SemaDecl.cpp revision 669d5d74b880a8497b92a3ec159145713f4d6519
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/Parse/DeclSpec.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/SourceManager.h" 24// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/HeaderSearch.h" 27#include "llvm/ADT/SmallSet.h" 28#include "llvm/ADT/StringExtras.h" 29using namespace clang; 30 31Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S, 32 const CXXScopeSpec *SS) { 33 DeclContext *DC = 0; 34 if (SS) { 35 if (SS->isInvalid()) 36 return 0; 37 DC = static_cast<DeclContext*>(SS->getScopeRep()); 38 } 39 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 40 41 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 42 isa<ObjCInterfaceDecl>(IIDecl) || 43 isa<TagDecl>(IIDecl))) 44 return IIDecl; 45 return 0; 46} 47 48DeclContext *Sema::getContainingDC(DeclContext *DC) { 49 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 50 // A C++ out-of-line method will return to the file declaration context. 51 if (MD->isOutOfLineDefinition()) 52 return MD->getLexicalDeclContext(); 53 54 // A C++ inline method is parsed *after* the topmost class it was declared in 55 // 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 case DeclSpec::SCS_mutable: 857 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 858 R.getAsString()); 859 InvalidDecl = true; 860 break; 861 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 862 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 863 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 864 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 865 } 866 867 bool isInline = D.getDeclSpec().isInlineSpecified(); 868 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 869 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 870 871 FunctionDecl *NewFD; 872 if (D.getKind() == Declarator::DK_Constructor) { 873 // This is a C++ constructor declaration. 874 assert(DC->isCXXRecord() && 875 "Constructors can only be declared in a member context"); 876 877 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 878 879 // Create the new declaration 880 NewFD = CXXConstructorDecl::Create(Context, 881 cast<CXXRecordDecl>(DC), 882 D.getIdentifierLoc(), II, R, 883 isExplicit, isInline, 884 /*isImplicitlyDeclared=*/false); 885 886 if (isInvalidDecl) 887 NewFD->setInvalidDecl(); 888 } else if (D.getKind() == Declarator::DK_Destructor) { 889 // This is a C++ destructor declaration. 890 if (DC->isCXXRecord()) { 891 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 892 893 NewFD = CXXDestructorDecl::Create(Context, 894 cast<CXXRecordDecl>(DC), 895 D.getIdentifierLoc(), II, R, 896 isInline, 897 /*isImplicitlyDeclared=*/false); 898 899 if (isInvalidDecl) 900 NewFD->setInvalidDecl(); 901 } else { 902 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 903 // Create a FunctionDecl to satisfy the function definition parsing 904 // code path. 905 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 906 II, R, SC, isInline, LastDeclarator, 907 // FIXME: Move to DeclGroup... 908 D.getDeclSpec().getSourceRange().getBegin()); 909 NewFD->setInvalidDecl(); 910 } 911 } else if (D.getKind() == Declarator::DK_Conversion) { 912 if (!DC->isCXXRecord()) { 913 Diag(D.getIdentifierLoc(), 914 diag::err_conv_function_not_member); 915 return 0; 916 } else { 917 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 918 919 NewFD = CXXConversionDecl::Create(Context, 920 cast<CXXRecordDecl>(DC), 921 D.getIdentifierLoc(), II, R, 922 isInline, isExplicit); 923 924 if (isInvalidDecl) 925 NewFD->setInvalidDecl(); 926 } 927 } else if (DC->isCXXRecord()) { 928 // This is a C++ method declaration. 929 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 930 D.getIdentifierLoc(), II, R, 931 (SC == FunctionDecl::Static), isInline, 932 LastDeclarator); 933 } else { 934 NewFD = FunctionDecl::Create(Context, DC, 935 D.getIdentifierLoc(), 936 II, R, SC, isInline, LastDeclarator, 937 // FIXME: Move to DeclGroup... 938 D.getDeclSpec().getSourceRange().getBegin()); 939 } 940 // Handle attributes. 941 ProcessDeclAttributes(NewFD, D); 942 943 // Handle GNU asm-label extension (encoded as an attribute). 944 if (Expr *E = (Expr*) D.getAsmLabel()) { 945 // The parser guarantees this is a string. 946 StringLiteral *SE = cast<StringLiteral>(E); 947 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 948 SE->getByteLength()))); 949 } 950 951 // Copy the parameter declarations from the declarator D to 952 // the function declaration NewFD, if they are available. 953 if (D.getNumTypeObjects() > 0) { 954 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 955 956 // Create Decl objects for each parameter, adding them to the 957 // FunctionDecl. 958 llvm::SmallVector<ParmVarDecl*, 16> Params; 959 960 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 961 // function that takes no arguments, not a function that takes a 962 // single void argument. 963 // We let through "const void" here because Sema::GetTypeForDeclarator 964 // already checks for that case. 965 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 966 FTI.ArgInfo[0].Param && 967 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 968 // empty arg list, don't push any params. 969 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 970 971 // In C++, the empty parameter-type-list must be spelled "void"; a 972 // typedef of void is not permitted. 973 if (getLangOptions().CPlusPlus && 974 Param->getType().getUnqualifiedType() != Context.VoidTy) { 975 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 976 } 977 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 978 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 979 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 980 } 981 982 NewFD->setParams(&Params[0], Params.size()); 983 } else if (R->getAsTypedefType()) { 984 // When we're declaring a function with a typedef, as in the 985 // following example, we'll need to synthesize (unnamed) 986 // parameters for use in the declaration. 987 // 988 // @code 989 // typedef void fn(int); 990 // fn f; 991 // @endcode 992 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 993 if (!FT) { 994 // This is a typedef of a function with no prototype, so we 995 // don't need to do anything. 996 } else if ((FT->getNumArgs() == 0) || 997 (FT->getNumArgs() == 1 && !FT->isVariadic() && 998 FT->getArgType(0)->isVoidType())) { 999 // This is a zero-argument function. We don't need to do anything. 1000 } else { 1001 // Synthesize a parameter for each argument type. 1002 llvm::SmallVector<ParmVarDecl*, 16> Params; 1003 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1004 ArgType != FT->arg_type_end(); ++ArgType) { 1005 Params.push_back(ParmVarDecl::Create(Context, DC, 1006 SourceLocation(), 0, 1007 *ArgType, VarDecl::None, 1008 0, 0)); 1009 } 1010 1011 NewFD->setParams(&Params[0], Params.size()); 1012 } 1013 } 1014 1015 // C++ constructors and destructors are handled by separate 1016 // routines, since they don't require any declaration merging (C++ 1017 // [class.mfct]p2) and they aren't ever pushed into scope, because 1018 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1019 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1020 return ActOnConstructorDeclarator(Constructor); 1021 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1022 return ActOnDestructorDeclarator(Destructor); 1023 else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1024 return ActOnConversionDeclarator(Conversion); 1025 1026 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1027 if (NewFD->isOverloadedOperator() && 1028 CheckOverloadedOperatorDeclaration(NewFD)) 1029 NewFD->setInvalidDecl(); 1030 1031 // Merge the decl with the existing one if appropriate. Since C functions 1032 // are in a flat namespace, make sure we consider decls in outer scopes. 1033 if (PrevDecl && 1034 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1035 bool Redeclaration = false; 1036 1037 // If C++, determine whether NewFD is an overload of PrevDecl or 1038 // a declaration that requires merging. If it's an overload, 1039 // there's no more work to do here; we'll just add the new 1040 // function to the scope. 1041 OverloadedFunctionDecl::function_iterator MatchedDecl; 1042 if (!getLangOptions().CPlusPlus || 1043 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1044 Decl *OldDecl = PrevDecl; 1045 1046 // If PrevDecl was an overloaded function, extract the 1047 // FunctionDecl that matched. 1048 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1049 OldDecl = *MatchedDecl; 1050 1051 // NewFD and PrevDecl represent declarations that need to be 1052 // merged. 1053 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1054 1055 if (NewFD == 0) return 0; 1056 if (Redeclaration) { 1057 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1058 1059 if (OldDecl == PrevDecl) { 1060 // Remove the name binding for the previous 1061 // declaration. We'll add the binding back later, but then 1062 // it will refer to the new declaration (which will 1063 // contain more information). 1064 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1065 } else { 1066 // We need to update the OverloadedFunctionDecl with the 1067 // latest declaration of this function, so that name 1068 // lookup will always refer to the latest declaration of 1069 // this function. 1070 *MatchedDecl = NewFD; 1071 1072 // Add the redeclaration to the current scope, since we'll 1073 // be skipping PushOnScopeChains. 1074 S->AddDecl(NewFD); 1075 1076 return NewFD; 1077 } 1078 } 1079 } 1080 } 1081 New = NewFD; 1082 1083 // In C++, check default arguments now that we have merged decls. 1084 if (getLangOptions().CPlusPlus) 1085 CheckCXXDefaultArguments(NewFD); 1086 } else { 1087 // Check that there are no default arguments (C++ only). 1088 if (getLangOptions().CPlusPlus) 1089 CheckExtraCXXDefaultArguments(D); 1090 1091 if (R.getTypePtr()->isObjCInterfaceType()) { 1092 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 1093 D.getIdentifier()->getName()); 1094 InvalidDecl = true; 1095 } 1096 1097 VarDecl *NewVD; 1098 VarDecl::StorageClass SC; 1099 switch (D.getDeclSpec().getStorageClassSpec()) { 1100 default: assert(0 && "Unknown storage class!"); 1101 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1102 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1103 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1104 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1105 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1106 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1107 case DeclSpec::SCS_mutable: 1108 // mutable can only appear on non-static class members, so it's always 1109 // an error here 1110 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1111 InvalidDecl = true; 1112 } 1113 if (DC->isCXXRecord()) { 1114 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1115 // This is a static data member for a C++ class. 