SemaDecl.cpp revision 2bac0f6b3724734d7bb7bf8231bd8511cb49570f
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" 28using namespace clang; 29 30Sema::TypeTy *Sema::isTypeName(IdentifierInfo &II, Scope *S, 31 const CXXScopeSpec *SS) { 32 DeclContext *DC = 0; 33 if (SS) { 34 if (SS->isInvalid()) 35 return 0; 36 DC = static_cast<DeclContext*>(SS->getScopeRep()); 37 } 38 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 39 40 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 41 isa<ObjCInterfaceDecl>(IIDecl) || 42 isa<TagDecl>(IIDecl))) 43 return IIDecl; 44 return 0; 45} 46 47DeclContext *Sema::getContainingDC(DeclContext *DC) { 48 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 49 // A C++ out-of-line method will return to the file declaration context. 50 if (MD->isOutOfLineDefinition()) 51 return MD->getLexicalDeclContext(); 52 53 // A C++ inline method is parsed *after* the topmost class it was declared in 54 // is fully parsed (it's "complete"). 55 // The parsing of a C++ inline method happens at the declaration context of 56 // the topmost (non-nested) class it is lexically declared in. 57 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 58 DC = MD->getParent(); 59 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 60 DC = RD; 61 62 // Return the declaration context of the topmost class the inline method is 63 // declared in. 64 return DC; 65 } 66 67 if (isa<ObjCMethodDecl>(DC)) 68 return Context.getTranslationUnitDecl(); 69 70 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC)) 71 return SD->getLexicalDeclContext(); 72 73 return DC->getLexicalParent(); 74} 75 76void Sema::PushDeclContext(DeclContext *DC) { 77 assert(getContainingDC(DC) == CurContext && 78 "The next DeclContext should be lexically contained in the current one."); 79 CurContext = DC; 80} 81 82void Sema::PopDeclContext() { 83 assert(CurContext && "DeclContext imbalance!"); 84 CurContext = getContainingDC(CurContext); 85} 86 87/// Add this decl to the scope shadowed decl chains. 88void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 89 S->AddDecl(D); 90 91 // C++ [basic.scope]p4: 92 // -- exactly one declaration shall declare a class name or 93 // enumeration name that is not a typedef name and the other 94 // declarations shall all refer to the same object or 95 // enumerator, or all refer to functions and function templates; 96 // in this case the class name or enumeration name is hidden. 97 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 98 // We are pushing the name of a tag (enum or class). 99 IdentifierResolver::iterator 100 I = IdResolver.begin(TD->getIdentifier(), 101 TD->getDeclContext(), false/*LookInParentCtx*/); 102 if (I != IdResolver.end() && isDeclInScope(*I, TD->getDeclContext(), S)) { 103 // There is already a declaration with the same name in the same 104 // scope. It must be found before we find the new declaration, 105 // so swap the order on the shadowed declaration chain. 106 107 IdResolver.AddShadowedDecl(TD, *I); 108 return; 109 } 110 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 111 FunctionDecl *FD = cast<FunctionDecl>(D); 112 // We are pushing the name of a function, which might be an 113 // overloaded name. 114 IdentifierResolver::iterator 115 I = IdResolver.begin(FD->getDeclName(), 116 FD->getDeclContext(), false/*LookInParentCtx*/); 117 if (I != IdResolver.end() && 118 IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) && 119 (isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) { 120 // There is already a declaration with the same name in the same 121 // scope. It must be a function or an overloaded function. 122 OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I); 123 if (!Ovl) { 124 // We haven't yet overloaded this function. Take the existing 125 // FunctionDecl and put it into an OverloadedFunctionDecl. 126 Ovl = OverloadedFunctionDecl::Create(Context, 127 FD->getDeclContext(), 128 FD->getDeclName()); 129 Ovl->addOverload(dyn_cast<FunctionDecl>(*I)); 130 131 // Remove the name binding to the existing FunctionDecl... 132 IdResolver.RemoveDecl(*I); 133 134 // ... and put the OverloadedFunctionDecl in its place. 135 IdResolver.AddDecl(Ovl); 136 } 137 138 // We have an OverloadedFunctionDecl. Add the new FunctionDecl 139 // to its list of overloads. 140 Ovl->addOverload(FD); 141 142 return; 143 } 144 } 145 146 IdResolver.AddDecl(D); 147} 148 149void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 150 if (S->decl_empty()) return; 151 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 152 153 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 154 I != E; ++I) { 155 Decl *TmpD = static_cast<Decl*>(*I); 156 assert(TmpD && "This decl didn't get pushed??"); 157 158 if (isa<CXXFieldDecl>(TmpD)) continue; 159 160 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 161 ScopedDecl *D = cast<ScopedDecl>(TmpD); 162 163 IdentifierInfo *II = D->getIdentifier(); 164 if (!II) continue; 165 166 // We only want to remove the decls from the identifier decl chains for 167 // local scopes, when inside a function/method. 168 if (S->getFnParent() != 0) 169 IdResolver.RemoveDecl(D); 170 171 // Chain this decl to the containing DeclContext. 172 D->setNext(CurContext->getDeclChain()); 173 CurContext->setDeclChain(D); 174 } 175} 176 177/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 178/// return 0 if one not found. 179ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 180 // The third "scope" argument is 0 since we aren't enabling lazy built-in 181 // creation from this context. 182 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 183 184 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 185} 186 187/// LookupDecl - Look up the inner-most declaration in the specified 188/// namespace. 189Decl *Sema::LookupDecl(DeclarationName Name, unsigned NSI, Scope *S, 190 const DeclContext *LookupCtx, 191 bool enableLazyBuiltinCreation) { 192 if (!Name) return 0; 193 unsigned NS = NSI; 194 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 195 NS |= Decl::IDNS_Tag; 196 197 IdentifierResolver::iterator 198 I = LookupCtx ? IdResolver.begin(Name, LookupCtx, false/*LookInParentCtx*/) 199 : IdResolver.begin(Name, CurContext, true/*LookInParentCtx*/); 200 // Scan up the scope chain looking for a decl that matches this identifier 201 // that is in the appropriate namespace. This search should not take long, as 202 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 203 for (; I != IdResolver.end(); ++I) 204 if ((*I)->getIdentifierNamespace() & NS) 205 return *I; 206 207 // If we didn't find a use of this identifier, and if the identifier 208 // corresponds to a compiler builtin, create the decl object for the builtin 209 // now, injecting it into translation unit scope, and return it. 210 if (NS & Decl::IDNS_Ordinary) { 211 IdentifierInfo *II = Name.getAsIdentifierInfo(); 212 if (enableLazyBuiltinCreation && II && 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 && II) { 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 *TypeID = New->getIdentifier(); 298 switch (TypeID->getLength()) { 299 default: break; 300 case 2: 301 if (!TypeID->isStr("id")) 302 break; 303 Context.setObjCIdType(New); 304 return New; 305 case 5: 306 if (!TypeID->isStr("Class")) 307 break; 308 Context.setObjCClassType(New); 309 return New; 310 case 3: 311 if (!TypeID->isStr("SEL")) 312 break; 313 Context.setObjCSelType(New); 314 return New; 315 case 8: 316 if (!TypeID->isStr("Protocol")) 317 break; 318 Context.setObjCProtoType(New->getUnderlyingType()); 319 return New; 320 } 321 // Fall through - the typedef name was not a builtin type. 322 } 323 // Verify the old decl was also a typedef. 324 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 325 if (!Old) { 326 Diag(New->getLocation(), diag::err_redefinition_different_kind, 327 New->getName()); 328 Diag(OldD->getLocation(), diag::err_previous_definition); 329 return New; 330 } 331 332 // If the typedef types are not identical, reject them in all languages and 333 // with any extensions enabled. 334 if (Old->getUnderlyingType() != New->getUnderlyingType() && 335 Context.getCanonicalType(Old->getUnderlyingType()) != 336 Context.getCanonicalType(New->getUnderlyingType())) { 337 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 338 New->getUnderlyingType().getAsString(), 339 Old->getUnderlyingType().getAsString()); 340 Diag(Old->getLocation(), diag::err_previous_definition); 341 return Old; 342 } 343 344 if (getLangOptions().Microsoft) return New; 345 346 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 347 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 348 // *either* declaration is in a system header. The code below implements 349 // this adhoc compatibility rule. FIXME: The following code will not 350 // work properly when compiling ".i" files (containing preprocessed output). 351 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 352 SourceManager &SrcMgr = Context.getSourceManager(); 353 if (SrcMgr.isInSystemHeader(Old->getLocation())) 354 return New; 355 if (SrcMgr.isInSystemHeader(New->getLocation())) 356 return New; 357 } 358 359 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 360 Diag(Old->getLocation(), diag::err_previous_definition); 361 return New; 362} 363 364/// DeclhasAttr - returns true if decl Declaration already has the target 365/// attribute. 366static bool DeclHasAttr(const Decl *decl, const Attr *target) { 367 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 368 if (attr->getKind() == target->getKind()) 369 return true; 370 371 return false; 372} 373 374/// MergeAttributes - append attributes from the Old decl to the New one. 375static void MergeAttributes(Decl *New, Decl *Old) { 376 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 377 378 while (attr) { 379 tmp = attr; 380 attr = attr->getNext(); 381 382 if (!DeclHasAttr(New, tmp)) { 383 New->addAttr(tmp); 384 } else { 385 tmp->setNext(0); 386 delete(tmp); 387 } 388 } 389 390 Old->invalidateAttrs(); 391} 392 393/// MergeFunctionDecl - We just parsed a function 'New' from 394/// declarator D which has the same name and scope as a previous 395/// declaration 'Old'. Figure out how to resolve this situation, 396/// merging decls or emitting diagnostics as appropriate. 397/// Redeclaration will be set true if this New is a redeclaration OldD. 398/// 399/// In C++, New and Old must be declarations that are not 400/// overloaded. Use IsOverload to determine whether New and Old are 401/// overloaded, and to select the Old declaration that New should be 402/// merged with. 403FunctionDecl * 404Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 405 assert(!isa<OverloadedFunctionDecl>(OldD) && 406 "Cannot merge with an overloaded function declaration"); 407 408 Redeclaration = false; 409 // Verify the old decl was also a function. 410 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 411 if (!Old) { 412 Diag(New->getLocation(), diag::err_redefinition_different_kind, 413 New->getName()); 414 Diag(OldD->getLocation(), diag::err_previous_definition); 415 return New; 416 } 417 418 // Determine whether the previous declaration was a definition, 419 // implicit declaration, or a declaration. 420 diag::kind PrevDiag; 421 if (Old->isThisDeclarationADefinition()) 422 PrevDiag = diag::err_previous_definition; 423 else if (Old->isImplicit()) 424 PrevDiag = diag::err_previous_implicit_declaration; 425 else 426 PrevDiag = diag::err_previous_declaration; 427 428 QualType OldQType = Context.getCanonicalType(Old->getType()); 429 QualType NewQType = Context.getCanonicalType(New->getType()); 430 431 if (getLangOptions().CPlusPlus) { 432 // (C++98 13.1p2): 433 // Certain function declarations cannot be overloaded: 434 // -- Function declarations that differ only in the return type 435 // cannot be overloaded. 436 QualType OldReturnType 437 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 438 QualType NewReturnType 439 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 440 if (OldReturnType != NewReturnType) { 441 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 442 Diag(Old->getLocation(), PrevDiag); 443 return New; 444 } 445 446 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 447 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 448 if (OldMethod && NewMethod) { 449 // -- Member function declarations with the same name and the 450 // same parameter types cannot be overloaded if any of them 451 // is a static member function declaration. 452 if (OldMethod->isStatic() || NewMethod->isStatic()) { 453 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 454 Diag(Old->getLocation(), PrevDiag); 455 return New; 456 } 457 } 458 459 // (C++98 8.3.5p3): 460 // All declarations for a function shall agree exactly in both the 461 // return type and the parameter-type-list. 462 if (OldQType == NewQType) { 463 // We have a redeclaration. 464 MergeAttributes(New, Old); 465 Redeclaration = true; 466 return MergeCXXFunctionDecl(New, Old); 467 } 468 469 // Fall through for conflicting redeclarations and redefinitions. 470 } 471 472 // C: Function types need to be compatible, not identical. This handles 473 // duplicate function decls like "void f(int); void f(enum X);" properly. 474 if (!getLangOptions().CPlusPlus && 475 Context.typesAreCompatible(OldQType, NewQType)) { 476 MergeAttributes(New, Old); 477 Redeclaration = true; 478 return New; 479 } 480 481 // A function that has already been declared has been redeclared or defined 482 // with a different type- show appropriate diagnostic 483 484 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 485 // TODO: This is totally simplistic. It should handle merging functions 486 // together etc, merging extern int X; int X; ... 487 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 488 Diag(Old->getLocation(), PrevDiag); 489 return New; 490} 491 492/// Predicate for C "tentative" external object definitions (C99 6.9.2). 493static bool isTentativeDefinition(VarDecl *VD) { 494 if (VD->isFileVarDecl()) 495 return (!VD->getInit() && 496 (VD->getStorageClass() == VarDecl::None || 497 VD->getStorageClass() == VarDecl::Static)); 498 return false; 499} 500 501/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 502/// when dealing with C "tentative" external object definitions (C99 6.9.2). 