SemaDecl.cpp revision b529d830b3b1667157da92ab0b5c32e1acfafbab
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 Diag(Init->getExprLoc(), 1080 diag::err_init_element_not_constant, Init->getSourceRange()); 1081 return true; 1082 } 1083 case Expr::CompoundLiteralExprClass: 1084 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1085 // but vectors are allowed to be magic. 1086 if (Init->getType()->isVectorType()) 1087 return false; 1088 Diag(Init->getExprLoc(), 1089 diag::err_init_element_not_constant, Init->getSourceRange()); 1090 return true; 1091 case Expr::UnaryOperatorClass: { 1092 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1093 1094 switch (Exp->getOpcode()) { 1095 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1096 // See C99 6.6p3. 1097 default: 1098 Diag(Init->getExprLoc(), 1099 diag::err_init_element_not_constant, Init->getSourceRange()); 1100 return true; 1101 case UnaryOperator::SizeOf: 1102 case UnaryOperator::AlignOf: 1103 case UnaryOperator::OffsetOf: 1104 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1105 // See C99 6.5.3.4p2 and 6.6p3. 1106 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1107 return false; 1108 Diag(Init->getExprLoc(), 1109 diag::err_init_element_not_constant, Init->getSourceRange()); 1110 return true; 1111 case UnaryOperator::Extension: 1112 case UnaryOperator::LNot: 1113 case UnaryOperator::Plus: 1114 case UnaryOperator::Minus: 1115 case UnaryOperator::Not: 1116 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1117 } 1118 } 1119 case Expr::SizeOfAlignOfTypeExprClass: { 1120 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1121 // Special check for void types, which are allowed as an extension 1122 if (Exp->getArgumentType()->isVoidType()) 1123 return false; 1124 // alignof always evaluates to a constant. 1125 // FIXME: is sizeof(int[3.0]) a constant expression? 1126 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1127 Diag(Init->getExprLoc(), 1128 diag::err_init_element_not_constant, Init->getSourceRange()); 1129 return true; 1130 } 1131 return false; 1132 } 1133 case Expr::BinaryOperatorClass: { 1134 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1135 1136 if (Exp->getLHS()->getType()->isArithmeticType() && 1137 Exp->getRHS()->getType()->isArithmeticType()) { 1138 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1139 CheckArithmeticConstantExpression(Exp->getRHS()); 1140 } 1141 1142 if (Exp->getLHS()->getType()->isPointerType() && 1143 Exp->getRHS()->getType()->isPointerType()) { 1144 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1145 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1146 1147 // Only allow a null (constant integer) base; we could 1148 // allow some additional cases if necessary, but this 1149 // is sufficient to cover offsetof-like constructs. 1150 if (!LHSBase && !RHSBase) { 1151 return CheckAddressConstantExpression(Exp->getLHS()) || 1152 CheckAddressConstantExpression(Exp->getRHS()); 1153 } 1154 } 1155 1156 Diag(Init->getExprLoc(), 1157 diag::err_init_element_not_constant, Init->getSourceRange()); 1158 return true; 1159 } 1160 case Expr::ImplicitCastExprClass: 1161 case Expr::ExplicitCastExprClass: { 1162 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1163 if (SubExpr->getType()->isArithmeticType()) 1164 return CheckArithmeticConstantExpression(SubExpr); 1165 1166 if (SubExpr->getType()->isPointerType()) { 1167 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1168 // If the pointer has a null base, this is an offsetof-like construct 1169 if (!Base) 1170 return CheckAddressConstantExpression(SubExpr); 1171 } 1172 1173 Diag(Init->getExprLoc(), 1174 diag::err_init_element_not_constant, Init->getSourceRange()); 1175 return true; 1176 } 1177 case Expr::ConditionalOperatorClass: { 1178 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1179 if (CheckArithmeticConstantExpression(Exp->getCond())) 1180 return true; 1181 if (Exp->getLHS() && 1182 CheckArithmeticConstantExpression(Exp->getLHS())) 1183 return true; 1184 return CheckArithmeticConstantExpression(Exp->getRHS()); 1185 } 1186 } 1187} 1188 1189bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1190 Init = Init->IgnoreParens(); 1191 1192 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1193 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1194 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1195 1196 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1197 return CheckForConstantInitializer(e->getInitializer(), DclT); 1198 1199 if (Init->getType()->isReferenceType()) { 1200 // FIXME: Work out how the heck reference types work 1201 return false; 1202#if 0 1203 // A reference is constant if the address of the expression 1204 // is constant 1205 // We look through initlists here to simplify 1206 // CheckAddressConstantExpressionLValue. 1207 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1208 assert(Exp->getNumInits() > 0 && 1209 "Refernce initializer cannot be empty"); 1210 Init = Exp->getInit(0); 1211 } 1212 return CheckAddressConstantExpressionLValue(Init); 1213#endif 1214 } 1215 1216 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1217 unsigned numInits = Exp->getNumInits(); 1218 for (unsigned i = 0; i < numInits; i++) { 1219 // FIXME: Need to get the type of the declaration for C++, 1220 // because it could be a reference? 