SemaDecl.cpp revision 108229a2eece5159ea6451d9446d29b7bd7a6e29
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 isa<TemplateTypeParmDecl>(IIDecl))) 44 return IIDecl; 45 return 0; 46} 47 48DeclContext *Sema::getContainingDC(DeclContext *DC) { 49 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 50 // A C++ out-of-line method will return to the file declaration context. 51 if (MD->isOutOfLineDefinition()) 52 return MD->getLexicalDeclContext(); 53 54 // A C++ inline method is parsed *after* the topmost class it was declared in 55 // is fully parsed (it's "complete"). 56 // The parsing of a C++ inline method happens at the declaration context of 57 // the topmost (non-nested) class it is lexically declared in. 58 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 59 DC = MD->getParent(); 60 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 61 DC = RD; 62 63 // Return the declaration context of the topmost class the inline method is 64 // declared in. 65 return DC; 66 } 67 68 if (isa<ObjCMethodDecl>(DC)) 69 return Context.getTranslationUnitDecl(); 70 71 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC)) 72 return SD->getLexicalDeclContext(); 73 74 return DC->getLexicalParent(); 75} 76 77void Sema::PushDeclContext(DeclContext *DC) { 78 assert(getContainingDC(DC) == CurContext && 79 "The next DeclContext should be lexically contained in the current one."); 80 CurContext = DC; 81} 82 83void Sema::PopDeclContext() { 84 assert(CurContext && "DeclContext imbalance!"); 85 CurContext = getContainingDC(CurContext); 86} 87 88/// Add this decl to the scope shadowed decl chains. 89void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 90 S->AddDecl(D); 91 92 // C++ [basic.scope]p4: 93 // -- exactly one declaration shall declare a class name or 94 // enumeration name that is not a typedef name and the other 95 // declarations shall all refer to the same object or 96 // enumerator, or all refer to functions and function templates; 97 // in this case the class name or enumeration name is hidden. 98 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 99 // We are pushing the name of a tag (enum or class). 100 IdentifierResolver::iterator 101 I = IdResolver.begin(TD->getIdentifier(), 102 TD->getDeclContext(), false/*LookInParentCtx*/); 103 if (I != IdResolver.end() && isDeclInScope(*I, TD->getDeclContext(), S)) { 104 // There is already a declaration with the same name in the same 105 // scope. It must be found before we find the new declaration, 106 // so swap the order on the shadowed declaration chain. 107 108 IdResolver.AddShadowedDecl(TD, *I); 109 return; 110 } 111 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 112 FunctionDecl *FD = cast<FunctionDecl>(D); 113 // We are pushing the name of a function, which might be an 114 // overloaded name. 115 IdentifierResolver::iterator 116 I = IdResolver.begin(FD->getDeclName(), 117 FD->getDeclContext(), false/*LookInParentCtx*/); 118 if (I != IdResolver.end() && 119 IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) && 120 (isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) { 121 // There is already a declaration with the same name in the same 122 // scope. It must be a function or an overloaded function. 123 OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I); 124 if (!Ovl) { 125 // We haven't yet overloaded this function. Take the existing 126 // FunctionDecl and put it into an OverloadedFunctionDecl. 127 Ovl = OverloadedFunctionDecl::Create(Context, 128 FD->getDeclContext(), 129 FD->getDeclName()); 130 Ovl->addOverload(dyn_cast<FunctionDecl>(*I)); 131 132 // Remove the name binding to the existing FunctionDecl... 133 IdResolver.RemoveDecl(*I); 134 135 // ... and put the OverloadedFunctionDecl in its place. 136 IdResolver.AddDecl(Ovl); 137 } 138 139 // We have an OverloadedFunctionDecl. Add the new FunctionDecl 140 // to its list of overloads. 141 Ovl->addOverload(FD); 142 143 return; 144 } 145 } 146 147 IdResolver.AddDecl(D); 148} 149 150void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 151 if (S->decl_empty()) return; 152 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && 153 "Scope shouldn't contain decls!"); 154 155 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 156 I != E; ++I) { 157 Decl *TmpD = static_cast<Decl*>(*I); 158 assert(TmpD && "This decl didn't get pushed??"); 159 160 if (isa<CXXFieldDecl>(TmpD)) continue; 161 162 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 163 ScopedDecl *D = cast<ScopedDecl>(TmpD); 164 165 IdentifierInfo *II = D->getIdentifier(); 166 if (!II) continue; 167 168 // We only want to remove the decls from the identifier decl chains for 169 // local scopes, when inside a function/method. 170 // However, we *always* remove template parameters, since they are 171 // purely lexically scoped (and can never be found by qualified 172 // name lookup). 173 if (S->getFnParent() != 0 || isa<TemplateTypeParmDecl>(D)) 174 IdResolver.RemoveDecl(D); 175 176 // Chain this decl to the containing DeclContext. 177 D->setNext(CurContext->getDeclChain()); 178 CurContext->setDeclChain(D); 179 } 180} 181 182/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 183/// return 0 if one not found. 184ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 185 // The third "scope" argument is 0 since we aren't enabling lazy built-in 186 // creation from this context. 187 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 188 189 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 190} 191 192/// LookupDecl - Look up the inner-most declaration in the specified 193/// namespace. 194Decl *Sema::LookupDecl(DeclarationName Name, unsigned NSI, Scope *S, 195 const DeclContext *LookupCtx, 196 bool enableLazyBuiltinCreation) { 197 if (!Name) return 0; 198 unsigned NS = NSI; 199 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 200 NS |= Decl::IDNS_Tag; 201 202 IdentifierResolver::iterator 203 I = LookupCtx ? IdResolver.begin(Name, LookupCtx, false/*LookInParentCtx*/) 204 : IdResolver.begin(Name, CurContext, true/*LookInParentCtx*/); 205 // Scan up the scope chain looking for a decl that matches this identifier 206 // that is in the appropriate namespace. This search should not take long, as 207 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 208 for (; I != IdResolver.end(); ++I) 209 if ((*I)->getIdentifierNamespace() & NS) 210 return *I; 211 212 // If we didn't find a use of this identifier, and if the identifier 213 // corresponds to a compiler builtin, create the decl object for the builtin 214 // now, injecting it into translation unit scope, and return it. 215 if (NS & Decl::IDNS_Ordinary) { 216 IdentifierInfo *II = Name.getAsIdentifierInfo(); 217 if (enableLazyBuiltinCreation && II && 218 (LookupCtx == 0 || isa<TranslationUnitDecl>(LookupCtx))) { 219 // If this is a builtin on this (or all) targets, create the decl. 220 if (unsigned BuiltinID = II->getBuiltinID()) 221 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 222 } 223 if (getLangOptions().ObjC1 && II) { 224 // @interface and @compatibility_alias introduce typedef-like names. 225 // Unlike typedef's, they can only be introduced at file-scope (and are 226 // therefore not scoped decls). They can, however, be shadowed by 227 // other names in IDNS_Ordinary. 228 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 229 if (IDI != ObjCInterfaceDecls.end()) 230 return IDI->second; 231 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 232 if (I != ObjCAliasDecls.end()) 233 return I->second->getClassInterface(); 234 } 235 } 236 return 0; 237} 238 239void Sema::InitBuiltinVaListType() { 240 if (!Context.getBuiltinVaListType().isNull()) 241 return; 242 243 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 244 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 245 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 246 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 247} 248 249/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 250/// lazily create a decl for it. 251ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 252 Scope *S) { 253 Builtin::ID BID = (Builtin::ID)bid; 254 255 if (Context.BuiltinInfo.hasVAListUse(BID)) 256 InitBuiltinVaListType(); 257 258 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 259 FunctionDecl *New = FunctionDecl::Create(Context, 260 Context.getTranslationUnitDecl(), 261 SourceLocation(), II, R, 262 FunctionDecl::Extern, false, 0); 263 264 // Create Decl objects for each parameter, adding them to the 265 // FunctionDecl. 266 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 267 llvm::SmallVector<ParmVarDecl*, 16> Params; 268 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 269 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 270 FT->getArgType(i), VarDecl::None, 0, 271 0)); 272 New->setParams(&Params[0], Params.size()); 273 } 274 275 276 277 // TUScope is the translation-unit scope to insert this function into. 278 PushOnScopeChains(New, TUScope); 279 return New; 280} 281 282/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 283/// everything from the standard library is defined. 284NamespaceDecl *Sema::GetStdNamespace() { 285 if (!StdNamespace) { 286 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 287 DeclContext *Global = Context.getTranslationUnitDecl(); 288 Decl *Std = LookupDecl(StdIdent, Decl::IDNS_Tag | Decl::IDNS_Ordinary, 289 0, Global, /*enableLazyBuiltinCreation=*/false); 290 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 291 } 292 return StdNamespace; 293} 294 295/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 296/// and scope as a previous declaration 'Old'. Figure out how to resolve this 297/// situation, merging decls or emitting diagnostics as appropriate. 298/// 299TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 300 // Allow multiple definitions for ObjC built-in typedefs. 301 // FIXME: Verify the underlying types are equivalent! 302 if (getLangOptions().ObjC1) { 303 const IdentifierInfo *TypeID = New->getIdentifier(); 304 switch (TypeID->getLength()) { 305 default: break; 306 case 2: 307 if (!TypeID->isStr("id")) 308 break; 309 Context.setObjCIdType(New); 310 return New; 311 case 5: 312 if (!TypeID->isStr("Class")) 313 break; 314 Context.setObjCClassType(New); 315 return New; 316 case 3: 317 if (!TypeID->isStr("SEL")) 318 break; 319 Context.setObjCSelType(New); 320 return New; 321 case 8: 322 if (!TypeID->isStr("Protocol")) 323 break; 324 Context.setObjCProtoType(New->getUnderlyingType()); 325 return New; 326 } 327 // Fall through - the typedef name was not a builtin type. 328 } 329 // Verify the old decl was also a typedef. 330 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 331 if (!Old) { 332 Diag(New->getLocation(), diag::err_redefinition_different_kind) 333 << New->getDeclName(); 334 Diag(OldD->getLocation(), diag::note_previous_definition); 335 return New; 336 } 337 338 // If the typedef types are not identical, reject them in all languages and 339 // with any extensions enabled. 340 if (Old->getUnderlyingType() != New->getUnderlyingType() && 341 Context.getCanonicalType(Old->getUnderlyingType()) != 342 Context.getCanonicalType(New->getUnderlyingType())) { 343 Diag(New->getLocation(), diag::err_redefinition_different_typedef) 344 << New->getUnderlyingType() << Old->getUnderlyingType(); 345 Diag(Old->getLocation(), diag::note_previous_definition); 346 return Old; 347 } 348 349 if (getLangOptions().Microsoft) return New; 350 351 // C++ [dcl.typedef]p2: 352 // In a given non-class scope, a typedef specifier can be used to 353 // redefine the name of any type declared in that scope to refer 354 // to the type to which it already refers. 355 if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext)) 356 return New; 357 358 // In C, redeclaration of a type is a constraint violation (6.7.2.3p1). 359 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 360 // *either* declaration is in a system header. The code below implements 361 // this adhoc compatibility rule. FIXME: The following code will not 362 // work properly when compiling ".i" files (containing preprocessed output). 363 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 364 SourceManager &SrcMgr = Context.getSourceManager(); 365 if (SrcMgr.isInSystemHeader(Old->getLocation())) 366 return New; 367 if (SrcMgr.isInSystemHeader(New->getLocation())) 368 return New; 369 } 370 371 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 372 Diag(Old->getLocation(), diag::note_previous_definition); 373 return New; 374} 375 376/// DeclhasAttr - returns true if decl Declaration already has the target 377/// attribute. 378static bool DeclHasAttr(const Decl *decl, const Attr *target) { 379 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 380 if (attr->getKind() == target->getKind()) 381 return true; 382 383 return false; 384} 385 386/// MergeAttributes - append attributes from the Old decl to the New one. 387static void MergeAttributes(Decl *New, Decl *Old) { 388 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 389 390 while (attr) { 391 tmp = attr; 392 attr = attr->getNext(); 393 394 if (!DeclHasAttr(New, tmp)) { 395 New->addAttr(tmp); 396 } else { 397 tmp->setNext(0); 398 delete(tmp); 399 } 400 } 401 402 Old->invalidateAttrs(); 403} 404 405/// MergeFunctionDecl - We just parsed a function 'New' from 406/// declarator D which has the same name and scope as a previous 407/// declaration 'Old'. Figure out how to resolve this situation, 408/// merging decls or emitting diagnostics as appropriate. 409/// Redeclaration will be set true if this New is a redeclaration OldD. 410/// 411/// In C++, New and Old must be declarations that are not 412/// overloaded. Use IsOverload to determine whether New and Old are 413/// overloaded, and to select the Old declaration that New should be 414/// merged with. 415FunctionDecl * 416Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 417 assert(!isa<OverloadedFunctionDecl>(OldD) && 418 "Cannot merge with an overloaded function declaration"); 419 420 Redeclaration = false; 421 // Verify the old decl was also a function. 422 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 423 if (!Old) { 424 Diag(New->getLocation(), diag::err_redefinition_different_kind) 425 << New->getDeclName(); 426 Diag(OldD->getLocation(), diag::note_previous_definition); 427 return New; 428 } 429 430 // Determine whether the previous declaration was a definition, 431 // implicit declaration, or a declaration. 432 diag::kind PrevDiag; 433 if (Old->isThisDeclarationADefinition()) 434 PrevDiag = diag::note_previous_definition; 435 else if (Old->isImplicit()) 436 PrevDiag = diag::note_previous_implicit_declaration; 437 else 438 PrevDiag = diag::note_previous_declaration; 439 440 QualType OldQType = Context.getCanonicalType(Old->getType()); 441 QualType NewQType = Context.getCanonicalType(New->getType()); 442 443 if (getLangOptions().CPlusPlus) { 444 // (C++98 13.1p2): 445 // Certain function declarations cannot be overloaded: 446 // -- Function declarations that differ only in the return type 447 // cannot be overloaded. 