1116 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1117 D.getIdentifierLoc(), II, 1118 R, LastDeclarator); 1119 } else { 1120 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1121 if (S->getFnParent() == 0) { 1122 // C99 6.9p2: The storage-class specifiers auto and register shall not 1123 // appear in the declaration specifiers in an external declaration. 1124 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1125 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 1126 R.getAsString()); 1127 InvalidDecl = true; 1128 } 1129 } 1130 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1131 II, R, SC, LastDeclarator, 1132 // FIXME: Move to DeclGroup... 1133 D.getDeclSpec().getSourceRange().getBegin()); 1134 NewVD->setThreadSpecified(ThreadSpecified); 1135 } 1136 // Handle attributes prior to checking for duplicates in MergeVarDecl 1137 ProcessDeclAttributes(NewVD, D); 1138 1139 // Handle GNU asm-label extension (encoded as an attribute). 1140 if (Expr *E = (Expr*) D.getAsmLabel()) { 1141 // The parser guarantees this is a string. 1142 StringLiteral *SE = cast<StringLiteral>(E); 1143 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1144 SE->getByteLength()))); 1145 } 1146 1147 // Emit an error if an address space was applied to decl with local storage. 1148 // This includes arrays of objects with address space qualifiers, but not 1149 // automatic variables that point to other address spaces. 1150 // ISO/IEC TR 18037 S5.1.2 1151 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1152 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1153 InvalidDecl = true; 1154 } 1155 // Merge the decl with the existing one if appropriate. If the decl is 1156 // in an outer scope, it isn't the same thing. 1157 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1158 NewVD = MergeVarDecl(NewVD, PrevDecl); 1159 if (NewVD == 0) return 0; 1160 } 1161 New = NewVD; 1162 } 1163 1164 // Set the lexical context. If the declarator has a C++ scope specifier, the 1165 // lexical context will be different from the semantic context. 1166 New->setLexicalDeclContext(CurContext); 1167 1168 // If this has an identifier, add it to the scope stack. 1169 if (II) 1170 PushOnScopeChains(New, S); 1171 // If any semantic error occurred, mark the decl as invalid. 1172 if (D.getInvalidType() || InvalidDecl) 1173 New->setInvalidDecl(); 1174 1175 return New; 1176} 1177 1178void Sema::InitializerElementNotConstant(const Expr *Init) { 1179 Diag(Init->getExprLoc(), 1180 diag::err_init_element_not_constant, Init->getSourceRange()); 1181} 1182 1183bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1184 switch (Init->getStmtClass()) { 1185 default: 1186 InitializerElementNotConstant(Init); 1187 return true; 1188 case Expr::ParenExprClass: { 1189 const ParenExpr* PE = cast<ParenExpr>(Init); 1190 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1191 } 1192 case Expr::CompoundLiteralExprClass: 1193 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1194 case Expr::DeclRefExprClass: { 1195 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1196 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1197 if (VD->hasGlobalStorage()) 1198 return false; 1199 InitializerElementNotConstant(Init); 1200 return true; 1201 } 1202 if (isa<FunctionDecl>(D)) 1203 return false; 1204 InitializerElementNotConstant(Init); 1205 return true; 1206 } 1207 case Expr::MemberExprClass: { 1208 const MemberExpr *M = cast<MemberExpr>(Init); 1209 if (M->isArrow()) 1210 return CheckAddressConstantExpression(M->getBase()); 1211 return CheckAddressConstantExpressionLValue(M->getBase()); 1212 } 1213 case Expr::ArraySubscriptExprClass: { 1214 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1215 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1216 return CheckAddressConstantExpression(ASE->getBase()) || 1217 CheckArithmeticConstantExpression(ASE->getIdx()); 1218 } 1219 case Expr::StringLiteralClass: 1220 case Expr::PredefinedExprClass: 1221 return false; 1222 case Expr::UnaryOperatorClass: { 1223 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1224 1225 // C99 6.6p9 1226 if (Exp->getOpcode() == UnaryOperator::Deref) 1227 return CheckAddressConstantExpression(Exp->getSubExpr()); 1228 1229 InitializerElementNotConstant(Init); 1230 return true; 1231 } 1232 } 1233} 1234 1235bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1236 switch (Init->getStmtClass()) { 1237 default: 1238 InitializerElementNotConstant(Init); 1239 return true; 1240 case Expr::ParenExprClass: 1241 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1242 case Expr::StringLiteralClass: 1243 case Expr::ObjCStringLiteralClass: 1244 return false; 1245 case Expr::CallExprClass: 1246 case Expr::CXXOperatorCallExprClass: 1247 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1248 if (cast<CallExpr>(Init)->isBuiltinCall() == 1249 Builtin::BI__builtin___CFStringMakeConstantString) 1250 return false; 1251 1252 InitializerElementNotConstant(Init); 1253 return true; 1254 1255 case Expr::UnaryOperatorClass: { 1256 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1257 1258 // C99 6.6p9 1259 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1260 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1261 1262 if (Exp->getOpcode() == UnaryOperator::Extension) 1263 return CheckAddressConstantExpression(Exp->getSubExpr()); 1264 1265 InitializerElementNotConstant(Init); 1266 return true; 1267 } 1268 case Expr::BinaryOperatorClass: { 1269 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1270 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1271 1272 Expr *PExp = Exp->getLHS(); 1273 Expr *IExp = Exp->getRHS(); 1274 if (IExp->getType()->isPointerType()) 1275 std::swap(PExp, IExp); 1276 1277 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1278 return CheckAddressConstantExpression(PExp) || 1279 CheckArithmeticConstantExpression(IExp); 1280 } 1281 case Expr::ImplicitCastExprClass: 1282 case Expr::CStyleCastExprClass: { 1283 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1284 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1285 // Check for implicit promotion 1286 if (SubExpr->getType()->isFunctionType() || 1287 SubExpr->getType()->isArrayType()) 1288 return CheckAddressConstantExpressionLValue(SubExpr); 1289 } 1290 1291 // Check for pointer->pointer cast 1292 if (SubExpr->getType()->isPointerType()) 1293 return CheckAddressConstantExpression(SubExpr); 1294 1295 if (SubExpr->getType()->isIntegralType()) { 1296 // Check for the special-case of a pointer->int->pointer cast; 1297 // this isn't standard, but some code requires it. See 1298 // PR2720 for an example. 1299 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1300 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1301 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1302 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1303 if (IntWidth >= PointerWidth) { 1304 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1305 } 1306 } 1307 } 1308 } 1309 if (SubExpr->getType()->isArithmeticType()) { 1310 return CheckArithmeticConstantExpression(SubExpr); 1311 } 1312 1313 InitializerElementNotConstant(Init); 1314 return true; 1315 } 1316 case Expr::ConditionalOperatorClass: { 1317 // FIXME: Should we pedwarn here? 1318 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1319 if (!Exp->getCond()->getType()->isArithmeticType()) { 1320 InitializerElementNotConstant(Init); 1321 return true; 1322 } 1323 if (CheckArithmeticConstantExpression(Exp->getCond())) 1324 return true; 1325 if (Exp->getLHS() && 1326 CheckAddressConstantExpression(Exp->getLHS())) 1327 return true; 1328 return CheckAddressConstantExpression(Exp->getRHS()); 1329 } 1330 case Expr::AddrLabelExprClass: 1331 return false; 1332 } 1333} 1334 1335static const Expr* FindExpressionBaseAddress(const Expr* E); 1336 1337static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1338 switch (E->getStmtClass()) { 1339 default: 1340 return E; 1341 case Expr::ParenExprClass: { 1342 const ParenExpr* PE = cast<ParenExpr>(E); 1343 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1344 } 1345 case Expr::MemberExprClass: { 1346 const MemberExpr *M = cast<MemberExpr>(E); 1347 if (M->isArrow()) 1348 return FindExpressionBaseAddress(M->getBase()); 1349 return FindExpressionBaseAddressLValue(M->getBase()); 1350 } 1351 case Expr::ArraySubscriptExprClass: { 1352 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1353 return FindExpressionBaseAddress(ASE->getBase()); 1354 } 1355 case Expr::UnaryOperatorClass: { 1356 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1357 1358 if (Exp->getOpcode() == UnaryOperator::Deref) 1359 return FindExpressionBaseAddress(Exp->getSubExpr()); 1360 1361 return E; 1362 } 1363 } 1364} 1365 1366static const Expr* FindExpressionBaseAddress(const Expr* E) { 1367 switch (E->getStmtClass()) { 1368 default: 1369 return E; 1370 case Expr::ParenExprClass: { 1371 const ParenExpr* PE = cast<ParenExpr>(E); 1372 return FindExpressionBaseAddress(PE->getSubExpr()); 1373 } 1374 case Expr::UnaryOperatorClass: { 1375 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1376 1377 // C99 6.6p9 1378 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1379 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1380 1381 if (Exp->getOpcode() == UnaryOperator::Extension) 1382 return FindExpressionBaseAddress(Exp->getSubExpr()); 1383 1384 return E; 1385 } 1386 case Expr::BinaryOperatorClass: { 1387 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1388 1389 Expr *PExp = Exp->getLHS(); 1390 Expr *IExp = Exp->getRHS(); 1391 if (IExp->getType()->isPointerType()) 1392 std::swap(PExp, IExp); 1393 1394 return FindExpressionBaseAddress(PExp); 1395 } 1396 case Expr::ImplicitCastExprClass: { 1397 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1398 1399 // Check for implicit promotion 1400 if (SubExpr->getType()->isFunctionType() || 1401 SubExpr->getType()->isArrayType()) 1402 return FindExpressionBaseAddressLValue(SubExpr); 1403 1404 // Check for pointer->pointer cast 1405 if (SubExpr->getType()->isPointerType()) 1406 return FindExpressionBaseAddress(SubExpr); 1407 1408 // We assume that we have an arithmetic expression here; 1409 // if we don't, we'll figure it out later 1410 return 0; 1411 } 1412 case Expr::CStyleCastExprClass: { 1413 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1414 1415 // Check for pointer->pointer cast 1416 if (SubExpr->getType()->isPointerType()) 1417 return FindExpressionBaseAddress(SubExpr); 1418 1419 // We assume that we have an arithmetic expression here; 1420 // if we don't, we'll figure it out later 1421 return 0; 1422 } 1423 } 1424} 1425 1426bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1427 switch (Init->getStmtClass()) { 1428 default: 1429 InitializerElementNotConstant(Init); 1430 return true; 1431 case Expr::ParenExprClass: { 1432 const ParenExpr* PE = cast<ParenExpr>(Init); 1433 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1434 } 1435 case Expr::FloatingLiteralClass: 1436 case Expr::IntegerLiteralClass: 1437 case Expr::CharacterLiteralClass: 1438 case Expr::ImaginaryLiteralClass: 1439 case Expr::TypesCompatibleExprClass: 1440 case Expr::CXXBoolLiteralExprClass: 1441 return false; 1442 case Expr::CallExprClass: 1443 case Expr::CXXOperatorCallExprClass: { 1444 const CallExpr *CE = cast<CallExpr>(Init); 1445 1446 // Allow any constant foldable calls to builtins. 