SemaDecl.cpp revision a735ad8be5536a1cd3e9817ec27dfeb2a0c1d5ca
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/Attr.h" 19#include "clang/AST/Builtins.h" 20#include "clang/AST/Decl.h" 21#include "clang/AST/DeclCXX.h" 22#include "clang/AST/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/AST/Type.h" 25#include "clang/Parse/DeclSpec.h" 26#include "clang/Parse/Scope.h" 27#include "clang/Basic/LangOptions.h" 28#include "clang/Basic/TargetInfo.h" 29#include "clang/Basic/SourceManager.h" 30// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 31#include "clang/Lex/Preprocessor.h" 32#include "clang/Lex/HeaderSearch.h" 33#include "llvm/ADT/SmallString.h" 34#include "llvm/ADT/SmallSet.h" 35#include "llvm/ADT/DenseSet.h" 36using namespace clang; 37 38Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { 39 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); 40 41 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 42 isa<ObjCInterfaceDecl>(IIDecl) || 43 isa<TagDecl>(IIDecl))) 44 return IIDecl; 45 return 0; 46} 47 48DeclContext *Sema::getDCParent(DeclContext *DC) { 49 // If CurContext is a ObjC method, getParent() will return NULL. 50 if (isa<ObjCMethodDecl>(DC)) 51 return Context.getTranslationUnitDecl(); 52 53 // A C++ inline method is parsed *after* the topmost class it was declared in 54 // is fully parsed (it's "complete"). 55 // The parsing of a C++ inline method happens at the declaration context of 56 // the topmost (non-nested) class it is declared in. 57 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 58 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 59 DC = MD->getParent(); 60 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 61 DC = RD; 62 63 // Return the declaration context of the topmost class the inline method is 64 // declared in. 65 return DC; 66 } 67 68 return DC->getParent(); 69} 70 71void Sema::PushDeclContext(DeclContext *DC) { 72 assert(getDCParent(DC) == CurContext && 73 "The next DeclContext should be directly contained in the current one."); 74 CurContext = DC; 75} 76 77void Sema::PopDeclContext() { 78 assert(CurContext && "DeclContext imbalance!"); 79 CurContext = getDCParent(CurContext); 80} 81 82/// Add this decl to the scope shadowed decl chains. 83void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 84 S->AddDecl(D); 85 86 // C++ [basic.scope]p4: 87 // -- exactly one declaration shall declare a class name or 88 // enumeration name that is not a typedef name and the other 89 // declarations shall all refer to the same object or 90 // enumerator, or all refer to functions and function templates; 91 // in this case the class name or enumeration name is hidden. 92 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 93 // We are pushing the name of a tag (enum or class). 94 IdentifierResolver::iterator 95 I = IdResolver.begin(TD->getIdentifier(), 96 TD->getDeclContext(), false/*LookInParentCtx*/); 97 if (I != IdResolver.end() && 98 IdResolver.isDeclInScope(*I, TD->getDeclContext(), S)) { 99 // There is already a declaration with the same name in the same 100 // scope. It must be found before we find the new declaration, 101 // so swap the order on the shadowed declaration chain. 102 103 IdResolver.AddShadowedDecl(TD, *I); 104 return; 105 } 106 } 107 108 IdResolver.AddDecl(D); 109} 110 111void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 112 if (S->decl_empty()) return; 113 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 114 115 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 116 I != E; ++I) { 117 Decl *TmpD = static_cast<Decl*>(*I); 118 assert(TmpD && "This decl didn't get pushed??"); 119 120 if (isa<CXXFieldDecl>(TmpD)) continue; 121 122 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 123 ScopedDecl *D = cast<ScopedDecl>(TmpD); 124 125 IdentifierInfo *II = D->getIdentifier(); 126 if (!II) continue; 127 128 // We only want to remove the decls from the identifier decl chains for local 129 // scopes, when inside a function/method. 130 if (S->getFnParent() != 0) 131 IdResolver.RemoveDecl(D); 132 133 // Chain this decl to the containing DeclContext. 134 D->setNext(CurContext->getDeclChain()); 135 CurContext->setDeclChain(D); 136 } 137} 138 139/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 140/// return 0 if one not found. 141ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 142 // The third "scope" argument is 0 since we aren't enabling lazy built-in 143 // creation from this context. 144 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 145 146 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 147} 148 149/// LookupDecl - Look up the inner-most declaration in the specified 150/// namespace. 151Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 152 Scope *S, bool enableLazyBuiltinCreation) { 153 if (II == 0) return 0; 154 unsigned NS = NSI; 155 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 156 NS |= Decl::IDNS_Tag; 157 158 // Scan up the scope chain looking for a decl that matches this identifier 159 // that is in the appropriate namespace. This search should not take long, as 160 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 161 for (IdentifierResolver::iterator 162 I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) 163 if ((*I)->getIdentifierNamespace() & NS) 164 return *I; 165 166 // If we didn't find a use of this identifier, and if the identifier 167 // corresponds to a compiler builtin, create the decl object for the builtin 168 // now, injecting it into translation unit scope, and return it. 169 if (NS & Decl::IDNS_Ordinary) { 170 if (enableLazyBuiltinCreation) { 171 // If this is a builtin on this (or all) targets, create the decl. 172 if (unsigned BuiltinID = II->getBuiltinID()) 173 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 174 } 175 if (getLangOptions().ObjC1) { 176 // @interface and @compatibility_alias introduce typedef-like names. 177 // Unlike typedef's, they can only be introduced at file-scope (and are 178 // therefore not scoped decls). They can, however, be shadowed by 179 // other names in IDNS_Ordinary. 180 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 181 if (IDI != ObjCInterfaceDecls.end()) 182 return IDI->second; 183 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 184 if (I != ObjCAliasDecls.end()) 185 return I->second->getClassInterface(); 186 } 187 } 188 return 0; 189} 190 191void Sema::InitBuiltinVaListType() { 192 if (!Context.getBuiltinVaListType().isNull()) 193 return; 194 195 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 196 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 197 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 198 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 199} 200 201/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 202/// lazily create a decl for it. 203ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 204 Scope *S) { 205 Builtin::ID BID = (Builtin::ID)bid; 206 207 if (BID == Builtin::BI__builtin_va_start || 208 BID == Builtin::BI__builtin_va_copy || 209 BID == Builtin::BI__builtin_va_end || 210 BID == Builtin::BI__builtin_stdarg_start) 211 InitBuiltinVaListType(); 212 213 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 214 FunctionDecl *New = FunctionDecl::Create(Context, 215 Context.getTranslationUnitDecl(), 216 SourceLocation(), II, R, 217 FunctionDecl::Extern, false, 0); 218 219 // Create Decl objects for each parameter, adding them to the 220 // FunctionDecl. 221 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 222 llvm::SmallVector<ParmVarDecl*, 16> Params; 223 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 224 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 225 FT->getArgType(i), VarDecl::None, 0, 226 0)); 227 New->setParams(&Params[0], Params.size()); 228 } 229 230 231 232 // TUScope is the translation-unit scope to insert this function into. 233 PushOnScopeChains(New, TUScope); 234 return New; 235} 236 237/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 238/// and scope as a previous declaration 'Old'. Figure out how to resolve this 239/// situation, merging decls or emitting diagnostics as appropriate. 240/// 241TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 242 // Verify the old decl was also a typedef. 243 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 244 if (!Old) { 245 Diag(New->getLocation(), diag::err_redefinition_different_kind, 246 New->getName()); 247 Diag(OldD->getLocation(), diag::err_previous_definition); 248 return New; 249 } 250 251 // If the typedef types are not identical, reject them in all languages and 252 // with any extensions enabled. 253 if (Old->getUnderlyingType() != New->getUnderlyingType() && 254 Context.getCanonicalType(Old->getUnderlyingType()) != 255 Context.getCanonicalType(New->getUnderlyingType())) { 256 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 257 New->getUnderlyingType().getAsString(), 258 Old->getUnderlyingType().getAsString()); 259 Diag(Old->getLocation(), diag::err_previous_definition); 260 return Old; 261 } 262 263 // Allow multiple definitions for ObjC built-in typedefs. 264 // FIXME: Verify the underlying types are equivalent! 265 if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) 266 return Old; 267 268 if (getLangOptions().Microsoft) return New; 269 270 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 271 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 272 // *either* declaration is in a system header. The code below implements 273 // this adhoc compatibility rule. FIXME: The following code will not 274 // work properly when compiling ".i" files (containing preprocessed output). 275 SourceManager &SrcMgr = Context.getSourceManager(); 276 HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); 277 const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); 278 if (OldDeclFile) { 279 DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); 280 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 281 if (OldDirType != DirectoryLookup::NormalHeaderDir) 282 return New; 283 } 284 const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); 285 if (NewDeclFile) { 286 DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); 287 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 288 if (NewDirType != DirectoryLookup::NormalHeaderDir) 289 return New; 290 } 291 292 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 293 Diag(Old->getLocation(), diag::err_previous_definition); 294 return New; 295} 296 297/// DeclhasAttr - returns true if decl Declaration already has the target 298/// attribute. 