SemaDecl.cpp revision b4609806e9232593ece09ce08b630836e825865c
10b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 20b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// 30b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// The LLVM Compiler Infrastructure 40b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// 50b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// This file is distributed under the University of Illinois Open Source 60b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// License. See LICENSE.TXT for details. 70b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// 80b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach//===----------------------------------------------------------------------===// 90b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// 100b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// This file implements semantic analysis for declarations. 110b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach// 120b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach//===----------------------------------------------------------------------===// 130b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach 140b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "Sema.h" 157c788888872233748da10a8177a9a1eb176c1bc8Peter Collingbourne#include "clang/AST/APValue.h" 160b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/AST/ASTConsumer.h" 170b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/AST/ASTContext.h" 180b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/AST/DeclObjC.h" 190b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/AST/ExprCXX.h" 200b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/Parse/DeclSpec.h" 210b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/Basic/Diagnostic.h" 220b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach#include "clang/Basic/TargetInfo.h" 2397c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach#include "clang/Basic/SourceManager.h" 2497c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 2597c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach#include "clang/Lex/Preprocessor.h" 2697c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach#include "clang/Lex/HeaderSearch.h" 2797c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach#include "llvm/ADT/SmallSet.h" 2897c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach#include "llvm/ADT/StringExtras.h" 2997c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbachusing namespace clang; 3097c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach 3197c02bf2409bccdb43c3822c438e3ff977d8514eJim GrosbachSema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S, 3228b810e9e4b11074a241aad87e1e09ec7859a691Jim Grosbach const CXXScopeSpec *SS) { 3397c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach DeclContext *DC = 0; 3497c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach if (SS) { 3597c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach if (SS->isInvalid()) 3697c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach return 0; 3797c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach DC = static_cast<DeclContext*>(SS->getScopeRep()); 3897c02bf2409bccdb43c3822c438e3ff977d8514eJim Grosbach } 390b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 403f2d5f60b31fd057c10f77b2e607b23a8c94f6d3Chris Lattner 410b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach if (IIDecl && (isa<TypedefDecl>(IIDecl) || 420b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach isa<ObjCInterfaceDecl>(IIDecl) || 430b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach isa<TagDecl>(IIDecl))) 443f2d5f60b31fd057c10f77b2e607b23a8c94f6d3Chris Lattner return IIDecl; 450b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach return 0; 460b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach} 470b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach 480b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim GrosbachDeclContext *Sema::getContainingDC(DeclContext *DC) { 490b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 500b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach // A C++ out-of-line method will return to the file declaration context. 510b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach if (MD->isOutOfLineDefinition()) 520b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach return MD->getLexicalDeclContext(); 530b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach 540b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach // A C++ inline method is parsed *after* the topmost class it was declared in 550b6a44afb92fed0365b6709c1f46b0c5e49e1a72Jim Grosbach // is fully parsed (it's "complete"). 56 // The parsing of a C++ inline method happens at the declaration context of 57 // the topmost (non-nested) class it is declared in. 58 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 59 DC = MD->getParent(); 60 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 61 DC = RD; 62 63 // Return the declaration context of the topmost class the inline method is 64 // declared in. 65 return DC; 66 } 67 68 if (isa<ObjCMethodDecl>(DC)) 69 return Context.getTranslationUnitDecl(); 70 71 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC)) 72 return SD->getLexicalDeclContext(); 73 74 return DC->getParent(); 75} 76 77void Sema::PushDeclContext(DeclContext *DC) { 78 assert(getContainingDC(DC) == CurContext && 79 "The next DeclContext should be lexically contained in the current one."); 80 CurContext = DC; 81} 82 83void Sema::PopDeclContext() { 84 assert(CurContext && "DeclContext imbalance!"); 85 CurContext = getContainingDC(CurContext); 86} 87 88/// Add this decl to the scope shadowed decl chains. 89void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 90 S->AddDecl(D); 91 92 // C++ [basic.scope]p4: 93 // -- exactly one declaration shall declare a class name or 94 // enumeration name that is not a typedef name and the other 95 // declarations shall all refer to the same object or 96 // enumerator, or all refer to functions and function templates; 97 // in this case the class name or enumeration name is hidden. 98 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 99 // We are pushing the name of a tag (enum or class). 100 IdentifierResolver::iterator 101 I = IdResolver.begin(TD->getIdentifier(), 102 TD->getDeclContext(), false/*LookInParentCtx*/); 103 if (I != IdResolver.end() && isDeclInScope(*I, TD->getDeclContext(), S)) { 104 // There is already a declaration with the same name in the same 105 // scope. It must be found before we find the new declaration, 106 // so swap the order on the shadowed declaration chain. 107 108 IdResolver.AddShadowedDecl(TD, *I); 109 return; 110 } 111 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 112 FunctionDecl *FD = cast<FunctionDecl>(D); 113 // We are pushing the name of a function, which might be an 114 // overloaded name. 115 IdentifierResolver::iterator 116 I = IdResolver.begin(FD->getIdentifier(), 117 FD->getDeclContext(), false/*LookInParentCtx*/); 118 if (I != IdResolver.end() && 119 IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) && 120 (isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) { 121 // There is already a declaration with the same name in the same 122 // scope. It must be a function or an overloaded function. 123 OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I); 124 if (!Ovl) { 125 // We haven't yet overloaded this function. Take the existing 126 // FunctionDecl and put it into an OverloadedFunctionDecl. 127 Ovl = OverloadedFunctionDecl::Create(Context, 128 FD->getDeclContext(), 129 FD->getIdentifier()); 130 Ovl->addOverload(dyn_cast<FunctionDecl>(*I)); 131 132 // Remove the name binding to the existing FunctionDecl... 133 IdResolver.RemoveDecl(*I); 134 135 // ... and put the OverloadedFunctionDecl in its place. 136 IdResolver.AddDecl(Ovl); 137 } 138 139 // We have an OverloadedFunctionDecl. Add the new FunctionDecl 140 // to its list of overloads. 141 Ovl->addOverload(FD); 142 143 return; 144 } 145 } 146 147 IdResolver.AddDecl(D); 148} 149 150void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 151 if (S->decl_empty()) return; 152 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 153 154 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 155 I != E; ++I) { 156 Decl *TmpD = static_cast<Decl*>(*I); 157 assert(TmpD && "This decl didn't get pushed??"); 158 159 if (isa<CXXFieldDecl>(TmpD)) continue; 160 161 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 162 ScopedDecl *D = cast<ScopedDecl>(TmpD); 163 164 IdentifierInfo *II = D->getIdentifier(); 165 if (!II) continue; 166 167 // We only want to remove the decls from the identifier decl chains for 168 // local scopes, when inside a function/method. 169 if (S->getFnParent() != 0) 170 IdResolver.RemoveDecl(D); 171 172 // Chain this decl to the containing DeclContext. 173 D->setNext(CurContext->getDeclChain()); 174 CurContext->setDeclChain(D); 175 } 176} 177 178/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 179/// return 0 if one not found. 180ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 181 // The third "scope" argument is 0 since we aren't enabling lazy built-in 182 // creation from this context. 183 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 184 185 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 186} 187 188/// LookupDecl - Look up the inner-most declaration in the specified 189/// namespace. 190Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, Scope *S, 191 const DeclContext *LookupCtx, 192 bool enableLazyBuiltinCreation) { 193 if (II == 0) return 0; 194 unsigned NS = NSI; 195 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 196 NS |= Decl::IDNS_Tag; 197 198 IdentifierResolver::iterator 199 I = LookupCtx ? IdResolver.begin(II, LookupCtx, false/*LookInParentCtx*/) : 200 IdResolver.begin(II, CurContext, true/*LookInParentCtx*/); 201 // Scan up the scope chain looking for a decl that matches this identifier 202 // that is in the appropriate namespace. This search should not take long, as 203 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 204 for (; I != IdResolver.end(); ++I) 205 if ((*I)->getIdentifierNamespace() & NS) 206 return *I; 207 208 // If we didn't find a use of this identifier, and if the identifier 209 // corresponds to a compiler builtin, create the decl object for the builtin 210 // now, injecting it into translation unit scope, and return it. 211 if (NS & Decl::IDNS_Ordinary) { 212 if (enableLazyBuiltinCreation && 213 (LookupCtx == 0 || isa<TranslationUnitDecl>(LookupCtx))) { 214 // If this is a builtin on this (or all) targets, create the decl. 215 if (unsigned BuiltinID = II->getBuiltinID()) 216 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 217 } 218 if (getLangOptions().ObjC1) { 219 // @interface and @compatibility_alias introduce typedef-like names. 220 // Unlike typedef's, they can only be introduced at file-scope (and are 221 // therefore not scoped decls). They can, however, be shadowed by 222 // other names in IDNS_Ordinary. 223 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 224 if (IDI != ObjCInterfaceDecls.end()) 225 return IDI->second; 226 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 227 if (I != ObjCAliasDecls.end()) 228 return I->second->getClassInterface(); 229 } 230 } 231 return 0; 232} 233 234void Sema::InitBuiltinVaListType() { 235 if (!Context.getBuiltinVaListType().isNull()) 236 return; 237 238 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 239 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 240 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 241 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 242} 243 244/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 245/// lazily create a decl for it. 246ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 247 Scope *S) { 248 Builtin::ID BID = (Builtin::ID)bid; 249 250 if (Context.BuiltinInfo.hasVAListUse(BID)) 251 InitBuiltinVaListType(); 252 253 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 254 FunctionDecl *New = FunctionDecl::Create(Context, 255 Context.getTranslationUnitDecl(), 256 SourceLocation(), II, R, 257 FunctionDecl::Extern, false, 0); 258 259 // Create Decl objects for each parameter, adding them to the 260 // FunctionDecl. 261 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 262 llvm::SmallVector<ParmVarDecl*, 16> Params; 263 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 264 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 265 FT->getArgType(i), VarDecl::None, 0, 266 0)); 267 New->setParams(&Params[0], Params.size()); 268 } 269 270 271 272 // TUScope is the translation-unit scope to insert this function into. 273 PushOnScopeChains(New, TUScope); 274 return New; 275} 276 277/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 278/// everything from the standard library is defined. 279NamespaceDecl *Sema::GetStdNamespace() { 280 if (!StdNamespace) { 281 DeclContext *Global = Context.getTranslationUnitDecl(); 282 Decl *Std = LookupDecl(Ident_StdNs, Decl::IDNS_Tag | Decl::IDNS_Ordinary, 283 0, Global, /*enableLazyBuiltinCreation=*/false); 284 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 285 } 286 return StdNamespace; 287} 288 289/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 290/// and scope as a previous declaration 'Old'. Figure out how to resolve this 291/// situation, merging decls or emitting diagnostics as appropriate. 292/// 293TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 294 // Allow multiple definitions for ObjC built-in typedefs. 295 // FIXME: Verify the underlying types are equivalent! 296 if (getLangOptions().ObjC1) { 297 const IdentifierInfo *typeIdent = New->getIdentifier(); 298 if (typeIdent == Ident_id) { 299 Context.setObjCIdType(New); 300 return New; 301 } else if (typeIdent == Ident_Class) { 302 Context.setObjCClassType(New); 303 return New; 304 } else if (typeIdent == Ident_SEL) { 305 Context.setObjCSelType(New); 306 return New; 307 } else if (typeIdent == Ident_Protocol) { 308 Context.setObjCProtoType(New->getUnderlyingType()); 309 return New; 310 } 311 // Fall through - the typedef name was not a builtin type. 312 } 313 // Verify the old decl was also a typedef. 314 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 315 if (!Old) { 316 Diag(New->getLocation(), diag::err_redefinition_different_kind, 317 New->getName()); 318 Diag(OldD->getLocation(), diag::err_previous_definition); 319 return New; 320 } 321 322 // If the typedef types are not identical, reject them in all languages and 323 // with any extensions enabled. 