SemaDecl.cpp revision a73e220722f6a7e30f2992a9830551f26b8be947
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/Parse/DeclSpec.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/SourceManager.h" 24// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/HeaderSearch.h" 27#include "llvm/ADT/SmallSet.h" 28#include "llvm/ADT/StringExtras.h" 29using namespace clang; 30 31Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S, 32 const CXXScopeSpec *SS) { 33 DeclContext *DC = 0; 34 if (SS) { 35 if (SS->isInvalid()) 36 return 0; 37 DC = static_cast<DeclContext*>(SS->getScopeRep()); 38 } 39 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 40 41 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 42 isa<ObjCInterfaceDecl>(IIDecl) || 43 isa<TagDecl>(IIDecl))) 44 return IIDecl; 45 return 0; 46} 47 48std::string Sema::getTypeAsString(TypeTy *Type) { 49 QualType Ty = QualType::getFromOpaquePtr(Type); 50 return Ty.getAsString(); 51} 52 53DeclContext *Sema::getContainingDC(DeclContext *DC) { 54 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 55 // A C++ out-of-line method will return to the file declaration context. 56 if (MD->isOutOfLineDefinition()) 57 return MD->getLexicalDeclContext(); 58 59 // A C++ inline method is parsed *after* the topmost class it was declared in 60 // is fully parsed (it's "complete"). 61 // The parsing of a C++ inline method happens at the declaration context of 62 // the topmost (non-nested) class it is declared in. 63 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 64 DC = MD->getParent(); 65 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 66 DC = RD; 67 68 // Return the declaration context of the topmost class the inline method is 69 // declared in. 70 return DC; 71 } 72 73 if (isa<ObjCMethodDecl>(DC)) 74 return Context.getTranslationUnitDecl(); 75 76 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC)) 77 return SD->getLexicalDeclContext(); 78 79 return DC->getParent(); 80} 81 82void Sema::PushDeclContext(DeclContext *DC) { 83 assert(getContainingDC(DC) == CurContext && 84 "The next DeclContext should be lexically contained in the current one."); 85 CurContext = DC; 86} 87 88void Sema::PopDeclContext() { 89 assert(CurContext && "DeclContext imbalance!"); 90 CurContext = getContainingDC(CurContext); 91} 92 93/// Add this decl to the scope shadowed decl chains. 94void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 95 S->AddDecl(D); 96 97 // C++ [basic.scope]p4: 98 // -- exactly one declaration shall declare a class name or 99 // enumeration name that is not a typedef name and the other 100 // declarations shall all refer to the same object or 101 // enumerator, or all refer to functions and function templates; 102 // in this case the class name or enumeration name is hidden. 103 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 104 // We are pushing the name of a tag (enum or class). 105 IdentifierResolver::iterator 106 I = IdResolver.begin(TD->getIdentifier(), 107 TD->getDeclContext(), false/*LookInParentCtx*/); 108 if (I != IdResolver.end() && isDeclInScope(*I, TD->getDeclContext(), S)) { 109 // There is already a declaration with the same name in the same 110 // scope. It must be found before we find the new declaration, 111 // so swap the order on the shadowed declaration chain. 112 113 IdResolver.AddShadowedDecl(TD, *I); 114 return; 115 } 116 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 117 FunctionDecl *FD = cast<FunctionDecl>(D); 118 // We are pushing the name of a function, which might be an 119 // overloaded name. 120 IdentifierResolver::iterator 121 I = IdResolver.begin(FD->getIdentifier(), 122 FD->getDeclContext(), false/*LookInParentCtx*/); 123 if (I != IdResolver.end() && 124 IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) && 125 (isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) { 126 // There is already a declaration with the same name in the same 127 // scope. It must be a function or an overloaded function. 128 OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I); 129 if (!Ovl) { 130 // We haven't yet overloaded this function. Take the existing 131 // FunctionDecl and put it into an OverloadedFunctionDecl. 132 Ovl = OverloadedFunctionDecl::Create(Context, 133 FD->getDeclContext(), 134 FD->getIdentifier()); 135 Ovl->addOverload(dyn_cast<FunctionDecl>(*I)); 136 137 // Remove the name binding to the existing FunctionDecl... 138 IdResolver.RemoveDecl(*I); 139 140 // ... and put the OverloadedFunctionDecl in its place. 141 IdResolver.AddDecl(Ovl); 142 } 143 144 // We have an OverloadedFunctionDecl. Add the new FunctionDecl 145 // to its list of overloads. 146 Ovl->addOverload(FD); 147 148 return; 149 } 150 } 151 152 IdResolver.AddDecl(D); 153} 154 155void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 156 if (S->decl_empty()) return; 157 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 158 159 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 160 I != E; ++I) { 161 Decl *TmpD = static_cast<Decl*>(*I); 162 assert(TmpD && "This decl didn't get pushed??"); 163 164 if (isa<CXXFieldDecl>(TmpD)) continue; 165 166 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 167 ScopedDecl *D = cast<ScopedDecl>(TmpD); 168 169 IdentifierInfo *II = D->getIdentifier(); 170 if (!II) continue; 171 172 // We only want to remove the decls from the identifier decl chains for 173 // local scopes, when inside a function/method. 174 if (S->getFnParent() != 0) 175 IdResolver.RemoveDecl(D); 176 177 // Chain this decl to the containing DeclContext. 178 D->setNext(CurContext->getDeclChain()); 179 CurContext->setDeclChain(D); 180 } 181} 182 183/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 184/// return 0 if one not found. 185ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 186 // The third "scope" argument is 0 since we aren't enabling lazy built-in 187 // creation from this context. 188 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 189 190 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 191} 192 193/// LookupDecl - Look up the inner-most declaration in the specified 194/// namespace. 195Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, Scope *S, 196 const DeclContext *LookupCtx, 197 bool enableLazyBuiltinCreation) { 198 if (II == 0) return 0; 199 unsigned NS = NSI; 200 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 201 NS |= Decl::IDNS_Tag; 202 203 IdentifierResolver::iterator 204 I = LookupCtx ? IdResolver.begin(II, LookupCtx, false/*LookInParentCtx*/) : 205 IdResolver.begin(II, CurContext, true/*LookInParentCtx*/); 206 // Scan up the scope chain looking for a decl that matches this identifier 207 // that is in the appropriate namespace. This search should not take long, as 208 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 209 for (; I != IdResolver.end(); ++I) 210 if ((*I)->getIdentifierNamespace() & NS) 211 return *I; 212 213 // If we didn't find a use of this identifier, and if the identifier 214 // corresponds to a compiler builtin, create the decl object for the builtin 215 // now, injecting it into translation unit scope, and return it. 216 if (NS & Decl::IDNS_Ordinary) { 217 if (enableLazyBuiltinCreation && 218 (LookupCtx == 0 || isa<TranslationUnitDecl>(LookupCtx))) { 219 // If this is a builtin on this (or all) targets, create the decl. 220 if (unsigned BuiltinID = II->getBuiltinID()) 221 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 222 } 223 if (getLangOptions().ObjC1) { 224 // @interface and @compatibility_alias introduce typedef-like names. 225 // Unlike typedef's, they can only be introduced at file-scope (and are 226 // therefore not scoped decls). They can, however, be shadowed by 227 // other names in IDNS_Ordinary. 228 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 229 if (IDI != ObjCInterfaceDecls.end()) 230 return IDI->second; 231 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 232 if (I != ObjCAliasDecls.end()) 233 return I->second->getClassInterface(); 234 } 235 } 236 return 0; 237} 238 239void Sema::InitBuiltinVaListType() { 240 if (!Context.getBuiltinVaListType().isNull()) 241 return; 242 243 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 244 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 245 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 246 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 247} 248 249/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 250/// lazily create a decl for it. 251ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 252 Scope *S) { 253 Builtin::ID BID = (Builtin::ID)bid; 254 255 if (Context.BuiltinInfo.hasVAListUse(BID)) 256 InitBuiltinVaListType(); 257 258 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 259 FunctionDecl *New = FunctionDecl::Create(Context, 260 Context.getTranslationUnitDecl(), 261 SourceLocation(), II, R, 262 FunctionDecl::Extern, false, 0); 263 264 // Create Decl objects for each parameter, adding them to the 265 // FunctionDecl. 266 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 267 llvm::SmallVector<ParmVarDecl*, 16> Params; 268 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 269 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 270 FT->getArgType(i), VarDecl::None, 0, 271 0)); 272 New->setParams(&Params[0], Params.size()); 273 } 274 275 276 277 // TUScope is the translation-unit scope to insert this function into. 278 PushOnScopeChains(New, TUScope); 279 return New; 280} 281 282/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 283/// everything from the standard library is defined. 284NamespaceDecl *Sema::GetStdNamespace() { 285 if (!StdNamespace) { 286 DeclContext *Global = Context.getTranslationUnitDecl(); 287 Decl *Std = LookupDecl(Ident_StdNs, Decl::IDNS_Tag | Decl::IDNS_Ordinary, 288 0, Global, /*enableLazyBuiltinCreation=*/false); 289 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 290 } 291 return StdNamespace; 292} 293 294/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 295/// and scope as a previous declaration 'Old'. Figure out how to resolve this 296/// situation, merging decls or emitting diagnostics as appropriate. 297/// 298TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 299 // Allow multiple definitions for ObjC built-in typedefs. 300 // FIXME: Verify the underlying types are equivalent! 301 if (getLangOptions().ObjC1) { 302 const IdentifierInfo *typeIdent = New->getIdentifier(); 303 if (typeIdent == Ident_id) { 304 Context.setObjCIdType(New); 305 return New; 306 } else if (typeIdent == Ident_Class) { 307 Context.setObjCClassType(New); 308 return New; 309 } else if (typeIdent == Ident_SEL) { 310 Context.setObjCSelType(New); 311 return New; 312 } else if (typeIdent == Ident_Protocol) { 313 Context.setObjCProtoType(New->getUnderlyingType()); 314 return New; 315 } 316 // Fall through - the typedef name was not a builtin type. 317 } 318 // Verify the old decl was also a typedef. 319 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 320 if (!Old) { 321 Diag(New->getLocation(), diag::err_redefinition_different_kind, 322 New->getName()); 323 Diag(OldD->getLocation(), diag::err_previous_definition); 324 return New; 325 } 326 327 // If the typedef types are not identical, reject them in all languages and 328 // with any extensions enabled. 329 if (Old->getUnderlyingType() != New->getUnderlyingType() && 330 Context.getCanonicalType(Old->getUnderlyingType()) != 331 Context.getCanonicalType(New->getUnderlyingType())) { 332 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 333 New->getUnderlyingType().getAsString(), 334 Old->getUnderlyingType().getAsString()); 335 Diag(Old->getLocation(), diag::err_previous_definition); 336 return Old; 337 } 338 339 if (getLangOptions().Microsoft) return New; 340 341 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 342 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 343 // *either* declaration is in a system header. The code below implements 344 // this adhoc compatibility rule. FIXME: The following code will not 345 // work properly when compiling ".i" files (containing preprocessed output). 346 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 347 SourceManager &SrcMgr = Context.getSourceManager(); 348 if (SrcMgr.isInSystemHeader(Old->getLocation())) 349 return New; 350 if (SrcMgr.isInSystemHeader(New->getLocation())) 351 return New; 352 } 353 354 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 355 Diag(Old->getLocation(), diag::err_previous_definition); 356 return New; 357} 358 359/// DeclhasAttr - returns true if decl Declaration already has the target 360/// attribute. 361static bool DeclHasAttr(const Decl *decl, const Attr *target) { 362 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 363 if (attr->getKind() == target->getKind()) 364 return true; 365 366 return false; 367} 368 369/// MergeAttributes - append attributes from the Old decl to the New one. 370static void MergeAttributes(Decl *New, Decl *Old) { 371 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 372 373 while (attr) { 374 tmp = attr; 375 attr = attr->getNext(); 376 377 if (!DeclHasAttr(New, tmp)) { 378 New->addAttr(tmp); 379 } else { 380 tmp->setNext(0); 381 delete(tmp); 382 } 383 } 384 385 Old->invalidateAttrs(); 386} 387 388/// MergeFunctionDecl - We just parsed a function 'New' from 389/// declarator D which has the same name and scope as a previous 390/// declaration 'Old'. Figure out how to resolve this situation, 391/// merging decls or emitting diagnostics as appropriate. 392/// Redeclaration will be set true if this New is a redeclaration OldD. 393/// 394/// In C++, New and Old must be declarations that are not 395/// overloaded. Use IsOverload to determine whether New and Old are 396/// overloaded, and to select the Old declaration that New should be 397/// merged with. 398FunctionDecl * 399Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 400 assert(!isa<OverloadedFunctionDecl>(OldD) && 401 "Cannot merge with an overloaded function declaration"); 402 403 Redeclaration = false; 404 // Verify the old decl was also a function. 405 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 406 if (!Old) { 407 Diag(New->getLocation(), diag::err_redefinition_different_kind, 408 New->getName()); 409 Diag(OldD->getLocation(), diag::err_previous_definition); 410 return New; 411 } 412 413 // Determine whether the previous declaration was a definition, 414 // implicit declaration, or a declaration. 