SemaDecl.cpp revision 8edea83d4d45d912191eac97b861309af6c74acd
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/Parse/DeclSpec.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/SourceManager.h" 24// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/HeaderSearch.h" 27#include "llvm/ADT/SmallSet.h" 28using namespace clang; 29 30Sema::TypeTy *Sema::isTypeName(IdentifierInfo &II, Scope *S, 31 const CXXScopeSpec *SS) { 32 DeclContext *DC = 0; 33 if (SS) { 34 if (SS->isInvalid()) 35 return 0; 36 DC = static_cast<DeclContext*>(SS->getScopeRep()); 37 } 38 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false); 39 40 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 41 isa<ObjCInterfaceDecl>(IIDecl) || 42 isa<TagDecl>(IIDecl))) 43 return IIDecl; 44 return 0; 45} 46 47DeclContext *Sema::getContainingDC(DeclContext *DC) { 48 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 49 // A C++ out-of-line method will return to the file declaration context. 50 if (MD->isOutOfLineDefinition()) 51 return MD->getLexicalDeclContext(); 52 53 // A C++ inline method is parsed *after* the topmost class it was declared in 54 // is fully parsed (it's "complete"). 55 // The parsing of a C++ inline method happens at the declaration context of 56 // the topmost (non-nested) class it is lexically declared in. 57 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 58 DC = MD->getParent(); 59 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent())) 60 DC = RD; 61 62 // Return the declaration context of the topmost class the inline method is 63 // declared in. 64 return DC; 65 } 66 67 if (isa<ObjCMethodDecl>(DC)) 68 return Context.getTranslationUnitDecl(); 69 70 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC)) 71 return SD->getLexicalDeclContext(); 72 73 return DC->getLexicalParent(); 74} 75 76void Sema::PushDeclContext(DeclContext *DC) { 77 assert(getContainingDC(DC) == CurContext && 78 "The next DeclContext should be lexically contained in the current one."); 79 CurContext = DC; 80} 81 82void Sema::PopDeclContext() { 83 assert(CurContext && "DeclContext imbalance!"); 84 CurContext = getContainingDC(CurContext); 85} 86 87/// Add this decl to the scope shadowed decl chains. 88void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 89 S->AddDecl(D); 90 91 // C++ [basic.scope]p4: 92 // -- exactly one declaration shall declare a class name or 93 // enumeration name that is not a typedef name and the other 94 // declarations shall all refer to the same object or 95 // enumerator, or all refer to functions and function templates; 96 // in this case the class name or enumeration name is hidden. 97 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 98 // We are pushing the name of a tag (enum or class). 99 IdentifierResolver::iterator 100 I = IdResolver.begin(TD->getIdentifier(), 101 TD->getDeclContext(), false/*LookInParentCtx*/); 102 if (I != IdResolver.end() && isDeclInScope(*I, TD->getDeclContext(), S)) { 103 // There is already a declaration with the same name in the same 104 // scope. It must be found before we find the new declaration, 105 // so swap the order on the shadowed declaration chain. 106 107 IdResolver.AddShadowedDecl(TD, *I); 108 return; 109 } 110 } else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 111 FunctionDecl *FD = cast<FunctionDecl>(D); 112 // We are pushing the name of a function, which might be an 113 // overloaded name. 114 IdentifierResolver::iterator 115 I = IdResolver.begin(FD->getDeclName(), 116 FD->getDeclContext(), false/*LookInParentCtx*/); 117 if (I != IdResolver.end() && 118 IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) && 119 (isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) { 120 // There is already a declaration with the same name in the same 121 // scope. It must be a function or an overloaded function. 122 OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I); 123 if (!Ovl) { 124 // We haven't yet overloaded this function. Take the existing 125 // FunctionDecl and put it into an OverloadedFunctionDecl. 126 Ovl = OverloadedFunctionDecl::Create(Context, 127 FD->getDeclContext(), 128 FD->getDeclName()); 129 Ovl->addOverload(dyn_cast<FunctionDecl>(*I)); 130 131 // Remove the name binding to the existing FunctionDecl... 132 IdResolver.RemoveDecl(*I); 133 134 // ... and put the OverloadedFunctionDecl in its place. 135 IdResolver.AddDecl(Ovl); 136 } 137 138 // We have an OverloadedFunctionDecl. Add the new FunctionDecl 139 // to its list of overloads. 140 Ovl->addOverload(FD); 141 142 return; 143 } 144 } 145 146 IdResolver.AddDecl(D); 147} 148 149void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 150 if (S->decl_empty()) return; 151 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 152 153 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 154 I != E; ++I) { 155 Decl *TmpD = static_cast<Decl*>(*I); 156 assert(TmpD && "This decl didn't get pushed??"); 157 158 if (isa<CXXFieldDecl>(TmpD)) continue; 159 160 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 161 ScopedDecl *D = cast<ScopedDecl>(TmpD); 162 163 IdentifierInfo *II = D->getIdentifier(); 164 if (!II) continue; 165 166 // We only want to remove the decls from the identifier decl chains for 167 // local scopes, when inside a function/method. 168 if (S->getFnParent() != 0) 169 IdResolver.RemoveDecl(D); 170 171 // Chain this decl to the containing DeclContext. 172 D->setNext(CurContext->getDeclChain()); 173 CurContext->setDeclChain(D); 174 } 175} 176 177/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 178/// return 0 if one not found. 179ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 180 // The third "scope" argument is 0 since we aren't enabling lazy built-in 181 // creation from this context. 182 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 183 184 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 185} 186 187/// LookupDecl - Look up the inner-most declaration in the specified 188/// namespace. 189Decl *Sema::LookupDecl(DeclarationName Name, unsigned NSI, Scope *S, 190 const DeclContext *LookupCtx, 191 bool enableLazyBuiltinCreation) { 192 if (!Name) return 0; 193 unsigned NS = NSI; 194 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 195 NS |= Decl::IDNS_Tag; 196 197 IdentifierResolver::iterator 198 I = LookupCtx ? IdResolver.begin(Name, LookupCtx, false/*LookInParentCtx*/) 199 : IdResolver.begin(Name, CurContext, true/*LookInParentCtx*/); 200 // Scan up the scope chain looking for a decl that matches this identifier 201 // that is in the appropriate namespace. This search should not take long, as 202 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 203 for (; I != IdResolver.end(); ++I) 204 if ((*I)->getIdentifierNamespace() & NS) 205 return *I; 206 207 // If we didn't find a use of this identifier, and if the identifier 208 // corresponds to a compiler builtin, create the decl object for the builtin 209 // now, injecting it into translation unit scope, and return it. 210 if (NS & Decl::IDNS_Ordinary) { 211 IdentifierInfo *II = Name.getAsIdentifierInfo(); 212 if (enableLazyBuiltinCreation && II && 213 (LookupCtx == 0 || isa<TranslationUnitDecl>(LookupCtx))) { 214 // If this is a builtin on this (or all) targets, create the decl. 215 if (unsigned BuiltinID = II->getBuiltinID()) 216 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 217 } 218 if (getLangOptions().ObjC1 && II) { 219 // @interface and @compatibility_alias introduce typedef-like names. 220 // Unlike typedef's, they can only be introduced at file-scope (and are 221 // therefore not scoped decls). They can, however, be shadowed by 222 // other names in IDNS_Ordinary. 223 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 224 if (IDI != ObjCInterfaceDecls.end()) 225 return IDI->second; 226 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 227 if (I != ObjCAliasDecls.end()) 228 return I->second->getClassInterface(); 229 } 230 } 231 return 0; 232} 233 234void Sema::InitBuiltinVaListType() { 235 if (!Context.getBuiltinVaListType().isNull()) 236 return; 237 238 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 239 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 240 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 241 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 242} 243 244/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 245/// lazily create a decl for it. 246ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 247 Scope *S) { 248 Builtin::ID BID = (Builtin::ID)bid; 249 250 if (Context.BuiltinInfo.hasVAListUse(BID)) 251 InitBuiltinVaListType(); 252 253 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 254 FunctionDecl *New = FunctionDecl::Create(Context, 255 Context.getTranslationUnitDecl(), 256 SourceLocation(), II, R, 257 FunctionDecl::Extern, false, 0); 258 259 // Create Decl objects for each parameter, adding them to the 260 // FunctionDecl. 261 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 262 llvm::SmallVector<ParmVarDecl*, 16> Params; 263 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 264 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 265 FT->getArgType(i), VarDecl::None, 0, 266 0)); 267 New->setParams(&Params[0], Params.size()); 268 } 269 270 271 272 // TUScope is the translation-unit scope to insert this function into. 273 PushOnScopeChains(New, TUScope); 274 return New; 275} 276 277/// GetStdNamespace - This method gets the C++ "std" namespace. This is where 278/// everything from the standard library is defined. 279NamespaceDecl *Sema::GetStdNamespace() { 280 if (!StdNamespace) { 281 IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std"); 282 DeclContext *Global = Context.getTranslationUnitDecl(); 283 Decl *Std = LookupDecl(StdIdent, Decl::IDNS_Tag | Decl::IDNS_Ordinary, 284 0, Global, /*enableLazyBuiltinCreation=*/false); 285 StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std); 286 } 287 return StdNamespace; 288} 289 290/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 291/// and scope as a previous declaration 'Old'. Figure out how to resolve this 292/// situation, merging decls or emitting diagnostics as appropriate. 293/// 294TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 295 // Allow multiple definitions for ObjC built-in typedefs. 296 // FIXME: Verify the underlying types are equivalent! 297 if (getLangOptions().ObjC1) { 298 const IdentifierInfo *TypeID = New->getIdentifier(); 299 switch (TypeID->getLength()) { 300 default: break; 301 case 2: 302 if (!TypeID->isStr("id")) 303 break; 304 Context.setObjCIdType(New); 305 return New; 306 case 5: 307 if (!TypeID->isStr("Class")) 308 break; 309 Context.setObjCClassType(New); 310 return New; 311 case 3: 312 if (!TypeID->isStr("SEL")) 313 break; 314 Context.setObjCSelType(New); 315 return New; 316 case 8: 317 if (!TypeID->isStr("Protocol")) 318 break; 319 Context.setObjCProtoType(New->getUnderlyingType()); 320 return New; 321 } 322 // Fall through - the typedef name was not a builtin type. 323 } 324 // Verify the old decl was also a typedef. 325 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 326 if (!Old) { 327 Diag(New->getLocation(), diag::err_redefinition_different_kind, 328 New->getName()); 329 Diag(OldD->getLocation(), diag::err_previous_definition); 330 return New; 331 } 332 333 // If the typedef types are not identical, reject them in all languages and 334 // with any extensions enabled. 335 if (Old->getUnderlyingType() != New->getUnderlyingType() && 336 Context.getCanonicalType(Old->getUnderlyingType()) != 337 Context.getCanonicalType(New->getUnderlyingType())) { 338 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 339 New->getUnderlyingType().getAsString(), 340 Old->getUnderlyingType().getAsString()); 341 Diag(Old->getLocation(), diag::err_previous_definition); 342 return Old; 343 } 344 345 if (getLangOptions().Microsoft) return New; 346 347 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 348 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 349 // *either* declaration is in a system header. The code below implements 350 // this adhoc compatibility rule. FIXME: The following code will not 351 // work properly when compiling ".i" files (containing preprocessed output). 352 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 353 SourceManager &SrcMgr = Context.getSourceManager(); 354 if (SrcMgr.isInSystemHeader(Old->getLocation())) 355 return New; 356 if (SrcMgr.isInSystemHeader(New->getLocation())) 357 return New; 358 } 359 360 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 361 Diag(Old->getLocation(), diag::err_previous_definition); 362 return New; 363} 364 365/// DeclhasAttr - returns true if decl Declaration already has the target 366/// attribute. 367static bool DeclHasAttr(const Decl *decl, const Attr *target) { 368 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 369 if (attr->getKind() == target->getKind()) 370 return true; 371 372 return false; 373} 374 375/// MergeAttributes - append attributes from the Old decl to the New one. 376static void MergeAttributes(Decl *New, Decl *Old) { 377 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 378 379 while (attr) { 380 tmp = attr; 381 attr = attr->getNext(); 382 383 if (!DeclHasAttr(New, tmp)) { 384 New->addAttr(tmp); 385 } else { 386 tmp->setNext(0); 387 delete(tmp); 388 } 389 } 390 391 Old->invalidateAttrs(); 392} 393 394/// MergeFunctionDecl - We just parsed a function 'New' from 395/// declarator D which has the same name and scope as a previous 396/// declaration 'Old'. Figure out how to resolve this situation, 397/// merging decls or emitting diagnostics as appropriate. 398/// Redeclaration will be set true if this New is a redeclaration OldD. 399/// 400/// In C++, New and Old must be declarations that are not 401/// overloaded. Use IsOverload to determine whether New and Old are 402/// overloaded, and to select the Old declaration that New should be 403/// merged with. 404FunctionDecl * 405Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 406 assert(!isa<OverloadedFunctionDecl>(OldD) && 407 "Cannot merge with an overloaded function declaration"); 408 409 Redeclaration = false; 410 // Verify the old decl was also a function. 411 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 412 if (!Old) { 413 Diag(New->getLocation(), diag::err_redefinition_different_kind, 414 New->getName()); 415 Diag(OldD->getLocation(), diag::err_previous_definition); 416 return New; 417 } 418 419 // Determine whether the previous declaration was a definition, 420 // implicit declaration, or a declaration. 