1221 if (CheckForConstantInitializer(Exp->getInit(i), 1222 Exp->getInit(i)->getType())) 1223 return true; 1224 } 1225 return false; 1226 } 1227 1228 if (Init->isNullPointerConstant(Context)) 1229 return false; 1230 if (Init->getType()->isArithmeticType()) { 1231 QualType InitTy = Context.getCanonicalType(Init->getType()) 1232 .getUnqualifiedType(); 1233 if (InitTy == Context.BoolTy) { 1234 // Special handling for pointers implicitly cast to bool; 1235 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1236 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1237 Expr* SubE = ICE->getSubExpr(); 1238 if (SubE->getType()->isPointerType() || 1239 SubE->getType()->isArrayType() || 1240 SubE->getType()->isFunctionType()) { 1241 return CheckAddressConstantExpression(Init); 1242 } 1243 } 1244 } else if (InitTy->isIntegralType()) { 1245 Expr* SubE = 0; 1246 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1247 SubE = CE->getSubExpr(); 1248 // Special check for pointer cast to int; we allow as an extension 1249 // an address constant cast to an integer if the integer 1250 // is of an appropriate width (this sort of code is apparently used 1251 // in some places). 1252 // FIXME: Add pedwarn? 1253 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1254 if (SubE && (SubE->getType()->isPointerType() || 1255 SubE->getType()->isArrayType() || 1256 SubE->getType()->isFunctionType())) { 1257 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1258 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1259 if (IntWidth >= PointerWidth) 1260 return CheckAddressConstantExpression(Init); 1261 } 1262 } 1263 1264 return CheckArithmeticConstantExpression(Init); 1265 } 1266 1267 if (Init->getType()->isPointerType()) 1268 return CheckAddressConstantExpression(Init); 1269 1270 // An array type at the top level that isn't an init-list must 1271 // be a string literal 1272 if (Init->getType()->isArrayType()) 1273 return false; 1274 1275 if (Init->getType()->isFunctionType()) 1276 return false; 1277 1278 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1279 Init->getSourceRange()); 1280 return true; 1281} 1282 1283void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1284 Decl *RealDecl = static_cast<Decl *>(dcl); 1285 Expr *Init = static_cast<Expr *>(init); 1286 assert(Init && "missing initializer"); 1287 1288 // If there is no declaration, there was an error parsing it. Just ignore 1289 // the initializer. 1290 if (RealDecl == 0) { 1291 delete Init; 1292 return; 1293 } 1294 1295 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1296 if (!VDecl) { 1297 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1298 diag::err_illegal_initializer); 1299 RealDecl->setInvalidDecl(); 1300 return; 1301 } 1302 // Get the decls type and save a reference for later, since 1303 // CheckInitializerTypes may change it. 1304 QualType DclT = VDecl->getType(), SavT = DclT; 1305 if (VDecl->isBlockVarDecl()) { 1306 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1307 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1308 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1309 VDecl->setInvalidDecl(); 1310 } else if (!VDecl->isInvalidDecl()) { 1311 if (CheckInitializerTypes(Init, DclT)) 1312 VDecl->setInvalidDecl(); 1313 1314 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1315 if (!getLangOptions().CPlusPlus) { 1316 if (SC == VarDecl::Static) // C99 6.7.8p4. 1317 CheckForConstantInitializer(Init, DclT); 1318 } 1319 } 1320 } else if (VDecl->isFileVarDecl()) { 1321 if (VDecl->getStorageClass() == VarDecl::Extern) 1322 Diag(VDecl->getLocation(), diag::warn_extern_init); 1323 if (!VDecl->isInvalidDecl()) 1324 if (CheckInitializerTypes(Init, DclT)) 1325 VDecl->setInvalidDecl(); 1326 1327 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1328 if (!getLangOptions().CPlusPlus) { 1329 // C99 6.7.8p4. All file scoped initializers need to be constant. 1330 CheckForConstantInitializer(Init, DclT); 1331 } 1332 } 1333 // If the type changed, it means we had an incomplete type that was 1334 // completed by the initializer. For example: 1335 // int ary[] = { 1, 3, 5 }; 1336 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1337 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1338 VDecl->setType(DclT); 1339 Init->setType(DclT); 1340 } 1341 1342 // Attach the initializer to the decl. 1343 VDecl->setInit(Init); 1344 return; 1345} 1346 1347/// The declarators are chained together backwards, reverse the list. 1348Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1349 // Often we have single declarators, handle them quickly. 1350 Decl *GroupDecl = static_cast<Decl*>(group); 1351 if (GroupDecl == 0) 1352 return 0; 1353 1354 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1355 ScopedDecl *NewGroup = 0; 1356 if (Group->getNextDeclarator() == 0) 1357 NewGroup = Group; 1358 else { // reverse the list. 1359 while (Group) { 1360 ScopedDecl *Next = Group->getNextDeclarator(); 1361 Group->setNextDeclarator(NewGroup); 1362 NewGroup = Group; 1363 Group = Next; 1364 } 1365 } 1366 // Perform semantic analysis that depends on having fully processed both 1367 // the declarator and initializer. 1368 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1369 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1370 if (!IDecl) 1371 continue; 1372 QualType T = IDecl->getType(); 1373 1374 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1375 // static storage duration, it shall not have a variable length array. 1376 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1377 IDecl->getStorageClass() == VarDecl::Static) { 1378 if (T->isVariableArrayType()) { 1379 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1380 IDecl->setInvalidDecl(); 1381 } 1382 } 1383 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1384 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1385 if (IDecl->isBlockVarDecl() && 1386 IDecl->getStorageClass() != VarDecl::Extern) { 1387 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1388 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1389 T.getAsString()); 1390 IDecl->setInvalidDecl(); 1391 } 1392 } 1393 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1394 // object that has file scope without an initializer, and without a 1395 // storage-class specifier or with the storage-class specifier "static", 1396 // constitutes a tentative definition. Note: A tentative definition with 1397 // external linkage is valid (C99 6.2.2p5). 