SemaDecl.cpp revision 9aa77f137b9b368f5bf46e2ab7bc7bd1d5755a5b
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/Parse/DeclSpec.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/SourceManager.h" 24// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/HeaderSearch.h" 27#include "llvm/ADT/SmallSet.h" 28using namespace clang; 29 30Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { 31 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); 32 33 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 34 isa<ObjCInterfaceDecl>(IIDecl) || 35 isa<TagDecl>(IIDecl))) 36 return IIDecl; 37 return 0; 38} 39 40DeclContext *Sema::getDCParent(DeclContext *DC) { 41 // If CurContext is a ObjC method, getParent() will return NULL. 42 if (isa<ObjCMethodDecl>(DC)) 43 return Context.getTranslationUnitDecl(); 44 45 // A C++ inline method is parsed *after* the topmost class it was declared in 46 // is fully parsed (it's "complete"). 47 // The parsing of a C++ inline method happens at the declaration context of 48 // the topmost (non-nested) class it is declared in. 49 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 50 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 51 DC = MD->getParent(); 52 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 53 DC = RD; 54 55 // Return the declaration context of the topmost class the inline method is 56 // declared in. 57 return DC; 58 } 59 60 return DC->getParent(); 61} 62 63void Sema::PushDeclContext(DeclContext *DC) { 64 assert(getDCParent(DC) == CurContext && 65 "The next DeclContext should be directly contained in the current one."); 66 CurContext = DC; 67} 68 69void Sema::PopDeclContext() { 70 assert(CurContext && "DeclContext imbalance!"); 71 CurContext = getDCParent(CurContext); 72} 73 74/// Add this decl to the scope shadowed decl chains. 75void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 76 S->AddDecl(D); 77 78 // C++ [basic.scope]p4: 79 // -- exactly one declaration shall declare a class name or 80 // enumeration name that is not a typedef name and the other 81 // declarations shall all refer to the same object or 82 // enumerator, or all refer to functions and function templates; 83 // in this case the class name or enumeration name is hidden. 84 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 85 // We are pushing the name of a tag (enum or class). 86 IdentifierResolver::iterator 87 I = IdResolver.begin(TD->getIdentifier(), 88 TD->getDeclContext(), false/*LookInParentCtx*/); 89 if (I != IdResolver.end() && 90 IdResolver.isDeclInScope(*I, TD->getDeclContext(), S)) { 91 // There is already a declaration with the same name in the same 92 // scope. It must be found before we find the new declaration, 93 // so swap the order on the shadowed declaration chain. 94 95 IdResolver.AddShadowedDecl(TD, *I); 96 return; 97 } 98 } 99 IdResolver.AddDecl(D); 100} 101 102void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 103 if (S->decl_empty()) return; 104 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 105 106 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 107 I != E; ++I) { 108 Decl *TmpD = static_cast<Decl*>(*I); 109 assert(TmpD && "This decl didn't get pushed??"); 110 111 if (isa<CXXFieldDecl>(TmpD)) continue; 112 113 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 114 ScopedDecl *D = cast<ScopedDecl>(TmpD); 115 116 IdentifierInfo *II = D->getIdentifier(); 117 if (!II) continue; 118 119 // We only want to remove the decls from the identifier decl chains for local 120 // scopes, when inside a function/method. 121 if (S->getFnParent() != 0) 122 IdResolver.RemoveDecl(D); 123 124 // Chain this decl to the containing DeclContext. 125 D->setNext(CurContext->getDeclChain()); 126 CurContext->setDeclChain(D); 127 } 128} 129 130/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 131/// return 0 if one not found. 132ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 133 // The third "scope" argument is 0 since we aren't enabling lazy built-in 134 // creation from this context. 135 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 136 137 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 138} 139 140/// LookupDecl - Look up the inner-most declaration in the specified 141/// namespace. 142Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 143 Scope *S, bool enableLazyBuiltinCreation) { 144 if (II == 0) return 0; 145 unsigned NS = NSI; 146 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 147 NS |= Decl::IDNS_Tag; 148 149 // Scan up the scope chain looking for a decl that matches this identifier 150 // that is in the appropriate namespace. This search should not take long, as 151 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 152 for (IdentifierResolver::iterator 153 I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) 154 if ((*I)->getIdentifierNamespace() & NS) 155 return *I; 156 157 // If we didn't find a use of this identifier, and if the identifier 158 // corresponds to a compiler builtin, create the decl object for the builtin 159 // now, injecting it into translation unit scope, and return it. 160 if (NS & Decl::IDNS_Ordinary) { 161 if (enableLazyBuiltinCreation) { 162 // If this is a builtin on this (or all) targets, create the decl. 163 if (unsigned BuiltinID = II->getBuiltinID()) 164 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 165 } 166 if (getLangOptions().ObjC1) { 167 // @interface and @compatibility_alias introduce typedef-like names. 168 // Unlike typedef's, they can only be introduced at file-scope (and are 169 // therefore not scoped decls). They can, however, be shadowed by 170 // other names in IDNS_Ordinary. 171 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 172 if (IDI != ObjCInterfaceDecls.end()) 173 return IDI->second; 174 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 175 if (I != ObjCAliasDecls.end()) 176 return I->second->getClassInterface(); 177 } 178 } 179 return 0; 180} 181 182void Sema::InitBuiltinVaListType() { 183 if (!Context.getBuiltinVaListType().isNull()) 184 return; 185 186 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 187 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 188 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 189 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 190} 191 192/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 193/// lazily create a decl for it. 194ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 195 Scope *S) { 196 Builtin::ID BID = (Builtin::ID)bid; 197 198 if (BID == Builtin::BI__builtin_va_start || 199 BID == Builtin::BI__builtin_va_copy || 200 BID == Builtin::BI__builtin_va_end || 201 BID == Builtin::BI__builtin_stdarg_start) 202 InitBuiltinVaListType(); 203 204 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 205 FunctionDecl *New = FunctionDecl::Create(Context, 206 Context.getTranslationUnitDecl(), 207 SourceLocation(), II, R, 208 FunctionDecl::Extern, false, 0); 209 210 // Create Decl objects for each parameter, adding them to the 211 // FunctionDecl. 212 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 213 llvm::SmallVector<ParmVarDecl*, 16> Params; 214 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 215 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 216 FT->getArgType(i), VarDecl::None, 0, 217 0)); 218 New->setParams(&Params[0], Params.size()); 219 } 220 221 222 223 // TUScope is the translation-unit scope to insert this function into. 224 PushOnScopeChains(New, TUScope); 225 return New; 226} 227 228/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 229/// and scope as a previous declaration 'Old'. Figure out how to resolve this 230/// situation, merging decls or emitting diagnostics as appropriate. 231/// 232TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 233 // Verify the old decl was also a typedef. 234 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 235 if (!Old) { 236 Diag(New->getLocation(), diag::err_redefinition_different_kind, 237 New->getName()); 238 Diag(OldD->getLocation(), diag::err_previous_definition); 239 return New; 240 } 241 242 // If the typedef types are not identical, reject them in all languages and 243 // with any extensions enabled. 244 if (Old->getUnderlyingType() != New->getUnderlyingType() && 245 Context.getCanonicalType(Old->getUnderlyingType()) != 246 Context.getCanonicalType(New->getUnderlyingType())) { 247 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 248 New->getUnderlyingType().getAsString(), 249 Old->getUnderlyingType().getAsString()); 250 Diag(Old->getLocation(), diag::err_previous_definition); 251 return Old; 252 } 253 254 // Allow multiple definitions for ObjC built-in typedefs. 255 // FIXME: Verify the underlying types are equivalent! 256 if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) 257 return Old; 258 259 if (getLangOptions().Microsoft) return New; 260 261 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 262 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 263 // *either* declaration is in a system header. The code below implements 264 // this adhoc compatibility rule. FIXME: The following code will not 265 // work properly when compiling ".i" files (containing preprocessed output). 266 SourceManager &SrcMgr = Context.getSourceManager(); 267 HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); 268 const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); 269 if (OldDeclFile) { 270 DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); 271 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 272 if (OldDirType != DirectoryLookup::NormalHeaderDir) 273 return New; 274 } 275 const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); 276 if (NewDeclFile) { 277 DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); 278 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 279 if (NewDirType != DirectoryLookup::NormalHeaderDir) 280 return New; 281 } 282 283 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 284 Diag(Old->getLocation(), diag::err_previous_definition); 285 return New; 286} 287 288/// DeclhasAttr - returns true if decl Declaration already has the target 289/// attribute. 290static bool DeclHasAttr(const Decl *decl, const Attr *target) { 291 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 292 if (attr->getKind() == target->getKind()) 293 return true; 294 295 return false; 296} 297 298/// MergeAttributes - append attributes from the Old decl to the New one. 299static void MergeAttributes(Decl *New, Decl *Old) { 300 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 301 302 while (attr) { 303 tmp = attr; 304 attr = attr->getNext(); 305 306 if (!DeclHasAttr(New, tmp)) { 307 New->addAttr(tmp); 308 } else { 309 tmp->setNext(0); 310 delete(tmp); 311 } 312 } 313 314 Old->invalidateAttrs(); 315} 316 317/// MergeFunctionDecl - We just parsed a function 'New' from 318/// declarator D which has the same name and scope as a previous 319/// declaration 'Old'. Figure out how to resolve this situation, 320/// merging decls or emitting diagnostics as appropriate. 