421 diag::kind PrevDiag; 422 if (Old->isThisDeclarationADefinition()) 423 PrevDiag = diag::err_previous_definition; 424 else if (Old->isImplicit()) 425 PrevDiag = diag::err_previous_implicit_declaration; 426 else 427 PrevDiag = diag::err_previous_declaration; 428 429 QualType OldQType = Context.getCanonicalType(Old->getType()); 430 QualType NewQType = Context.getCanonicalType(New->getType()); 431 432 if (getLangOptions().CPlusPlus) { 433 // (C++98 13.1p2): 434 // Certain function declarations cannot be overloaded: 435 // -- Function declarations that differ only in the return type 436 // cannot be overloaded. 437 QualType OldReturnType 438 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 439 QualType NewReturnType 440 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 441 if (OldReturnType != NewReturnType) { 442 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 443 Diag(Old->getLocation(), PrevDiag); 444 return New; 445 } 446 447 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 448 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 449 if (OldMethod && NewMethod) { 450 // -- Member function declarations with the same name and the 451 // same parameter types cannot be overloaded if any of them 452 // is a static member function declaration. 453 if (OldMethod->isStatic() || NewMethod->isStatic()) { 454 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 455 Diag(Old->getLocation(), PrevDiag); 456 return New; 457 } 458 } 459 460 // (C++98 8.3.5p3): 461 // All declarations for a function shall agree exactly in both the 462 // return type and the parameter-type-list. 463 if (OldQType == NewQType) { 464 // We have a redeclaration. 465 MergeAttributes(New, Old); 466 Redeclaration = true; 467 return MergeCXXFunctionDecl(New, Old); 468 } 469 470 // Fall through for conflicting redeclarations and redefinitions. 471 } 472 473 // C: Function types need to be compatible, not identical. This handles 474 // duplicate function decls like "void f(int); void f(enum X);" properly. 475 if (!getLangOptions().CPlusPlus && 476 Context.typesAreCompatible(OldQType, NewQType)) { 477 MergeAttributes(New, Old); 478 Redeclaration = true; 479 return New; 480 } 481 482 // A function that has already been declared has been redeclared or defined 483 // with a different type- show appropriate diagnostic 484 485 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 486 // TODO: This is totally simplistic. It should handle merging functions 487 // together etc, merging extern int X; int X; ... 488 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 489 Diag(Old->getLocation(), PrevDiag); 490 return New; 491} 492 493/// Predicate for C "tentative" external object definitions (C99 6.9.2). 494static bool isTentativeDefinition(VarDecl *VD) { 495 if (VD->isFileVarDecl()) 496 return (!VD->getInit() && 497 (VD->getStorageClass() == VarDecl::None || 498 VD->getStorageClass() == VarDecl::Static)); 499 return false; 500} 501 502/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 503/// when dealing with C "tentative" external object definitions (C99 6.9.2). 504void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 505 bool VDIsTentative = isTentativeDefinition(VD); 506 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 507 508 for (IdentifierResolver::iterator 509 I = IdResolver.begin(VD->getIdentifier(), 510 VD->getDeclContext(), false/*LookInParentCtx*/), 511 E = IdResolver.end(); I != E; ++I) { 512 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 513 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 514 515 // Handle the following case: 516 // int a[10]; 517 // int a[]; - the code below makes sure we set the correct type. 518 // int a[11]; - this is an error, size isn't 10. 519 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 520 OldDecl->getType()->isConstantArrayType()) 521 VD->setType(OldDecl->getType()); 522 523 // Check for "tentative" definitions. We can't accomplish this in 524 // MergeVarDecl since the initializer hasn't been attached. 525 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 526 continue; 527 528 // Handle __private_extern__ just like extern. 529 if (OldDecl->getStorageClass() != VarDecl::Extern && 530 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 531 VD->getStorageClass() != VarDecl::Extern && 532 VD->getStorageClass() != VarDecl::PrivateExtern) { 533 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 534 Diag(OldDecl->getLocation(), diag::err_previous_definition); 535 } 536 } 537 } 538} 539 540/// MergeVarDecl - We just parsed a variable 'New' which has the same name 541/// and scope as a previous declaration 'Old'. Figure out how to resolve this 542/// situation, merging decls or emitting diagnostics as appropriate. 543/// 544/// Tentative definition rules (C99 6.9.2p2) are checked by 545/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 546/// definitions here, since the initializer hasn't been attached. 547/// 548VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 549 // Verify the old decl was also a variable. 550 VarDecl *Old = dyn_cast<VarDecl>(OldD); 551 if (!Old) { 552 Diag(New->getLocation(), diag::err_redefinition_different_kind, 553 New->getName()); 554 Diag(OldD->getLocation(), diag::err_previous_definition); 555 return New; 556 } 557 558 MergeAttributes(New, Old); 559 560 // Verify the types match. 561 QualType OldCType = Context.getCanonicalType(Old->getType()); 562 QualType NewCType = Context.getCanonicalType(New->getType()); 563 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 564 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 565 Diag(Old->getLocation(), diag::err_previous_definition); 566 return New; 567 } 568 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 569 if (New->getStorageClass() == VarDecl::Static && 570 (Old->getStorageClass() == VarDecl::None || 571 Old->getStorageClass() == VarDecl::Extern)) { 572 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 573 Diag(Old->getLocation(), diag::err_previous_definition); 574 return New; 575 } 576 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 577 if (New->getStorageClass() != VarDecl::Static && 578 Old->getStorageClass() == VarDecl::Static) { 579 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 580 Diag(Old->getLocation(), diag::err_previous_definition); 581 return New; 582 } 583 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 584 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 585 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 586 Diag(Old->getLocation(), diag::err_previous_definition); 587 } 588 return New; 589} 590 591/// CheckParmsForFunctionDef - Check that the parameters of the given 592/// function are appropriate for the definition of a function. This 593/// takes care of any checks that cannot be performed on the 594/// declaration itself, e.g., that the types of each of the function 595/// parameters are complete. 596bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 597 bool HasInvalidParm = false; 598 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 599 ParmVarDecl *Param = FD->getParamDecl(p); 600 601 // C99 6.7.5.3p4: the parameters in a parameter type list in a 602 // function declarator that is part of a function definition of 603 // that function shall not have incomplete type. 604 if (Param->getType()->isIncompleteType() && 605 !Param->isInvalidDecl()) { 606 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 607 Param->getType().getAsString()); 608 Param->setInvalidDecl(); 609 HasInvalidParm = true; 610 } 611 } 612 613 return HasInvalidParm; 614} 615 616/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 617/// no declarator (e.g. "struct foo;") is parsed. 618Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 619 // TODO: emit error on 'int;' or 'const enum foo;'. 620 // TODO: emit error on 'typedef int;' 621 // if (!DS.isMissingDeclaratorOk()) Diag(...); 622 623 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 624} 625 626bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 627 // Get the type before calling CheckSingleAssignmentConstraints(), since 628 // it can promote the expression. 629 QualType InitType = Init->getType(); 630 631 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 632 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 633 InitType, Init, "initializing"); 634} 635 636bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 637 const ArrayType *AT = Context.getAsArrayType(DeclT); 638 639 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 640 // C99 6.7.8p14. We have an array of character type with unknown size 641 // being initialized to a string literal. 642 llvm::APSInt ConstVal(32); 643 ConstVal = strLiteral->getByteLength() + 1; 644 // Return a new array type (C99 6.7.8p22). 645 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 646 ArrayType::Normal, 0); 647 } else { 648 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 649 // C99 6.7.8p14. We have an array of character type with known size. 650 // FIXME: Avoid truncation for 64-bit length strings. 651 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 652 Diag(strLiteral->getSourceRange().getBegin(), 653 diag::warn_initializer_string_for_char_array_too_long) 654 << strLiteral->getSourceRange(); 655 } 656 // Set type from "char *" to "constant array of char". 657 strLiteral->setType(DeclT); 658 // For now, we always return false (meaning success). 659 return false; 660} 661 662StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 663 const ArrayType *AT = Context.getAsArrayType(DeclType); 664 if (AT && AT->getElementType()->isCharType()) { 665 return dyn_cast<StringLiteral>(Init); 666 } 667 return 0; 668} 669 670bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 671 SourceLocation InitLoc, 672 std::string InitEntity) { 673 // C++ [dcl.init.ref]p1: 674 // A variable declared to be a T&, that is “reference to type T” 675 // (8.3.2), shall be initialized by an object, or function, of 676 // type T or by an object that can be converted into a T. 677 if (DeclType->isReferenceType()) 678 return CheckReferenceInit(Init, DeclType); 679 680 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 681 // of unknown size ("[]") or an object type that is not a variable array type. 682 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 683 return Diag(InitLoc, diag::err_variable_object_no_init) 684 << VAT->getSizeExpr()->getSourceRange(); 685 686 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 687 if (!InitList) { 688 // FIXME: Handle wide strings 689 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 690 return CheckStringLiteralInit(strLiteral, DeclType); 691 692 // C++ [dcl.init]p14: 693 // -- If the destination type is a (possibly cv-qualified) class 694 // type: 695 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 696 QualType DeclTypeC = Context.getCanonicalType(DeclType); 697 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 698 699 // -- If the initialization is direct-initialization, or if it is 700 // copy-initialization where the cv-unqualified version of the 701 // source type is the same class as, or a derived class of, the 702 // class of the destination, constructors are considered. 703 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 704 IsDerivedFrom(InitTypeC, DeclTypeC)) { 705 CXXConstructorDecl *Constructor 706 = PerformInitializationByConstructor(DeclType, &Init, 1, 707 InitLoc, Init->getSourceRange(), 708 InitEntity, IK_Copy); 709 return Constructor == 0; 710 } 711 712 // -- Otherwise (i.e., for the remaining copy-initialization 713 // cases), user-defined conversion sequences that can 714 // convert from the source type to the destination type or 715 // (when a conversion function is used) to a derived class 716 // thereof are enumerated as described in 13.3.1.4, and the 717 // best one is chosen through overload resolution 718 // (13.3). If the conversion cannot be done or is 719 // ambiguous, the initialization is ill-formed. The 720 // function selected is called with the initializer 721 // expression as its argument; if the function is a 722 // constructor, the call initializes a temporary of the 723 // destination type. 724 // FIXME: We're pretending to do copy elision here; return to 725 // this when we have ASTs for such things. 726 if (!PerformImplicitConversion(Init, DeclType)) 727 return false; 728 729 return Diag(InitLoc, diag::err_typecheck_convert_incompatible) 730 << DeclType.getAsString() << InitEntity << "initializing" 731 << Init->getSourceRange(); 732 } 733 734 // C99 6.7.8p16. 735 if (DeclType->isArrayType()) 736 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 737 << Init->getSourceRange(); 738 739 return CheckSingleInitializer(Init, DeclType); 740 } else if (getLangOptions().CPlusPlus) { 741 // C++ [dcl.init]p14: 742 // [...] If the class is an aggregate (8.5.1), and the initializer 743 // is a brace-enclosed list, see 8.5.1. 744 // 745 // Note: 8.5.1 is handled below; here, we diagnose the case where 746 // we have an initializer list and a destination type that is not 747 // an aggregate. 748 // FIXME: In C++0x, this is yet another form of initialization. 749 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 750 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 751 if (!ClassDecl->isAggregate()) 752 return Diag(InitLoc, diag::err_init_non_aggr_init_list) 753 << DeclType.getAsString() << Init->getSourceRange(); 754 } 755 } 756 757 InitListChecker CheckInitList(this, InitList, DeclType); 758 return CheckInitList.HadError(); 759} 760 761/// GetNameForDeclarator - Determine the full declaration name for the 762/// given Declarator. 763DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 764 switch (D.getKind()) { 765 case Declarator::DK_Abstract: 766 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 767 return DeclarationName(); 768 769 case Declarator::DK_Normal: 770 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 771 return DeclarationName(D.getIdentifier()); 772 773 case Declarator::DK_Constructor: { 774 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 775 Ty = Context.getCanonicalType(Ty); 776 return Context.DeclarationNames.getCXXConstructorName(Ty); 777 } 778 779 case Declarator::DK_Destructor: { 780 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 781 Ty = Context.getCanonicalType(Ty); 782 return Context.DeclarationNames.getCXXDestructorName(Ty); 783 } 784 785 case Declarator::DK_Conversion: { 786 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 787 Ty = Context.getCanonicalType(Ty); 788 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 789 } 790 791 case Declarator::DK_Operator: 792 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 793 return Context.DeclarationNames.getCXXOperatorName( 794 D.getOverloadedOperator()); 795 } 796 797 assert(false && "Unknown name kind"); 798 return DeclarationName(); 799} 800 801Sema::DeclTy * 802Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 803 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 804 DeclarationName Name = GetNameForDeclarator(D); 805 806 // All of these full declarators require an identifier. If it doesn't have 807 // one, the ParsedFreeStandingDeclSpec action should be used. 808 if (!Name) { 809 if (!D.getInvalidType()) // Reject this if we think it is valid. 