SemaDecl.cpp revision 1f6f54be86a514d531ec231fd837858a43cfe72e
1069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// 3069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// The LLVM Compiler Infrastructure 4069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// 5069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// This file is distributed under the University of Illinois Open Source 6069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// License. See LICENSE.TXT for details. 7069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// 8069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project//===----------------------------------------------------------------------===// 9069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// 10069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// This file implements semantic analysis for declarations. 11069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// 12069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project//===----------------------------------------------------------------------===// 13069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 14069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "Sema.h" 15069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/AST/APValue.h" 16069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/AST/ASTConsumer.h" 17069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/AST/ASTContext.h" 18069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/AST/DeclObjC.h" 19069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/AST/ExprCXX.h" 20069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/Parse/DeclSpec.h" 21069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/Basic/Diagnostic.h" 22069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/Basic/TargetInfo.h" 23069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/Basic/SourceManager.h" 24069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/Lex/Preprocessor.h" 26069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "clang/Lex/HeaderSearch.h" 27069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "llvm/ADT/SmallSet.h" 28069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project#include "llvm/ADT/StringExtras.h" 29069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Projectusing namespace clang; 30069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 31069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source ProjectSema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S, 32069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project const CXXScopeSpec *SS) { 33069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project DeclContext *DC = 0; 34069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project if (SS) { 35069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project if (SS->isInvalid()) 36069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project return 0; 37069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project DC = static_cast<DeclContext*>(SS->getScopeRep()); 38069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project } 39069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 40069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 41069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project if (IIDecl && (isa<TypedefDecl>(IIDecl) || 42069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project isa<ObjCInterfaceDecl>(IIDecl) || 43069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project isa<TagDecl>(IIDecl))) 44069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project return IIDecl; 45069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project return 0; 46069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project} 47069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 48069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Projectstd::string Sema::getTypeAsString(TypeTy *Type) { 49069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project QualType Ty = QualType::getFromOpaquePtr(Type); 50069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project return Ty.getAsString(); 51069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project} 52069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 53069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source ProjectDeclContext *Sema::getContainingDC(DeclContext *DC) { 54069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 55069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project // A C++ out-of-line method will return to the file declaration context. 56069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project if (MD->isOutOfLineDefinition()) 57069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project return MD->getLexicalDeclContext(); 58069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 59069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project // A C++ inline method is parsed *after* the topmost class it was declared in 60069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project // is fully parsed (it's "complete"). 61069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project // The parsing of a C++ inline method happens at the declaration context of 62069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project // the topmost (non-nested) class it is declared in. 63069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 64069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project DC = MD->getParent(); 65069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 66069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project DC = RD; 67069490a5ca2fd1988d29daf45d892f47ad665115The Android Open Source Project 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 DeclContext *LookupCtx, bool enableLazyBuiltinCreation) { 197 if (II == 0) return 0; 198 unsigned NS = NSI; 199 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 200 NS |= Decl::IDNS_Tag; 201 202 IdentifierResolver::iterator 203 I = LookupCtx ? IdResolver.begin(II, LookupCtx, false/*LookInParentCtx*/) : 204 IdResolver.begin(II, CurContext, true/*LookInParentCtx*/); 205 // Scan up the scope chain looking for a decl that matches this identifier 206 // that is in the appropriate namespace. This search should not take long, as 207 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 208 for (; I != IdResolver.end(); ++I) 209 if ((*I)->getIdentifierNamespace() & NS) 210 return *I; 211 212 // If we didn't find a use of this identifier, and if the identifier 213 // corresponds to a compiler builtin, create the decl object for the builtin 214 // now, injecting it into translation unit scope, and return it. 215 if (NS & Decl::IDNS_Ordinary) { 216 if (enableLazyBuiltinCreation && 217 (LookupCtx == 0 || isa<TranslationUnitDecl>(LookupCtx))) { 218 // If this is a builtin on this (or all) targets, create the decl. 219 if (unsigned BuiltinID = II->getBuiltinID()) 220 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 221 } 222 if (getLangOptions().ObjC1) { 223 // @interface and @compatibility_alias introduce typedef-like names. 224 // Unlike typedef's, they can only be introduced at file-scope (and are 225 // therefore not scoped decls). They can, however, be shadowed by 226 // other names in IDNS_Ordinary. 227 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 228 if (IDI != ObjCInterfaceDecls.end()) 229 return IDI->second; 230 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 231 if (I != ObjCAliasDecls.end()) 232 return I->second->getClassInterface(); 233 } 234 } 235 return 0; 236} 237 238void Sema::InitBuiltinVaListType() { 239 if (!Context.getBuiltinVaListType().isNull()) 240 return; 241 242 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 243 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 244 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 245 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 246} 247 248/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 249/// lazily create a decl for it. 250ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 251 Scope *S) { 252 Builtin::ID BID = (Builtin::ID)bid; 253 254 if (Context.BuiltinInfo.hasVAListUse(BID)) 255 InitBuiltinVaListType(); 256 257 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 258 FunctionDecl *New = FunctionDecl::Create(Context, 259 Context.getTranslationUnitDecl(), 260 SourceLocation(), II, R, 261 FunctionDecl::Extern, false, 0); 262 263 // Create Decl objects for each parameter, adding them to the 264 // FunctionDecl. 265 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 266 llvm::SmallVector<ParmVarDecl*, 16> Params; 267 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 268 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 269 FT->getArgType(i), VarDecl::None, 0, 270 0)); 271 New->setParams(&Params[0], Params.size()); 272 } 273 274 275 276 // TUScope is the translation-unit scope to insert this function into. 277 PushOnScopeChains(New, TUScope); 278 return New; 279} 280 281/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 282/// and scope as a previous declaration 'Old'. Figure out how to resolve this 283/// situation, merging decls or emitting diagnostics as appropriate. 284/// 285TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 286 // Allow multiple definitions for ObjC built-in typedefs. 287 // FIXME: Verify the underlying types are equivalent! 288 if (getLangOptions().ObjC1) { 289 const IdentifierInfo *typeIdent = New->getIdentifier(); 290 if (typeIdent == Ident_id) { 291 Context.setObjCIdType(New); 292 return New; 293 } else if (typeIdent == Ident_Class) { 294 Context.setObjCClassType(New); 295 return New; 296 } else if (typeIdent == Ident_SEL) { 297 Context.setObjCSelType(New); 298 return New; 299 } else if (typeIdent == Ident_Protocol) { 300 Context.setObjCProtoType(New->getUnderlyingType()); 301 return New; 302 } 303 // Fall through - the typedef name was not a builtin type. 304 } 305 // Verify the old decl was also a typedef. 306 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 307 if (!Old) { 308 Diag(New->getLocation(), diag::err_redefinition_different_kind, 309 New->getName()); 310 Diag(OldD->getLocation(), diag::err_previous_definition); 311 return New; 312 } 313 314 // If the typedef types are not identical, reject them in all languages and 315 // with any extensions enabled. 316 if (Old->getUnderlyingType() != New->getUnderlyingType() && 317 Context.getCanonicalType(Old->getUnderlyingType()) != 318 Context.getCanonicalType(New->getUnderlyingType())) { 319 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 320 New->getUnderlyingType().getAsString(), 321 Old->getUnderlyingType().getAsString()); 322 Diag(Old->getLocation(), diag::err_previous_definition); 323 return Old; 324 } 325 326 if (getLangOptions().Microsoft) return New; 327 328 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 329 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 330 // *either* declaration is in a system header. The code below implements 331 // this adhoc compatibility rule. FIXME: The following code will not 332 // work properly when compiling ".i" files (containing preprocessed output). 333 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 334 SourceManager &SrcMgr = Context.getSourceManager(); 335 if (SrcMgr.isInSystemHeader(Old->getLocation())) 336 return New; 337 if (SrcMgr.isInSystemHeader(New->getLocation())) 338 return New; 339 } 340 341 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 342 Diag(Old->getLocation(), diag::err_previous_definition); 343 return New; 344} 345 346/// DeclhasAttr - returns true if decl Declaration already has the target 347/// attribute. 348static bool DeclHasAttr(const Decl *decl, const Attr *target) { 349 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 350 if (attr->getKind() == target->getKind()) 351 return true; 352 353 return false; 354} 355 356/// MergeAttributes - append attributes from the Old decl to the New one. 357static void MergeAttributes(Decl *New, Decl *Old) { 358 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 359 360 while (attr) { 361 tmp = attr; 362 attr = attr->getNext(); 363 364 if (!DeclHasAttr(New, tmp)) { 365 New->addAttr(tmp); 366 } else { 367 tmp->setNext(0); 368 delete(tmp); 369 } 370 } 371 372 Old->invalidateAttrs(); 373} 374 375/// MergeFunctionDecl - We just parsed a function 'New' from 376/// declarator D which has the same name and scope as a previous 377/// declaration 'Old'. Figure out how to resolve this situation, 378/// merging decls or emitting diagnostics as appropriate. 379/// Redeclaration will be set true if this New is a redeclaration OldD. 380/// 381/// In C++, New and Old must be declarations that are not 382/// overloaded. Use IsOverload to determine whether New and Old are 383/// overloaded, and to select the Old declaration that New should be 384/// merged with. 385FunctionDecl * 386Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 387 assert(!isa<OverloadedFunctionDecl>(OldD) && 388 "Cannot merge with an overloaded function declaration"); 389 390 Redeclaration = false; 391 // Verify the old decl was also a function. 392 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 393 if (!Old) { 394 Diag(New->getLocation(), diag::err_redefinition_different_kind, 395 New->getName()); 396 Diag(OldD->getLocation(), diag::err_previous_definition); 397 return New; 398 } 399 400 // Determine whether the previous declaration was a definition, 401 // implicit declaration, or a declaration. 402 diag::kind PrevDiag; 403 if (Old->isThisDeclarationADefinition()) 404 PrevDiag = diag::err_previous_definition; 405 else if (Old->isImplicit()) 406 PrevDiag = diag::err_previous_implicit_declaration; 407 else 408 PrevDiag = diag::err_previous_declaration; 409 410 QualType OldQType = Context.getCanonicalType(Old->getType()); 411 QualType NewQType = Context.getCanonicalType(New->getType()); 412 413 if (getLangOptions().CPlusPlus) { 414 // (C++98 13.1p2): 415 // Certain function declarations cannot be overloaded: 416 // -- Function declarations that differ only in the return type 417 // cannot be overloaded. 