321/// Redeclaration will be set true if thisNew is a redeclaration OldD. 322FunctionDecl * 323Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 324 Redeclaration = false; 325 // Verify the old decl was also a function. 326 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 327 if (!Old) { 328 Diag(New->getLocation(), diag::err_redefinition_different_kind, 329 New->getName()); 330 Diag(OldD->getLocation(), diag::err_previous_definition); 331 return New; 332 } 333 334 QualType OldQType = Context.getCanonicalType(Old->getType()); 335 QualType NewQType = Context.getCanonicalType(New->getType()); 336 337 // C++ [dcl.fct]p3: 338 // All declarations for a function shall agree exactly in both the 339 // return type and the parameter-type-list. 340 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 341 MergeAttributes(New, Old); 342 Redeclaration = true; 343 return MergeCXXFunctionDecl(New, Old); 344 } 345 346 // C: Function types need to be compatible, not identical. This handles 347 // duplicate function decls like "void f(int); void f(enum X);" properly. 348 if (!getLangOptions().CPlusPlus && 349 Context.functionTypesAreCompatible(OldQType, NewQType)) { 350 MergeAttributes(New, Old); 351 Redeclaration = true; 352 return New; 353 } 354 355 // A function that has already been declared has been redeclared or defined 356 // with a different type- show appropriate diagnostic 357 diag::kind PrevDiag; 358 if (Old->isThisDeclarationADefinition()) 359 PrevDiag = diag::err_previous_definition; 360 else if (Old->isImplicit()) 361 PrevDiag = diag::err_previous_implicit_declaration; 362 else 363 PrevDiag = diag::err_previous_declaration; 364 365 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 366 // TODO: This is totally simplistic. It should handle merging functions 367 // together etc, merging extern int X; int X; ... 368 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 369 Diag(Old->getLocation(), PrevDiag); 370 return New; 371} 372 373/// Predicate for C "tentative" external object definitions (C99 6.9.2). 374static bool isTentativeDefinition(VarDecl *VD) { 375 if (VD->isFileVarDecl()) 376 return (!VD->getInit() && 377 (VD->getStorageClass() == VarDecl::None || 378 VD->getStorageClass() == VarDecl::Static)); 379 return false; 380} 381 382/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 383/// when dealing with C "tentative" external object definitions (C99 6.9.2). 384void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 385 bool VDIsTentative = isTentativeDefinition(VD); 386 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 387 388 for (IdentifierResolver::iterator 389 I = IdResolver.begin(VD->getIdentifier(), 390 VD->getDeclContext(), false/*LookInParentCtx*/), 391 E = IdResolver.end(); I != E; ++I) { 392 if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) { 393 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 394 395 // Handle the following case: 396 // int a[10]; 397 // int a[]; - the code below makes sure we set the correct type. 398 // int a[11]; - this is an error, size isn't 10. 399 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 400 OldDecl->getType()->isConstantArrayType()) 401 VD->setType(OldDecl->getType()); 402 403 // Check for "tentative" definitions. We can't accomplish this in 404 // MergeVarDecl since the initializer hasn't been attached. 405 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 406 continue; 407 408 // Handle __private_extern__ just like extern. 409 if (OldDecl->getStorageClass() != VarDecl::Extern && 410 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 411 VD->getStorageClass() != VarDecl::Extern && 412 VD->getStorageClass() != VarDecl::PrivateExtern) { 413 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 414 Diag(OldDecl->getLocation(), diag::err_previous_definition); 415 } 416 } 417 } 418} 419 420/// MergeVarDecl - We just parsed a variable 'New' which has the same name 421/// and scope as a previous declaration 'Old'. Figure out how to resolve this 422/// situation, merging decls or emitting diagnostics as appropriate. 423/// 424/// Tentative definition rules (C99 6.9.2p2) are checked by 425/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 426/// definitions here, since the initializer hasn't been attached. 427/// 428VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 429 // Verify the old decl was also a variable. 430 VarDecl *Old = dyn_cast<VarDecl>(OldD); 431 if (!Old) { 432 Diag(New->getLocation(), diag::err_redefinition_different_kind, 433 New->getName()); 434 Diag(OldD->getLocation(), diag::err_previous_definition); 435 return New; 436 } 437 438 MergeAttributes(New, Old); 439 440 // Verify the types match. 441 QualType OldCType = Context.getCanonicalType(Old->getType()); 442 QualType NewCType = Context.getCanonicalType(New->getType()); 443 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 444 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 445 Diag(Old->getLocation(), diag::err_previous_definition); 446 return New; 447 } 448 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 449 if (New->getStorageClass() == VarDecl::Static && 450 (Old->getStorageClass() == VarDecl::None || 451 Old->getStorageClass() == VarDecl::Extern)) { 452 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 453 Diag(Old->getLocation(), diag::err_previous_definition); 454 return New; 455 } 456 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 457 if (New->getStorageClass() != VarDecl::Static && 458 Old->getStorageClass() == VarDecl::Static) { 459 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 460 Diag(Old->getLocation(), diag::err_previous_definition); 461 return New; 462 } 463 // File scoped variables are analyzed in FinalizeDeclaratorGroup. 464 if (!New->isFileVarDecl()) { 465 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 466 Diag(Old->getLocation(), diag::err_previous_definition); 467 } 468 return New; 469} 470 471/// CheckParmsForFunctionDef - Check that the parameters of the given 472/// function are appropriate for the definition of a function. This 473/// takes care of any checks that cannot be performed on the 474/// declaration itself, e.g., that the types of each of the function 475/// parameters are complete. 476bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 477 bool HasInvalidParm = false; 478 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 479 ParmVarDecl *Param = FD->getParamDecl(p); 480 481 // C99 6.7.5.3p4: the parameters in a parameter type list in a 482 // function declarator that is part of a function definition of 483 // that function shall not have incomplete type. 484 if (Param->getType()->isIncompleteType() && 485 !Param->isInvalidDecl()) { 486 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 487 Param->getType().getAsString()); 488 Param->setInvalidDecl(); 489 HasInvalidParm = true; 490 } 491 } 492 493 return HasInvalidParm; 494} 495 496/// CreateImplicitParameter - Creates an implicit function parameter 497/// in the scope S and with the given type. This routine is used, for 498/// example, to create the implicit "self" parameter in an Objective-C 499/// method. 500ImplicitParamDecl * 501Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 502 SourceLocation IdLoc, QualType Type) { 503 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 504 IdLoc, Id, Type, 0); 505 if (Id) 506 PushOnScopeChains(New, S); 507 508 return New; 509} 510 511/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 512/// no declarator (e.g. "struct foo;") is parsed. 513Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 514 // TODO: emit error on 'int;' or 'const enum foo;'. 515 // TODO: emit error on 'typedef int;' 516 // if (!DS.isMissingDeclaratorOk()) Diag(...); 517 518 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 519} 520 521bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 522 // Get the type before calling CheckSingleAssignmentConstraints(), since 523 // it can promote the expression. 524 QualType InitType = Init->getType(); 525 526 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 527 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 528 InitType, Init, "initializing"); 529} 530 531bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 532 const ArrayType *AT = Context.getAsArrayType(DeclT); 533 534 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 535 // C99 6.7.8p14. We have an array of character type with unknown size 536 // being initialized to a string literal. 537 llvm::APSInt ConstVal(32); 538 ConstVal = strLiteral->getByteLength() + 1; 539 // Return a new array type (C99 6.7.8p22). 540 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 541 ArrayType::Normal, 0); 542 } else { 543 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 544 // C99 6.7.8p14. We have an array of character type with known size. 545 // FIXME: Avoid truncation for 64-bit length strings. 546 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 547 Diag(strLiteral->getSourceRange().getBegin(), 548 diag::warn_initializer_string_for_char_array_too_long, 549 strLiteral->getSourceRange()); 550 } 551 // Set type from "char *" to "constant array of char". 552 strLiteral->setType(DeclT); 553 // For now, we always return false (meaning success). 554 return false; 555} 556 557StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 558 const ArrayType *AT = Context.getAsArrayType(DeclType); 559 if (AT && AT->getElementType()->isCharType()) { 560 return dyn_cast<StringLiteral>(Init); 561 } 562 return 0; 563} 564 565bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 566 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 567 // of unknown size ("[]") or an object type that is not a variable array type. 568 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 569 return Diag(VAT->getSizeExpr()->getLocStart(), 570 diag::err_variable_object_no_init, 571 VAT->getSizeExpr()->getSourceRange()); 572 573 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 574 if (!InitList) { 575 // FIXME: Handle wide strings 576 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 577 return CheckStringLiteralInit(strLiteral, DeclType); 578 579 if (DeclType->isArrayType()) 580 return Diag(Init->getLocStart(), 581 diag::err_array_init_list_required, 582 Init->getSourceRange()); 583 584 return CheckSingleInitializer(Init, DeclType); 585 } 586 587 InitListChecker CheckInitList(this, InitList, DeclType); 588 return CheckInitList.HadError(); 589} 590 591Sema::DeclTy * 592Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 593 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 594 IdentifierInfo *II = D.getIdentifier(); 595 596 // All of these full declarators require an identifier. If it doesn't have 597 // one, the ParsedFreeStandingDeclSpec action should be used. 598 if (II == 0) { 599 Diag(D.getDeclSpec().getSourceRange().getBegin(), 600 diag::err_declarator_need_ident, 601 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 602 return 0; 603 } 604 605 // The scope passed in may not be a decl scope. Zip up the scope tree until 606 // we find one that is. 607 while ((S->getFlags() & Scope::DeclScope) == 0) 608 S = S->getParent(); 609 610 // See if this is a redefinition of a variable in the same scope. 