SemaDecl.cpp revision c4a1dea2dc56bd1357ec91b829a0b9e68229a13e
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/Attr.h" 19#include "clang/AST/Builtins.h" 20#include "clang/AST/Decl.h" 21#include "clang/AST/DeclCXX.h" 22#include "clang/AST/DeclObjC.h" 23#include "clang/AST/Expr.h" 24#include "clang/AST/ExprCXX.h" 25#include "clang/AST/Type.h" 26#include "clang/Parse/DeclSpec.h" 27#include "clang/Parse/Scope.h" 28#include "clang/Basic/Diagnostic.h" 29#include "clang/Basic/LangOptions.h" 30#include "clang/Basic/TargetInfo.h" 31#include "clang/Basic/SourceManager.h" 32// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 33#include "clang/Lex/Preprocessor.h" 34#include "clang/Lex/HeaderSearch.h" 35#include "llvm/ADT/SmallString.h" 36#include "llvm/ADT/SmallSet.h" 37#include "llvm/ADT/DenseSet.h" 38using namespace clang; 39 40Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { 41 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); 42 43 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 44 isa<ObjCInterfaceDecl>(IIDecl) || 45 isa<TagDecl>(IIDecl))) 46 return IIDecl; 47 return 0; 48} 49 50DeclContext *Sema::getDCParent(DeclContext *DC) { 51 // If CurContext is a ObjC method, getParent() will return NULL. 52 if (isa<ObjCMethodDecl>(DC)) 53 return Context.getTranslationUnitDecl(); 54 55 // A C++ inline method is parsed *after* the topmost class it was declared in 56 // is fully parsed (it's "complete"). 57 // The parsing of a C++ inline method happens at the declaration context of 58 // the topmost (non-nested) class it is declared in. 59 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 60 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 61 DC = MD->getParent(); 62 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 63 DC = RD; 64 65 // Return the declaration context of the topmost class the inline method is 66 // declared in. 67 return DC; 68 } 69 70 return DC->getParent(); 71} 72 73void Sema::PushDeclContext(DeclContext *DC) { 74 assert(getDCParent(DC) == CurContext && 75 "The next DeclContext should be directly contained in the current one."); 76 CurContext = DC; 77} 78 79void Sema::PopDeclContext() { 80 assert(CurContext && "DeclContext imbalance!"); 81 CurContext = getDCParent(CurContext); 82} 83 84/// Add this decl to the scope shadowed decl chains. 85void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 86 S->AddDecl(D); 87 88 // C++ [basic.scope]p4: 89 // -- exactly one declaration shall declare a class name or 90 // enumeration name that is not a typedef name and the other 91 // declarations shall all refer to the same object or 92 // enumerator, or all refer to functions and function templates; 93 // in this case the class name or enumeration name is hidden. 94 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 95 // We are pushing the name of a tag (enum or class). 96 IdentifierResolver::iterator 97 I = IdResolver.begin(TD->getIdentifier(), 98 TD->getDeclContext(), false/*LookInParentCtx*/); 99 if (I != IdResolver.end() && 100 IdResolver.isDeclInScope(*I, TD->getDeclContext(), S)) { 101 // There is already a declaration with the same name in the same 102 // scope. It must be found before we find the new declaration, 103 // so swap the order on the shadowed declaration chain. 104 105 IdResolver.AddShadowedDecl(TD, *I); 106 return; 107 } 108 } 109 IdResolver.AddDecl(D); 110} 111 112void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 113 if (S->decl_empty()) return; 114 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 115 116 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 117 I != E; ++I) { 118 Decl *TmpD = static_cast<Decl*>(*I); 119 assert(TmpD && "This decl didn't get pushed??"); 120 121 if (isa<CXXFieldDecl>(TmpD)) continue; 122 123 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 124 ScopedDecl *D = cast<ScopedDecl>(TmpD); 125 126 IdentifierInfo *II = D->getIdentifier(); 127 if (!II) continue; 128 129 // We only want to remove the decls from the identifier decl chains for local 130 // scopes, when inside a function/method. 131 if (S->getFnParent() != 0) 132 IdResolver.RemoveDecl(D); 133 134 // Chain this decl to the containing DeclContext. 135 D->setNext(CurContext->getDeclChain()); 136 CurContext->setDeclChain(D); 137 } 138} 139 140/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 141/// return 0 if one not found. 142ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 143 // The third "scope" argument is 0 since we aren't enabling lazy built-in 144 // creation from this context. 145 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 146 147 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 148} 149 150/// LookupDecl - Look up the inner-most declaration in the specified 151/// namespace. 152Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 153 Scope *S, bool enableLazyBuiltinCreation) { 154 if (II == 0) return 0; 155 unsigned NS = NSI; 156 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 157 NS |= Decl::IDNS_Tag; 158 159 // Scan up the scope chain looking for a decl that matches this identifier 160 // that is in the appropriate namespace. This search should not take long, as 161 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 162 for (IdentifierResolver::iterator 163 I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) 164 if ((*I)->getIdentifierNamespace() & NS) 165 return *I; 166 167 // If we didn't find a use of this identifier, and if the identifier 168 // corresponds to a compiler builtin, create the decl object for the builtin 169 // now, injecting it into translation unit scope, and return it. 170 if (NS & Decl::IDNS_Ordinary) { 171 if (enableLazyBuiltinCreation) { 172 // If this is a builtin on this (or all) targets, create the decl. 173 if (unsigned BuiltinID = II->getBuiltinID()) 174 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 175 } 176 if (getLangOptions().ObjC1) { 177 // @interface and @compatibility_alias introduce typedef-like names. 178 // Unlike typedef's, they can only be introduced at file-scope (and are 179 // therefore not scoped decls). They can, however, be shadowed by 180 // other names in IDNS_Ordinary. 181 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 182 if (IDI != ObjCInterfaceDecls.end()) 183 return IDI->second; 184 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 185 if (I != ObjCAliasDecls.end()) 186 return I->second->getClassInterface(); 187 } 188 } 189 return 0; 190} 191 192void Sema::InitBuiltinVaListType() { 193 if (!Context.getBuiltinVaListType().isNull()) 194 return; 195 196 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 197 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 198 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 199 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 200} 201 202/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 203/// lazily create a decl for it. 204ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 205 Scope *S) { 206 Builtin::ID BID = (Builtin::ID)bid; 207 208 if (BID == Builtin::BI__builtin_va_start || 209 BID == Builtin::BI__builtin_va_copy || 210 BID == Builtin::BI__builtin_va_end || 211 BID == Builtin::BI__builtin_stdarg_start) 212 InitBuiltinVaListType(); 213 214 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 215 FunctionDecl *New = FunctionDecl::Create(Context, 216 Context.getTranslationUnitDecl(), 217 SourceLocation(), II, R, 218 FunctionDecl::Extern, false, 0); 219 220 // Create Decl objects for each parameter, adding them to the 221 // FunctionDecl. 222 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 223 llvm::SmallVector<ParmVarDecl*, 16> Params; 224 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 225 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 226 FT->getArgType(i), VarDecl::None, 0, 227 0)); 228 New->setParams(&Params[0], Params.size()); 229 } 230 231 232 233 // TUScope is the translation-unit scope to insert this function into. 234 PushOnScopeChains(New, TUScope); 235 return New; 236} 237 238/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 239/// and scope as a previous declaration 'Old'. Figure out how to resolve this 240/// situation, merging decls or emitting diagnostics as appropriate. 241/// 242TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 243 // Verify the old decl was also a typedef. 244 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 245 if (!Old) { 246 Diag(New->getLocation(), diag::err_redefinition_different_kind, 247 New->getName()); 248 Diag(OldD->getLocation(), diag::err_previous_definition); 249 return New; 250 } 251 252 // If the typedef types are not identical, reject them in all languages and 253 // with any extensions enabled. 254 if (Old->getUnderlyingType() != New->getUnderlyingType() && 255 Context.getCanonicalType(Old->getUnderlyingType()) != 256 Context.getCanonicalType(New->getUnderlyingType())) { 257 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 258 New->getUnderlyingType().getAsString(), 259 Old->getUnderlyingType().getAsString()); 260 Diag(Old->getLocation(), diag::err_previous_definition); 261 return Old; 262 } 263 264 // Allow multiple definitions for ObjC built-in typedefs. 265 // FIXME: Verify the underlying types are equivalent! 266 if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) 267 return Old; 268 269 if (getLangOptions().Microsoft) return New; 270 271 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 272 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 273 // *either* declaration is in a system header. The code below implements 274 // this adhoc compatibility rule. FIXME: The following code will not 275 // work properly when compiling ".i" files (containing preprocessed output). 276 SourceManager &SrcMgr = Context.getSourceManager(); 277 HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); 278 const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); 279 if (OldDeclFile) { 280 DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); 281 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 282 if (OldDirType != DirectoryLookup::NormalHeaderDir) 283 return New; 284 } 285 const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); 286 if (NewDeclFile) { 287 DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); 288 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 289 if (NewDirType != DirectoryLookup::NormalHeaderDir) 290 return New; 291 } 292 293 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 294 Diag(Old->getLocation(), diag::err_previous_definition); 295 return New; 296} 297 298/// DeclhasAttr - returns true if decl Declaration already has the target 299/// attribute. 