415 diag::kind PrevDiag; 416 if (Old->isThisDeclarationADefinition()) 417 PrevDiag = diag::err_previous_definition; 418 else if (Old->isImplicit()) 419 PrevDiag = diag::err_previous_implicit_declaration; 420 else 421 PrevDiag = diag::err_previous_declaration; 422 423 QualType OldQType = Context.getCanonicalType(Old->getType()); 424 QualType NewQType = Context.getCanonicalType(New->getType()); 425 426 if (getLangOptions().CPlusPlus) { 427 // (C++98 13.1p2): 428 // Certain function declarations cannot be overloaded: 429 // -- Function declarations that differ only in the return type 430 // cannot be overloaded. 431 QualType OldReturnType 432 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 433 QualType NewReturnType 434 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 435 if (OldReturnType != NewReturnType) { 436 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 437 Diag(Old->getLocation(), PrevDiag); 438 return New; 439 } 440 441 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 442 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 443 if (OldMethod && NewMethod) { 444 // -- Member function declarations with the same name and the 445 // same parameter types cannot be overloaded if any of them 446 // is a static member function declaration. 447 if (OldMethod->isStatic() || NewMethod->isStatic()) { 448 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 449 Diag(Old->getLocation(), PrevDiag); 450 return New; 451 } 452 } 453 454 // (C++98 8.3.5p3): 455 // All declarations for a function shall agree exactly in both the 456 // return type and the parameter-type-list. 457 if (OldQType == NewQType) { 458 // We have a redeclaration. 459 MergeAttributes(New, Old); 460 Redeclaration = true; 461 return MergeCXXFunctionDecl(New, Old); 462 } 463 464 // Fall through for conflicting redeclarations and redefinitions. 465 } 466 467 // C: Function types need to be compatible, not identical. This handles 468 // duplicate function decls like "void f(int); void f(enum X);" properly. 469 if (!getLangOptions().CPlusPlus && 470 Context.typesAreCompatible(OldQType, NewQType)) { 471 MergeAttributes(New, Old); 472 Redeclaration = true; 473 return New; 474 } 475 476 // A function that has already been declared has been redeclared or defined 477 // with a different type- show appropriate diagnostic 478 479 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 480 // TODO: This is totally simplistic. It should handle merging functions 481 // together etc, merging extern int X; int X; ... 482 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 483 Diag(Old->getLocation(), PrevDiag); 484 return New; 485} 486 487/// Predicate for C "tentative" external object definitions (C99 6.9.2). 488static bool isTentativeDefinition(VarDecl *VD) { 489 if (VD->isFileVarDecl()) 490 return (!VD->getInit() && 491 (VD->getStorageClass() == VarDecl::None || 492 VD->getStorageClass() == VarDecl::Static)); 493 return false; 494} 495 496/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 497/// when dealing with C "tentative" external object definitions (C99 6.9.2). 498void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 499 bool VDIsTentative = isTentativeDefinition(VD); 500 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 501 502 for (IdentifierResolver::iterator 503 I = IdResolver.begin(VD->getIdentifier(), 504 VD->getDeclContext(), false/*LookInParentCtx*/), 505 E = IdResolver.end(); I != E; ++I) { 506 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 507 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 508 509 // Handle the following case: 510 // int a[10]; 511 // int a[]; - the code below makes sure we set the correct type. 512 // int a[11]; - this is an error, size isn't 10. 513 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 514 OldDecl->getType()->isConstantArrayType()) 515 VD->setType(OldDecl->getType()); 516 517 // Check for "tentative" definitions. We can't accomplish this in 518 // MergeVarDecl since the initializer hasn't been attached. 519 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 520 continue; 521 522 // Handle __private_extern__ just like extern. 523 if (OldDecl->getStorageClass() != VarDecl::Extern && 524 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 525 VD->getStorageClass() != VarDecl::Extern && 526 VD->getStorageClass() != VarDecl::PrivateExtern) { 527 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 528 Diag(OldDecl->getLocation(), diag::err_previous_definition); 529 } 530 } 531 } 532} 533 534/// MergeVarDecl - We just parsed a variable 'New' which has the same name 535/// and scope as a previous declaration 'Old'. Figure out how to resolve this 536/// situation, merging decls or emitting diagnostics as appropriate. 537/// 538/// Tentative definition rules (C99 6.9.2p2) are checked by 539/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 540/// definitions here, since the initializer hasn't been attached. 541/// 542VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 543 // Verify the old decl was also a variable. 544 VarDecl *Old = dyn_cast<VarDecl>(OldD); 545 if (!Old) { 546 Diag(New->getLocation(), diag::err_redefinition_different_kind, 547 New->getName()); 548 Diag(OldD->getLocation(), diag::err_previous_definition); 549 return New; 550 } 551 552 MergeAttributes(New, Old); 553 554 // Verify the types match. 555 QualType OldCType = Context.getCanonicalType(Old->getType()); 556 QualType NewCType = Context.getCanonicalType(New->getType()); 557 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 558 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 559 Diag(Old->getLocation(), diag::err_previous_definition); 560 return New; 561 } 562 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 563 if (New->getStorageClass() == VarDecl::Static && 564 (Old->getStorageClass() == VarDecl::None || 565 Old->getStorageClass() == VarDecl::Extern)) { 566 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 567 Diag(Old->getLocation(), diag::err_previous_definition); 568 return New; 569 } 570 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 571 if (New->getStorageClass() != VarDecl::Static && 572 Old->getStorageClass() == VarDecl::Static) { 573 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 574 Diag(Old->getLocation(), diag::err_previous_definition); 575 return New; 576 } 577 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 578 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 579 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 580 Diag(Old->getLocation(), diag::err_previous_definition); 581 } 582 return New; 583} 584 585/// CheckParmsForFunctionDef - Check that the parameters of the given 586/// function are appropriate for the definition of a function. This 587/// takes care of any checks that cannot be performed on the 588/// declaration itself, e.g., that the types of each of the function 589/// parameters are complete. 590bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 591 bool HasInvalidParm = false; 592 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 593 ParmVarDecl *Param = FD->getParamDecl(p); 594 595 // C99 6.7.5.3p4: the parameters in a parameter type list in a 596 // function declarator that is part of a function definition of 597 // that function shall not have incomplete type. 598 if (Param->getType()->isIncompleteType() && 599 !Param->isInvalidDecl()) { 600 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 601 Param->getType().getAsString()); 602 Param->setInvalidDecl(); 603 HasInvalidParm = true; 604 } 605 } 606 607 return HasInvalidParm; 608} 609 610/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 611/// no declarator (e.g. "struct foo;") is parsed. 612Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 613 // TODO: emit error on 'int;' or 'const enum foo;'. 614 // TODO: emit error on 'typedef int;' 615 // if (!DS.isMissingDeclaratorOk()) Diag(...); 616 617 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 618} 619 620bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 621 // Get the type before calling CheckSingleAssignmentConstraints(), since 622 // it can promote the expression. 623 QualType InitType = Init->getType(); 624 625 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 626 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 627 InitType, Init, "initializing"); 628} 629 630bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 631 const ArrayType *AT = Context.getAsArrayType(DeclT); 632 633 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 634 // C99 6.7.8p14. We have an array of character type with unknown size 635 // being initialized to a string literal. 636 llvm::APSInt ConstVal(32); 637 ConstVal = strLiteral->getByteLength() + 1; 638 // Return a new array type (C99 6.7.8p22). 639 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 640 ArrayType::Normal, 0); 641 } else { 642 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 643 // C99 6.7.8p14. We have an array of character type with known size. 644 // FIXME: Avoid truncation for 64-bit length strings. 645 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 646 Diag(strLiteral->getSourceRange().getBegin(), 647 diag::warn_initializer_string_for_char_array_too_long, 648 strLiteral->getSourceRange()); 649 } 650 // Set type from "char *" to "constant array of char". 651 strLiteral->setType(DeclT); 652 // For now, we always return false (meaning success). 653 return false; 654} 655 656StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 657 const ArrayType *AT = Context.getAsArrayType(DeclType); 658 if (AT && AT->getElementType()->isCharType()) { 659 return dyn_cast<StringLiteral>(Init); 660 } 661 return 0; 662} 663 664bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 665 SourceLocation InitLoc, 666 std::string InitEntity) { 667 // C++ [dcl.init.ref]p1: 668 // A variable declared to be a T&, that is “reference to type T” 669 // (8.3.2), shall be initialized by an object, or function, of 670 // type T or by an object that can be converted into a T. 671 if (DeclType->isReferenceType()) 672 return CheckReferenceInit(Init, DeclType); 673 674 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 675 // of unknown size ("[]") or an object type that is not a variable array type. 676 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 677 return Diag(InitLoc, 678 diag::err_variable_object_no_init, 679 VAT->getSizeExpr()->getSourceRange()); 680 681 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 682 if (!InitList) { 683 // FIXME: Handle wide strings 684 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 685 return CheckStringLiteralInit(strLiteral, DeclType); 686 687 // C++ [dcl.init]p14: 688 // -- If the destination type is a (possibly cv-qualified) class 689 // type: 690 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 691 QualType DeclTypeC = Context.getCanonicalType(DeclType); 692 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 693 694 // -- If the initialization is direct-initialization, or if it is 695 // copy-initialization where the cv-unqualified version of the 696 // source type is the same class as, or a derived class of, the 697 // class of the destination, constructors are considered. 698 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 699 IsDerivedFrom(InitTypeC, DeclTypeC)) { 700 CXXConstructorDecl *Constructor 701 = PerformInitializationByConstructor(DeclType, &Init, 1, 702 InitLoc, Init->getSourceRange(), 703 InitEntity, IK_Copy); 704 return Constructor == 0; 705 } 706 707 // -- Otherwise (i.e., for the remaining copy-initialization 708 // cases), user-defined conversion sequences that can 709 // convert from the source type to the destination type or 710 // (when a conversion function is used) to a derived class 711 // thereof are enumerated as described in 13.3.1.4, and the 712 // best one is chosen through overload resolution 713 // (13.3). If the conversion cannot be done or is 714 // ambiguous, the initialization is ill-formed. The 715 // function selected is called with the initializer 716 // expression as its argument; if the function is a 717 // constructor, the call initializes a temporary of the 718 // destination type. 719 // FIXME: We're pretending to do copy elision here; return to 720 // this when we have ASTs for such things. 721 if (PerformImplicitConversion(Init, DeclType)) 722 return Diag(InitLoc, 723 diag::err_typecheck_convert_incompatible, 724 DeclType.getAsString(), InitEntity, 725 "initializing", 726 Init->getSourceRange()); 727 else 728 return false; 729 } 730 731 // C99 6.7.8p16. 732 if (DeclType->isArrayType()) 733 return Diag(Init->getLocStart(), 734 diag::err_array_init_list_required, 735 Init->getSourceRange()); 736 737 return CheckSingleInitializer(Init, DeclType); 738 } else if (getLangOptions().CPlusPlus) { 739 // C++ [dcl.init]p14: 740 // [...] If the class is an aggregate (8.5.1), and the initializer 741 // is a brace-enclosed list, see 8.5.1. 742 // 743 // Note: 8.5.1 is handled below; here, we diagnose the case where 744 // we have an initializer list and a destination type that is not 745 // an aggregate. 746 // FIXME: In C++0x, this is yet another form of initialization. 747 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 748 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 749 if (!ClassDecl->isAggregate()) 750 return Diag(InitLoc, 751 diag::err_init_non_aggr_init_list, 752 DeclType.getAsString(), 753 Init->getSourceRange()); 754 } 755 } 756 757 InitListChecker CheckInitList(this, InitList, DeclType); 758 return CheckInitList.HadError(); 759} 760 761Sema::DeclTy * 762Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 763 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 764 IdentifierInfo *II = D.getIdentifier(); 765 766 // All of these full declarators require an identifier. If it doesn't have 767 // one, the ParsedFreeStandingDeclSpec action should be used. 768 if (II == 0) { 769 if (!D.getInvalidType()) // Reject this if we think it is valid. 