611 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 612 ScopedDecl *New; 613 bool InvalidDecl = false; 614 615 // In C++, the previous declaration we find might be a tag type 616 // (class or enum). In this case, the new declaration will hide the 617 // tag type. 618 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 619 PrevDecl = 0; 620 621 QualType R = GetTypeForDeclarator(D, S); 622 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 623 624 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 625 // Check that there are no default arguments (C++ only). 626 if (getLangOptions().CPlusPlus) 627 CheckExtraCXXDefaultArguments(D); 628 629 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 630 if (!NewTD) return 0; 631 632 // Handle attributes prior to checking for duplicates in MergeVarDecl 633 ProcessDeclAttributes(NewTD, D); 634 // Merge the decl with the existing one if appropriate. If the decl is 635 // in an outer scope, it isn't the same thing. 636 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 637 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 638 if (NewTD == 0) return 0; 639 } 640 New = NewTD; 641 if (S->getFnParent() == 0) { 642 // C99 6.7.7p2: If a typedef name specifies a variably modified type 643 // then it shall have block scope. 644 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 645 // FIXME: Diagnostic needs to be fixed. 646 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 647 InvalidDecl = true; 648 } 649 } 650 } else if (R.getTypePtr()->isFunctionType()) { 651 FunctionDecl::StorageClass SC = FunctionDecl::None; 652 switch (D.getDeclSpec().getStorageClassSpec()) { 653 default: assert(0 && "Unknown storage class!"); 654 case DeclSpec::SCS_auto: 655 case DeclSpec::SCS_register: 656 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 657 R.getAsString()); 658 InvalidDecl = true; 659 break; 660 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 661 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 662 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 663 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 664 } 665 666 bool isInline = D.getDeclSpec().isInlineSpecified(); 667 FunctionDecl *NewFD; 668 if (D.getContext() == Declarator::MemberContext) { 669 // This is a C++ method declaration. 670 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 671 D.getIdentifierLoc(), II, R, 672 (SC == FunctionDecl::Static), isInline, 673 LastDeclarator); 674 } else { 675 NewFD = FunctionDecl::Create(Context, CurContext, 676 D.getIdentifierLoc(), 677 II, R, SC, isInline, 678 LastDeclarator); 679 } 680 // Handle attributes. 681 ProcessDeclAttributes(NewFD, D); 682 683 // Handle GNU asm-label extension (encoded as an attribute). 684 if (Expr *E = (Expr*) D.getAsmLabel()) { 685 // The parser guarantees this is a string. 686 StringLiteral *SE = cast<StringLiteral>(E); 687 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 688 SE->getByteLength()))); 689 } 690 691 // Copy the parameter declarations from the declarator D to 692 // the function declaration NewFD, if they are available. 693 if (D.getNumTypeObjects() > 0 && 694 D.getTypeObject(0).Fun.hasPrototype) { 695 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 696 697 // Create Decl objects for each parameter, adding them to the 698 // FunctionDecl. 699 llvm::SmallVector<ParmVarDecl*, 16> Params; 700 701 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 702 // function that takes no arguments, not a function that takes a 703 // single void argument. 704 // We let through "const void" here because Sema::GetTypeForDeclarator 705 // already checks for that case. 706 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 707 FTI.ArgInfo[0].Param && 708 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 709 // empty arg list, don't push any params. 710 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 711 712 // In C++, the empty parameter-type-list must be spelled "void"; a 713 // typedef of void is not permitted. 714 if (getLangOptions().CPlusPlus && 715 Param->getType().getUnqualifiedType() != Context.VoidTy) { 716 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 717 } 718 719 } else { 720 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 721 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 722 } 723 724 NewFD->setParams(&Params[0], Params.size()); 725 } 726 727 // Merge the decl with the existing one if appropriate. Since C functions 728 // are in a flat namespace, make sure we consider decls in outer scopes. 729 if (PrevDecl && 730 (!getLangOptions().CPlusPlus || 731 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 732 bool Redeclaration = false; 733 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 734 if (NewFD == 0) return 0; 735 if (Redeclaration) { 736 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 737 } 738 } 739 New = NewFD; 740 741 // In C++, check default arguments now that we have merged decls. 742 if (getLangOptions().CPlusPlus) 743 CheckCXXDefaultArguments(NewFD); 744 } else { 745 // Check that there are no default arguments (C++ only). 746 if (getLangOptions().CPlusPlus) 747 CheckExtraCXXDefaultArguments(D); 748 749 if (R.getTypePtr()->isObjCInterfaceType()) { 750 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 751 D.getIdentifier()->getName()); 752 InvalidDecl = true; 753 } 754 755 VarDecl *NewVD; 756 VarDecl::StorageClass SC; 757 switch (D.getDeclSpec().getStorageClassSpec()) { 758 default: assert(0 && "Unknown storage class!"); 759 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 760 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 761 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 762 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 763 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 764 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 765 } 766 if (D.getContext() == Declarator::MemberContext) { 767 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 768 // This is a static data member for a C++ class. 769 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 770 D.getIdentifierLoc(), II, 771 R, LastDeclarator); 772 } else { 773 if (S->getFnParent() == 0) { 774 // C99 6.9p2: The storage-class specifiers auto and register shall not 775 // appear in the declaration specifiers in an external declaration. 776 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 777 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 778 R.getAsString()); 779 InvalidDecl = true; 780 } 781 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 782 II, R, SC, LastDeclarator); 783 } else { 784 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 785 II, R, SC, LastDeclarator); 786 } 787 } 788 // Handle attributes prior to checking for duplicates in MergeVarDecl 789 ProcessDeclAttributes(NewVD, D); 790 791 // Handle GNU asm-label extension (encoded as an attribute). 792 if (Expr *E = (Expr*) D.getAsmLabel()) { 793 // The parser guarantees this is a string. 794 StringLiteral *SE = cast<StringLiteral>(E); 795 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 796 SE->getByteLength()))); 797 } 798 799 // Emit an error if an address space was applied to decl with local storage. 800 // This includes arrays of objects with address space qualifiers, but not 801 // automatic variables that point to other address spaces. 802 // ISO/IEC TR 18037 S5.1.2 803 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 804 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 805 InvalidDecl = true; 806 } 807 // Merge the decl with the existing one if appropriate. If the decl is 808 // in an outer scope, it isn't the same thing. 809 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 810 NewVD = MergeVarDecl(NewVD, PrevDecl); 811 if (NewVD == 0) return 0; 812 } 813 New = NewVD; 814 } 815 816 // If this has an identifier, add it to the scope stack. 817 if (II) 818 PushOnScopeChains(New, S); 819 // If any semantic error occurred, mark the decl as invalid. 820 if (D.getInvalidType() || InvalidDecl) 821 New->setInvalidDecl(); 822 823 return New; 824} 825 826bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 827 switch (Init->getStmtClass()) { 828 default: 829 Diag(Init->getExprLoc(), 830 diag::err_init_element_not_constant, Init->getSourceRange()); 831 return true; 832 case Expr::ParenExprClass: { 833 const ParenExpr* PE = cast<ParenExpr>(Init); 834 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 835 } 836 case Expr::CompoundLiteralExprClass: 837 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 838 case Expr::DeclRefExprClass: { 839 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 840 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 841 if (VD->hasGlobalStorage()) 842 return false; 843 Diag(Init->getExprLoc(), 844 diag::err_init_element_not_constant, Init->getSourceRange()); 845 return true; 846 } 847 if (isa<FunctionDecl>(D)) 848 return false; 849 Diag(Init->getExprLoc(), 850 diag::err_init_element_not_constant, Init->getSourceRange()); 851 return true; 852 } 853 case Expr::MemberExprClass: { 854 const MemberExpr *M = cast<MemberExpr>(Init); 855 if (M->isArrow()) 856 return CheckAddressConstantExpression(M->getBase()); 857 return CheckAddressConstantExpressionLValue(M->getBase()); 858 } 859 case Expr::ArraySubscriptExprClass: { 860 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 861 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 862 return CheckAddressConstantExpression(ASE->getBase()) || 863 CheckArithmeticConstantExpression(ASE->getIdx()); 864 } 865 case Expr::StringLiteralClass: 866 case Expr::PredefinedExprClass: 867 return false; 868 case Expr::UnaryOperatorClass: { 869 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 870 871 // C99 6.6p9 872 if (Exp->getOpcode() == UnaryOperator::Deref) 873 return CheckAddressConstantExpression(Exp->getSubExpr()); 874 875 Diag(Init->getExprLoc(), 876 diag::err_init_element_not_constant, Init->getSourceRange()); 877 