SemaDecl.cpp revision 907747b3a67a41420ead8ef1fc5e6bd9dc9e0ad9
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). 382bool Sema::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); 394 395 for (IdentifierResolver::iterator 396 I = IdResolver.begin(VD->getIdentifier(), 397 VD->getDeclContext(), false/*LookInParentCtx*/), 398 E = IdResolver.end(); I != E; ++I) { 399 if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) { 400 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 401 402 // Check for "tentative" definitions. We can't accomplish this in 403 // MergeVarDecl since the initializer hasn't been attached. 404 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 405 continue; 406 407 // Handle __private_extern__ just like extern. 408 if (OldDecl->getStorageClass() != VarDecl::Extern && 409 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 410 VD->getStorageClass() != VarDecl::Extern && 411 VD->getStorageClass() != VarDecl::PrivateExtern) { 412 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 413 Diag(OldDecl->getLocation(), diag::err_previous_definition); 414 } 415 } 416 } 417} 418 419/// MergeVarDecl - We just parsed a variable 'New' which has the same name 420/// and scope as a previous declaration 'Old'. Figure out how to resolve this 421/// situation, merging decls or emitting diagnostics as appropriate. 422/// 423/// Tentative definition rules (C99 6.9.2p2) are checked by 424/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 425/// definitions here, since the initializer hasn't been attached. 426/// 427VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 428 // Verify the old decl was also a variable. 429 VarDecl *Old = dyn_cast<VarDecl>(OldD); 430 if (!Old) { 431 Diag(New->getLocation(), diag::err_redefinition_different_kind, 432 New->getName()); 433 Diag(OldD->getLocation(), diag::err_previous_definition); 434 return New; 435 } 436 437 MergeAttributes(New, Old); 438 439 // Verify the types match. 440 QualType OldCType = Context.getCanonicalType(Old->getType()); 441 QualType NewCType = Context.getCanonicalType(New->getType()); 442 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 443 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 444 Diag(Old->getLocation(), diag::err_previous_definition); 445 return New; 446 } 447 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 448 if (New->getStorageClass() == VarDecl::Static && 449 (Old->getStorageClass() == VarDecl::None || 450 Old->getStorageClass() == VarDecl::Extern)) { 451 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 452 Diag(Old->getLocation(), diag::err_previous_definition); 453 return New; 454 } 455 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 456 if (New->getStorageClass() != VarDecl::Static && 457 Old->getStorageClass() == VarDecl::Static) { 458 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 459 Diag(Old->getLocation(), diag::err_previous_definition); 460 return New; 461 } 462 // File scoped variables are analyzed in FinalizeDeclaratorGroup. 463 if (!New->isFileVarDecl()) { 464 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 465 Diag(Old->getLocation(), diag::err_previous_definition); 466 } 467 return New; 468} 469 470/// CheckParmsForFunctionDef - Check that the parameters of the given 471/// function are appropriate for the definition of a function. This 472/// takes care of any checks that cannot be performed on the 473/// declaration itself, e.g., that the types of each of the function 474/// parameters are complete. 475bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 476 bool HasInvalidParm = false; 477 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 478 ParmVarDecl *Param = FD->getParamDecl(p); 479 480 // C99 6.7.5.3p4: the parameters in a parameter type list in a 481 // function declarator that is part of a function definition of 482 // that function shall not have incomplete type. 483 if (Param->getType()->isIncompleteType() && 484 !Param->isInvalidDecl()) { 485 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 486 Param->getType().getAsString()); 487 Param->setInvalidDecl(); 488 HasInvalidParm = true; 489 } 490 } 491 492 return HasInvalidParm; 493} 494 495/// CreateImplicitParameter - Creates an implicit function parameter 496/// in the scope S and with the given type. This routine is used, for 497/// example, to create the implicit "self" parameter in an Objective-C 498/// method. 499ImplicitParamDecl * 500Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 501 SourceLocation IdLoc, QualType Type) { 502 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 503 IdLoc, Id, Type, 0); 504 if (Id) 505 PushOnScopeChains(New, S); 506 507 return New; 508} 509 510/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 511/// no declarator (e.g. "struct foo;") is parsed. 512Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 513 // TODO: emit error on 'int;' or 'const enum foo;'. 514 // TODO: emit error on 'typedef int;' 515 // if (!DS.isMissingDeclaratorOk()) Diag(...); 516 517 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 518} 519 520bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 521 // Get the type before calling CheckSingleAssignmentConstraints(), since 522 // it can promote the expression. 523 QualType InitType = Init->getType(); 524 525 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 526 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 527 InitType, Init, "initializing"); 528} 529 530bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 531 const ArrayType *AT = Context.getAsArrayType(DeclT); 532 533 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 534 // C99 6.7.8p14. We have an array of character type with unknown size 535 // being initialized to a string literal. 536 llvm::APSInt ConstVal(32); 537 ConstVal = strLiteral->getByteLength() + 1; 538 // Return a new array type (C99 6.7.8p22). 539 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 540 ArrayType::Normal, 0); 541 } else { 542 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 543 // C99 6.7.8p14. We have an array of character type with known size. 544 // FIXME: Avoid truncation for 64-bit length strings. 545 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 546 Diag(strLiteral->getSourceRange().getBegin(), 547 diag::warn_initializer_string_for_char_array_too_long, 548 strLiteral->getSourceRange()); 549 } 550 // Set type from "char *" to "constant array of char". 551 strLiteral->setType(DeclT); 552 // For now, we always return false (meaning success). 553 return false; 554} 555 556StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 557 const ArrayType *AT = Context.getAsArrayType(DeclType); 558 if (AT && AT->getElementType()->isCharType()) { 559 return dyn_cast<StringLiteral>(Init); 560 } 561 return 0; 562} 563 564bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 565 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 566 // of unknown size ("[]") or an object type that is not a variable array type. 567 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 568 return Diag(VAT->getSizeExpr()->getLocStart(), 569 diag::err_variable_object_no_init, 570 VAT->getSizeExpr()->getSourceRange()); 571 572 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 573 if (!InitList) { 574 // FIXME: Handle wide strings 575 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 576 return CheckStringLiteralInit(strLiteral, DeclType); 577 578 if (DeclType->isArrayType()) 579 return Diag(Init->getLocStart(), 580 diag::err_array_init_list_required, 581 Init->getSourceRange()); 582 583 return CheckSingleInitializer(Init, DeclType); 584 } 585 586 InitListChecker CheckInitList(this, InitList, DeclType); 587 return CheckInitList.HadError(); 588} 589 590Sema::DeclTy * 591Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 592 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 593 IdentifierInfo *II = D.getIdentifier(); 594 595 // All of these full declarators require an identifier. If it doesn't have 596 // one, the ParsedFreeStandingDeclSpec action should be used. 597 if (II == 0) { 598 Diag(D.getDeclSpec().getSourceRange().getBegin(), 599 diag::err_declarator_need_ident, 600 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 601 return 0; 602 } 603 604 // The scope passed in may not be a decl scope. Zip up the scope tree until 605 // we find one that is. 606 while ((S->getFlags() & Scope::DeclScope) == 0) 607 S = S->getParent(); 608 609 // See if this is a redefinition of a variable in the same scope. 610 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 611 ScopedDecl *New; 612 bool InvalidDecl = false; 613 614 // In C++, the previous declaration we find might be a tag type 615 // (class or enum). In this case, the new declaration will hide the 616 // tag type. 617 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 618 PrevDecl = 0; 619 620 QualType R = GetTypeForDeclarator(D, S); 621 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 622 623 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 624 // Check that there are no default arguments (C++ only). 