SemaDecl.cpp revision 2b255c4dabe6a04314e3659a0f8b61e1382ec287
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for declarations. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/Parse/DeclSpec.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/SourceManager.h" 24// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/HeaderSearch.h" 27#include "llvm/ADT/SmallSet.h" 28using namespace clang; 29 30Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { 31 Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); 32 33 if (IIDecl && (isa<TypedefDecl>(IIDecl) || 34 isa<ObjCInterfaceDecl>(IIDecl) || 35 isa<TagDecl>(IIDecl))) 36 return IIDecl; 37 return 0; 38} 39 40DeclContext *Sema::getDCParent(DeclContext *DC) { 41 // If CurContext is a ObjC method, getParent() will return NULL. 42 if (isa<ObjCMethodDecl>(DC)) 43 return Context.getTranslationUnitDecl(); 44 45 // A C++ inline method is parsed *after* the topmost class it was declared in 46 // is fully parsed (it's "complete"). 47 // The parsing of a C++ inline method happens at the declaration context of 48 // the topmost (non-nested) class it is declared in. 49 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 50 assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record."); 51 DC = MD->getParent(); 52 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent())) 53 DC = RD; 54 55 // Return the declaration context of the topmost class the inline method is 56 // declared in. 57 return DC; 58 } 59 60 return DC->getParent(); 61} 62 63void Sema::PushDeclContext(DeclContext *DC) { 64 assert(getDCParent(DC) == CurContext && 65 "The next DeclContext should be directly contained in the current one."); 66 CurContext = DC; 67} 68 69void Sema::PopDeclContext() { 70 assert(CurContext && "DeclContext imbalance!"); 71 CurContext = getDCParent(CurContext); 72} 73 74/// Add this decl to the scope shadowed decl chains. 75void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { 76 S->AddDecl(D); 77 78 // C++ [basic.scope]p4: 79 // -- exactly one declaration shall declare a class name or 80 // enumeration name that is not a typedef name and the other 81 // declarations shall all refer to the same object or 82 // enumerator, or all refer to functions and function templates; 83 // in this case the class name or enumeration name is hidden. 84 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 85 // We are pushing the name of a tag (enum or class). 86 IdentifierResolver::iterator 87 I = IdResolver.begin(TD->getIdentifier(), 88 TD->getDeclContext(), false/*LookInParentCtx*/); 89 if (I != IdResolver.end() && 90 IdResolver.isDeclInScope(*I, TD->getDeclContext(), S)) { 91 // There is already a declaration with the same name in the same 92 // scope. It must be found before we find the new declaration, 93 // so swap the order on the shadowed declaration chain. 94 95 IdResolver.AddShadowedDecl(TD, *I); 96 return; 97 } 98 } 99 IdResolver.AddDecl(D); 100} 101 102void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 103 if (S->decl_empty()) return; 104 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 105 106 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 107 I != E; ++I) { 108 Decl *TmpD = static_cast<Decl*>(*I); 109 assert(TmpD && "This decl didn't get pushed??"); 110 111 if (isa<CXXFieldDecl>(TmpD)) continue; 112 113 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 114 ScopedDecl *D = cast<ScopedDecl>(TmpD); 115 116 IdentifierInfo *II = D->getIdentifier(); 117 if (!II) continue; 118 119 // We only want to remove the decls from the identifier decl chains for 120 // local scopes, when inside a function/method. 121 if (S->getFnParent() != 0) 122 IdResolver.RemoveDecl(D); 123 124 // Chain this decl to the containing DeclContext. 125 D->setNext(CurContext->getDeclChain()); 126 CurContext->setDeclChain(D); 127 } 128} 129 130/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 131/// return 0 if one not found. 132ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 133 // The third "scope" argument is 0 since we aren't enabling lazy built-in 134 // creation from this context. 135 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 136 137 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 138} 139 140/// LookupDecl - Look up the inner-most declaration in the specified 141/// namespace. 142Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 143 Scope *S, bool enableLazyBuiltinCreation) { 144 if (II == 0) return 0; 145 unsigned NS = NSI; 146 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 147 NS |= Decl::IDNS_Tag; 148 149 // Scan up the scope chain looking for a decl that matches this identifier 150 // that is in the appropriate namespace. This search should not take long, as 151 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 152 for (IdentifierResolver::iterator 153 I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) 154 if ((*I)->getIdentifierNamespace() & NS) 155 return *I; 156 157 // If we didn't find a use of this identifier, and if the identifier 158 // corresponds to a compiler builtin, create the decl object for the builtin 159 // now, injecting it into translation unit scope, and return it. 160 if (NS & Decl::IDNS_Ordinary) { 161 if (enableLazyBuiltinCreation) { 162 // If this is a builtin on this (or all) targets, create the decl. 163 if (unsigned BuiltinID = II->getBuiltinID()) 164 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 165 } 166 if (getLangOptions().ObjC1) { 167 // @interface and @compatibility_alias introduce typedef-like names. 168 // Unlike typedef's, they can only be introduced at file-scope (and are 169 // therefore not scoped decls). They can, however, be shadowed by 170 // other names in IDNS_Ordinary. 171 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 172 if (IDI != ObjCInterfaceDecls.end()) 173 return IDI->second; 174 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 175 if (I != ObjCAliasDecls.end()) 176 return I->second->getClassInterface(); 177 } 178 } 179 return 0; 180} 181 182void Sema::InitBuiltinVaListType() { 183 if (!Context.getBuiltinVaListType().isNull()) 184 return; 185 186 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 187 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 188 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 189 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 190} 191 192/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 193/// lazily create a decl for it. 194ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 195 Scope *S) { 196 Builtin::ID BID = (Builtin::ID)bid; 197 198 if (BID == Builtin::BI__builtin_va_start || 199 BID == Builtin::BI__builtin_va_copy || 200 BID == Builtin::BI__builtin_va_end || 201 BID == Builtin::BI__builtin_stdarg_start) 202 InitBuiltinVaListType(); 203 204 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 205 FunctionDecl *New = FunctionDecl::Create(Context, 206 Context.getTranslationUnitDecl(), 207 SourceLocation(), II, R, 208 FunctionDecl::Extern, false, 0); 209 210 // Create Decl objects for each parameter, adding them to the 211 // FunctionDecl. 212 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 213 llvm::SmallVector<ParmVarDecl*, 16> Params; 214 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 215 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 216 FT->getArgType(i), VarDecl::None, 0, 217 0)); 218 New->setParams(&Params[0], Params.size()); 219 } 220 221 222 223 // TUScope is the translation-unit scope to insert this function into. 224 PushOnScopeChains(New, TUScope); 225 return New; 226} 227 228/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 229/// and scope as a previous declaration 'Old'. Figure out how to resolve this 230/// situation, merging decls or emitting diagnostics as appropriate. 231/// 232TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 233 // Allow multiple definitions for ObjC built-in typedefs. 234 // FIXME: Verify the underlying types are equivalent! 235 if (getLangOptions().ObjC1) { 236 const IdentifierInfo *typeIdent = New->getIdentifier(); 237 if (typeIdent == Ident_id) { 238 Context.setObjCIdType(New); 239 return New; 240 } else if (typeIdent == Ident_Class) { 241 Context.setObjCClassType(New); 242 return New; 243 } else if (typeIdent == Ident_SEL) { 244 Context.setObjCSelType(New); 245 return New; 246 } else if (typeIdent == Ident_Protocol) { 247 Context.setObjCProtoType(New->getUnderlyingType()); 248 return New; 249 } 250 // Fall through - the typedef name was not a builtin type. 251 } 252 // Verify the old decl was also a typedef. 253 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 254 if (!Old) { 255 Diag(New->getLocation(), diag::err_redefinition_different_kind, 256 New->getName()); 257 Diag(OldD->getLocation(), diag::err_previous_definition); 258 return New; 259 } 260 261 // If the typedef types are not identical, reject them in all languages and 262 // with any extensions enabled. 