300static bool DeclHasAttr(const Decl *decl, const Attr *target) { 301 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 302 if (attr->getKind() == target->getKind()) 303 return true; 304 305 return false; 306} 307 308/// MergeAttributes - append attributes from the Old decl to the New one. 309static void MergeAttributes(Decl *New, Decl *Old) { 310 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 311 312 while (attr) { 313 tmp = attr; 314 attr = attr->getNext(); 315 316 if (!DeclHasAttr(New, tmp)) { 317 New->addAttr(tmp); 318 } else { 319 tmp->setNext(0); 320 delete(tmp); 321 } 322 } 323 324 Old->invalidateAttrs(); 325} 326 327/// MergeFunctionDecl - We just parsed a function 'New' from 328/// declarator D which has the same name and scope as a previous 329/// declaration 'Old'. Figure out how to resolve this situation, 330/// merging decls or emitting diagnostics as appropriate. 331/// Redeclaration will be set true if thisNew is a redeclaration OldD. 332FunctionDecl * 333Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 334 Redeclaration = false; 335 // Verify the old decl was also a function. 336 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 337 if (!Old) { 338 Diag(New->getLocation(), diag::err_redefinition_different_kind, 339 New->getName()); 340 Diag(OldD->getLocation(), diag::err_previous_definition); 341 return New; 342 } 343 344 QualType OldQType = Context.getCanonicalType(Old->getType()); 345 QualType NewQType = Context.getCanonicalType(New->getType()); 346 347 // C++ [dcl.fct]p3: 348 // All declarations for a function shall agree exactly in both the 349 // return type and the parameter-type-list. 350 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 351 MergeAttributes(New, Old); 352 Redeclaration = true; 353 return MergeCXXFunctionDecl(New, Old); 354 } 355 356 // C: Function types need to be compatible, not identical. This handles 357 // duplicate function decls like "void f(int); void f(enum X);" properly. 358 if (!getLangOptions().CPlusPlus && 359 Context.functionTypesAreCompatible(OldQType, NewQType)) { 360 MergeAttributes(New, Old); 361 Redeclaration = true; 362 return New; 363 } 364 365 // A function that has already been declared has been redeclared or defined 366 // with a different type- show appropriate diagnostic 367 diag::kind PrevDiag; 368 if (Old->isThisDeclarationADefinition()) 369 PrevDiag = diag::err_previous_definition; 370 else if (Old->isImplicit()) 371 PrevDiag = diag::err_previous_implicit_declaration; 372 else 373 PrevDiag = diag::err_previous_declaration; 374 375 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 376 // TODO: This is totally simplistic. It should handle merging functions 377 // together etc, merging extern int X; int X; ... 378 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 379 Diag(Old->getLocation(), PrevDiag); 380 return New; 381} 382 383/// Predicate for C "tentative" external object definitions (C99 6.9.2). 384static bool isTentativeDefinition(VarDecl *VD) { 385 if (VD->isFileVarDecl()) 386 return (!VD->getInit() && 387 (VD->getStorageClass() == VarDecl::None || 388 VD->getStorageClass() == VarDecl::Static)); 389 return false; 390} 391 392/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 393/// when dealing with C "tentative" external object definitions (C99 6.9.2). 394void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 395 bool VDIsTentative = isTentativeDefinition(VD); 396 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 397 398 for (IdentifierResolver::iterator 399 I = IdResolver.begin(VD->getIdentifier(), 400 VD->getDeclContext(), false/*LookInParentCtx*/), 401 E = IdResolver.end(); I != E; ++I) { 402 if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) { 403 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 404 405 // Handle the following case: 406 // int a[10]; 407 // int a[]; - the code below makes sure we set the correct type. 408 // int a[11]; - this is an error, size isn't 10. 409 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 410 OldDecl->getType()->isConstantArrayType()) 411 VD->setType(OldDecl->getType()); 412 413 // Check for "tentative" definitions. We can't accomplish this in 414 // MergeVarDecl since the initializer hasn't been attached. 415 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 416 continue; 417 418 // Handle __private_extern__ just like extern. 419 if (OldDecl->getStorageClass() != VarDecl::Extern && 420 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 421 VD->getStorageClass() != VarDecl::Extern && 422 VD->getStorageClass() != VarDecl::PrivateExtern) { 423 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 424 Diag(OldDecl->getLocation(), diag::err_previous_definition); 425 } 426 } 427 } 428} 429 430/// MergeVarDecl - We just parsed a variable 'New' which has the same name 431/// and scope as a previous declaration 'Old'. Figure out how to resolve this 432/// situation, merging decls or emitting diagnostics as appropriate. 433/// 434/// Tentative definition rules (C99 6.9.2p2) are checked by 435/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 436/// definitions here, since the initializer hasn't been attached. 437/// 438VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 439 // Verify the old decl was also a variable. 440 VarDecl *Old = dyn_cast<VarDecl>(OldD); 441 if (!Old) { 442 Diag(New->getLocation(), diag::err_redefinition_different_kind, 443 New->getName()); 444 Diag(OldD->getLocation(), diag::err_previous_definition); 445 return New; 446 } 447 448 MergeAttributes(New, Old); 449 450 // Verify the types match. 451 QualType OldCType = Context.getCanonicalType(Old->getType()); 452 QualType NewCType = Context.getCanonicalType(New->getType()); 453 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 454 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 455 Diag(Old->getLocation(), diag::err_previous_definition); 456 return New; 457 } 458 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 459 if (New->getStorageClass() == VarDecl::Static && 460 (Old->getStorageClass() == VarDecl::None || 461 Old->getStorageClass() == VarDecl::Extern)) { 462 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 463 Diag(Old->getLocation(), diag::err_previous_definition); 464 return New; 465 } 466 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 467 if (New->getStorageClass() != VarDecl::Static && 468 Old->getStorageClass() == VarDecl::Static) { 469 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 470 Diag(Old->getLocation(), diag::err_previous_definition); 471 return New; 472 } 473 // File scoped variables are analyzed in FinalizeDeclaratorGroup. 474 if (!New->isFileVarDecl()) { 475 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 476 Diag(Old->getLocation(), diag::err_previous_definition); 477 } 478 return New; 479} 480 481/// CheckParmsForFunctionDef - Check that the parameters of the given 482/// function are appropriate for the definition of a function. This 483/// takes care of any checks that cannot be performed on the 484/// declaration itself, e.g., that the types of each of the function 485/// parameters are complete. 486bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 487 bool HasInvalidParm = false; 488 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 489 ParmVarDecl *Param = FD->getParamDecl(p); 490 491 // C99 6.7.5.3p4: the parameters in a parameter type list in a 492 // function declarator that is part of a function definition of 493 // that function shall not have incomplete type. 494 if (Param->getType()->isIncompleteType() && 495 !Param->isInvalidDecl()) { 496 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 497 Param->getType().getAsString()); 498 Param->setInvalidDecl(); 499 HasInvalidParm = true; 500 } 501 } 502 503 return HasInvalidParm; 504} 505 506/// CreateImplicitParameter - Creates an implicit function parameter 507/// in the scope S and with the given type. This routine is used, for 508/// example, to create the implicit "self" parameter in an Objective-C 509/// method. 510ImplicitParamDecl * 511Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 512 SourceLocation IdLoc, QualType Type) { 513 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 514 IdLoc, Id, Type, 0); 515 if (Id) 516 PushOnScopeChains(New, S); 517 518 return New; 519} 520 521/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 522/// no declarator (e.g. "struct foo;") is parsed. 523Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 524 // TODO: emit error on 'int;' or 'const enum foo;'. 525 // TODO: emit error on 'typedef int;' 526 // if (!DS.isMissingDeclaratorOk()) Diag(...); 527 528 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 529} 530 531bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 532 // Get the type before calling CheckSingleAssignmentConstraints(), since 533 // it can promote the expression. 534 QualType InitType = Init->getType(); 535 536 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 537 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 538 InitType, Init, "initializing"); 539} 540 541bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 542 const ArrayType *AT = Context.getAsArrayType(DeclT); 543 544 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 545 // C99 6.7.8p14. We have an array of character type with unknown size 546 // being initialized to a string literal. 547 llvm::APSInt ConstVal(32); 548 ConstVal = strLiteral->getByteLength() + 1; 549 // Return a new array type (C99 6.7.8p22). 550 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 551 ArrayType::Normal, 0); 552 } else { 553 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 554 // C99 6.7.8p14. We have an array of character type with known size. 555 // FIXME: Avoid truncation for 64-bit length strings. 556 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 557 Diag(strLiteral->getSourceRange().getBegin(), 558 diag::warn_initializer_string_for_char_array_too_long, 559 strLiteral->getSourceRange()); 560 } 561 // Set type from "char *" to "constant array of char". 562 strLiteral->setType(DeclT); 563 // For now, we always return false (meaning success). 