SemaDecl.cpp revision 011bb4edf731d529da1cbf71c7c2696aaf5a054f
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 // C++ [dcl.typedef]p2: 348 // In a given non-class scope, a typedef specifier can be used to 349 // redefine the name of any type declared in that scope to refer 350 // to the type to which it already refers. 351 if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext)) 352 return New; 353 354 // In C, redeclaration of a type is a constraint violation (6.7.2.3p1). 355 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 356 // *either* declaration is in a system header. The code below implements 357 // this adhoc compatibility rule. FIXME: The following code will not 358 // work properly when compiling ".i" files (containing preprocessed output). 359 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 360 SourceManager &SrcMgr = Context.getSourceManager(); 361 if (SrcMgr.isInSystemHeader(Old->getLocation())) 362 return New; 363 if (SrcMgr.isInSystemHeader(New->getLocation())) 364 return New; 365 } 366 367 Diag(New->getLocation(), diag::err_redefinition) << New->getName(); 368 Diag(Old->getLocation(), diag::err_previous_definition); 369 return New; 370} 371 372/// DeclhasAttr - returns true if decl Declaration already has the target 373/// attribute. 374static bool DeclHasAttr(const Decl *decl, const Attr *target) { 375 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 376 if (attr->getKind() == target->getKind()) 377 return true; 378 379 return false; 380} 381 382/// MergeAttributes - append attributes from the Old decl to the New one. 383static void MergeAttributes(Decl *New, Decl *Old) { 384 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 385 386 while (attr) { 387 tmp = attr; 388 attr = attr->getNext(); 389 390 if (!DeclHasAttr(New, tmp)) { 391 New->addAttr(tmp); 392 } else { 393 tmp->setNext(0); 394 delete(tmp); 395 } 396 } 397 398 Old->invalidateAttrs(); 399} 400 401/// MergeFunctionDecl - We just parsed a function 'New' from 402/// declarator D which has the same name and scope as a previous 403/// declaration 'Old'. Figure out how to resolve this situation, 404/// merging decls or emitting diagnostics as appropriate. 405/// Redeclaration will be set true if this New is a redeclaration OldD. 406/// 407/// In C++, New and Old must be declarations that are not 408/// overloaded. Use IsOverload to determine whether New and Old are 409/// overloaded, and to select the Old declaration that New should be 410/// merged with. 411FunctionDecl * 412Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 413 assert(!isa<OverloadedFunctionDecl>(OldD) && 414 "Cannot merge with an overloaded function declaration"); 415 416 Redeclaration = false; 417 // Verify the old decl was also a function. 418 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 419 if (!Old) { 420 Diag(New->getLocation(), diag::err_redefinition_different_kind) 421 << New->getName(); 422 Diag(OldD->getLocation(), diag::err_previous_definition); 423 return New; 424 } 425 426 // Determine whether the previous declaration was a definition, 427 // implicit declaration, or a declaration. 428 diag::kind PrevDiag; 429 if (Old->isThisDeclarationADefinition()) 430 PrevDiag = diag::err_previous_definition; 431 else if (Old->isImplicit()) 432 PrevDiag = diag::err_previous_implicit_declaration; 433 else 434 PrevDiag = diag::err_previous_declaration; 435 436 QualType OldQType = Context.getCanonicalType(Old->getType()); 437 QualType NewQType = Context.getCanonicalType(New->getType()); 438 439 if (getLangOptions().CPlusPlus) { 440 // (C++98 13.1p2): 441 // Certain function declarations cannot be overloaded: 442 // -- Function declarations that differ only in the return type 443 // cannot be overloaded. 444 QualType OldReturnType 445 = cast<FunctionType>(OldQType.getTypePtr())->getResultType(); 446 QualType NewReturnType 447 = cast<FunctionType>(NewQType.getTypePtr())->getResultType(); 448 if (OldReturnType != NewReturnType) { 449 Diag(New->getLocation(), diag::err_ovl_diff_return_type); 450 Diag(Old->getLocation(), PrevDiag); 451 return New; 452 } 453 454 const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 455 const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 456 if (OldMethod && NewMethod) { 457 // -- Member function declarations with the same name and the 458 // same parameter types cannot be overloaded if any of them 459 // is a static member function declaration. 460 if (OldMethod->isStatic() || NewMethod->isStatic()) { 461 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); 462 Diag(Old->getLocation(), PrevDiag); 463 return New; 464 } 465 } 466 467 // (C++98 8.3.5p3): 468 // All declarations for a function shall agree exactly in both the 469 // return type and the parameter-type-list. 470 if (OldQType == NewQType) { 471 // We have a redeclaration. 472 MergeAttributes(New, Old); 473 Redeclaration = true; 474 return MergeCXXFunctionDecl(New, Old); 475 } 476 477 // Fall through for conflicting redeclarations and redefinitions. 478 } 479 480 // C: Function types need to be compatible, not identical. This handles 481 // duplicate function decls like "void f(int); void f(enum X);" properly. 482 if (!getLangOptions().CPlusPlus && 483 Context.typesAreCompatible(OldQType, NewQType)) { 484 MergeAttributes(New, Old); 485 Redeclaration = true; 486 return New; 487 } 488 489 // A function that has already been declared has been redeclared or defined 490 // with a different type- show appropriate diagnostic 491 492 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 493 // TODO: This is totally simplistic. It should handle merging functions 494 // together etc, merging extern int X; int X; ... 495 Diag(New->getLocation(), diag::err_conflicting_types) << New->getName(); 496 Diag(Old->getLocation(), PrevDiag); 497 return New; 498} 499 500/// Predicate for C "tentative" external object definitions (C99 6.9.2). 501static bool isTentativeDefinition(VarDecl *VD) { 502 if (VD->isFileVarDecl()) 503 return (!VD->getInit() && 504 (VD->getStorageClass() == VarDecl::None || 505 VD->getStorageClass() == VarDecl::Static)); 506 return false; 507} 508 509/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 510/// when dealing with C "tentative" external object definitions (C99 6.9.2). 511void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 512 bool VDIsTentative = isTentativeDefinition(VD); 513 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 514 515 for (IdentifierResolver::iterator 516 I = IdResolver.begin(VD->getIdentifier(), 517 VD->getDeclContext(), false/*LookInParentCtx*/), 518 E = IdResolver.end(); I != E; ++I) { 519 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 520 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 521 522 // Handle the following case: 523 // int a[10]; 524 // int a[]; - the code below makes sure we set the correct type. 525 // int a[11]; - this is an error, size isn't 10. 526 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 527 OldDecl->getType()->isConstantArrayType()) 528 VD->setType(OldDecl->getType()); 529 530 // Check for "tentative" definitions. We can't accomplish this in 531 // MergeVarDecl since the initializer hasn't been attached. 532 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 533 continue; 534 535 // Handle __private_extern__ just like extern. 536 if (OldDecl->getStorageClass() != VarDecl::Extern && 537 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 538 VD->getStorageClass() != VarDecl::Extern && 539 VD->getStorageClass() != VarDecl::PrivateExtern) { 540 Diag(VD->getLocation(), diag::err_redefinition) << VD->getName(); 541 Diag(OldDecl->getLocation(), diag::err_previous_definition); 542 } 543 } 544 } 545} 546 547/// MergeVarDecl - We just parsed a variable 'New' which has the same name 548/// and scope as a previous declaration 'Old'. Figure out how to resolve this 549/// situation, merging decls or emitting diagnostics as appropriate. 550/// 551/// Tentative definition rules (C99 6.9.2p2) are checked by 552/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 553/// definitions here, since the initializer hasn't been attached. 554/// 555VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 556 // Verify the old decl was also a variable. 557 VarDecl *Old = dyn_cast<VarDecl>(OldD); 558 if (!Old) { 559 Diag(New->getLocation(), diag::err_redefinition_different_kind) 560 << New->getName(); 561 Diag(OldD->getLocation(), diag::err_previous_definition); 562 return New; 563 } 564 565 MergeAttributes(New, Old); 566 567 // Verify the types match. 568 QualType OldCType = Context.getCanonicalType(Old->getType()); 569 QualType NewCType = Context.getCanonicalType(New->getType()); 570 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 571 Diag(New->getLocation(), diag::err_redefinition) << New->getName(); 572 Diag(Old->getLocation(), diag::err_previous_definition); 573 return New; 574 } 575 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 576 if (New->getStorageClass() == VarDecl::Static && 577 (Old->getStorageClass() == VarDecl::None || 578 Old->getStorageClass() == VarDecl::Extern)) { 579 Diag(New->getLocation(), diag::err_static_non_static) << New->getName(); 580 Diag(Old->getLocation(), diag::err_previous_definition); 581 return New; 582 } 583 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 584 if (New->getStorageClass() != VarDecl::Static && 585 Old->getStorageClass() == VarDecl::Static) { 586 Diag(New->getLocation(), diag::err_non_static_static) << New->getName(); 587 Diag(Old->getLocation(), diag::err_previous_definition); 588 return New; 589 } 590 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 591 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 592 Diag(New->getLocation(), diag::err_redefinition) << New->getName(); 593 Diag(Old->getLocation(), diag::err_previous_definition); 594 } 595 return New; 596} 597 598/// CheckParmsForFunctionDef - Check that the parameters of the given 599/// function are appropriate for the definition of a function. This 600/// takes care of any checks that cannot be performed on the 601/// declaration itself, e.g., that the types of each of the function 602/// parameters are complete. 603bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 604 bool HasInvalidParm = false; 605 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 606 ParmVarDecl *Param = FD->getParamDecl(p); 607 608 // C99 6.7.5.3p4: the parameters in a parameter type list in a 609 // function declarator that is part of a function definition of 610 // that function shall not have incomplete type. 611 if (Param->getType()->isIncompleteType() && 612 !Param->isInvalidDecl()) { 613 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type) 614 << Param->getType().getAsString(); 615 Param->setInvalidDecl(); 616 HasInvalidParm = true; 617 } 618 } 619 620 return HasInvalidParm; 621} 622 623/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 624/// no declarator (e.g. "struct foo;") is parsed. 625Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 626 // TODO: emit error on 'int;' or 'const enum foo;'. 627 // TODO: emit error on 'typedef int;' 628 // if (!DS.isMissingDeclaratorOk()) Diag(...); 629 630 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 631} 632 633bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 634 // Get the type before calling CheckSingleAssignmentConstraints(), since 635 // it can promote the expression. 636 QualType InitType = Init->getType(); 637 638 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 639 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 640 InitType, Init, "initializing"); 641} 642 643bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 644 const ArrayType *AT = Context.getAsArrayType(DeclT); 645 646 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 647 // C99 6.7.8p14. We have an array of character type with unknown size 648 // being initialized to a string literal. 649 llvm::APSInt ConstVal(32); 650 ConstVal = strLiteral->getByteLength() + 1; 651 // Return a new array type (C99 6.7.8p22). 652 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 653 ArrayType::Normal, 0); 654 } else { 655 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 656 // C99 6.7.8p14. We have an array of character type with known size. 657 // FIXME: Avoid truncation for 64-bit length strings. 658 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 659 Diag(strLiteral->getSourceRange().getBegin(), 660 diag::warn_initializer_string_for_char_array_too_long) 661 << strLiteral->getSourceRange(); 662 } 663 // Set type from "char *" to "constant array of char". 664 strLiteral->setType(DeclT); 665 // For now, we always return false (meaning success). 