (T->isVariablyModifiedType()) { 1390 bool SizeIsNegative; 1391 QualType FixedTy = 1392 TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative); 1393 if (!FixedTy.isNull()) { 1394 Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size); 1395 NewTD->setUnderlyingType(FixedTy); 1396 } else { 1397 if (SizeIsNegative) 1398 Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size); 1399 else if (T->isVariableArrayType()) 1400 Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope); 1401 else 1402 Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope); 1403 InvalidDecl = true; 1404 } 1405 } 1406 } 1407 return NewTD; 1408} 1409 1410/// \brief Determines whether the given declaration is an out-of-scope 1411/// previous declaration. 1412/// 1413/// This routine should be invoked when name lookup has found a 1414/// previous declaration (PrevDecl) that is not in the scope where a 1415/// new declaration by the same name is being introduced. If the new 1416/// declaration occurs in a local scope, previous declarations with 1417/// linkage may still be considered previous declarations (C99 1418/// 6.2.2p4-5, C++ [basic.link]p6). 1419/// 1420/// \param PrevDecl the previous declaration found by name 1421/// lookup 1422/// 1423/// \param DC the context in which the new declaration is being 1424/// declared. 1425/// 1426/// \returns true if PrevDecl is an out-of-scope previous declaration 1427/// for a new delcaration with the same name. 1428static bool 1429isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, 1430 ASTContext &Context) { 1431 if (!PrevDecl) 1432 return 0; 1433 1434 // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which 1435 // case we need to check each of the overloaded functions. 1436 if (!PrevDecl->hasLinkage()) 1437 return false; 1438 1439 if (Context.getLangOptions().CPlusPlus) { 1440 // C++ [basic.link]p6: 1441 // If there is a visible declaration of an entity with linkage 1442 // having the same name and type, ignoring entities declared 1443 // outside the innermost enclosing namespace scope, the block 1444 // scope declaration declares that same entity and receives the 1445 // linkage of the previous declaration. 1446 DeclContext *OuterContext = DC->getLookupContext(); 1447 if (!OuterContext->isFunctionOrMethod()) 1448 // This rule only applies to block-scope declarations. 1449 return false; 1450 else { 1451 DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); 1452 if (PrevOuterContext->isRecord()) 1453 // We found a member function: ignore it. 1454 return false; 1455 else { 1456 // Find the innermost enclosing namespace for the new and 1457 // previous declarations. 1458 while (!OuterContext->isFileContext()) 1459 OuterContext = OuterContext->getParent(); 1460 while (!PrevOuterContext->isFileContext()) 1461 PrevOuterContext = PrevOuterContext->getParent(); 1462 1463 // The previous declaration is in a different namespace, so it 1464 // isn't the same function. 1465 if (OuterContext->getPrimaryContext() != 1466 PrevOuterContext->getPrimaryContext()) 1467 return false; 1468 } 1469 } 1470 } 1471 1472 return true; 1473} 1474 1475/// \brief Inject a locally-scoped declaration with external linkage 1476/// into the appropriate namespace scope. 1477/// 1478/// Given a declaration of an entity with linkage that occurs within a 1479/// local scope, this routine inject that declaration into top-level 1480/// scope so that it will be visible for later uses and declarations 1481/// of the same entity. 1482void Sema::InjectLocallyScopedExternalDeclaration(ValueDecl *VD) { 1483 // FIXME: We don't do this in C++ because, although we would like 1484 // to get the extra checking that this operation implies, 1485 // the declaration itself is not visible according to C++'s rules. 1486 assert(!getLangOptions().CPlusPlus && 1487 "Can't inject locally-scoped declarations in C++"); 1488 IdentifierResolver::iterator I = IdResolver.begin(VD->getDeclName()), 1489 IEnd = IdResolver.end(); 1490 NamedDecl *PrevDecl = 0; 1491 while (I != IEnd && !isa<TranslationUnitDecl>((*I)->getDeclContext())) { 1492 PrevDecl = *I; 1493 ++I; 1494 } 1495 1496 if (I == IEnd) { 1497 // No name with this identifier has been declared at translation 1498 // unit scope. Add this name into the appropriate scope. 1499 if (PrevDecl) 1500 IdResolver.AddShadowedDecl(VD, PrevDecl); 1501 else 1502 IdResolver.AddDecl(VD); 1503 TUScope->AddDecl(VD); 1504 return; 1505 } 1506 1507 if (isa<TagDecl>(*I)) { 1508 // The first thing we found was a tag declaration, so insert 1509 // this function so that it will be found before the tag 1510 // declaration. 1511 if (PrevDecl) 1512 IdResolver.AddShadowedDecl(VD, PrevDecl); 1513 else 1514 IdResolver.AddDecl(VD); 1515 TUScope->AddDecl(VD); 1516 return; 1517 } 1518 1519 if (VD->declarationReplaces(*I)) { 1520 // We found a previous declaration of the same entity. Replace 1521 // that declaration with this one. 1522 TUScope->RemoveDecl(*I); 1523 TUScope->AddDecl(VD); 1524 IdResolver.RemoveDecl(*I); 1525 if (PrevDecl) 1526 IdResolver.AddShadowedDecl(VD, PrevDecl); 1527 else 1528 IdResolver.AddDecl(VD); 1529 } 1530} 1531 1532NamedDecl* 1533Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1534 QualType R, Decl* LastDeclarator, 1535 NamedDecl* PrevDecl, bool& InvalidDecl, 1536 bool &Redeclaration) { 1537 DeclarationName Name = GetNameForDeclarator(D); 1538 1539 // Check that there are no default arguments (C++ only). 1540 if (getLangOptions().CPlusPlus) 1541 CheckExtraCXXDefaultArguments(D); 1542 1543 if (R.getTypePtr()->isObjCInterfaceType()) { 1544 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object); 1545 InvalidDecl = true; 1546 } 1547 1548 VarDecl *NewVD; 1549 VarDecl::StorageClass SC; 1550 switch (D.getDeclSpec().getStorageClassSpec()) { 1551 default: assert(0 && "Unknown storage class!"); 1552 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1553 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1554 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1555 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1556 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1557 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1558 case DeclSpec::SCS_mutable: 1559 // mutable can only appear on non-static class members, so it's always 1560 // an error here 1561 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1562 InvalidDecl = true; 1563 SC = VarDecl::None; 1564 break; 1565 } 1566 1567 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1568 if (!II) { 1569 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1570 << Name.getAsString(); 1571 return 0; 1572 } 1573 1574 if (DC->isRecord()) { 1575 // This is a static data member for a C++ class. 1576 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1577 D.getIdentifierLoc(), II, 1578 R); 1579 } else { 1580 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1581 if (S->getFnParent() == 0) { 1582 // C99 6.9p2: The storage-class specifiers auto and register shall not 1583 // appear in the declaration specifiers in an external declaration. 1584 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1585 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 1586 InvalidDecl = true; 1587 } 1588 } 1589 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1590 II, R, SC, 1591 // FIXME: Move to DeclGroup... 1592 D.getDeclSpec().getSourceRange().getBegin()); 1593 NewVD->setThreadSpecified(ThreadSpecified); 1594 } 1595 NewVD->setNextDeclarator(LastDeclarator); 1596 1597 // Handle attributes prior to checking for duplicates in MergeVarDecl 1598 ProcessDeclAttributes(NewVD, D); 1599 1600 // Handle GNU asm-label extension (encoded as an attribute). 1601 if (Expr *E = (Expr*) D.getAsmLabel()) { 1602 // The parser guarantees this is a string. 1603 StringLiteral *SE = cast<StringLiteral>(E); 1604 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1605 SE->getByteLength()))); 1606 } 1607 1608 // Emit an error if an address space was applied to decl with local storage. 1609 // This includes arrays of objects with address space qualifiers, but not 1610 // automatic variables that point to other address spaces. 1611 // ISO/IEC TR 18037 S5.1.2 1612 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1613 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1614 InvalidDecl = true; 1615 } 1616 1617 if (NewVD->hasLocalStorage() && NewVD->getType().isObjCGCWeak()) { 1618 Diag(D.getIdentifierLoc(), diag::warn_attribute_weak_on_local); 1619 } 1620 1621 // If name lookup finds a previous declaration that is not in the 1622 // same scope as the new declaration, this may still be an 1623 // acceptable redeclaration. 1624 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 1625 !(NewVD->hasLinkage() && 1626 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 1627 PrevDecl = 0; 1628 1629 // Merge the decl with the existing one if appropriate. 1630 if (PrevDecl) { 1631 if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) { 1632 // The user tried to define a non-static data member 1633 // out-of-line (C++ [dcl.meaning]p1). 1634 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) 1635 << D.getCXXScopeSpec().getRange(); 1636 NewVD->Destroy(Context); 1637 return 0; 1638 } 1639 1640 Redeclaration = true; 1641 if (MergeVarDecl(NewVD, PrevDecl)) 1642 InvalidDecl = true; 1643 1644 if (D.getCXXScopeSpec().isSet()) { 1645 // No previous declaration in the qualifying scope. 1646 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 1647 << Name << D.getCXXScopeSpec().getRange(); 1648 InvalidDecl = true; 1649 } 1650 } 1651 1652 // If this is a locally-scoped extern variable in C, inject a 1653 // declaration into translation unit scope so that all external 1654 // declarations are visible. 1655 if (!getLangOptions().CPlusPlus && CurContext->isFunctionOrMethod() && 1656 NewVD->hasLinkage()) 1657 InjectLocallyScopedExternalDeclaration(NewVD); 1658 1659 return NewVD; 1660} 1661 1662NamedDecl* 1663Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC, 1664 QualType R, Decl *LastDeclarator, 1665 NamedDecl* PrevDecl, bool IsFunctionDefinition, 1666 bool& InvalidDecl, bool &Redeclaration) { 1667 assert(R.getTypePtr()->isFunctionType()); 1668 1669 DeclarationName Name = GetNameForDeclarator(D); 1670 FunctionDecl::StorageClass SC = FunctionDecl::None; 1671 switch (D.getDeclSpec().getStorageClassSpec()) { 1672 default: assert(0 && "Unknown storage class!"); 1673 case DeclSpec::SCS_auto: 1674 case DeclSpec::SCS_register: 1675 case DeclSpec::SCS_mutable: 1676 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1677 diag::err_typecheck_sclass_func); 1678 InvalidDecl = true; 1679 break; 1680 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 1681 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 1682 case DeclSpec::SCS_static: { 1683 if (DC->getLookupContext()->isFunctionOrMethod()) { 1684 // C99 6.7.1p5: 1685 // The declaration of an identifier for a function that has 1686 // block scope shall have no explicit storage-class specifier 1687 // other than extern 1688 // See also (C++ [dcl.stc]p4). 1689 Diag(D.getDeclSpec().getStorageClassSpecLoc(), 1690 diag::err_static_block_func); 1691 SC = FunctionDecl::None; 1692 } else 1693 SC = FunctionDecl::Static; 1694 break; 1695 } 1696 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 1697 } 1698 1699 bool isInline = D.getDeclSpec().isInlineSpecified(); 1700 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 1701 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 1702 1703 FunctionDecl *NewFD; 1704 if (D.getKind() == Declarator::DK_Constructor) { 1705 // This is a C++ constructor declaration. 1706 assert(DC->isRecord() && 1707 "Constructors can only be declared in a member context"); 1708 1709 InvalidDecl = InvalidDecl || CheckConstructorDeclarator(D, R, SC); 1710 1711 // Create the new declaration 1712 NewFD = CXXConstructorDecl::Create(Context, 1713 cast<CXXRecordDecl>(DC), 1714 D.getIdentifierLoc(), Name, R, 1715 isExplicit, isInline, 1716 /*isImplicitlyDeclared=*/false); 1717 1718 if (InvalidDecl) 1719 NewFD->setInvalidDecl(); 1720 } else if (D.getKind() == Declarator::DK_Destructor) { 1721 // This is a C++ destructor declaration. 