1447 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1448 return false; 1449 1450 InitializerElementNotConstant(Init); 1451 return true; 1452 } 1453 case Expr::DeclRefExprClass: { 1454 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1455 if (isa<EnumConstantDecl>(D)) 1456 return false; 1457 InitializerElementNotConstant(Init); 1458 return true; 1459 } 1460 case Expr::CompoundLiteralExprClass: 1461 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1462 // but vectors are allowed to be magic. 1463 if (Init->getType()->isVectorType()) 1464 return false; 1465 InitializerElementNotConstant(Init); 1466 return true; 1467 case Expr::UnaryOperatorClass: { 1468 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1469 1470 switch (Exp->getOpcode()) { 1471 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1472 // See C99 6.6p3. 1473 default: 1474 InitializerElementNotConstant(Init); 1475 return true; 1476 case UnaryOperator::OffsetOf: 1477 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1478 return false; 1479 InitializerElementNotConstant(Init); 1480 return true; 1481 case UnaryOperator::Extension: 1482 case UnaryOperator::LNot: 1483 case UnaryOperator::Plus: 1484 case UnaryOperator::Minus: 1485 case UnaryOperator::Not: 1486 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1487 } 1488 } 1489 case Expr::SizeOfAlignOfExprClass: { 1490 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1491 // Special check for void types, which are allowed as an extension 1492 if (Exp->getTypeOfArgument()->isVoidType()) 1493 return false; 1494 // alignof always evaluates to a constant. 1495 // FIXME: is sizeof(int[3.0]) a constant expression? 1496 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1497 InitializerElementNotConstant(Init); 1498 return true; 1499 } 1500 return false; 1501 } 1502 case Expr::BinaryOperatorClass: { 1503 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1504 1505 if (Exp->getLHS()->getType()->isArithmeticType() && 1506 Exp->getRHS()->getType()->isArithmeticType()) { 1507 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1508 CheckArithmeticConstantExpression(Exp->getRHS()); 1509 } 1510 1511 if (Exp->getLHS()->getType()->isPointerType() && 1512 Exp->getRHS()->getType()->isPointerType()) { 1513 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1514 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1515 1516 // Only allow a null (constant integer) base; we could 1517 // allow some additional cases if necessary, but this 1518 // is sufficient to cover offsetof-like constructs. 1519 if (!LHSBase && !RHSBase) { 1520 return CheckAddressConstantExpression(Exp->getLHS()) || 1521 CheckAddressConstantExpression(Exp->getRHS()); 1522 } 1523 } 1524 1525 InitializerElementNotConstant(Init); 1526 return true; 1527 } 1528 case Expr::ImplicitCastExprClass: 1529 case Expr::CStyleCastExprClass: { 1530 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1531 if (SubExpr->getType()->isArithmeticType()) 1532 return CheckArithmeticConstantExpression(SubExpr); 1533 1534 if (SubExpr->getType()->isPointerType()) { 1535 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1536 // If the pointer has a null base, this is an offsetof-like construct 1537 if (!Base) 1538 return CheckAddressConstantExpression(SubExpr); 1539 } 1540 1541 InitializerElementNotConstant(Init); 1542 return true; 1543 } 1544 case Expr::ConditionalOperatorClass: { 1545 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1546 1547 // If GNU extensions are disabled, we require all operands to be arithmetic 1548 // constant expressions. 1549 if (getLangOptions().NoExtensions) { 1550 return CheckArithmeticConstantExpression(Exp->getCond()) || 1551 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1552 CheckArithmeticConstantExpression(Exp->getRHS()); 1553 } 1554 1555 // Otherwise, we have to emulate some of the behavior of fold here. 1556 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1557 // because it can constant fold things away. To retain compatibility with 1558 // GCC code, we see if we can fold the condition to a constant (which we 1559 // should always be able to do in theory). If so, we only require the 1560 // specified arm of the conditional to be a constant. This is a horrible 1561 // hack, but is require by real world code that uses __builtin_constant_p. 1562 APValue Val; 1563 if (!Exp->getCond()->tryEvaluate(Val, Context)) { 1564 // If the tryEvaluate couldn't fold it, CheckArithmeticConstantExpression 1565 // won't be able to either. Use it to emit the diagnostic though. 1566 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1567 assert(Res && "tryEvaluate couldn't evaluate this constant?"); 1568 return Res; 1569 } 1570 1571 // Verify that the side following the condition is also a constant. 1572 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1573 if (Val.getInt() == 0) 1574 std::swap(TrueSide, FalseSide); 1575 1576 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1577 return true; 1578 1579 // Okay, the evaluated side evaluates to a constant, so we accept this. 1580 // Check to see if the other side is obviously not a constant. If so, 1581 // emit a warning that this is a GNU extension. 1582 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1583 Diag(Init->getExprLoc(), 1584 diag::ext_typecheck_expression_not_constant_but_accepted, 1585 FalseSide->getSourceRange()); 1586 return false; 1587 } 1588 } 1589} 1590 1591bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1592 Init = Init->IgnoreParens(); 1593 1594 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1595 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1596 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1597 1598 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1599 return CheckForConstantInitializer(e->getInitializer(), DclT); 1600 1601 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1602 unsigned numInits = Exp->getNumInits(); 1603 for (unsigned i = 0; i < numInits; i++) { 1604 // FIXME: Need to get the type of the declaration for C++, 1605 // because it could be a reference? 1606 if (CheckForConstantInitializer(Exp->getInit(i), 1607 Exp->getInit(i)->getType())) 1608 return true; 1609 } 1610 return false; 1611 } 1612 1613 if (Init->isNullPointerConstant(Context)) 1614 return false; 1615 if (Init->getType()->isArithmeticType()) { 1616 QualType InitTy = Context.getCanonicalType(Init->getType()) 1617 .getUnqualifiedType(); 1618 if (InitTy == Context.BoolTy) { 1619 // Special handling for pointers implicitly cast to bool; 1620 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1621 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1622 Expr* SubE = ICE->getSubExpr(); 1623 if (SubE->getType()->isPointerType() || 1624 SubE->getType()->isArrayType() || 1625 SubE->getType()->isFunctionType()) { 1626 return CheckAddressConstantExpression(Init); 1627 } 1628 } 1629 } else if (InitTy->isIntegralType()) { 1630 Expr* SubE = 0; 1631 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1632 SubE = CE->getSubExpr(); 1633 // Special check for pointer cast to int; we allow as an extension 1634 // an address constant cast to an integer if the integer 1635 // is of an appropriate width (this sort of code is apparently used 1636 // in some places). 1637 // FIXME: Add pedwarn? 1638 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1639 if (SubE && (SubE->getType()->isPointerType() || 1640 SubE->getType()->isArrayType() || 1641 SubE->getType()->isFunctionType())) { 1642 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1643 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1644 if (IntWidth >= PointerWidth) 1645 return CheckAddressConstantExpression(Init); 1646 } 1647 } 1648 1649 return CheckArithmeticConstantExpression(Init); 1650 } 1651 1652 if (Init->getType()->isPointerType()) 1653 return CheckAddressConstantExpression(Init); 1654 1655 // An array type at the top level that isn't an init-list must 1656 // be a string literal 1657 if (Init->getType()->isArrayType()) 1658 return false; 1659 1660 if (Init->getType()->isFunctionType()) 1661 return false; 1662 1663 // Allow block exprs at top level. 1664 if (Init->getType()->isBlockPointerType()) 1665 return false; 1666 1667 InitializerElementNotConstant(Init); 1668 return true; 1669} 1670 1671void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1672 Decl *RealDecl = static_cast<Decl *>(dcl); 1673 Expr *Init = static_cast<Expr *>(init); 1674 assert(Init && "missing initializer"); 1675 1676 // If there is no declaration, there was an error parsing it. Just ignore 1677 // the initializer. 