666 return false; 667} 668 669StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 670 const ArrayType *AT = Context.getAsArrayType(DeclType); 671 if (AT && AT->getElementType()->isCharType()) { 672 return dyn_cast<StringLiteral>(Init); 673 } 674 return 0; 675} 676 677bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 678 SourceLocation InitLoc, 679 std::string InitEntity) { 680 // C++ [dcl.init.ref]p1: 681 // A variable declared to be a T&, that is “reference to type T” 682 // (8.3.2), shall be initialized by an object, or function, of 683 // type T or by an object that can be converted into a T. 684 if (DeclType->isReferenceType()) 685 return CheckReferenceInit(Init, DeclType); 686 687 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 688 // of unknown size ("[]") or an object type that is not a variable array type. 689 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 690 return Diag(InitLoc, diag::err_variable_object_no_init) 691 << VAT->getSizeExpr()->getSourceRange(); 692 693 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 694 if (!InitList) { 695 // FIXME: Handle wide strings 696 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 697 return CheckStringLiteralInit(strLiteral, DeclType); 698 699 // C++ [dcl.init]p14: 700 // -- If the destination type is a (possibly cv-qualified) class 701 // type: 702 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 703 QualType DeclTypeC = Context.getCanonicalType(DeclType); 704 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 705 706 // -- If the initialization is direct-initialization, or if it is 707 // copy-initialization where the cv-unqualified version of the 708 // source type is the same class as, or a derived class of, the 709 // class of the destination, constructors are considered. 710 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 711 IsDerivedFrom(InitTypeC, DeclTypeC)) { 712 CXXConstructorDecl *Constructor 713 = PerformInitializationByConstructor(DeclType, &Init, 1, 714 InitLoc, Init->getSourceRange(), 715 InitEntity, IK_Copy); 716 return Constructor == 0; 717 } 718 719 // -- Otherwise (i.e., for the remaining copy-initialization 720 // cases), user-defined conversion sequences that can 721 // convert from the source type to the destination type or 722 // (when a conversion function is used) to a derived class 723 // thereof are enumerated as described in 13.3.1.4, and the 724 // best one is chosen through overload resolution 725 // (13.3). If the conversion cannot be done or is 726 // ambiguous, the initialization is ill-formed. The 727 // function selected is called with the initializer 728 // expression as its argument; if the function is a 729 // constructor, the call initializes a temporary of the 730 // destination type. 731 // FIXME: We're pretending to do copy elision here; return to 732 // this when we have ASTs for such things. 733 if (!PerformImplicitConversion(Init, DeclType)) 734 return false; 735 736 return Diag(InitLoc, diag::err_typecheck_convert_incompatible) 737 << DeclType.getAsString() << InitEntity << "initializing" 738 << Init->getSourceRange(); 739 } 740 741 // C99 6.7.8p16. 742 if (DeclType->isArrayType()) 743 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 744 << Init->getSourceRange(); 745 746 return CheckSingleInitializer(Init, DeclType); 747 } else if (getLangOptions().CPlusPlus) { 748 // C++ [dcl.init]p14: 749 // [...] If the class is an aggregate (8.5.1), and the initializer 750 // is a brace-enclosed list, see 8.5.1. 751 // 752 // Note: 8.5.1 is handled below; here, we diagnose the case where 753 // we have an initializer list and a destination type that is not 754 // an aggregate. 755 // FIXME: In C++0x, this is yet another form of initialization. 756 if (const RecordType *ClassRec = DeclType->getAsRecordType()) { 757 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl()); 758 if (!ClassDecl->isAggregate()) 759 return Diag(InitLoc, diag::err_init_non_aggr_init_list) 760 << DeclType.getAsString() << Init->getSourceRange(); 761 } 762 } 763 764 InitListChecker CheckInitList(this, InitList, DeclType); 765 return CheckInitList.HadError(); 766} 767 768/// GetNameForDeclarator - Determine the full declaration name for the 769/// given Declarator. 770DeclarationName Sema::GetNameForDeclarator(Declarator &D) { 771 switch (D.getKind()) { 772 case Declarator::DK_Abstract: 773 assert(D.getIdentifier() == 0 && "abstract declarators have no name"); 774 return DeclarationName(); 775 776 case Declarator::DK_Normal: 777 assert (D.getIdentifier() != 0 && "normal declarators have an identifier"); 778 return DeclarationName(D.getIdentifier()); 779 780 case Declarator::DK_Constructor: { 781 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 782 Ty = Context.getCanonicalType(Ty); 783 return Context.DeclarationNames.getCXXConstructorName(Ty); 784 } 785 786 case Declarator::DK_Destructor: { 787 QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType()); 788 Ty = Context.getCanonicalType(Ty); 789 return Context.DeclarationNames.getCXXDestructorName(Ty); 790 } 791 792 case Declarator::DK_Conversion: { 793 QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType()); 794 Ty = Context.getCanonicalType(Ty); 795 return Context.DeclarationNames.getCXXConversionFunctionName(Ty); 796 } 797 798 case Declarator::DK_Operator: 799 assert(D.getIdentifier() == 0 && "operator names have no identifier"); 800 return Context.DeclarationNames.getCXXOperatorName( 801 D.getOverloadedOperator()); 802 } 803 804 assert(false && "Unknown name kind"); 805 return DeclarationName(); 806} 807 808Sema::DeclTy * 809Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 810 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 811 DeclarationName Name = GetNameForDeclarator(D); 812 813 // All of these full declarators require an identifier. If it doesn't have 814 // one, the ParsedFreeStandingDeclSpec action should be used. 815 if (!Name) { 816 if (!D.getInvalidType()) // Reject this if we think it is valid. 817 Diag(D.getDeclSpec().getSourceRange().getBegin(), 818 diag::err_declarator_need_ident) 819 << D.getDeclSpec().getSourceRange() << D.getSourceRange(); 820 return 0; 821 } 822 823 // The scope passed in may not be a decl scope. Zip up the scope tree until 824 // we find one that is. 825 while ((S->getFlags() & Scope::DeclScope) == 0) 826 S = S->getParent(); 827 828 DeclContext *DC; 829 Decl *PrevDecl; 830 ScopedDecl *New; 831 bool InvalidDecl = false; 832 833 // See if this is a redefinition of a variable in the same scope. 834 if (!D.getCXXScopeSpec().isSet()) { 835 DC = CurContext; 836 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S); 837 } else { // Something like "int foo::x;" 838 DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep()); 839 PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC); 840 841 // C++ 7.3.1.2p2: 842 // Members (including explicit specializations of templates) of a named 843 // namespace can also be defined outside that namespace by explicit 844 // qualification of the name being defined, provided that the entity being 845 // defined was already declared in the namespace and the definition appears 846 // after the point of declaration in a namespace that encloses the 847 // declarations namespace. 848 // 849 if (PrevDecl == 0) { 850 // No previous declaration in the qualifying scope. 851 Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member) 852 << Name.getAsString() << D.getCXXScopeSpec().getRange(); 853 } else if (!CurContext->Encloses(DC)) { 854 // The qualifying scope doesn't enclose the original declaration. 855 // Emit diagnostic based on current scope. 856 SourceLocation L = D.getIdentifierLoc(); 857 SourceRange R = D.getCXXScopeSpec().getRange(); 858 if (isa<FunctionDecl>(CurContext)) { 859 Diag(L, diag::err_invalid_declarator_in_function) << Name << R; 860 } else { 861 Diag(L, diag::err_invalid_declarator_scope) 862 << Name.getAsString() << cast<NamedDecl>(DC)->getName() << R; 863 } 864 } 865 } 866 867 // In C++, the previous declaration we find might be a tag type 868 // (class or enum). In this case, the new declaration will hide the 869 // tag type. 870 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 871 PrevDecl = 0; 872 873 QualType R = GetTypeForDeclarator(D, S); 874 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 875 876 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 877 // Check that there are no default arguments (C++ only). 878 if (getLangOptions().CPlusPlus) 879 CheckExtraCXXDefaultArguments(D); 880 881 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 882 if (!NewTD) return 0; 883 884 // Handle attributes prior to checking for duplicates in MergeVarDecl 885 ProcessDeclAttributes(NewTD, D); 886 // Merge the decl with the existing one if appropriate. If the decl is 887 // in an outer scope, it isn't the same thing. 888 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 889 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 890 if (NewTD == 0) return 0; 891 } 892 New = NewTD; 893 if (S->getFnParent() == 0) { 894 // C99 6.7.7p2: If a typedef name specifies a variably modified type 895 // then it shall have block scope. 896 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 897 // FIXME: Diagnostic needs to be fixed. 898 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 899 InvalidDecl = true; 900 } 901 } 902 } else if (R.getTypePtr()->isFunctionType()) { 903 FunctionDecl::StorageClass SC = FunctionDecl::None; 904 switch (D.getDeclSpec().getStorageClassSpec()) { 905 default: assert(0 && "Unknown storage class!"); 906 case DeclSpec::SCS_auto: 907 case DeclSpec::SCS_register: 908 case DeclSpec::SCS_mutable: 909 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func) 910 << R.getAsString(); 911 InvalidDecl = true; 912 break; 913 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 914 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 915 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 916 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 917 } 918 919 bool isInline = D.getDeclSpec().isInlineSpecified(); 920 // bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 921 bool isExplicit = D.getDeclSpec().isExplicitSpecified(); 922 923 FunctionDecl *NewFD; 924 if (D.getKind() == Declarator::DK_Constructor) { 925 // This is a C++ constructor declaration. 926 assert(DC->isCXXRecord() && 927 "Constructors can only be declared in a member context"); 928 929 bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC); 930 931 // Create the new declaration 932 NewFD = CXXConstructorDecl::Create(Context, 933 cast<CXXRecordDecl>(DC), 934 D.getIdentifierLoc(), Name, R, 935 isExplicit, isInline, 936 /*isImplicitlyDeclared=*/false); 937 938 if (isInvalidDecl) 939 NewFD->setInvalidDecl(); 940 } else if (D.getKind() == Declarator::DK_Destructor) { 941 // This is a C++ destructor declaration. 942 if (DC->isCXXRecord()) { 943 bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC); 944 945 NewFD = CXXDestructorDecl::Create(Context, 946 cast<CXXRecordDecl>(DC), 947 D.getIdentifierLoc(), Name, R, 948 isInline, 949 /*isImplicitlyDeclared=*/false); 950 951 if (isInvalidDecl) 952 NewFD->setInvalidDecl(); 953 } else { 954 Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); 955 // Create a FunctionDecl to satisfy the function definition parsing 956 // code path. 957 NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(), 958 Name, R, SC, isInline, LastDeclarator, 959 // FIXME: Move to DeclGroup... 960 D.getDeclSpec().getSourceRange().getBegin()); 961 NewFD->setInvalidDecl(); 962 } 963 } else if (D.getKind() == Declarator::DK_Conversion) { 964 if (!DC->isCXXRecord()) { 965 Diag(D.getIdentifierLoc(), 966 diag::err_conv_function_not_member); 967 return 0; 968 } else { 969 bool isInvalidDecl = CheckConversionDeclarator(D, R, SC); 970 971 NewFD = CXXConversionDecl::Create(Context, 972 cast<CXXRecordDecl>(DC), 973 D.getIdentifierLoc(), Name, R, 974 isInline, isExplicit); 975 976 if (isInvalidDecl) 977 NewFD->setInvalidDecl(); 978 } 979 } else if (DC->isCXXRecord()) { 980 // This is a C++ method declaration. 981 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC), 982 D.getIdentifierLoc(), Name, R, 983 (SC == FunctionDecl::Static), isInline, 984 LastDeclarator); 985 } else { 986 NewFD = FunctionDecl::Create(Context, DC, 987 D.getIdentifierLoc(), 988 Name, R, SC, isInline, LastDeclarator, 989 // FIXME: Move to DeclGroup... 990 D.getDeclSpec().getSourceRange().getBegin()); 991 } 992 // Handle attributes. 993 ProcessDeclAttributes(NewFD, D); 994 995 // Handle GNU asm-label extension (encoded as an attribute). 996 if (Expr *E = (Expr*) D.getAsmLabel()) { 997 // The parser guarantees this is a string. 998 StringLiteral *SE = cast<StringLiteral>(E); 999 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1000 SE->getByteLength()))); 1001 } 1002 1003 // Copy the parameter declarations from the declarator D to 1004 // the function declaration NewFD, if they are available. 1005 if (D.getNumTypeObjects() > 0) { 1006 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1007 1008 // Create Decl objects for each parameter, adding them to the 1009 // FunctionDecl. 1010 llvm::SmallVector<ParmVarDecl*, 16> Params; 1011 1012 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 1013 // function that takes no arguments, not a function that takes a 1014 // single void argument. 1015 // We let through "const void" here because Sema::GetTypeForDeclarator 1016 // already checks for that case. 1017 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 1018 FTI.ArgInfo[0].Param && 1019 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 1020 // empty arg list, don't push any params. 