299static bool DeclHasAttr(const Decl *decl, const Attr *target) { 300 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 301 if (attr->getKind() == target->getKind()) 302 return true; 303 304 return false; 305} 306 307/// MergeAttributes - append attributes from the Old decl to the New one. 308static void MergeAttributes(Decl *New, Decl *Old) { 309 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 310 311 while (attr) { 312 tmp = attr; 313 attr = attr->getNext(); 314 315 if (!DeclHasAttr(New, tmp)) { 316 New->addAttr(tmp); 317 } else { 318 tmp->setNext(0); 319 delete(tmp); 320 } 321 } 322 323 Old->invalidateAttrs(); 324} 325 326/// MergeFunctionDecl - We just parsed a function 'New' from 327/// declarator D which has the same name and scope as a previous 328/// declaration 'Old'. Figure out how to resolve this situation, 329/// merging decls or emitting diagnostics as appropriate. 330/// Redeclaration will be set true if thisNew is a redeclaration OldD. 331FunctionDecl * 332Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 333 Redeclaration = false; 334 // Verify the old decl was also a function. 335 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 336 if (!Old) { 337 Diag(New->getLocation(), diag::err_redefinition_different_kind, 338 New->getName()); 339 Diag(OldD->getLocation(), diag::err_previous_definition); 340 return New; 341 } 342 343 QualType OldQType = Context.getCanonicalType(Old->getType()); 344 QualType NewQType = Context.getCanonicalType(New->getType()); 345 346 // C++ [dcl.fct]p3: 347 // All declarations for a function shall agree exactly in both the 348 // return type and the parameter-type-list. 349 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 350 MergeAttributes(New, Old); 351 Redeclaration = true; 352 return MergeCXXFunctionDecl(New, Old); 353 } 354 355 // C: Function types need to be compatible, not identical. This handles 356 // duplicate function decls like "void f(int); void f(enum X);" properly. 357 if (!getLangOptions().CPlusPlus && 358 Context.functionTypesAreCompatible(OldQType, NewQType)) { 359 MergeAttributes(New, Old); 360 Redeclaration = true; 361 return New; 362 } 363 364 // A function that has already been declared has been redeclared or defined 365 // with a different type- show appropriate diagnostic 366 diag::kind PrevDiag; 367 if (Old->isThisDeclarationADefinition()) 368 PrevDiag = diag::err_previous_definition; 369 else if (Old->isImplicit()) 370 PrevDiag = diag::err_previous_implicit_declaration; 371 else 372 PrevDiag = diag::err_previous_declaration; 373 374 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 375 // TODO: This is totally simplistic. It should handle merging functions 376 // together etc, merging extern int X; int X; ... 377 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 378 Diag(Old->getLocation(), PrevDiag); 379 return New; 380} 381 382/// equivalentArrayTypes - Used to determine whether two array types are 383/// equivalent. 384/// We need to check this explicitly as an incomplete array definition is 385/// considered a VariableArrayType, so will not match a complete array 386/// definition that would be otherwise equivalent. 387static bool areEquivalentArrayTypes(QualType NewQType, QualType OldQType, 388 ASTContext &Context) { 389 const ArrayType *NewAT = Context.getAsArrayType(NewQType); 390 const ArrayType *OldAT = Context.getAsArrayType(OldQType); 391 392 if (!NewAT || !OldAT) 393 return false; 394 395 // If either (or both) array types in incomplete we need to strip off the 396 // outer VariableArrayType. Once the outer VAT is removed the remaining 397 // types must be identical if the array types are to be considered 398 // equivalent. 399 // eg. int[][1] and int[1][1] become 400 // VAT(null, CAT(1, int)) and CAT(1, CAT(1, int)) 401 // removing the outermost VAT gives 402 // CAT(1, int) and CAT(1, int) 403 // which are equal, therefore the array types are equivalent. 404 if (NewAT->isIncompleteArrayType() || OldAT->isIncompleteArrayType()) { 405 if (NewAT->getIndexTypeQualifier() != OldAT->getIndexTypeQualifier()) 406 return false; 407 NewQType = Context.getCanonicalType(NewAT->getElementType()); 408 OldQType = Context.getCanonicalType(OldAT->getElementType()); 409 } 410 411 return NewQType == OldQType; 412} 413 414/// MergeVarDecl - We just parsed a variable 'New' which has the same name 415/// and scope as a previous declaration 'Old'. Figure out how to resolve this 416/// situation, merging decls or emitting diagnostics as appropriate. 417/// 418/// FIXME: Need to carefully consider tentative definition rules (C99 6.9.2p2). 419/// For example, we incorrectly complain about i1, i4 from C99 6.9.2p4. 420/// 421VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 422 // Verify the old decl was also a variable. 423 VarDecl *Old = dyn_cast<VarDecl>(OldD); 424 if (!Old) { 425 Diag(New->getLocation(), diag::err_redefinition_different_kind, 426 New->getName()); 427 Diag(OldD->getLocation(), diag::err_previous_definition); 428 return New; 429 } 430 431 MergeAttributes(New, Old); 432 433 // Verify the types match. 434 QualType OldCType = Context.getCanonicalType(Old->getType()); 435 QualType NewCType = Context.getCanonicalType(New->getType()); 436 if (OldCType != NewCType && 437 !areEquivalentArrayTypes(NewCType, OldCType, Context)) { 438 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 439 Diag(Old->getLocation(), diag::err_previous_definition); 440 return New; 441 } 442 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 443 if (New->getStorageClass() == VarDecl::Static && 444 (Old->getStorageClass() == VarDecl::None || 445 Old->getStorageClass() == VarDecl::Extern)) { 446 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 447 Diag(Old->getLocation(), diag::err_previous_definition); 448 return New; 449 } 450 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 451 if (New->getStorageClass() != VarDecl::Static && 452 Old->getStorageClass() == VarDecl::Static) { 453 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 454 Diag(Old->getLocation(), diag::err_previous_definition); 455 return New; 456 } 457 // We've verified the types match, now handle "tentative" definitions. 458 if (Old->isFileVarDecl() && New->isFileVarDecl()) { 459 // Handle C "tentative" external object definitions (C99 6.9.2). 460 bool OldIsTentative = false; 461 bool NewIsTentative = false; 462 463 if (!Old->getInit() && 464 (Old->getStorageClass() == VarDecl::None || 465 Old->getStorageClass() == VarDecl::Static)) 466 OldIsTentative = true; 467 468 // FIXME: this check doesn't work (since the initializer hasn't been 469 // attached yet). This check should be moved to FinalizeDeclaratorGroup. 470 // Unfortunately, by the time we get to FinializeDeclaratorGroup, we've 471 // thrown out the old decl. 472 if (!New->getInit() && 473 (New->getStorageClass() == VarDecl::None || 474 New->getStorageClass() == VarDecl::Static)) 475 ; // change to NewIsTentative = true; once the code is moved. 476 477 if (NewIsTentative || OldIsTentative) 478 return New; 479 } 480 // Handle __private_extern__ just like extern. 481 if (Old->getStorageClass() != VarDecl::Extern && 482 Old->getStorageClass() != VarDecl::PrivateExtern && 483 New->getStorageClass() != VarDecl::Extern && 484 New->getStorageClass() != VarDecl::PrivateExtern) { 485 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 486 Diag(Old->getLocation(), diag::err_previous_definition); 487 } 488 return New; 489} 490 491/// CheckParmsForFunctionDef - Check that the parameters of the given 492/// function are appropriate for the definition of a function. This 493/// takes care of any checks that cannot be performed on the 494/// declaration itself, e.g., that the types of each of the function 495/// parameters are complete. 496bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 497 bool HasInvalidParm = false; 498 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 499 ParmVarDecl *Param = FD->getParamDecl(p); 500 501 // C99 6.7.5.3p4: the parameters in a parameter type list in a 502 // function declarator that is part of a function definition of 503 // that function shall not have incomplete type. 504 if (Param->getType()->isIncompleteType() && 505 !Param->isInvalidDecl()) { 506 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 507 Param->getType().getAsString()); 508 Param->setInvalidDecl(); 509 HasInvalidParm = true; 510 } 511 } 512 513 return HasInvalidParm; 514} 515 516/// CreateImplicitParameter - Creates an implicit function parameter 517/// in the scope S and with the given type. This routine is used, for 518/// example, to create the implicit "self" parameter in an Objective-C 519/// method. 520ImplicitParamDecl * 521Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 522 SourceLocation IdLoc, QualType Type) { 523 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 524 IdLoc, Id, Type, 0); 525 if (Id) 526 PushOnScopeChains(New, S); 527 528 return New; 529} 530 531/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 532/// no declarator (e.g. "struct foo;") is parsed. 533Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 534 // TODO: emit error on 'int;' or 'const enum foo;'. 535 // TODO: emit error on 'typedef int;' 536 // if (!DS.isMissingDeclaratorOk()) Diag(...); 537 538 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 539} 540 541bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 542 // Get the type before calling CheckSingleAssignmentConstraints(), since 543 // it can promote the expression. 544 QualType InitType = Init->getType(); 545 546 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 547 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 548 InitType, Init, "initializing"); 549} 550 551bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 552 const ArrayType *AT = Context.getAsArrayType(DeclT); 553 554 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 555 // C99 6.7.8p14. We have an array of character type with unknown size 556 // being initialized to a string literal. 557 llvm::APSInt ConstVal(32); 558 ConstVal = strLiteral->getByteLength() + 1; 559 // Return a new array type (C99 6.7.8p22). 560 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 561 ArrayType::Normal, 0); 562 } else { 563 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 564 // C99 6.7.8p14. We have an array of character type with known size. 565 // FIXME: Avoid truncation for 64-bit length strings. 566 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 567 Diag(strLiteral->getSourceRange().getBegin(), 568 diag::warn_initializer_string_for_char_array_too_long, 569 strLiteral->getSourceRange()); 570 } 571 // Set type from "char *" to "constant array of char". 572 strLiteral->setType(DeclT); 573 // For now, we always return false (meaning success). 