SemaDecl.cpp revision d580209c39d62c52110b39401efec74ddd9762da
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/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/AST/Type.h" 25#include "clang/Parse/DeclSpec.h" 26#include "clang/Parse/Scope.h" 27#include "clang/Basic/LangOptions.h" 28#include "clang/Basic/TargetInfo.h" 29#include "clang/Basic/SourceManager.h" 30// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 31#include "clang/Lex/Preprocessor.h" 32#include "clang/Lex/HeaderSearch.h" 33#include "llvm/ADT/SmallString.h" 34#include "llvm/ADT/SmallSet.h" 35#include "llvm/ADT/DenseSet.h" 36using namespace clang; 37 38Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { 39 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); 40 41 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 42 isa<ObjCInterfaceDecl>(IIDecl) || 43 isa<TagDecl>(IIDecl))) 44 return IIDecl; 45 return 0; 46} 47 48DeclContext *Sema::getDCParent(DeclContext *DC) { 49 // If CurContext is a ObjC method, getParent() will return NULL. 50 if (isa<ObjCMethodDecl>(DC)) 51 return Context.getTranslationUnitDecl(); 52 53 // A C++ inline method is parsed *after* the topmost class it was declared in 54 // is fully parsed (it's "complete"). 55 // The parsing of a C++ inline method happens at the declaration context of 56 // the topmost (non-nested) class it is declared in. 57 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 58 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 59 DC = MD->getParent(); 60 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 61 DC = RD; 62 63 // Return the declaration context of the topmost class the inline method is 64 // declared in. 65 return DC; 66 } 67 68 return DC->getParent(); 69} 70 71void Sema::PushDeclContext(DeclContext *DC) { 72 assert(getDCParent(DC) == CurContext && 73 "The next DeclContext should be directly contained in the current one."); 74 CurContext = DC; 75} 76 77void Sema::PopDeclContext() { 78 assert(CurContext && "DeclContext imbalance!"); 79 CurContext = getDCParent(CurContext); 80} 81 82/// Add this decl to the scope shadowed decl chains. 83void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 84 S->AddDecl(D); 85 86 // C++ [basic.scope]p4: 87 // -- exactly one declaration shall declare a class name or 88 // enumeration name that is not a typedef name and the other 89 // declarations shall all refer to the same object or 90 // enumerator, or all refer to functions and function templates; 91 // in this case the class name or enumeration name is hidden. 92 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 93 // We are pushing the name of a tag (enum or class). 94 IdentifierResolver::iterator 95 I = IdResolver.begin(TD->getIdentifier(), 96 TD->getDeclContext(), false/*LookInParentCtx*/); 97 if (I != IdResolver.end() && 98 IdResolver.isDeclInScope(*I, TD->getDeclContext(), S)) { 99 // There is already a declaration with the same name in the same 100 // scope. It must be found before we find the new declaration, 101 // so swap the order on the shadowed declaration chain. 102 103 IdResolver.AddShadowedDecl(TD, *I); 104 return; 105 } 106 } 107 IdResolver.AddDecl(D); 108} 109 110void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 111 if (S->decl_empty()) return; 112 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 113 114 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 115 I != E; ++I) { 116 Decl *TmpD = static_cast<Decl*>(*I); 117 assert(TmpD && "This decl didn't get pushed??"); 118 119 if (isa<CXXFieldDecl>(TmpD)) continue; 120 121 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 122 ScopedDecl *D = cast<ScopedDecl>(TmpD); 123 124 IdentifierInfo *II = D->getIdentifier(); 125 if (!II) continue; 126 127 // We only want to remove the decls from the identifier decl chains for local 128 // scopes, when inside a function/method. 129 if (S->getFnParent() != 0) 130 IdResolver.RemoveDecl(D); 131 132 // Chain this decl to the containing DeclContext. 133 D->setNext(CurContext->getDeclChain()); 134 CurContext->setDeclChain(D); 135 } 136} 137 138/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 139/// return 0 if one not found. 140ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 141 // The third "scope" argument is 0 since we aren't enabling lazy built-in 142 // creation from this context. 143 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 144 145 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 146} 147 148/// LookupDecl - Look up the inner-most declaration in the specified 149/// namespace. 150Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 151 Scope *S, bool enableLazyBuiltinCreation) { 152 if (II == 0) return 0; 153 unsigned NS = NSI; 154 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 155 NS |= Decl::IDNS_Tag; 156 157 // Scan up the scope chain looking for a decl that matches this identifier 158 // that is in the appropriate namespace. This search should not take long, as 159 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 160 for (IdentifierResolver::iterator 161 I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) 162 if ((*I)->getIdentifierNamespace() & NS) 163 return *I; 164 165 // If we didn't find a use of this identifier, and if the identifier 166 // corresponds to a compiler builtin, create the decl object for the builtin 167 // now, injecting it into translation unit scope, and return it. 168 if (NS & Decl::IDNS_Ordinary) { 169 if (enableLazyBuiltinCreation) { 170 // If this is a builtin on this (or all) targets, create the decl. 171 if (unsigned BuiltinID = II->getBuiltinID()) 172 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 173 } 174 if (getLangOptions().ObjC1) { 175 // @interface and @compatibility_alias introduce typedef-like names. 176 // Unlike typedef's, they can only be introduced at file-scope (and are 177 // therefore not scoped decls). They can, however, be shadowed by 178 // other names in IDNS_Ordinary. 179 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 180 if (IDI != ObjCInterfaceDecls.end()) 181 return IDI->second; 182 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 183 if (I != ObjCAliasDecls.end()) 184 return I->second->getClassInterface(); 185 } 186 } 187 return 0; 188} 189 190void Sema::InitBuiltinVaListType() { 191 if (!Context.getBuiltinVaListType().isNull()) 192 return; 193 194 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 195 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 196 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 197 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 198} 199 200/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 201/// lazily create a decl for it. 202ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 203 Scope *S) { 204 Builtin::ID BID = (Builtin::ID)bid; 205 206 if (BID == Builtin::BI__builtin_va_start || 207 BID == Builtin::BI__builtin_va_copy || 208 BID == Builtin::BI__builtin_va_end || 209 BID == Builtin::BI__builtin_stdarg_start) 210 InitBuiltinVaListType(); 211 212 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 213 FunctionDecl *New = FunctionDecl::Create(Context, 214 Context.getTranslationUnitDecl(), 215 SourceLocation(), II, R, 216 FunctionDecl::Extern, false, 0); 217 218 // Create Decl objects for each parameter, adding them to the 219 // FunctionDecl. 220 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 221 llvm::SmallVector<ParmVarDecl*, 16> Params; 222 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 223 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 224 FT->getArgType(i), VarDecl::None, 0, 225 0)); 226 New->setParams(&Params[0], Params.size()); 227 } 228 229 230 231 // TUScope is the translation-unit scope to insert this function into. 232 PushOnScopeChains(New, TUScope); 233 return New; 234} 235 236/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 237/// and scope as a previous declaration 'Old'. Figure out how to resolve this 238/// situation, merging decls or emitting diagnostics as appropriate. 239/// 240TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 241 // Verify the old decl was also a typedef. 242 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 243 if (!Old) { 244 Diag(New->getLocation(), diag::err_redefinition_different_kind, 245 New->getName()); 246 Diag(OldD->getLocation(), diag::err_previous_definition); 247 return New; 248 } 249 250 // If the typedef types are not identical, reject them in all languages and 251 // with any extensions enabled. 252 if (Old->getUnderlyingType() != New->getUnderlyingType() && 253 Context.getCanonicalType(Old->getUnderlyingType()) != 254 Context.getCanonicalType(New->getUnderlyingType())) { 255 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 256 New->getUnderlyingType().getAsString(), 257 Old->getUnderlyingType().getAsString()); 258 Diag(Old->getLocation(), diag::err_previous_definition); 259 return Old; 260 } 261 262 // Allow multiple definitions for ObjC built-in typedefs. 263 // FIXME: Verify the underlying types are equivalent! 264 if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) 265 return Old; 266 267 if (getLangOptions().Microsoft) return New; 268 269 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 270 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 271 // *either* declaration is in a system header. The code below implements 272 // this adhoc compatibility rule. FIXME: The following code will not 273 // work properly when compiling ".i" files (containing preprocessed output). 274 SourceManager &SrcMgr = Context.getSourceManager(); 275 HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); 276 const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); 277 if (OldDeclFile) { 278 DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); 279 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 280 if (OldDirType != DirectoryLookup::NormalHeaderDir) 281 return New; 282 } 283 const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); 284 if (NewDeclFile) { 285 DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); 286 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 287 if (NewDirType != DirectoryLookup::NormalHeaderDir) 288 return New; 289 } 290 291 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 292 Diag(Old->getLocation(), diag::err_previous_definition); 293 return New; 294} 295 296/// DeclhasAttr - returns true if decl Declaration already has the target 297/// attribute. 