810 Diag(D.getDeclSpec().getSourceRange().getBegin(), 811 diag::err_declarator_need_ident) 812 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 813 return 0; 814 } 815 816 // The scope passed in may not be a decl scope. Zip up the scope tree until 817 // we find one that is. 818 while ((S->getFlags() & Scope::DeclScope) == 0) 819 S = S->getParent(); 820 821 DeclContext *DC; 822 Decl *PrevDecl; 823 ScopedDecl *New; 824 bool InvalidDecl = false; 825 826 // See if this is a redefinition of a variable in the same scope. 827 if (!D.getCXXScopeSpec().isSet()) { 828 DC = CurContext; 829 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S); 830 } else { // Something like "int foo::x;" 831 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 832 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 833 834 // C++ 7.3.1.2p2: 835 // Members (including explicit specializations of templates) of a named 836 // namespace can also be defined outside that namespace by explicit 837 // qualification of the name being defined, provided that the entity being 838 // defined was already declared in the namespace and the definition appears 839 // after the point of declaration in a namespace that encloses the 840 // declarations namespace. 841 // 842 if (PrevDecl == 0) { 843 // No previous declaration in the qualifying scope. 844 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member, 845 Name.getAsString(), D.getCXXScopeSpec().getRange()); 846 } else if (!CurContext->Encloses(DC)) { 847 // The qualifying scope doesn't enclose the original declaration. 848 // Emit diagnostic based on current scope. 849 SourceLocation L = D.getIdentifierLoc(); 850 SourceRange R = D.getCXXScopeSpec().getRange(); 851 if (isa<FunctionDecl>(CurContext)) { 852 Diag(L, diag::err_invalid_declarator_in_function, Name.getAsString(), 853 R); 854 } else { 855 Diag(L, diag::err_invalid_declarator_scope) 856 << Name.getAsString() << cast<NamedDecl>(DC)->getName() << R; 857 } 858 } 859 } 860 861 // In C++, the previous declaration we find might be a tag type 862 // (class or enum). In this case, the new declaration will hide the 863 // tag type. 864 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 865 PrevDecl = 0; 866 867 QualType R = GetTypeForDeclarator(D, S); 868 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 869 870 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 871 // Check that there are no default arguments (C++ only). 872 if (getLangOptions().CPlusPlus) 873 CheckExtraCXXDefaultArguments(D); 874 875 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 876 if (!NewTD) return 0; 877 878 // Handle attributes prior to checking for duplicates in MergeVarDecl 879 ProcessDeclAttributes(NewTD, D); 880 // Merge the decl with the existing one if appropriate. If the decl is 881 // in an outer scope, it isn't the same thing. 882 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 883 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 884 if (NewTD == 0) return 0; 885 } 886 New = NewTD; 887 if (S->getFnParent() == 0) { 888 // C99 6.7.7p2: If a typedef name specifies a variably modified type 889 // then it shall have block scope. 890 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 891 // FIXME: Diagnostic needs to be fixed. 892 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 893 InvalidDecl = true; 894 } 895 } 896 } else if (R.getTypePtr()->isFunctionType()) { 897 FunctionDecl::StorageClass SC = FunctionDecl::None; 898 switch (D.getDeclSpec().getStorageClassSpec()) { 899 default: assert(0 && "Unknown storage class!"); 900 case DeclSpec::SCS_auto: 901 case DeclSpec::SCS_register: 902 case DeclSpec::SCS_mutable: 903 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 904 R.getAsString()); 905 InvalidDecl = true; 906 break; 907 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 908 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 909 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 910 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 911 } 912 913 bool isInline = D.getDeclSpec().isInlineSpecified(); 914 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 915 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 916 917 FunctionDecl *NewFD; 918 if (D.getKind() == Declarator::DK_Constructor) { 919 // This is a C++ constructor declaration. 920 assert(DC->isCXXRecord() && 921 "Constructors can only be declared in a member context"); 922 923 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 924 925 // Create the new declaration 926 NewFD = CXXConstructorDecl::Create(Context, 927 cast<CXXRecordDecl>(DC), 928 D.getIdentifierLoc(), Name, R, 929 isExplicit, isInline, 930 /*isImplicitlyDeclared=*/false); 931 932 if (isInvalidDecl) 933 NewFD->setInvalidDecl(); 934 } else if (D.getKind() == Declarator::DK_Destructor) { 935 // This is a C++ destructor declaration. 936 if (DC->isCXXRecord()) { 937 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 938 939 NewFD = CXXDestructorDecl::Create(Context, 940 cast<CXXRecordDecl>(DC), 941 D.getIdentifierLoc(), Name, R, 942 isInline, 943 /*isImplicitlyDeclared=*/false); 944 945 if (isInvalidDecl) 946 NewFD->setInvalidDecl(); 947 } else { 948 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 949 // Create a FunctionDecl to satisfy the function definition parsing 950 // code path. 951 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 952 Name, R, SC, isInline, LastDeclarator, 953 // FIXME: Move to DeclGroup... 954 D.getDeclSpec().getSourceRange().getBegin()); 955 NewFD->setInvalidDecl(); 956 } 957 } else if (D.getKind() == Declarator::DK_Conversion) { 958 if (!DC->isCXXRecord()) { 959 Diag(D.getIdentifierLoc(), 960 diag::err_conv_function_not_member); 961 return 0; 962 } else { 963 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 964 965 NewFD = CXXConversionDecl::Create(Context, 966 cast<CXXRecordDecl>(DC), 967 D.getIdentifierLoc(), Name, R, 968 isInline, isExplicit); 969 970 if (isInvalidDecl) 971 NewFD->setInvalidDecl(); 972 } 973 } else if (DC->isCXXRecord()) { 974 // This is a C++ method declaration. 975 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 976 D.getIdentifierLoc(), Name, R, 977 (SC == FunctionDecl::Static), isInline, 978 LastDeclarator); 979 } else { 980 NewFD = FunctionDecl::Create(Context, DC, 981 D.getIdentifierLoc(), 982 Name, R, SC, isInline, LastDeclarator, 983 // FIXME: Move to DeclGroup... 984 D.getDeclSpec().getSourceRange().getBegin()); 985 } 986 // Handle attributes. 987 ProcessDeclAttributes(NewFD, D); 988 989 // Handle GNU asm-label extension (encoded as an attribute). 990 if (Expr *E = (Expr*) D.getAsmLabel()) { 991 // The parser guarantees this is a string. 992 StringLiteral *SE = cast<StringLiteral>(E); 993 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 994 SE->getByteLength()))); 995 } 996 997 // Copy the parameter declarations from the declarator D to 998 // the function declaration NewFD, if they are available. 999 if (D.getNumTypeObjects() > 0) { 1000 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1001 1002 // Create Decl objects for each parameter, adding them to the 1003 // FunctionDecl. 1004 llvm::SmallVector<ParmVarDecl*, 16> Params; 1005 1006 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1007 // function that takes no arguments, not a function that takes a 1008 // single void argument. 1009 // We let through "const void" here because Sema::GetTypeForDeclarator 1010 // already checks for that case. 1011 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1012 FTI.ArgInfo[0].Param && 1013 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1014 // empty arg list, don't push any params. 1015 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1016 1017 // In C++, the empty parameter-type-list must be spelled "void"; a 1018 // typedef of void is not permitted. 1019 if (getLangOptions().CPlusPlus && 1020 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1021 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1022 } 1023 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1024 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1025 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1026 } 1027 1028 NewFD->setParams(&Params[0], Params.size()); 1029 } else if (R->getAsTypedefType()) { 1030 // When we're declaring a function with a typedef, as in the 1031 // following example, we'll need to synthesize (unnamed) 1032 // parameters for use in the declaration. 1033 // 1034 // @code 1035 // typedef void fn(int); 1036 // fn f; 1037 // @endcode 1038 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1039 if (!FT) { 1040 // This is a typedef of a function with no prototype, so we 1041 // don't need to do anything. 1042 } else if ((FT->getNumArgs() == 0) || 1043 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1044 FT->getArgType(0)->isVoidType())) { 1045 // This is a zero-argument function. We don't need to do anything. 1046 } else { 1047 // Synthesize a parameter for each argument type. 1048 llvm::SmallVector<ParmVarDecl*, 16> Params; 1049 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1050 ArgType != FT->arg_type_end(); ++ArgType) { 1051 Params.push_back(ParmVarDecl::Create(Context, DC, 1052 SourceLocation(), 0, 1053 *ArgType, VarDecl::None, 1054 0, 0)); 1055 } 1056 1057 NewFD->setParams(&Params[0], Params.size()); 1058 } 1059 } 1060 1061 // C++ constructors and destructors are handled by separate 1062 // routines, since they don't require any declaration merging (C++ 1063 // [class.mfct]p2) and they aren't ever pushed into scope, because 1064 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1065 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1066 return ActOnConstructorDeclarator(Constructor); 1067 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1068 return ActOnDestructorDeclarator(Destructor); 1069 1070 // Extra checking for conversion functions, including recording 1071 // the conversion function in its class. 1072 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1073 ActOnConversionDeclarator(Conversion); 1074 1075 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1076 if (NewFD->isOverloadedOperator() && 1077 CheckOverloadedOperatorDeclaration(NewFD)) 1078 NewFD->setInvalidDecl(); 1079 1080 // Merge the decl with the existing one if appropriate. Since C functions 1081 // are in a flat namespace, make sure we consider decls in outer scopes. 1082 if (PrevDecl && 1083 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1084 bool Redeclaration = false; 1085 1086 // If C++, determine whether NewFD is an overload of PrevDecl or 1087 // a declaration that requires merging. If it's an overload, 1088 // there's no more work to do here; we'll just add the new 1089 // function to the scope. 1090 OverloadedFunctionDecl::function_iterator MatchedDecl; 1091 if (!getLangOptions().CPlusPlus || 1092 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1093 Decl *OldDecl = PrevDecl; 1094 1095 // If PrevDecl was an overloaded function, extract the 1096 // FunctionDecl that matched. 1097 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1098 OldDecl = *MatchedDecl; 1099 1100 // NewFD and PrevDecl represent declarations that need to be 1101 // merged. 1102 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1103 1104 if (NewFD == 0) return 0; 1105 if (Redeclaration) { 1106 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1107 1108 if (OldDecl == PrevDecl) { 1109 // Remove the name binding for the previous 1110 // declaration. We'll add the binding back later, but then 1111 // it will refer to the new declaration (which will 1112 // contain more information). 1113 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1114 } else { 1115 // We need to update the OverloadedFunctionDecl with the 1116 // latest declaration of this function, so that name 1117 // lookup will always refer to the latest declaration of 1118 // this function. 1119 *MatchedDecl = NewFD; 1120 1121 // Add the redeclaration to the current scope, since we'll 1122 // be skipping PushOnScopeChains. 1123 S->AddDecl(NewFD); 1124 1125 return NewFD; 1126 } 1127 } 1128 } 1129 } 1130 New = NewFD; 1131 1132 // In C++, check default arguments now that we have merged decls. 1133 if (getLangOptions().CPlusPlus) 1134 CheckCXXDefaultArguments(NewFD); 1135 } else { 1136 // Check that there are no default arguments (C++ only). 1137 if (getLangOptions().CPlusPlus) 1138 CheckExtraCXXDefaultArguments(D); 1139 1140 if (R.getTypePtr()->isObjCInterfaceType()) { 1141 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object) 1142 << D.getIdentifier(); 1143 InvalidDecl = true; 1144 } 1145 1146 VarDecl *NewVD; 1147 VarDecl::StorageClass SC; 1148 switch (D.getDeclSpec().getStorageClassSpec()) { 1149 default: assert(0 && "Unknown storage class!"); 1150 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1151 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1152 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1153 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1154 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1155 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1156 case DeclSpec::SCS_mutable: 1157 // mutable can only appear on non-static class members, so it's always 1158 // an error here 1159 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1160 InvalidDecl = true; 1161 break; 1162 } 1163 1164 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1165 if (!II) { 1166 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name, 1167 Name.getAsString()); 1168 return 0; 1169 } 1170 1171 if (DC->isCXXRecord()) { 1172 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1173 // This is a static data member for a C++ class. 