1678 if (RealDecl == 0) { 1679 delete Init; 1680 return; 1681 } 1682 1683 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1684 if (!VDecl) { 1685 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1686 diag::err_illegal_initializer); 1687 RealDecl->setInvalidDecl(); 1688 return; 1689 } 1690 // Get the decls type and save a reference for later, since 1691 // CheckInitializerTypes may change it. 1692 QualType DclT = VDecl->getType(), SavT = DclT; 1693 if (VDecl->isBlockVarDecl()) { 1694 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1695 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1696 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1697 VDecl->setInvalidDecl(); 1698 } else if (!VDecl->isInvalidDecl()) { 1699 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1700 VDecl->getName())) 1701 VDecl->setInvalidDecl(); 1702 1703 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1704 if (!getLangOptions().CPlusPlus) { 1705 if (SC == VarDecl::Static) // C99 6.7.8p4. 1706 CheckForConstantInitializer(Init, DclT); 1707 } 1708 } 1709 } else if (VDecl->isFileVarDecl()) { 1710 if (VDecl->getStorageClass() == VarDecl::Extern) 1711 Diag(VDecl->getLocation(), diag::warn_extern_init); 1712 if (!VDecl->isInvalidDecl()) 1713 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1714 VDecl->getName())) 1715 VDecl->setInvalidDecl(); 1716 1717 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1718 if (!getLangOptions().CPlusPlus) { 1719 // C99 6.7.8p4. All file scoped initializers need to be constant. 1720 CheckForConstantInitializer(Init, DclT); 1721 } 1722 } 1723 // If the type changed, it means we had an incomplete type that was 1724 // completed by the initializer. For example: 1725 // int ary[] = { 1, 3, 5 }; 1726 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1727 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1728 VDecl->setType(DclT); 1729 Init->setType(DclT); 1730 } 1731 1732 // Attach the initializer to the decl. 1733 VDecl->setInit(Init); 1734 return; 1735} 1736 1737void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1738 Decl *RealDecl = static_cast<Decl *>(dcl); 1739 1740 // If there is no declaration, there was an error parsing it. Just ignore it. 1741 if (RealDecl == 0) 1742 return; 1743 1744 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1745 QualType Type = Var->getType(); 1746 // C++ [dcl.init.ref]p3: 1747 // The initializer can be omitted for a reference only in a 1748 // parameter declaration (8.3.5), in the declaration of a 1749 // function return type, in the declaration of a class member 1750 // within its class declaration (9.2), and where the extern 1751 // specifier is explicitly used. 1752 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1753 Diag(Var->getLocation(), 1754 diag::err_reference_var_requires_init, 1755 Var->getName(), 1756 SourceRange(Var->getLocation(), Var->getLocation())); 1757 Var->setInvalidDecl(); 1758 return; 1759 } 1760 1761 // C++ [dcl.init]p9: 1762 // 1763 // If no initializer is specified for an object, and the object 1764 // is of (possibly cv-qualified) non-POD class type (or array 1765 // thereof), the object shall be default-initialized; if the 1766 // object is of const-qualified type, the underlying class type 1767 // shall have a user-declared default constructor. 1768 if (getLangOptions().CPlusPlus) { 1769 QualType InitType = Type; 1770 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1771 InitType = Array->getElementType(); 1772 if (InitType->isRecordType()) { 1773 const CXXConstructorDecl *Constructor 1774 = PerformInitializationByConstructor(InitType, 0, 0, 1775 Var->getLocation(), 1776 SourceRange(Var->getLocation(), 1777 Var->getLocation()), 1778 Var->getName(), 1779 IK_Default); 1780 if (!Constructor) 1781 Var->setInvalidDecl(); 1782 } 1783 } 1784 1785#if 0 1786 // FIXME: Temporarily disabled because we are not properly parsing 1787 // linkage specifications on declarations, e.g., 1788 // 1789 // extern "C" const CGPoint CGPointerZero; 1790 // 1791 // C++ [dcl.init]p9: 1792 // 1793 // If no initializer is specified for an object, and the 1794 // object is of (possibly cv-qualified) non-POD class type (or 1795 // array thereof), the object shall be default-initialized; if 1796 // the object is of const-qualified type, the underlying class 1797 // type shall have a user-declared default 1798 // constructor. Otherwise, if no initializer is specified for 1799 // an object, the object and its subobjects, if any, have an 1800 // indeterminate initial value; if the object or any of its 1801 // subobjects are of const-qualified type, the program is 1802 // ill-formed. 1803 // 1804 // This isn't technically an error in C, so we don't diagnose it. 1805 // 1806 // FIXME: Actually perform the POD/user-defined default 1807 // constructor check. 1808 if (getLangOptions().CPlusPlus && 1809 Context.getCanonicalType(Type).isConstQualified() && 1810 Var->getStorageClass() != VarDecl::Extern) 1811 Diag(Var->getLocation(), 1812 diag::err_const_var_requires_init, 1813 Var->getName(), 1814 SourceRange(Var->getLocation(), Var->getLocation())); 1815#endif 1816 } 1817} 1818 1819/// The declarators are chained together backwards, reverse the list. 1820Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1821 // Often we have single declarators, handle them quickly. 1822 Decl *GroupDecl = static_cast<Decl*>(group); 1823 if (GroupDecl == 0) 1824 return 0; 1825 1826 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1827 ScopedDecl *NewGroup = 0; 1828 if (Group->getNextDeclarator() == 0) 1829 NewGroup = Group; 1830 else { // reverse the list. 1831 while (Group) { 1832 ScopedDecl *Next = Group->getNextDeclarator(); 1833 Group->setNextDeclarator(NewGroup); 1834 NewGroup = Group; 1835 Group = Next; 1836 } 1837 } 1838 // Perform semantic analysis that depends on having fully processed both 1839 // the declarator and initializer. 1840 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1841 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1842 if (!IDecl) 1843 continue; 1844 QualType T = IDecl->getType(); 1845 1846 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1847 // static storage duration, it shall not have a variable length array. 1848 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1849 IDecl->getStorageClass() == VarDecl::Static) { 1850 if (T->isVariableArrayType()) { 1851 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1852 IDecl->setInvalidDecl(); 1853 } 1854 } 1855 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1856 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1857 if (IDecl->isBlockVarDecl() && 1858 IDecl->getStorageClass() != VarDecl::Extern) { 1859 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1860 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1861 T.getAsString()); 1862 IDecl->setInvalidDecl(); 1863 } 1864 } 1865 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1866 // object that has file scope without an initializer, and without a 1867 // storage-class specifier or with the storage-class specifier "static", 1868 // constitutes a tentative definition. Note: A tentative definition with 1869 // external linkage is valid (C99 6.2.2p5). 1870 if (isTentativeDefinition(IDecl)) { 1871 if (T->isIncompleteArrayType()) { 1872 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1873 // array to be completed. Don't issue a diagnostic. 1874 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1875 // C99 6.9.2p3: If the declaration of an identifier for an object is 1876 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1877 // declared type shall not be an incomplete type. 1878 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1879 T.getAsString()); 1880 IDecl->setInvalidDecl(); 1881 } 1882 } 1883 if (IDecl->isFileVarDecl()) 1884 CheckForFileScopedRedefinitions(S, IDecl); 1885 } 1886 return NewGroup; 1887} 1888 1889/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1890/// to introduce parameters into function prototype scope. 1891Sema::DeclTy * 1892Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1893 // FIXME: disallow CXXScopeSpec for param declarators. 1894 const DeclSpec &DS = D.getDeclSpec(); 1895 1896 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1897 VarDecl::StorageClass StorageClass = VarDecl::None; 1898 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1899 StorageClass = VarDecl::Register; 1900 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1901 Diag(DS.getStorageClassSpecLoc(), 1902 diag::err_invalid_storage_class_in_func_decl); 1903 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1904 } 1905 if (DS.isThreadSpecified()) { 1906 Diag(DS.getThreadSpecLoc(), 1907 diag::err_invalid_storage_class_in_func_decl); 1908 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1909 } 1910 1911 // Check that there are no default arguments inside the type of this 1912 // parameter (C++ only). 1913 if (getLangOptions().CPlusPlus) 1914 CheckExtraCXXDefaultArguments(D); 1915 1916 // In this context, we *do not* check D.getInvalidType(). If the declarator 1917 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1918 // though it will not reflect the user specified type. 1919 QualType parmDeclType = GetTypeForDeclarator(D, S); 1920 1921 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1922 1923 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1924 // Can this happen for params? We already checked that they don't conflict 1925 // among each other. Here they can only shadow globals, which is ok. 1926 IdentifierInfo *II = D.getIdentifier(); 1927 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1928 if (S->isDeclScope(PrevDecl)) { 1929 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1930 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1931 1932 // Recover by removing the name 1933 II = 0; 1934 D.SetIdentifier(0, D.getIdentifierLoc()); 1935 } 1936 } 1937 1938 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1939 // Doing the promotion here has a win and a loss. The win is the type for 1940 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1941 // code generator). The loss is the orginal type isn't preserved. For example: 1942 // 1943 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1944 // int blockvardecl[5]; 1945 // sizeof(parmvardecl); // size == 4 1946 // sizeof(blockvardecl); // size == 20 1947 // } 1948 // 1949 // For expressions, all implicit conversions are captured using the 1950 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1951 // 1952 // FIXME: If a source translation tool needs to see the original type, then 1953 // we need to consider storing both types (in ParmVarDecl)... 