1021 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 1022 1023 // In C++, the empty parameter-type-list must be spelled "void"; a 1024 // typedef of void is not permitted. 1025 if (getLangOptions().CPlusPlus && 1026 Param->getType().getUnqualifiedType() != Context.VoidTy) { 1027 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 1028 } 1029 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 1030 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 1031 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 1032 } 1033 1034 NewFD->setParams(&Params[0], Params.size()); 1035 } else if (R->getAsTypedefType()) { 1036 // When we're declaring a function with a typedef, as in the 1037 // following example, we'll need to synthesize (unnamed) 1038 // parameters for use in the declaration. 1039 // 1040 // @code 1041 // typedef void fn(int); 1042 // fn f; 1043 // @endcode 1044 const FunctionTypeProto *FT = R->getAsFunctionTypeProto(); 1045 if (!FT) { 1046 // This is a typedef of a function with no prototype, so we 1047 // don't need to do anything. 1048 } else if ((FT->getNumArgs() == 0) || 1049 (FT->getNumArgs() == 1 && !FT->isVariadic() && 1050 FT->getArgType(0)->isVoidType())) { 1051 // This is a zero-argument function. We don't need to do anything. 1052 } else { 1053 // Synthesize a parameter for each argument type. 1054 llvm::SmallVector<ParmVarDecl*, 16> Params; 1055 for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin(); 1056 ArgType != FT->arg_type_end(); ++ArgType) { 1057 Params.push_back(ParmVarDecl::Create(Context, DC, 1058 SourceLocation(), 0, 1059 *ArgType, VarDecl::None, 1060 0, 0)); 1061 } 1062 1063 NewFD->setParams(&Params[0], Params.size()); 1064 } 1065 } 1066 1067 // C++ constructors and destructors are handled by separate 1068 // routines, since they don't require any declaration merging (C++ 1069 // [class.mfct]p2) and they aren't ever pushed into scope, because 1070 // they can't be found by name lookup anyway (C++ [class.ctor]p2). 1071 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) 1072 return ActOnConstructorDeclarator(Constructor); 1073 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD)) 1074 return ActOnDestructorDeclarator(Destructor); 1075 1076 // Extra checking for conversion functions, including recording 1077 // the conversion function in its class. 1078 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 1079 ActOnConversionDeclarator(Conversion); 1080 1081 // Extra checking for C++ overloaded operators (C++ [over.oper]). 1082 if (NewFD->isOverloadedOperator() && 1083 CheckOverloadedOperatorDeclaration(NewFD)) 1084 NewFD->setInvalidDecl(); 1085 1086 // Merge the decl with the existing one if appropriate. Since C functions 1087 // are in a flat namespace, make sure we consider decls in outer scopes. 1088 if (PrevDecl && 1089 (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, DC, S))) { 1090 bool Redeclaration = false; 1091 1092 // If C++, determine whether NewFD is an overload of PrevDecl or 1093 // a declaration that requires merging. If it's an overload, 1094 // there's no more work to do here; we'll just add the new 1095 // function to the scope. 1096 OverloadedFunctionDecl::function_iterator MatchedDecl; 1097 if (!getLangOptions().CPlusPlus || 1098 !IsOverload(NewFD, PrevDecl, MatchedDecl)) { 1099 Decl *OldDecl = PrevDecl; 1100 1101 // If PrevDecl was an overloaded function, extract the 1102 // FunctionDecl that matched. 1103 if (isa<OverloadedFunctionDecl>(PrevDecl)) 1104 OldDecl = *MatchedDecl; 1105 1106 // NewFD and PrevDecl represent declarations that need to be 1107 // merged. 1108 NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration); 1109 1110 if (NewFD == 0) return 0; 1111 if (Redeclaration) { 1112 NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl)); 1113 1114 if (OldDecl == PrevDecl) { 1115 // Remove the name binding for the previous 1116 // declaration. We'll add the binding back later, but then 1117 // it will refer to the new declaration (which will 1118 // contain more information). 1119 IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl)); 1120 } else { 1121 // We need to update the OverloadedFunctionDecl with the 1122 // latest declaration of this function, so that name 1123 // lookup will always refer to the latest declaration of 1124 // this function. 1125 *MatchedDecl = NewFD; 1126 1127 // Add the redeclaration to the current scope, since we'll 1128 // be skipping PushOnScopeChains. 1129 S->AddDecl(NewFD); 1130 1131 return NewFD; 1132 } 1133 } 1134 } 1135 } 1136 New = NewFD; 1137 1138 // In C++, check default arguments now that we have merged decls. 1139 if (getLangOptions().CPlusPlus) 1140 CheckCXXDefaultArguments(NewFD); 1141 } else { 1142 // Check that there are no default arguments (C++ only). 1143 if (getLangOptions().CPlusPlus) 1144 CheckExtraCXXDefaultArguments(D); 1145 1146 if (R.getTypePtr()->isObjCInterfaceType()) { 1147 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object) 1148 << D.getIdentifier(); 1149 InvalidDecl = true; 1150 } 1151 1152 VarDecl *NewVD; 1153 VarDecl::StorageClass SC; 1154 switch (D.getDeclSpec().getStorageClassSpec()) { 1155 default: assert(0 && "Unknown storage class!"); 1156 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 1157 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 1158 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 1159 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 1160 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 1161 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 1162 case DeclSpec::SCS_mutable: 1163 // mutable can only appear on non-static class members, so it's always 1164 // an error here 1165 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); 1166 InvalidDecl = true; 1167 break; 1168 } 1169 1170 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1171 if (!II) { 1172 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) 1173 << Name.getAsString(); 1174 return 0; 1175 } 1176 1177 if (DC->isCXXRecord()) { 1178 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 1179 // This is a static data member for a C++ class. 1180 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC), 1181 D.getIdentifierLoc(), II, 1182 R, LastDeclarator); 1183 } else { 1184 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 1185 if (S->getFnParent() == 0) { 1186 // C99 6.9p2: The storage-class specifiers auto and register shall not 1187 // appear in the declaration specifiers in an external declaration. 1188 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 1189 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope) 1190 << R.getAsString(); 1191 InvalidDecl = true; 1192 } 1193 } 1194 NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(), 1195 II, R, SC, LastDeclarator, 1196 // FIXME: Move to DeclGroup... 1197 D.getDeclSpec().getSourceRange().getBegin()); 1198 NewVD->setThreadSpecified(ThreadSpecified); 1199 } 1200 // Handle attributes prior to checking for duplicates in MergeVarDecl 1201 ProcessDeclAttributes(NewVD, D); 1202 1203 // Handle GNU asm-label extension (encoded as an attribute). 1204 if (Expr *E = (Expr*) D.getAsmLabel()) { 1205 // The parser guarantees this is a string. 1206 StringLiteral *SE = cast<StringLiteral>(E); 1207 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 1208 SE->getByteLength()))); 1209 } 1210 1211 // Emit an error if an address space was applied to decl with local storage. 1212 // This includes arrays of objects with address space qualifiers, but not 1213 // automatic variables that point to other address spaces. 1214 // ISO/IEC TR 18037 S5.1.2 1215 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 1216 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 1217 InvalidDecl = true; 1218 } 1219 // Merge the decl with the existing one if appropriate. If the decl is 1220 // in an outer scope, it isn't the same thing. 1221 if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) { 1222 NewVD = MergeVarDecl(NewVD, PrevDecl); 1223 if (NewVD == 0) return 0; 1224 } 1225 New = NewVD; 1226 } 1227 1228 // Set the lexical context. If the declarator has a C++ scope specifier, the 1229 // lexical context will be different from the semantic context. 1230 New->setLexicalDeclContext(CurContext); 1231 1232 // If this has an identifier, add it to the scope stack. 1233 if (Name) 1234 PushOnScopeChains(New, S); 1235 // If any semantic error occurred, mark the decl as invalid. 1236 if (D.getInvalidType() || InvalidDecl) 1237 New->setInvalidDecl(); 1238 1239 return New; 1240} 1241 1242void Sema::InitializerElementNotConstant(const Expr *Init) { 1243 Diag(Init->getExprLoc(), diag::err_init_element_not_constant) 1244 << Init->getSourceRange(); 1245} 1246 1247bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 1248 switch (Init->getStmtClass()) { 1249 default: 1250 InitializerElementNotConstant(Init); 1251 return true; 1252 case Expr::ParenExprClass: { 1253 const ParenExpr* PE = cast<ParenExpr>(Init); 1254 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 1255 } 1256 case Expr::CompoundLiteralExprClass: 1257 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 1258 case Expr::DeclRefExprClass: { 1259 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1260 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 1261 if (VD->hasGlobalStorage()) 1262 return false; 1263 InitializerElementNotConstant(Init); 1264 return true; 1265 } 1266 if (isa<FunctionDecl>(D)) 1267 return false; 1268 InitializerElementNotConstant(Init); 1269 return true; 1270 } 1271 case Expr::MemberExprClass: { 1272 const MemberExpr *M = cast<MemberExpr>(Init); 1273 if (M->isArrow()) 1274 return CheckAddressConstantExpression(M->getBase()); 1275 return CheckAddressConstantExpressionLValue(M->getBase()); 1276 } 1277 case Expr::ArraySubscriptExprClass: { 1278 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 1279 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 1280 return CheckAddressConstantExpression(ASE->getBase()) || 1281 CheckArithmeticConstantExpression(ASE->getIdx()); 1282 } 1283 case Expr::StringLiteralClass: 1284 case Expr::PredefinedExprClass: 1285 return false; 1286 case Expr::UnaryOperatorClass: { 1287 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1288 1289 // C99 6.6p9 1290 if (Exp->getOpcode() == UnaryOperator::Deref) 1291 return CheckAddressConstantExpression(Exp->getSubExpr()); 1292 1293 InitializerElementNotConstant(Init); 1294 return true; 1295 } 1296 } 1297} 1298 1299bool Sema::CheckAddressConstantExpression(const Expr* Init) { 1300 switch (Init->getStmtClass()) { 1301 default: 1302 InitializerElementNotConstant(Init); 1303 return true; 1304 case Expr::ParenExprClass: 1305 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 1306 case Expr::StringLiteralClass: 1307 case Expr::ObjCStringLiteralClass: 1308 return false; 1309 case Expr::CallExprClass: 1310 case Expr::CXXOperatorCallExprClass: 1311 // __builtin___CFStringMakeConstantString is a valid constant l-value. 1312 if (cast<CallExpr>(Init)->isBuiltinCall() == 1313 Builtin::BI__builtin___CFStringMakeConstantString) 1314 return false; 1315 1316 InitializerElementNotConstant(Init); 1317 return true; 1318 1319 case Expr::UnaryOperatorClass: { 1320 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1321 1322 // C99 6.6p9 1323 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1324 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 1325 1326 if (Exp->getOpcode() == UnaryOperator::Extension) 1327 return CheckAddressConstantExpression(Exp->getSubExpr()); 1328 1329 InitializerElementNotConstant(Init); 1330 return true; 1331 } 1332 case Expr::BinaryOperatorClass: { 1333 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 1334 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1335 1336 Expr *PExp = Exp->getLHS(); 1337 Expr *IExp = Exp->getRHS(); 1338 if (IExp->getType()->isPointerType()) 1339 std::swap(PExp, IExp); 1340 1341 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 1342 return CheckAddressConstantExpression(PExp) || 1343 CheckArithmeticConstantExpression(IExp); 1344 } 1345 case Expr::ImplicitCastExprClass: 1346 case Expr::CStyleCastExprClass: { 1347 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1348 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 1349 // Check for implicit promotion 1350 if (SubExpr->getType()->isFunctionType() || 1351 SubExpr->getType()->isArrayType()) 1352 return CheckAddressConstantExpressionLValue(SubExpr); 1353 } 1354 1355 // Check for pointer->pointer cast 1356 if (SubExpr->getType()->isPointerType()) 1357 return CheckAddressConstantExpression(SubExpr); 1358 1359 if (SubExpr->getType()->isIntegralType()) { 1360 // Check for the special-case of a pointer->int->pointer cast; 1361 // this isn't standard, but some code requires it. See 1362 // PR2720 for an example. 