324 if (Old->getUnderlyingType() != New->getUnderlyingType() && 325 Context.getCanonicalType(Old->getUnderlyingType()) != 326 Context.getCanonicalType(New->getUnderlyingType())) { 327 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 328 New->getUnderlyingType().getAsString(), 329 Old->getUnderlyingType().getAsString()); 330 Diag(Old->getLocation(), diag::err_previous_definition); 331 return Old; 332 } 333 334 if (getLangOptions().Microsoft) return New; 335 336 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 337 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 338 // *either* declaration is in a system header. The code below implements 339 // this adhoc compatibility rule. FIXME: The following code will not 340 // work properly when compiling ".i" files (containing preprocessed output). 341 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 342 SourceManager &SrcMgr = Context.getSourceManager(); 343 if (SrcMgr.isInSystemHeader(Old->getLocation())) 344 return New; 345 if (SrcMgr.isInSystemHeader(New->getLocation())) 346 return New; 347 } 348 349 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 350 Diag(Old->getLocation(), diag::err_previous_definition); 351 return New; 352} 353 354/// DeclhasAttr - returns true if decl Declaration already has the target 355/// attribute. 356static bool DeclHasAttr(const Decl *decl, const Attr *target) { 357 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 358 if (attr->getKind() == target->getKind()) 359 return true; 360 361 return false; 362} 363 364/// MergeAttributes - append attributes from the Old decl to the New one. 365static void MergeAttributes(Decl *New, Decl *Old) { 366 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 367 368 while (attr) { 369 tmp = attr; 370 attr = attr->getNext(); 371 372 if (!DeclHasAttr(New, tmp)) { 373 New->addAttr(tmp); 374 } else { 375 tmp->setNext(0); 376 delete(tmp); 377 } 378 } 379 380 Old->invalidateAttrs(); 381} 382 383/// MergeFunctionDecl - We just parsed a function 'New' from 384/// declarator D which has the same name and scope as a previous 385/// declaration 'Old'. Figure out how to resolve this situation, 386/// merging decls or emitting diagnostics as appropriate. 387/// Redeclaration will be set true if this New is a redeclaration OldD. 388/// 389/// In C++, New and Old must be declarations that are not 390/// overloaded. Use IsOverload to determine whether New and Old are 391/// overloaded, and to select the Old declaration that New should be 392/// merged with. 393FunctionDecl * 394Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 395 assert(!isa<OverloadedFunctionDecl>(OldD) && 396 "Cannot merge with an overloaded function declaration"); 397 398 Redeclaration = false; 399 // Verify the old decl was also a function. 400 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 401 if (!Old) { 402 Diag(New->getLocation(), diag::err_redefinition_different_kind, 403 New->getName()); 404 Diag(OldD->getLocation(), diag::err_previous_definition); 405 return New; 406 } 407 408 // Determine whether the previous declaration was a definition, 409 // implicit declaration, or a declaration. 410 diag::kind PrevDiag; 411 if (Old->isThisDeclarationADefinition()) 412 PrevDiag = diag::err_previous_definition; 413 else if (Old->isImplicit()) 414 PrevDiag = diag::err_previous_implicit_declaration; 415 else 416 PrevDiag = diag::err_previous_declaration; 417 418 QualType OldQType = Context.getCanonicalType(Old->getType()); 419 QualType NewQType = Context.getCanonicalType(New->getType()); 420 421 if (getLangOptions().CPlusPlus) { 422 // (C++98 13.1p2): 423 // Certain function declarations cannot be overloaded: 424 // -- Function declarations that differ only in the return type 425 // cannot be overloaded. 426 QualType OldReturnType 427 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 428 QualType NewReturnType 429 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 430 if (OldReturnType != NewReturnType) { 431 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 432 Diag(Old->getLocation(), PrevDiag); 433 return New; 434 } 435 436 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 437 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 438 if (OldMethod && NewMethod) { 439 // -- Member function declarations with the same name and the 440 // same parameter types cannot be overloaded if any of them 441 // is a static member function declaration. 442 if (OldMethod->isStatic() || NewMethod->isStatic()) { 443 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 444 Diag(Old->getLocation(), PrevDiag); 445 return New; 446 } 447 } 448 449 // (C++98 8.3.5p3): 450 // All declarations for a function shall agree exactly in both the 451 // return type and the parameter-type-list. 452 if (OldQType == NewQType) { 453 // We have a redeclaration. 454 MergeAttributes(New, Old); 455 Redeclaration = true; 456 return MergeCXXFunctionDecl(New, Old); 457 } 458 459 // Fall through for conflicting redeclarations and redefinitions. 460 } 461 462 // C: Function types need to be compatible, not identical. This handles 463 // duplicate function decls like "void f(int); void f(enum X);" properly. 464 if (!getLangOptions().CPlusPlus && 465 Context.typesAreCompatible(OldQType, NewQType)) { 466 MergeAttributes(New, Old); 467 Redeclaration = true; 468 return New; 469 } 470 471 // A function that has already been declared has been redeclared or defined 472 // with a different type- show appropriate diagnostic 473 474 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 475 // TODO: This is totally simplistic. It should handle merging functions 476 // together etc, merging extern int X; int X; ... 477 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 478 Diag(Old->getLocation(), PrevDiag); 479 return New; 480} 481 482/// Predicate for C "tentative" external object definitions (C99 6.9.2). 483static bool isTentativeDefinition(VarDecl *VD) { 484 if (VD->isFileVarDecl()) 485 return (!VD->getInit() && 486 (VD->getStorageClass() == VarDecl::None || 487 VD->getStorageClass() == VarDecl::Static)); 488 return false; 489} 490 491/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 492/// when dealing with C "tentative" external object definitions (C99 6.9.2). 493void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 494 bool VDIsTentative = isTentativeDefinition(VD); 495 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 496 497 for (IdentifierResolver::iterator 498 I = IdResolver.begin(VD->getIdentifier(), 499 VD->getDeclContext(), false/*LookInParentCtx*/), 500 E = IdResolver.end(); I != E; ++I) { 501 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 502 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 503 504 // Handle the following case: 505 // int a[10]; 506 // int a[]; - the code below makes sure we set the correct type. 507 // int a[11]; - this is an error, size isn't 10. 508 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 509 OldDecl->getType()->isConstantArrayType()) 510 VD->setType(OldDecl->getType()); 511 512 // Check for "tentative" definitions. We can't accomplish this in 513 // MergeVarDecl since the initializer hasn't been attached. 514 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 515 continue; 516 517 // Handle __private_extern__ just like extern. 518 if (OldDecl->getStorageClass() != VarDecl::Extern && 519 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 520 VD->getStorageClass() != VarDecl::Extern && 521 VD->getStorageClass() != VarDecl::PrivateExtern) { 522 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 523 Diag(OldDecl->getLocation(), diag::err_previous_definition); 524 } 525 } 526 } 527} 528 529/// MergeVarDecl - We just parsed a variable 'New' which has the same name 530/// and scope as a previous declaration 'Old'. Figure out how to resolve this 531/// situation, merging decls or emitting diagnostics as appropriate. 532/// 533/// Tentative definition rules (C99 6.9.2p2) are checked by 534/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 535/// definitions here, since the initializer hasn't been attached. 536/// 537VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 538 // Verify the old decl was also a variable. 539 VarDecl *Old = dyn_cast<VarDecl>(OldD); 540 if (!Old) { 541 Diag(New->getLocation(), diag::err_redefinition_different_kind, 542 New->getName()); 543 Diag(OldD->getLocation(), diag::err_previous_definition); 544 return New; 545 } 546 547 MergeAttributes(New, Old); 548 549 // Verify the types match. 550 QualType OldCType = Context.getCanonicalType(Old->getType()); 551 QualType NewCType = Context.getCanonicalType(New->getType()); 552 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 553 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 554 Diag(Old->getLocation(), diag::err_previous_definition); 555 return New; 556 } 557 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 558 if (New->getStorageClass() == VarDecl::Static && 559 (Old->getStorageClass() == VarDecl::None || 560 Old->getStorageClass() == VarDecl::Extern)) { 561 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 562 Diag(Old->getLocation(), diag::err_previous_definition); 563 return New; 564 } 565 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 566 if (New->getStorageClass() != VarDecl::Static && 567 Old->getStorageClass() == VarDecl::Static) { 568 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 569 Diag(Old->getLocation(), diag::err_previous_definition); 570 return New; 571 } 572 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 573 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 574 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 575 Diag(Old->getLocation(), diag::err_previous_definition); 576 } 577 return New; 578} 579 580/// CheckParmsForFunctionDef - Check that the parameters of the given 581/// function are appropriate for the definition of a function. This 582/// takes care of any checks that cannot be performed on the 583/// declaration itself, e.g., that the types of each of the function 584/// parameters are complete. 585bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 586 bool HasInvalidParm = false; 587 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 588 ParmVarDecl *Param = FD->getParamDecl(p); 589 590 // C99 6.7.5.3p4: the parameters in a parameter type list in a 591 // function declarator that is part of a function definition of 592 // that function shall not have incomplete type. 593 if (Param->getType()->isIncompleteType() && 594 !Param->isInvalidDecl()) { 595 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 596 Param->getType().getAsString()); 597 Param->setInvalidDecl(); 598 HasInvalidParm = true; 599 } 600 } 601 602 return HasInvalidParm; 603} 604 605/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 606/// no declarator (e.g. "struct foo;") is parsed. 607Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 608 // TODO: emit error on 'int;' or 'const enum foo;'. 609 // TODO: emit error on 'typedef int;' 610 // if (!DS.isMissingDeclaratorOk()) Diag(...); 611 612 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 613} 614 615bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 616 // Get the type before calling CheckSingleAssignmentConstraints(), since 617 // it can promote the expression. 618 QualType InitType = Init->getType(); 619 620 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 621 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 622 InitType, Init, "initializing"); 623} 624 625bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 626 const ArrayType *AT = Context.getAsArrayType(DeclT); 627 628 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 629 // C99 6.7.8p14. We have an array of character type with unknown size 630 // being initialized to a string literal. 631 llvm::APSInt ConstVal(32); 632 ConstVal = strLiteral->getByteLength() + 1; 633 // Return a new array type (C99 6.7.8p22). 634 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 635 ArrayType::Normal, 0); 636 } else { 637 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 638 // C99 6.7.8p14. We have an array of character type with known size. 639 // FIXME: Avoid truncation for 64-bit length strings. 640 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 641 Diag(strLiteral->getSourceRange().getBegin(), 642 diag::warn_initializer_string_for_char_array_too_long, 643 strLiteral->getSourceRange()); 644 } 645 // Set type from "char *" to "constant array of char". 646 strLiteral->setType(DeclT); 647 // For now, we always return false (meaning success). 648 return false; 649} 650 651StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 652 const ArrayType *AT = Context.getAsArrayType(DeclType); 653 if (AT && AT->getElementType()->isCharType()) { 654 return dyn_cast<StringLiteral>(Init); 655 } 656 return 0; 657} 658 659bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 660 SourceLocation InitLoc, 661 std::string InitEntity) { 662 // C++ [dcl.init.ref]p1: 663 // A variable declared to be a T&, that is “reference to type T” 664 // (8.3.2), shall be initialized by an object, or function, of 665 // type T or by an object that can be converted into a T. 666 if (DeclType->isReferenceType()) 667 return CheckReferenceInit(Init, DeclType); 668 669 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 670 // of unknown size ("[]") or an object type that is not a variable array type. 671 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 672 return Diag(InitLoc, 673 diag::err_variable_object_no_init, 674 VAT->getSizeExpr()->getSourceRange()); 675 676 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 677 if (!InitList) { 678 // FIXME: Handle wide strings 679 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 680 return CheckStringLiteralInit(strLiteral, DeclType); 681 682 // C++ [dcl.init]p14: 683 // -- If the destination type is a (possibly cv-qualified) class 684 // type: 685 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 686 QualType DeclTypeC = Context.getCanonicalType(DeclType); 687 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 688 689 // -- If the initialization is direct-initialization, or if it is 690 // copy-initialization where the cv-unqualified version of the 691 // source type is the same class as, or a derived class of, the 692 // class of the destination, constructors are considered. 