418 QualType OldReturnType 419 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 420 QualType NewReturnType 421 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 422 if (OldReturnType != NewReturnType) { 423 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 424 Diag(Old->getLocation(), PrevDiag); 425 return New; 426 } 427 428 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 429 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 430 if (OldMethod && NewMethod) { 431 // -- Member function declarations with the same name and the 432 // same parameter types cannot be overloaded if any of them 433 // is a static member function declaration. 434 if (OldMethod->isStatic() || NewMethod->isStatic()) { 435 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 436 Diag(Old->getLocation(), PrevDiag); 437 return New; 438 } 439 } 440 441 // (C++98 8.3.5p3): 442 // All declarations for a function shall agree exactly in both the 443 // return type and the parameter-type-list. 444 if (OldQType == NewQType) { 445 // We have a redeclaration. 446 MergeAttributes(New, Old); 447 Redeclaration = true; 448 return MergeCXXFunctionDecl(New, Old); 449 } 450 451 // Fall through for conflicting redeclarations and redefinitions. 452 } 453 454 // C: Function types need to be compatible, not identical. This handles 455 // duplicate function decls like "void f(int); void f(enum X);" properly. 456 if (!getLangOptions().CPlusPlus && 457 Context.typesAreCompatible(OldQType, NewQType)) { 458 MergeAttributes(New, Old); 459 Redeclaration = true; 460 return New; 461 } 462 463 // A function that has already been declared has been redeclared or defined 464 // with a different type- show appropriate diagnostic 465 466 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 467 // TODO: This is totally simplistic. It should handle merging functions 468 // together etc, merging extern int X; int X; ... 469 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 470 Diag(Old->getLocation(), PrevDiag); 471 return New; 472} 473 474/// Predicate for C "tentative" external object definitions (C99 6.9.2). 475static bool isTentativeDefinition(VarDecl *VD) { 476 if (VD->isFileVarDecl()) 477 return (!VD->getInit() && 478 (VD->getStorageClass() == VarDecl::None || 479 VD->getStorageClass() == VarDecl::Static)); 480 return false; 481} 482 483/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 484/// when dealing with C "tentative" external object definitions (C99 6.9.2). 485void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 486 bool VDIsTentative = isTentativeDefinition(VD); 487 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 488 489 for (IdentifierResolver::iterator 490 I = IdResolver.begin(VD->getIdentifier(), 491 VD->getDeclContext(), false/*LookInParentCtx*/), 492 E = IdResolver.end(); I != E; ++I) { 493 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 494 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 495 496 // Handle the following case: 497 // int a[10]; 498 // int a[]; - the code below makes sure we set the correct type. 499 // int a[11]; - this is an error, size isn't 10. 500 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 501 OldDecl->getType()->isConstantArrayType()) 502 VD->setType(OldDecl->getType()); 503 504 // Check for "tentative" definitions. We can't accomplish this in 505 // MergeVarDecl since the initializer hasn't been attached. 506 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 507 continue; 508 509 // Handle __private_extern__ just like extern. 510 if (OldDecl->getStorageClass() != VarDecl::Extern && 511 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 512 VD->getStorageClass() != VarDecl::Extern && 513 VD->getStorageClass() != VarDecl::PrivateExtern) { 514 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 515 Diag(OldDecl->getLocation(), diag::err_previous_definition); 516 } 517 } 518 } 519} 520 521/// MergeVarDecl - We just parsed a variable 'New' which has the same name 522/// and scope as a previous declaration 'Old'. Figure out how to resolve this 523/// situation, merging decls or emitting diagnostics as appropriate. 524/// 525/// Tentative definition rules (C99 6.9.2p2) are checked by 526/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 527/// definitions here, since the initializer hasn't been attached. 528/// 529VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 530 // Verify the old decl was also a variable. 531 VarDecl *Old = dyn_cast<VarDecl>(OldD); 532 if (!Old) { 533 Diag(New->getLocation(), diag::err_redefinition_different_kind, 534 New->getName()); 535 Diag(OldD->getLocation(), diag::err_previous_definition); 536 return New; 537 } 538 539 MergeAttributes(New, Old); 540 541 // Verify the types match. 542 QualType OldCType = Context.getCanonicalType(Old->getType()); 543 QualType NewCType = Context.getCanonicalType(New->getType()); 544 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 545 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 546 Diag(Old->getLocation(), diag::err_previous_definition); 547 return New; 548 } 549 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 550 if (New->getStorageClass() == VarDecl::Static && 551 (Old->getStorageClass() == VarDecl::None || 552 Old->getStorageClass() == VarDecl::Extern)) { 553 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 554 Diag(Old->getLocation(), diag::err_previous_definition); 555 return New; 556 } 557 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 558 if (New->getStorageClass() != VarDecl::Static && 559 Old->getStorageClass() == VarDecl::Static) { 560 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 561 Diag(Old->getLocation(), diag::err_previous_definition); 562 return New; 563 } 564 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 565 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 566 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 567 Diag(Old->getLocation(), diag::err_previous_definition); 568 } 569 return New; 570} 571 572/// CheckParmsForFunctionDef - Check that the parameters of the given 573/// function are appropriate for the definition of a function. This 574/// takes care of any checks that cannot be performed on the 575/// declaration itself, e.g., that the types of each of the function 576/// parameters are complete. 577bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 578 bool HasInvalidParm = false; 579 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 580 ParmVarDecl *Param = FD->getParamDecl(p); 581 582 // C99 6.7.5.3p4: the parameters in a parameter type list in a 583 // function declarator that is part of a function definition of 584 // that function shall not have incomplete type. 585 if (Param->getType()->isIncompleteType() && 586 !Param->isInvalidDecl()) { 587 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 588 Param->getType().getAsString()); 589 Param->setInvalidDecl(); 590 HasInvalidParm = true; 591 } 592 } 593 594 return HasInvalidParm; 595} 596 597/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 598/// no declarator (e.g. "struct foo;") is parsed. 599Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 600 // TODO: emit error on 'int;' or 'const enum foo;'. 601 // TODO: emit error on 'typedef int;' 602 // if (!DS.isMissingDeclaratorOk()) Diag(...); 603 604 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 605} 606 607bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 608 // Get the type before calling CheckSingleAssignmentConstraints(), since 609 // it can promote the expression. 610 QualType InitType = Init->getType(); 611 612 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 613 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 614 InitType, Init, "initializing"); 615} 616 617bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 618 const ArrayType *AT = Context.getAsArrayType(DeclT); 619 620 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 621 // C99 6.7.8p14. We have an array of character type with unknown size 622 // being initialized to a string literal. 623 llvm::APSInt ConstVal(32); 624 ConstVal = strLiteral->getByteLength() + 1; 625 // Return a new array type (C99 6.7.8p22). 626 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 627 ArrayType::Normal, 0); 628 } else { 629 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 630 // C99 6.7.8p14. We have an array of character type with known size. 631 // FIXME: Avoid truncation for 64-bit length strings. 632 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 633 Diag(strLiteral->getSourceRange().getBegin(), 634 diag::warn_initializer_string_for_char_array_too_long, 635 strLiteral->getSourceRange()); 636 } 637 // Set type from "char *" to "constant array of char". 638 strLiteral->setType(DeclT); 639 // For now, we always return false (meaning success). 640 return false; 641} 642 643StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 644 const ArrayType *AT = Context.getAsArrayType(DeclType); 645 if (AT && AT->getElementType()->isCharType()) { 646 return dyn_cast<StringLiteral>(Init); 647 } 648 return 0; 649} 650 651bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 652 SourceLocation InitLoc, 653 std::string InitEntity) { 654 // C++ [dcl.init.ref]p1: 655 // A variable declared to be a T&, that is “reference to type T” 656 // (8.3.2), shall be initialized by an object, or function, of 657 // type T or by an object that can be converted into a T. 658 if (DeclType->isReferenceType()) 659 return CheckReferenceInit(Init, DeclType); 660 661 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 662 // of unknown size ("[]") or an object type that is not a variable array type. 663 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 664 return Diag(InitLoc, 665 diag::err_variable_object_no_init, 666 VAT->getSizeExpr()->getSourceRange()); 667 668 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 669 if (!InitList) { 670 // FIXME: Handle wide strings 671 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 672 return CheckStringLiteralInit(strLiteral, DeclType); 673 674 // C++ [dcl.init]p14: 675 // -- If the destination type is a (possibly cv-qualified) class 676 // type: 677 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 678 QualType DeclTypeC = Context.getCanonicalType(DeclType); 679 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 680 681 // -- If the initialization is direct-initialization, or if it is 682 // copy-initialization where the cv-unqualified version of the 683 // source type is the same class as, or a derived class of, the 684 // class of the destination, constructors are considered. 685 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 686 IsDerivedFrom(InitTypeC, DeclTypeC)) { 687 CXXConstructorDecl *Constructor 688 = PerformInitializationByConstructor(DeclType, &Init, 1, 689 InitLoc, Init->getSourceRange(), 690 InitEntity, IK_Copy); 691 return Constructor == 0; 692 } 693 694 // -- Otherwise (i.e., for the remaining copy-initialization 695 // cases), user-defined conversion sequences that can 696 // convert from the source type to the destination type or 697 // (when a conversion function is used) to a derived class 698 // thereof are enumerated as described in 13.3.1.4, and the 699 // best one is chosen through overload resolution 700 // (13.3). If the conversion cannot be done or is 701 // ambiguous, the initialization is ill-formed. The 702 // function selected is called with the initializer 703 // expression as its argument; if the function is a 704 // constructor, the call initializes a temporary of the 705 // destination type. 706 // FIXME: We're pretending to do copy elision here; return to 707 // this when we have ASTs for such things. 708 if (PerformImplicitConversion(Init, DeclType)) 709 return Diag(InitLoc, 710 diag::err_typecheck_convert_incompatible, 711 DeclType.getAsString(), InitEntity, 712 "initializing", 713 Init->getSourceRange()); 714 else 715 return false; 716 } 717 718 // C99 6.7.8p16. 719 if (DeclType->isArrayType()) 720 return Diag(Init->getLocStart(), 721 diag::err_array_init_list_required, 722 Init->getSourceRange()); 723 724 return CheckSingleInitializer(Init, DeclType); 725 } else if (getLangOptions().CPlusPlus) { 726 // C++ [dcl.init]p14: 727 // [...] If the class is an aggregate (8.5.1), and the initializer 728 // is a brace-enclosed list, see 8.5.1. 729 // 730 // Note: 8.5.1 is handled below; here, we diagnose the case where 731 // we have an initializer list and a destination type that is not 732 // an aggregate. 733 // FIXME: In C++0x, this is yet another form of initialization. 734 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 735 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 736 if (!ClassDecl->isAggregate()) 737 return Diag(InitLoc, 738 diag::err_init_non_aggr_init_list, 739 DeclType.getAsString(), 740 Init->getSourceRange()); 741 } 742 } 743 744 InitListChecker CheckInitList(this, InitList, DeclType); 745 return CheckInitList.HadError(); 746} 747 748Sema::DeclTy * 749Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 750 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 751 IdentifierInfo *II = D.getIdentifier(); 752 753 // All of these full declarators require an identifier. If it doesn't have 754 // one, the ParsedFreeStandingDeclSpec action should be used. 755 if (II == 0) { 756 if (!D.getInvalidType()) // Reject this if we think it is valid. 757 Diag(D.getDeclSpec().getSourceRange().getBegin(), 758 diag::err_declarator_need_ident, 759 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 760 return 0; 761 } 762 763 // The scope passed in may not be a decl scope. Zip up the scope tree until 764 // we find one that is. 765 while ((S->getFlags() & Scope::DeclScope) == 0) 766 S = S->getParent(); 767 768 DeclContext *DC; 769 Decl *PrevDecl; 770 ScopedDecl *New; 771 bool InvalidDecl = false; 772 773 // See if this is a redefinition of a variable in the same scope. 