1722 if (DC->isRecord()) { 1723 InvalidDecl = InvalidDecl || CheckDestructorDeclarator(D, R, SC); 1724 1725 NewFD = CXXDestructorDecl::Create(Context, 1726 cast<CXXRecordDecl>(DC), 1727 D.getIdentifierLoc(), Name, R, 1728 isInline, 1729 /*isImplicitlyDeclared=*/false); 1730 1731 if (InvalidDecl) 1732 NewFD->setInvalidDecl(); 1733 } else { 1734 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 1735 1736 // Create a FunctionDecl to satisfy the function definition parsing 1737 // code path. 1738 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 1739 Name, R, SC, isInline, 1740 /*hasPrototype=*/true, 1741 // FIXME: Move to DeclGroup... 1742 D.getDeclSpec().getSourceRange().getBegin()); 1743 InvalidDecl = true; 1744 NewFD->setInvalidDecl(); 1745 } 1746 } else if (D.getKind() == Declarator::DK_Conversion) { 1747 if (!DC->isRecord()) { 1748 Diag(D.getIdentifierLoc(), 1749 diag::err_conv_function_not_member); 1750 return 0; 1751 } else { 1752 InvalidDecl = InvalidDecl || CheckConversionDeclarator(D, R, SC); 1753 1754 NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC), 1755 D.getIdentifierLoc(), Name, R, 1756 isInline, isExplicit); 1757 1758 if (InvalidDecl) 1759 NewFD->setInvalidDecl(); 1760 } 1761 } else if (DC->isRecord()) { 1762 // This is a C++ method declaration. 1763 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 1764 D.getIdentifierLoc(), Name, R, 1765 (SC == FunctionDecl::Static), isInline); 1766 } else { 1767 NewFD = FunctionDecl::Create(Context, DC, 1768 D.getIdentifierLoc(), 1769 Name, R, SC, isInline, 1770 /*hasPrototype=*/ 1771 (getLangOptions().CPlusPlus || 1772 (D.getNumTypeObjects() && 1773 D.getTypeObject(0).Fun.hasPrototype)), 1774 // FIXME: Move to DeclGroup... 1775 D.getDeclSpec().getSourceRange().getBegin()); 1776 } 1777 NewFD->setNextDeclarator(LastDeclarator); 1778 1779 // Set the lexical context. If the declarator has a C++ 1780 // scope specifier, the lexical context will be different 1781 // from the semantic context. 1782 NewFD->setLexicalDeclContext(CurContext); 1783 1784 // Handle GNU asm-label extension (encoded as an attribute). 1785 if (Expr *E = (Expr*) D.getAsmLabel()) { 1786 // The parser guarantees this is a string. 1787 StringLiteral *SE = cast<StringLiteral>(E); 1788 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1789 SE->getByteLength()))); 1790 } 1791 1792 // Copy the parameter declarations from the declarator D to 1793 // the function declaration NewFD, if they are available. 1794 if (D.getNumTypeObjects() > 0) { 1795 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1796 1797 // Create Decl objects for each parameter, adding them to the 1798 // FunctionDecl. 1799 llvm::SmallVector<ParmVarDecl*, 16> Params; 1800 1801 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1802 // function that takes no arguments, not a function that takes a 1803 // single void argument. 1804 // We let through "const void" here because Sema::GetTypeForDeclarator 1805 // already checks for that case. 1806 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1807 FTI.ArgInfo[0].Param && 1808 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1809 // empty arg list, don't push any params. 1810 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1811 1812 // In C++, the empty parameter-type-list must be spelled "void"; a 1813 // typedef of void is not permitted. 1814 if (getLangOptions().CPlusPlus && 1815 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1816 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1817 } 1818 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1819 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1820 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1821 } 1822 1823 NewFD->setParams(Context, &Params[0], Params.size()); 1824 } else if (R->getAsTypedefType()) { 1825 // When we're declaring a function with a typedef, as in the 1826 // following example, we'll need to synthesize (unnamed) 1827 // parameters for use in the declaration. 1828 // 1829 // @code 1830 // typedef void fn(int); 1831 // fn f; 1832 // @endcode 1833 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1834 if (!FT) { 1835 // This is a typedef of a function with no prototype, so we 1836 // don't need to do anything. 1837 } else if ((FT->getNumArgs() == 0) || 1838 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1839 FT->getArgType(0)->isVoidType())) { 1840 // This is a zero-argument function. We don't need to do anything. 1841 } else { 1842 // Synthesize a parameter for each argument type. 1843 llvm::SmallVector<ParmVarDecl*, 16> Params; 1844 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1845 ArgType != FT->arg_type_end(); ++ArgType) { 1846 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, 1847 SourceLocation(), 0, 1848 *ArgType, VarDecl::None, 1849 0); 1850 Param->setImplicit(); 1851 Params.push_back(Param); 1852 } 1853 1854 NewFD->setParams(Context, &Params[0], Params.size()); 1855 } 1856 } 1857 1858 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1859 InvalidDecl = InvalidDecl || CheckConstructor(Constructor); 1860 else if (isa<CXXDestructorDecl>(NewFD)) { 1861 CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent()); 1862 Record->setUserDeclaredDestructor(true); 1863 // C++ [class]p4: A POD-struct is an aggregate class that has [...] no 1864 // user-defined destructor. 1865 Record->setPOD(false); 1866 } else if (CXXConversionDecl *Conversion = 1867 dyn_cast<CXXConversionDecl>(NewFD)) 1868 ActOnConversionDeclarator(Conversion); 1869 1870 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1871 if (NewFD->isOverloadedOperator() && 1872 CheckOverloadedOperatorDeclaration(NewFD)) 1873 NewFD->setInvalidDecl(); 1874 1875 // If name lookup finds a previous declaration that is not in the 1876 // same scope as the new declaration, this may still be an 1877 // acceptable redeclaration. 1878 if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) && 1879 !(NewFD->hasLinkage() && 1880 isOutOfScopePreviousDeclaration(PrevDecl, DC, Context))) 1881 PrevDecl = 0; 1882 1883 // Merge or overload the declaration with an existing declaration of 1884 // the same name, if appropriate. 1885 bool OverloadableAttrRequired = false; 1886 if (PrevDecl) { 1887 // Determine whether NewFD is an overload of PrevDecl or 1888 // a declaration that requires merging. If it's an overload, 1889 // there's no more work to do here; we'll just add the new 1890 // function to the scope. 1891 OverloadedFunctionDecl::function_iterator MatchedDecl; 1892 1893 if (!getLangOptions().CPlusPlus && 1894 AllowOverloadingOfFunction(PrevDecl, Context)) { 1895 OverloadableAttrRequired = true; 1896 1897 // Functions marked "overloadable" must have a prototype (that 1898 // we can't get through declaration merging). 1899 if (!R->getAsFunctionTypeProto()) { 1900 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype) 1901 << NewFD; 1902 InvalidDecl = true; 1903 Redeclaration = true; 1904 1905 // Turn this into a variadic function with no parameters. 1906 R = Context.getFunctionType(R->getAsFunctionType()->getResultType(), 1907 0, 0, true, 0); 1908 NewFD->setType(R); 1909 } 1910 } 1911 1912 if (PrevDecl && 1913 (!AllowOverloadingOfFunction(PrevDecl, Context) || 1914 !IsOverload(NewFD, PrevDecl, MatchedDecl))) { 1915 Redeclaration = true; 1916 Decl *OldDecl = PrevDecl; 1917 1918 // If PrevDecl was an overloaded function, extract the 1919 // FunctionDecl that matched. 1920 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1921 OldDecl = *MatchedDecl; 1922 1923 // NewFD and PrevDecl represent declarations that need to be 1924 // merged. 1925 if (MergeFunctionDecl(NewFD, OldDecl)) 1926 InvalidDecl = true; 1927 1928 if (!InvalidDecl) { 1929 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1930 1931 // An out-of-line member function declaration must also be a 1932 // definition (C++ [dcl.meaning]p1). 1933 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && 1934 !InvalidDecl) { 1935 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 1936 << D.getCXXScopeSpec().getRange(); 1937 NewFD->setInvalidDecl(); 1938 } 1939 } 1940 } 1941 } 1942 1943 if (D.getCXXScopeSpec().isSet() && 1944 (!PrevDecl || !Redeclaration)) { 1945 // The user tried to provide an out-of-line definition for a 1946 // function that is a member of a class or namespace, but there 1947 // was no such member function declared (C++ [class.mfct]p2, 1948 // C++ [namespace.memdef]p2). For example: 1949 // 1950 // class X { 1951 // void f() const; 1952 // }; 1953 // 1954 // void X::f() { } // ill-formed 1955 // 1956 // Complain about this problem, and attempt to suggest close 1957 // matches (e.g., those that differ only in cv-qualifiers and 1958 // whether the parameter types are references). 1959 Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match) 1960 << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange(); 1961 InvalidDecl = true; 1962 1963 LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName, 1964 true); 1965 assert(!Prev.isAmbiguous() && 1966 "Cannot have an ambiguity in previous-declaration lookup"); 1967 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); 1968 Func != FuncEnd; ++Func) { 1969 if (isa<FunctionDecl>(*Func) && 1970 isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD)) 1971 Diag((*Func)->getLocation(), diag::note_member_def_close_match); 1972 } 1973 1974 PrevDecl = 0; 1975 } 1976 1977 // Handle attributes. We need to have merged decls when handling attributes 1978 // (for example to check for conflicts, etc). 1979 ProcessDeclAttributes(NewFD, D); 1980 AddKnownFunctionAttributes(NewFD); 1981 1982 if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) { 1983 // If a function name is overloadable in C, then every function 1984 // with that name must be marked "overloadable". 1985 Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing) 1986 << Redeclaration << NewFD; 1987 if (PrevDecl) 1988 Diag(PrevDecl->getLocation(), 1989 diag::note_attribute_overloadable_prev_overload); 1990 NewFD->addAttr(new OverloadableAttr); 1991 } 1992 1993 if (getLangOptions().CPlusPlus) { 1994 // In C++, check default arguments now that we have merged decls. Unless 1995 // the lexical context is the class, because in this case this is done 1996 // during delayed parsing anyway. 1997 if (!CurContext->isRecord()) 1998 CheckCXXDefaultArguments(NewFD); 1999 2000 // An out-of-line member function declaration must also be a 2001 // definition (C++ [dcl.meaning]p1). 2002 if (!IsFunctionDefinition && D.getCXXScopeSpec().isSet() && !InvalidDecl) { 2003 Diag(NewFD->getLocation(), diag::err_out_of_line_declaration) 2004 << D.getCXXScopeSpec().getRange(); 2005 InvalidDecl = true; 2006 } 2007 } 2008 2009 // If this is a locally-scoped function in C, inject a declaration 2010 // into translation unit scope so that all external declarations are 2011 // visible. 2012 if (!getLangOptions().CPlusPlus && CurContext->isFunctionOrMethod()) 2013 InjectLocallyScopedExternalDeclaration(NewFD); 2014 2015 return NewFD; 2016} 2017 2018void Sema::InitializerElementNotConstant(const Expr *Init) { 2019 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 2020 << Init->getSourceRange(); 2021} 2022 2023bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 2024 switch (Init->getStmtClass()) { 2025 default: 2026 InitializerElementNotConstant(Init); 2027 return true; 2028 case Expr::ParenExprClass: { 2029 const ParenExpr* PE = cast<ParenExpr>(Init); 2030 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 2031 } 2032 case Expr::CompoundLiteralExprClass: 2033 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 2034 case Expr::DeclRefExprClass: 2035 case Expr::QualifiedDeclRefExprClass: { 2036 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 2037 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 2038 if (VD->hasGlobalStorage()) 2039 return false; 2040 InitializerElementNotConstant(Init); 2041 return true; 2042 } 2043 if (isa<FunctionDecl>(D)) 2044 return false; 2045 InitializerElementNotConstant(Init); 2046 return true; 2047 } 2048 case Expr::MemberExprClass: { 2049 const MemberExpr *M = cast<MemberExpr>(Init); 2050 if (M->isArrow()) 2051 return CheckAddressConstantExpression(M->getBase()); 2052 return CheckAddressConstantExpressionLValue(M->getBase()); 2053 } 2054 case Expr::ArraySubscriptExprClass: { 2055 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 2056 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 2057 return CheckAddressConstantExpression(ASE->getBase()) || 2058 CheckArithmeticConstantExpression(ASE->getIdx()); 2059 } 2060 case Expr::StringLiteralClass: 2061 case Expr::ObjCEncodeExprClass: 2062 case Expr::PredefinedExprClass: 2063 return false; 2064 case Expr::UnaryOperatorClass: { 2065 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2066 2067 // C99 6.6p9 2068 if (Exp->getOpcode() == UnaryOperator::Deref) 2069 return CheckAddressConstantExpression(Exp->getSubExpr()); 2070 2071 InitializerElementNotConstant(Init); 2072 return true; 2073 } 2074 } 2075} 2076 2077bool Sema::CheckAddressConstantExpression(const Expr* Init) { 2078 switch (Init->getStmtClass()) { 2079 default: 2080 InitializerElementNotConstant(Init); 2081 return true; 2082 case Expr::ParenExprClass: 2083 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 2084 case Expr::StringLiteralClass: 2085 case Expr::ObjCEncodeExprClass: 2086 case Expr::ObjCStringLiteralClass: 2087 return false; 2088 case Expr::CallExprClass: 2089 case Expr::CXXOperatorCallExprClass: 2090 // __builtin___CFStringMakeConstantString is a valid constant l-value. 