770 Diag(D.getDeclSpec().getSourceRange().getBegin(), 771 diag::err_declarator_need_ident, 772 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 773 return 0; 774 } 775 776 // The scope passed in may not be a decl scope. Zip up the scope tree until 777 // we find one that is. 778 while ((S->getFlags() & Scope::DeclScope) == 0) 779 S = S->getParent(); 780 781 DeclContext *DC; 782 Decl *PrevDecl; 783 ScopedDecl *New; 784 bool InvalidDecl = false; 785 786 // See if this is a redefinition of a variable in the same scope. 787 if (!D.getCXXScopeSpec().isSet()) { 788 DC = CurContext; 789 PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 790 } else { // Something like "int foo::x;" 791 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 792 PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S, DC); 793 794 // C++ 7.3.1.2p2: 795 // Members (including explicit specializations of templates) of a named 796 // namespace can also be defined outside that namespace by explicit 797 // qualification of the name being defined, provided that the entity being 798 // defined was already declared in the namespace and the definition appears 799 // after the point of declaration in a namespace that encloses the 800 // declarations namespace. 801 // 802 if (PrevDecl == 0) { 803 // No previous declaration in the qualifying scope. 804 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member, 805 II->getName(), D.getCXXScopeSpec().getRange()); 806 } else if (!CurContext->Encloses(DC)) { 807 // The qualifying scope doesn't enclose the original declaration. 808 // Emit diagnostic based on current scope. 809 SourceLocation L = D.getIdentifierLoc(); 810 SourceRange R = D.getCXXScopeSpec().getRange(); 811 if (isa<FunctionDecl>(CurContext)) { 812 Diag(L, diag::err_invalid_declarator_in_function, II->getName(), R); 813 } else { 814 Diag(L, diag::err_invalid_declarator_scope, II->getName(), 815 cast<NamedDecl>(DC)->getName(), R); 816 } 817 } 818 } 819 820 // In C++, the previous declaration we find might be a tag type 821 // (class or enum). In this case, the new declaration will hide the 822 // tag type. 823 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 824 PrevDecl = 0; 825 826 QualType R = GetTypeForDeclarator(D, S); 827 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 828 829 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 830 // Check that there are no default arguments (C++ only). 831 if (getLangOptions().CPlusPlus) 832 CheckExtraCXXDefaultArguments(D); 833 834 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 835 if (!NewTD) return 0; 836 837 // Handle attributes prior to checking for duplicates in MergeVarDecl 838 ProcessDeclAttributes(NewTD, D); 839 // Merge the decl with the existing one if appropriate. If the decl is 840 // in an outer scope, it isn't the same thing. 841 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 842 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 843 if (NewTD == 0) return 0; 844 } 845 New = NewTD; 846 if (S->getFnParent() == 0) { 847 // C99 6.7.7p2: If a typedef name specifies a variably modified type 848 // then it shall have block scope. 849 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 850 // FIXME: Diagnostic needs to be fixed. 851 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 852 InvalidDecl = true; 853 } 854 } 855 } else if (R.getTypePtr()->isFunctionType()) { 856 FunctionDecl::StorageClass SC = FunctionDecl::None; 857 switch (D.getDeclSpec().getStorageClassSpec()) { 858 default: assert(0 && "Unknown storage class!"); 859 case DeclSpec::SCS_auto: 860 case DeclSpec::SCS_register: 861 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 862 R.getAsString()); 863 InvalidDecl = true; 864 break; 865 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 866 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 867 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 868 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 869 } 870 871 bool isInline = D.getDeclSpec().isInlineSpecified(); 872 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 873 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 874 875 FunctionDecl *NewFD; 876 if (D.getKind() == Declarator::DK_Constructor) { 877 // This is a C++ constructor declaration. 878 assert(DC->isCXXRecord() && 879 "Constructors can only be declared in a member context"); 880 881 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 882 883 // Create the new declaration 884 NewFD = CXXConstructorDecl::Create(Context, 885 cast<CXXRecordDecl>(DC), 886 D.getIdentifierLoc(), II, R, 887 isExplicit, isInline, 888 /*isImplicitlyDeclared=*/false); 889 890 if (isInvalidDecl) 891 NewFD->setInvalidDecl(); 892 } else if (D.getKind() == Declarator::DK_Destructor) { 893 // This is a C++ destructor declaration. 894 if (DC->isCXXRecord()) { 895 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 896 897 NewFD = CXXDestructorDecl::Create(Context, 898 cast<CXXRecordDecl>(DC), 899 D.getIdentifierLoc(), II, R, 900 isInline, 901 /*isImplicitlyDeclared=*/false); 902 903 if (isInvalidDecl) 904 NewFD->setInvalidDecl(); 905 } else { 906 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 907 // Create a FunctionDecl to satisfy the function definition parsing 908 // code path. 909 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 910 II, R, SC, isInline, LastDeclarator, 911 // FIXME: Move to DeclGroup... 912 D.getDeclSpec().getSourceRange().getBegin()); 913 NewFD->setInvalidDecl(); 914 } 915 } else if (D.getKind() == Declarator::DK_Conversion) { 916 if (!DC->isCXXRecord()) { 917 Diag(D.getIdentifierLoc(), 918 diag::err_conv_function_not_member); 919 return 0; 920 } else { 921 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 922 923 NewFD = CXXConversionDecl::Create(Context, 924 cast<CXXRecordDecl>(DC), 925 D.getIdentifierLoc(), II, R, 926 isInline, isExplicit); 927 928 if (isInvalidDecl) 929 NewFD->setInvalidDecl(); 930 } 931 } else if (DC->isCXXRecord()) { 932 // This is a C++ method declaration. 933 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 934 D.getIdentifierLoc(), II, R, 935 (SC == FunctionDecl::Static), isInline, 936 LastDeclarator); 937 } else { 938 NewFD = FunctionDecl::Create(Context, DC, 939 D.getIdentifierLoc(), 940 II, R, SC, isInline, LastDeclarator, 941 // FIXME: Move to DeclGroup... 942 D.getDeclSpec().getSourceRange().getBegin()); 943 } 944 // Handle attributes. 945 ProcessDeclAttributes(NewFD, D); 946 947 // Handle GNU asm-label extension (encoded as an attribute). 948 if (Expr *E = (Expr*) D.getAsmLabel()) { 949 // The parser guarantees this is a string. 950 StringLiteral *SE = cast<StringLiteral>(E); 951 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 952 SE->getByteLength()))); 953 } 954 955 // Copy the parameter declarations from the declarator D to 956 // the function declaration NewFD, if they are available. 957 if (D.getNumTypeObjects() > 0) { 958 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 959 960 // Create Decl objects for each parameter, adding them to the 961 // FunctionDecl. 962 llvm::SmallVector<ParmVarDecl*, 16> Params; 963 964 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 965 // function that takes no arguments, not a function that takes a 966 // single void argument. 967 // We let through "const void" here because Sema::GetTypeForDeclarator 968 // already checks for that case. 969 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 970 FTI.ArgInfo[0].Param && 971 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 972 // empty arg list, don't push any params. 973 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 974 975 // In C++, the empty parameter-type-list must be spelled "void"; a 976 // typedef of void is not permitted. 977 if (getLangOptions().CPlusPlus && 978 Param->getType().getUnqualifiedType() != Context.VoidTy) { 979 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 980 } 981 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 982 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 983 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 984 } 985 986 NewFD->setParams(&Params[0], Params.size()); 987 } else if (R->getAsTypedefType()) { 988 // When we're declaring a function with a typedef, as in the 989 // following example, we'll need to synthesize (unnamed) 990 // parameters for use in the declaration. 991 // 992 // @code 993 // typedef void fn(int); 994 // fn f; 995 // @endcode 996 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 997 if (!FT) { 998 // This is a typedef of a function with no prototype, so we 999 // don't need to do anything. 1000 } else if ((FT->getNumArgs() == 0) || 1001 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1002 FT->getArgType(0)->isVoidType())) { 1003 // This is a zero-argument function. We don't need to do anything. 1004 } else { 1005 // Synthesize a parameter for each argument type. 1006 llvm::SmallVector<ParmVarDecl*, 16> Params; 1007 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1008 ArgType != FT->arg_type_end(); ++ArgType) { 1009 Params.push_back(ParmVarDecl::Create(Context, DC, 1010 SourceLocation(), 0, 1011 *ArgType, VarDecl::None, 1012 0, 0)); 1013 } 1014 1015 NewFD->setParams(&Params[0], Params.size()); 1016 } 1017 } 1018 1019 // C++ constructors and destructors are handled by separate 1020 // routines, since they don't require any declaration merging (C++ 1021 // [class.mfct]p2) and they aren't ever pushed into scope, because 1022 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1023 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1024 return ActOnConstructorDeclarator(Constructor); 1025 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1026 return ActOnDestructorDeclarator(Destructor); 1027 else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1028 return ActOnConversionDeclarator(Conversion); 1029 1030 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1031 if (NewFD->isOverloadedOperator() && 1032 CheckOverloadedOperatorDeclaration(NewFD)) 1033 NewFD->setInvalidDecl(); 1034 1035 // Merge the decl with the existing one if appropriate. Since C functions 1036 // are in a flat namespace, make sure we consider decls in outer scopes. 1037 if (PrevDecl && 1038 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1039 bool Redeclaration = false; 1040 1041 // If C++, determine whether NewFD is an overload of PrevDecl or 1042 // a declaration that requires merging. If it's an overload, 1043 // there's no more work to do here; we'll just add the new 1044 // function to the scope. 1045 OverloadedFunctionDecl::function_iterator MatchedDecl; 1046 if (!getLangOptions().CPlusPlus || 1047 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1048 Decl *OldDecl = PrevDecl; 1049 1050 // If PrevDecl was an overloaded function, extract the 1051 // FunctionDecl that matched. 1052 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1053 OldDecl = *MatchedDecl; 1054 1055 // NewFD and PrevDecl represent declarations that need to be 1056 // merged. 1057 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1058 1059 if (NewFD == 0) return 0; 1060 if (Redeclaration) { 1061 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1062 1063 if (OldDecl == PrevDecl) { 1064 // Remove the name binding for the previous 1065 // declaration. We'll add the binding back later, but then 1066 // it will refer to the new declaration (which will 1067 // contain more information). 1068 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1069 } else { 1070 // We need to update the OverloadedFunctionDecl with the 1071 // latest declaration of this function, so that name 1072 // lookup will always refer to the latest declaration of 1073 // this function. 1074 *MatchedDecl = NewFD; 1075 1076 // Add the redeclaration to the current scope, since we'll 1077 // be skipping PushOnScopeChains. 1078 S->AddDecl(NewFD); 1079 1080 return NewFD; 1081 } 1082 } 1083 } 1084 } 1085 New = NewFD; 1086 1087 // In C++, check default arguments now that we have merged decls. 1088 if (getLangOptions().CPlusPlus) 1089 CheckCXXDefaultArguments(NewFD); 1090 } else { 1091 // Check that there are no default arguments (C++ only). 1092 if (getLangOptions().CPlusPlus) 1093 CheckExtraCXXDefaultArguments(D); 1094 1095 if (R.getTypePtr()->isObjCInterfaceType()) { 1096 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 1097 D.getIdentifier()->getName()); 1098 InvalidDecl = true; 1099 } 1100 1101 VarDecl *NewVD; 1102 VarDecl::StorageClass SC; 1103 switch (D.getDeclSpec().getStorageClassSpec()) { 1104 default: assert(0 && "Unknown storage class!"); 1105 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1106 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1107 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1108 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1109 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1110 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1111 } 1112 if (DC->isCXXRecord()) { 1113 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1114 // This is a static data member for a C++ class. 1115 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1116 D.getIdentifierLoc(), II, 1117 R, LastDeclarator); 1118 } else { 1119 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1120 if (S->getFnParent() == 0) { 1121 // C99 6.9p2: The storage-class specifiers auto and register shall not 1122 // appear in the declaration specifiers in an external declaration. 1123 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1124 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 1125 R.getAsString()); 1126 InvalidDecl = true; 1127 } 1128 } 1129 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1130 II, R, SC, LastDeclarator, 1131 // FIXME: Move to DeclGroup... 1132 D.getDeclSpec().getSourceRange().getBegin()); 1133 NewVD->setThreadSpecified(ThreadSpecified); 1134 } 1135 // Handle attributes prior to checking for duplicates in MergeVarDecl 1136 ProcessDeclAttributes(NewVD, D); 1137 1138 // Handle GNU asm-label extension (encoded as an attribute). 1139 if (Expr *E = (Expr*) D.getAsmLabel()) { 1140 // The parser guarantees this is a string. 1141 StringLiteral *SE = cast<StringLiteral>(E); 1142 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1143 SE->getByteLength()))); 1144 } 1145 1146 // Emit an error if an address space was applied to decl with local storage. 