SemaDecl.cpp revision 6b6b5372f4b60b1c5ee101709e71a04642c835f4
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/ASTConsumer.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/Attr.h" 18#include "clang/AST/Builtins.h" 19#include "clang/AST/Decl.h" 20#include "clang/AST/DeclCXX.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/Type.h" 24#include "clang/Parse/DeclSpec.h" 25#include "clang/Parse/Scope.h" 26#include "clang/Basic/LangOptions.h" 27#include "clang/Basic/TargetInfo.h" 28#include "clang/Basic/SourceManager.h" 29// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 30#include "clang/Lex/Preprocessor.h" 31#include "clang/Lex/HeaderSearch.h" 32#include "llvm/ADT/SmallString.h" 33#include "llvm/ADT/SmallSet.h" 34#include "llvm/ADT/DenseSet.h" 35using namespace clang; 36 37Sema::DeclTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { 38 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); 39 40 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 41 isa<ObjCInterfaceDecl>(IIDecl) || 42 isa<TagDecl>(IIDecl))) 43 return IIDecl; 44 return 0; 45} 46 47void Sema::PushDeclContext(DeclContext *DC) { 48 assert( ( (isa<ObjCMethodDecl>(DC) && isa<TranslationUnitDecl>(CurContext)) 49 || DC->getParent() == CurContext ) && 50 "The next DeclContext should be directly contained in the current one."); 51 CurContext = DC; 52} 53 54void Sema::PopDeclContext() { 55 assert(CurContext && "DeclContext imbalance!"); 56 // If CurContext is a ObjC method, getParent() will return NULL. 57 CurContext = isa<ObjCMethodDecl>(CurContext) 58 ? Context.getTranslationUnitDecl() 59 : CurContext->getParent(); 60} 61 62/// Add this decl to the scope shadowed decl chains. 63void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 64 S->AddDecl(D); 65 66 // C++ [basic.scope]p4: 67 // -- exactly one declaration shall declare a class name or 68 // enumeration name that is not a typedef name and the other 69 // declarations shall all refer to the same object or 70 // enumerator, or all refer to functions and function templates; 71 // in this case the class name or enumeration name is hidden. 72 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 73 // We are pushing the name of a tag (enum or class). 74 IdentifierResolver::ctx_iterator 75 CIT = IdResolver.ctx_begin(TD->getIdentifier(), TD->getDeclContext()); 76 if (CIT != IdResolver.ctx_end(TD->getIdentifier()) && 77 IdResolver.isDeclInScope(*CIT, TD->getDeclContext(), S)) { 78 // There is already a declaration with the same name in the same 79 // scope. It must be found before we find the new declaration, 80 // so swap the order on the shadowed declaration chain. 81 82 IdResolver.AddShadowedDecl(TD, *CIT); 83 return; 84 } 85 } 86 87 IdResolver.AddDecl(D); 88} 89 90void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 91 if (S->decl_empty()) return; 92 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 93 94 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 95 I != E; ++I) { 96 Decl *TmpD = static_cast<Decl*>(*I); 97 assert(TmpD && "This decl didn't get pushed??"); 98 99 if (isa<CXXFieldDecl>(TmpD)) continue; 100 101 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 102 ScopedDecl *D = cast<ScopedDecl>(TmpD); 103 104 IdentifierInfo *II = D->getIdentifier(); 105 if (!II) continue; 106 107 // We only want to remove the decls from the identifier decl chains for local 108 // scopes, when inside a function/method. 109 if (S->getFnParent() != 0) 110 IdResolver.RemoveDecl(D); 111 112 // Chain this decl to the containing DeclContext. 113 D->setNext(CurContext->getDeclChain()); 114 CurContext->setDeclChain(D); 115 } 116} 117 118/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 119/// return 0 if one not found. 120ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 121 // The third "scope" argument is 0 since we aren't enabling lazy built-in 122 // creation from this context. 123 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 124 125 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 126} 127 128/// LookupDecl - Look up the inner-most declaration in the specified 129/// namespace. 130Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 131 Scope *S, bool enableLazyBuiltinCreation) { 132 if (II == 0) return 0; 133 unsigned NS = NSI; 134 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 135 NS |= Decl::IDNS_Tag; 136 137 // Scan up the scope chain looking for a decl that matches this identifier 138 // that is in the appropriate namespace. This search should not take long, as 139 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 140 for (IdentifierResolver::iterator 141 I = IdResolver.begin(II, CurContext), E = IdResolver.end(II); I != E; ++I) 142 if ((*I)->getIdentifierNamespace() & NS) 143 return *I; 144 145 // If we didn't find a use of this identifier, and if the identifier 146 // corresponds to a compiler builtin, create the decl object for the builtin 147 // now, injecting it into translation unit scope, and return it. 148 if (NS & Decl::IDNS_Ordinary) { 149 if (enableLazyBuiltinCreation) { 150 // If this is a builtin on this (or all) targets, create the decl. 151 if (unsigned BuiltinID = II->getBuiltinID()) 152 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 153 } 154 if (getLangOptions().ObjC1) { 155 // @interface and @compatibility_alias introduce typedef-like names. 156 // Unlike typedef's, they can only be introduced at file-scope (and are 157 // therefore not scoped decls). They can, however, be shadowed by 158 // other names in IDNS_Ordinary. 159 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 160 if (IDI != ObjCInterfaceDecls.end()) 161 return IDI->second; 162 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 163 if (I != ObjCAliasDecls.end()) 164 return I->second->getClassInterface(); 165 } 166 } 167 return 0; 168} 169 170void Sema::InitBuiltinVaListType() { 171 if (!Context.getBuiltinVaListType().isNull()) 172 return; 173 174 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 175 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 176 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 177 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 178} 179 180/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 181/// lazily create a decl for it. 182ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 183 Scope *S) { 184 Builtin::ID BID = (Builtin::ID)bid; 185 186 if (BID == Builtin::BI__builtin_va_start || 187 BID == Builtin::BI__builtin_va_copy || 188 BID == Builtin::BI__builtin_va_end) 189 InitBuiltinVaListType(); 190 191 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 192 FunctionDecl *New = FunctionDecl::Create(Context, 193 Context.getTranslationUnitDecl(), 194 SourceLocation(), II, R, 195 FunctionDecl::Extern, false, 0); 196 197 // Create Decl objects for each parameter, adding them to the 198 // FunctionDecl. 199 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 200 llvm::SmallVector<ParmVarDecl*, 16> Params; 201 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 202 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 203 FT->getArgType(i), VarDecl::None, 0, 204 0)); 205 New->setParams(&Params[0], Params.size()); 206 } 207 208 209 210 // TUScope is the translation-unit scope to insert this function into. 211 PushOnScopeChains(New, TUScope); 212 return New; 213} 214 215/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 216/// and scope as a previous declaration 'Old'. Figure out how to resolve this 217/// situation, merging decls or emitting diagnostics as appropriate. 218/// 219TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 220 // Verify the old decl was also a typedef. 221 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 222 if (!Old) { 223 Diag(New->getLocation(), diag::err_redefinition_different_kind, 224 New->getName()); 225 Diag(OldD->getLocation(), diag::err_previous_definition); 226 return New; 227 } 228 229 // Allow multiple definitions for ObjC built-in typedefs. 230 // FIXME: Verify the underlying types are equivalent! 231 if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) 232 return Old; 233 234 if (getLangOptions().Microsoft) return New; 235 236 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 237 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 238 // *either* declaration is in a system header. The code below implements 239 // this adhoc compatibility rule. FIXME: The following code will not 240 // work properly when compiling ".i" files (containing preprocessed output). 241 SourceManager &SrcMgr = Context.getSourceManager(); 242 HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); 243 const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); 244 if (OldDeclFile) { 245 DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); 246 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 247 if (OldDirType != DirectoryLookup::NormalHeaderDir) 248 return New; 249 } 250 const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); 251 if (NewDeclFile) { 252 DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); 253 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 254 if (NewDirType != DirectoryLookup::NormalHeaderDir) 255 return New; 256 } 257 258 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 259 Diag(Old->getLocation(), diag::err_previous_definition); 260 return New; 261} 262 263/// DeclhasAttr - returns true if decl Declaration already has the target 264/// attribute. 265static bool DeclHasAttr(const Decl *decl, const Attr *target) { 266 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 267 if (attr->getKind() == target->getKind()) 268 return true; 269 270 return false; 271} 272 273/// MergeAttributes - append attributes from the Old decl to the New one. 274static void MergeAttributes(Decl *New, Decl *Old) { 275 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 276 277 while (attr) { 278 tmp = attr; 279 attr = attr->getNext(); 280 281 if (!DeclHasAttr(New, tmp)) { 282 New->addAttr(tmp); 283 } else { 284 tmp->setNext(0); 285 delete(tmp); 286 } 287 } 288 289 Old->invalidateAttrs(); 290} 291 292/// MergeFunctionDecl - We just parsed a function 'New' from 293/// declarator D which has the same name and scope as a previous 294/// declaration 'Old'. Figure out how to resolve this situation, 295/// merging decls or emitting diagnostics as appropriate. 296/// Redeclaration will be set true if thisNew is a redeclaration OldD. 297FunctionDecl * 298Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 299 Redeclaration = false; 300 // Verify the old decl was also a function. 