448 QualType OldReturnType 449 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 450 QualType NewReturnType 451 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 452 if (OldReturnType != NewReturnType) { 453 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 454 Diag(Old->getLocation(), PrevDiag); 455 return New; 456 } 457 458 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 459 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 460 if (OldMethod && NewMethod) { 461 // -- Member function declarations with the same name and the 462 // same parameter types cannot be overloaded if any of them 463 // is a static member function declaration. 464 if (OldMethod->isStatic() || NewMethod->isStatic()) { 465 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 466 Diag(Old->getLocation(), PrevDiag); 467 return New; 468 } 469 } 470 471 // (C++98 8.3.5p3): 472 // All declarations for a function shall agree exactly in both the 473 // return type and the parameter-type-list. 474 if (OldQType == NewQType) { 475 // We have a redeclaration. 476 MergeAttributes(New, Old); 477 Redeclaration = true; 478 return MergeCXXFunctionDecl(New, Old); 479 } 480 481 // Fall through for conflicting redeclarations and redefinitions. 482 } 483 484 // C: Function types need to be compatible, not identical. This handles 485 // duplicate function decls like "void f(int); void f(enum X);" properly. 486 if (!getLangOptions().CPlusPlus && 487 Context.typesAreCompatible(OldQType, NewQType)) { 488 MergeAttributes(New, Old); 489 Redeclaration = true; 490 return New; 491 } 492 493 // A function that has already been declared has been redeclared or defined 494 // with a different type- show appropriate diagnostic 495 496 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 497 // TODO: This is totally simplistic. It should handle merging functions 498 // together etc, merging extern int X; int X; ... 499 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); 500 Diag(Old->getLocation(), PrevDiag); 501 return New; 502} 503 504/// Predicate for C "tentative" external object definitions (C99 6.9.2). 505static bool isTentativeDefinition(VarDecl *VD) { 506 if (VD->isFileVarDecl()) 507 return (!VD->getInit() && 508 (VD->getStorageClass() == VarDecl::None || 509 VD->getStorageClass() == VarDecl::Static)); 510 return false; 511} 512 513/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 514/// when dealing with C "tentative" external object definitions (C99 6.9.2). 515void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 516 bool VDIsTentative = isTentativeDefinition(VD); 517 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 518 519 for (IdentifierResolver::iterator 520 I = IdResolver.begin(VD->getIdentifier(), 521 VD->getDeclContext(), false/*LookInParentCtx*/), 522 E = IdResolver.end(); I != E; ++I) { 523 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 524 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 525 526 // Handle the following case: 527 // int a[10]; 528 // int a[]; - the code below makes sure we set the correct type. 529 // int a[11]; - this is an error, size isn't 10. 530 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 531 OldDecl->getType()->isConstantArrayType()) 532 VD->setType(OldDecl->getType()); 533 534 // Check for "tentative" definitions. We can't accomplish this in 535 // MergeVarDecl since the initializer hasn't been attached. 536 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 537 continue; 538 539 // Handle __private_extern__ just like extern. 540 if (OldDecl->getStorageClass() != VarDecl::Extern && 541 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 542 VD->getStorageClass() != VarDecl::Extern && 543 VD->getStorageClass() != VarDecl::PrivateExtern) { 544 Diag(VD->getLocation(), diag::err_redefinition) << VD->getDeclName(); 545 Diag(OldDecl->getLocation(), diag::note_previous_definition); 546 } 547 } 548 } 549} 550 551/// MergeVarDecl - We just parsed a variable 'New' which has the same name 552/// and scope as a previous declaration 'Old'. Figure out how to resolve this 553/// situation, merging decls or emitting diagnostics as appropriate. 554/// 555/// Tentative definition rules (C99 6.9.2p2) are checked by 556/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 557/// definitions here, since the initializer hasn't been attached. 558/// 559VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 560 // Verify the old decl was also a variable. 561 VarDecl *Old = dyn_cast<VarDecl>(OldD); 562 if (!Old) { 563 Diag(New->getLocation(), diag::err_redefinition_different_kind) 564 << New->getDeclName(); 565 Diag(OldD->getLocation(), diag::note_previous_definition); 566 return New; 567 } 568 569 MergeAttributes(New, Old); 570 571 // Verify the types match. 572 QualType OldCType = Context.getCanonicalType(Old->getType()); 573 QualType NewCType = Context.getCanonicalType(New->getType()); 574 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 575 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 576 Diag(Old->getLocation(), diag::note_previous_definition); 577 return New; 578 } 579 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 580 if (New->getStorageClass() == VarDecl::Static && 581 (Old->getStorageClass() == VarDecl::None || 582 Old->getStorageClass() == VarDecl::Extern)) { 583 Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName(); 584 Diag(Old->getLocation(), diag::note_previous_definition); 585 return New; 586 } 587 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 588 if (New->getStorageClass() != VarDecl::Static && 589 Old->getStorageClass() == VarDecl::Static) { 590 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); 591 Diag(Old->getLocation(), diag::note_previous_definition); 592 return New; 593 } 594 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 595 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 596 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); 597 Diag(Old->getLocation(), diag::note_previous_definition); 598 } 599 return New; 600} 601 602/// CheckParmsForFunctionDef - Check that the parameters of the given 603/// function are appropriate for the definition of a function. This 604/// takes care of any checks that cannot be performed on the 605/// declaration itself, e.g., that the types of each of the function 606/// parameters are complete. 607bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 608 bool HasInvalidParm = false; 609 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 610 ParmVarDecl *Param = FD->getParamDecl(p); 611 612 // C99 6.7.5.3p4: the parameters in a parameter type list in a 613 // function declarator that is part of a function definition of 614 // that function shall not have incomplete type. 615 if (Param->getType()->isIncompleteType() && 616 !Param->isInvalidDecl()) { 617 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type) 618 << Param->getType(); 619 Param->setInvalidDecl(); 620 HasInvalidParm = true; 621 } 622 } 623 624 return HasInvalidParm; 625} 626 627/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 628/// no declarator (e.g. "struct foo;") is parsed. 629Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 630 // TODO: emit error on 'int;' or 'const enum foo;'. 631 // TODO: emit error on 'typedef int;' 632 // if (!DS.isMissingDeclaratorOk()) Diag(...); 633 634 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 635} 636 637bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 638 // Get the type before calling CheckSingleAssignmentConstraints(), since 639 // it can promote the expression. 640 QualType InitType = Init->getType(); 641 642 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 643 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 644 InitType, Init, "initializing"); 645} 646 647bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 648 const ArrayType *AT = Context.getAsArrayType(DeclT); 649 650 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 651 // C99 6.7.8p14. We have an array of character type with unknown size 652 // being initialized to a string literal. 653 llvm::APSInt ConstVal(32); 654 ConstVal = strLiteral->getByteLength() + 1; 655 // Return a new array type (C99 6.7.8p22). 656 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 657 ArrayType::Normal, 0); 658 } else { 659 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 660 // C99 6.7.8p14. We have an array of character type with known size. 661 // FIXME: Avoid truncation for 64-bit length strings. 662 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 663 Diag(strLiteral->getSourceRange().getBegin(), 664 diag::warn_initializer_string_for_char_array_too_long) 665 << strLiteral->getSourceRange(); 666 } 667 // Set type from "char *" to "constant array of char". 668 strLiteral->setType(DeclT); 669 // For now, we always return false (meaning success). 670 return false; 671} 672 673StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 674 const ArrayType *AT = Context.getAsArrayType(DeclType); 675 if (AT && AT->getElementType()->isCharType()) { 676 return dyn_cast<StringLiteral>(Init); 677 } 678 return 0; 679} 680 681bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 682 SourceLocation InitLoc, 683 DeclarationName InitEntity) { 684 // C++ [dcl.init.ref]p1: 685 // A variable declared to be a T&, that is "reference to type T" 686 // (8.3.2), shall be initialized by an object, or function, of 687 // type T or by an object that can be converted into a T. 688 if (DeclType->isReferenceType()) 689 return CheckReferenceInit(Init, DeclType); 690 691 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 692 // of unknown size ("[]") or an object type that is not a variable array type. 693 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 694 return Diag(InitLoc, diag::err_variable_object_no_init) 695 << VAT->getSizeExpr()->getSourceRange(); 696 697 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 698 if (!InitList) { 699 // FIXME: Handle wide strings 700 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 701 return CheckStringLiteralInit(strLiteral, DeclType); 702 703 // C++ [dcl.init]p14: 704 // -- If the destination type is a (possibly cv-qualified) class 705 // type: 706 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 707 QualType DeclTypeC = Context.getCanonicalType(DeclType); 708 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 709 710 // -- If the initialization is direct-initialization, or if it is 711 // copy-initialization where the cv-unqualified version of the 712 // source type is the same class as, or a derived class of, the 713 // class of the destination, constructors are considered. 714 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 715 IsDerivedFrom(InitTypeC, DeclTypeC)) { 716 CXXConstructorDecl *Constructor 717 = PerformInitializationByConstructor(DeclType, &Init, 1, 718 InitLoc, Init->getSourceRange(), 719 InitEntity, IK_Copy); 720 return Constructor == 0; 721 } 722 723 // -- Otherwise (i.e., for the remaining copy-initialization 724 // cases), user-defined conversion sequences that can 725 // convert from the source type to the destination type or 726 // (when a conversion function is used) to a derived class 727 // thereof are enumerated as described in 13.3.1.4, and the 728 // best one is chosen through overload resolution 729 // (13.3). If the conversion cannot be done or is 730 // ambiguous, the initialization is ill-formed. The 731 // function selected is called with the initializer 732 // expression as its argument; if the function is a 733 // constructor, the call initializes a temporary of the 734 // destination type. 735 // FIXME: We're pretending to do copy elision here; return to 736 // this when we have ASTs for such things. 737 if (!PerformImplicitConversion(Init, DeclType)) 738 return false; 739 740 return Diag(InitLoc, diag::err_typecheck_convert_incompatible) 741 << DeclType << InitEntity << "initializing" 742 << Init->getSourceRange(); 743 } 744 745 // C99 6.7.8p16. 746 if (DeclType->isArrayType()) 747 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 748 << Init->getSourceRange(); 749 750 return CheckSingleInitializer(Init, DeclType); 751 } else if (getLangOptions().CPlusPlus) { 752 // C++ [dcl.init]p14: 753 // [...] If the class is an aggregate (8.5.1), and the initializer 754 // is a brace-enclosed list, see 8.5.1. 755 // 756 // Note: 8.5.1 is handled below; here, we diagnose the case where 757 // we have an initializer list and a destination type that is not 758 // an aggregate. 759 // FIXME: In C++0x, this is yet another form of initialization. 760 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 761 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 762 if (!ClassDecl->isAggregate()) 763 return Diag(InitLoc, diag::err_init_non_aggr_init_list) 764 << DeclType << Init->getSourceRange(); 765 } 766 } 767 768 InitListChecker CheckInitList(this, InitList, DeclType); 769 return CheckInitList.HadError(); 770} 771 772/// GetNameForDeclarator - Determine the full declaration name for the 773/// given Declarator. 774DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 775 switch (D.getKind()) { 776 case Declarator::DK_Abstract: 777 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 778 return DeclarationName(); 779 780 case Declarator::DK_Normal: 781 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 782 return DeclarationName(D.getIdentifier()); 783 784 case Declarator::DK_Constructor: { 785 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 786 Ty = Context.getCanonicalType(Ty); 787 return Context.DeclarationNames.getCXXConstructorName(Ty); 788 } 789 790 case Declarator::DK_Destructor: { 791 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 792 Ty = Context.getCanonicalType(Ty); 793 return Context.DeclarationNames.getCXXDestructorName(Ty); 794 } 795 796 case Declarator::DK_Conversion: { 797 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 798 Ty = Context.getCanonicalType(Ty); 799 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 800 } 801 802 case Declarator::DK_Operator: 803 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 804 return Context.DeclarationNames.getCXXOperatorName( 805 D.getOverloadedOperator()); 806 } 807 808 assert(false && "Unknown name kind"); 809 return DeclarationName(); 810} 811 812Sema::DeclTy * 813Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 814 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 815 DeclarationName Name = GetNameForDeclarator(D); 816 817 // All of these full declarators require an identifier. If it doesn't have 818 // one, the ParsedFreeStandingDeclSpec action should be used. 819 if (!Name) { 820 if (!D.getInvalidType()) // Reject this if we think it is valid. 