SemaDecl.cpp revision 73419bf6cbf8e5f7a0f9b8855d6531db264ae899
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 if (SrcMgr.isInSystemHeader(Old->getLocation())) 268 return New; 269 if (SrcMgr.isInSystemHeader(New->getLocation())) 270 return New; 271 272 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 273 Diag(Old->getLocation(), diag::err_previous_definition); 274 return New; 275} 276 277/// DeclhasAttr - returns true if decl Declaration already has the target 278/// attribute. 279static bool DeclHasAttr(const Decl *decl, const Attr *target) { 280 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 281 if (attr->getKind() == target->getKind()) 282 return true; 283 284 return false; 285} 286 287/// MergeAttributes - append attributes from the Old decl to the New one. 288static void MergeAttributes(Decl *New, Decl *Old) { 289 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 290 291 while (attr) { 292 tmp = attr; 293 attr = attr->getNext(); 294 295 if (!DeclHasAttr(New, tmp)) { 296 New->addAttr(tmp); 297 } else { 298 tmp->setNext(0); 299 delete(tmp); 300 } 301 } 302 303 Old->invalidateAttrs(); 304} 305 306/// MergeFunctionDecl - We just parsed a function 'New' from 307/// declarator D which has the same name and scope as a previous 308/// declaration 'Old'. Figure out how to resolve this situation, 309/// merging decls or emitting diagnostics as appropriate. 310/// Redeclaration will be set true if thisNew is a redeclaration OldD. 311FunctionDecl * 312Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 313 Redeclaration = false; 314 // Verify the old decl was also a function. 315 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 316 if (!Old) { 317 Diag(New->getLocation(), diag::err_redefinition_different_kind, 318 New->getName()); 319 Diag(OldD->getLocation(), diag::err_previous_definition); 320 return New; 321 } 322 323 QualType OldQType = Context.getCanonicalType(Old->getType()); 324 QualType NewQType = Context.getCanonicalType(New->getType()); 325 326 // C++ [dcl.fct]p3: 327 // All declarations for a function shall agree exactly in both the 328 // return type and the parameter-type-list. 329 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 330 MergeAttributes(New, Old); 331 Redeclaration = true; 332 return MergeCXXFunctionDecl(New, Old); 333 } 334 335 // C: Function types need to be compatible, not identical. This handles 336 // duplicate function decls like "void f(int); void f(enum X);" properly. 337 if (!getLangOptions().CPlusPlus && 338 Context.typesAreCompatible(OldQType, NewQType)) { 339 MergeAttributes(New, Old); 340 Redeclaration = true; 341 return New; 342 } 343 344 // A function that has already been declared has been redeclared or defined 345 // with a different type- show appropriate diagnostic 346 diag::kind PrevDiag; 347 if (Old->isThisDeclarationADefinition()) 348 PrevDiag = diag::err_previous_definition; 349 else if (Old->isImplicit()) 350 PrevDiag = diag::err_previous_implicit_declaration; 351 else 352 PrevDiag = diag::err_previous_declaration; 353 354 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 355 // TODO: This is totally simplistic. It should handle merging functions 356 // together etc, merging extern int X; int X; ... 357 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 358 Diag(Old->getLocation(), PrevDiag); 359 return New; 360} 361 362/// Predicate for C "tentative" external object definitions (C99 6.9.2). 363static bool isTentativeDefinition(VarDecl *VD) { 364 if (VD->isFileVarDecl()) 365 return (!VD->getInit() && 366 (VD->getStorageClass() == VarDecl::None || 367 VD->getStorageClass() == VarDecl::Static)); 368 return false; 369} 370 371/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 372/// when dealing with C "tentative" external object definitions (C99 6.9.2). 373void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 374 bool VDIsTentative = isTentativeDefinition(VD); 375 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 376 377 for (IdentifierResolver::iterator 378 I = IdResolver.begin(VD->getIdentifier(), 379 VD->getDeclContext(), false/*LookInParentCtx*/), 380 E = IdResolver.end(); I != E; ++I) { 381 if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) { 382 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 383 384 // Handle the following case: 385 // int a[10]; 386 // int a[]; - the code below makes sure we set the correct type. 387 // int a[11]; - this is an error, size isn't 10. 388 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 389 OldDecl->getType()->isConstantArrayType()) 390 VD->setType(OldDecl->getType()); 391 392 // Check for "tentative" definitions. We can't accomplish this in 393 // MergeVarDecl since the initializer hasn't been attached. 394 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 395 continue; 396 397 // Handle __private_extern__ just like extern. 398 if (OldDecl->getStorageClass() != VarDecl::Extern && 399 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 400 VD->getStorageClass() != VarDecl::Extern && 401 VD->getStorageClass() != VarDecl::PrivateExtern) { 402 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 403 Diag(OldDecl->getLocation(), diag::err_previous_definition); 404 } 405 } 406 } 407} 408 409/// MergeVarDecl - We just parsed a variable 'New' which has the same name 410/// and scope as a previous declaration 'Old'. Figure out how to resolve this 411/// situation, merging decls or emitting diagnostics as appropriate. 412/// 413/// Tentative definition rules (C99 6.9.2p2) are checked by 414/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 415/// definitions here, since the initializer hasn't been attached. 416/// 417VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 418 // Verify the old decl was also a variable. 419 VarDecl *Old = dyn_cast<VarDecl>(OldD); 420 if (!Old) { 421 Diag(New->getLocation(), diag::err_redefinition_different_kind, 422 New->getName()); 423 Diag(OldD->getLocation(), diag::err_previous_definition); 424 return New; 425 } 426 427 MergeAttributes(New, Old); 428 429 // Verify the types match. 430 QualType OldCType = Context.getCanonicalType(Old->getType()); 431 QualType NewCType = Context.getCanonicalType(New->getType()); 432 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 433 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 434 Diag(Old->getLocation(), diag::err_previous_definition); 435 return New; 436 } 437 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 438 if (New->getStorageClass() == VarDecl::Static && 439 (Old->getStorageClass() == VarDecl::None || 440 Old->getStorageClass() == VarDecl::Extern)) { 441 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 442 Diag(Old->getLocation(), diag::err_previous_definition); 443 return New; 444 } 445 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 446 if (New->getStorageClass() != VarDecl::Static && 447 Old->getStorageClass() == VarDecl::Static) { 448 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 449 Diag(Old->getLocation(), diag::err_previous_definition); 450 return New; 451 } 452 // File scoped variables are analyzed in FinalizeDeclaratorGroup. 453 if (!New->isFileVarDecl()) { 454 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 455 Diag(Old->getLocation(), diag::err_previous_definition); 456 } 457 return New; 458} 459 460/// CheckParmsForFunctionDef - Check that the parameters of the given 461/// function are appropriate for the definition of a function. This 462/// takes care of any checks that cannot be performed on the 463/// declaration itself, e.g., that the types of each of the function 464/// parameters are complete. 465bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 466 bool HasInvalidParm = false; 467 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 468 ParmVarDecl *Param = FD->getParamDecl(p); 469 470 // C99 6.7.5.3p4: the parameters in a parameter type list in a 471 // function declarator that is part of a function definition of 472 // that function shall not have incomplete type. 473 if (Param->getType()->isIncompleteType() && 474 !Param->isInvalidDecl()) { 475 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 476 Param->getType().getAsString()); 477 Param->setInvalidDecl(); 478 HasInvalidParm = true; 479 } 480 } 481 482 return HasInvalidParm; 483} 484 485/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 486/// no declarator (e.g. "struct foo;") is parsed. 487Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 488 // TODO: emit error on 'int;' or 'const enum foo;'. 489 // TODO: emit error on 'typedef int;' 490 // if (!DS.isMissingDeclaratorOk()) Diag(...); 491 492 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 493} 494 495bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 496 // Get the type before calling CheckSingleAssignmentConstraints(), since 497 // it can promote the expression. 498 QualType InitType = Init->getType(); 499 500 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 501 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 502 InitType, Init, "initializing"); 503} 504 505bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 506 const ArrayType *AT = Context.getAsArrayType(DeclT); 507 508 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 509 // C99 6.7.8p14. We have an array of character type with unknown size 510 // being initialized to a string literal. 511 llvm::APSInt ConstVal(32); 512 ConstVal = strLiteral->getByteLength() + 1; 513 // Return a new array type (C99 6.7.8p22). 