774 if (!D.getCXXScopeSpec().isSet()) { 775 DC = CurContext; 776 PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 777 } else { // Something like "int foo::x;" 778 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 779 PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S, DC); 780 781 // C++ 7.3.1.2p2: 782 // Members (including explicit specializations of templates) of a named 783 // namespace can also be defined outside that namespace by explicit 784 // qualification of the name being defined, provided that the entity being 785 // defined was already declared in the namespace and the definition appears 786 // after the point of declaration in a namespace that encloses the 787 // declarations namespace. 788 // 789 if (PrevDecl == 0) { 790 // No previous declaration in the qualifying scope. 791 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member, 792 II->getName(), D.getCXXScopeSpec().getRange()); 793 } else if (!CurContext->Encloses(DC)) { 794 // The qualifying scope doesn't enclose the original declaration. 795 // Emit diagnostic based on current scope. 796 SourceLocation L = D.getIdentifierLoc(); 797 SourceRange R = D.getCXXScopeSpec().getRange(); 798 if (isa<FunctionDecl>(CurContext)) { 799 Diag(L, diag::err_invalid_declarator_in_function, II->getName(), R); 800 } else { 801 Diag(L, diag::err_invalid_declarator_scope, II->getName(), 802 cast<NamedDecl>(DC)->getName(), R); 803 } 804 } 805 } 806 807 // In C++, the previous declaration we find might be a tag type 808 // (class or enum). In this case, the new declaration will hide the 809 // tag type. 810 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 811 PrevDecl = 0; 812 813 QualType R = GetTypeForDeclarator(D, S); 814 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 815 816 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 817 // Check that there are no default arguments (C++ only). 818 if (getLangOptions().CPlusPlus) 819 CheckExtraCXXDefaultArguments(D); 820 821 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 822 if (!NewTD) return 0; 823 824 // Handle attributes prior to checking for duplicates in MergeVarDecl 825 ProcessDeclAttributes(NewTD, D); 826 // Merge the decl with the existing one if appropriate. If the decl is 827 // in an outer scope, it isn't the same thing. 828 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 829 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 830 if (NewTD == 0) return 0; 831 } 832 New = NewTD; 833 if (S->getFnParent() == 0) { 834 // C99 6.7.7p2: If a typedef name specifies a variably modified type 835 // then it shall have block scope. 836 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 837 // FIXME: Diagnostic needs to be fixed. 838 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 839 InvalidDecl = true; 840 } 841 } 842 } else if (R.getTypePtr()->isFunctionType()) { 843 FunctionDecl::StorageClass SC = FunctionDecl::None; 844 switch (D.getDeclSpec().getStorageClassSpec()) { 845 default: assert(0 && "Unknown storage class!"); 846 case DeclSpec::SCS_auto: 847 case DeclSpec::SCS_register: 848 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 849 R.getAsString()); 850 InvalidDecl = true; 851 break; 852 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 853 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 854 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 855 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 856 } 857 858 bool isInline = D.getDeclSpec().isInlineSpecified(); 859 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 860 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 861 862 FunctionDecl *NewFD; 863 if (D.getKind() == Declarator::DK_Constructor) { 864 // This is a C++ constructor declaration. 865 assert(DC->isCXXRecord() && 866 "Constructors can only be declared in a member context"); 867 868 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 869 870 // Create the new declaration 871 NewFD = CXXConstructorDecl::Create(Context, 872 cast<CXXRecordDecl>(DC), 873 D.getIdentifierLoc(), II, R, 874 isExplicit, isInline, 875 /*isImplicitlyDeclared=*/false); 876 877 if (isInvalidDecl) 878 NewFD->setInvalidDecl(); 879 } else if (D.getKind() == Declarator::DK_Destructor) { 880 // This is a C++ destructor declaration. 881 if (DC->isCXXRecord()) { 882 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 883 884 NewFD = CXXDestructorDecl::Create(Context, 885 cast<CXXRecordDecl>(DC), 886 D.getIdentifierLoc(), II, R, 887 isInline, 888 /*isImplicitlyDeclared=*/false); 889 890 if (isInvalidDecl) 891 NewFD->setInvalidDecl(); 892 } else { 893 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 894 // Create a FunctionDecl to satisfy the function definition parsing 895 // code path. 896 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 897 II, R, SC, isInline, LastDeclarator, 898 // FIXME: Move to DeclGroup... 899 D.getDeclSpec().getSourceRange().getBegin()); 900 NewFD->setInvalidDecl(); 901 } 902 } else if (D.getKind() == Declarator::DK_Conversion) { 903 if (!DC->isCXXRecord()) { 904 Diag(D.getIdentifierLoc(), 905 diag::err_conv_function_not_member); 906 return 0; 907 } else { 908 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 909 910 NewFD = CXXConversionDecl::Create(Context, 911 cast<CXXRecordDecl>(DC), 912 D.getIdentifierLoc(), II, R, 913 isInline, isExplicit); 914 915 if (isInvalidDecl) 916 NewFD->setInvalidDecl(); 917 } 918 } else if (DC->isCXXRecord()) { 919 // This is a C++ method declaration. 920 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 921 D.getIdentifierLoc(), II, R, 922 (SC == FunctionDecl::Static), isInline, 923 LastDeclarator); 924 } else { 925 NewFD = FunctionDecl::Create(Context, DC, 926 D.getIdentifierLoc(), 927 II, R, SC, isInline, LastDeclarator, 928 // FIXME: Move to DeclGroup... 929 D.getDeclSpec().getSourceRange().getBegin()); 930 } 931 // Handle attributes. 932 ProcessDeclAttributes(NewFD, D); 933 934 // Handle GNU asm-label extension (encoded as an attribute). 935 if (Expr *E = (Expr*) D.getAsmLabel()) { 936 // The parser guarantees this is a string. 937 StringLiteral *SE = cast<StringLiteral>(E); 938 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 939 SE->getByteLength()))); 940 } 941 942 // Copy the parameter declarations from the declarator D to 943 // the function declaration NewFD, if they are available. 944 if (D.getNumTypeObjects() > 0) { 945 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 946 947 // Create Decl objects for each parameter, adding them to the 948 // FunctionDecl. 949 llvm::SmallVector<ParmVarDecl*, 16> Params; 950 951 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 952 // function that takes no arguments, not a function that takes a 953 // single void argument. 954 // We let through "const void" here because Sema::GetTypeForDeclarator 955 // already checks for that case. 956 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 957 FTI.ArgInfo[0].Param && 958 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 959 // empty arg list, don't push any params. 960 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 961 962 // In C++, the empty parameter-type-list must be spelled "void"; a 963 // typedef of void is not permitted. 964 if (getLangOptions().CPlusPlus && 965 Param->getType().getUnqualifiedType() != Context.VoidTy) { 966 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 967 } 968 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 969 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 970 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 971 } 972 973 NewFD->setParams(&Params[0], Params.size()); 974 } else if (R->getAsTypedefType()) { 975 // When we're declaring a function with a typedef, as in the 976 // following example, we'll need to synthesize (unnamed) 977 // parameters for use in the declaration. 978 // 979 // @code 980 // typedef void fn(int); 981 // fn f; 982 // @endcode 983 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 984 if (!FT) { 985 // This is a typedef of a function with no prototype, so we 986 // don't need to do anything. 987 } else if ((FT->getNumArgs() == 0) || 988 (FT->getNumArgs() == 1 && !FT->isVariadic() && 989 FT->getArgType(0)->isVoidType())) { 990 // This is a zero-argument function. We don't need to do anything. 991 } else { 992 // Synthesize a parameter for each argument type. 993 llvm::SmallVector<ParmVarDecl*, 16> Params; 994 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 995 ArgType != FT->arg_type_end(); ++ArgType) { 996 Params.push_back(ParmVarDecl::Create(Context, DC, 997 SourceLocation(), 0, 998 *ArgType, VarDecl::None, 999 0, 0)); 1000 } 1001 1002 NewFD->setParams(&Params[0], Params.size()); 1003 } 1004 } 1005 1006 // C++ constructors and destructors are handled by separate 1007 // routines, since they don't require any declaration merging (C++ 1008 // [class.mfct]p2) and they aren't ever pushed into scope, because 1009 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1010 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1011 return ActOnConstructorDeclarator(Constructor); 1012 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1013 return ActOnDestructorDeclarator(Destructor); 1014 else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1015 return ActOnConversionDeclarator(Conversion); 1016 1017 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1018 if (NewFD->isOverloadedOperator() && 1019 CheckOverloadedOperatorDeclaration(NewFD)) 1020 NewFD->setInvalidDecl(); 1021 1022 // Merge the decl with the existing one if appropriate. Since C functions 1023 // are in a flat namespace, make sure we consider decls in outer scopes. 1024 if (PrevDecl && 1025 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1026 bool Redeclaration = false; 1027 1028 // If C++, determine whether NewFD is an overload of PrevDecl or 1029 // a declaration that requires merging. If it's an overload, 1030 // there's no more work to do here; we'll just add the new 1031 // function to the scope. 1032 OverloadedFunctionDecl::function_iterator MatchedDecl; 1033 if (!getLangOptions().CPlusPlus || 1034 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1035 Decl *OldDecl = PrevDecl; 1036 1037 // If PrevDecl was an overloaded function, extract the 1038 // FunctionDecl that matched. 1039 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1040 OldDecl = *MatchedDecl; 1041 1042 // NewFD and PrevDecl represent declarations that need to be 1043 // merged. 1044 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1045 1046 if (NewFD == 0) return 0; 1047 if (Redeclaration) { 1048 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1049 1050 if (OldDecl == PrevDecl) { 1051 // Remove the name binding for the previous 1052 // declaration. We'll add the binding back later, but then 1053 // it will refer to the new declaration (which will 1054 // contain more information). 1055 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1056 } else { 1057 // We need to update the OverloadedFunctionDecl with the 1058 // latest declaration of this function, so that name 1059 // lookup will always refer to the latest declaration of 1060 // this function. 1061 *MatchedDecl = NewFD; 1062 1063 // Add the redeclaration to the current scope, since we'll 1064 // be skipping PushOnScopeChains. 1065 S->AddDecl(NewFD); 1066 1067 return NewFD; 1068 } 1069 } 1070 } 1071 } 1072 New = NewFD; 1073 1074 // In C++, check default arguments now that we have merged decls. 1075 if (getLangOptions().CPlusPlus) 1076 CheckCXXDefaultArguments(NewFD); 1077 } else { 1078 // Check that there are no default arguments (C++ only). 1079 if (getLangOptions().CPlusPlus) 1080 CheckExtraCXXDefaultArguments(D); 1081 1082 if (R.getTypePtr()->isObjCInterfaceType()) { 1083 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 1084 D.getIdentifier()->getName()); 1085 InvalidDecl = true; 1086 } 1087 1088 VarDecl *NewVD; 1089 VarDecl::StorageClass SC; 1090 switch (D.getDeclSpec().getStorageClassSpec()) { 1091 default: assert(0 && "Unknown storage class!"); 1092 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1093 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1094 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1095 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1096 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1097 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1098 } 1099 if (DC->isCXXRecord()) { 1100 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1101 // This is a static data member for a C++ class. 1102 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1103 D.getIdentifierLoc(), II, 1104 R, LastDeclarator); 1105 } else { 1106 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1107 if (S->getFnParent() == 0) { 1108 // C99 6.9p2: The storage-class specifiers auto and register shall not 1109 // appear in the declaration specifiers in an external declaration. 1110 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1111 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 1112 R.getAsString()); 1113 InvalidDecl = true; 1114 } 1115 } 1116 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1117 II, R, SC, LastDeclarator, 1118 // FIXME: Move to DeclGroup... 1119 D.getDeclSpec().getSourceRange().getBegin()); 1120 NewVD->setThreadSpecified(ThreadSpecified); 1121 } 1122 // Handle attributes prior to checking for duplicates in MergeVarDecl 1123 ProcessDeclAttributes(NewVD, D); 1124 1125 // Handle GNU asm-label extension (encoded as an attribute). 1126 if (Expr *E = (Expr*) D.getAsmLabel()) { 1127 // The parser guarantees this is a string. 1128 StringLiteral *SE = cast<StringLiteral>(E); 1129 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1130 SE->getByteLength()))); 1131 } 1132 1133 // Emit an error if an address space was applied to decl with local storage. 1134 // This includes arrays of objects with address space qualifiers, but not 1135 // automatic variables that point to other address spaces. 1136 // ISO/IEC TR 18037 S5.1.2 1137 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1138 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1139 InvalidDecl = true; 1140 } 1141 // Merge the decl with the existing one if appropriate. If the decl is 1142 // in an outer scope, it isn't the same thing. 