SemaDecl.cpp revision 4f071ec3fbc1de7a46e38fb61e80804838bda73a
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::DeclTy *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::ctx_iterator 95 CIT = IdResolver.ctx_begin(TD->getIdentifier(), TD->getDeclContext()); 96 if (CIT != IdResolver.ctx_end(TD->getIdentifier()) && 97 IdResolver.isDeclInScope(*CIT, TD->getDeclContext(), S)) { 98 // There is already a declaration with the same name in the same 99 // scope. It must be found before we find the new declaration, 100 // so swap the order on the shadowed declaration chain. 101 102 IdResolver.AddShadowedDecl(TD, *CIT); 103 return; 104 } 105 } 106 107 IdResolver.AddDecl(D); 108} 109 110void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 111 if (S->decl_empty()) return; 112 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 113 114 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 115 I != E; ++I) { 116 Decl *TmpD = static_cast<Decl*>(*I); 117 assert(TmpD && "This decl didn't get pushed??"); 118 119 if (isa<CXXFieldDecl>(TmpD)) continue; 120 121 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 122 ScopedDecl *D = cast<ScopedDecl>(TmpD); 123 124 IdentifierInfo *II = D->getIdentifier(); 125 if (!II) continue; 126 127 // We only want to remove the decls from the identifier decl chains for local 128 // scopes, when inside a function/method. 129 if (S->getFnParent() != 0) 130 IdResolver.RemoveDecl(D); 131 132 // Chain this decl to the containing DeclContext. 133 D->setNext(CurContext->getDeclChain()); 134 CurContext->setDeclChain(D); 135 } 136} 137 138/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 139/// return 0 if one not found. 140ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 141 // The third "scope" argument is 0 since we aren't enabling lazy built-in 142 // creation from this context. 143 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 144 145 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 146} 147 148/// LookupDecl - Look up the inner-most declaration in the specified 149/// namespace. 150Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 151 Scope *S, bool enableLazyBuiltinCreation) { 152 if (II == 0) return 0; 153 unsigned NS = NSI; 154 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 155 NS |= Decl::IDNS_Tag; 156 157 // Scan up the scope chain looking for a decl that matches this identifier 158 // that is in the appropriate namespace. This search should not take long, as 159 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 160 for (IdentifierResolver::iterator 161 I = IdResolver.begin(II, CurContext), E = IdResolver.end(II); I != E; ++I) 162 if ((*I)->getIdentifierNamespace() & NS) 163 return *I; 164 165 // If we didn't find a use of this identifier, and if the identifier 166 // corresponds to a compiler builtin, create the decl object for the builtin 167 // now, injecting it into translation unit scope, and return it. 168 if (NS & Decl::IDNS_Ordinary) { 169 if (enableLazyBuiltinCreation) { 170 // If this is a builtin on this (or all) targets, create the decl. 171 if (unsigned BuiltinID = II->getBuiltinID()) 172 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 173 } 174 if (getLangOptions().ObjC1) { 175 // @interface and @compatibility_alias introduce typedef-like names. 176 // Unlike typedef's, they can only be introduced at file-scope (and are 177 // therefore not scoped decls). They can, however, be shadowed by 178 // other names in IDNS_Ordinary. 179 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 180 if (IDI != ObjCInterfaceDecls.end()) 181 return IDI->second; 182 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 183 if (I != ObjCAliasDecls.end()) 184 return I->second->getClassInterface(); 185 } 186 } 187 return 0; 188} 189 190void Sema::InitBuiltinVaListType() { 191 if (!Context.getBuiltinVaListType().isNull()) 192 return; 193 194 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 195 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 196 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 197 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 198} 199 200/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 201/// lazily create a decl for it. 202ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 203 Scope *S) { 204 Builtin::ID BID = (Builtin::ID)bid; 205 206 if (BID == Builtin::BI__builtin_va_start || 207 BID == Builtin::BI__builtin_va_copy || 208 BID == Builtin::BI__builtin_va_end || 209 BID == Builtin::BI__builtin_stdarg_start) 210 InitBuiltinVaListType(); 211 212 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 213 FunctionDecl *New = FunctionDecl::Create(Context, 214 Context.getTranslationUnitDecl(), 215 SourceLocation(), II, R, 216 FunctionDecl::Extern, false, 0); 217 218 // Create Decl objects for each parameter, adding them to the 219 // FunctionDecl. 220 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 221 llvm::SmallVector<ParmVarDecl*, 16> Params; 222 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 223 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 224 FT->getArgType(i), VarDecl::None, 0, 225 0)); 226 New->setParams(&Params[0], Params.size()); 227 } 228 229 230 231 // TUScope is the translation-unit scope to insert this function into. 232 PushOnScopeChains(New, TUScope); 233 return New; 234} 235 236/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 237/// and scope as a previous declaration 'Old'. Figure out how to resolve this 238/// situation, merging decls or emitting diagnostics as appropriate. 239/// 240TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 241 // Verify the old decl was also a typedef. 242 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 243 if (!Old) { 244 Diag(New->getLocation(), diag::err_redefinition_different_kind, 245 New->getName()); 246 Diag(OldD->getLocation(), diag::err_previous_definition); 247 return New; 248 } 249 250 // Allow multiple definitions for ObjC built-in typedefs. 251 // FIXME: Verify the underlying types are equivalent! 252 if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) 253 return Old; 254 255 if (getLangOptions().Microsoft) return New; 256 257 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 258 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 259 // *either* declaration is in a system header. The code below implements 260 // this adhoc compatibility rule. FIXME: The following code will not 261 // work properly when compiling ".i" files (containing preprocessed output). 262 SourceManager &SrcMgr = Context.getSourceManager(); 263 HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); 264 const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); 265 if (OldDeclFile) { 266 DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); 267 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 268 if (OldDirType != DirectoryLookup::NormalHeaderDir) 269 return New; 270 } 271 const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); 272 if (NewDeclFile) { 273 DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); 274 // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir. 275 if (NewDirType != DirectoryLookup::NormalHeaderDir) 276 return New; 277 } 278 279 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 280 Diag(Old->getLocation(), diag::err_previous_definition); 281 return New; 282} 283 284/// DeclhasAttr - returns true if decl Declaration already has the target 285/// attribute. 286static bool DeclHasAttr(const Decl *decl, const Attr *target) { 287 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 288 if (attr->getKind() == target->getKind()) 289 return true; 290 291 return false; 292} 293 294/// MergeAttributes - append attributes from the Old decl to the New one. 295static void MergeAttributes(Decl *New, Decl *Old) { 296 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 297 298 while (attr) { 299 tmp = attr; 300 attr = attr->getNext(); 301 302 if (!DeclHasAttr(New, tmp)) { 303 New->addAttr(tmp); 304 } else { 305 tmp->setNext(0); 306 delete(tmp); 307 } 308 } 309 310 Old->invalidateAttrs(); 311} 312 313/// MergeFunctionDecl - We just parsed a function 'New' from 314/// declarator D which has the same name and scope as a previous 315/// declaration 'Old'. Figure out how to resolve this situation, 316/// merging decls or emitting diagnostics as appropriate. 317/// Redeclaration will be set true if thisNew is a redeclaration OldD. 318FunctionDecl * 319Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 320 Redeclaration = false; 321 // Verify the old decl was also a function. 322 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 323 if (!Old) { 324 Diag(New->getLocation(), diag::err_redefinition_different_kind, 325 New->getName()); 326 Diag(OldD->getLocation(), diag::err_previous_definition); 327 return New; 328 } 329 330 QualType OldQType = Context.getCanonicalType(Old->getType()); 331 QualType NewQType = Context.getCanonicalType(New->getType()); 332 333 // C++ [dcl.fct]p3: 334 // All declarations for a function shall agree exactly in both the 335 // return type and the parameter-type-list. 336 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 337 MergeAttributes(New, Old); 338 Redeclaration = true; 339 return MergeCXXFunctionDecl(New, Old); 340 } 341 342 // C: Function types need to be compatible, not identical. This handles 343 // duplicate function decls like "void f(int); void f(enum X);" properly. 344 if (!getLangOptions().CPlusPlus && 345 Context.functionTypesAreCompatible(OldQType, NewQType)) { 346 MergeAttributes(New, Old); 347 Redeclaration = true; 348 return New; 349 } 350 351 // A function that has already been declared has been redeclared or defined 352 // with a different type- show appropriate diagnostic 353 diag::kind PrevDiag; 354 if (Old->isThisDeclarationADefinition()) 355 PrevDiag = diag::err_previous_definition; 356 else if (Old->isImplicit()) 357 PrevDiag = diag::err_previous_implicit_declaration; 358 else 359 PrevDiag = diag::err_previous_declaration; 360 361 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 362 // TODO: This is totally simplistic. It should handle merging functions 363 // together etc, merging extern int X; int X; ... 364 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 365 Diag(Old->getLocation(), PrevDiag); 366 return New; 367} 368 369/// equivalentArrayTypes - Used to determine whether two array types are 370/// equivalent. 