SemaDecl.cpp revision c42e1183846228a7fa5143ad76507d6d60f5c6f3
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::SizeOf: 1474 case UnaryOperator::AlignOf: 1475 case UnaryOperator::OffsetOf: 1476 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1477 // See C99 6.5.3.4p2 and 6.6p3. 1478 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1479 return false; 1480 InitializerElementNotConstant(Init); 1481 return true; 1482 case UnaryOperator::Extension: 1483 case UnaryOperator::LNot: 1484 case UnaryOperator::Plus: 1485 case UnaryOperator::Minus: 1486 case UnaryOperator::Not: 1487 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1488 } 1489 } 1490 case Expr::SizeOfAlignOfTypeExprClass: { 1491 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1492 // Special check for void types, which are allowed as an extension 1493 if (Exp->getArgumentType()->isVoidType()) 1494 return false; 1495 // alignof always evaluates to a constant. 1496 // FIXME: is sizeof(int[3.0]) a constant expression? 1497 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1498 InitializerElementNotConstant(Init); 1499 return true; 1500 } 1501 return false; 1502 } 1503 case Expr::BinaryOperatorClass: { 1504 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1505 1506 if (Exp->getLHS()->getType()->isArithmeticType() && 1507 Exp->getRHS()->getType()->isArithmeticType()) { 1508 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1509 CheckArithmeticConstantExpression(Exp->getRHS()); 1510 } 1511 1512 if (Exp->getLHS()->getType()->isPointerType() && 1513 Exp->getRHS()->getType()->isPointerType()) { 1514 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1515 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1516 1517 // Only allow a null (constant integer) base; we could 1518 // allow some additional cases if necessary, but this 1519 // is sufficient to cover offsetof-like constructs. 1520 if (!LHSBase && !RHSBase) { 1521 return CheckAddressConstantExpression(Exp->getLHS()) || 1522 CheckAddressConstantExpression(Exp->getRHS()); 1523 } 1524 } 1525 1526 InitializerElementNotConstant(Init); 1527 return true; 1528 } 1529 case Expr::ImplicitCastExprClass: 1530 case Expr::CStyleCastExprClass: { 1531 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1532 if (SubExpr->getType()->isArithmeticType()) 1533 return CheckArithmeticConstantExpression(SubExpr); 1534 1535 if (SubExpr->getType()->isPointerType()) { 1536 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1537 // If the pointer has a null base, this is an offsetof-like construct 1538 if (!Base) 1539 return CheckAddressConstantExpression(SubExpr); 1540 } 1541 1542 InitializerElementNotConstant(Init); 1543 return true; 1544 } 1545 case Expr::ConditionalOperatorClass: { 1546 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1547 1548 // If GNU extensions are disabled, we require all operands to be arithmetic 1549 // constant expressions. 1550 if (getLangOptions().NoExtensions) { 1551 return CheckArithmeticConstantExpression(Exp->getCond()) || 1552 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1553 CheckArithmeticConstantExpression(Exp->getRHS()); 1554 } 1555 1556 // Otherwise, we have to emulate some of the behavior of fold here. 1557 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1558 // because it can constant fold things away. To retain compatibility with 1559 // GCC code, we see if we can fold the condition to a constant (which we 1560 // should always be able to do in theory). If so, we only require the 1561 // specified arm of the conditional to be a constant. This is a horrible 1562 // hack, but is require by real world code that uses __builtin_constant_p. 1563 APValue Val; 1564 if (!Exp->getCond()->tryEvaluate(Val, Context)) { 1565 // If the tryEvaluate couldn't fold it, CheckArithmeticConstantExpression 1566 // won't be able to either. Use it to emit the diagnostic though. 1567 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1568 assert(Res && "tryEvaluate couldn't evaluate this constant?"); 1569 return Res; 1570 } 1571 1572 // Verify that the side following the condition is also a constant. 1573 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1574 if (Val.getInt() == 0) 1575 std::swap(TrueSide, FalseSide); 1576 1577 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1578 return true; 1579 1580 // Okay, the evaluated side evaluates to a constant, so we accept this. 1581 // Check to see if the other side is obviously not a constant. If so, 1582 // emit a warning that this is a GNU extension. 1583 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1584 Diag(Init->getExprLoc(), 1585 diag::ext_typecheck_expression_not_constant_but_accepted, 1586 FalseSide->getSourceRange()); 1587 return false; 1588 } 1589 } 1590} 1591 1592bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1593 Init = Init->IgnoreParens(); 1594 1595 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1596 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1597 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1598 1599 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1600 return CheckForConstantInitializer(e->getInitializer(), DclT); 1601 1602 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1603 unsigned numInits = Exp->getNumInits(); 1604 for (unsigned i = 0; i < numInits; i++) { 1605 // FIXME: Need to get the type of the declaration for C++, 1606 // because it could be a reference? 1607 if (CheckForConstantInitializer(Exp->getInit(i), 1608 Exp->getInit(i)->getType())) 1609 return true; 1610 } 1611 return false; 1612 } 1613 1614 if (Init->isNullPointerConstant(Context)) 1615 return false; 1616 if (Init->getType()->isArithmeticType()) { 1617 QualType InitTy = Context.getCanonicalType(Init->getType()) 1618 .getUnqualifiedType(); 1619 if (InitTy == Context.BoolTy) { 1620 // Special handling for pointers implicitly cast to bool; 1621 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1622 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1623 Expr* SubE = ICE->getSubExpr(); 1624 if (SubE->getType()->isPointerType() || 1625 SubE->getType()->isArrayType() || 1626 SubE->getType()->isFunctionType()) { 1627 return CheckAddressConstantExpression(Init); 1628 } 1629 } 1630 } else if (InitTy->isIntegralType()) { 1631 Expr* SubE = 0; 1632 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1633 SubE = CE->getSubExpr(); 1634 // Special check for pointer cast to int; we allow as an extension 1635 // an address constant cast to an integer if the integer 1636 // is of an appropriate width (this sort of code is apparently used 1637 // in some places). 1638 // FIXME: Add pedwarn? 1639 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1640 if (SubE && (SubE->getType()->isPointerType() || 1641 SubE->getType()->isArrayType() || 1642 SubE->getType()->isFunctionType())) { 1643 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1644 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1645 if (IntWidth >= PointerWidth) 1646 return CheckAddressConstantExpression(Init); 1647 } 1648 } 1649 1650 return CheckArithmeticConstantExpression(Init); 1651 } 1652 1653 if (Init->getType()->isPointerType()) 1654 return CheckAddressConstantExpression(Init); 1655 1656 // An array type at the top level that isn't an init-list must 1657 // be a string literal 1658 if (Init->getType()->isArrayType()) 1659 return false; 1660 1661 if (Init->getType()->isFunctionType()) 1662 return false; 1663 1664 // Allow block exprs at top level. 