1143 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1144 NewVD = MergeVarDecl(NewVD, PrevDecl); 1145 if (NewVD == 0) return 0; 1146 } 1147 New = NewVD; 1148 } 1149 1150 // Set the lexical context. If the declarator has a C++ scope specifier, the 1151 // lexical context will be different from the semantic context. 1152 New->setLexicalDeclContext(CurContext); 1153 1154 // If this has an identifier, add it to the scope stack. 1155 if (II) 1156 PushOnScopeChains(New, S); 1157 // If any semantic error occurred, mark the decl as invalid. 1158 if (D.getInvalidType() || InvalidDecl) 1159 New->setInvalidDecl(); 1160 1161 return New; 1162} 1163 1164void Sema::InitializerElementNotConstant(const Expr *Init) { 1165 Diag(Init->getExprLoc(), 1166 diag::err_init_element_not_constant, Init->getSourceRange()); 1167} 1168 1169bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1170 switch (Init->getStmtClass()) { 1171 default: 1172 InitializerElementNotConstant(Init); 1173 return true; 1174 case Expr::ParenExprClass: { 1175 const ParenExpr* PE = cast<ParenExpr>(Init); 1176 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1177 } 1178 case Expr::CompoundLiteralExprClass: 1179 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1180 case Expr::DeclRefExprClass: { 1181 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1182 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1183 if (VD->hasGlobalStorage()) 1184 return false; 1185 InitializerElementNotConstant(Init); 1186 return true; 1187 } 1188 if (isa<FunctionDecl>(D)) 1189 return false; 1190 InitializerElementNotConstant(Init); 1191 return true; 1192 } 1193 case Expr::MemberExprClass: { 1194 const MemberExpr *M = cast<MemberExpr>(Init); 1195 if (M->isArrow()) 1196 return CheckAddressConstantExpression(M->getBase()); 1197 return CheckAddressConstantExpressionLValue(M->getBase()); 1198 } 1199 case Expr::ArraySubscriptExprClass: { 1200 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1201 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1202 return CheckAddressConstantExpression(ASE->getBase()) || 1203 CheckArithmeticConstantExpression(ASE->getIdx()); 1204 } 1205 case Expr::StringLiteralClass: 1206 case Expr::PredefinedExprClass: 1207 return false; 1208 case Expr::UnaryOperatorClass: { 1209 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1210 1211 // C99 6.6p9 1212 if (Exp->getOpcode() == UnaryOperator::Deref) 1213 return CheckAddressConstantExpression(Exp->getSubExpr()); 1214 1215 InitializerElementNotConstant(Init); 1216 return true; 1217 } 1218 } 1219} 1220 1221bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1222 switch (Init->getStmtClass()) { 1223 default: 1224 InitializerElementNotConstant(Init); 1225 return true; 1226 case Expr::ParenExprClass: 1227 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1228 case Expr::StringLiteralClass: 1229 case Expr::ObjCStringLiteralClass: 1230 return false; 1231 case Expr::CallExprClass: 1232 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1233 if (cast<CallExpr>(Init)->isBuiltinCall() == 1234 Builtin::BI__builtin___CFStringMakeConstantString) 1235 return false; 1236 1237 InitializerElementNotConstant(Init); 1238 return true; 1239 1240 case Expr::UnaryOperatorClass: { 1241 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1242 1243 // C99 6.6p9 1244 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1245 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1246 1247 if (Exp->getOpcode() == UnaryOperator::Extension) 1248 return CheckAddressConstantExpression(Exp->getSubExpr()); 1249 1250 InitializerElementNotConstant(Init); 1251 return true; 1252 } 1253 case Expr::BinaryOperatorClass: { 1254 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1255 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1256 1257 Expr *PExp = Exp->getLHS(); 1258 Expr *IExp = Exp->getRHS(); 1259 if (IExp->getType()->isPointerType()) 1260 std::swap(PExp, IExp); 1261 1262 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1263 return CheckAddressConstantExpression(PExp) || 1264 CheckArithmeticConstantExpression(IExp); 1265 } 1266 case Expr::ImplicitCastExprClass: 1267 case Expr::CStyleCastExprClass: { 1268 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1269 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1270 // Check for implicit promotion 1271 if (SubExpr->getType()->isFunctionType() || 1272 SubExpr->getType()->isArrayType()) 1273 return CheckAddressConstantExpressionLValue(SubExpr); 1274 } 1275 1276 // Check for pointer->pointer cast 1277 if (SubExpr->getType()->isPointerType()) 1278 return CheckAddressConstantExpression(SubExpr); 1279 1280 if (SubExpr->getType()->isIntegralType()) { 1281 // Check for the special-case of a pointer->int->pointer cast; 1282 // this isn't standard, but some code requires it. See 1283 // PR2720 for an example. 1284 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1285 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1286 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1287 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1288 if (IntWidth >= PointerWidth) { 1289 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1290 } 1291 } 1292 } 1293 } 1294 if (SubExpr->getType()->isArithmeticType()) { 1295 return CheckArithmeticConstantExpression(SubExpr); 1296 } 1297 1298 InitializerElementNotConstant(Init); 1299 return true; 1300 } 1301 case Expr::ConditionalOperatorClass: { 1302 // FIXME: Should we pedwarn here? 1303 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1304 if (!Exp->getCond()->getType()->isArithmeticType()) { 1305 InitializerElementNotConstant(Init); 1306 return true; 1307 } 1308 if (CheckArithmeticConstantExpression(Exp->getCond())) 1309 return true; 1310 if (Exp->getLHS() && 1311 CheckAddressConstantExpression(Exp->getLHS())) 1312 return true; 1313 return CheckAddressConstantExpression(Exp->getRHS()); 1314 } 1315 case Expr::AddrLabelExprClass: 1316 return false; 1317 } 1318} 1319 1320static const Expr* FindExpressionBaseAddress(const Expr* E); 1321 1322static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1323 switch (E->getStmtClass()) { 1324 default: 1325 return E; 1326 case Expr::ParenExprClass: { 1327 const ParenExpr* PE = cast<ParenExpr>(E); 1328 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1329 } 1330 case Expr::MemberExprClass: { 1331 const MemberExpr *M = cast<MemberExpr>(E); 1332 if (M->isArrow()) 1333 return FindExpressionBaseAddress(M->getBase()); 1334 return FindExpressionBaseAddressLValue(M->getBase()); 1335 } 1336 case Expr::ArraySubscriptExprClass: { 1337 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1338 return FindExpressionBaseAddress(ASE->getBase()); 1339 } 1340 case Expr::UnaryOperatorClass: { 1341 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1342 1343 if (Exp->getOpcode() == UnaryOperator::Deref) 1344 return FindExpressionBaseAddress(Exp->getSubExpr()); 1345 1346 return E; 1347 } 1348 } 1349} 1350 1351static const Expr* FindExpressionBaseAddress(const Expr* E) { 1352 switch (E->getStmtClass()) { 1353 default: 1354 return E; 1355 case Expr::ParenExprClass: { 1356 const ParenExpr* PE = cast<ParenExpr>(E); 1357 return FindExpressionBaseAddress(PE->getSubExpr()); 1358 } 1359 case Expr::UnaryOperatorClass: { 1360 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1361 1362 // C99 6.6p9 1363 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1364 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1365 1366 if (Exp->getOpcode() == UnaryOperator::Extension) 1367 return FindExpressionBaseAddress(Exp->getSubExpr()); 1368 1369 return E; 1370 } 1371 case Expr::BinaryOperatorClass: { 1372 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1373 1374 Expr *PExp = Exp->getLHS(); 1375 Expr *IExp = Exp->getRHS(); 1376 if (IExp->getType()->isPointerType()) 1377 std::swap(PExp, IExp); 1378 1379 return FindExpressionBaseAddress(PExp); 1380 } 1381 case Expr::ImplicitCastExprClass: { 1382 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1383 1384 // Check for implicit promotion 1385 if (SubExpr->getType()->isFunctionType() || 1386 SubExpr->getType()->isArrayType()) 1387 return FindExpressionBaseAddressLValue(SubExpr); 1388 1389 // Check for pointer->pointer cast 1390 if (SubExpr->getType()->isPointerType()) 1391 return FindExpressionBaseAddress(SubExpr); 1392 1393 // We assume that we have an arithmetic expression here; 1394 // if we don't, we'll figure it out later 1395 return 0; 1396 } 1397 case Expr::CStyleCastExprClass: { 1398 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1399 1400 // Check for pointer->pointer cast 1401 if (SubExpr->getType()->isPointerType()) 1402 return FindExpressionBaseAddress(SubExpr); 1403 1404 // We assume that we have an arithmetic expression here; 1405 // if we don't, we'll figure it out later 1406 return 0; 1407 } 1408 } 1409} 1410 1411bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1412 switch (Init->getStmtClass()) { 1413 default: 1414 InitializerElementNotConstant(Init); 1415 return true; 1416 case Expr::ParenExprClass: { 1417 const ParenExpr* PE = cast<ParenExpr>(Init); 1418 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1419 } 1420 case Expr::FloatingLiteralClass: 1421 case Expr::IntegerLiteralClass: 1422 case Expr::CharacterLiteralClass: 1423 case Expr::ImaginaryLiteralClass: 1424 case Expr::TypesCompatibleExprClass: 1425 case Expr::CXXBoolLiteralExprClass: 1426 return false; 1427 case Expr::CallExprClass: { 1428 const CallExpr *CE = cast<CallExpr>(Init); 1429 1430 // Allow any constant foldable calls to builtins. 1431 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1432 return false; 1433 1434 InitializerElementNotConstant(Init); 1435 return true; 1436 } 1437 case Expr::DeclRefExprClass: { 1438 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1439 if (isa<EnumConstantDecl>(D)) 1440 return false; 1441 InitializerElementNotConstant(Init); 1442 return true; 1443 } 1444 case Expr::CompoundLiteralExprClass: 1445 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1446 // but vectors are allowed to be magic. 1447 if (Init->getType()->isVectorType()) 1448 return false; 1449 InitializerElementNotConstant(Init); 1450 return true; 1451 case Expr::UnaryOperatorClass: { 1452 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1453 1454 switch (Exp->getOpcode()) { 1455 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1456 // See C99 6.6p3. 1457 default: 1458 InitializerElementNotConstant(Init); 1459 return true; 1460 case UnaryOperator::SizeOf: 1461 case UnaryOperator::AlignOf: 1462 case UnaryOperator::OffsetOf: 1463 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1464 // See C99 6.5.3.4p2 and 6.6p3. 1465 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1466 return false; 1467 InitializerElementNotConstant(Init); 1468 return true; 1469 case UnaryOperator::Extension: 1470 case UnaryOperator::LNot: 1471 case UnaryOperator::Plus: 1472 case UnaryOperator::Minus: 1473 case UnaryOperator::Not: 1474 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1475 } 1476 } 1477 case Expr::SizeOfAlignOfTypeExprClass: { 1478 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1479 // Special check for void types, which are allowed as an extension 1480 if (Exp->getArgumentType()->isVoidType()) 1481 return false; 1482 // alignof always evaluates to a constant. 1483 // FIXME: is sizeof(int[3.0]) a constant expression? 1484 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1485 InitializerElementNotConstant(Init); 1486 return true; 1487 } 1488 return false; 1489 } 1490 case Expr::BinaryOperatorClass: { 1491 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1492 1493 if (Exp->getLHS()->getType()->isArithmeticType() && 1494 Exp->getRHS()->getType()->isArithmeticType()) { 1495 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1496 CheckArithmeticConstantExpression(Exp->getRHS()); 1497 } 1498 1499 if (Exp->getLHS()->getType()->isPointerType() && 1500 Exp->getRHS()->getType()->isPointerType()) { 1501 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1502 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1503 1504 // Only allow a null (constant integer) base; we could 1505 // allow some additional cases if necessary, but this 1506 // is sufficient to cover offsetof-like constructs. 1507 if (!LHSBase && !RHSBase) { 1508 return CheckAddressConstantExpression(Exp->getLHS()) || 1509 CheckAddressConstantExpression(Exp->getRHS()); 1510 } 1511 } 1512 1513 InitializerElementNotConstant(Init); 1514 return true; 1515 } 1516 case Expr::ImplicitCastExprClass: 1517 case Expr::CStyleCastExprClass: { 1518 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1519 if (SubExpr->getType()->isArithmeticType()) 1520 return CheckArithmeticConstantExpression(SubExpr); 1521 1522 if (SubExpr->getType()->isPointerType()) { 1523 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1524 // If the pointer has a null base, this is an offsetof-like construct 1525 if (!Base) 1526 return CheckAddressConstantExpression(SubExpr); 1527 } 1528 1529 InitializerElementNotConstant(Init); 1530 return true; 1531 } 1532 case Expr::ConditionalOperatorClass: { 1533 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1534 1535 // If GNU extensions are disabled, we require all operands to be arithmetic 1536 // constant expressions. 1537 if (getLangOptions().NoExtensions) { 1538 return CheckArithmeticConstantExpression(Exp->getCond()) || 1539 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1540 CheckArithmeticConstantExpression(Exp->getRHS()); 1541 } 1542 1543 // Otherwise, we have to emulate some of the behavior of fold here. 1544 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1545 // because it can constant fold things away. To retain compatibility with 1546 // GCC code, we see if we can fold the condition to a constant (which we 1547 // should always be able to do in theory). If so, we only require the 1548 // specified arm of the conditional to be a constant. This is a horrible 1549 // hack, but is require by real world code that uses __builtin_constant_p. 1550 APValue Val; 1551 if (!Exp->getCond()->tryEvaluate(Val, Context)) { 1552 // If the tryEvaluate couldn't fold it, CheckArithmeticConstantExpression 1553 // won't be able to either. Use it to emit the diagnostic though. 