263 if (Old->getUnderlyingType() != New->getUnderlyingType() && 264 Context.getCanonicalType(Old->getUnderlyingType()) != 265 Context.getCanonicalType(New->getUnderlyingType())) { 266 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 267 New->getUnderlyingType().getAsString(), 268 Old->getUnderlyingType().getAsString()); 269 Diag(Old->getLocation(), diag::err_previous_definition); 270 return Old; 271 } 272 273 if (getLangOptions().Microsoft) return New; 274 275 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 276 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 277 // *either* declaration is in a system header. The code below implements 278 // this adhoc compatibility rule. FIXME: The following code will not 279 // work properly when compiling ".i" files (containing preprocessed output). 280 SourceManager &SrcMgr = Context.getSourceManager(); 281 if (SrcMgr.isInSystemHeader(Old->getLocation())) 282 return New; 283 if (SrcMgr.isInSystemHeader(New->getLocation())) 284 return New; 285 286 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 287 Diag(Old->getLocation(), diag::err_previous_definition); 288 return New; 289} 290 291/// DeclhasAttr - returns true if decl Declaration already has the target 292/// attribute. 293static bool DeclHasAttr(const Decl *decl, const Attr *target) { 294 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 295 if (attr->getKind() == target->getKind()) 296 return true; 297 298 return false; 299} 300 301/// MergeAttributes - append attributes from the Old decl to the New one. 302static void MergeAttributes(Decl *New, Decl *Old) { 303 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 304 305 while (attr) { 306 tmp = attr; 307 attr = attr->getNext(); 308 309 if (!DeclHasAttr(New, tmp)) { 310 New->addAttr(tmp); 311 } else { 312 tmp->setNext(0); 313 delete(tmp); 314 } 315 } 316 317 Old->invalidateAttrs(); 318} 319 320/// MergeFunctionDecl - We just parsed a function 'New' from 321/// declarator D which has the same name and scope as a previous 322/// declaration 'Old'. Figure out how to resolve this situation, 323/// merging decls or emitting diagnostics as appropriate. 324/// Redeclaration will be set true if thisNew is a redeclaration OldD. 325FunctionDecl * 326Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 327 Redeclaration = false; 328 // Verify the old decl was also a function. 329 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 330 if (!Old) { 331 Diag(New->getLocation(), diag::err_redefinition_different_kind, 332 New->getName()); 333 Diag(OldD->getLocation(), diag::err_previous_definition); 334 return New; 335 } 336 337 QualType OldQType = Context.getCanonicalType(Old->getType()); 338 QualType NewQType = Context.getCanonicalType(New->getType()); 339 340 // C++ [dcl.fct]p3: 341 // All declarations for a function shall agree exactly in both the 342 // return type and the parameter-type-list. 343 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 344 MergeAttributes(New, Old); 345 Redeclaration = true; 346 return MergeCXXFunctionDecl(New, Old); 347 } 348 349 // C: Function types need to be compatible, not identical. This handles 350 // duplicate function decls like "void f(int); void f(enum X);" properly. 351 if (!getLangOptions().CPlusPlus && 352 Context.typesAreCompatible(OldQType, NewQType)) { 353 MergeAttributes(New, Old); 354 Redeclaration = true; 355 return New; 356 } 357 358 // A function that has already been declared has been redeclared or defined 359 // with a different type- show appropriate diagnostic 360 diag::kind PrevDiag; 361 if (Old->isThisDeclarationADefinition()) 362 PrevDiag = diag::err_previous_definition; 363 else if (Old->isImplicit()) 364 PrevDiag = diag::err_previous_implicit_declaration; 365 else 366 PrevDiag = diag::err_previous_declaration; 367 368 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 369 // TODO: This is totally simplistic. It should handle merging functions 370 // together etc, merging extern int X; int X; ... 371 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 372 Diag(Old->getLocation(), PrevDiag); 373 return New; 374} 375 376/// Predicate for C "tentative" external object definitions (C99 6.9.2). 