1398 if (isTentativeDefinition(IDecl)) { 1399 if (T->isIncompleteArrayType()) { 1400 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1401 // array to be completed. Don't issue a diagnostic. 1402 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1403 // C99 6.9.2p3: If the declaration of an identifier for an object is 1404 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1405 // declared type shall not be an incomplete type. 1406 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1407 T.getAsString()); 1408 IDecl->setInvalidDecl(); 1409 } 1410 } 1411 if (IDecl->isFileVarDecl()) 1412 CheckForFileScopedRedefinitions(S, IDecl); 1413 } 1414 return NewGroup; 1415} 1416 1417/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1418/// to introduce parameters into function prototype scope. 1419Sema::DeclTy * 1420Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1421 const DeclSpec &DS = D.getDeclSpec(); 1422 1423 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1424 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1425 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1426 Diag(DS.getStorageClassSpecLoc(), 1427 diag::err_invalid_storage_class_in_func_decl); 1428 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1429 } 1430 if (DS.isThreadSpecified()) { 1431 Diag(DS.getThreadSpecLoc(), 1432 diag::err_invalid_storage_class_in_func_decl); 1433 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1434 } 1435 1436 // Check that there are no default arguments inside the type of this 1437 // parameter (C++ only). 1438 if (getLangOptions().CPlusPlus) 1439 CheckExtraCXXDefaultArguments(D); 1440 1441 // In this context, we *do not* check D.getInvalidType(). If the declarator 1442 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1443 // though it will not reflect the user specified type. 1444 QualType parmDeclType = GetTypeForDeclarator(D, S); 1445 1446 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1447 1448 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1449 // Can this happen for params? We already checked that they don't conflict 1450 // among each other. Here they can only shadow globals, which is ok. 1451 IdentifierInfo *II = D.getIdentifier(); 1452 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1453 if (S->isDeclScope(PrevDecl)) { 1454 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1455 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1456 1457 // Recover by removing the name 1458 II = 0; 1459 D.SetIdentifier(0, D.getIdentifierLoc()); 1460 } 1461 } 1462 1463 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1464 // Doing the promotion here has a win and a loss. The win is the type for 1465 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1466 // code generator). The loss is the orginal type isn't preserved. For example: 1467 // 1468 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1469 // int blockvardecl[5]; 1470 // sizeof(parmvardecl); // size == 4 1471 // sizeof(blockvardecl); // size == 20 1472 // } 1473 // 1474 // For expressions, all implicit conversions are captured using the 1475 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1476 // 1477 // FIXME: If a source translation tool needs to see the original type, then 1478 // we need to consider storing both types (in ParmVarDecl)... 1479 // 1480 if (parmDeclType->isArrayType()) { 1481 // int x[restrict 4] -> int *restrict 1482 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1483 } else if (parmDeclType->isFunctionType()) 1484 parmDeclType = Context.getPointerType(parmDeclType); 1485 1486 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1487 D.getIdentifierLoc(), II, 1488 parmDeclType, VarDecl::None, 1489 0, 0); 1490 1491 if (D.getInvalidType()) 1492 New->setInvalidDecl(); 1493 1494 if (II) 1495 PushOnScopeChains(New, S); 1496 1497 ProcessDeclAttributes(New, D); 1498 return New; 1499 1500} 1501 1502Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1503 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1504 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1505 "Not a function declarator!"); 1506 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1507 1508 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1509 // for a K&R function. 1510 if (!FTI.hasPrototype) { 1511 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1512 if (FTI.ArgInfo[i].Param == 0) { 1513 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1514 FTI.ArgInfo[i].Ident->getName()); 1515 // Implicitly declare the argument as type 'int' for lack of a better 1516 // type. 1517 DeclSpec DS; 1518 const char* PrevSpec; // unused 1519 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1520 PrevSpec); 1521 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1522 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1523 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1524 } 1525 } 1526 } else { 1527 // FIXME: Diagnose arguments without names in C. 1528 } 1529 1530 Scope *GlobalScope = FnBodyScope->getParent(); 1531 1532 // See if this is a redefinition. 1533 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1534 GlobalScope); 1535 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1536 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1537 const FunctionDecl *Definition; 1538 if (FD->getBody(Definition)) { 1539 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1540 D.getIdentifier()->getName()); 1541 Diag(Definition->getLocation(), diag::err_previous_definition); 1542 } 1543 } 1544 } 1545 1546 return ActOnStartOfFunctionDef(FnBodyScope, 1547 ActOnDeclarator(GlobalScope, D, 0)); 1548} 1549 1550Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1551 Decl *decl = static_cast<Decl*>(D); 1552 FunctionDecl *FD = cast<FunctionDecl>(decl); 1553 PushDeclContext(FD); 1554 1555 // Check the validity of our function parameters 1556 CheckParmsForFunctionDef(FD); 1557 1558 // Introduce our parameters into the function scope 1559 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1560 ParmVarDecl *Param = FD->getParamDecl(p); 1561 // If this has an identifier, add it to the scope stack. 