1665 if (Init->getType()->isBlockPointerType()) 1666 return false; 1667 1668 InitializerElementNotConstant(Init); 1669 return true; 1670} 1671 1672void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1673 Decl *RealDecl = static_cast<Decl *>(dcl); 1674 Expr *Init = static_cast<Expr *>(init); 1675 assert(Init && "missing initializer"); 1676 1677 // If there is no declaration, there was an error parsing it. Just ignore 1678 // the initializer. 1679 if (RealDecl == 0) { 1680 delete Init; 1681 return; 1682 } 1683 1684 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1685 if (!VDecl) { 1686 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1687 diag::err_illegal_initializer); 1688 RealDecl->setInvalidDecl(); 1689 return; 1690 } 1691 // Get the decls type and save a reference for later, since 1692 // CheckInitializerTypes may change it. 1693 QualType DclT = VDecl->getType(), SavT = DclT; 1694 if (VDecl->isBlockVarDecl()) { 1695 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1696 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1697 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1698 VDecl->setInvalidDecl(); 1699 } else if (!VDecl->isInvalidDecl()) { 1700 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1701 VDecl->getName())) 1702 VDecl->setInvalidDecl(); 1703 1704 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1705 if (!getLangOptions().CPlusPlus) { 1706 if (SC == VarDecl::Static) // C99 6.7.8p4. 1707 CheckForConstantInitializer(Init, DclT); 1708 } 1709 } 1710 } else if (VDecl->isFileVarDecl()) { 1711 if (VDecl->getStorageClass() == VarDecl::Extern) 1712 Diag(VDecl->getLocation(), diag::warn_extern_init); 1713 if (!VDecl->isInvalidDecl()) 1714 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1715 VDecl->getName())) 1716 VDecl->setInvalidDecl(); 1717 1718 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1719 if (!getLangOptions().CPlusPlus) { 1720 // C99 6.7.8p4. All file scoped initializers need to be constant. 1721 CheckForConstantInitializer(Init, DclT); 1722 } 1723 } 1724 // If the type changed, it means we had an incomplete type that was 1725 // completed by the initializer. For example: 1726 // int ary[] = { 1, 3, 5 }; 1727 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1728 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1729 VDecl->setType(DclT); 1730 Init->setType(DclT); 1731 } 1732 1733 // Attach the initializer to the decl. 1734 VDecl->setInit(Init); 1735 return; 1736} 1737 1738void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1739 Decl *RealDecl = static_cast<Decl *>(dcl); 1740 1741 // If there is no declaration, there was an error parsing it. Just ignore it. 1742 if (RealDecl == 0) 1743 return; 1744 1745 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1746 QualType Type = Var->getType(); 1747 // C++ [dcl.init.ref]p3: 1748 // The initializer can be omitted for a reference only in a 1749 // parameter declaration (8.3.5), in the declaration of a 1750 // function return type, in the declaration of a class member 1751 // within its class declaration (9.2), and where the extern 1752 // specifier is explicitly used. 1753 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1754 Diag(Var->getLocation(), 1755 diag::err_reference_var_requires_init, 1756 Var->getName(), 1757 SourceRange(Var->getLocation(), Var->getLocation())); 1758 Var->setInvalidDecl(); 1759 return; 1760 } 1761 1762 // C++ [dcl.init]p9: 1763 // 1764 // If no initializer is specified for an object, and the object 1765 // is of (possibly cv-qualified) non-POD class type (or array 1766 // thereof), the object shall be default-initialized; if the 1767 // object is of const-qualified type, the underlying class type 1768 // shall have a user-declared default constructor. 1769 if (getLangOptions().CPlusPlus) { 1770 QualType InitType = Type; 1771 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1772 InitType = Array->getElementType(); 1773 if (InitType->isRecordType()) { 1774 const CXXConstructorDecl *Constructor 1775 = PerformInitializationByConstructor(InitType, 0, 0, 1776 Var->getLocation(), 1777 SourceRange(Var->getLocation(), 1778 Var->getLocation()), 1779 Var->getName(), 1780 IK_Default); 1781 if (!Constructor) 1782 Var->setInvalidDecl(); 1783 } 1784 } 1785 1786#if 0 1787 // FIXME: Temporarily disabled because we are not properly parsing 1788 // linkage specifications on declarations, e.g., 1789 // 1790 // extern "C" const CGPoint CGPointerZero; 1791 // 1792 // C++ [dcl.init]p9: 1793 // 1794 // If no initializer is specified for an object, and the 1795 // object is of (possibly cv-qualified) non-POD class type (or 1796 // array thereof), the object shall be default-initialized; if 1797 // the object is of const-qualified type, the underlying class 1798 // type shall have a user-declared default 1799 // constructor. Otherwise, if no initializer is specified for 1800 // an object, the object and its subobjects, if any, have an 1801 // indeterminate initial value; if the object or any of its 1802 // subobjects are of const-qualified type, the program is 1803 // ill-formed. 1804 // 1805 // This isn't technically an error in C, so we don't diagnose it. 1806 // 1807 // FIXME: Actually perform the POD/user-defined default 1808 // constructor check. 1809 if (getLangOptions().CPlusPlus && 1810 Context.getCanonicalType(Type).isConstQualified() && 1811 Var->getStorageClass() != VarDecl::Extern) 1812 Diag(Var->getLocation(), 1813 diag::err_const_var_requires_init, 1814 Var->getName(), 1815 SourceRange(Var->getLocation(), Var->getLocation())); 1816#endif 1817 } 1818} 1819 1820/// The declarators are chained together backwards, reverse the list. 1821Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1822 // Often we have single declarators, handle them quickly. 1823 Decl *GroupDecl = static_cast<Decl*>(group); 1824 if (GroupDecl == 0) 1825 return 0; 1826 1827 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1828 ScopedDecl *NewGroup = 0; 1829 if (Group->getNextDeclarator() == 0) 1830 NewGroup = Group; 1831 else { // reverse the list. 1832 while (Group) { 1833 ScopedDecl *Next = Group->getNextDeclarator(); 1834 Group->setNextDeclarator(NewGroup); 1835 NewGroup = Group; 1836 Group = Next; 1837 } 1838 } 1839 // Perform semantic analysis that depends on having fully processed both 1840 // the declarator and initializer. 1841 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1842 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1843 if (!IDecl) 1844 continue; 1845 QualType T = IDecl->getType(); 1846 1847 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1848 // static storage duration, it shall not have a variable length array. 1849 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1850 IDecl->getStorageClass() == VarDecl::Static) { 1851 if (T->isVariableArrayType()) { 1852 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1853 IDecl->setInvalidDecl(); 1854 } 1855 } 1856 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1857 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1858 if (IDecl->isBlockVarDecl() && 1859 IDecl->getStorageClass() != VarDecl::Extern) { 1860 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1861 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1862 T.getAsString()); 1863 IDecl->setInvalidDecl(); 1864 } 1865 } 1866 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1867 // object that has file scope without an initializer, and without a 1868 // storage-class specifier or with the storage-class specifier "static", 1869 // constitutes a tentative definition. Note: A tentative definition with 1870 // external linkage is valid (C99 6.2.2p5). 