1954 // 1955 if (parmDeclType->isArrayType()) { 1956 // int x[restrict 4] -> int *restrict 1957 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1958 } else if (parmDeclType->isFunctionType()) 1959 parmDeclType = Context.getPointerType(parmDeclType); 1960 1961 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1962 D.getIdentifierLoc(), II, 1963 parmDeclType, StorageClass, 1964 0, 0); 1965 1966 if (D.getInvalidType()) 1967 New->setInvalidDecl(); 1968 1969 if (II) 1970 PushOnScopeChains(New, S); 1971 1972 ProcessDeclAttributes(New, D); 1973 return New; 1974 1975} 1976 1977Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1978 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1979 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1980 "Not a function declarator!"); 1981 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1982 1983 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1984 // for a K&R function. 1985 if (!FTI.hasPrototype) { 1986 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1987 if (FTI.ArgInfo[i].Param == 0) { 1988 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1989 FTI.ArgInfo[i].Ident->getName()); 1990 // Implicitly declare the argument as type 'int' for lack of a better 1991 // type. 1992 DeclSpec DS; 1993 const char* PrevSpec; // unused 1994 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1995 PrevSpec); 1996 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1997 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1998 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1999 } 2000 } 2001 } else { 2002 // FIXME: Diagnose arguments without names in C. 2003 } 2004 2005 Scope *GlobalScope = FnBodyScope->getParent(); 2006 2007 return ActOnStartOfFunctionDef(FnBodyScope, 2008 ActOnDeclarator(GlobalScope, D, 0)); 2009} 2010 2011Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2012 Decl *decl = static_cast<Decl*>(D); 2013 FunctionDecl *FD = cast<FunctionDecl>(decl); 2014 2015 // See if this is a redefinition. 2016 const FunctionDecl *Definition; 2017 if (FD->getBody(Definition)) { 2018 Diag(FD->getLocation(), diag::err_redefinition, 2019 FD->getName()); 2020 Diag(Definition->getLocation(), diag::err_previous_definition); 2021 } 2022 2023 PushDeclContext(FD); 2024 2025 // Check the validity of our function parameters 2026 CheckParmsForFunctionDef(FD); 2027 2028 // Introduce our parameters into the function scope 2029 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2030 ParmVarDecl *Param = FD->getParamDecl(p); 2031 // If this has an identifier, add it to the scope stack. 2032 if (Param->getIdentifier()) 2033 PushOnScopeChains(Param, FnBodyScope); 2034 } 2035 2036 return FD; 2037} 2038 2039Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2040 Decl *dcl = static_cast<Decl *>(D); 2041 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2042 FD->setBody((Stmt*)Body); 2043 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2044 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2045 MD->setBody((Stmt*)Body); 2046 } else 2047 return 0; 2048 PopDeclContext(); 2049 // Verify and clean out per-function state. 2050 2051 // Check goto/label use. 2052 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2053 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2054 // Verify that we have no forward references left. If so, there was a goto 2055 // or address of a label taken, but no definition of it. Label fwd 2056 // definitions are indicated with a null substmt. 2057 if (I->second->getSubStmt() == 0) { 2058 LabelStmt *L = I->second; 2059 // Emit error. 2060 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2061 2062 // At this point, we have gotos that use the bogus label. Stitch it into 2063 // the function body so that they aren't leaked and that the AST is well 2064 // formed. 2065 if (Body) { 2066 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2067 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2068 } else { 2069 // The whole function wasn't parsed correctly, just delete this. 2070 delete L; 2071 } 2072 } 2073 } 2074 LabelMap.clear(); 2075 2076 return D; 2077} 2078 2079/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2080/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2081ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2082 IdentifierInfo &II, Scope *S) { 2083 // Extension in C99. Legal in C90, but warn about it. 2084 if (getLangOptions().C99) 2085 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 2086 else 2087 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 2088 2089 // FIXME: handle stuff like: 2090 // void foo() { extern float X(); } 2091 // void bar() { X(); } <-- implicit decl for X in another scope. 2092 2093 // Set a Declarator for the implicit definition: int foo(); 2094 const char *Dummy; 2095 DeclSpec DS; 2096 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2097 Error = Error; // Silence warning. 2098 assert(!Error && "Error setting up implicit decl!"); 2099 Declarator D(DS, Declarator::BlockContext); 2100 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2101 D.SetIdentifier(&II, Loc); 2102 2103 // Insert this function into translation-unit scope. 2104 2105 DeclContext *PrevDC = CurContext; 2106 CurContext = Context.getTranslationUnitDecl(); 2107 2108 FunctionDecl *FD = 2109 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2110 FD->setImplicit(); 2111 2112 CurContext = PrevDC; 2113 2114 return FD; 2115} 2116 2117 2118TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2119 ScopedDecl *LastDeclarator) { 2120 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2121 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2122 2123 // Scope manipulation handled by caller. 2124 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2125 D.getIdentifierLoc(), 2126 D.getIdentifier(), 2127 T, LastDeclarator); 2128 if (D.getInvalidType()) 2129 NewTD->setInvalidDecl(); 2130 return NewTD; 2131} 2132 2133/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2134/// former case, Name will be non-null. In the later case, Name will be null. 2135/// TagType indicates what kind of tag this is. TK indicates whether this is a 2136/// reference/declaration/definition of a tag. 2137Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2138 SourceLocation KWLoc, const CXXScopeSpec &SS, 2139 IdentifierInfo *Name, SourceLocation NameLoc, 2140 AttributeList *Attr) { 2141 // If this is a use of an existing tag, it must have a name. 2142 assert((Name != 0 || TK == TK_Definition) && 2143 "Nameless record must be a definition!"); 2144 2145 TagDecl::TagKind Kind; 2146 switch (TagType) { 2147 default: assert(0 && "Unknown tag type!"); 2148 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2149 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2150 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2151 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2152 } 2153 2154 // Two code paths: a new one for structs/unions/classes where we create 2155 // separate decls for forward declarations, and an old (eventually to 2156 // be removed) code path for enums. 2157 if (Kind != TagDecl::TK_enum) 2158 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2159 2160 DeclContext *DC = CurContext; 2161 ScopedDecl *PrevDecl = 0; 2162 2163 if (Name && SS.isNotEmpty()) { 2164 // We have a nested-name tag ('struct foo::bar'). 2165 2166 // Check for invalid 'foo::'. 2167 if (SS.isInvalid()) { 2168 Name = 0; 2169 goto CreateNewDecl; 2170 } 2171 2172 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2173 // Look-up name inside 'foo::'. 2174 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2175 2176 // A tag 'foo::bar' must already exist. 2177 if (PrevDecl == 0) { 2178 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2179 SS.getRange()); 2180 Name = 0; 2181 goto CreateNewDecl; 2182 } 2183 } else { 2184 // If this is a named struct, check to see if there was a previous forward 2185 // declaration or definition. 2186 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2187 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2188 } 2189 2190 if (PrevDecl) { 2191 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2192 "unexpected Decl type"); 2193 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2194 // If this is a use of a previous tag, or if the tag is already declared 2195 // in the same scope (so that the definition/declaration completes or 2196 // rementions the tag), reuse the decl. 2197 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2198 // Make sure that this wasn't declared as an enum and now used as a 2199 // struct or something similar. 2200 if (PrevTagDecl->getTagKind() != Kind) { 2201 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2202 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2203 // Recover by making this an anonymous redefinition. 2204 Name = 0; 2205 PrevDecl = 0; 2206 } else { 2207 // If this is a use or a forward declaration, we're good. 2208 if (TK != TK_Definition) 2209 return PrevDecl; 2210 2211 // Diagnose attempts to redefine a tag. 2212 if (PrevTagDecl->isDefinition()) { 2213 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2214 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2215 // If this is a redefinition, recover by making this struct be 2216 // anonymous, which will make any later references get the previous 2217 // definition. 2218 Name = 0; 2219 } else { 2220 // Okay, this is definition of a previously declared or referenced 2221 // tag. Move the location of the decl to be the definition site. 2222 PrevDecl->setLocation(NameLoc); 2223 return PrevDecl; 2224 } 2225 } 2226 } 2227 // If we get here, this is a definition of a new struct type in a nested 2228 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2229 // type. 2230 } else { 2231 // PrevDecl is a namespace. 2232 if (isDeclInScope(PrevDecl, DC, S)) { 2233 // The tag name clashes with a namespace name, issue an error and 2234 // recover by making this tag be anonymous. 2235 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2236 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2237 Name = 0; 2238 } 2239 } 2240 } 2241 2242 CreateNewDecl: 2243 2244 // If there is an identifier, use the location of the identifier as the 2245 // location of the decl, otherwise use the location of the struct/union 2246 // keyword. 2247 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2248 2249 // Otherwise, if this is the first time we've seen this tag, create the decl. 2250 TagDecl *New; 2251 if (Kind == TagDecl::TK_enum) { 2252 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2253 // enum X { A, B, C } D; D should chain to X. 2254 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2255 // If this is an undefined enum, warn. 2256 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2257 } else { 2258 // struct/union/class 2259 2260 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2261 // struct X { int A; } D; D should chain to X. 2262 if (getLangOptions().CPlusPlus) 2263 // FIXME: Look for a way to use RecordDecl for simple structs. 