1554 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1555 assert(Res && "tryEvaluate couldn't evaluate this constant?"); 1556 return Res; 1557 } 1558 1559 // Verify that the side following the condition is also a constant. 1560 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1561 if (Val.getInt() == 0) 1562 std::swap(TrueSide, FalseSide); 1563 1564 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1565 return true; 1566 1567 // Okay, the evaluated side evaluates to a constant, so we accept this. 1568 // Check to see if the other side is obviously not a constant. If so, 1569 // emit a warning that this is a GNU extension. 1570 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1571 Diag(Init->getExprLoc(), 1572 diag::ext_typecheck_expression_not_constant_but_accepted, 1573 FalseSide->getSourceRange()); 1574 return false; 1575 } 1576 } 1577} 1578 1579bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1580 Init = Init->IgnoreParens(); 1581 1582 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1583 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1584 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1585 1586 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1587 return CheckForConstantInitializer(e->getInitializer(), DclT); 1588 1589 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1590 unsigned numInits = Exp->getNumInits(); 1591 for (unsigned i = 0; i < numInits; i++) { 1592 // FIXME: Need to get the type of the declaration for C++, 1593 // because it could be a reference? 1594 if (CheckForConstantInitializer(Exp->getInit(i), 1595 Exp->getInit(i)->getType())) 1596 return true; 1597 } 1598 return false; 1599 } 1600 1601 if (Init->isNullPointerConstant(Context)) 1602 return false; 1603 if (Init->getType()->isArithmeticType()) { 1604 QualType InitTy = Context.getCanonicalType(Init->getType()) 1605 .getUnqualifiedType(); 1606 if (InitTy == Context.BoolTy) { 1607 // Special handling for pointers implicitly cast to bool; 1608 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1609 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1610 Expr* SubE = ICE->getSubExpr(); 1611 if (SubE->getType()->isPointerType() || 1612 SubE->getType()->isArrayType() || 1613 SubE->getType()->isFunctionType()) { 1614 return CheckAddressConstantExpression(Init); 1615 } 1616 } 1617 } else if (InitTy->isIntegralType()) { 1618 Expr* SubE = 0; 1619 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1620 SubE = CE->getSubExpr(); 1621 // Special check for pointer cast to int; we allow as an extension 1622 // an address constant cast to an integer if the integer 1623 // is of an appropriate width (this sort of code is apparently used 1624 // in some places). 1625 // FIXME: Add pedwarn? 1626 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1627 if (SubE && (SubE->getType()->isPointerType() || 1628 SubE->getType()->isArrayType() || 1629 SubE->getType()->isFunctionType())) { 1630 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1631 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1632 if (IntWidth >= PointerWidth) 1633 return CheckAddressConstantExpression(Init); 1634 } 1635 } 1636 1637 return CheckArithmeticConstantExpression(Init); 1638 } 1639 1640 if (Init->getType()->isPointerType()) 1641 return CheckAddressConstantExpression(Init); 1642 1643 // An array type at the top level that isn't an init-list must 1644 // be a string literal 1645 if (Init->getType()->isArrayType()) 1646 return false; 1647 1648 if (Init->getType()->isFunctionType()) 1649 return false; 1650 1651 // Allow block exprs at top level. 1652 if (Init->getType()->isBlockPointerType()) 1653 return false; 1654 1655 InitializerElementNotConstant(Init); 1656 return true; 1657} 1658 1659void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1660 Decl *RealDecl = static_cast<Decl *>(dcl); 1661 Expr *Init = static_cast<Expr *>(init); 1662 assert(Init && "missing initializer"); 1663 1664 // If there is no declaration, there was an error parsing it. Just ignore 1665 // the initializer. 1666 if (RealDecl == 0) { 1667 delete Init; 1668 return; 1669 } 1670 1671 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1672 if (!VDecl) { 1673 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1674 diag::err_illegal_initializer); 1675 RealDecl->setInvalidDecl(); 1676 return; 1677 } 1678 // Get the decls type and save a reference for later, since 1679 // CheckInitializerTypes may change it. 1680 QualType DclT = VDecl->getType(), SavT = DclT; 1681 if (VDecl->isBlockVarDecl()) { 1682 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1683 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1684 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1685 VDecl->setInvalidDecl(); 1686 } else if (!VDecl->isInvalidDecl()) { 1687 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1688 VDecl->getName())) 1689 VDecl->setInvalidDecl(); 1690 1691 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1692 if (!getLangOptions().CPlusPlus) { 1693 if (SC == VarDecl::Static) // C99 6.7.8p4. 1694 CheckForConstantInitializer(Init, DclT); 1695 } 1696 } 1697 } else if (VDecl->isFileVarDecl()) { 1698 if (VDecl->getStorageClass() == VarDecl::Extern) 1699 Diag(VDecl->getLocation(), diag::warn_extern_init); 1700 if (!VDecl->isInvalidDecl()) 1701 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1702 VDecl->getName())) 1703 VDecl->setInvalidDecl(); 1704 1705 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1706 if (!getLangOptions().CPlusPlus) { 1707 // C99 6.7.8p4. All file scoped initializers need to be constant. 1708 CheckForConstantInitializer(Init, DclT); 1709 } 1710 } 1711 // If the type changed, it means we had an incomplete type that was 1712 // completed by the initializer. For example: 1713 // int ary[] = { 1, 3, 5 }; 1714 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1715 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1716 VDecl->setType(DclT); 1717 Init->setType(DclT); 1718 } 1719 1720 // Attach the initializer to the decl. 1721 VDecl->setInit(Init); 1722 return; 1723} 1724 1725void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1726 Decl *RealDecl = static_cast<Decl *>(dcl); 1727 1728 // If there is no declaration, there was an error parsing it. Just ignore it. 1729 if (RealDecl == 0) 1730 return; 1731 1732 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1733 QualType Type = Var->getType(); 1734 // C++ [dcl.init.ref]p3: 1735 // The initializer can be omitted for a reference only in a 1736 // parameter declaration (8.3.5), in the declaration of a 1737 // function return type, in the declaration of a class member 1738 // within its class declaration (9.2), and where the extern 1739 // specifier is explicitly used. 1740 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1741 Diag(Var->getLocation(), 1742 diag::err_reference_var_requires_init, 1743 Var->getName(), 1744 SourceRange(Var->getLocation(), Var->getLocation())); 1745 Var->setInvalidDecl(); 1746 return; 1747 } 1748 1749 // C++ [dcl.init]p9: 1750 // 1751 // If no initializer is specified for an object, and the object 1752 // is of (possibly cv-qualified) non-POD class type (or array 1753 // thereof), the object shall be default-initialized; if the 1754 // object is of const-qualified type, the underlying class type 1755 // shall have a user-declared default constructor. 1756 if (getLangOptions().CPlusPlus) { 1757 QualType InitType = Type; 1758 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1759 InitType = Array->getElementType(); 1760 if (InitType->isRecordType()) { 1761 const CXXConstructorDecl *Constructor 1762 = PerformInitializationByConstructor(InitType, 0, 0, 1763 Var->getLocation(), 1764 SourceRange(Var->getLocation(), 1765 Var->getLocation()), 1766 Var->getName(), 1767 IK_Default); 1768 if (!Constructor) 1769 Var->setInvalidDecl(); 1770 } 1771 } 1772 1773#if 0 1774 // FIXME: Temporarily disabled because we are not properly parsing 1775 // linkage specifications on declarations, e.g., 1776 // 1777 // extern "C" const CGPoint CGPointerZero; 1778 // 1779 // C++ [dcl.init]p9: 1780 // 1781 // If no initializer is specified for an object, and the 1782 // object is of (possibly cv-qualified) non-POD class type (or 1783 // array thereof), the object shall be default-initialized; if 1784 // the object is of const-qualified type, the underlying class 1785 // type shall have a user-declared default 1786 // constructor. Otherwise, if no initializer is specified for 1787 // an object, the object and its subobjects, if any, have an 1788 // indeterminate initial value; if the object or any of its 1789 // subobjects are of const-qualified type, the program is 1790 // ill-formed. 1791 // 1792 // This isn't technically an error in C, so we don't diagnose it. 1793 // 1794 // FIXME: Actually perform the POD/user-defined default 1795 // constructor check. 1796 if (getLangOptions().CPlusPlus && 1797 Context.getCanonicalType(Type).isConstQualified() && 1798 Var->getStorageClass() != VarDecl::Extern) 1799 Diag(Var->getLocation(), 1800 diag::err_const_var_requires_init, 1801 Var->getName(), 1802 SourceRange(Var->getLocation(), Var->getLocation())); 1803#endif 1804 } 1805} 1806 1807/// The declarators are chained together backwards, reverse the list. 1808Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1809 // Often we have single declarators, handle them quickly. 1810 Decl *GroupDecl = static_cast<Decl*>(group); 1811 if (GroupDecl == 0) 1812 return 0; 1813 1814 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1815 ScopedDecl *NewGroup = 0; 1816 if (Group->getNextDeclarator() == 0) 1817 NewGroup = Group; 1818 else { // reverse the list. 1819 while (Group) { 1820 ScopedDecl *Next = Group->getNextDeclarator(); 1821 Group->setNextDeclarator(NewGroup); 1822 NewGroup = Group; 1823 Group = Next; 1824 } 1825 } 1826 // Perform semantic analysis that depends on having fully processed both 1827 // the declarator and initializer. 1828 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1829 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1830 if (!IDecl) 1831 continue; 1832 QualType T = IDecl->getType(); 1833 1834 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1835 // static storage duration, it shall not have a variable length array. 1836 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1837 IDecl->getStorageClass() == VarDecl::Static) { 1838 if (T->isVariableArrayType()) { 1839 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1840 IDecl->setInvalidDecl(); 1841 } 1842 } 1843 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1844 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1845 if (IDecl->isBlockVarDecl() && 1846 IDecl->getStorageClass() != VarDecl::Extern) { 1847 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1848 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1849 T.getAsString()); 1850 IDecl->setInvalidDecl(); 1851 } 1852 } 1853 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1854 // object that has file scope without an initializer, and without a 1855 // storage-class specifier or with the storage-class specifier "static", 1856 // constitutes a tentative definition. Note: A tentative definition with 1857 // external linkage is valid (C99 6.2.2p5). 1858 if (isTentativeDefinition(IDecl)) { 1859 if (T->isIncompleteArrayType()) { 1860 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1861 // array to be completed. Don't issue a diagnostic. 1862 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1863 // C99 6.9.2p3: If the declaration of an identifier for an object is 1864 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1865 // declared type shall not be an incomplete type. 1866 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1867 T.getAsString()); 1868 IDecl->setInvalidDecl(); 1869 } 1870 } 1871 if (IDecl->isFileVarDecl()) 1872 CheckForFileScopedRedefinitions(S, IDecl); 1873 } 1874 return NewGroup; 1875} 1876 1877/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1878/// to introduce parameters into function prototype scope. 1879Sema::DeclTy * 1880Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1881 // FIXME: disallow CXXScopeSpec for param declarators. 1882 const DeclSpec &DS = D.getDeclSpec(); 1883 1884 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1885 VarDecl::StorageClass StorageClass = VarDecl::None; 1886 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1887 StorageClass = VarDecl::Register; 1888 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1889 Diag(DS.getStorageClassSpecLoc(), 1890 diag::err_invalid_storage_class_in_func_decl); 1891 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1892 } 1893 if (DS.isThreadSpecified()) { 1894 Diag(DS.getThreadSpecLoc(), 1895 diag::err_invalid_storage_class_in_func_decl); 1896 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1897 } 1898 1899 // Check that there are no default arguments inside the type of this 1900 // parameter (C++ only). 1901 if (getLangOptions().CPlusPlus) 1902 CheckExtraCXXDefaultArguments(D); 1903 1904 // In this context, we *do not* check D.getInvalidType(). If the declarator 1905 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1906 // though it will not reflect the user specified type. 1907 QualType parmDeclType = GetTypeForDeclarator(D, S); 1908 1909 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1910 1911 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1912 // Can this happen for params? We already checked that they don't conflict 1913 // among each other. Here they can only shadow globals, which is ok. 1914 IdentifierInfo *II = D.getIdentifier(); 1915 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1916 if (S->isDeclScope(PrevDecl)) { 1917 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1918 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1919 1920 // Recover by removing the name 1921 II = 0; 1922 D.SetIdentifier(0, D.getIdentifierLoc()); 1923 } 1924 } 1925 1926 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1927 // Doing the promotion here has a win and a loss. The win is the type for 1928 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1929 // code generator). The loss is the orginal type isn't preserved. For example: 1930 // 1931 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1932 // int blockvardecl[5]; 1933 // sizeof(parmvardecl); // size == 4 1934 // sizeof(blockvardecl); // size == 20 1935 // } 1936 // 1937 // For expressions, all implicit conversions are captured using the 1938 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1939 // 1940 // FIXME: If a source translation tool needs to see the original type, then 1941 // we need to consider storing both types (in ParmVarDecl)... 