503void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 504 bool VDIsTentative = isTentativeDefinition(VD); 505 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 506 507 for (IdentifierResolver::iterator 508 I = IdResolver.begin(VD->getIdentifier(), 509 VD->getDeclContext(), false/*LookInParentCtx*/), 510 E = IdResolver.end(); I != E; ++I) { 511 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 512 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 513 514 // Handle the following case: 515 // int a[10]; 516 // int a[]; - the code below makes sure we set the correct type. 517 // int a[11]; - this is an error, size isn't 10. 518 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 519 OldDecl->getType()->isConstantArrayType()) 520 VD->setType(OldDecl->getType()); 521 522 // Check for "tentative" definitions. We can't accomplish this in 523 // MergeVarDecl since the initializer hasn't been attached. 524 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 525 continue; 526 527 // Handle __private_extern__ just like extern. 528 if (OldDecl->getStorageClass() != VarDecl::Extern && 529 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 530 VD->getStorageClass() != VarDecl::Extern && 531 VD->getStorageClass() != VarDecl::PrivateExtern) { 532 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 533 Diag(OldDecl->getLocation(), diag::err_previous_definition); 534 } 535 } 536 } 537} 538 539/// MergeVarDecl - We just parsed a variable 'New' which has the same name 540/// and scope as a previous declaration 'Old'. Figure out how to resolve this 541/// situation, merging decls or emitting diagnostics as appropriate. 542/// 543/// Tentative definition rules (C99 6.9.2p2) are checked by 544/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 545/// definitions here, since the initializer hasn't been attached. 546/// 547VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 548 // Verify the old decl was also a variable. 549 VarDecl *Old = dyn_cast<VarDecl>(OldD); 550 if (!Old) { 551 Diag(New->getLocation(), diag::err_redefinition_different_kind, 552 New->getName()); 553 Diag(OldD->getLocation(), diag::err_previous_definition); 554 return New; 555 } 556 557 MergeAttributes(New, Old); 558 559 // Verify the types match. 560 QualType OldCType = Context.getCanonicalType(Old->getType()); 561 QualType NewCType = Context.getCanonicalType(New->getType()); 562 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 563 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 564 Diag(Old->getLocation(), diag::err_previous_definition); 565 return New; 566 } 567 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 568 if (New->getStorageClass() == VarDecl::Static && 569 (Old->getStorageClass() == VarDecl::None || 570 Old->getStorageClass() == VarDecl::Extern)) { 571 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 572 Diag(Old->getLocation(), diag::err_previous_definition); 573 return New; 574 } 575 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 576 if (New->getStorageClass() != VarDecl::Static && 577 Old->getStorageClass() == VarDecl::Static) { 578 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 579 Diag(Old->getLocation(), diag::err_previous_definition); 580 return New; 581 } 582 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 583 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 584 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 585 Diag(Old->getLocation(), diag::err_previous_definition); 586 } 587 return New; 588} 589 590/// CheckParmsForFunctionDef - Check that the parameters of the given 591/// function are appropriate for the definition of a function. This 592/// takes care of any checks that cannot be performed on the 593/// declaration itself, e.g., that the types of each of the function 594/// parameters are complete. 595bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 596 bool HasInvalidParm = false; 597 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 598 ParmVarDecl *Param = FD->getParamDecl(p); 599 600 // C99 6.7.5.3p4: the parameters in a parameter type list in a 601 // function declarator that is part of a function definition of 602 // that function shall not have incomplete type. 603 if (Param->getType()->isIncompleteType() && 604 !Param->isInvalidDecl()) { 605 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 606 Param->getType().getAsString()); 607 Param->setInvalidDecl(); 608 HasInvalidParm = true; 609 } 610 } 611 612 return HasInvalidParm; 613} 614 615/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 616/// no declarator (e.g. "struct foo;") is parsed. 617Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 618 // TODO: emit error on 'int;' or 'const enum foo;'. 619 // TODO: emit error on 'typedef int;' 620 // if (!DS.isMissingDeclaratorOk()) Diag(...); 621 622 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 623} 624 625bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 626 // Get the type before calling CheckSingleAssignmentConstraints(), since 627 // it can promote the expression. 628 QualType InitType = Init->getType(); 629 630 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 631 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 632 InitType, Init, "initializing"); 633} 634 635bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 636 const ArrayType *AT = Context.getAsArrayType(DeclT); 637 638 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 639 // C99 6.7.8p14. We have an array of character type with unknown size 640 // being initialized to a string literal. 641 llvm::APSInt ConstVal(32); 642 ConstVal = strLiteral->getByteLength() + 1; 643 // Return a new array type (C99 6.7.8p22). 644 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 645 ArrayType::Normal, 0); 646 } else { 647 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 648 // C99 6.7.8p14. We have an array of character type with known size. 649 // FIXME: Avoid truncation for 64-bit length strings. 650 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 651 Diag(strLiteral->getSourceRange().getBegin(), 652 diag::warn_initializer_string_for_char_array_too_long) 653 << strLiteral->getSourceRange(); 654 } 655 // Set type from "char *" to "constant array of char". 656 strLiteral->setType(DeclT); 657 // For now, we always return false (meaning success). 658 return false; 659} 660 661StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 662 const ArrayType *AT = Context.getAsArrayType(DeclType); 663 if (AT && AT->getElementType()->isCharType()) { 664 return dyn_cast<StringLiteral>(Init); 665 } 666 return 0; 667} 668 669bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 670 SourceLocation InitLoc, 671 std::string InitEntity) { 672 // C++ [dcl.init.ref]p1: 673 // A variable declared to be a T&, that is “reference to type T” 674 // (8.3.2), shall be initialized by an object, or function, of 675 // type T or by an object that can be converted into a T. 676 if (DeclType->isReferenceType()) 677 return CheckReferenceInit(Init, DeclType); 678 679 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 680 // of unknown size ("[]") or an object type that is not a variable array type. 681 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 682 return Diag(InitLoc, diag::err_variable_object_no_init) 683 << VAT->getSizeExpr()->getSourceRange(); 684 685 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 686 if (!InitList) { 687 // FIXME: Handle wide strings 688 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 689 return CheckStringLiteralInit(strLiteral, DeclType); 690 691 // C++ [dcl.init]p14: 692 // -- If the destination type is a (possibly cv-qualified) class 693 // type: 694 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 695 QualType DeclTypeC = Context.getCanonicalType(DeclType); 696 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 697 698 // -- If the initialization is direct-initialization, or if it is 699 // copy-initialization where the cv-unqualified version of the 700 // source type is the same class as, or a derived class of, the 701 // class of the destination, constructors are considered. 702 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 703 IsDerivedFrom(InitTypeC, DeclTypeC)) { 704 CXXConstructorDecl *Constructor 705 = PerformInitializationByConstructor(DeclType, &Init, 1, 706 InitLoc, Init->getSourceRange(), 707 InitEntity, IK_Copy); 708 return Constructor == 0; 709 } 710 711 // -- Otherwise (i.e., for the remaining copy-initialization 712 // cases), user-defined conversion sequences that can 713 // convert from the source type to the destination type or 714 // (when a conversion function is used) to a derived class 715 // thereof are enumerated as described in 13.3.1.4, and the 716 // best one is chosen through overload resolution 717 // (13.3). If the conversion cannot be done or is 718 // ambiguous, the initialization is ill-formed. The 719 // function selected is called with the initializer 720 // expression as its argument; if the function is a 721 // constructor, the call initializes a temporary of the 722 // destination type. 723 // FIXME: We're pretending to do copy elision here; return to 724 // this when we have ASTs for such things. 725 if (!PerformImplicitConversion(Init, DeclType)) 726 return false; 727 728 return Diag(InitLoc, diag::err_typecheck_convert_incompatible) 729 << DeclType.getAsString() << InitEntity << "initializing" 730 << Init->getSourceRange(); 731 } 732 733 // C99 6.7.8p16. 734 if (DeclType->isArrayType()) 735 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 736 << Init->getSourceRange(); 737 738 return CheckSingleInitializer(Init, DeclType); 739 } else if (getLangOptions().CPlusPlus) { 740 // C++ [dcl.init]p14: 741 // [...] If the class is an aggregate (8.5.1), and the initializer 742 // is a brace-enclosed list, see 8.5.1. 743 // 744 // Note: 8.5.1 is handled below; here, we diagnose the case where 745 // we have an initializer list and a destination type that is not 746 // an aggregate. 747 // FIXME: In C++0x, this is yet another form of initialization. 748 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 749 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 750 if (!ClassDecl->isAggregate()) 751 return Diag(InitLoc, diag::err_init_non_aggr_init_list) 752 << DeclType.getAsString() << Init->getSourceRange(); 753 } 754 } 755 756 InitListChecker CheckInitList(this, InitList, DeclType); 757 return CheckInitList.HadError(); 758} 759 760/// GetNameForDeclarator - Determine the full declaration name for the 761/// given Declarator. 762DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 763 switch (D.getKind()) { 764 case Declarator::DK_Abstract: 765 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 766 return DeclarationName(); 767 768 case Declarator::DK_Normal: 769 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 770 return DeclarationName(D.getIdentifier()); 771 772 case Declarator::DK_Constructor: { 773 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 774 Ty = Context.getCanonicalType(Ty); 775 return Context.DeclarationNames.getCXXConstructorName(Ty); 776 } 777 778 case Declarator::DK_Destructor: { 779 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 780 Ty = Context.getCanonicalType(Ty); 781 return Context.DeclarationNames.getCXXDestructorName(Ty); 782 } 783 784 case Declarator::DK_Conversion: { 785 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 786 Ty = Context.getCanonicalType(Ty); 787 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 788 } 789 790 case Declarator::DK_Operator: 791 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 792 return Context.DeclarationNames.getCXXOperatorName( 793 D.getOverloadedOperator()); 794 } 795 796 assert(false && "Unknown name kind"); 797 return DeclarationName(); 798} 799 800Sema::DeclTy * 801Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 802 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 803 DeclarationName Name = GetNameForDeclarator(D); 804 805 // All of these full declarators require an identifier. If it doesn't have 806 // one, the ParsedFreeStandingDeclSpec action should be used. 807 if (!Name) { 808 if (!D.getInvalidType()) // Reject this if we think it is valid. 809 Diag(D.getDeclSpec().getSourceRange().getBegin(), 810 diag::err_declarator_need_ident) 811 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 812 return 0; 813 } 814 815 // The scope passed in may not be a decl scope. Zip up the scope tree until 816 // we find one that is. 817 while ((S->getFlags() & Scope::DeclScope) == 0) 818 S = S->getParent(); 819 820 DeclContext *DC; 821 Decl *PrevDecl; 822 ScopedDecl *New; 823 bool InvalidDecl = false; 824 825 // See if this is a redefinition of a variable in the same scope. 826 if (!D.getCXXScopeSpec().isSet()) { 827 DC = CurContext; 828 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S); 829 } else { // Something like "int foo::x;" 830 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 831 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 832 833 // C++ 7.3.1.2p2: 834 // Members (including explicit specializations of templates) of a named 835 // namespace can also be defined outside that namespace by explicit 836 // qualification of the name being defined, provided that the entity being 837 // defined was already declared in the namespace and the definition appears 838 // after the point of declaration in a namespace that encloses the 839 // declarations namespace. 840 // 841 if (PrevDecl == 0) { 842 // No previous declaration in the qualifying scope. 843 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member, 844 Name.getAsString(), D.getCXXScopeSpec().getRange()); 845 } else if (!CurContext->Encloses(DC)) { 846 // The qualifying scope doesn't enclose the original declaration. 847 // Emit diagnostic based on current scope. 