371/// We need to check this explicitly as an incomplete array definition is 372/// considered a VariableArrayType, so will not match a complete array 373/// definition that would be otherwise equivalent. 374static bool areEquivalentArrayTypes(QualType NewQType, QualType OldQType) { 375 const ArrayType *NewAT = NewQType->getAsArrayType(); 376 const ArrayType *OldAT = OldQType->getAsArrayType(); 377 378 if (!NewAT || !OldAT) 379 return false; 380 381 // If either (or both) array types in incomplete we need to strip off the 382 // outer VariableArrayType. Once the outer VAT is removed the remaining 383 // types must be identical if the array types are to be considered 384 // equivalent. 385 // eg. int[][1] and int[1][1] become 386 // VAT(null, CAT(1, int)) and CAT(1, CAT(1, int)) 387 // removing the outermost VAT gives 388 // CAT(1, int) and CAT(1, int) 389 // which are equal, therefore the array types are equivalent. 390 if (NewAT->isIncompleteArrayType() || OldAT->isIncompleteArrayType()) { 391 if (NewAT->getIndexTypeQualifier() != OldAT->getIndexTypeQualifier()) 392 return false; 393 NewQType = NewAT->getElementType().getCanonicalType(); 394 OldQType = OldAT->getElementType().getCanonicalType(); 395 } 396 397 return NewQType == OldQType; 398} 399 400/// MergeVarDecl - We just parsed a variable 'New' which has the same name 401/// and scope as a previous declaration 'Old'. Figure out how to resolve this 402/// situation, merging decls or emitting diagnostics as appropriate. 403/// 404/// FIXME: Need to carefully consider tentative definition rules (C99 6.9.2p2). 405/// For example, we incorrectly complain about i1, i4 from C99 6.9.2p4. 406/// 407VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 408 // Verify the old decl was also a variable. 409 VarDecl *Old = dyn_cast<VarDecl>(OldD); 410 if (!Old) { 411 Diag(New->getLocation(), diag::err_redefinition_different_kind, 412 New->getName()); 413 Diag(OldD->getLocation(), diag::err_previous_definition); 414 return New; 415 } 416 417 MergeAttributes(New, Old); 418 419 // Verify the types match. 420 QualType OldCType = Context.getCanonicalType(Old->getType()); 421 QualType NewCType = Context.getCanonicalType(New->getType()); 422 if (OldCType != NewCType && !areEquivalentArrayTypes(NewCType, OldCType)) { 423 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 424 Diag(Old->getLocation(), diag::err_previous_definition); 425 return New; 426 } 427 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 428 if (New->getStorageClass() == VarDecl::Static && 429 (Old->getStorageClass() == VarDecl::None || 430 Old->getStorageClass() == VarDecl::Extern)) { 431 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 432 Diag(Old->getLocation(), diag::err_previous_definition); 433 return New; 434 } 435 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 436 if (New->getStorageClass() != VarDecl::Static && 437 Old->getStorageClass() == VarDecl::Static) { 438 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 439 Diag(Old->getLocation(), diag::err_previous_definition); 440 return New; 441 } 442 // We've verified the types match, now handle "tentative" definitions. 443 if (Old->isFileVarDecl() && New->isFileVarDecl()) { 444 // Handle C "tentative" external object definitions (C99 6.9.2). 445 bool OldIsTentative = false; 446 bool NewIsTentative = false; 447 448 if (!Old->getInit() && 449 (Old->getStorageClass() == VarDecl::None || 450 Old->getStorageClass() == VarDecl::Static)) 451 OldIsTentative = true; 452 453 // FIXME: this check doesn't work (since the initializer hasn't been 454 // attached yet). This check should be moved to FinalizeDeclaratorGroup. 455 // Unfortunately, by the time we get to FinializeDeclaratorGroup, we've 456 // thrown out the old decl. 457 if (!New->getInit() && 458 (New->getStorageClass() == VarDecl::None || 459 New->getStorageClass() == VarDecl::Static)) 460 ; // change to NewIsTentative = true; once the code is moved. 461 462 if (NewIsTentative || OldIsTentative) 463 return New; 464 } 465 // Handle __private_extern__ just like extern. 466 if (Old->getStorageClass() != VarDecl::Extern && 467 Old->getStorageClass() != VarDecl::PrivateExtern && 468 New->getStorageClass() != VarDecl::Extern && 469 New->getStorageClass() != VarDecl::PrivateExtern) { 470 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 471 Diag(Old->getLocation(), diag::err_previous_definition); 472 } 473 return New; 474} 475 476/// CheckParmsForFunctionDef - Check that the parameters of the given 477/// function are appropriate for the definition of a function. This 478/// takes care of any checks that cannot be performed on the 479/// declaration itself, e.g., that the types of each of the function 480/// parameters are complete. 481bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 482 bool HasInvalidParm = false; 483 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 484 ParmVarDecl *Param = FD->getParamDecl(p); 485 486 // C99 6.7.5.3p4: the parameters in a parameter type list in a 487 // function declarator that is part of a function definition of 488 // that function shall not have incomplete type. 489 if (Param->getType()->isIncompleteType() && 490 !Param->isInvalidDecl()) { 491 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 492 Param->getType().getAsString()); 493 Param->setInvalidDecl(); 494 HasInvalidParm = true; 495 } 496 } 497 498 return HasInvalidParm; 499} 500 501/// CreateImplicitParameter - Creates an implicit function parameter 502/// in the scope S and with the given type. This routine is used, for 503/// example, to create the implicit "self" parameter in an Objective-C 504/// method. 505ImplicitParamDecl * 506Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id, 507 SourceLocation IdLoc, QualType Type) { 508 ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext, 509 IdLoc, Id, Type, 0); 510 if (Id) 511 PushOnScopeChains(New, S); 512 513 return New; 514} 515 516/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 517/// no declarator (e.g. "struct foo;") is parsed. 518Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 519 // TODO: emit error on 'int;' or 'const enum foo;'. 520 // TODO: emit error on 'typedef int;' 521 // if (!DS.isMissingDeclaratorOk()) Diag(...); 522 523 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 524} 525 526bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 527 // Get the type before calling CheckSingleAssignmentConstraints(), since 528 // it can promote the expression. 529 QualType InitType = Init->getType(); 530 531 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 532 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 533 InitType, Init, "initializing"); 534} 535 536bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 537 if (const IncompleteArrayType *IAT = DeclT->getAsIncompleteArrayType()) { 538 // C99 6.7.8p14. We have an array of character type with unknown size 539 // being initialized to a string literal. 540 llvm::APSInt ConstVal(32); 541 ConstVal = strLiteral->getByteLength() + 1; 542 // Return a new array type (C99 6.7.8p22). 543 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 544 ArrayType::Normal, 0); 545 } else if (const ConstantArrayType *CAT = DeclT->getAsConstantArrayType()) { 546 // C99 6.7.8p14. We have an array of character type with known size. 547 if (strLiteral->getByteLength() > (unsigned)CAT->getMaximumElements()) 548 Diag(strLiteral->getSourceRange().getBegin(), 549 diag::warn_initializer_string_for_char_array_too_long, 550 strLiteral->getSourceRange()); 551 } else { 552 assert(0 && "HandleStringLiteralInit(): Invalid array type"); 553 } 554 // Set type from "char *" to "constant array of char". 555 strLiteral->setType(DeclT); 556 // For now, we always return false (meaning success). 557 return false; 558} 559 560StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 561 const ArrayType *AT = DeclType->getAsArrayType(); 562 if (AT && AT->getElementType()->isCharType()) { 563 return dyn_cast<StringLiteral>(Init); 564 } 565 return 0; 566} 567 568bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 569 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 570 // of unknown size ("[]") or an object type that is not a variable array type. 571 if (const VariableArrayType *VAT = DeclType->getAsVariableArrayType()) 572 return Diag(VAT->getSizeExpr()->getLocStart(), 573 diag::err_variable_object_no_init, 574 VAT->getSizeExpr()->getSourceRange()); 575 576 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 577 if (!InitList) { 578 // FIXME: Handle wide strings 579 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 580 return CheckStringLiteralInit(strLiteral, DeclType); 581 582 if (DeclType->isArrayType()) 583 return Diag(Init->getLocStart(), 584 diag::err_array_init_list_required, 585 Init->getSourceRange()); 586 587 return CheckSingleInitializer(Init, DeclType); 588 } 589 590 InitListChecker CheckInitList(this, InitList, DeclType); 591 return CheckInitList.HadError(); 592} 593 594Sema::DeclTy * 595Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 596 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 597 IdentifierInfo *II = D.getIdentifier(); 598 599 // All of these full declarators require an identifier. If it doesn't have 600 // one, the ParsedFreeStandingDeclSpec action should be used. 601 if (II == 0) { 602 Diag(D.getDeclSpec().getSourceRange().getBegin(), 603 diag::err_declarator_need_ident, 604 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 605 return 0; 606 } 607 608 // The scope passed in may not be a decl scope. Zip up the scope tree until 609 // we find one that is. 610 while ((S->getFlags() & Scope::DeclScope) == 0) 611 S = S->getParent(); 612 613 // See if this is a redefinition of a variable in the same scope. 614 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 615 ScopedDecl *New; 616 bool InvalidDecl = false; 617 618 // In C++, the previous declaration we find might be a tag type 619 // (class or enum). In this case, the new declaration will hide the 620 // tag type. 621 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 622 PrevDecl = 0; 623 624 QualType R = GetTypeForDeclarator(D, S); 625 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 626 627 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 628 // Check that there are no default arguments (C++ only). 