2091 if (cast<CallExpr>(Init)->isBuiltinCall(Context) == 2092 Builtin::BI__builtin___CFStringMakeConstantString) 2093 return false; 2094 2095 InitializerElementNotConstant(Init); 2096 return true; 2097 2098 case Expr::UnaryOperatorClass: { 2099 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2100 2101 // C99 6.6p9 2102 if (Exp->getOpcode() == UnaryOperator::AddrOf) 2103 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 2104 2105 if (Exp->getOpcode() == UnaryOperator::Extension) 2106 return CheckAddressConstantExpression(Exp->getSubExpr()); 2107 2108 InitializerElementNotConstant(Init); 2109 return true; 2110 } 2111 case Expr::BinaryOperatorClass: { 2112 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 2113 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 2114 2115 Expr *PExp = Exp->getLHS(); 2116 Expr *IExp = Exp->getRHS(); 2117 if (IExp->getType()->isPointerType()) 2118 std::swap(PExp, IExp); 2119 2120 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 2121 return CheckAddressConstantExpression(PExp) || 2122 CheckArithmeticConstantExpression(IExp); 2123 } 2124 case Expr::ImplicitCastExprClass: 2125 case Expr::CStyleCastExprClass: { 2126 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 2127 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 2128 // Check for implicit promotion 2129 if (SubExpr->getType()->isFunctionType() || 2130 SubExpr->getType()->isArrayType()) 2131 return CheckAddressConstantExpressionLValue(SubExpr); 2132 } 2133 2134 // Check for pointer->pointer cast 2135 if (SubExpr->getType()->isPointerType()) 2136 return CheckAddressConstantExpression(SubExpr); 2137 2138 if (SubExpr->getType()->isIntegralType()) { 2139 // Check for the special-case of a pointer->int->pointer cast; 2140 // this isn't standard, but some code requires it. See 2141 // PR2720 for an example. 2142 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 2143 if (SubCast->getSubExpr()->getType()->isPointerType()) { 2144 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 2145 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 2146 if (IntWidth >= PointerWidth) { 2147 return CheckAddressConstantExpression(SubCast->getSubExpr()); 2148 } 2149 } 2150 } 2151 } 2152 if (SubExpr->getType()->isArithmeticType()) { 2153 return CheckArithmeticConstantExpression(SubExpr); 2154 } 2155 2156 InitializerElementNotConstant(Init); 2157 return true; 2158 } 2159 case Expr::ConditionalOperatorClass: { 2160 // FIXME: Should we pedwarn here? 2161 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 2162 if (!Exp->getCond()->getType()->isArithmeticType()) { 2163 InitializerElementNotConstant(Init); 2164 return true; 2165 } 2166 if (CheckArithmeticConstantExpression(Exp->getCond())) 2167 return true; 2168 if (Exp->getLHS() && 2169 CheckAddressConstantExpression(Exp->getLHS())) 2170 return true; 2171 return CheckAddressConstantExpression(Exp->getRHS()); 2172 } 2173 case Expr::AddrLabelExprClass: 2174 return false; 2175 } 2176} 2177 2178static const Expr* FindExpressionBaseAddress(const Expr* E); 2179 2180static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 2181 switch (E->getStmtClass()) { 2182 default: 2183 return E; 2184 case Expr::ParenExprClass: { 2185 const ParenExpr* PE = cast<ParenExpr>(E); 2186 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 2187 } 2188 case Expr::MemberExprClass: { 2189 const MemberExpr *M = cast<MemberExpr>(E); 2190 if (M->isArrow()) 2191 return FindExpressionBaseAddress(M->getBase()); 2192 return FindExpressionBaseAddressLValue(M->getBase()); 2193 } 2194 case Expr::ArraySubscriptExprClass: { 2195 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 2196 return FindExpressionBaseAddress(ASE->getBase()); 2197 } 2198 case Expr::UnaryOperatorClass: { 2199 const UnaryOperator *Exp = cast<UnaryOperator>(E); 2200 2201 if (Exp->getOpcode() == UnaryOperator::Deref) 2202 return FindExpressionBaseAddress(Exp->getSubExpr()); 2203 2204 return E; 2205 } 2206 } 2207} 2208 2209static const Expr* FindExpressionBaseAddress(const Expr* E) { 2210 switch (E->getStmtClass()) { 2211 default: 2212 return E; 2213 case Expr::ParenExprClass: { 2214 const ParenExpr* PE = cast<ParenExpr>(E); 2215 return FindExpressionBaseAddress(PE->getSubExpr()); 2216 } 2217 case Expr::UnaryOperatorClass: { 2218 const UnaryOperator *Exp = cast<UnaryOperator>(E); 2219 2220 // C99 6.6p9 2221 if (Exp->getOpcode() == UnaryOperator::AddrOf) 2222 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 2223 2224 if (Exp->getOpcode() == UnaryOperator::Extension) 2225 return FindExpressionBaseAddress(Exp->getSubExpr()); 2226 2227 return E; 2228 } 2229 case Expr::BinaryOperatorClass: { 2230 const BinaryOperator *Exp = cast<BinaryOperator>(E); 2231 2232 Expr *PExp = Exp->getLHS(); 2233 Expr *IExp = Exp->getRHS(); 2234 if (IExp->getType()->isPointerType()) 2235 std::swap(PExp, IExp); 2236 2237 return FindExpressionBaseAddress(PExp); 2238 } 2239 case Expr::ImplicitCastExprClass: { 2240 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 2241 2242 // Check for implicit promotion 2243 if (SubExpr->getType()->isFunctionType() || 2244 SubExpr->getType()->isArrayType()) 2245 return FindExpressionBaseAddressLValue(SubExpr); 2246 2247 // Check for pointer->pointer cast 2248 if (SubExpr->getType()->isPointerType()) 2249 return FindExpressionBaseAddress(SubExpr); 2250 2251 // We assume that we have an arithmetic expression here; 2252 // if we don't, we'll figure it out later 2253 return 0; 2254 } 2255 case Expr::CStyleCastExprClass: { 2256 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 2257 2258 // Check for pointer->pointer cast 2259 if (SubExpr->getType()->isPointerType()) 2260 return FindExpressionBaseAddress(SubExpr); 2261 2262 // We assume that we have an arithmetic expression here; 2263 // if we don't, we'll figure it out later 2264 return 0; 2265 } 2266 } 2267} 2268 2269bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 2270 switch (Init->getStmtClass()) { 2271 default: 2272 InitializerElementNotConstant(Init); 2273 return true; 2274 case Expr::ParenExprClass: { 2275 const ParenExpr* PE = cast<ParenExpr>(Init); 2276 return CheckArithmeticConstantExpression(PE->getSubExpr()); 2277 } 2278 case Expr::FloatingLiteralClass: 2279 case Expr::IntegerLiteralClass: 2280 case Expr::CharacterLiteralClass: 2281 case Expr::ImaginaryLiteralClass: 2282 case Expr::TypesCompatibleExprClass: 2283 case Expr::CXXBoolLiteralExprClass: 2284 return false; 2285 case Expr::CallExprClass: 2286 case Expr::CXXOperatorCallExprClass: { 2287 const CallExpr *CE = cast<CallExpr>(Init); 2288 2289 // Allow any constant foldable calls to builtins. 2290 if (CE->isBuiltinCall(Context) && CE->isEvaluatable(Context)) 2291 return false; 2292 2293 InitializerElementNotConstant(Init); 2294 return true; 2295 } 2296 case Expr::DeclRefExprClass: 2297 case Expr::QualifiedDeclRefExprClass: { 2298 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 2299 if (isa<EnumConstantDecl>(D)) 2300 return false; 2301 InitializerElementNotConstant(Init); 2302 return true; 2303 } 2304 case Expr::CompoundLiteralExprClass: 2305 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 2306 // but vectors are allowed to be magic. 2307 if (Init->getType()->isVectorType()) 2308 return false; 2309 InitializerElementNotConstant(Init); 2310 return true; 2311 case Expr::UnaryOperatorClass: { 2312 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 2313 2314 switch (Exp->getOpcode()) { 2315 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 2316 // See C99 6.6p3. 2317 default: 2318 InitializerElementNotConstant(Init); 2319 return true; 2320 case UnaryOperator::OffsetOf: 2321 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 2322 return false; 2323 InitializerElementNotConstant(Init); 2324 return true; 2325 case UnaryOperator::Extension: 2326 case UnaryOperator::LNot: 2327 case UnaryOperator::Plus: 2328 case UnaryOperator::Minus: 2329 case UnaryOperator::Not: 2330 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 2331 } 2332 } 2333 case Expr::SizeOfAlignOfExprClass: { 2334 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 2335 // Special check for void types, which are allowed as an extension 2336 if (Exp->getTypeOfArgument()->isVoidType()) 2337 return false; 2338 // alignof always evaluates to a constant. 2339 // FIXME: is sizeof(int[3.0]) a constant expression? 2340 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 2341 InitializerElementNotConstant(Init); 2342 return true; 2343 } 2344 return false; 2345 } 2346 case Expr::BinaryOperatorClass: { 2347 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 2348 2349 if (Exp->getLHS()->getType()->isArithmeticType() && 2350 Exp->getRHS()->getType()->isArithmeticType()) { 2351 return CheckArithmeticConstantExpression(Exp->getLHS()) || 2352 CheckArithmeticConstantExpression(Exp->getRHS()); 2353 } 2354 2355 if (Exp->getLHS()->getType()->isPointerType() && 2356 Exp->getRHS()->getType()->isPointerType()) { 2357 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 2358 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 2359 2360 // Only allow a null (constant integer) base; we could 2361 // allow some additional cases if necessary, but this 2362 // is sufficient to cover offsetof-like constructs. 2363 if (!LHSBase && !RHSBase) { 2364 return CheckAddressConstantExpression(Exp->getLHS()) || 2365 CheckAddressConstantExpression(Exp->getRHS()); 2366 } 2367 } 2368 2369 InitializerElementNotConstant(Init); 2370 return true; 2371 } 2372 case Expr::ImplicitCastExprClass: 2373 case Expr::CStyleCastExprClass: { 2374 const CastExpr *CE = cast<CastExpr>(Init); 2375 const Expr *SubExpr = CE->getSubExpr(); 2376 2377 if (SubExpr->getType()->isArithmeticType()) 2378 return CheckArithmeticConstantExpression(SubExpr); 2379 2380 if (SubExpr->getType()->isPointerType()) { 2381 const Expr* Base = FindExpressionBaseAddress(SubExpr); 2382 if (Base) { 2383 // the cast is only valid if done to a wide enough type 2384 if (Context.getTypeSize(CE->getType()) >= 2385 Context.getTypeSize(SubExpr->getType())) 2386 return false; 2387 } else { 2388 // If the pointer has a null base, this is an offsetof-like construct 2389 return CheckAddressConstantExpression(SubExpr); 2390 } 2391 } 2392 2393 InitializerElementNotConstant(Init); 2394 return true; 2395 } 2396 case Expr::ConditionalOperatorClass: { 2397 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 2398 2399 // If GNU extensions are disabled, we require all operands to be arithmetic 2400 // constant expressions. 2401 if (getLangOptions().NoExtensions) { 2402 return CheckArithmeticConstantExpression(Exp->getCond()) || 2403 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 2404 CheckArithmeticConstantExpression(Exp->getRHS()); 2405 } 2406 2407 // Otherwise, we have to emulate some of the behavior of fold here. 2408 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 2409 // because it can constant fold things away. To retain compatibility with 2410 // GCC code, we see if we can fold the condition to a constant (which we 2411 // should always be able to do in theory). If so, we only require the 2412 // specified arm of the conditional to be a constant. This is a horrible 2413 // hack, but is require by real world code that uses __builtin_constant_p. 2414 Expr::EvalResult EvalResult; 2415 if (!Exp->getCond()->Evaluate(EvalResult, Context) || 2416 EvalResult.HasSideEffects) { 2417 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 2418 // won't be able to either. Use it to emit the diagnostic though. 