298static bool DeclHasAttr(const Decl *decl, const Attr *target) { 299 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 300 if (attr->getKind() == target->getKind()) 301 return true; 302 303 return false; 304} 305 306/// MergeAttributes - append attributes from the Old decl to the New one. 307static void MergeAttributes(Decl *New, Decl *Old) { 308 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 309 310 while (attr) { 311 tmp = attr; 312 attr = attr->getNext(); 313 314 if (!DeclHasAttr(New, tmp)) { 315 New->addAttr(tmp); 316 } else { 317 tmp->setNext(0); 318 delete(tmp); 319 } 320 } 321 322 Old->invalidateAttrs(); 323} 324 325/// MergeFunctionDecl - We just parsed a function 'New' from 326/// declarator D which has the same name and scope as a previous 327/// declaration 'Old'. Figure out how to resolve this situation, 328/// merging decls or emitting diagnostics as appropriate. 329/// Redeclaration will be set true if thisNew is a redeclaration OldD. 330FunctionDecl * 331Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 332 Redeclaration = false; 333 // Verify the old decl was also a function. 334 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 335 if (!Old) { 336 Diag(New->getLocation(), diag::err_redefinition_different_kind, 337 New->getName()); 338 Diag(OldD->getLocation(), diag::err_previous_definition); 339 return New; 340 } 341 342 QualType OldQType = Context.getCanonicalType(Old->getType()); 343 QualType NewQType = Context.getCanonicalType(New->getType()); 344 345 // C++ [dcl.fct]p3: 346 // All declarations for a function shall agree exactly in both the 347 // return type and the parameter-type-list. 348 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 349 MergeAttributes(New, Old); 350 Redeclaration = true; 351 return MergeCXXFunctionDecl(New, Old); 352 } 353 354 // C: Function types need to be compatible, not identical. This handles 355 // duplicate function decls like "void f(int); void f(enum X);" properly. 356 if (!getLangOptions().CPlusPlus && 357 Context.functionTypesAreCompatible(OldQType, NewQType)) { 358 MergeAttributes(New, Old); 359 Redeclaration = true; 360 return New; 361 } 362 363 // A function that has already been declared has been redeclared or defined 364 // with a different type- show appropriate diagnostic 365 diag::kind PrevDiag; 366 if (Old->isThisDeclarationADefinition()) 367 PrevDiag = diag::err_previous_definition; 368 else if (Old->isImplicit()) 369 PrevDiag = diag::err_previous_implicit_declaration; 370 else 371 PrevDiag = diag::err_previous_declaration; 372 373 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 374 // TODO: This is totally simplistic. It should handle merging functions 375 // together etc, merging extern int X; int X; ... 376 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 377 Diag(Old->getLocation(), PrevDiag); 378 return New; 379} 380 381/// Predicate for C "tentative" external object definitions (C99 6.9.2). 382static bool isTentativeDefinition(VarDecl *VD) { 383 if (VD->isFileVarDecl()) 384 return (!VD->getInit() && 385 (VD->getStorageClass() == VarDecl::None || 386 VD->getStorageClass() == VarDecl::Static)); 387 return false; 388} 389 390/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 391/// when dealing with C "tentative" external object definitions (C99 6.9.2). 392void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 393 bool VDIsTentative = isTentativeDefinition(VD); 394 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 395 396 for (IdentifierResolver::iterator 397 I = IdResolver.begin(VD->getIdentifier(), 398 VD->getDeclContext(), false/*LookInParentCtx*/), 399 E = IdResolver.end(); I != E; ++I) { 400 if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) { 401 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 402 403 // Handle the following case: 404 // int a[10]; 405 // int a[]; - the code below makes sure we set the correct type. 406 // int a[11]; - this is an error, size isn't 10. 407 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 408 OldDecl->getType()->isConstantArrayType()) 409 VD->setType(OldDecl->getType()); 410 411 // Check for "tentative" definitions. We can't accomplish this in 412 // MergeVarDecl since the initializer hasn't been attached. 413 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 414 continue; 415 416 // Handle __private_extern__ just like extern. 417 if (OldDecl->getStorageClass() != VarDecl::Extern && 418 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 419 VD->getStorageClass() != VarDecl::Extern && 420 VD->getStorageClass() != VarDecl::PrivateExtern) { 421 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 422 Diag(OldDecl->getLocation(), diag::err_previous_definition); 423 } 424 } 425 } 426} 427 428/// MergeVarDecl - We just parsed a variable 'New' which has the same name 429/// and scope as a previous declaration 'Old'. Figure out how to resolve this 430/// situation, merging decls or emitting diagnostics as appropriate. 431/// 432/// Tentative definition rules (C99 6.9.2p2) are checked by 433/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 434/// definitions here, since the initializer hasn't been attached. 435/// 436VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 437 // Verify the old decl was also a variable. 438 VarDecl *Old = dyn_cast<VarDecl>(OldD); 439 if (!Old) { 440 Diag(New->getLocation(), diag::err_redefinition_different_kind, 441 New->getName()); 442 Diag(OldD->getLocation(), diag::err_previous_definition); 443 return New; 444 } 445 446 MergeAttributes(New, Old); 447 448 // Verify the types match. 449 QualType OldCType = Context.getCanonicalType(Old->getType()); 450 QualType NewCType = Context.getCanonicalType(New->getType()); 451 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 452 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 453 Diag(Old->getLocation(), diag::err_previous_definition); 454 return New; 455 } 456 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 457 if (New->getStorageClass() == VarDecl::Static && 458 (Old->getStorageClass() == VarDecl::None || 459 Old->getStorageClass() == VarDecl::Extern)) { 460 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 461 Diag(Old->getLocation(), diag::err_previous_definition); 462 return New; 463 } 464 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 465 if (New->getStorageClass() != VarDecl::Static && 466 Old->getStorageClass() == VarDecl::Static) { 467 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 468 Diag(Old->getLocation(), diag::err_previous_definition); 469 return New; 470 } 471 // File scoped variables are analyzed in FinalizeDeclaratorGroup. 472 if (!New->isFileVarDecl()) { 473 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 474 Diag(Old->getLocation(), diag::err_previous_definition); 475 } 476 return New; 477} 478 479/// CheckParmsForFunctionDef - Check that the parameters of the given 480/// function are appropriate for the definition of a function. This 481/// takes care of any checks that cannot be performed on the 482/// declaration itself, e.g., that the types of each of the function 483/// parameters are complete. 484bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 485 bool HasInvalidParm = false; 486 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 487 ParmVarDecl *Param = FD->getParamDecl(p); 488 489 // C99 6.7.5.3p4: the parameters in a parameter type list in a 490 // function declarator that is part of a function definition of 491 // that function shall not have incomplete type. 492 if (Param->getType()->isIncompleteType() && 493 !Param->isInvalidDecl()) { 494 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 495 Param->getType().getAsString()); 496 Param->setInvalidDecl(); 497 HasInvalidParm = true; 498 } 499 } 500 501 return HasInvalidParm; 502} 503 504/// CreateImplicitParameter - Creates an implicit function parameter 505/// in the scope S and with the given type. This routine is used, for 506/// example, to create the implicit "self" parameter in an Objective-C 507/// method. 508ImplicitParamDecl * 509Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 510 SourceLocation IdLoc, QualType Type) { 511 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 512 IdLoc, Id, Type, 0); 513 if (Id) 514 PushOnScopeChains(New, S); 515 516 return New; 517} 518 519/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 520/// no declarator (e.g. "struct foo;") is parsed. 521Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 522 // TODO: emit error on 'int;' or 'const enum foo;'. 523 // TODO: emit error on 'typedef int;' 524 // if (!DS.isMissingDeclaratorOk()) Diag(...); 525 526 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 527} 528 529bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 530 // Get the type before calling CheckSingleAssignmentConstraints(), since 531 // it can promote the expression. 532 QualType InitType = Init->getType(); 533 534 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 535 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 536 InitType, Init, "initializing"); 537} 538 539bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 540 const ArrayType *AT = Context.getAsArrayType(DeclT); 541 542 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 543 // C99 6.7.8p14. We have an array of character type with unknown size 544 // being initialized to a string literal. 545 llvm::APSInt ConstVal(32); 546 ConstVal = strLiteral->getByteLength() + 1; 547 // Return a new array type (C99 6.7.8p22). 548 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 549 ArrayType::Normal, 0); 550 } else { 551 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 552 // C99 6.7.8p14. We have an array of character type with known size. 553 // FIXME: Avoid truncation for 64-bit length strings. 554 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 555 Diag(strLiteral->getSourceRange().getBegin(), 556 diag::warn_initializer_string_for_char_array_too_long, 557 strLiteral->getSourceRange()); 558 } 559 // Set type from "char *" to "constant array of char". 560 strLiteral->setType(DeclT); 561 // For now, we always return false (meaning success). 