1147 // This includes arrays of objects with address space qualifiers, but not 1148 // automatic variables that point to other address spaces. 1149 // ISO/IEC TR 18037 S5.1.2 1150 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1151 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1152 InvalidDecl = true; 1153 } 1154 // Merge the decl with the existing one if appropriate. If the decl is 1155 // in an outer scope, it isn't the same thing. 1156 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1157 NewVD = MergeVarDecl(NewVD, PrevDecl); 1158 if (NewVD == 0) return 0; 1159 } 1160 New = NewVD; 1161 } 1162 1163 // Set the lexical context. If the declarator has a C++ scope specifier, the 1164 // lexical context will be different from the semantic context. 1165 New->setLexicalDeclContext(CurContext); 1166 1167 // If this has an identifier, add it to the scope stack. 1168 if (II) 1169 PushOnScopeChains(New, S); 1170 // If any semantic error occurred, mark the decl as invalid. 1171 if (D.getInvalidType() || InvalidDecl) 1172 New->setInvalidDecl(); 1173 1174 return New; 1175} 1176 1177void Sema::InitializerElementNotConstant(const Expr *Init) { 1178 Diag(Init->getExprLoc(), 1179 diag::err_init_element_not_constant, Init->getSourceRange()); 1180} 1181 1182bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1183 switch (Init->getStmtClass()) { 1184 default: 1185 InitializerElementNotConstant(Init); 1186 return true; 1187 case Expr::ParenExprClass: { 1188 const ParenExpr* PE = cast<ParenExpr>(Init); 1189 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1190 } 1191 case Expr::CompoundLiteralExprClass: 1192 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1193 case Expr::DeclRefExprClass: { 1194 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1195 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1196 if (VD->hasGlobalStorage()) 1197 return false; 1198 InitializerElementNotConstant(Init); 1199 return true; 1200 } 1201 if (isa<FunctionDecl>(D)) 1202 return false; 1203 InitializerElementNotConstant(Init); 1204 return true; 1205 } 1206 case Expr::MemberExprClass: { 1207 const MemberExpr *M = cast<MemberExpr>(Init); 1208 if (M->isArrow()) 1209 return CheckAddressConstantExpression(M->getBase()); 1210 return CheckAddressConstantExpressionLValue(M->getBase()); 1211 } 1212 case Expr::ArraySubscriptExprClass: { 1213 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1214 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1215 return CheckAddressConstantExpression(ASE->getBase()) || 1216 CheckArithmeticConstantExpression(ASE->getIdx()); 1217 } 1218 case Expr::StringLiteralClass: 1219 case Expr::PredefinedExprClass: 1220 return false; 1221 case Expr::UnaryOperatorClass: { 1222 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1223 1224 // C99 6.6p9 1225 if (Exp->getOpcode() == UnaryOperator::Deref) 1226 return CheckAddressConstantExpression(Exp->getSubExpr()); 1227 1228 InitializerElementNotConstant(Init); 1229 return true; 1230 } 1231 } 1232} 1233 1234bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1235 switch (Init->getStmtClass()) { 1236 default: 1237 InitializerElementNotConstant(Init); 1238 return true; 1239 case Expr::ParenExprClass: 1240 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1241 case Expr::StringLiteralClass: 1242 case Expr::ObjCStringLiteralClass: 1243 return false; 1244 case Expr::CallExprClass: 1245 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1246 if (cast<CallExpr>(Init)->isBuiltinCall() == 1247 Builtin::BI__builtin___CFStringMakeConstantString) 1248 return false; 1249 1250 InitializerElementNotConstant(Init); 1251 return true; 1252 1253 case Expr::UnaryOperatorClass: { 1254 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1255 1256 // C99 6.6p9 1257 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1258 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1259 1260 if (Exp->getOpcode() == UnaryOperator::Extension) 1261 return CheckAddressConstantExpression(Exp->getSubExpr()); 1262 1263 InitializerElementNotConstant(Init); 1264 return true; 1265 } 1266 case Expr::BinaryOperatorClass: { 1267 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1268 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1269 1270 Expr *PExp = Exp->getLHS(); 1271 Expr *IExp = Exp->getRHS(); 1272 if (IExp->getType()->isPointerType()) 1273 std::swap(PExp, IExp); 1274 1275 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1276 return CheckAddressConstantExpression(PExp) || 1277 CheckArithmeticConstantExpression(IExp); 1278 } 1279 case Expr::ImplicitCastExprClass: 1280 case Expr::CStyleCastExprClass: { 1281 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1282 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1283 // Check for implicit promotion 1284 if (SubExpr->getType()->isFunctionType() || 1285 SubExpr->getType()->isArrayType()) 1286 return CheckAddressConstantExpressionLValue(SubExpr); 1287 } 1288 1289 // Check for pointer->pointer cast 1290 if (SubExpr->getType()->isPointerType()) 1291 return CheckAddressConstantExpression(SubExpr); 1292 1293 if (SubExpr->getType()->isIntegralType()) { 1294 // Check for the special-case of a pointer->int->pointer cast; 1295 // this isn't standard, but some code requires it. See 1296 // PR2720 for an example. 1297 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1298 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1299 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1300 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1301 if (IntWidth >= PointerWidth) { 1302 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1303 } 1304 } 1305 } 1306 } 1307 if (SubExpr->getType()->isArithmeticType()) { 1308 return CheckArithmeticConstantExpression(SubExpr); 1309 } 1310 1311 InitializerElementNotConstant(Init); 1312 return true; 1313 } 1314 case Expr::ConditionalOperatorClass: { 1315 // FIXME: Should we pedwarn here? 1316 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1317 if (!Exp->getCond()->getType()->isArithmeticType()) { 1318 InitializerElementNotConstant(Init); 1319 return true; 1320 } 1321 if (CheckArithmeticConstantExpression(Exp->getCond())) 1322 return true; 1323 if (Exp->getLHS() && 1324 CheckAddressConstantExpression(Exp->getLHS())) 1325 return true; 1326 return CheckAddressConstantExpression(Exp->getRHS()); 1327 } 1328 case Expr::AddrLabelExprClass: 1329 return false; 1330 } 1331} 1332 1333static const Expr* FindExpressionBaseAddress(const Expr* E); 1334 1335static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1336 switch (E->getStmtClass()) { 1337 default: 1338 return E; 1339 case Expr::ParenExprClass: { 1340 const ParenExpr* PE = cast<ParenExpr>(E); 1341 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1342 } 1343 case Expr::MemberExprClass: { 1344 const MemberExpr *M = cast<MemberExpr>(E); 1345 if (M->isArrow()) 1346 return FindExpressionBaseAddress(M->getBase()); 1347 return FindExpressionBaseAddressLValue(M->getBase()); 1348 } 1349 case Expr::ArraySubscriptExprClass: { 1350 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1351 return FindExpressionBaseAddress(ASE->getBase()); 1352 } 1353 case Expr::UnaryOperatorClass: { 1354 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1355 1356 if (Exp->getOpcode() == UnaryOperator::Deref) 1357 return FindExpressionBaseAddress(Exp->getSubExpr()); 1358 1359 return E; 1360 } 1361 } 1362} 1363 1364static const Expr* FindExpressionBaseAddress(const Expr* E) { 1365 switch (E->getStmtClass()) { 1366 default: 1367 return E; 1368 case Expr::ParenExprClass: { 1369 const ParenExpr* PE = cast<ParenExpr>(E); 1370 return FindExpressionBaseAddress(PE->getSubExpr()); 1371 } 1372 case Expr::UnaryOperatorClass: { 1373 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1374 1375 // C99 6.6p9 1376 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1377 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1378 1379 if (Exp->getOpcode() == UnaryOperator::Extension) 1380 return FindExpressionBaseAddress(Exp->getSubExpr()); 1381 1382 return E; 1383 } 1384 case Expr::BinaryOperatorClass: { 1385 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1386 1387 Expr *PExp = Exp->getLHS(); 1388 Expr *IExp = Exp->getRHS(); 1389 if (IExp->getType()->isPointerType()) 1390 std::swap(PExp, IExp); 1391 1392 return FindExpressionBaseAddress(PExp); 1393 } 1394 case Expr::ImplicitCastExprClass: { 1395 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1396 1397 // Check for implicit promotion 1398 if (SubExpr->getType()->isFunctionType() || 1399 SubExpr->getType()->isArrayType()) 1400 return FindExpressionBaseAddressLValue(SubExpr); 1401 1402 // Check for pointer->pointer cast 1403 if (SubExpr->getType()->isPointerType()) 1404 return FindExpressionBaseAddress(SubExpr); 1405 1406 // We assume that we have an arithmetic expression here; 1407 // if we don't, we'll figure it out later 1408 return 0; 1409 } 1410 case Expr::CStyleCastExprClass: { 1411 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1412 1413 // Check for pointer->pointer cast 1414 if (SubExpr->getType()->isPointerType()) 1415 return FindExpressionBaseAddress(SubExpr); 1416 1417 // We assume that we have an arithmetic expression here; 1418 // if we don't, we'll figure it out later 1419 return 0; 1420 } 1421 } 1422} 1423 1424bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1425 switch (Init->getStmtClass()) { 1426 default: 1427 InitializerElementNotConstant(Init); 1428 return true; 1429 case Expr::ParenExprClass: { 1430 const ParenExpr* PE = cast<ParenExpr>(Init); 1431 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1432 } 1433 case Expr::FloatingLiteralClass: 1434 case Expr::IntegerLiteralClass: 1435 case Expr::CharacterLiteralClass: 1436 case Expr::ImaginaryLiteralClass: 1437 case Expr::TypesCompatibleExprClass: 1438 case Expr::CXXBoolLiteralExprClass: 1439 return false; 1440 case Expr::CallExprClass: { 1441 const CallExpr *CE = cast<CallExpr>(Init); 1442 1443 // Allow any constant foldable calls to builtins. 1444 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1445 return false; 1446 1447 InitializerElementNotConstant(Init); 1448 return true; 1449 } 1450 case Expr::DeclRefExprClass: { 1451 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1452 if (isa<EnumConstantDecl>(D)) 1453 return false; 1454 InitializerElementNotConstant(Init); 1455 return true; 1456 } 1457 case Expr::CompoundLiteralExprClass: 1458 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1459 // but vectors are allowed to be magic. 1460 if (Init->getType()->isVectorType()) 1461 return false; 1462 InitializerElementNotConstant(Init); 1463 return true; 1464 case Expr::UnaryOperatorClass: { 1465 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1466 1467 switch (Exp->getOpcode()) { 1468 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1469 // See C99 6.6p3. 1470 default: 1471 InitializerElementNotConstant(Init); 1472 return true; 1473 case UnaryOperator::OffsetOf: 1474 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1475 return false; 1476 InitializerElementNotConstant(Init); 1477 return true; 1478 case UnaryOperator::Extension: 1479 case UnaryOperator::LNot: 1480 case UnaryOperator::Plus: 1481 case UnaryOperator::Minus: 1482 case UnaryOperator::Not: 1483 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1484 } 1485 } 1486 case Expr::SizeOfAlignOfExprClass: { 1487 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1488 // Special check for void types, which are allowed as an extension 1489 if (Exp->getTypeOfArgument()->isVoidType()) 1490 return false; 1491 // alignof always evaluates to a constant. 1492 // FIXME: is sizeof(int[3.0]) a constant expression? 1493 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1494 InitializerElementNotConstant(Init); 1495 return true; 1496 } 1497 return false; 1498 } 1499 case Expr::BinaryOperatorClass: { 1500 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1501 1502 if (Exp->getLHS()->getType()->isArithmeticType() && 1503 Exp->getRHS()->getType()->isArithmeticType()) { 1504 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1505 CheckArithmeticConstantExpression(Exp->getRHS()); 1506 } 1507 1508 if (Exp->getLHS()->getType()->isPointerType() && 1509 Exp->getRHS()->getType()->isPointerType()) { 1510 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1511 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1512 1513 // Only allow a null (constant integer) base; we could 1514 // allow some additional cases if necessary, but this 1515 // is sufficient to cover offsetof-like constructs. 1516 if (!LHSBase && !RHSBase) { 1517 return CheckAddressConstantExpression(Exp->getLHS()) || 1518 CheckAddressConstantExpression(Exp->getRHS()); 1519 } 1520 } 1521 1522 InitializerElementNotConstant(Init); 1523 return true; 1524 } 1525 case Expr::ImplicitCastExprClass: 1526 case Expr::CStyleCastExprClass: { 1527 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1528 if (SubExpr->getType()->isArithmeticType()) 1529 return CheckArithmeticConstantExpression(SubExpr); 1530 1531 if (SubExpr->getType()->isPointerType()) { 1532 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1533 // If the pointer has a null base, this is an offsetof-like construct 1534 if (!Base) 1535 return CheckAddressConstantExpression(SubExpr); 1536 } 1537 1538 InitializerElementNotConstant(Init); 1539 return true; 1540 } 1541 case Expr::ConditionalOperatorClass: { 1542 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1543 1544 // If GNU extensions are disabled, we require all operands to be arithmetic 1545 // constant expressions. 1546 if (getLangOptions().NoExtensions) { 1547 return CheckArithmeticConstantExpression(Exp->getCond()) || 1548 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1549 CheckArithmeticConstantExpression(Exp->getRHS()); 1550 } 1551 1552 // Otherwise, we have to emulate some of the behavior of fold here. 1553 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1554 // because it can constant fold things away. To retain compatibility with 1555 // GCC code, we see if we can fold the condition to a constant (which we 1556 // should always be able to do in theory). If so, we only require the 1557 // specified arm of the conditional to be a constant. This is a horrible 1558 // hack, but is require by real world code that uses __builtin_constant_p. 1559 APValue Val; 1560 if (!Exp->getCond()->tryEvaluate(Val, Context)) { 1561 // If the tryEvaluate couldn't fold it, CheckArithmeticConstantExpression 1562 // won't be able to either. Use it to emit the diagnostic though. 