821 Diag(D.getDeclSpec().getSourceRange().getBegin(), 822 diag::err_declarator_need_ident) 823 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 824 return 0; 825 } 826 827 // The scope passed in may not be a decl scope. Zip up the scope tree until 828 // we find one that is. 829 while ((S->getFlags() & Scope::DeclScope) == 0) 830 S = S->getParent(); 831 832 DeclContext *DC; 833 Decl *PrevDecl; 834 ScopedDecl *New; 835 bool InvalidDecl = false; 836 837 // See if this is a redefinition of a variable in the same scope. 838 if (!D.getCXXScopeSpec().isSet()) { 839 DC = CurContext; 840 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S); 841 } else { // Something like "int foo::x;" 842 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 843 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 844 845 // C++ 7.3.1.2p2: 846 // Members (including explicit specializations of templates) of a named 847 // namespace can also be defined outside that namespace by explicit 848 // qualification of the name being defined, provided that the entity being 849 // defined was already declared in the namespace and the definition appears 850 // after the point of declaration in a namespace that encloses the 851 // declarations namespace. 852 // 853 if (PrevDecl == 0) { 854 // No previous declaration in the qualifying scope. 855 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 856 << Name << D.getCXXScopeSpec().getRange(); 857 } else if (!CurContext->Encloses(DC)) { 858 // The qualifying scope doesn't enclose the original declaration. 859 // Emit diagnostic based on current scope. 860 SourceLocation L = D.getIdentifierLoc(); 861 SourceRange R = D.getCXXScopeSpec().getRange(); 862 if (isa<FunctionDecl>(CurContext)) { 863 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 864 } else { 865 Diag(L, diag::err_invalid_declarator_scope) 866 << Name << cast<NamedDecl>(DC)->getDeclName() << R; 867 } 868 } 869 } 870 871 if (PrevDecl && isTemplateParameterDecl(PrevDecl)) { 872 // Maybe we will complain about the shadowed template parameter. 873 InvalidDecl = InvalidDecl 874 || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 875 // Just pretend that we didn't see the previous declaration. 876 PrevDecl = 0; 877 } 878 879 // In C++, the previous declaration we find might be a tag type 880 // (class or enum). In this case, the new declaration will hide the 881 // tag type. 882 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 883 PrevDecl = 0; 884 885 QualType R = GetTypeForDeclarator(D, S); 886 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 887 888 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 889 // Check that there are no default arguments (C++ only). 890 if (getLangOptions().CPlusPlus) 891 CheckExtraCXXDefaultArguments(D); 892 893 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 894 if (!NewTD) return 0; 895 896 // Handle attributes prior to checking for duplicates in MergeVarDecl 897 ProcessDeclAttributes(NewTD, D); 898 // Merge the decl with the existing one if appropriate. If the decl is 899 // in an outer scope, it isn't the same thing. 900 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 901 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 902 if (NewTD == 0) return 0; 903 } 904 New = NewTD; 905 if (S->getFnParent() == 0) { 906 // C99 6.7.7p2: If a typedef name specifies a variably modified type 907 // then it shall have block scope. 908 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 909 // FIXME: Diagnostic needs to be fixed. 910 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 911 InvalidDecl = true; 912 } 913 } 914 } else if (R.getTypePtr()->isFunctionType()) { 915 FunctionDecl::StorageClass SC = FunctionDecl::None; 916 switch (D.getDeclSpec().getStorageClassSpec()) { 917 default: assert(0 && "Unknown storage class!"); 918 case DeclSpec::SCS_auto: 919 case DeclSpec::SCS_register: 920 case DeclSpec::SCS_mutable: 921 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func); 922 InvalidDecl = true; 923 break; 924 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 925 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 926 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 927 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 928 } 929 930 bool isInline = D.getDeclSpec().isInlineSpecified(); 931 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 932 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 933 934 FunctionDecl *NewFD; 935 if (D.getKind() == Declarator::DK_Constructor) { 936 // This is a C++ constructor declaration. 937 assert(DC->isCXXRecord() && 938 "Constructors can only be declared in a member context"); 939 940 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 941 942 // Create the new declaration 943 NewFD = CXXConstructorDecl::Create(Context, 944 cast<CXXRecordDecl>(DC), 945 D.getIdentifierLoc(), Name, R, 946 isExplicit, isInline, 947 /*isImplicitlyDeclared=*/false); 948 949 if (isInvalidDecl) 950 NewFD->setInvalidDecl(); 951 } else if (D.getKind() == Declarator::DK_Destructor) { 952 // This is a C++ destructor declaration. 953 if (DC->isCXXRecord()) { 954 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 955 956 NewFD = CXXDestructorDecl::Create(Context, 957 cast<CXXRecordDecl>(DC), 958 D.getIdentifierLoc(), Name, R, 959 isInline, 960 /*isImplicitlyDeclared=*/false); 961 962 if (isInvalidDecl) 963 NewFD->setInvalidDecl(); 964 } else { 965 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 966 // Create a FunctionDecl to satisfy the function definition parsing 967 // code path. 968 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 969 Name, R, SC, isInline, LastDeclarator, 970 // FIXME: Move to DeclGroup... 971 D.getDeclSpec().getSourceRange().getBegin()); 972 NewFD->setInvalidDecl(); 973 } 974 } else if (D.getKind() == Declarator::DK_Conversion) { 975 if (!DC->isCXXRecord()) { 976 Diag(D.getIdentifierLoc(), 977 diag::err_conv_function_not_member); 978 return 0; 979 } else { 980 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 981 982 NewFD = CXXConversionDecl::Create(Context, 983 cast<CXXRecordDecl>(DC), 984 D.getIdentifierLoc(), Name, R, 985 isInline, isExplicit); 986 987 if (isInvalidDecl) 988 NewFD->setInvalidDecl(); 989 } 990 } else if (DC->isCXXRecord()) { 991 // This is a C++ method declaration. 992 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 993 D.getIdentifierLoc(), Name, R, 994 (SC == FunctionDecl::Static), isInline, 995 LastDeclarator); 996 } else { 997 NewFD = FunctionDecl::Create(Context, DC, 998 D.getIdentifierLoc(), 999 Name, R, SC, isInline, LastDeclarator, 1000 // FIXME: Move to DeclGroup... 1001 D.getDeclSpec().getSourceRange().getBegin()); 1002 } 1003 // Handle attributes. 1004 ProcessDeclAttributes(NewFD, D); 1005 1006 // Handle GNU asm-label extension (encoded as an attribute). 1007 if (Expr *E = (Expr*) D.getAsmLabel()) { 1008 // The parser guarantees this is a string. 1009 StringLiteral *SE = cast<StringLiteral>(E); 1010 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1011 SE->getByteLength()))); 1012 } 1013 1014 // Copy the parameter declarations from the declarator D to 1015 // the function declaration NewFD, if they are available. 1016 if (D.getNumTypeObjects() > 0) { 1017 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1018 1019 // Create Decl objects for each parameter, adding them to the 1020 // FunctionDecl. 1021 llvm::SmallVector<ParmVarDecl*, 16> Params; 1022 1023 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1024 // function that takes no arguments, not a function that takes a 1025 // single void argument. 1026 // We let through "const void" here because Sema::GetTypeForDeclarator 1027 // already checks for that case. 1028 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1029 FTI.ArgInfo[0].Param && 1030 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1031 // empty arg list, don't push any params. 1032 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1033 1034 // In C++, the empty parameter-type-list must be spelled "void"; a 1035 // typedef of void is not permitted. 1036 if (getLangOptions().CPlusPlus && 1037 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1038 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1039 } 1040 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1041 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1042 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1043 } 1044 1045 NewFD->setParams(&Params[0], Params.size()); 1046 } else if (R->getAsTypedefType()) { 1047 // When we're declaring a function with a typedef, as in the 1048 // following example, we'll need to synthesize (unnamed) 1049 // parameters for use in the declaration. 1050 // 1051 // @code 1052 // typedef void fn(int); 1053 // fn f; 1054 // @endcode 1055 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1056 if (!FT) { 1057 // This is a typedef of a function with no prototype, so we 1058 // don't need to do anything. 1059 } else if ((FT->getNumArgs() == 0) || 1060 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1061 FT->getArgType(0)->isVoidType())) { 1062 // This is a zero-argument function. We don't need to do anything. 1063 } else { 1064 // Synthesize a parameter for each argument type. 1065 llvm::SmallVector<ParmVarDecl*, 16> Params; 1066 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1067 ArgType != FT->arg_type_end(); ++ArgType) { 1068 Params.push_back(ParmVarDecl::Create(Context, DC, 1069 SourceLocation(), 0, 1070 *ArgType, VarDecl::None, 1071 0, 0)); 1072 } 1073 1074 NewFD->setParams(&Params[0], Params.size()); 1075 } 1076 } 1077 1078 // C++ constructors and destructors are handled by separate 1079 // routines, since they don't require any declaration merging (C++ 1080 // [class.mfct]p2) and they aren't ever pushed into scope, because 1081 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1082 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1083 return ActOnConstructorDeclarator(Constructor); 1084 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1085 return ActOnDestructorDeclarator(Destructor); 1086 1087 // Extra checking for conversion functions, including recording 1088 // the conversion function in its class. 1089 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1090 ActOnConversionDeclarator(Conversion); 1091 1092 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1093 if (NewFD->isOverloadedOperator() && 1094 CheckOverloadedOperatorDeclaration(NewFD)) 1095 NewFD->setInvalidDecl(); 1096 1097 // Merge the decl with the existing one if appropriate. Since C functions 1098 // are in a flat namespace, make sure we consider decls in outer scopes. 1099 if (PrevDecl && 1100 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1101 bool Redeclaration = false; 1102 1103 // If C++, determine whether NewFD is an overload of PrevDecl or 1104 // a declaration that requires merging. If it's an overload, 1105 // there's no more work to do here; we'll just add the new 1106 // function to the scope. 1107 OverloadedFunctionDecl::function_iterator MatchedDecl; 1108 if (!getLangOptions().CPlusPlus || 1109 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1110 Decl *OldDecl = PrevDecl; 1111 1112 // If PrevDecl was an overloaded function, extract the 1113 // FunctionDecl that matched. 1114 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1115 OldDecl = *MatchedDecl; 1116 1117 // NewFD and PrevDecl represent declarations that need to be 1118 // merged. 1119 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1120 1121 if (NewFD == 0) return 0; 1122 if (Redeclaration) { 1123 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1124 1125 if (OldDecl == PrevDecl) { 1126 // Remove the name binding for the previous 1127 // declaration. We'll add the binding back later, but then 1128 // it will refer to the new declaration (which will 1129 // contain more information). 1130 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1131 } else { 1132 // We need to update the OverloadedFunctionDecl with the 1133 // latest declaration of this function, so that name 1134 // lookup will always refer to the latest declaration of 1135 // this function. 1136 *MatchedDecl = NewFD; 1137 1138 // Add the redeclaration to the current scope, since we'll 1139 // be skipping PushOnScopeChains. 1140 S->AddDecl(NewFD); 1141 1142 return NewFD; 1143 } 1144 } 1145 } 1146 } 1147 New = NewFD; 1148 1149 // In C++, check default arguments now that we have merged decls. 1150 if (getLangOptions().CPlusPlus) 1151 CheckCXXDefaultArguments(NewFD); 1152 } else { 1153 // Check that there are no default arguments (C++ only). 1154 if (getLangOptions().CPlusPlus) 1155 CheckExtraCXXDefaultArguments(D); 1156 1157 if (R.getTypePtr()->isObjCInterfaceType()) { 1158 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object) 1159 << D.getIdentifier(); 1160 InvalidDecl = true; 1161 } 1162 1163 VarDecl *NewVD; 1164 VarDecl::StorageClass SC; 1165 switch (D.getDeclSpec().getStorageClassSpec()) { 1166 default: assert(0 && "Unknown storage class!"); 1167 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1168 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1169 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1170 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1171 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1172 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1173 case DeclSpec::SCS_mutable: 1174 // mutable can only appear on non-static class members, so it's always 1175 // an error here 1176 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1177 InvalidDecl = true; 1178 SC = VarDecl::None; 1179 break; 1180 } 1181 1182 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1183 if (!II) { 1184 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1185 << Name.getAsString(); 1186 return 0; 1187 } 1188 1189 if (DC->isCXXRecord()) { 1190 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1191 // This is a static data member for a C++ class. 1192 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1193 D.getIdentifierLoc(), II, 1194 R, LastDeclarator); 1195 } else { 1196 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1197 if (S->getFnParent() == 0) { 1198 // C99 6.9p2: The storage-class specifiers auto and register shall not 1199 // appear in the declaration specifiers in an external declaration. 1200 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1201 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); 1202 InvalidDecl = true; 1203 } 1204 } 1205 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1206 II, R, SC, LastDeclarator, 1207 // FIXME: Move to DeclGroup... 