2419 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 2420 assert(Res && "Evaluate couldn't evaluate this constant?"); 2421 return Res; 2422 } 2423 2424 // Verify that the side following the condition is also a constant. 2425 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 2426 if (EvalResult.Val.getInt() == 0) 2427 std::swap(TrueSide, FalseSide); 2428 2429 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 2430 return true; 2431 2432 // Okay, the evaluated side evaluates to a constant, so we accept this. 2433 // Check to see if the other side is obviously not a constant. If so, 2434 // emit a warning that this is a GNU extension. 2435 if (FalseSide && !FalseSide->isEvaluatable(Context)) 2436 Diag(Init->getExprLoc(), 2437 diag::ext_typecheck_expression_not_constant_but_accepted) 2438 << FalseSide->getSourceRange(); 2439 return false; 2440 } 2441 } 2442} 2443 2444bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 2445 if (Init->isConstantInitializer(Context)) 2446 return false; 2447 InitializerElementNotConstant(Init); 2448 return true; 2449 2450 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) 2451 Init = DIE->getInit(); 2452 2453 Init = Init->IgnoreParens(); 2454 2455 if (Init->isEvaluatable(Context)) 2456 return false; 2457 2458 // Look through CXXDefaultArgExprs; they have no meaning in this context. 2459 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 2460 return CheckForConstantInitializer(DAE->getExpr(), DclT); 2461 2462 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 2463 return CheckForConstantInitializer(e->getInitializer(), DclT); 2464 2465 if (isa<ImplicitValueInitExpr>(Init)) { 2466 // FIXME: In C++, check for non-POD types. 2467 return false; 2468 } 2469 2470 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 2471 unsigned numInits = Exp->getNumInits(); 2472 for (unsigned i = 0; i < numInits; i++) { 2473 // FIXME: Need to get the type of the declaration for C++, 2474 // because it could be a reference? 2475 2476 if (CheckForConstantInitializer(Exp->getInit(i), 2477 Exp->getInit(i)->getType())) 2478 return true; 2479 } 2480 return false; 2481 } 2482 2483 // FIXME: We can probably remove some of this code below, now that 2484 // Expr::Evaluate is doing the heavy lifting for scalars. 2485 2486 if (Init->isNullPointerConstant(Context)) 2487 return false; 2488 if (Init->getType()->isArithmeticType()) { 2489 QualType InitTy = Context.getCanonicalType(Init->getType()) 2490 .getUnqualifiedType(); 2491 if (InitTy == Context.BoolTy) { 2492 // Special handling for pointers implicitly cast to bool; 2493 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 2494 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 2495 Expr* SubE = ICE->getSubExpr(); 2496 if (SubE->getType()->isPointerType() || 2497 SubE->getType()->isArrayType() || 2498 SubE->getType()->isFunctionType()) { 2499 return CheckAddressConstantExpression(Init); 2500 } 2501 } 2502 } else if (InitTy->isIntegralType()) { 2503 Expr* SubE = 0; 2504 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 2505 SubE = CE->getSubExpr(); 2506 // Special check for pointer cast to int; we allow as an extension 2507 // an address constant cast to an integer if the integer 2508 // is of an appropriate width (this sort of code is apparently used 2509 // in some places). 2510 // FIXME: Add pedwarn? 2511 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 2512 if (SubE && (SubE->getType()->isPointerType() || 2513 SubE->getType()->isArrayType() || 2514 SubE->getType()->isFunctionType())) { 2515 unsigned IntWidth = Context.getTypeSize(Init->getType()); 2516 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 2517 if (IntWidth >= PointerWidth) 2518 return CheckAddressConstantExpression(Init); 2519 } 2520 } 2521 2522 return CheckArithmeticConstantExpression(Init); 2523 } 2524 2525 if (Init->getType()->isPointerType()) 2526 return CheckAddressConstantExpression(Init); 2527 2528 // An array type at the top level that isn't an init-list must 2529 // be a string literal 2530 if (Init->getType()->isArrayType()) 2531 return false; 2532 2533 if (Init->getType()->isFunctionType()) 2534 return false; 2535 2536 // Allow block exprs at top level. 2537 if (Init->getType()->isBlockPointerType()) 2538 return false; 2539 2540 // GCC cast to union extension 2541 // note: the validity of the cast expr is checked by CheckCastTypes() 2542 if (CastExpr *C = dyn_cast<CastExpr>(Init)) { 2543 QualType T = C->getType(); 2544 return T->isUnionType() && CheckForConstantInitializer(C->getSubExpr(), T); 2545 } 2546 2547 InitializerElementNotConstant(Init); 2548 return true; 2549} 2550 2551void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init) { 2552 AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false); 2553} 2554 2555/// AddInitializerToDecl - Adds the initializer Init to the 2556/// declaration dcl. If DirectInit is true, this is C++ direct 2557/// initialization rather than copy initialization. 2558void Sema::AddInitializerToDecl(DeclTy *dcl, ExprArg init, bool DirectInit) { 2559 Decl *RealDecl = static_cast<Decl *>(dcl); 2560 Expr *Init = static_cast<Expr *>(init.release()); 2561 assert(Init && "missing initializer"); 2562 2563 // If there is no declaration, there was an error parsing it. Just ignore 2564 // the initializer. 2565 if (RealDecl == 0) { 2566 Init->Destroy(Context); 2567 return; 2568 } 2569 2570 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 2571 if (!VDecl) { 2572 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 2573 RealDecl->setInvalidDecl(); 2574 return; 2575 } 2576 // Get the decls type and save a reference for later, since 2577 // CheckInitializerTypes may change it. 2578 QualType DclT = VDecl->getType(), SavT = DclT; 2579 if (VDecl->isBlockVarDecl()) { 2580 VarDecl::StorageClass SC = VDecl->getStorageClass(); 2581 if (SC == VarDecl::Extern) { // C99 6.7.8p5 2582 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 2583 VDecl->setInvalidDecl(); 2584 } else if (!VDecl->isInvalidDecl()) { 2585 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2586 VDecl->getDeclName(), DirectInit)) 2587 VDecl->setInvalidDecl(); 2588 2589 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2590 // Don't check invalid declarations to avoid emitting useless diagnostics. 2591 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 2592 if (SC == VarDecl::Static) // C99 6.7.8p4. 2593 CheckForConstantInitializer(Init, DclT); 2594 } 2595 } 2596 } else if (VDecl->isFileVarDecl()) { 2597 if (VDecl->getStorageClass() == VarDecl::Extern) 2598 Diag(VDecl->getLocation(), diag::warn_extern_init); 2599 if (!VDecl->isInvalidDecl()) 2600 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 2601 VDecl->getDeclName(), DirectInit)) 2602 VDecl->setInvalidDecl(); 2603 2604 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 2605 // Don't check invalid declarations to avoid emitting useless diagnostics. 2606 if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) { 2607 // C99 6.7.8p4. All file scoped initializers need to be constant. 2608 CheckForConstantInitializer(Init, DclT); 2609 } 2610 } 2611 // If the type changed, it means we had an incomplete type that was 2612 // completed by the initializer. For example: 2613 // int ary[] = { 1, 3, 5 }; 2614 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 2615 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 2616 VDecl->setType(DclT); 2617 Init->setType(DclT); 2618 } 2619 2620 // Attach the initializer to the decl. 2621 VDecl->setInit(Init); 2622 return; 2623} 2624 2625void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 2626 Decl *RealDecl = static_cast<Decl *>(dcl); 2627 2628 // If there is no declaration, there was an error parsing it. Just ignore it. 2629 if (RealDecl == 0) 2630 return; 2631 2632 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 2633 QualType Type = Var->getType(); 2634 // C++ [dcl.init.ref]p3: 2635 // The initializer can be omitted for a reference only in a 2636 // parameter declaration (8.3.5), in the declaration of a 2637 // function return type, in the declaration of a class member 2638 // within its class declaration (9.2), and where the extern 2639 // specifier is explicitly used. 2640 if (Type->isReferenceType() && 2641 Var->getStorageClass() != VarDecl::Extern && 2642 Var->getStorageClass() != VarDecl::PrivateExtern) { 2643 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 2644 << Var->getDeclName() 2645 << SourceRange(Var->getLocation(), Var->getLocation()); 2646 Var->setInvalidDecl(); 2647 return; 2648 } 2649 2650 // C++ [dcl.init]p9: 2651 // 2652 // If no initializer is specified for an object, and the object 2653 // is of (possibly cv-qualified) non-POD class type (or array 2654 // thereof), the object shall be default-initialized; if the 2655 // object is of const-qualified type, the underlying class type 2656 // shall have a user-declared default constructor. 2657 if (getLangOptions().CPlusPlus) { 2658 QualType InitType = Type; 2659 if (const ArrayType *Array = Context.getAsArrayType(Type)) 2660 InitType = Array->getElementType(); 2661 if (Var->getStorageClass() != VarDecl::Extern && 2662 Var->getStorageClass() != VarDecl::PrivateExtern && 2663 InitType->isRecordType()) { 2664 const CXXConstructorDecl *Constructor 2665 = PerformInitializationByConstructor(InitType, 0, 0, 2666 Var->getLocation(), 2667 SourceRange(Var->getLocation(), 2668 Var->getLocation()), 2669 Var->getDeclName(), 2670 IK_Default); 2671 if (!Constructor) 2672 Var->setInvalidDecl(); 2673 } 2674 } 2675 2676#if 0 2677 // FIXME: Temporarily disabled because we are not properly parsing 2678 // linkage specifications on declarations, e.g., 2679 // 2680 // extern "C" const CGPoint CGPointerZero; 2681 // 2682 // C++ [dcl.init]p9: 2683 // 2684 // If no initializer is specified for an object, and the 2685 // object is of (possibly cv-qualified) non-POD class type (or 2686 // array thereof), the object shall be default-initialized; if 2687 // the object is of const-qualified type, the underlying class 2688 // type shall have a user-declared default 2689 // constructor. Otherwise, if no initializer is specified for 2690 // an object, the object and its subobjects, if any, have an 2691 // indeterminate initial value; if the object or any of its 2692 // subobjects are of const-qualified type, the program is 2693 // ill-formed. 2694 // 2695 // This isn't technically an error in C, so we don't diagnose it. 2696 // 2697 // FIXME: Actually perform the POD/user-defined default 2698 // constructor check. 2699 if (getLangOptions().CPlusPlus && 2700 Context.getCanonicalType(Type).isConstQualified() && 2701 Var->getStorageClass() != VarDecl::Extern) 2702 Diag(Var->getLocation(), diag::err_const_var_requires_init) 2703 << Var->getName() 2704 << SourceRange(Var->getLocation(), Var->getLocation()); 2705#endif 2706 } 2707} 2708 2709/// The declarators are chained together backwards, reverse the list. 2710Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 2711 // Often we have single declarators, handle them quickly. 2712 Decl *Group = static_cast<Decl*>(group); 2713 if (Group == 0) 2714 return 0; 2715 2716 Decl *NewGroup = 0; 2717 if (Group->getNextDeclarator() == 0) 2718 NewGroup = Group; 2719 else { // reverse the list. 2720 while (Group) { 2721 Decl *Next = Group->getNextDeclarator(); 2722 Group->setNextDeclarator(NewGroup); 2723 NewGroup = Group; 2724 Group = Next; 2725 } 2726 } 2727 // Perform semantic analysis that depends on having fully processed both 2728 // the declarator and initializer. 2729 for (Decl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 2730 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 2731 if (!IDecl) 2732 continue; 2733 QualType T = IDecl->getType(); 2734 2735 if (T->isVariableArrayType()) { 2736 const VariableArrayType *VAT = Context.getAsVariableArrayType(T); 2737 2738 // FIXME: This won't give the correct result for 2739 // int a[10][n]; 2740 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); 2741 if (IDecl->isFileVarDecl()) { 2742 Diag(IDecl->getLocation(), diag::err_vla_decl_in_file_scope) << 2743 SizeRange; 2744 2745 IDecl->setInvalidDecl(); 2746 } else { 2747 // C99 6.7.5.2p2: If an identifier is declared to be an object with 2748 // static storage duration, it shall not have a variable length array. 