301 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 302 if (!Old) { 303 Diag(New->getLocation(), diag::err_redefinition_different_kind, 304 New->getName()); 305 Diag(OldD->getLocation(), diag::err_previous_definition); 306 return New; 307 } 308 309 QualType OldQType = Context.getCanonicalType(Old->getType()); 310 QualType NewQType = Context.getCanonicalType(New->getType()); 311 312 // C++ [dcl.fct]p3: 313 // All declarations for a function shall agree exactly in both the 314 // return type and the parameter-type-list. 315 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 316 MergeAttributes(New, Old); 317 Redeclaration = true; 318 return MergeCXXFunctionDecl(New, Old); 319 } 320 321 // C: Function types need to be compatible, not identical. This handles 322 // duplicate function decls like "void f(int); void f(enum X);" properly. 323 if (!getLangOptions().CPlusPlus && 324 Context.functionTypesAreCompatible(OldQType, NewQType)) { 325 MergeAttributes(New, Old); 326 Redeclaration = true; 327 return New; 328 } 329 330 // A function that has already been declared has been redeclared or defined 331 // with a different type- show appropriate diagnostic 332 diag::kind PrevDiag; 333 if (Old->isThisDeclarationADefinition()) 334 PrevDiag = diag::err_previous_definition; 335 else if (Old->isImplicit()) 336 PrevDiag = diag::err_previous_implicit_declaration; 337 else 338 PrevDiag = diag::err_previous_declaration; 339 340 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 341 // TODO: This is totally simplistic. It should handle merging functions 342 // together etc, merging extern int X; int X; ... 343 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 344 Diag(Old->getLocation(), PrevDiag); 345 return New; 346} 347 348/// equivalentArrayTypes - Used to determine whether two array types are 349/// equivalent. 350/// We need to check this explicitly as an incomplete array definition is 351/// considered a VariableArrayType, so will not match a complete array 352/// definition that would be otherwise equivalent. 353static bool areEquivalentArrayTypes(QualType NewQType, QualType OldQType) { 354 const ArrayType *NewAT = NewQType->getAsArrayType(); 355 const ArrayType *OldAT = OldQType->getAsArrayType(); 356 357 if (!NewAT || !OldAT) 358 return false; 359 360 // If either (or both) array types in incomplete we need to strip off the 361 // outer VariableArrayType. Once the outer VAT is removed the remaining 362 // types must be identical if the array types are to be considered 363 // equivalent. 364 // eg. int[][1] and int[1][1] become 365 // VAT(null, CAT(1, int)) and CAT(1, CAT(1, int)) 366 // removing the outermost VAT gives 367 // CAT(1, int) and CAT(1, int) 368 // which are equal, therefore the array types are equivalent. 369 if (NewAT->isIncompleteArrayType() || OldAT->isIncompleteArrayType()) { 370 if (NewAT->getIndexTypeQualifier() != OldAT->getIndexTypeQualifier()) 371 return false; 372 NewQType = NewAT->getElementType().getCanonicalType(); 373 OldQType = OldAT->getElementType().getCanonicalType(); 374 } 375 376 return NewQType == OldQType; 377} 378 379/// MergeVarDecl - We just parsed a variable 'New' which has the same name 380/// and scope as a previous declaration 'Old'. Figure out how to resolve this 381/// situation, merging decls or emitting diagnostics as appropriate. 382/// 383/// FIXME: Need to carefully consider tentative definition rules (C99 6.9.2p2). 384/// For example, we incorrectly complain about i1, i4 from C99 6.9.2p4. 385/// 386VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 387 // Verify the old decl was also a variable. 388 VarDecl *Old = dyn_cast<VarDecl>(OldD); 389 if (!Old) { 390 Diag(New->getLocation(), diag::err_redefinition_different_kind, 391 New->getName()); 392 Diag(OldD->getLocation(), diag::err_previous_definition); 393 return New; 394 } 395 396 MergeAttributes(New, Old); 397 398 // Verify the types match. 399 QualType OldCType = Context.getCanonicalType(Old->getType()); 400 QualType NewCType = Context.getCanonicalType(New->getType()); 401 if (OldCType != NewCType && !areEquivalentArrayTypes(NewCType, OldCType)) { 402 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 403 Diag(Old->getLocation(), diag::err_previous_definition); 404 return New; 405 } 406 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 407 if (New->getStorageClass() == VarDecl::Static && 408 (Old->getStorageClass() == VarDecl::None || 409 Old->getStorageClass() == VarDecl::Extern)) { 410 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 411 Diag(Old->getLocation(), diag::err_previous_definition); 412 return New; 413 } 414 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 415 if (New->getStorageClass() != VarDecl::Static && 416 Old->getStorageClass() == VarDecl::Static) { 417 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 418 Diag(Old->getLocation(), diag::err_previous_definition); 419 return New; 420 } 421 // We've verified the types match, now handle "tentative" definitions. 422 if (Old->isFileVarDecl() && New->isFileVarDecl()) { 423 // Handle C "tentative" external object definitions (C99 6.9.2). 424 bool OldIsTentative = false; 425 bool NewIsTentative = false; 426 427 if (!Old->getInit() && 428 (Old->getStorageClass() == VarDecl::None || 429 Old->getStorageClass() == VarDecl::Static)) 430 OldIsTentative = true; 431 432 // FIXME: this check doesn't work (since the initializer hasn't been 433 // attached yet). This check should be moved to FinalizeDeclaratorGroup. 434 // Unfortunately, by the time we get to FinializeDeclaratorGroup, we've 435 // thrown out the old decl. 436 if (!New->getInit() && 437 (New->getStorageClass() == VarDecl::None || 438 New->getStorageClass() == VarDecl::Static)) 439 ; // change to NewIsTentative = true; once the code is moved. 440 441 if (NewIsTentative || OldIsTentative) 442 return New; 443 } 444 // Handle __private_extern__ just like extern. 445 if (Old->getStorageClass() != VarDecl::Extern && 446 Old->getStorageClass() != VarDecl::PrivateExtern && 447 New->getStorageClass() != VarDecl::Extern && 448 New->getStorageClass() != VarDecl::PrivateExtern) { 449 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 450 Diag(Old->getLocation(), diag::err_previous_definition); 451 } 452 return New; 453} 454 455/// CheckParmsForFunctionDef - Check that the parameters of the given 456/// function are appropriate for the definition of a function. This 457/// takes care of any checks that cannot be performed on the 458/// declaration itself, e.g., that the types of each of the function 459/// parameters are complete. 460bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 461 bool HasInvalidParm = false; 462 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 463 ParmVarDecl *Param = FD->getParamDecl(p); 464 465 // C99 6.7.5.3p4: the parameters in a parameter type list in a 466 // function declarator that is part of a function definition of 467 // that function shall not have incomplete type. 468 if (Param->getType()->isIncompleteType() && 469 !Param->isInvalidDecl()) { 470 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 471 Param->getType().getAsString()); 472 Param->setInvalidDecl(); 473 HasInvalidParm = true; 474 } 475 } 476 477 return HasInvalidParm; 478} 479 480/// CreateImplicitParameter - Creates an implicit function parameter 481/// in the scope S and with the given type. This routine is used, for 482/// example, to create the implicit "self" parameter in an Objective-C 483/// method. 484ImplicitParamDecl * 485Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 486 SourceLocation IdLoc, QualType Type) { 487 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 488 IdLoc, Id, Type, 0); 489 if (Id) 490 PushOnScopeChains(New, S); 491 492 return New; 493} 494 495/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 496/// no declarator (e.g. "struct foo;") is parsed. 497Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 498 // TODO: emit error on 'int;' or 'const enum foo;'. 499 // TODO: emit error on 'typedef int;' 500 // if (!DS.isMissingDeclaratorOk()) Diag(...); 501 502 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 503} 504 505bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 506 // Get the type before calling CheckSingleAssignmentConstraints(), since 507 // it can promote the expression. 508 QualType InitType = Init->getType(); 509 510 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 511 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 512 InitType, Init, "initializing"); 513} 514 515bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 516 if (const IncompleteArrayType *IAT = DeclT->getAsIncompleteArrayType()) { 517 // C99 6.7.8p14. We have an array of character type with unknown size 518 // being initialized to a string literal. 519 llvm::APSInt ConstVal(32); 520 ConstVal = strLiteral->getByteLength() + 1; 521 // Return a new array type (C99 6.7.8p22). 522 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 523 ArrayType::Normal, 0); 524 } else if (const ConstantArrayType *CAT = DeclT->getAsConstantArrayType()) { 525 // C99 6.7.8p14. We have an array of character type with known size. 526 if (strLiteral->getByteLength() > (unsigned)CAT->getMaximumElements()) 527 Diag(strLiteral->getSourceRange().getBegin(), 528 diag::warn_initializer_string_for_char_array_too_long, 529 strLiteral->getSourceRange()); 530 } else { 531 assert(0 && "HandleStringLiteralInit(): Invalid array type"); 532 } 533 // Set type from "char *" to "constant array of char". 534 strLiteral->setType(DeclT); 535 // For now, we always return false (meaning success). 