1208 D.getDeclSpec().getSourceRange().getBegin()); 1209 NewVD->setThreadSpecified(ThreadSpecified); 1210 } 1211 // Handle attributes prior to checking for duplicates in MergeVarDecl 1212 ProcessDeclAttributes(NewVD, D); 1213 1214 // Handle GNU asm-label extension (encoded as an attribute). 1215 if (Expr *E = (Expr*) D.getAsmLabel()) { 1216 // The parser guarantees this is a string. 1217 StringLiteral *SE = cast<StringLiteral>(E); 1218 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1219 SE->getByteLength()))); 1220 } 1221 1222 // Emit an error if an address space was applied to decl with local storage. 1223 // This includes arrays of objects with address space qualifiers, but not 1224 // automatic variables that point to other address spaces. 1225 // ISO/IEC TR 18037 S5.1.2 1226 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1227 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1228 InvalidDecl = true; 1229 } 1230 // Merge the decl with the existing one if appropriate. If the decl is 1231 // in an outer scope, it isn't the same thing. 1232 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1233 NewVD = MergeVarDecl(NewVD, PrevDecl); 1234 if (NewVD == 0) return 0; 1235 } 1236 New = NewVD; 1237 } 1238 1239 // Set the lexical context. If the declarator has a C++ scope specifier, the 1240 // lexical context will be different from the semantic context. 1241 New->setLexicalDeclContext(CurContext); 1242 1243 // If this has an identifier, add it to the scope stack. 1244 if (Name) 1245 PushOnScopeChains(New, S); 1246 // If any semantic error occurred, mark the decl as invalid. 1247 if (D.getInvalidType() || InvalidDecl) 1248 New->setInvalidDecl(); 1249 1250 return New; 1251} 1252 1253void Sema::InitializerElementNotConstant(const Expr *Init) { 1254 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 1255 << Init->getSourceRange(); 1256} 1257 1258bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1259 switch (Init->getStmtClass()) { 1260 default: 1261 InitializerElementNotConstant(Init); 1262 return true; 1263 case Expr::ParenExprClass: { 1264 const ParenExpr* PE = cast<ParenExpr>(Init); 1265 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1266 } 1267 case Expr::CompoundLiteralExprClass: 1268 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1269 case Expr::DeclRefExprClass: { 1270 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1271 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1272 if (VD->hasGlobalStorage()) 1273 return false; 1274 InitializerElementNotConstant(Init); 1275 return true; 1276 } 1277 if (isa<FunctionDecl>(D)) 1278 return false; 1279 InitializerElementNotConstant(Init); 1280 return true; 1281 } 1282 case Expr::MemberExprClass: { 1283 const MemberExpr *M = cast<MemberExpr>(Init); 1284 if (M->isArrow()) 1285 return CheckAddressConstantExpression(M->getBase()); 1286 return CheckAddressConstantExpressionLValue(M->getBase()); 1287 } 1288 case Expr::ArraySubscriptExprClass: { 1289 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1290 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1291 return CheckAddressConstantExpression(ASE->getBase()) || 1292 CheckArithmeticConstantExpression(ASE->getIdx()); 1293 } 1294 case Expr::StringLiteralClass: 1295 case Expr::PredefinedExprClass: 1296 return false; 1297 case Expr::UnaryOperatorClass: { 1298 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1299 1300 // C99 6.6p9 1301 if (Exp->getOpcode() == UnaryOperator::Deref) 1302 return CheckAddressConstantExpression(Exp->getSubExpr()); 1303 1304 InitializerElementNotConstant(Init); 1305 return true; 1306 } 1307 } 1308} 1309 1310bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1311 switch (Init->getStmtClass()) { 1312 default: 1313 InitializerElementNotConstant(Init); 1314 return true; 1315 case Expr::ParenExprClass: 1316 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1317 case Expr::StringLiteralClass: 1318 case Expr::ObjCStringLiteralClass: 1319 return false; 1320 case Expr::CallExprClass: 1321 case Expr::CXXOperatorCallExprClass: 1322 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1323 if (cast<CallExpr>(Init)->isBuiltinCall() == 1324 Builtin::BI__builtin___CFStringMakeConstantString) 1325 return false; 1326 1327 InitializerElementNotConstant(Init); 1328 return true; 1329 1330 case Expr::UnaryOperatorClass: { 1331 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1332 1333 // C99 6.6p9 1334 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1335 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1336 1337 if (Exp->getOpcode() == UnaryOperator::Extension) 1338 return CheckAddressConstantExpression(Exp->getSubExpr()); 1339 1340 InitializerElementNotConstant(Init); 1341 return true; 1342 } 1343 case Expr::BinaryOperatorClass: { 1344 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1345 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1346 1347 Expr *PExp = Exp->getLHS(); 1348 Expr *IExp = Exp->getRHS(); 1349 if (IExp->getType()->isPointerType()) 1350 std::swap(PExp, IExp); 1351 1352 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1353 return CheckAddressConstantExpression(PExp) || 1354 CheckArithmeticConstantExpression(IExp); 1355 } 1356 case Expr::ImplicitCastExprClass: 1357 case Expr::CStyleCastExprClass: { 1358 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1359 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1360 // Check for implicit promotion 1361 if (SubExpr->getType()->isFunctionType() || 1362 SubExpr->getType()->isArrayType()) 1363 return CheckAddressConstantExpressionLValue(SubExpr); 1364 } 1365 1366 // Check for pointer->pointer cast 1367 if (SubExpr->getType()->isPointerType()) 1368 return CheckAddressConstantExpression(SubExpr); 1369 1370 if (SubExpr->getType()->isIntegralType()) { 1371 // Check for the special-case of a pointer->int->pointer cast; 1372 // this isn't standard, but some code requires it. See 1373 // PR2720 for an example. 1374 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1375 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1376 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1377 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1378 if (IntWidth >= PointerWidth) { 1379 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1380 } 1381 } 1382 } 1383 } 1384 if (SubExpr->getType()->isArithmeticType()) { 1385 return CheckArithmeticConstantExpression(SubExpr); 1386 } 1387 1388 InitializerElementNotConstant(Init); 1389 return true; 1390 } 1391 case Expr::ConditionalOperatorClass: { 1392 // FIXME: Should we pedwarn here? 1393 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1394 if (!Exp->getCond()->getType()->isArithmeticType()) { 1395 InitializerElementNotConstant(Init); 1396 return true; 1397 } 1398 if (CheckArithmeticConstantExpression(Exp->getCond())) 1399 return true; 1400 if (Exp->getLHS() && 1401 CheckAddressConstantExpression(Exp->getLHS())) 1402 return true; 1403 return CheckAddressConstantExpression(Exp->getRHS()); 1404 } 1405 case Expr::AddrLabelExprClass: 1406 return false; 1407 } 1408} 1409 1410static const Expr* FindExpressionBaseAddress(const Expr* E); 1411 1412static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1413 switch (E->getStmtClass()) { 1414 default: 1415 return E; 1416 case Expr::ParenExprClass: { 1417 const ParenExpr* PE = cast<ParenExpr>(E); 1418 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1419 } 1420 case Expr::MemberExprClass: { 1421 const MemberExpr *M = cast<MemberExpr>(E); 1422 if (M->isArrow()) 1423 return FindExpressionBaseAddress(M->getBase()); 1424 return FindExpressionBaseAddressLValue(M->getBase()); 1425 } 1426 case Expr::ArraySubscriptExprClass: { 1427 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1428 return FindExpressionBaseAddress(ASE->getBase()); 1429 } 1430 case Expr::UnaryOperatorClass: { 1431 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1432 1433 if (Exp->getOpcode() == UnaryOperator::Deref) 1434 return FindExpressionBaseAddress(Exp->getSubExpr()); 1435 1436 return E; 1437 } 1438 } 1439} 1440 1441static const Expr* FindExpressionBaseAddress(const Expr* E) { 1442 switch (E->getStmtClass()) { 1443 default: 1444 return E; 1445 case Expr::ParenExprClass: { 1446 const ParenExpr* PE = cast<ParenExpr>(E); 1447 return FindExpressionBaseAddress(PE->getSubExpr()); 1448 } 1449 case Expr::UnaryOperatorClass: { 1450 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1451 1452 // C99 6.6p9 1453 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1454 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1455 1456 if (Exp->getOpcode() == UnaryOperator::Extension) 1457 return FindExpressionBaseAddress(Exp->getSubExpr()); 1458 1459 return E; 1460 } 1461 case Expr::BinaryOperatorClass: { 1462 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1463 1464 Expr *PExp = Exp->getLHS(); 1465 Expr *IExp = Exp->getRHS(); 1466 if (IExp->getType()->isPointerType()) 1467 std::swap(PExp, IExp); 1468 1469 return FindExpressionBaseAddress(PExp); 1470 } 1471 case Expr::ImplicitCastExprClass: { 1472 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1473 1474 // Check for implicit promotion 1475 if (SubExpr->getType()->isFunctionType() || 1476 SubExpr->getType()->isArrayType()) 1477 return FindExpressionBaseAddressLValue(SubExpr); 1478 1479 // Check for pointer->pointer cast 1480 if (SubExpr->getType()->isPointerType()) 1481 return FindExpressionBaseAddress(SubExpr); 1482 1483 // We assume that we have an arithmetic expression here; 1484 // if we don't, we'll figure it out later 1485 return 0; 1486 } 1487 case Expr::CStyleCastExprClass: { 1488 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1489 1490 // Check for pointer->pointer cast 1491 if (SubExpr->getType()->isPointerType()) 1492 return FindExpressionBaseAddress(SubExpr); 1493 1494 // We assume that we have an arithmetic expression here; 1495 // if we don't, we'll figure it out later 1496 return 0; 1497 } 1498 } 1499} 1500 1501bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1502 switch (Init->getStmtClass()) { 1503 default: 1504 InitializerElementNotConstant(Init); 1505 return true; 1506 case Expr::ParenExprClass: { 1507 const ParenExpr* PE = cast<ParenExpr>(Init); 1508 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1509 } 1510 case Expr::FloatingLiteralClass: 1511 case Expr::IntegerLiteralClass: 1512 case Expr::CharacterLiteralClass: 1513 case Expr::ImaginaryLiteralClass: 1514 case Expr::TypesCompatibleExprClass: 1515 case Expr::CXXBoolLiteralExprClass: 1516 return false; 1517 case Expr::CallExprClass: 1518 case Expr::CXXOperatorCallExprClass: { 1519 const CallExpr *CE = cast<CallExpr>(Init); 1520 1521 // Allow any constant foldable calls to builtins. 1522 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1523 return false; 1524 1525 InitializerElementNotConstant(Init); 1526 return true; 1527 } 1528 case Expr::DeclRefExprClass: { 1529 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1530 if (isa<EnumConstantDecl>(D)) 1531 return false; 1532 InitializerElementNotConstant(Init); 1533 return true; 1534 } 1535 case Expr::CompoundLiteralExprClass: 1536 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1537 // but vectors are allowed to be magic. 1538 if (Init->getType()->isVectorType()) 1539 return false; 1540 InitializerElementNotConstant(Init); 1541 return true; 1542 case Expr::UnaryOperatorClass: { 1543 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1544 1545 switch (Exp->getOpcode()) { 1546 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1547 // See C99 6.6p3. 1548 default: 1549 InitializerElementNotConstant(Init); 1550 return true; 1551 case UnaryOperator::OffsetOf: 1552 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1553 return false; 1554 InitializerElementNotConstant(Init); 1555 return true; 1556 case UnaryOperator::Extension: 1557 case UnaryOperator::LNot: 1558 case UnaryOperator::Plus: 1559 case UnaryOperator::Minus: 1560 case UnaryOperator::Not: 1561 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1562 } 1563 } 1564 case Expr::SizeOfAlignOfExprClass: { 1565 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1566 // Special check for void types, which are allowed as an extension 1567 if (Exp->getTypeOfArgument()->isVoidType()) 1568 return false; 1569 // alignof always evaluates to a constant. 1570 // FIXME: is sizeof(int[3.0]) a constant expression? 1571 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1572 InitializerElementNotConstant(Init); 1573 return true; 1574 } 1575 return false; 1576 } 1577 case Expr::BinaryOperatorClass: { 1578 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1579 1580 if (Exp->getLHS()->getType()->isArithmeticType() && 1581 Exp->getRHS()->getType()->isArithmeticType()) { 1582 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1583 CheckArithmeticConstantExpression(Exp->getRHS()); 1584 } 1585 1586 if (Exp->getLHS()->getType()->isPointerType() && 1587 Exp->getRHS()->getType()->isPointerType()) { 1588 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1589 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1590 1591 // Only allow a null (constant integer) base; we could 1592 // allow some additional cases if necessary, but this 1593 // is sufficient to cover offsetof-like constructs. 1594 if (!LHSBase && !RHSBase) { 1595 return CheckAddressConstantExpression(Exp->getLHS()) || 1596 CheckAddressConstantExpression(Exp->getRHS()); 1597 } 1598 } 1599 1600 InitializerElementNotConstant(Init); 1601 return true; 1602 } 1603 case Expr::ImplicitCastExprClass: 1604 case Expr::CStyleCastExprClass: { 1605 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1606 if (SubExpr->getType()->isArithmeticType()) 1607 return CheckArithmeticConstantExpression(SubExpr); 1608 1609 if (SubExpr->getType()->isPointerType()) { 1610 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1611 // If the pointer has a null base, this is an offsetof-like construct 1612 if (!Base) 1613 return CheckAddressConstantExpression(SubExpr); 1614 } 1615 1616 InitializerElementNotConstant(Init); 1617 return true; 1618 } 1619 case Expr::ConditionalOperatorClass: { 1620 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1621 1622 // If GNU extensions are disabled, we require all operands to be arithmetic 1623 // constant expressions. 1624 if (getLangOptions().NoExtensions) { 1625 return CheckArithmeticConstantExpression(Exp->getCond()) || 1626 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1627 CheckArithmeticConstantExpression(Exp->getRHS()); 1628 } 1629 1630 // Otherwise, we have to emulate some of the behavior of fold here. 1631 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1632 // because it can constant fold things away. To retain compatibility with 1633 // GCC code, we see if we can fold the condition to a constant (which we 1634 // should always be able to do in theory). If so, we only require the 1635 // specified arm of the conditional to be a constant. This is a horrible 1636 // hack, but is require by real world code that uses __builtin_constant_p. 1637 APValue Val; 1638 if (!Exp->getCond()->Evaluate(Val, Context)) { 1639 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 1640 // won't be able to either. Use it to emit the diagnostic though. 