514 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 515 ArrayType::Normal, 0); 516 } else { 517 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 518 // C99 6.7.8p14. We have an array of character type with known size. 519 // FIXME: Avoid truncation for 64-bit length strings. 520 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 521 Diag(strLiteral->getSourceRange().getBegin(), 522 diag::warn_initializer_string_for_char_array_too_long, 523 strLiteral->getSourceRange()); 524 } 525 // Set type from "char *" to "constant array of char". 526 strLiteral->setType(DeclT); 527 // For now, we always return false (meaning success). 528 return false; 529} 530 531StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 532 const ArrayType *AT = Context.getAsArrayType(DeclType); 533 if (AT && AT->getElementType()->isCharType()) { 534 return dyn_cast<StringLiteral>(Init); 535 } 536 return 0; 537} 538 539bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 540 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 541 // of unknown size ("[]") or an object type that is not a variable array type. 542 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 543 return Diag(VAT->getSizeExpr()->getLocStart(), 544 diag::err_variable_object_no_init, 545 VAT->getSizeExpr()->getSourceRange()); 546 547 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 548 if (!InitList) { 549 // FIXME: Handle wide strings 550 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 551 return CheckStringLiteralInit(strLiteral, DeclType); 552 553 if (DeclType->isArrayType()) 554 return Diag(Init->getLocStart(), 555 diag::err_array_init_list_required, 556 Init->getSourceRange()); 557 558 return CheckSingleInitializer(Init, DeclType); 559 } 560 561 InitListChecker CheckInitList(this, InitList, DeclType); 562 return CheckInitList.HadError(); 563} 564 565Sema::DeclTy * 566Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 567 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 568 IdentifierInfo *II = D.getIdentifier(); 569 570 // All of these full declarators require an identifier. If it doesn't have 571 // one, the ParsedFreeStandingDeclSpec action should be used. 572 if (II == 0) { 573 Diag(D.getDeclSpec().getSourceRange().getBegin(), 574 diag::err_declarator_need_ident, 575 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 576 return 0; 577 } 578 579 // The scope passed in may not be a decl scope. Zip up the scope tree until 580 // we find one that is. 581 while ((S->getFlags() & Scope::DeclScope) == 0) 582 S = S->getParent(); 583 584 // See if this is a redefinition of a variable in the same scope. 585 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 586 ScopedDecl *New; 587 bool InvalidDecl = false; 588 589 // In C++, the previous declaration we find might be a tag type 590 // (class or enum). In this case, the new declaration will hide the 591 // tag type. 592 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 593 PrevDecl = 0; 594 595 QualType R = GetTypeForDeclarator(D, S); 596 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 597 598 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 599 // Check that there are no default arguments (C++ only). 600 if (getLangOptions().CPlusPlus) 601 CheckExtraCXXDefaultArguments(D); 602 603 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 604 if (!NewTD) return 0; 605 606 // Handle attributes prior to checking for duplicates in MergeVarDecl 607 ProcessDeclAttributes(NewTD, D); 608 // Merge the decl with the existing one if appropriate. If the decl is 609 // in an outer scope, it isn't the same thing. 610 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 611 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 612 if (NewTD == 0) return 0; 613 } 614 New = NewTD; 615 if (S->getFnParent() == 0) { 616 // C99 6.7.7p2: If a typedef name specifies a variably modified type 617 // then it shall have block scope. 618 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 619 // FIXME: Diagnostic needs to be fixed. 620 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 621 InvalidDecl = true; 622 } 623 } 624 } else if (R.getTypePtr()->isFunctionType()) { 625 FunctionDecl::StorageClass SC = FunctionDecl::None; 626 switch (D.getDeclSpec().getStorageClassSpec()) { 627 default: assert(0 && "Unknown storage class!"); 628 case DeclSpec::SCS_auto: 629 case DeclSpec::SCS_register: 630 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 631 R.getAsString()); 632 InvalidDecl = true; 633 break; 634 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 635 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 636 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 637 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 638 } 639 640 bool isInline = D.getDeclSpec().isInlineSpecified(); 641 FunctionDecl *NewFD; 642 if (D.getContext() == Declarator::MemberContext) { 643 // This is a C++ method declaration. 644 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 645 D.getIdentifierLoc(), II, R, 646 (SC == FunctionDecl::Static), isInline, 647 LastDeclarator); 648 } else { 649 NewFD = FunctionDecl::Create(Context, CurContext, 650 D.getIdentifierLoc(), 651 II, R, SC, isInline, 652 LastDeclarator); 653 } 654 // Handle attributes. 655 ProcessDeclAttributes(NewFD, D); 656 657 // Handle GNU asm-label extension (encoded as an attribute). 658 if (Expr *E = (Expr*) D.getAsmLabel()) { 659 // The parser guarantees this is a string. 660 StringLiteral *SE = cast<StringLiteral>(E); 661 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 662 SE->getByteLength()))); 663 } 664 665 // Copy the parameter declarations from the declarator D to 666 // the function declaration NewFD, if they are available. 667 if (D.getNumTypeObjects() > 0) { 668 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 669 670 // Create Decl objects for each parameter, adding them to the 671 // FunctionDecl. 672 llvm::SmallVector<ParmVarDecl*, 16> Params; 673 674 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 675 // function that takes no arguments, not a function that takes a 676 // single void argument. 677 // We let through "const void" here because Sema::GetTypeForDeclarator 678 // already checks for that case. 679 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 680 FTI.ArgInfo[0].Param && 681 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 682 // empty arg list, don't push any params. 683 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 684 685 // In C++, the empty parameter-type-list must be spelled "void"; a 686 // typedef of void is not permitted. 687 if (getLangOptions().CPlusPlus && 688 Param->getType().getUnqualifiedType() != Context.VoidTy) { 689 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 690 } 691 692 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 693 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 694 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 695 } 696 697 NewFD->setParams(&Params[0], Params.size()); 698 } 699 700 // Merge the decl with the existing one if appropriate. Since C functions 701 // are in a flat namespace, make sure we consider decls in outer scopes. 702 if (PrevDecl && 703 (!getLangOptions().CPlusPlus || 704 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 705 bool Redeclaration = false; 706 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 707 if (NewFD == 0) return 0; 708 if (Redeclaration) { 709 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 710 } 711 } 712 New = NewFD; 713 714 // In C++, check default arguments now that we have merged decls. 715 if (getLangOptions().CPlusPlus) 716 CheckCXXDefaultArguments(NewFD); 717 } else { 718 // Check that there are no default arguments (C++ only). 719 if (getLangOptions().CPlusPlus) 720 CheckExtraCXXDefaultArguments(D); 721 722 if (R.getTypePtr()->isObjCInterfaceType()) { 723 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 724 D.getIdentifier()->getName()); 725 InvalidDecl = true; 726 } 727 728 VarDecl *NewVD; 729 VarDecl::StorageClass SC; 730 switch (D.getDeclSpec().getStorageClassSpec()) { 731 default: assert(0 && "Unknown storage class!"); 732 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 733 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 734 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 735 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 736 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 737 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 738 } 739 if (D.getContext() == Declarator::MemberContext) { 740 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 741 // This is a static data member for a C++ class. 742 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 743 D.getIdentifierLoc(), II, 744 R, LastDeclarator); 745 } else { 746 if (S->getFnParent() == 0) { 747 // C99 6.9p2: The storage-class specifiers auto and register shall not 748 // appear in the declaration specifiers in an external declaration. 749 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 750 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 751 R.getAsString()); 752 InvalidDecl = true; 753 } 754 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 755 II, R, SC, LastDeclarator); 756 } else { 757 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 758 II, R, SC, LastDeclarator); 759 } 760 } 761 // Handle attributes prior to checking for duplicates in MergeVarDecl 762 ProcessDeclAttributes(NewVD, D); 763 764 // Handle GNU asm-label extension (encoded as an attribute). 