848 SourceLocation L = D.getIdentifierLoc(); 849 SourceRange R = D.getCXXScopeSpec().getRange(); 850 if (isa<FunctionDecl>(CurContext)) { 851 Diag(L, diag::err_invalid_declarator_in_function, Name.getAsString(), 852 R); 853 } else { 854 Diag(L, diag::err_invalid_declarator_scope) 855 << Name.getAsString() << cast<NamedDecl>(DC)->getName() << R; 856 } 857 } 858 } 859 860 // In C++, the previous declaration we find might be a tag type 861 // (class or enum). In this case, the new declaration will hide the 862 // tag type. 863 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 864 PrevDecl = 0; 865 866 QualType R = GetTypeForDeclarator(D, S); 867 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 868 869 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 870 // Check that there are no default arguments (C++ only). 871 if (getLangOptions().CPlusPlus) 872 CheckExtraCXXDefaultArguments(D); 873 874 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 875 if (!NewTD) return 0; 876 877 // Handle attributes prior to checking for duplicates in MergeVarDecl 878 ProcessDeclAttributes(NewTD, D); 879 // Merge the decl with the existing one if appropriate. If the decl is 880 // in an outer scope, it isn't the same thing. 881 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 882 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 883 if (NewTD == 0) return 0; 884 } 885 New = NewTD; 886 if (S->getFnParent() == 0) { 887 // C99 6.7.7p2: If a typedef name specifies a variably modified type 888 // then it shall have block scope. 889 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 890 // FIXME: Diagnostic needs to be fixed. 891 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 892 InvalidDecl = true; 893 } 894 } 895 } else if (R.getTypePtr()->isFunctionType()) { 896 FunctionDecl::StorageClass SC = FunctionDecl::None; 897 switch (D.getDeclSpec().getStorageClassSpec()) { 898 default: assert(0 && "Unknown storage class!"); 899 case DeclSpec::SCS_auto: 900 case DeclSpec::SCS_register: 901 case DeclSpec::SCS_mutable: 902 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 903 R.getAsString()); 904 InvalidDecl = true; 905 break; 906 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 907 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 908 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 909 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 910 } 911 912 bool isInline = D.getDeclSpec().isInlineSpecified(); 913 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 914 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 915 916 FunctionDecl *NewFD; 917 if (D.getKind() == Declarator::DK_Constructor) { 918 // This is a C++ constructor declaration. 919 assert(DC->isCXXRecord() && 920 "Constructors can only be declared in a member context"); 921 922 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 923 924 // Create the new declaration 925 NewFD = CXXConstructorDecl::Create(Context, 926 cast<CXXRecordDecl>(DC), 927 D.getIdentifierLoc(), Name, R, 928 isExplicit, isInline, 929 /*isImplicitlyDeclared=*/false); 930 931 if (isInvalidDecl) 932 NewFD->setInvalidDecl(); 933 } else if (D.getKind() == Declarator::DK_Destructor) { 934 // This is a C++ destructor declaration. 935 if (DC->isCXXRecord()) { 936 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 937 938 NewFD = CXXDestructorDecl::Create(Context, 939 cast<CXXRecordDecl>(DC), 940 D.getIdentifierLoc(), Name, R, 941 isInline, 942 /*isImplicitlyDeclared=*/false); 943 944 if (isInvalidDecl) 945 NewFD->setInvalidDecl(); 946 } else { 947 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 948 // Create a FunctionDecl to satisfy the function definition parsing 949 // code path. 950 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 951 Name, R, SC, isInline, LastDeclarator, 952 // FIXME: Move to DeclGroup... 953 D.getDeclSpec().getSourceRange().getBegin()); 954 NewFD->setInvalidDecl(); 955 } 956 } else if (D.getKind() == Declarator::DK_Conversion) { 957 if (!DC->isCXXRecord()) { 958 Diag(D.getIdentifierLoc(), 959 diag::err_conv_function_not_member); 960 return 0; 961 } else { 962 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 963 964 NewFD = CXXConversionDecl::Create(Context, 965 cast<CXXRecordDecl>(DC), 966 D.getIdentifierLoc(), Name, R, 967 isInline, isExplicit); 968 969 if (isInvalidDecl) 970 NewFD->setInvalidDecl(); 971 } 972 } else if (DC->isCXXRecord()) { 973 // This is a C++ method declaration. 974 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 975 D.getIdentifierLoc(), Name, R, 976 (SC == FunctionDecl::Static), isInline, 977 LastDeclarator); 978 } else { 979 NewFD = FunctionDecl::Create(Context, DC, 980 D.getIdentifierLoc(), 981 Name, R, SC, isInline, LastDeclarator, 982 // FIXME: Move to DeclGroup... 983 D.getDeclSpec().getSourceRange().getBegin()); 984 } 985 // Handle attributes. 986 ProcessDeclAttributes(NewFD, D); 987 988 // Handle GNU asm-label extension (encoded as an attribute). 989 if (Expr *E = (Expr*) D.getAsmLabel()) { 990 // The parser guarantees this is a string. 991 StringLiteral *SE = cast<StringLiteral>(E); 992 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 993 SE->getByteLength()))); 994 } 995 996 // Copy the parameter declarations from the declarator D to 997 // the function declaration NewFD, if they are available. 998 if (D.getNumTypeObjects() > 0) { 999 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1000 1001 // Create Decl objects for each parameter, adding them to the 1002 // FunctionDecl. 1003 llvm::SmallVector<ParmVarDecl*, 16> Params; 1004 1005 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1006 // function that takes no arguments, not a function that takes a 1007 // single void argument. 1008 // We let through "const void" here because Sema::GetTypeForDeclarator 1009 // already checks for that case. 1010 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1011 FTI.ArgInfo[0].Param && 1012 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1013 // empty arg list, don't push any params. 1014 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1015 1016 // In C++, the empty parameter-type-list must be spelled "void"; a 1017 // typedef of void is not permitted. 1018 if (getLangOptions().CPlusPlus && 1019 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1020 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1021 } 1022 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1023 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1024 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1025 } 1026 1027 NewFD->setParams(&Params[0], Params.size()); 1028 } else if (R->getAsTypedefType()) { 1029 // When we're declaring a function with a typedef, as in the 1030 // following example, we'll need to synthesize (unnamed) 1031 // parameters for use in the declaration. 1032 // 1033 // @code 1034 // typedef void fn(int); 1035 // fn f; 1036 // @endcode 1037 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1038 if (!FT) { 1039 // This is a typedef of a function with no prototype, so we 1040 // don't need to do anything. 1041 } else if ((FT->getNumArgs() == 0) || 1042 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1043 FT->getArgType(0)->isVoidType())) { 1044 // This is a zero-argument function. We don't need to do anything. 1045 } else { 1046 // Synthesize a parameter for each argument type. 1047 llvm::SmallVector<ParmVarDecl*, 16> Params; 1048 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1049 ArgType != FT->arg_type_end(); ++ArgType) { 1050 Params.push_back(ParmVarDecl::Create(Context, DC, 1051 SourceLocation(), 0, 1052 *ArgType, VarDecl::None, 1053 0, 0)); 1054 } 1055 1056 NewFD->setParams(&Params[0], Params.size()); 1057 } 1058 } 1059 1060 // C++ constructors and destructors are handled by separate 1061 // routines, since they don't require any declaration merging (C++ 1062 // [class.mfct]p2) and they aren't ever pushed into scope, because 1063 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1064 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1065 return ActOnConstructorDeclarator(Constructor); 1066 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1067 return ActOnDestructorDeclarator(Destructor); 1068 1069 // Extra checking for conversion functions, including recording 1070 // the conversion function in its class. 1071 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1072 ActOnConversionDeclarator(Conversion); 1073 1074 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1075 if (NewFD->isOverloadedOperator() && 1076 CheckOverloadedOperatorDeclaration(NewFD)) 1077 NewFD->setInvalidDecl(); 1078 1079 // Merge the decl with the existing one if appropriate. Since C functions 1080 // are in a flat namespace, make sure we consider decls in outer scopes. 1081 if (PrevDecl && 1082 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1083 bool Redeclaration = false; 1084 1085 // If C++, determine whether NewFD is an overload of PrevDecl or 1086 // a declaration that requires merging. If it's an overload, 1087 // there's no more work to do here; we'll just add the new 1088 // function to the scope. 1089 OverloadedFunctionDecl::function_iterator MatchedDecl; 1090 if (!getLangOptions().CPlusPlus || 1091 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1092 Decl *OldDecl = PrevDecl; 1093 1094 // If PrevDecl was an overloaded function, extract the 1095 // FunctionDecl that matched. 1096 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1097 OldDecl = *MatchedDecl; 1098 1099 // NewFD and PrevDecl represent declarations that need to be 1100 // merged. 1101 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1102 1103 if (NewFD == 0) return 0; 1104 if (Redeclaration) { 1105 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1106 1107 if (OldDecl == PrevDecl) { 1108 // Remove the name binding for the previous 1109 // declaration. We'll add the binding back later, but then 1110 // it will refer to the new declaration (which will 1111 // contain more information). 1112 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1113 } else { 1114 // We need to update the OverloadedFunctionDecl with the 1115 // latest declaration of this function, so that name 1116 // lookup will always refer to the latest declaration of 1117 // this function. 1118 *MatchedDecl = NewFD; 1119 1120 // Add the redeclaration to the current scope, since we'll 1121 // be skipping PushOnScopeChains. 1122 S->AddDecl(NewFD); 1123 1124 return NewFD; 1125 } 1126 } 1127 } 1128 } 1129 New = NewFD; 1130 1131 // In C++, check default arguments now that we have merged decls. 1132 if (getLangOptions().CPlusPlus) 1133 CheckCXXDefaultArguments(NewFD); 1134 } else { 1135 // Check that there are no default arguments (C++ only). 1136 if (getLangOptions().CPlusPlus) 1137 CheckExtraCXXDefaultArguments(D); 1138 1139 if (R.getTypePtr()->isObjCInterfaceType()) { 1140 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object) 1141 << D.getIdentifier(); 1142 InvalidDecl = true; 1143 } 1144 1145 VarDecl *NewVD; 1146 VarDecl::StorageClass SC; 1147 switch (D.getDeclSpec().getStorageClassSpec()) { 1148 default: assert(0 && "Unknown storage class!"); 1149 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1150 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1151 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1152 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1153 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1154 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1155 case DeclSpec::SCS_mutable: 1156 // mutable can only appear on non-static class members, so it's always 1157 // an error here 1158 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1159 InvalidDecl = true; 1160 break; 1161 } 1162 1163 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1164 if (!II) { 1165 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name, 1166 Name.getAsString()); 1167 return 0; 1168 } 1169 1170 if (DC->isCXXRecord()) { 1171 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1172 // This is a static data member for a C++ class. 1173 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1174 D.getIdentifierLoc(), II, 1175 R, LastDeclarator); 1176 } else { 1177 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1178 if (S->getFnParent() == 0) { 1179 // C99 6.9p2: The storage-class specifiers auto and register shall not 1180 // appear in the declaration specifiers in an external declaration. 1181 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1182 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 1183 R.getAsString()); 1184 InvalidDecl = true; 1185 } 1186 } 1187 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1188 II, R, SC, LastDeclarator, 1189 // FIXME: Move to DeclGroup... 1190 D.getDeclSpec().getSourceRange().getBegin()); 1191 NewVD->setThreadSpecified(ThreadSpecified); 1192 } 1193 // Handle attributes prior to checking for duplicates in MergeVarDecl 1194 ProcessDeclAttributes(NewVD, D); 1195 1196 // Handle GNU asm-label extension (encoded as an attribute). 1197 if (Expr *E = (Expr*) D.getAsmLabel()) { 1198 // The parser guarantees this is a string. 1199 StringLiteral *SE = cast<StringLiteral>(E); 1200 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1201 SE->getByteLength()))); 1202 } 1203 1204 // Emit an error if an address space was applied to decl with local storage. 1205 // This includes arrays of objects with address space qualifiers, but not 1206 // automatic variables that point to other address spaces. 1207 // ISO/IEC TR 18037 S5.1.2 1208 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1209 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1210 InvalidDecl = true; 1211 } 1212 // Merge the decl with the existing one if appropriate. If the decl is 1213 // in an outer scope, it isn't the same thing. 1214 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1215 NewVD = MergeVarDecl(NewVD, PrevDecl); 1216 if (NewVD == 0) return 0; 1217 } 1218 New = NewVD; 1219 } 1220 1221 // Set the lexical context. If the declarator has a C++ scope specifier, the 1222 // lexical context will be different from the semantic context. 1223 New->setLexicalDeclContext(CurContext); 1224 1225 // If this has an identifier, add it to the scope stack. 