1641 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1642 assert(Res && "Evaluate couldn't evaluate this constant?"); 1643 return Res; 1644 } 1645 1646 // Verify that the side following the condition is also a constant. 1647 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1648 if (Val.getInt() == 0) 1649 std::swap(TrueSide, FalseSide); 1650 1651 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1652 return true; 1653 1654 // Okay, the evaluated side evaluates to a constant, so we accept this. 1655 // Check to see if the other side is obviously not a constant. If so, 1656 // emit a warning that this is a GNU extension. 1657 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1658 Diag(Init->getExprLoc(), 1659 diag::ext_typecheck_expression_not_constant_but_accepted) 1660 << FalseSide->getSourceRange(); 1661 return false; 1662 } 1663 } 1664} 1665 1666bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1667 Expr::EvalResult Result; 1668 1669 Init = Init->IgnoreParens(); 1670 1671 if (Init->Evaluate(Result, Context) && !Result.HasSideEffects) 1672 return false; 1673 1674 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1675 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1676 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1677 1678 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1679 return CheckForConstantInitializer(e->getInitializer(), DclT); 1680 1681 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1682 unsigned numInits = Exp->getNumInits(); 1683 for (unsigned i = 0; i < numInits; i++) { 1684 // FIXME: Need to get the type of the declaration for C++, 1685 // because it could be a reference? 1686 if (CheckForConstantInitializer(Exp->getInit(i), 1687 Exp->getInit(i)->getType())) 1688 return true; 1689 } 1690 return false; 1691 } 1692 1693 // FIXME: We can probably remove some of this code below, now that 1694 // Expr::Evaluate is doing the heavy lifting for scalars. 1695 1696 if (Init->isNullPointerConstant(Context)) 1697 return false; 1698 if (Init->getType()->isArithmeticType()) { 1699 QualType InitTy = Context.getCanonicalType(Init->getType()) 1700 .getUnqualifiedType(); 1701 if (InitTy == Context.BoolTy) { 1702 // Special handling for pointers implicitly cast to bool; 1703 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1704 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1705 Expr* SubE = ICE->getSubExpr(); 1706 if (SubE->getType()->isPointerType() || 1707 SubE->getType()->isArrayType() || 1708 SubE->getType()->isFunctionType()) { 1709 return CheckAddressConstantExpression(Init); 1710 } 1711 } 1712 } else if (InitTy->isIntegralType()) { 1713 Expr* SubE = 0; 1714 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1715 SubE = CE->getSubExpr(); 1716 // Special check for pointer cast to int; we allow as an extension 1717 // an address constant cast to an integer if the integer 1718 // is of an appropriate width (this sort of code is apparently used 1719 // in some places). 1720 // FIXME: Add pedwarn? 1721 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1722 if (SubE && (SubE->getType()->isPointerType() || 1723 SubE->getType()->isArrayType() || 1724 SubE->getType()->isFunctionType())) { 1725 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1726 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1727 if (IntWidth >= PointerWidth) 1728 return CheckAddressConstantExpression(Init); 1729 } 1730 } 1731 1732 return CheckArithmeticConstantExpression(Init); 1733 } 1734 1735 if (Init->getType()->isPointerType()) 1736 return CheckAddressConstantExpression(Init); 1737 1738 // An array type at the top level that isn't an init-list must 1739 // be a string literal 1740 if (Init->getType()->isArrayType()) 1741 return false; 1742 1743 if (Init->getType()->isFunctionType()) 1744 return false; 1745 1746 // Allow block exprs at top level. 1747 if (Init->getType()->isBlockPointerType()) 1748 return false; 1749 1750 InitializerElementNotConstant(Init); 1751 return true; 1752} 1753 1754void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1755 Decl *RealDecl = static_cast<Decl *>(dcl); 1756 Expr *Init = static_cast<Expr *>(init); 1757 assert(Init && "missing initializer"); 1758 1759 // If there is no declaration, there was an error parsing it. Just ignore 1760 // the initializer. 1761 if (RealDecl == 0) { 1762 delete Init; 1763 return; 1764 } 1765 1766 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1767 if (!VDecl) { 1768 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1769 diag::err_illegal_initializer); 1770 RealDecl->setInvalidDecl(); 1771 return; 1772 } 1773 // Get the decls type and save a reference for later, since 1774 // CheckInitializerTypes may change it. 1775 QualType DclT = VDecl->getType(), SavT = DclT; 1776 if (VDecl->isBlockVarDecl()) { 1777 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1778 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1779 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1780 VDecl->setInvalidDecl(); 1781 } else if (!VDecl->isInvalidDecl()) { 1782 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1783 VDecl->getDeclName())) 1784 VDecl->setInvalidDecl(); 1785 1786 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1787 if (!getLangOptions().CPlusPlus) { 1788 if (SC == VarDecl::Static) // C99 6.7.8p4. 1789 CheckForConstantInitializer(Init, DclT); 1790 } 1791 } 1792 } else if (VDecl->isFileVarDecl()) { 1793 if (VDecl->getStorageClass() == VarDecl::Extern) 1794 Diag(VDecl->getLocation(), diag::warn_extern_init); 1795 if (!VDecl->isInvalidDecl()) 1796 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1797 VDecl->getDeclName())) 1798 VDecl->setInvalidDecl(); 1799 1800 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1801 if (!getLangOptions().CPlusPlus) { 1802 // C99 6.7.8p4. All file scoped initializers need to be constant. 1803 CheckForConstantInitializer(Init, DclT); 1804 } 1805 } 1806 // If the type changed, it means we had an incomplete type that was 1807 // completed by the initializer. For example: 1808 // int ary[] = { 1, 3, 5 }; 1809 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1810 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1811 VDecl->setType(DclT); 1812 Init->setType(DclT); 1813 } 1814 1815 // Attach the initializer to the decl. 1816 VDecl->setInit(Init); 1817 return; 1818} 1819 1820void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1821 Decl *RealDecl = static_cast<Decl *>(dcl); 1822 1823 // If there is no declaration, there was an error parsing it. Just ignore it. 1824 if (RealDecl == 0) 1825 return; 1826 1827 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1828 QualType Type = Var->getType(); 1829 // C++ [dcl.init.ref]p3: 1830 // The initializer can be omitted for a reference only in a 1831 // parameter declaration (8.3.5), in the declaration of a 1832 // function return type, in the declaration of a class member 1833 // within its class declaration (9.2), and where the extern 1834 // specifier is explicitly used. 1835 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1836 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 1837 << Var->getDeclName() 1838 << SourceRange(Var->getLocation(), Var->getLocation()); 1839 Var->setInvalidDecl(); 1840 return; 1841 } 1842 1843 // C++ [dcl.init]p9: 1844 // 1845 // If no initializer is specified for an object, and the object 1846 // is of (possibly cv-qualified) non-POD class type (or array 1847 // thereof), the object shall be default-initialized; if the 1848 // object is of const-qualified type, the underlying class type 1849 // shall have a user-declared default constructor. 1850 if (getLangOptions().CPlusPlus) { 1851 QualType InitType = Type; 1852 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1853 InitType = Array->getElementType(); 1854 if (InitType->isRecordType()) { 1855 const CXXConstructorDecl *Constructor 1856 = PerformInitializationByConstructor(InitType, 0, 0, 1857 Var->getLocation(), 1858 SourceRange(Var->getLocation(), 1859 Var->getLocation()), 1860 Var->getDeclName(), 1861 IK_Default); 1862 if (!Constructor) 1863 Var->setInvalidDecl(); 1864 } 1865 } 1866 1867#if 0 1868 // FIXME: Temporarily disabled because we are not properly parsing 1869 // linkage specifications on declarations, e.g., 1870 // 1871 // extern "C" const CGPoint CGPointerZero; 1872 // 1873 // C++ [dcl.init]p9: 1874 // 1875 // If no initializer is specified for an object, and the 1876 // object is of (possibly cv-qualified) non-POD class type (or 1877 // array thereof), the object shall be default-initialized; if 1878 // the object is of const-qualified type, the underlying class 1879 // type shall have a user-declared default 1880 // constructor. Otherwise, if no initializer is specified for 1881 // an object, the object and its subobjects, if any, have an 1882 // indeterminate initial value; if the object or any of its 1883 // subobjects are of const-qualified type, the program is 1884 // ill-formed. 1885 // 1886 // This isn't technically an error in C, so we don't diagnose it. 1887 // 1888 // FIXME: Actually perform the POD/user-defined default 1889 // constructor check. 1890 if (getLangOptions().CPlusPlus && 1891 Context.getCanonicalType(Type).isConstQualified() && 1892 Var->getStorageClass() != VarDecl::Extern) 1893 Diag(Var->getLocation(), diag::err_const_var_requires_init) 1894 << Var->getName() 1895 << SourceRange(Var->getLocation(), Var->getLocation()); 1896#endif 1897 } 1898} 1899 1900/// The declarators are chained together backwards, reverse the list. 1901Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1902 // Often we have single declarators, handle them quickly. 1903 Decl *GroupDecl = static_cast<Decl*>(group); 1904 if (GroupDecl == 0) 1905 return 0; 1906 1907 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1908 ScopedDecl *NewGroup = 0; 1909 if (Group->getNextDeclarator() == 0) 1910 NewGroup = Group; 1911 else { // reverse the list. 1912 while (Group) { 1913 ScopedDecl *Next = Group->getNextDeclarator(); 1914 Group->setNextDeclarator(NewGroup); 1915 NewGroup = Group; 1916 Group = Next; 1917 } 1918 } 1919 // Perform semantic analysis that depends on having fully processed both 1920 // the declarator and initializer. 1921 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1922 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1923 if (!IDecl) 1924 continue; 1925 QualType T = IDecl->getType(); 1926 1927 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1928 // static storage duration, it shall not have a variable length array. 1929 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1930 IDecl->getStorageClass() == VarDecl::Static) { 1931 if (T->isVariableArrayType()) { 1932 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1933 IDecl->setInvalidDecl(); 1934 } 1935 } 1936 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1937 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1938 if (IDecl->isBlockVarDecl() && 1939 IDecl->getStorageClass() != VarDecl::Extern) { 1940 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1941 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type)<<T; 1942 IDecl->setInvalidDecl(); 1943 } 1944 } 1945 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1946 // object that has file scope without an initializer, and without a 1947 // storage-class specifier or with the storage-class specifier "static", 1948 // constitutes a tentative definition. Note: A tentative definition with 1949 // external linkage is valid (C99 6.2.2p5). 1950 if (isTentativeDefinition(IDecl)) { 1951 if (T->isIncompleteArrayType()) { 1952 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1953 // array to be completed. Don't issue a diagnostic. 1954 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1955 // C99 6.9.2p3: If the declaration of an identifier for an object is 1956 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1957 // declared type shall not be an incomplete type. 1958 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type)<<T; 1959 IDecl->setInvalidDecl(); 1960 } 1961 } 1962 if (IDecl->isFileVarDecl()) 1963 CheckForFileScopedRedefinitions(S, IDecl); 1964 } 1965 return NewGroup; 1966} 1967 1968/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1969/// to introduce parameters into function prototype scope. 1970Sema::DeclTy * 1971Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1972 // FIXME: disallow CXXScopeSpec for param declarators. 1973 const DeclSpec &DS = D.getDeclSpec(); 1974 1975 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1976 VarDecl::StorageClass StorageClass = VarDecl::None; 1977 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1978 StorageClass = VarDecl::Register; 1979 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1980 Diag(DS.getStorageClassSpecLoc(), 1981 diag::err_invalid_storage_class_in_func_decl); 1982 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1983 } 1984 if (DS.isThreadSpecified()) { 1985 Diag(DS.getThreadSpecLoc(), 1986 diag::err_invalid_storage_class_in_func_decl); 1987 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1988 } 1989 1990 // Check that there are no default arguments inside the type of this 1991 // parameter (C++ only). 1992 if (getLangOptions().CPlusPlus) 1993 CheckExtraCXXDefaultArguments(D); 1994 1995 // In this context, we *do not* check D.getInvalidType(). If the declarator 1996 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1997 // though it will not reflect the user specified type. 1998 QualType parmDeclType = GetTypeForDeclarator(D, S); 1999 2000 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 2001 2002 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 2003 // Can this happen for params? We already checked that they don't conflict 2004 // among each other. Here they can only shadow globals, which is ok. 2005 IdentifierInfo *II = D.getIdentifier(); 2006 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 2007 if (isTemplateParameterDecl(PrevDecl)) { 2008 // Maybe we will complain about the shadowed template parameter. 2009 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 2010 // Just pretend that we didn't see the previous declaration. 