564 return false; 565} 566 567StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 568 const ArrayType *AT = Context.getAsArrayType(DeclType); 569 if (AT && AT->getElementType()->isCharType()) { 570 return dyn_cast<StringLiteral>(Init); 571 } 572 return 0; 573} 574 575bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 576 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 577 // of unknown size ("[]") or an object type that is not a variable array type. 578 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 579 return Diag(VAT->getSizeExpr()->getLocStart(), 580 diag::err_variable_object_no_init, 581 VAT->getSizeExpr()->getSourceRange()); 582 583 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 584 if (!InitList) { 585 // FIXME: Handle wide strings 586 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 587 return CheckStringLiteralInit(strLiteral, DeclType); 588 589 if (DeclType->isArrayType()) 590 return Diag(Init->getLocStart(), 591 diag::err_array_init_list_required, 592 Init->getSourceRange()); 593 594 return CheckSingleInitializer(Init, DeclType); 595 } 596 597 InitListChecker CheckInitList(this, InitList, DeclType); 598 return CheckInitList.HadError(); 599} 600 601Sema::DeclTy * 602Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 603 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 604 IdentifierInfo *II = D.getIdentifier(); 605 606 // All of these full declarators require an identifier. If it doesn't have 607 // one, the ParsedFreeStandingDeclSpec action should be used. 608 if (II == 0) { 609 Diag(D.getDeclSpec().getSourceRange().getBegin(), 610 diag::err_declarator_need_ident, 611 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 612 return 0; 613 } 614 615 // The scope passed in may not be a decl scope. Zip up the scope tree until 616 // we find one that is. 617 while ((S->getFlags() & Scope::DeclScope) == 0) 618 S = S->getParent(); 619 620 // See if this is a redefinition of a variable in the same scope. 621 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 622 ScopedDecl *New; 623 bool InvalidDecl = false; 624 625 // In C++, the previous declaration we find might be a tag type 626 // (class or enum). In this case, the new declaration will hide the 627 // tag type. 628 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 629 PrevDecl = 0; 630 631 QualType R = GetTypeForDeclarator(D, S); 632 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 633 634 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 635 // Check that there are no default arguments (C++ only). 636 if (getLangOptions().CPlusPlus) 637 CheckExtraCXXDefaultArguments(D); 638 639 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 640 if (!NewTD) return 0; 641 642 // Handle attributes prior to checking for duplicates in MergeVarDecl 643 ProcessDeclAttributes(NewTD, D); 644 // Merge the decl with the existing one if appropriate. If the decl is 645 // in an outer scope, it isn't the same thing. 646 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 647 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 648 if (NewTD == 0) return 0; 649 } 650 New = NewTD; 651 if (S->getFnParent() == 0) { 652 // C99 6.7.7p2: If a typedef name specifies a variably modified type 653 // then it shall have block scope. 654 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 655 // FIXME: Diagnostic needs to be fixed. 656 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 657 InvalidDecl = true; 658 } 659 } 660 } else if (R.getTypePtr()->isFunctionType()) { 661 FunctionDecl::StorageClass SC = FunctionDecl::None; 662 switch (D.getDeclSpec().getStorageClassSpec()) { 663 default: assert(0 && "Unknown storage class!"); 664 case DeclSpec::SCS_auto: 665 case DeclSpec::SCS_register: 666 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 667 R.getAsString()); 668 InvalidDecl = true; 669 break; 670 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 671 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 672 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 673 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 674 } 675 676 bool isInline = D.getDeclSpec().isInlineSpecified(); 677 FunctionDecl *NewFD; 678 if (D.getContext() == Declarator::MemberContext) { 679 // This is a C++ method declaration. 680 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 681 D.getIdentifierLoc(), II, R, 682 (SC == FunctionDecl::Static), isInline, 683 LastDeclarator); 684 } else { 685 NewFD = FunctionDecl::Create(Context, CurContext, 686 D.getIdentifierLoc(), 687 II, R, SC, isInline, 688 LastDeclarator); 689 } 690 // Handle attributes. 691 ProcessDeclAttributes(NewFD, D); 692 693 // Handle GNU asm-label extension (encoded as an attribute). 694 if (Expr *E = (Expr*) D.getAsmLabel()) { 695 // The parser guarantees this is a string. 696 StringLiteral *SE = cast<StringLiteral>(E); 697 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 698 SE->getByteLength()))); 699 } 700 701 // Copy the parameter declarations from the declarator D to 702 // the function declaration NewFD, if they are available. 703 if (D.getNumTypeObjects() > 0 && 704 D.getTypeObject(0).Fun.hasPrototype) { 705 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 706 707 // Create Decl objects for each parameter, adding them to the 708 // FunctionDecl. 709 llvm::SmallVector<ParmVarDecl*, 16> Params; 710 711 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 712 // function that takes no arguments, not a function that takes a 713 // single void argument. 714 // We let through "const void" here because Sema::GetTypeForDeclarator 715 // already checks for that case. 716 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 717 FTI.ArgInfo[0].Param && 718 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 719 // empty arg list, don't push any params. 720 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 721 722 // In C++, the empty parameter-type-list must be spelled "void"; a 723 // typedef of void is not permitted. 724 if (getLangOptions().CPlusPlus && 725 Param->getType().getUnqualifiedType() != Context.VoidTy) { 726 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 727 } 728 729 } else { 730 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 731 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 732 } 733 734 NewFD->setParams(&Params[0], Params.size()); 735 } 736 737 // Merge the decl with the existing one if appropriate. Since C functions 738 // are in a flat namespace, make sure we consider decls in outer scopes. 739 if (PrevDecl && 740 (!getLangOptions().CPlusPlus || 741 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 742 bool Redeclaration = false; 743 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 744 if (NewFD == 0) return 0; 745 if (Redeclaration) { 746 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 747 } 748 } 749 New = NewFD; 750 751 // In C++, check default arguments now that we have merged decls. 752 if (getLangOptions().CPlusPlus) 753 CheckCXXDefaultArguments(NewFD); 754 } else { 755 // Check that there are no default arguments (C++ only). 756 if (getLangOptions().CPlusPlus) 757 CheckExtraCXXDefaultArguments(D); 758 759 if (R.getTypePtr()->isObjCInterfaceType()) { 760 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 761 D.getIdentifier()->getName()); 762 InvalidDecl = true; 763 } 764 765 VarDecl *NewVD; 766 VarDecl::StorageClass SC; 767 switch (D.getDeclSpec().getStorageClassSpec()) { 768 default: assert(0 && "Unknown storage class!"); 769 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 770 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 771 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 772 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 773 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 774 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 775 } 776 if (D.getContext() == Declarator::MemberContext) { 777 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 778 // This is a static data member for a C++ class. 779 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 780 D.getIdentifierLoc(), II, 781 R, LastDeclarator); 782 } else { 783 if (S->getFnParent() == 0) { 784 // C99 6.9p2: The storage-class specifiers auto and register shall not 785 // appear in the declaration specifiers in an external declaration. 786 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 787 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 788 R.getAsString()); 789 InvalidDecl = true; 790 } 791 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 792 II, R, SC, LastDeclarator); 793 } else { 794 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 795 II, R, SC, LastDeclarator); 796 } 797 } 798 // Handle attributes prior to checking for duplicates in MergeVarDecl 799 ProcessDeclAttributes(NewVD, D); 800 801 // Handle GNU asm-label extension (encoded as an attribute). 802 if (Expr *E = (Expr*) D.getAsmLabel()) { 803 // The parser guarantees this is a string. 804 StringLiteral *SE = cast<StringLiteral>(E); 805 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 806 SE->getByteLength()))); 807 } 808 809 // Emit an error if an address space was applied to decl with local storage. 810 // This includes arrays of objects with address space qualifiers, but not 811 // automatic variables that point to other address spaces. 812 // ISO/IEC TR 18037 S5.1.2 813 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 814 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 815 InvalidDecl = true; 816 } 817 // Merge the decl with the existing one if appropriate. If the decl is 818 // in an outer scope, it isn't the same thing. 819 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 820 NewVD = MergeVarDecl(NewVD, PrevDecl); 821 if (NewVD == 0) return 0; 822 } 823 New = NewVD; 824 } 825 826 // If this has an identifier, add it to the scope stack. 827 if (II) 828 PushOnScopeChains(New, S); 829 // If any semantic error occurred, mark the decl as invalid. 830 if (D.getInvalidType() || InvalidDecl) 831 New->setInvalidDecl(); 832 833 return New; 834} 835 836bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 837 switch (Init->getStmtClass()) { 838 default: 839 Diag(Init->getExprLoc(), 840 diag::err_init_element_not_constant, Init->getSourceRange()); 841 return true; 842 case Expr::ParenExprClass: { 843 const ParenExpr* PE = cast<ParenExpr>(Init); 844 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 845 } 846 case Expr::CompoundLiteralExprClass: 847 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 848 case Expr::DeclRefExprClass: { 849 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 850 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 851 if (VD->hasGlobalStorage()) 852 return false; 853 Diag(Init->getExprLoc(), 854 diag::err_init_element_not_constant, Init->getSourceRange()); 855 return true; 856 } 857 if (isa<FunctionDecl>(D)) 858 return false; 859 Diag(Init->getExprLoc(), 860 diag::err_init_element_not_constant, Init->getSourceRange()); 861 return true; 862 } 863 case Expr::MemberExprClass: { 864 const MemberExpr *M = cast<MemberExpr>(Init); 865 if (M->isArrow()) 866 return CheckAddressConstantExpression(M->getBase()); 867 return CheckAddressConstantExpressionLValue(M->getBase()); 868 } 869 case Expr::ArraySubscriptExprClass: { 870 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 871 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 872 return CheckAddressConstantExpression(ASE->getBase()) || 873 CheckArithmeticConstantExpression(ASE->getIdx()); 874 } 875 case Expr::StringLiteralClass: 876 case Expr::PredefinedExprClass: 877 return false; 878 case