625 if (getLangOptions().CPlusPlus) 626 CheckExtraCXXDefaultArguments(D); 627 628 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 629 if (!NewTD) return 0; 630 631 // Handle attributes prior to checking for duplicates in MergeVarDecl 632 ProcessDeclAttributes(NewTD, D); 633 // Merge the decl with the existing one if appropriate. If the decl is 634 // in an outer scope, it isn't the same thing. 635 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 636 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 637 if (NewTD == 0) return 0; 638 } 639 New = NewTD; 640 if (S->getFnParent() == 0) { 641 // C99 6.7.7p2: If a typedef name specifies a variably modified type 642 // then it shall have block scope. 643 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 644 // FIXME: Diagnostic needs to be fixed. 645 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 646 InvalidDecl = true; 647 } 648 } 649 } else if (R.getTypePtr()->isFunctionType()) { 650 FunctionDecl::StorageClass SC = FunctionDecl::None; 651 switch (D.getDeclSpec().getStorageClassSpec()) { 652 default: assert(0 && "Unknown storage class!"); 653 case DeclSpec::SCS_auto: 654 case DeclSpec::SCS_register: 655 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 656 R.getAsString()); 657 InvalidDecl = true; 658 break; 659 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 660 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 661 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 662 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 663 } 664 665 bool isInline = D.getDeclSpec().isInlineSpecified(); 666 FunctionDecl *NewFD; 667 if (D.getContext() == Declarator::MemberContext) { 668 // This is a C++ method declaration. 669 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 670 D.getIdentifierLoc(), II, R, 671 (SC == FunctionDecl::Static), isInline, 672 LastDeclarator); 673 } else { 674 NewFD = FunctionDecl::Create(Context, CurContext, 675 D.getIdentifierLoc(), 676 II, R, SC, isInline, 677 LastDeclarator); 678 } 679 // Handle attributes. 680 ProcessDeclAttributes(NewFD, D); 681 682 // Handle GNU asm-label extension (encoded as an attribute). 683 if (Expr *E = (Expr*) D.getAsmLabel()) { 684 // The parser guarantees this is a string. 685 StringLiteral *SE = cast<StringLiteral>(E); 686 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 687 SE->getByteLength()))); 688 } 689 690 // Copy the parameter declarations from the declarator D to 691 // the function declaration NewFD, if they are available. 692 if (D.getNumTypeObjects() > 0 && 693 D.getTypeObject(0).Fun.hasPrototype) { 694 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 695 696 // Create Decl objects for each parameter, adding them to the 697 // FunctionDecl. 698 llvm::SmallVector<ParmVarDecl*, 16> Params; 699 700 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 701 // function that takes no arguments, not a function that takes a 702 // single void argument. 703 // We let through "const void" here because Sema::GetTypeForDeclarator 704 // already checks for that case. 705 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 706 FTI.ArgInfo[0].Param && 707 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 708 // empty arg list, don't push any params. 709 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 710 711 // In C++, the empty parameter-type-list must be spelled "void"; a 712 // typedef of void is not permitted. 713 if (getLangOptions().CPlusPlus && 714 Param->getType().getUnqualifiedType() != Context.VoidTy) { 715 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 716 } 717 718 } else { 719 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 720 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 721 } 722 723 NewFD->setParams(&Params[0], Params.size()); 724 } 725 726 // Merge the decl with the existing one if appropriate. Since C functions 727 // are in a flat namespace, make sure we consider decls in outer scopes. 728 if (PrevDecl && 729 (!getLangOptions().CPlusPlus || 730 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 731 bool Redeclaration = false; 732 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 733 if (NewFD == 0) return 0; 734 if (Redeclaration) { 735 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 736 } 737 } 738 New = NewFD; 739 740 // In C++, check default arguments now that we have merged decls. 741 if (getLangOptions().CPlusPlus) 742 CheckCXXDefaultArguments(NewFD); 743 } else { 744 // Check that there are no default arguments (C++ only). 745 if (getLangOptions().CPlusPlus) 746 CheckExtraCXXDefaultArguments(D); 747 748 if (R.getTypePtr()->isObjCInterfaceType()) { 749 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 750 D.getIdentifier()->getName()); 751 InvalidDecl = true; 752 } 753 754 VarDecl *NewVD; 755 VarDecl::StorageClass SC; 756 switch (D.getDeclSpec().getStorageClassSpec()) { 757 default: assert(0 && "Unknown storage class!"); 758 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 759 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 760 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 761 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 762 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 763 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 764 } 765 if (D.getContext() == Declarator::MemberContext) { 766 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 767 // This is a static data member for a C++ class. 768 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 769 D.getIdentifierLoc(), II, 770 R, LastDeclarator); 771 } else { 772 if (S->getFnParent() == 0) { 773 // C99 6.9p2: The storage-class specifiers auto and register shall not 774 // appear in the declaration specifiers in an external declaration. 775 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 776 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 777 R.getAsString()); 778 InvalidDecl = true; 779 } 780 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 781 II, R, SC, LastDeclarator); 782 } else { 783 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 784 II, R, SC, LastDeclarator); 785 } 786 } 787 // Handle attributes prior to checking for duplicates in MergeVarDecl 788 ProcessDeclAttributes(NewVD, D); 789 790 // Handle GNU asm-label extension (encoded as an attribute). 791 if (Expr *E = (Expr*) D.getAsmLabel()) { 792 // The parser guarantees this is a string. 793 StringLiteral *SE = cast<StringLiteral>(E); 794 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 795 SE->getByteLength()))); 796 } 797 798 // Emit an error if an address space was applied to decl with local storage. 799 // This includes arrays of objects with address space qualifiers, but not 800 // automatic variables that point to other address spaces. 801 // ISO/IEC TR 18037 S5.1.2 802 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 803 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 804 InvalidDecl = true; 805 } 806 // Merge the decl with the existing one if appropriate. If the decl is 807 // in an outer scope, it isn't the same thing. 808 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 809 NewVD = MergeVarDecl(NewVD, PrevDecl); 810 if (NewVD == 0) return 0; 811 } 812 New = NewVD; 813 } 814 815 // If this has an identifier, add it to the scope stack. 816 if (II) 817 PushOnScopeChains(New, S); 818 // If any semantic error occurred, mark the decl as invalid. 819 if (D.getInvalidType() || InvalidDecl) 820 New->setInvalidDecl(); 821 822 return New; 823} 824 825bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 826 switch (Init->getStmtClass()) { 827 default: 828 Diag(Init->getExprLoc(), 829 diag::err_init_element_not_constant, Init->getSourceRange()); 830 return true; 831 case Expr::ParenExprClass: { 832 const ParenExpr* PE = cast<ParenExpr>(Init); 833 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 834 } 835 case Expr::CompoundLiteralExprClass: 836 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 837 case Expr::DeclRefExprClass: { 838 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 839 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 840 if (VD->hasGlobalStorage()) 841 return false; 842 Diag(Init->getExprLoc(), 843 diag::err_init_element_not_constant, Init->getSourceRange()); 844 return true; 845 } 846 if (isa<FunctionDecl>(D)) 847 return false; 848 Diag(Init->getExprLoc(), 849 diag::err_init_element_not_constant, Init->getSourceRange()); 850 return true; 851 } 852 case Expr::MemberExprClass: { 853 const MemberExpr *M = cast<MemberExpr>(Init); 854 if (M->isArrow()) 855 return CheckAddressConstantExpression(M->getBase()); 856 return CheckAddressConstantExpressionLValue(M->getBase()); 857 } 858 case Expr::ArraySubscriptExprClass: { 859 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 860 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 861 return CheckAddressConstantExpression(ASE->getBase()) || 