2749 if (IDecl->getStorageClass() == VarDecl::Static) { 2750 Diag(IDecl->getLocation(), diag::err_vla_decl_has_static_storage) 2751 << SizeRange; 2752 IDecl->setInvalidDecl(); 2753 } else if (IDecl->getStorageClass() == VarDecl::Extern) { 2754 Diag(IDecl->getLocation(), diag::err_vla_decl_has_extern_linkage) 2755 << SizeRange; 2756 IDecl->setInvalidDecl(); 2757 } 2758 } 2759 } else if (T->isVariablyModifiedType()) { 2760 if (IDecl->isFileVarDecl()) { 2761 Diag(IDecl->getLocation(), diag::err_vm_decl_in_file_scope); 2762 IDecl->setInvalidDecl(); 2763 } else { 2764 if (IDecl->getStorageClass() == VarDecl::Extern) { 2765 Diag(IDecl->getLocation(), diag::err_vm_decl_has_extern_linkage); 2766 IDecl->setInvalidDecl(); 2767 } 2768 } 2769 } 2770 2771 // Block scope. C99 6.7p7: If an identifier for an object is declared with 2772 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 2773 if (IDecl->isBlockVarDecl() && 2774 IDecl->getStorageClass() != VarDecl::Extern) { 2775 if (!IDecl->isInvalidDecl() && 2776 DiagnoseIncompleteType(IDecl->getLocation(), T, 2777 diag::err_typecheck_decl_incomplete_type)) 2778 IDecl->setInvalidDecl(); 2779 } 2780 // File scope. C99 6.9.2p2: A declaration of an identifier for and 2781 // object that has file scope without an initializer, and without a 2782 // storage-class specifier or with the storage-class specifier "static", 2783 // constitutes a tentative definition. Note: A tentative definition with 2784 // external linkage is valid (C99 6.2.2p5). 2785 if (isTentativeDefinition(IDecl)) { 2786 if (T->isIncompleteArrayType()) { 2787 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 2788 // array to be completed. Don't issue a diagnostic. 2789 } else if (!IDecl->isInvalidDecl() && 2790 DiagnoseIncompleteType(IDecl->getLocation(), T, 2791 diag::err_typecheck_decl_incomplete_type)) 2792 // C99 6.9.2p3: If the declaration of an identifier for an object is 2793 // a tentative definition and has internal linkage (C99 6.2.2p3), the 2794 // declared type shall not be an incomplete type. 2795 IDecl->setInvalidDecl(); 2796 } 2797 if (IDecl->isFileVarDecl()) 2798 CheckForFileScopedRedefinitions(S, IDecl); 2799 } 2800 return NewGroup; 2801} 2802 2803/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 2804/// to introduce parameters into function prototype scope. 2805Sema::DeclTy * 2806Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 2807 const DeclSpec &DS = D.getDeclSpec(); 2808 2809 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 2810 VarDecl::StorageClass StorageClass = VarDecl::None; 2811 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 2812 StorageClass = VarDecl::Register; 2813 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 2814 Diag(DS.getStorageClassSpecLoc(), 2815 diag::err_invalid_storage_class_in_func_decl); 2816 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2817 } 2818 if (DS.isThreadSpecified()) { 2819 Diag(DS.getThreadSpecLoc(), 2820 diag::err_invalid_storage_class_in_func_decl); 2821 D.getMutableDeclSpec().ClearStorageClassSpecs(); 2822 } 2823 2824 // Check that there are no default arguments inside the type of this 2825 // parameter (C++ only). 2826 if (getLangOptions().CPlusPlus) 2827 CheckExtraCXXDefaultArguments(D); 2828 2829 // In this context, we *do not* check D.getInvalidType(). If the declarator 2830 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 2831 // though it will not reflect the user specified type. 2832 QualType parmDeclType = GetTypeForDeclarator(D, S); 2833 2834 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 2835 2836 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 2837 // Can this happen for params? We already checked that they don't conflict 2838 // among each other. Here they can only shadow globals, which is ok. 2839 IdentifierInfo *II = D.getIdentifier(); 2840 if (II) { 2841 if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) { 2842 if (PrevDecl->isTemplateParameter()) { 2843 // Maybe we will complain about the shadowed template parameter. 2844 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 2845 // Just pretend that we didn't see the previous declaration. 2846 PrevDecl = 0; 2847 } else if (S->isDeclScope(PrevDecl)) { 2848 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 2849 2850 // Recover by removing the name 2851 II = 0; 2852 D.SetIdentifier(0, D.getIdentifierLoc()); 2853 } 2854 } 2855 } 2856 2857 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 2858 // Doing the promotion here has a win and a loss. The win is the type for 2859 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 2860 // code generator). The loss is the orginal type isn't preserved. For example: 2861 // 2862 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2863 // int blockvardecl[5]; 2864 // sizeof(parmvardecl); // size == 4 2865 // sizeof(blockvardecl); // size == 20 2866 // } 2867 // 2868 // For expressions, all implicit conversions are captured using the 2869 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2870 // 2871 // FIXME: If a source translation tool needs to see the original type, then 2872 // we need to consider storing both types (in ParmVarDecl)... 2873 // 2874 if (parmDeclType->isArrayType()) { 2875 // int x[restrict 4] -> int *restrict 2876 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2877 } else if (parmDeclType->isFunctionType()) 2878 parmDeclType = Context.getPointerType(parmDeclType); 2879 2880 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2881 D.getIdentifierLoc(), II, 2882 parmDeclType, StorageClass, 2883 0); 2884 2885 if (D.getInvalidType()) 2886 New->setInvalidDecl(); 2887 2888 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 2889 if (D.getCXXScopeSpec().isSet()) { 2890 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 2891 << D.getCXXScopeSpec().getRange(); 2892 New->setInvalidDecl(); 2893 } 2894 // Parameter declarators cannot be interface types. All ObjC objects are 2895 // passed by reference. 2896 if (parmDeclType->isObjCInterfaceType()) { 2897 Diag(D.getIdentifierLoc(), diag::err_object_cannot_be_by_value) 2898 << "passed"; 2899 New->setInvalidDecl(); 2900 } 2901 2902 // Add the parameter declaration into this scope. 2903 S->AddDecl(New); 2904 if (II) 2905 IdResolver.AddDecl(New); 2906 2907 ProcessDeclAttributes(New, D); 2908 return New; 2909 2910} 2911 2912void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D) { 2913 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2914 "Not a function declarator!"); 2915 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2916 2917 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2918 // for a K&R function. 2919 if (!FTI.hasPrototype) { 2920 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2921 if (FTI.ArgInfo[i].Param == 0) { 2922 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2923 << FTI.ArgInfo[i].Ident; 2924 // Implicitly declare the argument as type 'int' for lack of a better 2925 // type. 2926 DeclSpec DS; 2927 const char* PrevSpec; // unused 2928 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2929 PrevSpec); 2930 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2931 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2932 FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD); 2933 } 2934 } 2935 } 2936} 2937 2938Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2939 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2940 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2941 "Not a function declarator!"); 2942 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2943 2944 if (FTI.hasPrototype) { 2945 // FIXME: Diagnose arguments without names in C. 2946 } 2947 2948 Scope *ParentScope = FnBodyScope->getParent(); 2949 2950 return ActOnStartOfFunctionDef(FnBodyScope, 2951 ActOnDeclarator(ParentScope, D, 0, 2952 /*IsFunctionDefinition=*/true)); 2953} 2954 2955Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2956 Decl *decl = static_cast<Decl*>(D); 2957 FunctionDecl *FD = cast<FunctionDecl>(decl); 2958 2959 // See if this is a redefinition. 2960 const FunctionDecl *Definition; 2961 if (FD->getBody(Definition)) { 2962 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 2963 Diag(Definition->getLocation(), diag::note_previous_definition); 2964 } 2965 2966 // Builtin functions cannot be defined. 2967 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 2968 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { 2969 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 2970 FD->setInvalidDecl(); 2971 } 2972 } 2973 2974 PushDeclContext(FnBodyScope, FD); 2975 2976 // Check the validity of our function parameters 2977 CheckParmsForFunctionDef(FD); 2978 2979 // Introduce our parameters into the function scope 2980 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2981 ParmVarDecl *Param = FD->getParamDecl(p); 2982 Param->setOwningFunction(FD); 2983 2984 // If this has an identifier, add it to the scope stack. 2985 if (Param->getIdentifier()) 2986 PushOnScopeChains(Param, FnBodyScope); 2987 } 2988 2989 // Checking attributes of current function definition 2990 // dllimport attribute. 2991 if (FD->getAttr<DLLImportAttr>() && (!FD->getAttr<DLLExportAttr>())) { 2992 // dllimport attribute cannot be applied to definition. 2993 if (!(FD->getAttr<DLLImportAttr>())->isInherited()) { 2994 Diag(FD->getLocation(), 2995 diag::err_attribute_can_be_applied_only_to_symbol_declaration) 2996 << "dllimport"; 2997 FD->setInvalidDecl(); 2998 return FD; 2999 } else { 3000 // If a symbol previously declared dllimport is later defined, the 3001 // attribute is ignored in subsequent references, and a warning is 3002 // emitted. 3003 Diag(FD->getLocation(), 3004 diag::warn_redeclaration_without_attribute_prev_attribute_ignored) 3005 << FD->getNameAsCString() << "dllimport"; 3006 } 3007 } 3008 return FD; 3009} 3010 3011Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtArg BodyArg) { 3012 Decl *dcl = static_cast<Decl *>(D); 3013 Stmt *Body = static_cast<Stmt*>(BodyArg.release()); 3014 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 3015 FD->setBody(Body); 3016 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 3017 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 3018 assert(MD == getCurMethodDecl() && "Method parsing confused"); 3019 MD->setBody((Stmt*)Body); 3020 } else { 3021 Body->Destroy(Context); 3022 return 0; 3023 } 3024 PopDeclContext(); 3025 // Verify and clean out per-function state. 3026 3027 // Check goto/label use. 3028 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 3029 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 3030 // Verify that we have no forward references left. If so, there was a goto 3031 // or address of a label taken, but no definition of it. Label fwd 3032 // definitions are indicated with a null substmt. 3033 if (I->second->getSubStmt() == 0) { 3034 LabelStmt *L = I->second; 3035 // Emit error. 3036 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 3037 3038 // At this point, we have gotos that use the bogus label. Stitch it into 3039 // the function body so that they aren't leaked and that the AST is well 3040 // formed. 3041 if (Body) { 3042#if 0 3043 // FIXME: Why do this? Having a 'push_back' in CompoundStmt is ugly, 3044 // and the AST is malformed anyway. We should just blow away 'L'. 3045 L->setSubStmt(new (Context) NullStmt(L->getIdentLoc())); 3046 cast<CompoundStmt>(Body)->push_back(L); 3047#else 3048 L->Destroy(Context); 3049#endif 3050 } else { 3051 // The whole function wasn't parsed correctly, just delete this. 3052 L->Destroy(Context); 3053 } 3054 } 3055 } 3056 LabelMap.clear(); 3057 3058 return D; 3059} 3060 3061/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 3062/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 3063NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 3064 IdentifierInfo &II, Scope *S) { 3065 // Extension in C99. Legal in C90, but warn about it. 3066 if (getLangOptions().C99) 3067 Diag(Loc, diag::ext_implicit_function_decl) << &II; 3068 else 3069 Diag(Loc, diag::warn_implicit_function_decl) << &II; 3070 3071 // FIXME: handle stuff like: 3072 // void foo() { extern float X(); } 3073 // void bar() { X(); } <-- implicit decl for X in another scope. 3074 3075 // Set a Declarator for the implicit definition: int foo(); 3076 const char *Dummy; 3077 DeclSpec DS; 3078 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 3079 Error = Error; // Silence warning. 3080 assert(!Error && "Error setting up implicit decl!"); 3081 Declarator D(DS, Declarator::BlockContext); 3082 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 3083 0, 0, 0, Loc, D), 3084 SourceLocation()); 3085 D.SetIdentifier(&II, Loc); 3086 3087 // Insert this function into translation-unit scope. 