1871 if (isTentativeDefinition(IDecl)) { 1872 if (T->isIncompleteArrayType()) { 1873 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1874 // array to be completed. Don't issue a diagnostic. 1875 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1876 // C99 6.9.2p3: If the declaration of an identifier for an object is 1877 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1878 // declared type shall not be an incomplete type. 1879 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1880 T.getAsString()); 1881 IDecl->setInvalidDecl(); 1882 } 1883 } 1884 if (IDecl->isFileVarDecl()) 1885 CheckForFileScopedRedefinitions(S, IDecl); 1886 } 1887 return NewGroup; 1888} 1889 1890/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1891/// to introduce parameters into function prototype scope. 1892Sema::DeclTy * 1893Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1894 // FIXME: disallow CXXScopeSpec for param declarators. 1895 const DeclSpec &DS = D.getDeclSpec(); 1896 1897 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1898 VarDecl::StorageClass StorageClass = VarDecl::None; 1899 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1900 StorageClass = VarDecl::Register; 1901 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1902 Diag(DS.getStorageClassSpecLoc(), 1903 diag::err_invalid_storage_class_in_func_decl); 1904 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1905 } 1906 if (DS.isThreadSpecified()) { 1907 Diag(DS.getThreadSpecLoc(), 1908 diag::err_invalid_storage_class_in_func_decl); 1909 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1910 } 1911 1912 // Check that there are no default arguments inside the type of this 1913 // parameter (C++ only). 1914 if (getLangOptions().CPlusPlus) 1915 CheckExtraCXXDefaultArguments(D); 1916 1917 // In this context, we *do not* check D.getInvalidType(). If the declarator 1918 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1919 // though it will not reflect the user specified type. 1920 QualType parmDeclType = GetTypeForDeclarator(D, S); 1921 1922 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1923 1924 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1925 // Can this happen for params? We already checked that they don't conflict 1926 // among each other. Here they can only shadow globals, which is ok. 1927 IdentifierInfo *II = D.getIdentifier(); 1928 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1929 if (S->isDeclScope(PrevDecl)) { 1930 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1931 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1932 1933 // Recover by removing the name 1934 II = 0; 1935 D.SetIdentifier(0, D.getIdentifierLoc()); 1936 } 1937 } 1938 1939 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1940 // Doing the promotion here has a win and a loss. The win is the type for 1941 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1942 // code generator). The loss is the orginal type isn't preserved. For example: 1943 // 1944 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1945 // int blockvardecl[5]; 1946 // sizeof(parmvardecl); // size == 4 1947 // sizeof(blockvardecl); // size == 20 1948 // } 1949 // 1950 // For expressions, all implicit conversions are captured using the 1951 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1952 // 1953 // FIXME: If a source translation tool needs to see the original type, then 1954 // we need to consider storing both types (in ParmVarDecl)... 1955 // 1956 if (parmDeclType->isArrayType()) { 1957 // int x[restrict 4] -> int *restrict 1958 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1959 } else if (parmDeclType->isFunctionType()) 1960 parmDeclType = Context.getPointerType(parmDeclType); 1961 1962 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1963 D.getIdentifierLoc(), II, 1964 parmDeclType, StorageClass, 1965 0, 0); 1966 1967 if (D.getInvalidType()) 1968 New->setInvalidDecl(); 1969 1970 if (II) 1971 PushOnScopeChains(New, S); 1972 1973 ProcessDeclAttributes(New, D); 1974 return New; 1975 1976} 1977 1978Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1979 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1980 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1981 "Not a function declarator!"); 1982 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1983 1984 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1985 // for a K&R function. 1986 if (!FTI.hasPrototype) { 1987 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1988 if (FTI.ArgInfo[i].Param == 0) { 1989 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1990 FTI.ArgInfo[i].Ident->getName()); 1991 // Implicitly declare the argument as type 'int' for lack of a better 1992 // type. 1993 DeclSpec DS; 1994 const char* PrevSpec; // unused 1995 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1996 PrevSpec); 1997 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1998 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1999 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2000 } 2001 } 2002 } else { 2003 // FIXME: Diagnose arguments without names in C. 2004 } 2005 2006 Scope *GlobalScope = FnBodyScope->getParent(); 2007 2008 return ActOnStartOfFunctionDef(FnBodyScope, 2009 ActOnDeclarator(GlobalScope, D, 0)); 2010} 2011 2012Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2013 Decl *decl = static_cast<Decl*>(D); 2014 FunctionDecl *FD = cast<FunctionDecl>(decl); 2015 2016 // See if this is a redefinition. 2017 const FunctionDecl *Definition; 2018 if (FD->getBody(Definition)) { 2019 Diag(FD->getLocation(), diag::err_redefinition, 2020 FD->getName()); 2021 Diag(Definition->getLocation(), diag::err_previous_definition); 2022 } 2023 2024 PushDeclContext(FD); 2025 2026 // Check the validity of our function parameters 2027 CheckParmsForFunctionDef(FD); 2028 2029 // Introduce our parameters into the function scope 2030 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2031 ParmVarDecl *Param = FD->getParamDecl(p); 2032 // If this has an identifier, add it to the scope stack. 2033 if (Param->getIdentifier()) 2034 PushOnScopeChains(Param, FnBodyScope); 2035 } 2036 2037 return FD; 2038} 2039 2040Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2041 Decl *dcl = static_cast<Decl *>(D); 2042 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2043 FD->setBody((Stmt*)Body); 2044 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2045 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2046 MD->setBody((Stmt*)Body); 2047 } else 2048 return 0; 2049 PopDeclContext(); 2050 // Verify and clean out per-function state. 2051 2052 // Check goto/label use. 2053 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2054 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2055 // Verify that we have no forward references left. If so, there was a goto 2056 // or address of a label taken, but no definition of it. Label fwd 2057 // definitions are indicated with a null substmt. 2058 if (I->second->getSubStmt() == 0) { 2059 LabelStmt *L = I->second; 2060 // Emit error. 2061 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2062 2063 // At this point, we have gotos that use the bogus label. Stitch it into 2064 // the function body so that they aren't leaked and that the AST is well 2065 // formed. 