574 return false; 575} 576 577StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 578 const ArrayType *AT = Context.getAsArrayType(DeclType); 579 if (AT && AT->getElementType()->isCharType()) { 580 return dyn_cast<StringLiteral>(Init); 581 } 582 return 0; 583} 584 585bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 586 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 587 // of unknown size ("[]") or an object type that is not a variable array type. 588 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 589 return Diag(VAT->getSizeExpr()->getLocStart(), 590 diag::err_variable_object_no_init, 591 VAT->getSizeExpr()->getSourceRange()); 592 593 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 594 if (!InitList) { 595 // FIXME: Handle wide strings 596 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 597 return CheckStringLiteralInit(strLiteral, DeclType); 598 599 if (DeclType->isArrayType()) 600 return Diag(Init->getLocStart(), 601 diag::err_array_init_list_required, 602 Init->getSourceRange()); 603 604 return CheckSingleInitializer(Init, DeclType); 605 } 606 607 InitListChecker CheckInitList(this, InitList, DeclType); 608 return CheckInitList.HadError(); 609} 610 611Sema::DeclTy * 612Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 613 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 614 IdentifierInfo *II = D.getIdentifier(); 615 616 // All of these full declarators require an identifier. If it doesn't have 617 // one, the ParsedFreeStandingDeclSpec action should be used. 618 if (II == 0) { 619 Diag(D.getDeclSpec().getSourceRange().getBegin(), 620 diag::err_declarator_need_ident, 621 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 622 return 0; 623 } 624 625 // The scope passed in may not be a decl scope. Zip up the scope tree until 626 // we find one that is. 627 while ((S->getFlags() & Scope::DeclScope) == 0) 628 S = S->getParent(); 629 630 // See if this is a redefinition of a variable in the same scope. 631 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 632 ScopedDecl *New; 633 bool InvalidDecl = false; 634 635 // In C++, the previous declaration we find might be a tag type 636 // (class or enum). In this case, the new declaration will hide the 637 // tag type. 638 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 639 PrevDecl = 0; 640 641 QualType R = GetTypeForDeclarator(D, S); 642 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 643 644 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 645 // Check that there are no default arguments (C++ only). 646 if (getLangOptions().CPlusPlus) 647 CheckExtraCXXDefaultArguments(D); 648 649 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 650 if (!NewTD) return 0; 651 652 // Handle attributes prior to checking for duplicates in MergeVarDecl 653 ProcessDeclAttributes(NewTD, D); 654 // Merge the decl with the existing one if appropriate. If the decl is 655 // in an outer scope, it isn't the same thing. 656 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 657 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 658 if (NewTD == 0) return 0; 659 } 660 New = NewTD; 661 if (S->getFnParent() == 0) { 662 // C99 6.7.7p2: If a typedef name specifies a variably modified type 663 // then it shall have block scope. 664 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 665 // FIXME: Diagnostic needs to be fixed. 666 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 667 InvalidDecl = true; 668 } 669 } 670 } else if (R.getTypePtr()->isFunctionType()) { 671 FunctionDecl::StorageClass SC = FunctionDecl::None; 672 switch (D.getDeclSpec().getStorageClassSpec()) { 673 default: assert(0 && "Unknown storage class!"); 674 case DeclSpec::SCS_auto: 675 case DeclSpec::SCS_register: 676 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 677 R.getAsString()); 678 InvalidDecl = true; 679 break; 680 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 681 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 682 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 683 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 684 } 685 686 bool isInline = D.getDeclSpec().isInlineSpecified(); 687 FunctionDecl *NewFD; 688 if (D.getContext() == Declarator::MemberContext) { 689 // This is a C++ method declaration. 690 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 691 D.getIdentifierLoc(), II, R, 692 (SC == FunctionDecl::Static), isInline, 693 LastDeclarator); 694 } else { 695 NewFD = FunctionDecl::Create(Context, CurContext, 696 D.getIdentifierLoc(), 697 II, R, SC, isInline, 698 LastDeclarator); 699 } 700 // Handle attributes. 701 ProcessDeclAttributes(NewFD, D); 702 703 // Handle GNU asm-label extension (encoded as an attribute). 704 if (Expr *E = (Expr*) D.getAsmLabel()) { 705 // The parser guarantees this is a string. 706 StringLiteral *SE = cast<StringLiteral>(E); 707 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 708 SE->getByteLength()))); 709 } 710 711 // Copy the parameter declarations from the declarator D to 712 // the function declaration NewFD, if they are available. 713 if (D.getNumTypeObjects() > 0 && 714 D.getTypeObject(0).Fun.hasPrototype) { 715 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 716 717 // Create Decl objects for each parameter, adding them to the 718 // FunctionDecl. 719 llvm::SmallVector<ParmVarDecl*, 16> Params; 720 721 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 722 // function that takes no arguments, not a function that takes a 723 // single void argument. 724 // We let through "const void" here because Sema::GetTypeForDeclarator 725 // already checks for that case. 726 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 727 FTI.ArgInfo[0].Param && 728 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 729 // empty arg list, don't push any params. 730 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 731 732 // In C++, the empty parameter-type-list must be spelled "void"; a 733 // typedef of void is not permitted. 734 if (getLangOptions().CPlusPlus && 735 Param->getType().getUnqualifiedType() != Context.VoidTy) { 736 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 737 } 738 739 } else { 740 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 741 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 742 } 743 744 NewFD->setParams(&Params[0], Params.size()); 745 } 746 747 // Merge the decl with the existing one if appropriate. Since C functions 748 // are in a flat namespace, make sure we consider decls in outer scopes. 749 if (PrevDecl && 750 (!getLangOptions().CPlusPlus || 751 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 752 bool Redeclaration = false; 753 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 754 if (NewFD == 0) return 0; 755 if (Redeclaration) { 756 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 757 } 758 } 759 New = NewFD; 760 761 // In C++, check default arguments now that we have merged decls. 762 if (getLangOptions().CPlusPlus) 763 CheckCXXDefaultArguments(NewFD); 764 } else { 765 // Check that there are no default arguments (C++ only). 766 if (getLangOptions().CPlusPlus) 767 CheckExtraCXXDefaultArguments(D); 768 769 if (R.getTypePtr()->isObjCInterfaceType()) { 770 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 771 D.getIdentifier()->getName()); 772 InvalidDecl = true; 773 } 774 775 VarDecl *NewVD; 776 VarDecl::StorageClass SC; 777 switch (D.getDeclSpec().getStorageClassSpec()) { 778 default: assert(0 && "Unknown storage class!"); 779 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 780 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 781 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 782 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 783 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 784 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 785 } 786 if (D.getContext() == Declarator::MemberContext) { 787 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 788 // This is a static data member for a C++ class. 789 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 790 D.getIdentifierLoc(), II, 791 R, LastDeclarator); 792 } else { 793 if (S->getFnParent() == 0) { 794 // C99 6.9p2: The storage-class specifiers auto and register shall not 795 // appear in the declaration specifiers in an external declaration. 796 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 797 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 798 R.getAsString()); 799 InvalidDecl = true; 800 } 801 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 802 II, R, SC, LastDeclarator); 803 } else { 804 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 805 II, R, SC, LastDeclarator); 806 } 807 } 808 // Handle attributes prior to checking for duplicates in MergeVarDecl 809 ProcessDeclAttributes(NewVD, D); 810 811 // Handle GNU asm-label extension (encoded as an attribute). 812 if (Expr *E = (Expr*) D.getAsmLabel()) { 813 // The parser guarantees this is a string. 814 StringLiteral *SE = cast<StringLiteral>(E); 815 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 816 SE->getByteLength()))); 817 } 818 819 // Emit an error if an address space was applied to decl with local storage. 820 // This includes arrays of objects with address space qualifiers, but not 821 // automatic variables that point to other address spaces. 822 // ISO/IEC TR 18037 S5.1.2 823 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 824 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 825 InvalidDecl = true; 826 } 827 // Merge the decl with the existing one if appropriate. If the decl is 828 // in an outer scope, it isn't the same thing. 829 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 830 NewVD = MergeVarDecl(NewVD, PrevDecl); 831 if (NewVD == 0) return 0; 832 } 833 New = NewVD; 834 } 835 836 // If this has an identifier, add it to the scope stack. 837 if (II) 838 PushOnScopeChains(New, S); 839 // If any semantic error occurred, mark the decl as invalid. 