3088 3089 DeclContext *PrevDC = CurContext; 3090 CurContext = Context.getTranslationUnitDecl(); 3091 3092 FunctionDecl *FD = 3093 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 3094 FD->setImplicit(); 3095 3096 CurContext = PrevDC; 3097 3098 AddKnownFunctionAttributes(FD); 3099 3100 return FD; 3101} 3102 3103/// \brief Adds any function attributes that we know a priori based on 3104/// the declaration of this function. 3105/// 3106/// These attributes can apply both to implicitly-declared builtins 3107/// (like __builtin___printf_chk) or to library-declared functions 3108/// like NSLog or printf. 3109void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 3110 if (FD->isInvalidDecl()) 3111 return; 3112 3113 // If this is a built-in function, map its builtin attributes to 3114 // actual attributes. 3115 if (unsigned BuiltinID = FD->getBuiltinID(Context)) { 3116 // Handle printf-formatting attributes. 3117 unsigned FormatIdx; 3118 bool HasVAListArg; 3119 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 3120 if (!FD->getAttr<FormatAttr>()) 3121 FD->addAttr(new FormatAttr("printf", FormatIdx + 1, FormatIdx + 2)); 3122 } 3123 3124 // Mark const if we don't care about errno and that is the only 3125 // thing preventing the function from being const. This allows 3126 // IRgen to use LLVM intrinsics for such functions. 3127 if (!getLangOptions().MathErrno && 3128 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) { 3129 if (!FD->getAttr<ConstAttr>()) 3130 FD->addAttr(new ConstAttr()); 3131 } 3132 } 3133 3134 IdentifierInfo *Name = FD->getIdentifier(); 3135 if (!Name) 3136 return; 3137 if ((!getLangOptions().CPlusPlus && 3138 FD->getDeclContext()->isTranslationUnit()) || 3139 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 3140 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 3141 LinkageSpecDecl::lang_c)) { 3142 // Okay: this could be a libc/libm/Objective-C function we know 3143 // about. 3144 } else 3145 return; 3146 3147 unsigned KnownID; 3148 for (KnownID = 0; KnownID != id_num_known_functions; ++KnownID) 3149 if (KnownFunctionIDs[KnownID] == Name) 3150 break; 3151 3152 switch (KnownID) { 3153 case id_NSLog: 3154 case id_NSLogv: 3155 if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) { 3156 // FIXME: We known better than our headers. 3157 const_cast<FormatAttr *>(Format)->setType("printf"); 3158 } else 3159 FD->addAttr(new FormatAttr("printf", 1, 2)); 3160 break; 3161 3162 case id_asprintf: 3163 case id_vasprintf: 3164 if (!FD->getAttr<FormatAttr>()) 3165 FD->addAttr(new FormatAttr("printf", 2, 3)); 3166 break; 3167 3168 default: 3169 // Unknown function or known function without any attributes to 3170 // add. Do nothing. 3171 break; 3172 } 3173} 3174 3175TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 3176 Decl *LastDeclarator) { 3177 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 3178 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3179 3180 // Scope manipulation handled by caller. 3181 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 3182 D.getIdentifierLoc(), 3183 D.getIdentifier(), 3184 T); 3185 NewTD->setNextDeclarator(LastDeclarator); 3186 if (D.getInvalidType()) 3187 NewTD->setInvalidDecl(); 3188 return NewTD; 3189} 3190 3191/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 3192/// former case, Name will be non-null. In the later case, Name will be null. 3193/// TagSpec indicates what kind of tag this is. TK indicates whether this is a 3194/// reference/declaration/definition of a tag. 3195Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK, 3196 SourceLocation KWLoc, const CXXScopeSpec &SS, 3197 IdentifierInfo *Name, SourceLocation NameLoc, 3198 AttributeList *Attr) { 3199 // If this is not a definition, it must have a name. 3200 assert((Name != 0 || TK == TK_Definition) && 3201 "Nameless record must be a definition!"); 3202 3203 TagDecl::TagKind Kind; 3204 switch (TagSpec) { 3205 default: assert(0 && "Unknown tag type!"); 3206 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3207 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3208 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3209 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 3210 } 3211 3212 DeclContext *SearchDC = CurContext; 3213 DeclContext *DC = CurContext; 3214 NamedDecl *PrevDecl = 0; 3215 3216 bool Invalid = false; 3217 3218 if (Name && SS.isNotEmpty()) { 3219 // We have a nested-name tag ('struct foo::bar'). 3220 3221 // Check for invalid 'foo::'. 3222 if (SS.isInvalid()) { 3223 Name = 0; 3224 goto CreateNewDecl; 3225 } 3226 3227 DC = static_cast<DeclContext*>(SS.getScopeRep()); 3228 SearchDC = DC; 3229 // Look-up name inside 'foo::'. 3230 PrevDecl = dyn_cast_or_null<TagDecl>( 3231 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl()); 3232 3233 // A tag 'foo::bar' must already exist. 3234 if (PrevDecl == 0) { 3235 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 3236 Name = 0; 3237 goto CreateNewDecl; 3238 } 3239 } else if (Name) { 3240 // If this is a named struct, check to see if there was a previous forward 3241 // declaration or definition. 3242 // FIXME: We're looking into outer scopes here, even when we 3243 // shouldn't be. Doing so can result in ambiguities that we 3244 // shouldn't be diagnosing. 3245 LookupResult R = LookupName(S, Name, LookupTagName, 3246 /*RedeclarationOnly=*/(TK != TK_Reference)); 3247 if (R.isAmbiguous()) { 3248 DiagnoseAmbiguousLookup(R, Name, NameLoc); 3249 // FIXME: This is not best way to recover from case like: 3250 // 3251 // struct S s; 3252 // 3253 // causes needless err_ovl_no_viable_function_in_init latter. 3254 Name = 0; 3255 PrevDecl = 0; 3256 Invalid = true; 3257 } 3258 else 3259 PrevDecl = R; 3260 3261 if (!getLangOptions().CPlusPlus && TK != TK_Reference) { 3262 // FIXME: This makes sure that we ignore the contexts associated 3263 // with C structs, unions, and enums when looking for a matching 3264 // tag declaration or definition. See the similar lookup tweak 3265 // in Sema::LookupName; is there a better way to deal with this? 3266 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 3267 SearchDC = SearchDC->getParent(); 3268 } 3269 } 3270 3271 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3272 // Maybe we will complain about the shadowed template parameter. 3273 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 3274 // Just pretend that we didn't see the previous declaration. 3275 PrevDecl = 0; 3276 } 3277 3278 if (PrevDecl) { 3279 // Check whether the previous declaration is usable. 3280 (void)DiagnoseUseOfDecl(PrevDecl, NameLoc); 3281 3282 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 3283 // If this is a use of a previous tag, or if the tag is already declared 3284 // in the same scope (so that the definition/declaration completes or 3285 // rementions the tag), reuse the decl. 3286 if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) { 3287 // Make sure that this wasn't declared as an enum and now used as a 3288 // struct or something similar. 3289 if (PrevTagDecl->getTagKind() != Kind) { 3290 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 3291 Diag(PrevDecl->getLocation(), diag::note_previous_use); 3292 // Recover by making this an anonymous redefinition. 3293 Name = 0; 3294 PrevDecl = 0; 3295 Invalid = true; 3296 } else { 3297 // If this is a use, just return the declaration we found. 3298 3299 // FIXME: In the future, return a variant or some other clue 3300 // for the consumer of this Decl to know it doesn't own it. 3301 // For our current ASTs this shouldn't be a problem, but will 3302 // need to be changed with DeclGroups. 3303 if (TK == TK_Reference) 3304 return PrevDecl; 3305 3306 // Diagnose attempts to redefine a tag. 3307 if (TK == TK_Definition) { 3308 if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) { 3309 Diag(NameLoc, diag::err_redefinition) << Name; 3310 Diag(Def->getLocation(), diag::note_previous_definition); 3311 // If this is a redefinition, recover by making this 3312 // struct be anonymous, which will make any later 3313 // references get the previous definition. 3314 Name = 0; 3315 PrevDecl = 0; 3316 Invalid = true; 3317 } else { 3318 // If the type is currently being defined, complain 3319 // about a nested redefinition. 3320 TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl)); 3321 if (Tag->isBeingDefined()) { 3322 Diag(NameLoc, diag::err_nested_redefinition) << Name; 3323 Diag(PrevTagDecl->getLocation(), 3324 diag::note_previous_definition); 3325 Name = 0; 3326 PrevDecl = 0; 3327 Invalid = true; 3328 } 3329 } 3330 3331 // Okay, this is definition of a previously declared or referenced 3332 // tag PrevDecl. We're going to create a new Decl for it. 3333 } 3334 } 3335 // If we get here we have (another) forward declaration or we 3336 // have a definition. Just create a new decl. 3337 } else { 3338 // If we get here, this is a definition of a new tag type in a nested 3339 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 3340 // new decl/type. We set PrevDecl to NULL so that the entities 3341 // have distinct types. 3342 PrevDecl = 0; 3343 } 3344 // If we get here, we're going to create a new Decl. If PrevDecl 3345 // is non-NULL, it's a definition of the tag declared by 3346 // PrevDecl. If it's NULL, we have a new definition. 3347 } else { 3348 // PrevDecl is a namespace, template, or anything else 3349 // that lives in the IDNS_Tag identifier namespace. 3350 if (isDeclInScope(PrevDecl, SearchDC, S)) { 3351 // The tag name clashes with a namespace name, issue an error and 3352 // recover by making this tag be anonymous. 3353 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 3354 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3355 Name = 0; 3356 PrevDecl = 0; 3357 Invalid = true; 3358 } else { 3359 // The existing declaration isn't relevant to us; we're in a 3360 // new scope, so clear out the previous declaration. 3361 PrevDecl = 0; 3362 } 3363 } 3364 } else if (TK == TK_Reference && SS.isEmpty() && Name && 3365 (Kind != TagDecl::TK_enum)) { 3366 // C++ [basic.scope.pdecl]p5: 3367 // -- for an elaborated-type-specifier of the form 3368 // 3369 // class-key identifier 3370 // 3371 // if the elaborated-type-specifier is used in the 3372 // decl-specifier-seq or parameter-declaration-clause of a 3373 // function defined in namespace scope, the identifier is 3374 // declared as a class-name in the namespace that contains 3375 // the declaration; otherwise, except as a friend 3376 // declaration, the identifier is declared in the smallest 3377 // non-class, non-function-prototype scope that contains the 3378 // declaration. 3379 // 3380 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 3381 // C structs and unions. 3382 3383 // Find the context where we'll be declaring the tag. 3384 // FIXME: We would like to maintain the current DeclContext as the 3385 // lexical context, 3386 while (SearchDC->isRecord()) 3387 SearchDC = SearchDC->getParent(); 3388 3389 // Find the scope where we'll be declaring the tag. 3390 while (S->isClassScope() || 3391 (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) || 3392 ((S->getFlags() & Scope::DeclScope) == 0) || 3393 (S->getEntity() && 3394 ((DeclContext *)S->getEntity())->isTransparentContext())) 3395 S = S->getParent(); 3396 } 3397 3398CreateNewDecl: 3399 3400 // If there is an identifier, use the location of the identifier as the 3401 // location of the decl, otherwise use the location of the struct/union 3402 // keyword. 3403 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 3404 3405 // Otherwise, create a new declaration. If there is a previous 3406 // declaration of the same entity, the two will be linked via 3407 // PrevDecl. 3408 TagDecl *New; 3409 3410 if (Kind == TagDecl::TK_enum) { 3411 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3412 // enum X { A, B, C } D; D should chain to X. 3413 New = EnumDecl::Create(Context, SearchDC, Loc, Name, 3414 cast_or_null<EnumDecl>(PrevDecl)); 3415 // If this is an undefined enum, warn. 3416 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 3417 } else { 3418 // struct/union/class 3419 3420 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 3421 // struct X { int A; } D; D should chain to X. 3422 if (getLangOptions().CPlusPlus) 3423 // FIXME: Look for a way to use RecordDecl for simple structs. 