536 return false; 537} 538 539StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 540 const ArrayType *AT = DeclType->getAsArrayType(); 541 if (AT && AT->getElementType()->isCharType()) { 542 return dyn_cast<StringLiteral>(Init); 543 } 544 return 0; 545} 546 547bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 548 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 549 // of unknown size ("[]") or an object type that is not a variable array type. 550 if (const VariableArrayType *VAT = DeclType->getAsVariableArrayType()) 551 return Diag(VAT->getSizeExpr()->getLocStart(), 552 diag::err_variable_object_no_init, 553 VAT->getSizeExpr()->getSourceRange()); 554 555 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 556 if (!InitList) { 557 // FIXME: Handle wide strings 558 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 559 return CheckStringLiteralInit(strLiteral, DeclType); 560 561 if (DeclType->isArrayType()) 562 return Diag(Init->getLocStart(), 563 diag::err_array_init_list_required, 564 Init->getSourceRange()); 565 566 return CheckSingleInitializer(Init, DeclType); 567 } 568 569 InitListChecker CheckInitList(this, InitList, DeclType); 570 return CheckInitList.HadError(); 571} 572 573Sema::DeclTy * 574Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 575 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 576 IdentifierInfo *II = D.getIdentifier(); 577 578 // All of these full declarators require an identifier. If it doesn't have 579 // one, the ParsedFreeStandingDeclSpec action should be used. 580 if (II == 0) { 581 Diag(D.getDeclSpec().getSourceRange().getBegin(), 582 diag::err_declarator_need_ident, 583 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 584 return 0; 585 } 586 587 // The scope passed in may not be a decl scope. Zip up the scope tree until 588 // we find one that is. 589 while ((S->getFlags() & Scope::DeclScope) == 0) 590 S = S->getParent(); 591 592 // See if this is a redefinition of a variable in the same scope. 593 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 594 ScopedDecl *New; 595 bool InvalidDecl = false; 596 597 // In C++, the previous declaration we find might be a tag type 598 // (class or enum). In this case, the new declaration will hide the 599 // tag type. 600 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 601 PrevDecl = 0; 602 603 QualType R = GetTypeForDeclarator(D, S); 604 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 605 606 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 607 // Check that there are no default arguments (C++ only). 608 if (getLangOptions().CPlusPlus) 609 CheckExtraCXXDefaultArguments(D); 610 611 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 612 if (!NewTD) return 0; 613 614 // Handle attributes prior to checking for duplicates in MergeVarDecl 615 HandleDeclAttributes(NewTD, D.getDeclSpec().getAttributes(), 616 D.getAttributes()); 617 // Merge the decl with the existing one if appropriate. If the decl is 618 // in an outer scope, it isn't the same thing. 619 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 620 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 621 if (NewTD == 0) return 0; 622 } 623 New = NewTD; 624 if (S->getFnParent() == 0) { 625 // C99 6.7.7p2: If a typedef name specifies a variably modified type 626 // then it shall have block scope. 627 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 628 // FIXME: Diagnostic needs to be fixed. 629 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 630 InvalidDecl = true; 631 } 632 } 633 } else if (R.getTypePtr()->isFunctionType()) { 634 FunctionDecl::StorageClass SC = FunctionDecl::None; 635 switch (D.getDeclSpec().getStorageClassSpec()) { 636 default: assert(0 && "Unknown storage class!"); 637 case DeclSpec::SCS_auto: 638 case DeclSpec::SCS_register: 639 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 640 R.getAsString()); 641 InvalidDecl = true; 642 break; 643 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 644 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 645 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 646 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 647 } 648 649 bool isInline = D.getDeclSpec().isInlineSpecified(); 650 FunctionDecl *NewFD = FunctionDecl::Create(Context, CurContext, 651 D.getIdentifierLoc(), 652 II, R, SC, isInline, 653 LastDeclarator); 654 // Handle attributes. 655 HandleDeclAttributes(NewFD, D.getDeclSpec().getAttributes(), 656 D.getAttributes()); 657 658 // Copy the parameter declarations from the declarator D to 659 // the function declaration NewFD, if they are available. 660 if (D.getNumTypeObjects() > 0 && 661 D.getTypeObject(0).Fun.hasPrototype) { 662 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 663 664 // Create Decl objects for each parameter, adding them to the 665 // FunctionDecl. 666 llvm::SmallVector<ParmVarDecl*, 16> Params; 667 668 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 669 // function that takes no arguments, not a function that takes a 670 // single void argument. 671 // We let through "const void" here because Sema::GetTypeForDeclarator 672 // already checks for that case. 673 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 674 FTI.ArgInfo[0].Param && 675 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 676 // empty arg list, don't push any params. 677 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 678 679 // In C++, the empty parameter-type-list must be spelled "void"; a 680 // typedef of void is not permitted. 681 if (getLangOptions().CPlusPlus && 682 Param->getType().getUnqualifiedType() != Context.VoidTy) { 683 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 684 } 685 686 } else { 687 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 688 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 689 } 690 691 NewFD->setParams(&Params[0], Params.size()); 692 } 693 694 // Merge the decl with the existing one if appropriate. Since C functions 695 // are in a flat namespace, make sure we consider decls in outer scopes. 696 if (PrevDecl && 697 (!getLangOptions().CPlusPlus || 698 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 699 bool Redeclaration = false; 700 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 701 if (NewFD == 0) return 0; 702 if (Redeclaration) { 703 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 704 } 705 } 706 New = NewFD; 707 708 // In C++, check default arguments now that we have merged decls. 709 if (getLangOptions().CPlusPlus) 710 CheckCXXDefaultArguments(NewFD); 711 } else { 712 // Check that there are no default arguments (C++ only). 713 if (getLangOptions().CPlusPlus) 714 CheckExtraCXXDefaultArguments(D); 715 716 if (R.getTypePtr()->isObjCInterfaceType()) { 717 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 718 D.getIdentifier()->getName()); 719 InvalidDecl = true; 720 } 721 722 VarDecl *NewVD; 723 VarDecl::StorageClass SC; 724 switch (D.getDeclSpec().getStorageClassSpec()) { 725 default: assert(0 && "Unknown storage class!"); 726 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 727 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 728 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 729 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 730 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 731 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 732 } 733 if (S->getFnParent() == 0) { 734 // C99 6.9p2: The storage-class specifiers auto and register shall not 735 // appear in the declaration specifiers in an external declaration. 736 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 737 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 738 R.getAsString()); 739 InvalidDecl = true; 740 } 741 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 742 II, R, SC, LastDeclarator); 743 } else { 744 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 745 II, R, SC, LastDeclarator); 746 } 747 // Handle attributes prior to checking for duplicates in MergeVarDecl 748 HandleDeclAttributes(NewVD, D.getDeclSpec().getAttributes(), 749 D.getAttributes()); 750 751 // Emit an error if an address space was applied to decl with local storage. 752 // This includes arrays of objects with address space qualifiers, but not 753 // automatic variables that point to other address spaces. 754 // ISO/IEC TR 18037 S5.1.2 755 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 756 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 757 InvalidDecl = true; 758 } 759 // Merge the decl with the existing one if appropriate. If the decl is 760 // in an outer scope, it isn't the same thing. 761 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 762 NewVD = MergeVarDecl(NewVD, PrevDecl); 763 if (NewVD == 0) return 0; 764 } 765 New = NewVD; 766 } 767 768 // If this has an identifier, add it to the scope stack. 769 if (II) 770 PushOnScopeChains(New, S); 771 // If any semantic error occurred, mark the decl as invalid. 772 if (D.getInvalidType() || InvalidDecl) 773 New->setInvalidDecl(); 774 775 return New; 776} 777 778bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 779 switch (Init->getStmtClass()) { 780 default: 781 Diag(Init->getExprLoc(), 782 diag::err_init_element_not_constant, Init->getSourceRange()); 783 return true; 784 case Expr::ParenExprClass: { 785 const ParenExpr* PE = cast<ParenExpr>(Init); 786 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 787 } 788 case Expr::CompoundLiteralExprClass: 789 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 790 case Expr::DeclRefExprClass: { 791 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 792 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 793 if (VD->hasGlobalStorage()) 794 return false; 795 Diag(Init->getExprLoc(), 796 diag::err_init_element_not_constant, Init->getSourceRange()); 797 return true; 798 } 799 if (isa<FunctionDecl>(D)) 800 return false; 801 Diag(Init->getExprLoc(), 802 diag::err_init_element_not_constant, Init->getSourceRange()); 803 return true; 804 } 805 case Expr::MemberExprClass: { 806 const MemberExpr *M = cast<MemberExpr>(Init); 807 if (M->isArrow()) 808 return CheckAddressConstantExpression(M->getBase()); 809 return CheckAddressConstantExpressionLValue(M->getBase()); 810 } 811 case Expr::ArraySubscriptExprClass: { 812 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 813 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 814 return CheckAddressConstantExpression(ASE->getBase()) || 815 CheckArithmeticConstantExpression(ASE->getIdx()); 816 } 817 case Expr::StringLiteralClass: 818 case Expr::PreDefinedExprClass: 819 return false; 820 case Expr::UnaryOperatorClass: { 821 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 822 823 // C99 6.6p9 824 if (Exp->getOpcode() == UnaryOperator::Deref) 825 return CheckAddressConstantExpression(Exp->getSubExpr()); 826 827 Diag(Init->getExprLoc(), 828 diag::err_init_element_not_constant, Init->getSourceRange()); 829 return true; 830 } 831 } 832} 833 834bool Sema::CheckAddressConstantExpression(const Expr* Init) { 835 switch (Init->getStmtClass()) { 836 default: 837 Diag(Init->getExprLoc(), 838 diag::err_init_element_not_constant, Init->getSourceRange()); 839 return true; 840 case Expr::ParenExprClass: { 841 const ParenExpr* PE = cast<ParenExpr>(Init); 842 return CheckAddressConstantExpression(PE->getSubExpr()); 843 } 844 case Expr::StringLiteralClass: 845 case Expr::ObjCStringLiteralClass: 