862 CheckArithmeticConstantExpression(ASE->getIdx()); 863 } 864 case Expr::StringLiteralClass: 865 case Expr::PreDefinedExprClass: 866 return false; 867 case Expr::UnaryOperatorClass: { 868 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 869 870 // C99 6.6p9 871 if (Exp->getOpcode() == UnaryOperator::Deref) 872 return CheckAddressConstantExpression(Exp->getSubExpr()); 873 874 Diag(Init->getExprLoc(), 875 diag::err_init_element_not_constant, Init->getSourceRange()); 876 return true; 877 } 878 } 879} 880 881bool Sema::CheckAddressConstantExpression(const Expr* Init) { 882 switch (Init->getStmtClass()) { 883 default: 884 Diag(Init->getExprLoc(), 885 diag::err_init_element_not_constant, Init->getSourceRange()); 886 return true; 887 case Expr::ParenExprClass: { 888 const ParenExpr* PE = cast<ParenExpr>(Init); 889 return CheckAddressConstantExpression(PE->getSubExpr()); 890 } 891 case Expr::StringLiteralClass: 892 case Expr::ObjCStringLiteralClass: 893 return false; 894 case Expr::CallExprClass: { 895 const CallExpr *CE = cast<CallExpr>(Init); 896 if (CE->isBuiltinConstantExpr()) 897 return false; 898 Diag(Init->getExprLoc(), 899 diag::err_init_element_not_constant, Init->getSourceRange()); 900 return true; 901 } 902 case Expr::UnaryOperatorClass: { 903 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 904 905 // C99 6.6p9 906 if (Exp->getOpcode() == UnaryOperator::AddrOf) 907 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 908 909 if (Exp->getOpcode() == UnaryOperator::Extension) 910 return CheckAddressConstantExpression(Exp->getSubExpr()); 911 912 Diag(Init->getExprLoc(), 913 diag::err_init_element_not_constant, Init->getSourceRange()); 914 return true; 915 } 916 case Expr::BinaryOperatorClass: { 917 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 918 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 919 920 Expr *PExp = Exp->getLHS(); 921 Expr *IExp = Exp->getRHS(); 922 if (IExp->getType()->isPointerType()) 923 std::swap(PExp, IExp); 924 925 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 926 return CheckAddressConstantExpression(PExp) || 927 CheckArithmeticConstantExpression(IExp); 928 } 929 case Expr::ImplicitCastExprClass: { 930 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 931 932 // Check for implicit promotion 933 if (SubExpr->getType()->isFunctionType() || 934 SubExpr->getType()->isArrayType()) 935 return CheckAddressConstantExpressionLValue(SubExpr); 936 937 // Check for pointer->pointer cast 938 if (SubExpr->getType()->isPointerType()) 939 return CheckAddressConstantExpression(SubExpr); 940 941 if (SubExpr->getType()->isArithmeticType()) 942 return CheckArithmeticConstantExpression(SubExpr); 943 944 Diag(Init->getExprLoc(), 945 diag::err_init_element_not_constant, Init->getSourceRange()); 946 return true; 947 } 948 case Expr::CastExprClass: { 949 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 950 951 // Check for pointer->pointer cast 952 if (SubExpr->getType()->isPointerType()) 953 return CheckAddressConstantExpression(SubExpr); 954 955 // FIXME: Should we pedwarn for (int*)(0+0)? 956 if (SubExpr->getType()->isArithmeticType()) 957 return CheckArithmeticConstantExpression(SubExpr); 958 959 Diag(Init->getExprLoc(), 960 diag::err_init_element_not_constant, Init->getSourceRange()); 961 return true; 962 } 963 case Expr::ConditionalOperatorClass: { 964 // FIXME: Should we pedwarn here? 965 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 966 if (!Exp->getCond()->getType()->isArithmeticType()) { 967 Diag(Init->getExprLoc(), 968 diag::err_init_element_not_constant, Init->getSourceRange()); 969 return true; 970 } 971 if (CheckArithmeticConstantExpression(Exp->getCond())) 972 return true; 973 if (Exp->getLHS() && 974 CheckAddressConstantExpression(Exp->getLHS())) 975 return true; 976 return CheckAddressConstantExpression(Exp->getRHS()); 977 } 978 case Expr::AddrLabelExprClass: 979 return false; 980 } 981} 982 983static const Expr* FindExpressionBaseAddress(const Expr* E); 984 985static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 986 switch (E->getStmtClass()) { 987 default: 988 return E; 989 case Expr::ParenExprClass: { 990 const ParenExpr* PE = cast<ParenExpr>(E); 991 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 992 } 993 case Expr::MemberExprClass: { 994 const MemberExpr *M = cast<MemberExpr>(E); 995 if (M->isArrow()) 996 return FindExpressionBaseAddress(M->getBase()); 997 return FindExpressionBaseAddressLValue(M->getBase()); 998 } 999 case Expr::ArraySubscriptExprClass: { 1000 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1001 return FindExpressionBaseAddress(ASE->getBase()); 1002 } 1003 case Expr::UnaryOperatorClass: { 1004 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1005 1006 if (Exp->getOpcode() == UnaryOperator::Deref) 1007 return FindExpressionBaseAddress(Exp->getSubExpr()); 1008 1009 return E; 1010 } 1011 } 1012} 1013 1014static const Expr* FindExpressionBaseAddress(const Expr* E) { 1015 switch (E->getStmtClass()) { 1016 default: 1017 return E; 1018 case Expr::ParenExprClass: { 1019 const ParenExpr* PE = cast<ParenExpr>(E); 1020 return FindExpressionBaseAddress(PE->getSubExpr()); 1021 } 1022 case Expr::UnaryOperatorClass: { 1023 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1024 1025 // C99 6.6p9 1026 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1027 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1028 1029 if (Exp->getOpcode() == UnaryOperator::Extension) 1030 return FindExpressionBaseAddress(Exp->getSubExpr()); 1031 1032 return E; 1033 } 1034 case Expr::BinaryOperatorClass: { 1035 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1036 1037 Expr *PExp = Exp->getLHS(); 1038 Expr *IExp = Exp->getRHS(); 1039 if (IExp->getType()->isPointerType()) 1040 std::swap(PExp, IExp); 1041 1042 return FindExpressionBaseAddress(PExp); 1043 } 1044 case Expr::ImplicitCastExprClass: { 1045 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1046 1047 // Check for implicit promotion 1048 if (SubExpr->getType()->isFunctionType() || 1049 SubExpr->getType()->isArrayType()) 1050 return FindExpressionBaseAddressLValue(SubExpr); 1051 1052 // Check for pointer->pointer cast 1053 if (SubExpr->getType()->isPointerType()) 1054 return FindExpressionBaseAddress(SubExpr); 1055 1056 // We assume that we have an arithmetic expression here; 1057 // if we don't, we'll figure it out later 1058 return 0; 1059 } 1060 case Expr::CastExprClass: { 1061 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 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 } 1072} 1073 1074bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1075 switch (Init->getStmtClass()) { 1076 default: 1077 Diag(Init->getExprLoc(), 1078 diag::err_init_element_not_constant, Init->getSourceRange()); 1079 return true; 1080 case Expr::ParenExprClass: { 1081 const ParenExpr* PE = cast<ParenExpr>(Init); 1082 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1083 } 1084 case Expr::FloatingLiteralClass: 1085 case Expr::IntegerLiteralClass: 1086 case Expr::CharacterLiteralClass: 1087 case Expr::ImaginaryLiteralClass: 1088 case Expr::TypesCompatibleExprClass: 1089 case Expr::CXXBoolLiteralExprClass: 1090 return false; 1091 case Expr::CallExprClass: { 1092 const CallExpr *CE = cast<CallExpr>(Init); 1093 if (CE->isBuiltinConstantExpr()) 1094 return false; 1095 Diag(Init->getExprLoc(), 1096 diag::err_init_element_not_constant, Init->getSourceRange()); 1097 return true; 1098 } 1099 case Expr::DeclRefExprClass: { 1100 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1101 if (isa<EnumConstantDecl>(D)) 1102 return false; 1103 Diag(Init->getExprLoc(), 1104 diag::err_init_element_not_constant, Init->getSourceRange()); 1105 return true; 1106 } 1107 case Expr::CompoundLiteralExprClass: 1108 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1109 // but vectors are allowed to be magic. 1110 if (Init->getType()->isVectorType()) 1111 return false; 1112 Diag(Init->getExprLoc(), 1113 diag::err_init_element_not_constant, Init->getSourceRange()); 1114 return true; 1115 case Expr::UnaryOperatorClass: { 1116 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1117 1118 switch (Exp->getOpcode()) { 1119 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1120 // See C99 6.6p3. 1121 default: 1122 Diag(Init->getExprLoc(), 1123 diag::err_init_element_not_constant, Init->getSourceRange()); 1124 return true; 1125 case UnaryOperator::SizeOf: 1126 case UnaryOperator::AlignOf: 1127 case UnaryOperator::OffsetOf: 1128 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1129 // See C99 6.5.3.4p2 and 6.6p3. 1130 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1131 return false; 1132 Diag(Init->getExprLoc(), 1133 diag::err_init_element_not_constant, Init->getSourceRange()); 1134 return true; 1135 case UnaryOperator::Extension: 1136 case UnaryOperator::LNot: 1137 case UnaryOperator::Plus: 1138 case UnaryOperator::Minus: 1139 case UnaryOperator::Not: 1140 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1141 } 1142 } 1143 case Expr::SizeOfAlignOfTypeExprClass: { 1144 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1145 // Special check for void types, which are allowed as an extension 1146 if (Exp->getArgumentType()->isVoidType()) 1147 return false; 1148 // alignof always evaluates to a constant. 