2066 if (Body) { 2067 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2068 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2069 } else { 2070 // The whole function wasn't parsed correctly, just delete this. 2071 delete L; 2072 } 2073 } 2074 } 2075 LabelMap.clear(); 2076 2077 return D; 2078} 2079 2080/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2081/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2082ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2083 IdentifierInfo &II, Scope *S) { 2084 // Extension in C99. Legal in C90, but warn about it. 2085 if (getLangOptions().C99) 2086 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 2087 else 2088 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 2089 2090 // FIXME: handle stuff like: 2091 // void foo() { extern float X(); } 2092 // void bar() { X(); } <-- implicit decl for X in another scope. 2093 2094 // Set a Declarator for the implicit definition: int foo(); 2095 const char *Dummy; 2096 DeclSpec DS; 2097 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2098 Error = Error; // Silence warning. 2099 assert(!Error && "Error setting up implicit decl!"); 2100 Declarator D(DS, Declarator::BlockContext); 2101 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2102 D.SetIdentifier(&II, Loc); 2103 2104 // Insert this function into translation-unit scope. 2105 2106 DeclContext *PrevDC = CurContext; 2107 CurContext = Context.getTranslationUnitDecl(); 2108 2109 FunctionDecl *FD = 2110 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2111 FD->setImplicit(); 2112 2113 CurContext = PrevDC; 2114 2115 return FD; 2116} 2117 2118 2119TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2120 ScopedDecl *LastDeclarator) { 2121 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2122 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2123 2124 // Scope manipulation handled by caller. 2125 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2126 D.getIdentifierLoc(), 2127 D.getIdentifier(), 2128 T, LastDeclarator); 2129 if (D.getInvalidType()) 2130 NewTD->setInvalidDecl(); 2131 return NewTD; 2132} 2133 2134/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2135/// former case, Name will be non-null. In the later case, Name will be null. 2136/// TagType indicates what kind of tag this is. TK indicates whether this is a 2137/// reference/declaration/definition of a tag. 2138Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2139 SourceLocation KWLoc, const CXXScopeSpec &SS, 2140 IdentifierInfo *Name, SourceLocation NameLoc, 2141 AttributeList *Attr) { 2142 // If this is a use of an existing tag, it must have a name. 2143 assert((Name != 0 || TK == TK_Definition) && 2144 "Nameless record must be a definition!"); 2145 2146 TagDecl::TagKind Kind; 2147 switch (TagType) { 2148 default: assert(0 && "Unknown tag type!"); 2149 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2150 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2151 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2152 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2153 } 2154 2155 // Two code paths: a new one for structs/unions/classes where we create 2156 // separate decls for forward declarations, and an old (eventually to 2157 // be removed) code path for enums. 2158 if (Kind != TagDecl::TK_enum) 2159 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2160 2161 DeclContext *DC = CurContext; 2162 ScopedDecl *PrevDecl = 0; 2163 2164 if (Name && SS.isNotEmpty()) { 2165 // We have a nested-name tag ('struct foo::bar'). 2166 2167 // Check for invalid 'foo::'. 2168 if (SS.isInvalid()) { 2169 Name = 0; 2170 goto CreateNewDecl; 2171 } 2172 2173 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2174 // Look-up name inside 'foo::'. 2175 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2176 2177 // A tag 'foo::bar' must already exist. 2178 if (PrevDecl == 0) { 2179 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2180 SS.getRange()); 2181 Name = 0; 2182 goto CreateNewDecl; 2183 } 2184 } else { 2185 // If this is a named struct, check to see if there was a previous forward 2186 // declaration or definition. 2187 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2188 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2189 } 2190 2191 if (PrevDecl) { 2192 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2193 "unexpected Decl type"); 2194 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2195 // If this is a use of a previous tag, or if the tag is already declared 2196 // in the same scope (so that the definition/declaration completes or 2197 // rementions the tag), reuse the decl. 2198 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2199 // Make sure that this wasn't declared as an enum and now used as a 2200 // struct or something similar. 2201 if (PrevTagDecl->getTagKind() != Kind) { 2202 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2203 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2204 // Recover by making this an anonymous redefinition. 2205 Name = 0; 2206 PrevDecl = 0; 2207 } else { 2208 // If this is a use or a forward declaration, we're good. 2209 if (TK != TK_Definition) 2210 return PrevDecl; 2211 2212 // Diagnose attempts to redefine a tag. 2213 if (PrevTagDecl->isDefinition()) { 2214 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2215 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2216 // If this is a redefinition, recover by making this struct be 2217 // anonymous, which will make any later references get the previous 2218 // definition. 2219 Name = 0; 2220 } else { 2221 // Okay, this is definition of a previously declared or referenced 2222 // tag. Move the location of the decl to be the definition site. 2223 PrevDecl->setLocation(NameLoc); 2224 return PrevDecl; 2225 } 2226 } 2227 } 2228 // If we get here, this is a definition of a new struct type in a nested 2229 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2230 // type. 2231 } else { 2232 // PrevDecl is a namespace. 2233 if (isDeclInScope(PrevDecl, DC, S)) { 2234 // The tag name clashes with a namespace name, issue an error and 2235 // recover by making this tag be anonymous. 2236 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2237 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2238 Name = 0; 2239 } 2240 } 2241 } 2242 2243 CreateNewDecl: 2244 2245 // If there is an identifier, use the location of the identifier as the 2246 // location of the decl, otherwise use the location of the struct/union 2247 // keyword. 2248 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2249 2250 // Otherwise, if this is the first time we've seen this tag, create the decl. 2251 TagDecl *New; 2252 if (Kind == TagDecl::TK_enum) { 2253 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2254 // enum X { A, B, C } D; D should chain to X. 2255 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2256 // If this is an undefined enum, warn. 2257 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2258 } else { 2259 // struct/union/class 2260 2261 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2262 // struct X { int A; } D; D should chain to X. 2263 if (getLangOptions().CPlusPlus) 2264 // FIXME: Look for a way to use RecordDecl for simple structs. 2265 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2266 else 2267 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2268 } 2269 2270 // If this has an identifier, add it to the scope stack. 2271 if (Name) { 2272 // The scope passed in may not be a decl scope. Zip up the scope tree until 2273 // we find one that is. 2274 while ((S->getFlags() & Scope::DeclScope) == 0) 2275 S = S->getParent(); 2276 2277 // Add it to the decl chain. 