840 if (D.getInvalidType() || InvalidDecl) 841 New->setInvalidDecl(); 842 843 return New; 844} 845 846bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 847 switch (Init->getStmtClass()) { 848 default: 849 Diag(Init->getExprLoc(), 850 diag::err_init_element_not_constant, Init->getSourceRange()); 851 return true; 852 case Expr::ParenExprClass: { 853 const ParenExpr* PE = cast<ParenExpr>(Init); 854 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 855 } 856 case Expr::CompoundLiteralExprClass: 857 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 858 case Expr::DeclRefExprClass: { 859 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 860 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 861 if (VD->hasGlobalStorage()) 862 return false; 863 Diag(Init->getExprLoc(), 864 diag::err_init_element_not_constant, Init->getSourceRange()); 865 return true; 866 } 867 if (isa<FunctionDecl>(D)) 868 return false; 869 Diag(Init->getExprLoc(), 870 diag::err_init_element_not_constant, Init->getSourceRange()); 871 return true; 872 } 873 case Expr::MemberExprClass: { 874 const MemberExpr *M = cast<MemberExpr>(Init); 875 if (M->isArrow()) 876 return CheckAddressConstantExpression(M->getBase()); 877 return CheckAddressConstantExpressionLValue(M->getBase()); 878 } 879 case Expr::ArraySubscriptExprClass: { 880 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 881 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 882 return CheckAddressConstantExpression(ASE->getBase()) || 883 CheckArithmeticConstantExpression(ASE->getIdx()); 884 } 885 case Expr::StringLiteralClass: 886 case Expr::PreDefinedExprClass: 887 return false; 888 case Expr::UnaryOperatorClass: { 889 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 890 891 // C99 6.6p9 892 if (Exp->getOpcode() == UnaryOperator::Deref) 893 return CheckAddressConstantExpression(Exp->getSubExpr()); 894 895 Diag(Init->getExprLoc(), 896 diag::err_init_element_not_constant, Init->getSourceRange()); 897 return true; 898 } 899 } 900} 901 902bool Sema::CheckAddressConstantExpression(const Expr* Init) { 903 switch (Init->getStmtClass()) { 904 default: 905 Diag(Init->getExprLoc(), 906 diag::err_init_element_not_constant, Init->getSourceRange()); 907 return true; 908 case Expr::ParenExprClass: { 909 const ParenExpr* PE = cast<ParenExpr>(Init); 910 return CheckAddressConstantExpression(PE->getSubExpr()); 911 } 912 case Expr::StringLiteralClass: 913 case Expr::ObjCStringLiteralClass: 914 return false; 915 case Expr::CallExprClass: { 916 const CallExpr *CE = cast<CallExpr>(Init); 917 if (CE->isBuiltinConstantExpr()) 918 return false; 919 Diag(Init->getExprLoc(), 920 diag::err_init_element_not_constant, Init->getSourceRange()); 921 return true; 922 } 923 case Expr::UnaryOperatorClass: { 924 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 925 926 // C99 6.6p9 927 if (Exp->getOpcode() == UnaryOperator::AddrOf) 928 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 929 930 if (Exp->getOpcode() == UnaryOperator::Extension) 931 return CheckAddressConstantExpression(Exp->getSubExpr()); 932 933 Diag(Init->getExprLoc(), 934 diag::err_init_element_not_constant, Init->getSourceRange()); 935 return true; 936 } 937 case Expr::BinaryOperatorClass: { 938 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 939 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 940 941 Expr *PExp = Exp->getLHS(); 942 Expr *IExp = Exp->getRHS(); 943 if (IExp->getType()->isPointerType()) 944 std::swap(PExp, IExp); 945 946 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 947 return CheckAddressConstantExpression(PExp) || 948 CheckArithmeticConstantExpression(IExp); 949 } 950 case Expr::ImplicitCastExprClass: { 951 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 952 953 // Check for implicit promotion 954 if (SubExpr->getType()->isFunctionType() || 955 SubExpr->getType()->isArrayType()) 956 return CheckAddressConstantExpressionLValue(SubExpr); 957 958 // Check for pointer->pointer cast 959 if (SubExpr->getType()->isPointerType()) 960 return CheckAddressConstantExpression(SubExpr); 961 962 if (SubExpr->getType()->isArithmeticType()) 963 return CheckArithmeticConstantExpression(SubExpr); 964 965 Diag(Init->getExprLoc(), 966 diag::err_init_element_not_constant, Init->getSourceRange()); 967 return true; 968 } 969 case Expr::CastExprClass: { 970 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 971 972 // Check for pointer->pointer cast 973 if (SubExpr->getType()->isPointerType()) 974 return CheckAddressConstantExpression(SubExpr); 975 976 // FIXME: Should we pedwarn for (int*)(0+0)? 977 if (SubExpr->getType()->isArithmeticType()) 978 return CheckArithmeticConstantExpression(SubExpr); 979 980 Diag(Init->getExprLoc(), 981 diag::err_init_element_not_constant, Init->getSourceRange()); 982 return true; 983 } 984 case Expr::ConditionalOperatorClass: { 985 // FIXME: Should we pedwarn here? 986 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 987 if (!Exp->getCond()->getType()->isArithmeticType()) { 988 Diag(Init->getExprLoc(), 989 diag::err_init_element_not_constant, Init->getSourceRange()); 990 return true; 991 } 992 if (CheckArithmeticConstantExpression(Exp->getCond())) 993 return true; 994 if (Exp->getLHS() && 995 CheckAddressConstantExpression(Exp->getLHS())) 996 return true; 997 return CheckAddressConstantExpression(Exp->getRHS()); 998 } 999 case Expr::AddrLabelExprClass: 1000 return false; 1001 } 1002} 1003 1004static const Expr* FindExpressionBaseAddress(const Expr* E); 1005 1006static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 1007 switch (E->getStmtClass()) { 1008 default: 1009 return E; 1010 case Expr::ParenExprClass: { 1011 const ParenExpr* PE = cast<ParenExpr>(E); 1012 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 1013 } 1014 case Expr::MemberExprClass: { 1015 const MemberExpr *M = cast<MemberExpr>(E); 1016 if (M->isArrow()) 1017 return FindExpressionBaseAddress(M->getBase()); 1018 return FindExpressionBaseAddressLValue(M->getBase()); 1019 } 1020 case Expr::ArraySubscriptExprClass: { 1021 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 1022 return FindExpressionBaseAddress(ASE->getBase()); 1023 } 1024 case Expr::UnaryOperatorClass: { 1025 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1026 1027 if (Exp->getOpcode() == UnaryOperator::Deref) 1028 return FindExpressionBaseAddress(Exp->getSubExpr()); 1029 1030 return E; 1031 } 1032 } 1033} 1034 1035static const Expr* FindExpressionBaseAddress(const Expr* E) { 1036 switch (E->getStmtClass()) { 1037 default: 1038 return E; 1039 case Expr::ParenExprClass: { 1040 const ParenExpr* PE = cast<ParenExpr>(E); 1041 return FindExpressionBaseAddress(PE->getSubExpr()); 1042 } 1043 case Expr::UnaryOperatorClass: { 1044 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1045 1046 // C99 6.6p9 1047 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1048 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1049 1050 if (Exp->getOpcode() == UnaryOperator::Extension) 1051 return FindExpressionBaseAddress(Exp->getSubExpr()); 1052 1053 return E; 1054 } 1055 case Expr::BinaryOperatorClass: { 1056 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1057 1058 Expr *PExp = Exp->getLHS(); 1059 Expr *IExp = Exp->getRHS(); 1060 if (IExp->getType()->isPointerType()) 1061 std::swap(PExp, IExp); 1062 1063 return FindExpressionBaseAddress(PExp); 1064 } 1065 case Expr::ImplicitCastExprClass: { 1066 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1067 1068 // Check for implicit promotion 1069 if (SubExpr->getType()->isFunctionType() || 1070 SubExpr->getType()->isArrayType()) 1071 return FindExpressionBaseAddressLValue(SubExpr); 1072 1073 // Check for pointer->pointer cast 1074 if (SubExpr->getType()->isPointerType()) 1075 return FindExpressionBaseAddress(SubExpr); 1076 1077 // We assume that we have an arithmetic expression here; 1078 // if we don't, we'll figure it out later 1079 return 0; 1080 } 1081 case Expr::CastExprClass: { 1082 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1083 1084 // Check for pointer->pointer cast 1085 if (SubExpr->getType()->isPointerType()) 1086 return FindExpressionBaseAddress(SubExpr); 1087 1088 // We assume that we have an arithmetic expression here; 1089 // if we don't, we'll figure it out later 1090 return 0; 1091 } 1092 } 1093} 1094 1095bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1096 switch (Init->getStmtClass()) { 1097 default: 1098 Diag(Init->getExprLoc(), 1099 diag::err_init_element_not_constant, Init->getSourceRange()); 1100 return true; 1101 case Expr::ParenExprClass: { 1102 const ParenExpr* PE = cast<ParenExpr>(Init); 1103 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1104 } 1105 case Expr::FloatingLiteralClass: 1106 case Expr::IntegerLiteralClass: 1107 case Expr::CharacterLiteralClass: 1108 case Expr::ImaginaryLiteralClass: 1109 case Expr::TypesCompatibleExprClass: 1110 case Expr::CXXBoolLiteralExprClass: 1111 return false; 1112 case Expr::CallExprClass: { 1113 const CallExpr *CE = cast<CallExpr>(Init); 1114 if (CE->isBuiltinConstantExpr()) 1115 return false; 1116 Diag(Init->getExprLoc(), 1117 diag::err_init_element_not_constant, Init->getSourceRange()); 1118 return true; 1119 } 1120 case Expr::DeclRefExprClass: { 1121 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1122 if (isa<EnumConstantDecl>(D)) 1123 return false; 1124 Diag(Init->getExprLoc(), 1125 diag::err_init_element_not_constant, Init->getSourceRange()); 1126 return true; 1127 } 1128 case Expr::CompoundLiteralExprClass: 1129 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1130 // but vectors are allowed to be magic. 1131 if (Init->getType()->isVectorType()) 1132 return false; 1133 Diag(Init->getExprLoc(), 1134 diag::err_init_element_not_constant, Init->getSourceRange()); 1135 return true; 1136 case Expr::UnaryOperatorClass: { 1137 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1138 1139 switch (Exp->getOpcode()) { 1140 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1141 // See C99 6.6p3. 1142 default: 1143 Diag(Init->getExprLoc(), 1144 diag::err_init_element_not_constant, Init->getSourceRange()); 1145 return true; 1146 case UnaryOperator::SizeOf: 1147 case UnaryOperator::AlignOf: 1148 case UnaryOperator::OffsetOf: 1149 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1150 // See C99 6.5.3.4p2 and 6.6p3. 1151 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1152 return false; 1153 Diag(Init->getExprLoc(), 1154 diag::err_init_element_not_constant, Init->getSourceRange()); 1155 return true; 1156 case UnaryOperator::Extension: 1157 case UnaryOperator::LNot: 1158 case UnaryOperator::Plus: 1159 case UnaryOperator::Minus: 1160 case UnaryOperator::Not: 1161 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1162 } 1163 } 1164 case Expr::SizeOfAlignOfTypeExprClass: { 1165 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1166 // Special check for void types, which are allowed as an extension 1167 if (Exp->getArgumentType()->isVoidType()) 1168 return false; 1169 // alignof always evaluates to a constant. 1170 // FIXME: is sizeof(int[3.0]) a constant expression? 1171 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1172 Diag(Init->getExprLoc(), 1173 diag::err_init_element_not_constant, Init->getSourceRange()); 1174 return true; 1175 } 1176 return false; 1177 } 1178 case Expr::BinaryOperatorClass: { 1179 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1180 1181 if (Exp->getLHS()->getType()->isArithmeticType() && 1182 Exp->getRHS()->getType()->isArithmeticType()) { 1183 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1184 CheckArithmeticConstantExpression(Exp->getRHS()); 1185 } 1186 1187 if (Exp->getLHS()->getType()->isPointerType() && 1188 Exp->getRHS()->getType()->isPointerType()) { 1189 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1190 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1191 1192 // Only allow a null (constant integer) base; we could 1193 // allow some additional cases if necessary, but this 1194 // is sufficient to cover offsetof-like constructs. 