1149 // FIXME: is sizeof(int[3.0]) a constant expression? 1150 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1151 Diag(Init->getExprLoc(), 1152 diag::err_init_element_not_constant, Init->getSourceRange()); 1153 return true; 1154 } 1155 return false; 1156 } 1157 case Expr::BinaryOperatorClass: { 1158 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1159 1160 if (Exp->getLHS()->getType()->isArithmeticType() && 1161 Exp->getRHS()->getType()->isArithmeticType()) { 1162 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1163 CheckArithmeticConstantExpression(Exp->getRHS()); 1164 } 1165 1166 if (Exp->getLHS()->getType()->isPointerType() && 1167 Exp->getRHS()->getType()->isPointerType()) { 1168 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1169 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1170 1171 // Only allow a null (constant integer) base; we could 1172 // allow some additional cases if necessary, but this 1173 // is sufficient to cover offsetof-like constructs. 1174 if (!LHSBase && !RHSBase) { 1175 return CheckAddressConstantExpression(Exp->getLHS()) || 1176 CheckAddressConstantExpression(Exp->getRHS()); 1177 } 1178 } 1179 1180 Diag(Init->getExprLoc(), 1181 diag::err_init_element_not_constant, Init->getSourceRange()); 1182 return true; 1183 } 1184 case Expr::ImplicitCastExprClass: 1185 case Expr::CastExprClass: { 1186 const Expr *SubExpr; 1187 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1188 SubExpr = C->getSubExpr(); 1189 } else { 1190 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1191 } 1192 1193 if (SubExpr->getType()->isArithmeticType()) 1194 return CheckArithmeticConstantExpression(SubExpr); 1195 1196 Diag(Init->getExprLoc(), 1197 diag::err_init_element_not_constant, Init->getSourceRange()); 1198 return true; 1199 } 1200 case Expr::ConditionalOperatorClass: { 1201 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1202 if (CheckArithmeticConstantExpression(Exp->getCond())) 1203 return true; 1204 if (Exp->getLHS() && 1205 CheckArithmeticConstantExpression(Exp->getLHS())) 1206 return true; 1207 return CheckArithmeticConstantExpression(Exp->getRHS()); 1208 } 1209 } 1210} 1211 1212bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1213 Init = Init->IgnoreParens(); 1214 1215 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1216 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1217 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1218 1219 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1220 return CheckForConstantInitializer(e->getInitializer(), DclT); 1221 1222 if (Init->getType()->isReferenceType()) { 1223 // FIXME: Work out how the heck reference types work 1224 return false; 1225#if 0 1226 // A reference is constant if the address of the expression 1227 // is constant 1228 // We look through initlists here to simplify 1229 // CheckAddressConstantExpressionLValue. 1230 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1231 assert(Exp->getNumInits() > 0 && 1232 "Refernce initializer cannot be empty"); 1233 Init = Exp->getInit(0); 1234 } 1235 return CheckAddressConstantExpressionLValue(Init); 1236#endif 1237 } 1238 1239 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1240 unsigned numInits = Exp->getNumInits(); 1241 for (unsigned i = 0; i < numInits; i++) { 1242 // FIXME: Need to get the type of the declaration for C++, 1243 // because it could be a reference? 1244 if (CheckForConstantInitializer(Exp->getInit(i), 1245 Exp->getInit(i)->getType())) 1246 return true; 1247 } 1248 return false; 1249 } 1250 1251 if (Init->isNullPointerConstant(Context)) 1252 return false; 1253 if (Init->getType()->isArithmeticType()) { 1254 QualType InitTy = Context.getCanonicalType(Init->getType()) 1255 .getUnqualifiedType(); 1256 if (InitTy == Context.BoolTy) { 1257 // Special handling for pointers implicitly cast to bool; 1258 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1259 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1260 Expr* SubE = ICE->getSubExpr(); 1261 if (SubE->getType()->isPointerType() || 1262 SubE->getType()->isArrayType() || 1263 SubE->getType()->isFunctionType()) { 1264 return CheckAddressConstantExpression(Init); 1265 } 1266 } 1267 } else if (InitTy->isIntegralType()) { 1268 Expr* SubE = 0; 1269 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1270 SubE = ICE->getSubExpr(); 1271 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1272 SubE = CE->getSubExpr(); 1273 // Special check for pointer cast to int; we allow as an extension 1274 // an address constant cast to an integer if the integer 1275 // is of an appropriate width (this sort of code is apparently used 1276 // in some places). 1277 // FIXME: Add pedwarn? 1278 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1279 if (SubE && (SubE->getType()->isPointerType() || 1280 SubE->getType()->isArrayType() || 1281 SubE->getType()->isFunctionType())) { 1282 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1283 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1284 if (IntWidth >= PointerWidth) 1285 return CheckAddressConstantExpression(Init); 1286 } 1287 } 1288 1289 return CheckArithmeticConstantExpression(Init); 1290 } 1291 1292 if (Init->getType()->isPointerType()) 1293 return CheckAddressConstantExpression(Init); 1294 1295 // An array type at the top level that isn't an init-list must 1296 // be a string literal 1297 if (Init->getType()->isArrayType()) 1298 return false; 1299 1300 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1301 Init->getSourceRange()); 1302 return true; 1303} 1304 1305void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1306 Decl *RealDecl = static_cast<Decl *>(dcl); 1307 Expr *Init = static_cast<Expr *>(init); 1308 assert(Init && "missing initializer"); 1309 1310 // If there is no declaration, there was an error parsing it. Just ignore 1311 // the initializer. 1312 if (RealDecl == 0) { 1313 delete Init; 1314 return; 1315 } 1316 1317 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1318 if (!VDecl) { 1319 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1320 diag::err_illegal_initializer); 1321 RealDecl->setInvalidDecl(); 1322 return; 1323 } 1324 // Get the decls type and save a reference for later, since 1325 // CheckInitializerTypes may change it. 1326 QualType DclT = VDecl->getType(), SavT = DclT; 1327 if (VDecl->isBlockVarDecl()) { 1328 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1329 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1330 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1331 VDecl->setInvalidDecl(); 1332 } else if (!VDecl->isInvalidDecl()) { 1333 if (CheckInitializerTypes(Init, DclT)) 1334 VDecl->setInvalidDecl(); 1335 if (SC == VarDecl::Static) // C99 6.7.8p4. 1336 CheckForConstantInitializer(Init, DclT); 1337 } 1338 } else if (VDecl->isFileVarDecl()) { 1339 if (VDecl->getStorageClass() == VarDecl::Extern) 1340 Diag(VDecl->getLocation(), diag::warn_extern_init); 1341 if (!VDecl->isInvalidDecl()) 1342 if (CheckInitializerTypes(Init, DclT)) 1343 VDecl->setInvalidDecl(); 1344 1345 // C99 6.7.8p4. All file scoped initializers need to be constant. 1346 CheckForConstantInitializer(Init, DclT); 1347 } 1348 // If the type changed, it means we had an incomplete type that was 1349 // completed by the initializer. For example: 1350 // int ary[] = { 1, 3, 5 }; 1351 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1352 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1353 VDecl->setType(DclT); 1354 Init->setType(DclT); 1355 } 1356 1357 // Attach the initializer to the decl. 1358 VDecl->setInit(Init); 1359 return; 1360} 1361 1362/// The declarators are chained together backwards, reverse the list. 1363Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1364 // Often we have single declarators, handle them quickly. 1365 Decl *GroupDecl = static_cast<Decl*>(group); 1366 if (GroupDecl == 0) 1367 return 0; 1368 1369 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1370 ScopedDecl *NewGroup = 0; 1371 if (Group->getNextDeclarator() == 0) 1372 NewGroup = Group; 1373 else { // reverse the list. 1374 while (Group) { 1375 ScopedDecl *Next = Group->getNextDeclarator(); 1376 Group->setNextDeclarator(NewGroup); 1377 NewGroup = Group; 1378 Group = Next; 1379 } 1380 } 1381 // Perform semantic analysis that depends on having fully processed both 1382 // the declarator and initializer. 1383 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1384 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1385 if (!IDecl) 1386 continue; 1387 QualType T = IDecl->getType(); 1388 1389 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1390 // static storage duration, it shall not have a variable length array. 