1226 if (Name) 1227 PushOnScopeChains(New, S); 1228 // If any semantic error occurred, mark the decl as invalid. 1229 if (D.getInvalidType() || InvalidDecl) 1230 New->setInvalidDecl(); 1231 1232 return New; 1233} 1234 1235void Sema::InitializerElementNotConstant(const Expr *Init) { 1236 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 1237 << Init->getSourceRange(); 1238} 1239 1240bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1241 switch (Init->getStmtClass()) { 1242 default: 1243 InitializerElementNotConstant(Init); 1244 return true; 1245 case Expr::ParenExprClass: { 1246 const ParenExpr* PE = cast<ParenExpr>(Init); 1247 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1248 } 1249 case Expr::CompoundLiteralExprClass: 1250 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1251 case Expr::DeclRefExprClass: { 1252 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1253 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1254 if (VD->hasGlobalStorage()) 1255 return false; 1256 InitializerElementNotConstant(Init); 1257 return true; 1258 } 1259 if (isa<FunctionDecl>(D)) 1260 return false; 1261 InitializerElementNotConstant(Init); 1262 return true; 1263 } 1264 case Expr::MemberExprClass: { 1265 const MemberExpr *M = cast<MemberExpr>(Init); 1266 if (M->isArrow()) 1267 return CheckAddressConstantExpression(M->getBase()); 1268 return CheckAddressConstantExpressionLValue(M->getBase()); 1269 } 1270 case Expr::ArraySubscriptExprClass: { 1271 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1272 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1273 return CheckAddressConstantExpression(ASE->getBase()) || 1274 CheckArithmeticConstantExpression(ASE->getIdx()); 1275 } 1276 case Expr::StringLiteralClass: 1277 case Expr::PredefinedExprClass: 1278 return false; 1279 case Expr::UnaryOperatorClass: { 1280 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1281 1282 // C99 6.6p9 1283 if (Exp->getOpcode() == UnaryOperator::Deref) 1284 return CheckAddressConstantExpression(Exp->getSubExpr()); 1285 1286 InitializerElementNotConstant(Init); 1287 return true; 1288 } 1289 } 1290} 1291 1292bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1293 switch (Init->getStmtClass()) { 1294 default: 1295 InitializerElementNotConstant(Init); 1296 return true; 1297 case Expr::ParenExprClass: 1298 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1299 case Expr::StringLiteralClass: 1300 case Expr::ObjCStringLiteralClass: 1301 return false; 1302 case Expr::CallExprClass: 1303 case Expr::CXXOperatorCallExprClass: 1304 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1305 if (cast<CallExpr>(Init)->isBuiltinCall() == 1306 Builtin::BI__builtin___CFStringMakeConstantString) 1307 return false; 1308 1309 InitializerElementNotConstant(Init); 1310 return true; 1311 1312 case Expr::UnaryOperatorClass: { 1313 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1314 1315 // C99 6.6p9 1316 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1317 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1318 1319 if (Exp->getOpcode() == UnaryOperator::Extension) 1320 return CheckAddressConstantExpression(Exp->getSubExpr()); 1321 1322 InitializerElementNotConstant(Init); 1323 return true; 1324 } 1325 case Expr::BinaryOperatorClass: { 1326 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1327 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1328 1329 Expr *PExp = Exp->getLHS(); 1330 Expr *IExp = Exp->getRHS(); 1331 if (IExp->getType()->isPointerType()) 1332 std::swap(PExp, IExp); 1333 1334 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1335 return CheckAddressConstantExpression(PExp) || 1336 CheckArithmeticConstantExpression(IExp); 1337 } 1338 case Expr::ImplicitCastExprClass: 1339 case Expr::CStyleCastExprClass: { 1340 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1341 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1342 // Check for implicit promotion 1343 if (SubExpr->getType()->isFunctionType() || 1344 SubExpr->getType()->isArrayType()) 1345 return CheckAddressConstantExpressionLValue(SubExpr); 1346 } 1347 1348 // Check for pointer->pointer cast 1349 if (SubExpr->getType()->isPointerType()) 1350 return CheckAddressConstantExpression(SubExpr); 1351 1352 if (SubExpr->getType()->isIntegralType()) { 1353 // Check for the special-case of a pointer->int->pointer cast; 1354 // this isn't standard, but some code requires it. See 1355 // PR2720 for an example. 1356 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1357 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1358 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1359 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1360 if (IntWidth >= PointerWidth) { 1361 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1362 } 1363 } 1364 } 1365 } 1366 if (SubExpr->getType()->isArithmeticType()) { 1367 return CheckArithmeticConstantExpression(SubExpr); 1368 } 1369 1370 InitializerElementNotConstant(Init); 1371 return true; 1372 } 1373 case Expr::ConditionalOperatorClass: { 1374 // FIXME: Should we pedwarn here? 1375 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1376 if (!Exp->getCond()->getType()->isArithmeticType()) { 1377 InitializerElementNotConstant(Init); 1378 return true; 1379 } 1380 if (CheckArithmeticConstantExpression(Exp->getCond())) 1381 return true; 1382 if (Exp->getLHS() && 1383 CheckAddressConstantExpression(Exp->getLHS())) 1384 return true; 1385 return CheckAddressConstantExpression(Exp->getRHS()); 1386 } 1387 case Expr::AddrLabelExprClass: 1388 return false; 1389 } 1390} 1391 1392static const Expr* FindExpressionBaseAddress(const Expr* E); 1393 1394static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1395 switch (E->getStmtClass()) { 1396 default: 1397 return E; 1398 case Expr::ParenExprClass: { 1399 const ParenExpr* PE = cast<ParenExpr>(E); 1400 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1401 } 1402 case Expr::MemberExprClass: { 1403 const MemberExpr *M = cast<MemberExpr>(E); 1404 if (M->isArrow()) 1405 return FindExpressionBaseAddress(M->getBase()); 1406 return FindExpressionBaseAddressLValue(M->getBase()); 1407 } 1408 case Expr::ArraySubscriptExprClass: { 1409 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1410 return FindExpressionBaseAddress(ASE->getBase()); 1411 } 1412 case Expr::UnaryOperatorClass: { 1413 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1414 1415 if (Exp->getOpcode() == UnaryOperator::Deref) 1416 return FindExpressionBaseAddress(Exp->getSubExpr()); 1417 1418 return E; 1419 } 1420 } 1421} 1422 1423static const Expr* FindExpressionBaseAddress(const Expr* E) { 1424 switch (E->getStmtClass()) { 1425 default: 1426 return E; 1427 case Expr::ParenExprClass: { 1428 const ParenExpr* PE = cast<ParenExpr>(E); 1429 return FindExpressionBaseAddress(PE->getSubExpr()); 1430 } 1431 case Expr::UnaryOperatorClass: { 1432 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1433 1434 // C99 6.6p9 1435 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1436 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1437 1438 if (Exp->getOpcode() == UnaryOperator::Extension) 1439 return FindExpressionBaseAddress(Exp->getSubExpr()); 1440 1441 return E; 1442 } 1443 case Expr::BinaryOperatorClass: { 1444 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1445 1446 Expr *PExp = Exp->getLHS(); 1447 Expr *IExp = Exp->getRHS(); 1448 if (IExp->getType()->isPointerType()) 1449 std::swap(PExp, IExp); 1450 1451 return FindExpressionBaseAddress(PExp); 1452 } 1453 case Expr::ImplicitCastExprClass: { 1454 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1455 1456 // Check for implicit promotion 1457 if (SubExpr->getType()->isFunctionType() || 1458 SubExpr->getType()->isArrayType()) 1459 return FindExpressionBaseAddressLValue(SubExpr); 1460 1461 // Check for pointer->pointer cast 1462 if (SubExpr->getType()->isPointerType()) 1463 return FindExpressionBaseAddress(SubExpr); 1464 1465 // We assume that we have an arithmetic expression here; 1466 // if we don't, we'll figure it out later 1467 return 0; 1468 } 1469 case Expr::CStyleCastExprClass: { 1470 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1471 1472 // Check for pointer->pointer cast 1473 if (SubExpr->getType()->isPointerType()) 1474 return FindExpressionBaseAddress(SubExpr); 1475 1476 // We assume that we have an arithmetic expression here; 1477 // if we don't, we'll figure it out later 1478 return 0; 1479 } 1480 } 1481} 1482 1483bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1484 switch (Init->getStmtClass()) { 1485 default: 1486 InitializerElementNotConstant(Init); 1487 return true; 1488 case Expr::ParenExprClass: { 1489 const ParenExpr* PE = cast<ParenExpr>(Init); 1490 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1491 } 1492 case Expr::FloatingLiteralClass: 1493 case Expr::IntegerLiteralClass: 1494 case Expr::CharacterLiteralClass: 1495 case Expr::ImaginaryLiteralClass: 1496 case Expr::TypesCompatibleExprClass: 1497 case Expr::CXXBoolLiteralExprClass: 1498 return false; 1499 case Expr::CallExprClass: 1500 case Expr::CXXOperatorCallExprClass: { 1501 const CallExpr *CE = cast<CallExpr>(Init); 1502 1503 // Allow any constant foldable calls to builtins. 1504 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1505 return false; 1506 1507 InitializerElementNotConstant(Init); 1508 return true; 1509 } 1510 case Expr::DeclRefExprClass: { 1511 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1512 if (isa<EnumConstantDecl>(D)) 1513 return false; 1514 InitializerElementNotConstant(Init); 1515 return true; 1516 } 1517 case Expr::CompoundLiteralExprClass: 1518 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1519 // but vectors are allowed to be magic. 1520 if (Init->getType()->isVectorType()) 1521 return false; 1522 InitializerElementNotConstant(Init); 1523 return true; 1524 case Expr::UnaryOperatorClass: { 1525 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1526 1527 switch (Exp->getOpcode()) { 1528 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1529 // See C99 6.6p3. 1530 default: 1531 InitializerElementNotConstant(Init); 1532 return true; 1533 case UnaryOperator::OffsetOf: 1534 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1535 return false; 1536 InitializerElementNotConstant(Init); 1537 return true; 1538 case UnaryOperator::Extension: 1539 case UnaryOperator::LNot: 1540 case UnaryOperator::Plus: 1541 case UnaryOperator::Minus: 1542 case UnaryOperator::Not: 1543 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1544 } 1545 } 1546 case Expr::SizeOfAlignOfExprClass: { 1547 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1548 // Special check for void types, which are allowed as an extension 1549 if (Exp->getTypeOfArgument()->isVoidType()) 1550 return false; 1551 // alignof always evaluates to a constant. 1552 // FIXME: is sizeof(int[3.0]) a constant expression? 1553 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1554 InitializerElementNotConstant(Init); 1555 return true; 1556 } 1557 return false; 1558 } 1559 case Expr::BinaryOperatorClass: { 1560 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1561 1562 if (Exp->getLHS()->getType()->isArithmeticType() && 1563 Exp->getRHS()->getType()->isArithmeticType()) { 1564 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1565 CheckArithmeticConstantExpression(Exp->getRHS()); 1566 } 1567 1568 if (Exp->getLHS()->getType()->isPointerType() && 1569 Exp->getRHS()->getType()->isPointerType()) { 1570 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1571 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1572 1573 // Only allow a null (constant integer) base; we could 1574 // allow some additional cases if necessary, but this 1575 // is sufficient to cover offsetof-like constructs. 1576 if (!LHSBase && !RHSBase) { 1577 return CheckAddressConstantExpression(Exp->getLHS()) || 1578 CheckAddressConstantExpression(Exp->getRHS()); 1579 } 1580 } 1581 1582 InitializerElementNotConstant(Init); 1583 return true; 1584 } 1585 case Expr::ImplicitCastExprClass: 1586 case Expr::CStyleCastExprClass: { 1587 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1588 if (SubExpr->getType()->isArithmeticType()) 1589 return CheckArithmeticConstantExpression(SubExpr); 1590 1591 if (SubExpr->getType()->isPointerType()) { 1592 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1593 // If the pointer has a null base, this is an offsetof-like construct 1594 if (!Base) 1595 return CheckAddressConstantExpression(SubExpr); 1596 } 1597 1598 InitializerElementNotConstant(Init); 1599 return true; 1600 } 1601 case Expr::ConditionalOperatorClass: { 1602 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1603 1604 // If GNU extensions are disabled, we require all operands to be arithmetic 1605 // constant expressions. 1606 if (getLangOptions().NoExtensions) { 1607 return CheckArithmeticConstantExpression(Exp->getCond()) || 1608 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1609 CheckArithmeticConstantExpression(Exp->getRHS()); 1610 } 1611 1612 // Otherwise, we have to emulate some of the behavior of fold here. 1613 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1614 // because it can constant fold things away. To retain compatibility with 1615 // GCC code, we see if we can fold the condition to a constant (which we 1616 // should always be able to do in theory). If so, we only require the 1617 // specified arm of the conditional to be a constant. This is a horrible 1618 // hack, but is require by real world code that uses __builtin_constant_p. 1619 APValue Val; 1620 if (!Exp->getCond()->Evaluate(Val, Context)) { 1621 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 1622 // won't be able to either. Use it to emit the diagnostic though. 1623 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1624 assert(Res && "Evaluate couldn't evaluate this constant?"); 1625 return Res; 1626 } 1627 1628 // Verify that the side following the condition is also a constant. 