2011 PrevDecl = 0; 2012 } else if (S->isDeclScope(PrevDecl)) { 2013 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 2014 2015 // Recover by removing the name 2016 II = 0; 2017 D.SetIdentifier(0, D.getIdentifierLoc()); 2018 } 2019 } 2020 2021 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 2022 // Doing the promotion here has a win and a loss. The win is the type for 2023 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 2024 // code generator). The loss is the orginal type isn't preserved. For example: 2025 // 2026 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2027 // int blockvardecl[5]; 2028 // sizeof(parmvardecl); // size == 4 2029 // sizeof(blockvardecl); // size == 20 2030 // } 2031 // 2032 // For expressions, all implicit conversions are captured using the 2033 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2034 // 2035 // FIXME: If a source translation tool needs to see the original type, then 2036 // we need to consider storing both types (in ParmVarDecl)... 2037 // 2038 if (parmDeclType->isArrayType()) { 2039 // int x[restrict 4] -> int *restrict 2040 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2041 } else if (parmDeclType->isFunctionType()) 2042 parmDeclType = Context.getPointerType(parmDeclType); 2043 2044 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2045 D.getIdentifierLoc(), II, 2046 parmDeclType, StorageClass, 2047 0, 0); 2048 2049 if (D.getInvalidType()) 2050 New->setInvalidDecl(); 2051 2052 if (II) 2053 PushOnScopeChains(New, S); 2054 2055 ProcessDeclAttributes(New, D); 2056 return New; 2057 2058} 2059 2060Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2061 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2062 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2063 "Not a function declarator!"); 2064 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2065 2066 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2067 // for a K&R function. 2068 if (!FTI.hasPrototype) { 2069 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2070 if (FTI.ArgInfo[i].Param == 0) { 2071 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2072 << FTI.ArgInfo[i].Ident; 2073 // Implicitly declare the argument as type 'int' for lack of a better 2074 // type. 2075 DeclSpec DS; 2076 const char* PrevSpec; // unused 2077 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2078 PrevSpec); 2079 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2080 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2081 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2082 } 2083 } 2084 } else { 2085 // FIXME: Diagnose arguments without names in C. 2086 } 2087 2088 Scope *GlobalScope = FnBodyScope->getParent(); 2089 2090 return ActOnStartOfFunctionDef(FnBodyScope, 2091 ActOnDeclarator(GlobalScope, D, 0)); 2092} 2093 2094Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2095 Decl *decl = static_cast<Decl*>(D); 2096 FunctionDecl *FD = cast<FunctionDecl>(decl); 2097 2098 // See if this is a redefinition. 2099 const FunctionDecl *Definition; 2100 if (FD->getBody(Definition)) { 2101 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); 2102 Diag(Definition->getLocation(), diag::note_previous_definition); 2103 } 2104 2105 PushDeclContext(FD); 2106 2107 // Check the validity of our function parameters 2108 CheckParmsForFunctionDef(FD); 2109 2110 // Introduce our parameters into the function scope 2111 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2112 ParmVarDecl *Param = FD->getParamDecl(p); 2113 // If this has an identifier, add it to the scope stack. 2114 if (Param->getIdentifier()) 2115 PushOnScopeChains(Param, FnBodyScope); 2116 } 2117 2118 return FD; 2119} 2120 2121Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2122 Decl *dcl = static_cast<Decl *>(D); 2123 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2124 FD->setBody((Stmt*)Body); 2125 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2126 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2127 MD->setBody((Stmt*)Body); 2128 } else 2129 return 0; 2130 PopDeclContext(); 2131 // Verify and clean out per-function state. 2132 2133 // Check goto/label use. 2134 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2135 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2136 // Verify that we have no forward references left. If so, there was a goto 2137 // or address of a label taken, but no definition of it. Label fwd 2138 // definitions are indicated with a null substmt. 2139 if (I->second->getSubStmt() == 0) { 2140 LabelStmt *L = I->second; 2141 // Emit error. 2142 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 2143 2144 // At this point, we have gotos that use the bogus label. Stitch it into 2145 // the function body so that they aren't leaked and that the AST is well 2146 // formed. 2147 if (Body) { 2148 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2149 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2150 } else { 2151 // The whole function wasn't parsed correctly, just delete this. 2152 delete L; 2153 } 2154 } 2155 } 2156 LabelMap.clear(); 2157 2158 return D; 2159} 2160 2161/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2162/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2163ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2164 IdentifierInfo &II, Scope *S) { 2165 // Extension in C99. Legal in C90, but warn about it. 2166 if (getLangOptions().C99) 2167 Diag(Loc, diag::ext_implicit_function_decl) << &II; 2168 else 2169 Diag(Loc, diag::warn_implicit_function_decl) << &II; 2170 2171 // FIXME: handle stuff like: 2172 // void foo() { extern float X(); } 2173 // void bar() { X(); } <-- implicit decl for X in another scope. 2174 2175 // Set a Declarator for the implicit definition: int foo(); 2176 const char *Dummy; 2177 DeclSpec DS; 2178 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2179 Error = Error; // Silence warning. 2180 assert(!Error && "Error setting up implicit decl!"); 2181 Declarator D(DS, Declarator::BlockContext); 2182 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2183 D.SetIdentifier(&II, Loc); 2184 2185 // Insert this function into translation-unit scope. 2186 2187 DeclContext *PrevDC = CurContext; 2188 CurContext = Context.getTranslationUnitDecl(); 2189 2190 FunctionDecl *FD = 2191 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2192 FD->setImplicit(); 2193 2194 CurContext = PrevDC; 2195 2196 return FD; 2197} 2198 2199 2200TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2201 ScopedDecl *LastDeclarator) { 2202 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2203 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2204 2205 // Scope manipulation handled by caller. 2206 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2207 D.getIdentifierLoc(), 2208 D.getIdentifier(), 2209 T, LastDeclarator); 2210 if (D.getInvalidType()) 2211 NewTD->setInvalidDecl(); 2212 return NewTD; 2213} 2214 2215/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2216/// former case, Name will be non-null. In the later case, Name will be null. 2217/// TagType indicates what kind of tag this is. TK indicates whether this is a 2218/// reference/declaration/definition of a tag. 2219Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2220 SourceLocation KWLoc, const CXXScopeSpec &SS, 2221 IdentifierInfo *Name, SourceLocation NameLoc, 2222 AttributeList *Attr) { 2223 // If this is a use of an existing tag, it must have a name. 2224 assert((Name != 0 || TK == TK_Definition) && 2225 "Nameless record must be a definition!"); 2226 2227 TagDecl::TagKind Kind; 2228 switch (TagType) { 2229 default: assert(0 && "Unknown tag type!"); 2230 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2231 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2232 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2233 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2234 } 2235 2236 // Two code paths: a new one for structs/unions/classes where we create 2237 // separate decls for forward declarations, and an old (eventually to 2238 // be removed) code path for enums. 2239 if (Kind != TagDecl::TK_enum) 2240 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2241 2242 DeclContext *DC = CurContext; 2243 ScopedDecl *PrevDecl = 0; 2244 2245 if (Name && SS.isNotEmpty()) { 2246 // We have a nested-name tag ('struct foo::bar'). 2247 2248 // Check for invalid 'foo::'. 2249 if (SS.isInvalid()) { 2250 Name = 0; 2251 goto CreateNewDecl; 2252 } 2253 2254 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2255 // Look-up name inside 'foo::'. 2256 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2257 2258 // A tag 'foo::bar' must already exist. 2259 if (PrevDecl == 0) { 2260 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2261 Name = 0; 2262 goto CreateNewDecl; 2263 } 2264 } else { 2265 // If this is a named struct, check to see if there was a previous forward 2266 // declaration or definition. 2267 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2268 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2269 } 2270 2271 if (PrevDecl && isTemplateParameterDecl(PrevDecl)) { 2272 // Maybe we will complain about the shadowed template parameter. 2273 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 2274 // Just pretend that we didn't see the previous declaration. 2275 PrevDecl = 0; 2276 } 2277 2278 if (PrevDecl) { 2279 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2280 "unexpected Decl type"); 2281 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2282 // If this is a use of a previous tag, or if the tag is already declared 2283 // in the same scope (so that the definition/declaration completes or 2284 // rementions the tag), reuse the decl. 2285 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2286 // Make sure that this wasn't declared as an enum and now used as a 2287 // struct or something similar. 2288 if (PrevTagDecl->getTagKind() != Kind) { 2289 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2290 Diag(PrevDecl->getLocation(), diag::note_previous_use); 2291 // Recover by making this an anonymous redefinition. 2292 Name = 0; 2293 PrevDecl = 0; 2294 } else { 2295 // If this is a use or a forward declaration, we're good. 2296 if (TK != TK_Definition) 2297 return PrevDecl; 2298 2299 // Diagnose attempts to redefine a tag. 2300 if (PrevTagDecl->isDefinition()) { 2301 Diag(NameLoc, diag::err_redefinition) << Name; 2302 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 2303 // If this is a redefinition, recover by making this struct be 2304 // anonymous, which will make any later references get the previous 2305 // definition. 2306 Name = 0; 2307 } else { 2308 // Okay, this is definition of a previously declared or referenced 2309 // tag. Move the location of the decl to be the definition site. 2310 PrevDecl->setLocation(NameLoc); 2311 return PrevDecl; 2312 } 2313 } 2314 } 2315 // If we get here, this is a definition of a new struct type in a nested 2316 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2317 // type. 2318 } else { 2319 // PrevDecl is a namespace. 2320 if (isDeclInScope(PrevDecl, DC, S)) { 2321 // The tag name clashes with a namespace name, issue an error and 2322 // recover by making this tag be anonymous. 2323 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2324 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 2325 Name = 0; 2326 } 2327 } 2328 } 2329 2330 CreateNewDecl: 2331 2332 // If there is an identifier, use the location of the identifier as the 2333 // location of the decl, otherwise use the location of the struct/union 2334 // keyword. 2335 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2336 2337 // Otherwise, if this is the first time we've seen this tag, create the decl. 2338 TagDecl *New; 2339 if (Kind == TagDecl::TK_enum) { 2340 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2341 // enum X { A, B, C } D; D should chain to X. 2342 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2343 // If this is an undefined enum, warn. 2344 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2345 } else { 2346 // struct/union/class 2347 2348 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2349 // struct X { int A; } D; D should chain to X. 2350 if (getLangOptions().CPlusPlus) 2351 // FIXME: Look for a way to use RecordDecl for simple structs. 2352 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2353 else 2354 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2355 } 2356 2357 // If this has an identifier, add it to the scope stack. 2358 if (Name) { 2359 // The scope passed in may not be a decl scope. Zip up the scope tree until 2360 // we find one that is. 2361 while ((S->getFlags() & Scope::DeclScope) == 0) 2362 S = S->getParent(); 2363 2364 // Add it to the decl chain. 2365 PushOnScopeChains(New, S); 2366 } 2367 2368 if (Attr) 2369 ProcessDeclAttributeList(New, Attr); 2370 2371 // Set the lexical context. If the tag has a C++ scope specifier, the 2372 // lexical context will be different from the semantic context. 2373 New->setLexicalDeclContext(CurContext); 2374 2375 return New; 2376} 2377 2378/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2379/// the logic for enums, we create separate decls for forward declarations. 2380/// This is called by ActOnTag, but eventually will replace its logic. 2381Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2382 SourceLocation KWLoc, const CXXScopeSpec &SS, 2383 IdentifierInfo *Name, SourceLocation NameLoc, 2384 AttributeList *Attr) { 2385 DeclContext *DC = CurContext; 2386 ScopedDecl *PrevDecl = 0; 2387 2388 if (Name && SS.isNotEmpty()) { 2389 // We have a nested-name tag ('struct foo::bar'). 2390 2391 // Check for invalid 'foo::'. 2392 if (SS.isInvalid()) { 2393 Name = 0; 2394 goto CreateNewDecl; 2395 } 2396 2397 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2398 // Look-up name inside 'foo::'. 2399 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2400 2401 // A tag 'foo::bar' must already exist. 2402 if (PrevDecl == 0) { 2403 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2404 Name = 0; 2405 goto CreateNewDecl; 2406 } 2407 } else { 2408 // If this is a named struct, check to see if there was a previous forward 2409 // declaration or definition. 2410 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2411 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2412 } 2413 2414 if (PrevDecl && isTemplateParameterDecl(PrevDecl)) { 2415 // Maybe we will complain about the shadowed template parameter. 2416 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 2417 // Just pretend that we didn't see the previous declaration. 2418 PrevDecl = 0; 2419 } 2420 2421 if (PrevDecl) { 2422 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2423 "unexpected Decl type"); 2424 2425 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2426 // If this is a use of a previous tag, or if the tag is already declared 2427 // in the same scope (so that the definition/declaration completes or 2428 // rementions the tag), reuse the decl. 2429 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2430 // Make sure that this wasn't declared as an enum and now used as a 2431 // struct or something similar. 