1562 if (Param->getIdentifier()) 1563 PushOnScopeChains(Param, FnBodyScope); 1564 } 1565 1566 return FD; 1567} 1568 1569Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1570 Decl *dcl = static_cast<Decl *>(D); 1571 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1572 FD->setBody((Stmt*)Body); 1573 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1574 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1575 MD->setBody((Stmt*)Body); 1576 } else 1577 return 0; 1578 PopDeclContext(); 1579 // Verify and clean out per-function state. 1580 1581 // Check goto/label use. 1582 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1583 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1584 // Verify that we have no forward references left. If so, there was a goto 1585 // or address of a label taken, but no definition of it. Label fwd 1586 // definitions are indicated with a null substmt. 1587 if (I->second->getSubStmt() == 0) { 1588 LabelStmt *L = I->second; 1589 // Emit error. 1590 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1591 1592 // At this point, we have gotos that use the bogus label. Stitch it into 1593 // the function body so that they aren't leaked and that the AST is well 1594 // formed. 1595 if (Body) { 1596 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1597 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1598 } else { 1599 // The whole function wasn't parsed correctly, just delete this. 1600 delete L; 1601 } 1602 } 1603 } 1604 LabelMap.clear(); 1605 1606 return D; 1607} 1608 1609/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1610/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1611ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1612 IdentifierInfo &II, Scope *S) { 1613 // Extension in C99. Legal in C90, but warn about it. 1614 if (getLangOptions().C99) 1615 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1616 else 1617 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1618 1619 // FIXME: handle stuff like: 1620 // void foo() { extern float X(); } 1621 // void bar() { X(); } <-- implicit decl for X in another scope. 1622 1623 // Set a Declarator for the implicit definition: int foo(); 1624 const char *Dummy; 1625 DeclSpec DS; 1626 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1627 Error = Error; // Silence warning. 1628 assert(!Error && "Error setting up implicit decl!"); 1629 Declarator D(DS, Declarator::BlockContext); 1630 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1631 D.SetIdentifier(&II, Loc); 1632 1633 // Insert this function into translation-unit scope. 1634 1635 DeclContext *PrevDC = CurContext; 1636 CurContext = Context.getTranslationUnitDecl(); 1637 1638 FunctionDecl *FD = 1639 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1640 FD->setImplicit(); 1641 1642 CurContext = PrevDC; 1643 1644 return FD; 1645} 1646 1647 1648TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1649 ScopedDecl *LastDeclarator) { 1650 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1651 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1652 1653 // Scope manipulation handled by caller. 1654 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1655 D.getIdentifierLoc(), 1656 D.getIdentifier(), 1657 T, LastDeclarator); 1658 if (D.getInvalidType()) 1659 NewTD->setInvalidDecl(); 1660 return NewTD; 1661} 1662 1663/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1664/// former case, Name will be non-null. In the later case, Name will be null. 1665/// TagType indicates what kind of tag this is. TK indicates whether this is a 1666/// reference/declaration/definition of a tag. 1667Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1668 SourceLocation KWLoc, IdentifierInfo *Name, 1669 SourceLocation NameLoc, AttributeList *Attr) { 1670 // If this is a use of an existing tag, it must have a name. 1671 assert((Name != 0 || TK == TK_Definition) && 1672 "Nameless record must be a definition!"); 1673 1674 TagDecl::TagKind Kind; 1675 switch (TagType) { 1676 default: assert(0 && "Unknown tag type!"); 1677 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1678 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1679 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1680 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1681 } 1682 1683 // If this is a named struct, check to see if there was a previous forward 1684 // declaration or definition. 1685 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1686 if (ScopedDecl *PrevDecl = 1687 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1688 1689 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1690 "unexpected Decl type"); 1691 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1692 // If this is a use of a previous tag, or if the tag is already declared 1693 // in the same scope (so that the definition/declaration completes or 1694 // rementions the tag), reuse the decl. 1695 if (TK == TK_Reference || 1696 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1697 // Make sure that this wasn't declared as an enum and now used as a 1698 // struct or something similar. 1699 if (PrevTagDecl->getTagKind() != Kind) { 1700 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1701 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1702 // Recover by making this an anonymous redefinition. 