1174 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1175 D.getIdentifierLoc(), II, 1176 R, LastDeclarator); 1177 } else { 1178 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1179 if (S->getFnParent() == 0) { 1180 // C99 6.9p2: The storage-class specifiers auto and register shall not 1181 // appear in the declaration specifiers in an external declaration. 1182 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1183 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 1184 R.getAsString()); 1185 InvalidDecl = true; 1186 } 1187 } 1188 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1189 II, R, SC, LastDeclarator, 1190 // FIXME: Move to DeclGroup... 1191 D.getDeclSpec().getSourceRange().getBegin()); 1192 NewVD->setThreadSpecified(ThreadSpecified); 1193 } 1194 // Handle attributes prior to checking for duplicates in MergeVarDecl 1195 ProcessDeclAttributes(NewVD, D); 1196 1197 // Handle GNU asm-label extension (encoded as an attribute). 1198 if (Expr *E = (Expr*) D.getAsmLabel()) { 1199 // The parser guarantees this is a string. 1200 StringLiteral *SE = cast<StringLiteral>(E); 1201 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1202 SE->getByteLength()))); 1203 } 1204 1205 // Emit an error if an address space was applied to decl with local storage. 1206 // This includes arrays of objects with address space qualifiers, but not 1207 // automatic variables that point to other address spaces. 1208 // ISO/IEC TR 18037 S5.1.2 1209 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1210 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1211 InvalidDecl = true; 1212 } 1213 // Merge the decl with the existing one if appropriate. If the decl is 1214 // in an outer scope, it isn't the same thing. 1215 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1216 NewVD = MergeVarDecl(NewVD, PrevDecl); 1217 if (NewVD == 0) return 0; 1218 } 1219 New = NewVD; 1220 } 1221 1222 // Set the lexical context. If the declarator has a C++ scope specifier, the 1223 // lexical context will be different from the semantic context. 1224 New->setLexicalDeclContext(CurContext); 1225 1226 // If this has an identifier, add it to the scope stack. 1227 if (Name) 1228 PushOnScopeChains(New, S); 1229 // If any semantic error occurred, mark the decl as invalid. 1230 if (D.getInvalidType() || InvalidDecl) 1231 New->setInvalidDecl(); 1232 1233 return New; 1234} 1235 1236void Sema::InitializerElementNotConstant(const Expr *Init) { 1237 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 1238 << Init->getSourceRange(); 1239} 1240 1241bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1242 switch (Init->getStmtClass()) { 1243 default: 1244 InitializerElementNotConstant(Init); 1245 return true; 1246 case Expr::ParenExprClass: { 1247 const ParenExpr* PE = cast<ParenExpr>(Init); 1248 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1249 } 1250 case Expr::CompoundLiteralExprClass: 1251 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1252 case Expr::DeclRefExprClass: { 1253 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1254 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1255 if (VD->hasGlobalStorage()) 1256 return false; 1257 InitializerElementNotConstant(Init); 1258 return true; 1259 } 1260 if (isa<FunctionDecl>(D)) 1261 return false; 1262 InitializerElementNotConstant(Init); 1263 return true; 1264 } 1265 case Expr::MemberExprClass: { 1266 const MemberExpr *M = cast<MemberExpr>(Init); 1267 if (M->isArrow()) 1268 return CheckAddressConstantExpression(M->getBase()); 1269 return CheckAddressConstantExpressionLValue(M->getBase()); 1270 } 1271 case Expr::ArraySubscriptExprClass: { 1272 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1273 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1274 return CheckAddressConstantExpression(ASE->getBase()) || 1275 CheckArithmeticConstantExpression(ASE->getIdx()); 1276 } 1277 case Expr::StringLiteralClass: 1278 case Expr::PredefinedExprClass: 1279 return false; 1280 case Expr::UnaryOperatorClass: { 1281 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1282 1283 // C99 6.6p9 1284 if (Exp->getOpcode() == UnaryOperator::Deref) 1285 return CheckAddressConstantExpression(Exp->getSubExpr()); 1286 1287 InitializerElementNotConstant(Init); 1288 return true; 1289 } 1290 } 1291} 1292 1293bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1294 switch (Init->getStmtClass()) { 1295 default: 1296 InitializerElementNotConstant(Init); 1297 return true; 1298 case Expr::ParenExprClass: 1299 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1300 case Expr::StringLiteralClass: 1301 case Expr::ObjCStringLiteralClass: 1302 return false; 1303 case Expr::CallExprClass: 1304 case Expr::CXXOperatorCallExprClass: 1305 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1306 if (cast<CallExpr>(Init)->isBuiltinCall() == 1307 Builtin::BI__builtin___CFStringMakeConstantString) 1308 return false; 1309 1310 InitializerElementNotConstant(Init); 1311 return true; 1312 1313 case Expr::UnaryOperatorClass: { 1314 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1315 1316 // C99 6.6p9 1317 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1318 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1319 1320 if (Exp->getOpcode() == UnaryOperator::Extension) 1321 return CheckAddressConstantExpression(Exp->getSubExpr()); 1322 1323 InitializerElementNotConstant(Init); 1324 return true; 1325 } 1326 case Expr::BinaryOperatorClass: { 1327 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1328 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1329 1330 Expr *PExp = Exp->getLHS(); 1331 Expr *IExp = Exp->getRHS(); 1332 if (IExp->getType()->isPointerType()) 1333 std::swap(PExp, IExp); 1334 1335 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1336 return CheckAddressConstantExpression(PExp) || 1337 CheckArithmeticConstantExpression(IExp); 1338 } 1339 case Expr::ImplicitCastExprClass: 1340 case Expr::CStyleCastExprClass: { 1341 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1342 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1343 // Check for implicit promotion 1344 if (SubExpr->getType()->isFunctionType() || 1345 SubExpr->getType()->isArrayType()) 1346 return CheckAddressConstantExpressionLValue(SubExpr); 1347 } 1348 1349 // Check for pointer->pointer cast 1350 if (SubExpr->getType()->isPointerType()) 1351 return CheckAddressConstantExpression(SubExpr); 1352 1353 if (SubExpr->getType()->isIntegralType()) { 1354 // Check for the special-case of a pointer->int->pointer cast; 1355 // this isn't standard, but some code requires it. See 1356 // PR2720 for an example. 1357 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1358 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1359 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1360 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1361 if (IntWidth >= PointerWidth) { 1362 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1363 } 1364 } 1365 } 1366 } 1367 if (SubExpr->getType()->isArithmeticType()) { 1368 return CheckArithmeticConstantExpression(SubExpr); 1369 } 1370 1371 InitializerElementNotConstant(Init); 1372 return true; 1373 } 1374 case Expr::ConditionalOperatorClass: { 1375 // FIXME: Should we pedwarn here? 1376 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1377 if (!Exp->getCond()->getType()->isArithmeticType()) { 1378 InitializerElementNotConstant(Init); 1379 return true; 1380 } 1381 if (CheckArithmeticConstantExpression(Exp->getCond())) 1382 return true; 1383 if (Exp->getLHS() && 1384 CheckAddressConstantExpression(Exp->getLHS())) 1385 return true; 1386 return CheckAddressConstantExpression(Exp->getRHS()); 1387 } 1388 case Expr::AddrLabelExprClass: 1389 return false; 1390 } 1391} 1392 1393static const Expr* FindExpressionBaseAddress(const Expr* E); 1394 1395static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1396 switch (E->getStmtClass()) { 1397 default: 1398 return E; 1399 case Expr::ParenExprClass: { 1400 const ParenExpr* PE = cast<ParenExpr>(E); 1401 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1402 } 1403 case Expr::MemberExprClass: { 1404 const MemberExpr *M = cast<MemberExpr>(E); 1405 if (M->isArrow()) 1406 return FindExpressionBaseAddress(M->getBase()); 1407 return FindExpressionBaseAddressLValue(M->getBase()); 1408 } 1409 case Expr::ArraySubscriptExprClass: { 1410 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1411 return FindExpressionBaseAddress(ASE->getBase()); 1412 } 1413 case Expr::UnaryOperatorClass: { 1414 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1415 1416 if (Exp->getOpcode() == UnaryOperator::Deref) 1417 return FindExpressionBaseAddress(Exp->getSubExpr()); 1418 1419 return E; 1420 } 1421 } 1422} 1423 1424static const Expr* FindExpressionBaseAddress(const Expr* E) { 1425 switch (E->getStmtClass()) { 1426 default: 1427 return E; 1428 case Expr::ParenExprClass: { 1429 const ParenExpr* PE = cast<ParenExpr>(E); 1430 return FindExpressionBaseAddress(PE->getSubExpr()); 1431 } 1432 case Expr::UnaryOperatorClass: { 1433 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1434 1435 // C99 6.6p9 1436 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1437 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1438 1439 if (Exp->getOpcode() == UnaryOperator::Extension) 1440 return FindExpressionBaseAddress(Exp->getSubExpr()); 1441 1442 return E; 1443 } 1444 case Expr::BinaryOperatorClass: { 1445 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1446 1447 Expr *PExp = Exp->getLHS(); 1448 Expr *IExp = Exp->getRHS(); 1449 if (IExp->getType()->isPointerType()) 1450 std::swap(PExp, IExp); 1451 1452 return FindExpressionBaseAddress(PExp); 1453 } 1454 case Expr::ImplicitCastExprClass: { 1455 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1456 1457 // Check for implicit promotion 1458 if (SubExpr->getType()->isFunctionType() || 1459 SubExpr->getType()->isArrayType()) 1460 return FindExpressionBaseAddressLValue(SubExpr); 1461 1462 // Check for pointer->pointer cast 1463 if (SubExpr->getType()->isPointerType()) 1464 return FindExpressionBaseAddress(SubExpr); 1465 1466 // We assume that we have an arithmetic expression here; 1467 // if we don't, we'll figure it out later 1468 return 0; 1469 } 1470 case Expr::CStyleCastExprClass: { 1471 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1472 1473 // Check for pointer->pointer cast 1474 if (SubExpr->getType()->isPointerType()) 1475 return FindExpressionBaseAddress(SubExpr); 1476 1477 // We assume that we have an arithmetic expression here; 1478 // if we don't, we'll figure it out later 1479 return 0; 1480 } 1481 } 1482} 1483 1484bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1485 switch (Init->getStmtClass()) { 1486 default: 1487 InitializerElementNotConstant(Init); 1488 return true; 1489 case Expr::ParenExprClass: { 1490 const ParenExpr* PE = cast<ParenExpr>(Init); 1491 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1492 } 1493 case Expr::FloatingLiteralClass: 1494 case Expr::IntegerLiteralClass: 1495 case Expr::CharacterLiteralClass: 1496 case Expr::ImaginaryLiteralClass: 1497 case Expr::TypesCompatibleExprClass: 1498 case Expr::CXXBoolLiteralExprClass: 1499 return false; 1500 case Expr::CallExprClass: 1501 case Expr::CXXOperatorCallExprClass: { 1502 const CallExpr *CE = cast<CallExpr>(Init); 1503 1504 // Allow any constant foldable calls to builtins. 1505 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1506 return false; 1507 1508 InitializerElementNotConstant(Init); 1509 return true; 1510 } 1511 case Expr::DeclRefExprClass: { 1512 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1513 if (isa<EnumConstantDecl>(D)) 1514 return false; 1515 InitializerElementNotConstant(Init); 1516 return true; 1517 } 1518 case Expr::CompoundLiteralExprClass: 1519 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1520 // but vectors are allowed to be magic. 1521 if (Init->getType()->isVectorType()) 1522 return false; 1523 InitializerElementNotConstant(Init); 1524 return true; 1525 case Expr::UnaryOperatorClass: { 1526 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1527 1528 switch (Exp->getOpcode()) { 1529 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1530 // See C99 6.6p3. 1531 default: 1532 InitializerElementNotConstant(Init); 1533 return true; 1534 case UnaryOperator::OffsetOf: 1535 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1536 return false; 1537 InitializerElementNotConstant(Init); 1538 return true; 1539 case UnaryOperator::Extension: 1540 case UnaryOperator::LNot: 1541 case UnaryOperator::Plus: 1542 case UnaryOperator::Minus: 1543 case UnaryOperator::Not: 1544 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1545 } 1546 } 1547 case Expr::SizeOfAlignOfExprClass: { 1548 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1549 // Special check for void types, which are allowed as an extension 1550 if (Exp->getTypeOfArgument()->isVoidType()) 1551 return false; 1552 // alignof always evaluates to a constant. 1553 // FIXME: is sizeof(int[3.0]) a constant expression? 1554 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1555 InitializerElementNotConstant(Init); 1556 return true; 1557 } 1558 return false; 1559 } 1560 case Expr::BinaryOperatorClass: { 1561 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1562 1563 if (Exp->getLHS()->getType()->isArithmeticType() && 1564 Exp->getRHS()->getType()->isArithmeticType()) { 1565 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1566 CheckArithmeticConstantExpression(Exp->getRHS()); 1567 } 1568 1569 if (Exp->getLHS()->getType()->isPointerType() && 1570 Exp->getRHS()->getType()->isPointerType()) { 1571 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1572 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1573 1574 // Only allow a null (constant integer) base; we could 1575 // allow some additional cases if necessary, but this 1576 // is sufficient to cover offsetof-like constructs. 1577 if (!LHSBase && !RHSBase) { 1578 return CheckAddressConstantExpression(Exp->getLHS()) || 1579 CheckAddressConstantExpression(Exp->getRHS()); 1580 } 1581 } 1582 1583 InitializerElementNotConstant(Init); 1584 return true; 1585 } 1586 case Expr::ImplicitCastExprClass: 1587 case Expr::CStyleCastExprClass: { 1588 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1589 if (SubExpr->getType()->isArithmeticType()) 1590 return CheckArithmeticConstantExpression(SubExpr); 1591 1592 if (SubExpr->getType()->isPointerType()) { 1593 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1594 // If the pointer has a null base, this is an offsetof-like construct 1595 if (!Base) 1596 return CheckAddressConstantExpression(SubExpr); 1597 } 1598 1599 InitializerElementNotConstant(Init); 1600 return true; 1601 } 1602 case Expr::ConditionalOperatorClass: { 1603 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1604 1605 // If GNU extensions are disabled, we require all operands to be arithmetic 1606 // constant expressions. 