562 return false; 563} 564 565StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 566 const ArrayType *AT = Context.getAsArrayType(DeclType); 567 if (AT && AT->getElementType()->isCharType()) { 568 return dyn_cast<StringLiteral>(Init); 569 } 570 return 0; 571} 572 573bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 574 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 575 // of unknown size ("[]") or an object type that is not a variable array type. 576 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 577 return Diag(VAT->getSizeExpr()->getLocStart(), 578 diag::err_variable_object_no_init, 579 VAT->getSizeExpr()->getSourceRange()); 580 581 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 582 if (!InitList) { 583 // FIXME: Handle wide strings 584 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 585 return CheckStringLiteralInit(strLiteral, DeclType); 586 587 if (DeclType->isArrayType()) 588 return Diag(Init->getLocStart(), 589 diag::err_array_init_list_required, 590 Init->getSourceRange()); 591 592 return CheckSingleInitializer(Init, DeclType); 593 } 594 595 InitListChecker CheckInitList(this, InitList, DeclType); 596 return CheckInitList.HadError(); 597} 598 599Sema::DeclTy * 600Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 601 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 602 IdentifierInfo *II = D.getIdentifier(); 603 604 // All of these full declarators require an identifier. If it doesn't have 605 // one, the ParsedFreeStandingDeclSpec action should be used. 606 if (II == 0) { 607 Diag(D.getDeclSpec().getSourceRange().getBegin(), 608 diag::err_declarator_need_ident, 609 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 610 return 0; 611 } 612 613 // The scope passed in may not be a decl scope. Zip up the scope tree until 614 // we find one that is. 615 while ((S->getFlags() & Scope::DeclScope) == 0) 616 S = S->getParent(); 617 618 // See if this is a redefinition of a variable in the same scope. 619 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 620 ScopedDecl *New; 621 bool InvalidDecl = false; 622 623 // In C++, the previous declaration we find might be a tag type 624 // (class or enum). In this case, the new declaration will hide the 625 // tag type. 626 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 627 PrevDecl = 0; 628 629 QualType R = GetTypeForDeclarator(D, S); 630 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 631 632 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 633 // Check that there are no default arguments (C++ only). 634 if (getLangOptions().CPlusPlus) 635 CheckExtraCXXDefaultArguments(D); 636 637 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 638 if (!NewTD) return 0; 639 640 // Handle attributes prior to checking for duplicates in MergeVarDecl 641 ProcessDeclAttributes(NewTD, D); 642 // Merge the decl with the existing one if appropriate. If the decl is 643 // in an outer scope, it isn't the same thing. 644 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 645 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 646 if (NewTD == 0) return 0; 647 } 648 New = NewTD; 649 if (S->getFnParent() == 0) { 650 // C99 6.7.7p2: If a typedef name specifies a variably modified type 651 // then it shall have block scope. 652 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 653 // FIXME: Diagnostic needs to be fixed. 654 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 655 InvalidDecl = true; 656 } 657 } 658 } else if (R.getTypePtr()->isFunctionType()) { 659 FunctionDecl::StorageClass SC = FunctionDecl::None; 660 switch (D.getDeclSpec().getStorageClassSpec()) { 661 default: assert(0 && "Unknown storage class!"); 662 case DeclSpec::SCS_auto: 663 case DeclSpec::SCS_register: 664 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 665 R.getAsString()); 666 InvalidDecl = true; 667 break; 668 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 669 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 670 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 671 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 672 } 673 674 bool isInline = D.getDeclSpec().isInlineSpecified(); 675 FunctionDecl *NewFD; 676 if (D.getContext() == Declarator::MemberContext) { 677 // This is a C++ method declaration. 678 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 679 D.getIdentifierLoc(), II, R, 680 (SC == FunctionDecl::Static), isInline, 681 LastDeclarator); 682 } else { 683 NewFD = FunctionDecl::Create(Context, CurContext, 684 D.getIdentifierLoc(), 685 II, R, SC, isInline, 686 LastDeclarator); 687 } 688 // Handle attributes. 689 ProcessDeclAttributes(NewFD, D); 690 691 // Handle GNU asm-label extension (encoded as an attribute). 692 if (Expr *E = (Expr*) D.getAsmLabel()) { 693 // The parser guarantees this is a string. 694 StringLiteral *SE = cast<StringLiteral>(E); 695 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 696 SE->getByteLength()))); 697 } 698 699 // Copy the parameter declarations from the declarator D to 700 // the function declaration NewFD, if they are available. 701 if (D.getNumTypeObjects() > 0 && 702 D.getTypeObject(0).Fun.hasPrototype) { 703 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 704 705 // Create Decl objects for each parameter, adding them to the 706 // FunctionDecl. 707 llvm::SmallVector<ParmVarDecl*, 16> Params; 708 709 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 710 // function that takes no arguments, not a function that takes a 711 // single void argument. 712 // We let through "const void" here because Sema::GetTypeForDeclarator 713 // already checks for that case. 714 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 715 FTI.ArgInfo[0].Param && 716 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 717 // empty arg list, don't push any params. 718 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 719 720 // In C++, the empty parameter-type-list must be spelled "void"; a 721 // typedef of void is not permitted. 722 if (getLangOptions().CPlusPlus && 723 Param->getType().getUnqualifiedType() != Context.VoidTy) { 724 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 725 } 726 727 } else { 728 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 729 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 730 } 731 732 NewFD->setParams(&Params[0], Params.size()); 733 } 734 735 // Merge the decl with the existing one if appropriate. Since C functions 736 // are in a flat namespace, make sure we consider decls in outer scopes. 737 if (PrevDecl && 738 (!getLangOptions().CPlusPlus || 739 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 740 bool Redeclaration = false; 741 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 742 if (NewFD == 0) return 0; 743 if (Redeclaration) { 744 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 745 } 746 } 747 New = NewFD; 748 749 // In C++, check default arguments now that we have merged decls. 750 if (getLangOptions().CPlusPlus) 751 CheckCXXDefaultArguments(NewFD); 752 } else { 753 // Check that there are no default arguments (C++ only). 754 if (getLangOptions().CPlusPlus) 755 CheckExtraCXXDefaultArguments(D); 756 757 if (R.getTypePtr()->isObjCInterfaceType()) { 758 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 759 D.getIdentifier()->getName()); 760 InvalidDecl = true; 761 } 762 763 VarDecl *NewVD; 764 VarDecl::StorageClass SC; 765 switch (D.getDeclSpec().getStorageClassSpec()) { 766 default: assert(0 && "Unknown storage class!"); 767 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 768 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 769 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 770 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 771 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 772 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 773 } 774 if (D.getContext() == Declarator::MemberContext) { 775 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 776 // This is a static data member for a C++ class. 777 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 778 D.getIdentifierLoc(), II, 779 R, LastDeclarator); 780 } else { 781 if (S->getFnParent() == 0) { 782 // C99 6.9p2: The storage-class specifiers auto and register shall not 783 // appear in the declaration specifiers in an external declaration. 784 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 785 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 786 R.getAsString()); 787 InvalidDecl = true; 788 } 789 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 790 II, R, SC, LastDeclarator); 791 } else { 792 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 793 II, R, SC, LastDeclarator); 794 } 795 } 796 // Handle attributes prior to checking for duplicates in MergeVarDecl 797 ProcessDeclAttributes(NewVD, D); 798 799 // Handle GNU asm-label extension (encoded as an attribute). 800 if (Expr *E = (Expr*) D.getAsmLabel()) { 801 // The parser guarantees this is a string. 802 StringLiteral *SE = cast<StringLiteral>(E); 803 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 804 SE->getByteLength()))); 805 } 806 807 // Emit an error if an address space was applied to decl with local storage. 808 // This includes arrays of objects with address space qualifiers, but not 809 // automatic variables that point to other address spaces. 810 // ISO/IEC TR 18037 S5.1.2 811 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 812 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 813 InvalidDecl = true; 814 } 815 // Merge the decl with the existing one if appropriate. If the decl is 816 // in an outer scope, it isn't the same thing. 817 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 818 NewVD = MergeVarDecl(NewVD, PrevDecl); 819 if (NewVD == 0) return 0; 820 } 821 New = NewVD; 822 } 823 824 // If this has an identifier, add it to the scope stack. 825 if (II) 826 PushOnScopeChains(New, S); 827 // If any semantic error occurred, mark the decl as invalid. 828 if (D.getInvalidType() || InvalidDecl) 829 New->setInvalidDecl(); 830 831 return New; 832} 833 834bool Sema::CheckAddressConstantExpressionLValue(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 CheckAddressConstantExpressionLValue(PE->getSubExpr()); 843 } 844 case Expr::CompoundLiteralExprClass: 845 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 846 case Expr::DeclRefExprClass: { 847 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 848 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 849 if (VD->hasGlobalStorage()) 850 return false; 851 Diag(Init->getExprLoc(), 852 diag::err_init_element_not_constant, Init->getSourceRange()); 853 return true; 854 } 855 if (isa<FunctionDecl>(D)) 856 return false; 857 Diag(Init->getExprLoc(), 858 diag::err_init_element_not_constant, Init->getSourceRange()); 859 return true; 860 } 861 case Expr::MemberExprClass: { 862 const MemberExpr *M = cast<MemberExpr>(Init); 863 if (M->isArrow()) 864 return CheckAddressConstantExpression(M->getBase()); 865 return CheckAddressConstantExpressionLValue(M->getBase()); 866 } 867 case Expr::ArraySubscriptExprClass: { 868 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 869 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 870 return CheckAddressConstantExpression(ASE->getBase()) || 871 CheckArithmeticConstantExpression(ASE->getIdx()); 872 } 873 case Expr::StringLiteralClass: 874 case Expr::PredefinedExprClass: 875 return false; 876 case Expr::UnaryOperatorClass: { 877 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 878 879 // C99 6.6p9 880 if (Exp->getOpcode() == UnaryOperator::Deref) 881 return CheckAddressConstantExpression(Exp->getSubExpr()); 882 883 Diag(Init->getExprLoc(), 884 