2278 PushOnScopeChains(New, S); 2279 } 2280 2281 if (Attr) 2282 ProcessDeclAttributeList(New, Attr); 2283 2284 // Set the lexical context. If the tag has a C++ scope specifier, the 2285 // lexical context will be different from the semantic context. 2286 New->setLexicalDeclContext(CurContext); 2287 2288 return New; 2289} 2290 2291/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2292/// the logic for enums, we create separate decls for forward declarations. 2293/// This is called by ActOnTag, but eventually will replace its logic. 2294Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2295 SourceLocation KWLoc, const CXXScopeSpec &SS, 2296 IdentifierInfo *Name, SourceLocation NameLoc, 2297 AttributeList *Attr) { 2298 DeclContext *DC = CurContext; 2299 ScopedDecl *PrevDecl = 0; 2300 2301 if (Name && SS.isNotEmpty()) { 2302 // We have a nested-name tag ('struct foo::bar'). 2303 2304 // Check for invalid 'foo::'. 2305 if (SS.isInvalid()) { 2306 Name = 0; 2307 goto CreateNewDecl; 2308 } 2309 2310 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2311 // Look-up name inside 'foo::'. 2312 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2313 2314 // A tag 'foo::bar' must already exist. 2315 if (PrevDecl == 0) { 2316 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2317 SS.getRange()); 2318 Name = 0; 2319 goto CreateNewDecl; 2320 } 2321 } else { 2322 // If this is a named struct, check to see if there was a previous forward 2323 // declaration or definition. 2324 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2325 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2326 } 2327 2328 if (PrevDecl) { 2329 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2330 "unexpected Decl type"); 2331 2332 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2333 // If this is a use of a previous tag, or if the tag is already declared 2334 // in the same scope (so that the definition/declaration completes or 2335 // rementions the tag), reuse the decl. 2336 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2337 // Make sure that this wasn't declared as an enum and now used as a 2338 // struct or something similar. 2339 if (PrevTagDecl->getTagKind() != Kind) { 2340 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2341 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2342 // Recover by making this an anonymous redefinition. 2343 Name = 0; 2344 PrevDecl = 0; 2345 } else { 2346 // If this is a use, return the original decl. 2347 2348 // FIXME: In the future, return a variant or some other clue 2349 // for the consumer of this Decl to know it doesn't own it. 2350 // For our current ASTs this shouldn't be a problem, but will 2351 // need to be changed with DeclGroups. 2352 if (TK == TK_Reference) 2353 return PrevDecl; 2354 2355 // The new decl is a definition? 2356 if (TK == TK_Definition) { 2357 // Diagnose attempts to redefine a tag. 2358 if (RecordDecl* DefRecord = 2359 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2360 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2361 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2362 // If this is a redefinition, recover by making this struct be 2363 // anonymous, which will make any later references get the previous 2364 // definition. 2365 Name = 0; 2366 PrevDecl = 0; 2367 } 2368 // Okay, this is definition of a previously declared or referenced 2369 // tag. We're going to create a new Decl. 2370 } 2371 } 2372 // If we get here we have (another) forward declaration. Just create 2373 // a new decl. 2374 } 2375 else { 2376 // If we get here, this is a definition of a new struct type in a nested 2377 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2378 // new decl/type. We set PrevDecl to NULL so that the Records 2379 // have distinct types. 2380 PrevDecl = 0; 2381 } 2382 } else { 2383 // PrevDecl is a namespace. 2384 if (isDeclInScope(PrevDecl, DC, S)) { 2385 // The tag name clashes with a namespace name, issue an error and 2386 // recover by making this tag be anonymous. 2387 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2388 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2389 Name = 0; 2390 } 2391 } 2392 } 2393 2394 CreateNewDecl: 2395 2396 // If there is an identifier, use the location of the identifier as the 2397 // location of the decl, otherwise use the location of the struct/union 2398 // keyword. 2399 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2400 2401 // Otherwise, if this is the first time we've seen this tag, create the decl. 2402 TagDecl *New; 2403 2404 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2405 // struct X { int A; } D; D should chain to X. 2406 if (getLangOptions().CPlusPlus) 2407 // FIXME: Look for a way to use RecordDecl for simple structs. 2408 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2409 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2410 else 2411 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2412 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2413 2414 // If this has an identifier, add it to the scope stack. 2415 if ((TK == TK_Definition || !PrevDecl) && Name) { 2416 // The scope passed in may not be a decl scope. Zip up the scope tree until 2417 // we find one that is. 2418 while ((S->getFlags() & Scope::DeclScope) == 0) 2419 S = S->getParent(); 2420 2421 // Add it to the decl chain. 2422 PushOnScopeChains(New, S); 2423 } 2424 2425 // Handle #pragma pack: if the #pragma pack stack has non-default 2426 // alignment, make up a packed attribute for this decl. These 2427 // attributes are checked when the ASTContext lays out the 2428 // structure. 2429 // 2430 // It is important for implementing the correct semantics that this 2431 // happen here (in act on tag decl). The #pragma pack stack is 2432 // maintained as a result of parser callbacks which can occur at 2433 // many points during the parsing of a struct declaration (because 2434 // the #pragma tokens are effectively skipped over during the 2435 // parsing of the struct). 2436 if (unsigned Alignment = PackContext.getAlignment()) 2437 New->addAttr(new PackedAttr(Alignment * 8)); 2438 2439 if (Attr) 2440 ProcessDeclAttributeList(New, Attr); 2441 2442 // Set the lexical context. If the tag has a C++ scope specifier, the 2443 // lexical context will be different from the semantic context. 2444 New->setLexicalDeclContext(CurContext); 2445 2446 return New; 2447} 2448 2449 2450/// Collect the instance variables declared in an Objective-C object. Used in 2451/// the creation of structures from objects using the @defs directive. 2452static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2453 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2454 if (Class->getSuperClass()) 2455 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2456 2457 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2458 for (ObjCInterfaceDecl::ivar_iterator 2459 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2460 2461 ObjCIvarDecl* ID = *I; 2462 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2463 ID->getIdentifier(), 2464 ID->getType(), 2465 ID->getBitWidth())); 2466 } 2467} 2468 2469/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2470/// instance variables of ClassName into Decls. 