return true; 878 } 879 } 880} 881 882bool Sema::CheckAddressConstantExpression(const Expr* Init) { 883 switch (Init->getStmtClass()) { 884 default: 885 Diag(Init->getExprLoc(), 886 diag::err_init_element_not_constant, Init->getSourceRange()); 887 return true; 888 case Expr::ParenExprClass: { 889 const ParenExpr* PE = cast<ParenExpr>(Init); 890 return CheckAddressConstantExpression(PE->getSubExpr()); 891 } 892 case Expr::StringLiteralClass: 893 case Expr::ObjCStringLiteralClass: 894 return false; 895 case Expr::CallExprClass: { 896 const CallExpr *CE = cast<CallExpr>(Init); 897 if (CE->isBuiltinConstantExpr()) 898 return false; 899 Diag(Init->getExprLoc(), 900 diag::err_init_element_not_constant, Init->getSourceRange()); 901 return true; 902 } 903 case Expr::UnaryOperatorClass: { 904 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 905 906 // C99 6.6p9 907 if (Exp->getOpcode() == UnaryOperator::AddrOf) 908 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 909 910 if (Exp->getOpcode() == UnaryOperator::Extension) 911 return CheckAddressConstantExpression(Exp->getSubExpr()); 912 913 Diag(Init->getExprLoc(), 914 diag::err_init_element_not_constant, Init->getSourceRange()); 915 return true; 916 } 917 case Expr::BinaryOperatorClass: { 918 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 919 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 920 921 Expr *PExp = Exp->getLHS(); 922 Expr *IExp = Exp->getRHS(); 923 if (IExp->getType()->isPointerType()) 924 std::swap(PExp, IExp); 925 926 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 927 return CheckAddressConstantExpression(PExp) || 928 CheckArithmeticConstantExpression(IExp); 929 } 930 case Expr::ImplicitCastExprClass: { 931 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 932 933 // Check for implicit promotion 934 if (SubExpr->getType()->isFunctionType() || 935 SubExpr->getType()->isArrayType()) 936 return CheckAddressConstantExpressionLValue(SubExpr); 937 938 // Check for pointer->pointer cast 939 if (SubExpr->getType()->isPointerType()) 940 return CheckAddressConstantExpression(SubExpr); 941 942 if (SubExpr->getType()->isArithmeticType()) 943 return CheckArithmeticConstantExpression(SubExpr); 944 945 Diag(Init->getExprLoc(), 946 diag::err_init_element_not_constant, Init->getSourceRange()); 947 return true; 948 } 949 case Expr::CastExprClass: { 950 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 951 952 // Check for pointer->pointer cast 953 if (SubExpr->getType()->isPointerType()) 954 return CheckAddressConstantExpression(SubExpr); 955 956 // FIXME: Should we pedwarn for (int*)(0+0)? 957 if (SubExpr->getType()->isArithmeticType()) 958 return CheckArithmeticConstantExpression(SubExpr); 959 960 Diag(Init->getExprLoc(), 961 diag::err_init_element_not_constant, Init->getSourceRange()); 962 return true; 963 } 964 case Expr::ConditionalOperatorClass: { 965 // FIXME: Should we pedwarn here? 966 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 967 if (!Exp->getCond()->getType()->isArithmeticType()) { 968 Diag(Init->getExprLoc(), 969 diag::err_init_element_not_constant, Init->getSourceRange()); 970 return true; 971 } 972 if (CheckArithmeticConstantExpression(Exp->getCond())) 973 return true; 974 if (Exp->getLHS() && 975 CheckAddressConstantExpression(Exp->getLHS())) 976 return true; 977 return CheckAddressConstantExpression(Exp->getRHS()); 978 } 979 case Expr::AddrLabelExprClass: 980 return false; 981 } 982} 983 984static const Expr* FindExpressionBaseAddress(const Expr* E); 985 986static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 987 switch (E->getStmtClass()) { 988 default: 989 return E; 990 case Expr::ParenExprClass: { 991 const ParenExpr* PE = cast<ParenExpr>(E); 992 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 993 } 994 case Expr::MemberExprClass: { 995 const MemberExpr *M = cast<MemberExpr>(E); 996 if (M->isArrow()) 997 return FindExpressionBaseAddress(M->getBase()); 998 return FindExpressionBaseAddressLValue(M->getBase()); 999 } 1000 case Expr::ArraySubscriptExprClass: { 1001 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1002 return FindExpressionBaseAddress(ASE->getBase()); 1003 } 1004 case Expr::UnaryOperatorClass: { 1005 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1006 1007 if (Exp->getOpcode() == UnaryOperator::Deref) 1008 return FindExpressionBaseAddress(Exp->getSubExpr()); 1009 1010 return E; 1011 } 1012 } 1013} 1014 1015static const Expr* FindExpressionBaseAddress(const Expr* E) { 1016 switch (E->getStmtClass()) { 1017 default: 1018 return E; 1019 case Expr::ParenExprClass: { 1020 const ParenExpr* PE = cast<ParenExpr>(E); 1021 return FindExpressionBaseAddress(PE->getSubExpr()); 1022 } 1023 case Expr::UnaryOperatorClass: { 1024 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1025 1026 // C99 6.6p9 1027 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1028 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1029 1030 if (Exp->getOpcode() == UnaryOperator::Extension) 1031 return FindExpressionBaseAddress(Exp->getSubExpr()); 1032 1033 return E; 1034 } 1035 case Expr::BinaryOperatorClass: { 1036 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1037 1038 Expr *PExp = Exp->getLHS(); 1039 Expr *IExp = Exp->getRHS(); 1040 if (IExp->getType()->isPointerType()) 1041 std::swap(PExp, IExp); 1042 1043 return FindExpressionBaseAddress(PExp); 1044 } 1045 case Expr::ImplicitCastExprClass: { 1046 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1047 1048 // Check for implicit promotion 1049 if (SubExpr->getType()->isFunctionType() || 1050 SubExpr->getType()->isArrayType()) 1051 return FindExpressionBaseAddressLValue(SubExpr); 1052 1053 // Check for pointer->pointer cast 1054 if (SubExpr->getType()->isPointerType()) 1055 return FindExpressionBaseAddress(SubExpr); 1056 1057 // We assume that we have an arithmetic expression here; 1058 // if we don't, we'll figure it out later 1059 return 0; 1060 } 1061 case Expr::CastExprClass: { 1062 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1063 1064 // Check for pointer->pointer cast 1065 if (SubExpr->getType()->isPointerType()) 1066 return FindExpressionBaseAddress(SubExpr); 1067 1068 // We assume that we have an arithmetic expression here; 1069 // if we don't, we'll figure it out later 1070 return 0; 1071 } 1072 } 1073} 1074 1075bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1076 switch (Init->getStmtClass()) { 1077 default: 1078 Diag(Init->getExprLoc(), 1079 diag::err_init_element_not_constant, Init->getSourceRange()); 1080 return true; 1081 case Expr::ParenExprClass: { 1082 const ParenExpr* PE = cast<ParenExpr>(Init); 1083 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1084 } 1085 case Expr::FloatingLiteralClass: 1086 case Expr::IntegerLiteralClass: 1087 case Expr::CharacterLiteralClass: 1088 case Expr::ImaginaryLiteralClass: 1089 case Expr::TypesCompatibleExprClass: 1090 case Expr::CXXBoolLiteralExprClass: 1091 return false; 1092 case Expr::CallExprClass: { 1093 const CallExpr *CE = cast<CallExpr>(Init); 1094 if (CE->isBuiltinConstantExpr()) 1095 return false; 1096 Diag(Init->getExprLoc(), 1097 diag::err_init_element_not_constant, Init->getSourceRange()); 1098 return true; 1099 } 1100 case Expr::DeclRefExprClass: { 1101 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1102 if (isa<EnumConstantDecl>(D)) 1103 return false; 1104 Diag(Init->getExprLoc(), 1105 diag::err_init_element_not_constant, Init->getSourceRange()); 1106 return true; 1107 } 1108 case Expr::CompoundLiteralExprClass: 1109 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1110 // but vectors are allowed to be magic. 1111 if (Init->getType()->isVectorType()) 1112 return false; 1113 Diag(Init->getExprLoc(), 1114 diag::err_init_element_not_constant, Init->getSourceRange()); 1115 return true; 1116 case Expr::UnaryOperatorClass: { 1117 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1118 1119 switch (Exp->getOpcode()) { 1120 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1121 // See C99 6.6p3. 1122 default: 1123 Diag(Init->getExprLoc(), 1124 diag::err_init_element_not_constant, Init->getSourceRange()); 1125 return true; 1126 case UnaryOperator::SizeOf: 1127 case UnaryOperator::AlignOf: 1128 case UnaryOperator::OffsetOf: 1129 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1130 // See C99 6.5.3.4p2 and 6.6p3. 1131 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1132 return false; 1133 Diag(Init->getExprLoc(), 1134 diag::err_init_element_not_constant, Init->getSourceRange()); 1135 return true; 1136 case UnaryOperator::Extension: 1137 case UnaryOperator::LNot: 1138 case UnaryOperator::Plus: 1139 case UnaryOperator::Minus: 1140 case UnaryOperator::Not: 1141 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1142 } 1143 } 1144 case Expr::SizeOfAlignOfTypeExprClass: { 1145 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1146 // Special check for void types, which are allowed as an extension 1147 if (Exp->getArgumentType()->isVoidType()) 1148 return false; 1149 // alignof always evaluates to a constant. 1150 // FIXME: is sizeof(int[3.0]) a constant expression? 1151 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1152 Diag(Init->getExprLoc(), 1153 diag::err_init_element_not_constant, Init->getSourceRange()); 1154 return true; 1155 } 1156 return false; 1157 } 1158 case Expr::BinaryOperatorClass: { 1159 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1160 1161 if (Exp->getLHS()->getType()->isArithmeticType() && 1162 Exp->getRHS()->getType()->isArithmeticType()) { 1163 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1164 CheckArithmeticConstantExpression(Exp->getRHS()); 1165 } 1166 1167 if (Exp->getLHS()->getType()->isPointerType() && 1168 Exp->getRHS()->getType()->isPointerType()) { 1169 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1170 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1171 1172 // Only allow a null (constant integer) base; we could 1173 // allow some additional cases if necessary, but this 1174 // is sufficient to cover offsetof-like constructs. 