846 return false; 847 case Expr::CallExprClass: { 848 const CallExpr *CE = cast<CallExpr>(Init); 849 if (CE->isBuiltinConstantExpr()) 850 return false; 851 Diag(Init->getExprLoc(), 852 diag::err_init_element_not_constant, Init->getSourceRange()); 853 return true; 854 } 855 case Expr::UnaryOperatorClass: { 856 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 857 858 // C99 6.6p9 859 if (Exp->getOpcode() == UnaryOperator::AddrOf) 860 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 861 862 if (Exp->getOpcode() == UnaryOperator::Extension) 863 return CheckAddressConstantExpression(Exp->getSubExpr()); 864 865 Diag(Init->getExprLoc(), 866 diag::err_init_element_not_constant, Init->getSourceRange()); 867 return true; 868 } 869 case Expr::BinaryOperatorClass: { 870 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 871 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 872 873 Expr *PExp = Exp->getLHS(); 874 Expr *IExp = Exp->getRHS(); 875 if (IExp->getType()->isPointerType()) 876 std::swap(PExp, IExp); 877 878 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 879 return CheckAddressConstantExpression(PExp) || 880 CheckArithmeticConstantExpression(IExp); 881 } 882 case Expr::ImplicitCastExprClass: { 883 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 884 885 // Check for implicit promotion 886 if (SubExpr->getType()->isFunctionType() || 887 SubExpr->getType()->isArrayType()) 888 return CheckAddressConstantExpressionLValue(SubExpr); 889 890 // Check for pointer->pointer cast 891 if (SubExpr->getType()->isPointerType()) 892 return CheckAddressConstantExpression(SubExpr); 893 894 if (SubExpr->getType()->isArithmeticType()) 895 return CheckArithmeticConstantExpression(SubExpr); 896 897 Diag(Init->getExprLoc(), 898 diag::err_init_element_not_constant, Init->getSourceRange()); 899 return true; 900 } 901 case Expr::CastExprClass: { 902 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 903 904 // Check for pointer->pointer cast 905 if (SubExpr->getType()->isPointerType()) 906 return CheckAddressConstantExpression(SubExpr); 907 908 // FIXME: Should we pedwarn for (int*)(0+0)? 909 if (SubExpr->getType()->isArithmeticType()) 910 return CheckArithmeticConstantExpression(SubExpr); 911 912 Diag(Init->getExprLoc(), 913 diag::err_init_element_not_constant, Init->getSourceRange()); 914 return true; 915 } 916 case Expr::ConditionalOperatorClass: { 917 // FIXME: Should we pedwarn here? 918 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 919 if (!Exp->getCond()->getType()->isArithmeticType()) { 920 Diag(Init->getExprLoc(), 921 diag::err_init_element_not_constant, Init->getSourceRange()); 922 return true; 923 } 924 if (CheckArithmeticConstantExpression(Exp->getCond())) 925 return true; 926 if (Exp->getLHS() && 927 CheckAddressConstantExpression(Exp->getLHS())) 928 return true; 929 return CheckAddressConstantExpression(Exp->getRHS()); 930 } 931 case Expr::AddrLabelExprClass: 932 return false; 933 } 934} 935 936static const Expr* FindExpressionBaseAddress(const Expr* E); 937 938static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 939 switch (E->getStmtClass()) { 940 default: 941 return E; 942 case Expr::ParenExprClass: { 943 const ParenExpr* PE = cast<ParenExpr>(E); 944 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 945 } 946 case Expr::MemberExprClass: { 947 const MemberExpr *M = cast<MemberExpr>(E); 948 if (M->isArrow()) 949 return FindExpressionBaseAddress(M->getBase()); 950 return FindExpressionBaseAddressLValue(M->getBase()); 951 } 952 case Expr::ArraySubscriptExprClass: { 953 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 954 return FindExpressionBaseAddress(ASE->getBase()); 955 } 956 case Expr::UnaryOperatorClass: { 957 const UnaryOperator *Exp = cast<UnaryOperator>(E); 958 959 if (Exp->getOpcode() == UnaryOperator::Deref) 960 return FindExpressionBaseAddress(Exp->getSubExpr()); 961 962 return E; 963 } 964 } 965} 966 967static const Expr* FindExpressionBaseAddress(const Expr* E) { 968 switch (E->getStmtClass()) { 969 default: 970 return E; 971 case Expr::ParenExprClass: { 972 const ParenExpr* PE = cast<ParenExpr>(E); 973 return FindExpressionBaseAddress(PE->getSubExpr()); 974 } 975 case Expr::UnaryOperatorClass: { 976 const UnaryOperator *Exp = cast<UnaryOperator>(E); 977 978 // C99 6.6p9 979 if (Exp->getOpcode() == UnaryOperator::AddrOf) 980 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 981 982 if (Exp->getOpcode() == UnaryOperator::Extension) 983 return FindExpressionBaseAddress(Exp->getSubExpr()); 984 985 return E; 986 } 987 case Expr::BinaryOperatorClass: { 988 const BinaryOperator *Exp = cast<BinaryOperator>(E); 989 990 Expr *PExp = Exp->getLHS(); 991 Expr *IExp = Exp->getRHS(); 992 if (IExp->getType()->isPointerType()) 993 std::swap(PExp, IExp); 994 995 return FindExpressionBaseAddress(PExp); 996 } 997 case Expr::ImplicitCastExprClass: { 998 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 999 1000 // Check for implicit promotion 1001 if (SubExpr->getType()->isFunctionType() || 1002 SubExpr->getType()->isArrayType()) 1003 return FindExpressionBaseAddressLValue(SubExpr); 1004 1005 // Check for pointer->pointer cast 1006 if (SubExpr->getType()->isPointerType()) 1007 return FindExpressionBaseAddress(SubExpr); 1008 1009 // We assume that we have an arithmetic expression here; 1010 // if we don't, we'll figure it out later 1011 return 0; 1012 } 1013 case Expr::CastExprClass: { 1014 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1015 1016 // Check for pointer->pointer cast 1017 if (SubExpr->getType()->isPointerType()) 1018 return FindExpressionBaseAddress(SubExpr); 1019 1020 // We assume that we have an arithmetic expression here; 1021 // if we don't, we'll figure it out later 1022 return 0; 1023 } 1024 } 1025} 1026 1027bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1028 switch (Init->getStmtClass()) { 1029 default: 1030 Diag(Init->getExprLoc(), 1031 diag::err_init_element_not_constant, Init->getSourceRange()); 1032 return true; 1033 case Expr::ParenExprClass: { 1034 const ParenExpr* PE = cast<ParenExpr>(Init); 1035 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1036 } 1037 case Expr::FloatingLiteralClass: 1038 case Expr::IntegerLiteralClass: 1039 case Expr::CharacterLiteralClass: 1040 case Expr::ImaginaryLiteralClass: 1041 case Expr::TypesCompatibleExprClass: 1042 case Expr::CXXBoolLiteralExprClass: 1043 return false; 1044 case Expr::CallExprClass: { 1045 const CallExpr *CE = cast<CallExpr>(Init); 1046 if (CE->isBuiltinConstantExpr()) 1047 return false; 1048 Diag(Init->getExprLoc(), 1049 diag::err_init_element_not_constant, Init->getSourceRange()); 1050 return true; 1051 } 1052 case Expr::DeclRefExprClass: { 1053 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1054 if (isa<EnumConstantDecl>(D)) 1055 return false; 1056 Diag(Init->getExprLoc(), 1057 diag::err_init_element_not_constant, Init->getSourceRange()); 1058 return true; 1059 } 1060 case Expr::CompoundLiteralExprClass: 1061 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1062 // but vectors are allowed to be magic. 1063 if (Init->getType()->isVectorType()) 1064 return false; 1065 Diag(Init->getExprLoc(), 1066 diag::err_init_element_not_constant, Init->getSourceRange()); 1067 return true; 1068 case Expr::UnaryOperatorClass: { 1069 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1070 1071 switch (Exp->getOpcode()) { 1072 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1073 // See C99 6.6p3. 1074 default: 1075 Diag(Init->getExprLoc(), 1076 diag::err_init_element_not_constant, Init->getSourceRange()); 1077 return true; 1078 case UnaryOperator::SizeOf: 1079 case UnaryOperator::AlignOf: 1080 case UnaryOperator::OffsetOf: 1081 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1082 // See C99 6.5.3.4p2 and 6.6p3. 1083 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1084 return false; 1085 Diag(Init->getExprLoc(), 1086 diag::err_init_element_not_constant, Init->getSourceRange()); 1087 return true; 1088 case UnaryOperator::Extension: 1089 case UnaryOperator::LNot: 1090 case UnaryOperator::Plus: 1091 case UnaryOperator::Minus: 1092 case UnaryOperator::Not: 1093 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1094 } 1095 } 1096 case Expr::SizeOfAlignOfTypeExprClass: { 1097 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1098 // Special check for void types, which are allowed as an extension 1099 if (Exp->getArgumentType()->isVoidType()) 1100 return false; 1101 // alignof always evaluates to a constant. 1102 // FIXME: is sizeof(int[3.0]) a constant expression? 1103 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1104 Diag(Init->getExprLoc(), 1105 diag::err_init_element_not_constant, Init->getSourceRange()); 1106 return true; 1107 } 1108 return false; 1109 } 1110 case Expr::BinaryOperatorClass: { 1111 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1112 1113 if (Exp->getLHS()->getType()->isArithmeticType() && 1114 Exp->getRHS()->getType()->isArithmeticType()) { 1115 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1116 CheckArithmeticConstantExpression(Exp->getRHS()); 1117 } 1118 1119 if (Exp->getLHS()->getType()->isPointerType() && 1120 Exp->getRHS()->getType()->isPointerType()) { 1121 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1122 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1123 1124 // Only allow a null (constant integer) base; we could 1125 // allow some additional cases if necessary, but this 1126 // is sufficient to cover offsetof-like constructs. 1127 if (!LHSBase && !RHSBase) { 1128 return CheckAddressConstantExpression(Exp->getLHS()) || 1129 CheckAddressConstantExpression(Exp->getRHS()); 1130 } 1131 } 1132 1133 Diag(Init->getExprLoc(), 1134 diag::err_init_element_not_constant, Init->getSourceRange()); 1135 return true; 1136 } 1137 case Expr::ImplicitCastExprClass: 1138 case Expr::CastExprClass: { 1139 const Expr *SubExpr; 1140 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1141 SubExpr = C->getSubExpr(); 1142 } else { 1143 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1144 } 1145 1146 if (SubExpr->getType()->isArithmeticType()) 1147 return CheckArithmeticConstantExpression(SubExpr); 1148 1149 Diag(Init->getExprLoc(), 1150 diag::err_init_element_not_constant, Init->getSourceRange()); 1151 return true; 1152 } 1153 case Expr::ConditionalOperatorClass: { 1154 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1155 if (CheckArithmeticConstantExpression(Exp->getCond())) 1156 return true; 1157 if (Exp->getLHS() && 1158 CheckArithmeticConstantExpression(Exp->getLHS())) 1159 return true; 1160 return CheckArithmeticConstantExpression(Exp->getRHS()); 1161 } 1162 } 1163} 1164 1165bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1166 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1167 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1168 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1169 1170 if (Init->getType()->isReferenceType()) { 1171 // FIXME: Work out how the heck reference types work 1172 return false; 1173#if 0 1174 // A reference is constant if the address of the expression 1175 // is constant 1176 // We look through initlists here to simplify 1177 // CheckAddressConstantExpressionLValue. 