1629 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1630 if (Val.getInt() == 0) 1631 std::swap(TrueSide, FalseSide); 1632 1633 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1634 return true; 1635 1636 // Okay, the evaluated side evaluates to a constant, so we accept this. 1637 // Check to see if the other side is obviously not a constant. If so, 1638 // emit a warning that this is a GNU extension. 1639 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1640 Diag(Init->getExprLoc(), 1641 diag::ext_typecheck_expression_not_constant_but_accepted) 1642 << FalseSide->getSourceRange(); 1643 return false; 1644 } 1645 } 1646} 1647 1648bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1649 Init = Init->IgnoreParens(); 1650 1651 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1652 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1653 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1654 1655 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1656 return CheckForConstantInitializer(e->getInitializer(), DclT); 1657 1658 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1659 unsigned numInits = Exp->getNumInits(); 1660 for (unsigned i = 0; i < numInits; i++) { 1661 // FIXME: Need to get the type of the declaration for C++, 1662 // because it could be a reference? 1663 if (CheckForConstantInitializer(Exp->getInit(i), 1664 Exp->getInit(i)->getType())) 1665 return true; 1666 } 1667 return false; 1668 } 1669 1670 if (Init->isNullPointerConstant(Context)) 1671 return false; 1672 if (Init->getType()->isArithmeticType()) { 1673 QualType InitTy = Context.getCanonicalType(Init->getType()) 1674 .getUnqualifiedType(); 1675 if (InitTy == Context.BoolTy) { 1676 // Special handling for pointers implicitly cast to bool; 1677 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1678 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1679 Expr* SubE = ICE->getSubExpr(); 1680 if (SubE->getType()->isPointerType() || 1681 SubE->getType()->isArrayType() || 1682 SubE->getType()->isFunctionType()) { 1683 return CheckAddressConstantExpression(Init); 1684 } 1685 } 1686 } else if (InitTy->isIntegralType()) { 1687 Expr* SubE = 0; 1688 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1689 SubE = CE->getSubExpr(); 1690 // Special check for pointer cast to int; we allow as an extension 1691 // an address constant cast to an integer if the integer 1692 // is of an appropriate width (this sort of code is apparently used 1693 // in some places). 1694 // FIXME: Add pedwarn? 1695 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1696 if (SubE && (SubE->getType()->isPointerType() || 1697 SubE->getType()->isArrayType() || 1698 SubE->getType()->isFunctionType())) { 1699 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1700 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1701 if (IntWidth >= PointerWidth) 1702 return CheckAddressConstantExpression(Init); 1703 } 1704 } 1705 1706 return CheckArithmeticConstantExpression(Init); 1707 } 1708 1709 if (Init->getType()->isPointerType()) 1710 return CheckAddressConstantExpression(Init); 1711 1712 // An array type at the top level that isn't an init-list must 1713 // be a string literal 1714 if (Init->getType()->isArrayType()) 1715 return false; 1716 1717 if (Init->getType()->isFunctionType()) 1718 return false; 1719 1720 // Allow block exprs at top level. 1721 if (Init->getType()->isBlockPointerType()) 1722 return false; 1723 1724 InitializerElementNotConstant(Init); 1725 return true; 1726} 1727 1728void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1729 Decl *RealDecl = static_cast<Decl *>(dcl); 1730 Expr *Init = static_cast<Expr *>(init); 1731 assert(Init && "missing initializer"); 1732 1733 // If there is no declaration, there was an error parsing it. Just ignore 1734 // the initializer. 1735 if (RealDecl == 0) { 1736 delete Init; 1737 return; 1738 } 1739 1740 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1741 if (!VDecl) { 1742 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1743 diag::err_illegal_initializer); 1744 RealDecl->setInvalidDecl(); 1745 return; 1746 } 1747 // Get the decls type and save a reference for later, since 1748 // CheckInitializerTypes may change it. 1749 QualType DclT = VDecl->getType(), SavT = DclT; 1750 if (VDecl->isBlockVarDecl()) { 1751 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1752 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1753 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1754 VDecl->setInvalidDecl(); 1755 } else if (!VDecl->isInvalidDecl()) { 1756 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1757 VDecl->getName())) 1758 VDecl->setInvalidDecl(); 1759 1760 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1761 if (!getLangOptions().CPlusPlus) { 1762 if (SC == VarDecl::Static) // C99 6.7.8p4. 1763 CheckForConstantInitializer(Init, DclT); 1764 } 1765 } 1766 } else if (VDecl->isFileVarDecl()) { 1767 if (VDecl->getStorageClass() == VarDecl::Extern) 1768 Diag(VDecl->getLocation(), diag::warn_extern_init); 1769 if (!VDecl->isInvalidDecl()) 1770 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1771 VDecl->getName())) 1772 VDecl->setInvalidDecl(); 1773 1774 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1775 if (!getLangOptions().CPlusPlus) { 1776 // C99 6.7.8p4. All file scoped initializers need to be constant. 1777 CheckForConstantInitializer(Init, DclT); 1778 } 1779 } 1780 // If the type changed, it means we had an incomplete type that was 1781 // completed by the initializer. For example: 1782 // int ary[] = { 1, 3, 5 }; 1783 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1784 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1785 VDecl->setType(DclT); 1786 Init->setType(DclT); 1787 } 1788 1789 // Attach the initializer to the decl. 1790 VDecl->setInit(Init); 1791 return; 1792} 1793 1794void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1795 Decl *RealDecl = static_cast<Decl *>(dcl); 1796 1797 // If there is no declaration, there was an error parsing it. Just ignore it. 1798 if (RealDecl == 0) 1799 return; 1800 1801 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1802 QualType Type = Var->getType(); 1803 // C++ [dcl.init.ref]p3: 1804 // The initializer can be omitted for a reference only in a 1805 // parameter declaration (8.3.5), in the declaration of a 1806 // function return type, in the declaration of a class member 1807 // within its class declaration (9.2), and where the extern 1808 // specifier is explicitly used. 1809 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1810 Diag(Var->getLocation(), 1811 diag::err_reference_var_requires_init, 1812 Var->getName(), 1813 SourceRange(Var->getLocation(), Var->getLocation())); 1814 Var->setInvalidDecl(); 1815 return; 1816 } 1817 1818 // C++ [dcl.init]p9: 1819 // 1820 // If no initializer is specified for an object, and the object 1821 // is of (possibly cv-qualified) non-POD class type (or array 1822 // thereof), the object shall be default-initialized; if the 1823 // object is of const-qualified type, the underlying class type 1824 // shall have a user-declared default constructor. 1825 if (getLangOptions().CPlusPlus) { 1826 QualType InitType = Type; 1827 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1828 InitType = Array->getElementType(); 1829 if (InitType->isRecordType()) { 1830 const CXXConstructorDecl *Constructor 1831 = PerformInitializationByConstructor(InitType, 0, 0, 1832 Var->getLocation(), 1833 SourceRange(Var->getLocation(), 1834 Var->getLocation()), 1835 Var->getName(), 1836 IK_Default); 1837 if (!Constructor) 1838 Var->setInvalidDecl(); 1839 } 1840 } 1841 1842#if 0 1843 // FIXME: Temporarily disabled because we are not properly parsing 1844 // linkage specifications on declarations, e.g., 1845 // 1846 // extern "C" const CGPoint CGPointerZero; 1847 // 1848 // C++ [dcl.init]p9: 1849 // 1850 // If no initializer is specified for an object, and the 1851 // object is of (possibly cv-qualified) non-POD class type (or 1852 // array thereof), the object shall be default-initialized; if 1853 // the object is of const-qualified type, the underlying class 1854 // type shall have a user-declared default 1855 // constructor. Otherwise, if no initializer is specified for 1856 // an object, the object and its subobjects, if any, have an 1857 // indeterminate initial value; if the object or any of its 1858 // subobjects are of const-qualified type, the program is 1859 // ill-formed. 1860 // 1861 // This isn't technically an error in C, so we don't diagnose it. 1862 // 1863 // FIXME: Actually perform the POD/user-defined default 1864 // constructor check. 1865 if (getLangOptions().CPlusPlus && 1866 Context.getCanonicalType(Type).isConstQualified() && 1867 Var->getStorageClass() != VarDecl::Extern) 1868 Diag(Var->getLocation(), 1869 diag::err_const_var_requires_init, 1870 Var->getName(), 1871 SourceRange(Var->getLocation(), Var->getLocation())); 1872#endif 1873 } 1874} 1875 1876/// The declarators are chained together backwards, reverse the list. 1877Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1878 // Often we have single declarators, handle them quickly. 1879 Decl *GroupDecl = static_cast<Decl*>(group); 1880 if (GroupDecl == 0) 1881 return 0; 1882 1883 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1884 ScopedDecl *NewGroup = 0; 1885 if (Group->getNextDeclarator() == 0) 1886 NewGroup = Group; 1887 else { // reverse the list. 1888 while (Group) { 1889 ScopedDecl *Next = Group->getNextDeclarator(); 1890 Group->setNextDeclarator(NewGroup); 1891 NewGroup = Group; 1892 Group = Next; 1893 } 1894 } 1895 // Perform semantic analysis that depends on having fully processed both 1896 // the declarator and initializer. 1897 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1898 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1899 if (!IDecl) 1900 continue; 1901 QualType T = IDecl->getType(); 1902 1903 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1904 // static storage duration, it shall not have a variable length array. 1905 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1906 IDecl->getStorageClass() == VarDecl::Static) { 1907 if (T->isVariableArrayType()) { 1908 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1909 IDecl->setInvalidDecl(); 1910 } 1911 } 1912 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1913 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1914 if (IDecl->isBlockVarDecl() && 1915 IDecl->getStorageClass() != VarDecl::Extern) { 1916 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1917 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1918 T.getAsString()); 1919 IDecl->setInvalidDecl(); 1920 } 1921 } 1922 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1923 // object that has file scope without an initializer, and without a 1924 // storage-class specifier or with the storage-class specifier "static", 1925 // constitutes a tentative definition. Note: A tentative definition with 1926 // external linkage is valid (C99 6.2.2p5). 1927 if (isTentativeDefinition(IDecl)) { 1928 if (T->isIncompleteArrayType()) { 1929 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1930 // array to be completed. Don't issue a diagnostic. 1931 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1932 // C99 6.9.2p3: If the declaration of an identifier for an object is 1933 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1934 // declared type shall not be an incomplete type. 1935 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1936 T.getAsString()); 1937 IDecl->setInvalidDecl(); 1938 } 1939 } 1940 if (IDecl->isFileVarDecl()) 1941 CheckForFileScopedRedefinitions(S, IDecl); 1942 } 1943 return NewGroup; 1944} 1945 1946/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1947/// to introduce parameters into function prototype scope. 1948Sema::DeclTy * 1949Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1950 // FIXME: disallow CXXScopeSpec for param declarators. 1951 const DeclSpec &DS = D.getDeclSpec(); 1952 1953 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1954 VarDecl::StorageClass StorageClass = VarDecl::None; 1955 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1956 StorageClass = VarDecl::Register; 1957 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1958 Diag(DS.getStorageClassSpecLoc(), 1959 diag::err_invalid_storage_class_in_func_decl); 1960 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1961 } 1962 if (DS.isThreadSpecified()) { 1963 Diag(DS.getThreadSpecLoc(), 1964 diag::err_invalid_storage_class_in_func_decl); 1965 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1966 } 1967 1968 // Check that there are no default arguments inside the type of this 1969 // parameter (C++ only). 1970 if (getLangOptions().CPlusPlus) 1971 CheckExtraCXXDefaultArguments(D); 1972 1973 // In this context, we *do not* check D.getInvalidType(). If the declarator 1974 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1975 // though it will not reflect the user specified type. 1976 QualType parmDeclType = GetTypeForDeclarator(D, S); 1977 1978 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1979 1980 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1981 // Can this happen for params? We already checked that they don't conflict 1982 // among each other. Here they can only shadow globals, which is ok. 1983 IdentifierInfo *II = D.getIdentifier(); 1984 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1985 if (S->isDeclScope(PrevDecl)) { 1986 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1987 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1988 1989 // Recover by removing the name 1990 II = 0; 1991 D.SetIdentifier(0, D.getIdentifierLoc()); 1992 } 1993 } 1994 1995 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1996 // Doing the promotion here has a win and a loss. The win is the type for 1997 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1998 // code generator). The loss is the orginal type isn't preserved. For example: 1999 // 2000 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2001 // int blockvardecl[5]; 2002 // sizeof(parmvardecl); // size == 4 2003 // sizeof(blockvardecl); // size == 20 2004 // } 2005 // 2006 // For expressions, all implicit conversions are captured using the 2007 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2008 // 2009 // FIXME: If a source translation tool needs to see the original type, then 2010 // we need to consider storing both types (in ParmVarDecl)... 