1391 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1392 IDecl->getStorageClass() == VarDecl::Static) { 1393 if (T->isVariableArrayType()) { 1394 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1395 IDecl->setInvalidDecl(); 1396 } 1397 } 1398 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1399 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1400 if (IDecl->isBlockVarDecl() && 1401 IDecl->getStorageClass() != VarDecl::Extern) { 1402 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1403 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1404 T.getAsString()); 1405 IDecl->setInvalidDecl(); 1406 } 1407 } 1408 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1409 // object that has file scope without an initializer, and without a 1410 // storage-class specifier or with the storage-class specifier "static", 1411 // constitutes a tentative definition. Note: A tentative definition with 1412 // external linkage is valid (C99 6.2.2p5). 1413 if (isTentativeDefinition(IDecl)) { 1414 if (T->isIncompleteArrayType()) { 1415 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1416 // array to be completed. Don't issue a diagnostic. 1417 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1418 // C99 6.9.2p3: If the declaration of an identifier for an object is 1419 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1420 // declared type shall not be an incomplete type. 1421 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1422 T.getAsString()); 1423 IDecl->setInvalidDecl(); 1424 } 1425 } 1426 if (IDecl->isFileVarDecl()) 1427 CheckForFileScopedRedefinitions(S, IDecl); 1428 } 1429 return NewGroup; 1430} 1431 1432/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1433/// to introduce parameters into function prototype scope. 1434Sema::DeclTy * 1435Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1436 const DeclSpec &DS = D.getDeclSpec(); 1437 1438 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1439 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1440 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1441 Diag(DS.getStorageClassSpecLoc(), 1442 diag::err_invalid_storage_class_in_func_decl); 1443 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1444 } 1445 if (DS.isThreadSpecified()) { 1446 Diag(DS.getThreadSpecLoc(), 1447 diag::err_invalid_storage_class_in_func_decl); 1448 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1449 } 1450 1451 // Check that there are no default arguments inside the type of this 1452 // parameter (C++ only). 1453 if (getLangOptions().CPlusPlus) 1454 CheckExtraCXXDefaultArguments(D); 1455 1456 // In this context, we *do not* check D.getInvalidType(). If the declarator 1457 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1458 // though it will not reflect the user specified type. 1459 QualType parmDeclType = GetTypeForDeclarator(D, S); 1460 1461 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1462 1463 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1464 // Can this happen for params? We already checked that they don't conflict 1465 // among each other. Here they can only shadow globals, which is ok. 1466 IdentifierInfo *II = D.getIdentifier(); 1467 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1468 if (S->isDeclScope(PrevDecl)) { 1469 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1470 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1471 1472 // Recover by removing the name 1473 II = 0; 1474 D.SetIdentifier(0, D.getIdentifierLoc()); 1475 } 1476 } 1477 1478 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1479 // Doing the promotion here has a win and a loss. The win is the type for 1480 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1481 // code generator). The loss is the orginal type isn't preserved. For example: 1482 // 1483 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1484 // int blockvardecl[5]; 1485 // sizeof(parmvardecl); // size == 4 1486 // sizeof(blockvardecl); // size == 20 1487 // } 1488 // 1489 // For expressions, all implicit conversions are captured using the 1490 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1491 // 1492 // FIXME: If a source translation tool needs to see the original type, then 1493 // we need to consider storing both types (in ParmVarDecl)... 1494 // 1495 if (parmDeclType->isArrayType()) { 1496 // int x[restrict 4] -> int *restrict 1497 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1498 } else if (parmDeclType->isFunctionType()) 1499 parmDeclType = Context.getPointerType(parmDeclType); 1500 1501 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1502 D.getIdentifierLoc(), II, 1503 parmDeclType, VarDecl::None, 1504 0, 0); 1505 1506 if (D.getInvalidType()) 1507 New->setInvalidDecl(); 1508 1509 if (II) 1510 PushOnScopeChains(New, S); 1511 1512 ProcessDeclAttributes(New, D); 1513 return New; 1514 1515} 1516 1517Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1518 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1519 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1520 "Not a function declarator!"); 1521 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1522 1523 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1524 // for a K&R function. 1525 if (!FTI.hasPrototype) { 1526 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1527 if (FTI.ArgInfo[i].Param == 0) { 1528 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1529 FTI.ArgInfo[i].Ident->getName()); 1530 // Implicitly declare the argument as type 'int' for lack of a better 1531 // type. 1532 DeclSpec DS; 1533 const char* PrevSpec; // unused 1534 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1535 PrevSpec); 1536 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1537 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1538 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1539 } 1540 } 1541 1542 // Since this is a function definition, act as though we have information 1543 // about the arguments. 1544 if (FTI.NumArgs) 1545 FTI.hasPrototype = true; 1546 } else { 1547 // FIXME: Diagnose arguments without names in C. 1548 } 1549 1550 Scope *GlobalScope = FnBodyScope->getParent(); 1551 1552 // See if this is a redefinition. 1553 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1554 GlobalScope); 1555 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1556 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1557 const FunctionDecl *Definition; 1558 if (FD->getBody(Definition)) { 1559 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1560 D.getIdentifier()->getName()); 1561 Diag(Definition->getLocation(), diag::err_previous_definition); 1562 } 1563 } 1564 } 1565 1566 return ActOnStartOfFunctionDef(FnBodyScope, 1567 ActOnDeclarator(GlobalScope, D, 0)); 1568} 1569 1570Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1571 Decl *decl = static_cast<Decl*>(D); 1572 FunctionDecl *FD = cast<FunctionDecl>(decl); 1573 PushDeclContext(FD); 1574 1575 // Check the validity of our function parameters 1576 CheckParmsForFunctionDef(FD); 1577 1578 // Introduce our parameters into the function scope 1579 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1580 ParmVarDecl *Param = FD->getParamDecl(p); 1581 // If this has an identifier, add it to the scope stack. 1582 if (Param->getIdentifier()) 1583 PushOnScopeChains(Param, FnBodyScope); 1584 } 1585 1586 return FD; 1587} 1588 1589Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1590 Decl *dcl = static_cast<Decl *>(D); 1591 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1592 FD->setBody((Stmt*)Body); 1593 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1594 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1595 MD->setBody((Stmt*)Body); 1596 } else 1597 return 0; 1598 PopDeclContext(); 1599 // Verify and clean out per-function state. 1600 1601 // Check goto/label use. 1602 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1603 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1604 // Verify that we have no forward references left. If so, there was a goto 1605 // or address of a label taken, but no definition of it. Label fwd 1606 // definitions are indicated with a null substmt. 1607 if (I->second->getSubStmt() == 0) { 1608 LabelStmt *L = I->second; 1609 // Emit error. 1610 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1611 1612 // At this point, we have gotos that use the bogus label. Stitch it into 1613 // the function body so that they aren't leaked and that the AST is well 1614 // formed. 1615 if (Body) { 1616 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1617 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1618 } else { 1619 // The whole function wasn't parsed correctly, just delete this. 1620 delete L; 1621 } 1622 } 1623 } 1624 LabelMap.clear(); 1625 1626 return D; 1627} 1628 1629/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1630/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1631ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1632 IdentifierInfo &II, Scope *S) { 1633 // Extension in C99. Legal in C90, but warn about it. 1634 if (getLangOptions().C99) 1635 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1636 else 1637 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1638 1639 // FIXME: handle stuff like: 1640 // void foo() { extern float X(); } 1641 // void bar() { X(); } <-- implicit decl for X in another scope. 