1178 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1179 assert(Exp->getNumInits() > 0 && 1180 "Refernce initializer cannot be empty"); 1181 Init = Exp->getInit(0); 1182 } 1183 return CheckAddressConstantExpressionLValue(Init); 1184#endif 1185 } 1186 1187 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1188 unsigned numInits = Exp->getNumInits(); 1189 for (unsigned i = 0; i < numInits; i++) { 1190 // FIXME: Need to get the type of the declaration for C++, 1191 // because it could be a reference? 1192 if (CheckForConstantInitializer(Exp->getInit(i), 1193 Exp->getInit(i)->getType())) 1194 return true; 1195 } 1196 return false; 1197 } 1198 1199 if (Init->isNullPointerConstant(Context)) 1200 return false; 1201 if (Init->getType()->isArithmeticType()) { 1202 QualType InitTy = Init->getType().getCanonicalType().getUnqualifiedType(); 1203 if (InitTy == Context.BoolTy) { 1204 // Special handling for pointers implicitly cast to bool; 1205 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1206 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1207 Expr* SubE = ICE->getSubExpr(); 1208 if (SubE->getType()->isPointerType() || 1209 SubE->getType()->isArrayType() || 1210 SubE->getType()->isFunctionType()) { 1211 return CheckAddressConstantExpression(Init); 1212 } 1213 } 1214 } else if (InitTy->isIntegralType()) { 1215 Expr* SubE = 0; 1216 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1217 SubE = ICE->getSubExpr(); 1218 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1219 SubE = CE->getSubExpr(); 1220 // Special check for pointer cast to int; we allow as an extension 1221 // an address constant cast to an integer if the integer 1222 // is of an appropriate width (this sort of code is apparently used 1223 // in some places). 1224 // FIXME: Add pedwarn? 1225 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1226 if (SubE && (SubE->getType()->isPointerType() || 1227 SubE->getType()->isArrayType() || 1228 SubE->getType()->isFunctionType())) { 1229 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1230 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1231 if (IntWidth >= PointerWidth) 1232 return CheckAddressConstantExpression(Init); 1233 } 1234 } 1235 1236 return CheckArithmeticConstantExpression(Init); 1237 } 1238 1239 if (Init->getType()->isPointerType()) 1240 return CheckAddressConstantExpression(Init); 1241 1242 // An array type at the top level that isn't an init-list must 1243 // be a string literal 1244 if (Init->getType()->isArrayType()) 1245 return false; 1246 1247 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1248 Init->getSourceRange()); 1249 return true; 1250} 1251 1252void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1253 Decl *RealDecl = static_cast<Decl *>(dcl); 1254 Expr *Init = static_cast<Expr *>(init); 1255 assert(Init && "missing initializer"); 1256 1257 // If there is no declaration, there was an error parsing it. Just ignore 1258 // the initializer. 1259 if (RealDecl == 0) { 1260 delete Init; 1261 return; 1262 } 1263 1264 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1265 if (!VDecl) { 1266 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1267 diag::err_illegal_initializer); 1268 RealDecl->setInvalidDecl(); 1269 return; 1270 } 1271 // Get the decls type and save a reference for later, since 1272 // CheckInitializerTypes may change it. 1273 QualType DclT = VDecl->getType(), SavT = DclT; 1274 if (VDecl->isBlockVarDecl()) { 1275 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1276 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1277 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1278 VDecl->setInvalidDecl(); 1279 } else if (!VDecl->isInvalidDecl()) { 1280 if (CheckInitializerTypes(Init, DclT)) 1281 VDecl->setInvalidDecl(); 1282 if (SC == VarDecl::Static) // C99 6.7.8p4. 1283 CheckForConstantInitializer(Init, DclT); 1284 } 1285 } else if (VDecl->isFileVarDecl()) { 1286 if (VDecl->getStorageClass() == VarDecl::Extern) 1287 Diag(VDecl->getLocation(), diag::warn_extern_init); 1288 if (!VDecl->isInvalidDecl()) 1289 if (CheckInitializerTypes(Init, DclT)) 1290 VDecl->setInvalidDecl(); 1291 1292 // C99 6.7.8p4. All file scoped initializers need to be constant. 1293 CheckForConstantInitializer(Init, DclT); 1294 } 1295 // If the type changed, it means we had an incomplete type that was 1296 // completed by the initializer. For example: 1297 // int ary[] = { 1, 3, 5 }; 1298 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1299 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1300 VDecl->setType(DclT); 1301 Init->setType(DclT); 1302 } 1303 1304 // Attach the initializer to the decl. 1305 VDecl->setInit(Init); 1306 return; 1307} 1308 1309/// The declarators are chained together backwards, reverse the list. 1310Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1311 // Often we have single declarators, handle them quickly. 1312 Decl *GroupDecl = static_cast<Decl*>(group); 1313 if (GroupDecl == 0) 1314 return 0; 1315 1316 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1317 ScopedDecl *NewGroup = 0; 1318 if (Group->getNextDeclarator() == 0) 1319 NewGroup = Group; 1320 else { // reverse the list. 1321 while (Group) { 1322 ScopedDecl *Next = Group->getNextDeclarator(); 1323 Group->setNextDeclarator(NewGroup); 1324 NewGroup = Group; 1325 Group = Next; 1326 } 1327 } 1328 // Perform semantic analysis that depends on having fully processed both 1329 // the declarator and initializer. 1330 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1331 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1332 if (!IDecl) 1333 continue; 1334 QualType T = IDecl->getType(); 1335 1336 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1337 // static storage duration, it shall not have a variable length array. 1338 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1339 IDecl->getStorageClass() == VarDecl::Static) { 1340 if (T->getAsVariableArrayType()) { 1341 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1342 IDecl->setInvalidDecl(); 1343 } 1344 } 1345 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1346 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1347 if (IDecl->isBlockVarDecl() && 1348 IDecl->getStorageClass() != VarDecl::Extern) { 1349 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1350 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1351 T.getAsString()); 1352 IDecl->setInvalidDecl(); 1353 } 1354 } 1355 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1356 // object that has file scope without an initializer, and without a 1357 // storage-class specifier or with the storage-class specifier "static", 1358 // constitutes a tentative definition. Note: A tentative definition with 1359 // external linkage is valid (C99 6.2.2p5). 1360 if (IDecl && !IDecl->getInit() && 1361 (IDecl->getStorageClass() == VarDecl::Static || 1362 IDecl->getStorageClass() == VarDecl::None)) { 1363 if (T->isIncompleteArrayType()) { 1364 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1365 // array to be completed. Don't issue a diagnostic. 1366 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1367 // C99 6.9.2p3: If the declaration of an identifier for an object is 1368 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1369 // declared type shall not be an incomplete type. 1370 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1371 T.getAsString()); 1372 IDecl->setInvalidDecl(); 1373 } 1374 } 1375 } 1376 return NewGroup; 1377} 1378 1379/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1380/// to introduce parameters into function prototype scope. 1381Sema::DeclTy * 1382Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1383 const DeclSpec &DS = D.getDeclSpec(); 1384 1385 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1386 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1387 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1388 Diag(DS.getStorageClassSpecLoc(), 1389 diag::err_invalid_storage_class_in_func_decl); 1390 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1391 } 1392 if (DS.isThreadSpecified()) { 1393 Diag(DS.getThreadSpecLoc(), 1394 diag::err_invalid_storage_class_in_func_decl); 1395 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1396 } 1397 1398 // Check that there are no default arguments inside the type of this 1399 // parameter (C++ only). 1400 if (getLangOptions().CPlusPlus) 1401 CheckExtraCXXDefaultArguments(D); 1402 1403 // In this context, we *do not* check D.getInvalidType(). If the declarator 1404 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1405 // though it will not reflect the user specified type. 1406 QualType parmDeclType = GetTypeForDeclarator(D, S); 1407 1408 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1409 1410 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1411 // Can this happen for params? We already checked that they don't conflict 1412 // among each other. Here they can only shadow globals, which is ok. 1413 IdentifierInfo *II = D.getIdentifier(); 1414 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1415 if (S->isDeclScope(PrevDecl)) { 1416 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1417 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1418 1419 // Recover by removing the name 1420 II = 0; 1421 D.SetIdentifier(0, D.getIdentifierLoc()); 1422 } 1423 } 1424 1425 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1426 // Doing the promotion here has a win and a loss. The win is the type for 1427 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1428 // code generator). The loss is the orginal type isn't preserved. For example: 1429 // 1430 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1431 // int blockvardecl[5]; 1432 // sizeof(parmvardecl); // size == 4 1433 // sizeof(blockvardecl); // size == 20 1434 // } 1435 // 1436 // For expressions, all implicit conversions are captured using the 1437 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1438 // 1439 // FIXME: If a source translation tool needs to see the original type, then 1440 // we need to consider storing both types (in ParmVarDecl)... 