diag::err_init_element_not_constant, Init->getSourceRange()); 885 return true; 886 } 887 } 888} 889 890bool Sema::CheckAddressConstantExpression(const Expr* Init) { 891 switch (Init->getStmtClass()) { 892 default: 893 Diag(Init->getExprLoc(), 894 diag::err_init_element_not_constant, Init->getSourceRange()); 895 return true; 896 case Expr::ParenExprClass: { 897 const ParenExpr* PE = cast<ParenExpr>(Init); 898 return CheckAddressConstantExpression(PE->getSubExpr()); 899 } 900 case Expr::StringLiteralClass: 901 case Expr::ObjCStringLiteralClass: 902 return false; 903 case Expr::CallExprClass: { 904 const CallExpr *CE = cast<CallExpr>(Init); 905 if (CE->isBuiltinConstantExpr()) 906 return false; 907 Diag(Init->getExprLoc(), 908 diag::err_init_element_not_constant, Init->getSourceRange()); 909 return true; 910 } 911 case Expr::UnaryOperatorClass: { 912 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 913 914 // C99 6.6p9 915 if (Exp->getOpcode() == UnaryOperator::AddrOf) 916 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 917 918 if (Exp->getOpcode() == UnaryOperator::Extension) 919 return CheckAddressConstantExpression(Exp->getSubExpr()); 920 921 Diag(Init->getExprLoc(), 922 diag::err_init_element_not_constant, Init->getSourceRange()); 923 return true; 924 } 925 case Expr::BinaryOperatorClass: { 926 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 927 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 928 929 Expr *PExp = Exp->getLHS(); 930 Expr *IExp = Exp->getRHS(); 931 if (IExp->getType()->isPointerType()) 932 std::swap(PExp, IExp); 933 934 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 935 return CheckAddressConstantExpression(PExp) || 936 CheckArithmeticConstantExpression(IExp); 937 } 938 case Expr::ImplicitCastExprClass: { 939 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 940 941 // Check for implicit promotion 942 if (SubExpr->getType()->isFunctionType() || 943 SubExpr->getType()->isArrayType()) 944 return CheckAddressConstantExpressionLValue(SubExpr); 945 946 // Check for pointer->pointer cast 947 if (SubExpr->getType()->isPointerType()) 948 return CheckAddressConstantExpression(SubExpr); 949 950 if (SubExpr->getType()->isArithmeticType()) 951 return CheckArithmeticConstantExpression(SubExpr); 952 953 Diag(Init->getExprLoc(), 954 diag::err_init_element_not_constant, Init->getSourceRange()); 955 return true; 956 } 957 case Expr::CastExprClass: { 958 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 959 960 // Check for pointer->pointer cast 961 if (SubExpr->getType()->isPointerType()) 962 return CheckAddressConstantExpression(SubExpr); 963 964 // FIXME: Should we pedwarn for (int*)(0+0)? 965 if (SubExpr->getType()->isArithmeticType()) 966 return CheckArithmeticConstantExpression(SubExpr); 967 968 Diag(Init->getExprLoc(), 969 diag::err_init_element_not_constant, Init->getSourceRange()); 970 return true; 971 } 972 case Expr::ConditionalOperatorClass: { 973 // FIXME: Should we pedwarn here? 974 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 975 if (!Exp->getCond()->getType()->isArithmeticType()) { 976 Diag(Init->getExprLoc(), 977 diag::err_init_element_not_constant, Init->getSourceRange()); 978 return true; 979 } 980 if (CheckArithmeticConstantExpression(Exp->getCond())) 981 return true; 982 if (Exp->getLHS() && 983 CheckAddressConstantExpression(Exp->getLHS())) 984 return true; 985 return CheckAddressConstantExpression(Exp->getRHS()); 986 } 987 case Expr::AddrLabelExprClass: 988 return false; 989 } 990} 991 992static const Expr* FindExpressionBaseAddress(const Expr* E); 993 994static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 995 switch (E->getStmtClass()) { 996 default: 997 return E; 998 case Expr::ParenExprClass: { 999 const ParenExpr* PE = cast<ParenExpr>(E); 1000 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1001 } 1002 case Expr::MemberExprClass: { 1003 const MemberExpr *M = cast<MemberExpr>(E); 1004 if (M->isArrow()) 1005 return FindExpressionBaseAddress(M->getBase()); 1006 return FindExpressionBaseAddressLValue(M->getBase()); 1007 } 1008 case Expr::ArraySubscriptExprClass: { 1009 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1010 return FindExpressionBaseAddress(ASE->getBase()); 1011 } 1012 case Expr::UnaryOperatorClass: { 1013 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1014 1015 if (Exp->getOpcode() == UnaryOperator::Deref) 1016 return FindExpressionBaseAddress(Exp->getSubExpr()); 1017 1018 return E; 1019 } 1020 } 1021} 1022 1023static const Expr* FindExpressionBaseAddress(const Expr* E) { 1024 switch (E->getStmtClass()) { 1025 default: 1026 return E; 1027 case Expr::ParenExprClass: { 1028 const ParenExpr* PE = cast<ParenExpr>(E); 1029 return FindExpressionBaseAddress(PE->getSubExpr()); 1030 } 1031 case Expr::UnaryOperatorClass: { 1032 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1033 1034 // C99 6.6p9 1035 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1036 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1037 1038 if (Exp->getOpcode() == UnaryOperator::Extension) 1039 return FindExpressionBaseAddress(Exp->getSubExpr()); 1040 1041 return E; 1042 } 1043 case Expr::BinaryOperatorClass: { 1044 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1045 1046 Expr *PExp = Exp->getLHS(); 1047 Expr *IExp = Exp->getRHS(); 1048 if (IExp->getType()->isPointerType()) 1049 std::swap(PExp, IExp); 1050 1051 return FindExpressionBaseAddress(PExp); 1052 } 1053 case Expr::ImplicitCastExprClass: { 1054 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1055 1056 // Check for implicit promotion 1057 if (SubExpr->getType()->isFunctionType() || 1058 SubExpr->getType()->isArrayType()) 1059 return FindExpressionBaseAddressLValue(SubExpr); 1060 1061 // Check for pointer->pointer cast 1062 if (SubExpr->getType()->isPointerType()) 1063 return FindExpressionBaseAddress(SubExpr); 1064 1065 // We assume that we have an arithmetic expression here; 1066 // if we don't, we'll figure it out later 1067 return 0; 1068 } 1069 case Expr::CastExprClass: { 1070 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1071 1072 // Check for pointer->pointer cast 1073 if (SubExpr->getType()->isPointerType()) 1074 return FindExpressionBaseAddress(SubExpr); 1075 1076 // We assume that we have an arithmetic expression here; 1077 // if we don't, we'll figure it out later 1078 return 0; 1079 } 1080 } 1081} 1082 1083bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1084 switch (Init->getStmtClass()) { 1085 default: 1086 Diag(Init->getExprLoc(), 1087 diag::err_init_element_not_constant, Init->getSourceRange()); 1088 return true; 1089 case Expr::ParenExprClass: { 1090 const ParenExpr* PE = cast<ParenExpr>(Init); 1091 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1092 } 1093 case Expr::FloatingLiteralClass: 1094 case Expr::IntegerLiteralClass: 1095 case Expr::CharacterLiteralClass: 1096 case Expr::ImaginaryLiteralClass: 1097 case Expr::TypesCompatibleExprClass: 1098 case Expr::CXXBoolLiteralExprClass: 1099 return false; 1100 case Expr::CallExprClass: { 1101 const CallExpr *CE = cast<CallExpr>(Init); 1102 if (CE->isBuiltinConstantExpr()) 1103 return false; 1104 Diag(Init->getExprLoc(), 1105 diag::err_init_element_not_constant, Init->getSourceRange()); 1106 return true; 1107 } 1108 case Expr::DeclRefExprClass: { 1109 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1110 if (isa<EnumConstantDecl>(D)) 1111 return false; 1112 Diag(Init->getExprLoc(), 1113 diag::err_init_element_not_constant, Init->getSourceRange()); 1114 return true; 1115 } 1116 case Expr::CompoundLiteralExprClass: 1117 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1118 // but vectors are allowed to be magic. 1119 if (Init->getType()->isVectorType()) 1120 return false; 1121 Diag(Init->getExprLoc(), 1122 diag::err_init_element_not_constant, Init->getSourceRange()); 1123 return true; 1124 case Expr::UnaryOperatorClass: { 1125 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1126 1127 switch (Exp->getOpcode()) { 1128 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1129 // See C99 6.6p3. 1130 default: 1131 Diag(Init->getExprLoc(), 1132 diag::err_init_element_not_constant, Init->getSourceRange()); 1133 return true; 1134 case UnaryOperator::SizeOf: 1135 case UnaryOperator::AlignOf: 1136 case UnaryOperator::OffsetOf: 1137 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1138 // See C99 6.5.3.4p2 and 6.6p3. 1139 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1140 return false; 1141 Diag(Init->getExprLoc(), 1142 diag::err_init_element_not_constant, Init->getSourceRange()); 1143 return true; 1144 case UnaryOperator::Extension: 1145 case UnaryOperator::LNot: 1146 case UnaryOperator::Plus: 1147 case UnaryOperator::Minus: 1148 case UnaryOperator::Not: 1149 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1150 } 1151 } 1152 case Expr::SizeOfAlignOfTypeExprClass: { 1153 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1154 // Special check for void types, which are allowed as an extension 1155 if (Exp->getArgumentType()->isVoidType()) 1156 return false; 1157 // alignof always evaluates to a constant. 1158 // FIXME: is sizeof(int[3.0]) a constant expression? 1159 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1160 Diag(Init->getExprLoc(), 1161 diag::err_init_element_not_constant, Init->getSourceRange()); 1162 return true; 1163 } 1164 return false; 1165 } 1166 case Expr::BinaryOperatorClass: { 1167 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1168 1169 if (Exp->getLHS()->getType()->isArithmeticType() && 1170 Exp->getRHS()->getType()->isArithmeticType()) { 1171 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1172 CheckArithmeticConstantExpression(Exp->getRHS()); 1173 } 1174 1175 if (Exp->getLHS()->getType()->isPointerType() && 1176 Exp->getRHS()->getType()->isPointerType()) { 1177 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1178 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1179 1180 // Only allow a null (constant integer) base; we could 1181 // allow some additional cases if necessary, but this 1182 // is sufficient to cover offsetof-like constructs. 