1942 // 1943 if (parmDeclType->isArrayType()) { 1944 // int x[restrict 4] -> int *restrict 1945 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1946 } else if (parmDeclType->isFunctionType()) 1947 parmDeclType = Context.getPointerType(parmDeclType); 1948 1949 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1950 D.getIdentifierLoc(), II, 1951 parmDeclType, StorageClass, 1952 0, 0); 1953 1954 if (D.getInvalidType()) 1955 New->setInvalidDecl(); 1956 1957 if (II) 1958 PushOnScopeChains(New, S); 1959 1960 ProcessDeclAttributes(New, D); 1961 return New; 1962 1963} 1964 1965Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1966 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1967 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1968 "Not a function declarator!"); 1969 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1970 1971 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1972 // for a K&R function. 1973 if (!FTI.hasPrototype) { 1974 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1975 if (FTI.ArgInfo[i].Param == 0) { 1976 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1977 FTI.ArgInfo[i].Ident->getName()); 1978 // Implicitly declare the argument as type 'int' for lack of a better 1979 // type. 1980 DeclSpec DS; 1981 const char* PrevSpec; // unused 1982 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1983 PrevSpec); 1984 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1985 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1986 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1987 } 1988 } 1989 } else { 1990 // FIXME: Diagnose arguments without names in C. 1991 } 1992 1993 Scope *GlobalScope = FnBodyScope->getParent(); 1994 1995 return ActOnStartOfFunctionDef(FnBodyScope, 1996 ActOnDeclarator(GlobalScope, D, 0)); 1997} 1998 1999Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2000 Decl *decl = static_cast<Decl*>(D); 2001 FunctionDecl *FD = cast<FunctionDecl>(decl); 2002 2003 // See if this is a redefinition. 2004 const FunctionDecl *Definition; 2005 if (FD->getBody(Definition)) { 2006 Diag(FD->getLocation(), diag::err_redefinition, 2007 FD->getName()); 2008 Diag(Definition->getLocation(), diag::err_previous_definition); 2009 } 2010 2011 PushDeclContext(FD); 2012 2013 // Check the validity of our function parameters 2014 CheckParmsForFunctionDef(FD); 2015 2016 // Introduce our parameters into the function scope 2017 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2018 ParmVarDecl *Param = FD->getParamDecl(p); 2019 // If this has an identifier, add it to the scope stack. 2020 if (Param->getIdentifier()) 2021 PushOnScopeChains(Param, FnBodyScope); 2022 } 2023 2024 return FD; 2025} 2026 2027Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2028 Decl *dcl = static_cast<Decl *>(D); 2029 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2030 FD->setBody((Stmt*)Body); 2031 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2032 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2033 MD->setBody((Stmt*)Body); 2034 } else 2035 return 0; 2036 PopDeclContext(); 2037 // Verify and clean out per-function state. 2038 2039 // Check goto/label use. 2040 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2041 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2042 // Verify that we have no forward references left. If so, there was a goto 2043 // or address of a label taken, but no definition of it. Label fwd 2044 // definitions are indicated with a null substmt. 2045 if (I->second->getSubStmt() == 0) { 2046 LabelStmt *L = I->second; 2047 // Emit error. 2048 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2049 2050 // At this point, we have gotos that use the bogus label. Stitch it into 2051 // the function body so that they aren't leaked and that the AST is well 2052 // formed. 2053 if (Body) { 2054 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2055 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2056 } else { 2057 // The whole function wasn't parsed correctly, just delete this. 2058 delete L; 2059 } 2060 } 2061 } 2062 LabelMap.clear(); 2063 2064 return D; 2065} 2066 2067/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2068/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2069ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2070 IdentifierInfo &II, Scope *S) { 2071 // Extension in C99. Legal in C90, but warn about it. 2072 if (getLangOptions().C99) 2073 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 2074 else 2075 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 2076 2077 // FIXME: handle stuff like: 2078 // void foo() { extern float X(); } 2079 // void bar() { X(); } <-- implicit decl for X in another scope. 2080 2081 // Set a Declarator for the implicit definition: int foo(); 2082 const char *Dummy; 2083 DeclSpec DS; 2084 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2085 Error = Error; // Silence warning. 2086 assert(!Error && "Error setting up implicit decl!"); 2087 Declarator D(DS, Declarator::BlockContext); 2088 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2089 D.SetIdentifier(&II, Loc); 2090 2091 // Insert this function into translation-unit scope. 2092 2093 DeclContext *PrevDC = CurContext; 2094 CurContext = Context.getTranslationUnitDecl(); 2095 2096 FunctionDecl *FD = 2097 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2098 FD->setImplicit(); 2099 2100 CurContext = PrevDC; 2101 2102 return FD; 2103} 2104 2105 2106TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2107 ScopedDecl *LastDeclarator) { 2108 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2109 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2110 2111 // Scope manipulation handled by caller. 2112 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2113 D.getIdentifierLoc(), 2114 D.getIdentifier(), 2115 T, LastDeclarator); 2116 if (D.getInvalidType()) 2117 NewTD->setInvalidDecl(); 2118 return NewTD; 2119} 2120 2121/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2122/// former case, Name will be non-null. In the later case, Name will be null. 2123/// TagType indicates what kind of tag this is. TK indicates whether this is a 2124/// reference/declaration/definition of a tag. 2125Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2126 SourceLocation KWLoc, const CXXScopeSpec &SS, 2127 IdentifierInfo *Name, SourceLocation NameLoc, 2128 AttributeList *Attr) { 2129 // If this is a use of an existing tag, it must have a name. 2130 assert((Name != 0 || TK == TK_Definition) && 2131 "Nameless record must be a definition!"); 2132 2133 TagDecl::TagKind Kind; 2134 switch (TagType) { 2135 default: assert(0 && "Unknown tag type!"); 2136 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2137 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2138 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2139 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2140 } 2141 2142 // Two code paths: a new one for structs/unions/classes where we create 2143 // separate decls for forward declarations, and an old (eventually to 2144 // be removed) code path for enums. 2145 if (Kind != TagDecl::TK_enum) 2146 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2147 2148 DeclContext *DC = CurContext; 2149 ScopedDecl *PrevDecl = 0; 2150 2151 if (Name && SS.isNotEmpty()) { 2152 // We have a nested-name tag ('struct foo::bar'). 2153 2154 // Check for invalid 'foo::'. 2155 if (SS.isInvalid()) { 2156 Name = 0; 2157 goto CreateNewDecl; 2158 } 2159 2160 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2161 // Look-up name inside 'foo::'. 2162 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2163 2164 // A tag 'foo::bar' must already exist. 2165 if (PrevDecl == 0) { 2166 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2167 SS.getRange()); 2168 Name = 0; 2169 goto CreateNewDecl; 2170 } 2171 } else { 2172 // If this is a named struct, check to see if there was a previous forward 2173 // declaration or definition. 2174 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2175 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2176 } 2177 2178 if (PrevDecl) { 2179 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2180 "unexpected Decl type"); 2181 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2182 // If this is a use of a previous tag, or if the tag is already declared 2183 // in the same scope (so that the definition/declaration completes or 2184 // rementions the tag), reuse the decl. 2185 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2186 // Make sure that this wasn't declared as an enum and now used as a 2187 // struct or something similar. 2188 if (PrevTagDecl->getTagKind() != Kind) { 2189 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2190 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2191 // Recover by making this an anonymous redefinition. 2192 Name = 0; 2193 PrevDecl = 0; 2194 } else { 2195 // If this is a use or a forward declaration, we're good. 2196 if (TK != TK_Definition) 2197 return PrevDecl; 2198 2199 // Diagnose attempts to redefine a tag. 2200 if (PrevTagDecl->isDefinition()) { 2201 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2202 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2203 // If this is a redefinition, recover by making this struct be 2204 // anonymous, which will make any later references get the previous 2205 // definition. 2206 Name = 0; 2207 } else { 2208 // Okay, this is definition of a previously declared or referenced 2209 // tag. Move the location of the decl to be the definition site. 2210 PrevDecl->setLocation(NameLoc); 2211 return PrevDecl; 2212 } 2213 } 2214 } 2215 // If we get here, this is a definition of a new struct type in a nested 2216 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2217 // type. 2218 } else { 2219 // PrevDecl is a namespace. 2220 if (isDeclInScope(PrevDecl, DC, S)) { 2221 // The tag name clashes with a namespace name, issue an error and 2222 // recover by making this tag be anonymous. 2223 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2224 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2225 Name = 0; 2226 } 2227 } 2228 } 2229 2230 CreateNewDecl: 2231 2232 // If there is an identifier, use the location of the identifier as the 2233 // location of the decl, otherwise use the location of the struct/union 2234 // keyword. 2235 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2236 2237 // Otherwise, if this is the first time we've seen this tag, create the decl. 2238 TagDecl *New; 2239 if (Kind == TagDecl::TK_enum) { 2240 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2241 // enum X { A, B, C } D; D should chain to X. 2242 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2243 // If this is an undefined enum, warn. 2244 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2245 } else { 2246 // struct/union/class 2247 2248 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2249 // struct X { int A; } D; D should chain to X. 2250 if (getLangOptions().CPlusPlus) 2251 // FIXME: Look for a way to use RecordDecl for simple structs. 2252 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2253 else 2254 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2255 } 2256 2257 // If this has an identifier, add it to the scope stack. 2258 if (Name) { 2259 // The scope passed in may not be a decl scope. Zip up the scope tree until 2260 // we find one that is. 2261 while ((S->getFlags() & Scope::DeclScope) == 0) 2262 S = S->getParent(); 2263 2264 // Add it to the decl chain. 2265 PushOnScopeChains(New, S); 2266 } 2267 2268 if (Attr) 2269 ProcessDeclAttributeList(New, Attr); 2270 2271 // Set the lexical context. If the tag has a C++ scope specifier, the 2272 // lexical context will be different from the semantic context. 2273 New->setLexicalDeclContext(CurContext); 2274 2275 return New; 2276} 2277 2278/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2279/// the logic for enums, we create separate decls for forward declarations. 2280/// This is called by ActOnTag, but eventually will replace its logic. 2281Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2282 SourceLocation KWLoc, const CXXScopeSpec &SS, 2283 IdentifierInfo *Name, SourceLocation NameLoc, 2284 AttributeList *Attr) { 2285 DeclContext *DC = CurContext; 2286 ScopedDecl *PrevDecl = 0; 2287 2288 if (Name && SS.isNotEmpty()) { 2289 // We have a nested-name tag ('struct foo::bar'). 2290 2291 // Check for invalid 'foo::'. 2292 if (SS.isInvalid()) { 2293 Name = 0; 2294 goto CreateNewDecl; 2295 } 2296 2297 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2298 // Look-up name inside 'foo::'. 2299 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2300 2301 // A tag 'foo::bar' must already exist. 2302 if (PrevDecl == 0) { 2303 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2304 SS.getRange()); 2305 Name = 0; 2306 goto CreateNewDecl; 2307 } 2308 } else { 2309 // If this is a named struct, check to see if there was a previous forward 2310 // declaration or definition. 2311 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2312 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2313 } 2314 2315 if (PrevDecl) { 2316 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2317 "unexpected Decl type"); 2318 2319 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2320 // If this is a use of a previous tag, or if the tag is already declared 2321 // in the same scope (so that the definition/declaration completes or 2322 // rementions the tag), reuse the decl. 2323 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2324 // Make sure that this wasn't declared as an enum and now used as a 2325 // struct or something similar. 