629 if (getLangOptions().CPlusPlus) 630 CheckExtraCXXDefaultArguments(D); 631 632 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 633 if (!NewTD) return 0; 634 635 // Handle attributes prior to checking for duplicates in MergeVarDecl 636 ProcessDeclAttributes(NewTD, D); 637 // Merge the decl with the existing one if appropriate. If the decl is 638 // in an outer scope, it isn't the same thing. 639 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 640 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 641 if (NewTD == 0) return 0; 642 } 643 New = NewTD; 644 if (S->getFnParent() == 0) { 645 // C99 6.7.7p2: If a typedef name specifies a variably modified type 646 // then it shall have block scope. 647 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 648 // FIXME: Diagnostic needs to be fixed. 649 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 650 InvalidDecl = true; 651 } 652 } 653 } else if (R.getTypePtr()->isFunctionType()) { 654 FunctionDecl::StorageClass SC = FunctionDecl::None; 655 switch (D.getDeclSpec().getStorageClassSpec()) { 656 default: assert(0 && "Unknown storage class!"); 657 case DeclSpec::SCS_auto: 658 case DeclSpec::SCS_register: 659 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 660 R.getAsString()); 661 InvalidDecl = true; 662 break; 663 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 664 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 665 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 666 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 667 } 668 669 bool isInline = D.getDeclSpec().isInlineSpecified(); 670 FunctionDecl *NewFD; 671 if (D.getContext() == Declarator::MemberContext) { 672 // This is a C++ method declaration. 673 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 674 D.getIdentifierLoc(), II, R, 675 (SC == FunctionDecl::Static), isInline, 676 LastDeclarator); 677 } else { 678 NewFD = FunctionDecl::Create(Context, CurContext, 679 D.getIdentifierLoc(), 680 II, R, SC, isInline, 681 LastDeclarator); 682 } 683 // Handle attributes. 684 ProcessDeclAttributes(NewFD, D); 685 686 // Copy the parameter declarations from the declarator D to 687 // the function declaration NewFD, if they are available. 688 if (D.getNumTypeObjects() > 0 && 689 D.getTypeObject(0).Fun.hasPrototype) { 690 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 691 692 // Create Decl objects for each parameter, adding them to the 693 // FunctionDecl. 694 llvm::SmallVector<ParmVarDecl*, 16> Params; 695 696 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 697 // function that takes no arguments, not a function that takes a 698 // single void argument. 699 // We let through "const void" here because Sema::GetTypeForDeclarator 700 // already checks for that case. 701 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 702 FTI.ArgInfo[0].Param && 703 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 704 // empty arg list, don't push any params. 705 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 706 707 // In C++, the empty parameter-type-list must be spelled "void"; a 708 // typedef of void is not permitted. 709 if (getLangOptions().CPlusPlus && 710 Param->getType().getUnqualifiedType() != Context.VoidTy) { 711 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 712 } 713 714 } else { 715 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 716 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 717 } 718 719 NewFD->setParams(&Params[0], Params.size()); 720 } 721 722 // Merge the decl with the existing one if appropriate. Since C functions 723 // are in a flat namespace, make sure we consider decls in outer scopes. 724 if (PrevDecl && 725 (!getLangOptions().CPlusPlus || 726 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 727 bool Redeclaration = false; 728 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 729 if (NewFD == 0) return 0; 730 if (Redeclaration) { 731 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 732 } 733 } 734 New = NewFD; 735 736 // In C++, check default arguments now that we have merged decls. 737 if (getLangOptions().CPlusPlus) 738 CheckCXXDefaultArguments(NewFD); 739 } else { 740 // Check that there are no default arguments (C++ only). 741 if (getLangOptions().CPlusPlus) 742 CheckExtraCXXDefaultArguments(D); 743 744 if (R.getTypePtr()->isObjCInterfaceType()) { 745 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 746 D.getIdentifier()->getName()); 747 InvalidDecl = true; 748 } 749 750 VarDecl *NewVD; 751 VarDecl::StorageClass SC; 752 switch (D.getDeclSpec().getStorageClassSpec()) { 753 default: assert(0 && "Unknown storage class!"); 754 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 755 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 756 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 757 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 758 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 759 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 760 } 761 if (D.getContext() == Declarator::MemberContext) { 762 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 763 // This is a static data member for a C++ class. 764 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 765 D.getIdentifierLoc(), II, 766 R, LastDeclarator); 767 } else { 768 if (S->getFnParent() == 0) { 769 // C99 6.9p2: The storage-class specifiers auto and register shall not 770 // appear in the declaration specifiers in an external declaration. 771 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 772 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 773 R.getAsString()); 774 InvalidDecl = true; 775 } 776 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 777 II, R, SC, LastDeclarator); 778 } else { 779 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 780 II, R, SC, LastDeclarator); 781 } 782 } 783 // Handle attributes prior to checking for duplicates in MergeVarDecl 784 ProcessDeclAttributes(NewVD, D); 785 786 // Emit an error if an address space was applied to decl with local storage. 787 // This includes arrays of objects with address space qualifiers, but not 788 // automatic variables that point to other address spaces. 789 // ISO/IEC TR 18037 S5.1.2 790 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 791 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 792 InvalidDecl = true; 793 } 794 // Merge the decl with the existing one if appropriate. If the decl is 795 // in an outer scope, it isn't the same thing. 796 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 797 NewVD = MergeVarDecl(NewVD, PrevDecl); 798 if (NewVD == 0) return 0; 799 } 800 New = NewVD; 801 } 802 803 // If this has an identifier, add it to the scope stack. 804 if (II) 805 PushOnScopeChains(New, S); 806 // If any semantic error occurred, mark the decl as invalid. 807 if (D.getInvalidType() || InvalidDecl) 808 New->setInvalidDecl(); 809 810 return New; 811} 812 813bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 814 switch (Init->getStmtClass()) { 815 default: 816 Diag(Init->getExprLoc(), 817 diag::err_init_element_not_constant, Init->getSourceRange()); 818 return true; 819 case Expr::ParenExprClass: { 820 const ParenExpr* PE = cast<ParenExpr>(Init); 821 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 822 } 823 case Expr::CompoundLiteralExprClass: 824 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 825 case Expr::DeclRefExprClass: { 826 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 827 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 828 if (VD->hasGlobalStorage()) 829 return false; 830 Diag(Init->getExprLoc(), 831 diag::err_init_element_not_constant, Init->getSourceRange()); 832 return true; 833 } 834 if (isa<FunctionDecl>(D)) 835 return false; 836 Diag(Init->getExprLoc(), 837 diag::err_init_element_not_constant, Init->getSourceRange()); 838 return true; 839 } 840 case Expr::MemberExprClass: { 841 const MemberExpr *M = cast<MemberExpr>(Init); 842 if (M->isArrow()) 843 return CheckAddressConstantExpression(M->getBase()); 844 return CheckAddressConstantExpressionLValue(M->getBase()); 845 } 846 case Expr::ArraySubscriptExprClass: { 847 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 848 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 849 return CheckAddressConstantExpression(ASE->getBase()) || 850 CheckArithmeticConstantExpression(ASE->getIdx()); 851 } 852 case Expr::StringLiteralClass: 853 case Expr::PreDefinedExprClass: 854 return false; 855 case Expr::UnaryOperatorClass: { 856 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 857 858 // C99 6.6p9 859 if (Exp->getOpcode() == UnaryOperator::Deref) 860 return CheckAddressConstantExpression(Exp->getSubExpr()); 861 862 Diag(Init->getExprLoc(), 863 diag::err_init_element_not_constant, Init->getSourceRange()); 864 return true; 865 } 866 } 867} 868 869bool Sema::CheckAddressConstantExpression(const Expr* Init) { 870 switch (Init->getStmtClass()) { 871 default: 872 Diag(Init->getExprLoc(), 873 diag::err_init_element_not_constant, Init->getSourceRange()); 874 return true; 875 case Expr::ParenExprClass: { 876 const ParenExpr* PE = cast<ParenExpr>(Init); 877 return CheckAddressConstantExpression(PE->getSubExpr()); 878 } 879 case Expr::StringLiteralClass: 880 case Expr::ObjCStringLiteralClass: 881 return false; 882 case Expr::CallExprClass: { 883 const CallExpr *CE = cast<CallExpr>(Init); 884 if (CE->isBuiltinConstantExpr()) 885 return false; 886 Diag(Init->getExprLoc(), 887 diag::err_init_element_not_constant, Init->getSourceRange()); 888 return true; 889 } 890 case Expr::UnaryOperatorClass: { 891 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 892 893 // C99 6.6p9 894 if (Exp->getOpcode() == UnaryOperator::AddrOf) 895 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 896 897 if (Exp->getOpcode() == UnaryOperator::Extension) 898 return CheckAddressConstantExpression(Exp->getSubExpr()); 899 900 Diag(Init->getExprLoc(), 901 diag::err_init_element_not_constant, Init->getSourceRange()); 902 return true; 903 } 904 case Expr::BinaryOperatorClass: { 905 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 906 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 907 908 Expr *PExp = Exp->getLHS(); 909 Expr *IExp = Exp->getRHS(); 910 if (IExp->getType()->isPointerType()) 911 std::swap(PExp, IExp); 912 913 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 914 return CheckAddressConstantExpression(PExp) || 915 CheckArithmeticConstantExpression(IExp); 916 } 917 case Expr::ImplicitCastExprClass: { 918 const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 919 920 // Check for implicit promotion 921 if (SubExpr->getType()->isFunctionType() || 922 SubExpr->getType()->isArrayType()) 923 return CheckAddressConstantExpressionLValue(SubExpr); 924 925 // Check for pointer->pointer cast 926 if (SubExpr->getType()->isPointerType()) 927 return CheckAddressConstantExpression(SubExpr); 928 929 if (SubExpr->getType()->isArithmeticType()) 930 return CheckArithmeticConstantExpression(SubExpr); 931 932 Diag(Init->getExprLoc(), 933 diag::err_init_element_not_constant, Init->getSourceRange()); 934 return true; 935 } 936 case Expr::CastExprClass: { 937 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 938 939 // Check for pointer->pointer cast 940 if (SubExpr->getType()->isPointerType()) 941 return CheckAddressConstantExpression(SubExpr); 942 943 // FIXME: Should we pedwarn for (int*)(0+0)? 