2432 if (PrevTagDecl->getTagKind() != Kind) { 2433 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2434 Diag(PrevDecl->getLocation(), diag::note_previous_use); 2435 // Recover by making this an anonymous redefinition. 2436 Name = 0; 2437 PrevDecl = 0; 2438 } else { 2439 // If this is a use, return the original decl. 2440 2441 // FIXME: In the future, return a variant or some other clue 2442 // for the consumer of this Decl to know it doesn't own it. 2443 // For our current ASTs this shouldn't be a problem, but will 2444 // need to be changed with DeclGroups. 2445 if (TK == TK_Reference) 2446 return PrevDecl; 2447 2448 // The new decl is a definition? 2449 if (TK == TK_Definition) { 2450 // Diagnose attempts to redefine a tag. 2451 if (RecordDecl* DefRecord = 2452 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2453 Diag(NameLoc, diag::err_redefinition) << Name; 2454 Diag(DefRecord->getLocation(), diag::note_previous_definition); 2455 // If this is a redefinition, recover by making this struct be 2456 // anonymous, which will make any later references get the previous 2457 // definition. 2458 Name = 0; 2459 PrevDecl = 0; 2460 } 2461 // Okay, this is definition of a previously declared or referenced 2462 // tag. We're going to create a new Decl. 2463 } 2464 } 2465 // If we get here we have (another) forward declaration. Just create 2466 // a new decl. 2467 } 2468 else { 2469 // If we get here, this is a definition of a new struct type in a nested 2470 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2471 // new decl/type. We set PrevDecl to NULL so that the Records 2472 // have distinct types. 2473 PrevDecl = 0; 2474 } 2475 } else { 2476 // PrevDecl is a namespace. 2477 if (isDeclInScope(PrevDecl, DC, S)) { 2478 // The tag name clashes with a namespace name, issue an error and 2479 // recover by making this tag be anonymous. 2480 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2481 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 2482 Name = 0; 2483 } 2484 } 2485 } 2486 2487 CreateNewDecl: 2488 2489 // If there is an identifier, use the location of the identifier as the 2490 // location of the decl, otherwise use the location of the struct/union 2491 // keyword. 2492 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2493 2494 // Otherwise, if this is the first time we've seen this tag, create the decl. 2495 TagDecl *New; 2496 2497 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2498 // struct X { int A; } D; D should chain to X. 2499 if (getLangOptions().CPlusPlus) 2500 // FIXME: Look for a way to use RecordDecl for simple structs. 2501 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2502 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2503 else 2504 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2505 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2506 2507 // If this has an identifier, add it to the scope stack. 2508 if ((TK == TK_Definition || !PrevDecl) && Name) { 2509 // The scope passed in may not be a decl scope. Zip up the scope tree until 2510 // we find one that is. 2511 while ((S->getFlags() & Scope::DeclScope) == 0) 2512 S = S->getParent(); 2513 2514 // Add it to the decl chain. 2515 PushOnScopeChains(New, S); 2516 } 2517 2518 // Handle #pragma pack: if the #pragma pack stack has non-default 2519 // alignment, make up a packed attribute for this decl. These 2520 // attributes are checked when the ASTContext lays out the 2521 // structure. 2522 // 2523 // It is important for implementing the correct semantics that this 2524 // happen here (in act on tag decl). The #pragma pack stack is 2525 // maintained as a result of parser callbacks which can occur at 2526 // many points during the parsing of a struct declaration (because 2527 // the #pragma tokens are effectively skipped over during the 2528 // parsing of the struct). 2529 if (unsigned Alignment = PackContext.getAlignment()) 2530 New->addAttr(new PackedAttr(Alignment * 8)); 2531 2532 if (Attr) 2533 ProcessDeclAttributeList(New, Attr); 2534 2535 // Set the lexical context. If the tag has a C++ scope specifier, the 2536 // lexical context will be different from the semantic context. 2537 New->setLexicalDeclContext(CurContext); 2538 2539 return New; 2540} 2541 2542 2543/// Collect the instance variables declared in an Objective-C object. Used in 2544/// the creation of structures from objects using the @defs directive. 2545static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2546 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2547 if (Class->getSuperClass()) 2548 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2549 2550 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2551 for (ObjCInterfaceDecl::ivar_iterator 2552 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2553 2554 ObjCIvarDecl* ID = *I; 2555 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2556 ID->getIdentifier(), 2557 ID->getType(), 2558 ID->getBitWidth())); 2559 } 2560} 2561 2562/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2563/// instance variables of ClassName into Decls. 2564void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2565 IdentifierInfo *ClassName, 2566 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2567 // Check that ClassName is a valid class 2568 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2569 if (!Class) { 2570 Diag(DeclStart, diag::err_undef_interface) << ClassName; 2571 return; 2572 } 2573 // Collect the instance variables 2574 CollectIvars(Class, Context, Decls); 2575} 2576 2577/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2578/// types into constant array types in certain situations which would otherwise 2579/// be errors (for GCC compatibility). 2580static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2581 ASTContext &Context) { 2582 // This method tries to turn a variable array into a constant 2583 // array even when the size isn't an ICE. This is necessary 2584 // for compatibility with code that depends on gcc's buggy 2585 // constant expression folding, like struct {char x[(int)(char*)2];} 2586 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2587 if (!VLATy) return QualType(); 2588 2589 APValue Result; 2590 if (!VLATy->getSizeExpr() || 2591 !VLATy->getSizeExpr()->Evaluate(Result, Context)) 2592 return QualType(); 2593 2594 assert(Result.isInt() && "Size expressions must be integers!"); 2595 llvm::APSInt &Res = Result.getInt(); 2596 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2597 return Context.getConstantArrayType(VLATy->getElementType(), 2598 Res, ArrayType::Normal, 0); 2599 return QualType(); 2600} 2601 2602bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 2603 QualType FieldTy, const Expr *BitWidth) 2604{ 2605 // FIXME: 6.7.2.1p4 - verify the field type. 2606 2607 llvm::APSInt Value; 2608 if (VerifyIntegerConstantExpression(BitWidth, &Value)) 2609 return true; 2610 2611 if (Value.isNegative()) { 2612 Diag(FieldLoc, diag::err_bitfield_has_negative_width) << FieldName; 2613 return true; 2614 } 2615 2616 uint64_t TypeSize = Context.getTypeSize(FieldTy); 2617 // FIXME: We won't need the 0 size once we check that the field type is valid. 2618 if (TypeSize && Value.getZExtValue() > TypeSize) { 2619 Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size) << 2620 FieldName << (unsigned)TypeSize; 2621 return true; 2622 } 2623 2624 return false; 2625} 2626 2627/// ActOnField - Each field of a struct/union/class is passed into this in order 2628/// to create a FieldDecl object for it. 2629Sema::DeclTy *Sema::ActOnField(Scope *S, 2630 SourceLocation DeclStart, 2631 Declarator &D, ExprTy *BitfieldWidth) { 2632 IdentifierInfo *II = D.getIdentifier(); 2633 Expr *BitWidth = (Expr*)BitfieldWidth; 2634 SourceLocation Loc = DeclStart; 2635 if (II) Loc = D.getIdentifierLoc(); 2636 2637 // FIXME: Unnamed fields can be handled in various different ways, for 2638 // example, unnamed unions inject all members into the struct namespace! 2639 2640 QualType T = GetTypeForDeclarator(D, S); 2641 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2642 bool InvalidDecl = false; 2643 2644 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2645 // than a variably modified type. 2646 if (T->isVariablyModifiedType()) { 2647 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2648 if (!FixedTy.isNull()) { 2649 Diag(Loc, diag::warn_illegal_constant_array_size); 2650 T = FixedTy; 2651 } else { 2652 Diag(Loc, diag::err_typecheck_field_variable_size); 2653 T = Context.IntTy; 2654 InvalidDecl = true; 2655 } 2656 } 2657 2658 if (BitWidth) { 2659 if (VerifyBitField(Loc, II, T, BitWidth)) 2660 InvalidDecl = true; 2661 } else { 2662 // Not a bitfield. 2663 2664 // validate II. 2665 2666 } 2667 2668 // FIXME: Chain fielddecls together. 2669 FieldDecl *NewFD; 2670 2671 if (getLangOptions().CPlusPlus) { 2672 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2673 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2674 Loc, II, T, 2675 D.getDeclSpec().getStorageClassSpec() == 2676 DeclSpec::SCS_mutable, BitWidth); 2677 if (II) 2678 PushOnScopeChains(NewFD, S); 2679 } 2680 else 2681 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2682 2683 ProcessDeclAttributes(NewFD, D); 2684 2685 if (D.getInvalidType() || InvalidDecl) 2686 NewFD->setInvalidDecl(); 2687 return NewFD; 2688} 2689 2690/// TranslateIvarVisibility - Translate visibility from a token ID to an 2691/// AST enum value. 2692static ObjCIvarDecl::AccessControl 2693TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2694 switch (ivarVisibility) { 2695 default: assert(0 && "Unknown visitibility kind"); 2696 case tok::objc_private: return ObjCIvarDecl::Private; 2697 case tok::objc_public: return ObjCIvarDecl::Public; 2698 case tok::objc_protected: return ObjCIvarDecl::Protected; 2699 case tok::objc_package: return ObjCIvarDecl::Package; 2700 } 2701} 2702 2703/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2704/// in order to create an IvarDecl object for it. 2705Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2706 SourceLocation DeclStart, 2707 Declarator &D, ExprTy *BitfieldWidth, 2708 tok::ObjCKeywordKind Visibility) { 2709 IdentifierInfo *II = D.getIdentifier(); 2710 Expr *BitWidth = (Expr*)BitfieldWidth; 2711 SourceLocation Loc = DeclStart; 2712 if (II) Loc = D.getIdentifierLoc(); 2713 2714 // FIXME: Unnamed fields can be handled in various different ways, for 2715 // example, unnamed unions inject all members into the struct namespace! 2716 2717 QualType T = GetTypeForDeclarator(D, S); 2718 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2719 bool InvalidDecl = false; 2720 2721 if (BitWidth) { 2722 // TODO: Validate. 2723 //printf("WARNING: BITFIELDS IGNORED!\n"); 2724 2725 // 6.7.2.1p3 2726 // 6.7.2.1p4 2727 2728 } else { 2729 // Not a bitfield. 2730 2731 // validate II. 2732 2733 } 2734 2735 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2736 // than a variably modified type. 2737 if (T->isVariablyModifiedType()) { 2738 // FIXME: This diagnostic needs work 2739 Diag(Loc, diag::err_typecheck_illegal_vla) << SourceRange(Loc); 2740 InvalidDecl = true; 2741 } 2742 2743 // Get the visibility (access control) for this ivar. 2744 ObjCIvarDecl::AccessControl ac = 2745 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2746 : ObjCIvarDecl::None; 2747 2748 // Construct the decl. 2749 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2750 (Expr *)BitfieldWidth); 2751 2752 // Process attributes attached to the ivar. 2753 ProcessDeclAttributes(NewID, D); 2754 2755 if (D.getInvalidType() || InvalidDecl) 2756 NewID->setInvalidDecl(); 2757 2758 return NewID; 2759} 2760 2761void Sema::ActOnFields(Scope* S, 2762 SourceLocation RecLoc, DeclTy *RecDecl, 2763 DeclTy **Fields, unsigned NumFields, 2764 SourceLocation LBrac, SourceLocation RBrac, 2765 AttributeList *Attr) { 2766 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2767 assert(EnclosingDecl && "missing record or interface decl"); 2768 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2769 2770 if (Record) 2771 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2772 // Diagnose code like: 2773 // struct S { struct S {} X; }; 2774 // We discover this when we complete the outer S. Reject and ignore the 2775 // outer S. 2776 Diag(DefRecord->getLocation(), diag::err_nested_redefinition) 2777 << DefRecord->getDeclName(); 2778 Diag(RecLoc, diag::note_previous_definition); 2779 Record->setInvalidDecl(); 2780 return; 2781 } 2782 2783 // Verify that all the fields are okay. 2784 unsigned NumNamedMembers = 0; 2785 llvm::SmallVector<FieldDecl*, 32> RecFields; 2786 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2787 2788 for (unsigned i = 0; i != NumFields; ++i) { 2789 2790 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2791 assert(FD && "missing field decl"); 2792 2793 // Remember all fields. 2794 RecFields.push_back(FD); 2795 2796 // Get the type for the field. 2797 Type *FDTy = FD->getType().getTypePtr(); 2798 2799 // C99 6.7.2.1p2 - A field may not be a function type. 2800 if (FDTy->isFunctionType()) { 2801 Diag(FD->getLocation(), diag::err_field_declared_as_function) 2802 << FD->getDeclName(); 2803 FD->setInvalidDecl(); 2804 EnclosingDecl->setInvalidDecl(); 2805 continue; 2806 } 2807 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2808 if (FDTy->isIncompleteType()) { 2809 if (!Record) { // Incomplete ivar type is always an error. 2810 Diag(FD->getLocation(), diag::err_field_incomplete) <<FD->getDeclName(); 2811 FD->setInvalidDecl(); 2812 EnclosingDecl->setInvalidDecl(); 2813 continue; 2814 } 2815 if (i != NumFields-1 || // ... that the last member ... 2816 !Record->isStruct() || // ... of a structure ... 2817 !FDTy->isArrayType()) { //... may have incomplete array type. 2818 Diag(FD->getLocation(), diag::err_field_incomplete) <<FD->getDeclName(); 2819 FD->setInvalidDecl(); 2820 EnclosingDecl->setInvalidDecl(); 2821 continue; 2822 } 2823 if (NumNamedMembers < 1) { //... must have more than named member ... 2824 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 2825 << FD->getDeclName(); 2826 FD->setInvalidDecl(); 2827 EnclosingDecl->setInvalidDecl(); 2828 continue; 2829 } 2830 // Okay, we have a legal flexible array member at the end of the struct. 2831 if (Record) 2832 Record->setHasFlexibleArrayMember(true); 2833 } 2834 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2835 /// field of another structure or the element of an array. 2836 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2837 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2838 // If this is a member of a union, then entire union becomes "flexible". 2839 if (Record && Record->isUnion()) { 2840 Record->setHasFlexibleArrayMember(true); 2841 } else { 2842 // If this is a struct/class and this is not the last element, reject 2843 // it. Note that GCC supports variable sized arrays in the middle of 2844 // structures. 