693 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 694 IsDerivedFrom(InitTypeC, DeclTypeC)) { 695 CXXConstructorDecl *Constructor 696 = PerformInitializationByConstructor(DeclType, &Init, 1, 697 InitLoc, Init->getSourceRange(), 698 InitEntity, IK_Copy); 699 return Constructor == 0; 700 } 701 702 // -- Otherwise (i.e., for the remaining copy-initialization 703 // cases), user-defined conversion sequences that can 704 // convert from the source type to the destination type or 705 // (when a conversion function is used) to a derived class 706 // thereof are enumerated as described in 13.3.1.4, and the 707 // best one is chosen through overload resolution 708 // (13.3). If the conversion cannot be done or is 709 // ambiguous, the initialization is ill-formed. The 710 // function selected is called with the initializer 711 // expression as its argument; if the function is a 712 // constructor, the call initializes a temporary of the 713 // destination type. 714 // FIXME: We're pretending to do copy elision here; return to 715 // this when we have ASTs for such things. 716 if (PerformImplicitConversion(Init, DeclType)) 717 return Diag(InitLoc, 718 diag::err_typecheck_convert_incompatible, 719 DeclType.getAsString(), InitEntity, 720 "initializing", 721 Init->getSourceRange()); 722 else 723 return false; 724 } 725 726 // C99 6.7.8p16. 727 if (DeclType->isArrayType()) 728 return Diag(Init->getLocStart(), 729 diag::err_array_init_list_required, 730 Init->getSourceRange()); 731 732 return CheckSingleInitializer(Init, DeclType); 733 } else if (getLangOptions().CPlusPlus) { 734 // C++ [dcl.init]p14: 735 // [...] If the class is an aggregate (8.5.1), and the initializer 736 // is a brace-enclosed list, see 8.5.1. 737 // 738 // Note: 8.5.1 is handled below; here, we diagnose the case where 739 // we have an initializer list and a destination type that is not 740 // an aggregate. 741 // FIXME: In C++0x, this is yet another form of initialization. 742 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 743 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 744 if (!ClassDecl->isAggregate()) 745 return Diag(InitLoc, 746 diag::err_init_non_aggr_init_list, 747 DeclType.getAsString(), 748 Init->getSourceRange()); 749 } 750 } 751 752 InitListChecker CheckInitList(this, InitList, DeclType); 753 return CheckInitList.HadError(); 754} 755 756Sema::DeclTy * 757Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 758 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 759 IdentifierInfo *II = D.getIdentifier(); 760 761 // All of these full declarators require an identifier. If it doesn't have 762 // one, the ParsedFreeStandingDeclSpec action should be used. 763 if (II == 0) { 764 if (!D.getInvalidType()) // Reject this if we think it is valid. 765 Diag(D.getDeclSpec().getSourceRange().getBegin(), 766 diag::err_declarator_need_ident, 767 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 768 return 0; 769 } 770 771 // The scope passed in may not be a decl scope. Zip up the scope tree until 772 // we find one that is. 773 while ((S->getFlags() & Scope::DeclScope) == 0) 774 S = S->getParent(); 775 776 DeclContext *DC; 777 Decl *PrevDecl; 778 ScopedDecl *New; 779 bool InvalidDecl = false; 780 781 // See if this is a redefinition of a variable in the same scope. 782 if (!D.getCXXScopeSpec().isSet()) { 783 DC = CurContext; 784 PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 785 } else { // Something like "int foo::x;" 786 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 787 PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S, DC); 788 789 // C++ 7.3.1.2p2: 790 // Members (including explicit specializations of templates) of a named 791 // namespace can also be defined outside that namespace by explicit 792 // qualification of the name being defined, provided that the entity being 793 // defined was already declared in the namespace and the definition appears 794 // after the point of declaration in a namespace that encloses the 795 // declarations namespace. 796 // 797 if (PrevDecl == 0) { 798 // No previous declaration in the qualifying scope. 799 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member, 800 II->getName(), D.getCXXScopeSpec().getRange()); 801 } else if (!CurContext->Encloses(DC)) { 802 // The qualifying scope doesn't enclose the original declaration. 803 // Emit diagnostic based on current scope. 804 SourceLocation L = D.getIdentifierLoc(); 805 SourceRange R = D.getCXXScopeSpec().getRange(); 806 if (isa<FunctionDecl>(CurContext)) { 807 Diag(L, diag::err_invalid_declarator_in_function, II->getName(), R); 808 } else { 809 Diag(L, diag::err_invalid_declarator_scope, II->getName(), 810 cast<NamedDecl>(DC)->getName(), R); 811 } 812 } 813 } 814 815 // In C++, the previous declaration we find might be a tag type 816 // (class or enum). In this case, the new declaration will hide the 817 // tag type. 818 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 819 PrevDecl = 0; 820 821 QualType R = GetTypeForDeclarator(D, S); 822 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 823 824 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 825 // Check that there are no default arguments (C++ only). 826 if (getLangOptions().CPlusPlus) 827 CheckExtraCXXDefaultArguments(D); 828 829 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 830 if (!NewTD) return 0; 831 832 // Handle attributes prior to checking for duplicates in MergeVarDecl 833 ProcessDeclAttributes(NewTD, D); 834 // Merge the decl with the existing one if appropriate. If the decl is 835 // in an outer scope, it isn't the same thing. 836 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 837 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 838 if (NewTD == 0) return 0; 839 } 840 New = NewTD; 841 if (S->getFnParent() == 0) { 842 // C99 6.7.7p2: If a typedef name specifies a variably modified type 843 // then it shall have block scope. 844 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 845 // FIXME: Diagnostic needs to be fixed. 846 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 847 InvalidDecl = true; 848 } 849 } 850 } else if (R.getTypePtr()->isFunctionType()) { 851 FunctionDecl::StorageClass SC = FunctionDecl::None; 852 switch (D.getDeclSpec().getStorageClassSpec()) { 853 default: assert(0 && "Unknown storage class!"); 854 case DeclSpec::SCS_auto: 855 case DeclSpec::SCS_register: 856 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 857 R.getAsString()); 858 InvalidDecl = true; 859 break; 860 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 861 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 862 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 863 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 864 } 865 866 bool isInline = D.getDeclSpec().isInlineSpecified(); 867 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 868 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 869 870 FunctionDecl *NewFD; 871 if (D.getKind() == Declarator::DK_Constructor) { 872 // This is a C++ constructor declaration. 873 assert(DC->isCXXRecord() && 874 "Constructors can only be declared in a member context"); 875 876 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 877 878 // Create the new declaration 879 NewFD = CXXConstructorDecl::Create(Context, 880 cast<CXXRecordDecl>(DC), 881 D.getIdentifierLoc(), II, R, 882 isExplicit, isInline, 883 /*isImplicitlyDeclared=*/false); 884 885 if (isInvalidDecl) 886 NewFD->setInvalidDecl(); 887 } else if (D.getKind() == Declarator::DK_Destructor) { 888 // This is a C++ destructor declaration. 889 if (DC->isCXXRecord()) { 890 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 891 892 NewFD = CXXDestructorDecl::Create(Context, 893 cast<CXXRecordDecl>(DC), 894 D.getIdentifierLoc(), II, R, 895 isInline, 896 /*isImplicitlyDeclared=*/false); 897 898 if (isInvalidDecl) 899 NewFD->setInvalidDecl(); 900 } else { 901 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 902 // Create a FunctionDecl to satisfy the function definition parsing 903 // code path. 904 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 905 II, R, SC, isInline, LastDeclarator, 906 // FIXME: Move to DeclGroup... 907 D.getDeclSpec().getSourceRange().getBegin()); 908 NewFD->setInvalidDecl(); 909 } 910 } else if (D.getKind() == Declarator::DK_Conversion) { 911 if (!DC->isCXXRecord()) { 912 Diag(D.getIdentifierLoc(), 913 diag::err_conv_function_not_member); 914 return 0; 915 } else { 916 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 917 918 NewFD = CXXConversionDecl::Create(Context, 919 cast<CXXRecordDecl>(DC), 920 D.getIdentifierLoc(), II, R, 921 isInline, isExplicit); 922 923 if (isInvalidDecl) 924 NewFD->setInvalidDecl(); 925 } 926 } else if (DC->isCXXRecord()) { 927 // This is a C++ method declaration. 928 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 929 D.getIdentifierLoc(), II, R, 930 (SC == FunctionDecl::Static), isInline, 931 LastDeclarator); 932 } else { 933 NewFD = FunctionDecl::Create(Context, DC, 934 D.getIdentifierLoc(), 935 II, R, SC, isInline, LastDeclarator, 936 // FIXME: Move to DeclGroup... 937 D.getDeclSpec().getSourceRange().getBegin()); 938 } 939 // Handle attributes. 940 ProcessDeclAttributes(NewFD, D); 941 942 // Handle GNU asm-label extension (encoded as an attribute). 943 if (Expr *E = (Expr*) D.getAsmLabel()) { 944 // The parser guarantees this is a string. 945 StringLiteral *SE = cast<StringLiteral>(E); 946 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 947 SE->getByteLength()))); 948 } 949 950 // Copy the parameter declarations from the declarator D to 951 // the function declaration NewFD, if they are available. 952 if (D.getNumTypeObjects() > 0) { 953 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 954 955 // Create Decl objects for each parameter, adding them to the 956 // FunctionDecl. 957 llvm::SmallVector<ParmVarDecl*, 16> Params; 958 959 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 960 // function that takes no arguments, not a function that takes a 961 // single void argument. 962 // We let through "const void" here because Sema::GetTypeForDeclarator 963 // already checks for that case. 964 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 965 FTI.ArgInfo[0].Param && 966 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 967 // empty arg list, don't push any params. 968 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 969 970 // In C++, the empty parameter-type-list must be spelled "void"; a 971 // typedef of void is not permitted. 972 if (getLangOptions().CPlusPlus && 973 Param->getType().getUnqualifiedType() != Context.VoidTy) { 974 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 975 } 976 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 977 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 978 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 979 } 980 981 NewFD->setParams(&Params[0], Params.size()); 982 } else if (R->getAsTypedefType()) { 983 // When we're declaring a function with a typedef, as in the 984 // following example, we'll need to synthesize (unnamed) 985 // parameters for use in the declaration. 986 // 987 // @code 988 // typedef void fn(int); 989 // fn f; 990 // @endcode 991 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 992 if (!FT) { 993 // This is a typedef of a function with no prototype, so we 994 // don't need to do anything. 995 } else if ((FT->getNumArgs() == 0) || 996 (FT->getNumArgs() == 1 && !FT->isVariadic() && 997 FT->getArgType(0)->isVoidType())) { 998 // This is a zero-argument function. We don't need to do anything. 999 } else { 1000 // Synthesize a parameter for each argument type. 1001 llvm::SmallVector<ParmVarDecl*, 16> Params; 1002 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1003 ArgType != FT->arg_type_end(); ++ArgType) { 1004 Params.push_back(ParmVarDecl::Create(Context, DC, 1005 SourceLocation(), 0, 1006 *ArgType, VarDecl::None, 1007 0, 0)); 1008 } 1009 1010 NewFD->setParams(&Params[0], Params.size()); 1011 } 1012 } 1013 1014 // C++ constructors and destructors are handled by separate 1015 // routines, since they don't require any declaration merging (C++ 1016 // [class.mfct]p2) and they aren't ever pushed into scope, because 1017 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1018 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1019 return ActOnConstructorDeclarator(Constructor); 1020 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1021 return ActOnDestructorDeclarator(Destructor); 1022 else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1023 return ActOnConversionDeclarator(Conversion); 1024 1025 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1026 if (NewFD->isOverloadedOperator() && 1027 CheckOverloadedOperatorDeclaration(NewFD)) 1028 NewFD->setInvalidDecl(); 1029 1030 // Merge the decl with the existing one if appropriate. Since C functions 1031 // are in a flat namespace, make sure we consider decls in outer scopes. 1032 if (PrevDecl && 1033 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1034 bool Redeclaration = false; 1035 1036 // If C++, determine whether NewFD is an overload of PrevDecl or 1037 // a declaration that requires merging. If it's an overload, 1038 // there's no more work to do here; we'll just add the new 1039 // function to the scope. 1040 OverloadedFunctionDecl::function_iterator MatchedDecl; 1041 if (!getLangOptions().CPlusPlus || 1042 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1043 Decl *OldDecl = PrevDecl; 1044 1045 // If PrevDecl was an overloaded function, extract the 1046 // FunctionDecl that matched. 1047 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1048 OldDecl = *MatchedDecl; 1049 1050 // NewFD and PrevDecl represent declarations that need to be 1051 // merged. 1052 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1053 1054 if (NewFD == 0) return 0; 1055 if (Redeclaration) { 1056 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1057 1058 if (OldDecl == PrevDecl) { 1059 // Remove the name binding for the previous 1060 // declaration. We'll add the binding back later, but then 1061 // it will refer to the new declaration (which will 1062 // contain more information). 1063 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1064 } else { 1065 // We need to update the OverloadedFunctionDecl with the 1066 // latest declaration of this function, so that name 1067 // lookup will always refer to the latest declaration of 1068 // this function. 1069 *MatchedDecl = NewFD; 1070 1071 // Add the redeclaration to the current scope, since we'll 1072 // be skipping PushOnScopeChains. 1073 S->AddDecl(NewFD); 1074 1075 return NewFD; 1076 } 1077 } 1078 } 1079 } 1080 New = NewFD; 1081 1082 // In C++, check default arguments now that we have merged decls. 1083 if (getLangOptions().CPlusPlus) 1084 CheckCXXDefaultArguments(NewFD); 1085 } else { 1086 // Check that there are no default arguments (C++ only). 