944 if (SubExpr->getType()->isArithmeticType()) 945 return CheckArithmeticConstantExpression(SubExpr); 946 947 Diag(Init->getExprLoc(), 948 diag::err_init_element_not_constant, Init->getSourceRange()); 949 return true; 950 } 951 case Expr::ConditionalOperatorClass: { 952 // FIXME: Should we pedwarn here? 953 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 954 if (!Exp->getCond()->getType()->isArithmeticType()) { 955 Diag(Init->getExprLoc(), 956 diag::err_init_element_not_constant, Init->getSourceRange()); 957 return true; 958 } 959 if (CheckArithmeticConstantExpression(Exp->getCond())) 960 return true; 961 if (Exp->getLHS() && 962 CheckAddressConstantExpression(Exp->getLHS())) 963 return true; 964 return CheckAddressConstantExpression(Exp->getRHS()); 965 } 966 case Expr::AddrLabelExprClass: 967 return false; 968 } 969} 970 971static const Expr* FindExpressionBaseAddress(const Expr* E); 972 973static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 974 switch (E->getStmtClass()) { 975 default: 976 return E; 977 case Expr::ParenExprClass: { 978 const ParenExpr* PE = cast<ParenExpr>(E); 979 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 980 } 981 case Expr::MemberExprClass: { 982 const MemberExpr *M = cast<MemberExpr>(E); 983 if (M->isArrow()) 984 return FindExpressionBaseAddress(M->getBase()); 985 return FindExpressionBaseAddressLValue(M->getBase()); 986 } 987 case Expr::ArraySubscriptExprClass: { 988 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 989 return FindExpressionBaseAddress(ASE->getBase()); 990 } 991 case Expr::UnaryOperatorClass: { 992 const UnaryOperator *Exp = cast<UnaryOperator>(E); 993 994 if (Exp->getOpcode() == UnaryOperator::Deref) 995 return FindExpressionBaseAddress(Exp->getSubExpr()); 996 997 return E; 998 } 999 } 1000} 1001 1002static const Expr* FindExpressionBaseAddress(const Expr* E) { 1003 switch (E->getStmtClass()) { 1004 default: 1005 return E; 1006 case Expr::ParenExprClass: { 1007 const ParenExpr* PE = cast<ParenExpr>(E); 1008 return FindExpressionBaseAddress(PE->getSubExpr()); 1009 } 1010 case Expr::UnaryOperatorClass: { 1011 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1012 1013 // C99 6.6p9 1014 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1015 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1016 1017 if (Exp->getOpcode() == UnaryOperator::Extension) 1018 return FindExpressionBaseAddress(Exp->getSubExpr()); 1019 1020 return E; 1021 } 1022 case Expr::BinaryOperatorClass: { 1023 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1024 1025 Expr *PExp = Exp->getLHS(); 1026 Expr *IExp = Exp->getRHS(); 1027 if (IExp->getType()->isPointerType()) 1028 std::swap(PExp, IExp); 1029 1030 return FindExpressionBaseAddress(PExp); 1031 } 1032 case Expr::ImplicitCastExprClass: { 1033 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1034 1035 // Check for implicit promotion 1036 if (SubExpr->getType()->isFunctionType() || 1037 SubExpr->getType()->isArrayType()) 1038 return FindExpressionBaseAddressLValue(SubExpr); 1039 1040 // Check for pointer->pointer cast 1041 if (SubExpr->getType()->isPointerType()) 1042 return FindExpressionBaseAddress(SubExpr); 1043 1044 // We assume that we have an arithmetic expression here; 1045 // if we don't, we'll figure it out later 1046 return 0; 1047 } 1048 case Expr::CastExprClass: { 1049 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1050 1051 // Check for pointer->pointer cast 1052 if (SubExpr->getType()->isPointerType()) 1053 return FindExpressionBaseAddress(SubExpr); 1054 1055 // We assume that we have an arithmetic expression here; 1056 // if we don't, we'll figure it out later 1057 return 0; 1058 } 1059 } 1060} 1061 1062bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1063 switch (Init->getStmtClass()) { 1064 default: 1065 Diag(Init->getExprLoc(), 1066 diag::err_init_element_not_constant, Init->getSourceRange()); 1067 return true; 1068 case Expr::ParenExprClass: { 1069 const ParenExpr* PE = cast<ParenExpr>(Init); 1070 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1071 } 1072 case Expr::FloatingLiteralClass: 1073 case Expr::IntegerLiteralClass: 1074 case Expr::CharacterLiteralClass: 1075 case Expr::ImaginaryLiteralClass: 1076 case Expr::TypesCompatibleExprClass: 1077 case Expr::CXXBoolLiteralExprClass: 1078 return false; 1079 case Expr::CallExprClass: { 1080 const CallExpr *CE = cast<CallExpr>(Init); 1081 if (CE->isBuiltinConstantExpr()) 1082 return false; 1083 Diag(Init->getExprLoc(), 1084 diag::err_init_element_not_constant, Init->getSourceRange()); 1085 return true; 1086 } 1087 case Expr::DeclRefExprClass: { 1088 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1089 if (isa<EnumConstantDecl>(D)) 1090 return false; 1091 Diag(Init->getExprLoc(), 1092 diag::err_init_element_not_constant, Init->getSourceRange()); 1093 return true; 1094 } 1095 case Expr::CompoundLiteralExprClass: 1096 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1097 // but vectors are allowed to be magic. 1098 if (Init->getType()->isVectorType()) 1099 return false; 1100 Diag(Init->getExprLoc(), 1101 diag::err_init_element_not_constant, Init->getSourceRange()); 1102 return true; 1103 case Expr::UnaryOperatorClass: { 1104 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1105 1106 switch (Exp->getOpcode()) { 1107 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1108 // See C99 6.6p3. 1109 default: 1110 Diag(Init->getExprLoc(), 1111 diag::err_init_element_not_constant, Init->getSourceRange()); 1112 return true; 1113 case UnaryOperator::SizeOf: 1114 case UnaryOperator::AlignOf: 1115 case UnaryOperator::OffsetOf: 1116 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1117 // See C99 6.5.3.4p2 and 6.6p3. 1118 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1119 return false; 1120 Diag(Init->getExprLoc(), 1121 diag::err_init_element_not_constant, Init->getSourceRange()); 1122 return true; 1123 case UnaryOperator::Extension: 1124 case UnaryOperator::LNot: 1125 case UnaryOperator::Plus: 1126 case UnaryOperator::Minus: 1127 case UnaryOperator::Not: 1128 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1129 } 1130 } 1131 case Expr::SizeOfAlignOfTypeExprClass: { 1132 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1133 // Special check for void types, which are allowed as an extension 1134 if (Exp->getArgumentType()->isVoidType()) 1135 return false; 1136 // alignof always evaluates to a constant. 1137 // FIXME: is sizeof(int[3.0]) a constant expression? 1138 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1139 Diag(Init->getExprLoc(), 1140 diag::err_init_element_not_constant, Init->getSourceRange()); 1141 return true; 1142 } 1143 return false; 1144 } 1145 case Expr::BinaryOperatorClass: { 1146 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1147 1148 if (Exp->getLHS()->getType()->isArithmeticType() && 1149 Exp->getRHS()->getType()->isArithmeticType()) { 1150 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1151 CheckArithmeticConstantExpression(Exp->getRHS()); 1152 } 1153 1154 if (Exp->getLHS()->getType()->isPointerType() && 1155 Exp->getRHS()->getType()->isPointerType()) { 1156 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1157 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1158 1159 // Only allow a null (constant integer) base; we could 1160 // allow some additional cases if necessary, but this 1161 // is sufficient to cover offsetof-like constructs. 1162 if (!LHSBase && !RHSBase) { 1163 return CheckAddressConstantExpression(Exp->getLHS()) || 1164 CheckAddressConstantExpression(Exp->getRHS()); 1165 } 1166 } 1167 1168 Diag(Init->getExprLoc(), 1169 diag::err_init_element_not_constant, Init->getSourceRange()); 1170 return true; 1171 } 1172 case Expr::ImplicitCastExprClass: 1173 case Expr::CastExprClass: { 1174 const Expr *SubExpr; 1175 if (const CastExpr *C = dyn_cast<CastExpr>(Init)) { 1176 SubExpr = C->getSubExpr(); 1177 } else { 1178 SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr(); 1179 } 1180 1181 if (SubExpr->getType()->isArithmeticType()) 1182 return CheckArithmeticConstantExpression(SubExpr); 1183 1184 Diag(Init->getExprLoc(), 1185 diag::err_init_element_not_constant, Init->getSourceRange()); 1186 return true; 1187 } 1188 case Expr::ConditionalOperatorClass: { 1189 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1190 if (CheckArithmeticConstantExpression(Exp->getCond())) 1191 return true; 1192 if (Exp->getLHS() && 1193 CheckArithmeticConstantExpression(Exp->getLHS())) 1194 return true; 1195 return CheckArithmeticConstantExpression(Exp->getRHS()); 1196 } 1197 } 1198} 1199 1200bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1201 Init = Init->IgnoreParens(); 1202 1203 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1204 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1205 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1206 1207 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1208 return CheckForConstantInitializer(e->getInitializer(), DclT); 1209 1210 if (Init->getType()->isReferenceType()) { 1211 // FIXME: Work out how the heck reference types work 1212 return false; 1213#if 0 1214 // A reference is constant if the address of the expression 1215 // is constant 1216 // We look through initlists here to simplify 1217 // CheckAddressConstantExpressionLValue. 