1607 if (getLangOptions().NoExtensions) { 1608 return CheckArithmeticConstantExpression(Exp->getCond()) || 1609 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1610 CheckArithmeticConstantExpression(Exp->getRHS()); 1611 } 1612 1613 // Otherwise, we have to emulate some of the behavior of fold here. 1614 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1615 // because it can constant fold things away. To retain compatibility with 1616 // GCC code, we see if we can fold the condition to a constant (which we 1617 // should always be able to do in theory). If so, we only require the 1618 // specified arm of the conditional to be a constant. This is a horrible 1619 // hack, but is require by real world code that uses __builtin_constant_p. 1620 APValue Val; 1621 if (!Exp->getCond()->Evaluate(Val, Context)) { 1622 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 1623 // won't be able to either. Use it to emit the diagnostic though. 1624 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1625 assert(Res && "Evaluate couldn't evaluate this constant?"); 1626 return Res; 1627 } 1628 1629 // Verify that the side following the condition is also a constant. 1630 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1631 if (Val.getInt() == 0) 1632 std::swap(TrueSide, FalseSide); 1633 1634 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1635 return true; 1636 1637 // Okay, the evaluated side evaluates to a constant, so we accept this. 1638 // Check to see if the other side is obviously not a constant. If so, 1639 // emit a warning that this is a GNU extension. 1640 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1641 Diag(Init->getExprLoc(), 1642 diag::ext_typecheck_expression_not_constant_but_accepted) 1643 << FalseSide->getSourceRange(); 1644 return false; 1645 } 1646 } 1647} 1648 1649bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1650 Init = Init->IgnoreParens(); 1651 1652 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1653 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1654 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1655 1656 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1657 return CheckForConstantInitializer(e->getInitializer(), DclT); 1658 1659 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1660 unsigned numInits = Exp->getNumInits(); 1661 for (unsigned i = 0; i < numInits; i++) { 1662 // FIXME: Need to get the type of the declaration for C++, 1663 // because it could be a reference? 1664 if (CheckForConstantInitializer(Exp->getInit(i), 1665 Exp->getInit(i)->getType())) 1666 return true; 1667 } 1668 return false; 1669 } 1670 1671 if (Init->isNullPointerConstant(Context)) 1672 return false; 1673 if (Init->getType()->isArithmeticType()) { 1674 QualType InitTy = Context.getCanonicalType(Init->getType()) 1675 .getUnqualifiedType(); 1676 if (InitTy == Context.BoolTy) { 1677 // Special handling for pointers implicitly cast to bool; 1678 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1679 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1680 Expr* SubE = ICE->getSubExpr(); 1681 if (SubE->getType()->isPointerType() || 1682 SubE->getType()->isArrayType() || 1683 SubE->getType()->isFunctionType()) { 1684 return CheckAddressConstantExpression(Init); 1685 } 1686 } 1687 } else if (InitTy->isIntegralType()) { 1688 Expr* SubE = 0; 1689 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1690 SubE = CE->getSubExpr(); 1691 // Special check for pointer cast to int; we allow as an extension 1692 // an address constant cast to an integer if the integer 1693 // is of an appropriate width (this sort of code is apparently used 1694 // in some places). 1695 // FIXME: Add pedwarn? 1696 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1697 if (SubE && (SubE->getType()->isPointerType() || 1698 SubE->getType()->isArrayType() || 1699 SubE->getType()->isFunctionType())) { 1700 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1701 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1702 if (IntWidth >= PointerWidth) 1703 return CheckAddressConstantExpression(Init); 1704 } 1705 } 1706 1707 return CheckArithmeticConstantExpression(Init); 1708 } 1709 1710 if (Init->getType()->isPointerType()) 1711 return CheckAddressConstantExpression(Init); 1712 1713 // An array type at the top level that isn't an init-list must 1714 // be a string literal 1715 if (Init->getType()->isArrayType()) 1716 return false; 1717 1718 if (Init->getType()->isFunctionType()) 1719 return false; 1720 1721 // Allow block exprs at top level. 1722 if (Init->getType()->isBlockPointerType()) 1723 return false; 1724 1725 InitializerElementNotConstant(Init); 1726 return true; 1727} 1728 1729void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1730 Decl *RealDecl = static_cast<Decl *>(dcl); 1731 Expr *Init = static_cast<Expr *>(init); 1732 assert(Init && "missing initializer"); 1733 1734 // If there is no declaration, there was an error parsing it. Just ignore 1735 // the initializer. 1736 if (RealDecl == 0) { 1737 delete Init; 1738 return; 1739 } 1740 1741 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1742 if (!VDecl) { 1743 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1744 diag::err_illegal_initializer); 1745 RealDecl->setInvalidDecl(); 1746 return; 1747 } 1748 // Get the decls type and save a reference for later, since 1749 // CheckInitializerTypes may change it. 1750 QualType DclT = VDecl->getType(), SavT = DclT; 1751 if (VDecl->isBlockVarDecl()) { 1752 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1753 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1754 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1755 VDecl->setInvalidDecl(); 1756 } else if (!VDecl->isInvalidDecl()) { 1757 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1758 VDecl->getName())) 1759 VDecl->setInvalidDecl(); 1760 1761 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1762 if (!getLangOptions().CPlusPlus) { 1763 if (SC == VarDecl::Static) // C99 6.7.8p4. 1764 CheckForConstantInitializer(Init, DclT); 1765 } 1766 } 1767 } else if (VDecl->isFileVarDecl()) { 1768 if (VDecl->getStorageClass() == VarDecl::Extern) 1769 Diag(VDecl->getLocation(), diag::warn_extern_init); 1770 if (!VDecl->isInvalidDecl()) 1771 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1772 VDecl->getName())) 1773 VDecl->setInvalidDecl(); 1774 1775 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1776 if (!getLangOptions().CPlusPlus) { 1777 // C99 6.7.8p4. All file scoped initializers need to be constant. 1778 CheckForConstantInitializer(Init, DclT); 1779 } 1780 } 1781 // If the type changed, it means we had an incomplete type that was 1782 // completed by the initializer. For example: 1783 // int ary[] = { 1, 3, 5 }; 1784 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1785 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1786 VDecl->setType(DclT); 1787 Init->setType(DclT); 1788 } 1789 1790 // Attach the initializer to the decl. 1791 VDecl->setInit(Init); 1792 return; 1793} 1794 1795void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1796 Decl *RealDecl = static_cast<Decl *>(dcl); 1797 1798 // If there is no declaration, there was an error parsing it. Just ignore it. 1799 if (RealDecl == 0) 1800 return; 1801 1802 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1803 QualType Type = Var->getType(); 1804 // C++ [dcl.init.ref]p3: 1805 // The initializer can be omitted for a reference only in a 1806 // parameter declaration (8.3.5), in the declaration of a 1807 // function return type, in the declaration of a class member 1808 // within its class declaration (9.2), and where the extern 1809 // specifier is explicitly used. 1810 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1811 Diag(Var->getLocation(), 1812 diag::err_reference_var_requires_init, 1813 Var->getName(), 1814 SourceRange(Var->getLocation(), Var->getLocation())); 1815 Var->setInvalidDecl(); 1816 return; 1817 } 1818 1819 // C++ [dcl.init]p9: 1820 // 1821 // If no initializer is specified for an object, and the object 1822 // is of (possibly cv-qualified) non-POD class type (or array 1823 // thereof), the object shall be default-initialized; if the 1824 // object is of const-qualified type, the underlying class type 1825 // shall have a user-declared default constructor. 1826 if (getLangOptions().CPlusPlus) { 1827 QualType InitType = Type; 1828 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1829 InitType = Array->getElementType(); 1830 if (InitType->isRecordType()) { 1831 const CXXConstructorDecl *Constructor 1832 = PerformInitializationByConstructor(InitType, 0, 0, 1833 Var->getLocation(), 1834 SourceRange(Var->getLocation(), 1835 Var->getLocation()), 1836 Var->getName(), 1837 IK_Default); 1838 if (!Constructor) 1839 Var->setInvalidDecl(); 1840 } 1841 } 1842 1843#if 0 1844 // FIXME: Temporarily disabled because we are not properly parsing 1845 // linkage specifications on declarations, e.g., 1846 // 1847 // extern "C" const CGPoint CGPointerZero; 1848 // 1849 // C++ [dcl.init]p9: 1850 // 1851 // If no initializer is specified for an object, and the 1852 // object is of (possibly cv-qualified) non-POD class type (or 1853 // array thereof), the object shall be default-initialized; if 1854 // the object is of const-qualified type, the underlying class 1855 // type shall have a user-declared default 1856 // constructor. Otherwise, if no initializer is specified for 1857 // an object, the object and its subobjects, if any, have an 1858 // indeterminate initial value; if the object or any of its 1859 // subobjects are of const-qualified type, the program is 1860 // ill-formed. 1861 // 1862 // This isn't technically an error in C, so we don't diagnose it. 1863 // 1864 // FIXME: Actually perform the POD/user-defined default 1865 // constructor check. 1866 if (getLangOptions().CPlusPlus && 1867 Context.getCanonicalType(Type).isConstQualified() && 1868 Var->getStorageClass() != VarDecl::Extern) 1869 Diag(Var->getLocation(), 1870 diag::err_const_var_requires_init, 1871 Var->getName(), 1872 SourceRange(Var->getLocation(), Var->getLocation())); 1873#endif 1874 } 1875} 1876 1877/// The declarators are chained together backwards, reverse the list. 1878Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1879 // Often we have single declarators, handle them quickly. 1880 Decl *GroupDecl = static_cast<Decl*>(group); 1881 if (GroupDecl == 0) 1882 return 0; 1883 1884 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1885 ScopedDecl *NewGroup = 0; 1886 if (Group->getNextDeclarator() == 0) 1887 NewGroup = Group; 1888 else { // reverse the list. 1889 while (Group) { 1890 ScopedDecl *Next = Group->getNextDeclarator(); 1891 Group->setNextDeclarator(NewGroup); 1892 NewGroup = Group; 1893 Group = Next; 1894 } 1895 } 1896 // Perform semantic analysis that depends on having fully processed both 1897 // the declarator and initializer. 1898 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1899 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1900 if (!IDecl) 1901 continue; 1902 QualType T = IDecl->getType(); 1903 1904 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1905 // static storage duration, it shall not have a variable length array. 1906 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1907 IDecl->getStorageClass() == VarDecl::Static) { 1908 if (T->isVariableArrayType()) { 1909 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1910 IDecl->setInvalidDecl(); 1911 } 1912 } 1913 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1914 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1915 if (IDecl->isBlockVarDecl() && 1916 IDecl->getStorageClass() != VarDecl::Extern) { 1917 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1918 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1919 T.getAsString()); 1920 IDecl->setInvalidDecl(); 1921 } 1922 } 1923 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1924 // object that has file scope without an initializer, and without a 1925 // storage-class specifier or with the storage-class specifier "static", 1926 // constitutes a tentative definition. Note: A tentative definition with 1927 // external linkage is valid (C99 6.2.2p5). 1928 if (isTentativeDefinition(IDecl)) { 1929 if (T->isIncompleteArrayType()) { 1930 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1931 // array to be completed. Don't issue a diagnostic. 1932 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1933 // C99 6.9.2p3: If the declaration of an identifier for an object is 1934 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1935 // declared type shall not be an incomplete type. 1936 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1937 T.getAsString()); 1938 IDecl->setInvalidDecl(); 1939 } 1940 } 1941 if (IDecl->isFileVarDecl()) 1942 CheckForFileScopedRedefinitions(S, IDecl); 1943 } 1944 return NewGroup; 1945} 1946 1947/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1948/// to introduce parameters into function prototype scope. 1949Sema::DeclTy * 1950Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1951 // FIXME: disallow CXXScopeSpec for param declarators. 1952 const DeclSpec &DS = D.getDeclSpec(); 1953 1954 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1955 VarDecl::StorageClass StorageClass = VarDecl::None; 1956 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1957 StorageClass = VarDecl::Register; 1958 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1959 Diag(DS.getStorageClassSpecLoc(), 1960 diag::err_invalid_storage_class_in_func_decl); 1961 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1962 } 1963 if (DS.isThreadSpecified()) { 1964 Diag(DS.getThreadSpecLoc(), 1965 diag::err_invalid_storage_class_in_func_decl); 1966 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1967 } 1968 1969 // Check that there are no default arguments inside the type of this 1970 // parameter (C++ only). 