1195 if (!LHSBase && !RHSBase) { 1196 return CheckAddressConstantExpression(Exp->getLHS()) || 1197 CheckAddressConstantExpression(Exp->getRHS()); 1198 } 1199 } 1200 1201 Diag(Init->getExprLoc(), 1202 diag::err_init_element_not_constant, Init->getSourceRange()); 1203 return true; 1204 } 1205 case Expr::ImplicitCastExprClass: 1206 case Expr::CastExprClass: { 1207 const Expr *SubExpr; 1208 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1209 SubExpr = C->getSubExpr(); 1210 } else { 1211 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1212 } 1213 1214 if (SubExpr->getType()->isArithmeticType()) 1215 return CheckArithmeticConstantExpression(SubExpr); 1216 1217 Diag(Init->getExprLoc(), 1218 diag::err_init_element_not_constant, Init->getSourceRange()); 1219 return true; 1220 } 1221 case Expr::ConditionalOperatorClass: { 1222 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1223 if (CheckArithmeticConstantExpression(Exp->getCond())) 1224 return true; 1225 if (Exp->getLHS() && 1226 CheckArithmeticConstantExpression(Exp->getLHS())) 1227 return true; 1228 return CheckArithmeticConstantExpression(Exp->getRHS()); 1229 } 1230 } 1231} 1232 1233bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1234 Init = Init->IgnoreParens(); 1235 1236 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1237 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1238 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1239 1240 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1241 return CheckForConstantInitializer(e->getInitializer(), DclT); 1242 1243 if (Init->getType()->isReferenceType()) { 1244 // FIXME: Work out how the heck reference types work 1245 return false; 1246#if 0 1247 // A reference is constant if the address of the expression 1248 // is constant 1249 // We look through initlists here to simplify 1250 // CheckAddressConstantExpressionLValue. 1251 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1252 assert(Exp->getNumInits() > 0 && 1253 "Refernce initializer cannot be empty"); 1254 Init = Exp->getInit(0); 1255 } 1256 return CheckAddressConstantExpressionLValue(Init); 1257#endif 1258 } 1259 1260 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1261 unsigned numInits = Exp->getNumInits(); 1262 for (unsigned i = 0; i < numInits; i++) { 1263 // FIXME: Need to get the type of the declaration for C++, 1264 // because it could be a reference? 1265 if (CheckForConstantInitializer(Exp->getInit(i), 1266 Exp->getInit(i)->getType())) 1267 return true; 1268 } 1269 return false; 1270 } 1271 1272 if (Init->isNullPointerConstant(Context)) 1273 return false; 1274 if (Init->getType()->isArithmeticType()) { 1275 QualType InitTy = Context.getCanonicalType(Init->getType()) 1276 .getUnqualifiedType(); 1277 if (InitTy == Context.BoolTy) { 1278 // Special handling for pointers implicitly cast to bool; 1279 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1280 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1281 Expr* SubE = ICE->getSubExpr(); 1282 if (SubE->getType()->isPointerType() || 1283 SubE->getType()->isArrayType() || 1284 SubE->getType()->isFunctionType()) { 1285 return CheckAddressConstantExpression(Init); 1286 } 1287 } 1288 } else if (InitTy->isIntegralType()) { 1289 Expr* SubE = 0; 1290 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1291 SubE = ICE->getSubExpr(); 1292 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1293 SubE = CE->getSubExpr(); 1294 // Special check for pointer cast to int; we allow as an extension 1295 // an address constant cast to an integer if the integer 1296 // is of an appropriate width (this sort of code is apparently used 1297 // in some places). 1298 // FIXME: Add pedwarn? 1299 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1300 if (SubE && (SubE->getType()->isPointerType() || 1301 SubE->getType()->isArrayType() || 1302 SubE->getType()->isFunctionType())) { 1303 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1304 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1305 if (IntWidth >= PointerWidth) 1306 return CheckAddressConstantExpression(Init); 1307 } 1308 } 1309 1310 return CheckArithmeticConstantExpression(Init); 1311 } 1312 1313 if (Init->getType()->isPointerType()) 1314 return CheckAddressConstantExpression(Init); 1315 1316 // An array type at the top level that isn't an init-list must 1317 // be a string literal 1318 if (Init->getType()->isArrayType()) 1319 return false; 1320 1321 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1322 Init->getSourceRange()); 1323 return true; 1324} 1325 1326void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1327 Decl *RealDecl = static_cast<Decl *>(dcl); 1328 Expr *Init = static_cast<Expr *>(init); 1329 assert(Init && "missing initializer"); 1330 1331 // If there is no declaration, there was an error parsing it. Just ignore 1332 // the initializer. 1333 if (RealDecl == 0) { 1334 delete Init; 1335 return; 1336 } 1337 1338 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1339 if (!VDecl) { 1340 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1341 diag::err_illegal_initializer); 1342 RealDecl->setInvalidDecl(); 1343 return; 1344 } 1345 // Get the decls type and save a reference for later, since 1346 // CheckInitializerTypes may change it. 1347 QualType DclT = VDecl->getType(), SavT = DclT; 1348 if (VDecl->isBlockVarDecl()) { 1349 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1350 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1351 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1352 VDecl->setInvalidDecl(); 1353 } else if (!VDecl->isInvalidDecl()) { 1354 if (CheckInitializerTypes(Init, DclT)) 1355 VDecl->setInvalidDecl(); 1356 if (SC == VarDecl::Static) // C99 6.7.8p4. 1357 CheckForConstantInitializer(Init, DclT); 1358 } 1359 } else if (VDecl->isFileVarDecl()) { 1360 if (VDecl->getStorageClass() == VarDecl::Extern) 1361 Diag(VDecl->getLocation(), diag::warn_extern_init); 1362 if (!VDecl->isInvalidDecl()) 1363 if (CheckInitializerTypes(Init, DclT)) 1364 VDecl->setInvalidDecl(); 1365 1366 // C99 6.7.8p4. All file scoped initializers need to be constant. 1367 CheckForConstantInitializer(Init, DclT); 1368 } 1369 // If the type changed, it means we had an incomplete type that was 1370 // completed by the initializer. For example: 1371 // int ary[] = { 1, 3, 5 }; 1372 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1373 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1374 VDecl->setType(DclT); 1375 Init->setType(DclT); 1376 } 1377 1378 // Attach the initializer to the decl. 1379 VDecl->setInit(Init); 1380 return; 1381} 1382 1383/// The declarators are chained together backwards, reverse the list. 1384Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1385 // Often we have single declarators, handle them quickly. 1386 Decl *GroupDecl = static_cast<Decl*>(group); 1387 if (GroupDecl == 0) 1388 return 0; 1389 1390 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1391 ScopedDecl *NewGroup = 0; 1392 if (Group->getNextDeclarator() == 0) 1393 NewGroup = Group; 1394 else { // reverse the list. 1395 while (Group) { 1396 ScopedDecl *Next = Group->getNextDeclarator(); 1397 Group->setNextDeclarator(NewGroup); 1398 NewGroup = Group; 1399 Group = Next; 1400 } 1401 } 1402 // Perform semantic analysis that depends on having fully processed both 1403 // the declarator and initializer. 1404 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1405 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1406 if (!IDecl) 1407 continue; 1408 QualType T = IDecl->getType(); 1409 1410 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1411 // static storage duration, it shall not have a variable length array. 1412 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1413 IDecl->getStorageClass() == VarDecl::Static) { 1414 if (T->isVariableArrayType()) { 1415 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1416 IDecl->setInvalidDecl(); 1417 } 1418 } 1419 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1420 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1421 if (IDecl->isBlockVarDecl() && 1422 IDecl->getStorageClass() != VarDecl::Extern) { 1423 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1424 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1425 T.getAsString()); 1426 IDecl->setInvalidDecl(); 1427 } 1428 } 1429 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1430 // object that has file scope without an initializer, and without a 1431 // storage-class specifier or with the storage-class specifier "static", 1432 // constitutes a tentative definition. Note: A tentative definition with 1433 // external linkage is valid (C99 6.2.2p5). 1434 if (IDecl && !IDecl->getInit() && 1435 (IDecl->getStorageClass() == VarDecl::Static || 1436 IDecl->getStorageClass() == VarDecl::None)) { 1437 if (T->isIncompleteArrayType()) { 1438 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1439 // array to be completed. Don't issue a diagnostic. 1440 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1441 // C99 6.9.2p3: If the declaration of an identifier for an object is 1442 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1443 // declared type shall not be an incomplete type. 1444 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1445 T.getAsString()); 1446 IDecl->setInvalidDecl(); 1447 } 1448 } 1449 } 1450 return NewGroup; 1451} 1452 1453/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1454/// to introduce parameters into function prototype scope. 1455Sema::DeclTy * 1456Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1457 const DeclSpec &DS = D.getDeclSpec(); 1458 1459 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1460 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1461 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1462 Diag(DS.getStorageClassSpecLoc(), 1463 diag::err_invalid_storage_class_in_func_decl); 1464 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1465 } 1466 if (DS.isThreadSpecified()) { 1467 Diag(DS.getThreadSpecLoc(), 1468 diag::err_invalid_storage_class_in_func_decl); 1469 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1470 } 1471 1472 // Check that there are no default arguments inside the type of this 1473 // parameter (C++ only). 