1218 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1219 assert(Exp->getNumInits() > 0 && 1220 "Refernce initializer cannot be empty"); 1221 Init = Exp->getInit(0); 1222 } 1223 return CheckAddressConstantExpressionLValue(Init); 1224#endif 1225 } 1226 1227 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1228 unsigned numInits = Exp->getNumInits(); 1229 for (unsigned i = 0; i < numInits; i++) { 1230 // FIXME: Need to get the type of the declaration for C++, 1231 // because it could be a reference? 1232 if (CheckForConstantInitializer(Exp->getInit(i), 1233 Exp->getInit(i)->getType())) 1234 return true; 1235 } 1236 return false; 1237 } 1238 1239 if (Init->isNullPointerConstant(Context)) 1240 return false; 1241 if (Init->getType()->isArithmeticType()) { 1242 QualType InitTy = Init->getType().getCanonicalType().getUnqualifiedType(); 1243 if (InitTy == Context.BoolTy) { 1244 // Special handling for pointers implicitly cast to bool; 1245 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1246 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1247 Expr* SubE = ICE->getSubExpr(); 1248 if (SubE->getType()->isPointerType() || 1249 SubE->getType()->isArrayType() || 1250 SubE->getType()->isFunctionType()) { 1251 return CheckAddressConstantExpression(Init); 1252 } 1253 } 1254 } else if (InitTy->isIntegralType()) { 1255 Expr* SubE = 0; 1256 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) 1257 SubE = ICE->getSubExpr(); 1258 else if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1259 SubE = CE->getSubExpr(); 1260 // Special check for pointer cast to int; we allow as an extension 1261 // an address constant cast to an integer if the integer 1262 // is of an appropriate width (this sort of code is apparently used 1263 // in some places). 1264 // FIXME: Add pedwarn? 1265 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1266 if (SubE && (SubE->getType()->isPointerType() || 1267 SubE->getType()->isArrayType() || 1268 SubE->getType()->isFunctionType())) { 1269 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1270 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1271 if (IntWidth >= PointerWidth) 1272 return CheckAddressConstantExpression(Init); 1273 } 1274 } 1275 1276 return CheckArithmeticConstantExpression(Init); 1277 } 1278 1279 if (Init->getType()->isPointerType()) 1280 return CheckAddressConstantExpression(Init); 1281 1282 // An array type at the top level that isn't an init-list must 1283 // be a string literal 1284 if (Init->getType()->isArrayType()) 1285 return false; 1286 1287 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1288 Init->getSourceRange()); 1289 return true; 1290} 1291 1292void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1293 Decl *RealDecl = static_cast<Decl *>(dcl); 1294 Expr *Init = static_cast<Expr *>(init); 1295 assert(Init && "missing initializer"); 1296 1297 // If there is no declaration, there was an error parsing it. Just ignore 1298 // the initializer. 1299 if (RealDecl == 0) { 1300 delete Init; 1301 return; 1302 } 1303 1304 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1305 if (!VDecl) { 1306 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1307 diag::err_illegal_initializer); 1308 RealDecl->setInvalidDecl(); 1309 return; 1310 } 1311 // Get the decls type and save a reference for later, since 1312 // CheckInitializerTypes may change it. 1313 QualType DclT = VDecl->getType(), SavT = DclT; 1314 if (VDecl->isBlockVarDecl()) { 1315 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1316 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1317 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1318 VDecl->setInvalidDecl(); 1319 } else if (!VDecl->isInvalidDecl()) { 1320 if (CheckInitializerTypes(Init, DclT)) 1321 VDecl->setInvalidDecl(); 1322 if (SC == VarDecl::Static) // C99 6.7.8p4. 1323 CheckForConstantInitializer(Init, DclT); 1324 } 1325 } else if (VDecl->isFileVarDecl()) { 1326 if (VDecl->getStorageClass() == VarDecl::Extern) 1327 Diag(VDecl->getLocation(), diag::warn_extern_init); 1328 if (!VDecl->isInvalidDecl()) 1329 if (CheckInitializerTypes(Init, DclT)) 1330 VDecl->setInvalidDecl(); 1331 1332 // C99 6.7.8p4. All file scoped initializers need to be constant. 1333 CheckForConstantInitializer(Init, DclT); 1334 } 1335 // If the type changed, it means we had an incomplete type that was 1336 // completed by the initializer. For example: 1337 // int ary[] = { 1, 3, 5 }; 1338 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1339 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1340 VDecl->setType(DclT); 1341 Init->setType(DclT); 1342 } 1343 1344 // Attach the initializer to the decl. 1345 VDecl->setInit(Init); 1346 return; 1347} 1348 1349/// The declarators are chained together backwards, reverse the list. 1350Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1351 // Often we have single declarators, handle them quickly. 1352 Decl *GroupDecl = static_cast<Decl*>(group); 1353 if (GroupDecl == 0) 1354 return 0; 1355 1356 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1357 ScopedDecl *NewGroup = 0; 1358 if (Group->getNextDeclarator() == 0) 1359 NewGroup = Group; 1360 else { // reverse the list. 1361 while (Group) { 1362 ScopedDecl *Next = Group->getNextDeclarator(); 1363 Group->setNextDeclarator(NewGroup); 1364 NewGroup = Group; 1365 Group = Next; 1366 } 1367 } 1368 // Perform semantic analysis that depends on having fully processed both 1369 // the declarator and initializer. 1370 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1371 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1372 if (!IDecl) 1373 continue; 1374 QualType T = IDecl->getType(); 1375 1376 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1377 // static storage duration, it shall not have a variable length array. 1378 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1379 IDecl->getStorageClass() == VarDecl::Static) { 1380 if (T->getAsVariableArrayType()) { 1381 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1382 IDecl->setInvalidDecl(); 1383 } 1384 } 1385 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1386 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1387 if (IDecl->isBlockVarDecl() && 1388 IDecl->getStorageClass() != VarDecl::Extern) { 1389 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1390 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1391 T.getAsString()); 1392 IDecl->setInvalidDecl(); 1393 } 1394 } 1395 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1396 // object that has file scope without an initializer, and without a 1397 // storage-class specifier or with the storage-class specifier "static", 1398 // constitutes a tentative definition. Note: A tentative definition with 1399 // external linkage is valid (C99 6.2.2p5). 1400 if (IDecl && !IDecl->getInit() && 1401 (IDecl->getStorageClass() == VarDecl::Static || 1402 IDecl->getStorageClass() == VarDecl::None)) { 1403 if (T->isIncompleteArrayType()) { 1404 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1405 // array to be completed. Don't issue a diagnostic. 1406 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1407 // C99 6.9.2p3: If the declaration of an identifier for an object is 1408 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1409 // declared type shall not be an incomplete type. 1410 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1411 T.getAsString()); 1412 IDecl->setInvalidDecl(); 1413 } 1414 } 1415 } 1416 return NewGroup; 1417} 1418 1419/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1420/// to introduce parameters into function prototype scope. 1421Sema::DeclTy * 1422Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1423 const DeclSpec &DS = D.getDeclSpec(); 1424 1425 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1426 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 1427 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 1428 Diag(DS.getStorageClassSpecLoc(), 1429 diag::err_invalid_storage_class_in_func_decl); 1430 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1431 } 1432 if (DS.isThreadSpecified()) { 1433 Diag(DS.getThreadSpecLoc(), 1434 diag::err_invalid_storage_class_in_func_decl); 1435 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1436 } 1437 1438 // Check that there are no default arguments inside the type of this 1439 // parameter (C++ only). 1440 if (getLangOptions().CPlusPlus) 1441 CheckExtraCXXDefaultArguments(D); 1442 1443 // In this context, we *do not* check D.getInvalidType(). If the declarator 1444 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1445 // though it will not reflect the user specified type. 1446 QualType parmDeclType = GetTypeForDeclarator(D, S); 1447 1448 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1449 1450 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1451 // Can this happen for params? We already checked that they don't conflict 1452 // among each other. Here they can only shadow globals, which is ok. 1453 IdentifierInfo *II = D.getIdentifier(); 1454 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1455 if (S->isDeclScope(PrevDecl)) { 1456 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1457 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1458 1459 // Recover by removing the name 1460 II = 0; 1461 D.SetIdentifier(0, D.getIdentifierLoc()); 1462 } 1463 } 1464 1465 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1466 // Doing the promotion here has a win and a loss. The win is the type for 1467 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1468 // code generator). The loss is the orginal type isn't preserved. For example: 1469 // 1470 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1471 // int blockvardecl[5]; 1472 // sizeof(parmvardecl); // size == 4 1473 // sizeof(blockvardecl); // size == 20 1474 // } 1475 // 1476 // For expressions, all implicit conversions are captured using the 1477 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1478 // 1479 // FIXME: If a source translation tool needs to see the original type, then 1480 // we need to consider storing both types (in ParmVarDecl)... 