2845 if (i != NumFields-1) { 2846 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct) 2847 << FD->getDeclName(); 2848 FD->setInvalidDecl(); 2849 EnclosingDecl->setInvalidDecl(); 2850 continue; 2851 } 2852 // We support flexible arrays at the end of structs in other structs 2853 // as an extension. 2854 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 2855 << FD->getDeclName(); 2856 if (Record) 2857 Record->setHasFlexibleArrayMember(true); 2858 } 2859 } 2860 } 2861 /// A field cannot be an Objective-c object 2862 if (FDTy->isObjCInterfaceType()) { 2863 Diag(FD->getLocation(), diag::err_statically_allocated_object) 2864 << FD->getDeclName(); 2865 FD->setInvalidDecl(); 2866 EnclosingDecl->setInvalidDecl(); 2867 continue; 2868 } 2869 // Keep track of the number of named members. 2870 if (IdentifierInfo *II = FD->getIdentifier()) { 2871 // Detect duplicate member names. 2872 if (!FieldIDs.insert(II)) { 2873 Diag(FD->getLocation(), diag::err_duplicate_member) << II; 2874 // Find the previous decl. 2875 SourceLocation PrevLoc; 2876 for (unsigned i = 0; ; ++i) { 2877 assert(i != RecFields.size() && "Didn't find previous def!"); 2878 if (RecFields[i]->getIdentifier() == II) { 2879 PrevLoc = RecFields[i]->getLocation(); 2880 break; 2881 } 2882 } 2883 Diag(PrevLoc, diag::note_previous_definition); 2884 FD->setInvalidDecl(); 2885 EnclosingDecl->setInvalidDecl(); 2886 continue; 2887 } 2888 ++NumNamedMembers; 2889 } 2890 } 2891 2892 // Okay, we successfully defined 'Record'. 2893 if (Record) { 2894 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2895 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2896 // Sema::ActOnFinishCXXClassDef. 2897 if (!isa<CXXRecordDecl>(Record)) 2898 Consumer.HandleTagDeclDefinition(Record); 2899 } else { 2900 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2901 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2902 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2903 else if (ObjCImplementationDecl *IMPDecl = 2904 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2905 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2906 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2907 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2908 } 2909 } 2910 2911 if (Attr) 2912 ProcessDeclAttributeList(Record, Attr); 2913} 2914 2915Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2916 DeclTy *lastEnumConst, 2917 SourceLocation IdLoc, IdentifierInfo *Id, 2918 SourceLocation EqualLoc, ExprTy *val) { 2919 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2920 EnumConstantDecl *LastEnumConst = 2921 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2922 Expr *Val = static_cast<Expr*>(val); 2923 2924 // The scope passed in may not be a decl scope. Zip up the scope tree until 2925 // we find one that is. 2926 while ((S->getFlags() & Scope::DeclScope) == 0) 2927 S = S->getParent(); 2928 2929 // Verify that there isn't already something declared with this name in this 2930 // scope. 2931 Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S); 2932 if (PrevDecl && isTemplateParameterDecl(PrevDecl)) { 2933 // Maybe we will complain about the shadowed template parameter. 2934 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 2935 // Just pretend that we didn't see the previous declaration. 2936 PrevDecl = 0; 2937 } 2938 2939 if (PrevDecl) { 2940 // When in C++, we may get a TagDecl with the same name; in this case the 2941 // enum constant will 'hide' the tag. 2942 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2943 "Received TagDecl when not in C++!"); 2944 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2945 if (isa<EnumConstantDecl>(PrevDecl)) 2946 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 2947 else 2948 Diag(IdLoc, diag::err_redefinition) << Id; 2949 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 2950 delete Val; 2951 return 0; 2952 } 2953 } 2954 2955 llvm::APSInt EnumVal(32); 2956 QualType EltTy; 2957 if (Val) { 2958 // Make sure to promote the operand type to int. 2959 UsualUnaryConversions(Val); 2960 2961 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2962 SourceLocation ExpLoc; 2963 if (VerifyIntegerConstantExpression(Val, &EnumVal)) { 2964 delete Val; 2965 Val = 0; // Just forget about it. 2966 } else { 2967 EltTy = Val->getType(); 2968 } 2969 } 2970 2971 if (!Val) { 2972 if (LastEnumConst) { 2973 // Assign the last value + 1. 2974 EnumVal = LastEnumConst->getInitVal(); 2975 ++EnumVal; 2976 2977 // Check for overflow on increment. 2978 if (EnumVal < LastEnumConst->getInitVal()) 2979 Diag(IdLoc, diag::warn_enum_value_overflow); 2980 2981 EltTy = LastEnumConst->getType(); 2982 } else { 2983 // First value, set to zero. 2984 EltTy = Context.IntTy; 2985 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2986 } 2987 } 2988 2989 EnumConstantDecl *New = 2990 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2991 Val, EnumVal, 2992 LastEnumConst); 2993 2994 // Register this decl in the current scope stack. 2995 PushOnScopeChains(New, S); 2996 return New; 2997} 2998 2999// FIXME: For consistency with ActOnFields(), we should have the parser 3000// pass in the source location for the left/right braces. 3001void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 3002 DeclTy **Elements, unsigned NumElements) { 3003 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 3004 3005 if (Enum && Enum->isDefinition()) { 3006 // Diagnose code like: 3007 // enum e0 { 3008 // E0 = sizeof(enum e0 { E1 }) 3009 // }; 3010 Diag(Enum->getLocation(), diag::err_nested_redefinition) 3011 << Enum->getDeclName(); 3012 Diag(EnumLoc, diag::note_previous_definition); 3013 Enum->setInvalidDecl(); 3014 return; 3015 } 3016 // TODO: If the result value doesn't fit in an int, it must be a long or long 3017 // long value. ISO C does not support this, but GCC does as an extension, 3018 // emit a warning. 3019 unsigned IntWidth = Context.Target.getIntWidth(); 3020 3021 // Verify that all the values are okay, compute the size of the values, and 3022 // reverse the list. 3023 unsigned NumNegativeBits = 0; 3024 unsigned NumPositiveBits = 0; 3025 3026 // Keep track of whether all elements have type int. 3027 bool AllElementsInt = true; 3028 3029 EnumConstantDecl *EltList = 0; 3030 for (unsigned i = 0; i != NumElements; ++i) { 3031 EnumConstantDecl *ECD = 3032 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3033 if (!ECD) continue; // Already issued a diagnostic. 3034 3035 // If the enum value doesn't fit in an int, emit an extension warning. 3036 const llvm::APSInt &InitVal = ECD->getInitVal(); 3037 assert(InitVal.getBitWidth() >= IntWidth && 3038 "Should have promoted value to int"); 3039 if (InitVal.getBitWidth() > IntWidth) { 3040 llvm::APSInt V(InitVal); 3041 V.trunc(IntWidth); 3042 V.extend(InitVal.getBitWidth()); 3043 if (V != InitVal) 3044 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 3045 << InitVal.toString(10); 3046 } 3047 3048 // Keep track of the size of positive and negative values. 3049 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 3050 NumPositiveBits = std::max(NumPositiveBits, 3051 (unsigned)InitVal.getActiveBits()); 3052 else 3053 NumNegativeBits = std::max(NumNegativeBits, 3054 (unsigned)InitVal.getMinSignedBits()); 3055 3056 // Keep track of whether every enum element has type int (very commmon). 3057 if (AllElementsInt) 3058 AllElementsInt = ECD->getType() == Context.IntTy; 3059 3060 ECD->setNextDeclarator(EltList); 3061 EltList = ECD; 3062 } 3063 3064 // Figure out the type that should be used for this enum. 3065 // FIXME: Support attribute(packed) on enums and -fshort-enums. 3066 QualType BestType; 3067 unsigned BestWidth; 3068 3069 if (NumNegativeBits) { 3070 // If there is a negative value, figure out the smallest integer type (of 3071 // int/long/longlong) that fits. 3072 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 3073 BestType = Context.IntTy; 3074 BestWidth = IntWidth; 3075 } else { 3076 BestWidth = Context.Target.getLongWidth(); 3077 3078 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 3079 BestType = Context.LongTy; 3080 else { 3081 BestWidth = Context.Target.getLongLongWidth(); 3082 3083 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 3084 Diag(Enum->getLocation(), diag::warn_enum_too_large); 3085 BestType = Context.LongLongTy; 3086 } 3087 } 3088 } else { 3089 // If there is no negative value, figure out which of uint, ulong, ulonglong 3090 // fits. 3091 if (NumPositiveBits <= IntWidth) { 3092 BestType = Context.UnsignedIntTy; 3093 BestWidth = IntWidth; 3094 } else if (NumPositiveBits <= 3095 (BestWidth = Context.Target.getLongWidth())) { 3096 BestType = Context.UnsignedLongTy; 3097 } else { 3098 BestWidth = Context.Target.getLongLongWidth(); 3099 assert(NumPositiveBits <= BestWidth && 3100 "How could an initializer get larger than ULL?"); 3101 BestType = Context.UnsignedLongLongTy; 3102 } 3103 } 3104 3105 // Loop over all of the enumerator constants, changing their types to match 3106 // the type of the enum if needed. 3107 for (unsigned i = 0; i != NumElements; ++i) { 3108 EnumConstantDecl *ECD = 3109 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3110 if (!ECD) continue; // Already issued a diagnostic. 3111 3112 // Standard C says the enumerators have int type, but we allow, as an 3113 // extension, the enumerators to be larger than int size. If each 3114 // enumerator value fits in an int, type it as an int, otherwise type it the 3115 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 3116 // that X has type 'int', not 'unsigned'. 3117 if (ECD->getType() == Context.IntTy) { 3118 // Make sure the init value is signed. 3119 llvm::APSInt IV = ECD->getInitVal(); 3120 IV.setIsSigned(true); 3121 ECD->setInitVal(IV); 3122 continue; // Already int type. 3123 } 3124 3125 // Determine whether the value fits into an int. 3126 llvm::APSInt InitVal = ECD->getInitVal(); 3127 bool FitsInInt; 3128 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3129 FitsInInt = InitVal.getActiveBits() < IntWidth; 3130 else 3131 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3132 3133 // If it fits into an integer type, force it. Otherwise force it to match 3134 // the enum decl type. 3135 QualType NewTy; 3136 unsigned NewWidth; 3137 bool NewSign; 3138 if (FitsInInt) { 3139 NewTy = Context.IntTy; 3140 NewWidth = IntWidth; 3141 NewSign = true; 3142 } else if (ECD->getType() == BestType) { 3143 // Already the right type! 3144 continue; 3145 } else { 3146 NewTy = BestType; 3147 NewWidth = BestWidth; 3148 NewSign = BestType->isSignedIntegerType(); 3149 } 3150 3151 // Adjust the APSInt value. 3152 InitVal.extOrTrunc(NewWidth); 3153 InitVal.setIsSigned(NewSign); 3154 ECD->setInitVal(InitVal); 3155 3156 // Adjust the Expr initializer and type. 3157 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3158 /*isLvalue=*/false)); 3159 ECD->setType(NewTy); 3160 } 3161 3162 Enum->defineElements(EltList, BestType); 3163 Consumer.HandleTagDeclDefinition(Enum); 3164} 3165 3166Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3167 ExprTy *expr) { 3168 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3169 3170 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3171} 3172 3173Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3174 SourceLocation LBrace, 3175 SourceLocation RBrace, 3176 const char *Lang, 3177 unsigned StrSize, 3178 DeclTy *D) { 3179 LinkageSpecDecl::LanguageIDs Language; 3180 Decl *dcl = static_cast<Decl *>(D); 3181 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3182 Language = LinkageSpecDecl::lang_c; 3183 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3184 Language = LinkageSpecDecl::lang_cxx; 3185 else { 3186 Diag(Loc, diag::err_bad_language); 3187 return 0; 3188 } 3189 3190 // FIXME: Add all the various semantics of linkage specifications 3191 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3192} 3193 3194void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3195 ExprTy *alignment, SourceLocation PragmaLoc, 3196 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3197 Expr *Alignment = static_cast<Expr *>(alignment); 3198 3199 // If specified then alignment must be a "small" power of two. 3200 unsigned AlignmentVal = 0; 3201 if (Alignment) { 3202 llvm::APSInt Val; 3203 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3204 !Val.isPowerOf2() || 3205 Val.getZExtValue() > 16) { 3206 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3207 delete Alignment; 3208 return; // Ignore 3209 } 3210 3211 AlignmentVal = (unsigned) Val.getZExtValue(); 3212 } 3213 3214 switch (Kind) { 3215 case Action::PPK_Default: // pack([n]) 3216 PackContext.setAlignment(AlignmentVal); 3217 break; 3218 3219 case Action::PPK_Show: // pack(show) 3220 // Show the current alignment, making sure to show the right value 3221 // for the default. 3222 AlignmentVal = PackContext.getAlignment(); 3223 // FIXME: This should come from the target. 3224 if (AlignmentVal == 0) 3225 AlignmentVal = 8; 3226 Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 3227 break; 3228 3229 case Action::PPK_Push: // pack(push [, id] [, [n]) 3230 PackContext.push(Name); 3231 // Set the new alignment if specified. 3232 if (Alignment) 3233 PackContext.setAlignment(AlignmentVal); 3234 break; 3235 3236 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3237 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3238 // "#pragma pack(pop, identifier, n) is undefined" 3239 if (Alignment && Name) 3240 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3241 3242 // Do the pop. 3243 if (!PackContext.pop(Name)) { 3244 // If a name was specified then failure indicates the name 3245 // wasn't found. Otherwise failure indicates the stack was 3246 // empty. 3247 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed) 3248 << (Name ? "no record matching name" : "stack empty"); 3249 3250 // FIXME: Warn about popping named records as MSVC does. 3251 } else { 3252 // Pop succeeded, set the new alignment if specified. 3253 if (Alignment) 3254 PackContext.setAlignment(AlignmentVal); 3255 } 3256 break; 3257 3258 default: 3259 assert(0 && "Invalid #pragma pack kind."); 3260 } 3261} 3262 3263bool PragmaPackStack::pop(IdentifierInfo *Name) { 3264 if (Stack.empty()) 3265 return false; 3266 3267 // If name is empty just pop top. 3268 if (!Name) { 3269 Alignment = Stack.back().first; 3270 Stack.pop_back(); 3271 return true; 3272 } 3273 3274 // Otherwise, find the named record. 3275 for (unsigned i = Stack.size(); i != 0; ) { 3276 --i; 3277 if (Stack[i].second == Name) { 3278 // Found it, pop up to and including this record. 3279 Alignment = Stack[i].first; 3280 Stack.erase(Stack.begin() + i, Stack.end()); 3281 return true; 3282 } 3283 } 3284 3285 return false; 3286} 3287