765 if (Expr *E = (Expr*) D.getAsmLabel()) { 766 // The parser guarantees this is a string. 767 StringLiteral *SE = cast<StringLiteral>(E); 768 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 769 SE->getByteLength()))); 770 } 771 772 // Emit an error if an address space was applied to decl with local storage. 773 // This includes arrays of objects with address space qualifiers, but not 774 // automatic variables that point to other address spaces. 775 // ISO/IEC TR 18037 S5.1.2 776 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 777 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 778 InvalidDecl = true; 779 } 780 // Merge the decl with the existing one if appropriate. If the decl is 781 // in an outer scope, it isn't the same thing. 782 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 783 NewVD = MergeVarDecl(NewVD, PrevDecl); 784 if (NewVD == 0) return 0; 785 } 786 New = NewVD; 787 } 788 789 // If this has an identifier, add it to the scope stack. 790 if (II) 791 PushOnScopeChains(New, S); 792 // If any semantic error occurred, mark the decl as invalid. 793 if (D.getInvalidType() || InvalidDecl) 794 New->setInvalidDecl(); 795 796 return New; 797} 798 799bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 800 switch (Init->getStmtClass()) { 801 default: 802 Diag(Init->getExprLoc(), 803 diag::err_init_element_not_constant, Init->getSourceRange()); 804 return true; 805 case Expr::ParenExprClass: { 806 const ParenExpr* PE = cast<ParenExpr>(Init); 807 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 808 } 809 case Expr::CompoundLiteralExprClass: 810 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 811 case Expr::DeclRefExprClass: { 812 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 813 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 814 if (VD->hasGlobalStorage()) 815 return false; 816 Diag(Init->getExprLoc(), 817 diag::err_init_element_not_constant, Init->getSourceRange()); 818 return true; 819 } 820 if (isa<FunctionDecl>(D)) 821 return false; 822 Diag(Init->getExprLoc(), 823 diag::err_init_element_not_constant, Init->getSourceRange()); 824 return true; 825 } 826 case Expr::MemberExprClass: { 827 const MemberExpr *M = cast<MemberExpr>(Init); 828 if (M->isArrow()) 829 return CheckAddressConstantExpression(M->getBase()); 830 return CheckAddressConstantExpressionLValue(M->getBase()); 831 } 832 case Expr::ArraySubscriptExprClass: { 833 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 834 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 835 return CheckAddressConstantExpression(ASE->getBase()) || 836 CheckArithmeticConstantExpression(ASE->getIdx()); 837 } 838 case Expr::StringLiteralClass: 839 case Expr::PredefinedExprClass: 840 return false; 841 case Expr::UnaryOperatorClass: { 842 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 843 844 // C99 6.6p9 845 if (Exp->getOpcode() == UnaryOperator::Deref) 846 return CheckAddressConstantExpression(Exp->getSubExpr()); 847 848 Diag(Init->getExprLoc(), 849 diag::err_init_element_not_constant, Init->getSourceRange()); 850 return true; 851 } 852 } 853} 854 855bool Sema::CheckAddressConstantExpression(const Expr* Init) { 856 switch (Init->getStmtClass()) { 857 default: 858 Diag(Init->getExprLoc(), 859 diag::err_init_element_not_constant, Init->getSourceRange()); 860 return true; 861 case Expr::ParenExprClass: { 862 const ParenExpr* PE = cast<ParenExpr>(Init); 863 return CheckAddressConstantExpression(PE->getSubExpr()); 864 } 865 case Expr::StringLiteralClass: 866 case Expr::ObjCStringLiteralClass: 867 return false; 868 case Expr::CallExprClass: { 869 const CallExpr *CE = cast<CallExpr>(Init); 870 if (CE->isBuiltinConstantExpr()) 871 return false; 872 Diag(Init->getExprLoc(), 873 diag::err_init_element_not_constant, Init->getSourceRange()); 874 return true; 875 } 876 case Expr::UnaryOperatorClass: { 877 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 878 879 // C99 6.6p9 880 if (Exp->getOpcode() == UnaryOperator::AddrOf) 881 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 882 883 if (Exp->getOpcode() == UnaryOperator::Extension) 884 return CheckAddressConstantExpression(Exp->getSubExpr()); 885 886 Diag(Init->getExprLoc(), 887 diag::err_init_element_not_constant, Init->getSourceRange()); 888 return true; 889 } 890 case Expr::BinaryOperatorClass: { 891 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 892 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 893 894 Expr *PExp = Exp->getLHS(); 895 Expr *IExp = Exp->getRHS(); 896 if (IExp->getType()->isPointerType()) 897 std::swap(PExp, IExp); 898 899 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 900 return CheckAddressConstantExpression(PExp) || 901 CheckArithmeticConstantExpression(IExp); 902 } 903 case Expr::ImplicitCastExprClass: 904 case Expr::ExplicitCastExprClass: { 905 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 906 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 907 // Check for implicit promotion 908 if (SubExpr->getType()->isFunctionType() || 909 SubExpr->getType()->isArrayType()) 910 return CheckAddressConstantExpressionLValue(SubExpr); 911 } 912 913 // Check for pointer->pointer cast 914 if (SubExpr->getType()->isPointerType()) 915 return CheckAddressConstantExpression(SubExpr); 916 917 if (SubExpr->getType()->isIntegralType()) { 918 // Check for the special-case of a pointer->int->pointer cast; 919 // this isn't standard, but some code requires it. See 920 // PR2720 for an example. 921 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 922 if (SubCast->getSubExpr()->getType()->isPointerType()) { 923 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 924 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 925 if (IntWidth >= PointerWidth) { 926 return CheckAddressConstantExpression(SubCast->getSubExpr()); 927 } 928 } 929 } 930 } 931 if (SubExpr->getType()->isArithmeticType()) { 932 return CheckArithmeticConstantExpression(SubExpr); 933 } 934 935 Diag(Init->getExprLoc(), 936 diag::err_init_element_not_constant, Init->getSourceRange()); 937 return true; 938 } 939 case Expr::ConditionalOperatorClass: { 940 // FIXME: Should we pedwarn here? 941 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 942 if (!Exp->getCond()->getType()->isArithmeticType()) { 943 Diag(Init->getExprLoc(), 944 diag::err_init_element_not_constant, Init->getSourceRange()); 945 return true; 946 } 947 if (CheckArithmeticConstantExpression(Exp->getCond())) 948 return true; 949 if (Exp->getLHS() && 950 CheckAddressConstantExpression(Exp->getLHS())) 951 return true; 952 return CheckAddressConstantExpression(Exp->getRHS()); 953 } 954 case Expr::AddrLabelExprClass: 955 return false; 956 } 957} 958 959static const Expr* FindExpressionBaseAddress(const Expr* E); 960 961static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 962 switch (E->getStmtClass()) { 963 default: 964 return E; 965 case Expr::ParenExprClass: { 966 const ParenExpr* PE = cast<ParenExpr>(E); 967 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 968 } 969 case Expr::MemberExprClass: { 970 const MemberExpr *M = cast<MemberExpr>(E); 971 if (M->isArrow()) 972 return FindExpressionBaseAddress(M->getBase()); 973 return FindExpressionBaseAddressLValue(M->getBase()); 974 } 975 case Expr::ArraySubscriptExprClass: { 976 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 977 return FindExpressionBaseAddress(ASE->getBase()); 978 } 979 case Expr::UnaryOperatorClass: { 980 const UnaryOperator *Exp = cast<UnaryOperator>(E); 981 982 if (Exp->getOpcode() == UnaryOperator::Deref) 983 return FindExpressionBaseAddress(Exp->getSubExpr()); 984 985 return E; 986 } 987 } 988} 989 990static const Expr* FindExpressionBaseAddress(const Expr* E) { 991 switch (E->getStmtClass()) { 992 default: 993 return E; 994 case Expr::ParenExprClass: { 995 const ParenExpr* PE = cast<ParenExpr>(E); 996 return FindExpressionBaseAddress(PE->getSubExpr()); 997 } 998 case Expr::UnaryOperatorClass: { 999 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1000 1001 // C99 6.6p9 1002 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1003 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1004 1005 if (Exp->getOpcode() == UnaryOperator::Extension) 1006 return FindExpressionBaseAddress(Exp->getSubExpr()); 1007 1008 return E; 1009 } 1010 case Expr::BinaryOperatorClass: { 1011 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1012 1013 Expr *PExp = Exp->getLHS(); 1014 Expr *IExp = Exp->getRHS(); 1015 if (IExp->getType()->isPointerType()) 1016 std::swap(PExp, IExp); 1017 1018 return FindExpressionBaseAddress(PExp); 1019 } 1020 case Expr::ImplicitCastExprClass: { 1021 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1022 1023 // Check for implicit promotion 1024 if (SubExpr->getType()->isFunctionType() || 1025 SubExpr->getType()->isArrayType()) 1026 return FindExpressionBaseAddressLValue(SubExpr); 1027 1028 // Check for pointer->pointer cast 1029 if (SubExpr->getType()->isPointerType()) 1030 return FindExpressionBaseAddress(SubExpr); 1031 1032 // We assume that we have an arithmetic expression here; 1033 // if we don't, we'll figure it out later 1034 return 0; 1035 } 1036 case Expr::ExplicitCastExprClass: { 1037 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1038 1039 // Check for pointer->pointer cast 1040 if (SubExpr->getType()->isPointerType()) 1041 return FindExpressionBaseAddress(SubExpr); 1042 1043 // We assume that we have an arithmetic expression here; 1044 // if we don't, we'll figure it out later 1045 return 0; 1046 } 1047 } 1048} 1049 1050bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1051 