2011 // 2012 if (parmDeclType->isArrayType()) { 2013 // int x[restrict 4] -> int *restrict 2014 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2015 } else if (parmDeclType->isFunctionType()) 2016 parmDeclType = Context.getPointerType(parmDeclType); 2017 2018 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2019 D.getIdentifierLoc(), II, 2020 parmDeclType, StorageClass, 2021 0, 0); 2022 2023 if (D.getInvalidType()) 2024 New->setInvalidDecl(); 2025 2026 if (II) 2027 PushOnScopeChains(New, S); 2028 2029 ProcessDeclAttributes(New, D); 2030 return New; 2031 2032} 2033 2034Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2035 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2036 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2037 "Not a function declarator!"); 2038 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2039 2040 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2041 // for a K&R function. 2042 if (!FTI.hasPrototype) { 2043 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2044 if (FTI.ArgInfo[i].Param == 0) { 2045 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2046 << FTI.ArgInfo[i].Ident; 2047 // Implicitly declare the argument as type 'int' for lack of a better 2048 // type. 2049 DeclSpec DS; 2050 const char* PrevSpec; // unused 2051 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2052 PrevSpec); 2053 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2054 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2055 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2056 } 2057 } 2058 } else { 2059 // FIXME: Diagnose arguments without names in C. 2060 } 2061 2062 Scope *GlobalScope = FnBodyScope->getParent(); 2063 2064 return ActOnStartOfFunctionDef(FnBodyScope, 2065 ActOnDeclarator(GlobalScope, D, 0)); 2066} 2067 2068Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2069 Decl *decl = static_cast<Decl*>(D); 2070 FunctionDecl *FD = cast<FunctionDecl>(decl); 2071 2072 // See if this is a redefinition. 2073 const FunctionDecl *Definition; 2074 if (FD->getBody(Definition)) { 2075 Diag(FD->getLocation(), diag::err_redefinition, 2076 FD->getName()); 2077 Diag(Definition->getLocation(), diag::err_previous_definition); 2078 } 2079 2080 PushDeclContext(FD); 2081 2082 // Check the validity of our function parameters 2083 CheckParmsForFunctionDef(FD); 2084 2085 // Introduce our parameters into the function scope 2086 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2087 ParmVarDecl *Param = FD->getParamDecl(p); 2088 // If this has an identifier, add it to the scope stack. 2089 if (Param->getIdentifier()) 2090 PushOnScopeChains(Param, FnBodyScope); 2091 } 2092 2093 return FD; 2094} 2095 2096Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2097 Decl *dcl = static_cast<Decl *>(D); 2098 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2099 FD->setBody((Stmt*)Body); 2100 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2101 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2102 MD->setBody((Stmt*)Body); 2103 } else 2104 return 0; 2105 PopDeclContext(); 2106 // Verify and clean out per-function state. 2107 2108 // Check goto/label use. 2109 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2110 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2111 // Verify that we have no forward references left. If so, there was a goto 2112 // or address of a label taken, but no definition of it. Label fwd 2113 // definitions are indicated with a null substmt. 2114 if (I->second->getSubStmt() == 0) { 2115 LabelStmt *L = I->second; 2116 // Emit error. 2117 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2118 2119 // At this point, we have gotos that use the bogus label. Stitch it into 2120 // the function body so that they aren't leaked and that the AST is well 2121 // formed. 2122 if (Body) { 2123 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2124 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2125 } else { 2126 // The whole function wasn't parsed correctly, just delete this. 2127 delete L; 2128 } 2129 } 2130 } 2131 LabelMap.clear(); 2132 2133 return D; 2134} 2135 2136/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2137/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2138ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2139 IdentifierInfo &II, Scope *S) { 2140 // Extension in C99. Legal in C90, but warn about it. 2141 if (getLangOptions().C99) 2142 Diag(Loc, diag::ext_implicit_function_decl) << &II; 2143 else 2144 Diag(Loc, diag::warn_implicit_function_decl) << &II; 2145 2146 // FIXME: handle stuff like: 2147 // void foo() { extern float X(); } 2148 // void bar() { X(); } <-- implicit decl for X in another scope. 2149 2150 // Set a Declarator for the implicit definition: int foo(); 2151 const char *Dummy; 2152 DeclSpec DS; 2153 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2154 Error = Error; // Silence warning. 2155 assert(!Error && "Error setting up implicit decl!"); 2156 Declarator D(DS, Declarator::BlockContext); 2157 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2158 D.SetIdentifier(&II, Loc); 2159 2160 // Insert this function into translation-unit scope. 2161 2162 DeclContext *PrevDC = CurContext; 2163 CurContext = Context.getTranslationUnitDecl(); 2164 2165 FunctionDecl *FD = 2166 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2167 FD->setImplicit(); 2168 2169 CurContext = PrevDC; 2170 2171 return FD; 2172} 2173 2174 2175TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2176 ScopedDecl *LastDeclarator) { 2177 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2178 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2179 2180 // Scope manipulation handled by caller. 2181 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2182 D.getIdentifierLoc(), 2183 D.getIdentifier(), 2184 T, LastDeclarator); 2185 if (D.getInvalidType()) 2186 NewTD->setInvalidDecl(); 2187 return NewTD; 2188} 2189 2190/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2191/// former case, Name will be non-null. In the later case, Name will be null. 2192/// TagType indicates what kind of tag this is. TK indicates whether this is a 2193/// reference/declaration/definition of a tag. 2194Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2195 SourceLocation KWLoc, const CXXScopeSpec &SS, 2196 IdentifierInfo *Name, SourceLocation NameLoc, 2197 AttributeList *Attr) { 2198 // If this is a use of an existing tag, it must have a name. 2199 assert((Name != 0 || TK == TK_Definition) && 2200 "Nameless record must be a definition!"); 2201 2202 TagDecl::TagKind Kind; 2203 switch (TagType) { 2204 default: assert(0 && "Unknown tag type!"); 2205 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2206 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2207 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2208 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2209 } 2210 2211 // Two code paths: a new one for structs/unions/classes where we create 2212 // separate decls for forward declarations, and an old (eventually to 2213 // be removed) code path for enums. 2214 if (Kind != TagDecl::TK_enum) 2215 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2216 2217 DeclContext *DC = CurContext; 2218 ScopedDecl *PrevDecl = 0; 2219 2220 if (Name && SS.isNotEmpty()) { 2221 // We have a nested-name tag ('struct foo::bar'). 2222 2223 // Check for invalid 'foo::'. 2224 if (SS.isInvalid()) { 2225 Name = 0; 2226 goto CreateNewDecl; 2227 } 2228 2229 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2230 // Look-up name inside 'foo::'. 2231 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2232 2233 // A tag 'foo::bar' must already exist. 2234 if (PrevDecl == 0) { 2235 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2236 Name = 0; 2237 goto CreateNewDecl; 2238 } 2239 } else { 2240 // If this is a named struct, check to see if there was a previous forward 2241 // declaration or definition. 2242 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2243 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2244 } 2245 2246 if (PrevDecl) { 2247 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2248 "unexpected Decl type"); 2249 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2250 // If this is a use of a previous tag, or if the tag is already declared 2251 // in the same scope (so that the definition/declaration completes or 2252 // rementions the tag), reuse the decl. 2253 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2254 // Make sure that this wasn't declared as an enum and now used as a 2255 // struct or something similar. 2256 if (PrevTagDecl->getTagKind() != Kind) { 2257 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2258 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2259 // Recover by making this an anonymous redefinition. 2260 Name = 0; 2261 PrevDecl = 0; 2262 } else { 2263 // If this is a use or a forward declaration, we're good. 2264 if (TK != TK_Definition) 2265 return PrevDecl; 2266 2267 // Diagnose attempts to redefine a tag. 2268 if (PrevTagDecl->isDefinition()) { 2269 Diag(NameLoc, diag::err_redefinition) << Name; 2270 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2271 // If this is a redefinition, recover by making this struct be 2272 // anonymous, which will make any later references get the previous 2273 // definition. 2274 Name = 0; 2275 } else { 2276 // Okay, this is definition of a previously declared or referenced 2277 // tag. Move the location of the decl to be the definition site. 2278 PrevDecl->setLocation(NameLoc); 2279 return PrevDecl; 2280 } 2281 } 2282 } 2283 // If we get here, this is a definition of a new struct type in a nested 2284 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2285 // type. 2286 } else { 2287 // PrevDecl is a namespace. 2288 if (isDeclInScope(PrevDecl, DC, S)) { 2289 // The tag name clashes with a namespace name, issue an error and 2290 // recover by making this tag be anonymous. 2291 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2292 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2293 Name = 0; 2294 } 2295 } 2296 } 2297 2298 CreateNewDecl: 2299 2300 // If there is an identifier, use the location of the identifier as the 2301 // location of the decl, otherwise use the location of the struct/union 2302 // keyword. 2303 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2304 2305 // Otherwise, if this is the first time we've seen this tag, create the decl. 2306 TagDecl *New; 2307 if (Kind == TagDecl::TK_enum) { 2308 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2309 // enum X { A, B, C } D; D should chain to X. 2310 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2311 // If this is an undefined enum, warn. 2312 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2313 } else { 2314 // struct/union/class 2315 2316 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2317 // struct X { int A; } D; D should chain to X. 2318 if (getLangOptions().CPlusPlus) 2319 // FIXME: Look for a way to use RecordDecl for simple structs. 2320 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2321 else 2322 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2323 } 2324 2325 // If this has an identifier, add it to the scope stack. 2326 if (Name) { 2327 // The scope passed in may not be a decl scope. Zip up the scope tree until 2328 // we find one that is. 2329 while ((S->getFlags() & Scope::DeclScope) == 0) 2330 S = S->getParent(); 2331 2332 // Add it to the decl chain. 2333 PushOnScopeChains(New, S); 2334 } 2335 2336 if (Attr) 2337 ProcessDeclAttributeList(New, Attr); 2338 2339 // Set the lexical context. If the tag has a C++ scope specifier, the 2340 // lexical context will be different from the semantic context. 2341 New->setLexicalDeclContext(CurContext); 2342 2343 return New; 2344} 2345 2346/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2347/// the logic for enums, we create separate decls for forward declarations. 2348/// This is called by ActOnTag, but eventually will replace its logic. 2349Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2350 SourceLocation KWLoc, const CXXScopeSpec &SS, 2351 IdentifierInfo *Name, SourceLocation NameLoc, 2352 AttributeList *Attr) { 2353 DeclContext *DC = CurContext; 2354 ScopedDecl *PrevDecl = 0; 2355 2356 if (Name && SS.isNotEmpty()) { 2357 // We have a nested-name tag ('struct foo::bar'). 2358 2359 // Check for invalid 'foo::'. 2360 if (SS.isInvalid()) { 2361 Name = 0; 2362 goto CreateNewDecl; 2363 } 2364 2365 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2366 // Look-up name inside 'foo::'. 2367 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2368 2369 // A tag 'foo::bar' must already exist. 2370 if (PrevDecl == 0) { 2371 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2372 Name = 0; 2373 goto CreateNewDecl; 2374 } 2375 } else { 2376 // If this is a named struct, check to see if there was a previous forward 2377 // declaration or definition. 2378 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2379 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2380 } 2381 2382 if (PrevDecl) { 2383 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2384 "unexpected Decl type"); 2385 2386 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2387 // If this is a use of a previous tag, or if the tag is already declared 2388 // in the same scope (so that the definition/declaration completes or 2389 // rementions the tag), reuse the decl. 2390 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2391 // Make sure that this wasn't declared as an enum and now used as a 2392 // struct or something similar. 2393 if (PrevTagDecl->getTagKind() != Kind) { 2394 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2395 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2396 // Recover by making this an anonymous redefinition. 