Expr::UnaryOperatorClass: { 879 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 880 881 // C99 6.6p9 882 if (Exp->getOpcode() == UnaryOperator::Deref) 883 return CheckAddressConstantExpression(Exp->getSubExpr()); 884 885 Diag(Init->getExprLoc(), 886 diag::err_init_element_not_constant, Init->getSourceRange()); 887 return true; 888 } 889 } 890} 891 892bool Sema::CheckAddressConstantExpression(const Expr* Init) { 893 switch (Init->getStmtClass()) { 894 default: 895 Diag(Init->getExprLoc(), 896 diag::err_init_element_not_constant, Init->getSourceRange()); 897 return true; 898 case Expr::ParenExprClass: { 899 const ParenExpr* PE = cast<ParenExpr>(Init); 900 return CheckAddressConstantExpression(PE->getSubExpr()); 901 } 902 case Expr::StringLiteralClass: 903 case Expr::ObjCStringLiteralClass: 904 return false; 905 case Expr::CallExprClass: { 906 const CallExpr *CE = cast<CallExpr>(Init); 907 if (CE->isBuiltinConstantExpr()) 908 return false; 909 Diag(Init->getExprLoc(), 910 diag::err_init_element_not_constant, Init->getSourceRange()); 911 return true; 912 } 913 case Expr::UnaryOperatorClass: { 914 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 915 916 // C99 6.6p9 917 if (Exp->getOpcode() == UnaryOperator::AddrOf) 918 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 919 920 if (Exp->getOpcode() == UnaryOperator::Extension) 921 return CheckAddressConstantExpression(Exp->getSubExpr()); 922 923 Diag(Init->getExprLoc(), 924 diag::err_init_element_not_constant, Init->getSourceRange()); 925 return true; 926 } 927 case Expr::BinaryOperatorClass: { 928 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 929 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 930 931 Expr *PExp = Exp->getLHS(); 932 Expr *IExp = Exp->getRHS(); 933 if (IExp->getType()->isPointerType()) 934 std::swap(PExp, IExp); 935 936 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 937 return CheckAddressConstantExpression(PExp) || 938 CheckArithmeticConstantExpression(IExp); 939 } 940 case Expr::ImplicitCastExprClass: { 941 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 942 943 // Check for implicit promotion 944 if (SubExpr->getType()->isFunctionType() || 945 SubExpr->getType()->isArrayType()) 946 return CheckAddressConstantExpressionLValue(SubExpr); 947 948 // Check for pointer->pointer cast 949 if (SubExpr->getType()->isPointerType()) 950 return CheckAddressConstantExpression(SubExpr); 951 952 if (SubExpr->getType()->isArithmeticType()) 953 return CheckArithmeticConstantExpression(SubExpr); 954 955 Diag(Init->getExprLoc(), 956 diag::err_init_element_not_constant, Init->getSourceRange()); 957 return true; 958 } 959 case Expr::CastExprClass: { 960 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 961 962 // Check for pointer->pointer cast 963 if (SubExpr->getType()->isPointerType()) 964 return CheckAddressConstantExpression(SubExpr); 965 966 // FIXME: Should we pedwarn for (int*)(0+0)? 967 if (SubExpr->getType()->isArithmeticType()) 968 return CheckArithmeticConstantExpression(SubExpr); 969 970 Diag(Init->getExprLoc(), 971 diag::err_init_element_not_constant, Init->getSourceRange()); 972 return true; 973 } 974 case Expr::ConditionalOperatorClass: { 975 // FIXME: Should we pedwarn here? 976 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 977 if (!Exp->getCond()->getType()->isArithmeticType()) { 978 Diag(Init->getExprLoc(), 979 diag::err_init_element_not_constant, Init->getSourceRange()); 980 return true; 981 } 982 if (CheckArithmeticConstantExpression(Exp->getCond())) 983 return true; 984 if (Exp->getLHS() && 985 CheckAddressConstantExpression(Exp->getLHS())) 986 return true; 987 return CheckAddressConstantExpression(Exp->getRHS()); 988 } 989 case Expr::AddrLabelExprClass: 990 return false; 991 } 992} 993 994static const Expr* FindExpressionBaseAddress(const Expr* E); 995 996static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 997 switch (E->getStmtClass()) { 998 default: 999 return E; 1000 case Expr::ParenExprClass: { 1001 const ParenExpr* PE = cast<ParenExpr>(E); 1002 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1003 } 1004 case Expr::MemberExprClass: { 1005 const MemberExpr *M = cast<MemberExpr>(E); 1006 if (M->isArrow()) 1007 return FindExpressionBaseAddress(M->getBase()); 1008 return FindExpressionBaseAddressLValue(M->getBase()); 1009 } 1010 case Expr::ArraySubscriptExprClass: { 1011 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1012 return FindExpressionBaseAddress(ASE->getBase()); 1013 } 1014 case Expr::UnaryOperatorClass: { 1015 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1016 1017 if (Exp->getOpcode() == UnaryOperator::Deref) 1018 return FindExpressionBaseAddress(Exp->getSubExpr()); 1019 1020 return E; 1021 } 1022 } 1023} 1024 1025static const Expr* FindExpressionBaseAddress(const Expr* E) { 1026 switch (E->getStmtClass()) { 1027 default: 1028 return E; 1029 case Expr::ParenExprClass: { 1030 const ParenExpr* PE = cast<ParenExpr>(E); 1031 return FindExpressionBaseAddress(PE->getSubExpr()); 1032 } 1033 case Expr::UnaryOperatorClass: { 1034 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1035 1036 // C99 6.6p9 1037 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1038 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1039 1040 if (Exp->getOpcode() == UnaryOperator::Extension) 1041 return FindExpressionBaseAddress(Exp->getSubExpr()); 1042 1043 return E; 1044 } 1045 case Expr::BinaryOperatorClass: { 1046 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1047 1048 Expr *PExp = Exp->getLHS(); 1049 Expr *IExp = Exp->getRHS(); 1050 if (IExp->getType()->isPointerType()) 1051 std::swap(PExp, IExp); 1052 1053 return FindExpressionBaseAddress(PExp); 1054 } 1055 case Expr::ImplicitCastExprClass: { 1056 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1057 1058 // Check for implicit promotion 1059 if (SubExpr->getType()->isFunctionType() || 1060 SubExpr->getType()->isArrayType()) 1061 return FindExpressionBaseAddressLValue(SubExpr); 1062 1063 // Check for pointer->pointer cast 1064 if (SubExpr->getType()->isPointerType()) 1065 return FindExpressionBaseAddress(SubExpr); 1066 1067 // We assume that we have an arithmetic expression here; 1068 // if we don't, we'll figure it out later 1069 return 0; 1070 } 1071 case Expr::CastExprClass: { 1072 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1073 1074 // Check for pointer->pointer cast 1075 if (SubExpr->getType()->isPointerType()) 1076 return FindExpressionBaseAddress(SubExpr); 1077 1078 // We assume that we have an arithmetic expression here; 1079 // if we don't, we'll figure it out later 1080 return 0; 1081 } 1082 } 1083} 1084 1085bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1086 switch (Init->getStmtClass()) { 1087 default: 1088 Diag(Init->getExprLoc(), 1089 diag::err_init_element_not_constant, Init->getSourceRange()); 1090 return true; 1091 case Expr::ParenExprClass: { 1092 const ParenExpr* PE = cast<ParenExpr>(Init); 1093 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1094 } 1095 case Expr::FloatingLiteralClass: 1096 case Expr::IntegerLiteralClass: 1097 case Expr::CharacterLiteralClass: 1098 case Expr::ImaginaryLiteralClass: 1099 case Expr::TypesCompatibleExprClass: 1100 case Expr::CXXBoolLiteralExprClass: 1101 return false; 1102 case Expr::CallExprClass: { 1103 const CallExpr *CE = cast<CallExpr>(Init); 1104 if (CE->isBuiltinConstantExpr()) 1105 return false; 1106 Diag(Init->getExprLoc(), 1107 diag::err_init_element_not_constant, Init->getSourceRange()); 1108 return true; 1109 } 1110 case Expr::DeclRefExprClass: { 1111 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1112 if (isa<EnumConstantDecl>(D)) 1113 return false; 1114 Diag(Init->getExprLoc(), 1115 diag::err_init_element_not_constant, Init->getSourceRange()); 1116 return true; 1117 } 1118 case Expr::CompoundLiteralExprClass: 1119 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1120 // but vectors are allowed to be magic. 1121 if (Init->getType()->isVectorType()) 1122 return false; 1123 Diag(Init->getExprLoc(), 1124 diag::err_init_element_not_constant, Init->getSourceRange()); 1125 return true; 1126 case Expr::UnaryOperatorClass: { 1127 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1128 1129 switch (Exp->getOpcode()) { 1130 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1131 // See C99 6.6p3. 1132 default: 1133 Diag(Init->getExprLoc(), 1134 diag::err_init_element_not_constant, Init->getSourceRange()); 1135 return true; 1136 case UnaryOperator::SizeOf: 1137 case UnaryOperator::AlignOf: 1138 case UnaryOperator::OffsetOf: 1139 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1140 // See C99 6.5.3.4p2 and 6.6p3. 1141 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1142 return false; 1143 Diag(Init->getExprLoc(), 1144 diag::err_init_element_not_constant, Init->getSourceRange()); 1145 return true; 1146 case UnaryOperator::Extension: 1147 case UnaryOperator::LNot: 1148 case UnaryOperator::Plus: 1149 case UnaryOperator::Minus: 1150 case UnaryOperator::Not: 1151 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1152 } 1153 } 1154 case Expr::SizeOfAlignOfTypeExprClass: { 1155 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1156 // Special check for void types, which are allowed as an extension 1157 if (Exp->getArgumentType()->isVoidType()) 1158 return false; 1159 // alignof always evaluates to a constant. 1160 // FIXME: is sizeof(int[3.0]) a constant expression? 1161 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1162 Diag(Init->getExprLoc(), 1163 diag::err_init_element_not_constant, Init->getSourceRange()); 1164 return true; 1165 } 1166 return false; 1167 } 1168 case Expr::BinaryOperatorClass: { 1169 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1170 1171 if (Exp->getLHS()->getType()->isArithmeticType() && 1172 Exp->getRHS()->getType()->isArithmeticType()) { 1173 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1174 CheckArithmeticConstantExpression(Exp->getRHS()); 1175 } 1176 1177 if (Exp->getLHS()->getType()->isPointerType() && 1178 Exp->getRHS()->getType()->isPointerType()) { 1179 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1180 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1181 1182 // Only allow a null (constant integer) base; we could 1183 // allow some additional cases if necessary, but this 1184 // is sufficient to cover offsetof-like constructs. 