1563 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1564 assert(Res && "tryEvaluate couldn't evaluate this constant?"); 1565 return Res; 1566 } 1567 1568 // Verify that the side following the condition is also a constant. 1569 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1570 if (Val.getInt() == 0) 1571 std::swap(TrueSide, FalseSide); 1572 1573 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1574 return true; 1575 1576 // Okay, the evaluated side evaluates to a constant, so we accept this. 1577 // Check to see if the other side is obviously not a constant. If so, 1578 // emit a warning that this is a GNU extension. 1579 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1580 Diag(Init->getExprLoc(), 1581 diag::ext_typecheck_expression_not_constant_but_accepted, 1582 FalseSide->getSourceRange()); 1583 return false; 1584 } 1585 } 1586} 1587 1588bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1589 Init = Init->IgnoreParens(); 1590 1591 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1592 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1593 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1594 1595 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1596 return CheckForConstantInitializer(e->getInitializer(), DclT); 1597 1598 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1599 unsigned numInits = Exp->getNumInits(); 1600 for (unsigned i = 0; i < numInits; i++) { 1601 // FIXME: Need to get the type of the declaration for C++, 1602 // because it could be a reference? 1603 if (CheckForConstantInitializer(Exp->getInit(i), 1604 Exp->getInit(i)->getType())) 1605 return true; 1606 } 1607 return false; 1608 } 1609 1610 if (Init->isNullPointerConstant(Context)) 1611 return false; 1612 if (Init->getType()->isArithmeticType()) { 1613 QualType InitTy = Context.getCanonicalType(Init->getType()) 1614 .getUnqualifiedType(); 1615 if (InitTy == Context.BoolTy) { 1616 // Special handling for pointers implicitly cast to bool; 1617 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1618 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1619 Expr* SubE = ICE->getSubExpr(); 1620 if (SubE->getType()->isPointerType() || 1621 SubE->getType()->isArrayType() || 1622 SubE->getType()->isFunctionType()) { 1623 return CheckAddressConstantExpression(Init); 1624 } 1625 } 1626 } else if (InitTy->isIntegralType()) { 1627 Expr* SubE = 0; 1628 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1629 SubE = CE->getSubExpr(); 1630 // Special check for pointer cast to int; we allow as an extension 1631 // an address constant cast to an integer if the integer 1632 // is of an appropriate width (this sort of code is apparently used 1633 // in some places). 1634 // FIXME: Add pedwarn? 1635 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1636 if (SubE && (SubE->getType()->isPointerType() || 1637 SubE->getType()->isArrayType() || 1638 SubE->getType()->isFunctionType())) { 1639 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1640 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1641 if (IntWidth >= PointerWidth) 1642 return CheckAddressConstantExpression(Init); 1643 } 1644 } 1645 1646 return CheckArithmeticConstantExpression(Init); 1647 } 1648 1649 if (Init->getType()->isPointerType()) 1650 return CheckAddressConstantExpression(Init); 1651 1652 // An array type at the top level that isn't an init-list must 1653 // be a string literal 1654 if (Init->getType()->isArrayType()) 1655 return false; 1656 1657 if (Init->getType()->isFunctionType()) 1658 return false; 1659 1660 // Allow block exprs at top level. 1661 if (Init->getType()->isBlockPointerType()) 1662 return false; 1663 1664 InitializerElementNotConstant(Init); 1665 return true; 1666} 1667 1668void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1669 Decl *RealDecl = static_cast<Decl *>(dcl); 1670 Expr *Init = static_cast<Expr *>(init); 1671 assert(Init && "missing initializer"); 1672 1673 // If there is no declaration, there was an error parsing it. Just ignore 1674 // the initializer. 1675 if (RealDecl == 0) { 1676 delete Init; 1677 return; 1678 } 1679 1680 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1681 if (!VDecl) { 1682 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1683 diag::err_illegal_initializer); 1684 RealDecl->setInvalidDecl(); 1685 return; 1686 } 1687 // Get the decls type and save a reference for later, since 1688 // CheckInitializerTypes may change it. 1689 QualType DclT = VDecl->getType(), SavT = DclT; 1690 if (VDecl->isBlockVarDecl()) { 1691 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1692 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1693 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1694 VDecl->setInvalidDecl(); 1695 } else if (!VDecl->isInvalidDecl()) { 1696 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1697 VDecl->getName())) 1698 VDecl->setInvalidDecl(); 1699 1700 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1701 if (!getLangOptions().CPlusPlus) { 1702 if (SC == VarDecl::Static) // C99 6.7.8p4. 1703 CheckForConstantInitializer(Init, DclT); 1704 } 1705 } 1706 } else if (VDecl->isFileVarDecl()) { 1707 if (VDecl->getStorageClass() == VarDecl::Extern) 1708 Diag(VDecl->getLocation(), diag::warn_extern_init); 1709 if (!VDecl->isInvalidDecl()) 1710 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1711 VDecl->getName())) 1712 VDecl->setInvalidDecl(); 1713 1714 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1715 if (!getLangOptions().CPlusPlus) { 1716 // C99 6.7.8p4. All file scoped initializers need to be constant. 1717 CheckForConstantInitializer(Init, DclT); 1718 } 1719 } 1720 // If the type changed, it means we had an incomplete type that was 1721 // completed by the initializer. For example: 1722 // int ary[] = { 1, 3, 5 }; 1723 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1724 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1725 VDecl->setType(DclT); 1726 Init->setType(DclT); 1727 } 1728 1729 // Attach the initializer to the decl. 1730 VDecl->setInit(Init); 1731 return; 1732} 1733 1734void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1735 Decl *RealDecl = static_cast<Decl *>(dcl); 1736 1737 // If there is no declaration, there was an error parsing it. Just ignore it. 1738 if (RealDecl == 0) 1739 return; 1740 1741 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1742 QualType Type = Var->getType(); 1743 // C++ [dcl.init.ref]p3: 1744 // The initializer can be omitted for a reference only in a 1745 // parameter declaration (8.3.5), in the declaration of a 1746 // function return type, in the declaration of a class member 1747 // within its class declaration (9.2), and where the extern 1748 // specifier is explicitly used. 1749 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1750 Diag(Var->getLocation(), 1751 diag::err_reference_var_requires_init, 1752 Var->getName(), 1753 SourceRange(Var->getLocation(), Var->getLocation())); 1754 Var->setInvalidDecl(); 1755 return; 1756 } 1757 1758 // C++ [dcl.init]p9: 1759 // 1760 // If no initializer is specified for an object, and the object 1761 // is of (possibly cv-qualified) non-POD class type (or array 1762 // thereof), the object shall be default-initialized; if the 1763 // object is of const-qualified type, the underlying class type 1764 // shall have a user-declared default constructor. 1765 if (getLangOptions().CPlusPlus) { 1766 QualType InitType = Type; 1767 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1768 InitType = Array->getElementType(); 1769 if (InitType->isRecordType()) { 1770 const CXXConstructorDecl *Constructor 1771 = PerformInitializationByConstructor(InitType, 0, 0, 1772 Var->getLocation(), 1773 SourceRange(Var->getLocation(), 1774 Var->getLocation()), 1775 Var->getName(), 1776 IK_Default); 1777 if (!Constructor) 1778 Var->setInvalidDecl(); 1779 } 1780 } 1781 1782#if 0 1783 // FIXME: Temporarily disabled because we are not properly parsing 1784 // linkage specifications on declarations, e.g., 1785 // 1786 // extern "C" const CGPoint CGPointerZero; 1787 // 1788 // C++ [dcl.init]p9: 1789 // 1790 // If no initializer is specified for an object, and the 1791 // object is of (possibly cv-qualified) non-POD class type (or 1792 // array thereof), the object shall be default-initialized; if 1793 // the object is of const-qualified type, the underlying class 1794 // type shall have a user-declared default 1795 // constructor. Otherwise, if no initializer is specified for 1796 // an object, the object and its subobjects, if any, have an 1797 // indeterminate initial value; if the object or any of its 1798 // subobjects are of const-qualified type, the program is 1799 // ill-formed. 1800 // 1801 // This isn't technically an error in C, so we don't diagnose it. 1802 // 1803 // FIXME: Actually perform the POD/user-defined default 1804 // constructor check. 1805 if (getLangOptions().CPlusPlus && 1806 Context.getCanonicalType(Type).isConstQualified() && 1807 Var->getStorageClass() != VarDecl::Extern) 1808 Diag(Var->getLocation(), 1809 diag::err_const_var_requires_init, 1810 Var->getName(), 1811 SourceRange(Var->getLocation(), Var->getLocation())); 1812#endif 1813 } 1814} 1815 1816/// The declarators are chained together backwards, reverse the list. 1817Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1818 // Often we have single declarators, handle them quickly. 1819 Decl *GroupDecl = static_cast<Decl*>(group); 1820 if (GroupDecl == 0) 1821 return 0; 1822 1823 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1824 ScopedDecl *NewGroup = 0; 1825 if (Group->getNextDeclarator() == 0) 1826 NewGroup = Group; 1827 else { // reverse the list. 1828 while (Group) { 1829 ScopedDecl *Next = Group->getNextDeclarator(); 1830 Group->setNextDeclarator(NewGroup); 1831 NewGroup = Group; 1832 Group = Next; 1833 } 1834 } 1835 // Perform semantic analysis that depends on having fully processed both 1836 // the declarator and initializer. 1837 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1838 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1839 if (!IDecl) 1840 continue; 1841 QualType T = IDecl->getType(); 1842 1843 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1844 // static storage duration, it shall not have a variable length array. 1845 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1846 IDecl->getStorageClass() == VarDecl::Static) { 1847 if (T->isVariableArrayType()) { 1848 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1849 IDecl->setInvalidDecl(); 1850 } 1851 } 1852 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1853 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1854 if (IDecl->isBlockVarDecl() && 1855 IDecl->getStorageClass() != VarDecl::Extern) { 1856 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1857 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1858 T.getAsString()); 1859 IDecl->setInvalidDecl(); 1860 } 1861 } 1862 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1863 // object that has file scope without an initializer, and without a 1864 // storage-class specifier or with the storage-class specifier "static", 1865 // constitutes a tentative definition. Note: A tentative definition with 1866 // external linkage is valid (C99 6.2.2p5). 1867 if (isTentativeDefinition(IDecl)) { 1868 if (T->isIncompleteArrayType()) { 1869 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1870 // array to be completed. Don't issue a diagnostic. 1871 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1872 // C99 6.9.2p3: If the declaration of an identifier for an object is 1873 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1874 // declared type shall not be an incomplete type. 1875 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1876 T.getAsString()); 1877 IDecl->setInvalidDecl(); 1878 } 1879 } 1880 if (IDecl->isFileVarDecl()) 1881 CheckForFileScopedRedefinitions(S, IDecl); 1882 } 1883 return NewGroup; 1884} 1885 1886/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1887/// to introduce parameters into function prototype scope. 1888Sema::DeclTy * 1889Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1890 // FIXME: disallow CXXScopeSpec for param declarators. 1891 const DeclSpec &DS = D.getDeclSpec(); 1892 1893 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1894 VarDecl::StorageClass StorageClass = VarDecl::None; 1895 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1896 StorageClass = VarDecl::Register; 1897 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1898 Diag(DS.getStorageClassSpecLoc(), 1899 diag::err_invalid_storage_class_in_func_decl); 1900 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1901 } 1902 if (DS.isThreadSpecified()) { 1903 Diag(DS.getThreadSpecLoc(), 1904 diag::err_invalid_storage_class_in_func_decl); 1905 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1906 } 1907 1908 // Check that there are no default arguments inside the type of this 1909 // parameter (C++ only). 1910 if (getLangOptions().CPlusPlus) 1911 CheckExtraCXXDefaultArguments(D); 1912 1913 // In this context, we *do not* check D.getInvalidType(). If the declarator 1914 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1915 // though it will not reflect the user specified type. 1916 QualType parmDeclType = GetTypeForDeclarator(D, S); 1917 1918 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1919 1920 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1921 // Can this happen for params? We already checked that they don't conflict 1922 // among each other. Here they can only shadow globals, which is ok. 1923 IdentifierInfo *II = D.getIdentifier(); 1924 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1925 if (S->isDeclScope(PrevDecl)) { 1926 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1927 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1928 1929 // Recover by removing the name 1930 II = 0; 1931 D.SetIdentifier(0, D.getIdentifierLoc()); 1932 } 1933 } 1934 1935 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1936 // Doing the promotion here has a win and a loss. The win is the type for 1937 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1938 // code generator). The loss is the orginal type isn't preserved. For example: 1939 // 1940 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1941 // int blockvardecl[5]; 1942 // sizeof(parmvardecl); // size == 4 1943 // sizeof(blockvardecl); // size == 20 1944 // } 1945 // 1946 // For expressions, all implicit conversions are captured using the 1947 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1948 // 1949 // FIXME: If a source translation tool needs to see the original type, then 1950 // we need to consider storing both types (in ParmVarDecl)... 