switch (Init->getStmtClass()) { 1052 default: 1053 Diag(Init->getExprLoc(), 1054 diag::err_init_element_not_constant, Init->getSourceRange()); 1055 return true; 1056 case Expr::ParenExprClass: { 1057 const ParenExpr* PE = cast<ParenExpr>(Init); 1058 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1059 } 1060 case Expr::FloatingLiteralClass: 1061 case Expr::IntegerLiteralClass: 1062 case Expr::CharacterLiteralClass: 1063 case Expr::ImaginaryLiteralClass: 1064 case Expr::TypesCompatibleExprClass: 1065 case Expr::CXXBoolLiteralExprClass: 1066 return false; 1067 case Expr::CallExprClass: { 1068 const CallExpr *CE = cast<CallExpr>(Init); 1069 if (CE->isBuiltinConstantExpr()) 1070 return false; 1071 Diag(Init->getExprLoc(), 1072 diag::err_init_element_not_constant, Init->getSourceRange()); 1073 return true; 1074 } 1075 case Expr::DeclRefExprClass: { 1076 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1077 if (isa<EnumConstantDecl>(D)) 1078 return false; 1079 1080 if (const ValueDecl *VD = dyn_cast<ValueDecl>(D)) { 1081 QualType Ty = VD->getType(); 1082 if (Ty->isPointerLikeType() || Ty->isArrayType()) 1083 return false; 1084 } 1085 1086 Diag(Init->getExprLoc(), 1087 diag::err_init_element_not_constant, Init->getSourceRange()); 1088 return true; 1089 } 1090 case Expr::CompoundLiteralExprClass: 1091 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1092 // but vectors are allowed to be magic. 1093 if (Init->getType()->isVectorType()) 1094 return false; 1095 Diag(Init->getExprLoc(), 1096 diag::err_init_element_not_constant, Init->getSourceRange()); 1097 return true; 1098 case Expr::UnaryOperatorClass: { 1099 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1100 1101 switch (Exp->getOpcode()) { 1102 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1103 // See C99 6.6p3. 1104 default: 1105 Diag(Init->getExprLoc(), 1106 diag::err_init_element_not_constant, Init->getSourceRange()); 1107 return true; 1108 case UnaryOperator::AddrOf: 1109 return false; 1110 case UnaryOperator::SizeOf: 1111 case UnaryOperator::AlignOf: 1112 case UnaryOperator::OffsetOf: 1113 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1114 // See C99 6.5.3.4p2 and 6.6p3. 1115 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1116 return false; 1117 Diag(Init->getExprLoc(), 1118 diag::err_init_element_not_constant, Init->getSourceRange()); 1119 return true; 1120 case UnaryOperator::Extension: 1121 case UnaryOperator::LNot: 1122 case UnaryOperator::Plus: 1123 case UnaryOperator::Minus: 1124 case UnaryOperator::Not: 1125 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1126 } 1127 } 1128 case Expr::SizeOfAlignOfTypeExprClass: { 1129 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1130 // Special check for void types, which are allowed as an extension 1131 if (Exp->getArgumentType()->isVoidType()) 1132 return false; 1133 // alignof always evaluates to a constant. 1134 // FIXME: is sizeof(int[3.0]) a constant expression? 1135 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1136 Diag(Init->getExprLoc(), 1137 diag::err_init_element_not_constant, Init->getSourceRange()); 1138 return true; 1139 } 1140 return false; 1141 } 1142 case Expr::BinaryOperatorClass: { 1143 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1144 1145 if (Exp->getLHS()->getType()->isArithmeticType() && 1146 Exp->getRHS()->getType()->isArithmeticType()) { 1147 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1148 CheckArithmeticConstantExpression(Exp->getRHS()); 1149 } 1150 1151 if (Exp->getLHS()->getType()->isPointerType() && 1152 Exp->getRHS()->getType()->isPointerType()) { 1153 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1154 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1155 1156 // Only allow a null (constant integer) base; we could 1157 // allow some additional cases if necessary, but this 1158 // is sufficient to cover offsetof-like constructs. 1159 if (!LHSBase && !RHSBase) { 1160 return CheckAddressConstantExpression(Exp->getLHS()) || 1161 CheckAddressConstantExpression(Exp->getRHS()); 1162 } 1163 } 1164 1165 Diag(Init->getExprLoc(), 1166 diag::err_init_element_not_constant, Init->getSourceRange()); 1167 return true; 1168 } 1169 case Expr::ImplicitCastExprClass: 1170 case Expr::ExplicitCastExprClass: { 1171 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1172 return CheckArithmeticConstantExpression(SubExpr); 1173 } 1174 case Expr::ConditionalOperatorClass: { 1175 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1176 if (CheckArithmeticConstantExpression(Exp->getCond())) 1177 return true; 1178 if (Exp->getLHS() && 1179 CheckArithmeticConstantExpression(Exp->getLHS())) 1180 return true; 1181 return CheckArithmeticConstantExpression(Exp->getRHS()); 1182 } 1183 } 1184} 1185 1186bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1187 Init = Init->IgnoreParens(); 1188 1189 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1190 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1191 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1192 1193 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1194 return CheckForConstantInitializer(e->getInitializer(), DclT); 1195 1196 if (Init->getType()->isReferenceType()) { 1197 // FIXME: Work out how the heck reference types work 1198 return false; 1199#if 0 1200 // A reference is constant if the address of the expression 1201 // is constant 1202 // We look through initlists here to simplify 1203 // CheckAddressConstantExpressionLValue. 1204 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1205 assert(Exp->getNumInits() > 0 && 1206 "Refernce initializer cannot be empty"); 1207 Init = Exp->getInit(0); 1208 } 1209 return CheckAddressConstantExpressionLValue(Init); 1210#endif 1211 } 1212 1213 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1214 unsigned numInits = Exp->getNumInits(); 1215 for (unsigned i = 0; i < numInits; i++) { 1216 // FIXME: Need to get the type of the declaration for C++, 1217 // because it could be a reference? 1218 if (CheckForConstantInitializer(Exp->getInit(i), 1219 Exp->getInit(i)->getType())) 1220 return true; 1221 } 1222 return false; 1223 } 1224 1225 if (Init->isNullPointerConstant(Context)) 1226 return false; 1227 if (Init->getType()->isArithmeticType()) { 1228 QualType InitTy = Context.getCanonicalType(Init->getType()) 1229 .getUnqualifiedType(); 1230 if (InitTy == Context.BoolTy) { 1231 // Special handling for pointers implicitly cast to bool; 1232 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1233 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1234 Expr* SubE = ICE->getSubExpr(); 1235 if (SubE->getType()->isPointerType() || 1236 SubE->getType()->isArrayType() || 1237 SubE->getType()->isFunctionType()) { 1238 return CheckAddressConstantExpression(Init); 1239 } 1240 } 1241 } else if (InitTy->isIntegralType()) { 1242 Expr* SubE = 0; 1243 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1244 SubE = CE->getSubExpr(); 1245 // Special check for pointer cast to int; we allow as an extension 1246 // an address constant cast to an integer if the integer 1247 // is of an appropriate width (this sort of code is apparently used 1248 // in some places). 1249 // FIXME: Add pedwarn? 1250 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1251 if (SubE && (SubE->getType()->isPointerType() || 1252 SubE->getType()->isArrayType() || 1253 SubE->getType()->isFunctionType())) { 1254 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1255 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1256 if (IntWidth >= PointerWidth) 1257 return CheckAddressConstantExpression(Init); 1258 } 1259 } 1260 1261 return CheckArithmeticConstantExpression(Init); 1262 } 1263 1264 if (Init->getType()->isPointerType()) 1265 return CheckAddressConstantExpression(Init); 1266 1267 // An array type at the top level that isn't an init-list must 1268 // be a string literal 1269 if (Init->getType()->isArrayType()) 1270 return false; 1271 1272 if (Init->getType()->isFunctionType()) 1273 return false; 1274 1275 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1276 Init->getSourceRange()); 1277 return true; 1278} 1279 1280void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1281 Decl *RealDecl = static_cast<Decl *>(dcl); 1282 Expr *Init = static_cast<Expr *>(init); 1283 assert(Init && "missing initializer"); 1284 1285 // If there is no declaration, there was an error parsing it. Just ignore 1286 // the initializer. 1287 if (RealDecl == 0) { 1288 delete Init; 1289 return; 1290 } 1291 1292 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1293 if (!VDecl) { 1294 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1295 diag::err_illegal_initializer); 1296 RealDecl->setInvalidDecl(); 1297 return; 1298 } 1299 // Get the decls type and save a reference for later, since 1300 // CheckInitializerTypes may change it. 1301 QualType DclT = VDecl->getType(), SavT = DclT; 1302 if (VDecl->isBlockVarDecl()) { 1303 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1304 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1305 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1306 VDecl->setInvalidDecl(); 1307 } else if (!VDecl->isInvalidDecl()) { 1308 if (CheckInitializerTypes(Init, DclT)) 1309 VDecl->setInvalidDecl(); 1310 1311 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1312 if (!getLangOptions().CPlusPlus) { 1313 if (SC == VarDecl::Static) // C99 6.7.8p4. 