1703 Name = 0; 1704 PrevDecl = 0; 1705 } else { 1706 // If this is a use or a forward declaration, we're good. 1707 if (TK != TK_Definition) 1708 return PrevDecl; 1709 1710 // Diagnose attempts to redefine a tag. 1711 if (PrevTagDecl->isDefinition()) { 1712 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1713 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1714 // If this is a redefinition, recover by making this struct be 1715 // anonymous, which will make any later references get the previous 1716 // definition. 1717 Name = 0; 1718 } else { 1719 // Okay, this is definition of a previously declared or referenced 1720 // tag. Move the location of the decl to be the definition site. 1721 PrevDecl->setLocation(NameLoc); 1722 return PrevDecl; 1723 } 1724 } 1725 } 1726 // If we get here, this is a definition of a new struct type in a nested 1727 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1728 // type. 1729 } else { 1730 // PrevDecl is a namespace. 1731 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1732 // The tag name clashes with a namespace name, issue an error and recover 1733 // by making this tag be anonymous. 1734 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1735 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1736 Name = 0; 1737 } 1738 } 1739 } 1740 1741 // If there is an identifier, use the location of the identifier as the 1742 // location of the decl, otherwise use the location of the struct/union 1743 // keyword. 1744 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1745 1746 // Otherwise, if this is the first time we've seen this tag, create the decl. 1747 TagDecl *New; 1748 if (Kind == TagDecl::TK_enum) { 1749 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1750 // enum X { A, B, C } D; D should chain to X. 1751 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1752 // If this is an undefined enum, warn. 1753 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1754 } else { 1755 // struct/union/class 1756 1757 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1758 // struct X { int A; } D; D should chain to X. 1759 if (getLangOptions().CPlusPlus) 1760 // FIXME: Look for a way to use RecordDecl for simple structs. 1761 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1762 else 1763 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1764 } 1765 1766 // If this has an identifier, add it to the scope stack. 1767 if (Name) { 1768 // The scope passed in may not be a decl scope. Zip up the scope tree until 1769 // we find one that is. 1770 while ((S->getFlags() & Scope::DeclScope) == 0) 1771 S = S->getParent(); 1772 1773 // Add it to the decl chain. 1774 PushOnScopeChains(New, S); 1775 } 1776 1777 if (Attr) 1778 ProcessDeclAttributeList(New, Attr); 1779 return New; 1780} 1781 1782/// Collect the instance variables declared in an Objective-C object. Used in 1783/// the creation of structures from objects using the @defs directive. 1784static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 1785 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1786 if (Class->getSuperClass()) 1787 CollectIvars(Class->getSuperClass(), Ctx, ivars); 1788 1789 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 1790 for (ObjCInterfaceDecl::ivar_iterator I=Class->ivar_begin(), E=Class->ivar_end(); 1791 I!=E; ++I) { 1792 1793 ObjCIvarDecl* ID = *I; 1794 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 1795 ID->getIdentifier(), 1796 ID->getType(), 1797 ID->getBitWidth())); 1798 } 1799} 1800 1801/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1802/// instance variables of ClassName into Decls. 1803void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1804 IdentifierInfo *ClassName, 1805 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1806 // Check that ClassName is a valid class 1807 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1808 if (!Class) { 1809 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1810 return; 1811 } 1812 // Collect the instance variables 1813 CollectIvars(Class, Context, Decls); 1814} 1815 1816QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1817 // This method tries to turn a variable array into a constant 1818 // array even when the size isn't an ICE. This is necessary 1819 // for compatibility with code that depends on gcc's buggy 1820 // constant expression folding, like struct {char x[(int)(char*)2];} 1821 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1822 APValue Result; 1823 if (VLATy->getSizeExpr() && 1824 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1825 llvm::APSInt &Res = Result.getInt(); 1826 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1827 return Context.getConstantArrayType(VLATy->getElementType(), 1828 Res, ArrayType::Normal, 0); 1829 } 1830 } 1831 return QualType(); 1832} 1833 1834/// ActOnField - Each field of a struct/union/class is passed into this in order 1835/// to create a FieldDecl object for it. 1836Sema::DeclTy *Sema::ActOnField(Scope *S, 1837 SourceLocation DeclStart, 1838 Declarator &D, ExprTy *BitfieldWidth) { 1839 IdentifierInfo *II = D.getIdentifier(); 1840 Expr *BitWidth = (Expr*)BitfieldWidth; 1841 SourceLocation Loc = DeclStart; 1842 if (II) Loc = D.getIdentifierLoc(); 1843 1844 // FIXME: Unnamed fields can be handled in various different ways, for 1845 // example, unnamed unions inject all members into the struct namespace! 1846 1847 1848 if (BitWidth) { 1849 // TODO: Validate. 1850 //printf("WARNING: BITFIELDS IGNORED!\n"); 1851 1852 // 6.7.2.1p3 1853 // 6.7.2.1p4 1854 1855 } else { 1856 // Not a bitfield. 1857 1858 // validate II. 1859 1860 } 1861 1862 QualType T = GetTypeForDeclarator(D, S); 1863 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1864 bool InvalidDecl = false; 1865 1866 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1867 // than a variably modified type. 1868 if (T->isVariablyModifiedType()) { 1869 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1870 if (!FixedTy.isNull()) { 1871 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1872 T = FixedTy; 1873 } else { 1874 // FIXME: This diagnostic needs work 1875 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1876 InvalidDecl = true; 1877 } 1878 } 1879 // FIXME: Chain fielddecls together. 