1175 if (!LHSBase && !RHSBase) { 1176 return CheckAddressConstantExpression(Exp->getLHS()) || 1177 CheckAddressConstantExpression(Exp->getRHS()); 1178 } 1179 } 1180 1181 Diag(Init->getExprLoc(), 1182 diag::err_init_element_not_constant, Init->getSourceRange()); 1183 return true; 1184 } 1185 case Expr::ImplicitCastExprClass: 1186 case Expr::CastExprClass: { 1187 const Expr *SubExpr; 1188 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1189 SubExpr = C->getSubExpr(); 1190 } else { 1191 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1192 } 1193 1194 if (SubExpr->getType()->isArithmeticType()) 1195 return CheckArithmeticConstantExpression(SubExpr); 1196 1197 Diag(Init->getExprLoc(), 1198 diag::err_init_element_not_constant, Init->getSourceRange()); 1199 return true; 1200 } 1201 case Expr::ConditionalOperatorClass: { 1202 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1203 if (CheckArithmeticConstantExpression(Exp->getCond())) 1204 return true; 1205 if (Exp->getLHS() && 1206 CheckArithmeticConstantExpression(Exp->getLHS())) 1207 return true; 1208 return CheckArithmeticConstantExpression(Exp->getRHS()); 1209 } 1210 } 1211} 1212 1213bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1214 Init = Init->IgnoreParens(); 1215 1216 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1217 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1218 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1219 1220 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1221 return CheckForConstantInitializer(e->getInitializer(), DclT); 1222 1223 if (Init->getType()->isReferenceType()) { 1224 // FIXME: Work out how the heck reference types work 1225 return false; 1226#if 0 1227 // A reference is constant if the address of the expression 1228 // is constant 1229 // We look through initlists here to simplify 1230 // CheckAddressConstantExpressionLValue. 1231 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1232 assert(Exp->getNumInits() > 0 && 1233 "Refernce initializer cannot be empty"); 1234 Init = Exp->getInit(0); 1235 } 1236 return CheckAddressConstantExpressionLValue(Init); 1237#endif 1238 } 1239 1240 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1241 unsigned numInits = Exp->getNumInits(); 1242 for (unsigned i = 0; i < numInits; i++) { 1243 // FIXME: Need to get the type of the declaration for C++, 1244 // because it could be a reference? 1245 if (CheckForConstantInitializer(Exp->getInit(i), 1246 Exp->getInit(i)->getType())) 1247 return true; 1248 } 1249 return false; 1250 } 1251 1252 if (Init->isNullPointerConstant(Context)) 1253 return false; 1254 if (Init->getType()->isArithmeticType()) { 1255 QualType InitTy = Context.getCanonicalType(Init->getType()) 1256 .getUnqualifiedType(); 1257 if (InitTy == Context.BoolTy) { 1258 // Special handling for pointers implicitly cast to bool; 1259 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1260 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1261 Expr* SubE = ICE->getSubExpr(); 1262 if (SubE->getType()->isPointerType() || 1263 SubE->getType()->isArrayType() || 1264 SubE->getType()->isFunctionType()) { 1265 return CheckAddressConstantExpression(Init); 1266 } 1267 } 1268 } else if (InitTy->isIntegralType()) { 1269 Expr* SubE = 0; 1270 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1271 SubE = ICE->getSubExpr(); 1272 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1273 SubE = CE->getSubExpr(); 1274 // Special check for pointer cast to int; we allow as an extension 1275 // an address constant cast to an integer if the integer 1276 // is of an appropriate width (this sort of code is apparently used 1277 // in some places). 1278 // FIXME: Add pedwarn? 1279 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1280 if (SubE && (SubE->getType()->isPointerType() || 1281 SubE->getType()->isArrayType() || 1282 SubE->getType()->isFunctionType())) { 1283 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1284 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1285 if (IntWidth >= PointerWidth) 1286 return CheckAddressConstantExpression(Init); 1287 } 1288 } 1289 1290 return CheckArithmeticConstantExpression(Init); 1291 } 1292 1293 if (Init->getType()->isPointerType()) 1294 return CheckAddressConstantExpression(Init); 1295 1296 // An array type at the top level that isn't an init-list must 1297 // be a string literal 1298 if (Init->getType()->isArrayType()) 1299 return false; 1300 1301 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1302 Init->getSourceRange()); 1303 return true; 1304} 1305 1306void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1307 Decl *RealDecl = static_cast<Decl *>(dcl); 1308 Expr *Init = static_cast<Expr *>(init); 1309 assert(Init && "missing initializer"); 1310 1311 // If there is no declaration, there was an error parsing it. Just ignore 1312 // the initializer. 1313 if (RealDecl == 0) { 1314 delete Init; 1315 return; 1316 } 1317 1318 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1319 if (!VDecl) { 1320 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1321 diag::err_illegal_initializer); 1322 RealDecl->setInvalidDecl(); 1323 return; 1324 } 1325 // Get the decls type and save a reference for later, since 1326 // CheckInitializerTypes may change it. 1327 QualType DclT = VDecl->getType(), SavT = DclT; 1328 if (VDecl->isBlockVarDecl()) { 1329 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1330 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1331 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1332 VDecl->setInvalidDecl(); 1333 } else if (!VDecl->isInvalidDecl()) { 1334 if (CheckInitializerTypes(Init, DclT)) 1335 VDecl->setInvalidDecl(); 1336 if (SC == VarDecl::Static) // C99 6.7.8p4. 1337 CheckForConstantInitializer(Init, DclT); 1338 } 1339 } else if (VDecl->isFileVarDecl()) { 1340 if (VDecl->getStorageClass() == VarDecl::Extern) 1341 Diag(VDecl->getLocation(), diag::warn_extern_init); 1342 if (!VDecl->isInvalidDecl()) 1343 if (CheckInitializerTypes(Init, DclT)) 1344 VDecl->setInvalidDecl(); 1345 1346 // C99 6.7.8p4. All file scoped initializers need to be constant. 1347 CheckForConstantInitializer(Init, DclT); 1348 } 1349 // If the type changed, it means we had an incomplete type that was 1350 // completed by the initializer. For example: 1351 // int ary[] = { 1, 3, 5 }; 1352 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1353 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1354 VDecl->setType(DclT); 1355 Init->setType(DclT); 1356 } 1357 1358 // Attach the initializer to the decl. 1359 VDecl->setInit(Init); 1360 return; 1361} 1362 1363/// The declarators are chained together backwards, reverse the list. 1364Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1365 // Often we have single declarators, handle them quickly. 1366 Decl *GroupDecl = static_cast<Decl*>(group); 1367 if (GroupDecl == 0) 1368 return 0; 1369 1370 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1371 ScopedDecl *NewGroup = 0; 1372 if (Group->getNextDeclarator() == 0) 1373 NewGroup = Group; 1374 else { // reverse the list. 1375 while (Group) { 1376 ScopedDecl *Next = Group->getNextDeclarator(); 1377 Group->setNextDeclarator(NewGroup); 1378 NewGroup = Group; 1379 Group = Next; 1380 } 1381 } 1382 // Perform semantic analysis that depends on having fully processed both 1383 // the declarator and initializer. 1384 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1385 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1386 if (!IDecl) 1387 continue; 1388 QualType T = IDecl->getType(); 1389 1390 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1391 // static storage duration, it shall not have a variable length array. 1392 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1393 IDecl->getStorageClass() == VarDecl::Static) { 1394 if (T->isVariableArrayType()) { 1395 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1396 IDecl->setInvalidDecl(); 1397 } 1398 } 1399 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1400 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1401 if (IDecl->isBlockVarDecl() && 1402 IDecl->getStorageClass() != VarDecl::Extern) { 1403 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1404 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1405 T.getAsString()); 1406 IDecl->setInvalidDecl(); 1407 } 1408 } 1409 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1410 // object that has file scope without an initializer, and without a 1411 // storage-class specifier or with the storage-class specifier "static", 1412 // constitutes a tentative definition. Note: A tentative definition with 1413 // external linkage is valid (C99 6.2.2p5). 1414 if (isTentativeDefinition(IDecl)) { 1415 if (T->isIncompleteArrayType()) { 1416 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1417 // array to be completed. Don't issue a diagnostic. 1418 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1419 // C99 6.9.2p3: If the declaration of an identifier for an object is 1420 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1421 // declared type shall not be an incomplete type. 1422 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1423 T.getAsString()); 1424 IDecl->setInvalidDecl(); 1425 } 1426 } 1427 if (IDecl->isFileVarDecl()) 1428 CheckForFileScopedRedefinitions(S, IDecl); 1429 } 1430 return NewGroup; 1431} 1432 1433/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1434/// to introduce parameters into function prototype scope. 1435Sema::DeclTy * 1436Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1437 const DeclSpec &DS = D.getDeclSpec(); 1438 1439 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1440 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1441 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1442 Diag(DS.getStorageClassSpecLoc(), 1443 diag::err_invalid_storage_class_in_func_decl); 1444 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1445 } 1446 if (DS.isThreadSpecified()) { 1447 Diag(DS.getThreadSpecLoc(), 1448 diag::err_invalid_storage_class_in_func_decl); 1449 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1450 } 1451 1452 // Check that there are no default arguments inside the type of this 1453 // parameter (C++ only). 1454 if (getLangOptions().CPlusPlus) 1455 CheckExtraCXXDefaultArguments(D); 1456 1457 // In this context, we *do not* check D.getInvalidType(). If the declarator 1458 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1459 // though it will not reflect the user specified type. 1460 QualType parmDeclType = GetTypeForDeclarator(D, S); 1461 1462 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1463 1464 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1465 // Can this happen for params? We already checked that they don't conflict 1466 // among each other. Here they can only shadow globals, which is ok. 1467 IdentifierInfo *II = D.getIdentifier(); 1468 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1469 if (S->isDeclScope(PrevDecl)) { 1470 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1471 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1472 1473 // Recover by removing the name 1474 II = 0; 1475 D.SetIdentifier(0, D.getIdentifierLoc()); 1476 } 1477 } 1478 1479 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1480 // Doing the promotion here has a win and a loss. The win is the type for 1481 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1482 // code generator). The loss is the orginal type isn't preserved. For example: 1483 // 1484 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1485 // int blockvardecl[5]; 1486 // sizeof(parmvardecl); // size == 4 1487 // sizeof(blockvardecl); // size == 20 1488 // } 1489 // 1490 // For expressions, all implicit conversions are captured using the 1491 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1492 // 1493 // FIXME: If a source translation tool needs to see the original type, then 1494 // we need to consider storing both types (in ParmVarDecl)... 