1087 if (getLangOptions().CPlusPlus) 1088 CheckExtraCXXDefaultArguments(D); 1089 1090 if (R.getTypePtr()->isObjCInterfaceType()) { 1091 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 1092 D.getIdentifier()->getName()); 1093 InvalidDecl = true; 1094 } 1095 1096 VarDecl *NewVD; 1097 VarDecl::StorageClass SC; 1098 switch (D.getDeclSpec().getStorageClassSpec()) { 1099 default: assert(0 && "Unknown storage class!"); 1100 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1101 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1102 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1103 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1104 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1105 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1106 } 1107 if (DC->isCXXRecord()) { 1108 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1109 // This is a static data member for a C++ class. 1110 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1111 D.getIdentifierLoc(), II, 1112 R, LastDeclarator); 1113 } else { 1114 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1115 if (S->getFnParent() == 0) { 1116 // C99 6.9p2: The storage-class specifiers auto and register shall not 1117 // appear in the declaration specifiers in an external declaration. 1118 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1119 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 1120 R.getAsString()); 1121 InvalidDecl = true; 1122 } 1123 } 1124 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1125 II, R, SC, LastDeclarator, 1126 // FIXME: Move to DeclGroup... 1127 D.getDeclSpec().getSourceRange().getBegin()); 1128 NewVD->setThreadSpecified(ThreadSpecified); 1129 } 1130 // Handle attributes prior to checking for duplicates in MergeVarDecl 1131 ProcessDeclAttributes(NewVD, D); 1132 1133 // Handle GNU asm-label extension (encoded as an attribute). 1134 if (Expr *E = (Expr*) D.getAsmLabel()) { 1135 // The parser guarantees this is a string. 1136 StringLiteral *SE = cast<StringLiteral>(E); 1137 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1138 SE->getByteLength()))); 1139 } 1140 1141 // Emit an error if an address space was applied to decl with local storage. 1142 // This includes arrays of objects with address space qualifiers, but not 1143 // automatic variables that point to other address spaces. 1144 // ISO/IEC TR 18037 S5.1.2 1145 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1146 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1147 InvalidDecl = true; 1148 } 1149 // Merge the decl with the existing one if appropriate. If the decl is 1150 // in an outer scope, it isn't the same thing. 1151 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1152 NewVD = MergeVarDecl(NewVD, PrevDecl); 1153 if (NewVD == 0) return 0; 1154 } 1155 New = NewVD; 1156 } 1157 1158 // Set the lexical context. If the declarator has a C++ scope specifier, the 1159 // lexical context will be different from the semantic context. 1160 New->setLexicalDeclContext(CurContext); 1161 1162 // If this has an identifier, add it to the scope stack. 1163 if (II) 1164 PushOnScopeChains(New, S); 1165 // If any semantic error occurred, mark the decl as invalid. 1166 if (D.getInvalidType() || InvalidDecl) 1167 New->setInvalidDecl(); 1168 1169 return New; 1170} 1171 1172void Sema::InitializerElementNotConstant(const Expr *Init) { 1173 Diag(Init->getExprLoc(), 1174 diag::err_init_element_not_constant, Init->getSourceRange()); 1175} 1176 1177bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1178 switch (Init->getStmtClass()) { 1179 default: 1180 InitializerElementNotConstant(Init); 1181 return true; 1182 case Expr::ParenExprClass: { 1183 const ParenExpr* PE = cast<ParenExpr>(Init); 1184 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1185 } 1186 case Expr::CompoundLiteralExprClass: 1187 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1188 case Expr::DeclRefExprClass: { 1189 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1190 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1191 if (VD->hasGlobalStorage()) 1192 return false; 1193 InitializerElementNotConstant(Init); 1194 return true; 1195 } 1196 if (isa<FunctionDecl>(D)) 1197 return false; 1198 InitializerElementNotConstant(Init); 1199 return true; 1200 } 1201 case Expr::MemberExprClass: { 1202 const MemberExpr *M = cast<MemberExpr>(Init); 1203 if (M->isArrow()) 1204 return CheckAddressConstantExpression(M->getBase()); 1205 return CheckAddressConstantExpressionLValue(M->getBase()); 1206 } 1207 case Expr::ArraySubscriptExprClass: { 1208 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1209 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1210 return CheckAddressConstantExpression(ASE->getBase()) || 1211 CheckArithmeticConstantExpression(ASE->getIdx()); 1212 } 1213 case Expr::StringLiteralClass: 1214 case Expr::PredefinedExprClass: 1215 return false; 1216 case Expr::UnaryOperatorClass: { 1217 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1218 1219 // C99 6.6p9 1220 if (Exp->getOpcode() == UnaryOperator::Deref) 1221 return CheckAddressConstantExpression(Exp->getSubExpr()); 1222 1223 InitializerElementNotConstant(Init); 1224 return true; 1225 } 1226 } 1227} 1228 1229bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1230 switch (Init->getStmtClass()) { 1231 default: 1232 InitializerElementNotConstant(Init); 1233 return true; 1234 case Expr::ParenExprClass: 1235 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1236 case Expr::StringLiteralClass: 1237 case Expr::ObjCStringLiteralClass: 1238 return false; 1239 case Expr::CallExprClass: 1240 case Expr::CXXOperatorCallExprClass: 1241 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1242 if (cast<CallExpr>(Init)->isBuiltinCall() == 1243 Builtin::BI__builtin___CFStringMakeConstantString) 1244 return false; 1245 1246 InitializerElementNotConstant(Init); 1247 return true; 1248 1249 case Expr::UnaryOperatorClass: { 1250 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1251 1252 // C99 6.6p9 1253 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1254 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1255 1256 if (Exp->getOpcode() == UnaryOperator::Extension) 1257 return CheckAddressConstantExpression(Exp->getSubExpr()); 1258 1259 InitializerElementNotConstant(Init); 1260 return true; 1261 } 1262 case Expr::BinaryOperatorClass: { 1263 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1264 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1265 1266 Expr *PExp = Exp->getLHS(); 1267 Expr *IExp = Exp->getRHS(); 1268 if (IExp->getType()->isPointerType()) 1269 std::swap(PExp, IExp); 1270 1271 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1272 return CheckAddressConstantExpression(PExp) || 1273 CheckArithmeticConstantExpression(IExp); 1274 } 1275 case Expr::ImplicitCastExprClass: 1276 case Expr::CStyleCastExprClass: { 1277 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1278 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1279 // Check for implicit promotion 1280 if (SubExpr->getType()->isFunctionType() || 1281 SubExpr->getType()->isArrayType()) 1282 return CheckAddressConstantExpressionLValue(SubExpr); 1283 } 1284 1285 // Check for pointer->pointer cast 1286 if (SubExpr->getType()->isPointerType()) 1287 return CheckAddressConstantExpression(SubExpr); 1288 1289 if (SubExpr->getType()->isIntegralType()) { 1290 // Check for the special-case of a pointer->int->pointer cast; 1291 // this isn't standard, but some code requires it. See 1292 // PR2720 for an example. 1293 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1294 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1295 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1296 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1297 if (IntWidth >= PointerWidth) { 1298 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1299 } 1300 } 1301 } 1302 } 1303 if (SubExpr->getType()->isArithmeticType()) { 1304 return CheckArithmeticConstantExpression(SubExpr); 1305 } 1306 1307 InitializerElementNotConstant(Init); 1308 return true; 1309 } 1310 case Expr::ConditionalOperatorClass: { 1311 // FIXME: Should we pedwarn here? 1312 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1313 if (!Exp->getCond()->getType()->isArithmeticType()) { 1314 InitializerElementNotConstant(Init); 1315 return true; 1316 } 1317 if (CheckArithmeticConstantExpression(Exp->getCond())) 1318 return true; 1319 if (Exp->getLHS() && 1320 CheckAddressConstantExpression(Exp->getLHS())) 1321 return true; 1322 return CheckAddressConstantExpression(Exp->getRHS()); 1323 } 1324 case Expr::AddrLabelExprClass: 1325 return false; 1326 } 1327} 1328 1329static const Expr* FindExpressionBaseAddress(const Expr* E); 1330 1331static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1332 switch (E->getStmtClass()) { 1333 default: 1334 return E; 1335 case Expr::ParenExprClass: { 1336 const ParenExpr* PE = cast<ParenExpr>(E); 1337 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1338 } 1339 case Expr::MemberExprClass: { 1340 const MemberExpr *M = cast<MemberExpr>(E); 1341 if (M->isArrow()) 1342 return FindExpressionBaseAddress(M->getBase()); 1343 return FindExpressionBaseAddressLValue(M->getBase()); 1344 } 1345 case Expr::ArraySubscriptExprClass: { 1346 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1347 return FindExpressionBaseAddress(ASE->getBase()); 1348 } 1349 case Expr::UnaryOperatorClass: { 1350 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1351 1352 if (Exp->getOpcode() == UnaryOperator::Deref) 1353 return FindExpressionBaseAddress(Exp->getSubExpr()); 1354 1355 return E; 1356 } 1357 } 1358} 1359 1360static const Expr* FindExpressionBaseAddress(const Expr* E) { 1361 switch (E->getStmtClass()) { 1362 default: 1363 return E; 1364 case Expr::ParenExprClass: { 1365 const ParenExpr* PE = cast<ParenExpr>(E); 1366 return FindExpressionBaseAddress(PE->getSubExpr()); 1367 } 1368 case Expr::UnaryOperatorClass: { 1369 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1370 1371 // C99 6.6p9 1372 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1373 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1374 1375 if (Exp->getOpcode() == UnaryOperator::Extension) 1376 return FindExpressionBaseAddress(Exp->getSubExpr()); 1377 1378 return E; 1379 } 1380 case Expr::BinaryOperatorClass: { 1381 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1382 1383 Expr *PExp = Exp->getLHS(); 1384 Expr *IExp = Exp->getRHS(); 1385 if (IExp->getType()->isPointerType()) 1386 std::swap(PExp, IExp); 1387 1388 return FindExpressionBaseAddress(PExp); 1389 } 1390 case Expr::ImplicitCastExprClass: { 1391 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1392 1393 // Check for implicit promotion 1394 if (SubExpr->getType()->isFunctionType() || 1395 SubExpr->getType()->isArrayType()) 1396 return FindExpressionBaseAddressLValue(SubExpr); 1397 1398 // Check for pointer->pointer cast 1399 if (SubExpr->getType()->isPointerType()) 1400 return FindExpressionBaseAddress(SubExpr); 1401 1402 // We assume that we have an arithmetic expression here; 1403 // if we don't, we'll figure it out later 1404 return 0; 1405 } 1406 case Expr::CStyleCastExprClass: { 1407 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1408 1409 // Check for pointer->pointer cast 1410 if (SubExpr->getType()->isPointerType()) 1411 return FindExpressionBaseAddress(SubExpr); 1412 1413 // We assume that we have an arithmetic expression here; 1414 // if we don't, we'll figure it out later 1415 return 0; 1416 } 1417 } 1418} 1419 1420bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1421 switch (Init->getStmtClass()) { 1422 default: 1423 InitializerElementNotConstant(Init); 1424 return true; 1425 case Expr::ParenExprClass: { 1426 const ParenExpr* PE = cast<ParenExpr>(Init); 1427 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1428 } 1429 case Expr::FloatingLiteralClass: 1430 case Expr::IntegerLiteralClass: 1431 case Expr::CharacterLiteralClass: 1432 case Expr::ImaginaryLiteralClass: 1433 case Expr::TypesCompatibleExprClass: 1434 case Expr::CXXBoolLiteralExprClass: 1435 return false; 1436 case Expr::CallExprClass: 1437 case Expr::CXXOperatorCallExprClass: { 1438 const CallExpr *CE = cast<CallExpr>(Init); 1439 1440 // Allow any constant foldable calls to builtins. 1441 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1442 return false; 1443 1444 InitializerElementNotConstant(Init); 1445 return true; 1446 } 1447 case Expr::DeclRefExprClass: { 1448 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1449 if (isa<EnumConstantDecl>(D)) 1450 return false; 1451 InitializerElementNotConstant(Init); 1452 return true; 1453 } 1454 case Expr::CompoundLiteralExprClass: 1455 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1456 // but vectors are allowed to be magic. 1457 if (Init->getType()->isVectorType()) 1458 return false; 1459 InitializerElementNotConstant(Init); 1460 return true; 1461 case Expr::UnaryOperatorClass: { 1462 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1463 1464 switch (Exp->getOpcode()) { 1465 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1466 // See C99 6.6p3. 1467 default: 1468 InitializerElementNotConstant(Init); 1469 return true; 1470 case UnaryOperator::OffsetOf: 1471 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1472 return false; 1473 InitializerElementNotConstant(Init); 1474 return true; 1475 case UnaryOperator::Extension: 1476 case UnaryOperator::LNot: 1477 case UnaryOperator::Plus: 1478 case UnaryOperator::Minus: 1479 case UnaryOperator::Not: 1480 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1481 } 1482 } 1483 case Expr::SizeOfAlignOfExprClass: { 1484 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1485 // Special check for void types, which are allowed as an extension 1486 if (Exp->getTypeOfArgument()->isVoidType()) 1487 return false; 1488 // alignof always evaluates to a constant. 1489 // FIXME: is sizeof(int[3.0]) a constant expression? 1490 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1491 InitializerElementNotConstant(Init); 1492 return true; 1493 } 1494 return false; 1495 } 1496 case Expr::BinaryOperatorClass: { 1497 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1498 1499 if (Exp->getLHS()->getType()->isArithmeticType() && 1500 Exp->getRHS()->getType()->isArithmeticType()) { 1501 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1502 CheckArithmeticConstantExpression(Exp->getRHS()); 1503 } 1504 1505 if (Exp->getLHS()->getType()->isPointerType() && 1506 Exp->getRHS()->getType()->isPointerType()) { 1507 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1508 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1509 1510 // Only allow a null (constant integer) base; we could 1511 // allow some additional cases if necessary, but this 1512 // is sufficient to cover offsetof-like constructs. 