1441 // 1442 if (parmDeclType->isArrayType()) { 1443 // int x[restrict 4] -> int *restrict 1444 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1445 } else if (parmDeclType->isFunctionType()) 1446 parmDeclType = Context.getPointerType(parmDeclType); 1447 1448 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1449 D.getIdentifierLoc(), II, 1450 parmDeclType, VarDecl::None, 1451 0, 0); 1452 1453 if (D.getInvalidType()) 1454 New->setInvalidDecl(); 1455 1456 if (II) 1457 PushOnScopeChains(New, S); 1458 1459 HandleDeclAttributes(New, D.getDeclSpec().getAttributes(), 1460 D.getAttributes()); 1461 return New; 1462 1463} 1464 1465Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1466 assert(CurFunctionDecl == 0 && "Function parsing confused"); 1467 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1468 "Not a function declarator!"); 1469 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1470 1471 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1472 // for a K&R function. 1473 if (!FTI.hasPrototype) { 1474 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1475 if (FTI.ArgInfo[i].Param == 0) { 1476 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1477 FTI.ArgInfo[i].Ident->getName()); 1478 // Implicitly declare the argument as type 'int' for lack of a better 1479 // type. 1480 DeclSpec DS; 1481 const char* PrevSpec; // unused 1482 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1483 PrevSpec); 1484 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1485 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1486 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1487 } 1488 } 1489 1490 // Since this is a function definition, act as though we have information 1491 // about the arguments. 1492 if (FTI.NumArgs) 1493 FTI.hasPrototype = true; 1494 } else { 1495 // FIXME: Diagnose arguments without names in C. 1496 } 1497 1498 Scope *GlobalScope = FnBodyScope->getParent(); 1499 1500 // See if this is a redefinition. 1501 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1502 GlobalScope); 1503 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1504 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1505 const FunctionDecl *Definition; 1506 if (FD->getBody(Definition)) { 1507 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1508 D.getIdentifier()->getName()); 1509 Diag(Definition->getLocation(), diag::err_previous_definition); 1510 } 1511 } 1512 } 1513 Decl *decl = static_cast<Decl*>(ActOnDeclarator(GlobalScope, D, 0)); 1514 FunctionDecl *FD = cast<FunctionDecl>(decl); 1515 CurFunctionDecl = FD; 1516 PushDeclContext(FD); 1517 1518 // Check the validity of our function parameters 1519 CheckParmsForFunctionDef(FD); 1520 1521 // Introduce our parameters into the function scope 1522 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1523 ParmVarDecl *Param = FD->getParamDecl(p); 1524 // If this has an identifier, add it to the scope stack. 1525 if (Param->getIdentifier()) 1526 PushOnScopeChains(Param, FnBodyScope); 1527 } 1528 1529 return FD; 1530} 1531 1532Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1533 Decl *dcl = static_cast<Decl *>(D); 1534 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(dcl)) { 1535 FD->setBody((Stmt*)Body); 1536 assert(FD == CurFunctionDecl && "Function parsing confused"); 1537 CurFunctionDecl = 0; 1538 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(dcl)) { 1539 MD->setBody((Stmt*)Body); 1540 CurMethodDecl = 0; 1541 } 1542 PopDeclContext(); 1543 // Verify and clean out per-function state. 1544 1545 // Check goto/label use. 1546 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1547 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1548 // Verify that we have no forward references left. If so, there was a goto 1549 // or address of a label taken, but no definition of it. Label fwd 1550 // definitions are indicated with a null substmt. 1551 if (I->second->getSubStmt() == 0) { 1552 LabelStmt *L = I->second; 1553 // Emit error. 1554 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1555 1556 // At this point, we have gotos that use the bogus label. Stitch it into 1557 // the function body so that they aren't leaked and that the AST is well 1558 // formed. 1559 if (Body) { 1560 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1561 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1562 } else { 1563 // The whole function wasn't parsed correctly, just delete this. 1564 delete L; 1565 } 1566 } 1567 } 1568 LabelMap.clear(); 1569 1570 return D; 1571} 1572 1573/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1574/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1575ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1576 IdentifierInfo &II, Scope *S) { 1577 // Extension in C99. Legal in C90, but warn about it. 1578 if (getLangOptions().C99) 1579 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1580 else 1581 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1582 1583 // FIXME: handle stuff like: 1584 // void foo() { extern float X(); } 1585 // void bar() { X(); } <-- implicit decl for X in another scope. 1586 1587 // Set a Declarator for the implicit definition: int foo(); 1588 const char *Dummy; 1589 DeclSpec DS; 1590 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1591 Error = Error; // Silence warning. 1592 assert(!Error && "Error setting up implicit decl!"); 1593 Declarator D(DS, Declarator::BlockContext); 1594 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1595 D.SetIdentifier(&II, Loc); 1596 1597 // Insert this function into translation-unit scope. 1598 1599 DeclContext *PrevDC = CurContext; 1600 CurContext = Context.getTranslationUnitDecl(); 1601 1602 FunctionDecl *FD = 1603 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1604 FD->setImplicit(); 1605 1606 CurContext = PrevDC; 1607 1608 return FD; 1609} 1610 1611 1612TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1613 ScopedDecl *LastDeclarator) { 1614 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1615 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1616 1617 // Scope manipulation handled by caller. 1618 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1619 D.getIdentifierLoc(), 1620 D.getIdentifier(), 1621 T, LastDeclarator); 1622 if (D.getInvalidType()) 1623 NewTD->setInvalidDecl(); 1624 return NewTD; 1625} 1626 1627/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1628/// former case, Name will be non-null. In the later case, Name will be null. 1629/// TagType indicates what kind of tag this is. TK indicates whether this is a 1630/// reference/declaration/definition of a tag. 1631Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1632 SourceLocation KWLoc, IdentifierInfo *Name, 1633 SourceLocation NameLoc, AttributeList *Attr) { 1634 // If this is a use of an existing tag, it must have a name. 1635 assert((Name != 0 || TK == TK_Definition) && 1636 "Nameless record must be a definition!"); 1637 1638 TagDecl::TagKind Kind; 1639 switch (TagType) { 1640 default: assert(0 && "Unknown tag type!"); 1641 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1642 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1643 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1644 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1645 } 1646 1647 // If this is a named struct, check to see if there was a previous forward 1648 // declaration or definition. 1649 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1650 if (ScopedDecl *PrevDecl = 1651 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1652 1653 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1654 "unexpected Decl type"); 1655 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1656 // If this is a use of a previous tag, or if the tag is already declared in 1657 // the same scope (so that the definition/declaration completes or 1658 // rementions the tag), reuse the decl. 1659 if (TK == TK_Reference || 1660 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1661 // Make sure that this wasn't declared as an enum and now used as a struct 1662 // or something similar. 1663 if (PrevTagDecl->getTagKind() != Kind) { 1664 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1665 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1666 } 1667 1668 // If this is a use or a forward declaration, we're good. 1669 if (TK != TK_Definition) 1670 return PrevDecl; 1671 1672 // Diagnose attempts to redefine a tag. 1673 if (PrevTagDecl->isDefinition()) { 1674 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1675 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1676 // If this is a redefinition, recover by making this struct be 1677 // anonymous, which will make any later references get the previous 1678 // definition. 1679 Name = 0; 1680 } else { 1681 // Okay, this is definition of a previously declared or referenced tag. 1682 // Move the location of the decl to be the definition site. 1683 PrevDecl->setLocation(NameLoc); 1684 return PrevDecl; 1685 } 1686 } 1687 // If we get here, this is a definition of a new struct type in a nested 1688 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1689 // type. 1690 } else { 1691 // The tag name clashes with a namespace name, issue an error and recover 1692 // by making this tag be anonymous. 1693 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1694 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1695 Name = 0; 1696 } 1697 } 1698 1699 // If there is an identifier, use the location of the identifier as the 1700 // location of the decl, otherwise use the location of the struct/union 1701 // keyword. 1702 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1703 1704 // Otherwise, if this is the first time we've seen this tag, create the decl. 1705 TagDecl *New; 1706 if (Kind == TagDecl::TK_enum) { 1707 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1708 // enum X { A, B, C } D; D should chain to X. 1709 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1710 // If this is an undefined enum, warn. 1711 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1712 } else { 1713 // struct/union/class 1714 1715 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1716 // struct X { int A; } D; D should chain to X. 1717 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1718 } 1719 1720 // If this has an identifier, add it to the scope stack. 