1642 1643 // Set a Declarator for the implicit definition: int foo(); 1644 const char *Dummy; 1645 DeclSpec DS; 1646 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1647 Error = Error; // Silence warning. 1648 assert(!Error && "Error setting up implicit decl!"); 1649 Declarator D(DS, Declarator::BlockContext); 1650 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1651 D.SetIdentifier(&II, Loc); 1652 1653 // Insert this function into translation-unit scope. 1654 1655 DeclContext *PrevDC = CurContext; 1656 CurContext = Context.getTranslationUnitDecl(); 1657 1658 FunctionDecl *FD = 1659 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1660 FD->setImplicit(); 1661 1662 CurContext = PrevDC; 1663 1664 return FD; 1665} 1666 1667 1668TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1669 ScopedDecl *LastDeclarator) { 1670 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1671 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1672 1673 // Scope manipulation handled by caller. 1674 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1675 D.getIdentifierLoc(), 1676 D.getIdentifier(), 1677 T, LastDeclarator); 1678 if (D.getInvalidType()) 1679 NewTD->setInvalidDecl(); 1680 return NewTD; 1681} 1682 1683/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1684/// former case, Name will be non-null. In the later case, Name will be null. 1685/// TagType indicates what kind of tag this is. TK indicates whether this is a 1686/// reference/declaration/definition of a tag. 1687Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1688 SourceLocation KWLoc, IdentifierInfo *Name, 1689 SourceLocation NameLoc, AttributeList *Attr) { 1690 // If this is a use of an existing tag, it must have a name. 1691 assert((Name != 0 || TK == TK_Definition) && 1692 "Nameless record must be a definition!"); 1693 1694 TagDecl::TagKind Kind; 1695 switch (TagType) { 1696 default: assert(0 && "Unknown tag type!"); 1697 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1698 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1699 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1700 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1701 } 1702 1703 // If this is a named struct, check to see if there was a previous forward 1704 // declaration or definition. 1705 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1706 if (ScopedDecl *PrevDecl = 1707 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1708 1709 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1710 "unexpected Decl type"); 1711 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1712 // If this is a use of a previous tag, or if the tag is already declared 1713 // in the same scope (so that the definition/declaration completes or 1714 // rementions the tag), reuse the decl. 1715 if (TK == TK_Reference || 1716 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1717 // Make sure that this wasn't declared as an enum and now used as a 1718 // struct or something similar. 1719 if (PrevTagDecl->getTagKind() != Kind) { 1720 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1721 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1722 // Recover by making this an anonymous redefinition. 1723 Name = 0; 1724 PrevDecl = 0; 1725 } else { 1726 // If this is a use or a forward declaration, we're good. 1727 if (TK != TK_Definition) 1728 return PrevDecl; 1729 1730 // Diagnose attempts to redefine a tag. 1731 if (PrevTagDecl->isDefinition()) { 1732 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1733 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1734 // If this is a redefinition, recover by making this struct be 1735 // anonymous, which will make any later references get the previous 1736 // definition. 1737 Name = 0; 1738 } else { 1739 // Okay, this is definition of a previously declared or referenced 1740 // tag. Move the location of the decl to be the definition site. 1741 PrevDecl->setLocation(NameLoc); 1742 return PrevDecl; 1743 } 1744 } 1745 } 1746 // If we get here, this is a definition of a new struct type in a nested 1747 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1748 // type. 1749 } else { 1750 // PrevDecl is a namespace. 1751 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1752 // The tag name clashes with a namespace name, issue an error and recover 1753 // by making this tag be anonymous. 1754 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1755 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1756 Name = 0; 1757 } 1758 } 1759 } 1760 1761 // If there is an identifier, use the location of the identifier as the 1762 // location of the decl, otherwise use the location of the struct/union 1763 // keyword. 1764 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1765 1766 // Otherwise, if this is the first time we've seen this tag, create the decl. 1767 TagDecl *New; 1768 if (Kind == TagDecl::TK_enum) { 1769 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1770 // enum X { A, B, C } D; D should chain to X. 1771 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1772 // If this is an undefined enum, warn. 1773 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1774 } else { 1775 // struct/union/class 1776 1777 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1778 // struct X { int A; } D; D should chain to X. 1779 if (getLangOptions().CPlusPlus) 1780 // FIXME: Look for a way to use RecordDecl for simple structs. 1781 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1782 else 1783 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1784 } 1785 1786 // If this has an identifier, add it to the scope stack. 1787 if (Name) { 1788 // The scope passed in may not be a decl scope. Zip up the scope tree until 1789 // we find one that is. 1790 while ((S->getFlags() & Scope::DeclScope) == 0) 1791 S = S->getParent(); 1792 1793 // Add it to the decl chain. 1794 PushOnScopeChains(New, S); 1795 } 1796 1797 if (Attr) 1798 ProcessDeclAttributeList(New, Attr); 1799 return New; 1800} 1801 1802/// Collect the instance variables declared in an Objective-C object. Used in 1803/// the creation of structures from objects using the @defs directive. 1804static void CollectIvars(ObjCInterfaceDecl *Class, 1805 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1806 if (Class->getSuperClass()) 1807 CollectIvars(Class->getSuperClass(), ivars); 1808 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1809} 1810 1811/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1812/// instance variables of ClassName into Decls. 1813void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1814 IdentifierInfo *ClassName, 1815 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1816 // Check that ClassName is a valid class 1817 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1818 if (!Class) { 1819 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1820 return; 1821 } 1822 // Collect the instance variables 1823 CollectIvars(Class, Decls); 1824} 1825 1826QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1827 // This method tries to turn a variable array into a constant 1828 // array even when the size isn't an ICE. This is necessary 1829 // for compatibility with code that depends on gcc's buggy 1830 // constant expression folding, like struct {char x[(int)(char*)2];} 1831 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1832 APValue Result; 1833 if (VLATy->getSizeExpr() && 1834 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1835 llvm::APSInt &Res = Result.getInt(); 1836 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1837 return Context.getConstantArrayType(VLATy->getElementType(), 1838 Res, ArrayType::Normal, 0); 1839 } 1840 } 1841 return QualType(); 1842} 1843 1844/// ActOnField - Each field of a struct/union/class is passed into this in order 1845/// to create a FieldDecl object for it. 1846Sema::DeclTy *Sema::ActOnField(Scope *S, 1847 SourceLocation DeclStart, 1848 Declarator &D, ExprTy *BitfieldWidth) { 1849 IdentifierInfo *II = D.getIdentifier(); 1850 Expr *BitWidth = (Expr*)BitfieldWidth; 1851 SourceLocation Loc = DeclStart; 1852 if (II) Loc = D.getIdentifierLoc(); 1853 1854 // FIXME: Unnamed fields can be handled in various different ways, for 1855 // example, unnamed unions inject all members into the struct namespace! 1856 1857 1858 if (BitWidth) { 1859 // TODO: Validate. 1860 //printf("WARNING: BITFIELDS IGNORED!\n"); 1861 1862 // 6.7.2.1p3 1863 // 6.7.2.1p4 1864 1865 } else { 1866 // Not a bitfield. 