1513 if (!LHSBase && !RHSBase) { 1514 return CheckAddressConstantExpression(Exp->getLHS()) || 1515 CheckAddressConstantExpression(Exp->getRHS()); 1516 } 1517 } 1518 1519 InitializerElementNotConstant(Init); 1520 return true; 1521 } 1522 case Expr::ImplicitCastExprClass: 1523 case Expr::CStyleCastExprClass: { 1524 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1525 if (SubExpr->getType()->isArithmeticType()) 1526 return CheckArithmeticConstantExpression(SubExpr); 1527 1528 if (SubExpr->getType()->isPointerType()) { 1529 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1530 // If the pointer has a null base, this is an offsetof-like construct 1531 if (!Base) 1532 return CheckAddressConstantExpression(SubExpr); 1533 } 1534 1535 InitializerElementNotConstant(Init); 1536 return true; 1537 } 1538 case Expr::ConditionalOperatorClass: { 1539 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1540 1541 // If GNU extensions are disabled, we require all operands to be arithmetic 1542 // constant expressions. 1543 if (getLangOptions().NoExtensions) { 1544 return CheckArithmeticConstantExpression(Exp->getCond()) || 1545 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1546 CheckArithmeticConstantExpression(Exp->getRHS()); 1547 } 1548 1549 // Otherwise, we have to emulate some of the behavior of fold here. 1550 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1551 // because it can constant fold things away. To retain compatibility with 1552 // GCC code, we see if we can fold the condition to a constant (which we 1553 // should always be able to do in theory). If so, we only require the 1554 // specified arm of the conditional to be a constant. This is a horrible 1555 // hack, but is require by real world code that uses __builtin_constant_p. 1556 APValue Val; 1557 if (!Exp->getCond()->tryEvaluate(Val, Context)) { 1558 // If the tryEvaluate couldn't fold it, CheckArithmeticConstantExpression 1559 // won't be able to either. Use it to emit the diagnostic though. 1560 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1561 assert(Res && "tryEvaluate couldn't evaluate this constant?"); 1562 return Res; 1563 } 1564 1565 // Verify that the side following the condition is also a constant. 1566 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1567 if (Val.getInt() == 0) 1568 std::swap(TrueSide, FalseSide); 1569 1570 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1571 return true; 1572 1573 // Okay, the evaluated side evaluates to a constant, so we accept this. 1574 // Check to see if the other side is obviously not a constant. If so, 1575 // emit a warning that this is a GNU extension. 1576 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1577 Diag(Init->getExprLoc(), 1578 diag::ext_typecheck_expression_not_constant_but_accepted, 1579 FalseSide->getSourceRange()); 1580 return false; 1581 } 1582 } 1583} 1584 1585bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1586 Init = Init->IgnoreParens(); 1587 1588 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1589 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1590 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1591 1592 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1593 return CheckForConstantInitializer(e->getInitializer(), DclT); 1594 1595 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1596 unsigned numInits = Exp->getNumInits(); 1597 for (unsigned i = 0; i < numInits; i++) { 1598 // FIXME: Need to get the type of the declaration for C++, 1599 // because it could be a reference? 1600 if (CheckForConstantInitializer(Exp->getInit(i), 1601 Exp->getInit(i)->getType())) 1602 return true; 1603 } 1604 return false; 1605 } 1606 1607 if (Init->isNullPointerConstant(Context)) 1608 return false; 1609 if (Init->getType()->isArithmeticType()) { 1610 QualType InitTy = Context.getCanonicalType(Init->getType()) 1611 .getUnqualifiedType(); 1612 if (InitTy == Context.BoolTy) { 1613 // Special handling for pointers implicitly cast to bool; 1614 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1615 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1616 Expr* SubE = ICE->getSubExpr(); 1617 if (SubE->getType()->isPointerType() || 1618 SubE->getType()->isArrayType() || 1619 SubE->getType()->isFunctionType()) { 1620 return CheckAddressConstantExpression(Init); 1621 } 1622 } 1623 } else if (InitTy->isIntegralType()) { 1624 Expr* SubE = 0; 1625 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1626 SubE = CE->getSubExpr(); 1627 // Special check for pointer cast to int; we allow as an extension 1628 // an address constant cast to an integer if the integer 1629 // is of an appropriate width (this sort of code is apparently used 1630 // in some places). 1631 // FIXME: Add pedwarn? 1632 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1633 if (SubE && (SubE->getType()->isPointerType() || 1634 SubE->getType()->isArrayType() || 1635 SubE->getType()->isFunctionType())) { 1636 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1637 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1638 if (IntWidth >= PointerWidth) 1639 return CheckAddressConstantExpression(Init); 1640 } 1641 } 1642 1643 return CheckArithmeticConstantExpression(Init); 1644 } 1645 1646 if (Init->getType()->isPointerType()) 1647 return CheckAddressConstantExpression(Init); 1648 1649 // An array type at the top level that isn't an init-list must 1650 // be a string literal 1651 if (Init->getType()->isArrayType()) 1652 return false; 1653 1654 if (Init->getType()->isFunctionType()) 1655 return false; 1656 1657 // Allow block exprs at top level. 1658 if (Init->getType()->isBlockPointerType()) 1659 return false; 1660 1661 InitializerElementNotConstant(Init); 1662 return true; 1663} 1664 1665void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1666 Decl *RealDecl = static_cast<Decl *>(dcl); 1667 Expr *Init = static_cast<Expr *>(init); 1668 assert(Init && "missing initializer"); 1669 1670 // If there is no declaration, there was an error parsing it. Just ignore 1671 // the initializer. 1672 if (RealDecl == 0) { 1673 delete Init; 1674 return; 1675 } 1676 1677 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1678 if (!VDecl) { 1679 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1680 diag::err_illegal_initializer); 1681 RealDecl->setInvalidDecl(); 1682 return; 1683 } 1684 // Get the decls type and save a reference for later, since 1685 // CheckInitializerTypes may change it. 1686 QualType DclT = VDecl->getType(), SavT = DclT; 1687 if (VDecl->isBlockVarDecl()) { 1688 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1689 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1690 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1691 VDecl->setInvalidDecl(); 1692 } else if (!VDecl->isInvalidDecl()) { 1693 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1694 VDecl->getName())) 1695 VDecl->setInvalidDecl(); 1696 1697 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1698 if (!getLangOptions().CPlusPlus) { 1699 if (SC == VarDecl::Static) // C99 6.7.8p4. 1700 CheckForConstantInitializer(Init, DclT); 1701 } 1702 } 1703 } else if (VDecl->isFileVarDecl()) { 1704 if (VDecl->getStorageClass() == VarDecl::Extern) 1705 Diag(VDecl->getLocation(), diag::warn_extern_init); 1706 if (!VDecl->isInvalidDecl()) 1707 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1708 VDecl->getName())) 1709 VDecl->setInvalidDecl(); 1710 1711 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1712 if (!getLangOptions().CPlusPlus) { 1713 // C99 6.7.8p4. All file scoped initializers need to be constant. 1714 CheckForConstantInitializer(Init, DclT); 1715 } 1716 } 1717 // If the type changed, it means we had an incomplete type that was 1718 // completed by the initializer. For example: 1719 // int ary[] = { 1, 3, 5 }; 1720 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1721 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1722 VDecl->setType(DclT); 1723 Init->setType(DclT); 1724 } 1725 1726 // Attach the initializer to the decl. 1727 VDecl->setInit(Init); 1728 return; 1729} 1730 1731void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1732 Decl *RealDecl = static_cast<Decl *>(dcl); 1733 1734 // If there is no declaration, there was an error parsing it. Just ignore it. 1735 if (RealDecl == 0) 1736 return; 1737 1738 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1739 QualType Type = Var->getType(); 1740 // C++ [dcl.init.ref]p3: 1741 // The initializer can be omitted for a reference only in a 1742 // parameter declaration (8.3.5), in the declaration of a 1743 // function return type, in the declaration of a class member 1744 // within its class declaration (9.2), and where the extern 1745 // specifier is explicitly used. 1746 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1747 Diag(Var->getLocation(), 1748 diag::err_reference_var_requires_init, 1749 Var->getName(), 1750 SourceRange(Var->getLocation(), Var->getLocation())); 1751 Var->setInvalidDecl(); 1752 return; 1753 } 1754 1755 // C++ [dcl.init]p9: 1756 // 1757 // If no initializer is specified for an object, and the object 1758 // is of (possibly cv-qualified) non-POD class type (or array 1759 // thereof), the object shall be default-initialized; if the 1760 // object is of const-qualified type, the underlying class type 1761 // shall have a user-declared default constructor. 1762 if (getLangOptions().CPlusPlus) { 1763 QualType InitType = Type; 1764 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1765 InitType = Array->getElementType(); 1766 if (InitType->isRecordType()) { 1767 const CXXConstructorDecl *Constructor 1768 = PerformInitializationByConstructor(InitType, 0, 0, 1769 Var->getLocation(), 1770 SourceRange(Var->getLocation(), 1771 Var->getLocation()), 1772 Var->getName(), 1773 IK_Default); 1774 if (!Constructor) 1775 Var->setInvalidDecl(); 1776 } 1777 } 1778 1779#if 0 1780 // FIXME: Temporarily disabled because we are not properly parsing 1781 // linkage specifications on declarations, e.g., 1782 // 1783 // extern "C" const CGPoint CGPointerZero; 1784 // 1785 // C++ [dcl.init]p9: 1786 // 1787 // If no initializer is specified for an object, and the 1788 // object is of (possibly cv-qualified) non-POD class type (or 1789 // array thereof), the object shall be default-initialized; if 1790 // the object is of const-qualified type, the underlying class 1791 // type shall have a user-declared default 1792 // constructor. Otherwise, if no initializer is specified for 1793 // an object, the object and its subobjects, if any, have an 1794 // indeterminate initial value; if the object or any of its 1795 // subobjects are of const-qualified type, the program is 1796 // ill-formed. 1797 // 1798 // This isn't technically an error in C, so we don't diagnose it. 1799 // 1800 // FIXME: Actually perform the POD/user-defined default 1801 // constructor check. 1802 if (getLangOptions().CPlusPlus && 1803 Context.getCanonicalType(Type).isConstQualified() && 1804 Var->getStorageClass() != VarDecl::Extern) 1805 Diag(Var->getLocation(), 1806 diag::err_const_var_requires_init, 1807 Var->getName(), 1808 SourceRange(Var->getLocation(), Var->getLocation())); 1809#endif 1810 } 1811} 1812 1813/// The declarators are chained together backwards, reverse the list. 1814Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1815 // Often we have single declarators, handle them quickly. 1816 Decl *GroupDecl = static_cast<Decl*>(group); 1817 if (GroupDecl == 0) 1818 return 0; 1819 1820 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1821 ScopedDecl *NewGroup = 0; 1822 if (Group->getNextDeclarator() == 0) 1823 NewGroup = Group; 1824 else { // reverse the list. 1825 while (Group) { 1826 ScopedDecl *Next = Group->getNextDeclarator(); 1827 Group->setNextDeclarator(NewGroup); 1828 NewGroup = Group; 1829 Group = Next; 1830 } 1831 } 1832 // Perform semantic analysis that depends on having fully processed both 1833 // the declarator and initializer. 1834 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1835 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1836 if (!IDecl) 1837 continue; 1838 QualType T = IDecl->getType(); 1839 1840 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1841 // static storage duration, it shall not have a variable length array. 1842 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1843 IDecl->getStorageClass() == VarDecl::Static) { 1844 if (T->isVariableArrayType()) { 1845 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1846 IDecl->setInvalidDecl(); 1847 } 1848 } 1849 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1850 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1851 if (IDecl->isBlockVarDecl() && 1852 IDecl->getStorageClass() != VarDecl::Extern) { 1853 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1854 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1855 T.getAsString()); 1856 IDecl->setInvalidDecl(); 1857 } 1858 } 1859 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1860 // object that has file scope without an initializer, and without a 1861 // storage-class specifier or with the storage-class specifier "static", 1862 // constitutes a tentative definition. Note: A tentative definition with 1863 // external linkage is valid (C99 6.2.2p5). 1864 if (isTentativeDefinition(IDecl)) { 1865 if (T->isIncompleteArrayType()) { 1866 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1867 // array to be completed. Don't issue a diagnostic. 1868 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1869 // C99 6.9.2p3: If the declaration of an identifier for an object is 1870 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1871 // declared type shall not be an incomplete type. 1872 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1873 T.getAsString()); 1874 IDecl->setInvalidDecl(); 1875 } 1876 } 1877 if (IDecl->isFileVarDecl()) 1878 CheckForFileScopedRedefinitions(S, IDecl); 1879 } 1880 return NewGroup; 1881} 1882 1883/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1884/// to introduce parameters into function prototype scope. 1885Sema::DeclTy * 1886Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1887 // FIXME: disallow CXXScopeSpec for param declarators. 1888 const DeclSpec &DS = D.getDeclSpec(); 1889 1890 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1891 VarDecl::StorageClass StorageClass = VarDecl::None; 1892 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1893 StorageClass = VarDecl::Register; 1894 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1895 Diag(DS.getStorageClassSpecLoc(), 1896 diag::err_invalid_storage_class_in_func_decl); 1897 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1898 } 1899 if (DS.isThreadSpecified()) { 1900 Diag(DS.getThreadSpecLoc(), 1901 diag::err_invalid_storage_class_in_func_decl); 1902 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1903 } 1904 1905 // Check that there are no default arguments inside the type of this 1906 // parameter (C++ only). 