1495 // 1496 if (parmDeclType->isArrayType()) { 1497 // int x[restrict 4] -> int *restrict 1498 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1499 } else if (parmDeclType->isFunctionType()) 1500 parmDeclType = Context.getPointerType(parmDeclType); 1501 1502 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1503 D.getIdentifierLoc(), II, 1504 parmDeclType, VarDecl::None, 1505 0, 0); 1506 1507 if (D.getInvalidType()) 1508 New->setInvalidDecl(); 1509 1510 if (II) 1511 PushOnScopeChains(New, S); 1512 1513 ProcessDeclAttributes(New, D); 1514 return New; 1515 1516} 1517 1518Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1519 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1520 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1521 "Not a function declarator!"); 1522 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1523 1524 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1525 // for a K&R function. 1526 if (!FTI.hasPrototype) { 1527 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1528 if (FTI.ArgInfo[i].Param == 0) { 1529 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1530 FTI.ArgInfo[i].Ident->getName()); 1531 // Implicitly declare the argument as type 'int' for lack of a better 1532 // type. 1533 DeclSpec DS; 1534 const char* PrevSpec; // unused 1535 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1536 PrevSpec); 1537 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1538 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1539 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1540 } 1541 } 1542 1543 // Since this is a function definition, act as though we have information 1544 // about the arguments. 1545 if (FTI.NumArgs) 1546 FTI.hasPrototype = true; 1547 } else { 1548 // FIXME: Diagnose arguments without names in C. 1549 } 1550 1551 Scope *GlobalScope = FnBodyScope->getParent(); 1552 1553 // See if this is a redefinition. 1554 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1555 GlobalScope); 1556 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1557 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1558 const FunctionDecl *Definition; 1559 if (FD->getBody(Definition)) { 1560 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1561 D.getIdentifier()->getName()); 1562 Diag(Definition->getLocation(), diag::err_previous_definition); 1563 } 1564 } 1565 } 1566 1567 return ActOnStartOfFunctionDef(FnBodyScope, 1568 ActOnDeclarator(GlobalScope, D, 0)); 1569} 1570 1571Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1572 Decl *decl = static_cast<Decl*>(D); 1573 FunctionDecl *FD = cast<FunctionDecl>(decl); 1574 PushDeclContext(FD); 1575 1576 // Check the validity of our function parameters 1577 CheckParmsForFunctionDef(FD); 1578 1579 // Introduce our parameters into the function scope 1580 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1581 ParmVarDecl *Param = FD->getParamDecl(p); 1582 // If this has an identifier, add it to the scope stack. 1583 if (Param->getIdentifier()) 1584 PushOnScopeChains(Param, FnBodyScope); 1585 } 1586 1587 return FD; 1588} 1589 1590Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1591 Decl *dcl = static_cast<Decl *>(D); 1592 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1593 FD->setBody((Stmt*)Body); 1594 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1595 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1596 MD->setBody((Stmt*)Body); 1597 } else 1598 return 0; 1599 PopDeclContext(); 1600 // Verify and clean out per-function state. 1601 1602 // Check goto/label use. 1603 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1604 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1605 // Verify that we have no forward references left. If so, there was a goto 1606 // or address of a label taken, but no definition of it. Label fwd 1607 // definitions are indicated with a null substmt. 1608 if (I->second->getSubStmt() == 0) { 1609 LabelStmt *L = I->second; 1610 // Emit error. 1611 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1612 1613 // At this point, we have gotos that use the bogus label. Stitch it into 1614 // the function body so that they aren't leaked and that the AST is well 1615 // formed. 1616 if (Body) { 1617 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1618 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1619 } else { 1620 // The whole function wasn't parsed correctly, just delete this. 1621 delete L; 1622 } 1623 } 1624 } 1625 LabelMap.clear(); 1626 1627 return D; 1628} 1629 1630/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1631/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1632ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1633 IdentifierInfo &II, Scope *S) { 1634 // Extension in C99. Legal in C90, but warn about it. 1635 if (getLangOptions().C99) 1636 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1637 else 1638 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1639 1640 // FIXME: handle stuff like: 1641 // void foo() { extern float X(); } 1642 // void bar() { X(); } <-- implicit decl for X in another scope. 1643 1644 // Set a Declarator for the implicit definition: int foo(); 1645 const char *Dummy; 1646 DeclSpec DS; 1647 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1648 Error = Error; // Silence warning. 1649 assert(!Error && "Error setting up implicit decl!"); 1650 Declarator D(DS, Declarator::BlockContext); 1651 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1652 D.SetIdentifier(&II, Loc); 1653 1654 // Insert this function into translation-unit scope. 1655 1656 DeclContext *PrevDC = CurContext; 1657 CurContext = Context.getTranslationUnitDecl(); 1658 1659 FunctionDecl *FD = 1660 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1661 FD->setImplicit(); 1662 1663 CurContext = PrevDC; 1664 1665 return FD; 1666} 1667 1668 1669TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1670 ScopedDecl *LastDeclarator) { 1671 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1672 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1673 1674 // Scope manipulation handled by caller. 1675 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1676 D.getIdentifierLoc(), 1677 D.getIdentifier(), 1678 T, LastDeclarator); 1679 if (D.getInvalidType()) 1680 NewTD->setInvalidDecl(); 1681 return NewTD; 1682} 1683 1684/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1685/// former case, Name will be non-null. In the later case, Name will be null. 1686/// TagType indicates what kind of tag this is. TK indicates whether this is a 1687/// reference/declaration/definition of a tag. 1688Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1689 SourceLocation KWLoc, IdentifierInfo *Name, 1690 SourceLocation NameLoc, AttributeList *Attr) { 1691 // If this is a use of an existing tag, it must have a name. 1692 assert((Name != 0 || TK == TK_Definition) && 1693 "Nameless record must be a definition!"); 1694 1695 TagDecl::TagKind Kind; 1696 switch (TagType) { 1697 default: assert(0 && "Unknown tag type!"); 1698 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1699 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1700 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1701 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1702 } 1703 1704 // If this is a named struct, check to see if there was a previous forward 1705 // declaration or definition. 1706 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1707 if (ScopedDecl *PrevDecl = 1708 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1709 1710 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1711 "unexpected Decl type"); 1712 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1713 // If this is a use of a previous tag, or if the tag is already declared 1714 // in the same scope (so that the definition/declaration completes or 1715 // rementions the tag), reuse the decl. 1716 if (TK == TK_Reference || 1717 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1718 // Make sure that this wasn't declared as an enum and now used as a 1719 // struct or something similar. 1720 if (PrevTagDecl->getTagKind() != Kind) { 1721 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1722 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1723 // Recover by making this an anonymous redefinition. 1724 Name = 0; 1725 PrevDecl = 0; 1726 } else { 1727 // If this is a use or a forward declaration, we're good. 1728 if (TK != TK_Definition) 1729 return PrevDecl; 1730 1731 // Diagnose attempts to redefine a tag. 1732 if (PrevTagDecl->isDefinition()) { 1733 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1734 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1735 // If this is a redefinition, recover by making this struct be 1736 // anonymous, which will make any later references get the previous 1737 // definition. 1738 Name = 0; 1739 } else { 1740 // Okay, this is definition of a previously declared or referenced 1741 // tag. Move the location of the decl to be the definition site. 1742 PrevDecl->setLocation(NameLoc); 1743 return PrevDecl; 1744 } 1745 } 1746 } 1747 // If we get here, this is a definition of a new struct type in a nested 1748 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1749 // type. 1750 } else { 1751 // PrevDecl is a namespace. 1752 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1753 // The tag name clashes with a namespace name, issue an error and recover 1754 // by making this tag be anonymous. 1755 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1756 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1757 Name = 0; 1758 } 1759 } 1760 } 1761 1762 // If there is an identifier, use the location of the identifier as the 1763 // location of the decl, otherwise use the location of the struct/union 1764 // keyword. 1765 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1766 1767 // Otherwise, if this is the first time we've seen this tag, create the decl. 1768 TagDecl *New; 1769 if (Kind == TagDecl::TK_enum) { 1770 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1771 // enum X { A, B, C } D; D should chain to X. 1772 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1773 // If this is an undefined enum, warn. 1774 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1775 } else { 1776 // struct/union/class 1777 1778 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1779 // struct X { int A; } D; D should chain to X. 1780 if (getLangOptions().CPlusPlus) 1781 // FIXME: Look for a way to use RecordDecl for simple structs. 