1474 if (getLangOptions().CPlusPlus) 1475 CheckExtraCXXDefaultArguments(D); 1476 1477 // In this context, we *do not* check D.getInvalidType(). If the declarator 1478 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1479 // though it will not reflect the user specified type. 1480 QualType parmDeclType = GetTypeForDeclarator(D, S); 1481 1482 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1483 1484 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1485 // Can this happen for params? We already checked that they don't conflict 1486 // among each other. Here they can only shadow globals, which is ok. 1487 IdentifierInfo *II = D.getIdentifier(); 1488 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1489 if (S->isDeclScope(PrevDecl)) { 1490 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1491 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1492 1493 // Recover by removing the name 1494 II = 0; 1495 D.SetIdentifier(0, D.getIdentifierLoc()); 1496 } 1497 } 1498 1499 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1500 // Doing the promotion here has a win and a loss. The win is the type for 1501 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1502 // code generator). The loss is the orginal type isn't preserved. For example: 1503 // 1504 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1505 // int blockvardecl[5]; 1506 // sizeof(parmvardecl); // size == 4 1507 // sizeof(blockvardecl); // size == 20 1508 // } 1509 // 1510 // For expressions, all implicit conversions are captured using the 1511 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1512 // 1513 // FIXME: If a source translation tool needs to see the original type, then 1514 // we need to consider storing both types (in ParmVarDecl)... 1515 // 1516 if (parmDeclType->isArrayType()) { 1517 // int x[restrict 4] -> int *restrict 1518 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1519 } else if (parmDeclType->isFunctionType()) 1520 parmDeclType = Context.getPointerType(parmDeclType); 1521 1522 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1523 D.getIdentifierLoc(), II, 1524 parmDeclType, VarDecl::None, 1525 0, 0); 1526 1527 if (D.getInvalidType()) 1528 New->setInvalidDecl(); 1529 1530 if (II) 1531 PushOnScopeChains(New, S); 1532 1533 ProcessDeclAttributes(New, D); 1534 return New; 1535 1536} 1537 1538Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1539 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1540 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1541 "Not a function declarator!"); 1542 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1543 1544 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1545 // for a K&R function. 1546 if (!FTI.hasPrototype) { 1547 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1548 if (FTI.ArgInfo[i].Param == 0) { 1549 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1550 FTI.ArgInfo[i].Ident->getName()); 1551 // Implicitly declare the argument as type 'int' for lack of a better 1552 // type. 1553 DeclSpec DS; 1554 const char* PrevSpec; // unused 1555 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1556 PrevSpec); 1557 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1558 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1559 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1560 } 1561 } 1562 1563 // Since this is a function definition, act as though we have information 1564 // about the arguments. 1565 if (FTI.NumArgs) 1566 FTI.hasPrototype = true; 1567 } else { 1568 // FIXME: Diagnose arguments without names in C. 1569 } 1570 1571 Scope *GlobalScope = FnBodyScope->getParent(); 1572 1573 // See if this is a redefinition. 1574 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1575 GlobalScope); 1576 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1577 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1578 const FunctionDecl *Definition; 1579 if (FD->getBody(Definition)) { 1580 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1581 D.getIdentifier()->getName()); 1582 Diag(Definition->getLocation(), diag::err_previous_definition); 1583 } 1584 } 1585 } 1586 1587 return ActOnStartOfFunctionDef(FnBodyScope, 1588 ActOnDeclarator(GlobalScope, D, 0)); 1589} 1590 1591Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1592 Decl *decl = static_cast<Decl*>(D); 1593 FunctionDecl *FD = cast<FunctionDecl>(decl); 1594 PushDeclContext(FD); 1595 1596 // Check the validity of our function parameters 1597 CheckParmsForFunctionDef(FD); 1598 1599 // Introduce our parameters into the function scope 1600 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1601 ParmVarDecl *Param = FD->getParamDecl(p); 1602 // If this has an identifier, add it to the scope stack. 1603 if (Param->getIdentifier()) 1604 PushOnScopeChains(Param, FnBodyScope); 1605 } 1606 1607 return FD; 1608} 1609 1610Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1611 Decl *dcl = static_cast<Decl *>(D); 1612 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1613 FD->setBody((Stmt*)Body); 1614 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1615 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1616 MD->setBody((Stmt*)Body); 1617 } else 1618 return 0; 1619 PopDeclContext(); 1620 // Verify and clean out per-function state. 1621 1622 // Check goto/label use. 1623 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1624 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1625 // Verify that we have no forward references left. If so, there was a goto 1626 // or address of a label taken, but no definition of it. Label fwd 1627 // definitions are indicated with a null substmt. 1628 if (I->second->getSubStmt() == 0) { 1629 LabelStmt *L = I->second; 1630 // Emit error. 1631 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1632 1633 // At this point, we have gotos that use the bogus label. Stitch it into 1634 // the function body so that they aren't leaked and that the AST is well 1635 // formed. 1636 if (Body) { 1637 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1638 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1639 } else { 1640 // The whole function wasn't parsed correctly, just delete this. 1641 delete L; 1642 } 1643 } 1644 } 1645 LabelMap.clear(); 1646 1647 return D; 1648} 1649 1650/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1651/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1652ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1653 IdentifierInfo &II, Scope *S) { 1654 // Extension in C99. Legal in C90, but warn about it. 1655 if (getLangOptions().C99) 1656 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1657 else 1658 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1659 1660 // FIXME: handle stuff like: 1661 // void foo() { extern float X(); } 1662 // void bar() { X(); } <-- implicit decl for X in another scope. 1663 1664 // Set a Declarator for the implicit definition: int foo(); 1665 const char *Dummy; 1666 DeclSpec DS; 1667 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1668 Error = Error; // Silence warning. 1669 assert(!Error && "Error setting up implicit decl!"); 1670 Declarator D(DS, Declarator::BlockContext); 1671 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1672 D.SetIdentifier(&II, Loc); 1673 1674 // Insert this function into translation-unit scope. 1675 1676 DeclContext *PrevDC = CurContext; 1677 CurContext = Context.getTranslationUnitDecl(); 1678 1679 FunctionDecl *FD = 1680 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1681 FD->setImplicit(); 1682 1683 CurContext = PrevDC; 1684 1685 return FD; 1686} 1687 1688 1689TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1690 ScopedDecl *LastDeclarator) { 1691 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1692 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1693 1694 // Scope manipulation handled by caller. 1695 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1696 D.getIdentifierLoc(), 1697 D.getIdentifier(), 1698 T, LastDeclarator); 1699 if (D.getInvalidType()) 1700 NewTD->setInvalidDecl(); 1701 return NewTD; 1702} 1703 1704/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1705/// former case, Name will be non-null. In the later case, Name will be null. 1706/// TagType indicates what kind of tag this is. TK indicates whether this is a 1707/// reference/declaration/definition of a tag. 1708Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1709 SourceLocation KWLoc, IdentifierInfo *Name, 1710 SourceLocation NameLoc, AttributeList *Attr) { 1711 // If this is a use of an existing tag, it must have a name. 1712 assert((Name != 0 || TK == TK_Definition) && 1713 "Nameless record must be a definition!"); 1714 1715 TagDecl::TagKind Kind; 1716 switch (TagType) { 1717 default: assert(0 && "Unknown tag type!"); 1718 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1719 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1720 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1721 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1722 } 1723 1724 // If this is a named struct, check to see if there was a previous forward 1725 // declaration or definition. 1726 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1727 if (ScopedDecl *PrevDecl = 1728 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1729 1730 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1731 "unexpected Decl type"); 1732 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1733 // If this is a use of a previous tag, or if the tag is already declared 1734 // in the same scope (so that the definition/declaration completes or 1735 // rementions the tag), reuse the decl. 1736 if (TK == TK_Reference || 1737 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1738 // Make sure that this wasn't declared as an enum and now used as a 1739 // struct or something similar. 1740 if (PrevTagDecl->getTagKind() != Kind) { 1741 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1742 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1743 // Recover by making this an anonymous redefinition. 1744 Name = 0; 1745 PrevDecl = 0; 1746 } else { 1747 // If this is a use or a forward declaration, we're good. 1748 if (TK != TK_Definition) 1749 return PrevDecl; 1750 1751 // Diagnose attempts to redefine a tag. 1752 if (PrevTagDecl->isDefinition()) { 1753 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1754 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1755 // If this is a redefinition, recover by making this struct be 1756 // anonymous, which will make any later references get the previous 1757 // definition. 1758 Name = 0; 1759 } else { 1760 // Okay, this is definition of a previously declared or referenced 1761 // tag. Move the location of the decl to be the definition site. 1762 PrevDecl->setLocation(NameLoc); 1763 return PrevDecl; 1764 } 1765 } 1766 } 1767 // If we get here, this is a definition of a new struct type in a nested 1768 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1769 // type. 1770 } else { 1771 // PrevDecl is a namespace. 1772 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1773 // The tag name clashes with a namespace name, issue an error and recover 1774 // by making this tag be anonymous. 