1183 if (!LHSBase && !RHSBase) { 1184 return CheckAddressConstantExpression(Exp->getLHS()) || 1185 CheckAddressConstantExpression(Exp->getRHS()); 1186 } 1187 } 1188 1189 Diag(Init->getExprLoc(), 1190 diag::err_init_element_not_constant, Init->getSourceRange()); 1191 return true; 1192 } 1193 case Expr::ImplicitCastExprClass: 1194 case Expr::CastExprClass: { 1195 const Expr *SubExpr; 1196 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1197 SubExpr = C->getSubExpr(); 1198 } else { 1199 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1200 } 1201 1202 if (SubExpr->getType()->isArithmeticType()) 1203 return CheckArithmeticConstantExpression(SubExpr); 1204 1205 Diag(Init->getExprLoc(), 1206 diag::err_init_element_not_constant, Init->getSourceRange()); 1207 return true; 1208 } 1209 case Expr::ConditionalOperatorClass: { 1210 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1211 if (CheckArithmeticConstantExpression(Exp->getCond())) 1212 return true; 1213 if (Exp->getLHS() && 1214 CheckArithmeticConstantExpression(Exp->getLHS())) 1215 return true; 1216 return CheckArithmeticConstantExpression(Exp->getRHS()); 1217 } 1218 } 1219} 1220 1221bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1222 Init = Init->IgnoreParens(); 1223 1224 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1225 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1226 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1227 1228 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1229 return CheckForConstantInitializer(e->getInitializer(), DclT); 1230 1231 if (Init->getType()->isReferenceType()) { 1232 // FIXME: Work out how the heck reference types work 1233 return false; 1234#if 0 1235 // A reference is constant if the address of the expression 1236 // is constant 1237 // We look through initlists here to simplify 1238 // CheckAddressConstantExpressionLValue. 1239 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1240 assert(Exp->getNumInits() > 0 && 1241 "Refernce initializer cannot be empty"); 1242 Init = Exp->getInit(0); 1243 } 1244 return CheckAddressConstantExpressionLValue(Init); 1245#endif 1246 } 1247 1248 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1249 unsigned numInits = Exp->getNumInits(); 1250 for (unsigned i = 0; i < numInits; i++) { 1251 // FIXME: Need to get the type of the declaration for C++, 1252 // because it could be a reference? 1253 if (CheckForConstantInitializer(Exp->getInit(i), 1254 Exp->getInit(i)->getType())) 1255 return true; 1256 } 1257 return false; 1258 } 1259 1260 if (Init->isNullPointerConstant(Context)) 1261 return false; 1262 if (Init->getType()->isArithmeticType()) { 1263 QualType InitTy = Context.getCanonicalType(Init->getType()) 1264 .getUnqualifiedType(); 1265 if (InitTy == Context.BoolTy) { 1266 // Special handling for pointers implicitly cast to bool; 1267 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1268 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1269 Expr* SubE = ICE->getSubExpr(); 1270 if (SubE->getType()->isPointerType() || 1271 SubE->getType()->isArrayType() || 1272 SubE->getType()->isFunctionType()) { 1273 return CheckAddressConstantExpression(Init); 1274 } 1275 } 1276 } else if (InitTy->isIntegralType()) { 1277 Expr* SubE = 0; 1278 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1279 SubE = ICE->getSubExpr(); 1280 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1281 SubE = CE->getSubExpr(); 1282 // Special check for pointer cast to int; we allow as an extension 1283 // an address constant cast to an integer if the integer 1284 // is of an appropriate width (this sort of code is apparently used 1285 // in some places). 1286 // FIXME: Add pedwarn? 1287 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1288 if (SubE && (SubE->getType()->isPointerType() || 1289 SubE->getType()->isArrayType() || 1290 SubE->getType()->isFunctionType())) { 1291 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1292 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1293 if (IntWidth >= PointerWidth) 1294 return CheckAddressConstantExpression(Init); 1295 } 1296 } 1297 1298 return CheckArithmeticConstantExpression(Init); 1299 } 1300 1301 if (Init->getType()->isPointerType()) 1302 return CheckAddressConstantExpression(Init); 1303 1304 // An array type at the top level that isn't an init-list must 1305 // be a string literal 1306 if (Init->getType()->isArrayType()) 1307 return false; 1308 1309 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1310 Init->getSourceRange()); 1311 return true; 1312} 1313 1314void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1315 Decl *RealDecl = static_cast<Decl *>(dcl); 1316 Expr *Init = static_cast<Expr *>(init); 1317 assert(Init && "missing initializer"); 1318 1319 // If there is no declaration, there was an error parsing it. Just ignore 1320 // the initializer. 1321 if (RealDecl == 0) { 1322 delete Init; 1323 return; 1324 } 1325 1326 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1327 if (!VDecl) { 1328 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1329 diag::err_illegal_initializer); 1330 RealDecl->setInvalidDecl(); 1331 return; 1332 } 1333 // Get the decls type and save a reference for later, since 1334 // CheckInitializerTypes may change it. 1335 QualType DclT = VDecl->getType(), SavT = DclT; 1336 if (VDecl->isBlockVarDecl()) { 1337 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1338 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1339 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1340 VDecl->setInvalidDecl(); 1341 } else if (!VDecl->isInvalidDecl()) { 1342 if (CheckInitializerTypes(Init, DclT)) 1343 VDecl->setInvalidDecl(); 1344 if (SC == VarDecl::Static) // C99 6.7.8p4. 1345 CheckForConstantInitializer(Init, DclT); 1346 } 1347 } else if (VDecl->isFileVarDecl()) { 1348 if (VDecl->getStorageClass() == VarDecl::Extern) 1349 Diag(VDecl->getLocation(), diag::warn_extern_init); 1350 if (!VDecl->isInvalidDecl()) 1351 if (CheckInitializerTypes(Init, DclT)) 1352 VDecl->setInvalidDecl(); 1353 1354 // C99 6.7.8p4. All file scoped initializers need to be constant. 1355 CheckForConstantInitializer(Init, DclT); 1356 } 1357 // If the type changed, it means we had an incomplete type that was 1358 // completed by the initializer. For example: 1359 // int ary[] = { 1, 3, 5 }; 1360 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1361 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1362 VDecl->setType(DclT); 1363 Init->setType(DclT); 1364 } 1365 1366 // Attach the initializer to the decl. 1367 VDecl->setInit(Init); 1368 return; 1369} 1370 1371/// The declarators are chained together backwards, reverse the list. 1372Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1373 // Often we have single declarators, handle them quickly. 1374 Decl *GroupDecl = static_cast<Decl*>(group); 1375 if (GroupDecl == 0) 1376 return 0; 1377 1378 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1379 ScopedDecl *NewGroup = 0; 1380 if (Group->getNextDeclarator() == 0) 1381 NewGroup = Group; 1382 else { // reverse the list. 1383 while (Group) { 1384 ScopedDecl *Next = Group->getNextDeclarator(); 1385 Group->setNextDeclarator(NewGroup); 1386 NewGroup = Group; 1387 Group = Next; 1388 } 1389 } 1390 // Perform semantic analysis that depends on having fully processed both 1391 // the declarator and initializer. 1392 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1393 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1394 if (!IDecl) 1395 continue; 1396 QualType T = IDecl->getType(); 1397 1398 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1399 // static storage duration, it shall not have a variable length array. 1400 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1401 IDecl->getStorageClass() == VarDecl::Static) { 1402 if (T->isVariableArrayType()) { 1403 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1404 IDecl->setInvalidDecl(); 1405 } 1406 } 1407 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1408 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1409 if (IDecl->isBlockVarDecl() && 1410 IDecl->getStorageClass() != VarDecl::Extern) { 1411 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1412 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1413 T.getAsString()); 1414 IDecl->setInvalidDecl(); 1415 } 1416 } 1417 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1418 // object that has file scope without an initializer, and without a 1419 // storage-class specifier or with the storage-class specifier "static", 1420 // constitutes a tentative definition. Note: A tentative definition with 1421 // external linkage is valid (C99 6.2.2p5). 1422 if (isTentativeDefinition(IDecl)) { 1423 if (T->isIncompleteArrayType()) { 1424 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1425 // array to be completed. Don't issue a diagnostic. 1426 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1427 // C99 6.9.2p3: If the declaration of an identifier for an object is 1428 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1429 // declared type shall not be an incomplete type. 1430 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1431 T.getAsString()); 1432 IDecl->setInvalidDecl(); 1433 } 1434 } 1435 if (IDecl->isFileVarDecl()) 1436 CheckForFileScopedRedefinitions(S, IDecl); 1437 } 1438 return NewGroup; 1439} 1440 1441/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1442/// to introduce parameters into function prototype scope. 1443Sema::DeclTy * 1444Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1445 const DeclSpec &DS = D.getDeclSpec(); 1446 1447 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1448 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1449 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1450 Diag(DS.getStorageClassSpecLoc(), 1451 diag::err_invalid_storage_class_in_func_decl); 1452 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1453 } 1454 if (DS.isThreadSpecified()) { 1455 Diag(DS.getThreadSpecLoc(), 1456 diag::err_invalid_storage_class_in_func_decl); 1457 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1458 } 1459 1460 // Check that there are no default arguments inside the type of this 1461 // parameter (C++ only). 1462 if (getLangOptions().CPlusPlus) 1463 CheckExtraCXXDefaultArguments(D); 1464 1465 // In this context, we *do not* check D.getInvalidType(). If the declarator 1466 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1467 // though it will not reflect the user specified type. 1468 QualType parmDeclType = GetTypeForDeclarator(D, S); 1469 1470 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1471 1472 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1473 // Can this happen for params? We already checked that they don't conflict 1474 // among each other. Here they can only shadow globals, which is ok. 1475 IdentifierInfo *II = D.getIdentifier(); 1476 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1477 if (S->isDeclScope(PrevDecl)) { 1478 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1479 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1480 1481 // Recover by removing the name 1482 II = 0; 1483 D.SetIdentifier(0, D.getIdentifierLoc()); 1484 } 1485 } 1486 1487 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1488 // Doing the promotion here has a win and a loss. The win is the type for 1489 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1490 // code generator). The loss is the orginal type isn't preserved. For example: 1491 // 1492 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1493 // int blockvardecl[5]; 1494 // sizeof(parmvardecl); // size == 4 1495 // sizeof(blockvardecl); // size == 20 1496 // } 1497 // 1498 // For expressions, all implicit conversions are captured using the 1499 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1500 // 1501 // FIXME: If a source translation tool needs to see the original type, then 1502 // we need to consider storing both types (in ParmVarDecl)... 