2264 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2265 else 2266 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2267 } 2268 2269 // If this has an identifier, add it to the scope stack. 2270 if (Name) { 2271 // The scope passed in may not be a decl scope. Zip up the scope tree until 2272 // we find one that is. 2273 while ((S->getFlags() & Scope::DeclScope) == 0) 2274 S = S->getParent(); 2275 2276 // Add it to the decl chain. 2277 PushOnScopeChains(New, S); 2278 } 2279 2280 if (Attr) 2281 ProcessDeclAttributeList(New, Attr); 2282 2283 // Set the lexical context. If the tag has a C++ scope specifier, the 2284 // lexical context will be different from the semantic context. 2285 New->setLexicalDeclContext(CurContext); 2286 2287 return New; 2288} 2289 2290/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2291/// the logic for enums, we create separate decls for forward declarations. 2292/// This is called by ActOnTag, but eventually will replace its logic. 2293Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2294 SourceLocation KWLoc, const CXXScopeSpec &SS, 2295 IdentifierInfo *Name, SourceLocation NameLoc, 2296 AttributeList *Attr) { 2297 DeclContext *DC = CurContext; 2298 ScopedDecl *PrevDecl = 0; 2299 2300 if (Name && SS.isNotEmpty()) { 2301 // We have a nested-name tag ('struct foo::bar'). 2302 2303 // Check for invalid 'foo::'. 2304 if (SS.isInvalid()) { 2305 Name = 0; 2306 goto CreateNewDecl; 2307 } 2308 2309 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2310 // Look-up name inside 'foo::'. 2311 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2312 2313 // A tag 'foo::bar' must already exist. 2314 if (PrevDecl == 0) { 2315 Diag(NameLoc, diag::err_not_tag_in_scope, Name->getName(), 2316 SS.getRange()); 2317 Name = 0; 2318 goto CreateNewDecl; 2319 } 2320 } else { 2321 // If this is a named struct, check to see if there was a previous forward 2322 // declaration or definition. 2323 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2324 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2325 } 2326 2327 if (PrevDecl) { 2328 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2329 "unexpected Decl type"); 2330 2331 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2332 // If this is a use of a previous tag, or if the tag is already declared 2333 // in the same scope (so that the definition/declaration completes or 2334 // rementions the tag), reuse the decl. 2335 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2336 // Make sure that this wasn't declared as an enum and now used as a 2337 // struct or something similar. 2338 if (PrevTagDecl->getTagKind() != Kind) { 2339 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 2340 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2341 // Recover by making this an anonymous redefinition. 2342 Name = 0; 2343 PrevDecl = 0; 2344 } else { 2345 // If this is a use, return the original decl. 2346 2347 // FIXME: In the future, return a variant or some other clue 2348 // for the consumer of this Decl to know it doesn't own it. 2349 // For our current ASTs this shouldn't be a problem, but will 2350 // need to be changed with DeclGroups. 2351 if (TK == TK_Reference) 2352 return PrevDecl; 2353 2354 // The new decl is a definition? 2355 if (TK == TK_Definition) { 2356 // Diagnose attempts to redefine a tag. 2357 if (RecordDecl* DefRecord = 2358 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2359 Diag(NameLoc, diag::err_redefinition, Name->getName()); 2360 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2361 // If this is a redefinition, recover by making this struct be 2362 // anonymous, which will make any later references get the previous 2363 // definition. 2364 Name = 0; 2365 PrevDecl = 0; 2366 } 2367 // Okay, this is definition of a previously declared or referenced 2368 // tag. We're going to create a new Decl. 2369 } 2370 } 2371 // If we get here we have (another) forward declaration. Just create 2372 // a new decl. 2373 } 2374 else { 2375 // If we get here, this is a definition of a new struct type in a nested 2376 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2377 // new decl/type. We set PrevDecl to NULL so that the Records 2378 // have distinct types. 2379 PrevDecl = 0; 2380 } 2381 } else { 2382 // PrevDecl is a namespace. 2383 if (isDeclInScope(PrevDecl, DC, S)) { 2384 // The tag name clashes with a namespace name, issue an error and 2385 // recover by making this tag be anonymous. 2386 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 2387 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2388 Name = 0; 2389 } 2390 } 2391 } 2392 2393 CreateNewDecl: 2394 2395 // If there is an identifier, use the location of the identifier as the 2396 // location of the decl, otherwise use the location of the struct/union 2397 // keyword. 2398 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2399 2400 // Otherwise, if this is the first time we've seen this tag, create the decl. 2401 TagDecl *New; 2402 2403 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2404 // struct X { int A; } D; D should chain to X. 2405 if (getLangOptions().CPlusPlus) 2406 // FIXME: Look for a way to use RecordDecl for simple structs. 2407 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2408 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2409 else 2410 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2411 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2412 2413 // If this has an identifier, add it to the scope stack. 2414 if ((TK == TK_Definition || !PrevDecl) && Name) { 2415 // The scope passed in may not be a decl scope. Zip up the scope tree until 2416 // we find one that is. 2417 while ((S->getFlags() & Scope::DeclScope) == 0) 2418 S = S->getParent(); 2419 2420 // Add it to the decl chain. 2421 PushOnScopeChains(New, S); 2422 } 2423 2424 // Handle #pragma pack: if the #pragma pack stack has non-default 2425 // alignment, make up a packed attribute for this decl. These 2426 // attributes are checked when the ASTContext lays out the 2427 // structure. 2428 // 2429 // It is important for implementing the correct semantics that this 2430 // happen here (in act on tag decl). The #pragma pack stack is 2431 // maintained as a result of parser callbacks which can occur at 2432 // many points during the parsing of a struct declaration (because 2433 // the #pragma tokens are effectively skipped over during the 2434 // parsing of the struct). 2435 if (unsigned Alignment = PackContext.getAlignment()) 2436 New->addAttr(new PackedAttr(Alignment * 8)); 2437 2438 if (Attr) 2439 ProcessDeclAttributeList(New, Attr); 2440 2441 // Set the lexical context. If the tag has a C++ scope specifier, the 2442 // lexical context will be different from the semantic context. 2443 New->setLexicalDeclContext(CurContext); 2444 2445 return New; 2446} 2447 2448 2449/// Collect the instance variables declared in an Objective-C object. Used in 2450/// the creation of structures from objects using the @defs directive. 2451static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2452 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2453 if (Class->getSuperClass()) 2454 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2455 2456 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2457 for (ObjCInterfaceDecl::ivar_iterator 2458 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2459 2460 ObjCIvarDecl* ID = *I; 2461 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2462 ID->getIdentifier(), 2463 ID->getType(), 2464 ID->getBitWidth())); 2465 } 2466} 2467 2468/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2469/// instance variables of ClassName into Decls. 2470void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2471 IdentifierInfo *ClassName, 2472 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2473 // Check that ClassName is a valid class 2474 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2475 if (!Class) { 2476 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 2477 return; 2478 } 2479 // Collect the instance variables 2480 CollectIvars(Class, Context, Decls); 2481} 2482 2483/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2484/// types into constant array types in certain situations which would otherwise 2485/// be errors (for GCC compatibility). 2486static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2487 ASTContext &Context) { 2488 // This method tries to turn a variable array into a constant 2489 // array even when the size isn't an ICE. This is necessary 2490 // for compatibility with code that depends on gcc's buggy 2491 // constant expression folding, like struct {char x[(int)(char*)2];} 2492 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2493 if (!VLATy) return QualType(); 2494 2495 APValue Result; 2496 if (!VLATy->getSizeExpr() || 2497 !VLATy->getSizeExpr()->tryEvaluate(Result, Context)) 2498 return QualType(); 2499 2500 assert(Result.isInt() && "Size expressions must be integers!"); 2501 llvm::APSInt &Res = Result.getInt(); 2502 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2503 return Context.getConstantArrayType(VLATy->getElementType(), 2504 Res, ArrayType::Normal, 0); 2505 return QualType(); 2506} 2507 2508/// ActOnField - Each field of a struct/union/class is passed into this in order 2509/// to create a FieldDecl object for it. 2510Sema::DeclTy *Sema::ActOnField(Scope *S, 2511 SourceLocation DeclStart, 2512 Declarator &D, ExprTy *BitfieldWidth) { 2513 IdentifierInfo *II = D.getIdentifier(); 2514 Expr *BitWidth = (Expr*)BitfieldWidth; 2515 SourceLocation Loc = DeclStart; 2516 if (II) Loc = D.getIdentifierLoc(); 2517 2518 // FIXME: Unnamed fields can be handled in various different ways, for 2519 // example, unnamed unions inject all members into the struct namespace! 2520 2521 if (BitWidth) { 2522 // TODO: Validate. 2523 //printf("WARNING: BITFIELDS IGNORED!\n"); 2524 2525 // 6.7.2.1p3 2526 // 6.7.2.1p4 2527 2528 } else { 2529 // Not a bitfield. 