2471void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2472 IdentifierInfo *ClassName, 2473 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2474 // Check that ClassName is a valid class 2475 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2476 if (!Class) { 2477 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 2478 return; 2479 } 2480 // Collect the instance variables 2481 CollectIvars(Class, Context, Decls); 2482} 2483 2484QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 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 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 2490 APValue Result; 2491 if (VLATy->getSizeExpr() && 2492 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 2493 llvm::APSInt &Res = Result.getInt(); 2494 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2495 return Context.getConstantArrayType(VLATy->getElementType(), 2496 Res, ArrayType::Normal, 0); 2497 } 2498 } 2499 return QualType(); 2500} 2501 2502/// ActOnField - Each field of a struct/union/class is passed into this in order 2503/// to create a FieldDecl object for it. 2504Sema::DeclTy *Sema::ActOnField(Scope *S, 2505 SourceLocation DeclStart, 2506 Declarator &D, ExprTy *BitfieldWidth) { 2507 IdentifierInfo *II = D.getIdentifier(); 2508 Expr *BitWidth = (Expr*)BitfieldWidth; 2509 SourceLocation Loc = DeclStart; 2510 if (II) Loc = D.getIdentifierLoc(); 2511 2512 // FIXME: Unnamed fields can be handled in various different ways, for 2513 // example, unnamed unions inject all members into the struct namespace! 2514 2515 if (BitWidth) { 2516 // TODO: Validate. 2517 //printf("WARNING: BITFIELDS IGNORED!\n"); 2518 2519 // 6.7.2.1p3 2520 // 6.7.2.1p4 2521 2522 } else { 2523 // Not a bitfield. 2524 2525 // validate II. 2526 2527 } 2528 2529 QualType T = GetTypeForDeclarator(D, S); 2530 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2531 bool InvalidDecl = false; 2532 2533 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2534 // than a variably modified type. 2535 if (T->isVariablyModifiedType()) { 2536 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 2537 if (!FixedTy.isNull()) { 2538 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 2539 T = FixedTy; 2540 } else { 2541 // FIXME: This diagnostic needs work 2542 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2543 InvalidDecl = true; 2544 } 2545 } 2546 // FIXME: Chain fielddecls together. 2547 FieldDecl *NewFD; 2548 2549 if (getLangOptions().CPlusPlus) { 2550 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2551 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2552 Loc, II, T, BitWidth); 2553 if (II) 2554 PushOnScopeChains(NewFD, S); 2555 } 2556 else 2557 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2558 2559 ProcessDeclAttributes(NewFD, D); 2560 2561 if (D.getInvalidType() || InvalidDecl) 2562 NewFD->setInvalidDecl(); 2563 return NewFD; 2564} 2565 2566/// TranslateIvarVisibility - Translate visibility from a token ID to an 2567/// AST enum value. 2568static ObjCIvarDecl::AccessControl 2569TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2570 switch (ivarVisibility) { 2571 default: assert(0 && "Unknown visitibility kind"); 2572 case tok::objc_private: return ObjCIvarDecl::Private; 2573 case tok::objc_public: return ObjCIvarDecl::Public; 2574 case tok::objc_protected: return ObjCIvarDecl::Protected; 2575 case tok::objc_package: return ObjCIvarDecl::Package; 2576 } 2577} 2578 2579/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2580/// in order to create an IvarDecl object for it. 2581Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2582 SourceLocation DeclStart, 2583 Declarator &D, ExprTy *BitfieldWidth, 2584 tok::ObjCKeywordKind Visibility) { 2585 IdentifierInfo *II = D.getIdentifier(); 2586 Expr *BitWidth = (Expr*)BitfieldWidth; 2587 SourceLocation Loc = DeclStart; 2588 if (II) Loc = D.getIdentifierLoc(); 2589 2590 // FIXME: Unnamed fields can be handled in various different ways, for 2591 // example, unnamed unions inject all members into the struct namespace! 2592 2593 2594 if (BitWidth) { 2595 // TODO: Validate. 2596 //printf("WARNING: BITFIELDS IGNORED!\n"); 2597 2598 // 6.7.2.1p3 2599 // 6.7.2.1p4 2600 2601 } else { 2602 // Not a bitfield. 2603 2604 // validate II. 2605 2606 } 2607 2608 QualType T = GetTypeForDeclarator(D, S); 2609 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2610 bool InvalidDecl = false; 2611 2612 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2613 // than a variably modified type. 2614 if (T->isVariablyModifiedType()) { 2615 // FIXME: This diagnostic needs work 2616 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2617 InvalidDecl = true; 2618 } 2619 2620 // Get the visibility (access control) for this ivar. 2621 ObjCIvarDecl::AccessControl ac = 2622 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2623 : ObjCIvarDecl::None; 2624 2625 // Construct the decl. 2626 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2627 (Expr *)BitfieldWidth); 2628 2629 // Process attributes attached to the ivar. 2630 ProcessDeclAttributes(NewID, D); 2631 2632 if (D.getInvalidType() || InvalidDecl) 2633 NewID->setInvalidDecl(); 2634 2635 return NewID; 2636} 2637 2638void Sema::ActOnFields(Scope* S, 2639 SourceLocation RecLoc, DeclTy *RecDecl, 2640 DeclTy **Fields, unsigned NumFields, 2641 SourceLocation LBrac, SourceLocation RBrac, 2642 AttributeList *Attr) { 2643 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2644 assert(EnclosingDecl && "missing record or interface decl"); 2645 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2646 2647 if (Record) 2648 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2649 // Diagnose code like: 2650 // struct S { struct S {} X; }; 2651 // We discover this when we complete the outer S. Reject and ignore the 2652 // outer S. 2653 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2654 DefRecord->getKindName()); 2655 Diag(RecLoc, diag::err_previous_definition); 2656 Record->setInvalidDecl(); 2657 return; 2658 } 2659 2660 // Verify that all the fields are okay. 2661 unsigned NumNamedMembers = 0; 2662 llvm::SmallVector<FieldDecl*, 32> RecFields; 2663 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2664 2665 for (unsigned i = 0; i != NumFields; ++i) { 2666 2667 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2668 assert(FD && "missing field decl"); 2669 2670 // Remember all fields. 2671 RecFields.push_back(FD); 2672 2673 // Get the type for the field. 2674 Type *FDTy = FD->getType().getTypePtr(); 2675 2676 // C99 6.7.2.1p2 - A field may not be a function type. 2677 if (FDTy->isFunctionType()) { 2678 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2679 FD->getName()); 2680 FD->setInvalidDecl(); 2681 EnclosingDecl->setInvalidDecl(); 2682 continue; 2683 } 2684 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2685 if (FDTy->isIncompleteType()) { 2686 if (!Record) { // Incomplete ivar type is always an error. 2687 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2688 FD->setInvalidDecl(); 2689 EnclosingDecl->setInvalidDecl(); 2690 continue; 2691 } 2692 if (i != NumFields-1 || // ... that the last member ... 2693 !Record->isStruct() || // ... of a structure ... 2694 !FDTy->isArrayType()) { //... may have incomplete array type. 2695 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2696 FD->setInvalidDecl(); 2697 EnclosingDecl->setInvalidDecl(); 2698 continue; 2699 } 2700 if (NumNamedMembers < 1) { //... must have more than named member ... 2701 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2702 FD->getName()); 2703 FD->setInvalidDecl(); 2704 EnclosingDecl->setInvalidDecl(); 2705 continue; 2706 } 2707 // Okay, we have a legal flexible array member at the end of the struct. 