377static bool isTentativeDefinition(VarDecl *VD) { 378 if (VD->isFileVarDecl()) 379 return (!VD->getInit() && 380 (VD->getStorageClass() == VarDecl::None || 381 VD->getStorageClass() == VarDecl::Static)); 382 return false; 383} 384 385/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 386/// when dealing with C "tentative" external object definitions (C99 6.9.2). 387void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 388 bool VDIsTentative = isTentativeDefinition(VD); 389 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 390 391 for (IdentifierResolver::iterator 392 I = IdResolver.begin(VD->getIdentifier(), 393 VD->getDeclContext(), false/*LookInParentCtx*/), 394 E = IdResolver.end(); I != E; ++I) { 395 if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) { 396 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 397 398 // Handle the following case: 399 // int a[10]; 400 // int a[]; - the code below makes sure we set the correct type. 401 // int a[11]; - this is an error, size isn't 10. 402 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 403 OldDecl->getType()->isConstantArrayType()) 404 VD->setType(OldDecl->getType()); 405 406 // Check for "tentative" definitions. We can't accomplish this in 407 // MergeVarDecl since the initializer hasn't been attached. 408 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 409 continue; 410 411 // Handle __private_extern__ just like extern. 412 if (OldDecl->getStorageClass() != VarDecl::Extern && 413 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 414 VD->getStorageClass() != VarDecl::Extern && 415 VD->getStorageClass() != VarDecl::PrivateExtern) { 416 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 417 Diag(OldDecl->getLocation(), diag::err_previous_definition); 418 } 419 } 420 } 421} 422 423/// MergeVarDecl - We just parsed a variable 'New' which has the same name 424/// and scope as a previous declaration 'Old'. Figure out how to resolve this 425/// situation, merging decls or emitting diagnostics as appropriate. 426/// 427/// Tentative definition rules (C99 6.9.2p2) are checked by 428/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 429/// definitions here, since the initializer hasn't been attached. 430/// 431VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 432 // Verify the old decl was also a variable. 433 VarDecl *Old = dyn_cast<VarDecl>(OldD); 434 if (!Old) { 435 Diag(New->getLocation(), diag::err_redefinition_different_kind, 436 New->getName()); 437 Diag(OldD->getLocation(), diag::err_previous_definition); 438 return New; 439 } 440 441 MergeAttributes(New, Old); 442 443 // Verify the types match. 444 QualType OldCType = Context.getCanonicalType(Old->getType()); 445 QualType NewCType = Context.getCanonicalType(New->getType()); 446 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 447 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 448 Diag(Old->getLocation(), diag::err_previous_definition); 449 return New; 450 } 451 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 452 if (New->getStorageClass() == VarDecl::Static && 453 (Old->getStorageClass() == VarDecl::None || 454 Old->getStorageClass() == VarDecl::Extern)) { 455 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 456 Diag(Old->getLocation(), diag::err_previous_definition); 457 return New; 458 } 459 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 460 if (New->getStorageClass() != VarDecl::Static && 461 Old->getStorageClass() == VarDecl::Static) { 462 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 463 Diag(Old->getLocation(), diag::err_previous_definition); 464 return New; 465 } 466 // File scoped variables are analyzed in FinalizeDeclaratorGroup. 467 if (!New->isFileVarDecl()) { 468 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 469 Diag(Old->getLocation(), diag::err_previous_definition); 470 } 471 return New; 472} 473 474/// CheckParmsForFunctionDef - Check that the parameters of the given 475/// function are appropriate for the definition of a function. This 476/// takes care of any checks that cannot be performed on the 477/// declaration itself, e.g., that the types of each of the function 478/// parameters are complete. 479bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 480 bool HasInvalidParm = false; 481 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 482 ParmVarDecl *Param = FD->getParamDecl(p); 483 484 // C99 6.7.5.3p4: the parameters in a parameter type list in a 485 // function declarator that is part of a function definition of 486 // that function shall not have incomplete type. 487 if (Param->getType()->isIncompleteType() && 488 !Param->isInvalidDecl()) { 489 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 490 Param->getType().getAsString()); 491 Param->setInvalidDecl(); 492 HasInvalidParm = true; 493 } 494 } 495 496 return HasInvalidParm; 497} 498 499/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 500/// no declarator (e.g. "struct foo;") is parsed. 501Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 502 // TODO: emit error on 'int;' or 'const enum foo;'. 503 // TODO: emit error on 'typedef int;' 504 // if (!DS.isMissingDeclaratorOk()) Diag(...); 505 506 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 507} 508 509bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 510 // Get the type before calling CheckSingleAssignmentConstraints(), since 511 // it can promote the expression. 512 QualType InitType = Init->getType(); 513 514 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 515 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 516 InitType, Init, "initializing"); 517} 518 519bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 520 const ArrayType *AT = Context.getAsArrayType(DeclT); 521 522 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 523 // C99 6.7.8p14. We have an array of character type with unknown size 524 // being initialized to a string literal. 525 llvm::APSInt ConstVal(32); 526 ConstVal = strLiteral->getByteLength() + 1; 527 // Return a new array type (C99 6.7.8p22). 528 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 529 ArrayType::Normal, 0); 530 } else { 531 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 532 // C99 6.7.8p14. We have an array of character type with known size. 533 // FIXME: Avoid truncation for 64-bit length strings. 534 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 535 Diag(strLiteral->getSourceRange().getBegin(), 536 diag::warn_initializer_string_for_char_array_too_long, 537 strLiteral->getSourceRange()); 538 } 539 // Set type from "char *" to "constant array of char". 540 strLiteral->setType(DeclT); 541 // For now, we always return false (meaning success). 542 return false; 543} 544 545StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 546 const ArrayType *AT = Context.getAsArrayType(DeclType); 547 if (AT && AT->getElementType()->isCharType()) { 548 return dyn_cast<StringLiteral>(Init); 549 } 550 return 0; 551} 552 553bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 554 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 555 // of unknown size ("[]") or an object type that is not a variable array type. 556 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 557 return Diag(VAT->getSizeExpr()->getLocStart(), 558 diag::err_variable_object_no_init, 559 VAT->getSizeExpr()->getSourceRange()); 560 561 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 562 if (!InitList) { 563 // FIXME: Handle wide strings 564 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 565 return CheckStringLiteralInit(strLiteral, DeclType); 566 567 if (DeclType->isArrayType()) 568 return Diag(Init->getLocStart(), 569 diag::err_array_init_list_required, 570 Init->getSourceRange()); 571 572 return CheckSingleInitializer(Init, DeclType); 573 } 574 575 InitListChecker CheckInitList(this, InitList, DeclType); 576 return CheckInitList.HadError(); 577} 578 579Sema::DeclTy * 580Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 581 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 582 IdentifierInfo *II = D.getIdentifier(); 583 584 // All of these full declarators require an identifier. If it doesn't have 585 // one, the ParsedFreeStandingDeclSpec action should be used. 586 if (II == 0) { 587 Diag(D.getDeclSpec().getSourceRange().getBegin(), 588 diag::err_declarator_need_ident, 589 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 590 return 0; 591 } 592 593 // The scope passed in may not be a decl scope. Zip up the scope tree until 594 // we find one that is. 595 while ((S->getFlags() & Scope::DeclScope) == 0) 596 S = S->getParent(); 597 598 // See if this is a redefinition of a variable in the same scope. 