1185 if (!LHSBase && !RHSBase) { 1186 return CheckAddressConstantExpression(Exp->getLHS()) || 1187 CheckAddressConstantExpression(Exp->getRHS()); 1188 } 1189 } 1190 1191 Diag(Init->getExprLoc(), 1192 diag::err_init_element_not_constant, Init->getSourceRange()); 1193 return true; 1194 } 1195 case Expr::ImplicitCastExprClass: 1196 case Expr::CastExprClass: { 1197 const Expr *SubExpr; 1198 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1199 SubExpr = C->getSubExpr(); 1200 } else { 1201 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1202 } 1203 1204 if (SubExpr->getType()->isArithmeticType()) 1205 return CheckArithmeticConstantExpression(SubExpr); 1206 1207 Diag(Init->getExprLoc(), 1208 diag::err_init_element_not_constant, Init->getSourceRange()); 1209 return true; 1210 } 1211 case Expr::ConditionalOperatorClass: { 1212 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1213 if (CheckArithmeticConstantExpression(Exp->getCond())) 1214 return true; 1215 if (Exp->getLHS() && 1216 CheckArithmeticConstantExpression(Exp->getLHS())) 1217 return true; 1218 return CheckArithmeticConstantExpression(Exp->getRHS()); 1219 } 1220 } 1221} 1222 1223bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1224 Init = Init->IgnoreParens(); 1225 1226 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1227 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1228 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1229 1230 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1231 return CheckForConstantInitializer(e->getInitializer(), DclT); 1232 1233 if (Init->getType()->isReferenceType()) { 1234 // FIXME: Work out how the heck reference types work 1235 return false; 1236#if 0 1237 // A reference is constant if the address of the expression 1238 // is constant 1239 // We look through initlists here to simplify 1240 // CheckAddressConstantExpressionLValue. 1241 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1242 assert(Exp->getNumInits() > 0 && 1243 "Refernce initializer cannot be empty"); 1244 Init = Exp->getInit(0); 1245 } 1246 return CheckAddressConstantExpressionLValue(Init); 1247#endif 1248 } 1249 1250 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1251 unsigned numInits = Exp->getNumInits(); 1252 for (unsigned i = 0; i < numInits; i++) { 1253 // FIXME: Need to get the type of the declaration for C++, 1254 // because it could be a reference? 1255 if (CheckForConstantInitializer(Exp->getInit(i), 1256 Exp->getInit(i)->getType())) 1257 return true; 1258 } 1259 return false; 1260 } 1261 1262 if (Init->isNullPointerConstant(Context)) 1263 return false; 1264 if (Init->getType()->isArithmeticType()) { 1265 QualType InitTy = Context.getCanonicalType(Init->getType()) 1266 .getUnqualifiedType(); 1267 if (InitTy == Context.BoolTy) { 1268 // Special handling for pointers implicitly cast to bool; 1269 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1270 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1271 Expr* SubE = ICE->getSubExpr(); 1272 if (SubE->getType()->isPointerType() || 1273 SubE->getType()->isArrayType() || 1274 SubE->getType()->isFunctionType()) { 1275 return CheckAddressConstantExpression(Init); 1276 } 1277 } 1278 } else if (InitTy->isIntegralType()) { 1279 Expr* SubE = 0; 1280 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1281 SubE = ICE->getSubExpr(); 1282 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1283 SubE = CE->getSubExpr(); 1284 // Special check for pointer cast to int; we allow as an extension 1285 // an address constant cast to an integer if the integer 1286 // is of an appropriate width (this sort of code is apparently used 1287 // in some places). 1288 // FIXME: Add pedwarn? 1289 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1290 if (SubE && (SubE->getType()->isPointerType() || 1291 SubE->getType()->isArrayType() || 1292 SubE->getType()->isFunctionType())) { 1293 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1294 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1295 if (IntWidth >= PointerWidth) 1296 return CheckAddressConstantExpression(Init); 1297 } 1298 } 1299 1300 return CheckArithmeticConstantExpression(Init); 1301 } 1302 1303 if (Init->getType()->isPointerType()) 1304 return CheckAddressConstantExpression(Init); 1305 1306 // An array type at the top level that isn't an init-list must 1307 // be a string literal 1308 if (Init->getType()->isArrayType()) 1309 return false; 1310 1311 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1312 Init->getSourceRange()); 1313 return true; 1314} 1315 1316void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1317 Decl *RealDecl = static_cast<Decl *>(dcl); 1318 Expr *Init = static_cast<Expr *>(init); 1319 assert(Init && "missing initializer"); 1320 1321 // If there is no declaration, there was an error parsing it. Just ignore 1322 // the initializer. 1323 if (RealDecl == 0) { 1324 delete Init; 1325 return; 1326 } 1327 1328 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1329 if (!VDecl) { 1330 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1331 diag::err_illegal_initializer); 1332 RealDecl->setInvalidDecl(); 1333 return; 1334 } 1335 // Get the decls type and save a reference for later, since 1336 // CheckInitializerTypes may change it. 1337 QualType DclT = VDecl->getType(), SavT = DclT; 1338 if (VDecl->isBlockVarDecl()) { 1339 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1340 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1341 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1342 VDecl->setInvalidDecl(); 1343 } else if (!VDecl->isInvalidDecl()) { 1344 if (CheckInitializerTypes(Init, DclT)) 1345 VDecl->setInvalidDecl(); 1346 if (SC == VarDecl::Static) // C99 6.7.8p4. 1347 CheckForConstantInitializer(Init, DclT); 1348 } 1349 } else if (VDecl->isFileVarDecl()) { 1350 if (VDecl->getStorageClass() == VarDecl::Extern) 1351 Diag(VDecl->getLocation(), diag::warn_extern_init); 1352 if (!VDecl->isInvalidDecl()) 1353 if (CheckInitializerTypes(Init, DclT)) 1354 VDecl->setInvalidDecl(); 1355 1356 // C99 6.7.8p4. All file scoped initializers need to be constant. 1357 CheckForConstantInitializer(Init, DclT); 1358 } 1359 // If the type changed, it means we had an incomplete type that was 1360 // completed by the initializer. For example: 1361 // int ary[] = { 1, 3, 5 }; 1362 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1363 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1364 VDecl->setType(DclT); 1365 Init->setType(DclT); 1366 } 1367 1368 // Attach the initializer to the decl. 1369 VDecl->setInit(Init); 1370 return; 1371} 1372 1373/// The declarators are chained together backwards, reverse the list. 1374Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1375 // Often we have single declarators, handle them quickly. 1376 Decl *GroupDecl = static_cast<Decl*>(group); 1377 if (GroupDecl == 0) 1378 return 0; 1379 1380 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1381 ScopedDecl *NewGroup = 0; 1382 if (Group->getNextDeclarator() == 0) 1383 NewGroup = Group; 1384 else { // reverse the list. 1385 while (Group) { 1386 ScopedDecl *Next = Group->getNextDeclarator(); 1387 Group->setNextDeclarator(NewGroup); 1388 NewGroup = Group; 1389 Group = Next; 1390 } 1391 } 1392 // Perform semantic analysis that depends on having fully processed both 1393 // the declarator and initializer. 1394 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1395 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1396 if (!IDecl) 1397 continue; 1398 QualType T = IDecl->getType(); 1399 1400 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1401 // static storage duration, it shall not have a variable length array. 1402 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1403 IDecl->getStorageClass() == VarDecl::Static) { 1404 if (T->isVariableArrayType()) { 1405 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1406 IDecl->setInvalidDecl(); 1407 } 1408 } 1409 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1410 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1411 if (IDecl->isBlockVarDecl() && 1412 IDecl->getStorageClass() != VarDecl::Extern) { 1413 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1414 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1415 T.getAsString()); 1416 IDecl->setInvalidDecl(); 1417 } 1418 } 1419 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1420 // object that has file scope without an initializer, and without a 1421 // storage-class specifier or with the storage-class specifier "static", 1422 // constitutes a tentative definition. Note: A tentative definition with 1423 // external linkage is valid (C99 6.2.2p5). 1424 if (isTentativeDefinition(IDecl)) { 1425 if (T->isIncompleteArrayType()) { 1426 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1427 // array to be completed. Don't issue a diagnostic. 1428 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1429 // C99 6.9.2p3: If the declaration of an identifier for an object is 1430 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1431 // declared type shall not be an incomplete type. 1432 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1433 T.getAsString()); 1434 IDecl->setInvalidDecl(); 1435 } 1436 } 1437 if (IDecl->isFileVarDecl()) 1438 CheckForFileScopedRedefinitions(S, IDecl); 1439 } 1440 return NewGroup; 1441} 1442 1443/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1444/// to introduce parameters into function prototype scope. 1445Sema::DeclTy * 1446Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1447 const DeclSpec &DS = D.getDeclSpec(); 1448 1449 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1450 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1451 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1452 Diag(DS.getStorageClassSpecLoc(), 1453 diag::err_invalid_storage_class_in_func_decl); 1454 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1455 } 1456 if (DS.isThreadSpecified()) { 1457 Diag(DS.getThreadSpecLoc(), 1458 diag::err_invalid_storage_class_in_func_decl); 1459 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1460 } 1461 1462 // Check that there are no default arguments inside the type of this 1463 // parameter (C++ only). 1464 if (getLangOptions().CPlusPlus) 1465 CheckExtraCXXDefaultArguments(D); 1466 1467 // In this context, we *do not* check D.getInvalidType(). If the declarator 1468 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1469 // though it will not reflect the user specified type. 1470 QualType parmDeclType = GetTypeForDeclarator(D, S); 1471 1472 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1473 1474 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1475 // Can this happen for params? We already checked that they don't conflict 1476 // among each other. Here they can only shadow globals, which is ok. 1477 IdentifierInfo *II = D.getIdentifier(); 1478 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1479 if (S->isDeclScope(PrevDecl)) { 1480 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1481 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1482 1483 // Recover by removing the name 1484 II = 0; 1485 D.SetIdentifier(0, D.getIdentifierLoc()); 1486 } 1487 } 1488 1489 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1490 // Doing the promotion here has a win and a loss. The win is the type for 1491 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1492 // code generator). The loss is the orginal type isn't preserved. For example: 1493 // 1494 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1495 // int blockvardecl[5]; 1496 // sizeof(parmvardecl); // size == 4 1497 // sizeof(blockvardecl); // size == 20 1498 // } 1499 // 1500 // For expressions, all implicit conversions are captured using the 1501 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1502 // 1503 // FIXME: If a source translation tool needs to see the original type, then 1504 // we need to consider storing both types (in ParmVarDecl)... 