1971 if (getLangOptions().CPlusPlus) 1972 CheckExtraCXXDefaultArguments(D); 1973 1974 // In this context, we *do not* check D.getInvalidType(). If the declarator 1975 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1976 // though it will not reflect the user specified type. 1977 QualType parmDeclType = GetTypeForDeclarator(D, S); 1978 1979 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1980 1981 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1982 // Can this happen for params? We already checked that they don't conflict 1983 // among each other. Here they can only shadow globals, which is ok. 1984 IdentifierInfo *II = D.getIdentifier(); 1985 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1986 if (S->isDeclScope(PrevDecl)) { 1987 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1988 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1989 1990 // Recover by removing the name 1991 II = 0; 1992 D.SetIdentifier(0, D.getIdentifierLoc()); 1993 } 1994 } 1995 1996 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1997 // Doing the promotion here has a win and a loss. The win is the type for 1998 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1999 // code generator). The loss is the orginal type isn't preserved. For example: 2000 // 2001 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2002 // int blockvardecl[5]; 2003 // sizeof(parmvardecl); // size == 4 2004 // sizeof(blockvardecl); // size == 20 2005 // } 2006 // 2007 // For expressions, all implicit conversions are captured using the 2008 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2009 // 2010 // FIXME: If a source translation tool needs to see the original type, then 2011 // we need to consider storing both types (in ParmVarDecl)... 2012 // 2013 if (parmDeclType->isArrayType()) { 2014 // int x[restrict 4] -> int *restrict 2015 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2016 } else if (parmDeclType->isFunctionType()) 2017 parmDeclType = Context.getPointerType(parmDeclType); 2018 2019 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2020 D.getIdentifierLoc(), II, 2021 parmDeclType, StorageClass, 2022 0, 0); 2023 2024 if (D.getInvalidType()) 2025 New->setInvalidDecl(); 2026 2027 if (II) 2028 PushOnScopeChains(New, S); 2029 2030 ProcessDeclAttributes(New, D); 2031 return New; 2032 2033} 2034 2035Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2036 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2037 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2038 "Not a function declarator!"); 2039 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2040 2041 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2042 // for a K&R function. 2043 if (!FTI.hasPrototype) { 2044 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2045 if (FTI.ArgInfo[i].Param == 0) { 2046 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2047 << FTI.ArgInfo[i].Ident; 2048 // Implicitly declare the argument as type 'int' for lack of a better 2049 // type. 2050 DeclSpec DS; 2051 const char* PrevSpec; // unused 2052 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2053 PrevSpec); 2054 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2055 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2056 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2057 } 2058 } 2059 } else { 2060 // FIXME: Diagnose arguments without names in C. 2061 } 2062 2063 Scope *GlobalScope = FnBodyScope->getParent(); 2064 2065 return ActOnStartOfFunctionDef(FnBodyScope, 2066 ActOnDeclarator(GlobalScope, D, 0)); 2067} 2068 2069Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2070 Decl *decl = static_cast<Decl*>(D); 2071 FunctionDecl *FD = cast<FunctionDecl>(decl); 2072 2073 // See if this is a redefinition. 2074 const FunctionDecl *Definition; 2075 if (FD->getBody(Definition)) { 2076 Diag(FD->getLocation(), diag::err_redefinition, 2077 FD->getName()); 2078 Diag(Definition->getLocation(), diag::err_previous_definition); 2079 } 2080 2081 PushDeclContext(FD); 2082 2083 // Check the validity of our function parameters 2084 CheckParmsForFunctionDef(FD); 2085 2086 // Introduce our parameters into the function scope 2087 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2088 ParmVarDecl *Param = FD->getParamDecl(p); 2089 // If this has an identifier, add it to the scope stack. 2090 if (Param->getIdentifier()) 2091 PushOnScopeChains(Param, FnBodyScope); 2092 } 2093 2094 return FD; 2095} 2096 2097Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2098 Decl *dcl = static_cast<Decl *>(D); 2099 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2100 FD->setBody((Stmt*)Body); 2101 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2102 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2103 MD->setBody((Stmt*)Body); 2104 } else 2105 return 0; 2106 PopDeclContext(); 2107 // Verify and clean out per-function state. 2108 2109 // Check goto/label use. 2110 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2111 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2112 // Verify that we have no forward references left. If so, there was a goto 2113 // or address of a label taken, but no definition of it. Label fwd 2114 // definitions are indicated with a null substmt. 2115 if (I->second->getSubStmt() == 0) { 2116 LabelStmt *L = I->second; 2117 // Emit error. 2118 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 2119 2120 // At this point, we have gotos that use the bogus label. Stitch it into 2121 // the function body so that they aren't leaked and that the AST is well 2122 // formed. 2123 if (Body) { 2124 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2125 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2126 } else { 2127 // The whole function wasn't parsed correctly, just delete this. 2128 delete L; 2129 } 2130 } 2131 } 2132 LabelMap.clear(); 2133 2134 return D; 2135} 2136 2137/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2138/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2139ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2140 IdentifierInfo &II, Scope *S) { 2141 // Extension in C99. Legal in C90, but warn about it. 2142 if (getLangOptions().C99) 2143 Diag(Loc, diag::ext_implicit_function_decl) << &II; 2144 else 2145 Diag(Loc, diag::warn_implicit_function_decl) << &II; 2146 2147 // FIXME: handle stuff like: 2148 // void foo() { extern float X(); } 2149 // void bar() { X(); } <-- implicit decl for X in another scope. 2150 2151 // Set a Declarator for the implicit definition: int foo(); 2152 const char *Dummy; 2153 DeclSpec DS; 2154 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2155 Error = Error; // Silence warning. 2156 assert(!Error && "Error setting up implicit decl!"); 2157 Declarator D(DS, Declarator::BlockContext); 2158 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2159 D.SetIdentifier(&II, Loc); 2160 2161 // Insert this function into translation-unit scope. 2162 2163 DeclContext *PrevDC = CurContext; 2164 CurContext = Context.getTranslationUnitDecl(); 2165 2166 FunctionDecl *FD = 2167 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2168 FD->setImplicit(); 2169 2170 CurContext = PrevDC; 2171 2172 return FD; 2173} 2174 2175 2176TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2177 ScopedDecl *LastDeclarator) { 2178 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2179 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2180 2181 // Scope manipulation handled by caller. 2182 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2183 D.getIdentifierLoc(), 2184 D.getIdentifier(), 2185 T, LastDeclarator); 2186 if (D.getInvalidType()) 2187 NewTD->setInvalidDecl(); 2188 return NewTD; 2189} 2190 2191/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2192/// former case, Name will be non-null. In the later case, Name will be null. 2193/// TagType indicates what kind of tag this is. TK indicates whether this is a 2194/// reference/declaration/definition of a tag. 2195Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2196 SourceLocation KWLoc, const CXXScopeSpec &SS, 2197 IdentifierInfo *Name, SourceLocation NameLoc, 2198 AttributeList *Attr) { 2199 // If this is a use of an existing tag, it must have a name. 2200 assert((Name != 0 || TK == TK_Definition) && 2201 "Nameless record must be a definition!"); 2202 2203 TagDecl::TagKind Kind; 2204 switch (TagType) { 2205 default: assert(0 && "Unknown tag type!"); 2206 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2207 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2208 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2209 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2210 } 2211 2212 // Two code paths: a new one for structs/unions/classes where we create 2213 // separate decls for forward declarations, and an old (eventually to 2214 // be removed) code path for enums. 2215 if (Kind != TagDecl::TK_enum) 2216 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2217 2218 DeclContext *DC = CurContext; 2219 ScopedDecl *PrevDecl = 0; 2220 2221 if (Name && SS.isNotEmpty()) { 2222 // We have a nested-name tag ('struct foo::bar'). 2223 2224 // Check for invalid 'foo::'. 2225 if (SS.isInvalid()) { 2226 Name = 0; 2227 goto CreateNewDecl; 2228 } 2229 2230 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2231 // Look-up name inside 'foo::'. 2232 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2233 2234 // A tag 'foo::bar' must already exist. 2235 if (PrevDecl == 0) { 2236 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2237 Name = 0; 2238 goto CreateNewDecl; 2239 } 2240 } else { 2241 // If this is a named struct, check to see if there was a previous forward 2242 // declaration or definition. 2243 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2244 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2245 } 2246 2247 if (PrevDecl) { 2248 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2249 "unexpected Decl type"); 2250 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2251 // If this is a use of a previous tag, or if the tag is already declared 2252 // in the same scope (so that the definition/declaration completes or 2253 // rementions the tag), reuse the decl. 2254 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2255 // Make sure that this wasn't declared as an enum and now used as a 2256 // struct or something similar. 2257 if (PrevTagDecl->getTagKind() != Kind) { 2258 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2259 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2260 // Recover by making this an anonymous redefinition. 2261 Name = 0; 2262 PrevDecl = 0; 2263 } else { 2264 // If this is a use or a forward declaration, we're good. 2265 if (TK != TK_Definition) 2266 return PrevDecl; 2267 2268 // Diagnose attempts to redefine a tag. 2269 if (PrevTagDecl->isDefinition()) { 2270 Diag(NameLoc, diag::err_redefinition) << Name; 2271 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2272 // If this is a redefinition, recover by making this struct be 2273 // anonymous, which will make any later references get the previous 2274 // definition. 2275 Name = 0; 2276 } else { 2277 // Okay, this is definition of a previously declared or referenced 2278 // tag. Move the location of the decl to be the definition site. 2279 PrevDecl->setLocation(NameLoc); 2280 return PrevDecl; 2281 } 2282 } 2283 } 2284 // If we get here, this is a definition of a new struct type in a nested 2285 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2286 // type. 2287 } else { 2288 // PrevDecl is a namespace. 2289 if (isDeclInScope(PrevDecl, DC, S)) { 2290 // The tag name clashes with a namespace name, issue an error and 2291 // recover by making this tag be anonymous. 2292 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2293 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2294 Name = 0; 2295 } 2296 } 2297 } 2298 2299 CreateNewDecl: 2300 2301 // If there is an identifier, use the location of the identifier as the 2302 // location of the decl, otherwise use the location of the struct/union 2303 // keyword. 2304 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2305 2306 // Otherwise, if this is the first time we've seen this tag, create the decl. 2307 TagDecl *New; 2308 if (Kind == TagDecl::TK_enum) { 2309 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2310 // enum X { A, B, C } D; D should chain to X. 2311 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2312 // If this is an undefined enum, warn. 2313 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2314 } else { 2315 // struct/union/class 2316 2317 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2318 // struct X { int A; } D; D should chain to X. 2319 if (getLangOptions().CPlusPlus) 2320 // FIXME: Look for a way to use RecordDecl for simple structs. 2321 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2322 else 2323 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2324 } 2325 2326 // If this has an identifier, add it to the scope stack. 2327 if (Name) { 2328 // The scope passed in may not be a decl scope. Zip up the scope tree until 2329 // we find one that is. 2330 while ((S->getFlags() & Scope::DeclScope) == 0) 2331 S = S->getParent(); 2332 2333 // Add it to the decl chain. 2334 PushOnScopeChains(New, S); 2335 } 2336 2337 if (Attr) 2338 ProcessDeclAttributeList(New, Attr); 2339 2340 // Set the lexical context. If the tag has a C++ scope specifier, the 2341 // lexical context will be different from the semantic context. 2342 New->setLexicalDeclContext(CurContext); 2343 2344 return New; 2345} 2346 2347/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2348/// the logic for enums, we create separate decls for forward declarations. 2349/// This is called by ActOnTag, but eventually will replace its logic. 2350Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2351 SourceLocation KWLoc, const CXXScopeSpec &SS, 2352 IdentifierInfo *Name, SourceLocation NameLoc, 2353 AttributeList *Attr) { 2354 DeclContext *DC = CurContext; 2355 ScopedDecl *PrevDecl = 0; 2356 2357 if (Name && SS.isNotEmpty()) { 2358 // We have a nested-name tag ('struct foo::bar'). 2359 2360 // Check for invalid 'foo::'. 2361 if (SS.isInvalid()) { 2362 Name = 0; 2363 goto CreateNewDecl; 2364 } 2365 2366 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2367 // Look-up name inside 'foo::'. 2368 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2369 2370 // A tag 'foo::bar' must already exist. 2371 if (PrevDecl == 0) { 2372 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2373 Name = 0; 2374 goto CreateNewDecl; 2375 } 2376 } else { 2377 // If this is a named struct, check to see if there was a previous forward 2378 // declaration or definition. 