1782 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1783 else 1784 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1785 } 1786 1787 // If this has an identifier, add it to the scope stack. 1788 if (Name) { 1789 // The scope passed in may not be a decl scope. Zip up the scope tree until 1790 // we find one that is. 1791 while ((S->getFlags() & Scope::DeclScope) == 0) 1792 S = S->getParent(); 1793 1794 // Add it to the decl chain. 1795 PushOnScopeChains(New, S); 1796 } 1797 1798 if (Attr) 1799 ProcessDeclAttributeList(New, Attr); 1800 return New; 1801} 1802 1803/// Collect the instance variables declared in an Objective-C object. Used in 1804/// the creation of structures from objects using the @defs directive. 1805static void CollectIvars(ObjCInterfaceDecl *Class, 1806 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1807 if (Class->getSuperClass()) 1808 CollectIvars(Class->getSuperClass(), ivars); 1809 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1810} 1811 1812/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1813/// instance variables of ClassName into Decls. 1814void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1815 IdentifierInfo *ClassName, 1816 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1817 // Check that ClassName is a valid class 1818 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1819 if (!Class) { 1820 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1821 return; 1822 } 1823 // Collect the instance variables 1824 CollectIvars(Class, Decls); 1825} 1826 1827QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1828 // This method tries to turn a variable array into a constant 1829 // array even when the size isn't an ICE. This is necessary 1830 // for compatibility with code that depends on gcc's buggy 1831 // constant expression folding, like struct {char x[(int)(char*)2];} 1832 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1833 APValue Result; 1834 if (VLATy->getSizeExpr() && 1835 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1836 llvm::APSInt &Res = Result.getInt(); 1837 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1838 return Context.getConstantArrayType(VLATy->getElementType(), 1839 Res, ArrayType::Normal, 0); 1840 } 1841 } 1842 return QualType(); 1843} 1844 1845/// ActOnField - Each field of a struct/union/class is passed into this in order 1846/// to create a FieldDecl object for it. 1847Sema::DeclTy *Sema::ActOnField(Scope *S, 1848 SourceLocation DeclStart, 1849 Declarator &D, ExprTy *BitfieldWidth) { 1850 IdentifierInfo *II = D.getIdentifier(); 1851 Expr *BitWidth = (Expr*)BitfieldWidth; 1852 SourceLocation Loc = DeclStart; 1853 if (II) Loc = D.getIdentifierLoc(); 1854 1855 // FIXME: Unnamed fields can be handled in various different ways, for 1856 // example, unnamed unions inject all members into the struct namespace! 1857 1858 1859 if (BitWidth) { 1860 // TODO: Validate. 1861 //printf("WARNING: BITFIELDS IGNORED!\n"); 1862 1863 // 6.7.2.1p3 1864 // 6.7.2.1p4 1865 1866 } else { 1867 // Not a bitfield. 1868 1869 // validate II. 1870 1871 } 1872 1873 QualType T = GetTypeForDeclarator(D, S); 1874 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1875 bool InvalidDecl = false; 1876 1877 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1878 // than a variably modified type. 1879 if (T->isVariablyModifiedType()) { 1880 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1881 if (!FixedTy.isNull()) { 1882 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1883 T = FixedTy; 1884 } else { 1885 // FIXME: This diagnostic needs work 1886 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1887 InvalidDecl = true; 1888 } 1889 } 1890 // FIXME: Chain fielddecls together. 1891 FieldDecl *NewFD; 1892 1893 if (getLangOptions().CPlusPlus) { 1894 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1895 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1896 Loc, II, T, BitWidth); 1897 if (II) 1898 PushOnScopeChains(NewFD, S); 1899 } 1900 else 1901 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1902 1903 ProcessDeclAttributes(NewFD, D); 1904 1905 if (D.getInvalidType() || InvalidDecl) 1906 NewFD->setInvalidDecl(); 1907 return NewFD; 1908} 1909 1910/// TranslateIvarVisibility - Translate visibility from a token ID to an 1911/// AST enum value. 1912static ObjCIvarDecl::AccessControl 1913TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1914 switch (ivarVisibility) { 1915 case tok::objc_private: return ObjCIvarDecl::Private; 1916 case tok::objc_public: return ObjCIvarDecl::Public; 1917 case tok::objc_protected: return ObjCIvarDecl::Protected; 1918 case tok::objc_package: return ObjCIvarDecl::Package; 1919 default: assert(false && "Unknown visitibility kind"); 1920 } 1921} 1922 1923/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1924/// in order to create an IvarDecl object for it. 1925Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1926 SourceLocation DeclStart, 1927 Declarator &D, ExprTy *BitfieldWidth, 1928 tok::ObjCKeywordKind Visibility) { 1929 IdentifierInfo *II = D.getIdentifier(); 1930 Expr *BitWidth = (Expr*)BitfieldWidth; 1931 SourceLocation Loc = DeclStart; 1932 if (II) Loc = D.getIdentifierLoc(); 1933 1934 // FIXME: Unnamed fields can be handled in various different ways, for 1935 // example, unnamed unions inject all members into the struct namespace! 1936 1937 1938 if (BitWidth) { 1939 // TODO: Validate. 1940 //printf("WARNING: BITFIELDS IGNORED!\n"); 1941 1942 // 6.7.2.1p3 1943 // 6.7.2.1p4 1944 1945 } else { 1946 // Not a bitfield. 1947 1948 // validate II. 1949 1950 } 1951 1952 QualType T = GetTypeForDeclarator(D, S); 1953 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1954 bool InvalidDecl = false; 1955 1956 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1957 // than a variably modified type. 1958 if (T->isVariablyModifiedType()) { 1959 // FIXME: This diagnostic needs work 1960 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1961 InvalidDecl = true; 1962 } 1963 1964 // Get the visibility (access control) for this ivar. 1965 ObjCIvarDecl::AccessControl ac = 1966 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1967 : ObjCIvarDecl::None; 1968 1969 // Construct the decl. 1970 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1971 (Expr *)BitfieldWidth); 1972 1973 // Process attributes attached to the ivar. 1974 ProcessDeclAttributes(NewID, D); 1975 1976 if (D.getInvalidType() || InvalidDecl) 1977 NewID->setInvalidDecl(); 1978 1979 return NewID; 1980} 1981 1982void Sema::ActOnFields(Scope* S, 1983 SourceLocation RecLoc, DeclTy *RecDecl, 1984 DeclTy **Fields, unsigned NumFields, 1985 SourceLocation LBrac, SourceLocation RBrac) { 1986 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1987 assert(EnclosingDecl && "missing record or interface decl"); 1988 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1989 1990 if (Record && Record->isDefinition()) { 1991 // Diagnose code like: 1992 // struct S { struct S {} X; }; 1993 // We discover this when we complete the outer S. Reject and ignore the 1994 // outer S. 1995 Diag(Record->getLocation(), diag::err_nested_redefinition, 1996 Record->getKindName()); 1997 Diag(RecLoc, diag::err_previous_definition); 1998 Record->setInvalidDecl(); 1999 return; 2000 } 2001 // Verify that all the fields are okay. 2002 unsigned NumNamedMembers = 0; 2003 llvm::SmallVector<FieldDecl*, 32> RecFields; 2004 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2005 2006 for (unsigned i = 0; i != NumFields; ++i) { 2007 2008 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2009 assert(FD && "missing field decl"); 2010 2011 // Remember all fields. 2012 RecFields.push_back(FD); 2013 2014 // Get the type for the field. 2015 Type *FDTy = FD->getType().getTypePtr(); 2016 2017 // C99 6.7.2.1p2 - A field may not be a function type. 2018 if (FDTy->isFunctionType()) { 2019 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2020 FD->getName()); 2021 FD->setInvalidDecl(); 2022 EnclosingDecl->setInvalidDecl(); 2023 continue; 2024 } 2025 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2026 if (FDTy->isIncompleteType()) { 2027 if (!Record) { // Incomplete ivar type is always an error. 2028 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2029 FD->setInvalidDecl(); 2030 EnclosingDecl->setInvalidDecl(); 2031 continue; 2032 } 2033 if (i != NumFields-1 || // ... that the last member ... 2034 !Record->isStruct() || // ... of a structure ... 2035 !FDTy->isArrayType()) { //... may have incomplete array type. 2036 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2037 FD->setInvalidDecl(); 2038 EnclosingDecl->setInvalidDecl(); 2039 continue; 2040 } 2041 if (NumNamedMembers < 1) { //... must have more than named member ... 2042 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2043 FD->getName()); 2044 FD->setInvalidDecl(); 2045 EnclosingDecl->setInvalidDecl(); 2046 continue; 2047 } 2048 // Okay, we have a legal flexible array member at the end of the struct. 2049 if (Record) 2050 Record->setHasFlexibleArrayMember(true); 2051 } 2052 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2053 /// field of another structure or the element of an array. 2054 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2055 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2056 // If this is a member of a union, then entire union becomes "flexible". 2057 if (Record && Record->isUnion()) { 2058 Record->setHasFlexibleArrayMember(true); 2059 } else { 2060 // If this is a struct/class and this is not the last element, reject 2061 // it. Note that GCC supports variable sized arrays in the middle of 2062 // structures. 2063 if (i != NumFields-1) { 2064 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2065 FD->getName()); 2066 FD->setInvalidDecl(); 2067 EnclosingDecl->setInvalidDecl(); 2068 continue; 2069 } 2070 // We support flexible arrays at the end of structs in other structs 2071 // as an extension. 2072 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2073 FD->getName()); 2074 if (Record) 2075 Record->setHasFlexibleArrayMember(true); 2076 } 2077 } 2078 } 2079 /// A field cannot be an Objective-c object 2080 if (FDTy->isObjCInterfaceType()) { 2081 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2082 FD->getName()); 2083 FD->setInvalidDecl(); 2084 EnclosingDecl->setInvalidDecl(); 2085 continue; 2086 } 2087 // Keep track of the number of named members. 