2397 Name = 0; 2398 PrevDecl = 0; 2399 } else { 2400 // If this is a use, return the original decl. 2401 2402 // FIXME: In the future, return a variant or some other clue 2403 // for the consumer of this Decl to know it doesn't own it. 2404 // For our current ASTs this shouldn't be a problem, but will 2405 // need to be changed with DeclGroups. 2406 if (TK == TK_Reference) 2407 return PrevDecl; 2408 2409 // The new decl is a definition? 2410 if (TK == TK_Definition) { 2411 // Diagnose attempts to redefine a tag. 2412 if (RecordDecl* DefRecord = 2413 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2414 Diag(NameLoc, diag::err_redefinition) << Name; 2415 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2416 // If this is a redefinition, recover by making this struct be 2417 // anonymous, which will make any later references get the previous 2418 // definition. 2419 Name = 0; 2420 PrevDecl = 0; 2421 } 2422 // Okay, this is definition of a previously declared or referenced 2423 // tag. We're going to create a new Decl. 2424 } 2425 } 2426 // If we get here we have (another) forward declaration. Just create 2427 // a new decl. 2428 } 2429 else { 2430 // If we get here, this is a definition of a new struct type in a nested 2431 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2432 // new decl/type. We set PrevDecl to NULL so that the Records 2433 // have distinct types. 2434 PrevDecl = 0; 2435 } 2436 } else { 2437 // PrevDecl is a namespace. 2438 if (isDeclInScope(PrevDecl, DC, S)) { 2439 // The tag name clashes with a namespace name, issue an error and 2440 // recover by making this tag be anonymous. 2441 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2442 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2443 Name = 0; 2444 } 2445 } 2446 } 2447 2448 CreateNewDecl: 2449 2450 // If there is an identifier, use the location of the identifier as the 2451 // location of the decl, otherwise use the location of the struct/union 2452 // keyword. 2453 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2454 2455 // Otherwise, if this is the first time we've seen this tag, create the decl. 2456 TagDecl *New; 2457 2458 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2459 // struct X { int A; } D; D should chain to X. 2460 if (getLangOptions().CPlusPlus) 2461 // FIXME: Look for a way to use RecordDecl for simple structs. 2462 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2463 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2464 else 2465 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2466 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2467 2468 // If this has an identifier, add it to the scope stack. 2469 if ((TK == TK_Definition || !PrevDecl) && Name) { 2470 // The scope passed in may not be a decl scope. Zip up the scope tree until 2471 // we find one that is. 2472 while ((S->getFlags() & Scope::DeclScope) == 0) 2473 S = S->getParent(); 2474 2475 // Add it to the decl chain. 2476 PushOnScopeChains(New, S); 2477 } 2478 2479 // Handle #pragma pack: if the #pragma pack stack has non-default 2480 // alignment, make up a packed attribute for this decl. These 2481 // attributes are checked when the ASTContext lays out the 2482 // structure. 2483 // 2484 // It is important for implementing the correct semantics that this 2485 // happen here (in act on tag decl). The #pragma pack stack is 2486 // maintained as a result of parser callbacks which can occur at 2487 // many points during the parsing of a struct declaration (because 2488 // the #pragma tokens are effectively skipped over during the 2489 // parsing of the struct). 2490 if (unsigned Alignment = PackContext.getAlignment()) 2491 New->addAttr(new PackedAttr(Alignment * 8)); 2492 2493 if (Attr) 2494 ProcessDeclAttributeList(New, Attr); 2495 2496 // Set the lexical context. If the tag has a C++ scope specifier, the 2497 // lexical context will be different from the semantic context. 2498 New->setLexicalDeclContext(CurContext); 2499 2500 return New; 2501} 2502 2503 2504/// Collect the instance variables declared in an Objective-C object. Used in 2505/// the creation of structures from objects using the @defs directive. 2506static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2507 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2508 if (Class->getSuperClass()) 2509 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2510 2511 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2512 for (ObjCInterfaceDecl::ivar_iterator 2513 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2514 2515 ObjCIvarDecl* ID = *I; 2516 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2517 ID->getIdentifier(), 2518 ID->getType(), 2519 ID->getBitWidth())); 2520 } 2521} 2522 2523/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2524/// instance variables of ClassName into Decls. 2525void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2526 IdentifierInfo *ClassName, 2527 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2528 // Check that ClassName is a valid class 2529 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2530 if (!Class) { 2531 Diag(DeclStart, diag::err_undef_interface) << ClassName; 2532 return; 2533 } 2534 // Collect the instance variables 2535 CollectIvars(Class, Context, Decls); 2536} 2537 2538/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2539/// types into constant array types in certain situations which would otherwise 2540/// be errors (for GCC compatibility). 2541static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2542 ASTContext &Context) { 2543 // This method tries to turn a variable array into a constant 2544 // array even when the size isn't an ICE. This is necessary 2545 // for compatibility with code that depends on gcc's buggy 2546 // constant expression folding, like struct {char x[(int)(char*)2];} 2547 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2548 if (!VLATy) return QualType(); 2549 2550 APValue Result; 2551 if (!VLATy->getSizeExpr() || 2552 !VLATy->getSizeExpr()->Evaluate(Result, Context)) 2553 return QualType(); 2554 2555 assert(Result.isInt() && "Size expressions must be integers!"); 2556 llvm::APSInt &Res = Result.getInt(); 2557 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2558 return Context.getConstantArrayType(VLATy->getElementType(), 2559 Res, ArrayType::Normal, 0); 2560 return QualType(); 2561} 2562 2563/// ActOnField - Each field of a struct/union/class is passed into this in order 2564/// to create a FieldDecl object for it. 2565Sema::DeclTy *Sema::ActOnField(Scope *S, 2566 SourceLocation DeclStart, 2567 Declarator &D, ExprTy *BitfieldWidth) { 2568 IdentifierInfo *II = D.getIdentifier(); 2569 Expr *BitWidth = (Expr*)BitfieldWidth; 2570 SourceLocation Loc = DeclStart; 2571 if (II) Loc = D.getIdentifierLoc(); 2572 2573 // FIXME: Unnamed fields can be handled in various different ways, for 2574 // example, unnamed unions inject all members into the struct namespace! 2575 2576 if (BitWidth) { 2577 // TODO: Validate. 2578 //printf("WARNING: BITFIELDS IGNORED!\n"); 2579 2580 // 6.7.2.1p3 2581 // 6.7.2.1p4 2582 2583 } else { 2584 // Not a bitfield. 2585 2586 // validate II. 2587 2588 } 2589 2590 QualType T = GetTypeForDeclarator(D, S); 2591 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2592 bool InvalidDecl = false; 2593 2594 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2595 // than a variably modified type. 2596 if (T->isVariablyModifiedType()) { 2597 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2598 if (!FixedTy.isNull()) { 2599 Diag(Loc, diag::warn_illegal_constant_array_size); 2600 T = FixedTy; 2601 } else { 2602 Diag(Loc, diag::err_typecheck_field_variable_size); 2603 T = Context.IntTy; 2604 InvalidDecl = true; 2605 } 2606 } 2607 // FIXME: Chain fielddecls together. 2608 FieldDecl *NewFD; 2609 2610 if (getLangOptions().CPlusPlus) { 2611 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2612 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2613 Loc, II, T, 2614 D.getDeclSpec().getStorageClassSpec() == 2615 DeclSpec::SCS_mutable, BitWidth); 2616 if (II) 2617 PushOnScopeChains(NewFD, S); 2618 } 2619 else 2620 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2621 2622 ProcessDeclAttributes(NewFD, D); 2623 2624 if (D.getInvalidType() || InvalidDecl) 2625 NewFD->setInvalidDecl(); 2626 return NewFD; 2627} 2628 2629/// TranslateIvarVisibility - Translate visibility from a token ID to an 2630/// AST enum value. 2631static ObjCIvarDecl::AccessControl 2632TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2633 switch (ivarVisibility) { 2634 default: assert(0 && "Unknown visitibility kind"); 2635 case tok::objc_private: return ObjCIvarDecl::Private; 2636 case tok::objc_public: return ObjCIvarDecl::Public; 2637 case tok::objc_protected: return ObjCIvarDecl::Protected; 2638 case tok::objc_package: return ObjCIvarDecl::Package; 2639 } 2640} 2641 2642/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2643/// in order to create an IvarDecl object for it. 2644Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2645 SourceLocation DeclStart, 2646 Declarator &D, ExprTy *BitfieldWidth, 2647 tok::ObjCKeywordKind Visibility) { 2648 IdentifierInfo *II = D.getIdentifier(); 2649 Expr *BitWidth = (Expr*)BitfieldWidth; 2650 SourceLocation Loc = DeclStart; 2651 if (II) Loc = D.getIdentifierLoc(); 2652 2653 // FIXME: Unnamed fields can be handled in various different ways, for 2654 // example, unnamed unions inject all members into the struct namespace! 2655 2656 2657 if (BitWidth) { 2658 // TODO: Validate. 2659 //printf("WARNING: BITFIELDS IGNORED!\n"); 2660 2661 // 6.7.2.1p3 2662 // 6.7.2.1p4 2663 2664 } else { 2665 // Not a bitfield. 2666 2667 // validate II. 2668 2669 } 2670 2671 QualType T = GetTypeForDeclarator(D, S); 2672 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2673 bool InvalidDecl = false; 2674 2675 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2676 // than a variably modified type. 2677 if (T->isVariablyModifiedType()) { 2678 // FIXME: This diagnostic needs work 2679 Diag(Loc, diag::err_typecheck_illegal_vla) << SourceRange(Loc); 2680 InvalidDecl = true; 2681 } 2682 2683 // Get the visibility (access control) for this ivar. 2684 ObjCIvarDecl::AccessControl ac = 2685 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2686 : ObjCIvarDecl::None; 2687 2688 // Construct the decl. 2689 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2690 (Expr *)BitfieldWidth); 2691 2692 // Process attributes attached to the ivar. 2693 ProcessDeclAttributes(NewID, D); 2694 2695 if (D.getInvalidType() || InvalidDecl) 2696 NewID->setInvalidDecl(); 2697 2698 return NewID; 2699} 2700 2701void Sema::ActOnFields(Scope* S, 2702 SourceLocation RecLoc, DeclTy *RecDecl, 2703 DeclTy **Fields, unsigned NumFields, 2704 SourceLocation LBrac, SourceLocation RBrac, 2705 AttributeList *Attr) { 2706 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2707 assert(EnclosingDecl && "missing record or interface decl"); 2708 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2709 2710 if (Record) 2711 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2712 // Diagnose code like: 2713 // struct S { struct S {} X; }; 2714 // We discover this when we complete the outer S. Reject and ignore the 2715 // outer S. 2716 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2717 DefRecord->getKindName()); 2718 Diag(RecLoc, diag::err_previous_definition); 2719 Record->setInvalidDecl(); 2720 return; 2721 } 2722 2723 // Verify that all the fields are okay. 2724 unsigned NumNamedMembers = 0; 2725 llvm::SmallVector<FieldDecl*, 32> RecFields; 2726 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2727 2728 for (unsigned i = 0; i != NumFields; ++i) { 2729 2730 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2731 assert(FD && "missing field decl"); 2732 2733 // Remember all fields. 2734 RecFields.push_back(FD); 2735 2736 // Get the type for the field. 2737 Type *FDTy = FD->getType().getTypePtr(); 2738 2739 // C99 6.7.2.1p2 - A field may not be a function type. 2740 if (FDTy->isFunctionType()) { 2741 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2742 FD->getName()); 2743 FD->setInvalidDecl(); 2744 EnclosingDecl->setInvalidDecl(); 2745 continue; 2746 } 2747 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2748 if (FDTy->isIncompleteType()) { 2749 if (!Record) { // Incomplete ivar type is always an error. 2750 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2751 FD->setInvalidDecl(); 2752 EnclosingDecl->setInvalidDecl(); 2753 continue; 2754 } 2755 if (i != NumFields-1 || // ... that the last member ... 2756 !Record->isStruct() || // ... of a structure ... 2757 !FDTy->isArrayType()) { //... may have incomplete array type. 2758 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2759 FD->setInvalidDecl(); 2760 EnclosingDecl->setInvalidDecl(); 2761 continue; 2762 } 2763 if (NumNamedMembers < 1) { //... must have more than named member ... 2764 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2765 FD->getName()); 2766 FD->setInvalidDecl(); 2767 EnclosingDecl->setInvalidDecl(); 2768 continue; 2769 } 2770 // Okay, we have a legal flexible array member at the end of the struct. 2771 if (Record) 2772 Record->setHasFlexibleArrayMember(true); 2773 } 2774 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2775 /// field of another structure or the element of an array. 2776 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2777 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2778 // If this is a member of a union, then entire union becomes "flexible". 2779 if (Record && Record->isUnion()) { 2780 Record->setHasFlexibleArrayMember(true); 2781 } else { 2782 // If this is a struct/class and this is not the last element, reject 2783 // it. Note that GCC supports variable sized arrays in the middle of 2784 // structures. 2785 if (i != NumFields-1) { 2786 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2787 FD->getName()); 2788 FD->setInvalidDecl(); 2789 EnclosingDecl->setInvalidDecl(); 2790 continue; 2791 } 2792 // We support flexible arrays at the end of structs in other structs 2793 // as an extension. 