2379 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2380 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2381 } 2382 2383 if (PrevDecl) { 2384 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2385 "unexpected Decl type"); 2386 2387 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2388 // If this is a use of a previous tag, or if the tag is already declared 2389 // in the same scope (so that the definition/declaration completes or 2390 // rementions the tag), reuse the decl. 2391 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2392 // Make sure that this wasn't declared as an enum and now used as a 2393 // struct or something similar. 2394 if (PrevTagDecl->getTagKind() != Kind) { 2395 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2396 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2397 // Recover by making this an anonymous redefinition. 2398 Name = 0; 2399 PrevDecl = 0; 2400 } else { 2401 // If this is a use, return the original decl. 2402 2403 // FIXME: In the future, return a variant or some other clue 2404 // for the consumer of this Decl to know it doesn't own it. 2405 // For our current ASTs this shouldn't be a problem, but will 2406 // need to be changed with DeclGroups. 2407 if (TK == TK_Reference) 2408 return PrevDecl; 2409 2410 // The new decl is a definition? 2411 if (TK == TK_Definition) { 2412 // Diagnose attempts to redefine a tag. 2413 if (RecordDecl* DefRecord = 2414 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2415 Diag(NameLoc, diag::err_redefinition) << Name; 2416 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2417 // If this is a redefinition, recover by making this struct be 2418 // anonymous, which will make any later references get the previous 2419 // definition. 2420 Name = 0; 2421 PrevDecl = 0; 2422 } 2423 // Okay, this is definition of a previously declared or referenced 2424 // tag. We're going to create a new Decl. 2425 } 2426 } 2427 // If we get here we have (another) forward declaration. Just create 2428 // a new decl. 2429 } 2430 else { 2431 // If we get here, this is a definition of a new struct type in a nested 2432 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2433 // new decl/type. We set PrevDecl to NULL so that the Records 2434 // have distinct types. 2435 PrevDecl = 0; 2436 } 2437 } else { 2438 // PrevDecl is a namespace. 2439 if (isDeclInScope(PrevDecl, DC, S)) { 2440 // The tag name clashes with a namespace name, issue an error and 2441 // recover by making this tag be anonymous. 2442 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2443 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2444 Name = 0; 2445 } 2446 } 2447 } 2448 2449 CreateNewDecl: 2450 2451 // If there is an identifier, use the location of the identifier as the 2452 // location of the decl, otherwise use the location of the struct/union 2453 // keyword. 2454 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2455 2456 // Otherwise, if this is the first time we've seen this tag, create the decl. 2457 TagDecl *New; 2458 2459 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2460 // struct X { int A; } D; D should chain to X. 2461 if (getLangOptions().CPlusPlus) 2462 // FIXME: Look for a way to use RecordDecl for simple structs. 2463 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2464 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2465 else 2466 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2467 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2468 2469 // If this has an identifier, add it to the scope stack. 2470 if ((TK == TK_Definition || !PrevDecl) && Name) { 2471 // The scope passed in may not be a decl scope. Zip up the scope tree until 2472 // we find one that is. 2473 while ((S->getFlags() & Scope::DeclScope) == 0) 2474 S = S->getParent(); 2475 2476 // Add it to the decl chain. 2477 PushOnScopeChains(New, S); 2478 } 2479 2480 // Handle #pragma pack: if the #pragma pack stack has non-default 2481 // alignment, make up a packed attribute for this decl. These 2482 // attributes are checked when the ASTContext lays out the 2483 // structure. 2484 // 2485 // It is important for implementing the correct semantics that this 2486 // happen here (in act on tag decl). The #pragma pack stack is 2487 // maintained as a result of parser callbacks which can occur at 2488 // many points during the parsing of a struct declaration (because 2489 // the #pragma tokens are effectively skipped over during the 2490 // parsing of the struct). 2491 if (unsigned Alignment = PackContext.getAlignment()) 2492 New->addAttr(new PackedAttr(Alignment * 8)); 2493 2494 if (Attr) 2495 ProcessDeclAttributeList(New, Attr); 2496 2497 // Set the lexical context. If the tag has a C++ scope specifier, the 2498 // lexical context will be different from the semantic context. 2499 New->setLexicalDeclContext(CurContext); 2500 2501 return New; 2502} 2503 2504 2505/// Collect the instance variables declared in an Objective-C object. Used in 2506/// the creation of structures from objects using the @defs directive. 2507static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2508 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2509 if (Class->getSuperClass()) 2510 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2511 2512 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2513 for (ObjCInterfaceDecl::ivar_iterator 2514 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2515 2516 ObjCIvarDecl* ID = *I; 2517 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2518 ID->getIdentifier(), 2519 ID->getType(), 2520 ID->getBitWidth())); 2521 } 2522} 2523 2524/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2525/// instance variables of ClassName into Decls. 2526void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2527 IdentifierInfo *ClassName, 2528 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2529 // Check that ClassName is a valid class 2530 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2531 if (!Class) { 2532 Diag(DeclStart, diag::err_undef_interface) << ClassName; 2533 return; 2534 } 2535 // Collect the instance variables 2536 CollectIvars(Class, Context, Decls); 2537} 2538 2539/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2540/// types into constant array types in certain situations which would otherwise 2541/// be errors (for GCC compatibility). 2542static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2543 ASTContext &Context) { 2544 // This method tries to turn a variable array into a constant 2545 // array even when the size isn't an ICE. This is necessary 2546 // for compatibility with code that depends on gcc's buggy 2547 // constant expression folding, like struct {char x[(int)(char*)2];} 2548 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2549 if (!VLATy) return QualType(); 2550 2551 APValue Result; 2552 if (!VLATy->getSizeExpr() || 2553 !VLATy->getSizeExpr()->Evaluate(Result, Context)) 2554 return QualType(); 2555 2556 assert(Result.isInt() && "Size expressions must be integers!"); 2557 llvm::APSInt &Res = Result.getInt(); 2558 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2559 return Context.getConstantArrayType(VLATy->getElementType(), 2560 Res, ArrayType::Normal, 0); 2561 return QualType(); 2562} 2563 2564/// ActOnField - Each field of a struct/union/class is passed into this in order 2565/// to create a FieldDecl object for it. 2566Sema::DeclTy *Sema::ActOnField(Scope *S, 2567 SourceLocation DeclStart, 2568 Declarator &D, ExprTy *BitfieldWidth) { 2569 IdentifierInfo *II = D.getIdentifier(); 2570 Expr *BitWidth = (Expr*)BitfieldWidth; 2571 SourceLocation Loc = DeclStart; 2572 if (II) Loc = D.getIdentifierLoc(); 2573 2574 // FIXME: Unnamed fields can be handled in various different ways, for 2575 // example, unnamed unions inject all members into the struct namespace! 2576 2577 if (BitWidth) { 2578 // TODO: Validate. 2579 //printf("WARNING: BITFIELDS IGNORED!\n"); 2580 2581 // 6.7.2.1p3 2582 // 6.7.2.1p4 2583 2584 } else { 2585 // Not a bitfield. 2586 2587 // validate II. 2588 2589 } 2590 2591 QualType T = GetTypeForDeclarator(D, S); 2592 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2593 bool InvalidDecl = false; 2594 2595 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2596 // than a variably modified type. 2597 if (T->isVariablyModifiedType()) { 2598 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2599 if (!FixedTy.isNull()) { 2600 Diag(Loc, diag::warn_illegal_constant_array_size); 2601 T = FixedTy; 2602 } else { 2603 Diag(Loc, diag::err_typecheck_field_variable_size); 2604 T = Context.IntTy; 2605 InvalidDecl = true; 2606 } 2607 } 2608 // FIXME: Chain fielddecls together. 2609 FieldDecl *NewFD; 2610 2611 if (getLangOptions().CPlusPlus) { 2612 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2613 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2614 Loc, II, T, 2615 D.getDeclSpec().getStorageClassSpec() == 2616 DeclSpec::SCS_mutable, BitWidth); 2617 if (II) 2618 PushOnScopeChains(NewFD, S); 2619 } 2620 else 2621 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2622 2623 ProcessDeclAttributes(NewFD, D); 2624 2625 if (D.getInvalidType() || InvalidDecl) 2626 NewFD->setInvalidDecl(); 2627 return NewFD; 2628} 2629 2630/// TranslateIvarVisibility - Translate visibility from a token ID to an 2631/// AST enum value. 2632static ObjCIvarDecl::AccessControl 2633TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2634 switch (ivarVisibility) { 2635 default: assert(0 && "Unknown visitibility kind"); 2636 case tok::objc_private: return ObjCIvarDecl::Private; 2637 case tok::objc_public: return ObjCIvarDecl::Public; 2638 case tok::objc_protected: return ObjCIvarDecl::Protected; 2639 case tok::objc_package: return ObjCIvarDecl::Package; 2640 } 2641} 2642 2643/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2644/// in order to create an IvarDecl object for it. 2645Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2646 SourceLocation DeclStart, 2647 Declarator &D, ExprTy *BitfieldWidth, 2648 tok::ObjCKeywordKind Visibility) { 2649 IdentifierInfo *II = D.getIdentifier(); 2650 Expr *BitWidth = (Expr*)BitfieldWidth; 2651 SourceLocation Loc = DeclStart; 2652 if (II) Loc = D.getIdentifierLoc(); 2653 2654 // FIXME: Unnamed fields can be handled in various different ways, for 2655 // example, unnamed unions inject all members into the struct namespace! 2656 2657 2658 if (BitWidth) { 2659 // TODO: Validate. 2660 //printf("WARNING: BITFIELDS IGNORED!\n"); 2661 2662 // 6.7.2.1p3 2663 // 6.7.2.1p4 2664 2665 } else { 2666 // Not a bitfield. 2667 2668 // validate II. 2669 2670 } 2671 2672 QualType T = GetTypeForDeclarator(D, S); 2673 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2674 bool InvalidDecl = false; 2675 2676 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2677 // than a variably modified type. 2678 if (T->isVariablyModifiedType()) { 2679 // FIXME: This diagnostic needs work 2680 Diag(Loc, diag::err_typecheck_illegal_vla) << SourceRange(Loc); 2681 InvalidDecl = true; 2682 } 2683 2684 // Get the visibility (access control) for this ivar. 2685 ObjCIvarDecl::AccessControl ac = 2686 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2687 : ObjCIvarDecl::None; 2688 2689 // Construct the decl. 2690 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2691 (Expr *)BitfieldWidth); 2692 2693 // Process attributes attached to the ivar. 2694 ProcessDeclAttributes(NewID, D); 2695 2696 if (D.getInvalidType() || InvalidDecl) 2697 NewID->setInvalidDecl(); 2698 2699 return NewID; 2700} 2701 2702void Sema::ActOnFields(Scope* S, 2703 SourceLocation RecLoc, DeclTy *RecDecl, 2704 DeclTy **Fields, unsigned NumFields, 2705 SourceLocation LBrac, SourceLocation RBrac, 2706 AttributeList *Attr) { 2707 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2708 assert(EnclosingDecl && "missing record or interface decl"); 2709 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2710 2711 if (Record) 2712 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2713 // Diagnose code like: 2714 // struct S { struct S {} X; }; 2715 // We discover this when we complete the outer S. Reject and ignore the 2716 // outer S. 2717 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2718 DefRecord->getKindName()); 2719 Diag(RecLoc, diag::err_previous_definition); 2720 Record->setInvalidDecl(); 2721 return; 2722 } 2723 2724 // Verify that all the fields are okay. 2725 unsigned NumNamedMembers = 0; 2726 llvm::SmallVector<FieldDecl*, 32> RecFields; 2727 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2728 2729 for (unsigned i = 0; i != NumFields; ++i) { 2730 2731 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2732 assert(FD && "missing field decl"); 2733 2734 // Remember all fields. 2735 RecFields.push_back(FD); 2736 2737 // Get the type for the field. 2738 Type *FDTy = FD->getType().getTypePtr(); 2739 2740 // C99 6.7.2.1p2 - A field may not be a function type. 2741 if (FDTy->isFunctionType()) { 2742 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2743 FD->getName()); 2744 FD->setInvalidDecl(); 2745 EnclosingDecl->setInvalidDecl(); 2746 continue; 2747 } 2748 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2749 if (FDTy->isIncompleteType()) { 2750 if (!Record) { // Incomplete ivar type is always an error. 2751 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2752 FD->setInvalidDecl(); 2753 EnclosingDecl->setInvalidDecl(); 2754 continue; 2755 } 2756 if (i != NumFields-1 || // ... that the last member ... 2757 !Record->isStruct() || // ... of a structure ... 2758 !FDTy->isArrayType()) { //... may have incomplete array type. 2759 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2760 FD->setInvalidDecl(); 2761 EnclosingDecl->setInvalidDecl(); 2762 continue; 2763 } 2764 if (NumNamedMembers < 1) { //... must have more than named member ... 2765 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2766 FD->getName()); 2767 FD->setInvalidDecl(); 2768 EnclosingDecl->setInvalidDecl(); 2769 continue; 2770 } 2771 // Okay, we have a legal flexible array member at the end of the struct. 2772 if (Record) 2773 Record->setHasFlexibleArrayMember(true); 2774 } 2775 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2776 /// field of another structure or the element of an array. 2777 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2778 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2779 // If this is a member of a union, then entire union becomes "flexible". 2780 if (Record && Record->isUnion()) { 2781 Record->setHasFlexibleArrayMember(true); 2782 } else { 2783 // If this is a struct/class and this is not the last element, reject 2784 // it. Note that GCC supports variable sized arrays in the middle of 2785 // structures. 