1907 if (getLangOptions().CPlusPlus) 1908 CheckExtraCXXDefaultArguments(D); 1909 1910 // In this context, we *do not* check D.getInvalidType(). If the declarator 1911 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1912 // though it will not reflect the user specified type. 1913 QualType parmDeclType = GetTypeForDeclarator(D, S); 1914 1915 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1916 1917 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1918 // Can this happen for params? We already checked that they don't conflict 1919 // among each other. Here they can only shadow globals, which is ok. 1920 IdentifierInfo *II = D.getIdentifier(); 1921 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1922 if (S->isDeclScope(PrevDecl)) { 1923 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1924 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1925 1926 // Recover by removing the name 1927 II = 0; 1928 D.SetIdentifier(0, D.getIdentifierLoc()); 1929 } 1930 } 1931 1932 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1933 // Doing the promotion here has a win and a loss. The win is the type for 1934 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1935 // code generator). The loss is the orginal type isn't preserved. For example: 1936 // 1937 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1938 // int blockvardecl[5]; 1939 // sizeof(parmvardecl); // size == 4 1940 // sizeof(blockvardecl); // size == 20 1941 // } 1942 // 1943 // For expressions, all implicit conversions are captured using the 1944 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1945 // 1946 // FIXME: If a source translation tool needs to see the original type, then 1947 // we need to consider storing both types (in ParmVarDecl)... 1948 // 1949 if (parmDeclType->isArrayType()) { 1950 // int x[restrict 4] -> int *restrict 1951 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1952 } else if (parmDeclType->isFunctionType()) 1953 parmDeclType = Context.getPointerType(parmDeclType); 1954 1955 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1956 D.getIdentifierLoc(), II, 1957 parmDeclType, StorageClass, 1958 0, 0); 1959 1960 if (D.getInvalidType()) 1961 New->setInvalidDecl(); 1962 1963 if (II) 1964 PushOnScopeChains(New, S); 1965 1966 ProcessDeclAttributes(New, D); 1967 return New; 1968 1969} 1970 1971Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1972 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1973 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1974 "Not a function declarator!"); 1975 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1976 1977 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1978 // for a K&R function. 1979 if (!FTI.hasPrototype) { 1980 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1981 if (FTI.ArgInfo[i].Param == 0) { 1982 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1983 FTI.ArgInfo[i].Ident->getName()); 1984 // Implicitly declare the argument as type 'int' for lack of a better 1985 // type. 1986 DeclSpec DS; 1987 const char* PrevSpec; // unused 1988 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1989 PrevSpec); 1990 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1991 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1992 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1993 } 1994 } 1995 } else { 1996 // FIXME: Diagnose arguments without names in C. 1997 } 1998 1999 Scope *GlobalScope = FnBodyScope->getParent(); 2000 2001 return ActOnStartOfFunctionDef(FnBodyScope, 2002 ActOnDeclarator(GlobalScope, D, 0)); 2003} 2004 2005Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2006 Decl *decl = static_cast<Decl*>(D); 2007 FunctionDecl *FD = cast<FunctionDecl>(decl); 2008 2009 // See if this is a redefinition. 2010 const FunctionDecl *Definition; 2011 if (FD->getBody(Definition)) { 2012 Diag(FD->getLocation(), diag::err_redefinition, 2013 FD->getName()); 2014 Diag(Definition->getLocation(), diag::err_previous_definition); 2015 } 2016 2017 PushDeclContext(FD); 2018 2019 // Check the validity of our function parameters 2020 CheckParmsForFunctionDef(FD); 2021 2022 // Introduce our parameters into the function scope 2023 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2024 ParmVarDecl *Param = FD->getParamDecl(p); 2025 // If this has an identifier, add it to the scope stack. 2026 if (Param->getIdentifier()) 2027 PushOnScopeChains(Param, FnBodyScope); 2028 } 2029 2030 return FD; 2031} 2032 2033Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2034 Decl *dcl = static_cast<Decl *>(D); 2035 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2036 FD->setBody((Stmt*)Body); 2037 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2038 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2039 MD->setBody((Stmt*)Body); 2040 } else 2041 return 0; 2042 PopDeclContext(); 2043 // Verify and clean out per-function state. 2044 2045 // Check goto/label use. 2046 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2047 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2048 // Verify that we have no forward references left. If so, there was a goto 2049 // or address of a label taken, but no definition of it. Label fwd 2050 // definitions are indicated with a null substmt. 2051 if (I->second->getSubStmt() == 0) { 2052 LabelStmt *L = I->second; 2053 // Emit error. 2054 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2055 2056 // At this point, we have gotos that use the bogus label. Stitch it into 2057 // the function body so that they aren't leaked and that the AST is well 2058 // formed. 2059 if (Body) { 2060 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2061 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2062 } else { 2063 // The whole function wasn't parsed correctly, just delete this. 2064 delete L; 2065 } 2066 } 2067 } 2068 LabelMap.clear(); 2069 2070 return D; 2071} 2072 2073/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2074/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2075ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2076 IdentifierInfo &II, Scope *S) { 2077 // Extension in C99. Legal in C90, but warn about it. 2078 if (getLangOptions().C99) 2079 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 2080 else 2081 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 2082 2083 // FIXME: handle stuff like: 2084 // void foo() { extern float X(); } 2085 // void bar() { X(); } <-- implicit decl for X in another scope. 2086 2087 // Set a Declarator for the implicit definition: int foo(); 2088 const char *Dummy; 2089 DeclSpec DS; 2090 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2091 Error = Error; // Silence warning. 2092 assert(!Error && "Error setting up implicit decl!"); 2093 Declarator D(DS, Declarator::BlockContext); 2094 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2095 D.SetIdentifier(&II, Loc); 2096 2097 // Insert this function into translation-unit scope. 2098 2099 DeclContext *PrevDC = CurContext; 2100 CurContext = Context.getTranslationUnitDecl(); 2101 2102 FunctionDecl *FD = 2103 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2104 FD->setImplicit(); 2105 2106 CurContext = PrevDC; 2107 2108 return FD; 2109} 2110 2111 2112TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2113 ScopedDecl *LastDeclarator) { 2114 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2115 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2116 2117 // Scope manipulation handled by caller. 2118 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2119 D.getIdentifierLoc(), 2120 D.getIdentifier(), 2121 T, LastDeclarator); 2122 if (D.getInvalidType()) 2123 NewTD->setInvalidDecl(); 2124 return NewTD; 2125} 2126 2127/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2128/// former case, Name will be non-null. In the later case, Name will be null. 2129/// TagType indicates what kind of tag this is. TK indicates whether this is a 2130/// reference/declaration/definition of a tag. 2131Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2132 SourceLocation KWLoc, const CXXScopeSpec &SS, 2133 IdentifierInfo *Name, SourceLocation NameLoc, 2134 AttributeList *Attr) { 2135 // If this is a use of an existing tag, it must have a name. 2136 assert((Name != 0 || TK == TK_Definition) && 2137 "Nameless record must be a definition!"); 2138 2139 TagDecl::TagKind Kind; 2140 switch (TagType) { 2141 default: assert(0 && "Unknown tag type!"); 2142 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2143 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2144 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2145 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2146 } 2147 2148 // Two code paths: a new one for structs/unions/classes where we create 2149 // separate decls for forward declarations, and an old (eventually to 2150 // be removed) code path for enums. 2151 if (Kind != TagDecl::TK_enum) 2152 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2153 2154 DeclContext *DC = CurContext; 2155 ScopedDecl *PrevDecl = 0; 2156 2157 if (Name && SS.isNotEmpty()) { 2158 // We have a nested-name tag ('struct foo::bar'). 2159 2160 // Check for invalid 'foo::'. 2161 if (SS.isInvalid()) { 2162 Name = 0; 2163 goto CreateNewDecl; 2164 } 2165 2166 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2167 // Look-up name inside 'foo::'. 2168 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2169 2170 // A tag 'foo::bar' must already exist. 2171 if (PrevDecl == 0) { 2172 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2173 SS.getRange()); 2174 Name = 0; 2175 goto CreateNewDecl; 2176 } 2177 } else { 2178 // If this is a named struct, check to see if there was a previous forward 2179 // declaration or definition. 2180 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2181 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2182 } 2183 2184 if (PrevDecl) { 2185 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2186 "unexpected Decl type"); 2187 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2188 // If this is a use of a previous tag, or if the tag is already declared 2189 // in the same scope (so that the definition/declaration completes or 2190 // rementions the tag), reuse the decl. 2191 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2192 // Make sure that this wasn't declared as an enum and now used as a 2193 // struct or something similar. 2194 if (PrevTagDecl->getTagKind() != Kind) { 2195 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2196 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2197 // Recover by making this an anonymous redefinition. 2198 Name = 0; 2199 PrevDecl = 0; 2200 } else { 2201 // If this is a use or a forward declaration, we're good. 2202 if (TK != TK_Definition) 2203 return PrevDecl; 2204 2205 // Diagnose attempts to redefine a tag. 2206 if (PrevTagDecl->isDefinition()) { 2207 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2208 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2209 // If this is a redefinition, recover by making this struct be 2210 // anonymous, which will make any later references get the previous 2211 // definition. 2212 Name = 0; 2213 } else { 2214 // Okay, this is definition of a previously declared or referenced 2215 // tag. Move the location of the decl to be the definition site. 2216 PrevDecl->setLocation(NameLoc); 2217 return PrevDecl; 2218 } 2219 } 2220 } 2221 // If we get here, this is a definition of a new struct type in a nested 2222 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2223 // type. 2224 } else { 2225 // PrevDecl is a namespace. 2226 if (isDeclInScope(PrevDecl, DC, S)) { 2227 // The tag name clashes with a namespace name, issue an error and 2228 // recover by making this tag be anonymous. 2229 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2230 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2231 Name = 0; 2232 } 2233 } 2234 } 2235 2236 CreateNewDecl: 2237 2238 // If there is an identifier, use the location of the identifier as the 2239 // location of the decl, otherwise use the location of the struct/union 2240 // keyword. 2241 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2242 2243 // Otherwise, if this is the first time we've seen this tag, create the decl. 2244 TagDecl *New; 2245 if (Kind == TagDecl::TK_enum) { 2246 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2247 // enum X { A, B, C } D; D should chain to X. 2248 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2249 // If this is an undefined enum, warn. 2250 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2251 } else { 2252 // struct/union/class 2253 2254 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2255 // struct X { int A; } D; D should chain to X. 2256 if (getLangOptions().CPlusPlus) 2257 // FIXME: Look for a way to use RecordDecl for simple structs. 2258 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2259 else 2260 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2261 } 2262 2263 // If this has an identifier, add it to the scope stack. 2264 if (Name) { 2265 // The scope passed in may not be a decl scope. Zip up the scope tree until 2266 // we find one that is. 2267 while ((S->getFlags() & Scope::DeclScope) == 0) 2268 S = S->getParent(); 2269 2270 // Add it to the decl chain. 2271 PushOnScopeChains(New, S); 2272 } 2273 2274 if (Attr) 2275 ProcessDeclAttributeList(New, Attr); 2276 2277 // Set the lexical context. If the tag has a C++ scope specifier, the 2278 // lexical context will be different from the semantic context. 2279 New->setLexicalDeclContext(CurContext); 2280 2281 return New; 2282} 2283 2284/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2285/// the logic for enums, we create separate decls for forward declarations. 2286/// This is called by ActOnTag, but eventually will replace its logic. 2287Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2288 SourceLocation KWLoc, const CXXScopeSpec &SS, 2289 IdentifierInfo *Name, SourceLocation NameLoc, 2290 AttributeList *Attr) { 2291 DeclContext *DC = CurContext; 2292 ScopedDecl *PrevDecl = 0; 2293 2294 if (Name && SS.isNotEmpty()) { 2295 // We have a nested-name tag ('struct foo::bar'). 2296 2297 // Check for invalid 'foo::'. 2298 if (SS.isInvalid()) { 2299 Name = 0; 2300 goto CreateNewDecl; 2301 } 2302 2303 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2304 // Look-up name inside 'foo::'. 2305 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2306 2307 // A tag 'foo::bar' must already exist. 