1481 // 1482 if (parmDeclType->isArrayType()) { 1483 // int x[restrict 4] -> int *restrict 1484 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1485 } else if (parmDeclType->isFunctionType()) 1486 parmDeclType = Context.getPointerType(parmDeclType); 1487 1488 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1489 D.getIdentifierLoc(), II, 1490 parmDeclType, VarDecl::None, 1491 0, 0); 1492 1493 if (D.getInvalidType()) 1494 New->setInvalidDecl(); 1495 1496 if (II) 1497 PushOnScopeChains(New, S); 1498 1499 ProcessDeclAttributes(New, D); 1500 return New; 1501 1502} 1503 1504Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1505 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1506 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1507 "Not a function declarator!"); 1508 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1509 1510 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1511 // for a K&R function. 1512 if (!FTI.hasPrototype) { 1513 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1514 if (FTI.ArgInfo[i].Param == 0) { 1515 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1516 FTI.ArgInfo[i].Ident->getName()); 1517 // Implicitly declare the argument as type 'int' for lack of a better 1518 // type. 1519 DeclSpec DS; 1520 const char* PrevSpec; // unused 1521 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1522 PrevSpec); 1523 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1524 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1525 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1526 } 1527 } 1528 1529 // Since this is a function definition, act as though we have information 1530 // about the arguments. 1531 if (FTI.NumArgs) 1532 FTI.hasPrototype = true; 1533 } else { 1534 // FIXME: Diagnose arguments without names in C. 1535 } 1536 1537 Scope *GlobalScope = FnBodyScope->getParent(); 1538 1539 // See if this is a redefinition. 1540 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1541 GlobalScope); 1542 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1543 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1544 const FunctionDecl *Definition; 1545 if (FD->getBody(Definition)) { 1546 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1547 D.getIdentifier()->getName()); 1548 Diag(Definition->getLocation(), diag::err_previous_definition); 1549 } 1550 } 1551 } 1552 1553 return ActOnStartOfFunctionDef(FnBodyScope, 1554 ActOnDeclarator(GlobalScope, D, 0)); 1555} 1556 1557Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1558 Decl *decl = static_cast<Decl*>(D); 1559 FunctionDecl *FD = cast<FunctionDecl>(decl); 1560 PushDeclContext(FD); 1561 1562 // Check the validity of our function parameters 1563 CheckParmsForFunctionDef(FD); 1564 1565 // Introduce our parameters into the function scope 1566 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1567 ParmVarDecl *Param = FD->getParamDecl(p); 1568 // If this has an identifier, add it to the scope stack. 1569 if (Param->getIdentifier()) 1570 PushOnScopeChains(Param, FnBodyScope); 1571 } 1572 1573 return FD; 1574} 1575 1576Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1577 Decl *dcl = static_cast<Decl *>(D); 1578 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(dcl)) { 1579 FD->setBody((Stmt*)Body); 1580 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1581 } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(dcl)) { 1582 MD->setBody((Stmt*)Body); 1583 } 1584 PopDeclContext(); 1585 // Verify and clean out per-function state. 1586 1587 // Check goto/label use. 1588 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1589 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1590 // Verify that we have no forward references left. If so, there was a goto 1591 // or address of a label taken, but no definition of it. Label fwd 1592 // definitions are indicated with a null substmt. 1593 if (I->second->getSubStmt() == 0) { 1594 LabelStmt *L = I->second; 1595 // Emit error. 1596 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1597 1598 // At this point, we have gotos that use the bogus label. Stitch it into 1599 // the function body so that they aren't leaked and that the AST is well 1600 // formed. 1601 if (Body) { 1602 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1603 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1604 } else { 1605 // The whole function wasn't parsed correctly, just delete this. 1606 delete L; 1607 } 1608 } 1609 } 1610 LabelMap.clear(); 1611 1612 return D; 1613} 1614 1615/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1616/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1617ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1618 IdentifierInfo &II, Scope *S) { 1619 // Extension in C99. Legal in C90, but warn about it. 1620 if (getLangOptions().C99) 1621 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1622 else 1623 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1624 1625 // FIXME: handle stuff like: 1626 // void foo() { extern float X(); } 1627 // void bar() { X(); } <-- implicit decl for X in another scope. 1628 1629 // Set a Declarator for the implicit definition: int foo(); 1630 const char *Dummy; 1631 DeclSpec DS; 1632 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1633 Error = Error; // Silence warning. 1634 assert(!Error && "Error setting up implicit decl!"); 1635 Declarator D(DS, Declarator::BlockContext); 1636 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1637 D.SetIdentifier(&II, Loc); 1638 1639 // Insert this function into translation-unit scope. 1640 1641 DeclContext *PrevDC = CurContext; 1642 CurContext = Context.getTranslationUnitDecl(); 1643 1644 FunctionDecl *FD = 1645 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1646 FD->setImplicit(); 1647 1648 CurContext = PrevDC; 1649 1650 return FD; 1651} 1652 1653 1654TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1655 ScopedDecl *LastDeclarator) { 1656 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1657 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1658 1659 // Scope manipulation handled by caller. 1660 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1661 D.getIdentifierLoc(), 1662 D.getIdentifier(), 1663 T, LastDeclarator); 1664 if (D.getInvalidType()) 1665 NewTD->setInvalidDecl(); 1666 return NewTD; 1667} 1668 1669/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1670/// former case, Name will be non-null. In the later case, Name will be null. 1671/// TagType indicates what kind of tag this is. TK indicates whether this is a 1672/// reference/declaration/definition of a tag. 1673Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1674 SourceLocation KWLoc, IdentifierInfo *Name, 1675 SourceLocation NameLoc, AttributeList *Attr) { 1676 // If this is a use of an existing tag, it must have a name. 1677 assert((Name != 0 || TK == TK_Definition) && 1678 "Nameless record must be a definition!"); 1679 1680 TagDecl::TagKind Kind; 1681 switch (TagType) { 1682 default: assert(0 && "Unknown tag type!"); 1683 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1684 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1685 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1686 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1687 } 1688 1689 // If this is a named struct, check to see if there was a previous forward 1690 // declaration or definition. 1691 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1692 if (ScopedDecl *PrevDecl = 1693 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) { 1694 1695 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1696 "unexpected Decl type"); 1697 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1698 // If this is a use of a previous tag, or if the tag is already declared 1699 // in the same scope (so that the definition/declaration completes or 1700 // rementions the tag), reuse the decl. 1701 if (TK == TK_Reference || 1702 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1703 // Make sure that this wasn't declared as an enum and now used as a 1704 // struct or something similar. 1705 if (PrevTagDecl->getTagKind() != Kind) { 1706 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1707 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1708 // Recover by making this an anonymous redefinition. 1709 Name = 0; 1710 PrevDecl = 0; 1711 } else { 1712 // If this is a use or a forward declaration, we're good. 1713 if (TK != TK_Definition) 1714 return PrevDecl; 1715 1716 // Diagnose attempts to redefine a tag. 1717 if (PrevTagDecl->isDefinition()) { 1718 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1719 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1720 // If this is a redefinition, recover by making this struct be 1721 // anonymous, which will make any later references get the previous 1722 // definition. 1723 Name = 0; 1724 } else { 1725 // Okay, this is definition of a previously declared or referenced 1726 // tag. Move the location of the decl to be the definition site. 1727 PrevDecl->setLocation(NameLoc); 1728 return PrevDecl; 1729 } 1730 } 1731 } 1732 // If we get here, this is a definition of a new struct type in a nested 1733 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1734 // type. 1735 } else { 1736 // PrevDecl is a namespace. 1737 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1738 // The tag name clashes with a namespace name, issue an error and recover 1739 // by making this tag be anonymous. 1740 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1741 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1742 Name = 0; 1743 } 1744 } 1745 } 1746 1747 // If there is an identifier, use the location of the identifier as the 1748 // location of the decl, otherwise use the location of the struct/union 1749 // keyword. 1750 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1751 1752 // Otherwise, if this is the first time we've seen this tag, create the decl. 1753 TagDecl *New; 1754 if (Kind == TagDecl::TK_enum) { 1755 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1756 // enum X { A, B, C } D; D should chain to X. 1757 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1758 // If this is an undefined enum, warn. 1759 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1760 } else { 1761 // struct/union/class 1762 1763 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1764 // struct X { int A; } D; D should chain to X. 1765 if (getLangOptions().CPlusPlus) 1766 // FIXME: Look for a way to use RecordDecl for simple structs. 