1867 1868 // validate II. 1869 1870 } 1871 1872 QualType T = GetTypeForDeclarator(D, S); 1873 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1874 bool InvalidDecl = false; 1875 1876 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1877 // than a variably modified type. 1878 if (T->isVariablyModifiedType()) { 1879 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1880 if (!FixedTy.isNull()) { 1881 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1882 T = FixedTy; 1883 } else { 1884 // FIXME: This diagnostic needs work 1885 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1886 InvalidDecl = true; 1887 } 1888 } 1889 // FIXME: Chain fielddecls together. 1890 FieldDecl *NewFD; 1891 1892 if (getLangOptions().CPlusPlus) { 1893 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1894 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1895 Loc, II, T, BitWidth); 1896 if (II) 1897 PushOnScopeChains(NewFD, S); 1898 } 1899 else 1900 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1901 1902 ProcessDeclAttributes(NewFD, D); 1903 1904 if (D.getInvalidType() || InvalidDecl) 1905 NewFD->setInvalidDecl(); 1906 return NewFD; 1907} 1908 1909/// TranslateIvarVisibility - Translate visibility from a token ID to an 1910/// AST enum value. 1911static ObjCIvarDecl::AccessControl 1912TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1913 switch (ivarVisibility) { 1914 case tok::objc_private: return ObjCIvarDecl::Private; 1915 case tok::objc_public: return ObjCIvarDecl::Public; 1916 case tok::objc_protected: return ObjCIvarDecl::Protected; 1917 case tok::objc_package: return ObjCIvarDecl::Package; 1918 default: assert(false && "Unknown visitibility kind"); 1919 } 1920} 1921 1922/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1923/// in order to create an IvarDecl object for it. 1924Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1925 SourceLocation DeclStart, 1926 Declarator &D, ExprTy *BitfieldWidth, 1927 tok::ObjCKeywordKind Visibility) { 1928 IdentifierInfo *II = D.getIdentifier(); 1929 Expr *BitWidth = (Expr*)BitfieldWidth; 1930 SourceLocation Loc = DeclStart; 1931 if (II) Loc = D.getIdentifierLoc(); 1932 1933 // FIXME: Unnamed fields can be handled in various different ways, for 1934 // example, unnamed unions inject all members into the struct namespace! 1935 1936 1937 if (BitWidth) { 1938 // TODO: Validate. 1939 //printf("WARNING: BITFIELDS IGNORED!\n"); 1940 1941 // 6.7.2.1p3 1942 // 6.7.2.1p4 1943 1944 } else { 1945 // Not a bitfield. 1946 1947 // validate II. 1948 1949 } 1950 1951 QualType T = GetTypeForDeclarator(D, S); 1952 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1953 bool InvalidDecl = false; 1954 1955 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1956 // than a variably modified type. 1957 if (T->isVariablyModifiedType()) { 1958 // FIXME: This diagnostic needs work 1959 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1960 InvalidDecl = true; 1961 } 1962 1963 // Get the visibility (access control) for this ivar. 1964 ObjCIvarDecl::AccessControl ac = 1965 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1966 : ObjCIvarDecl::None; 1967 1968 // Construct the decl. 1969 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1970 (Expr *)BitfieldWidth); 1971 1972 // Process attributes attached to the ivar. 1973 ProcessDeclAttributes(NewID, D); 1974 1975 if (D.getInvalidType() || InvalidDecl) 1976 NewID->setInvalidDecl(); 1977 1978 return NewID; 1979} 1980 1981void Sema::ActOnFields(Scope* S, 1982 SourceLocation RecLoc, DeclTy *RecDecl, 1983 DeclTy **Fields, unsigned NumFields, 1984 SourceLocation LBrac, SourceLocation RBrac) { 1985 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1986 assert(EnclosingDecl && "missing record or interface decl"); 1987 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1988 1989 if (Record && Record->isDefinition()) { 1990 // Diagnose code like: 1991 // struct S { struct S {} X; }; 1992 // We discover this when we complete the outer S. Reject and ignore the 1993 // outer S. 1994 Diag(Record->getLocation(), diag::err_nested_redefinition, 1995 Record->getKindName()); 1996 Diag(RecLoc, diag::err_previous_definition); 1997 Record->setInvalidDecl(); 1998 return; 1999 } 2000 // Verify that all the fields are okay. 2001 unsigned NumNamedMembers = 0; 2002 llvm::SmallVector<FieldDecl*, 32> RecFields; 2003 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2004 2005 for (unsigned i = 0; i != NumFields; ++i) { 2006 2007 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2008 assert(FD && "missing field decl"); 2009 2010 // Remember all fields. 2011 RecFields.push_back(FD); 2012 2013 // Get the type for the field. 2014 Type *FDTy = FD->getType().getTypePtr(); 2015 2016 // C99 6.7.2.1p2 - A field may not be a function type. 2017 if (FDTy->isFunctionType()) { 2018 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2019 FD->getName()); 2020 FD->setInvalidDecl(); 2021 EnclosingDecl->setInvalidDecl(); 2022 continue; 2023 } 2024 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2025 if (FDTy->isIncompleteType()) { 2026 if (!Record) { // Incomplete ivar type is always an error. 2027 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2028 FD->setInvalidDecl(); 2029 EnclosingDecl->setInvalidDecl(); 2030 continue; 2031 } 2032 if (i != NumFields-1 || // ... that the last member ... 2033 !Record->isStruct() || // ... of a structure ... 2034 !FDTy->isArrayType()) { //... may have incomplete array type. 2035 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2036 FD->setInvalidDecl(); 2037 EnclosingDecl->setInvalidDecl(); 2038 continue; 2039 } 2040 if (NumNamedMembers < 1) { //... must have more than named member ... 2041 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2042 FD->getName()); 2043 FD->setInvalidDecl(); 2044 EnclosingDecl->setInvalidDecl(); 2045 continue; 2046 } 2047 // Okay, we have a legal flexible array member at the end of the struct. 2048 if (Record) 2049 Record->setHasFlexibleArrayMember(true); 2050 } 2051 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2052 /// field of another structure or the element of an array. 2053 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2054 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2055 // If this is a member of a union, then entire union becomes "flexible". 2056 if (Record && Record->isUnion()) { 2057 Record->setHasFlexibleArrayMember(true); 2058 } else { 2059 // If this is a struct/class and this is not the last element, reject 2060 // it. Note that GCC supports variable sized arrays in the middle of 2061 // structures. 2062 if (i != NumFields-1) { 2063 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2064 FD->getName()); 2065 FD->setInvalidDecl(); 2066 EnclosingDecl->setInvalidDecl(); 2067 continue; 2068 } 2069 // We support flexible arrays at the end of structs in other structs 2070 // as an extension. 2071 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2072 FD->getName()); 2073 if (Record) 2074 Record->setHasFlexibleArrayMember(true); 2075 } 2076 } 2077 } 2078 /// A field cannot be an Objective-c object 2079 if (FDTy->isObjCInterfaceType()) { 2080 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2081 FD->getName()); 2082 FD->setInvalidDecl(); 2083 EnclosingDecl->setInvalidDecl(); 2084 continue; 2085 } 2086 // Keep track of the number of named members. 2087 if (IdentifierInfo *II = FD->getIdentifier()) { 2088 // Detect duplicate member names. 2089 if (!FieldIDs.insert(II)) { 2090 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2091 // Find the previous decl. 2092 SourceLocation PrevLoc; 2093 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2094 assert(i != e && "Didn't find previous def!"); 2095 if (RecFields[i]->getIdentifier() == II) { 2096 PrevLoc = RecFields[i]->getLocation(); 2097 break; 2098 } 2099 } 2100 Diag(PrevLoc, diag::err_previous_definition); 2101 FD->setInvalidDecl(); 2102 EnclosingDecl->setInvalidDecl(); 2103 continue; 2104 } 2105 ++NumNamedMembers; 2106 } 2107 } 2108 2109 // Okay, we successfully defined 'Record'. 2110 if (Record) { 2111 Record->defineBody(&RecFields[0], RecFields.size()); 2112 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2113 // Sema::ActOnFinishCXXClassDef. 2114 if (!isa<CXXRecordDecl>(Record)) 2115 Consumer.HandleTagDeclDefinition(Record); 2116 } else { 2117 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2118 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2119 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2120 else if (ObjCImplementationDecl *IMPDecl = 2121 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2122 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2123 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2124 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2125 } 2126 } 2127} 2128 2129Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2130 DeclTy *lastEnumConst, 2131 SourceLocation IdLoc, IdentifierInfo *Id, 2132 SourceLocation EqualLoc, ExprTy *val) { 2133 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2134 EnumConstantDecl *LastEnumConst = 2135 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2136 Expr *Val = static_cast<Expr*>(val); 2137 2138 // The scope passed in may not be a decl scope. Zip up the scope tree until 2139 // we find one that is. 2140 while ((S->getFlags() & Scope::DeclScope) == 0) 2141 S = S->getParent(); 2142 2143 // Verify that there isn't already something declared with this name in this 2144 // scope. 