2088 if (IdentifierInfo *II = FD->getIdentifier()) { 2089 // Detect duplicate member names. 2090 if (!FieldIDs.insert(II)) { 2091 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2092 // Find the previous decl. 2093 SourceLocation PrevLoc; 2094 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2095 assert(i != e && "Didn't find previous def!"); 2096 if (RecFields[i]->getIdentifier() == II) { 2097 PrevLoc = RecFields[i]->getLocation(); 2098 break; 2099 } 2100 } 2101 Diag(PrevLoc, diag::err_previous_definition); 2102 FD->setInvalidDecl(); 2103 EnclosingDecl->setInvalidDecl(); 2104 continue; 2105 } 2106 ++NumNamedMembers; 2107 } 2108 } 2109 2110 // Okay, we successfully defined 'Record'. 2111 if (Record) { 2112 Record->defineBody(&RecFields[0], RecFields.size()); 2113 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2114 // Sema::ActOnFinishCXXClassDef. 2115 if (!isa<CXXRecordDecl>(Record)) 2116 Consumer.HandleTagDeclDefinition(Record); 2117 } else { 2118 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2119 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2120 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2121 else if (ObjCImplementationDecl *IMPDecl = 2122 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2123 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2124 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2125 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2126 } 2127 } 2128} 2129 2130Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2131 DeclTy *lastEnumConst, 2132 SourceLocation IdLoc, IdentifierInfo *Id, 2133 SourceLocation EqualLoc, ExprTy *val) { 2134 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2135 EnumConstantDecl *LastEnumConst = 2136 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2137 Expr *Val = static_cast<Expr*>(val); 2138 2139 // The scope passed in may not be a decl scope. Zip up the scope tree until 2140 // we find one that is. 2141 while ((S->getFlags() & Scope::DeclScope) == 0) 2142 S = S->getParent(); 2143 2144 // Verify that there isn't already something declared with this name in this 2145 // scope. 2146 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2147 // When in C++, we may get a TagDecl with the same name; in this case the 2148 // enum constant will 'hide' the tag. 2149 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2150 "Received TagDecl when not in C++!"); 2151 if (!isa<TagDecl>(PrevDecl) && 2152 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2153 if (isa<EnumConstantDecl>(PrevDecl)) 2154 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2155 else 2156 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2157 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2158 delete Val; 2159 return 0; 2160 } 2161 } 2162 2163 llvm::APSInt EnumVal(32); 2164 QualType EltTy; 2165 if (Val) { 2166 // Make sure to promote the operand type to int. 2167 UsualUnaryConversions(Val); 2168 2169 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2170 SourceLocation ExpLoc; 2171 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2172 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2173 Id->getName()); 2174 delete Val; 2175 Val = 0; // Just forget about it. 2176 } else { 2177 EltTy = Val->getType(); 2178 } 2179 } 2180 2181 if (!Val) { 2182 if (LastEnumConst) { 2183 // Assign the last value + 1. 2184 EnumVal = LastEnumConst->getInitVal(); 2185 ++EnumVal; 2186 2187 // Check for overflow on increment. 2188 if (EnumVal < LastEnumConst->getInitVal()) 2189 Diag(IdLoc, diag::warn_enum_value_overflow); 2190 2191 EltTy = LastEnumConst->getType(); 2192 } else { 2193 // First value, set to zero. 2194 EltTy = Context.IntTy; 2195 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2196 } 2197 } 2198 2199 EnumConstantDecl *New = 2200 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2201 Val, EnumVal, 2202 LastEnumConst); 2203 2204 // Register this decl in the current scope stack. 2205 PushOnScopeChains(New, S); 2206 return New; 2207} 2208 2209// FIXME: For consistency with ActOnFields(), we should have the parser 2210// pass in the source location for the left/right braces. 2211void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2212 DeclTy **Elements, unsigned NumElements) { 2213 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2214 2215 if (Enum && Enum->isDefinition()) { 2216 // Diagnose code like: 2217 // enum e0 { 2218 // E0 = sizeof(enum e0 { E1 }) 2219 // }; 2220 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2221 Enum->getName()); 2222 Diag(EnumLoc, diag::err_previous_definition); 2223 Enum->setInvalidDecl(); 2224 return; 2225 } 2226 // TODO: If the result value doesn't fit in an int, it must be a long or long 2227 // long value. ISO C does not support this, but GCC does as an extension, 2228 // emit a warning. 2229 unsigned IntWidth = Context.Target.getIntWidth(); 2230 2231 // Verify that all the values are okay, compute the size of the values, and 2232 // reverse the list. 2233 unsigned NumNegativeBits = 0; 2234 unsigned NumPositiveBits = 0; 2235 2236 // Keep track of whether all elements have type int. 2237 bool AllElementsInt = true; 2238 2239 EnumConstantDecl *EltList = 0; 2240 for (unsigned i = 0; i != NumElements; ++i) { 2241 EnumConstantDecl *ECD = 2242 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2243 if (!ECD) continue; // Already issued a diagnostic. 2244 2245 // If the enum value doesn't fit in an int, emit an extension warning. 2246 const llvm::APSInt &InitVal = ECD->getInitVal(); 2247 assert(InitVal.getBitWidth() >= IntWidth && 2248 "Should have promoted value to int"); 2249 if (InitVal.getBitWidth() > IntWidth) { 2250 llvm::APSInt V(InitVal); 2251 V.trunc(IntWidth); 2252 V.extend(InitVal.getBitWidth()); 2253 if (V != InitVal) 2254 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2255 InitVal.toString(10)); 2256 } 2257 2258 // Keep track of the size of positive and negative values. 2259 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2260 NumPositiveBits = std::max(NumPositiveBits, 2261 (unsigned)InitVal.getActiveBits()); 2262 else 2263 NumNegativeBits = std::max(NumNegativeBits, 2264 (unsigned)InitVal.getMinSignedBits()); 2265 2266 // Keep track of whether every enum element has type int (very commmon). 2267 if (AllElementsInt) 2268 AllElementsInt = ECD->getType() == Context.IntTy; 2269 2270 ECD->setNextDeclarator(EltList); 2271 EltList = ECD; 2272 } 2273 2274 // Figure out the type that should be used for this enum. 2275 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2276 QualType BestType; 2277 unsigned BestWidth; 2278 2279 if (NumNegativeBits) { 2280 // If there is a negative value, figure out the smallest integer type (of 2281 // int/long/longlong) that fits. 2282 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2283 BestType = Context.IntTy; 2284 BestWidth = IntWidth; 2285 } else { 2286 BestWidth = Context.Target.getLongWidth(); 2287 2288 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2289 BestType = Context.LongTy; 2290 else { 2291 BestWidth = Context.Target.getLongLongWidth(); 2292 2293 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2294 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2295 BestType = Context.LongLongTy; 2296 } 2297 } 2298 } else { 2299 // If there is no negative value, figure out which of uint, ulong, ulonglong 2300 // fits. 2301 if (NumPositiveBits <= IntWidth) { 2302 BestType = Context.UnsignedIntTy; 2303 BestWidth = IntWidth; 2304 } else if (NumPositiveBits <= 2305 (BestWidth = Context.Target.getLongWidth())) { 2306 BestType = Context.UnsignedLongTy; 2307 } else { 2308 BestWidth = Context.Target.getLongLongWidth(); 2309 assert(NumPositiveBits <= BestWidth && 2310 "How could an initializer get larger than ULL?"); 2311 BestType = Context.UnsignedLongLongTy; 2312 } 2313 } 2314 2315 // Loop over all of the enumerator constants, changing their types to match 2316 // the type of the enum if needed. 2317 for (unsigned i = 0; i != NumElements; ++i) { 2318 EnumConstantDecl *ECD = 2319 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2320 if (!ECD) continue; // Already issued a diagnostic. 2321 2322 // Standard C says the enumerators have int type, but we allow, as an 2323 // extension, the enumerators to be larger than int size. If each 2324 // enumerator value fits in an int, type it as an int, otherwise type it the 2325 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2326 // that X has type 'int', not 'unsigned'. 2327 if (ECD->getType() == Context.IntTy) { 2328 // Make sure the init value is signed. 2329 llvm::APSInt IV = ECD->getInitVal(); 2330 IV.setIsSigned(true); 2331 ECD->setInitVal(IV); 2332 continue; // Already int type. 2333 } 2334 2335 // Determine whether the value fits into an int. 2336 llvm::APSInt InitVal = ECD->getInitVal(); 2337 bool FitsInInt; 2338 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2339 FitsInInt = InitVal.getActiveBits() < IntWidth; 2340 else 2341 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2342 2343 // If it fits into an integer type, force it. Otherwise force it to match 2344 // the enum decl type. 2345 QualType NewTy; 2346 unsigned NewWidth; 2347 bool NewSign; 2348 if (FitsInInt) { 2349 NewTy = Context.IntTy; 2350 NewWidth = IntWidth; 2351 NewSign = true; 2352 } else if (ECD->getType() == BestType) { 2353 // Already the right type! 2354 continue; 2355 } else { 2356 NewTy = BestType; 2357 NewWidth = BestWidth; 2358 NewSign = BestType->isSignedIntegerType(); 2359 } 2360 2361 // Adjust the APSInt value. 2362 InitVal.extOrTrunc(NewWidth); 2363 InitVal.setIsSigned(NewSign); 2364 ECD->setInitVal(InitVal); 2365 2366 // Adjust the Expr initializer and type. 2367 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2368 ECD->setType(NewTy); 2369 } 2370 2371 Enum->defineElements(EltList, BestType); 2372 Consumer.HandleTagDeclDefinition(Enum); 2373} 2374 2375Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2376 ExprTy *expr) { 2377 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2378 2379 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2380} 2381 2382Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2383 SourceLocation LBrace, 2384 SourceLocation RBrace, 2385 const char *Lang, 2386 unsigned StrSize, 2387 DeclTy *D) { 2388 LinkageSpecDecl::LanguageIDs Language; 2389 Decl *dcl = static_cast<Decl *>(D); 2390 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2391 Language = LinkageSpecDecl::lang_c; 2392 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2393 Language = LinkageSpecDecl::lang_cxx; 2394 else { 2395 Diag(Loc, diag::err_bad_language); 2396 return 0; 2397 } 2398 2399 // FIXME: Add all the various semantics of linkage specifications 2400 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2401} 2402