2708 if (Record) 2709 Record->setHasFlexibleArrayMember(true); 2710 } 2711 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2712 /// field of another structure or the element of an array. 2713 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2714 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2715 // If this is a member of a union, then entire union becomes "flexible". 2716 if (Record && Record->isUnion()) { 2717 Record->setHasFlexibleArrayMember(true); 2718 } else { 2719 // If this is a struct/class and this is not the last element, reject 2720 // it. Note that GCC supports variable sized arrays in the middle of 2721 // structures. 2722 if (i != NumFields-1) { 2723 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2724 FD->getName()); 2725 FD->setInvalidDecl(); 2726 EnclosingDecl->setInvalidDecl(); 2727 continue; 2728 } 2729 // We support flexible arrays at the end of structs in other structs 2730 // as an extension. 2731 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2732 FD->getName()); 2733 if (Record) 2734 Record->setHasFlexibleArrayMember(true); 2735 } 2736 } 2737 } 2738 /// A field cannot be an Objective-c object 2739 if (FDTy->isObjCInterfaceType()) { 2740 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2741 FD->getName()); 2742 FD->setInvalidDecl(); 2743 EnclosingDecl->setInvalidDecl(); 2744 continue; 2745 } 2746 // Keep track of the number of named members. 2747 if (IdentifierInfo *II = FD->getIdentifier()) { 2748 // Detect duplicate member names. 2749 if (!FieldIDs.insert(II)) { 2750 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2751 // Find the previous decl. 2752 SourceLocation PrevLoc; 2753 for (unsigned i = 0; ; ++i) { 2754 assert(i != RecFields.size() && "Didn't find previous def!"); 2755 if (RecFields[i]->getIdentifier() == II) { 2756 PrevLoc = RecFields[i]->getLocation(); 2757 break; 2758 } 2759 } 2760 Diag(PrevLoc, diag::err_previous_definition); 2761 FD->setInvalidDecl(); 2762 EnclosingDecl->setInvalidDecl(); 2763 continue; 2764 } 2765 ++NumNamedMembers; 2766 } 2767 } 2768 2769 // Okay, we successfully defined 'Record'. 2770 if (Record) { 2771 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2772 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2773 // Sema::ActOnFinishCXXClassDef. 2774 if (!isa<CXXRecordDecl>(Record)) 2775 Consumer.HandleTagDeclDefinition(Record); 2776 } else { 2777 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2778 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2779 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2780 else if (ObjCImplementationDecl *IMPDecl = 2781 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2782 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2783 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2784 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2785 } 2786 } 2787 2788 if (Attr) 2789 ProcessDeclAttributeList(Record, Attr); 2790} 2791 2792Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2793 DeclTy *lastEnumConst, 2794 SourceLocation IdLoc, IdentifierInfo *Id, 2795 SourceLocation EqualLoc, ExprTy *val) { 2796 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2797 EnumConstantDecl *LastEnumConst = 2798 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2799 Expr *Val = static_cast<Expr*>(val); 2800 2801 // The scope passed in may not be a decl scope. Zip up the scope tree until 2802 // we find one that is. 2803 while ((S->getFlags() & Scope::DeclScope) == 0) 2804 S = S->getParent(); 2805 2806 // Verify that there isn't already something declared with this name in this 2807 // scope. 2808 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2809 // When in C++, we may get a TagDecl with the same name; in this case the 2810 // enum constant will 'hide' the tag. 2811 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2812 "Received TagDecl when not in C++!"); 2813 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2814 if (isa<EnumConstantDecl>(PrevDecl)) 2815 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2816 else 2817 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2818 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2819 delete Val; 2820 return 0; 2821 } 2822 } 2823 2824 llvm::APSInt EnumVal(32); 2825 QualType EltTy; 2826 if (Val) { 2827 // Make sure to promote the operand type to int. 2828 UsualUnaryConversions(Val); 2829 2830 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2831 SourceLocation ExpLoc; 2832 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2833 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2834 Id->getName()); 2835 delete Val; 2836 Val = 0; // Just forget about it. 2837 } else { 2838 EltTy = Val->getType(); 2839 } 2840 } 2841 2842 if (!Val) { 2843 if (LastEnumConst) { 2844 // Assign the last value + 1. 2845 EnumVal = LastEnumConst->getInitVal(); 2846 ++EnumVal; 2847 2848 // Check for overflow on increment. 2849 if (EnumVal < LastEnumConst->getInitVal()) 2850 Diag(IdLoc, diag::warn_enum_value_overflow); 2851 2852 EltTy = LastEnumConst->getType(); 2853 } else { 2854 // First value, set to zero. 2855 EltTy = Context.IntTy; 2856 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2857 } 2858 } 2859 2860 EnumConstantDecl *New = 2861 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2862 Val, EnumVal, 2863 LastEnumConst); 2864 2865 // Register this decl in the current scope stack. 2866 PushOnScopeChains(New, S); 2867 return New; 2868} 2869 2870// FIXME: For consistency with ActOnFields(), we should have the parser 2871// pass in the source location for the left/right braces. 2872void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2873 DeclTy **Elements, unsigned NumElements) { 2874 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2875 2876 if (Enum && Enum->isDefinition()) { 2877 // Diagnose code like: 2878 // enum e0 { 2879 // E0 = sizeof(enum e0 { E1 }) 2880 // }; 2881 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2882 Enum->getName()); 2883 Diag(EnumLoc, diag::err_previous_definition); 2884 Enum->setInvalidDecl(); 2885 return; 2886 } 2887 // TODO: If the result value doesn't fit in an int, it must be a long or long 2888 // long value. ISO C does not support this, but GCC does as an extension, 2889 // emit a warning. 2890 unsigned IntWidth = Context.Target.getIntWidth(); 2891 2892 // Verify that all the values are okay, compute the size of the values, and 2893 // reverse the list. 2894 unsigned NumNegativeBits = 0; 2895 unsigned NumPositiveBits = 0; 2896 2897 // Keep track of whether all elements have type int. 2898 bool AllElementsInt = true; 2899 2900 EnumConstantDecl *EltList = 0; 2901 for (unsigned i = 0; i != NumElements; ++i) { 2902 EnumConstantDecl *ECD = 2903 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2904 if (!ECD) continue; // Already issued a diagnostic. 2905 2906 // If the enum value doesn't fit in an int, emit an extension warning. 2907 const llvm::APSInt &InitVal = ECD->getInitVal(); 2908 assert(InitVal.getBitWidth() >= IntWidth && 2909 "Should have promoted value to int"); 2910 if (InitVal.getBitWidth() > IntWidth) { 2911 llvm::APSInt V(InitVal); 2912 V.trunc(IntWidth); 2913 V.extend(InitVal.getBitWidth()); 2914 if (V != InitVal) 2915 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2916 InitVal.toString(10)); 2917 } 2918 2919 // Keep track of the size of positive and negative values. 2920 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2921 NumPositiveBits = std::max(NumPositiveBits, 2922 (unsigned)InitVal.getActiveBits()); 2923 else 2924 NumNegativeBits = std::max(NumNegativeBits, 2925 (unsigned)InitVal.getMinSignedBits()); 2926 2927 // Keep track of whether every enum element has type int (very commmon). 