1721 if (Name) { 1722 // The scope passed in may not be a decl scope. Zip up the scope tree until 1723 // we find one that is. 1724 while ((S->getFlags() & Scope::DeclScope) == 0) 1725 S = S->getParent(); 1726 1727 // Add it to the decl chain. 1728 PushOnScopeChains(New, S); 1729 } 1730 1731 HandleDeclAttributes(New, Attr, 0); 1732 return New; 1733} 1734 1735/// Collect the instance variables declared in an Objective-C object. Used in 1736/// the creation of structures from objects using the @defs directive. 1737static void CollectIvars(ObjCInterfaceDecl *Class, 1738 llvm::SmallVector<Sema::DeclTy*, 16> &ivars) { 1739 if (Class->getSuperClass()) 1740 CollectIvars(Class->getSuperClass(), ivars); 1741 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1742} 1743 1744/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1745/// instance variables of ClassName into Decls. 1746void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1747 IdentifierInfo *ClassName, 1748 llvm::SmallVector<DeclTy*, 16> &Decls) { 1749 // Check that ClassName is a valid class 1750 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1751 if (!Class) { 1752 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1753 return; 1754 } 1755 // Collect the instance variables 1756 CollectIvars(Class, Decls); 1757} 1758 1759 1760static bool CalcFakeICEVal(const Expr* Expr, 1761 llvm::APSInt& Result, 1762 ASTContext& Context) { 1763 // Calculate the value of an expression that has a calculatable 1764 // value, but isn't an ICE. Currently, this only supports 1765 // a very narrow set of extensions, but it can be expanded if needed. 1766 if (const ParenExpr *PE = dyn_cast<ParenExpr>(Expr)) 1767 return CalcFakeICEVal(PE->getSubExpr(), Result, Context); 1768 1769 if (const CastExpr *CE = dyn_cast<CastExpr>(Expr)) { 1770 QualType CETy = CE->getType(); 1771 if ((CETy->isIntegralType() && !CETy->isBooleanType()) || 1772 CETy->isPointerType()) { 1773 if (CalcFakeICEVal(CE->getSubExpr(), Result, Context)) { 1774 Result.extOrTrunc(Context.getTypeSize(CETy)); 1775 // FIXME: This assumes pointers are signed. 1776 Result.setIsSigned(CETy->isSignedIntegerType() || 1777 CETy->isPointerType()); 1778 return true; 1779 } 1780 } 1781 } 1782 1783 if (Expr->getType()->isIntegralType()) 1784 return Expr->isIntegerConstantExpr(Result, Context); 1785 1786 return false; 1787} 1788 1789QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1790 // This method tries to turn a variable array into a constant 1791 // array even when the size isn't an ICE. This is necessary 1792 // for compatibility with code that depends on gcc's buggy 1793 // constant expression folding, like struct {char x[(int)(char*)2];} 1794 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1795 llvm::APSInt Result(32); 1796 if (VLATy->getSizeExpr() && 1797 CalcFakeICEVal(VLATy->getSizeExpr(), Result, Context) && 1798 Result > llvm::APSInt(Result.getBitWidth(), Result.isUnsigned())) { 1799 return Context.getConstantArrayType(VLATy->getElementType(), 1800 Result, ArrayType::Normal, 0); 1801 } 1802 } 1803 return QualType(); 1804} 1805 1806/// ActOnField - Each field of a struct/union/class is passed into this in order 1807/// to create a FieldDecl object for it. 1808Sema::DeclTy *Sema::ActOnField(Scope *S, 1809 SourceLocation DeclStart, 1810 Declarator &D, ExprTy *BitfieldWidth) { 1811 IdentifierInfo *II = D.getIdentifier(); 1812 Expr *BitWidth = (Expr*)BitfieldWidth; 1813 SourceLocation Loc = DeclStart; 1814 if (II) Loc = D.getIdentifierLoc(); 1815 1816 // FIXME: Unnamed fields can be handled in various different ways, for 1817 // example, unnamed unions inject all members into the struct namespace! 1818 1819 1820 if (BitWidth) { 1821 // TODO: Validate. 1822 //printf("WARNING: BITFIELDS IGNORED!\n"); 1823 1824 // 6.7.2.1p3 1825 // 6.7.2.1p4 1826 1827 } else { 1828 // Not a bitfield. 1829 1830 // validate II. 1831 1832 } 1833 1834 QualType T = GetTypeForDeclarator(D, S); 1835 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1836 bool InvalidDecl = false; 1837 1838 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1839 // than a variably modified type. 1840 if (T->isVariablyModifiedType()) { 1841 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1842 if (!FixedTy.isNull()) { 1843 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1844 T = FixedTy; 1845 } else { 1846 // FIXME: This diagnostic needs work 1847 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1848 InvalidDecl = true; 1849 } 1850 } 1851 // FIXME: Chain fielddecls together. 1852 FieldDecl *NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1853 1854 HandleDeclAttributes(NewFD, D.getDeclSpec().getAttributes(), 1855 D.getAttributes()); 1856 1857 if (D.getInvalidType() || InvalidDecl) 1858 NewFD->setInvalidDecl(); 1859 return NewFD; 1860} 1861 1862/// TranslateIvarVisibility - Translate visibility from a token ID to an 1863/// AST enum value. 1864static ObjCIvarDecl::AccessControl 1865TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1866 switch (ivarVisibility) { 1867 case tok::objc_private: return ObjCIvarDecl::Private; 1868 case tok::objc_public: return ObjCIvarDecl::Public; 1869 case tok::objc_protected: return ObjCIvarDecl::Protected; 1870 case tok::objc_package: return ObjCIvarDecl::Package; 1871 default: assert(false && "Unknown visitibility kind"); 1872 } 1873} 1874 1875/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1876/// in order to create an IvarDecl object for it. 1877Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1878 SourceLocation DeclStart, 1879 Declarator &D, ExprTy *BitfieldWidth, 1880 tok::ObjCKeywordKind Visibility) { 1881 IdentifierInfo *II = D.getIdentifier(); 1882 Expr *BitWidth = (Expr*)BitfieldWidth; 1883 SourceLocation Loc = DeclStart; 1884 if (II) Loc = D.getIdentifierLoc(); 1885 1886 // FIXME: Unnamed fields can be handled in various different ways, for 1887 // example, unnamed unions inject all members into the struct namespace! 1888 1889 1890 if (BitWidth) { 1891 // TODO: Validate. 1892 //printf("WARNING: BITFIELDS IGNORED!\n"); 1893 1894 // 6.7.2.1p3 1895 // 6.7.2.1p4 1896 1897 } else { 1898 // Not a bitfield. 1899 1900 // validate II. 1901 1902 } 1903 1904 QualType T = GetTypeForDeclarator(D, S); 1905 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1906 bool InvalidDecl = false; 1907 1908 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1909 // than a variably modified type. 1910 if (T->isVariablyModifiedType()) { 1911 // FIXME: This diagnostic needs work 1912 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1913 InvalidDecl = true; 1914 } 1915 1916 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T); 1917 1918 HandleDeclAttributes(NewID, D.getDeclSpec().getAttributes(), 1919 D.getAttributes()); 1920 1921 if (D.getInvalidType() || InvalidDecl) 1922 NewID->setInvalidDecl(); 1923 // If we have visibility info, make sure the AST is set accordingly. 1924 if (Visibility != tok::objc_not_keyword) 1925 NewID->setAccessControl(TranslateIvarVisibility(Visibility)); 1926 return NewID; 1927} 1928 1929void Sema::ActOnFields(Scope* S, 1930 SourceLocation RecLoc, DeclTy *RecDecl, 1931 DeclTy **Fields, unsigned NumFields, 1932 SourceLocation LBrac, SourceLocation RBrac) { 1933 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1934 assert(EnclosingDecl && "missing record or interface decl"); 1935 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1936 1937 if (Record && Record->isDefinition()) { 1938 // Diagnose code like: 1939 // struct S { struct S {} X; }; 1940 // We discover this when we complete the outer S. Reject and ignore the 1941 // outer S. 1942 Diag(Record->getLocation(), diag::err_nested_redefinition, 1943 Record->getKindName()); 1944 Diag(RecLoc, diag::err_previous_definition); 1945 Record->setInvalidDecl(); 1946 return; 1947 } 1948 // Verify that all the fields are okay. 1949 unsigned NumNamedMembers = 0; 1950 llvm::SmallVector<FieldDecl*, 32> RecFields; 1951 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 1952 1953 for (unsigned i = 0; i != NumFields; ++i) { 1954 1955 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 1956 assert(FD && "missing field decl"); 1957 1958 // Remember all fields. 1959 RecFields.push_back(FD); 1960 1961 // Get the type for the field. 1962 Type *FDTy = FD->getType().getTypePtr(); 1963 1964 // C99 6.7.2.1p2 - A field may not be a function type. 1965 if (FDTy->isFunctionType()) { 1966 Diag(FD->getLocation(), diag::err_field_declared_as_function, 1967 FD->getName()); 1968 FD->setInvalidDecl(); 1969 EnclosingDecl->setInvalidDecl(); 1970 continue; 1971 } 1972 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 1973 if (FDTy->isIncompleteType()) { 1974 if (!Record) { // Incomplete ivar type is always an error. 1975 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 1976 FD->setInvalidDecl(); 1977 EnclosingDecl->setInvalidDecl(); 1978 continue; 1979 } 1980 if (i != NumFields-1 || // ... that the last member ... 1981 !Record->isStruct() || // ... of a structure ... 1982 !FDTy->isArrayType()) { //... may have incomplete array type. 1983 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 1984 FD->setInvalidDecl(); 1985 EnclosingDecl->setInvalidDecl(); 1986 continue; 1987 } 1988 if (NumNamedMembers < 1) { //... must have more than named member ... 1989 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 1990 FD->getName()); 1991 FD->setInvalidDecl(); 1992 EnclosingDecl->setInvalidDecl(); 1993 continue; 1994 } 1995 // Okay, we have a legal flexible array member at the end of the struct. 1996 if (Record) 1997 Record->setHasFlexibleArrayMember(true); 1998 } 1999 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2000 /// field of another structure or the element of an array. 2001 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2002 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2003 // If this is a member of a union, then entire union becomes "flexible". 2004 if (Record && Record->isUnion()) { 2005 Record->setHasFlexibleArrayMember(true); 2006 } else { 2007 // If this is a struct/class and this is not the last element, reject 2008 // it. Note that GCC supports variable sized arrays in the middle of 2009 // structures. 2010 if (i != NumFields-1) { 2011 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2012 FD->getName()); 2013 FD->setInvalidDecl(); 2014 EnclosingDecl->setInvalidDecl(); 2015 continue; 2016 } 2017 // We support flexible arrays at the end of structs in other structs 2018 // as an extension. 