1775 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1776 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1777 Name = 0; 1778 } 1779 } 1780 } 1781 1782 // If there is an identifier, use the location of the identifier as the 1783 // location of the decl, otherwise use the location of the struct/union 1784 // keyword. 1785 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1786 1787 // Otherwise, if this is the first time we've seen this tag, create the decl. 1788 TagDecl *New; 1789 if (Kind == TagDecl::TK_enum) { 1790 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1791 // enum X { A, B, C } D; D should chain to X. 1792 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1793 // If this is an undefined enum, warn. 1794 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1795 } else { 1796 // struct/union/class 1797 1798 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1799 // struct X { int A; } D; D should chain to X. 1800 if (getLangOptions().CPlusPlus) 1801 // FIXME: Look for a way to use RecordDecl for simple structs. 1802 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1803 else 1804 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1805 } 1806 1807 // If this has an identifier, add it to the scope stack. 1808 if (Name) { 1809 // The scope passed in may not be a decl scope. Zip up the scope tree until 1810 // we find one that is. 1811 while ((S->getFlags() & Scope::DeclScope) == 0) 1812 S = S->getParent(); 1813 1814 // Add it to the decl chain. 1815 PushOnScopeChains(New, S); 1816 } 1817 1818 if (Attr) 1819 ProcessDeclAttributeList(New, Attr); 1820 return New; 1821} 1822 1823/// Collect the instance variables declared in an Objective-C object. Used in 1824/// the creation of structures from objects using the @defs directive. 1825static void CollectIvars(ObjCInterfaceDecl *Class, 1826 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1827 if (Class->getSuperClass()) 1828 CollectIvars(Class->getSuperClass(), ivars); 1829 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1830} 1831 1832/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1833/// instance variables of ClassName into Decls. 1834void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1835 IdentifierInfo *ClassName, 1836 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1837 // Check that ClassName is a valid class 1838 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1839 if (!Class) { 1840 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1841 return; 1842 } 1843 // Collect the instance variables 1844 CollectIvars(Class, Decls); 1845} 1846 1847QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1848 // This method tries to turn a variable array into a constant 1849 // array even when the size isn't an ICE. This is necessary 1850 // for compatibility with code that depends on gcc's buggy 1851 // constant expression folding, like struct {char x[(int)(char*)2];} 1852 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1853 APValue Result; 1854 if (VLATy->getSizeExpr() && 1855 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1856 llvm::APSInt &Res = Result.getInt(); 1857 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1858 return Context.getConstantArrayType(VLATy->getElementType(), 1859 Res, ArrayType::Normal, 0); 1860 } 1861 } 1862 return QualType(); 1863} 1864 1865/// ActOnField - Each field of a struct/union/class is passed into this in order 1866/// to create a FieldDecl object for it. 1867Sema::DeclTy *Sema::ActOnField(Scope *S, 1868 SourceLocation DeclStart, 1869 Declarator &D, ExprTy *BitfieldWidth) { 1870 IdentifierInfo *II = D.getIdentifier(); 1871 Expr *BitWidth = (Expr*)BitfieldWidth; 1872 SourceLocation Loc = DeclStart; 1873 if (II) Loc = D.getIdentifierLoc(); 1874 1875 // FIXME: Unnamed fields can be handled in various different ways, for 1876 // example, unnamed unions inject all members into the struct namespace! 1877 1878 1879 if (BitWidth) { 1880 // TODO: Validate. 1881 //printf("WARNING: BITFIELDS IGNORED!\n"); 1882 1883 // 6.7.2.1p3 1884 // 6.7.2.1p4 1885 1886 } else { 1887 // Not a bitfield. 1888 1889 // validate II. 1890 1891 } 1892 1893 QualType T = GetTypeForDeclarator(D, S); 1894 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1895 bool InvalidDecl = false; 1896 1897 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1898 // than a variably modified type. 1899 if (T->isVariablyModifiedType()) { 1900 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1901 if (!FixedTy.isNull()) { 1902 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1903 T = FixedTy; 1904 } else { 1905 // FIXME: This diagnostic needs work 1906 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1907 InvalidDecl = true; 1908 } 1909 } 1910 // FIXME: Chain fielddecls together. 1911 FieldDecl *NewFD; 1912 1913 if (getLangOptions().CPlusPlus) { 1914 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1915 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1916 Loc, II, T, BitWidth); 1917 if (II) 1918 PushOnScopeChains(NewFD, S); 1919 } 1920 else 1921 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1922 1923 ProcessDeclAttributes(NewFD, D); 1924 1925 if (D.getInvalidType() || InvalidDecl) 1926 NewFD->setInvalidDecl(); 1927 return NewFD; 1928} 1929 1930/// TranslateIvarVisibility - Translate visibility from a token ID to an 1931/// AST enum value. 1932static ObjCIvarDecl::AccessControl 1933TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1934 switch (ivarVisibility) { 1935 case tok::objc_private: return ObjCIvarDecl::Private; 1936 case tok::objc_public: return ObjCIvarDecl::Public; 1937 case tok::objc_protected: return ObjCIvarDecl::Protected; 1938 case tok::objc_package: return ObjCIvarDecl::Package; 1939 default: assert(false && "Unknown visitibility kind"); 1940 } 1941} 1942 1943/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1944/// in order to create an IvarDecl object for it. 1945Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1946 SourceLocation DeclStart, 1947 Declarator &D, ExprTy *BitfieldWidth, 1948 tok::ObjCKeywordKind Visibility) { 1949 IdentifierInfo *II = D.getIdentifier(); 1950 Expr *BitWidth = (Expr*)BitfieldWidth; 1951 SourceLocation Loc = DeclStart; 1952 if (II) Loc = D.getIdentifierLoc(); 1953 1954 // FIXME: Unnamed fields can be handled in various different ways, for 1955 // example, unnamed unions inject all members into the struct namespace! 1956 1957 1958 if (BitWidth) { 1959 // TODO: Validate. 1960 //printf("WARNING: BITFIELDS IGNORED!\n"); 1961 1962 // 6.7.2.1p3 1963 // 6.7.2.1p4 1964 1965 } else { 1966 // Not a bitfield. 1967 1968 // validate II. 1969 1970 } 1971 1972 QualType T = GetTypeForDeclarator(D, S); 1973 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1974 bool InvalidDecl = false; 1975 1976 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1977 // than a variably modified type. 1978 if (T->isVariablyModifiedType()) { 1979 // FIXME: This diagnostic needs work 1980 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1981 InvalidDecl = true; 1982 } 1983 1984 // Get the visibility (access control) for this ivar. 1985 ObjCIvarDecl::AccessControl ac = 1986 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 1987 : ObjCIvarDecl::None; 1988 1989 // Construct the decl. 1990 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 1991 (Expr *)BitfieldWidth); 1992 1993 // Process attributes attached to the ivar. 1994 ProcessDeclAttributes(NewID, D); 1995 1996 if (D.getInvalidType() || InvalidDecl) 1997 NewID->setInvalidDecl(); 1998 1999 return NewID; 2000} 2001 2002void Sema::ActOnFields(Scope* S, 2003 SourceLocation RecLoc, DeclTy *RecDecl, 2004 DeclTy **Fields, unsigned NumFields, 2005 SourceLocation LBrac, SourceLocation RBrac) { 2006 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2007 assert(EnclosingDecl && "missing record or interface decl"); 2008 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2009 2010 if (Record && Record->isDefinition()) { 2011 // Diagnose code like: 2012 // struct S { struct S {} X; }; 2013 // We discover this when we complete the outer S. Reject and ignore the 2014 // outer S. 2015 Diag(Record->getLocation(), diag::err_nested_redefinition, 2016 Record->getKindName()); 2017 Diag(RecLoc, diag::err_previous_definition); 2018 Record->setInvalidDecl(); 2019 return; 2020 } 2021 // Verify that all the fields are okay. 2022 unsigned NumNamedMembers = 0; 2023 llvm::SmallVector<FieldDecl*, 32> RecFields; 2024 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2025 2026 for (unsigned i = 0; i != NumFields; ++i) { 2027 2028 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2029 assert(FD && "missing field decl"); 2030 2031 // Remember all fields. 2032 RecFields.push_back(FD); 2033 2034 // Get the type for the field. 2035 Type *FDTy = FD->getType().getTypePtr(); 2036 2037 // C99 6.7.2.1p2 - A field may not be a function type. 2038 if (FDTy->isFunctionType()) { 2039 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2040 FD->getName()); 2041 FD->setInvalidDecl(); 2042 EnclosingDecl->setInvalidDecl(); 2043 continue; 2044 } 2045 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2046 if (FDTy->isIncompleteType()) { 2047 if (!Record) { // Incomplete ivar type is always an error. 2048 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2049 FD->setInvalidDecl(); 2050 EnclosingDecl->setInvalidDecl(); 2051 continue; 2052 } 2053 if (i != NumFields-1 || // ... that the last member ... 2054 !Record->isStruct() || // ... of a structure ... 2055 !FDTy->isArrayType()) { //... may have incomplete array type. 2056 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2057 FD->setInvalidDecl(); 2058 EnclosingDecl->setInvalidDecl(); 2059 continue; 2060 } 2061 if (NumNamedMembers < 1) { //... must have more than named member ... 2062 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2063 FD->getName()); 2064 FD->setInvalidDecl(); 2065 EnclosingDecl->setInvalidDecl(); 2066 continue; 2067 } 2068 // Okay, we have a legal flexible array member at the end of the struct. 2069 if (Record) 2070 Record->setHasFlexibleArrayMember(true); 2071 } 2072 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2073 /// field of another structure or the element of an array. 2074 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2075 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2076 // If this is a member of a union, then entire union becomes "flexible". 2077 if (Record && Record->isUnion()) { 2078 Record->setHasFlexibleArrayMember(true); 2079 } else { 2080 // If this is a struct/class and this is not the last element, reject 2081 // it. Note that GCC supports variable sized arrays in the middle of 2082 // structures. 2083 if (i != NumFields-1) { 2084 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2085 FD->getName()); 2086 FD->setInvalidDecl(); 2087 EnclosingDecl->setInvalidDecl(); 2088 continue; 2089 } 2090 // We support flexible arrays at the end of structs in other structs 2091 // as an extension. 