1314 CheckForConstantInitializer(Init, DclT); 1315 } 1316 } 1317 } else if (VDecl->isFileVarDecl()) { 1318 if (VDecl->getStorageClass() == VarDecl::Extern) 1319 Diag(VDecl->getLocation(), diag::warn_extern_init); 1320 if (!VDecl->isInvalidDecl()) 1321 if (CheckInitializerTypes(Init, DclT)) 1322 VDecl->setInvalidDecl(); 1323 1324 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1325 if (!getLangOptions().CPlusPlus) { 1326 // C99 6.7.8p4. All file scoped initializers need to be constant. 1327 CheckForConstantInitializer(Init, DclT); 1328 } 1329 } 1330 // If the type changed, it means we had an incomplete type that was 1331 // completed by the initializer. For example: 1332 // int ary[] = { 1, 3, 5 }; 1333 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1334 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1335 VDecl->setType(DclT); 1336 Init->setType(DclT); 1337 } 1338 1339 // Attach the initializer to the decl. 1340 VDecl->setInit(Init); 1341 return; 1342} 1343 1344/// The declarators are chained together backwards, reverse the list. 1345Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1346 // Often we have single declarators, handle them quickly. 1347 Decl *GroupDecl = static_cast<Decl*>(group); 1348 if (GroupDecl == 0) 1349 return 0; 1350 1351 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1352 ScopedDecl *NewGroup = 0; 1353 if (Group->getNextDeclarator() == 0) 1354 NewGroup = Group; 1355 else { // reverse the list. 1356 while (Group) { 1357 ScopedDecl *Next = Group->getNextDeclarator(); 1358 Group->setNextDeclarator(NewGroup); 1359 NewGroup = Group; 1360 Group = Next; 1361 } 1362 } 1363 // Perform semantic analysis that depends on having fully processed both 1364 // the declarator and initializer. 1365 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1366 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1367 if (!IDecl) 1368 continue; 1369 QualType T = IDecl->getType(); 1370 1371 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1372 // static storage duration, it shall not have a variable length array. 1373 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1374 IDecl->getStorageClass() == VarDecl::Static) { 1375 if (T->isVariableArrayType()) { 1376 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1377 IDecl->setInvalidDecl(); 1378 } 1379 } 1380 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1381 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1382 if (IDecl->isBlockVarDecl() && 1383 IDecl->getStorageClass() != VarDecl::Extern) { 1384 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1385 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1386 T.getAsString()); 1387 IDecl->setInvalidDecl(); 1388 } 1389 } 1390 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1391 // object that has file scope without an initializer, and without a 1392 // storage-class specifier or with the storage-class specifier "static", 1393 // constitutes a tentative definition. Note: A tentative definition with 1394 // external linkage is valid (C99 6.2.2p5). 1395 if (isTentativeDefinition(IDecl)) { 1396 if (T->isIncompleteArrayType()) { 1397 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1398 // array to be completed. Don't issue a diagnostic. 1399 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1400 // C99 6.9.2p3: If the declaration of an identifier for an object is 1401 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1402 // declared type shall not be an incomplete type. 1403 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1404 T.getAsString()); 1405 IDecl->setInvalidDecl(); 1406 } 1407 } 1408 if (IDecl->isFileVarDecl()) 1409 CheckForFileScopedRedefinitions(S, IDecl); 1410 } 1411 return NewGroup; 1412} 1413 1414/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1415/// to introduce parameters into function prototype scope. 1416Sema::DeclTy * 1417Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1418 const DeclSpec &DS = D.getDeclSpec(); 1419 1420 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1421 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1422 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1423 Diag(DS.getStorageClassSpecLoc(), 1424 diag::err_invalid_storage_class_in_func_decl); 1425 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1426 } 1427 if (DS.isThreadSpecified()) { 1428 Diag(DS.getThreadSpecLoc(), 1429 diag::err_invalid_storage_class_in_func_decl); 1430 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1431 } 1432 1433 // Check that there are no default arguments inside the type of this 1434 // parameter (C++ only). 1435 if (getLangOptions().CPlusPlus) 1436 CheckExtraCXXDefaultArguments(D); 1437 1438 // In this context, we *do not* check D.getInvalidType(). If the declarator 1439 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1440 // though it will not reflect the user specified type. 1441 QualType parmDeclType = GetTypeForDeclarator(D, S); 1442 1443 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1444 1445 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1446 // Can this happen for params? We already checked that they don't conflict 1447 // among each other. Here they can only shadow globals, which is ok. 1448 IdentifierInfo *II = D.getIdentifier(); 1449 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1450 if (S->isDeclScope(PrevDecl)) { 1451 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1452 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1453 1454 // Recover by removing the name 1455 II = 0; 1456 D.SetIdentifier(0, D.getIdentifierLoc()); 1457 } 1458 } 1459 1460 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1461 // Doing the promotion here has a win and a loss. The win is the type for 1462 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1463 // code generator). The loss is the orginal type isn't preserved. For example: 1464 // 1465 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1466 // int blockvardecl[5]; 1467 // sizeof(parmvardecl); // size == 4 1468 // sizeof(blockvardecl); // size == 20 1469 // } 1470 // 1471 // For expressions, all implicit conversions are captured using the 1472 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1473 // 1474 // FIXME: If a source translation tool needs to see the original type, then 1475 // we need to consider storing both types (in ParmVarDecl)... 1476 // 1477 if (parmDeclType->isArrayType()) { 1478 // int x[restrict 4] -> int *restrict 1479 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1480 } else if (parmDeclType->isFunctionType()) 1481 parmDeclType = Context.getPointerType(parmDeclType); 1482 1483 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1484 D.getIdentifierLoc(), II, 1485 parmDeclType, VarDecl::None, 1486 0, 0); 1487 1488 if (D.getInvalidType()) 1489 New->setInvalidDecl(); 1490 1491 if (II) 1492 PushOnScopeChains(New, S); 1493 1494 ProcessDeclAttributes(New, D); 1495 return New; 1496 1497} 1498 1499Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1500 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1501 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1502 "Not a function declarator!"); 1503 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1504 1505 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1506 // for a K&R function. 1507 if (!FTI.hasPrototype) { 1508 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1509 if (FTI.ArgInfo[i].Param == 0) { 1510 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1511 FTI.ArgInfo[i].Ident->getName()); 1512 // Implicitly declare the argument as type 'int' for lack of a better 1513 // type. 1514 DeclSpec DS; 1515 const char* PrevSpec; // unused 1516 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1517 PrevSpec); 1518 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1519 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1520 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1521 } 1522 } 1523 } else { 1524 // FIXME: Diagnose arguments without names in C. 1525 } 1526 1527 Scope *GlobalScope = FnBodyScope->getParent(); 1528 1529 // See if this is a redefinition. 1530 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1531 GlobalScope); 1532 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1533 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1534 const FunctionDecl *Definition; 1535 if (FD->getBody(Definition)) { 1536 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1537 D.getIdentifier()->getName()); 1538 Diag(Definition->getLocation(), diag::err_previous_definition); 1539 } 1540 } 1541 } 1542 1543 return ActOnStartOfFunctionDef(FnBodyScope, 1544 ActOnDeclarator(GlobalScope, D, 0)); 1545} 1546 1547Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1548 Decl *decl = static_cast<Decl*>(D); 1549 FunctionDecl *FD = cast<FunctionDecl>(decl); 1550 PushDeclContext(FD); 1551 1552 // Check the validity of our function parameters 1553 CheckParmsForFunctionDef(FD); 1554 1555 // Introduce our parameters into the function scope 1556 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1557 ParmVarDecl *Param = FD->getParamDecl(p); 1558 // If this has an identifier, add it to the scope stack. 1559 if (Param->getIdentifier()) 1560 PushOnScopeChains(Param, FnBodyScope); 1561 } 1562 1563 return FD; 1564} 1565 1566Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1567 Decl *dcl = static_cast<Decl *>(D); 1568 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1569 FD->setBody((Stmt*)Body); 1570 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1571 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1572 MD->setBody((Stmt*)Body); 1573 } else 1574 return 0; 1575 PopDeclContext(); 1576 // Verify and clean out per-function state. 