599 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 600 ScopedDecl *New; 601 bool InvalidDecl = false; 602 603 // In C++, the previous declaration we find might be a tag type 604 // (class or enum). In this case, the new declaration will hide the 605 // tag type. 606 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 607 PrevDecl = 0; 608 609 QualType R = GetTypeForDeclarator(D, S); 610 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 611 612 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 613 // Check that there are no default arguments (C++ only). 614 if (getLangOptions().CPlusPlus) 615 CheckExtraCXXDefaultArguments(D); 616 617 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 618 if (!NewTD) return 0; 619 620 // Handle attributes prior to checking for duplicates in MergeVarDecl 621 ProcessDeclAttributes(NewTD, D); 622 // Merge the decl with the existing one if appropriate. If the decl is 623 // in an outer scope, it isn't the same thing. 624 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 625 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 626 if (NewTD == 0) return 0; 627 } 628 New = NewTD; 629 if (S->getFnParent() == 0) { 630 // C99 6.7.7p2: If a typedef name specifies a variably modified type 631 // then it shall have block scope. 632 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 633 // FIXME: Diagnostic needs to be fixed. 634 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 635 InvalidDecl = true; 636 } 637 } 638 } else if (R.getTypePtr()->isFunctionType()) { 639 FunctionDecl::StorageClass SC = FunctionDecl::None; 640 switch (D.getDeclSpec().getStorageClassSpec()) { 641 default: assert(0 && "Unknown storage class!"); 642 case DeclSpec::SCS_auto: 643 case DeclSpec::SCS_register: 644 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 645 R.getAsString()); 646 InvalidDecl = true; 647 break; 648 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 649 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 650 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 651 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 652 } 653 654 bool isInline = D.getDeclSpec().isInlineSpecified(); 655 FunctionDecl *NewFD; 656 if (D.getContext() == Declarator::MemberContext) { 657 // This is a C++ method declaration. 658 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 659 D.getIdentifierLoc(), II, R, 660 (SC == FunctionDecl::Static), isInline, 661 LastDeclarator); 662 } else { 663 NewFD = FunctionDecl::Create(Context, CurContext, 664 D.getIdentifierLoc(), 665 II, R, SC, isInline, 666 LastDeclarator); 667 } 668 // Handle attributes. 669 ProcessDeclAttributes(NewFD, D); 670 671 // Handle GNU asm-label extension (encoded as an attribute). 672 if (Expr *E = (Expr*) D.getAsmLabel()) { 673 // The parser guarantees this is a string. 674 StringLiteral *SE = cast<StringLiteral>(E); 675 NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 676 SE->getByteLength()))); 677 } 678 679 // Copy the parameter declarations from the declarator D to 680 // the function declaration NewFD, if they are available. 681 if (D.getNumTypeObjects() > 0) { 682 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 683 684 // Create Decl objects for each parameter, adding them to the 685 // FunctionDecl. 686 llvm::SmallVector<ParmVarDecl*, 16> Params; 687 688 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs 689 // function that takes no arguments, not a function that takes a 690 // single void argument. 691 // We let through "const void" here because Sema::GetTypeForDeclarator 692 // already checks for that case. 693 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 694 FTI.ArgInfo[0].Param && 695 ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { 696 // empty arg list, don't push any params. 697 ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; 698 699 // In C++, the empty parameter-type-list must be spelled "void"; a 700 // typedef of void is not permitted. 701 if (getLangOptions().CPlusPlus && 702 Param->getType().getUnqualifiedType() != Context.VoidTy) { 703 Diag(Param->getLocation(), diag::ext_param_typedef_of_void); 704 } 705 706 } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { 707 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) 708 Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); 709 } 710 711 NewFD->setParams(&Params[0], Params.size()); 712 } 713 714 // Merge the decl with the existing one if appropriate. Since C functions 715 // are in a flat namespace, make sure we consider decls in outer scopes. 