2530 2531 // validate II. 2532 2533 } 2534 2535 QualType T = GetTypeForDeclarator(D, S); 2536 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2537 bool InvalidDecl = false; 2538 2539 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2540 // than a variably modified type. 2541 if (T->isVariablyModifiedType()) { 2542 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2543 if (!FixedTy.isNull()) { 2544 Diag(Loc, diag::warn_illegal_constant_array_size); 2545 T = FixedTy; 2546 } else { 2547 Diag(Loc, diag::err_typecheck_field_variable_size); 2548 T = Context.IntTy; 2549 InvalidDecl = true; 2550 } 2551 } 2552 // FIXME: Chain fielddecls together. 2553 FieldDecl *NewFD; 2554 2555 if (getLangOptions().CPlusPlus) { 2556 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2557 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2558 Loc, II, T, BitWidth); 2559 if (II) 2560 PushOnScopeChains(NewFD, S); 2561 } 2562 else 2563 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2564 2565 ProcessDeclAttributes(NewFD, D); 2566 2567 if (D.getInvalidType() || InvalidDecl) 2568 NewFD->setInvalidDecl(); 2569 return NewFD; 2570} 2571 2572/// TranslateIvarVisibility - Translate visibility from a token ID to an 2573/// AST enum value. 2574static ObjCIvarDecl::AccessControl 2575TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2576 switch (ivarVisibility) { 2577 default: assert(0 && "Unknown visitibility kind"); 2578 case tok::objc_private: return ObjCIvarDecl::Private; 2579 case tok::objc_public: return ObjCIvarDecl::Public; 2580 case tok::objc_protected: return ObjCIvarDecl::Protected; 2581 case tok::objc_package: return ObjCIvarDecl::Package; 2582 } 2583} 2584 2585/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2586/// in order to create an IvarDecl object for it. 2587Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2588 SourceLocation DeclStart, 2589 Declarator &D, ExprTy *BitfieldWidth, 2590 tok::ObjCKeywordKind Visibility) { 2591 IdentifierInfo *II = D.getIdentifier(); 2592 Expr *BitWidth = (Expr*)BitfieldWidth; 2593 SourceLocation Loc = DeclStart; 2594 if (II) Loc = D.getIdentifierLoc(); 2595 2596 // FIXME: Unnamed fields can be handled in various different ways, for 2597 // example, unnamed unions inject all members into the struct namespace! 2598 2599 2600 if (BitWidth) { 2601 // TODO: Validate. 2602 //printf("WARNING: BITFIELDS IGNORED!\n"); 2603 2604 // 6.7.2.1p3 2605 // 6.7.2.1p4 2606 2607 } else { 2608 // Not a bitfield. 2609 2610 // validate II. 2611 2612 } 2613 2614 QualType T = GetTypeForDeclarator(D, S); 2615 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2616 bool InvalidDecl = false; 2617 2618 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2619 // than a variably modified type. 2620 if (T->isVariablyModifiedType()) { 2621 // FIXME: This diagnostic needs work 2622 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2623 InvalidDecl = true; 2624 } 2625 2626 // Get the visibility (access control) for this ivar. 2627 ObjCIvarDecl::AccessControl ac = 2628 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2629 : ObjCIvarDecl::None; 2630 2631 // Construct the decl. 2632 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2633 (Expr *)BitfieldWidth); 2634 2635 // Process attributes attached to the ivar. 2636 ProcessDeclAttributes(NewID, D); 2637 2638 if (D.getInvalidType() || InvalidDecl) 2639 NewID->setInvalidDecl(); 2640 2641 return NewID; 2642} 2643 2644void Sema::ActOnFields(Scope* S, 2645 SourceLocation RecLoc, DeclTy *RecDecl, 2646 DeclTy **Fields, unsigned NumFields, 2647 SourceLocation LBrac, SourceLocation RBrac, 2648 AttributeList *Attr) { 2649 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2650 assert(EnclosingDecl && "missing record or interface decl"); 2651 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2652 2653 if (Record) 2654 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2655 // Diagnose code like: 2656 // struct S { struct S {} X; }; 2657 // We discover this when we complete the outer S. Reject and ignore the 2658 // outer S. 2659 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2660 DefRecord->getKindName()); 2661 Diag(RecLoc, diag::err_previous_definition); 2662 Record->setInvalidDecl(); 2663 return; 2664 } 2665 2666 // Verify that all the fields are okay. 2667 unsigned NumNamedMembers = 0; 2668 llvm::SmallVector<FieldDecl*, 32> RecFields; 2669 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2670 2671 for (unsigned i = 0; i != NumFields; ++i) { 2672 2673 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2674 assert(FD && "missing field decl"); 2675 2676 // Remember all fields. 2677 RecFields.push_back(FD); 2678 2679 // Get the type for the field. 2680 Type *FDTy = FD->getType().getTypePtr(); 2681 2682 // C99 6.7.2.1p2 - A field may not be a function type. 2683 if (FDTy->isFunctionType()) { 2684 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2685 FD->getName()); 2686 FD->setInvalidDecl(); 2687 EnclosingDecl->setInvalidDecl(); 2688 continue; 2689 } 2690 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2691 if (FDTy->isIncompleteType()) { 2692 if (!Record) { // Incomplete ivar type is always an error. 2693 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2694 FD->setInvalidDecl(); 2695 EnclosingDecl->setInvalidDecl(); 2696 continue; 2697 } 2698 if (i != NumFields-1 || // ... that the last member ... 2699 !Record->isStruct() || // ... of a structure ... 2700 !FDTy->isArrayType()) { //... may have incomplete array type. 2701 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2702 FD->setInvalidDecl(); 2703 EnclosingDecl->setInvalidDecl(); 2704 continue; 2705 } 2706 if (NumNamedMembers < 1) { //... must have more than named member ... 2707 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2708 FD->getName()); 2709 FD->setInvalidDecl(); 2710 EnclosingDecl->setInvalidDecl(); 2711 continue; 2712 } 2713 // Okay, we have a legal flexible array member at the end of the struct. 2714 if (Record) 2715 Record->setHasFlexibleArrayMember(true); 2716 } 2717 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2718 /// field of another structure or the element of an array. 2719 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2720 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2721 // If this is a member of a union, then entire union becomes "flexible". 2722 if (Record && Record->isUnion()) { 2723 Record->setHasFlexibleArrayMember(true); 2724 } else { 2725 // If this is a struct/class and this is not the last element, reject 2726 // it. Note that GCC supports variable sized arrays in the middle of 2727 // structures. 2728 if (i != NumFields-1) { 2729 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2730 FD->getName()); 2731 FD->setInvalidDecl(); 2732 EnclosingDecl->setInvalidDecl(); 2733 continue; 2734 } 2735 // We support flexible arrays at the end of structs in other structs 2736 // as an extension. 2737 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2738 FD->getName()); 2739 if (Record) 2740 Record->setHasFlexibleArrayMember(true); 2741 } 2742 } 2743 } 2744 /// A field cannot be an Objective-c object 2745 if (FDTy->isObjCInterfaceType()) { 2746 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2747 FD->getName()); 2748 FD->setInvalidDecl(); 2749 EnclosingDecl->setInvalidDecl(); 2750 continue; 2751 } 2752 // Keep track of the number of named members. 2753 if (IdentifierInfo *II = FD->getIdentifier()) { 2754 // Detect duplicate member names. 2755 if (!FieldIDs.insert(II)) { 2756 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2757 // Find the previous decl. 2758 SourceLocation PrevLoc; 2759 for (unsigned i = 0; ; ++i) { 2760 assert(i != RecFields.size() && "Didn't find previous def!"); 2761 if (RecFields[i]->getIdentifier() == II) { 2762 PrevLoc = RecFields[i]->getLocation(); 2763 break; 2764 } 2765 } 2766 Diag(PrevLoc, diag::err_previous_definition); 2767 FD->setInvalidDecl(); 2768 EnclosingDecl->setInvalidDecl(); 2769 continue; 2770 } 2771 ++NumNamedMembers; 2772 } 2773 } 2774 2775 // Okay, we successfully defined 'Record'. 2776 if (Record) { 2777 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2778 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2779 // Sema::ActOnFinishCXXClassDef. 2780 if (!isa<CXXRecordDecl>(Record)) 2781 Consumer.HandleTagDeclDefinition(Record); 2782 } else { 2783 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2784 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2785 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2786 else if (ObjCImplementationDecl *IMPDecl = 2787 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2788 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2789 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2790 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2791 } 2792 } 2793 2794 if (Attr) 2795 ProcessDeclAttributeList(Record, Attr); 2796} 2797 2798Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2799 DeclTy *lastEnumConst, 2800 SourceLocation IdLoc, IdentifierInfo *Id, 2801 SourceLocation EqualLoc, ExprTy *val) { 2802 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2803 EnumConstantDecl *LastEnumConst = 2804 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2805 Expr *Val = static_cast<Expr*>(val); 2806 2807 // The scope passed in may not be a decl scope. Zip up the scope tree until 2808 // we find one that is. 2809 while ((S->getFlags() & Scope::DeclScope) == 0) 2810 S = S->getParent(); 2811 2812 // Verify that there isn't already something declared with this name in this 2813 // scope. 2814 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2815 // When in C++, we may get a TagDecl with the same name; in this case the 2816 // enum constant will 'hide' the tag. 2817 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2818 "Received TagDecl when not in C++!"); 2819 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2820 if (isa<EnumConstantDecl>(PrevDecl)) 2821 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2822 else 2823 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2824 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2825 delete Val; 2826 return 0; 2827 } 2828 } 2829 2830 llvm::APSInt EnumVal(32); 2831 QualType EltTy; 2832 if (Val) { 2833 // Make sure to promote the operand type to int. 2834 UsualUnaryConversions(Val); 2835 2836 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2837 SourceLocation ExpLoc; 2838 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2839 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2840 Id->getName()); 2841 delete Val; 2842 Val = 0; // Just forget about it. 2843 } else { 2844 EltTy = Val->getType(); 2845 } 2846 } 2847 2848 if (!Val) { 2849 if (LastEnumConst) { 2850 // Assign the last value + 1. 