1363 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 1364 if (SubCast->getSubExpr()->getType()->isPointerType()) { 1365 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 1366 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1367 if (IntWidth >= PointerWidth) { 1368 return CheckAddressConstantExpression(SubCast->getSubExpr()); 1369 } 1370 } 1371 } 1372 } 1373 if (SubExpr->getType()->isArithmeticType()) { 1374 return CheckArithmeticConstantExpression(SubExpr); 1375 } 1376 1377 InitializerElementNotConstant(Init); 1378 return true; 1379 } 1380 case Expr::ConditionalOperatorClass: { 1381 // FIXME: Should we pedwarn here? 1382 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1383 if (!Exp->getCond()->getType()->isArithmeticType()) { 1384 InitializerElementNotConstant(Init); 1385 return true; 1386 } 1387 if (CheckArithmeticConstantExpression(Exp->getCond())) 1388 return true; 1389 if (Exp->getLHS() && 1390 CheckAddressConstantExpression(Exp->getLHS())) 1391 return true; 1392 return CheckAddressConstantExpression(Exp->getRHS()); 1393 } 1394 case Expr::AddrLabelExprClass: 1395 return false; 1396 } 1397} 1398 1399static const Expr* FindExpressionBaseAddress(const Expr* E); 1400 1401static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1402 switch (E->getStmtClass()) { 1403 default: 1404 return E; 1405 case Expr::ParenExprClass: { 1406 const ParenExpr* PE = cast<ParenExpr>(E); 1407 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1408 } 1409 case Expr::MemberExprClass: { 1410 const MemberExpr *M = cast<MemberExpr>(E); 1411 if (M->isArrow()) 1412 return FindExpressionBaseAddress(M->getBase()); 1413 return FindExpressionBaseAddressLValue(M->getBase()); 1414 } 1415 case Expr::ArraySubscriptExprClass: { 1416 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1417 return FindExpressionBaseAddress(ASE->getBase()); 1418 } 1419 case Expr::UnaryOperatorClass: { 1420 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1421 1422 if (Exp->getOpcode() == UnaryOperator::Deref) 1423 return FindExpressionBaseAddress(Exp->getSubExpr()); 1424 1425 return E; 1426 } 1427 } 1428} 1429 1430static const Expr* FindExpressionBaseAddress(const Expr* E) { 1431 switch (E->getStmtClass()) { 1432 default: 1433 return E; 1434 case Expr::ParenExprClass: { 1435 const ParenExpr* PE = cast<ParenExpr>(E); 1436 return FindExpressionBaseAddress(PE->getSubExpr()); 1437 } 1438 case Expr::UnaryOperatorClass: { 1439 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1440 1441 // C99 6.6p9 1442 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1443 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1444 1445 if (Exp->getOpcode() == UnaryOperator::Extension) 1446 return FindExpressionBaseAddress(Exp->getSubExpr()); 1447 1448 return E; 1449 } 1450 case Expr::BinaryOperatorClass: { 1451 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1452 1453 Expr *PExp = Exp->getLHS(); 1454 Expr *IExp = Exp->getRHS(); 1455 if (IExp->getType()->isPointerType()) 1456 std::swap(PExp, IExp); 1457 1458 return FindExpressionBaseAddress(PExp); 1459 } 1460 case Expr::ImplicitCastExprClass: { 1461 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1462 1463 // Check for implicit promotion 1464 if (SubExpr->getType()->isFunctionType() || 1465 SubExpr->getType()->isArrayType()) 1466 return FindExpressionBaseAddressLValue(SubExpr); 1467 1468 // Check for pointer->pointer cast 1469 if (SubExpr->getType()->isPointerType()) 1470 return FindExpressionBaseAddress(SubExpr); 1471 1472 // We assume that we have an arithmetic expression here; 1473 // if we don't, we'll figure it out later 1474 return 0; 1475 } 1476 case Expr::CStyleCastExprClass: { 1477 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1478 1479 // Check for pointer->pointer cast 1480 if (SubExpr->getType()->isPointerType()) 1481 return FindExpressionBaseAddress(SubExpr); 1482 1483 // We assume that we have an arithmetic expression here; 1484 // if we don't, we'll figure it out later 1485 return 0; 1486 } 1487 } 1488} 1489 1490bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1491 switch (Init->getStmtClass()) { 1492 default: 1493 InitializerElementNotConstant(Init); 1494 return true; 1495 case Expr::ParenExprClass: { 1496 const ParenExpr* PE = cast<ParenExpr>(Init); 1497 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1498 } 1499 case Expr::FloatingLiteralClass: 1500 case Expr::IntegerLiteralClass: 1501 case Expr::CharacterLiteralClass: 1502 case Expr::ImaginaryLiteralClass: 1503 case Expr::TypesCompatibleExprClass: 1504 case Expr::CXXBoolLiteralExprClass: 1505 return false; 1506 case Expr::CallExprClass: 1507 case Expr::CXXOperatorCallExprClass: { 1508 const CallExpr *CE = cast<CallExpr>(Init); 1509 1510 // Allow any constant foldable calls to builtins. 1511 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1512 return false; 1513 1514 InitializerElementNotConstant(Init); 1515 return true; 1516 } 1517 case Expr::DeclRefExprClass: { 1518 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1519 if (isa<EnumConstantDecl>(D)) 1520 return false; 1521 InitializerElementNotConstant(Init); 1522 return true; 1523 } 1524 case Expr::CompoundLiteralExprClass: 1525 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1526 // but vectors are allowed to be magic. 1527 if (Init->getType()->isVectorType()) 1528 return false; 1529 InitializerElementNotConstant(Init); 1530 return true; 1531 case Expr::UnaryOperatorClass: { 1532 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1533 1534 switch (Exp->getOpcode()) { 1535 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1536 // See C99 6.6p3. 1537 default: 1538 InitializerElementNotConstant(Init); 1539 return true; 1540 case UnaryOperator::OffsetOf: 1541 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1542 return false; 1543 InitializerElementNotConstant(Init); 1544 return true; 1545 case UnaryOperator::Extension: 1546 case UnaryOperator::LNot: 1547 case UnaryOperator::Plus: 1548 case UnaryOperator::Minus: 1549 case UnaryOperator::Not: 1550 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1551 } 1552 } 1553 case Expr::SizeOfAlignOfExprClass: { 1554 const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init); 1555 // Special check for void types, which are allowed as an extension 1556 if (Exp->getTypeOfArgument()->isVoidType()) 1557 return false; 1558 // alignof always evaluates to a constant. 1559 // FIXME: is sizeof(int[3.0]) a constant expression? 1560 if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) { 1561 InitializerElementNotConstant(Init); 1562 return true; 1563 } 1564 return false; 1565 } 1566 case Expr::BinaryOperatorClass: { 1567 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1568 1569 if (Exp->getLHS()->getType()->isArithmeticType() && 1570 Exp->getRHS()->getType()->isArithmeticType()) { 1571 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1572 CheckArithmeticConstantExpression(Exp->getRHS()); 1573 } 1574 1575 if (Exp->getLHS()->getType()->isPointerType() && 1576 Exp->getRHS()->getType()->isPointerType()) { 1577 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1578 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1579 1580 // Only allow a null (constant integer) base; we could 1581 // allow some additional cases if necessary, but this 1582 // is sufficient to cover offsetof-like constructs. 1583 if (!LHSBase && !RHSBase) { 1584 return CheckAddressConstantExpression(Exp->getLHS()) || 1585 CheckAddressConstantExpression(Exp->getRHS()); 1586 } 1587 } 1588 1589 InitializerElementNotConstant(Init); 1590 return true; 1591 } 1592 case Expr::ImplicitCastExprClass: 1593 case Expr::CStyleCastExprClass: { 1594 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1595 if (SubExpr->getType()->isArithmeticType()) 1596 return CheckArithmeticConstantExpression(SubExpr); 1597 1598 if (SubExpr->getType()->isPointerType()) { 1599 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1600 // If the pointer has a null base, this is an offsetof-like construct 1601 if (!Base) 1602 return CheckAddressConstantExpression(SubExpr); 1603 } 1604 1605 InitializerElementNotConstant(Init); 1606 return true; 1607 } 1608 case Expr::ConditionalOperatorClass: { 1609 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1610 1611 // If GNU extensions are disabled, we require all operands to be arithmetic 1612 // constant expressions. 1613 if (getLangOptions().NoExtensions) { 1614 return CheckArithmeticConstantExpression(Exp->getCond()) || 1615 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1616 CheckArithmeticConstantExpression(Exp->getRHS()); 1617 } 1618 1619 // Otherwise, we have to emulate some of the behavior of fold here. 1620 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1621 // because it can constant fold things away. To retain compatibility with 1622 // GCC code, we see if we can fold the condition to a constant (which we 1623 // should always be able to do in theory). If so, we only require the 1624 // specified arm of the conditional to be a constant. This is a horrible 1625 // hack, but is require by real world code that uses __builtin_constant_p. 1626 APValue Val; 1627 if (!Exp->getCond()->Evaluate(Val, Context)) { 1628 // If Evaluate couldn't fold it, CheckArithmeticConstantExpression 1629 // won't be able to either. Use it to emit the diagnostic though. 1630 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1631 assert(Res && "Evaluate couldn't evaluate this constant?"); 1632 return Res; 1633 } 1634 1635 // Verify that the side following the condition is also a constant. 1636 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1637 if (Val.getInt() == 0) 1638 std::swap(TrueSide, FalseSide); 1639 1640 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1641 return true; 1642 1643 // Okay, the evaluated side evaluates to a constant, so we accept this. 1644 // Check to see if the other side is obviously not a constant. If so, 1645 // emit a warning that this is a GNU extension. 1646 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1647 Diag(Init->getExprLoc(), 1648 diag::ext_typecheck_expression_not_constant_but_accepted) 1649 << FalseSide->getSourceRange(); 1650 return false; 1651 } 1652 } 1653} 1654 1655bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1656 Init = Init->IgnoreParens(); 1657 1658 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1659 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1660 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1661 1662 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1663 return CheckForConstantInitializer(e->getInitializer(), DclT); 1664 1665 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1666 unsigned numInits = Exp->getNumInits(); 1667 for (unsigned i = 0; i < numInits; i++) { 1668 // FIXME: Need to get the type of the declaration for C++, 1669 // because it could be a reference? 1670 if (CheckForConstantInitializer(Exp->getInit(i), 1671 Exp->getInit(i)->getType())) 1672 return true; 1673 } 1674 return false; 1675 } 1676 1677 if (Init->isNullPointerConstant(Context)) 1678 return false; 1679 if (Init->getType()->isArithmeticType()) { 1680 QualType InitTy = Context.getCanonicalType(Init->getType()) 1681 .getUnqualifiedType(); 1682 if (InitTy == Context.BoolTy) { 1683 // Special handling for pointers implicitly cast to bool; 1684 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1685 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1686 Expr* SubE = ICE->getSubExpr(); 1687 if (SubE->getType()->isPointerType() || 1688 SubE->getType()->isArrayType() || 1689 SubE->getType()->isFunctionType()) { 1690 return CheckAddressConstantExpression(Init); 1691 } 1692 } 1693 } else if (InitTy->isIntegralType()) { 1694 Expr* SubE = 0; 1695 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1696 SubE = CE->getSubExpr(); 1697 // Special check for pointer cast to int; we allow as an extension 1698 // an address constant cast to an integer if the integer 1699 // is of an appropriate width (this sort of code is apparently used 1700 // in some places). 1701 // FIXME: Add pedwarn? 1702 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1703 if (SubE && (SubE->getType()->isPointerType() || 1704 SubE->getType()->isArrayType() || 1705 SubE->getType()->isFunctionType())) { 1706 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1707 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1708 if (IntWidth >= PointerWidth) 1709 return CheckAddressConstantExpression(Init); 1710 } 1711 } 1712 1713 return CheckArithmeticConstantExpression(Init); 1714 } 1715 1716 if (Init->getType()->isPointerType()) 1717 return CheckAddressConstantExpression(Init); 1718 1719 // An array type at the top level that isn't an init-list must 1720 // be a string literal 1721 if (Init->getType()->isArrayType()) 1722 return false; 1723 1724 if (Init->getType()->isFunctionType()) 1725 return false; 1726 1727 // Allow block exprs at top level. 1728 if (Init->getType()->isBlockPointerType()) 1729 return false; 1730 1731 InitializerElementNotConstant(Init); 1732 return true; 1733} 1734 1735void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1736 Decl *RealDecl = static_cast<Decl *>(dcl); 1737 Expr *Init = static_cast<Expr *>(init); 1738 assert(Init && "missing initializer"); 1739 1740 // If there is no declaration, there was an error parsing it. Just ignore 1741 // the initializer. 