1503 // 1504 if (parmDeclType->isArrayType()) { 1505 // int x[restrict 4] -> int *restrict 1506 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1507 } else if (parmDeclType->isFunctionType()) 1508 parmDeclType = Context.getPointerType(parmDeclType); 1509 1510 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1511 D.getIdentifierLoc(), II, 1512 parmDeclType, VarDecl::None, 1513 0, 0); 1514 1515 if (D.getInvalidType()) 1516 New->setInvalidDecl(); 1517 1518 if (II) 1519 PushOnScopeChains(New, S); 1520 1521 ProcessDeclAttributes(New, D); 1522 return New; 1523 1524} 1525 1526Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1527 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1528 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1529 "Not a function declarator!"); 1530 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1531 1532 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1533 // for a K&R function. 1534 if (!FTI.hasPrototype) { 1535 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1536 if (FTI.ArgInfo[i].Param == 0) { 1537 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1538 FTI.ArgInfo[i].Ident->getName()); 1539 // Implicitly declare the argument as type 'int' for lack of a better 1540 // type. 1541 DeclSpec DS; 1542 const char* PrevSpec; // unused 1543 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1544 PrevSpec); 1545 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1546 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1547 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1548 } 1549 } 1550 1551 // Since this is a function definition, act as though we have information 1552 // about the arguments. 1553 if (FTI.NumArgs) 1554 FTI.hasPrototype = true; 1555 } else { 1556 // FIXME: Diagnose arguments without names in C. 1557 } 1558 1559 Scope *GlobalScope = FnBodyScope->getParent(); 1560 1561 // See if this is a redefinition. 1562 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1563 GlobalScope); 1564 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1565 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1566 const FunctionDecl *Definition; 1567 if (FD->getBody(Definition)) { 1568 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1569 D.getIdentifier()->getName()); 1570 Diag(Definition->getLocation(), diag::err_previous_definition); 1571 } 1572 } 1573 } 1574 1575 return ActOnStartOfFunctionDef(FnBodyScope, 1576 ActOnDeclarator(GlobalScope, D, 0)); 1577} 1578 1579Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1580 Decl *decl = static_cast<Decl*>(D); 1581 FunctionDecl *FD = cast<FunctionDecl>(decl); 1582 PushDeclContext(FD); 1583 1584 // Check the validity of our function parameters 1585 CheckParmsForFunctionDef(FD); 1586 1587 // Introduce our parameters into the function scope 1588 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1589 ParmVarDecl *Param = FD->getParamDecl(p); 1590 // If this has an identifier, add it to the scope stack. 1591 if (Param->getIdentifier()) 1592 PushOnScopeChains(Param, FnBodyScope); 1593 } 1594 1595 return FD; 1596} 1597 1598Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1599 Decl *dcl = static_cast<Decl *>(D); 1600 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1601 FD->setBody((Stmt*)Body); 1602 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1603 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1604 MD->setBody((Stmt*)Body); 1605 } else 1606 return 0; 1607 PopDeclContext(); 1608 // Verify and clean out per-function state. 1609 1610 // Check goto/label use. 1611 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1612 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1613 // Verify that we have no forward references left. If so, there was a goto 1614 // or address of a label taken, but no definition of it. Label fwd 1615 // definitions are indicated with a null substmt. 1616 if (I->second->getSubStmt() == 0) { 1617 LabelStmt *L = I->second; 1618 // Emit error. 1619 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1620 1621 // At this point, we have gotos that use the bogus label. Stitch it into 1622 // the function body so that they aren't leaked and that the AST is well 1623 // formed. 1624 if (Body) { 1625 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1626 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1627 } else { 1628 // The whole function wasn't parsed correctly, just delete this. 1629 delete L; 1630 } 1631 } 1632 } 1633 LabelMap.clear(); 1634 1635 return D; 1636} 1637 1638/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1639/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1640ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1641 IdentifierInfo &II, Scope *S) { 1642 // Extension in C99. Legal in C90, but warn about it. 1643 if (getLangOptions().C99) 1644 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1645 else 1646 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1647 1648 // FIXME: handle stuff like: 1649 // void foo() { extern float X(); } 1650 // void bar() { X(); } <-- implicit decl for X in another scope. 1651 1652 // Set a Declarator for the implicit definition: int foo(); 1653 const char *Dummy; 1654 DeclSpec DS; 1655 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1656 Error = Error; // Silence warning. 1657 assert(!Error && "Error setting up implicit decl!"); 1658 Declarator D(DS, Declarator::BlockContext); 1659 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1660 D.SetIdentifier(&II, Loc); 1661 1662 // Insert this function into translation-unit scope. 1663 1664 DeclContext *PrevDC = CurContext; 1665 CurContext = Context.getTranslationUnitDecl(); 1666 1667 FunctionDecl *FD = 1668 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1669 FD->setImplicit(); 1670 1671 CurContext = PrevDC; 1672 1673 return FD; 1674} 1675 1676 1677TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1678 ScopedDecl *LastDeclarator) { 1679 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1680 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1681 1682 // Scope manipulation handled by caller. 1683 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1684 D.getIdentifierLoc(), 1685 D.getIdentifier(), 1686 T, LastDeclarator); 1687 if (D.getInvalidType()) 1688 NewTD->setInvalidDecl(); 1689 return NewTD; 1690} 1691 1692/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1693/// former case, Name will be non-null. In the later case, Name will be null. 1694/// TagType indicates what kind of tag this is. TK indicates whether this is a 1695/// reference/declaration/definition of a tag. 1696Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1697 SourceLocation KWLoc, IdentifierInfo *Name, 1698 SourceLocation NameLoc, AttributeList *Attr) { 1699 // If this is a use of an existing tag, it must have a name. 1700 assert((Name != 0 || TK == TK_Definition) && 1701 "Nameless record must be a definition!"); 1702 1703 TagDecl::TagKind Kind; 1704 switch (TagType) { 1705 default: assert(0 && "Unknown tag type!"); 1706 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1707 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1708 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1709 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1710 } 1711 1712 // If this is a named struct, check to see if there was a previous forward 1713 // declaration or definition. 1714 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1715 if (ScopedDecl *PrevDecl = 1716 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1717 1718 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1719 "unexpected Decl type"); 1720 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1721 // If this is a use of a previous tag, or if the tag is already declared 1722 // in the same scope (so that the definition/declaration completes or 1723 // rementions the tag), reuse the decl. 1724 if (TK == TK_Reference || 1725 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1726 // Make sure that this wasn't declared as an enum and now used as a 1727 // struct or something similar. 1728 if (PrevTagDecl->getTagKind() != Kind) { 1729 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1730 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1731 // Recover by making this an anonymous redefinition. 1732 Name = 0; 1733 PrevDecl = 0; 1734 } else { 1735 // If this is a use or a forward declaration, we're good. 1736 if (TK != TK_Definition) 1737 return PrevDecl; 1738 1739 // Diagnose attempts to redefine a tag. 1740 if (PrevTagDecl->isDefinition()) { 1741 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1742 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1743 // If this is a redefinition, recover by making this struct be 1744 // anonymous, which will make any later references get the previous 1745 // definition. 1746 Name = 0; 1747 } else { 1748 // Okay, this is definition of a previously declared or referenced 1749 // tag. Move the location of the decl to be the definition site. 1750 PrevDecl->setLocation(NameLoc); 1751 return PrevDecl; 1752 } 1753 } 1754 } 1755 // If we get here, this is a definition of a new struct type in a nested 1756 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1757 // type. 1758 } else { 1759 // PrevDecl is a namespace. 1760 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1761 // The tag name clashes with a namespace name, issue an error and recover 1762 // by making this tag be anonymous. 1763 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1764 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1765 Name = 0; 1766 } 1767 } 1768 } 1769 1770 // If there is an identifier, use the location of the identifier as the 1771 // location of the decl, otherwise use the location of the struct/union 1772 // keyword. 1773 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1774 1775 // Otherwise, if this is the first time we've seen this tag, create the decl. 1776 TagDecl *New; 1777 if (Kind == TagDecl::TK_enum) { 1778 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1779 // enum X { A, B, C } D; D should chain to X. 1780 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1781 // If this is an undefined enum, warn. 1782 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1783 } else { 1784 // struct/union/class 1785 1786 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1787 // struct X { int A; } D; D should chain to X. 1788 if (getLangOptions().CPlusPlus) 1789 // FIXME: Look for a way to use RecordDecl for simple structs. 