1951 // 1952 if (parmDeclType->isArrayType()) { 1953 // int x[restrict 4] -> int *restrict 1954 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1955 } else if (parmDeclType->isFunctionType()) 1956 parmDeclType = Context.getPointerType(parmDeclType); 1957 1958 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1959 D.getIdentifierLoc(), II, 1960 parmDeclType, StorageClass, 1961 0, 0); 1962 1963 if (D.getInvalidType()) 1964 New->setInvalidDecl(); 1965 1966 if (II) 1967 PushOnScopeChains(New, S); 1968 1969 ProcessDeclAttributes(New, D); 1970 return New; 1971 1972} 1973 1974Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1975 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1976 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1977 "Not a function declarator!"); 1978 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1979 1980 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1981 // for a K&R function. 1982 if (!FTI.hasPrototype) { 1983 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1984 if (FTI.ArgInfo[i].Param == 0) { 1985 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1986 FTI.ArgInfo[i].Ident->getName()); 1987 // Implicitly declare the argument as type 'int' for lack of a better 1988 // type. 1989 DeclSpec DS; 1990 const char* PrevSpec; // unused 1991 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1992 PrevSpec); 1993 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1994 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1995 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1996 } 1997 } 1998 } else { 1999 // FIXME: Diagnose arguments without names in C. 2000 } 2001 2002 Scope *GlobalScope = FnBodyScope->getParent(); 2003 2004 return ActOnStartOfFunctionDef(FnBodyScope, 2005 ActOnDeclarator(GlobalScope, D, 0)); 2006} 2007 2008Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2009 Decl *decl = static_cast<Decl*>(D); 2010 FunctionDecl *FD = cast<FunctionDecl>(decl); 2011 2012 // See if this is a redefinition. 2013 const FunctionDecl *Definition; 2014 if (FD->getBody(Definition)) { 2015 Diag(FD->getLocation(), diag::err_redefinition, 2016 FD->getName()); 2017 Diag(Definition->getLocation(), diag::err_previous_definition); 2018 } 2019 2020 PushDeclContext(FD); 2021 2022 // Check the validity of our function parameters 2023 CheckParmsForFunctionDef(FD); 2024 2025 // Introduce our parameters into the function scope 2026 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2027 ParmVarDecl *Param = FD->getParamDecl(p); 2028 // If this has an identifier, add it to the scope stack. 2029 if (Param->getIdentifier()) 2030 PushOnScopeChains(Param, FnBodyScope); 2031 } 2032 2033 return FD; 2034} 2035 2036Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2037 Decl *dcl = static_cast<Decl *>(D); 2038 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2039 FD->setBody((Stmt*)Body); 2040 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2041 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2042 MD->setBody((Stmt*)Body); 2043 } else 2044 return 0; 2045 PopDeclContext(); 2046 // Verify and clean out per-function state. 2047 2048 // Check goto/label use. 2049 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2050 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2051 // Verify that we have no forward references left. If so, there was a goto 2052 // or address of a label taken, but no definition of it. Label fwd 2053 // definitions are indicated with a null substmt. 2054 if (I->second->getSubStmt() == 0) { 2055 LabelStmt *L = I->second; 2056 // Emit error. 2057 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2058 2059 // At this point, we have gotos that use the bogus label. Stitch it into 2060 // the function body so that they aren't leaked and that the AST is well 2061 // formed. 2062 if (Body) { 2063 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2064 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2065 } else { 2066 // The whole function wasn't parsed correctly, just delete this. 2067 delete L; 2068 } 2069 } 2070 } 2071 LabelMap.clear(); 2072 2073 return D; 2074} 2075 2076/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2077/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2078ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2079 IdentifierInfo &II, Scope *S) { 2080 // Extension in C99. Legal in C90, but warn about it. 2081 if (getLangOptions().C99) 2082 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 2083 else 2084 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 2085 2086 // FIXME: handle stuff like: 2087 // void foo() { extern float X(); } 2088 // void bar() { X(); } <-- implicit decl for X in another scope. 2089 2090 // Set a Declarator for the implicit definition: int foo(); 2091 const char *Dummy; 2092 DeclSpec DS; 2093 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2094 Error = Error; // Silence warning. 2095 assert(!Error && "Error setting up implicit decl!"); 2096 Declarator D(DS, Declarator::BlockContext); 2097 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2098 D.SetIdentifier(&II, Loc); 2099 2100 // Insert this function into translation-unit scope. 2101 2102 DeclContext *PrevDC = CurContext; 2103 CurContext = Context.getTranslationUnitDecl(); 2104 2105 FunctionDecl *FD = 2106 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2107 FD->setImplicit(); 2108 2109 CurContext = PrevDC; 2110 2111 return FD; 2112} 2113 2114 2115TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2116 ScopedDecl *LastDeclarator) { 2117 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2118 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2119 2120 // Scope manipulation handled by caller. 2121 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2122 D.getIdentifierLoc(), 2123 D.getIdentifier(), 2124 T, LastDeclarator); 2125 if (D.getInvalidType()) 2126 NewTD->setInvalidDecl(); 2127 return NewTD; 2128} 2129 2130/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2131/// former case, Name will be non-null. In the later case, Name will be null. 2132/// TagType indicates what kind of tag this is. TK indicates whether this is a 2133/// reference/declaration/definition of a tag. 2134Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2135 SourceLocation KWLoc, const CXXScopeSpec &SS, 2136 IdentifierInfo *Name, SourceLocation NameLoc, 2137 AttributeList *Attr) { 2138 // If this is a use of an existing tag, it must have a name. 2139 assert((Name != 0 || TK == TK_Definition) && 2140 "Nameless record must be a definition!"); 2141 2142 TagDecl::TagKind Kind; 2143 switch (TagType) { 2144 default: assert(0 && "Unknown tag type!"); 2145 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2146 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2147 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2148 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2149 } 2150 2151 // Two code paths: a new one for structs/unions/classes where we create 2152 // separate decls for forward declarations, and an old (eventually to 2153 // be removed) code path for enums. 2154 if (Kind != TagDecl::TK_enum) 2155 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2156 2157 DeclContext *DC = CurContext; 2158 ScopedDecl *PrevDecl = 0; 2159 2160 if (Name && SS.isNotEmpty()) { 2161 // We have a nested-name tag ('struct foo::bar'). 2162 2163 // Check for invalid 'foo::'. 2164 if (SS.isInvalid()) { 2165 Name = 0; 2166 goto CreateNewDecl; 2167 } 2168 2169 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2170 // Look-up name inside 'foo::'. 2171 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2172 2173 // A tag 'foo::bar' must already exist. 2174 if (PrevDecl == 0) { 2175 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2176 SS.getRange()); 2177 Name = 0; 2178 goto CreateNewDecl; 2179 } 2180 } else { 2181 // If this is a named struct, check to see if there was a previous forward 2182 // declaration or definition. 2183 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2184 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2185 } 2186 2187 if (PrevDecl) { 2188 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2189 "unexpected Decl type"); 2190 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2191 // If this is a use of a previous tag, or if the tag is already declared 2192 // in the same scope (so that the definition/declaration completes or 2193 // rementions the tag), reuse the decl. 2194 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2195 // Make sure that this wasn't declared as an enum and now used as a 2196 // struct or something similar. 2197 if (PrevTagDecl->getTagKind() != Kind) { 2198 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2199 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2200 // Recover by making this an anonymous redefinition. 2201 Name = 0; 2202 PrevDecl = 0; 2203 } else { 2204 // If this is a use or a forward declaration, we're good. 2205 if (TK != TK_Definition) 2206 return PrevDecl; 2207 2208 // Diagnose attempts to redefine a tag. 2209 if (PrevTagDecl->isDefinition()) { 2210 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2211 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2212 // If this is a redefinition, recover by making this struct be 2213 // anonymous, which will make any later references get the previous 2214 // definition. 2215 Name = 0; 2216 } else { 2217 // Okay, this is definition of a previously declared or referenced 2218 // tag. Move the location of the decl to be the definition site. 2219 PrevDecl->setLocation(NameLoc); 2220 return PrevDecl; 2221 } 2222 } 2223 } 2224 // If we get here, this is a definition of a new struct type in a nested 2225 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2226 // type. 2227 } else { 2228 // PrevDecl is a namespace. 2229 if (isDeclInScope(PrevDecl, DC, S)) { 2230 // The tag name clashes with a namespace name, issue an error and 2231 // recover by making this tag be anonymous. 2232 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2233 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2234 Name = 0; 2235 } 2236 } 2237 } 2238 2239 CreateNewDecl: 2240 2241 // If there is an identifier, use the location of the identifier as the 2242 // location of the decl, otherwise use the location of the struct/union 2243 // keyword. 2244 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2245 2246 // Otherwise, if this is the first time we've seen this tag, create the decl. 2247 TagDecl *New; 2248 if (Kind == TagDecl::TK_enum) { 2249 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2250 // enum X { A, B, C } D; D should chain to X. 2251 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2252 // If this is an undefined enum, warn. 2253 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2254 } else { 2255 // struct/union/class 2256 2257 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2258 // struct X { int A; } D; D should chain to X. 2259 if (getLangOptions().CPlusPlus) 2260 // FIXME: Look for a way to use RecordDecl for simple structs. 2261 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2262 else 2263 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2264 } 2265 2266 // If this has an identifier, add it to the scope stack. 2267 if (Name) { 2268 // The scope passed in may not be a decl scope. Zip up the scope tree until 2269 // we find one that is. 2270 while ((S->getFlags() & Scope::DeclScope) == 0) 2271 S = S->getParent(); 2272 2273 // Add it to the decl chain. 2274 PushOnScopeChains(New, S); 2275 } 2276 2277 if (Attr) 2278 ProcessDeclAttributeList(New, Attr); 2279 2280 // Set the lexical context. If the tag has a C++ scope specifier, the 2281 // lexical context will be different from the semantic context. 2282 New->setLexicalDeclContext(CurContext); 2283 2284 return New; 2285} 2286 2287/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2288/// the logic for enums, we create separate decls for forward declarations. 2289/// This is called by ActOnTag, but eventually will replace its logic. 2290Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2291 SourceLocation KWLoc, const CXXScopeSpec &SS, 2292 IdentifierInfo *Name, SourceLocation NameLoc, 2293 AttributeList *Attr) { 2294 DeclContext *DC = CurContext; 2295 ScopedDecl *PrevDecl = 0; 2296 2297 if (Name && SS.isNotEmpty()) { 2298 // We have a nested-name tag ('struct foo::bar'). 2299 2300 // Check for invalid 'foo::'. 2301 if (SS.isInvalid()) { 2302 Name = 0; 2303 goto CreateNewDecl; 2304 } 2305 2306 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2307 // Look-up name inside 'foo::'. 2308 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2309 2310 // A tag 'foo::bar' must already exist. 2311 if (PrevDecl == 0) { 2312 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2313 SS.getRange()); 2314 Name = 0; 2315 goto CreateNewDecl; 2316 } 2317 } else { 2318 // If this is a named struct, check to see if there was a previous forward 2319 // declaration or definition. 2320 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2321 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2322 } 2323 2324 if (PrevDecl) { 2325 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2326 "unexpected Decl type"); 2327 2328 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2329 // If this is a use of a previous tag, or if the tag is already declared 2330 // in the same scope (so that the definition/declaration completes or 2331 // rementions the tag), reuse the decl. 2332 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2333 // Make sure that this wasn't declared as an enum and now used as a 2334 // struct or something similar. 