716 if (PrevDecl && 717 (!getLangOptions().CPlusPlus || 718 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) { 719 bool Redeclaration = false; 720 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 721 if (NewFD == 0) return 0; 722 if (Redeclaration) { 723 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 724 } 725 } 726 New = NewFD; 727 728 // In C++, check default arguments now that we have merged decls. 729 if (getLangOptions().CPlusPlus) 730 CheckCXXDefaultArguments(NewFD); 731 } else { 732 // Check that there are no default arguments (C++ only). 733 if (getLangOptions().CPlusPlus) 734 CheckExtraCXXDefaultArguments(D); 735 736 if (R.getTypePtr()->isObjCInterfaceType()) { 737 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 738 D.getIdentifier()->getName()); 739 InvalidDecl = true; 740 } 741 742 VarDecl *NewVD; 743 VarDecl::StorageClass SC; 744 switch (D.getDeclSpec().getStorageClassSpec()) { 745 default: assert(0 && "Unknown storage class!"); 746 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 747 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 748 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 749 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 750 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 751 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 752 } 753 if (D.getContext() == Declarator::MemberContext) { 754 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 755 // This is a static data member for a C++ class. 756 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 757 D.getIdentifierLoc(), II, 758 R, LastDeclarator); 759 } else { 760 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 761 if (S->getFnParent() == 0) { 762 // C99 6.9p2: The storage-class specifiers auto and register shall not 763 // appear in the declaration specifiers in an external declaration. 764 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 765 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 766 R.getAsString()); 767 InvalidDecl = true; 768 } 769 } 770 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 771 II, R, SC, LastDeclarator); 772 NewVD->setThreadSpecified(ThreadSpecified); 773 } 774 // Handle attributes prior to checking for duplicates in MergeVarDecl 775 ProcessDeclAttributes(NewVD, D); 776 777 // Handle GNU asm-label extension (encoded as an attribute). 778 if (Expr *E = (Expr*) D.getAsmLabel()) { 779 // The parser guarantees this is a string. 780 StringLiteral *SE = cast<StringLiteral>(E); 781 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 782 SE->getByteLength()))); 783 } 784 785 // Emit an error if an address space was applied to decl with local storage. 786 // This includes arrays of objects with address space qualifiers, but not 787 // automatic variables that point to other address spaces. 788 // ISO/IEC TR 18037 S5.1.2 789 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 790 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 791 InvalidDecl = true; 792 } 793 // Merge the decl with the existing one if appropriate. If the decl is 794 // in an outer scope, it isn't the same thing. 795 if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 796 NewVD = MergeVarDecl(NewVD, PrevDecl); 797 if (NewVD == 0) return 0; 798 } 799 New = NewVD; 800 } 801 802 // If this has an identifier, add it to the scope stack. 803 if (II) 804 PushOnScopeChains(New, S); 805 // If any semantic error occurred, mark the decl as invalid. 806 if (D.getInvalidType() || InvalidDecl) 807 New->setInvalidDecl(); 808 809 return New; 810} 811 812bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 813 switch (Init->getStmtClass()) { 814 default: 815 Diag(Init->getExprLoc(), 816 diag::err_init_element_not_constant, Init->getSourceRange()); 817 return true; 818 case Expr::ParenExprClass: { 819 const ParenExpr* PE = cast<ParenExpr>(Init); 820 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 821 } 822 case Expr::CompoundLiteralExprClass: 823 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 824 case Expr::DeclRefExprClass: { 825 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 826 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 827 if (VD->hasGlobalStorage()) 828 return false; 829 Diag(Init->getExprLoc(), 830 diag::err_init_element_not_constant, Init->getSourceRange()); 831 return true; 832 } 833 if (isa<FunctionDecl>(D)) 834 return false; 835 Diag(Init->getExprLoc(), 836 diag::err_init_element_not_constant, Init->getSourceRange()); 837 return true; 838 } 839 case Expr::MemberExprClass: { 840 const