1880 FieldDecl *NewFD; 1881 1882 if (getLangOptions().CPlusPlus) { 1883 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1884 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1885 Loc, II, T, BitWidth); 1886 if (II) 1887 PushOnScopeChains(NewFD, S); 1888 } 1889 else 1890 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1891 1892 ProcessDeclAttributes(NewFD, D); 1893 1894 if (D.getInvalidType() || InvalidDecl) 1895 NewFD->setInvalidDecl(); 1896 return NewFD; 1897} 1898 1899/// TranslateIvarVisibility - Translate visibility from a token ID to an 1900/// AST enum value. 1901static ObjCIvarDecl::AccessControl 1902TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1903 switch (ivarVisibility) { 1904 case tok::objc_private: return ObjCIvarDecl::Private; 1905 case tok::objc_public: return ObjCIvarDecl::Public; 1906 case tok::objc_protected: return ObjCIvarDecl::Protected; 1907 case tok::objc_package: return ObjCIvarDecl::Package; 1908 default: assert(false && "Unknown visitibility kind"); 1909 } 1910} 1911 1912/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1913/// in order to create an IvarDecl object for it. 1914Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1915 SourceLocation DeclStart, 1916 Declarator &D, ExprTy *BitfieldWidth, 1917 tok::ObjCKeywordKind Visibility) { 1918 IdentifierInfo *II = D.getIdentifier(); 1919 Expr *BitWidth = (Expr*)BitfieldWidth; 1920 SourceLocation Loc = DeclStart; 1921 if (II) Loc = D.getIdentifierLoc(); 1922 1923 // FIXME: Unnamed fields can be handled in various different ways, for 1924 // example, unnamed unions inject all members into the struct namespace! 1925 1926 1927 if (BitWidth) { 1928 // TODO: Validate. 1929 //printf("WARNING: BITFIELDS IGNORED!\n"); 1930 1931 // 6.7.2.1p3 1932 // 6.7.2.1p4 1933 1934 } else { 1935 // Not a bitfield. 1936 1937 // validate II. 1938 1939 } 1940 1941 QualType T = GetTypeForDeclarator(D, S); 1942 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1943 bool InvalidDecl = false; 1944 1945 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1946 // than a variably modified type. 1947 if (T->isVariablyModifiedType()) { 1948 // FIXME: This diagnostic needs work 1949 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1950 InvalidDecl = true; 1951 } 1952 1953 // Get the visibility (access control) for this ivar. 1954 ObjCIvarDecl::AccessControl ac = 1955 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1956 : ObjCIvarDecl::None; 1957 1958 // Construct the decl. 1959 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1960 (Expr *)BitfieldWidth); 1961 1962 // Process attributes attached to the ivar. 1963 ProcessDeclAttributes(NewID, D); 1964 1965 if (D.getInvalidType() || InvalidDecl) 1966 NewID->setInvalidDecl(); 1967 1968 return NewID; 1969} 1970 1971void Sema::ActOnFields(Scope* S, 1972 SourceLocation RecLoc, DeclTy *RecDecl, 1973 DeclTy **Fields, unsigned NumFields, 1974 SourceLocation LBrac, SourceLocation RBrac) { 1975 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1976 assert(EnclosingDecl && "missing record or interface decl"); 1977 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1978 1979 if (Record && Record->isDefinition()) { 1980 // Diagnose code like: 1981 // struct S { struct S {} X; }; 1982 // We discover this when we complete the outer S. Reject and ignore the 1983 // outer S. 1984 Diag(Record->getLocation(), diag::err_nested_redefinition, 1985 Record->getKindName()); 1986 Diag(RecLoc, diag::err_previous_definition); 1987 Record->setInvalidDecl(); 1988 return; 1989 } 1990 // Verify that all the fields are okay. 1991 unsigned NumNamedMembers = 0; 1992 llvm::SmallVector<FieldDecl*, 32> RecFields; 1993 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 1994 1995 for (unsigned i = 0; i != NumFields; ++i) { 1996 1997 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 1998 assert(FD && "missing field decl"); 1999 2000 // Remember all fields. 2001 RecFields.push_back(FD); 2002 2003 // Get the type for the field. 2004 Type *FDTy = FD->getType().getTypePtr(); 2005 2006 // C99 6.7.2.1p2 - A field may not be a function type. 2007 if (FDTy->isFunctionType()) { 2008 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2009 FD->getName()); 2010 FD->setInvalidDecl(); 2011 EnclosingDecl->setInvalidDecl(); 2012 continue; 2013 } 2014 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2015 if (FDTy->isIncompleteType()) { 2016 if (!Record) { // Incomplete ivar type is always an error. 2017 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2018 FD->setInvalidDecl(); 2019 EnclosingDecl->setInvalidDecl(); 2020 continue; 2021 } 2022 if (i != NumFields-1 || // ... that the last member ... 2023 !Record->isStruct() || // ... of a structure ... 2024 !FDTy->isArrayType()) { //... may have incomplete array type. 2025 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2026 FD->setInvalidDecl(); 2027 EnclosingDecl->setInvalidDecl(); 2028 continue; 2029 } 2030 if (NumNamedMembers < 1) { //... must have more than named member ... 2031 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2032 FD->getName()); 2033 FD->setInvalidDecl(); 2034 EnclosingDecl->setInvalidDecl(); 2035 continue; 2036 } 2037 // Okay, we have a legal flexible array member at the end of the struct. 2038 if (Record) 2039 Record->setHasFlexibleArrayMember(true); 2040 } 2041 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2042 /// field of another structure or the element of an array. 2043 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2044 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2045 // If this is a member of a union, then entire union becomes "flexible". 