1577 1578 // Check goto/label use. 1579 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1580 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1581 // Verify that we have no forward references left. If so, there was a goto 1582 // or address of a label taken, but no definition of it. Label fwd 1583 // definitions are indicated with a null substmt. 1584 if (I->second->getSubStmt() == 0) { 1585 LabelStmt *L = I->second; 1586 // Emit error. 1587 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1588 1589 // At this point, we have gotos that use the bogus label. Stitch it into 1590 // the function body so that they aren't leaked and that the AST is well 1591 // formed. 1592 if (Body) { 1593 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1594 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1595 } else { 1596 // The whole function wasn't parsed correctly, just delete this. 1597 delete L; 1598 } 1599 } 1600 } 1601 LabelMap.clear(); 1602 1603 return D; 1604} 1605 1606/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1607/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1608ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1609 IdentifierInfo &II, Scope *S) { 1610 // Extension in C99. Legal in C90, but warn about it. 1611 if (getLangOptions().C99) 1612 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1613 else 1614 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1615 1616 // FIXME: handle stuff like: 1617 // void foo() { extern float X(); } 1618 // void bar() { X(); } <-- implicit decl for X in another scope. 1619 1620 // Set a Declarator for the implicit definition: int foo(); 1621 const char *Dummy; 1622 DeclSpec DS; 1623 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1624 Error = Error; // Silence warning. 1625 assert(!Error && "Error setting up implicit decl!"); 1626 Declarator D(DS, Declarator::BlockContext); 1627 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1628 D.SetIdentifier(&II, Loc); 1629 1630 // Insert this function into translation-unit scope. 1631 1632 DeclContext *PrevDC = CurContext; 1633 CurContext = Context.getTranslationUnitDecl(); 1634 1635 FunctionDecl *FD = 1636 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1637 FD->setImplicit(); 1638 1639 CurContext = PrevDC; 1640 1641 return FD; 1642} 1643 1644 1645TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1646 ScopedDecl *LastDeclarator) { 1647 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1648 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1649 1650 // Scope manipulation handled by caller. 1651 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1652 D.getIdentifierLoc(), 1653 D.getIdentifier(), 1654 T, LastDeclarator); 1655 if (D.getInvalidType()) 1656 NewTD->setInvalidDecl(); 1657 return NewTD; 1658} 1659 1660/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1661/// former case, Name will be non-null. In the later case, Name will be null. 1662/// TagType indicates what kind of tag this is. TK indicates whether this is a 1663/// reference/declaration/definition of a tag. 1664Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1665 SourceLocation KWLoc, IdentifierInfo *Name, 1666 SourceLocation NameLoc, AttributeList *Attr) { 1667 // If this is a use of an existing tag, it must have a name. 1668 assert((Name != 0 || TK == TK_Definition) && 1669 "Nameless record must be a definition!"); 1670 1671 TagDecl::TagKind Kind; 1672 switch (TagType) { 1673 default: assert(0 && "Unknown tag type!"); 1674 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1675 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1676 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1677 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1678 } 1679 1680 // If this is a named struct, check to see if there was a previous forward 1681 // declaration or definition. 1682 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1683 if (ScopedDecl *PrevDecl = 1684 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1685 1686 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1687 "unexpected Decl type"); 1688 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1689 // If this is a use of a previous tag, or if the tag is already declared 1690 // in the same scope (so that the definition/declaration completes or 1691 // rementions the tag), reuse the decl. 1692 if (TK == TK_Reference || 1693 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1694 // Make sure that this wasn't declared as an enum and now used as a 1695 // struct or something similar. 1696 if (PrevTagDecl->getTagKind() != Kind) { 1697 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1698 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1699 // Recover by making this an anonymous redefinition. 1700 Name = 0; 1701 PrevDecl = 0; 1702 } else { 1703 // If this is a use or a forward declaration, we're good. 1704 if (TK != TK_Definition) 1705 return PrevDecl; 1706 1707 // Diagnose attempts to redefine a tag. 1708 if (PrevTagDecl->isDefinition()) { 1709 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1710 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1711 // If this is a redefinition, recover by making this struct be 1712 // anonymous, which will make any later references get the previous 1713 // definition. 1714 Name = 0; 1715 } else { 1716 // Okay, this is definition of a previously declared or referenced 1717 // tag. Move the location of the decl to be the definition site. 1718 PrevDecl->setLocation(NameLoc); 1719 return PrevDecl; 1720 } 1721 } 1722 } 1723 // If we get here, this is a definition of a new struct type in a nested 1724 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1725 // type. 1726 } else { 1727 // PrevDecl is a namespace. 1728 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1729 // The tag name clashes with a namespace name, issue an error and recover 1730 // by making this tag be anonymous. 1731 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1732 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1733 Name = 0; 1734 } 1735 } 1736 } 1737 1738 // If there is an identifier, use the location of the identifier as the 1739 // location of the decl, otherwise use the location of the struct/union 1740 // keyword. 1741 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1742 1743 // Otherwise, if this is the first time we've seen this tag, create the decl. 1744 TagDecl *New; 1745 if (Kind == TagDecl::TK_enum) { 1746 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1747 // enum X { A, B, C } D; D should chain to X. 1748 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1749 // If this is an undefined enum, warn. 1750 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1751 } else { 1752 // struct/union/class 1753 1754 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1755 // struct X { int A; } D; D should chain to X. 1756 if (getLangOptions().CPlusPlus) 1757 // FIXME: Look for a way to use RecordDecl for simple structs. 1758 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1759 else 1760 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1761 } 1762 1763 // If this has an identifier, add it to the scope stack. 1764 if (Name) { 1765 // The scope passed in may not be a decl scope. Zip up the scope tree until 1766 // we find one that is. 1767 while ((S->getFlags() & Scope::DeclScope) == 0) 1768 S = S->getParent(); 1769 1770 // Add it to the decl chain. 1771 PushOnScopeChains(New, S); 1772 } 1773 1774 if (Attr) 1775 ProcessDeclAttributeList(New, Attr); 1776 return New; 1777} 1778 1779/// Collect the instance variables declared in an Objective-C object. Used in 1780/// the creation of structures from objects using the @defs directive. 1781static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 1782 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1783 if (Class->getSuperClass()) 1784 CollectIvars(Class->getSuperClass(), Ctx, ivars); 1785 1786 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 1787 for (ObjCInterfaceDecl::ivar_iterator I=Class->ivar_begin(), E=Class->ivar_end(); 1788 I!=E; ++I) { 1789 1790 ObjCIvarDecl* ID = *I; 1791 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 1792 ID->getIdentifier(), 1793 ID->getType(), 1794 ID->getBitWidth())); 1795 } 1796} 1797 1798/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1799/// instance variables of ClassName into Decls. 1800void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1801 IdentifierInfo *ClassName, 1802 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1803 // Check that ClassName is a valid class 1804 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1805 if (!Class) { 1806 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1807 return; 1808 } 1809 // Collect the instance variables 1810 CollectIvars(Class, Context, Decls); 1811} 1812 1813QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1814 // This method tries to turn a variable array into a constant 1815 // array even when the size isn't an ICE. This is necessary 1816 // for compatibility with code that depends on gcc's buggy 1817 // constant expression folding, like struct {char x[(int)(char*)2];} 1818 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1819 APValue Result; 1820 if (VLATy->getSizeExpr() && 1821 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1822 llvm::APSInt &Res = Result.getInt(); 1823 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1824 return Context.getConstantArrayType(VLATy->getElementType(), 1825 Res, ArrayType::Normal, 0); 1826 } 1827 } 1828 return QualType(); 1829} 1830 1831/// ActOnField - Each field of a struct/union/class is passed into this in order 1832/// to create a FieldDecl object for it. 1833Sema::DeclTy *Sema::ActOnField(Scope *S, 1834 SourceLocation DeclStart, 1835 Declarator &D, ExprTy *BitfieldWidth) { 1836 IdentifierInfo *II = D.getIdentifier(); 1837 Expr *BitWidth = (Expr*)BitfieldWidth; 1838 SourceLocation Loc = DeclStart; 1839 if (II) Loc = D.getIdentifierLoc(); 1840 1841 // FIXME: Unnamed fields can be handled in various different ways, for 1842 // example, unnamed unions inject all members into the struct namespace! 