3424 New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name, 3425 cast_or_null<CXXRecordDecl>(PrevDecl)); 3426 else 3427 New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name, 3428 cast_or_null<RecordDecl>(PrevDecl)); 3429 } 3430 3431 if (Kind != TagDecl::TK_enum) { 3432 // Handle #pragma pack: if the #pragma pack stack has non-default 3433 // alignment, make up a packed attribute for this decl. These 3434 // attributes are checked when the ASTContext lays out the 3435 // structure. 3436 // 3437 // It is important for implementing the correct semantics that this 3438 // happen here (in act on tag decl). The #pragma pack stack is 3439 // maintained as a result of parser callbacks which can occur at 3440 // many points during the parsing of a struct declaration (because 3441 // the #pragma tokens are effectively skipped over during the 3442 // parsing of the struct). 3443 if (unsigned Alignment = getPragmaPackAlignment()) 3444 New->addAttr(new PackedAttr(Alignment * 8)); 3445 } 3446 3447 if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) { 3448 // C++ [dcl.typedef]p3: 3449 // [...] Similarly, in a given scope, a class or enumeration 3450 // shall not be declared with the same name as a typedef-name 3451 // that is declared in that scope and refers to a type other 3452 // than the class or enumeration itself. 3453 LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true); 3454 TypedefDecl *PrevTypedef = 0; 3455 if (Lookup.getKind() == LookupResult::Found) 3456 PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl()); 3457 3458 if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) && 3459 Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) != 3460 Context.getCanonicalType(Context.getTypeDeclType(New))) { 3461 Diag(Loc, diag::err_tag_definition_of_typedef) 3462 << Context.getTypeDeclType(New) 3463 << PrevTypedef->getUnderlyingType(); 3464 Diag(PrevTypedef->getLocation(), diag::note_previous_definition); 3465 Invalid = true; 3466 } 3467 } 3468 3469 if (Invalid) 3470 New->setInvalidDecl(); 3471 3472 if (Attr) 3473 ProcessDeclAttributeList(New, Attr); 3474 3475 // If we're declaring or defining a tag in function prototype scope 3476 // in C, note that this type can only be used within the function. 3477 if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus) 3478 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 3479 3480 // Set the lexical context. If the tag has a C++ scope specifier, the 3481 // lexical context will be different from the semantic context. 3482 New->setLexicalDeclContext(CurContext); 3483 3484 if (TK == TK_Definition) 3485 New->startDefinition(); 3486 3487 // If this has an identifier, add it to the scope stack. 3488 if (Name) { 3489 S = getNonFieldDeclScope(S); 3490 PushOnScopeChains(New, S); 3491 } else { 3492 CurContext->addDecl(New); 3493 } 3494 3495 return New; 3496} 3497 3498void Sema::ActOnTagStartDefinition(Scope *S, DeclTy *TagD) { 3499 AdjustDeclIfTemplate(TagD); 3500 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3501 3502 // Enter the tag context. 3503 PushDeclContext(S, Tag); 3504 3505 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) { 3506 FieldCollector->StartClass(); 3507 3508 if (Record->getIdentifier()) { 3509 // C++ [class]p2: 3510 // [...] The class-name is also inserted into the scope of the 3511 // class itself; this is known as the injected-class-name. For 3512 // purposes of access checking, the injected-class-name is treated 3513 // as if it were a public member name. 3514 RecordDecl *InjectedClassName 3515 = CXXRecordDecl::Create(Context, Record->getTagKind(), 3516 CurContext, Record->getLocation(), 3517 Record->getIdentifier(), Record); 3518 InjectedClassName->setImplicit(); 3519 PushOnScopeChains(InjectedClassName, S); 3520 } 3521 } 3522} 3523 3524void Sema::ActOnTagFinishDefinition(Scope *S, DeclTy *TagD) { 3525 AdjustDeclIfTemplate(TagD); 3526 TagDecl *Tag = cast<TagDecl>((Decl *)TagD); 3527 3528 if (isa<CXXRecordDecl>(Tag)) 3529 FieldCollector->FinishClass(); 3530 3531 // Exit this scope of this tag's definition. 3532 PopDeclContext(); 3533 3534 // Notify the consumer that we've defined a tag. 3535 Consumer.HandleTagDeclDefinition(Tag); 3536} 3537 3538bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 3539 QualType FieldTy, const Expr *BitWidth) { 3540 // FIXME: 6.7.2.1p4 - verify the field type. 3541 3542 llvm::APSInt Value; 3543 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 3544 return true; 3545 3546 // Zero-width bitfield is ok for anonymous field. 3547 if (Value == 0 && FieldName) 3548 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 3549 3550 if (Value.isNegative()) 3551 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) << FieldName; 3552 3553 uint64_t TypeSize = Context.getTypeSize(FieldTy); 3554 // FIXME: We won't need the 0 size once we check that the field type is valid. 3555 if (TypeSize && Value.getZExtValue() > TypeSize) 3556 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) 3557 << FieldName << (unsigned)TypeSize; 3558 3559 return false; 3560} 3561 3562/// ActOnField - Each field of a struct/union/class is passed into this in order 3563/// to create a FieldDecl object for it. 3564Sema::DeclTy *Sema::ActOnField(Scope *S, DeclTy *TagD, 3565 SourceLocation DeclStart, 3566 Declarator &D, ExprTy *BitfieldWidth) { 3567 IdentifierInfo *II = D.getIdentifier(); 3568 Expr *BitWidth = (Expr*)BitfieldWidth; 3569 SourceLocation Loc = DeclStart; 3570 RecordDecl *Record = (RecordDecl *)TagD; 3571 if (II) Loc = D.getIdentifierLoc(); 3572 3573 // FIXME: Unnamed fields can be handled in various different ways, for 3574 // example, unnamed unions inject all members into the struct namespace! 3575 3576 QualType T = GetTypeForDeclarator(D, S); 3577 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3578 bool InvalidDecl = false; 3579 3580 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3581 // than a variably modified type. 3582 if (T->isVariablyModifiedType()) { 3583 bool SizeIsNegative; 3584 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context, 3585 SizeIsNegative); 3586 if (!FixedTy.isNull()) { 3587 Diag(Loc, diag::warn_illegal_constant_array_size); 3588 T = FixedTy; 3589 } else { 3590 if (SizeIsNegative) 3591 Diag(Loc, diag::err_typecheck_negative_array_size); 3592 else 3593 Diag(Loc, diag::err_typecheck_field_variable_size); 3594 T = Context.IntTy; 3595 InvalidDecl = true; 3596 } 3597 } 3598 3599 if (BitWidth) { 3600 if (VerifyBitField(Loc, II, T, BitWidth)) 3601 InvalidDecl = true; 3602 } else { 3603 // Not a bitfield. 3604 3605 // validate II. 3606 3607 } 3608 3609 FieldDecl *NewFD = FieldDecl::Create(Context, Record, 3610 Loc, II, T, BitWidth, 3611 D.getDeclSpec().getStorageClassSpec() == 3612 DeclSpec::SCS_mutable); 3613 3614 if (II) { 3615 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 3616 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3617 && !isa<TagDecl>(PrevDecl)) { 3618 Diag(Loc, diag::err_duplicate_member) << II; 3619 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3620 NewFD->setInvalidDecl(); 3621 Record->setInvalidDecl(); 3622 } 3623 } 3624 3625 if (getLangOptions().CPlusPlus) { 3626 CheckExtraCXXDefaultArguments(D); 3627 if (!T->isPODType()) 3628 cast<CXXRecordDecl>(Record)->setPOD(false); 3629 } 3630 3631 ProcessDeclAttributes(NewFD, D); 3632 if (T.isObjCGCWeak()) 3633 Diag(Loc, diag::warn_attribute_weak_on_field); 3634 3635 if (D.getInvalidType() || InvalidDecl) 3636 NewFD->setInvalidDecl(); 3637 3638 if (II) { 3639 PushOnScopeChains(NewFD, S); 3640 } else 3641 Record->addDecl(NewFD); 3642 3643 return NewFD; 3644} 3645 3646/// TranslateIvarVisibility - Translate visibility from a token ID to an 3647/// AST enum value. 3648static ObjCIvarDecl::AccessControl 3649TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 3650 switch (ivarVisibility) { 3651 default: assert(0 && "Unknown visitibility kind"); 3652 case tok::objc_private: return ObjCIvarDecl::Private; 3653 case tok::objc_public: return ObjCIvarDecl::Public; 3654 case tok::objc_protected: return ObjCIvarDecl::Protected; 3655 case tok::objc_package: return ObjCIvarDecl::Package; 3656 } 3657} 3658 3659/// ActOnIvar - Each ivar field of an objective-c class is passed into this 3660/// in order to create an IvarDecl object for it. 3661Sema::DeclTy *Sema::ActOnIvar(Scope *S, 3662 SourceLocation DeclStart, 3663 Declarator &D, ExprTy *BitfieldWidth, 3664 tok::ObjCKeywordKind Visibility) { 3665 3666 IdentifierInfo *II = D.getIdentifier(); 3667 Expr *BitWidth = (Expr*)BitfieldWidth; 3668 SourceLocation Loc = DeclStart; 3669 if (II) Loc = D.getIdentifierLoc(); 3670 3671 // FIXME: Unnamed fields can be handled in various different ways, for 3672 // example, unnamed unions inject all members into the struct namespace! 3673 3674 QualType T = GetTypeForDeclarator(D, S); 3675 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 3676 bool InvalidDecl = false; 3677 3678 if (BitWidth) { 3679 // 6.7.2.1p3, 6.7.2.1p4 3680 if (VerifyBitField(Loc, II, T, BitWidth)) 3681 InvalidDecl = true; 3682 } else { 3683 // Not a bitfield. 3684 3685 // validate II. 3686 3687 } 3688 3689 // C99 6.7.2.1p8: A member of a structure or union may have any type other 3690 // than a variably modified type. 3691 if (T->isVariablyModifiedType()) { 3692 Diag(Loc, diag::err_typecheck_ivar_variable_size); 3693 InvalidDecl = true; 3694 } 3695 3696 // Get the visibility (access control) for this ivar. 3697 ObjCIvarDecl::AccessControl ac = 3698 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 3699 : ObjCIvarDecl::None; 3700 3701 // Construct the decl. 3702 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, CurContext, Loc, II, T,ac, 3703 (Expr *)BitfieldWidth); 3704 3705 if (II) { 3706 NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true); 3707 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S) 3708 && !isa<TagDecl>(PrevDecl)) { 3709 Diag(Loc, diag::err_duplicate_member) << II; 3710 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 3711 NewID->setInvalidDecl(); 3712 } 3713 } 3714 3715 // Process attributes attached to the ivar. 3716 ProcessDeclAttributes(NewID, D); 3717 3718 if (D.getInvalidType() || InvalidDecl) 3719 NewID->setInvalidDecl(); 3720 3721 if (II) { 3722 // FIXME: When interfaces are DeclContexts, we'll need to add 3723 // these to the interface. 3724 S->AddDecl(NewID); 3725 IdResolver.AddDecl(NewID); 3726 } 3727 3728 return NewID; 3729} 3730 3731void Sema::ActOnFields(Scope* S, 3732 SourceLocation RecLoc, DeclTy *RecDecl, 3733 DeclTy **Fields, unsigned NumFields, 3734 SourceLocation LBrac, SourceLocation RBrac, 3735 AttributeList *Attr) { 3736 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 3737 assert(EnclosingDecl && "missing record or interface decl"); 3738 3739 // If the decl this is being inserted into is invalid, then it may be a 3740 // redeclaration or some other bogus case. Don't try to add fields to it. 3741 if (EnclosingDecl->isInvalidDecl()) { 3742 // FIXME: Deallocate fields? 3743 return; 3744 } 3745 3746 3747 // Verify that all the fields are okay. 3748 unsigned NumNamedMembers = 0; 3749 llvm::SmallVector<FieldDecl*, 32> RecFields; 3750 3751 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 3752 for (unsigned i = 0; i != NumFields; ++i) { 3753 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 3754 assert(FD && "missing field decl"); 3755 3756 // Get the type for the field. 3757 Type *FDTy = FD->getType().getTypePtr(); 3758 3759 if (!FD->isAnonymousStructOrUnion()) { 3760 // Remember all fields written by the user. 3761 RecFields.push_back(FD); 3762 } 3763 3764 // C99 6.7.2.1p2 - A field may not be a function type. 3765 if (FDTy->isFunctionType()) { 3766 Diag(FD->getLocation(), diag::err_field_declared_as_function) 3767 << FD->getDeclName(); 3768 FD->setInvalidDecl(); 3769 EnclosingDecl->setInvalidDecl(); 3770 continue; 3771 } 3772 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 3773 if (FDTy->isIncompleteType()) { 3774 if (!Record) { // Incomplete ivar type is always an error. 3775 DiagnoseIncompleteType(FD->getLocation(), FD->getType(), 3776 diag::err_field_incomplete); 3777 FD->setInvalidDecl(); 3778 EnclosingDecl->setInvalidDecl(); 3779 continue; 3780 } 3781 if (i != NumFields-1 || // ... that the last member ... 3782 !Record->isStruct() || // ... of a structure ... 