2046 if (Record && Record->isUnion()) { 2047 Record->setHasFlexibleArrayMember(true); 2048 } else { 2049 // If this is a struct/class and this is not the last element, reject 2050 // it. Note that GCC supports variable sized arrays in the middle of 2051 // structures. 2052 if (i != NumFields-1) { 2053 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2054 FD->getName()); 2055 FD->setInvalidDecl(); 2056 EnclosingDecl->setInvalidDecl(); 2057 continue; 2058 } 2059 // We support flexible arrays at the end of structs in other structs 2060 // as an extension. 2061 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2062 FD->getName()); 2063 if (Record) 2064 Record->setHasFlexibleArrayMember(true); 2065 } 2066 } 2067 } 2068 /// A field cannot be an Objective-c object 2069 if (FDTy->isObjCInterfaceType()) { 2070 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2071 FD->getName()); 2072 FD->setInvalidDecl(); 2073 EnclosingDecl->setInvalidDecl(); 2074 continue; 2075 } 2076 // Keep track of the number of named members. 2077 if (IdentifierInfo *II = FD->getIdentifier()) { 2078 // Detect duplicate member names. 2079 if (!FieldIDs.insert(II)) { 2080 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2081 // Find the previous decl. 2082 SourceLocation PrevLoc; 2083 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2084 assert(i != e && "Didn't find previous def!"); 2085 if (RecFields[i]->getIdentifier() == II) { 2086 PrevLoc = RecFields[i]->getLocation(); 2087 break; 2088 } 2089 } 2090 Diag(PrevLoc, diag::err_previous_definition); 2091 FD->setInvalidDecl(); 2092 EnclosingDecl->setInvalidDecl(); 2093 continue; 2094 } 2095 ++NumNamedMembers; 2096 } 2097 } 2098 2099 // Okay, we successfully defined 'Record'. 2100 if (Record) { 2101 Record->defineBody(&RecFields[0], RecFields.size()); 2102 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2103 // Sema::ActOnFinishCXXClassDef. 2104 if (!isa<CXXRecordDecl>(Record)) 2105 Consumer.HandleTagDeclDefinition(Record); 2106 } else { 2107 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2108 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2109 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2110 else if (ObjCImplementationDecl *IMPDecl = 2111 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2112 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2113 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2114 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2115 } 2116 } 2117} 2118 2119Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2120 DeclTy *lastEnumConst, 2121 SourceLocation IdLoc, IdentifierInfo *Id, 2122 SourceLocation EqualLoc, ExprTy *val) { 2123 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2124 EnumConstantDecl *LastEnumConst = 2125 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2126 Expr *Val = static_cast<Expr*>(val); 2127 2128 // The scope passed in may not be a decl scope. Zip up the scope tree until 2129 // we find one that is. 2130 while ((S->getFlags() & Scope::DeclScope) == 0) 2131 S = S->getParent(); 2132 2133 // Verify that there isn't already something declared with this name in this 2134 // scope. 2135 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2136 // When in C++, we may get a TagDecl with the same name; in this case the 2137 // enum constant will 'hide' the tag. 2138 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2139 "Received TagDecl when not in C++!"); 2140 if (!isa<TagDecl>(PrevDecl) && 2141 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2142 if (isa<EnumConstantDecl>(PrevDecl)) 2143 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2144 else 2145 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2146 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2147 delete Val; 2148 return 0; 2149 } 2150 } 2151 2152 llvm::APSInt EnumVal(32); 2153 QualType EltTy; 2154 if (Val) { 2155 // Make sure to promote the operand type to int. 2156 UsualUnaryConversions(Val); 2157 2158 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2159 SourceLocation ExpLoc; 2160 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2161 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2162 Id->getName()); 2163 delete Val; 2164 Val = 0; // Just forget about it. 2165 } else { 2166 EltTy = Val->getType(); 2167 } 2168 } 2169 2170 if (!Val) { 2171 if (LastEnumConst) { 2172 // Assign the last value + 1. 2173 EnumVal = LastEnumConst->getInitVal(); 2174 ++EnumVal; 2175 2176 // Check for overflow on increment. 2177 if (EnumVal < LastEnumConst->getInitVal()) 2178 Diag(IdLoc, diag::warn_enum_value_overflow); 2179 2180 EltTy = LastEnumConst->getType(); 2181 } else { 2182 // First value, set to zero. 2183 EltTy = Context.IntTy; 2184 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2185 } 2186 } 2187 2188 EnumConstantDecl *New = 2189 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2190 Val, EnumVal, 2191 LastEnumConst); 2192 2193 // Register this decl in the current scope stack. 2194 PushOnScopeChains(New, S); 2195 return New; 2196} 2197 2198// FIXME: For consistency with ActOnFields(), we should have the parser 2199// pass in the source location for the left/right braces. 2200void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2201 DeclTy **Elements, unsigned NumElements) { 2202 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2203 2204 if (Enum && Enum->isDefinition()) { 2205 // Diagnose code like: 2206 // enum e0 { 2207 // E0 = sizeof(enum e0 { E1 }) 2208 // }; 2209 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2210 Enum->getName()); 2211 Diag(EnumLoc, diag::err_previous_definition); 2212 Enum->setInvalidDecl(); 2213 return; 2214 } 2215 // TODO: If the result value doesn't fit in an int, it must be a long or long 2216 // long value. ISO C does not support this, but GCC does as an extension, 2217 // emit a warning. 