2326 if (PrevTagDecl->getTagKind() != Kind) { 2327 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2328 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2329 // Recover by making this an anonymous redefinition. 2330 Name = 0; 2331 PrevDecl = 0; 2332 } else { 2333 // If this is a use, return the original decl. 2334 2335 // FIXME: In the future, return a variant or some other clue 2336 // for the consumer of this Decl to know it doesn't own it. 2337 // For our current ASTs this shouldn't be a problem, but will 2338 // need to be changed with DeclGroups. 2339 if (TK == TK_Reference) 2340 return PrevDecl; 2341 2342 // The new decl is a definition? 2343 if (TK == TK_Definition) { 2344 // Diagnose attempts to redefine a tag. 2345 if (RecordDecl* DefRecord = 2346 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2347 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2348 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2349 // If this is a redefinition, recover by making this struct be 2350 // anonymous, which will make any later references get the previous 2351 // definition. 2352 Name = 0; 2353 PrevDecl = 0; 2354 } 2355 // Okay, this is definition of a previously declared or referenced 2356 // tag. We're going to create a new Decl. 2357 } 2358 } 2359 // If we get here we have (another) forward declaration. Just create 2360 // a new decl. 2361 } 2362 else { 2363 // If we get here, this is a definition of a new struct type in a nested 2364 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2365 // new decl/type. We set PrevDecl to NULL so that the Records 2366 // have distinct types. 2367 PrevDecl = 0; 2368 } 2369 } else { 2370 // PrevDecl is a namespace. 2371 if (isDeclInScope(PrevDecl, DC, S)) { 2372 // The tag name clashes with a namespace name, issue an error and 2373 // recover by making this tag be anonymous. 2374 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2375 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2376 Name = 0; 2377 } 2378 } 2379 } 2380 2381 CreateNewDecl: 2382 2383 // If there is an identifier, use the location of the identifier as the 2384 // location of the decl, otherwise use the location of the struct/union 2385 // keyword. 2386 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2387 2388 // Otherwise, if this is the first time we've seen this tag, create the decl. 2389 TagDecl *New; 2390 2391 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2392 // struct X { int A; } D; D should chain to X. 2393 if (getLangOptions().CPlusPlus) 2394 // FIXME: Look for a way to use RecordDecl for simple structs. 2395 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2396 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2397 else 2398 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2399 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2400 2401 // If this has an identifier, add it to the scope stack. 2402 if ((TK == TK_Definition || !PrevDecl) && Name) { 2403 // The scope passed in may not be a decl scope. Zip up the scope tree until 2404 // we find one that is. 2405 while ((S->getFlags() & Scope::DeclScope) == 0) 2406 S = S->getParent(); 2407 2408 // Add it to the decl chain. 2409 PushOnScopeChains(New, S); 2410 } 2411 2412 // Handle #pragma pack: if the #pragma pack stack has non-default 2413 // alignment, make up a packed attribute for this decl. These 2414 // attributes are checked when the ASTContext lays out the 2415 // structure. 2416 // 2417 // It is important for implementing the correct semantics that this 2418 // happen here (in act on tag decl). The #pragma pack stack is 2419 // maintained as a result of parser callbacks which can occur at 2420 // many points during the parsing of a struct declaration (because 2421 // the #pragma tokens are effectively skipped over during the 2422 // parsing of the struct). 2423 if (unsigned Alignment = PackContext.getAlignment()) 2424 New->addAttr(new PackedAttr(Alignment * 8)); 2425 2426 if (Attr) 2427 ProcessDeclAttributeList(New, Attr); 2428 2429 // Set the lexical context. If the tag has a C++ scope specifier, the 2430 // lexical context will be different from the semantic context. 2431 New->setLexicalDeclContext(CurContext); 2432 2433 return New; 2434} 2435 2436 2437/// Collect the instance variables declared in an Objective-C object. Used in 2438/// the creation of structures from objects using the @defs directive. 2439static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2440 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2441 if (Class->getSuperClass()) 2442 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2443 2444 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2445 for (ObjCInterfaceDecl::ivar_iterator 2446 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2447 2448 ObjCIvarDecl* ID = *I; 2449 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2450 ID->getIdentifier(), 2451 ID->getType(), 2452 ID->getBitWidth())); 2453 } 2454} 2455 2456/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2457/// instance variables of ClassName into Decls. 2458void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2459 IdentifierInfo *ClassName, 2460 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2461 // Check that ClassName is a valid class 2462 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2463 if (!Class) { 2464 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 2465 return; 2466 } 2467 // Collect the instance variables 2468 CollectIvars(Class, Context, Decls); 2469} 2470 2471QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 2472 // This method tries to turn a variable array into a constant 2473 // array even when the size isn't an ICE. This is necessary 2474 // for compatibility with code that depends on gcc's buggy 2475 // constant expression folding, like struct {char x[(int)(char*)2];} 2476 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 2477 APValue Result; 2478 if (VLATy->getSizeExpr() && 2479 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 2480 llvm::APSInt &Res = Result.getInt(); 2481 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2482 return Context.getConstantArrayType(VLATy->getElementType(), 2483 Res, ArrayType::Normal, 0); 2484 } 2485 } 2486 return QualType(); 2487} 2488 2489/// ActOnField - Each field of a struct/union/class is passed into this in order 2490/// to create a FieldDecl object for it. 2491Sema::DeclTy *Sema::ActOnField(Scope *S, 2492 SourceLocation DeclStart, 2493 Declarator &D, ExprTy *BitfieldWidth) { 2494 IdentifierInfo *II = D.getIdentifier(); 2495 Expr *BitWidth = (Expr*)BitfieldWidth; 2496 SourceLocation Loc = DeclStart; 2497 if (II) Loc = D.getIdentifierLoc(); 2498 2499 // FIXME: Unnamed fields can be handled in various different ways, for 2500 // example, unnamed unions inject all members into the struct namespace! 2501 2502 if (BitWidth) { 2503 // TODO: Validate. 2504 //printf("WARNING: BITFIELDS IGNORED!\n"); 2505 2506 // 6.7.2.1p3 2507 // 6.7.2.1p4 2508 2509 } else { 2510 // Not a bitfield. 2511 2512 // validate II. 2513 2514 } 2515 2516 QualType T = GetTypeForDeclarator(D, S); 2517 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2518 bool InvalidDecl = false; 2519 2520 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2521 // than a variably modified type. 2522 if (T->isVariablyModifiedType()) { 2523 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 2524 if (!FixedTy.isNull()) { 2525 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 2526 T = FixedTy; 2527 } else { 2528 // FIXME: This diagnostic needs work 2529 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2530 InvalidDecl = true; 2531 } 2532 } 2533 // FIXME: Chain fielddecls together. 2534 FieldDecl *NewFD; 2535 2536 if (getLangOptions().CPlusPlus) { 2537 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2538 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2539 Loc, II, T, BitWidth); 2540 if (II) 2541 PushOnScopeChains(NewFD, S); 2542 } 2543 else 2544 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2545 2546 ProcessDeclAttributes(NewFD, D); 2547 2548 if (D.getInvalidType() || InvalidDecl) 2549 NewFD->setInvalidDecl(); 2550 return NewFD; 2551} 2552 2553/// TranslateIvarVisibility - Translate visibility from a token ID to an 2554/// AST enum value. 2555static ObjCIvarDecl::AccessControl 2556TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2557 switch (ivarVisibility) { 2558 default: assert(0 && "Unknown visitibility kind"); 2559 case tok::objc_private: return ObjCIvarDecl::Private; 2560 case tok::objc_public: return ObjCIvarDecl::Public; 2561 case tok::objc_protected: return ObjCIvarDecl::Protected; 2562 case tok::objc_package: return ObjCIvarDecl::Package; 2563 } 2564} 2565 2566/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2567/// in order to create an IvarDecl object for it. 2568Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2569 SourceLocation DeclStart, 2570 Declarator &D, ExprTy *BitfieldWidth, 2571 tok::ObjCKeywordKind Visibility) { 2572 IdentifierInfo *II = D.getIdentifier(); 2573 Expr *BitWidth = (Expr*)BitfieldWidth; 2574 SourceLocation Loc = DeclStart; 2575 if (II) Loc = D.getIdentifierLoc(); 2576 2577 // FIXME: Unnamed fields can be handled in various different ways, for 2578 // example, unnamed unions inject all members into the struct namespace! 2579 2580 2581 if (BitWidth) { 2582 // TODO: Validate. 2583 //printf("WARNING: BITFIELDS IGNORED!\n"); 2584 2585 // 6.7.2.1p3 2586 // 6.7.2.1p4 2587 2588 } else { 2589 // Not a bitfield. 2590 2591 // validate II. 2592 2593 } 2594 2595 QualType T = GetTypeForDeclarator(D, S); 2596 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2597 bool InvalidDecl = false; 2598 2599 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2600 // than a variably modified type. 2601 if (T->isVariablyModifiedType()) { 2602 // FIXME: This diagnostic needs work 2603 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2604 InvalidDecl = true; 2605 } 2606 2607 // Get the visibility (access control) for this ivar. 2608 ObjCIvarDecl::AccessControl ac = 2609 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2610 : ObjCIvarDecl::None; 2611 2612 // Construct the decl. 2613 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2614 (Expr *)BitfieldWidth); 2615 2616 // Process attributes attached to the ivar. 2617 ProcessDeclAttributes(NewID, D); 2618 2619 if (D.getInvalidType() || InvalidDecl) 2620 NewID->setInvalidDecl(); 2621 2622 return NewID; 2623} 2624 2625void Sema::ActOnFields(Scope* S, 2626 SourceLocation RecLoc, DeclTy *RecDecl, 2627 DeclTy **Fields, unsigned NumFields, 2628 SourceLocation LBrac, SourceLocation RBrac, 2629 AttributeList *Attr) { 2630 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2631 assert(EnclosingDecl && "missing record or interface decl"); 2632 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2633 2634 if (Record) 2635 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2636 // Diagnose code like: 2637 // struct S { struct S {} X; }; 2638 // We discover this when we complete the outer S. Reject and ignore the 2639 // outer S. 2640 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2641 DefRecord->getKindName()); 2642 Diag(RecLoc, diag::err_previous_definition); 2643 Record->setInvalidDecl(); 2644 return; 2645 } 2646 2647 // Verify that all the fields are okay. 2648 unsigned NumNamedMembers = 0; 2649 llvm::SmallVector<FieldDecl*, 32> RecFields; 2650 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2651 2652 for (unsigned i = 0; i != NumFields; ++i) { 2653 2654 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2655 assert(FD && "missing field decl"); 2656 2657 // Remember all fields. 2658 RecFields.push_back(FD); 2659 2660 // Get the type for the field. 2661 Type *FDTy = FD->getType().getTypePtr(); 2662 2663 // C99 6.7.2.1p2 - A field may not be a function type. 2664 if (FDTy->isFunctionType()) { 2665 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2666 FD->getName()); 2667 FD->setInvalidDecl(); 2668 EnclosingDecl->setInvalidDecl(); 2669 continue; 2670 } 2671 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2672 if (FDTy->isIncompleteType()) { 2673 if (!Record) { // Incomplete ivar type is always an error. 2674 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2675 FD->setInvalidDecl(); 2676 EnclosingDecl->setInvalidDecl(); 2677 continue; 2678 } 2679 if (i != NumFields-1 || // ... that the last member ... 2680 !Record->isStruct() || // ... of a structure ... 2681 !FDTy->isArrayType()) { //... may have incomplete array type. 2682 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2683 FD->setInvalidDecl(); 2684 EnclosingDecl->setInvalidDecl(); 2685 continue; 2686 } 2687 if (NumNamedMembers < 1) { //... must have more than named member ... 2688 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2689 FD->getName()); 2690 FD->setInvalidDecl(); 2691 EnclosingDecl->setInvalidDecl(); 2692 continue; 2693 } 2694 // Okay, we have a legal flexible array member at the end of the struct. 2695 if (Record) 2696 Record->setHasFlexibleArrayMember(true); 2697 } 2698 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2699 /// field of another structure or the element of an array. 2700 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2701 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2702 // If this is a member of a union, then entire union becomes "flexible". 2703 if (Record && Record->isUnion()) { 2704 Record->setHasFlexibleArrayMember(true); 2705 } else { 2706 // If this is a struct/class and this is not the last element, reject 2707 // it. Note that GCC supports variable sized arrays in the middle of 2708 // structures. 2709 if (i != NumFields-1) { 2710 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2711 FD->getName()); 2712 FD->setInvalidDecl(); 2713 EnclosingDecl->setInvalidDecl(); 2714 continue; 2715 } 2716 // We support flexible arrays at the end of structs in other structs 2717 // as an extension. 