2928 if (AllElementsInt) 2929 AllElementsInt = ECD->getType() == Context.IntTy; 2930 2931 ECD->setNextDeclarator(EltList); 2932 EltList = ECD; 2933 } 2934 2935 // Figure out the type that should be used for this enum. 2936 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2937 QualType BestType; 2938 unsigned BestWidth; 2939 2940 if (NumNegativeBits) { 2941 // If there is a negative value, figure out the smallest integer type (of 2942 // int/long/longlong) that fits. 2943 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2944 BestType = Context.IntTy; 2945 BestWidth = IntWidth; 2946 } else { 2947 BestWidth = Context.Target.getLongWidth(); 2948 2949 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2950 BestType = Context.LongTy; 2951 else { 2952 BestWidth = Context.Target.getLongLongWidth(); 2953 2954 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2955 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2956 BestType = Context.LongLongTy; 2957 } 2958 } 2959 } else { 2960 // If there is no negative value, figure out which of uint, ulong, ulonglong 2961 // fits. 2962 if (NumPositiveBits <= IntWidth) { 2963 BestType = Context.UnsignedIntTy; 2964 BestWidth = IntWidth; 2965 } else if (NumPositiveBits <= 2966 (BestWidth = Context.Target.getLongWidth())) { 2967 BestType = Context.UnsignedLongTy; 2968 } else { 2969 BestWidth = Context.Target.getLongLongWidth(); 2970 assert(NumPositiveBits <= BestWidth && 2971 "How could an initializer get larger than ULL?"); 2972 BestType = Context.UnsignedLongLongTy; 2973 } 2974 } 2975 2976 // Loop over all of the enumerator constants, changing their types to match 2977 // the type of the enum if needed. 2978 for (unsigned i = 0; i != NumElements; ++i) { 2979 EnumConstantDecl *ECD = 2980 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2981 if (!ECD) continue; // Already issued a diagnostic. 2982 2983 // Standard C says the enumerators have int type, but we allow, as an 2984 // extension, the enumerators to be larger than int size. If each 2985 // enumerator value fits in an int, type it as an int, otherwise type it the 2986 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2987 // that X has type 'int', not 'unsigned'. 2988 if (ECD->getType() == Context.IntTy) { 2989 // Make sure the init value is signed. 2990 llvm::APSInt IV = ECD->getInitVal(); 2991 IV.setIsSigned(true); 2992 ECD->setInitVal(IV); 2993 continue; // Already int type. 2994 } 2995 2996 // Determine whether the value fits into an int. 2997 llvm::APSInt InitVal = ECD->getInitVal(); 2998 bool FitsInInt; 2999 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3000 FitsInInt = InitVal.getActiveBits() < IntWidth; 3001 else 3002 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3003 3004 // If it fits into an integer type, force it. Otherwise force it to match 3005 // the enum decl type. 3006 QualType NewTy; 3007 unsigned NewWidth; 3008 bool NewSign; 3009 if (FitsInInt) { 3010 NewTy = Context.IntTy; 3011 NewWidth = IntWidth; 3012 NewSign = true; 3013 } else if (ECD->getType() == BestType) { 3014 // Already the right type! 3015 continue; 3016 } else { 3017 NewTy = BestType; 3018 NewWidth = BestWidth; 3019 NewSign = BestType->isSignedIntegerType(); 3020 } 3021 3022 // Adjust the APSInt value. 3023 InitVal.extOrTrunc(NewWidth); 3024 InitVal.setIsSigned(NewSign); 3025 ECD->setInitVal(InitVal); 3026 3027 // Adjust the Expr initializer and type. 3028 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 3029 ECD->setType(NewTy); 3030 } 3031 3032 Enum->defineElements(EltList, BestType); 3033 Consumer.HandleTagDeclDefinition(Enum); 3034} 3035 3036Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3037 ExprTy *expr) { 3038 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3039 3040 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3041} 3042 3043Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3044 SourceLocation LBrace, 3045 SourceLocation RBrace, 3046 const char *Lang, 3047 unsigned StrSize, 3048 DeclTy *D) { 3049 LinkageSpecDecl::LanguageIDs Language; 3050 Decl *dcl = static_cast<Decl *>(D); 3051 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3052 Language = LinkageSpecDecl::lang_c; 3053 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3054 Language = LinkageSpecDecl::lang_cxx; 3055 else { 3056 Diag(Loc, diag::err_bad_language); 3057 return 0; 3058 } 3059 3060 // FIXME: Add all the various semantics of linkage specifications 3061 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3062} 3063 3064void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3065 ExprTy *alignment, SourceLocation PragmaLoc, 3066 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3067 Expr *Alignment = static_cast<Expr *>(alignment); 3068 3069 // If specified then alignment must be a "small" power of two. 3070 unsigned AlignmentVal = 0; 3071 if (Alignment) { 3072 llvm::APSInt Val; 3073 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3074 !Val.isPowerOf2() || 3075 Val.getZExtValue() > 16) { 3076 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3077 delete Alignment; 3078 return; // Ignore 3079 } 3080 3081 AlignmentVal = (unsigned) Val.getZExtValue(); 3082 } 3083 3084 switch (Kind) { 3085 case Action::PPK_Default: // pack([n]) 3086 PackContext.setAlignment(AlignmentVal); 3087 break; 3088 3089 case Action::PPK_Show: // pack(show) 3090 // Show the current alignment, making sure to show the right value 3091 // for the default. 3092 AlignmentVal = PackContext.getAlignment(); 3093 // FIXME: This should come from the target. 3094 if (AlignmentVal == 0) 3095 AlignmentVal = 8; 3096 Diag(PragmaLoc, diag::warn_pragma_pack_show, llvm::utostr(AlignmentVal)); 3097 break; 3098 3099 case Action::PPK_Push: // pack(push [, id] [, [n]) 3100 PackContext.push(Name); 3101 // Set the new alignment if specified. 3102 if (Alignment) 3103 PackContext.setAlignment(AlignmentVal); 3104 break; 3105 3106 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3107 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3108 // "#pragma pack(pop, identifier, n) is undefined" 3109 if (Alignment && Name) 3110 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3111 3112 // Do the pop. 3113 if (!PackContext.pop(Name)) { 3114 // If a name was specified then failure indicates the name 3115 // wasn't found. Otherwise failure indicates the stack was 3116 // empty. 3117 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3118 Name ? "no record matching name" : "stack empty"); 3119 3120 // FIXME: Warn about popping named records as MSVC does. 3121 } else { 3122 // Pop succeeded, set the new alignment if specified. 3123 if (Alignment) 3124 PackContext.setAlignment(AlignmentVal); 3125 } 3126 break; 3127 3128 default: 3129 assert(0 && "Invalid #pragma pack kind."); 3130 } 3131} 3132 3133bool PragmaPackStack::pop(IdentifierInfo *Name) { 3134 if (Stack.empty()) 3135 return false; 3136 3137 // If name is empty just pop top. 3138 if (!Name) { 3139 Alignment = Stack.back().first; 3140 Stack.pop_back(); 3141 return true; 3142 } 3143 3144 // Otherwise, find the named record. 3145 for (unsigned i = Stack.size(); i != 0; ) { 3146 --i; 3147 if (strcmp(Stack[i].second.c_str(), Name->getName()) == 0) { 3148 // Found it, pop up to and including this record. 3149 Alignment = Stack[i].first; 3150 Stack.erase(Stack.begin() + i, Stack.end()); 3151 return true; 3152 } 3153 } 3154 3155 return false; 3156} 3157