2145 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2146 // When in C++, we may get a TagDecl with the same name; in this case the 2147 // enum constant will 'hide' the tag. 2148 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2149 "Received TagDecl when not in C++!"); 2150 if (!isa<TagDecl>(PrevDecl) && 2151 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2152 if (isa<EnumConstantDecl>(PrevDecl)) 2153 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2154 else 2155 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2156 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2157 delete Val; 2158 return 0; 2159 } 2160 } 2161 2162 llvm::APSInt EnumVal(32); 2163 QualType EltTy; 2164 if (Val) { 2165 // Make sure to promote the operand type to int. 2166 UsualUnaryConversions(Val); 2167 2168 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2169 SourceLocation ExpLoc; 2170 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2171 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2172 Id->getName()); 2173 delete Val; 2174 Val = 0; // Just forget about it. 2175 } else { 2176 EltTy = Val->getType(); 2177 } 2178 } 2179 2180 if (!Val) { 2181 if (LastEnumConst) { 2182 // Assign the last value + 1. 2183 EnumVal = LastEnumConst->getInitVal(); 2184 ++EnumVal; 2185 2186 // Check for overflow on increment. 2187 if (EnumVal < LastEnumConst->getInitVal()) 2188 Diag(IdLoc, diag::warn_enum_value_overflow); 2189 2190 EltTy = LastEnumConst->getType(); 2191 } else { 2192 // First value, set to zero. 2193 EltTy = Context.IntTy; 2194 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2195 } 2196 } 2197 2198 EnumConstantDecl *New = 2199 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2200 Val, EnumVal, 2201 LastEnumConst); 2202 2203 // Register this decl in the current scope stack. 2204 PushOnScopeChains(New, S); 2205 return New; 2206} 2207 2208// FIXME: For consistency with ActOnFields(), we should have the parser 2209// pass in the source location for the left/right braces. 2210void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2211 DeclTy **Elements, unsigned NumElements) { 2212 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2213 2214 if (Enum && Enum->isDefinition()) { 2215 // Diagnose code like: 2216 // enum e0 { 2217 // E0 = sizeof(enum e0 { E1 }) 2218 // }; 2219 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2220 Enum->getName()); 2221 Diag(EnumLoc, diag::err_previous_definition); 2222 Enum->setInvalidDecl(); 2223 return; 2224 } 2225 // TODO: If the result value doesn't fit in an int, it must be a long or long 2226 // long value. ISO C does not support this, but GCC does as an extension, 2227 // emit a warning. 2228 unsigned IntWidth = Context.Target.getIntWidth(); 2229 2230 // Verify that all the values are okay, compute the size of the values, and 2231 // reverse the list. 2232 unsigned NumNegativeBits = 0; 2233 unsigned NumPositiveBits = 0; 2234 2235 // Keep track of whether all elements have type int. 2236 bool AllElementsInt = true; 2237 2238 EnumConstantDecl *EltList = 0; 2239 for (unsigned i = 0; i != NumElements; ++i) { 2240 EnumConstantDecl *ECD = 2241 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2242 if (!ECD) continue; // Already issued a diagnostic. 2243 2244 // If the enum value doesn't fit in an int, emit an extension warning. 2245 const llvm::APSInt &InitVal = ECD->getInitVal(); 2246 assert(InitVal.getBitWidth() >= IntWidth && 2247 "Should have promoted value to int"); 2248 if (InitVal.getBitWidth() > IntWidth) { 2249 llvm::APSInt V(InitVal); 2250 V.trunc(IntWidth); 2251 V.extend(InitVal.getBitWidth()); 2252 if (V != InitVal) 2253 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2254 InitVal.toString()); 2255 } 2256 2257 // Keep track of the size of positive and negative values. 2258 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2259 NumPositiveBits = std::max(NumPositiveBits, 2260 (unsigned)InitVal.getActiveBits()); 2261 else 2262 NumNegativeBits = std::max(NumNegativeBits, 2263 (unsigned)InitVal.getMinSignedBits()); 2264 2265 // Keep track of whether every enum element has type int (very commmon). 2266 if (AllElementsInt) 2267 AllElementsInt = ECD->getType() == Context.IntTy; 2268 2269 ECD->setNextDeclarator(EltList); 2270 EltList = ECD; 2271 } 2272 2273 // Figure out the type that should be used for this enum. 2274 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2275 QualType BestType; 2276 unsigned BestWidth; 2277 2278 if (NumNegativeBits) { 2279 // If there is a negative value, figure out the smallest integer type (of 2280 // int/long/longlong) that fits. 2281 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2282 BestType = Context.IntTy; 2283 BestWidth = IntWidth; 2284 } else { 2285 BestWidth = Context.Target.getLongWidth(); 2286 2287 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2288 BestType = Context.LongTy; 2289 else { 2290 BestWidth = Context.Target.getLongLongWidth(); 2291 2292 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2293 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2294 BestType = Context.LongLongTy; 2295 } 2296 } 2297 } else { 2298 // If there is no negative value, figure out which of uint, ulong, ulonglong 2299 // fits. 2300 if (NumPositiveBits <= IntWidth) { 2301 BestType = Context.UnsignedIntTy; 2302 BestWidth = IntWidth; 2303 } else if (NumPositiveBits <= 2304 (BestWidth = Context.Target.getLongWidth())) { 2305 BestType = Context.UnsignedLongTy; 2306 } else { 2307 BestWidth = Context.Target.getLongLongWidth(); 2308 assert(NumPositiveBits <= BestWidth && 2309 "How could an initializer get larger than ULL?"); 2310 BestType = Context.UnsignedLongLongTy; 2311 } 2312 } 2313 2314 // Loop over all of the enumerator constants, changing their types to match 2315 // the type of the enum if needed. 2316 for (unsigned i = 0; i != NumElements; ++i) { 2317 EnumConstantDecl *ECD = 2318 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2319 if (!ECD) continue; // Already issued a diagnostic. 2320 2321 // Standard C says the enumerators have int type, but we allow, as an 2322 // extension, the enumerators to be larger than int size. If each 2323 // enumerator value fits in an int, type it as an int, otherwise type it the 2324 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2325 // that X has type 'int', not 'unsigned'. 2326 if (ECD->getType() == Context.IntTy) { 2327 // Make sure the init value is signed. 2328 llvm::APSInt IV = ECD->getInitVal(); 2329 IV.setIsSigned(true); 2330 ECD->setInitVal(IV); 2331 continue; // Already int type. 2332 } 2333 2334 // Determine whether the value fits into an int. 2335 llvm::APSInt InitVal = ECD->getInitVal(); 2336 bool FitsInInt; 2337 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2338 FitsInInt = InitVal.getActiveBits() < IntWidth; 2339 else 2340 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2341 2342 // If it fits into an integer type, force it. Otherwise force it to match 2343 // the enum decl type. 2344 QualType NewTy; 2345 unsigned NewWidth; 2346 bool NewSign; 2347 if (FitsInInt) { 2348 NewTy = Context.IntTy; 2349 NewWidth = IntWidth; 2350 NewSign = true; 2351 } else if (ECD->getType() == BestType) { 2352 // Already the right type! 2353 continue; 2354 } else { 2355 NewTy = BestType; 2356 NewWidth = BestWidth; 2357 NewSign = BestType->isSignedIntegerType(); 2358 } 2359 2360 // Adjust the APSInt value. 2361 InitVal.extOrTrunc(NewWidth); 2362 InitVal.setIsSigned(NewSign); 2363 ECD->setInitVal(InitVal); 2364 2365 // Adjust the Expr initializer and type. 2366 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2367 ECD->setType(NewTy); 2368 } 2369 2370 Enum->defineElements(EltList, BestType); 2371 Consumer.HandleTagDeclDefinition(Enum); 2372} 2373 2374Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2375 ExprTy *expr) { 2376 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2377 2378 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2379} 2380 2381Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2382 SourceLocation LBrace, 2383 SourceLocation RBrace, 2384 const char *Lang, 2385 unsigned StrSize, 2386 DeclTy *D) { 2387 LinkageSpecDecl::LanguageIDs Language; 2388 Decl *dcl = static_cast<Decl *>(D); 2389 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2390 Language = LinkageSpecDecl::lang_c; 2391 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2392 Language = LinkageSpecDecl::lang_cxx; 2393 else { 2394 Diag(Loc, diag::err_bad_language); 2395 return 0; 2396 } 2397 2398 // FIXME: Add all the various semantics of linkage specifications 2399 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2400} 2401