2308 if (PrevDecl == 0) { 2309 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2310 SS.getRange()); 2311 Name = 0; 2312 goto CreateNewDecl; 2313 } 2314 } else { 2315 // If this is a named struct, check to see if there was a previous forward 2316 // declaration or definition. 2317 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2318 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2319 } 2320 2321 if (PrevDecl) { 2322 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2323 "unexpected Decl type"); 2324 2325 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2326 // If this is a use of a previous tag, or if the tag is already declared 2327 // in the same scope (so that the definition/declaration completes or 2328 // rementions the tag), reuse the decl. 2329 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2330 // Make sure that this wasn't declared as an enum and now used as a 2331 // struct or something similar. 2332 if (PrevTagDecl->getTagKind() != Kind) { 2333 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2334 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2335 // Recover by making this an anonymous redefinition. 2336 Name = 0; 2337 PrevDecl = 0; 2338 } else { 2339 // If this is a use, return the original decl. 2340 2341 // FIXME: In the future, return a variant or some other clue 2342 // for the consumer of this Decl to know it doesn't own it. 2343 // For our current ASTs this shouldn't be a problem, but will 2344 // need to be changed with DeclGroups. 2345 if (TK == TK_Reference) 2346 return PrevDecl; 2347 2348 // The new decl is a definition? 2349 if (TK == TK_Definition) { 2350 // Diagnose attempts to redefine a tag. 2351 if (RecordDecl* DefRecord = 2352 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2353 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2354 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2355 // If this is a redefinition, recover by making this struct be 2356 // anonymous, which will make any later references get the previous 2357 // definition. 2358 Name = 0; 2359 PrevDecl = 0; 2360 } 2361 // Okay, this is definition of a previously declared or referenced 2362 // tag. We're going to create a new Decl. 2363 } 2364 } 2365 // If we get here we have (another) forward declaration. Just create 2366 // a new decl. 2367 } 2368 else { 2369 // If we get here, this is a definition of a new struct type in a nested 2370 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2371 // new decl/type. We set PrevDecl to NULL so that the Records 2372 // have distinct types. 2373 PrevDecl = 0; 2374 } 2375 } else { 2376 // PrevDecl is a namespace. 2377 if (isDeclInScope(PrevDecl, DC, S)) { 2378 // The tag name clashes with a namespace name, issue an error and 2379 // recover by making this tag be anonymous. 2380 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2381 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2382 Name = 0; 2383 } 2384 } 2385 } 2386 2387 CreateNewDecl: 2388 2389 // If there is an identifier, use the location of the identifier as the 2390 // location of the decl, otherwise use the location of the struct/union 2391 // keyword. 2392 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2393 2394 // Otherwise, if this is the first time we've seen this tag, create the decl. 2395 TagDecl *New; 2396 2397 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2398 // struct X { int A; } D; D should chain to X. 2399 if (getLangOptions().CPlusPlus) 2400 // FIXME: Look for a way to use RecordDecl for simple structs. 2401 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2402 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2403 else 2404 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2405 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2406 2407 // If this has an identifier, add it to the scope stack. 2408 if ((TK == TK_Definition || !PrevDecl) && Name) { 2409 // The scope passed in may not be a decl scope. Zip up the scope tree until 2410 // we find one that is. 2411 while ((S->getFlags() & Scope::DeclScope) == 0) 2412 S = S->getParent(); 2413 2414 // Add it to the decl chain. 2415 PushOnScopeChains(New, S); 2416 } 2417 2418 // Handle #pragma pack: if the #pragma pack stack has non-default 2419 // alignment, make up a packed attribute for this decl. These 2420 // attributes are checked when the ASTContext lays out the 2421 // structure. 2422 // 2423 // It is important for implementing the correct semantics that this 2424 // happen here (in act on tag decl). The #pragma pack stack is 2425 // maintained as a result of parser callbacks which can occur at 2426 // many points during the parsing of a struct declaration (because 2427 // the #pragma tokens are effectively skipped over during the 2428 // parsing of the struct). 2429 if (unsigned Alignment = PackContext.getAlignment()) 2430 New->addAttr(new PackedAttr(Alignment * 8)); 2431 2432 if (Attr) 2433 ProcessDeclAttributeList(New, Attr); 2434 2435 // Set the lexical context. If the tag has a C++ scope specifier, the 2436 // lexical context will be different from the semantic context. 2437 New->setLexicalDeclContext(CurContext); 2438 2439 return New; 2440} 2441 2442 2443/// Collect the instance variables declared in an Objective-C object. Used in 2444/// the creation of structures from objects using the @defs directive. 2445static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2446 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2447 if (Class->getSuperClass()) 2448 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2449 2450 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2451 for (ObjCInterfaceDecl::ivar_iterator 2452 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2453 2454 ObjCIvarDecl* ID = *I; 2455 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2456 ID->getIdentifier(), 2457 ID->getType(), 2458 ID->getBitWidth())); 2459 } 2460} 2461 2462/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2463/// instance variables of ClassName into Decls. 2464void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2465 IdentifierInfo *ClassName, 2466 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2467 // Check that ClassName is a valid class 2468 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2469 if (!Class) { 2470 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 2471 return; 2472 } 2473 // Collect the instance variables 2474 CollectIvars(Class, Context, Decls); 2475} 2476 2477/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2478/// types into constant array types in certain situations which would otherwise 2479/// be errors (for GCC compatibility). 2480static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2481 ASTContext &Context) { 2482 // This method tries to turn a variable array into a constant 2483 // array even when the size isn't an ICE. This is necessary 2484 // for compatibility with code that depends on gcc's buggy 2485 // constant expression folding, like struct {char x[(int)(char*)2];} 2486 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2487 if (!VLATy) return QualType(); 2488 2489 APValue Result; 2490 if (!VLATy->getSizeExpr() || 2491 !VLATy->getSizeExpr()->tryEvaluate(Result, Context)) 2492 return QualType(); 2493 2494 assert(Result.isInt() && "Size expressions must be integers!"); 2495 llvm::APSInt &Res = Result.getInt(); 2496 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2497 return Context.getConstantArrayType(VLATy->getElementType(), 2498 Res, ArrayType::Normal, 0); 2499 return QualType(); 2500} 2501 2502/// ActOnField - Each field of a struct/union/class is passed into this in order 2503/// to create a FieldDecl object for it. 2504Sema::DeclTy *Sema::ActOnField(Scope *S, 2505 SourceLocation DeclStart, 2506 Declarator &D, ExprTy *BitfieldWidth) { 2507 IdentifierInfo *II = D.getIdentifier(); 2508 Expr *BitWidth = (Expr*)BitfieldWidth; 2509 SourceLocation Loc = DeclStart; 2510 if (II) Loc = D.getIdentifierLoc(); 2511 2512 // FIXME: Unnamed fields can be handled in various different ways, for 2513 // example, unnamed unions inject all members into the struct namespace! 2514 2515 if (BitWidth) { 2516 // TODO: Validate. 2517 //printf("WARNING: BITFIELDS IGNORED!\n"); 2518 2519 // 6.7.2.1p3 2520 // 6.7.2.1p4 2521 2522 } else { 2523 // Not a bitfield. 2524 2525 // validate II. 2526 2527 } 2528 2529 QualType T = GetTypeForDeclarator(D, S); 2530 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2531 bool InvalidDecl = false; 2532 2533 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2534 // than a variably modified type. 2535 if (T->isVariablyModifiedType()) { 2536 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2537 if (!FixedTy.isNull()) { 2538 Diag(Loc, diag::warn_illegal_constant_array_size); 2539 T = FixedTy; 2540 } else { 2541 Diag(Loc, diag::err_typecheck_field_variable_size); 2542 T = Context.IntTy; 2543 InvalidDecl = true; 2544 } 2545 } 2546 // FIXME: Chain fielddecls together. 2547 FieldDecl *NewFD; 2548 2549 if (getLangOptions().CPlusPlus) { 2550 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2551 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2552 Loc, II, T, BitWidth); 2553 if (II) 2554 PushOnScopeChains(NewFD, S); 2555 } 2556 else 2557 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2558 2559 ProcessDeclAttributes(NewFD, D); 2560 2561 if (D.getInvalidType() || InvalidDecl) 2562 NewFD->setInvalidDecl(); 2563 return NewFD; 2564} 2565 2566/// TranslateIvarVisibility - Translate visibility from a token ID to an 2567/// AST enum value. 2568static ObjCIvarDecl::AccessControl 2569TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2570 switch (ivarVisibility) { 2571 default: assert(0 && "Unknown visitibility kind"); 2572 case tok::objc_private: return ObjCIvarDecl::Private; 2573 case tok::objc_public: return ObjCIvarDecl::Public; 2574 case tok::objc_protected: return ObjCIvarDecl::Protected; 2575 case tok::objc_package: return ObjCIvarDecl::Package; 2576 } 2577} 2578 2579/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2580/// in order to create an IvarDecl object for it. 2581Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2582 SourceLocation DeclStart, 2583 Declarator &D, ExprTy *BitfieldWidth, 2584 tok::ObjCKeywordKind Visibility) { 2585 IdentifierInfo *II = D.getIdentifier(); 2586 Expr *BitWidth = (Expr*)BitfieldWidth; 2587 SourceLocation Loc = DeclStart; 2588 if (II) Loc = D.getIdentifierLoc(); 2589 2590 // FIXME: Unnamed fields can be handled in various different ways, for 2591 // example, unnamed unions inject all members into the struct namespace! 2592 2593 2594 if (BitWidth) { 2595 // TODO: Validate. 2596 //printf("WARNING: BITFIELDS IGNORED!\n"); 2597 2598 // 6.7.2.1p3 2599 // 6.7.2.1p4 2600 2601 } else { 2602 // Not a bitfield. 2603 2604 // validate II. 2605 2606 } 2607 2608 QualType T = GetTypeForDeclarator(D, S); 2609 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2610 bool InvalidDecl = false; 2611 2612 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2613 // than a variably modified type. 2614 if (T->isVariablyModifiedType()) { 2615 // FIXME: This diagnostic needs work 2616 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2617 InvalidDecl = true; 2618 } 2619 2620 // Get the visibility (access control) for this ivar. 2621 ObjCIvarDecl::AccessControl ac = 2622 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2623 : ObjCIvarDecl::None; 2624 2625 // Construct the decl. 2626 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2627 (Expr *)BitfieldWidth); 2628 2629 // Process attributes attached to the ivar. 2630 ProcessDeclAttributes(NewID, D); 2631 2632 if (D.getInvalidType() || InvalidDecl) 2633 NewID->setInvalidDecl(); 2634 2635 return NewID; 2636} 2637 2638void Sema::ActOnFields(Scope* S, 2639 SourceLocation RecLoc, DeclTy *RecDecl, 2640 DeclTy **Fields, unsigned NumFields, 2641 SourceLocation LBrac, SourceLocation RBrac, 2642 AttributeList *Attr) { 2643 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2644 assert(EnclosingDecl && "missing record or interface decl"); 2645 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2646 2647 if (Record) 2648 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2649 // Diagnose code like: 2650 // struct S { struct S {} X; }; 2651 // We discover this when we complete the outer S. Reject and ignore the 2652 // outer S. 2653 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2654 DefRecord->getKindName()); 2655 Diag(RecLoc, diag::err_previous_definition); 2656 Record->setInvalidDecl(); 2657 return; 2658 } 2659 2660 // Verify that all the fields are okay. 2661 unsigned NumNamedMembers = 0; 2662 llvm::SmallVector<FieldDecl*, 32> RecFields; 2663 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2664 2665 for (unsigned i = 0; i != NumFields; ++i) { 2666 2667 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2668 assert(FD && "missing field decl"); 2669 2670 // Remember all fields. 2671 RecFields.push_back(FD); 2672 2673 // Get the type for the field. 2674 Type *FDTy = FD->getType().getTypePtr(); 2675 2676 // C99 6.7.2.1p2 - A field may not be a function type. 2677 if (FDTy->isFunctionType()) { 2678 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2679 FD->getName()); 2680 FD->setInvalidDecl(); 2681 EnclosingDecl->setInvalidDecl(); 2682 continue; 2683 } 2684 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2685 if (FDTy->isIncompleteType()) { 2686 if (!Record) { // Incomplete ivar type is always an error. 2687 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2688 FD->setInvalidDecl(); 2689 EnclosingDecl->setInvalidDecl(); 2690 continue; 2691 } 2692 if (i != NumFields-1 || // ... that the last member ... 2693 !Record->isStruct() || // ... of a structure ... 2694 !FDTy->isArrayType()) { //... may have incomplete array type. 2695 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2696 FD->setInvalidDecl(); 2697 EnclosingDecl->setInvalidDecl(); 2698 continue; 2699 } 2700 if (NumNamedMembers < 1) { //... must have more than named member ... 2701 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2702 FD->getName()); 2703 FD->setInvalidDecl(); 2704 EnclosingDecl->setInvalidDecl(); 2705 continue; 2706 } 2707 // Okay, we have a legal flexible array member at the end of the struct. 2708 if (Record) 2709 Record->setHasFlexibleArrayMember(true); 2710 } 2711 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2712 /// field of another structure or the element of an array. 2713 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2714 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2715 // If this is a member of a union, then entire union becomes "flexible". 