1790 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1791 else 1792 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1793 } 1794 1795 // If this has an identifier, add it to the scope stack. 1796 if (Name) { 1797 // The scope passed in may not be a decl scope. Zip up the scope tree until 1798 // we find one that is. 1799 while ((S->getFlags() & Scope::DeclScope) == 0) 1800 S = S->getParent(); 1801 1802 // Add it to the decl chain. 1803 PushOnScopeChains(New, S); 1804 } 1805 1806 if (Attr) 1807 ProcessDeclAttributeList(New, Attr); 1808 return New; 1809} 1810 1811/// Collect the instance variables declared in an Objective-C object. Used in 1812/// the creation of structures from objects using the @defs directive. 1813static void CollectIvars(ObjCInterfaceDecl *Class, 1814 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1815 if (Class->getSuperClass()) 1816 CollectIvars(Class->getSuperClass(), ivars); 1817 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1818} 1819 1820/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1821/// instance variables of ClassName into Decls. 1822void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1823 IdentifierInfo *ClassName, 1824 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1825 // Check that ClassName is a valid class 1826 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1827 if (!Class) { 1828 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1829 return; 1830 } 1831 // Collect the instance variables 1832 CollectIvars(Class, Decls); 1833} 1834 1835QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1836 // This method tries to turn a variable array into a constant 1837 // array even when the size isn't an ICE. This is necessary 1838 // for compatibility with code that depends on gcc's buggy 1839 // constant expression folding, like struct {char x[(int)(char*)2];} 1840 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1841 APValue Result; 1842 if (VLATy->getSizeExpr() && 1843 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1844 llvm::APSInt &Res = Result.getInt(); 1845 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1846 return Context.getConstantArrayType(VLATy->getElementType(), 1847 Res, ArrayType::Normal, 0); 1848 } 1849 } 1850 return QualType(); 1851} 1852 1853/// ActOnField - Each field of a struct/union/class is passed into this in order 1854/// to create a FieldDecl object for it. 1855Sema::DeclTy *Sema::ActOnField(Scope *S, 1856 SourceLocation DeclStart, 1857 Declarator &D, ExprTy *BitfieldWidth) { 1858 IdentifierInfo *II = D.getIdentifier(); 1859 Expr *BitWidth = (Expr*)BitfieldWidth; 1860 SourceLocation Loc = DeclStart; 1861 if (II) Loc = D.getIdentifierLoc(); 1862 1863 // FIXME: Unnamed fields can be handled in various different ways, for 1864 // example, unnamed unions inject all members into the struct namespace! 1865 1866 1867 if (BitWidth) { 1868 // TODO: Validate. 1869 //printf("WARNING: BITFIELDS IGNORED!\n"); 1870 1871 // 6.7.2.1p3 1872 // 6.7.2.1p4 1873 1874 } else { 1875 // Not a bitfield. 1876 1877 // validate II. 1878 1879 } 1880 1881 QualType T = GetTypeForDeclarator(D, S); 1882 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1883 bool InvalidDecl = false; 1884 1885 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1886 // than a variably modified type. 1887 if (T->isVariablyModifiedType()) { 1888 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1889 if (!FixedTy.isNull()) { 1890 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1891 T = FixedTy; 1892 } else { 1893 // FIXME: This diagnostic needs work 1894 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1895 InvalidDecl = true; 1896 } 1897 } 1898 // FIXME: Chain fielddecls together. 1899 FieldDecl *NewFD; 1900 1901 if (getLangOptions().CPlusPlus) { 1902 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1903 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1904 Loc, II, T, BitWidth); 1905 if (II) 1906 PushOnScopeChains(NewFD, S); 1907 } 1908 else 1909 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1910 1911 ProcessDeclAttributes(NewFD, D); 1912 1913 if (D.getInvalidType() || InvalidDecl) 1914 NewFD->setInvalidDecl(); 1915 return NewFD; 1916} 1917 1918/// TranslateIvarVisibility - Translate visibility from a token ID to an 1919/// AST enum value. 1920static ObjCIvarDecl::AccessControl 1921TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1922 switch (ivarVisibility) { 1923 case tok::objc_private: return ObjCIvarDecl::Private; 1924 case tok::objc_public: return ObjCIvarDecl::Public; 1925 case tok::objc_protected: return ObjCIvarDecl::Protected; 1926 case tok::objc_package: return ObjCIvarDecl::Package; 1927 default: assert(false && "Unknown visitibility kind"); 1928 } 1929} 1930 1931/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1932/// in order to create an IvarDecl object for it. 1933Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1934 SourceLocation DeclStart, 1935 Declarator &D, ExprTy *BitfieldWidth, 1936 tok::ObjCKeywordKind Visibility) { 1937 IdentifierInfo *II = D.getIdentifier(); 1938 Expr *BitWidth = (Expr*)BitfieldWidth; 1939 SourceLocation Loc = DeclStart; 1940 if (II) Loc = D.getIdentifierLoc(); 1941 1942 // FIXME: Unnamed fields can be handled in various different ways, for 1943 // example, unnamed unions inject all members into the struct namespace! 1944 1945 1946 if (BitWidth) { 1947 // TODO: Validate. 1948 //printf("WARNING: BITFIELDS IGNORED!\n"); 1949 1950 // 6.7.2.1p3 1951 // 6.7.2.1p4 1952 1953 } else { 1954 // Not a bitfield. 1955 1956 // validate II. 1957 1958 } 1959 1960 QualType T = GetTypeForDeclarator(D, S); 1961 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1962 bool InvalidDecl = false; 1963 1964 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1965 // than a variably modified type. 1966 if (T->isVariablyModifiedType()) { 1967 // FIXME: This diagnostic needs work 1968 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1969 InvalidDecl = true; 1970 } 1971 1972 // Get the visibility (access control) for this ivar. 1973 ObjCIvarDecl::AccessControl ac = 1974 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1975 : ObjCIvarDecl::None; 1976 1977 // Construct the decl. 1978 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1979 (Expr *)BitfieldWidth); 1980 1981 // Process attributes attached to the ivar. 1982 ProcessDeclAttributes(NewID, D); 1983 1984 if (D.getInvalidType() || InvalidDecl) 1985 NewID->setInvalidDecl(); 1986 1987 return NewID; 1988} 1989 1990void Sema::ActOnFields(Scope* S, 1991 SourceLocation RecLoc, DeclTy *RecDecl, 1992 DeclTy **Fields, unsigned NumFields, 1993 SourceLocation LBrac, SourceLocation RBrac) { 1994 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1995 assert(EnclosingDecl && "missing record or interface decl"); 1996 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1997 1998 if (Record && Record->isDefinition()) { 1999 // Diagnose code like: 2000 // struct S { struct S {} X; }; 2001 // We discover this when we complete the outer S. Reject and ignore the 2002 // outer S. 2003 Diag(Record->getLocation(), diag::err_nested_redefinition, 2004 Record->getKindName()); 2005 Diag(RecLoc, diag::err_previous_definition); 2006 Record->setInvalidDecl(); 2007 return; 2008 } 2009 // Verify that all the fields are okay. 2010 unsigned NumNamedMembers = 0; 2011 llvm::SmallVector<FieldDecl*, 32> RecFields; 2012 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2013 2014 for (unsigned i = 0; i != NumFields; ++i) { 2015 2016 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2017 assert(FD && "missing field decl"); 2018 2019 // Remember all fields. 2020 RecFields.push_back(FD); 2021 2022 // Get the type for the field. 2023 Type *FDTy = FD->getType().getTypePtr(); 2024 2025 // C99 6.7.2.1p2 - A field may not be a function type. 2026 if (FDTy->isFunctionType()) { 2027 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2028 FD->getName()); 2029 FD->setInvalidDecl(); 2030 EnclosingDecl->setInvalidDecl(); 2031 continue; 2032 } 2033 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2034 if (FDTy->isIncompleteType()) { 2035 if (!Record) { // Incomplete ivar type is always an error. 2036 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2037 FD->setInvalidDecl(); 2038 EnclosingDecl->setInvalidDecl(); 2039 continue; 2040 } 2041 if (i != NumFields-1 || // ... that the last member ... 2042 !Record->isStruct() || // ... of a structure ... 2043 !FDTy->isArrayType()) { //... may have incomplete array type. 2044 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2045 FD->setInvalidDecl(); 2046 EnclosingDecl->setInvalidDecl(); 2047 continue; 2048 } 2049 if (NumNamedMembers < 1) { //... must have more than named member ... 2050 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2051 FD->getName()); 2052 FD->setInvalidDecl(); 2053 EnclosingDecl->setInvalidDecl(); 2054 continue; 2055 } 2056 // Okay, we have a legal flexible array member at the end of the struct. 2057 if (Record) 2058 Record->setHasFlexibleArrayMember(true); 2059 } 2060 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2061 /// field of another structure or the element of an array. 2062 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2063 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2064 // If this is a member of a union, then entire union becomes "flexible". 2065 if (Record && Record->isUnion()) { 2066 Record->setHasFlexibleArrayMember(true); 2067 } else { 2068 // If this is a struct/class and this is not the last element, reject 2069 // it. Note that GCC supports variable sized arrays in the middle of 2070 // structures. 2071 if (i != NumFields-1) { 2072 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2073 FD->getName()); 2074 FD->setInvalidDecl(); 2075 EnclosingDecl->setInvalidDecl(); 2076 continue; 2077 } 2078 // We support flexible arrays at the end of structs in other structs 2079 // as an extension. 2080 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2081 FD->getName()); 2082 if (Record) 2083 Record->setHasFlexibleArrayMember(true); 2084 } 2085 } 2086 } 2087 /// A field cannot be an Objective-c object 2088 if (FDTy->isObjCInterfaceType()) { 2089 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2090 FD->getName()); 2091 FD->setInvalidDecl(); 2092 EnclosingDecl->setInvalidDecl(); 2093 continue; 2094 } 2095 // Keep track of the number of named members. 