2786 if (i != NumFields-1) { 2787 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2788 FD->getName()); 2789 FD->setInvalidDecl(); 2790 EnclosingDecl->setInvalidDecl(); 2791 continue; 2792 } 2793 // We support flexible arrays at the end of structs in other structs 2794 // as an extension. 2795 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2796 FD->getName()); 2797 if (Record) 2798 Record->setHasFlexibleArrayMember(true); 2799 } 2800 } 2801 } 2802 /// A field cannot be an Objective-c object 2803 if (FDTy->isObjCInterfaceType()) { 2804 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2805 FD->getName()); 2806 FD->setInvalidDecl(); 2807 EnclosingDecl->setInvalidDecl(); 2808 continue; 2809 } 2810 // Keep track of the number of named members. 2811 if (IdentifierInfo *II = FD->getIdentifier()) { 2812 // Detect duplicate member names. 2813 if (!FieldIDs.insert(II)) { 2814 Diag(FD->getLocation(), diag::err_duplicate_member) << II; 2815 // Find the previous decl. 2816 SourceLocation PrevLoc; 2817 for (unsigned i = 0; ; ++i) { 2818 assert(i != RecFields.size() && "Didn't find previous def!"); 2819 if (RecFields[i]->getIdentifier() == II) { 2820 PrevLoc = RecFields[i]->getLocation(); 2821 break; 2822 } 2823 } 2824 Diag(PrevLoc, diag::err_previous_definition); 2825 FD->setInvalidDecl(); 2826 EnclosingDecl->setInvalidDecl(); 2827 continue; 2828 } 2829 ++NumNamedMembers; 2830 } 2831 } 2832 2833 // Okay, we successfully defined 'Record'. 2834 if (Record) { 2835 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2836 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2837 // Sema::ActOnFinishCXXClassDef. 2838 if (!isa<CXXRecordDecl>(Record)) 2839 Consumer.HandleTagDeclDefinition(Record); 2840 } else { 2841 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2842 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2843 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2844 else if (ObjCImplementationDecl *IMPDecl = 2845 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2846 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2847 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2848 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2849 } 2850 } 2851 2852 if (Attr) 2853 ProcessDeclAttributeList(Record, Attr); 2854} 2855 2856Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2857 DeclTy *lastEnumConst, 2858 SourceLocation IdLoc, IdentifierInfo *Id, 2859 SourceLocation EqualLoc, ExprTy *val) { 2860 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2861 EnumConstantDecl *LastEnumConst = 2862 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2863 Expr *Val = static_cast<Expr*>(val); 2864 2865 // The scope passed in may not be a decl scope. Zip up the scope tree until 2866 // we find one that is. 2867 while ((S->getFlags() & Scope::DeclScope) == 0) 2868 S = S->getParent(); 2869 2870 // Verify that there isn't already something declared with this name in this 2871 // scope. 2872 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2873 // When in C++, we may get a TagDecl with the same name; in this case the 2874 // enum constant will 'hide' the tag. 2875 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2876 "Received TagDecl when not in C++!"); 2877 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2878 if (isa<EnumConstantDecl>(PrevDecl)) 2879 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 2880 else 2881 Diag(IdLoc, diag::err_redefinition) << Id; 2882 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2883 delete Val; 2884 return 0; 2885 } 2886 } 2887 2888 llvm::APSInt EnumVal(32); 2889 QualType EltTy; 2890 if (Val) { 2891 // Make sure to promote the operand type to int. 2892 UsualUnaryConversions(Val); 2893 2894 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2895 SourceLocation ExpLoc; 2896 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2897 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr) << Id; 2898 delete Val; 2899 Val = 0; // Just forget about it. 2900 } else { 2901 EltTy = Val->getType(); 2902 } 2903 } 2904 2905 if (!Val) { 2906 if (LastEnumConst) { 2907 // Assign the last value + 1. 2908 EnumVal = LastEnumConst->getInitVal(); 2909 ++EnumVal; 2910 2911 // Check for overflow on increment. 2912 if (EnumVal < LastEnumConst->getInitVal()) 2913 Diag(IdLoc, diag::warn_enum_value_overflow); 2914 2915 EltTy = LastEnumConst->getType(); 2916 } else { 2917 // First value, set to zero. 2918 EltTy = Context.IntTy; 2919 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2920 } 2921 } 2922 2923 EnumConstantDecl *New = 2924 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2925 Val, EnumVal, 2926 LastEnumConst); 2927 2928 // Register this decl in the current scope stack. 2929 PushOnScopeChains(New, S); 2930 return New; 2931} 2932 2933// FIXME: For consistency with ActOnFields(), we should have the parser 2934// pass in the source location for the left/right braces. 2935void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2936 DeclTy **Elements, unsigned NumElements) { 2937 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2938 2939 if (Enum && Enum->isDefinition()) { 2940 // Diagnose code like: 2941 // enum e0 { 2942 // E0 = sizeof(enum e0 { E1 }) 2943 // }; 2944 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2945 Enum->getName()); 2946 Diag(EnumLoc, diag::err_previous_definition); 2947 Enum->setInvalidDecl(); 2948 return; 2949 } 2950 // TODO: If the result value doesn't fit in an int, it must be a long or long 2951 // long value. ISO C does not support this, but GCC does as an extension, 2952 // emit a warning. 2953 unsigned IntWidth = Context.Target.getIntWidth(); 2954 2955 // Verify that all the values are okay, compute the size of the values, and 2956 // reverse the list. 2957 unsigned NumNegativeBits = 0; 2958 unsigned NumPositiveBits = 0; 2959 2960 // Keep track of whether all elements have type int. 2961 bool AllElementsInt = true; 2962 2963 EnumConstantDecl *EltList = 0; 2964 for (unsigned i = 0; i != NumElements; ++i) { 2965 EnumConstantDecl *ECD = 2966 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2967 if (!ECD) continue; // Already issued a diagnostic. 2968 2969 // If the enum value doesn't fit in an int, emit an extension warning. 2970 const llvm::APSInt &InitVal = ECD->getInitVal(); 2971 assert(InitVal.getBitWidth() >= IntWidth && 2972 "Should have promoted value to int"); 2973 if (InitVal.getBitWidth() > IntWidth) { 2974 llvm::APSInt V(InitVal); 2975 V.trunc(IntWidth); 2976 V.extend(InitVal.getBitWidth()); 2977 if (V != InitVal) 2978 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2979 InitVal.toString(10)); 2980 } 2981 2982 // Keep track of the size of positive and negative values. 2983 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2984 NumPositiveBits = std::max(NumPositiveBits, 2985 (unsigned)InitVal.getActiveBits()); 2986 else 2987 NumNegativeBits = std::max(NumNegativeBits, 2988 (unsigned)InitVal.getMinSignedBits()); 2989 2990 // Keep track of whether every enum element has type int (very commmon). 2991 if (AllElementsInt) 2992 AllElementsInt = ECD->getType() == Context.IntTy; 2993 2994 ECD->setNextDeclarator(EltList); 2995 EltList = ECD; 2996 } 2997 2998 // Figure out the type that should be used for this enum. 2999 // FIXME: Support attribute(packed) on enums and -fshort-enums. 3000 QualType BestType; 3001 unsigned BestWidth; 3002 3003 if (NumNegativeBits) { 3004 // If there is a negative value, figure out the smallest integer type (of 3005 // int/long/longlong) that fits. 3006 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 3007 BestType = Context.IntTy; 3008 BestWidth = IntWidth; 3009 } else { 3010 BestWidth = Context.Target.getLongWidth(); 3011 3012 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 3013 BestType = Context.LongTy; 3014 else { 3015 BestWidth = Context.Target.getLongLongWidth(); 3016 3017 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 3018 Diag(Enum->getLocation(), diag::warn_enum_too_large); 3019 BestType = Context.LongLongTy; 3020 } 3021 } 3022 } else { 3023 // If there is no negative value, figure out which of uint, ulong, ulonglong 3024 // fits. 3025 if (NumPositiveBits <= IntWidth) { 3026 BestType = Context.UnsignedIntTy; 3027 BestWidth = IntWidth; 3028 } else if (NumPositiveBits <= 3029 (BestWidth = Context.Target.getLongWidth())) { 3030 BestType = Context.UnsignedLongTy; 3031 } else { 3032 BestWidth = Context.Target.getLongLongWidth(); 3033 assert(NumPositiveBits <= BestWidth && 3034 "How could an initializer get larger than ULL?"); 3035 BestType = Context.UnsignedLongLongTy; 3036 } 3037 } 3038 3039 // Loop over all of the enumerator constants, changing their types to match 3040 // the type of the enum if needed. 3041 for (unsigned i = 0; i != NumElements; ++i) { 3042 EnumConstantDecl *ECD = 3043 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3044 if (!ECD) continue; // Already issued a diagnostic. 3045 3046 // Standard C says the enumerators have int type, but we allow, as an 3047 // extension, the enumerators to be larger than int size. If each 3048 // enumerator value fits in an int, type it as an int, otherwise type it the 3049 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 3050 // that X has type 'int', not 'unsigned'. 3051 if (ECD->getType() == Context.IntTy) { 3052 // Make sure the init value is signed. 3053 llvm::APSInt IV = ECD->getInitVal(); 3054 IV.setIsSigned(true); 3055 ECD->setInitVal(IV); 3056 continue; // Already int type. 3057 } 3058 3059 // Determine whether the value fits into an int. 3060 llvm::APSInt InitVal = ECD->getInitVal(); 3061 bool FitsInInt; 3062 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3063 FitsInInt = InitVal.getActiveBits() < IntWidth; 3064 else 3065 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3066 3067 // If it fits into an integer type, force it. Otherwise force it to match 3068 // the enum decl type. 3069 QualType NewTy; 3070 unsigned NewWidth; 3071 bool NewSign; 3072 if (FitsInInt) { 3073 NewTy = Context.IntTy; 3074 NewWidth = IntWidth; 3075 NewSign = true; 3076 } else if (ECD->getType() == BestType) { 3077 // Already the right type! 3078 continue; 3079 } else { 3080 NewTy = BestType; 3081 NewWidth = BestWidth; 3082 NewSign = BestType->isSignedIntegerType(); 3083 } 3084 3085 // Adjust the APSInt value. 3086 InitVal.extOrTrunc(NewWidth); 3087 InitVal.setIsSigned(NewSign); 3088 ECD->setInitVal(InitVal); 3089 3090 // Adjust the Expr initializer and type. 3091 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3092 /*isLvalue=*/false)); 3093 ECD->setType(NewTy); 3094 } 3095 3096 Enum->defineElements(EltList, BestType); 3097 Consumer.HandleTagDeclDefinition(Enum); 3098} 3099 3100Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3101 ExprTy *expr) { 3102 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3103 3104 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3105} 3106 3107Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3108 SourceLocation LBrace, 3109 SourceLocation RBrace, 3110 const char *Lang, 3111 unsigned StrSize, 3112 DeclTy *D) { 3113 LinkageSpecDecl::LanguageIDs Language; 3114 Decl *dcl = static_cast<Decl *>(D); 3115 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3116 Language = LinkageSpecDecl::lang_c; 3117 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3118 Language = LinkageSpecDecl::lang_cxx; 3119 else { 3120 Diag(Loc, diag::err_bad_language); 3121 return 0; 3122 } 3123 3124 // FIXME: Add all the various semantics of linkage specifications 3125 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3126} 3127 3128void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3129 ExprTy *alignment, SourceLocation PragmaLoc, 3130 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3131 Expr *Alignment = static_cast<Expr *>(alignment); 3132 3133 // If specified then alignment must be a "small" power of two. 3134 unsigned AlignmentVal = 0; 3135 if (Alignment) { 3136 llvm::APSInt Val; 3137 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3138 !Val.isPowerOf2() || 3139 Val.getZExtValue() > 16) { 3140 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3141 delete Alignment; 3142 return; // Ignore 3143 } 3144 3145 AlignmentVal = (unsigned) Val.getZExtValue(); 3146 } 3147 3148 switch (Kind) { 3149 case Action::PPK_Default: // pack([n]) 3150 PackContext.setAlignment(AlignmentVal); 3151 break; 3152 3153 case Action::PPK_Show: // pack(show) 3154 // Show the current alignment, making sure to show the right value 3155 // for the default. 3156 AlignmentVal = PackContext.getAlignment(); 3157 // FIXME: This should come from the target. 3158 if (AlignmentVal == 0) 3159 AlignmentVal = 8; 3160 Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 3161 break; 3162 3163 case Action::PPK_Push: // pack(push [, id] [, [n]) 3164 PackContext.push(Name); 3165 // Set the new alignment if specified. 3166 if (Alignment) 3167 PackContext.setAlignment(AlignmentVal); 3168 break; 3169 3170 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3171 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3172 // "#pragma pack(pop, identifier, n) is undefined" 3173 if (Alignment && Name) 3174 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3175 3176 // Do the pop. 3177 if (!PackContext.pop(Name)) { 3178 // If a name was specified then failure indicates the name 3179 // wasn't found. Otherwise failure indicates the stack was 3180 // empty. 3181 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed, 3182 Name ? "no record matching name" : "stack empty"); 3183 3184 // FIXME: Warn about popping named records as MSVC does. 3185 } else { 3186 // Pop succeeded, set the new alignment if specified. 3187 if (Alignment) 3188 PackContext.setAlignment(AlignmentVal); 3189 } 3190 break; 3191 3192 default: 3193 assert(0 && "Invalid #pragma pack kind."); 3194 } 3195} 3196 3197bool PragmaPackStack::pop(IdentifierInfo *Name) { 3198 if (Stack.empty()) 3199 return false; 3200 3201 // If name is empty just pop top. 3202 if (!Name) { 3203 Alignment = Stack.back().first; 3204 Stack.pop_back(); 3205 return true; 3206 } 3207 3208 // Otherwise, find the named record. 3209 for (unsigned i = Stack.size(); i != 0; ) { 3210 --i; 3211 if (Stack[i].second == Name) { 3212 // Found it, pop up to and including this record. 3213 Alignment = Stack[i].first; 3214 Stack.erase(Stack.begin() + i, Stack.end()); 3215 return true; 3216 } 3217 } 3218 3219 return false; 3220} 3221