1742 if (RealDecl == 0) { 1743 delete Init; 1744 return; 1745 } 1746 1747 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1748 if (!VDecl) { 1749 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1750 diag::err_illegal_initializer); 1751 RealDecl->setInvalidDecl(); 1752 return; 1753 } 1754 // Get the decls type and save a reference for later, since 1755 // CheckInitializerTypes may change it. 1756 QualType DclT = VDecl->getType(), SavT = DclT; 1757 if (VDecl->isBlockVarDecl()) { 1758 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1759 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1760 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1761 VDecl->setInvalidDecl(); 1762 } else if (!VDecl->isInvalidDecl()) { 1763 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1764 VDecl->getName())) 1765 VDecl->setInvalidDecl(); 1766 1767 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1768 if (!getLangOptions().CPlusPlus) { 1769 if (SC == VarDecl::Static) // C99 6.7.8p4. 1770 CheckForConstantInitializer(Init, DclT); 1771 } 1772 } 1773 } else if (VDecl->isFileVarDecl()) { 1774 if (VDecl->getStorageClass() == VarDecl::Extern) 1775 Diag(VDecl->getLocation(), diag::warn_extern_init); 1776 if (!VDecl->isInvalidDecl()) 1777 if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(), 1778 VDecl->getName())) 1779 VDecl->setInvalidDecl(); 1780 1781 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1782 if (!getLangOptions().CPlusPlus) { 1783 // C99 6.7.8p4. All file scoped initializers need to be constant. 1784 CheckForConstantInitializer(Init, DclT); 1785 } 1786 } 1787 // If the type changed, it means we had an incomplete type that was 1788 // completed by the initializer. For example: 1789 // int ary[] = { 1, 3, 5 }; 1790 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1791 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1792 VDecl->setType(DclT); 1793 Init->setType(DclT); 1794 } 1795 1796 // Attach the initializer to the decl. 1797 VDecl->setInit(Init); 1798 return; 1799} 1800 1801void Sema::ActOnUninitializedDecl(DeclTy *dcl) { 1802 Decl *RealDecl = static_cast<Decl *>(dcl); 1803 1804 // If there is no declaration, there was an error parsing it. Just ignore it. 1805 if (RealDecl == 0) 1806 return; 1807 1808 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 1809 QualType Type = Var->getType(); 1810 // C++ [dcl.init.ref]p3: 1811 // The initializer can be omitted for a reference only in a 1812 // parameter declaration (8.3.5), in the declaration of a 1813 // function return type, in the declaration of a class member 1814 // within its class declaration (9.2), and where the extern 1815 // specifier is explicitly used. 1816 if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) { 1817 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 1818 << Var->getName() << SourceRange(Var->getLocation(), Var->getLocation()); 1819 Var->setInvalidDecl(); 1820 return; 1821 } 1822 1823 // C++ [dcl.init]p9: 1824 // 1825 // If no initializer is specified for an object, and the object 1826 // is of (possibly cv-qualified) non-POD class type (or array 1827 // thereof), the object shall be default-initialized; if the 1828 // object is of const-qualified type, the underlying class type 1829 // shall have a user-declared default constructor. 1830 if (getLangOptions().CPlusPlus) { 1831 QualType InitType = Type; 1832 if (const ArrayType *Array = Context.getAsArrayType(Type)) 1833 InitType = Array->getElementType(); 1834 if (InitType->isRecordType()) { 1835 const CXXConstructorDecl *Constructor 1836 = PerformInitializationByConstructor(InitType, 0, 0, 1837 Var->getLocation(), 1838 SourceRange(Var->getLocation(), 1839 Var->getLocation()), 1840 Var->getName(), 1841 IK_Default); 1842 if (!Constructor) 1843 Var->setInvalidDecl(); 1844 } 1845 } 1846 1847#if 0 1848 // FIXME: Temporarily disabled because we are not properly parsing 1849 // linkage specifications on declarations, e.g., 1850 // 1851 // extern "C" const CGPoint CGPointerZero; 1852 // 1853 // C++ [dcl.init]p9: 1854 // 1855 // If no initializer is specified for an object, and the 1856 // object is of (possibly cv-qualified) non-POD class type (or 1857 // array thereof), the object shall be default-initialized; if 1858 // the object is of const-qualified type, the underlying class 1859 // type shall have a user-declared default 1860 // constructor. Otherwise, if no initializer is specified for 1861 // an object, the object and its subobjects, if any, have an 1862 // indeterminate initial value; if the object or any of its 1863 // subobjects are of const-qualified type, the program is 1864 // ill-formed. 1865 // 1866 // This isn't technically an error in C, so we don't diagnose it. 1867 // 1868 // FIXME: Actually perform the POD/user-defined default 1869 // constructor check. 1870 if (getLangOptions().CPlusPlus && 1871 Context.getCanonicalType(Type).isConstQualified() && 1872 Var->getStorageClass() != VarDecl::Extern) 1873 Diag(Var->getLocation(), diag::err_const_var_requires_init) 1874 << Var->getName() 1875 << SourceRange(Var->getLocation(), Var->getLocation()); 1876#endif 1877 } 1878} 1879 1880/// The declarators are chained together backwards, reverse the list. 1881Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1882 // Often we have single declarators, handle them quickly. 1883 Decl *GroupDecl = static_cast<Decl*>(group); 1884 if (GroupDecl == 0) 1885 return 0; 1886 1887 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1888 ScopedDecl *NewGroup = 0; 1889 if (Group->getNextDeclarator() == 0) 1890 NewGroup = Group; 1891 else { // reverse the list. 1892 while (Group) { 1893 ScopedDecl *Next = Group->getNextDeclarator(); 1894 Group->setNextDeclarator(NewGroup); 1895 NewGroup = Group; 1896 Group = Next; 1897 } 1898 } 1899 // Perform semantic analysis that depends on having fully processed both 1900 // the declarator and initializer. 1901 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1902 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1903 if (!IDecl) 1904 continue; 1905 QualType T = IDecl->getType(); 1906 1907 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1908 // static storage duration, it shall not have a variable length array. 1909 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1910 IDecl->getStorageClass() == VarDecl::Static) { 1911 if (T->isVariableArrayType()) { 1912 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1913 IDecl->setInvalidDecl(); 1914 } 1915 } 1916 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1917 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1918 if (IDecl->isBlockVarDecl() && 1919 IDecl->getStorageClass() != VarDecl::Extern) { 1920 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1921 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type) 1922 << T.getAsString(); 1923 IDecl->setInvalidDecl(); 1924 } 1925 } 1926 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1927 // object that has file scope without an initializer, and without a 1928 // storage-class specifier or with the storage-class specifier "static", 1929 // constitutes a tentative definition. Note: A tentative definition with 1930 // external linkage is valid (C99 6.2.2p5). 1931 if (isTentativeDefinition(IDecl)) { 1932 if (T->isIncompleteArrayType()) { 1933 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1934 // array to be completed. Don't issue a diagnostic. 1935 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1936 // C99 6.9.2p3: If the declaration of an identifier for an object is 1937 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1938 // declared type shall not be an incomplete type. 1939 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type) 1940 << T.getAsString(); 1941 IDecl->setInvalidDecl(); 1942 } 1943 } 1944 if (IDecl->isFileVarDecl()) 1945 CheckForFileScopedRedefinitions(S, IDecl); 1946 } 1947 return NewGroup; 1948} 1949 1950/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1951/// to introduce parameters into function prototype scope. 1952Sema::DeclTy * 1953Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1954 // FIXME: disallow CXXScopeSpec for param declarators. 1955 const DeclSpec &DS = D.getDeclSpec(); 1956 1957 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1958 VarDecl::StorageClass StorageClass = VarDecl::None; 1959 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1960 StorageClass = VarDecl::Register; 1961 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1962 Diag(DS.getStorageClassSpecLoc(), 1963 diag::err_invalid_storage_class_in_func_decl); 1964 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1965 } 1966 if (DS.isThreadSpecified()) { 1967 Diag(DS.getThreadSpecLoc(), 1968 diag::err_invalid_storage_class_in_func_decl); 1969 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1970 } 1971 1972 // Check that there are no default arguments inside the type of this 1973 // parameter (C++ only). 1974 if (getLangOptions().CPlusPlus) 1975 CheckExtraCXXDefaultArguments(D); 1976 1977 // In this context, we *do not* check D.getInvalidType(). If the declarator 1978 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1979 // though it will not reflect the user specified type. 1980 QualType parmDeclType = GetTypeForDeclarator(D, S); 1981 1982 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1983 1984 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1985 // Can this happen for params? We already checked that they don't conflict 1986 // among each other. Here they can only shadow globals, which is ok. 1987 IdentifierInfo *II = D.getIdentifier(); 1988 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1989 if (S->isDeclScope(PrevDecl)) { 1990 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) 1991 << cast<NamedDecl>(PrevDecl)->getName(); 1992 1993 // Recover by removing the name 1994 II = 0; 1995 D.SetIdentifier(0, D.getIdentifierLoc()); 1996 } 1997 } 1998 1999 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 2000 // Doing the promotion here has a win and a loss. The win is the type for 2001 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 2002 // code generator). The loss is the orginal type isn't preserved. For example: 2003 // 2004 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 2005 // int blockvardecl[5]; 2006 // sizeof(parmvardecl); // size == 4 2007 // sizeof(blockvardecl); // size == 20 2008 // } 2009 // 2010 // For expressions, all implicit conversions are captured using the 2011 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 2012 // 2013 // FIXME: If a source translation tool needs to see the original type, then 2014 // we need to consider storing both types (in ParmVarDecl)... 2015 // 2016 if (parmDeclType->isArrayType()) { 2017 // int x[restrict 4] -> int *restrict 2018 parmDeclType = Context.getArrayDecayedType(parmDeclType); 2019 } else if (parmDeclType->isFunctionType()) 2020 parmDeclType = Context.getPointerType(parmDeclType); 2021 2022 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 2023 D.getIdentifierLoc(), II, 2024 parmDeclType, StorageClass, 2025 0, 0); 2026 2027 if (D.getInvalidType()) 2028 New->setInvalidDecl(); 2029 2030 if (II) 2031 PushOnScopeChains(New, S); 2032 2033 ProcessDeclAttributes(New, D); 2034 return New; 2035 2036} 2037 2038Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 2039 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 2040 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 2041 "Not a function declarator!"); 2042 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 2043 2044 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 2045 // for a K&R function. 2046 if (!FTI.hasPrototype) { 2047 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 2048 if (FTI.ArgInfo[i].Param == 0) { 2049 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared) 2050 << FTI.ArgInfo[i].Ident; 2051 // Implicitly declare the argument as type 'int' for lack of a better 2052 // type. 2053 DeclSpec DS; 2054 const char* PrevSpec; // unused 2055 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 2056 PrevSpec); 2057 Declarator ParamD(DS, Declarator::KNRTypeListContext); 2058 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 2059 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 2060 } 2061 } 2062 } else { 2063 // FIXME: Diagnose arguments without names in C. 2064 } 2065 2066 Scope *GlobalScope = FnBodyScope->getParent(); 2067 2068 return ActOnStartOfFunctionDef(FnBodyScope, 2069 ActOnDeclarator(GlobalScope, D, 0)); 2070} 2071 2072Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 2073 Decl *decl = static_cast<Decl*>(D); 2074 FunctionDecl *FD = cast<FunctionDecl>(decl); 2075 2076 // See if this is a redefinition. 2077 const FunctionDecl *Definition; 2078 if (FD->getBody(Definition)) { 2079 Diag(FD->getLocation(), diag::err_redefinition) << FD->getName(); 2080 Diag(Definition->getLocation(), diag::err_previous_definition); 2081 } 2082 2083 PushDeclContext(FD); 2084 2085 // Check the validity of our function parameters 2086 CheckParmsForFunctionDef(FD); 2087 2088 // Introduce our parameters into the function scope 2089 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2090 ParmVarDecl *Param = FD->getParamDecl(p); 2091 // If this has an identifier, add it to the scope stack. 