2851 EnumVal = LastEnumConst->getInitVal(); 2852 ++EnumVal; 2853 2854 // Check for overflow on increment. 2855 if (EnumVal < LastEnumConst->getInitVal()) 2856 Diag(IdLoc, diag::warn_enum_value_overflow); 2857 2858 EltTy = LastEnumConst->getType(); 2859 } else { 2860 // First value, set to zero. 2861 EltTy = Context.IntTy; 2862 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2863 } 2864 } 2865 2866 EnumConstantDecl *New = 2867 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2868 Val, EnumVal, 2869 LastEnumConst); 2870 2871 // Register this decl in the current scope stack. 2872 PushOnScopeChains(New, S); 2873 return New; 2874} 2875 2876// FIXME: For consistency with ActOnFields(), we should have the parser 2877// pass in the source location for the left/right braces. 2878void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2879 DeclTy **Elements, unsigned NumElements) { 2880 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2881 2882 if (Enum && Enum->isDefinition()) { 2883 // Diagnose code like: 2884 // enum e0 { 2885 // E0 = sizeof(enum e0 { E1 }) 2886 // }; 2887 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2888 Enum->getName()); 2889 Diag(EnumLoc, diag::err_previous_definition); 2890 Enum->setInvalidDecl(); 2891 return; 2892 } 2893 // TODO: If the result value doesn't fit in an int, it must be a long or long 2894 // long value. ISO C does not support this, but GCC does as an extension, 2895 // emit a warning. 2896 unsigned IntWidth = Context.Target.getIntWidth(); 2897 2898 // Verify that all the values are okay, compute the size of the values, and 2899 // reverse the list. 2900 unsigned NumNegativeBits = 0; 2901 unsigned NumPositiveBits = 0; 2902 2903 // Keep track of whether all elements have type int. 2904 bool AllElementsInt = true; 2905 2906 EnumConstantDecl *EltList = 0; 2907 for (unsigned i = 0; i != NumElements; ++i) { 2908 EnumConstantDecl *ECD = 2909 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2910 if (!ECD) continue; // Already issued a diagnostic. 2911 2912 // If the enum value doesn't fit in an int, emit an extension warning. 2913 const llvm::APSInt &InitVal = ECD->getInitVal(); 2914 assert(InitVal.getBitWidth() >= IntWidth && 2915 "Should have promoted value to int"); 2916 if (InitVal.getBitWidth() > IntWidth) { 2917 llvm::APSInt V(InitVal); 2918 V.trunc(IntWidth); 2919 V.extend(InitVal.getBitWidth()); 2920 if (V != InitVal) 2921 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2922 InitVal.toString(10)); 2923 } 2924 2925 // Keep track of the size of positive and negative values. 2926 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2927 NumPositiveBits = std::max(NumPositiveBits, 2928 (unsigned)InitVal.getActiveBits()); 2929 else 2930 NumNegativeBits = std::max(NumNegativeBits, 2931 (unsigned)InitVal.getMinSignedBits()); 2932 2933 // Keep track of whether every enum element has type int (very commmon). 2934 if (AllElementsInt) 2935 AllElementsInt = ECD->getType() == Context.IntTy; 2936 2937 ECD->setNextDeclarator(EltList); 2938 EltList = ECD; 2939 } 2940 2941 // Figure out the type that should be used for this enum. 2942 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2943 QualType BestType; 2944 unsigned BestWidth; 2945 2946 if (NumNegativeBits) { 2947 // If there is a negative value, figure out the smallest integer type (of 2948 // int/long/longlong) that fits. 2949 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2950 BestType = Context.IntTy; 2951 BestWidth = IntWidth; 2952 } else { 2953 BestWidth = Context.Target.getLongWidth(); 2954 2955 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2956 BestType = Context.LongTy; 2957 else { 2958 BestWidth = Context.Target.getLongLongWidth(); 2959 2960 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2961 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2962 BestType = Context.LongLongTy; 2963 } 2964 } 2965 } else { 2966 // If there is no negative value, figure out which of uint, ulong, ulonglong 2967 // fits. 2968 if (NumPositiveBits <= IntWidth) { 2969 BestType = Context.UnsignedIntTy; 2970 BestWidth = IntWidth; 2971 } else if (NumPositiveBits <= 2972 (BestWidth = Context.Target.getLongWidth())) { 2973 BestType = Context.UnsignedLongTy; 2974 } else { 2975 BestWidth = Context.Target.getLongLongWidth(); 2976 assert(NumPositiveBits <= BestWidth && 2977 "How could an initializer get larger than ULL?"); 2978 BestType = Context.UnsignedLongLongTy; 2979 } 2980 } 2981 2982 // Loop over all of the enumerator constants, changing their types to match 2983 // the type of the enum if needed. 2984 for (unsigned i = 0; i != NumElements; ++i) { 2985 EnumConstantDecl *ECD = 2986 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2987 if (!ECD) continue; // Already issued a diagnostic. 2988 2989 // Standard C says the enumerators have int type, but we allow, as an 2990 // extension, the enumerators to be larger than int size. If each 2991 // enumerator value fits in an int, type it as an int, otherwise type it the 2992 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2993 // that X has type 'int', not 'unsigned'. 2994 if (ECD->getType() == Context.IntTy) { 2995 // Make sure the init value is signed. 2996 llvm::APSInt IV = ECD->getInitVal(); 2997 IV.setIsSigned(true); 2998 ECD->setInitVal(IV); 2999 continue; // Already int type. 3000 } 3001 3002 // Determine whether the value fits into an int. 3003 llvm::APSInt InitVal = ECD->getInitVal(); 3004 bool FitsInInt; 3005 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3006 FitsInInt = InitVal.getActiveBits() < IntWidth; 3007 else 3008 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3009 3010 // If it fits into an integer type, force it. Otherwise force it to match 3011 // the enum decl type. 3012 QualType NewTy; 3013 unsigned NewWidth; 3014 bool NewSign; 3015 if (FitsInInt) { 3016 NewTy = Context.IntTy; 3017 NewWidth = IntWidth; 3018 NewSign = true; 3019 } else if (ECD->getType() == BestType) { 3020 // Already the right type! 3021 continue; 3022 } else { 3023 NewTy = BestType; 3024 NewWidth = BestWidth; 3025 NewSign = BestType->isSignedIntegerType(); 3026 } 3027 3028 // Adjust the APSInt value. 3029 InitVal.extOrTrunc(NewWidth); 3030 InitVal.setIsSigned(NewSign); 3031 ECD->setInitVal(InitVal); 3032 3033 // Adjust the Expr initializer and type. 3034 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3035 /*isLvalue=*/false)); 3036 ECD->setType(NewTy); 3037 } 3038 3039 Enum->defineElements(EltList, BestType); 3040 Consumer.HandleTagDeclDefinition(Enum); 3041} 3042 3043Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3044 ExprTy *expr) { 3045 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3046 3047 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3048} 3049 3050Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3051 SourceLocation LBrace, 3052 SourceLocation RBrace, 3053 const char *Lang, 3054 unsigned StrSize, 3055 DeclTy *D) { 3056 LinkageSpecDecl::LanguageIDs Language; 3057 Decl *dcl = static_cast<Decl *>(D); 3058 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3059 Language = LinkageSpecDecl::lang_c; 3060 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3061 Language = LinkageSpecDecl::lang_cxx; 3062 else { 3063 Diag(Loc, diag::err_bad_language); 3064 return 0; 3065 } 3066 3067 // FIXME: Add all the various semantics of linkage specifications 3068 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3069} 3070 3071void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3072 ExprTy *alignment, SourceLocation PragmaLoc, 3073 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3074 Expr *Alignment = static_cast<Expr *>(alignment); 3075 3076 // If specified then alignment must be a "small" power of two. 3077 unsigned AlignmentVal = 0; 3078 if (Alignment) { 3079 llvm::APSInt Val; 3080 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3081 !Val.isPowerOf2() || 3082 Val.getZExtValue() > 16) { 3083 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3084 delete Alignment; 3085 return; // Ignore 3086 } 3087 3088 AlignmentVal = (unsigned) Val.getZExtValue(); 3089 } 3090 3091 switch (Kind) { 3092 case Action::PPK_Default: // pack([n]) 3093 PackContext.setAlignment(AlignmentVal); 3094 break; 3095 3096 case Action::PPK_Show: // pack(show) 3097 // Show the current alignment, making sure to show the right value 3098 // for the default. 3099 AlignmentVal = PackContext.getAlignment(); 3100 // FIXME: This should come from the target. 3101 if (AlignmentVal == 0) 3102 AlignmentVal = 8; 3103 Diag(PragmaLoc, diag::warn_pragma_pack_show, llvm::utostr(AlignmentVal)); 3104 break; 3105 3106 case Action::PPK_Push: // pack(push [, id] [, [n]) 3107 PackContext.push(Name); 3108 // Set the new alignment if specified. 3109 if (Alignment) 3110 PackContext.setAlignment(AlignmentVal); 3111 break; 3112 3113 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3114 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3115 // "#pragma pack(pop, identifier, n) is undefined" 3116 if (Alignment && Name) 3117 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3118 3119 // Do the pop. 3120 if (!PackContext.pop(Name)) { 3121 // If a name was specified then failure indicates the name 3122 // wasn't found. Otherwise failure indicates the stack was 3123 // empty. 3124 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3125 Name ? "no record matching name" : "stack empty"); 3126 3127 // FIXME: Warn about popping named records as MSVC does. 3128 } else { 3129 // Pop succeeded, set the new alignment if specified. 3130 if (Alignment) 3131 PackContext.setAlignment(AlignmentVal); 3132 } 3133 break; 3134 3135 default: 3136 assert(0 && "Invalid #pragma pack kind."); 3137 } 3138} 3139 3140bool PragmaPackStack::pop(IdentifierInfo *Name) { 3141 if (Stack.empty()) 3142 return false; 3143 3144 // If name is empty just pop top. 3145 if (!Name) { 3146 Alignment = Stack.back().first; 3147 Stack.pop_back(); 3148 return true; 3149 } 3150 3151 // Otherwise, find the named record. 3152 for (unsigned i = Stack.size(); i != 0; ) { 3153 --i; 3154 if (strcmp(Stack[i].second.c_str(), Name->getName()) == 0) { 3155 // Found it, pop up to and including this record. 3156 Alignment = Stack[i].first; 3157 Stack.erase(Stack.begin() + i, Stack.end()); 3158 return true; 3159 } 3160 } 3161 3162 return false; 3163} 3164