1505 // 1506 if (parmDeclType->isArrayType()) { 1507 // int x[restrict 4] -> int *restrict 1508 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1509 } else if (parmDeclType->isFunctionType()) 1510 parmDeclType = Context.getPointerType(parmDeclType); 1511 1512 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1513 D.getIdentifierLoc(), II, 1514 parmDeclType, VarDecl::None, 1515 0, 0); 1516 1517 if (D.getInvalidType()) 1518 New->setInvalidDecl(); 1519 1520 if (II) 1521 PushOnScopeChains(New, S); 1522 1523 ProcessDeclAttributes(New, D); 1524 return New; 1525 1526} 1527 1528Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1529 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1530 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1531 "Not a function declarator!"); 1532 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1533 1534 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1535 // for a K&R function. 1536 if (!FTI.hasPrototype) { 1537 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1538 if (FTI.ArgInfo[i].Param == 0) { 1539 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1540 FTI.ArgInfo[i].Ident->getName()); 1541 // Implicitly declare the argument as type 'int' for lack of a better 1542 // type. 1543 DeclSpec DS; 1544 const char* PrevSpec; // unused 1545 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1546 PrevSpec); 1547 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1548 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1549 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1550 } 1551 } 1552 1553 // Since this is a function definition, act as though we have information 1554 // about the arguments. 1555 if (FTI.NumArgs) 1556 FTI.hasPrototype = true; 1557 } else { 1558 // FIXME: Diagnose arguments without names in C. 1559 } 1560 1561 Scope *GlobalScope = FnBodyScope->getParent(); 1562 1563 // See if this is a redefinition. 1564 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1565 GlobalScope); 1566 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1567 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1568 const FunctionDecl *Definition; 1569 if (FD->getBody(Definition)) { 1570 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1571 D.getIdentifier()->getName()); 1572 Diag(Definition->getLocation(), diag::err_previous_definition); 1573 } 1574 } 1575 } 1576 1577 return ActOnStartOfFunctionDef(FnBodyScope, 1578 ActOnDeclarator(GlobalScope, D, 0)); 1579} 1580 1581Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1582 Decl *decl = static_cast<Decl*>(D); 1583 FunctionDecl *FD = cast<FunctionDecl>(decl); 1584 PushDeclContext(FD); 1585 1586 // Check the validity of our function parameters 1587 CheckParmsForFunctionDef(FD); 1588 1589 // Introduce our parameters into the function scope 1590 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1591 ParmVarDecl *Param = FD->getParamDecl(p); 1592 // If this has an identifier, add it to the scope stack. 1593 if (Param->getIdentifier()) 1594 PushOnScopeChains(Param, FnBodyScope); 1595 } 1596 1597 return FD; 1598} 1599 1600Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1601 Decl *dcl = static_cast<Decl *>(D); 1602 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1603 FD->setBody((Stmt*)Body); 1604 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1605 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1606 MD->setBody((Stmt*)Body); 1607 } else 1608 return 0; 1609 PopDeclContext(); 1610 // Verify and clean out per-function state. 1611 1612 // Check goto/label use. 1613 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1614 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1615 // Verify that we have no forward references left. If so, there was a goto 1616 // or address of a label taken, but no definition of it. Label fwd 1617 // definitions are indicated with a null substmt. 1618 if (I->second->getSubStmt() == 0) { 1619 LabelStmt *L = I->second; 1620 // Emit error. 1621 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1622 1623 // At this point, we have gotos that use the bogus label. Stitch it into 1624 // the function body so that they aren't leaked and that the AST is well 1625 // formed. 1626 if (Body) { 1627 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1628 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1629 } else { 1630 // The whole function wasn't parsed correctly, just delete this. 1631 delete L; 1632 } 1633 } 1634 } 1635 LabelMap.clear(); 1636 1637 return D; 1638} 1639 1640/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1641/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1642ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1643 IdentifierInfo &II, Scope *S) { 1644 // Extension in C99. Legal in C90, but warn about it. 1645 if (getLangOptions().C99) 1646 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1647 else 1648 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1649 1650 // FIXME: handle stuff like: 1651 // void foo() { extern float X(); } 1652 // void bar() { X(); } <-- implicit decl for X in another scope. 1653 1654 // Set a Declarator for the implicit definition: int foo(); 1655 const char *Dummy; 1656 DeclSpec DS; 1657 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1658 Error = Error; // Silence warning. 1659 assert(!Error && "Error setting up implicit decl!"); 1660 Declarator D(DS, Declarator::BlockContext); 1661 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1662 D.SetIdentifier(&II, Loc); 1663 1664 // Insert this function into translation-unit scope. 1665 1666 DeclContext *PrevDC = CurContext; 1667 CurContext = Context.getTranslationUnitDecl(); 1668 1669 FunctionDecl *FD = 1670 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1671 FD->setImplicit(); 1672 1673 CurContext = PrevDC; 1674 1675 return FD; 1676} 1677 1678 1679TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1680 ScopedDecl *LastDeclarator) { 1681 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1682 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1683 1684 // Scope manipulation handled by caller. 1685 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1686 D.getIdentifierLoc(), 1687 D.getIdentifier(), 1688 T, LastDeclarator); 1689 if (D.getInvalidType()) 1690 NewTD->setInvalidDecl(); 1691 return NewTD; 1692} 1693 1694/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1695/// former case, Name will be non-null. In the later case, Name will be null. 1696/// TagType indicates what kind of tag this is. TK indicates whether this is a 1697/// reference/declaration/definition of a tag. 1698Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1699 SourceLocation KWLoc, IdentifierInfo *Name, 1700 SourceLocation NameLoc, AttributeList *Attr) { 1701 // If this is a use of an existing tag, it must have a name. 1702 assert((Name != 0 || TK == TK_Definition) && 1703 "Nameless record must be a definition!"); 1704 1705 TagDecl::TagKind Kind; 1706 switch (TagType) { 1707 default: assert(0 && "Unknown tag type!"); 1708 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1709 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1710 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1711 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1712 } 1713 1714 // If this is a named struct, check to see if there was a previous forward 1715 // declaration or definition. 1716 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1717 if (ScopedDecl *PrevDecl = 1718 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1719 1720 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1721 "unexpected Decl type"); 1722 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1723 // If this is a use of a previous tag, or if the tag is already declared 1724 // in the same scope (so that the definition/declaration completes or 1725 // rementions the tag), reuse the decl. 1726 if (TK == TK_Reference || 1727 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1728 // Make sure that this wasn't declared as an enum and now used as a 1729 // struct or something similar. 1730 if (PrevTagDecl->getTagKind() != Kind) { 1731 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1732 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1733 // Recover by making this an anonymous redefinition. 1734 Name = 0; 1735 PrevDecl = 0; 1736 } else { 1737 // If this is a use or a forward declaration, we're good. 1738 if (TK != TK_Definition) 1739 return PrevDecl; 1740 1741 // Diagnose attempts to redefine a tag. 1742 if (PrevTagDecl->isDefinition()) { 1743 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1744 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1745 // If this is a redefinition, recover by making this struct be 1746 // anonymous, which will make any later references get the previous 1747 // definition. 1748 Name = 0; 1749 } else { 1750 // Okay, this is definition of a previously declared or referenced 1751 // tag. Move the location of the decl to be the definition site. 1752 PrevDecl->setLocation(NameLoc); 1753 return PrevDecl; 1754 } 1755 } 1756 } 1757 // If we get here, this is a definition of a new struct type in a nested 1758 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1759 // type. 1760 } else { 1761 // PrevDecl is a namespace. 1762 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1763 // The tag name clashes with a namespace name, issue an error and recover 1764 // by making this tag be anonymous. 1765 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1766 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1767 Name = 0; 1768 } 1769 } 1770 } 1771 1772 // If there is an identifier, use the location of the identifier as the 1773 // location of the decl, otherwise use the location of the struct/union 1774 // keyword. 