2718 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2719 FD->getName()); 2720 if (Record) 2721 Record->setHasFlexibleArrayMember(true); 2722 } 2723 } 2724 } 2725 /// A field cannot be an Objective-c object 2726 if (FDTy->isObjCInterfaceType()) { 2727 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2728 FD->getName()); 2729 FD->setInvalidDecl(); 2730 EnclosingDecl->setInvalidDecl(); 2731 continue; 2732 } 2733 // Keep track of the number of named members. 2734 if (IdentifierInfo *II = FD->getIdentifier()) { 2735 // Detect duplicate member names. 2736 if (!FieldIDs.insert(II)) { 2737 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2738 // Find the previous decl. 2739 SourceLocation PrevLoc; 2740 for (unsigned i = 0; ; ++i) { 2741 assert(i != RecFields.size() && "Didn't find previous def!"); 2742 if (RecFields[i]->getIdentifier() == II) { 2743 PrevLoc = RecFields[i]->getLocation(); 2744 break; 2745 } 2746 } 2747 Diag(PrevLoc, diag::err_previous_definition); 2748 FD->setInvalidDecl(); 2749 EnclosingDecl->setInvalidDecl(); 2750 continue; 2751 } 2752 ++NumNamedMembers; 2753 } 2754 } 2755 2756 // Okay, we successfully defined 'Record'. 2757 if (Record) { 2758 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2759 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2760 // Sema::ActOnFinishCXXClassDef. 2761 if (!isa<CXXRecordDecl>(Record)) 2762 Consumer.HandleTagDeclDefinition(Record); 2763 } else { 2764 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2765 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2766 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2767 else if (ObjCImplementationDecl *IMPDecl = 2768 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2769 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2770 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2771 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2772 } 2773 } 2774 2775 if (Attr) 2776 ProcessDeclAttributeList(Record, Attr); 2777} 2778 2779Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2780 DeclTy *lastEnumConst, 2781 SourceLocation IdLoc, IdentifierInfo *Id, 2782 SourceLocation EqualLoc, ExprTy *val) { 2783 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2784 EnumConstantDecl *LastEnumConst = 2785 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2786 Expr *Val = static_cast<Expr*>(val); 2787 2788 // The scope passed in may not be a decl scope. Zip up the scope tree until 2789 // we find one that is. 2790 while ((S->getFlags() & Scope::DeclScope) == 0) 2791 S = S->getParent(); 2792 2793 // Verify that there isn't already something declared with this name in this 2794 // scope. 2795 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2796 // When in C++, we may get a TagDecl with the same name; in this case the 2797 // enum constant will 'hide' the tag. 2798 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2799 "Received TagDecl when not in C++!"); 2800 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2801 if (isa<EnumConstantDecl>(PrevDecl)) 2802 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2803 else 2804 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2805 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2806 delete Val; 2807 return 0; 2808 } 2809 } 2810 2811 llvm::APSInt EnumVal(32); 2812 QualType EltTy; 2813 if (Val) { 2814 // Make sure to promote the operand type to int. 2815 UsualUnaryConversions(Val); 2816 2817 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2818 SourceLocation ExpLoc; 2819 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2820 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2821 Id->getName()); 2822 delete Val; 2823 Val = 0; // Just forget about it. 2824 } else { 2825 EltTy = Val->getType(); 2826 } 2827 } 2828 2829 if (!Val) { 2830 if (LastEnumConst) { 2831 // Assign the last value + 1. 2832 EnumVal = LastEnumConst->getInitVal(); 2833 ++EnumVal; 2834 2835 // Check for overflow on increment. 2836 if (EnumVal < LastEnumConst->getInitVal()) 2837 Diag(IdLoc, diag::warn_enum_value_overflow); 2838 2839 EltTy = LastEnumConst->getType(); 2840 } else { 2841 // First value, set to zero. 2842 EltTy = Context.IntTy; 2843 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2844 } 2845 } 2846 2847 EnumConstantDecl *New = 2848 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2849 Val, EnumVal, 2850 LastEnumConst); 2851 2852 // Register this decl in the current scope stack. 2853 PushOnScopeChains(New, S); 2854 return New; 2855} 2856 2857// FIXME: For consistency with ActOnFields(), we should have the parser 2858// pass in the source location for the left/right braces. 2859void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2860 DeclTy **Elements, unsigned NumElements) { 2861 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2862 2863 if (Enum && Enum->isDefinition()) { 2864 // Diagnose code like: 2865 // enum e0 { 2866 // E0 = sizeof(enum e0 { E1 }) 2867 // }; 2868 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2869 Enum->getName()); 2870 Diag(EnumLoc, diag::err_previous_definition); 2871 Enum->setInvalidDecl(); 2872 return; 2873 } 2874 // TODO: If the result value doesn't fit in an int, it must be a long or long 2875 // long value. ISO C does not support this, but GCC does as an extension, 2876 // emit a warning. 2877 unsigned IntWidth = Context.Target.getIntWidth(); 2878 2879 // Verify that all the values are okay, compute the size of the values, and 2880 // reverse the list. 2881 unsigned NumNegativeBits = 0; 2882 unsigned NumPositiveBits = 0; 2883 2884 // Keep track of whether all elements have type int. 2885 bool AllElementsInt = true; 2886 2887 EnumConstantDecl *EltList = 0; 2888 for (unsigned i = 0; i != NumElements; ++i) { 2889 EnumConstantDecl *ECD = 2890 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2891 if (!ECD) continue; // Already issued a diagnostic. 2892 2893 // If the enum value doesn't fit in an int, emit an extension warning. 2894 const llvm::APSInt &InitVal = ECD->getInitVal(); 2895 assert(InitVal.getBitWidth() >= IntWidth && 2896 "Should have promoted value to int"); 2897 if (InitVal.getBitWidth() > IntWidth) { 2898 llvm::APSInt V(InitVal); 2899 V.trunc(IntWidth); 2900 V.extend(InitVal.getBitWidth()); 2901 if (V != InitVal) 2902 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2903 InitVal.toString(10)); 2904 } 2905 2906 // Keep track of the size of positive and negative values. 2907 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2908 NumPositiveBits = std::max(NumPositiveBits, 2909 (unsigned)InitVal.getActiveBits()); 2910 else 2911 NumNegativeBits = std::max(NumNegativeBits, 2912 (unsigned)InitVal.getMinSignedBits()); 2913 2914 // Keep track of whether every enum element has type int (very commmon). 2915 if (AllElementsInt) 2916 AllElementsInt = ECD->getType() == Context.IntTy; 2917 2918 ECD->setNextDeclarator(EltList); 2919 EltList = ECD; 2920 } 2921 2922 // Figure out the type that should be used for this enum. 2923 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2924 QualType BestType; 2925 unsigned BestWidth; 2926 2927 if (NumNegativeBits) { 2928 // If there is a negative value, figure out the smallest integer type (of 2929 // int/long/longlong) that fits. 2930 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2931 BestType = Context.IntTy; 2932 BestWidth = IntWidth; 2933 } else { 2934 BestWidth = Context.Target.getLongWidth(); 2935 2936 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2937 BestType = Context.LongTy; 2938 else { 2939 BestWidth = Context.Target.getLongLongWidth(); 2940 2941 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2942 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2943 BestType = Context.LongLongTy; 2944 } 2945 } 2946 } else { 2947 // If there is no negative value, figure out which of uint, ulong, ulonglong 2948 // fits. 2949 if (NumPositiveBits <= IntWidth) { 2950 BestType = Context.UnsignedIntTy; 2951 BestWidth = IntWidth; 2952 } else if (NumPositiveBits <= 2953 (BestWidth = Context.Target.getLongWidth())) { 2954 BestType = Context.UnsignedLongTy; 2955 } else { 2956 BestWidth = Context.Target.getLongLongWidth(); 2957 assert(NumPositiveBits <= BestWidth && 2958 "How could an initializer get larger than ULL?"); 2959 BestType = Context.UnsignedLongLongTy; 2960 } 2961 } 2962 2963 // Loop over all of the enumerator constants, changing their types to match 2964 // the type of the enum if needed. 2965 for (unsigned i = 0; i != NumElements; ++i) { 2966 EnumConstantDecl *ECD = 2967 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2968 if (!ECD) continue; // Already issued a diagnostic. 2969 2970 // Standard C says the enumerators have int type, but we allow, as an 2971 // extension, the enumerators to be larger than int size. If each 2972 // enumerator value fits in an int, type it as an int, otherwise type it the 2973 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2974 // that X has type 'int', not 'unsigned'. 2975 if (ECD->getType() == Context.IntTy) { 2976 // Make sure the init value is signed. 2977 llvm::APSInt IV = ECD->getInitVal(); 2978 IV.setIsSigned(true); 2979 ECD->setInitVal(IV); 2980 continue; // Already int type. 2981 } 2982 2983 // Determine whether the value fits into an int. 2984 llvm::APSInt InitVal = ECD->getInitVal(); 2985 bool FitsInInt; 2986 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2987 FitsInInt = InitVal.getActiveBits() < IntWidth; 2988 else 2989 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2990 2991 // If it fits into an integer type, force it. Otherwise force it to match 2992 // the enum decl type. 2993 QualType NewTy; 2994 unsigned NewWidth; 2995 bool NewSign; 2996 if (FitsInInt) { 2997 NewTy = Context.IntTy; 2998 NewWidth = IntWidth; 2999 NewSign = true; 3000 } else if (ECD->getType() == BestType) { 3001 // Already the right type! 3002 continue; 3003 } else { 3004 NewTy = BestType; 3005 NewWidth = BestWidth; 3006 NewSign = BestType->isSignedIntegerType(); 3007 } 3008 3009 // Adjust the APSInt value. 3010 InitVal.extOrTrunc(NewWidth); 3011 InitVal.setIsSigned(NewSign); 3012 ECD->setInitVal(InitVal); 3013 3014 // Adjust the Expr initializer and type. 3015 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 3016 ECD->setType(NewTy); 3017 } 3018 3019 Enum->defineElements(EltList, BestType); 3020 Consumer.HandleTagDeclDefinition(Enum); 3021} 3022 3023Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3024 ExprTy *expr) { 3025 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3026 3027 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3028} 3029 3030Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3031 SourceLocation LBrace, 3032 SourceLocation RBrace, 3033 const char *Lang, 3034 unsigned StrSize, 3035 DeclTy *D) { 3036 LinkageSpecDecl::LanguageIDs Language; 3037 Decl *dcl = static_cast<Decl *>(D); 3038 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3039 Language = LinkageSpecDecl::lang_c; 3040 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3041 Language = LinkageSpecDecl::lang_cxx; 3042 else { 3043 Diag(Loc, diag::err_bad_language); 3044 return 0; 3045 } 3046 3047 // FIXME: Add all the various semantics of linkage specifications 3048 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3049} 3050 3051void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3052 ExprTy *alignment, SourceLocation PragmaLoc, 3053 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3054 Expr *Alignment = static_cast<Expr *>(alignment); 3055 3056 // If specified then alignment must be a "small" power of two. 3057 unsigned AlignmentVal = 0; 3058 if (Alignment) { 3059 llvm::APSInt Val; 3060 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3061 !Val.isPowerOf2() || 3062 Val.getZExtValue() > 16) { 3063 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3064 delete Alignment; 3065 return; // Ignore 3066 } 3067 3068 AlignmentVal = (unsigned) Val.getZExtValue(); 3069 } 3070 3071 switch (Kind) { 3072 case Action::PPK_Default: // pack([n]) 3073 PackContext.setAlignment(AlignmentVal); 3074 break; 3075 3076 case Action::PPK_Show: // pack(show) 3077 // Show the current alignment, making sure to show the right value 3078 // for the default. 3079 AlignmentVal = PackContext.getAlignment(); 3080 // FIXME: This should come from the target. 3081 if (AlignmentVal == 0) 3082 AlignmentVal = 8; 3083 Diag(PragmaLoc, diag::warn_pragma_pack_show, llvm::utostr(AlignmentVal)); 3084 break; 3085 3086 case Action::PPK_Push: // pack(push [, id] [, [n]) 3087 PackContext.push(Name); 3088 // Set the new alignment if specified. 3089 if (Alignment) 3090 PackContext.setAlignment(AlignmentVal); 3091 break; 3092 3093 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3094 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3095 // "#pragma pack(pop, identifier, n) is undefined" 3096 if (Alignment && Name) 3097 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3098 3099 // Do the pop. 3100 if (!PackContext.pop(Name)) { 3101 // If a name was specified then failure indicates the name 3102 // wasn't found. Otherwise failure indicates the stack was 3103 // empty. 3104 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3105 Name ? "no record matching name" : "stack empty"); 3106 3107 // FIXME: Warn about popping named records as MSVC does. 3108 } else { 3109 // Pop succeeded, set the new alignment if specified. 3110 if (Alignment) 3111 PackContext.setAlignment(AlignmentVal); 3112 } 3113 break; 3114 3115 default: 3116 assert(0 && "Invalid #pragma pack kind."); 3117 } 3118} 3119 3120bool PragmaPackStack::pop(IdentifierInfo *Name) { 3121 if (Stack.empty()) 3122 return false; 3123 3124 // If name is empty just pop top. 3125 if (!Name) { 3126 Alignment = Stack.back().first; 3127 Stack.pop_back(); 3128 return true; 3129 } 3130 3131 // Otherwise, find the named record. 3132 for (unsigned i = Stack.size(); i != 0; ) { 3133 --i; 3134 if (strcmp(Stack[i].second.c_str(), Name->getName()) == 0) { 3135 // Found it, pop up to and including this record. 3136 Alignment = Stack[i].first; 3137 Stack.erase(Stack.begin() + i, Stack.end()); 3138 return true; 3139 } 3140 } 3141 3142 return false; 3143} 3144