2716 if (Record && Record->isUnion()) { 2717 Record->setHasFlexibleArrayMember(true); 2718 } else { 2719 // If this is a struct/class and this is not the last element, reject 2720 // it. Note that GCC supports variable sized arrays in the middle of 2721 // structures. 2722 if (i != NumFields-1) { 2723 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2724 FD->getName()); 2725 FD->setInvalidDecl(); 2726 EnclosingDecl->setInvalidDecl(); 2727 continue; 2728 } 2729 // We support flexible arrays at the end of structs in other structs 2730 // as an extension. 2731 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2732 FD->getName()); 2733 if (Record) 2734 Record->setHasFlexibleArrayMember(true); 2735 } 2736 } 2737 } 2738 /// A field cannot be an Objective-c object 2739 if (FDTy->isObjCInterfaceType()) { 2740 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2741 FD->getName()); 2742 FD->setInvalidDecl(); 2743 EnclosingDecl->setInvalidDecl(); 2744 continue; 2745 } 2746 // Keep track of the number of named members. 2747 if (IdentifierInfo *II = FD->getIdentifier()) { 2748 // Detect duplicate member names. 2749 if (!FieldIDs.insert(II)) { 2750 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2751 // Find the previous decl. 2752 SourceLocation PrevLoc; 2753 for (unsigned i = 0; ; ++i) { 2754 assert(i != RecFields.size() && "Didn't find previous def!"); 2755 if (RecFields[i]->getIdentifier() == II) { 2756 PrevLoc = RecFields[i]->getLocation(); 2757 break; 2758 } 2759 } 2760 Diag(PrevLoc, diag::err_previous_definition); 2761 FD->setInvalidDecl(); 2762 EnclosingDecl->setInvalidDecl(); 2763 continue; 2764 } 2765 ++NumNamedMembers; 2766 } 2767 } 2768 2769 // Okay, we successfully defined 'Record'. 2770 if (Record) { 2771 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2772 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2773 // Sema::ActOnFinishCXXClassDef. 2774 if (!isa<CXXRecordDecl>(Record)) 2775 Consumer.HandleTagDeclDefinition(Record); 2776 } else { 2777 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2778 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2779 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2780 else if (ObjCImplementationDecl *IMPDecl = 2781 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2782 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2783 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2784 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2785 } 2786 } 2787 2788 if (Attr) 2789 ProcessDeclAttributeList(Record, Attr); 2790} 2791 2792Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2793 DeclTy *lastEnumConst, 2794 SourceLocation IdLoc, IdentifierInfo *Id, 2795 SourceLocation EqualLoc, ExprTy *val) { 2796 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2797 EnumConstantDecl *LastEnumConst = 2798 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2799 Expr *Val = static_cast<Expr*>(val); 2800 2801 // The scope passed in may not be a decl scope. Zip up the scope tree until 2802 // we find one that is. 2803 while ((S->getFlags() & Scope::DeclScope) == 0) 2804 S = S->getParent(); 2805 2806 // Verify that there isn't already something declared with this name in this 2807 // scope. 2808 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2809 // When in C++, we may get a TagDecl with the same name; in this case the 2810 // enum constant will 'hide' the tag. 2811 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2812 "Received TagDecl when not in C++!"); 2813 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2814 if (isa<EnumConstantDecl>(PrevDecl)) 2815 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2816 else 2817 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2818 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2819 delete Val; 2820 return 0; 2821 } 2822 } 2823 2824 llvm::APSInt EnumVal(32); 2825 QualType EltTy; 2826 if (Val) { 2827 // Make sure to promote the operand type to int. 2828 UsualUnaryConversions(Val); 2829 2830 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2831 SourceLocation ExpLoc; 2832 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2833 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2834 Id->getName()); 2835 delete Val; 2836 Val = 0; // Just forget about it. 2837 } else { 2838 EltTy = Val->getType(); 2839 } 2840 } 2841 2842 if (!Val) { 2843 if (LastEnumConst) { 2844 // Assign the last value + 1. 2845 EnumVal = LastEnumConst->getInitVal(); 2846 ++EnumVal; 2847 2848 // Check for overflow on increment. 2849 if (EnumVal < LastEnumConst->getInitVal()) 2850 Diag(IdLoc, diag::warn_enum_value_overflow); 2851 2852 EltTy = LastEnumConst->getType(); 2853 } else { 2854 // First value, set to zero. 2855 EltTy = Context.IntTy; 2856 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2857 } 2858 } 2859 2860 EnumConstantDecl *New = 2861 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2862 Val, EnumVal, 2863 LastEnumConst); 2864 2865 // Register this decl in the current scope stack. 2866 PushOnScopeChains(New, S); 2867 return New; 2868} 2869 2870// FIXME: For consistency with ActOnFields(), we should have the parser 2871// pass in the source location for the left/right braces. 2872void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2873 DeclTy **Elements, unsigned NumElements) { 2874 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2875 2876 if (Enum && Enum->isDefinition()) { 2877 // Diagnose code like: 2878 // enum e0 { 2879 // E0 = sizeof(enum e0 { E1 }) 2880 // }; 2881 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2882 Enum->getName()); 2883 Diag(EnumLoc, diag::err_previous_definition); 2884 Enum->setInvalidDecl(); 2885 return; 2886 } 2887 // TODO: If the result value doesn't fit in an int, it must be a long or long 2888 // long value. ISO C does not support this, but GCC does as an extension, 2889 // emit a warning. 2890 unsigned IntWidth = Context.Target.getIntWidth(); 2891 2892 // Verify that all the values are okay, compute the size of the values, and 2893 // reverse the list. 2894 unsigned NumNegativeBits = 0; 2895 unsigned NumPositiveBits = 0; 2896 2897 // Keep track of whether all elements have type int. 2898 bool AllElementsInt = true; 2899 2900 EnumConstantDecl *EltList = 0; 2901 for (unsigned i = 0; i != NumElements; ++i) { 2902 EnumConstantDecl *ECD = 2903 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2904 if (!ECD) continue; // Already issued a diagnostic. 2905 2906 // If the enum value doesn't fit in an int, emit an extension warning. 2907 const llvm::APSInt &InitVal = ECD->getInitVal(); 2908 assert(InitVal.getBitWidth() >= IntWidth && 2909 "Should have promoted value to int"); 2910 if (InitVal.getBitWidth() > IntWidth) { 2911 llvm::APSInt V(InitVal); 2912 V.trunc(IntWidth); 2913 V.extend(InitVal.getBitWidth()); 2914 if (V != InitVal) 2915 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2916 InitVal.toString(10)); 2917 } 2918 2919 // Keep track of the size of positive and negative values. 2920 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2921 NumPositiveBits = std::max(NumPositiveBits, 2922 (unsigned)InitVal.getActiveBits()); 2923 else 2924 NumNegativeBits = std::max(NumNegativeBits, 2925 (unsigned)InitVal.getMinSignedBits()); 2926 2927 // Keep track of whether every enum element has type int (very commmon). 2928 if (AllElementsInt) 2929 AllElementsInt = ECD->getType() == Context.IntTy; 2930 2931 ECD->setNextDeclarator(EltList); 2932 EltList = ECD; 2933 } 2934 2935 // Figure out the type that should be used for this enum. 2936 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2937 QualType BestType; 2938 unsigned BestWidth; 2939 2940 if (NumNegativeBits) { 2941 // If there is a negative value, figure out the smallest integer type (of 2942 // int/long/longlong) that fits. 2943 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2944 BestType = Context.IntTy; 2945 BestWidth = IntWidth; 2946 } else { 2947 BestWidth = Context.Target.getLongWidth(); 2948 2949 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2950 BestType = Context.LongTy; 2951 else { 2952 BestWidth = Context.Target.getLongLongWidth(); 2953 2954 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2955 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2956 BestType = Context.LongLongTy; 2957 } 2958 } 2959 } else { 2960 // If there is no negative value, figure out which of uint, ulong, ulonglong 2961 // fits. 2962 if (NumPositiveBits <= IntWidth) { 2963 BestType = Context.UnsignedIntTy; 2964 BestWidth = IntWidth; 2965 } else if (NumPositiveBits <= 2966 (BestWidth = Context.Target.getLongWidth())) { 2967 BestType = Context.UnsignedLongTy; 2968 } else { 2969 BestWidth = Context.Target.getLongLongWidth(); 2970 assert(NumPositiveBits <= BestWidth && 2971 "How could an initializer get larger than ULL?"); 2972 BestType = Context.UnsignedLongLongTy; 2973 } 2974 } 2975 2976 // Loop over all of the enumerator constants, changing their types to match 2977 // the type of the enum if needed. 2978 for (unsigned i = 0; i != NumElements; ++i) { 2979 EnumConstantDecl *ECD = 2980 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2981 if (!ECD) continue; // Already issued a diagnostic. 2982 2983 // Standard C says the enumerators have int type, but we allow, as an 2984 // extension, the enumerators to be larger than int size. If each 2985 // enumerator value fits in an int, type it as an int, otherwise type it the 2986 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2987 // that X has type 'int', not 'unsigned'. 2988 if (ECD->getType() == Context.IntTy) { 2989 // Make sure the init value is signed. 2990 llvm::APSInt IV = ECD->getInitVal(); 2991 IV.setIsSigned(true); 2992 ECD->setInitVal(IV); 2993 continue; // Already int type. 2994 } 2995 2996 // Determine whether the value fits into an int. 2997 llvm::APSInt InitVal = ECD->getInitVal(); 2998 bool FitsInInt; 2999 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3000 FitsInInt = InitVal.getActiveBits() < IntWidth; 3001 else 3002 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3003 3004 // If it fits into an integer type, force it. Otherwise force it to match 3005 // the enum decl type. 3006 QualType NewTy; 3007 unsigned NewWidth; 3008 bool NewSign; 3009 if (FitsInInt) { 3010 NewTy = Context.IntTy; 3011 NewWidth = IntWidth; 3012 NewSign = true; 3013 } else if (ECD->getType() == BestType) { 3014 // Already the right type! 3015 continue; 3016 } else { 3017 NewTy = BestType; 3018 NewWidth = BestWidth; 3019 NewSign = BestType->isSignedIntegerType(); 3020 } 3021 3022 // Adjust the APSInt value. 3023 InitVal.extOrTrunc(NewWidth); 3024 InitVal.setIsSigned(NewSign); 3025 ECD->setInitVal(InitVal); 3026 3027 // Adjust the Expr initializer and type. 3028 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3029 /*isLvalue=*/false)); 3030 ECD->setType(NewTy); 3031 } 3032 3033 Enum->defineElements(EltList, BestType); 3034 Consumer.HandleTagDeclDefinition(Enum); 3035} 3036 3037Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3038 ExprTy *expr) { 3039 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3040 3041 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3042} 3043 3044Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3045 SourceLocation LBrace, 3046 SourceLocation RBrace, 3047 const char *Lang, 3048 unsigned StrSize, 3049 DeclTy *D) { 3050 LinkageSpecDecl::LanguageIDs Language; 3051 Decl *dcl = static_cast<Decl *>(D); 3052 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3053 Language = LinkageSpecDecl::lang_c; 3054 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3055 Language = LinkageSpecDecl::lang_cxx; 3056 else { 3057 Diag(Loc, diag::err_bad_language); 3058 return 0; 3059 } 3060 3061 // FIXME: Add all the various semantics of linkage specifications 3062 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3063} 3064 3065void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3066 ExprTy *alignment, SourceLocation PragmaLoc, 3067 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3068 Expr *Alignment = static_cast<Expr *>(alignment); 3069 3070 // If specified then alignment must be a "small" power of two. 3071 unsigned AlignmentVal = 0; 3072 if (Alignment) { 3073 llvm::APSInt Val; 3074 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3075 !Val.isPowerOf2() || 3076 Val.getZExtValue() > 16) { 3077 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3078 delete Alignment; 3079 return; // Ignore 3080 } 3081 3082 AlignmentVal = (unsigned) Val.getZExtValue(); 3083 } 3084 3085 switch (Kind) { 3086 case Action::PPK_Default: // pack([n]) 3087 PackContext.setAlignment(AlignmentVal); 3088 break; 3089 3090 case Action::PPK_Show: // pack(show) 3091 // Show the current alignment, making sure to show the right value 3092 // for the default. 3093 AlignmentVal = PackContext.getAlignment(); 3094 // FIXME: This should come from the target. 3095 if (AlignmentVal == 0) 3096 AlignmentVal = 8; 3097 Diag(PragmaLoc, diag::warn_pragma_pack_show, llvm::utostr(AlignmentVal)); 3098 break; 3099 3100 case Action::PPK_Push: // pack(push [, id] [, [n]) 3101 PackContext.push(Name); 3102 // Set the new alignment if specified. 3103 if (Alignment) 3104 PackContext.setAlignment(AlignmentVal); 3105 break; 3106 3107 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3108 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3109 // "#pragma pack(pop, identifier, n) is undefined" 3110 if (Alignment && Name) 3111 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3112 3113 // Do the pop. 3114 if (!PackContext.pop(Name)) { 3115 // If a name was specified then failure indicates the name 3116 // wasn't found. Otherwise failure indicates the stack was 3117 // empty. 3118 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3119 Name ? "no record matching name" : "stack empty"); 3120 3121 // FIXME: Warn about popping named records as MSVC does. 3122 } else { 3123 // Pop succeeded, set the new alignment if specified. 3124 if (Alignment) 3125 PackContext.setAlignment(AlignmentVal); 3126 } 3127 break; 3128 3129 default: 3130 assert(0 && "Invalid #pragma pack kind."); 3131 } 3132} 3133 3134bool PragmaPackStack::pop(IdentifierInfo *Name) { 3135 if (Stack.empty()) 3136 return false; 3137 3138 // If name is empty just pop top. 3139 if (!Name) { 3140 Alignment = Stack.back().first; 3141 Stack.pop_back(); 3142 return true; 3143 } 3144 3145 // Otherwise, find the named record. 3146 for (unsigned i = Stack.size(); i != 0; ) { 3147 --i; 3148 if (strcmp(Stack[i].second.c_str(), Name->getName()) == 0) { 3149 // Found it, pop up to and including this record. 3150 Alignment = Stack[i].first; 3151 Stack.erase(Stack.begin() + i, Stack.end()); 3152 return true; 3153 } 3154 } 3155 3156 return false; 3157} 3158