1843 1844 1845 if (BitWidth) { 1846 // TODO: Validate. 1847 //printf("WARNING: BITFIELDS IGNORED!\n"); 1848 1849 // 6.7.2.1p3 1850 // 6.7.2.1p4 1851 1852 } else { 1853 // Not a bitfield. 1854 1855 // validate II. 1856 1857 } 1858 1859 QualType T = GetTypeForDeclarator(D, S); 1860 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1861 bool InvalidDecl = false; 1862 1863 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1864 // than a variably modified type. 1865 if (T->isVariablyModifiedType()) { 1866 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1867 if (!FixedTy.isNull()) { 1868 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1869 T = FixedTy; 1870 } else { 1871 // FIXME: This diagnostic needs work 1872 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1873 InvalidDecl = true; 1874 } 1875 } 1876 // FIXME: Chain fielddecls together. 1877 FieldDecl *NewFD; 1878 1879 if (getLangOptions().CPlusPlus) { 1880 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1881 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1882 Loc, II, T, BitWidth); 1883 if (II) 1884 PushOnScopeChains(NewFD, S); 1885 } 1886 else 1887 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1888 1889 ProcessDeclAttributes(NewFD, D); 1890 1891 if (D.getInvalidType() || InvalidDecl) 1892 NewFD->setInvalidDecl(); 1893 return NewFD; 1894} 1895 1896/// TranslateIvarVisibility - Translate visibility from a token ID to an 1897/// AST enum value. 1898static ObjCIvarDecl::AccessControl 1899TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1900 switch (ivarVisibility) { 1901 case tok::objc_private: return ObjCIvarDecl::Private; 1902 case tok::objc_public: return ObjCIvarDecl::Public; 1903 case tok::objc_protected: return ObjCIvarDecl::Protected; 1904 case tok::objc_package: return ObjCIvarDecl::Package; 1905 default: assert(false && "Unknown visitibility kind"); 1906 } 1907} 1908 1909/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1910/// in order to create an IvarDecl object for it. 1911Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1912 SourceLocation DeclStart, 1913 Declarator &D, ExprTy *BitfieldWidth, 1914 tok::ObjCKeywordKind Visibility) { 1915 IdentifierInfo *II = D.getIdentifier(); 1916 Expr *BitWidth = (Expr*)BitfieldWidth; 1917 SourceLocation Loc = DeclStart; 1918 if (II) Loc = D.getIdentifierLoc(); 1919 1920 // FIXME: Unnamed fields can be handled in various different ways, for 1921 // example, unnamed unions inject all members into the struct namespace! 1922 1923 1924 if (BitWidth) { 1925 // TODO: Validate. 1926 //printf("WARNING: BITFIELDS IGNORED!\n"); 1927 1928 // 6.7.2.1p3 1929 // 6.7.2.1p4 1930 1931 } else { 1932 // Not a bitfield. 1933 1934 // validate II. 1935 1936 } 1937 1938 QualType T = GetTypeForDeclarator(D, S); 1939 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1940 bool InvalidDecl = false; 1941 1942 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1943 // than a variably modified type. 1944 if (T->isVariablyModifiedType()) { 1945 // FIXME: This diagnostic needs work 1946 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1947 InvalidDecl = true; 1948 } 1949 1950 // Get the visibility (access control) for this ivar. 1951 ObjCIvarDecl::AccessControl ac = 1952 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1953 : ObjCIvarDecl::None; 1954 1955 // Construct the decl. 1956 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1957 (Expr *)BitfieldWidth); 1958 1959 // Process attributes attached to the ivar. 1960 ProcessDeclAttributes(NewID, D); 1961 1962 if (D.getInvalidType() || InvalidDecl) 1963 NewID->setInvalidDecl(); 1964 1965 return NewID; 1966} 1967 1968void Sema::ActOnFields(Scope* S, 1969 SourceLocation RecLoc, DeclTy *RecDecl, 1970 DeclTy **Fields, unsigned NumFields, 1971 SourceLocation LBrac, SourceLocation RBrac) { 1972 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1973 assert(EnclosingDecl && "missing record or interface decl"); 1974 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1975 1976 if (Record && Record->isDefinition()) { 1977 // Diagnose code like: 1978 // struct S { struct S {} X; }; 1979 // We discover this when we complete the outer S. Reject and ignore the 1980 // outer S. 1981 Diag(Record->getLocation(), diag::err_nested_redefinition, 1982 Record->getKindName()); 1983 Diag(RecLoc, diag::err_previous_definition); 1984 Record->setInvalidDecl(); 1985 return; 1986 } 1987 // Verify that all the fields are okay. 1988 unsigned NumNamedMembers = 0; 1989 llvm::SmallVector<FieldDecl*, 32> RecFields; 1990 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 1991 1992 for (unsigned i = 0; i != NumFields; ++i) { 1993 1994 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 1995 assert(FD && "missing field decl"); 1996 1997 // Remember all fields. 1998 RecFields.push_back(FD); 1999 2000 // Get the type for the field. 2001 Type *FDTy = FD->getType().getTypePtr(); 2002 2003 // C99 6.7.2.1p2 - A field may not be a function type. 2004 if (FDTy->isFunctionType()) { 2005 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2006 FD->getName()); 2007 FD->setInvalidDecl(); 2008 EnclosingDecl->setInvalidDecl(); 2009 continue; 2010 } 2011 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2012 if (FDTy->isIncompleteType()) { 2013 if (!Record) { // Incomplete ivar type is always an error. 2014 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2015 FD->setInvalidDecl(); 2016 EnclosingDecl->setInvalidDecl(); 2017 continue; 2018 } 2019 if (i != NumFields-1 || // ... that the last member ... 2020 !Record->isStruct() || // ... of a structure ... 2021 !FDTy->isArrayType()) { //... may have incomplete array type. 2022 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2023 FD->setInvalidDecl(); 2024 EnclosingDecl->setInvalidDecl(); 2025 continue; 2026 } 2027 if (NumNamedMembers < 1) { //... must have more than named member ... 2028 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2029 FD->getName()); 2030 FD->setInvalidDecl(); 2031 EnclosingDecl->setInvalidDecl(); 2032 continue; 2033 } 2034 // Okay, we have a legal flexible array member at the end of the struct. 2035 if (Record) 2036 Record->setHasFlexibleArrayMember(true); 2037 } 2038 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2039 /// field of another structure or the element of an array. 2040 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2041 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2042 // If this is a member of a union, then entire union becomes "flexible". 2043 if (Record && Record->isUnion()) { 2044 Record->setHasFlexibleArrayMember(true); 2045 } else { 2046 // If this is a struct/class and this is not the last element, reject 2047 // it. Note that GCC supports variable sized arrays in the middle of 2048 // structures. 2049 if (i != NumFields-1) { 2050 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2051 FD->getName()); 2052 FD->setInvalidDecl(); 2053 EnclosingDecl->setInvalidDecl(); 2054 continue; 2055 } 2056 // We support flexible arrays at the end of structs in other structs 2057 // as an extension. 2058 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2059 FD->getName()); 2060 if (Record) 2061 Record->setHasFlexibleArrayMember(true); 2062 } 2063 } 2064 } 2065 /// A field cannot be an Objective-c object 2066 if (FDTy->isObjCInterfaceType()) { 2067 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2068 FD->getName()); 2069 FD->setInvalidDecl(); 2070 EnclosingDecl->setInvalidDecl(); 2071 continue; 2072 } 2073 // Keep track of the number of named members. 2074 if (IdentifierInfo *II = FD->getIdentifier()) { 2075 // Detect duplicate member names. 2076 if (!FieldIDs.insert(II)) { 2077 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2078 // Find the previous decl. 2079 SourceLocation PrevLoc; 2080 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2081 assert(i != e && "Didn't find previous def!"); 2082 if (RecFields[i]->getIdentifier() == II) { 2083 PrevLoc = RecFields[i]->getLocation(); 2084 break; 2085 } 2086 } 2087 Diag(PrevLoc, diag::err_previous_definition); 2088 FD->setInvalidDecl(); 2089 EnclosingDecl->setInvalidDecl(); 2090 continue; 2091 } 2092 ++NumNamedMembers; 2093 } 2094 } 2095 2096 // Okay, we successfully defined 'Record'. 2097 if (Record) { 2098 Record->defineBody(&RecFields[0], RecFields.size()); 2099 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2100 // Sema::ActOnFinishCXXClassDef. 