2019 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2020 FD->getName()); 2021 if (Record) 2022 Record->setHasFlexibleArrayMember(true); 2023 } 2024 } 2025 } 2026 /// A field cannot be an Objective-c object 2027 if (FDTy->isObjCInterfaceType()) { 2028 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2029 FD->getName()); 2030 FD->setInvalidDecl(); 2031 EnclosingDecl->setInvalidDecl(); 2032 continue; 2033 } 2034 // Keep track of the number of named members. 2035 if (IdentifierInfo *II = FD->getIdentifier()) { 2036 // Detect duplicate member names. 2037 if (!FieldIDs.insert(II)) { 2038 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2039 // Find the previous decl. 2040 SourceLocation PrevLoc; 2041 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2042 assert(i != e && "Didn't find previous def!"); 2043 if (RecFields[i]->getIdentifier() == II) { 2044 PrevLoc = RecFields[i]->getLocation(); 2045 break; 2046 } 2047 } 2048 Diag(PrevLoc, diag::err_previous_definition); 2049 FD->setInvalidDecl(); 2050 EnclosingDecl->setInvalidDecl(); 2051 continue; 2052 } 2053 ++NumNamedMembers; 2054 } 2055 } 2056 2057 // Okay, we successfully defined 'Record'. 2058 if (Record) { 2059 Record->defineBody(&RecFields[0], RecFields.size()); 2060 Consumer.HandleTagDeclDefinition(Record); 2061 } else { 2062 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2063 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2064 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2065 else if (ObjCImplementationDecl *IMPDecl = 2066 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2067 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2068 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2069 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2070 } 2071 } 2072} 2073 2074Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2075 DeclTy *lastEnumConst, 2076 SourceLocation IdLoc, IdentifierInfo *Id, 2077 SourceLocation EqualLoc, ExprTy *val) { 2078 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2079 EnumConstantDecl *LastEnumConst = 2080 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2081 Expr *Val = static_cast<Expr*>(val); 2082 2083 // The scope passed in may not be a decl scope. Zip up the scope tree until 2084 // we find one that is. 2085 while ((S->getFlags() & Scope::DeclScope) == 0) 2086 S = S->getParent(); 2087 2088 // Verify that there isn't already something declared with this name in this 2089 // scope. 2090 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2091 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2092 if (isa<EnumConstantDecl>(PrevDecl)) 2093 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2094 else 2095 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2096 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2097 delete Val; 2098 return 0; 2099 } 2100 } 2101 2102 llvm::APSInt EnumVal(32); 2103 QualType EltTy; 2104 if (Val) { 2105 // Make sure to promote the operand type to int. 2106 UsualUnaryConversions(Val); 2107 2108 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2109 SourceLocation ExpLoc; 2110 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2111 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2112 Id->getName()); 2113 delete Val; 2114 Val = 0; // Just forget about it. 2115 } else { 2116 EltTy = Val->getType(); 2117 } 2118 } 2119 2120 if (!Val) { 2121 if (LastEnumConst) { 2122 // Assign the last value + 1. 2123 EnumVal = LastEnumConst->getInitVal(); 2124 ++EnumVal; 2125 2126 // Check for overflow on increment. 2127 if (EnumVal < LastEnumConst->getInitVal()) 2128 Diag(IdLoc, diag::warn_enum_value_overflow); 2129 2130 EltTy = LastEnumConst->getType(); 2131 } else { 2132 // First value, set to zero. 2133 EltTy = Context.IntTy; 2134 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2135 } 2136 } 2137 2138 EnumConstantDecl *New = 2139 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2140 Val, EnumVal, 2141 LastEnumConst); 2142 2143 // Register this decl in the current scope stack. 2144 PushOnScopeChains(New, S); 2145 return New; 2146} 2147 2148void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2149 DeclTy **Elements, unsigned NumElements) { 2150 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2151 assert(!Enum->isDefinition() && "Enum redefinitions can't reach here"); 2152 2153 // TODO: If the result value doesn't fit in an int, it must be a long or long 2154 // long value. ISO C does not support this, but GCC does as an extension, 2155 // emit a warning. 2156 unsigned IntWidth = Context.Target.getIntWidth(); 2157 2158 // Verify that all the values are okay, compute the size of the values, and 2159 // reverse the list. 2160 unsigned NumNegativeBits = 0; 2161 unsigned NumPositiveBits = 0; 2162 2163 // Keep track of whether all elements have type int. 2164 bool AllElementsInt = true; 2165 2166 EnumConstantDecl *EltList = 0; 2167 for (unsigned i = 0; i != NumElements; ++i) { 2168 EnumConstantDecl *ECD = 2169 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2170 if (!ECD) continue; // Already issued a diagnostic. 2171 2172 // If the enum value doesn't fit in an int, emit an extension warning. 2173 const llvm::APSInt &InitVal = ECD->getInitVal(); 2174 assert(InitVal.getBitWidth() >= IntWidth && 2175 "Should have promoted value to int"); 2176 if (InitVal.getBitWidth() > IntWidth) { 2177 llvm::APSInt V(InitVal); 2178 V.trunc(IntWidth); 2179 V.extend(InitVal.getBitWidth()); 2180 if (V != InitVal) 2181 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2182 InitVal.toString()); 2183 } 2184 2185 // Keep track of the size of positive and negative values. 2186 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2187 NumPositiveBits = std::max(NumPositiveBits, 2188 (unsigned)InitVal.getActiveBits()); 2189 else 2190 NumNegativeBits = std::max(NumNegativeBits, 2191 (unsigned)InitVal.getMinSignedBits()); 2192 2193 // Keep track of whether every enum element has type int (very commmon). 2194 if (AllElementsInt) 2195 AllElementsInt = ECD->getType() == Context.IntTy; 2196 2197 ECD->setNextDeclarator(EltList); 2198 EltList = ECD; 2199 } 2200 2201 // Figure out the type that should be used for this enum. 2202 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2203 QualType BestType; 2204 unsigned BestWidth; 2205 2206 if (NumNegativeBits) { 2207 // If there is a negative value, figure out the smallest integer type (of 2208 // int/long/longlong) that fits. 2209 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2210 BestType = Context.IntTy; 2211 BestWidth = IntWidth; 2212 } else { 2213 BestWidth = Context.Target.getLongWidth(); 2214 2215 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2216 BestType = Context.LongTy; 2217 else { 2218 BestWidth = Context.Target.getLongLongWidth(); 2219 2220 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2221 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2222 BestType = Context.LongLongTy; 2223 } 2224 } 2225 } else { 2226 // If there is no negative value, figure out which of uint, ulong, ulonglong 2227 // fits. 2228 if (NumPositiveBits <= IntWidth) { 2229 BestType = Context.UnsignedIntTy; 2230 BestWidth = IntWidth; 2231 } else if (NumPositiveBits <= 2232 (BestWidth = Context.Target.getLongWidth())) { 2233 BestType = Context.UnsignedLongTy; 2234 } else { 2235 BestWidth = Context.Target.getLongLongWidth(); 2236 assert(NumPositiveBits <= BestWidth && 2237 "How could an initializer get larger than ULL?"); 2238 BestType = Context.UnsignedLongLongTy; 2239 } 2240 } 2241 2242 // Loop over all of the enumerator constants, changing their types to match 2243 // the type of the enum if needed. 2244 for (unsigned i = 0; i != NumElements; ++i) { 2245 EnumConstantDecl *ECD = 2246 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2247 if (!ECD) continue; // Already issued a diagnostic. 2248 2249 // Standard C says the enumerators have int type, but we allow, as an 2250 // extension, the enumerators to be larger than int size. If each 2251 // enumerator value fits in an int, type it as an int, otherwise type it the 2252 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2253 // that X has type 'int', not 'unsigned'. 2254 if (ECD->getType() == Context.IntTy) { 2255 // Make sure the init value is signed. 2256 llvm::APSInt IV = ECD->getInitVal(); 2257 IV.setIsSigned(true); 2258 ECD->setInitVal(IV); 2259 continue; // Already int type. 2260 } 2261 2262 // Determine whether the value fits into an int. 2263 llvm::APSInt InitVal = ECD->getInitVal(); 2264 bool FitsInInt; 2265 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2266 FitsInInt = InitVal.getActiveBits() < IntWidth; 2267 else 2268 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2269 2270 // If it fits into an integer type, force it. Otherwise force it to match 2271 // the enum decl type. 2272 QualType NewTy; 2273 unsigned NewWidth; 2274 bool NewSign; 2275 if (FitsInInt) { 2276 NewTy = Context.IntTy; 2277 NewWidth = IntWidth; 2278 NewSign = true; 2279 } else if (ECD->getType() == BestType) { 2280 // Already the right type! 2281 continue; 2282 } else { 2283 NewTy = BestType; 2284 NewWidth = BestWidth; 2285 NewSign = BestType->isSignedIntegerType(); 2286 } 2287 2288 // Adjust the APSInt value. 2289 InitVal.extOrTrunc(NewWidth); 2290 InitVal.setIsSigned(NewSign); 2291 ECD->setInitVal(InitVal); 2292 2293 // Adjust the Expr initializer and type. 2294 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2295 ECD->setType(NewTy); 2296 } 2297 2298 Enum->defineElements(EltList, BestType); 2299 Consumer.HandleTagDeclDefinition(Enum); 2300} 2301 2302Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2303 ExprTy *expr) { 2304 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2305 2306 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2307} 2308 2309Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2310 SourceLocation LBrace, 2311 SourceLocation RBrace, 2312 const char *Lang, 2313 unsigned StrSize, 2314 DeclTy *D) { 2315 LinkageSpecDecl::LanguageIDs Language; 2316 Decl *dcl = static_cast<Decl *>(D); 2317 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2318 Language = LinkageSpecDecl::lang_c; 2319 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2320 Language = LinkageSpecDecl::lang_cxx; 2321 else { 2322 Diag(Loc, diag::err_bad_language); 2323 return 0; 2324 } 2325 2326 // FIXME: Add all the various semantics of linkage specifications 2327 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2328} 2329