2092 if (Param->getIdentifier()) 2093 PushOnScopeChains(Param, FnBodyScope); 2094 } 2095 2096 return FD; 2097} 2098 2099Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 2100 Decl *dcl = static_cast<Decl *>(D); 2101 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 2102 FD->setBody((Stmt*)Body); 2103 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 2104 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 2105 MD->setBody((Stmt*)Body); 2106 } else 2107 return 0; 2108 PopDeclContext(); 2109 // Verify and clean out per-function state. 2110 2111 // Check goto/label use. 2112 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 2113 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 2114 // Verify that we have no forward references left. If so, there was a goto 2115 // or address of a label taken, but no definition of it. Label fwd 2116 // definitions are indicated with a null substmt. 2117 if (I->second->getSubStmt() == 0) { 2118 LabelStmt *L = I->second; 2119 // Emit error. 2120 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 2121 2122 // At this point, we have gotos that use the bogus label. Stitch it into 2123 // the function body so that they aren't leaked and that the AST is well 2124 // formed. 2125 if (Body) { 2126 L->setSubStmt(new NullStmt(L->getIdentLoc())); 2127 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 2128 } else { 2129 // The whole function wasn't parsed correctly, just delete this. 2130 delete L; 2131 } 2132 } 2133 } 2134 LabelMap.clear(); 2135 2136 return D; 2137} 2138 2139/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 2140/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 2141ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 2142 IdentifierInfo &II, Scope *S) { 2143 // Extension in C99. Legal in C90, but warn about it. 2144 if (getLangOptions().C99) 2145 Diag(Loc, diag::ext_implicit_function_decl) << &II; 2146 else 2147 Diag(Loc, diag::warn_implicit_function_decl) << &II; 2148 2149 // FIXME: handle stuff like: 2150 // void foo() { extern float X(); } 2151 // void bar() { X(); } <-- implicit decl for X in another scope. 2152 2153 // Set a Declarator for the implicit definition: int foo(); 2154 const char *Dummy; 2155 DeclSpec DS; 2156 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 2157 Error = Error; // Silence warning. 2158 assert(!Error && "Error setting up implicit decl!"); 2159 Declarator D(DS, Declarator::BlockContext); 2160 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc)); 2161 D.SetIdentifier(&II, Loc); 2162 2163 // Insert this function into translation-unit scope. 2164 2165 DeclContext *PrevDC = CurContext; 2166 CurContext = Context.getTranslationUnitDecl(); 2167 2168 FunctionDecl *FD = 2169 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 2170 FD->setImplicit(); 2171 2172 CurContext = PrevDC; 2173 2174 return FD; 2175} 2176 2177 2178TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 2179 ScopedDecl *LastDeclarator) { 2180 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 2181 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2182 2183 // Scope manipulation handled by caller. 2184 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 2185 D.getIdentifierLoc(), 2186 D.getIdentifier(), 2187 T, LastDeclarator); 2188 if (D.getInvalidType()) 2189 NewTD->setInvalidDecl(); 2190 return NewTD; 2191} 2192 2193/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 2194/// former case, Name will be non-null. In the later case, Name will be null. 2195/// TagType indicates what kind of tag this is. TK indicates whether this is a 2196/// reference/declaration/definition of a tag. 2197Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 2198 SourceLocation KWLoc, const CXXScopeSpec &SS, 2199 IdentifierInfo *Name, SourceLocation NameLoc, 2200 AttributeList *Attr) { 2201 // If this is a use of an existing tag, it must have a name. 2202 assert((Name != 0 || TK == TK_Definition) && 2203 "Nameless record must be a definition!"); 2204 2205 TagDecl::TagKind Kind; 2206 switch (TagType) { 2207 default: assert(0 && "Unknown tag type!"); 2208 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 2209 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 2210 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 2211 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 2212 } 2213 2214 // Two code paths: a new one for structs/unions/classes where we create 2215 // separate decls for forward declarations, and an old (eventually to 2216 // be removed) code path for enums. 2217 if (Kind != TagDecl::TK_enum) 2218 return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr); 2219 2220 DeclContext *DC = CurContext; 2221 ScopedDecl *PrevDecl = 0; 2222 2223 if (Name && SS.isNotEmpty()) { 2224 // We have a nested-name tag ('struct foo::bar'). 2225 2226 // Check for invalid 'foo::'. 2227 if (SS.isInvalid()) { 2228 Name = 0; 2229 goto CreateNewDecl; 2230 } 2231 2232 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2233 // Look-up name inside 'foo::'. 2234 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2235 2236 // A tag 'foo::bar' must already exist. 2237 if (PrevDecl == 0) { 2238 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2239 Name = 0; 2240 goto CreateNewDecl; 2241 } 2242 } else { 2243 // If this is a named struct, check to see if there was a previous forward 2244 // declaration or definition. 2245 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2246 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2247 } 2248 2249 if (PrevDecl) { 2250 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2251 "unexpected Decl type"); 2252 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2253 // If this is a use of a previous tag, or if the tag is already declared 2254 // in the same scope (so that the definition/declaration completes or 2255 // rementions the tag), reuse the decl. 2256 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2257 // Make sure that this wasn't declared as an enum and now used as a 2258 // struct or something similar. 2259 if (PrevTagDecl->getTagKind() != Kind) { 2260 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2261 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2262 // Recover by making this an anonymous redefinition. 2263 Name = 0; 2264 PrevDecl = 0; 2265 } else { 2266 // If this is a use or a forward declaration, we're good. 2267 if (TK != TK_Definition) 2268 return PrevDecl; 2269 2270 // Diagnose attempts to redefine a tag. 2271 if (PrevTagDecl->isDefinition()) { 2272 Diag(NameLoc, diag::err_redefinition) << Name; 2273 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2274 // If this is a redefinition, recover by making this struct be 2275 // anonymous, which will make any later references get the previous 2276 // definition. 2277 Name = 0; 2278 } else { 2279 // Okay, this is definition of a previously declared or referenced 2280 // tag. Move the location of the decl to be the definition site. 2281 PrevDecl->setLocation(NameLoc); 2282 return PrevDecl; 2283 } 2284 } 2285 } 2286 // If we get here, this is a definition of a new struct type in a nested 2287 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 2288 // type. 2289 } else { 2290 // PrevDecl is a namespace. 2291 if (isDeclInScope(PrevDecl, DC, S)) { 2292 // The tag name clashes with a namespace name, issue an error and 2293 // recover by making this tag be anonymous. 2294 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2295 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2296 Name = 0; 2297 } 2298 } 2299 } 2300 2301 CreateNewDecl: 2302 2303 // If there is an identifier, use the location of the identifier as the 2304 // location of the decl, otherwise use the location of the struct/union 2305 // keyword. 2306 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2307 2308 // Otherwise, if this is the first time we've seen this tag, create the decl. 2309 TagDecl *New; 2310 if (Kind == TagDecl::TK_enum) { 2311 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2312 // enum X { A, B, C } D; D should chain to X. 2313 New = EnumDecl::Create(Context, DC, Loc, Name, 0); 2314 // If this is an undefined enum, warn. 2315 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 2316 } else { 2317 // struct/union/class 2318 2319 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2320 // struct X { int A; } D; D should chain to X. 2321 if (getLangOptions().CPlusPlus) 2322 // FIXME: Look for a way to use RecordDecl for simple structs. 2323 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name); 2324 else 2325 New = RecordDecl::Create(Context, Kind, DC, Loc, Name); 2326 } 2327 2328 // If this has an identifier, add it to the scope stack. 2329 if (Name) { 2330 // The scope passed in may not be a decl scope. Zip up the scope tree until 2331 // we find one that is. 2332 while ((S->getFlags() & Scope::DeclScope) == 0) 2333 S = S->getParent(); 2334 2335 // Add it to the decl chain. 2336 PushOnScopeChains(New, S); 2337 } 2338 2339 if (Attr) 2340 ProcessDeclAttributeList(New, Attr); 2341 2342 // Set the lexical context. If the tag has a C++ scope specifier, the 2343 // lexical context will be different from the semantic context. 2344 New->setLexicalDeclContext(CurContext); 2345 2346 return New; 2347} 2348 2349/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 2350/// the logic for enums, we create separate decls for forward declarations. 2351/// This is called by ActOnTag, but eventually will replace its logic. 2352Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 2353 SourceLocation KWLoc, const CXXScopeSpec &SS, 2354 IdentifierInfo *Name, SourceLocation NameLoc, 2355 AttributeList *Attr) { 2356 DeclContext *DC = CurContext; 2357 ScopedDecl *PrevDecl = 0; 2358 2359 if (Name && SS.isNotEmpty()) { 2360 // We have a nested-name tag ('struct foo::bar'). 2361 2362 // Check for invalid 'foo::'. 2363 if (SS.isInvalid()) { 2364 Name = 0; 2365 goto CreateNewDecl; 2366 } 2367 2368 DC = static_cast<DeclContext*>(SS.getScopeRep()); 2369 // Look-up name inside 'foo::'. 2370 PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC)); 2371 2372 // A tag 'foo::bar' must already exist. 2373 if (PrevDecl == 0) { 2374 Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); 2375 Name = 0; 2376 goto CreateNewDecl; 2377 } 2378 } else { 2379 // If this is a named struct, check to see if there was a previous forward 2380 // declaration or definition. 2381 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 2382 PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S)); 2383 } 2384 2385 if (PrevDecl) { 2386 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 2387 "unexpected Decl type"); 2388 2389 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 2390 // If this is a use of a previous tag, or if the tag is already declared 2391 // in the same scope (so that the definition/declaration completes or 2392 // rementions the tag), reuse the decl. 2393 if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) { 2394 // Make sure that this wasn't declared as an enum and now used as a 2395 // struct or something similar. 2396 if (PrevTagDecl->getTagKind() != Kind) { 2397 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 2398 Diag(PrevDecl->getLocation(), diag::err_previous_use); 2399 // Recover by making this an anonymous redefinition. 2400 Name = 0; 2401 PrevDecl = 0; 2402 } else { 2403 // If this is a use, return the original decl. 2404 2405 // FIXME: In the future, return a variant or some other clue 2406 // for the consumer of this Decl to know it doesn't own it. 2407 // For our current ASTs this shouldn't be a problem, but will 2408 // need to be changed with DeclGroups. 2409 if (TK == TK_Reference) 2410 return PrevDecl; 2411 2412 // The new decl is a definition? 2413 if (TK == TK_Definition) { 2414 // Diagnose attempts to redefine a tag. 2415 if (RecordDecl* DefRecord = 2416 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 2417 Diag(NameLoc, diag::err_redefinition) << Name; 2418 Diag(DefRecord->getLocation(), diag::err_previous_definition); 2419 // If this is a redefinition, recover by making this struct be 2420 // anonymous, which will make any later references get the previous 2421 // definition. 2422 Name = 0; 2423 PrevDecl = 0; 2424 } 2425 // Okay, this is definition of a previously declared or referenced 2426 // tag. We're going to create a new Decl. 2427 } 2428 } 2429 // If we get here we have (another) forward declaration. Just create 2430 // a new decl. 2431 } 2432 else { 2433 // If we get here, this is a definition of a new struct type in a nested 2434 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 2435 // new decl/type. We set PrevDecl to NULL so that the Records 2436 // have distinct types. 2437 PrevDecl = 0; 2438 } 2439 } else { 2440 // PrevDecl is a namespace. 2441 if (isDeclInScope(PrevDecl, DC, S)) { 2442 // The tag name clashes with a namespace name, issue an error and 2443 // recover by making this tag be anonymous. 2444 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 2445 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2446 Name = 0; 2447 } 2448 } 2449 } 2450 2451 CreateNewDecl: 2452 2453 // If there is an identifier, use the location of the identifier as the 2454 // location of the decl, otherwise use the location of the struct/union 2455 // keyword. 