1767 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1768 else 1769 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0); 1770 } 1771 1772 // If this has an identifier, add it to the scope stack. 1773 if (Name) { 1774 // The scope passed in may not be a decl scope. Zip up the scope tree until 1775 // we find one that is. 1776 while ((S->getFlags() & Scope::DeclScope) == 0) 1777 S = S->getParent(); 1778 1779 // Add it to the decl chain. 1780 PushOnScopeChains(New, S); 1781 } 1782 1783 if (Attr) 1784 ProcessDeclAttributeList(New, Attr); 1785 return New; 1786} 1787 1788/// Collect the instance variables declared in an Objective-C object. Used in 1789/// the creation of structures from objects using the @defs directive. 1790static void CollectIvars(ObjCInterfaceDecl *Class, 1791 llvm::SmallVector<Sema::DeclTy*, 16> &ivars) { 1792 if (Class->getSuperClass()) 1793 CollectIvars(Class->getSuperClass(), ivars); 1794 ivars.append(Class->ivar_begin(), Class->ivar_end()); 1795} 1796 1797/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1798/// instance variables of ClassName into Decls. 1799void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1800 IdentifierInfo *ClassName, 1801 llvm::SmallVector<DeclTy*, 16> &Decls) { 1802 // Check that ClassName is a valid class 1803 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1804 if (!Class) { 1805 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1806 return; 1807 } 1808 // Collect the instance variables 1809 CollectIvars(Class, Decls); 1810} 1811 1812QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1813 // This method tries to turn a variable array into a constant 1814 // array even when the size isn't an ICE. This is necessary 1815 // for compatibility with code that depends on gcc's buggy 1816 // constant expression folding, like struct {char x[(int)(char*)2];} 1817 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1818 APValue Result; 1819 if (VLATy->getSizeExpr() && 1820 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1821 llvm::APSInt &Res = Result.getInt(); 1822 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1823 return Context.getConstantArrayType(VLATy->getElementType(), 1824 Res, ArrayType::Normal, 0); 1825 } 1826 } 1827 return QualType(); 1828} 1829 1830/// ActOnField - Each field of a struct/union/class is passed into this in order 1831/// to create a FieldDecl object for it. 1832Sema::DeclTy *Sema::ActOnField(Scope *S, 1833 SourceLocation DeclStart, 1834 Declarator &D, ExprTy *BitfieldWidth) { 1835 IdentifierInfo *II = D.getIdentifier(); 1836 Expr *BitWidth = (Expr*)BitfieldWidth; 1837 SourceLocation Loc = DeclStart; 1838 if (II) Loc = D.getIdentifierLoc(); 1839 1840 // FIXME: Unnamed fields can be handled in various different ways, for 1841 // example, unnamed unions inject all members into the struct namespace! 1842 1843 1844 if (BitWidth) { 1845 // TODO: Validate. 1846 //printf("WARNING: BITFIELDS IGNORED!\n"); 1847 1848 // 6.7.2.1p3 1849 // 6.7.2.1p4 1850 1851 } else { 1852 // Not a bitfield. 1853 1854 // validate II. 1855 1856 } 1857 1858 QualType T = GetTypeForDeclarator(D, S); 1859 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1860 bool InvalidDecl = false; 1861 1862 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1863 // than a variably modified type. 1864 if (T->isVariablyModifiedType()) { 1865 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 1866 if (!FixedTy.isNull()) { 1867 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 1868 T = FixedTy; 1869 } else { 1870 // FIXME: This diagnostic needs work 1871 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1872 InvalidDecl = true; 1873 } 1874 } 1875 // FIXME: Chain fielddecls together. 1876 FieldDecl *NewFD; 1877 1878 if (getLangOptions().CPlusPlus) { 1879 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 1880 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 1881 Loc, II, T, BitWidth); 1882 if (II) 1883 PushOnScopeChains(NewFD, S); 1884 } 1885 else 1886 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 1887 1888 ProcessDeclAttributes(NewFD, D); 1889 1890 if (D.getInvalidType() || InvalidDecl) 1891 NewFD->setInvalidDecl(); 1892 return NewFD; 1893} 1894 1895/// TranslateIvarVisibility - Translate visibility from a token ID to an 1896/// AST enum value. 1897static ObjCIvarDecl::AccessControl 1898TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 1899 switch (ivarVisibility) { 1900 case tok::objc_private: return ObjCIvarDecl::Private; 1901 case tok::objc_public: return ObjCIvarDecl::Public; 1902 case tok::objc_protected: return ObjCIvarDecl::Protected; 1903 case tok::objc_package: return ObjCIvarDecl::Package; 1904 default: assert(false && "Unknown visitibility kind"); 1905 } 1906} 1907 1908/// ActOnIvar - Each ivar field of an objective-c class is passed into this 1909/// in order to create an IvarDecl object for it. 1910Sema::DeclTy *Sema::ActOnIvar(Scope *S, 1911 SourceLocation DeclStart, 1912 Declarator &D, ExprTy *BitfieldWidth, 1913 tok::ObjCKeywordKind Visibility) { 1914 IdentifierInfo *II = D.getIdentifier(); 1915 Expr *BitWidth = (Expr*)BitfieldWidth; 1916 SourceLocation Loc = DeclStart; 1917 if (II) Loc = D.getIdentifierLoc(); 1918 1919 // FIXME: Unnamed fields can be handled in various different ways, for 1920 // example, unnamed unions inject all members into the struct namespace! 1921 1922 1923 if (BitWidth) { 1924 // TODO: Validate. 1925 //printf("WARNING: BITFIELDS IGNORED!\n"); 1926 1927 // 6.7.2.1p3 1928 // 6.7.2.1p4 1929 1930 } else { 1931 // Not a bitfield. 1932 1933 // validate II. 1934 1935 } 1936 1937 QualType T = GetTypeForDeclarator(D, S); 1938 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1939 bool InvalidDecl = false; 1940 1941 // C99 6.7.2.1p8: A member of a structure or union may have any type other 1942 // than a variably modified type. 1943 if (T->isVariablyModifiedType()) { 1944 // FIXME: This diagnostic needs work 1945 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 1946 InvalidDecl = true; 1947 } 1948 1949 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, 1950 (Expr *)BitfieldWidth); 1951 1952 ProcessDeclAttributes(NewID, D); 1953 1954 if (D.getInvalidType() || InvalidDecl) 1955 NewID->setInvalidDecl(); 1956 // If we have visibility info, make sure the AST is set accordingly. 1957 if (Visibility != tok::objc_not_keyword) 1958 NewID->setAccessControl(TranslateIvarVisibility(Visibility)); 1959 return NewID; 1960} 1961 1962void Sema::ActOnFields(Scope* S, 1963 SourceLocation RecLoc, DeclTy *RecDecl, 1964 DeclTy **Fields, unsigned NumFields, 1965 SourceLocation LBrac, SourceLocation RBrac) { 1966 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 1967 assert(EnclosingDecl && "missing record or interface decl"); 1968 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 1969 1970 if (Record && Record->isDefinition()) { 1971 // Diagnose code like: 1972 // struct S { struct S {} X; }; 1973 // We discover this when we complete the outer S. Reject and ignore the 1974 // outer S. 1975 Diag(Record->getLocation(), diag::err_nested_redefinition, 1976 Record->getKindName()); 1977 Diag(RecLoc, diag::err_previous_definition); 1978 Record->setInvalidDecl(); 1979 return; 1980 } 1981 // Verify that all the fields are okay. 1982 unsigned NumNamedMembers = 0; 1983 llvm::SmallVector<FieldDecl*, 32> RecFields; 1984 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 1985 1986 for (unsigned i = 0; i != NumFields; ++i) { 1987 1988 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 1989 assert(FD && "missing field decl"); 1990 1991 // Remember all fields. 1992 RecFields.push_back(FD); 1993 1994 // Get the type for the field. 1995 Type *FDTy = FD->getType().getTypePtr(); 1996 1997 // C99 6.7.2.1p2 - A field may not be a function type. 1998 if (FDTy->isFunctionType()) { 1999 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2000 FD->getName()); 2001 FD->setInvalidDecl(); 2002 EnclosingDecl->setInvalidDecl(); 2003 continue; 2004 } 2005 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2006 if (FDTy->isIncompleteType()) { 2007 if (!Record) { // Incomplete ivar type is always an error. 2008 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2009 FD->setInvalidDecl(); 2010 EnclosingDecl->setInvalidDecl(); 2011 continue; 2012 } 2013 if (i != NumFields-1 || // ... that the last member ... 2014 !Record->isStruct() || // ... of a structure ... 2015 !FDTy->isArrayType()) { //... may have incomplete array type. 2016 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2017 FD->setInvalidDecl(); 2018 EnclosingDecl->setInvalidDecl(); 2019 continue; 2020 } 2021 if (NumNamedMembers < 1) { //... must have more than named member ... 2022 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2023 FD->getName()); 2024 FD->setInvalidDecl(); 2025 EnclosingDecl->setInvalidDecl(); 2026 continue; 2027 } 2028 // Okay, we have a legal flexible array member at the end of the struct. 2029 if (Record) 2030 Record->setHasFlexibleArrayMember(true); 2031 } 2032 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2033 /// field of another structure or the element of an array. 2034 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2035 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2036 // If this is a member of a union, then entire union becomes "flexible". 2037 if (Record && Record->isUnion()) { 2038 Record->setHasFlexibleArrayMember(true); 2039 } else { 2040 // If this is a struct/class and this is not the last element, reject 2041 // it. Note that GCC supports variable sized arrays in the middle of 2042 // structures. 2043 if (i != NumFields-1) { 2044 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2045 FD->getName()); 2046 FD->setInvalidDecl(); 2047 EnclosingDecl->setInvalidDecl(); 2048 continue; 2049 } 2050 // We support flexible arrays at the end of structs in other structs 2051 // as an extension. 2052 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2053 FD->getName()); 2054 if (Record) 2055 Record->setHasFlexibleArrayMember(true); 2056 } 2057 } 2058 } 2059 /// A field cannot be an Objective-c object 2060 if (FDTy->isObjCInterfaceType()) { 2061 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2062 FD->getName()); 2063 FD->setInvalidDecl(); 2064 EnclosingDecl->setInvalidDecl(); 2065 continue; 2066 } 2067 // Keep track of the number of named members. 