3783 !FDTy->isArrayType()) { //... may have incomplete array type. 3784 DiagnoseIncompleteType(FD->getLocation(), FD->getType(), 3785 diag::err_field_incomplete); 3786 FD->setInvalidDecl(); 3787 EnclosingDecl->setInvalidDecl(); 3788 continue; 3789 } 3790 if (NumNamedMembers < 1) { //... must have more than named member ... 3791 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 3792 << FD->getDeclName(); 3793 FD->setInvalidDecl(); 3794 EnclosingDecl->setInvalidDecl(); 3795 continue; 3796 } 3797 // Okay, we have a legal flexible array member at the end of the struct. 3798 if (Record) 3799 Record->setHasFlexibleArrayMember(true); 3800 } 3801 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 3802 /// field of another structure or the element of an array. 3803 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 3804 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 3805 // If this is a member of a union, then entire union becomes "flexible". 3806 if (Record && Record->isUnion()) { 3807 Record->setHasFlexibleArrayMember(true); 3808 } else { 3809 // If this is a struct/class and this is not the last element, reject 3810 // it. Note that GCC supports variable sized arrays in the middle of 3811 // structures. 3812 if (i != NumFields-1) { 3813 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct) 3814 << FD->getDeclName(); 3815 FD->setInvalidDecl(); 3816 EnclosingDecl->setInvalidDecl(); 3817 continue; 3818 } 3819 // We support flexible arrays at the end of structs in other structs 3820 // as an extension. 3821 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 3822 << FD->getDeclName(); 3823 if (Record) 3824 Record->setHasFlexibleArrayMember(true); 3825 } 3826 } 3827 } 3828 /// A field cannot be an Objective-c object 3829 if (FDTy->isObjCInterfaceType()) { 3830 Diag(FD->getLocation(), diag::err_statically_allocated_object); 3831 FD->setInvalidDecl(); 3832 EnclosingDecl->setInvalidDecl(); 3833 continue; 3834 } 3835 // Keep track of the number of named members. 3836 if (FD->getIdentifier()) 3837 ++NumNamedMembers; 3838 } 3839 3840 // Okay, we successfully defined 'Record'. 3841 if (Record) { 3842 Record->completeDefinition(Context); 3843 } else { 3844 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 3845 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 3846 ID->setIVarList(ClsFields, RecFields.size(), Context); 3847 ID->setLocEnd(RBrac); 3848 3849 // Must enforce the rule that ivars in the base classes may not be 3850 // duplicates. 3851 if (ID->getSuperClass()) { 3852 for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(), 3853 IVE = ID->ivar_end(); IVI != IVE; ++IVI) { 3854 ObjCIvarDecl* Ivar = (*IVI); 3855 IdentifierInfo *II = Ivar->getIdentifier(); 3856 ObjCIvarDecl* prevIvar = ID->getSuperClass()->lookupInstanceVariable(II); 3857 if (prevIvar) { 3858 Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; 3859 Diag(prevIvar->getLocation(), diag::note_previous_declaration); 3860 } 3861 } 3862 } 3863 } else if (ObjCImplementationDecl *IMPDecl = 3864 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 3865 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 3866 IMPDecl->setIVarList(ClsFields, RecFields.size(), Context); 3867 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 3868 } 3869 } 3870 3871 if (Attr) 3872 ProcessDeclAttributeList(Record, Attr); 3873} 3874 3875Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 3876 DeclTy *lastEnumConst, 3877 SourceLocation IdLoc, IdentifierInfo *Id, 3878 SourceLocation EqualLoc, ExprTy *val) { 3879 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 3880 EnumConstantDecl *LastEnumConst = 3881 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 3882 Expr *Val = static_cast<Expr*>(val); 3883 3884 // The scope passed in may not be a decl scope. Zip up the scope tree until 3885 // we find one that is. 3886 S = getNonFieldDeclScope(S); 3887 3888 // Verify that there isn't already something declared with this name in this 3889 // scope. 3890 NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName); 3891 if (PrevDecl && PrevDecl->isTemplateParameter()) { 3892 // Maybe we will complain about the shadowed template parameter. 3893 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 3894 // Just pretend that we didn't see the previous declaration. 3895 PrevDecl = 0; 3896 } 3897 3898 if (PrevDecl) { 3899 // When in C++, we may get a TagDecl with the same name; in this case the 3900 // enum constant will 'hide' the tag. 3901 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 3902 "Received TagDecl when not in C++!"); 3903 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 3904 if (isa<EnumConstantDecl>(PrevDecl)) 3905 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 3906 else 3907 Diag(IdLoc, diag::err_redefinition) << Id; 3908 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 3909 Val->Destroy(Context); 3910 return 0; 3911 } 3912 } 3913 3914 llvm::APSInt EnumVal(32); 3915 QualType EltTy; 3916 if (Val) { 3917 // Make sure to promote the operand type to int. 3918 UsualUnaryConversions(Val); 3919 3920 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 3921 SourceLocation ExpLoc; 3922 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 3923 Val->Destroy(Context); 3924 Val = 0; // Just forget about it. 3925 } else { 3926 EltTy = Val->getType(); 3927 } 3928 } 3929 3930 if (!Val) { 3931 if (LastEnumConst) { 3932 // Assign the last value + 1. 3933 EnumVal = LastEnumConst->getInitVal(); 3934 ++EnumVal; 3935 3936 // Check for overflow on increment. 3937 if (EnumVal < LastEnumConst->getInitVal()) 3938 Diag(IdLoc, diag::warn_enum_value_overflow); 3939 3940 EltTy = LastEnumConst->getType(); 3941 } else { 3942 // First value, set to zero. 3943 EltTy = Context.IntTy; 3944 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 3945 } 3946 } 3947 3948 EnumConstantDecl *New = 3949 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 3950 Val, EnumVal); 3951 3952 // Register this decl in the current scope stack. 3953 PushOnScopeChains(New, S); 3954 3955 return New; 3956} 3957 3958// FIXME: For consistency with ActOnFields(), we should have the parser 3959// pass in the source location for the left/right braces. 3960void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 3961 DeclTy **Elements, unsigned NumElements) { 3962 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 3963 QualType EnumType = Context.getTypeDeclType(Enum); 3964 3965 // TODO: If the result value doesn't fit in an int, it must be a long or long 3966 // long value. ISO C does not support this, but GCC does as an extension, 3967 // emit a warning. 3968 unsigned IntWidth = Context.Target.getIntWidth(); 3969 3970 // Verify that all the values are okay, compute the size of the values, and 3971 // reverse the list. 3972 unsigned NumNegativeBits = 0; 3973 unsigned NumPositiveBits = 0; 3974 3975 // Keep track of whether all elements have type int. 3976 bool AllElementsInt = true; 3977 3978 for (unsigned i = 0; i != NumElements; ++i) { 3979 EnumConstantDecl *ECD = 3980 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3981 if (!ECD) continue; // Already issued a diagnostic. 3982 3983 // If the enum value doesn't fit in an int, emit an extension warning. 3984 const llvm::APSInt &InitVal = ECD->getInitVal(); 3985 assert(InitVal.getBitWidth() >= IntWidth && 3986 "Should have promoted value to int"); 3987 if (InitVal.getBitWidth() > IntWidth) { 3988 llvm::APSInt V(InitVal); 3989 V.trunc(IntWidth); 3990 V.extend(InitVal.getBitWidth()); 3991 if (V != InitVal) 3992 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 3993 << InitVal.toString(10); 3994 } 3995 3996 // Keep track of the size of positive and negative values. 3997 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 3998 NumPositiveBits = std::max(NumPositiveBits, 3999 (unsigned)InitVal.getActiveBits()); 4000 else 4001 NumNegativeBits = std::max(NumNegativeBits, 4002 (unsigned)InitVal.getMinSignedBits()); 4003 4004 // Keep track of whether every enum element has type int (very commmon). 4005 if (AllElementsInt) 4006 AllElementsInt = ECD->getType() == Context.IntTy; 4007 } 4008 4009 // Figure out the type that should be used for this enum. 4010 // FIXME: Support attribute(packed) on enums and -fshort-enums. 4011 QualType BestType; 4012 unsigned BestWidth; 4013 4014 if (NumNegativeBits) { 4015 // If there is a negative value, figure out the smallest integer type (of 4016 // int/long/longlong) that fits. 4017 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 4018 BestType = Context.IntTy; 4019 BestWidth = IntWidth; 4020 } else { 4021 BestWidth = Context.Target.getLongWidth(); 4022 4023 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 4024 BestType = Context.LongTy; 4025 else { 4026 BestWidth = Context.Target.getLongLongWidth(); 4027 4028 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 4029 Diag(Enum->getLocation(), diag::warn_enum_too_large); 4030 BestType = Context.LongLongTy; 4031 } 4032 } 4033 } else { 4034 // If there is no negative value, figure out which of uint, ulong, ulonglong 4035 // fits. 4036 if (NumPositiveBits <= IntWidth) { 4037 BestType = Context.UnsignedIntTy; 4038 BestWidth = IntWidth; 4039 } else if (NumPositiveBits <= 4040 (BestWidth = Context.Target.getLongWidth())) { 4041 BestType = Context.UnsignedLongTy; 4042 } else { 4043 BestWidth = Context.Target.getLongLongWidth(); 4044 assert(NumPositiveBits <= BestWidth && 4045 "How could an initializer get larger than ULL?"); 4046 BestType = Context.UnsignedLongLongTy; 4047 } 4048 } 4049 4050 // Loop over all of the enumerator constants, changing their types to match 4051 // the type of the enum if needed. 4052 for (unsigned i = 0; i != NumElements; ++i) { 4053 EnumConstantDecl *ECD = 4054 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 4055 if (!ECD) continue; // Already issued a diagnostic. 4056 4057 // Standard C says the enumerators have int type, but we allow, as an 4058 // extension, the enumerators to be larger than int size. If each 4059 // enumerator value fits in an int, type it as an int, otherwise type it the 4060 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 4061 // that X has type 'int', not 'unsigned'. 4062 if (ECD->getType() == Context.IntTy) { 4063 // Make sure the init value is signed. 4064 llvm::APSInt IV = ECD->getInitVal(); 4065 IV.setIsSigned(true); 4066 ECD->setInitVal(IV); 4067 4068 if (getLangOptions().CPlusPlus) 4069 // C++ [dcl.enum]p4: Following the closing brace of an 4070 // enum-specifier, each enumerator has the type of its 4071 // enumeration. 4072 ECD->setType(EnumType); 4073 continue; // Already int type. 4074 } 4075 4076 // Determine whether the value fits into an int. 4077 llvm::APSInt InitVal = ECD->getInitVal(); 4078 bool FitsInInt; 4079 if (InitVal.isUnsigned() || !InitVal.isNegative()) 4080 FitsInInt = InitVal.getActiveBits() < IntWidth; 4081 else 4082 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 4083 4084 // If it fits into an integer type, force it. Otherwise force it to match 4085 // the enum decl type. 4086 QualType NewTy; 4087 unsigned NewWidth; 4088 bool NewSign; 4089 if (FitsInInt) { 4090 NewTy = Context.IntTy; 4091 NewWidth = IntWidth; 4092 NewSign = true; 4093 } else if (ECD->getType() == BestType) { 4094 // Already the right type! 4095 if (getLangOptions().CPlusPlus) 4096 // C++ [dcl.enum]p4: Following the closing brace of an 4097 // enum-specifier, each enumerator has the type of its 4098 // enumeration. 4099 ECD->setType(EnumType); 4100 continue; 4101 } else { 4102 NewTy = BestType; 4103 NewWidth = BestWidth; 4104 NewSign = BestType->isSignedIntegerType(); 4105 } 4106 4107 // Adjust the APSInt value. 4108 InitVal.extOrTrunc(NewWidth); 4109 InitVal.setIsSigned(NewSign); 4110 ECD->setInitVal(InitVal); 4111 4112 // Adjust the Expr initializer and type. 4113 if (ECD->getInitExpr()) 4114 ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, ECD->getInitExpr(), 4115 /*isLvalue=*/false)); 4116 if (getLangOptions().CPlusPlus) 4117 // C++ [dcl.enum]p4: Following the closing brace of an 4118 // enum-specifier, each enumerator has the type of its 4119 // enumeration. 4120 ECD->setType(EnumType); 4121 else 4122 ECD->setType(NewTy); 4123 } 4124 4125 Enum->completeDefinition(Context, BestType); 4126} 4127 4128Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 4129 ExprArg expr) { 4130 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr.release()); 4131 4132 return FileScopeAsmDecl::Create(Context, CurContext, Loc, AsmString); 4133} 4134 4135