2335 if (PrevTagDecl->getTagKind() != Kind) { 2336 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2337 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2338 // Recover by making this an anonymous redefinition. 2339 Name = 0; 2340 PrevDecl = 0; 2341 } else { 2342 // If this is a use, return the original decl. 2343 2344 // FIXME: In the future, return a variant or some other clue 2345 // for the consumer of this Decl to know it doesn't own it. 2346 // For our current ASTs this shouldn't be a problem, but will 2347 // need to be changed with DeclGroups. 2348 if (TK == TK_Reference) 2349 return PrevDecl; 2350 2351 // The new decl is a definition? 2352 if (TK == TK_Definition) { 2353 // Diagnose attempts to redefine a tag. 2354 if (RecordDecl* DefRecord = 2355 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2356 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2357 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2358 // If this is a redefinition, recover by making this struct be 2359 // anonymous, which will make any later references get the previous 2360 // definition. 2361 Name = 0; 2362 PrevDecl = 0; 2363 } 2364 // Okay, this is definition of a previously declared or referenced 2365 // tag. We're going to create a new Decl. 2366 } 2367 } 2368 // If we get here we have (another) forward declaration. Just create 2369 // a new decl. 2370 } 2371 else { 2372 // If we get here, this is a definition of a new struct type in a nested 2373 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2374 // new decl/type. We set PrevDecl to NULL so that the Records 2375 // have distinct types. 2376 PrevDecl = 0; 2377 } 2378 } else { 2379 // PrevDecl is a namespace. 2380 if (isDeclInScope(PrevDecl, DC, S)) { 2381 // The tag name clashes with a namespace name, issue an error and 2382 // recover by making this tag be anonymous. 2383 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2384 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2385 Name = 0; 2386 } 2387 } 2388 } 2389 2390 CreateNewDecl: 2391 2392 // If there is an identifier, use the location of the identifier as the 2393 // location of the decl, otherwise use the location of the struct/union 2394 // keyword. 2395 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2396 2397 // Otherwise, if this is the first time we've seen this tag, create the decl. 2398 TagDecl *New; 2399 2400 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2401 // struct X { int A; } D; D should chain to X. 2402 if (getLangOptions().CPlusPlus) 2403 // FIXME: Look for a way to use RecordDecl for simple structs. 2404 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2405 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2406 else 2407 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2408 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2409 2410 // If this has an identifier, add it to the scope stack. 2411 if ((TK == TK_Definition || !PrevDecl) && Name) { 2412 // The scope passed in may not be a decl scope. Zip up the scope tree until 2413 // we find one that is. 2414 while ((S->getFlags() & Scope::DeclScope) == 0) 2415 S = S->getParent(); 2416 2417 // Add it to the decl chain. 2418 PushOnScopeChains(New, S); 2419 } 2420 2421 // Handle #pragma pack: if the #pragma pack stack has non-default 2422 // alignment, make up a packed attribute for this decl. These 2423 // attributes are checked when the ASTContext lays out the 2424 // structure. 2425 // 2426 // It is important for implementing the correct semantics that this 2427 // happen here (in act on tag decl). The #pragma pack stack is 2428 // maintained as a result of parser callbacks which can occur at 2429 // many points during the parsing of a struct declaration (because 2430 // the #pragma tokens are effectively skipped over during the 2431 // parsing of the struct). 2432 if (unsigned Alignment = PackContext.getAlignment()) 2433 New->addAttr(new PackedAttr(Alignment * 8)); 2434 2435 if (Attr) 2436 ProcessDeclAttributeList(New, Attr); 2437 2438 // Set the lexical context. If the tag has a C++ scope specifier, the 2439 // lexical context will be different from the semantic context. 2440 New->setLexicalDeclContext(CurContext); 2441 2442 return New; 2443} 2444 2445 2446/// Collect the instance variables declared in an Objective-C object. Used in 2447/// the creation of structures from objects using the @defs directive. 2448static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2449 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2450 if (Class->getSuperClass()) 2451 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2452 2453 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2454 for (ObjCInterfaceDecl::ivar_iterator 2455 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2456 2457 ObjCIvarDecl* ID = *I; 2458 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2459 ID->getIdentifier(), 2460 ID->getType(), 2461 ID->getBitWidth())); 2462 } 2463} 2464 2465/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2466/// instance variables of ClassName into Decls. 2467void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2468 IdentifierInfo *ClassName, 2469 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2470 // Check that ClassName is a valid class 2471 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2472 if (!Class) { 2473 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 2474 return; 2475 } 2476 // Collect the instance variables 2477 CollectIvars(Class, Context, Decls); 2478} 2479 2480/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2481/// types into constant array types in certain situations which would otherwise 2482/// be errors (for GCC compatibility). 2483static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2484 ASTContext &Context) { 2485 // This method tries to turn a variable array into a constant 2486 // array even when the size isn't an ICE. This is necessary 2487 // for compatibility with code that depends on gcc's buggy 2488 // constant expression folding, like struct {char x[(int)(char*)2];} 2489 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2490 if (!VLATy) return QualType(); 2491 2492 APValue Result; 2493 if (!VLATy->getSizeExpr() || 2494 !VLATy->getSizeExpr()->tryEvaluate(Result, Context)) 2495 return QualType(); 2496 2497 assert(Result.isInt() && "Size expressions must be integers!"); 2498 llvm::APSInt &Res = Result.getInt(); 2499 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2500 return Context.getConstantArrayType(VLATy->getElementType(), 2501 Res, ArrayType::Normal, 0); 2502 return QualType(); 2503} 2504 2505/// ActOnField - Each field of a struct/union/class is passed into this in order 2506/// to create a FieldDecl object for it. 2507Sema::DeclTy *Sema::ActOnField(Scope *S, 2508 SourceLocation DeclStart, 2509 Declarator &D, ExprTy *BitfieldWidth) { 2510 IdentifierInfo *II = D.getIdentifier(); 2511 Expr *BitWidth = (Expr*)BitfieldWidth; 2512 SourceLocation Loc = DeclStart; 2513 if (II) Loc = D.getIdentifierLoc(); 2514 2515 // FIXME: Unnamed fields can be handled in various different ways, for 2516 // example, unnamed unions inject all members into the struct namespace! 2517 2518 if (BitWidth) { 2519 // TODO: Validate. 2520 //printf("WARNING: BITFIELDS IGNORED!\n"); 2521 2522 // 6.7.2.1p3 2523 // 6.7.2.1p4 2524 2525 } else { 2526 // Not a bitfield. 2527 2528 // validate II. 2529 2530 } 2531 2532 QualType T = GetTypeForDeclarator(D, S); 2533 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2534 bool InvalidDecl = false; 2535 2536 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2537 // than a variably modified type. 2538 if (T->isVariablyModifiedType()) { 2539 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2540 if (!FixedTy.isNull()) { 2541 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 2542 T = FixedTy; 2543 } else { 2544 // FIXME: This diagnostic needs work 2545 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2546 T = Context.IntTy; 2547 InvalidDecl = true; 2548 } 2549 } 2550 // FIXME: Chain fielddecls together. 2551 FieldDecl *NewFD; 2552 2553 if (getLangOptions().CPlusPlus) { 2554 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2555 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2556 Loc, II, T, BitWidth); 2557 if (II) 2558 PushOnScopeChains(NewFD, S); 2559 } 2560 else 2561 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2562 2563 ProcessDeclAttributes(NewFD, D); 2564 2565 if (D.getInvalidType() || InvalidDecl) 2566 NewFD->setInvalidDecl(); 2567 return NewFD; 2568} 2569 2570/// TranslateIvarVisibility - Translate visibility from a token ID to an 2571/// AST enum value. 2572static ObjCIvarDecl::AccessControl 2573TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2574 switch (ivarVisibility) { 2575 default: assert(0 && "Unknown visitibility kind"); 2576 case tok::objc_private: return ObjCIvarDecl::Private; 2577 case tok::objc_public: return ObjCIvarDecl::Public; 2578 case tok::objc_protected: return ObjCIvarDecl::Protected; 2579 case tok::objc_package: return ObjCIvarDecl::Package; 2580 } 2581} 2582 2583/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2584/// in order to create an IvarDecl object for it. 2585Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2586 SourceLocation DeclStart, 2587 Declarator &D, ExprTy *BitfieldWidth, 2588 tok::ObjCKeywordKind Visibility) { 2589 IdentifierInfo *II = D.getIdentifier(); 2590 Expr *BitWidth = (Expr*)BitfieldWidth; 2591 SourceLocation Loc = DeclStart; 2592 if (II) Loc = D.getIdentifierLoc(); 2593 2594 // FIXME: Unnamed fields can be handled in various different ways, for 2595 // example, unnamed unions inject all members into the struct namespace! 2596 2597 2598 if (BitWidth) { 2599 // TODO: Validate. 2600 //printf("WARNING: BITFIELDS IGNORED!\n"); 2601 2602 // 6.7.2.1p3 2603 // 6.7.2.1p4 2604 2605 } else { 2606 // Not a bitfield. 2607 2608 // validate II. 2609 2610 } 2611 2612 QualType T = GetTypeForDeclarator(D, S); 2613 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2614 bool InvalidDecl = false; 2615 2616 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2617 // than a variably modified type. 2618 if (T->isVariablyModifiedType()) { 2619 // FIXME: This diagnostic needs work 2620 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2621 InvalidDecl = true; 2622 } 2623 2624 // Get the visibility (access control) for this ivar. 2625 ObjCIvarDecl::AccessControl ac = 2626 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2627 : ObjCIvarDecl::None; 2628 2629 // Construct the decl. 2630 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2631 (Expr *)BitfieldWidth); 2632 2633 // Process attributes attached to the ivar. 2634 ProcessDeclAttributes(NewID, D); 2635 2636 if (D.getInvalidType() || InvalidDecl) 2637 NewID->setInvalidDecl(); 2638 2639 return NewID; 2640} 2641 2642void Sema::ActOnFields(Scope* S, 2643 SourceLocation RecLoc, DeclTy *RecDecl, 2644 DeclTy **Fields, unsigned NumFields, 2645 SourceLocation LBrac, SourceLocation RBrac, 2646 AttributeList *Attr) { 2647 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2648 assert(EnclosingDecl && "missing record or interface decl"); 2649 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2650 2651 if (Record) 2652 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2653 // Diagnose code like: 2654 // struct S { struct S {} X; }; 2655 // We discover this when we complete the outer S. Reject and ignore the 2656 // outer S. 2657 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2658 DefRecord->getKindName()); 2659 Diag(RecLoc, diag::err_previous_definition); 2660 Record->setInvalidDecl(); 2661 return; 2662 } 2663 2664 // Verify that all the fields are okay. 2665 unsigned NumNamedMembers = 0; 2666 llvm::SmallVector<FieldDecl*, 32> RecFields; 2667 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2668 2669 for (unsigned i = 0; i != NumFields; ++i) { 2670 2671 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2672 assert(FD && "missing field decl"); 2673 2674 // Remember all fields. 2675 RecFields.push_back(FD); 2676 2677 // Get the type for the field. 2678 Type *FDTy = FD->getType().getTypePtr(); 2679 2680 // C99 6.7.2.1p2 - A field may not be a function type. 2681 if (FDTy->isFunctionType()) { 2682 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2683 FD->getName()); 2684 FD->setInvalidDecl(); 2685 EnclosingDecl->setInvalidDecl(); 2686 continue; 2687 } 2688 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2689 if (FDTy->isIncompleteType()) { 2690 if (!Record) { // Incomplete ivar type is always an error. 2691 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2692 FD->setInvalidDecl(); 2693 EnclosingDecl->setInvalidDecl(); 2694 continue; 2695 } 2696 if (i != NumFields-1 || // ... that the last member ... 2697 !Record->isStruct() || // ... of a structure ... 2698 !FDTy->isArrayType()) { //... may have incomplete array type. 2699 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2700 FD->setInvalidDecl(); 2701 EnclosingDecl->setInvalidDecl(); 2702 continue; 2703 } 2704 if (NumNamedMembers < 1) { //... must have more than named member ... 2705 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2706 FD->getName()); 2707 FD->setInvalidDecl(); 2708 EnclosingDecl->setInvalidDecl(); 2709 continue; 2710 } 2711 // Okay, we have a legal flexible array member at the end of the struct. 2712 if (Record) 2713 Record->setHasFlexibleArrayMember(true); 2714 } 2715 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2716 /// field of another structure or the element of an array. 2717 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2718 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2719 // If this is a member of a union, then entire union becomes "flexible". 2720 if (Record && Record->isUnion()) { 2721 Record->setHasFlexibleArrayMember(true); 2722 } else { 2723 // If this is a struct/class and this is not the last element, reject 2724 // it. Note that GCC supports variable sized arrays in the middle of 2725 // structures. 2726 if (i != NumFields-1) { 2727 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2728 FD->getName()); 2729 FD->setInvalidDecl(); 2730 EnclosingDecl->setInvalidDecl(); 2731 continue; 2732 } 2733 // We support flexible arrays at the end of structs in other structs 2734 // as an extension. 