1775 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1776 1777 // Otherwise, if this is the first time we've seen this tag, create the decl. 1778 TagDecl *New; 1779 if (Kind == TagDecl::TK_enum) { 1780 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1781 // enum X { A, B, C } D; D should chain to X. 1782 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1783 // If this is an undefined enum, warn. 1784 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1785 } else { 1786 // struct/union/class 1787 1788 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1789 // struct X { int A; } D; D should chain to X. 1790 if (getLangOptions().CPlusPlus) 1791 // FIXME: Look for a way to use RecordDecl for simple structs. 1792 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1793 else 1794 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1795 } 1796 1797 // If this has an identifier, add it to the scope stack. 1798 if (Name) { 1799 // The scope passed in may not be a decl scope. Zip up the scope tree until 1800 // we find one that is. 1801 while ((S->getFlags() & Scope::DeclScope) == 0) 1802 S = S->getParent(); 1803 1804 // Add it to the decl chain. 1805 PushOnScopeChains(New, S); 1806 } 1807 1808 if (Attr) 1809 ProcessDeclAttributeList(New, Attr); 1810 return New; 1811} 1812 1813/// Collect the instance variables declared in an Objective-C object. Used in 1814/// the creation of structures from objects using the @defs directive. 1815static void CollectIvars(ObjCInterfaceDecl *Class, 1816 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1817 if (Class->getSuperClass()) 1818 CollectIvars(Class->getSuperClass(), ivars); 1819 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1820} 1821 1822/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1823/// instance variables of ClassName into Decls. 1824void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1825 IdentifierInfo *ClassName, 1826 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1827 // Check that ClassName is a valid class 1828 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1829 if (!Class) { 1830 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1831 return; 1832 } 1833 // Collect the instance variables 1834 CollectIvars(Class, Decls); 1835} 1836 1837QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1838 // This method tries to turn a variable array into a constant 1839 // array even when the size isn't an ICE. This is necessary 1840 // for compatibility with code that depends on gcc's buggy 1841 // constant expression folding, like struct {char x[(int)(char*)2];} 1842 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1843 APValue Result; 1844 if (VLATy->getSizeExpr() && 1845 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1846 llvm::APSInt &Res = Result.getInt(); 1847 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1848 return Context.getConstantArrayType(VLATy->getElementType(), 1849 Res, ArrayType::Normal, 0); 1850 } 1851 } 1852 return QualType(); 1853} 1854 1855/// ActOnField - Each field of a struct/union/class is passed into this in order 1856/// to create a FieldDecl object for it. 1857Sema::DeclTy *Sema::ActOnField(Scope *S, 1858 SourceLocation DeclStart, 1859 Declarator &D, ExprTy *BitfieldWidth) { 1860 IdentifierInfo *II = D.getIdentifier(); 1861 Expr *BitWidth = (Expr*)BitfieldWidth; 1862 SourceLocation Loc = DeclStart; 1863 if (II) Loc = D.getIdentifierLoc(); 1864 1865 // FIXME: Unnamed fields can be handled in various different ways, for 1866 // example, unnamed unions inject all members into the struct namespace! 1867 1868 1869 if (BitWidth) { 1870 // TODO: Validate. 1871 //printf("WARNING: BITFIELDS IGNORED!\n"); 1872 1873 // 6.7.2.1p3 1874 // 6.7.2.1p4 1875 1876 } else { 1877 // Not a bitfield. 1878 1879 // validate II. 1880 1881 } 1882 1883 QualType T = GetTypeForDeclarator(D, S); 1884 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1885 bool InvalidDecl = false; 1886 1887 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1888 // than a variably modified type. 1889 if (T->isVariablyModifiedType()) { 1890 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1891 if (!FixedTy.isNull()) { 1892 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1893 T = FixedTy; 1894 } else { 1895 // FIXME: This diagnostic needs work 1896 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1897 InvalidDecl = true; 1898 } 1899 } 1900 // FIXME: Chain fielddecls together. 1901 FieldDecl *NewFD; 1902 1903 if (getLangOptions().CPlusPlus) { 1904 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1905 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1906 Loc, II, T, BitWidth); 1907 if (II) 1908 PushOnScopeChains(NewFD, S); 1909 } 1910 else 1911 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1912 1913 ProcessDeclAttributes(NewFD, D); 1914 1915 if (D.getInvalidType() || InvalidDecl) 1916 NewFD->setInvalidDecl(); 1917 return NewFD; 1918} 1919 1920/// TranslateIvarVisibility - Translate visibility from a token ID to an 1921/// AST enum value. 1922static ObjCIvarDecl::AccessControl 1923TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1924 switch (ivarVisibility) { 1925 case tok::objc_private: return ObjCIvarDecl::Private; 1926 case tok::objc_public: return ObjCIvarDecl::Public; 1927 case tok::objc_protected: return ObjCIvarDecl::Protected; 1928 case tok::objc_package: return ObjCIvarDecl::Package; 1929 default: assert(false && "Unknown visitibility kind"); 1930 } 1931} 1932 1933/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1934/// in order to create an IvarDecl object for it. 1935Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1936 SourceLocation DeclStart, 1937 Declarator &D, ExprTy *BitfieldWidth, 1938 tok::ObjCKeywordKind Visibility) { 1939 IdentifierInfo *II = D.getIdentifier(); 1940 Expr *BitWidth = (Expr*)BitfieldWidth; 1941 SourceLocation Loc = DeclStart; 1942 if (II) Loc = D.getIdentifierLoc(); 1943 1944 // FIXME: Unnamed fields can be handled in various different ways, for 1945 // example, unnamed unions inject all members into the struct namespace! 1946 1947 1948 if (BitWidth) { 1949 // TODO: Validate. 1950 //printf("WARNING: BITFIELDS IGNORED!\n"); 1951 1952 // 6.7.2.1p3 1953 // 6.7.2.1p4 1954 1955 } else { 1956 // Not a bitfield. 1957 1958 // validate II. 1959 1960 } 1961 1962 QualType T = GetTypeForDeclarator(D, S); 1963 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1964 bool InvalidDecl = false; 1965 1966 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1967 // than a variably modified type. 1968 if (T->isVariablyModifiedType()) { 1969 // FIXME: This diagnostic needs work 1970 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1971 InvalidDecl = true; 1972 } 1973 1974 // Get the visibility (access control) for this ivar. 1975 ObjCIvarDecl::AccessControl ac = 1976 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1977 : ObjCIvarDecl::None; 1978 1979 // Construct the decl. 1980 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1981 (Expr *)BitfieldWidth); 1982 1983 // Process attributes attached to the ivar. 1984 ProcessDeclAttributes(NewID, D); 1985 1986 if (D.getInvalidType() || InvalidDecl) 1987 NewID->setInvalidDecl(); 1988 1989 return NewID; 1990} 1991 1992void Sema::ActOnFields(Scope* S, 1993 SourceLocation RecLoc, DeclTy *RecDecl, 1994 DeclTy **Fields, unsigned NumFields, 1995 SourceLocation LBrac, SourceLocation RBrac) { 1996 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1997 assert(EnclosingDecl && "missing record or interface decl"); 1998 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1999 2000 if (Record && Record->isDefinition()) { 2001 // Diagnose code like: 2002 // struct S { struct S {} X; }; 2003 // We discover this when we complete the outer S. Reject and ignore the 2004 // outer S. 2005 Diag(Record->getLocation(), diag::err_nested_redefinition, 2006 Record->getKindName()); 2007 Diag(RecLoc, diag::err_previous_definition); 2008 Record->setInvalidDecl(); 2009 return; 2010 } 2011 // Verify that all the fields are okay. 2012 unsigned NumNamedMembers = 0; 2013 llvm::SmallVector<FieldDecl*, 32> RecFields; 2014 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2015 2016 for (unsigned i = 0; i != NumFields; ++i) { 2017 2018 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2019 assert(FD && "missing field decl"); 2020 2021 // Remember all fields. 2022 RecFields.push_back(FD); 2023 2024 // Get the type for the field. 2025 Type *FDTy = FD->getType().getTypePtr(); 2026 2027 // C99 6.7.2.1p2 - A field may not be a function type. 2028 if (FDTy->isFunctionType()) { 2029 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2030 FD->getName()); 2031 FD->setInvalidDecl(); 2032 EnclosingDecl->setInvalidDecl(); 2033 continue; 2034 } 2035 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2036 if (FDTy->isIncompleteType()) { 2037 if (!Record) { // Incomplete ivar type is always an error. 2038 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2039 FD->setInvalidDecl(); 2040 EnclosingDecl->setInvalidDecl(); 2041 continue; 2042 } 2043 if (i != NumFields-1 || // ... that the last member ... 2044 !Record->isStruct() || // ... of a structure ... 2045 !FDTy->isArrayType()) { //... may have incomplete array type. 2046 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2047 FD->setInvalidDecl(); 2048 EnclosingDecl->setInvalidDecl(); 2049 continue; 2050 } 2051 if (NumNamedMembers < 1) { //... must have more than named member ... 2052 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2053 FD->getName()); 2054 FD->setInvalidDecl(); 2055 EnclosingDecl->setInvalidDecl(); 2056 continue; 2057 } 2058 // Okay, we have a legal flexible array member at the end of the struct. 2059 if (Record) 2060 Record->setHasFlexibleArrayMember(true); 2061 } 2062 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2063 /// field of another structure or the element of an array. 2064 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2065 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2066 // If this is a member of a union, then entire union becomes "flexible". 2067 if (Record && Record->isUnion()) { 2068 Record->setHasFlexibleArrayMember(true); 2069 } else { 2070 // If this is a struct/class and this is not the last element, reject 2071 // it. Note that GCC supports variable sized arrays in the middle of 2072 // structures. 2073 if (i != NumFields-1) { 2074 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2075 FD->getName()); 2076 FD->setInvalidDecl(); 2077 EnclosingDecl->setInvalidDecl(); 2078 continue; 2079 } 2080 // We support flexible arrays at the end of structs in other structs 2081 // as an extension. 2082 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2083 FD->getName()); 2084 if (Record) 2085 Record->setHasFlexibleArrayMember(true); 2086 } 2087 } 2088 } 2089 /// A field cannot be an Objective-c object 2090 if (FDTy->isObjCInterfaceType()) { 2091 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2092 FD->getName()); 2093 FD->setInvalidDecl(); 2094 EnclosingDecl->setInvalidDecl(); 2095 continue; 2096 } 2097 // Keep track of the number of named members. 