2068 if (IdentifierInfo *II = FD->getIdentifier()) { 2069 // Detect duplicate member names. 2070 if (!FieldIDs.insert(II)) { 2071 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2072 // Find the previous decl. 2073 SourceLocation PrevLoc; 2074 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2075 assert(i != e && "Didn't find previous def!"); 2076 if (RecFields[i]->getIdentifier() == II) { 2077 PrevLoc = RecFields[i]->getLocation(); 2078 break; 2079 } 2080 } 2081 Diag(PrevLoc, diag::err_previous_definition); 2082 FD->setInvalidDecl(); 2083 EnclosingDecl->setInvalidDecl(); 2084 continue; 2085 } 2086 ++NumNamedMembers; 2087 } 2088 } 2089 2090 // Okay, we successfully defined 'Record'. 2091 if (Record) { 2092 Record->defineBody(&RecFields[0], RecFields.size()); 2093 Consumer.HandleTagDeclDefinition(Record); 2094 } else { 2095 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2096 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2097 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2098 else if (ObjCImplementationDecl *IMPDecl = 2099 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2100 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2101 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2102 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2103 } 2104 } 2105} 2106 2107Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2108 DeclTy *lastEnumConst, 2109 SourceLocation IdLoc, IdentifierInfo *Id, 2110 SourceLocation EqualLoc, ExprTy *val) { 2111 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2112 EnumConstantDecl *LastEnumConst = 2113 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2114 Expr *Val = static_cast<Expr*>(val); 2115 2116 // The scope passed in may not be a decl scope. Zip up the scope tree until 2117 // we find one that is. 2118 while ((S->getFlags() & Scope::DeclScope) == 0) 2119 S = S->getParent(); 2120 2121 // Verify that there isn't already something declared with this name in this 2122 // scope. 2123 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2124 // When in C++, we may get a TagDecl with the same name; in this case the 2125 // enum constant will 'hide' the tag. 2126 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2127 "Received TagDecl when not in C++!"); 2128 if (!isa<TagDecl>(PrevDecl) && 2129 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2130 if (isa<EnumConstantDecl>(PrevDecl)) 2131 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2132 else 2133 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2134 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2135 delete Val; 2136 return 0; 2137 } 2138 } 2139 2140 llvm::APSInt EnumVal(32); 2141 QualType EltTy; 2142 if (Val) { 2143 // Make sure to promote the operand type to int. 2144 UsualUnaryConversions(Val); 2145 2146 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2147 SourceLocation ExpLoc; 2148 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2149 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2150 Id->getName()); 2151 delete Val; 2152 Val = 0; // Just forget about it. 2153 } else { 2154 EltTy = Val->getType(); 2155 } 2156 } 2157 2158 if (!Val) { 2159 if (LastEnumConst) { 2160 // Assign the last value + 1. 2161 EnumVal = LastEnumConst->getInitVal(); 2162 ++EnumVal; 2163 2164 // Check for overflow on increment. 2165 if (EnumVal < LastEnumConst->getInitVal()) 2166 Diag(IdLoc, diag::warn_enum_value_overflow); 2167 2168 EltTy = LastEnumConst->getType(); 2169 } else { 2170 // First value, set to zero. 2171 EltTy = Context.IntTy; 2172 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2173 } 2174 } 2175 2176 EnumConstantDecl *New = 2177 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2178 Val, EnumVal, 2179 LastEnumConst); 2180 2181 // Register this decl in the current scope stack. 2182 PushOnScopeChains(New, S); 2183 return New; 2184} 2185 2186void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2187 DeclTy **Elements, unsigned NumElements) { 2188 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2189 assert(!Enum->isDefinition() && "Enum redefinitions can't reach here"); 2190 2191 // TODO: If the result value doesn't fit in an int, it must be a long or long 2192 // long value. ISO C does not support this, but GCC does as an extension, 2193 // emit a warning. 2194 unsigned IntWidth = Context.Target.getIntWidth(); 2195 2196 // Verify that all the values are okay, compute the size of the values, and 2197 // reverse the list. 2198 unsigned NumNegativeBits = 0; 2199 unsigned NumPositiveBits = 0; 2200 2201 // Keep track of whether all elements have type int. 2202 bool AllElementsInt = true; 2203 2204 EnumConstantDecl *EltList = 0; 2205 for (unsigned i = 0; i != NumElements; ++i) { 2206 EnumConstantDecl *ECD = 2207 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2208 if (!ECD) continue; // Already issued a diagnostic. 2209 2210 // If the enum value doesn't fit in an int, emit an extension warning. 2211 const llvm::APSInt &InitVal = ECD->getInitVal(); 2212 assert(InitVal.getBitWidth() >= IntWidth && 2213 "Should have promoted value to int"); 2214 if (InitVal.getBitWidth() > IntWidth) { 2215 llvm::APSInt V(InitVal); 2216 V.trunc(IntWidth); 2217 V.extend(InitVal.getBitWidth()); 2218 if (V != InitVal) 2219 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2220 InitVal.toString()); 2221 } 2222 2223 // Keep track of the size of positive and negative values. 2224 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2225 NumPositiveBits = std::max(NumPositiveBits, 2226 (unsigned)InitVal.getActiveBits()); 2227 else 2228 NumNegativeBits = std::max(NumNegativeBits, 2229 (unsigned)InitVal.getMinSignedBits()); 2230 2231 // Keep track of whether every enum element has type int (very commmon). 2232 if (AllElementsInt) 2233 AllElementsInt = ECD->getType() == Context.IntTy; 2234 2235 ECD->setNextDeclarator(EltList); 2236 EltList = ECD; 2237 } 2238 2239 // Figure out the type that should be used for this enum. 2240 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2241 QualType BestType; 2242 unsigned BestWidth; 2243 2244 if (NumNegativeBits) { 2245 // If there is a negative value, figure out the smallest integer type (of 2246 // int/long/longlong) that fits. 2247 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2248 BestType = Context.IntTy; 2249 BestWidth = IntWidth; 2250 } else { 2251 BestWidth = Context.Target.getLongWidth(); 2252 2253 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2254 BestType = Context.LongTy; 2255 else { 2256 BestWidth = Context.Target.getLongLongWidth(); 2257 2258 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2259 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2260 BestType = Context.LongLongTy; 2261 } 2262 } 2263 } else { 2264 // If there is no negative value, figure out which of uint, ulong, ulonglong 2265 // fits. 2266 if (NumPositiveBits <= IntWidth) { 2267 BestType = Context.UnsignedIntTy; 2268 BestWidth = IntWidth; 2269 } else if (NumPositiveBits <= 2270 (BestWidth = Context.Target.getLongWidth())) { 2271 BestType = Context.UnsignedLongTy; 2272 } else { 2273 BestWidth = Context.Target.getLongLongWidth(); 2274 assert(NumPositiveBits <= BestWidth && 2275 "How could an initializer get larger than ULL?"); 2276 BestType = Context.UnsignedLongLongTy; 2277 } 2278 } 2279 2280 // Loop over all of the enumerator constants, changing their types to match 2281 // the type of the enum if needed. 2282 for (unsigned i = 0; i != NumElements; ++i) { 2283 EnumConstantDecl *ECD = 2284 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2285 if (!ECD) continue; // Already issued a diagnostic. 2286 2287 // Standard C says the enumerators have int type, but we allow, as an 2288 // extension, the enumerators to be larger than int size. If each 2289 // enumerator value fits in an int, type it as an int, otherwise type it the 2290 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2291 // that X has type 'int', not 'unsigned'. 2292 if (ECD->getType() == Context.IntTy) { 2293 // Make sure the init value is signed. 2294 llvm::APSInt IV = ECD->getInitVal(); 2295 IV.setIsSigned(true); 2296 ECD->setInitVal(IV); 2297 continue; // Already int type. 2298 } 2299 2300 // Determine whether the value fits into an int. 2301 llvm::APSInt InitVal = ECD->getInitVal(); 2302 bool FitsInInt; 2303 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2304 FitsInInt = InitVal.getActiveBits() < IntWidth; 2305 else 2306 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2307 2308 // If it fits into an integer type, force it. Otherwise force it to match 2309 // the enum decl type. 2310 QualType NewTy; 2311 unsigned NewWidth; 2312 bool NewSign; 2313 if (FitsInInt) { 2314 NewTy = Context.IntTy; 2315 NewWidth = IntWidth; 2316 NewSign = true; 2317 } else if (ECD->getType() == BestType) { 2318 // Already the right type! 2319 continue; 2320 } else { 2321 NewTy = BestType; 2322 NewWidth = BestWidth; 2323 NewSign = BestType->isSignedIntegerType(); 2324 } 2325 2326 // Adjust the APSInt value. 2327 InitVal.extOrTrunc(NewWidth); 2328 InitVal.setIsSigned(NewSign); 2329 ECD->setInitVal(InitVal); 2330 2331 // Adjust the Expr initializer and type. 2332 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2333 ECD->setType(NewTy); 2334 } 2335 2336 Enum->defineElements(EltList, BestType); 2337 Consumer.HandleTagDeclDefinition(Enum); 2338} 2339 2340Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2341 ExprTy *expr) { 2342 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2343 2344 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2345} 2346 2347Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2348 SourceLocation LBrace, 2349 SourceLocation RBrace, 2350 const char *Lang, 2351 unsigned StrSize, 2352 DeclTy *D) { 2353 LinkageSpecDecl::LanguageIDs Language; 2354 Decl *dcl = static_cast<Decl *>(D); 2355 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2356 Language = LinkageSpecDecl::lang_c; 2357 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2358 Language = LinkageSpecDecl::lang_cxx; 2359 else { 2360 Diag(Loc, diag::err_bad_language); 2361 return 0; 2362 } 2363 2364 // FIXME: Add all the various semantics of linkage specifications 2365 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2366} 2367