2735 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2736 FD->getName()); 2737 if (Record) 2738 Record->setHasFlexibleArrayMember(true); 2739 } 2740 } 2741 } 2742 /// A field cannot be an Objective-c object 2743 if (FDTy->isObjCInterfaceType()) { 2744 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2745 FD->getName()); 2746 FD->setInvalidDecl(); 2747 EnclosingDecl->setInvalidDecl(); 2748 continue; 2749 } 2750 // Keep track of the number of named members. 2751 if (IdentifierInfo *II = FD->getIdentifier()) { 2752 // Detect duplicate member names. 2753 if (!FieldIDs.insert(II)) { 2754 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2755 // Find the previous decl. 2756 SourceLocation PrevLoc; 2757 for (unsigned i = 0; ; ++i) { 2758 assert(i != RecFields.size() && "Didn't find previous def!"); 2759 if (RecFields[i]->getIdentifier() == II) { 2760 PrevLoc = RecFields[i]->getLocation(); 2761 break; 2762 } 2763 } 2764 Diag(PrevLoc, diag::err_previous_definition); 2765 FD->setInvalidDecl(); 2766 EnclosingDecl->setInvalidDecl(); 2767 continue; 2768 } 2769 ++NumNamedMembers; 2770 } 2771 } 2772 2773 // Okay, we successfully defined 'Record'. 2774 if (Record) { 2775 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2776 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2777 // Sema::ActOnFinishCXXClassDef. 2778 if (!isa<CXXRecordDecl>(Record)) 2779 Consumer.HandleTagDeclDefinition(Record); 2780 } else { 2781 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2782 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2783 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2784 else if (ObjCImplementationDecl *IMPDecl = 2785 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2786 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2787 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2788 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2789 } 2790 } 2791 2792 if (Attr) 2793 ProcessDeclAttributeList(Record, Attr); 2794} 2795 2796Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2797 DeclTy *lastEnumConst, 2798 SourceLocation IdLoc, IdentifierInfo *Id, 2799 SourceLocation EqualLoc, ExprTy *val) { 2800 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2801 EnumConstantDecl *LastEnumConst = 2802 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2803 Expr *Val = static_cast<Expr*>(val); 2804 2805 // The scope passed in may not be a decl scope. Zip up the scope tree until 2806 // we find one that is. 2807 while ((S->getFlags() & Scope::DeclScope) == 0) 2808 S = S->getParent(); 2809 2810 // Verify that there isn't already something declared with this name in this 2811 // scope. 2812 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2813 // When in C++, we may get a TagDecl with the same name; in this case the 2814 // enum constant will 'hide' the tag. 2815 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2816 "Received TagDecl when not in C++!"); 2817 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2818 if (isa<EnumConstantDecl>(PrevDecl)) 2819 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2820 else 2821 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2822 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2823 delete Val; 2824 return 0; 2825 } 2826 } 2827 2828 llvm::APSInt EnumVal(32); 2829 QualType EltTy; 2830 if (Val) { 2831 // Make sure to promote the operand type to int. 2832 UsualUnaryConversions(Val); 2833 2834 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2835 SourceLocation ExpLoc; 2836 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2837 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2838 Id->getName()); 2839 delete Val; 2840 Val = 0; // Just forget about it. 2841 } else { 2842 EltTy = Val->getType(); 2843 } 2844 } 2845 2846 if (!Val) { 2847 if (LastEnumConst) { 2848 // Assign the last value + 1. 2849 EnumVal = LastEnumConst->getInitVal(); 2850 ++EnumVal; 2851 2852 // Check for overflow on increment. 2853 if (EnumVal < LastEnumConst->getInitVal()) 2854 Diag(IdLoc, diag::warn_enum_value_overflow); 2855 2856 EltTy = LastEnumConst->getType(); 2857 } else { 2858 // First value, set to zero. 2859 EltTy = Context.IntTy; 2860 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2861 } 2862 } 2863 2864 EnumConstantDecl *New = 2865 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2866 Val, EnumVal, 2867 LastEnumConst); 2868 2869 // Register this decl in the current scope stack. 2870 PushOnScopeChains(New, S); 2871 return New; 2872} 2873 2874// FIXME: For consistency with ActOnFields(), we should have the parser 2875// pass in the source location for the left/right braces. 2876void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2877 DeclTy **Elements, unsigned NumElements) { 2878 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2879 2880 if (Enum && Enum->isDefinition()) { 2881 // Diagnose code like: 2882 // enum e0 { 2883 // E0 = sizeof(enum e0 { E1 }) 2884 // }; 2885 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2886 Enum->getName()); 2887 Diag(EnumLoc, diag::err_previous_definition); 2888 Enum->setInvalidDecl(); 2889 return; 2890 } 2891 // TODO: If the result value doesn't fit in an int, it must be a long or long 2892 // long value. ISO C does not support this, but GCC does as an extension, 2893 // emit a warning. 2894 unsigned IntWidth = Context.Target.getIntWidth(); 2895 2896 // Verify that all the values are okay, compute the size of the values, and 2897 // reverse the list. 2898 unsigned NumNegativeBits = 0; 2899 unsigned NumPositiveBits = 0; 2900 2901 // Keep track of whether all elements have type int. 2902 bool AllElementsInt = true; 2903 2904 EnumConstantDecl *EltList = 0; 2905 for (unsigned i = 0; i != NumElements; ++i) { 2906 EnumConstantDecl *ECD = 2907 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2908 if (!ECD) continue; // Already issued a diagnostic. 2909 2910 // If the enum value doesn't fit in an int, emit an extension warning. 2911 const llvm::APSInt &InitVal = ECD->getInitVal(); 2912 assert(InitVal.getBitWidth() >= IntWidth && 2913 "Should have promoted value to int"); 2914 if (InitVal.getBitWidth() > IntWidth) { 2915 llvm::APSInt V(InitVal); 2916 V.trunc(IntWidth); 2917 V.extend(InitVal.getBitWidth()); 2918 if (V != InitVal) 2919 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2920 InitVal.toString(10)); 2921 } 2922 2923 // Keep track of the size of positive and negative values. 2924 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2925 NumPositiveBits = std::max(NumPositiveBits, 2926 (unsigned)InitVal.getActiveBits()); 2927 else 2928 NumNegativeBits = std::max(NumNegativeBits, 2929 (unsigned)InitVal.getMinSignedBits()); 2930 2931 // Keep track of whether every enum element has type int (very commmon). 2932 if (AllElementsInt) 2933 AllElementsInt = ECD->getType() == Context.IntTy; 2934 2935 ECD->setNextDeclarator(EltList); 2936 EltList = ECD; 2937 } 2938 2939 // Figure out the type that should be used for this enum. 2940 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2941 QualType BestType; 2942 unsigned BestWidth; 2943 2944 if (NumNegativeBits) { 2945 // If there is a negative value, figure out the smallest integer type (of 2946 // int/long/longlong) that fits. 2947 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2948 BestType = Context.IntTy; 2949 BestWidth = IntWidth; 2950 } else { 2951 BestWidth = Context.Target.getLongWidth(); 2952 2953 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2954 BestType = Context.LongTy; 2955 else { 2956 BestWidth = Context.Target.getLongLongWidth(); 2957 2958 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2959 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2960 BestType = Context.LongLongTy; 2961 } 2962 } 2963 } else { 2964 // If there is no negative value, figure out which of uint, ulong, ulonglong 2965 // fits. 2966 if (NumPositiveBits <= IntWidth) { 2967 BestType = Context.UnsignedIntTy; 2968 BestWidth = IntWidth; 2969 } else if (NumPositiveBits <= 2970 (BestWidth = Context.Target.getLongWidth())) { 2971 BestType = Context.UnsignedLongTy; 2972 } else { 2973 BestWidth = Context.Target.getLongLongWidth(); 2974 assert(NumPositiveBits <= BestWidth && 2975 "How could an initializer get larger than ULL?"); 2976 BestType = Context.UnsignedLongLongTy; 2977 } 2978 } 2979 2980 // Loop over all of the enumerator constants, changing their types to match 2981 // the type of the enum if needed. 2982 for (unsigned i = 0; i != NumElements; ++i) { 2983 EnumConstantDecl *ECD = 2984 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2985 if (!ECD) continue; // Already issued a diagnostic. 2986 2987 // Standard C says the enumerators have int type, but we allow, as an 2988 // extension, the enumerators to be larger than int size. If each 2989 // enumerator value fits in an int, type it as an int, otherwise type it the 2990 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2991 // that X has type 'int', not 'unsigned'. 2992 if (ECD->getType() == Context.IntTy) { 2993 // Make sure the init value is signed. 2994 llvm::APSInt IV = ECD->getInitVal(); 2995 IV.setIsSigned(true); 2996 ECD->setInitVal(IV); 2997 continue; // Already int type. 2998 } 2999 3000 // Determine whether the value fits into an int. 3001 llvm::APSInt InitVal = ECD->getInitVal(); 3002 bool FitsInInt; 3003 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3004 FitsInInt = InitVal.getActiveBits() < IntWidth; 3005 else 3006 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3007 3008 // If it fits into an integer type, force it. Otherwise force it to match 3009 // the enum decl type. 3010 QualType NewTy; 3011 unsigned NewWidth; 3012 bool NewSign; 3013 if (FitsInInt) { 3014 NewTy = Context.IntTy; 3015 NewWidth = IntWidth; 3016 NewSign = true; 3017 } else if (ECD->getType() == BestType) { 3018 // Already the right type! 3019 continue; 3020 } else { 3021 NewTy = BestType; 3022 NewWidth = BestWidth; 3023 NewSign = BestType->isSignedIntegerType(); 3024 } 3025 3026 // Adjust the APSInt value. 3027 InitVal.extOrTrunc(NewWidth); 3028 InitVal.setIsSigned(NewSign); 3029 ECD->setInitVal(InitVal); 3030 3031 // Adjust the Expr initializer and type. 3032 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3033 /*isLvalue=*/false)); 3034 ECD->setType(NewTy); 3035 } 3036 3037 Enum->defineElements(EltList, BestType); 3038 Consumer.HandleTagDeclDefinition(Enum); 3039} 3040 3041Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3042 ExprTy *expr) { 3043 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3044 3045 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3046} 3047 3048Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3049 SourceLocation LBrace, 3050 SourceLocation RBrace, 3051 const char *Lang, 3052 unsigned StrSize, 3053 DeclTy *D) { 3054 LinkageSpecDecl::LanguageIDs Language; 3055 Decl *dcl = static_cast<Decl *>(D); 3056 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3057 Language = LinkageSpecDecl::lang_c; 3058 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3059 Language = LinkageSpecDecl::lang_cxx; 3060 else { 3061 Diag(Loc, diag::err_bad_language); 3062 return 0; 3063 } 3064 3065 // FIXME: Add all the various semantics of linkage specifications 3066 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3067} 3068 3069void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3070 ExprTy *alignment, SourceLocation PragmaLoc, 3071 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3072 Expr *Alignment = static_cast<Expr *>(alignment); 3073 3074 // If specified then alignment must be a "small" power of two. 3075 unsigned AlignmentVal = 0; 3076 if (Alignment) { 3077 llvm::APSInt Val; 3078 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3079 !Val.isPowerOf2() || 3080 Val.getZExtValue() > 16) { 3081 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3082 delete Alignment; 3083 return; // Ignore 3084 } 3085 3086 AlignmentVal = (unsigned) Val.getZExtValue(); 3087 } 3088 3089 switch (Kind) { 3090 case Action::PPK_Default: // pack([n]) 3091 PackContext.setAlignment(AlignmentVal); 3092 break; 3093 3094 case Action::PPK_Show: // pack(show) 3095 // Show the current alignment, making sure to show the right value 3096 // for the default. 3097 AlignmentVal = PackContext.getAlignment(); 3098 // FIXME: This should come from the target. 3099 if (AlignmentVal == 0) 3100 AlignmentVal = 8; 3101 Diag(PragmaLoc, diag::warn_pragma_pack_show, llvm::utostr(AlignmentVal)); 3102 break; 3103 3104 case Action::PPK_Push: // pack(push [, id] [, [n]) 3105 PackContext.push(Name); 3106 // Set the new alignment if specified. 3107 if (Alignment) 3108 PackContext.setAlignment(AlignmentVal); 3109 break; 3110 3111 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3112 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3113 // "#pragma pack(pop, identifier, n) is undefined" 3114 if (Alignment && Name) 3115 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3116 3117 // Do the pop. 3118 if (!PackContext.pop(Name)) { 3119 // If a name was specified then failure indicates the name 3120 // wasn't found. Otherwise failure indicates the stack was 3121 // empty. 3122 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3123 Name ? "no record matching name" : "stack empty"); 3124 3125 // FIXME: Warn about popping named records as MSVC does. 3126 } else { 3127 // Pop succeeded, set the new alignment if specified. 3128 if (Alignment) 3129 PackContext.setAlignment(AlignmentVal); 3130 } 3131 break; 3132 3133 default: 3134 assert(0 && "Invalid #pragma pack kind."); 3135 } 3136} 3137 3138bool PragmaPackStack::pop(IdentifierInfo *Name) { 3139 if (Stack.empty()) 3140 return false; 3141 3142 // If name is empty just pop top. 3143 if (!Name) { 3144 Alignment = Stack.back().first; 3145 Stack.pop_back(); 3146 return true; 3147 } 3148 3149 // Otherwise, find the named record. 3150 for (unsigned i = Stack.size(); i != 0; ) { 3151 --i; 3152 if (strcmp(Stack[i].second.c_str(), Name->getName()) == 0) { 3153 // Found it, pop up to and including this record. 3154 Alignment = Stack[i].first; 3155 Stack.erase(Stack.begin() + i, Stack.end()); 3156 return true; 3157 } 3158 } 3159 3160 return false; 3161} 3162