2098 if (IdentifierInfo *II = FD->getIdentifier()) { 2099 // Detect duplicate member names. 2100 if (!FieldIDs.insert(II)) { 2101 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2102 // Find the previous decl. 2103 SourceLocation PrevLoc; 2104 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2105 assert(i != e && "Didn't find previous def!"); 2106 if (RecFields[i]->getIdentifier() == II) { 2107 PrevLoc = RecFields[i]->getLocation(); 2108 break; 2109 } 2110 } 2111 Diag(PrevLoc, diag::err_previous_definition); 2112 FD->setInvalidDecl(); 2113 EnclosingDecl->setInvalidDecl(); 2114 continue; 2115 } 2116 ++NumNamedMembers; 2117 } 2118 } 2119 2120 // Okay, we successfully defined 'Record'. 2121 if (Record) { 2122 Record->defineBody(&RecFields[0], RecFields.size()); 2123 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2124 // Sema::ActOnFinishCXXClassDef. 2125 if (!isa<CXXRecordDecl>(Record)) 2126 Consumer.HandleTagDeclDefinition(Record); 2127 } else { 2128 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2129 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2130 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2131 else if (ObjCImplementationDecl *IMPDecl = 2132 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2133 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2134 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2135 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2136 } 2137 } 2138} 2139 2140Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2141 DeclTy *lastEnumConst, 2142 SourceLocation IdLoc, IdentifierInfo *Id, 2143 SourceLocation EqualLoc, ExprTy *val) { 2144 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2145 EnumConstantDecl *LastEnumConst = 2146 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2147 Expr *Val = static_cast<Expr*>(val); 2148 2149 // The scope passed in may not be a decl scope. Zip up the scope tree until 2150 // we find one that is. 2151 while ((S->getFlags() & Scope::DeclScope) == 0) 2152 S = S->getParent(); 2153 2154 // Verify that there isn't already something declared with this name in this 2155 // scope. 2156 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2157 // When in C++, we may get a TagDecl with the same name; in this case the 2158 // enum constant will 'hide' the tag. 2159 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2160 "Received TagDecl when not in C++!"); 2161 if (!isa<TagDecl>(PrevDecl) && 2162 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2163 if (isa<EnumConstantDecl>(PrevDecl)) 2164 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2165 else 2166 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2167 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2168 delete Val; 2169 return 0; 2170 } 2171 } 2172 2173 llvm::APSInt EnumVal(32); 2174 QualType EltTy; 2175 if (Val) { 2176 // Make sure to promote the operand type to int. 2177 UsualUnaryConversions(Val); 2178 2179 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2180 SourceLocation ExpLoc; 2181 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2182 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2183 Id->getName()); 2184 delete Val; 2185 Val = 0; // Just forget about it. 2186 } else { 2187 EltTy = Val->getType(); 2188 } 2189 } 2190 2191 if (!Val) { 2192 if (LastEnumConst) { 2193 // Assign the last value + 1. 2194 EnumVal = LastEnumConst->getInitVal(); 2195 ++EnumVal; 2196 2197 // Check for overflow on increment. 2198 if (EnumVal < LastEnumConst->getInitVal()) 2199 Diag(IdLoc, diag::warn_enum_value_overflow); 2200 2201 EltTy = LastEnumConst->getType(); 2202 } else { 2203 // First value, set to zero. 2204 EltTy = Context.IntTy; 2205 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2206 } 2207 } 2208 2209 EnumConstantDecl *New = 2210 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2211 Val, EnumVal, 2212 LastEnumConst); 2213 2214 // Register this decl in the current scope stack. 2215 PushOnScopeChains(New, S); 2216 return New; 2217} 2218 2219// FIXME: For consistency with ActOnFields(), we should have the parser 2220// pass in the source location for the left/right braces. 2221void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2222 DeclTy **Elements, unsigned NumElements) { 2223 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2224 2225 if (Enum && Enum->isDefinition()) { 2226 // Diagnose code like: 2227 // enum e0 { 2228 // E0 = sizeof(enum e0 { E1 }) 2229 // }; 2230 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2231 Enum->getName()); 2232 Diag(EnumLoc, diag::err_previous_definition); 2233 Enum->setInvalidDecl(); 2234 return; 2235 } 2236 // TODO: If the result value doesn't fit in an int, it must be a long or long 2237 // long value. ISO C does not support this, but GCC does as an extension, 2238 // emit a warning. 2239 unsigned IntWidth = Context.Target.getIntWidth(); 2240 2241 // Verify that all the values are okay, compute the size of the values, and 2242 // reverse the list. 2243 unsigned NumNegativeBits = 0; 2244 unsigned NumPositiveBits = 0; 2245 2246 // Keep track of whether all elements have type int. 2247 bool AllElementsInt = true; 2248 2249 EnumConstantDecl *EltList = 0; 2250 for (unsigned i = 0; i != NumElements; ++i) { 2251 EnumConstantDecl *ECD = 2252 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2253 if (!ECD) continue; // Already issued a diagnostic. 2254 2255 // If the enum value doesn't fit in an int, emit an extension warning. 2256 const llvm::APSInt &InitVal = ECD->getInitVal(); 2257 assert(InitVal.getBitWidth() >= IntWidth && 2258 "Should have promoted value to int"); 2259 if (InitVal.getBitWidth() > IntWidth) { 2260 llvm::APSInt V(InitVal); 2261 V.trunc(IntWidth); 2262 V.extend(InitVal.getBitWidth()); 2263 if (V != InitVal) 2264 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2265 InitVal.toString()); 2266 } 2267 2268 // Keep track of the size of positive and negative values. 2269 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2270 NumPositiveBits = std::max(NumPositiveBits, 2271 (unsigned)InitVal.getActiveBits()); 2272 else 2273 NumNegativeBits = std::max(NumNegativeBits, 2274 (unsigned)InitVal.getMinSignedBits()); 2275 2276 // Keep track of whether every enum element has type int (very commmon). 2277 if (AllElementsInt) 2278 AllElementsInt = ECD->getType() == Context.IntTy; 2279 2280 ECD->setNextDeclarator(EltList); 2281 EltList = ECD; 2282 } 2283 2284 // Figure out the type that should be used for this enum. 2285 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2286 QualType BestType; 2287 unsigned BestWidth; 2288 2289 if (NumNegativeBits) { 2290 // If there is a negative value, figure out the smallest integer type (of 2291 // int/long/longlong) that fits. 2292 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2293 BestType = Context.IntTy; 2294 BestWidth = IntWidth; 2295 } else { 2296 BestWidth = Context.Target.getLongWidth(); 2297 2298 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2299 BestType = Context.LongTy; 2300 else { 2301 BestWidth = Context.Target.getLongLongWidth(); 2302 2303 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2304 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2305 BestType = Context.LongLongTy; 2306 } 2307 } 2308 } else { 2309 // If there is no negative value, figure out which of uint, ulong, ulonglong 2310 // fits. 2311 if (NumPositiveBits <= IntWidth) { 2312 BestType = Context.UnsignedIntTy; 2313 BestWidth = IntWidth; 2314 } else if (NumPositiveBits <= 2315 (BestWidth = Context.Target.getLongWidth())) { 2316 BestType = Context.UnsignedLongTy; 2317 } else { 2318 BestWidth = Context.Target.getLongLongWidth(); 2319 assert(NumPositiveBits <= BestWidth && 2320 "How could an initializer get larger than ULL?"); 2321 BestType = Context.UnsignedLongLongTy; 2322 } 2323 } 2324 2325 // Loop over all of the enumerator constants, changing their types to match 2326 // the type of the enum if needed. 2327 for (unsigned i = 0; i != NumElements; ++i) { 2328 EnumConstantDecl *ECD = 2329 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2330 if (!ECD) continue; // Already issued a diagnostic. 2331 2332 // Standard C says the enumerators have int type, but we allow, as an 2333 // extension, the enumerators to be larger than int size. If each 2334 // enumerator value fits in an int, type it as an int, otherwise type it the 2335 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2336 // that X has type 'int', not 'unsigned'. 2337 if (ECD->getType() == Context.IntTy) { 2338 // Make sure the init value is signed. 2339 llvm::APSInt IV = ECD->getInitVal(); 2340 IV.setIsSigned(true); 2341 ECD->setInitVal(IV); 2342 continue; // Already int type. 2343 } 2344 2345 // Determine whether the value fits into an int. 2346 llvm::APSInt InitVal = ECD->getInitVal(); 2347 bool FitsInInt; 2348 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2349 FitsInInt = InitVal.getActiveBits() < IntWidth; 2350 else 2351 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2352 2353 // If it fits into an integer type, force it. Otherwise force it to match 2354 // the enum decl type. 2355 QualType NewTy; 2356 unsigned NewWidth; 2357 bool NewSign; 2358 if (FitsInInt) { 2359 NewTy = Context.IntTy; 2360 NewWidth = IntWidth; 2361 NewSign = true; 2362 } else if (ECD->getType() == BestType) { 2363 // Already the right type! 2364 continue; 2365 } else { 2366 NewTy = BestType; 2367 NewWidth = BestWidth; 2368 NewSign = BestType->isSignedIntegerType(); 2369 } 2370 2371 // Adjust the APSInt value. 2372 InitVal.extOrTrunc(NewWidth); 2373 InitVal.setIsSigned(NewSign); 2374 ECD->setInitVal(InitVal); 2375 2376 // Adjust the Expr initializer and type. 2377 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2378 ECD->setType(NewTy); 2379 } 2380 2381 Enum->defineElements(EltList, BestType); 2382 Consumer.HandleTagDeclDefinition(Enum); 2383} 2384 2385Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2386 ExprTy *expr) { 2387 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2388 2389 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2390} 2391 2392Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2393 SourceLocation LBrace, 2394 SourceLocation RBrace, 2395 const char *Lang, 2396 unsigned StrSize, 2397 DeclTy *D) { 2398 LinkageSpecDecl::LanguageIDs Language; 2399 Decl *dcl = static_cast<Decl *>(D); 2400 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2401 Language = LinkageSpecDecl::lang_c; 2402 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2403 Language = LinkageSpecDecl::lang_cxx; 2404 else { 2405 Diag(Loc, diag::err_bad_language); 2406 return 0; 2407 } 2408 2409 // FIXME: Add all the various semantics of linkage specifications 2410 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2411} 2412