2101 if (!isa<CXXRecordDecl>(Record)) 2102 Consumer.HandleTagDeclDefinition(Record); 2103 } else { 2104 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2105 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2106 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2107 else if (ObjCImplementationDecl *IMPDecl = 2108 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2109 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2110 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2111 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2112 } 2113 } 2114} 2115 2116Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2117 DeclTy *lastEnumConst, 2118 SourceLocation IdLoc, IdentifierInfo *Id, 2119 SourceLocation EqualLoc, ExprTy *val) { 2120 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2121 EnumConstantDecl *LastEnumConst = 2122 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2123 Expr *Val = static_cast<Expr*>(val); 2124 2125 // The scope passed in may not be a decl scope. Zip up the scope tree until 2126 // we find one that is. 2127 while ((S->getFlags() & Scope::DeclScope) == 0) 2128 S = S->getParent(); 2129 2130 // Verify that there isn't already something declared with this name in this 2131 // scope. 2132 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2133 // When in C++, we may get a TagDecl with the same name; in this case the 2134 // enum constant will 'hide' the tag. 2135 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2136 "Received TagDecl when not in C++!"); 2137 if (!isa<TagDecl>(PrevDecl) && 2138 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2139 if (isa<EnumConstantDecl>(PrevDecl)) 2140 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2141 else 2142 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2143 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2144 delete Val; 2145 return 0; 2146 } 2147 } 2148 2149 llvm::APSInt EnumVal(32); 2150 QualType EltTy; 2151 if (Val) { 2152 // Make sure to promote the operand type to int. 2153 UsualUnaryConversions(Val); 2154 2155 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2156 SourceLocation ExpLoc; 2157 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2158 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2159 Id->getName()); 2160 delete Val; 2161 Val = 0; // Just forget about it. 2162 } else { 2163 EltTy = Val->getType(); 2164 } 2165 } 2166 2167 if (!Val) { 2168 if (LastEnumConst) { 2169 // Assign the last value + 1. 2170 EnumVal = LastEnumConst->getInitVal(); 2171 ++EnumVal; 2172 2173 // Check for overflow on increment. 2174 if (EnumVal < LastEnumConst->getInitVal()) 2175 Diag(IdLoc, diag::warn_enum_value_overflow); 2176 2177 EltTy = LastEnumConst->getType(); 2178 } else { 2179 // First value, set to zero. 2180 EltTy = Context.IntTy; 2181 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2182 } 2183 } 2184 2185 EnumConstantDecl *New = 2186 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2187 Val, EnumVal, 2188 LastEnumConst); 2189 2190 // Register this decl in the current scope stack. 2191 PushOnScopeChains(New, S); 2192 return New; 2193} 2194 2195// FIXME: For consistency with ActOnFields(), we should have the parser 2196// pass in the source location for the left/right braces. 2197void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2198 DeclTy **Elements, unsigned NumElements) { 2199 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2200 2201 if (Enum && Enum->isDefinition()) { 2202 // Diagnose code like: 2203 // enum e0 { 2204 // E0 = sizeof(enum e0 { E1 }) 2205 // }; 2206 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2207 Enum->getName()); 2208 Diag(EnumLoc, diag::err_previous_definition); 2209 Enum->setInvalidDecl(); 2210 return; 2211 } 2212 // TODO: If the result value doesn't fit in an int, it must be a long or long 2213 // long value. ISO C does not support this, but GCC does as an extension, 2214 // emit a warning. 2215 unsigned IntWidth = Context.Target.getIntWidth(); 2216 2217 // Verify that all the values are okay, compute the size of the values, and 2218 // reverse the list. 2219 unsigned NumNegativeBits = 0; 2220 unsigned NumPositiveBits = 0; 2221 2222 // Keep track of whether all elements have type int. 2223 bool AllElementsInt = true; 2224 2225 EnumConstantDecl *EltList = 0; 2226 for (unsigned i = 0; i != NumElements; ++i) { 2227 EnumConstantDecl *ECD = 2228 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2229 if (!ECD) continue; // Already issued a diagnostic. 2230 2231 // If the enum value doesn't fit in an int, emit an extension warning. 2232 const llvm::APSInt &InitVal = ECD->getInitVal(); 2233 assert(InitVal.getBitWidth() >= IntWidth && 2234 "Should have promoted value to int"); 2235 if (InitVal.getBitWidth() > IntWidth) { 2236 llvm::APSInt V(InitVal); 2237 V.trunc(IntWidth); 2238 V.extend(InitVal.getBitWidth()); 2239 if (V != InitVal) 2240 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2241 InitVal.toString(10)); 2242 } 2243 2244 // Keep track of the size of positive and negative values. 2245 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2246 NumPositiveBits = std::max(NumPositiveBits, 2247 (unsigned)InitVal.getActiveBits()); 2248 else 2249 NumNegativeBits = std::max(NumNegativeBits, 2250 (unsigned)InitVal.getMinSignedBits()); 2251 2252 // Keep track of whether every enum element has type int (very commmon). 2253 if (AllElementsInt) 2254 AllElementsInt = ECD->getType() == Context.IntTy; 2255 2256 ECD->setNextDeclarator(EltList); 2257 EltList = ECD; 2258 } 2259 2260 // Figure out the type that should be used for this enum. 2261 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2262 QualType BestType; 2263 unsigned BestWidth; 2264 2265 if (NumNegativeBits) { 2266 // If there is a negative value, figure out the smallest integer type (of 2267 // int/long/longlong) that fits. 2268 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2269 BestType = Context.IntTy; 2270 BestWidth = IntWidth; 2271 } else { 2272 BestWidth = Context.Target.getLongWidth(); 2273 2274 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2275 BestType = Context.LongTy; 2276 else { 2277 BestWidth = Context.Target.getLongLongWidth(); 2278 2279 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2280 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2281 BestType = Context.LongLongTy; 2282 } 2283 } 2284 } else { 2285 // If there is no negative value, figure out which of uint, ulong, ulonglong 2286 // fits. 2287 if (NumPositiveBits <= IntWidth) { 2288 BestType = Context.UnsignedIntTy; 2289 BestWidth = IntWidth; 2290 } else if (NumPositiveBits <= 2291 (BestWidth = Context.Target.getLongWidth())) { 2292 BestType = Context.UnsignedLongTy; 2293 } else { 2294 BestWidth = Context.Target.getLongLongWidth(); 2295 assert(NumPositiveBits <= BestWidth && 2296 "How could an initializer get larger than ULL?"); 2297 BestType = Context.UnsignedLongLongTy; 2298 } 2299 } 2300 2301 // Loop over all of the enumerator constants, changing their types to match 2302 // the type of the enum if needed. 2303 for (unsigned i = 0; i != NumElements; ++i) { 2304 EnumConstantDecl *ECD = 2305 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2306 if (!ECD) continue; // Already issued a diagnostic. 2307 2308 // Standard C says the enumerators have int type, but we allow, as an 2309 // extension, the enumerators to be larger than int size. If each 2310 // enumerator value fits in an int, type it as an int, otherwise type it the 2311 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2312 // that X has type 'int', not 'unsigned'. 2313 if (ECD->getType() == Context.IntTy) { 2314 // Make sure the init value is signed. 2315 llvm::APSInt IV = ECD->getInitVal(); 2316 IV.setIsSigned(true); 2317 ECD->setInitVal(IV); 2318 continue; // Already int type. 2319 } 2320 2321 // Determine whether the value fits into an int. 2322 llvm::APSInt InitVal = ECD->getInitVal(); 2323 bool FitsInInt; 2324 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2325 FitsInInt = InitVal.getActiveBits() < IntWidth; 2326 else 2327 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2328 2329 // If it fits into an integer type, force it. Otherwise force it to match 2330 // the enum decl type. 2331 QualType NewTy; 2332 unsigned NewWidth; 2333 bool NewSign; 2334 if (FitsInInt) { 2335 NewTy = Context.IntTy; 2336 NewWidth = IntWidth; 2337 NewSign = true; 2338 } else if (ECD->getType() == BestType) { 2339 // Already the right type! 2340 continue; 2341 } else { 2342 NewTy = BestType; 2343 NewWidth = BestWidth; 2344 NewSign = BestType->isSignedIntegerType(); 2345 } 2346 2347 // Adjust the APSInt value. 2348 InitVal.extOrTrunc(NewWidth); 2349 InitVal.setIsSigned(NewSign); 2350 ECD->setInitVal(InitVal); 2351 2352 // Adjust the Expr initializer and type. 2353 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2354 ECD->setType(NewTy); 2355 } 2356 2357 Enum->defineElements(EltList, BestType); 2358 Consumer.HandleTagDeclDefinition(Enum); 2359} 2360 2361Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2362 ExprTy *expr) { 2363 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2364 2365 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2366} 2367 2368Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2369 SourceLocation LBrace, 2370 SourceLocation RBrace, 2371 const char *Lang, 2372 unsigned StrSize, 2373 DeclTy *D) { 2374 LinkageSpecDecl::LanguageIDs Language; 2375 Decl *dcl = static_cast<Decl *>(D); 2376 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2377 Language = LinkageSpecDecl::lang_c; 2378 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2379 Language = LinkageSpecDecl::lang_cxx; 2380 else { 2381 Diag(Loc, diag::err_bad_language); 2382 return 0; 2383 } 2384 2385 // FIXME: Add all the various semantics of linkage specifications 2386 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2387} 2388