2794 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2795 FD->getName()); 2796 if (Record) 2797 Record->setHasFlexibleArrayMember(true); 2798 } 2799 } 2800 } 2801 /// A field cannot be an Objective-c object 2802 if (FDTy->isObjCInterfaceType()) { 2803 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2804 FD->getName()); 2805 FD->setInvalidDecl(); 2806 EnclosingDecl->setInvalidDecl(); 2807 continue; 2808 } 2809 // Keep track of the number of named members. 2810 if (IdentifierInfo *II = FD->getIdentifier()) { 2811 // Detect duplicate member names. 2812 if (!FieldIDs.insert(II)) { 2813 Diag(FD->getLocation(), diag::err_duplicate_member) << II; 2814 // Find the previous decl. 2815 SourceLocation PrevLoc; 2816 for (unsigned i = 0; ; ++i) { 2817 assert(i != RecFields.size() && "Didn't find previous def!"); 2818 if (RecFields[i]->getIdentifier() == II) { 2819 PrevLoc = RecFields[i]->getLocation(); 2820 break; 2821 } 2822 } 2823 Diag(PrevLoc, diag::err_previous_definition); 2824 FD->setInvalidDecl(); 2825 EnclosingDecl->setInvalidDecl(); 2826 continue; 2827 } 2828 ++NumNamedMembers; 2829 } 2830 } 2831 2832 // Okay, we successfully defined 'Record'. 2833 if (Record) { 2834 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2835 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2836 // Sema::ActOnFinishCXXClassDef. 2837 if (!isa<CXXRecordDecl>(Record)) 2838 Consumer.HandleTagDeclDefinition(Record); 2839 } else { 2840 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2841 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2842 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2843 else if (ObjCImplementationDecl *IMPDecl = 2844 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2845 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2846 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2847 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2848 } 2849 } 2850 2851 if (Attr) 2852 ProcessDeclAttributeList(Record, Attr); 2853} 2854 2855Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2856 DeclTy *lastEnumConst, 2857 SourceLocation IdLoc, IdentifierInfo *Id, 2858 SourceLocation EqualLoc, ExprTy *val) { 2859 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2860 EnumConstantDecl *LastEnumConst = 2861 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2862 Expr *Val = static_cast<Expr*>(val); 2863 2864 // The scope passed in may not be a decl scope. Zip up the scope tree until 2865 // we find one that is. 2866 while ((S->getFlags() & Scope::DeclScope) == 0) 2867 S = S->getParent(); 2868 2869 // Verify that there isn't already something declared with this name in this 2870 // scope. 2871 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2872 // When in C++, we may get a TagDecl with the same name; in this case the 2873 // enum constant will 'hide' the tag. 2874 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2875 "Received TagDecl when not in C++!"); 2876 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2877 if (isa<EnumConstantDecl>(PrevDecl)) 2878 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 2879 else 2880 Diag(IdLoc, diag::err_redefinition) << Id; 2881 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2882 delete Val; 2883 return 0; 2884 } 2885 } 2886 2887 llvm::APSInt EnumVal(32); 2888 QualType EltTy; 2889 if (Val) { 2890 // Make sure to promote the operand type to int. 2891 UsualUnaryConversions(Val); 2892 2893 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2894 SourceLocation ExpLoc; 2895 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2896 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr) << Id; 2897 delete Val; 2898 Val = 0; // Just forget about it. 2899 } else { 2900 EltTy = Val->getType(); 2901 } 2902 } 2903 2904 if (!Val) { 2905 if (LastEnumConst) { 2906 // Assign the last value + 1. 2907 EnumVal = LastEnumConst->getInitVal(); 2908 ++EnumVal; 2909 2910 // Check for overflow on increment. 2911 if (EnumVal < LastEnumConst->getInitVal()) 2912 Diag(IdLoc, diag::warn_enum_value_overflow); 2913 2914 EltTy = LastEnumConst->getType(); 2915 } else { 2916 // First value, set to zero. 2917 EltTy = Context.IntTy; 2918 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2919 } 2920 } 2921 2922 EnumConstantDecl *New = 2923 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2924 Val, EnumVal, 2925 LastEnumConst); 2926 2927 // Register this decl in the current scope stack. 2928 PushOnScopeChains(New, S); 2929 return New; 2930} 2931 2932// FIXME: For consistency with ActOnFields(), we should have the parser 2933// pass in the source location for the left/right braces. 2934void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2935 DeclTy **Elements, unsigned NumElements) { 2936 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2937 2938 if (Enum && Enum->isDefinition()) { 2939 // Diagnose code like: 2940 // enum e0 { 2941 // E0 = sizeof(enum e0 { E1 }) 2942 // }; 2943 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2944 Enum->getName()); 2945 Diag(EnumLoc, diag::err_previous_definition); 2946 Enum->setInvalidDecl(); 2947 return; 2948 } 2949 // TODO: If the result value doesn't fit in an int, it must be a long or long 2950 // long value. ISO C does not support this, but GCC does as an extension, 2951 // emit a warning. 2952 unsigned IntWidth = Context.Target.getIntWidth(); 2953 2954 // Verify that all the values are okay, compute the size of the values, and 2955 // reverse the list. 2956 unsigned NumNegativeBits = 0; 2957 unsigned NumPositiveBits = 0; 2958 2959 // Keep track of whether all elements have type int. 2960 bool AllElementsInt = true; 2961 2962 EnumConstantDecl *EltList = 0; 2963 for (unsigned i = 0; i != NumElements; ++i) { 2964 EnumConstantDecl *ECD = 2965 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2966 if (!ECD) continue; // Already issued a diagnostic. 2967 2968 // If the enum value doesn't fit in an int, emit an extension warning. 2969 const llvm::APSInt &InitVal = ECD->getInitVal(); 2970 assert(InitVal.getBitWidth() >= IntWidth && 2971 "Should have promoted value to int"); 2972 if (InitVal.getBitWidth() > IntWidth) { 2973 llvm::APSInt V(InitVal); 2974 V.trunc(IntWidth); 2975 V.extend(InitVal.getBitWidth()); 2976 if (V != InitVal) 2977 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2978 InitVal.toString(10)); 2979 } 2980 2981 // Keep track of the size of positive and negative values. 2982 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2983 NumPositiveBits = std::max(NumPositiveBits, 2984 (unsigned)InitVal.getActiveBits()); 2985 else 2986 NumNegativeBits = std::max(NumNegativeBits, 2987 (unsigned)InitVal.getMinSignedBits()); 2988 2989 // Keep track of whether every enum element has type int (very commmon). 2990 if (AllElementsInt) 2991 AllElementsInt = ECD->getType() == Context.IntTy; 2992 2993 ECD->setNextDeclarator(EltList); 2994 EltList = ECD; 2995 } 2996 2997 // Figure out the type that should be used for this enum. 2998 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2999 QualType BestType; 3000 unsigned BestWidth; 3001 3002 if (NumNegativeBits) { 3003 // If there is a negative value, figure out the smallest integer type (of 3004 // int/long/longlong) that fits. 3005 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 3006 BestType = Context.IntTy; 3007 BestWidth = IntWidth; 3008 } else { 3009 BestWidth = Context.Target.getLongWidth(); 3010 3011 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 3012 BestType = Context.LongTy; 3013 else { 3014 BestWidth = Context.Target.getLongLongWidth(); 3015 3016 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 3017 Diag(Enum->getLocation(), diag::warn_enum_too_large); 3018 BestType = Context.LongLongTy; 3019 } 3020 } 3021 } else { 3022 // If there is no negative value, figure out which of uint, ulong, ulonglong 3023 // fits. 3024 if (NumPositiveBits <= IntWidth) { 3025 BestType = Context.UnsignedIntTy; 3026 BestWidth = IntWidth; 3027 } else if (NumPositiveBits <= 3028 (BestWidth = Context.Target.getLongWidth())) { 3029 BestType = Context.UnsignedLongTy; 3030 } else { 3031 BestWidth = Context.Target.getLongLongWidth(); 3032 assert(NumPositiveBits <= BestWidth && 3033 "How could an initializer get larger than ULL?"); 3034 BestType = Context.UnsignedLongLongTy; 3035 } 3036 } 3037 3038 // Loop over all of the enumerator constants, changing their types to match 3039 // the type of the enum if needed. 3040 for (unsigned i = 0; i != NumElements; ++i) { 3041 EnumConstantDecl *ECD = 3042 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3043 if (!ECD) continue; // Already issued a diagnostic. 3044 3045 // Standard C says the enumerators have int type, but we allow, as an 3046 // extension, the enumerators to be larger than int size. If each 3047 // enumerator value fits in an int, type it as an int, otherwise type it the 3048 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 3049 // that X has type 'int', not 'unsigned'. 3050 if (ECD->getType() == Context.IntTy) { 3051 // Make sure the init value is signed. 3052 llvm::APSInt IV = ECD->getInitVal(); 3053 IV.setIsSigned(true); 3054 ECD->setInitVal(IV); 3055 continue; // Already int type. 3056 } 3057 3058 // Determine whether the value fits into an int. 3059 llvm::APSInt InitVal = ECD->getInitVal(); 3060 bool FitsInInt; 3061 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3062 FitsInInt = InitVal.getActiveBits() < IntWidth; 3063 else 3064 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3065 3066 // If it fits into an integer type, force it. Otherwise force it to match 3067 // the enum decl type. 3068 QualType NewTy; 3069 unsigned NewWidth; 3070 bool NewSign; 3071 if (FitsInInt) { 3072 NewTy = Context.IntTy; 3073 NewWidth = IntWidth; 3074 NewSign = true; 3075 } else if (ECD->getType() == BestType) { 3076 // Already the right type! 3077 continue; 3078 } else { 3079 NewTy = BestType; 3080 NewWidth = BestWidth; 3081 NewSign = BestType->isSignedIntegerType(); 3082 } 3083 3084 // Adjust the APSInt value. 3085 InitVal.extOrTrunc(NewWidth); 3086 InitVal.setIsSigned(NewSign); 3087 ECD->setInitVal(InitVal); 3088 3089 // Adjust the Expr initializer and type. 3090 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3091 /*isLvalue=*/false)); 3092 ECD->setType(NewTy); 3093 } 3094 3095 Enum->defineElements(EltList, BestType); 3096 Consumer.HandleTagDeclDefinition(Enum); 3097} 3098 3099Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3100 ExprTy *expr) { 3101 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3102 3103 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3104} 3105 3106Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3107 SourceLocation LBrace, 3108 SourceLocation RBrace, 3109 const char *Lang, 3110 unsigned StrSize, 3111 DeclTy *D) { 3112 LinkageSpecDecl::LanguageIDs Language; 3113 Decl *dcl = static_cast<Decl *>(D); 3114 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3115 Language = LinkageSpecDecl::lang_c; 3116 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3117 Language = LinkageSpecDecl::lang_cxx; 3118 else { 3119 Diag(Loc, diag::err_bad_language); 3120 return 0; 3121 } 3122 3123 // FIXME: Add all the various semantics of linkage specifications 3124 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3125} 3126 3127void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3128 ExprTy *alignment, SourceLocation PragmaLoc, 3129 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3130 Expr *Alignment = static_cast<Expr *>(alignment); 3131 3132 // If specified then alignment must be a "small" power of two. 3133 unsigned AlignmentVal = 0; 3134 if (Alignment) { 3135 llvm::APSInt Val; 3136 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3137 !Val.isPowerOf2() || 3138 Val.getZExtValue() > 16) { 3139 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3140 delete Alignment; 3141 return; // Ignore 3142 } 3143 3144 AlignmentVal = (unsigned) Val.getZExtValue(); 3145 } 3146 3147 switch (Kind) { 3148 case Action::PPK_Default: // pack([n]) 3149 PackContext.setAlignment(AlignmentVal); 3150 break; 3151 3152 case Action::PPK_Show: // pack(show) 3153 // Show the current alignment, making sure to show the right value 3154 // for the default. 3155 AlignmentVal = PackContext.getAlignment(); 3156 // FIXME: This should come from the target. 3157 if (AlignmentVal == 0) 3158 AlignmentVal = 8; 3159 Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 3160 break; 3161 3162 case Action::PPK_Push: // pack(push [, id] [, [n]) 3163 PackContext.push(Name); 3164 // Set the new alignment if specified. 3165 if (Alignment) 3166 PackContext.setAlignment(AlignmentVal); 3167 break; 3168 3169 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3170 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3171 // "#pragma pack(pop, identifier, n) is undefined" 3172 if (Alignment && Name) 3173 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3174 3175 // Do the pop. 3176 if (!PackContext.pop(Name)) { 3177 // If a name was specified then failure indicates the name 3178 // wasn't found. Otherwise failure indicates the stack was 3179 // empty. 3180 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3181 Name ? "no record matching name" : "stack empty"); 3182 3183 // FIXME: Warn about popping named records as MSVC does. 3184 } else { 3185 // Pop succeeded, set the new alignment if specified. 3186 if (Alignment) 3187 PackContext.setAlignment(AlignmentVal); 3188 } 3189 break; 3190 3191 default: 3192 assert(0 && "Invalid #pragma pack kind."); 3193 } 3194} 3195 3196bool PragmaPackStack::pop(IdentifierInfo *Name) { 3197 if (Stack.empty()) 3198 return false; 3199 3200 // If name is empty just pop top. 3201 if (!Name) { 3202 Alignment = Stack.back().first; 3203 Stack.pop_back(); 3204 return true; 3205 } 3206 3207 // Otherwise, find the named record. 3208 for (unsigned i = Stack.size(); i != 0; ) { 3209 --i; 3210 if (Stack[i].second == Name) { 3211 // Found it, pop up to and including this record. 3212 Alignment = Stack[i].first; 3213 Stack.erase(Stack.begin() + i, Stack.end()); 3214 return true; 3215 } 3216 } 3217 3218 return false; 3219} 3220