2218 unsigned IntWidth = Context.Target.getIntWidth(); 2219 2220 // Verify that all the values are okay, compute the size of the values, and 2221 // reverse the list. 2222 unsigned NumNegativeBits = 0; 2223 unsigned NumPositiveBits = 0; 2224 2225 // Keep track of whether all elements have type int. 2226 bool AllElementsInt = true; 2227 2228 EnumConstantDecl *EltList = 0; 2229 for (unsigned i = 0; i != NumElements; ++i) { 2230 EnumConstantDecl *ECD = 2231 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2232 if (!ECD) continue; // Already issued a diagnostic. 2233 2234 // If the enum value doesn't fit in an int, emit an extension warning. 2235 const llvm::APSInt &InitVal = ECD->getInitVal(); 2236 assert(InitVal.getBitWidth() >= IntWidth && 2237 "Should have promoted value to int"); 2238 if (InitVal.getBitWidth() > IntWidth) { 2239 llvm::APSInt V(InitVal); 2240 V.trunc(IntWidth); 2241 V.extend(InitVal.getBitWidth()); 2242 if (V != InitVal) 2243 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2244 InitVal.toString(10)); 2245 } 2246 2247 // Keep track of the size of positive and negative values. 2248 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2249 NumPositiveBits = std::max(NumPositiveBits, 2250 (unsigned)InitVal.getActiveBits()); 2251 else 2252 NumNegativeBits = std::max(NumNegativeBits, 2253 (unsigned)InitVal.getMinSignedBits()); 2254 2255 // Keep track of whether every enum element has type int (very commmon). 2256 if (AllElementsInt) 2257 AllElementsInt = ECD->getType() == Context.IntTy; 2258 2259 ECD->setNextDeclarator(EltList); 2260 EltList = ECD; 2261 } 2262 2263 // Figure out the type that should be used for this enum. 2264 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2265 QualType BestType; 2266 unsigned BestWidth; 2267 2268 if (NumNegativeBits) { 2269 // If there is a negative value, figure out the smallest integer type (of 2270 // int/long/longlong) that fits. 2271 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2272 BestType = Context.IntTy; 2273 BestWidth = IntWidth; 2274 } else { 2275 BestWidth = Context.Target.getLongWidth(); 2276 2277 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2278 BestType = Context.LongTy; 2279 else { 2280 BestWidth = Context.Target.getLongLongWidth(); 2281 2282 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2283 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2284 BestType = Context.LongLongTy; 2285 } 2286 } 2287 } else { 2288 // If there is no negative value, figure out which of uint, ulong, ulonglong 2289 // fits. 2290 if (NumPositiveBits <= IntWidth) { 2291 BestType = Context.UnsignedIntTy; 2292 BestWidth = IntWidth; 2293 } else if (NumPositiveBits <= 2294 (BestWidth = Context.Target.getLongWidth())) { 2295 BestType = Context.UnsignedLongTy; 2296 } else { 2297 BestWidth = Context.Target.getLongLongWidth(); 2298 assert(NumPositiveBits <= BestWidth && 2299 "How could an initializer get larger than ULL?"); 2300 BestType = Context.UnsignedLongLongTy; 2301 } 2302 } 2303 2304 // Loop over all of the enumerator constants, changing their types to match 2305 // the type of the enum if needed. 2306 for (unsigned i = 0; i != NumElements; ++i) { 2307 EnumConstantDecl *ECD = 2308 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2309 if (!ECD) continue; // Already issued a diagnostic. 2310 2311 // Standard C says the enumerators have int type, but we allow, as an 2312 // extension, the enumerators to be larger than int size. If each 2313 // enumerator value fits in an int, type it as an int, otherwise type it the 2314 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2315 // that X has type 'int', not 'unsigned'. 2316 if (ECD->getType() == Context.IntTy) { 2317 // Make sure the init value is signed. 2318 llvm::APSInt IV = ECD->getInitVal(); 2319 IV.setIsSigned(true); 2320 ECD->setInitVal(IV); 2321 continue; // Already int type. 2322 } 2323 2324 // Determine whether the value fits into an int. 2325 llvm::APSInt InitVal = ECD->getInitVal(); 2326 bool FitsInInt; 2327 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2328 FitsInInt = InitVal.getActiveBits() < IntWidth; 2329 else 2330 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2331 2332 // If it fits into an integer type, force it. Otherwise force it to match 2333 // the enum decl type. 2334 QualType NewTy; 2335 unsigned NewWidth; 2336 bool NewSign; 2337 if (FitsInInt) { 2338 NewTy = Context.IntTy; 2339 NewWidth = IntWidth; 2340 NewSign = true; 2341 } else if (ECD->getType() == BestType) { 2342 // Already the right type! 2343 continue; 2344 } else { 2345 NewTy = BestType; 2346 NewWidth = BestWidth; 2347 NewSign = BestType->isSignedIntegerType(); 2348 } 2349 2350 // Adjust the APSInt value. 2351 InitVal.extOrTrunc(NewWidth); 2352 InitVal.setIsSigned(NewSign); 2353 ECD->setInitVal(InitVal); 2354 2355 // Adjust the Expr initializer and type. 2356 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2357 ECD->setType(NewTy); 2358 } 2359 2360 Enum->defineElements(EltList, BestType); 2361 Consumer.HandleTagDeclDefinition(Enum); 2362} 2363 2364Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2365 ExprTy *expr) { 2366 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2367 2368 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2369} 2370 2371Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2372 SourceLocation LBrace, 2373 SourceLocation RBrace, 2374 const char *Lang, 2375 unsigned StrSize, 2376 DeclTy *D) { 2377 LinkageSpecDecl::LanguageIDs Language; 2378 Decl *dcl = static_cast<Decl *>(D); 2379 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2380 Language = LinkageSpecDecl::lang_c; 2381 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2382 Language = LinkageSpecDecl::lang_cxx; 2383 else { 2384 Diag(Loc, diag::err_bad_language); 2385 return 0; 2386 } 2387 2388 // FIXME: Add all the various semantics of linkage specifications 2389 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2390} 2391