2092 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2093 FD->getName()); 2094 if (Record) 2095 Record->setHasFlexibleArrayMember(true); 2096 } 2097 } 2098 } 2099 /// A field cannot be an Objective-c object 2100 if (FDTy->isObjCInterfaceType()) { 2101 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2102 FD->getName()); 2103 FD->setInvalidDecl(); 2104 EnclosingDecl->setInvalidDecl(); 2105 continue; 2106 } 2107 // Keep track of the number of named members. 2108 if (IdentifierInfo *II = FD->getIdentifier()) { 2109 // Detect duplicate member names. 2110 if (!FieldIDs.insert(II)) { 2111 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2112 // Find the previous decl. 2113 SourceLocation PrevLoc; 2114 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2115 assert(i != e && "Didn't find previous def!"); 2116 if (RecFields[i]->getIdentifier() == II) { 2117 PrevLoc = RecFields[i]->getLocation(); 2118 break; 2119 } 2120 } 2121 Diag(PrevLoc, diag::err_previous_definition); 2122 FD->setInvalidDecl(); 2123 EnclosingDecl->setInvalidDecl(); 2124 continue; 2125 } 2126 ++NumNamedMembers; 2127 } 2128 } 2129 2130 // Okay, we successfully defined 'Record'. 2131 if (Record) { 2132 Record->defineBody(&RecFields[0], RecFields.size()); 2133 Consumer.HandleTagDeclDefinition(Record); 2134 } else { 2135 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2136 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2137 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2138 else if (ObjCImplementationDecl *IMPDecl = 2139 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2140 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2141 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2142 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2143 } 2144 } 2145} 2146 2147Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2148 DeclTy *lastEnumConst, 2149 SourceLocation IdLoc, IdentifierInfo *Id, 2150 SourceLocation EqualLoc, ExprTy *val) { 2151 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2152 EnumConstantDecl *LastEnumConst = 2153 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2154 Expr *Val = static_cast<Expr*>(val); 2155 2156 // The scope passed in may not be a decl scope. Zip up the scope tree until 2157 // we find one that is. 2158 while ((S->getFlags() & Scope::DeclScope) == 0) 2159 S = S->getParent(); 2160 2161 // Verify that there isn't already something declared with this name in this 2162 // scope. 2163 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2164 // When in C++, we may get a TagDecl with the same name; in this case the 2165 // enum constant will 'hide' the tag. 2166 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2167 "Received TagDecl when not in C++!"); 2168 if (!isa<TagDecl>(PrevDecl) && 2169 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2170 if (isa<EnumConstantDecl>(PrevDecl)) 2171 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2172 else 2173 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2174 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2175 delete Val; 2176 return 0; 2177 } 2178 } 2179 2180 llvm::APSInt EnumVal(32); 2181 QualType EltTy; 2182 if (Val) { 2183 // Make sure to promote the operand type to int. 2184 UsualUnaryConversions(Val); 2185 2186 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2187 SourceLocation ExpLoc; 2188 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2189 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2190 Id->getName()); 2191 delete Val; 2192 Val = 0; // Just forget about it. 2193 } else { 2194 EltTy = Val->getType(); 2195 } 2196 } 2197 2198 if (!Val) { 2199 if (LastEnumConst) { 2200 // Assign the last value + 1. 2201 EnumVal = LastEnumConst->getInitVal(); 2202 ++EnumVal; 2203 2204 // Check for overflow on increment. 2205 if (EnumVal < LastEnumConst->getInitVal()) 2206 Diag(IdLoc, diag::warn_enum_value_overflow); 2207 2208 EltTy = LastEnumConst->getType(); 2209 } else { 2210 // First value, set to zero. 2211 EltTy = Context.IntTy; 2212 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2213 } 2214 } 2215 2216 EnumConstantDecl *New = 2217 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2218 Val, EnumVal, 2219 LastEnumConst); 2220 2221 // Register this decl in the current scope stack. 2222 PushOnScopeChains(New, S); 2223 return New; 2224} 2225 2226void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2227 DeclTy **Elements, unsigned NumElements) { 2228 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2229 assert(!Enum->isDefinition() && "Enum redefinitions can't reach here"); 2230 2231 // TODO: If the result value doesn't fit in an int, it must be a long or long 2232 // long value. ISO C does not support this, but GCC does as an extension, 2233 // emit a warning. 2234 unsigned IntWidth = Context.Target.getIntWidth(); 2235 2236 // Verify that all the values are okay, compute the size of the values, and 2237 // reverse the list. 2238 unsigned NumNegativeBits = 0; 2239 unsigned NumPositiveBits = 0; 2240 2241 // Keep track of whether all elements have type int. 2242 bool AllElementsInt = true; 2243 2244 EnumConstantDecl *EltList = 0; 2245 for (unsigned i = 0; i != NumElements; ++i) { 2246 EnumConstantDecl *ECD = 2247 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2248 if (!ECD) continue; // Already issued a diagnostic. 2249 2250 // If the enum value doesn't fit in an int, emit an extension warning. 2251 const llvm::APSInt &InitVal = ECD->getInitVal(); 2252 assert(InitVal.getBitWidth() >= IntWidth && 2253 "Should have promoted value to int"); 2254 if (InitVal.getBitWidth() > IntWidth) { 2255 llvm::APSInt V(InitVal); 2256 V.trunc(IntWidth); 2257 V.extend(InitVal.getBitWidth()); 2258 if (V != InitVal) 2259 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2260 InitVal.toString()); 2261 } 2262 2263 // Keep track of the size of positive and negative values. 2264 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2265 NumPositiveBits = std::max(NumPositiveBits, 2266 (unsigned)InitVal.getActiveBits()); 2267 else 2268 NumNegativeBits = std::max(NumNegativeBits, 2269 (unsigned)InitVal.getMinSignedBits()); 2270 2271 // Keep track of whether every enum element has type int (very commmon). 2272 if (AllElementsInt) 2273 AllElementsInt = ECD->getType() == Context.IntTy; 2274 2275 ECD->setNextDeclarator(EltList); 2276 EltList = ECD; 2277 } 2278 2279 // Figure out the type that should be used for this enum. 2280 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2281 QualType BestType; 2282 unsigned BestWidth; 2283 2284 if (NumNegativeBits) { 2285 // If there is a negative value, figure out the smallest integer type (of 2286 // int/long/longlong) that fits. 2287 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2288 BestType = Context.IntTy; 2289 BestWidth = IntWidth; 2290 } else { 2291 BestWidth = Context.Target.getLongWidth(); 2292 2293 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2294 BestType = Context.LongTy; 2295 else { 2296 BestWidth = Context.Target.getLongLongWidth(); 2297 2298 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2299 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2300 BestType = Context.LongLongTy; 2301 } 2302 } 2303 } else { 2304 // If there is no negative value, figure out which of uint, ulong, ulonglong 2305 // fits. 2306 if (NumPositiveBits <= IntWidth) { 2307 BestType = Context.UnsignedIntTy; 2308 BestWidth = IntWidth; 2309 } else if (NumPositiveBits <= 2310 (BestWidth = Context.Target.getLongWidth())) { 2311 BestType = Context.UnsignedLongTy; 2312 } else { 2313 BestWidth = Context.Target.getLongLongWidth(); 2314 assert(NumPositiveBits <= BestWidth && 2315 "How could an initializer get larger than ULL?"); 2316 BestType = Context.UnsignedLongLongTy; 2317 } 2318 } 2319 2320 // Loop over all of the enumerator constants, changing their types to match 2321 // the type of the enum if needed. 2322 for (unsigned i = 0; i != NumElements; ++i) { 2323 EnumConstantDecl *ECD = 2324 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2325 if (!ECD) continue; // Already issued a diagnostic. 2326 2327 // Standard C says the enumerators have int type, but we allow, as an 2328 // extension, the enumerators to be larger than int size. If each 2329 // enumerator value fits in an int, type it as an int, otherwise type it the 2330 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2331 // that X has type 'int', not 'unsigned'. 2332 if (ECD->getType() == Context.IntTy) { 2333 // Make sure the init value is signed. 2334 llvm::APSInt IV = ECD->getInitVal(); 2335 IV.setIsSigned(true); 2336 ECD->setInitVal(IV); 2337 continue; // Already int type. 2338 } 2339 2340 // Determine whether the value fits into an int. 2341 llvm::APSInt InitVal = ECD->getInitVal(); 2342 bool FitsInInt; 2343 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2344 FitsInInt = InitVal.getActiveBits() < IntWidth; 2345 else 2346 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2347 2348 // If it fits into an integer type, force it. Otherwise force it to match 2349 // the enum decl type. 2350 QualType NewTy; 2351 unsigned NewWidth; 2352 bool NewSign; 2353 if (FitsInInt) { 2354 NewTy = Context.IntTy; 2355 NewWidth = IntWidth; 2356 NewSign = true; 2357 } else if (ECD->getType() == BestType) { 2358 // Already the right type! 2359 continue; 2360 } else { 2361 NewTy = BestType; 2362 NewWidth = BestWidth; 2363 NewSign = BestType->isSignedIntegerType(); 2364 } 2365 2366 // Adjust the APSInt value. 2367 InitVal.extOrTrunc(NewWidth); 2368 InitVal.setIsSigned(NewSign); 2369 ECD->setInitVal(InitVal); 2370 2371 // Adjust the Expr initializer and type. 2372 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2373 ECD->setType(NewTy); 2374 } 2375 2376 Enum->defineElements(EltList, BestType); 2377 Consumer.HandleTagDeclDefinition(Enum); 2378} 2379 2380Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2381 ExprTy *expr) { 2382 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2383 2384 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2385} 2386 2387Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2388 SourceLocation LBrace, 2389 SourceLocation RBrace, 2390 const char *Lang, 2391 unsigned StrSize, 2392 DeclTy *D) { 2393 LinkageSpecDecl::LanguageIDs Language; 2394 Decl *dcl = static_cast<Decl *>(D); 2395 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2396 Language = LinkageSpecDecl::lang_c; 2397 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2398 Language = LinkageSpecDecl::lang_cxx; 2399 else { 2400 Diag(Loc, diag::err_bad_language); 2401 return 0; 2402 } 2403 2404 // FIXME: Add all the various semantics of linkage specifications 2405 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2406} 2407