2456 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 2457 2458 // Otherwise, if this is the first time we've seen this tag, create the decl. 2459 TagDecl *New; 2460 2461 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 2462 // struct X { int A; } D; D should chain to X. 2463 if (getLangOptions().CPlusPlus) 2464 // FIXME: Look for a way to use RecordDecl for simple structs. 2465 New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name, 2466 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 2467 else 2468 New = RecordDecl::Create(Context, Kind, DC, Loc, Name, 2469 dyn_cast_or_null<RecordDecl>(PrevDecl)); 2470 2471 // If this has an identifier, add it to the scope stack. 2472 if ((TK == TK_Definition || !PrevDecl) && Name) { 2473 // The scope passed in may not be a decl scope. Zip up the scope tree until 2474 // we find one that is. 2475 while ((S->getFlags() & Scope::DeclScope) == 0) 2476 S = S->getParent(); 2477 2478 // Add it to the decl chain. 2479 PushOnScopeChains(New, S); 2480 } 2481 2482 // Handle #pragma pack: if the #pragma pack stack has non-default 2483 // alignment, make up a packed attribute for this decl. These 2484 // attributes are checked when the ASTContext lays out the 2485 // structure. 2486 // 2487 // It is important for implementing the correct semantics that this 2488 // happen here (in act on tag decl). The #pragma pack stack is 2489 // maintained as a result of parser callbacks which can occur at 2490 // many points during the parsing of a struct declaration (because 2491 // the #pragma tokens are effectively skipped over during the 2492 // parsing of the struct). 2493 if (unsigned Alignment = PackContext.getAlignment()) 2494 New->addAttr(new PackedAttr(Alignment * 8)); 2495 2496 if (Attr) 2497 ProcessDeclAttributeList(New, Attr); 2498 2499 // Set the lexical context. If the tag has a C++ scope specifier, the 2500 // lexical context will be different from the semantic context. 2501 New->setLexicalDeclContext(CurContext); 2502 2503 return New; 2504} 2505 2506 2507/// Collect the instance variables declared in an Objective-C object. Used in 2508/// the creation of structures from objects using the @defs directive. 2509static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 2510 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 2511 if (Class->getSuperClass()) 2512 CollectIvars(Class->getSuperClass(), Ctx, ivars); 2513 2514 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 2515 for (ObjCInterfaceDecl::ivar_iterator 2516 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 2517 2518 ObjCIvarDecl* ID = *I; 2519 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 2520 ID->getIdentifier(), 2521 ID->getType(), 2522 ID->getBitWidth())); 2523 } 2524} 2525 2526/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 2527/// instance variables of ClassName into Decls. 2528void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 2529 IdentifierInfo *ClassName, 2530 llvm::SmallVectorImpl<DeclTy*> &Decls) { 2531 // Check that ClassName is a valid class 2532 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 2533 if (!Class) { 2534 Diag(DeclStart, diag::err_undef_interface) << ClassName; 2535 return; 2536 } 2537 // Collect the instance variables 2538 CollectIvars(Class, Context, Decls); 2539} 2540 2541/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array 2542/// types into constant array types in certain situations which would otherwise 2543/// be errors (for GCC compatibility). 2544static QualType TryToFixInvalidVariablyModifiedType(QualType T, 2545 ASTContext &Context) { 2546 // This method tries to turn a variable array into a constant 2547 // array even when the size isn't an ICE. This is necessary 2548 // for compatibility with code that depends on gcc's buggy 2549 // constant expression folding, like struct {char x[(int)(char*)2];} 2550 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T); 2551 if (!VLATy) return QualType(); 2552 2553 APValue Result; 2554 if (!VLATy->getSizeExpr() || 2555 !VLATy->getSizeExpr()->Evaluate(Result, Context)) 2556 return QualType(); 2557 2558 assert(Result.isInt() && "Size expressions must be integers!"); 2559 llvm::APSInt &Res = Result.getInt(); 2560 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 2561 return Context.getConstantArrayType(VLATy->getElementType(), 2562 Res, ArrayType::Normal, 0); 2563 return QualType(); 2564} 2565 2566/// ActOnField - Each field of a struct/union/class is passed into this in order 2567/// to create a FieldDecl object for it. 2568Sema::DeclTy *Sema::ActOnField(Scope *S, 2569 SourceLocation DeclStart, 2570 Declarator &D, ExprTy *BitfieldWidth) { 2571 IdentifierInfo *II = D.getIdentifier(); 2572 Expr *BitWidth = (Expr*)BitfieldWidth; 2573 SourceLocation Loc = DeclStart; 2574 if (II) Loc = D.getIdentifierLoc(); 2575 2576 // FIXME: Unnamed fields can be handled in various different ways, for 2577 // example, unnamed unions inject all members into the struct namespace! 2578 2579 if (BitWidth) { 2580 // TODO: Validate. 2581 //printf("WARNING: BITFIELDS IGNORED!\n"); 2582 2583 // 6.7.2.1p3 2584 // 6.7.2.1p4 2585 2586 } else { 2587 // Not a bitfield. 2588 2589 // validate II. 2590 2591 } 2592 2593 QualType T = GetTypeForDeclarator(D, S); 2594 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2595 bool InvalidDecl = false; 2596 2597 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2598 // than a variably modified type. 2599 if (T->isVariablyModifiedType()) { 2600 QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context); 2601 if (!FixedTy.isNull()) { 2602 Diag(Loc, diag::warn_illegal_constant_array_size); 2603 T = FixedTy; 2604 } else { 2605 Diag(Loc, diag::err_typecheck_field_variable_size); 2606 T = Context.IntTy; 2607 InvalidDecl = true; 2608 } 2609 } 2610 // FIXME: Chain fielddecls together. 2611 FieldDecl *NewFD; 2612 2613 if (getLangOptions().CPlusPlus) { 2614 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2615 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2616 Loc, II, T, 2617 D.getDeclSpec().getStorageClassSpec() == 2618 DeclSpec::SCS_mutable, BitWidth); 2619 if (II) 2620 PushOnScopeChains(NewFD, S); 2621 } 2622 else 2623 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2624 2625 ProcessDeclAttributes(NewFD, D); 2626 2627 if (D.getInvalidType() || InvalidDecl) 2628 NewFD->setInvalidDecl(); 2629 return NewFD; 2630} 2631 2632/// TranslateIvarVisibility - Translate visibility from a token ID to an 2633/// AST enum value. 2634static ObjCIvarDecl::AccessControl 2635TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2636 switch (ivarVisibility) { 2637 default: assert(0 && "Unknown visitibility kind"); 2638 case tok::objc_private: return ObjCIvarDecl::Private; 2639 case tok::objc_public: return ObjCIvarDecl::Public; 2640 case tok::objc_protected: return ObjCIvarDecl::Protected; 2641 case tok::objc_package: return ObjCIvarDecl::Package; 2642 } 2643} 2644 2645/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2646/// in order to create an IvarDecl object for it. 2647Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2648 SourceLocation DeclStart, 2649 Declarator &D, ExprTy *BitfieldWidth, 2650 tok::ObjCKeywordKind Visibility) { 2651 IdentifierInfo *II = D.getIdentifier(); 2652 Expr *BitWidth = (Expr*)BitfieldWidth; 2653 SourceLocation Loc = DeclStart; 2654 if (II) Loc = D.getIdentifierLoc(); 2655 2656 // FIXME: Unnamed fields can be handled in various different ways, for 2657 // example, unnamed unions inject all members into the struct namespace! 2658 2659 2660 if (BitWidth) { 2661 // TODO: Validate. 2662 //printf("WARNING: BITFIELDS IGNORED!\n"); 2663 2664 // 6.7.2.1p3 2665 // 6.7.2.1p4 2666 2667 } else { 2668 // Not a bitfield. 2669 2670 // validate II. 2671 2672 } 2673 2674 QualType T = GetTypeForDeclarator(D, S); 2675 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2676 bool InvalidDecl = false; 2677 2678 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2679 // than a variably modified type. 2680 if (T->isVariablyModifiedType()) { 2681 // FIXME: This diagnostic needs work 2682 Diag(Loc, diag::err_typecheck_illegal_vla) << SourceRange(Loc); 2683 InvalidDecl = true; 2684 } 2685 2686 // Get the visibility (access control) for this ivar. 2687 ObjCIvarDecl::AccessControl ac = 2688 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2689 : ObjCIvarDecl::None; 2690 2691 // Construct the decl. 2692 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2693 (Expr *)BitfieldWidth); 2694 2695 // Process attributes attached to the ivar. 2696 ProcessDeclAttributes(NewID, D); 2697 2698 if (D.getInvalidType() || InvalidDecl) 2699 NewID->setInvalidDecl(); 2700 2701 return NewID; 2702} 2703 2704void Sema::ActOnFields(Scope* S, 2705 SourceLocation RecLoc, DeclTy *RecDecl, 2706 DeclTy **Fields, unsigned NumFields, 2707 SourceLocation LBrac, SourceLocation RBrac, 2708 AttributeList *Attr) { 2709 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2710 assert(EnclosingDecl && "missing record or interface decl"); 2711 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2712 2713 if (Record) 2714 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2715 // Diagnose code like: 2716 // struct S { struct S {} X; }; 2717 // We discover this when we complete the outer S. Reject and ignore the 2718 // outer S. 2719 Diag(DefRecord->getLocation(), diag::err_nested_redefinition) 2720 << DefRecord->getKindName(); 2721 Diag(RecLoc, diag::err_previous_definition); 2722 Record->setInvalidDecl(); 2723 return; 2724 } 2725 2726 // Verify that all the fields are okay. 2727 unsigned NumNamedMembers = 0; 2728 llvm::SmallVector<FieldDecl*, 32> RecFields; 2729 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2730 2731 for (unsigned i = 0; i != NumFields; ++i) { 2732 2733 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2734 assert(FD && "missing field decl"); 2735 2736 // Remember all fields. 2737 RecFields.push_back(FD); 2738 2739 // Get the type for the field. 2740 Type *FDTy = FD->getType().getTypePtr(); 2741 2742 // C99 6.7.2.1p2 - A field may not be a function type. 2743 if (FDTy->isFunctionType()) { 2744 Diag(FD->getLocation(), diag::err_field_declared_as_function) 2745 << FD->getName(); 2746 FD->setInvalidDecl(); 2747 EnclosingDecl->setInvalidDecl(); 2748 continue; 2749 } 2750 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2751 if (FDTy->isIncompleteType()) { 2752 if (!Record) { // Incomplete ivar type is always an error. 2753 Diag(FD->getLocation(), diag::err_field_incomplete) << FD->getName(); 2754 FD->setInvalidDecl(); 2755 EnclosingDecl->setInvalidDecl(); 2756 continue; 2757 } 2758 if (i != NumFields-1 || // ... that the last member ... 2759 !Record->isStruct() || // ... of a structure ... 2760 !FDTy->isArrayType()) { //... may have incomplete array type. 2761 Diag(FD->getLocation(), diag::err_field_incomplete) << FD->getName(); 2762 FD->setInvalidDecl(); 2763 EnclosingDecl->setInvalidDecl(); 2764 continue; 2765 } 2766 if (NumNamedMembers < 1) { //... must have more than named member ... 2767 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct) 2768 << FD->getName(); 2769 FD->setInvalidDecl(); 2770 EnclosingDecl->setInvalidDecl(); 2771 continue; 2772 } 2773 // Okay, we have a legal flexible array member at the end of the struct. 2774 if (Record) 2775 Record->setHasFlexibleArrayMember(true); 2776 } 2777 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2778 /// field of another structure or the element of an array. 2779 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2780 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2781 // If this is a member of a union, then entire union becomes "flexible". 2782 if (Record && Record->isUnion()) { 2783 Record->setHasFlexibleArrayMember(true); 2784 } else { 2785 // If this is a struct/class and this is not the last element, reject 2786 // it. Note that GCC supports variable sized arrays in the middle of 2787 // structures. 2788 if (i != NumFields-1) { 2789 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct) 2790 << FD->getName(); 2791 FD->setInvalidDecl(); 2792 EnclosingDecl->setInvalidDecl(); 2793 continue; 2794 } 2795 // We support flexible arrays at the end of structs in other structs 2796 // as an extension. 2797 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 2798 << FD->getName(); 2799 if (Record) 2800 Record->setHasFlexibleArrayMember(true); 2801 } 2802 } 2803 } 2804 /// A field cannot be an Objective-c object 2805 if (FDTy->isObjCInterfaceType()) { 2806 Diag(FD->getLocation(), diag::err_statically_allocated_object) 2807 << FD->getName(); 2808 FD->setInvalidDecl(); 2809 EnclosingDecl->setInvalidDecl(); 2810 continue; 2811 } 2812 // Keep track of the number of named members. 2813 if (IdentifierInfo *II = FD->getIdentifier()) { 2814 // Detect duplicate member names. 2815 if (!FieldIDs.insert(II)) { 2816 Diag(FD->getLocation(), diag::err_duplicate_member) << II; 2817 // Find the previous decl. 2818 SourceLocation PrevLoc; 2819 for (unsigned i = 0; ; ++i) { 2820 assert(i != RecFields.size() && "Didn't find previous def!"); 2821 if (RecFields[i]->getIdentifier() == II) { 2822 PrevLoc = RecFields[i]->getLocation(); 2823 break; 2824 } 2825 } 2826 Diag(PrevLoc, diag::err_previous_definition); 2827 FD->setInvalidDecl(); 2828 EnclosingDecl->setInvalidDecl(); 2829 continue; 2830 } 2831 ++NumNamedMembers; 2832 } 2833 } 2834 2835 // Okay, we successfully defined 'Record'. 