2096 if (IdentifierInfo *II = FD->getIdentifier()) { 2097 // Detect duplicate member names. 2098 if (!FieldIDs.insert(II)) { 2099 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2100 // Find the previous decl. 2101 SourceLocation PrevLoc; 2102 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2103 assert(i != e && "Didn't find previous def!"); 2104 if (RecFields[i]->getIdentifier() == II) { 2105 PrevLoc = RecFields[i]->getLocation(); 2106 break; 2107 } 2108 } 2109 Diag(PrevLoc, diag::err_previous_definition); 2110 FD->setInvalidDecl(); 2111 EnclosingDecl->setInvalidDecl(); 2112 continue; 2113 } 2114 ++NumNamedMembers; 2115 } 2116 } 2117 2118 // Okay, we successfully defined 'Record'. 2119 if (Record) { 2120 Record->defineBody(&RecFields[0], RecFields.size()); 2121 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2122 // Sema::ActOnFinishCXXClassDef. 2123 if (!isa<CXXRecordDecl>(Record)) 2124 Consumer.HandleTagDeclDefinition(Record); 2125 } else { 2126 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2127 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2128 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2129 else if (ObjCImplementationDecl *IMPDecl = 2130 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2131 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2132 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2133 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2134 } 2135 } 2136} 2137 2138Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2139 DeclTy *lastEnumConst, 2140 SourceLocation IdLoc, IdentifierInfo *Id, 2141 SourceLocation EqualLoc, ExprTy *val) { 2142 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2143 EnumConstantDecl *LastEnumConst = 2144 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2145 Expr *Val = static_cast<Expr*>(val); 2146 2147 // The scope passed in may not be a decl scope. Zip up the scope tree until 2148 // we find one that is. 2149 while ((S->getFlags() & Scope::DeclScope) == 0) 2150 S = S->getParent(); 2151 2152 // Verify that there isn't already something declared with this name in this 2153 // scope. 2154 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2155 // When in C++, we may get a TagDecl with the same name; in this case the 2156 // enum constant will 'hide' the tag. 2157 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2158 "Received TagDecl when not in C++!"); 2159 if (!isa<TagDecl>(PrevDecl) && 2160 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2161 if (isa<EnumConstantDecl>(PrevDecl)) 2162 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2163 else 2164 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2165 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2166 delete Val; 2167 return 0; 2168 } 2169 } 2170 2171 llvm::APSInt EnumVal(32); 2172 QualType EltTy; 2173 if (Val) { 2174 // Make sure to promote the operand type to int. 2175 UsualUnaryConversions(Val); 2176 2177 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2178 SourceLocation ExpLoc; 2179 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2180 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2181 Id->getName()); 2182 delete Val; 2183 Val = 0; // Just forget about it. 2184 } else { 2185 EltTy = Val->getType(); 2186 } 2187 } 2188 2189 if (!Val) { 2190 if (LastEnumConst) { 2191 // Assign the last value + 1. 2192 EnumVal = LastEnumConst->getInitVal(); 2193 ++EnumVal; 2194 2195 // Check for overflow on increment. 2196 if (EnumVal < LastEnumConst->getInitVal()) 2197 Diag(IdLoc, diag::warn_enum_value_overflow); 2198 2199 EltTy = LastEnumConst->getType(); 2200 } else { 2201 // First value, set to zero. 2202 EltTy = Context.IntTy; 2203 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2204 } 2205 } 2206 2207 EnumConstantDecl *New = 2208 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2209 Val, EnumVal, 2210 LastEnumConst); 2211 2212 // Register this decl in the current scope stack. 2213 PushOnScopeChains(New, S); 2214 return New; 2215} 2216 2217// FIXME: For consistency with ActOnFields(), we should have the parser 2218// pass in the source location for the left/right braces. 2219void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2220 DeclTy **Elements, unsigned NumElements) { 2221 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2222 2223 if (Enum && Enum->isDefinition()) { 2224 // Diagnose code like: 2225 // enum e0 { 2226 // E0 = sizeof(enum e0 { E1 }) 2227 // }; 2228 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2229 Enum->getName()); 2230 Diag(EnumLoc, diag::err_previous_definition); 2231 Enum->setInvalidDecl(); 2232 return; 2233 } 2234 // TODO: If the result value doesn't fit in an int, it must be a long or long 2235 // long value. ISO C does not support this, but GCC does as an extension, 2236 // emit a warning. 2237 unsigned IntWidth = Context.Target.getIntWidth(); 2238 2239 // Verify that all the values are okay, compute the size of the values, and 2240 // reverse the list. 2241 unsigned NumNegativeBits = 0; 2242 unsigned NumPositiveBits = 0; 2243 2244 // Keep track of whether all elements have type int. 2245 bool AllElementsInt = true; 2246 2247 EnumConstantDecl *EltList = 0; 2248 for (unsigned i = 0; i != NumElements; ++i) { 2249 EnumConstantDecl *ECD = 2250 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2251 if (!ECD) continue; // Already issued a diagnostic. 2252 2253 // If the enum value doesn't fit in an int, emit an extension warning. 2254 const llvm::APSInt &InitVal = ECD->getInitVal(); 2255 assert(InitVal.getBitWidth() >= IntWidth && 2256 "Should have promoted value to int"); 2257 if (InitVal.getBitWidth() > IntWidth) { 2258 llvm::APSInt V(InitVal); 2259 V.trunc(IntWidth); 2260 V.extend(InitVal.getBitWidth()); 2261 if (V != InitVal) 2262 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2263 InitVal.toString()); 2264 } 2265 2266 // Keep track of the size of positive and negative values. 2267 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2268 NumPositiveBits = std::max(NumPositiveBits, 2269 (unsigned)InitVal.getActiveBits()); 2270 else 2271 NumNegativeBits = std::max(NumNegativeBits, 2272 (unsigned)InitVal.getMinSignedBits()); 2273 2274 // Keep track of whether every enum element has type int (very commmon). 2275 if (AllElementsInt) 2276 AllElementsInt = ECD->getType() == Context.IntTy; 2277 2278 ECD->setNextDeclarator(EltList); 2279 EltList = ECD; 2280 } 2281 2282 // Figure out the type that should be used for this enum. 2283 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2284 QualType BestType; 2285 unsigned BestWidth; 2286 2287 if (NumNegativeBits) { 2288 // If there is a negative value, figure out the smallest integer type (of 2289 // int/long/longlong) that fits. 2290 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2291 BestType = Context.IntTy; 2292 BestWidth = IntWidth; 2293 } else { 2294 BestWidth = Context.Target.getLongWidth(); 2295 2296 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2297 BestType = Context.LongTy; 2298 else { 2299 BestWidth = Context.Target.getLongLongWidth(); 2300 2301 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2302 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2303 BestType = Context.LongLongTy; 2304 } 2305 } 2306 } else { 2307 // If there is no negative value, figure out which of uint, ulong, ulonglong 2308 // fits. 2309 if (NumPositiveBits <= IntWidth) { 2310 BestType = Context.UnsignedIntTy; 2311 BestWidth = IntWidth; 2312 } else if (NumPositiveBits <= 2313 (BestWidth = Context.Target.getLongWidth())) { 2314 BestType = Context.UnsignedLongTy; 2315 } else { 2316 BestWidth = Context.Target.getLongLongWidth(); 2317 assert(NumPositiveBits <= BestWidth && 2318 "How could an initializer get larger than ULL?"); 2319 BestType = Context.UnsignedLongLongTy; 2320 } 2321 } 2322 2323 // Loop over all of the enumerator constants, changing their types to match 2324 // the type of the enum if needed. 2325 for (unsigned i = 0; i != NumElements; ++i) { 2326 EnumConstantDecl *ECD = 2327 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2328 if (!ECD) continue; // Already issued a diagnostic. 2329 2330 // Standard C says the enumerators have int type, but we allow, as an 2331 // extension, the enumerators to be larger than int size. If each 2332 // enumerator value fits in an int, type it as an int, otherwise type it the 2333 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2334 // that X has type 'int', not 'unsigned'. 2335 if (ECD->getType() == Context.IntTy) { 2336 // Make sure the init value is signed. 2337 llvm::APSInt IV = ECD->getInitVal(); 2338 IV.setIsSigned(true); 2339 ECD->setInitVal(IV); 2340 continue; // Already int type. 2341 } 2342 2343 // Determine whether the value fits into an int. 2344 llvm::APSInt InitVal = ECD->getInitVal(); 2345 bool FitsInInt; 2346 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2347 FitsInInt = InitVal.getActiveBits() < IntWidth; 2348 else 2349 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2350 2351 // If it fits into an integer type, force it. Otherwise force it to match 2352 // the enum decl type. 2353 QualType NewTy; 2354 unsigned NewWidth; 2355 bool NewSign; 2356 if (FitsInInt) { 2357 NewTy = Context.IntTy; 2358 NewWidth = IntWidth; 2359 NewSign = true; 2360 } else if (ECD->getType() == BestType) { 2361 // Already the right type! 2362 continue; 2363 } else { 2364 NewTy = BestType; 2365 NewWidth = BestWidth; 2366 NewSign = BestType->isSignedIntegerType(); 2367 } 2368 2369 // Adjust the APSInt value. 2370 InitVal.extOrTrunc(NewWidth); 2371 InitVal.setIsSigned(NewSign); 2372 ECD->setInitVal(InitVal); 2373 2374 // Adjust the Expr initializer and type. 2375 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2376 ECD->setType(NewTy); 2377 } 2378 2379 Enum->defineElements(EltList, BestType); 2380 Consumer.HandleTagDeclDefinition(Enum); 2381} 2382 2383Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2384 ExprTy *expr) { 2385 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2386 2387 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2388} 2389 2390Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2391 SourceLocation LBrace, 2392 SourceLocation RBrace, 2393 const char *Lang, 2394 unsigned StrSize, 2395 DeclTy *D) { 2396 LinkageSpecDecl::LanguageIDs Language; 2397 Decl *dcl = static_cast<Decl *>(D); 2398 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2399 Language = LinkageSpecDecl::lang_c; 2400 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2401 Language = LinkageSpecDecl::lang_cxx; 2402 else { 2403 Diag(Loc, diag::err_bad_language); 2404 return 0; 2405 } 2406 2407 // FIXME: Add all the various semantics of linkage specifications 2408 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2409} 2410