2836 if (Record) { 2837 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2838 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2839 // Sema::ActOnFinishCXXClassDef. 2840 if (!isa<CXXRecordDecl>(Record)) 2841 Consumer.HandleTagDeclDefinition(Record); 2842 } else { 2843 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2844 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2845 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2846 else if (ObjCImplementationDecl *IMPDecl = 2847 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2848 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2849 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2850 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2851 } 2852 } 2853 2854 if (Attr) 2855 ProcessDeclAttributeList(Record, Attr); 2856} 2857 2858Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2859 DeclTy *lastEnumConst, 2860 SourceLocation IdLoc, IdentifierInfo *Id, 2861 SourceLocation EqualLoc, ExprTy *val) { 2862 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2863 EnumConstantDecl *LastEnumConst = 2864 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2865 Expr *Val = static_cast<Expr*>(val); 2866 2867 // The scope passed in may not be a decl scope. Zip up the scope tree until 2868 // we find one that is. 2869 while ((S->getFlags() & Scope::DeclScope) == 0) 2870 S = S->getParent(); 2871 2872 // Verify that there isn't already something declared with this name in this 2873 // scope. 2874 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2875 // When in C++, we may get a TagDecl with the same name; in this case the 2876 // enum constant will 'hide' the tag. 2877 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2878 "Received TagDecl when not in C++!"); 2879 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2880 if (isa<EnumConstantDecl>(PrevDecl)) 2881 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 2882 else 2883 Diag(IdLoc, diag::err_redefinition) << Id; 2884 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2885 delete Val; 2886 return 0; 2887 } 2888 } 2889 2890 llvm::APSInt EnumVal(32); 2891 QualType EltTy; 2892 if (Val) { 2893 // Make sure to promote the operand type to int. 2894 UsualUnaryConversions(Val); 2895 2896 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2897 SourceLocation ExpLoc; 2898 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2899 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr) << Id; 2900 delete Val; 2901 Val = 0; // Just forget about it. 2902 } else { 2903 EltTy = Val->getType(); 2904 } 2905 } 2906 2907 if (!Val) { 2908 if (LastEnumConst) { 2909 // Assign the last value + 1. 2910 EnumVal = LastEnumConst->getInitVal(); 2911 ++EnumVal; 2912 2913 // Check for overflow on increment. 2914 if (EnumVal < LastEnumConst->getInitVal()) 2915 Diag(IdLoc, diag::warn_enum_value_overflow); 2916 2917 EltTy = LastEnumConst->getType(); 2918 } else { 2919 // First value, set to zero. 2920 EltTy = Context.IntTy; 2921 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2922 } 2923 } 2924 2925 EnumConstantDecl *New = 2926 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2927 Val, EnumVal, 2928 LastEnumConst); 2929 2930 // Register this decl in the current scope stack. 2931 PushOnScopeChains(New, S); 2932 return New; 2933} 2934 2935// FIXME: For consistency with ActOnFields(), we should have the parser 2936// pass in the source location for the left/right braces. 2937void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2938 DeclTy **Elements, unsigned NumElements) { 2939 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2940 2941 if (Enum && Enum->isDefinition()) { 2942 // Diagnose code like: 2943 // enum e0 { 2944 // E0 = sizeof(enum e0 { E1 }) 2945 // }; 2946 Diag(Enum->getLocation(), diag::err_nested_redefinition) << Enum->getName(); 2947 Diag(EnumLoc, diag::err_previous_definition); 2948 Enum->setInvalidDecl(); 2949 return; 2950 } 2951 // TODO: If the result value doesn't fit in an int, it must be a long or long 2952 // long value. ISO C does not support this, but GCC does as an extension, 2953 // emit a warning. 2954 unsigned IntWidth = Context.Target.getIntWidth(); 2955 2956 // Verify that all the values are okay, compute the size of the values, and 2957 // reverse the list. 2958 unsigned NumNegativeBits = 0; 2959 unsigned NumPositiveBits = 0; 2960 2961 // Keep track of whether all elements have type int. 2962 bool AllElementsInt = true; 2963 2964 EnumConstantDecl *EltList = 0; 2965 for (unsigned i = 0; i != NumElements; ++i) { 2966 EnumConstantDecl *ECD = 2967 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2968 if (!ECD) continue; // Already issued a diagnostic. 2969 2970 // If the enum value doesn't fit in an int, emit an extension warning. 2971 const llvm::APSInt &InitVal = ECD->getInitVal(); 2972 assert(InitVal.getBitWidth() >= IntWidth && 2973 "Should have promoted value to int"); 2974 if (InitVal.getBitWidth() > IntWidth) { 2975 llvm::APSInt V(InitVal); 2976 V.trunc(IntWidth); 2977 V.extend(InitVal.getBitWidth()); 2978 if (V != InitVal) 2979 Diag(ECD->getLocation(), diag::ext_enum_value_not_int) 2980 << InitVal.toString(10); 2981 } 2982 2983 // Keep track of the size of positive and negative values. 2984 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2985 NumPositiveBits = std::max(NumPositiveBits, 2986 (unsigned)InitVal.getActiveBits()); 2987 else 2988 NumNegativeBits = std::max(NumNegativeBits, 2989 (unsigned)InitVal.getMinSignedBits()); 2990 2991 // Keep track of whether every enum element has type int (very commmon). 2992 if (AllElementsInt) 2993 AllElementsInt = ECD->getType() == Context.IntTy; 2994 2995 ECD->setNextDeclarator(EltList); 2996 EltList = ECD; 2997 } 2998 2999 // Figure out the type that should be used for this enum. 3000 // FIXME: Support attribute(packed) on enums and -fshort-enums. 3001 QualType BestType; 3002 unsigned BestWidth; 3003 3004 if (NumNegativeBits) { 3005 // If there is a negative value, figure out the smallest integer type (of 3006 // int/long/longlong) that fits. 3007 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 3008 BestType = Context.IntTy; 3009 BestWidth = IntWidth; 3010 } else { 3011 BestWidth = Context.Target.getLongWidth(); 3012 3013 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 3014 BestType = Context.LongTy; 3015 else { 3016 BestWidth = Context.Target.getLongLongWidth(); 3017 3018 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 3019 Diag(Enum->getLocation(), diag::warn_enum_too_large); 3020 BestType = Context.LongLongTy; 3021 } 3022 } 3023 } else { 3024 // If there is no negative value, figure out which of uint, ulong, ulonglong 3025 // fits. 3026 if (NumPositiveBits <= IntWidth) { 3027 BestType = Context.UnsignedIntTy; 3028 BestWidth = IntWidth; 3029 } else if (NumPositiveBits <= 3030 (BestWidth = Context.Target.getLongWidth())) { 3031 BestType = Context.UnsignedLongTy; 3032 } else { 3033 BestWidth = Context.Target.getLongLongWidth(); 3034 assert(NumPositiveBits <= BestWidth && 3035 "How could an initializer get larger than ULL?"); 3036 BestType = Context.UnsignedLongLongTy; 3037 } 3038 } 3039 3040 // Loop over all of the enumerator constants, changing their types to match 3041 // the type of the enum if needed. 3042 for (unsigned i = 0; i != NumElements; ++i) { 3043 EnumConstantDecl *ECD = 3044 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 3045 if (!ECD) continue; // Already issued a diagnostic. 3046 3047 // Standard C says the enumerators have int type, but we allow, as an 3048 // extension, the enumerators to be larger than int size. If each 3049 // enumerator value fits in an int, type it as an int, otherwise type it the 3050 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 3051 // that X has type 'int', not 'unsigned'. 3052 if (ECD->getType() == Context.IntTy) { 3053 // Make sure the init value is signed. 3054 llvm::APSInt IV = ECD->getInitVal(); 3055 IV.setIsSigned(true); 3056 ECD->setInitVal(IV); 3057 continue; // Already int type. 3058 } 3059 3060 // Determine whether the value fits into an int. 3061 llvm::APSInt InitVal = ECD->getInitVal(); 3062 bool FitsInInt; 3063 if (InitVal.isUnsigned() || !InitVal.isNegative()) 3064 FitsInInt = InitVal.getActiveBits() < IntWidth; 3065 else 3066 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 3067 3068 // If it fits into an integer type, force it. Otherwise force it to match 3069 // the enum decl type. 3070 QualType NewTy; 3071 unsigned NewWidth; 3072 bool NewSign; 3073 if (FitsInInt) { 3074 NewTy = Context.IntTy; 3075 NewWidth = IntWidth; 3076 NewSign = true; 3077 } else if (ECD->getType() == BestType) { 3078 // Already the right type! 3079 continue; 3080 } else { 3081 NewTy = BestType; 3082 NewWidth = BestWidth; 3083 NewSign = BestType->isSignedIntegerType(); 3084 } 3085 3086 // Adjust the APSInt value. 3087 InitVal.extOrTrunc(NewWidth); 3088 InitVal.setIsSigned(NewSign); 3089 ECD->setInitVal(InitVal); 3090 3091 // Adjust the Expr initializer and type. 3092 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr(), 3093 /*isLvalue=*/false)); 3094 ECD->setType(NewTy); 3095 } 3096 3097 Enum->defineElements(EltList, BestType); 3098 Consumer.HandleTagDeclDefinition(Enum); 3099} 3100 3101Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 3102 ExprTy *expr) { 3103 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 3104 3105 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 3106} 3107 3108Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 3109 SourceLocation LBrace, 3110 SourceLocation RBrace, 3111 const char *Lang, 3112 unsigned StrSize, 3113 DeclTy *D) { 3114 LinkageSpecDecl::LanguageIDs Language; 3115 Decl *dcl = static_cast<Decl *>(D); 3116 if (strncmp(Lang, "\"C\"", StrSize) == 0) 3117 Language = LinkageSpecDecl::lang_c; 3118 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 3119 Language = LinkageSpecDecl::lang_cxx; 3120 else { 3121 Diag(Loc, diag::err_bad_language); 3122 return 0; 3123 } 3124 3125 // FIXME: Add all the various semantics of linkage specifications 3126 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 3127} 3128 3129void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 3130 ExprTy *alignment, SourceLocation PragmaLoc, 3131 SourceLocation LParenLoc, SourceLocation RParenLoc) { 3132 Expr *Alignment = static_cast<Expr *>(alignment); 3133 3134 // If specified then alignment must be a "small" power of two. 3135 unsigned AlignmentVal = 0; 3136 if (Alignment) { 3137 llvm::APSInt Val; 3138 if (!Alignment->isIntegerConstantExpr(Val, Context) || 3139 !Val.isPowerOf2() || 3140 Val.getZExtValue() > 16) { 3141 Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 3142 delete Alignment; 3143 return; // Ignore 3144 } 3145 3146 AlignmentVal = (unsigned) Val.getZExtValue(); 3147 } 3148 3149 switch (Kind) { 3150 case Action::PPK_Default: // pack([n]) 3151 PackContext.setAlignment(AlignmentVal); 3152 break; 3153 3154 case Action::PPK_Show: // pack(show) 3155 // Show the current alignment, making sure to show the right value 3156 // for the default. 3157 AlignmentVal = PackContext.getAlignment(); 3158 // FIXME: This should come from the target. 3159 if (AlignmentVal == 0) 3160 AlignmentVal = 8; 3161 Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 3162 break; 3163 3164 case Action::PPK_Push: // pack(push [, id] [, [n]) 3165 PackContext.push(Name); 3166 // Set the new alignment if specified. 3167 if (Alignment) 3168 PackContext.setAlignment(AlignmentVal); 3169 break; 3170 3171 case Action::PPK_Pop: // pack(pop [, id] [, n]) 3172 // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 3173 // "#pragma pack(pop, identifier, n) is undefined" 3174 if (Alignment && Name) 3175 Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 3176 3177 // Do the pop. 3178 if (!PackContext.pop(Name)) { 3179 // If a name was specified then failure indicates the name 3180 // wasn't found. Otherwise failure indicates the stack was 3181 // empty. 3182 Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed) 3183 << (Name ? "no record matching name" : "stack empty"); 3184 3185 // FIXME: Warn about popping named records as MSVC does. 3186 } else { 3187 // Pop succeeded, set the new alignment if specified. 3188 if (Alignment) 3189 PackContext.setAlignment(AlignmentVal); 3190 } 3191 break; 3192 3193 default: 3194 assert(0 && "Invalid #pragma pack kind."); 3195 } 3196} 3197 3198bool PragmaPackStack::pop(IdentifierInfo *Name) { 3199 if (Stack.empty()) 3200 return false; 3201 3202 // If name is empty just pop top. 3203 if (!Name) { 3204 Alignment = Stack.back().first; 3205 Stack.pop_back(); 3206 return true; 3207 } 3208 3209 // Otherwise, find the named record. 3210 for (unsigned i = Stack.size(); i != 0; ) { 3211 --i; 3212 if (Stack[i].second == Name) { 3213 // Found it, pop up to and including this record. 3214 Alignment = Stack[i].first; 3215 Stack.erase(Stack.begin() + i, Stack.end()); 3216 return true; 3217 } 3218 } 3219 3220 return false; 3221} 3222