MemberExpr *M = cast<MemberExpr>(Init); 841 if (M->isArrow()) 842 return CheckAddressConstantExpression(M->getBase()); 843 return CheckAddressConstantExpressionLValue(M->getBase()); 844 } 845 case Expr::ArraySubscriptExprClass: { 846 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 847 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 848 return CheckAddressConstantExpression(ASE->getBase()) || 849 CheckArithmeticConstantExpression(ASE->getIdx()); 850 } 851 case Expr::StringLiteralClass: 852 case Expr::PredefinedExprClass: 853 return false; 854 case Expr::UnaryOperatorClass: { 855 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 856 857 // C99 6.6p9 858 if (Exp->getOpcode() == UnaryOperator::Deref) 859 return CheckAddressConstantExpression(Exp->getSubExpr()); 860 861 Diag(Init->getExprLoc(), 862 diag::err_init_element_not_constant, Init->getSourceRange()); 863 return true; 864 } 865 } 866} 867 868bool Sema::CheckAddressConstantExpression(const Expr* Init) { 869 switch (Init->getStmtClass()) { 870 default: 871 Diag(Init->getExprLoc(), 872 diag::err_init_element_not_constant, Init->getSourceRange()); 873 return true; 874 case Expr::ParenExprClass: { 875 const ParenExpr* PE = cast<ParenExpr>(Init); 876 return CheckAddressConstantExpression(PE->getSubExpr()); 877 } 878 case Expr::StringLiteralClass: 879 case Expr::ObjCStringLiteralClass: 880 return false; 881 case Expr::CallExprClass: { 882 const CallExpr *CE = cast<CallExpr>(Init); 883 if (CE->isBuiltinConstantExpr()) 884 return false; 885 Diag(Init->getExprLoc(), 886 diag::err_init_element_not_constant, Init->getSourceRange()); 887 return true; 888 } 889 case Expr::UnaryOperatorClass: { 890 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 891 892 // C99 6.6p9 893 if (Exp->getOpcode() == UnaryOperator::AddrOf) 894 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 895 896 if (Exp->getOpcode() == UnaryOperator::Extension) 897 return CheckAddressConstantExpression(Exp->getSubExpr()); 898 899 Diag(Init->getExprLoc(), 900 diag::err_init_element_not_constant, Init->getSourceRange()); 901 return true; 902 } 903 case Expr::BinaryOperatorClass: { 904 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 905 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 906 907 Expr *PExp = Exp->getLHS(); 908 Expr *IExp = Exp->getRHS(); 909 if (IExp->getType()->isPointerType()) 910 std::swap(PExp, IExp); 911 912 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 913 return CheckAddressConstantExpression(PExp) || 914 CheckArithmeticConstantExpression(IExp); 915 } 916 case Expr::ImplicitCastExprClass: 917 case Expr::ExplicitCastExprClass: { 918 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 919 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 920 // Check for implicit promotion 921 if (SubExpr->getType()->isFunctionType() || 922 SubExpr->getType()->isArrayType()) 923 return CheckAddressConstantExpressionLValue(SubExpr); 924 } 925 926 // Check for pointer->pointer cast 927 if (SubExpr->getType()->isPointerType()) 928 return CheckAddressConstantExpression(SubExpr); 929 930 if (SubExpr->getType()->isIntegralType()) { 931 // Check for the special-case of a pointer->int->pointer cast; 932 // this isn't standard, but some code requires it. See 933 // PR2720 for an example. 934 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 935 if (SubCast->getSubExpr()->getType()->isPointerType()) { 936 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 937 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 938 if (IntWidth >= PointerWidth) { 939 return CheckAddressConstantExpression(SubCast->getSubExpr()); 940 } 941 } 942 } 943 } 944 if (SubExpr->getType()->isArithmeticType()) { 945 return CheckArithmeticConstantExpression(SubExpr); 946 } 947 948 Diag(Init->getExprLoc(), 949 diag::err_init_element_not_constant, Init->getSourceRange()); 950 return true; 951 } 952 case Expr::ConditionalOperatorClass: { 953 // FIXME: Should we pedwarn here? 954 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 955 if (!Exp->getCond()->getType()->isArithmeticType()) { 956 Diag(Init->getExprLoc(), 957 diag::err_init_element_not_constant, Init->getSourceRange()); 958 return true; 959 } 960 if (CheckArithmeticConstantExpression(Exp->getCond())) 961 return true; 962 if (Exp->getLHS() && 963 CheckAddressConstantExpression(Exp->getLHS())) 964 return true; 965 return CheckAddressConstantExpression(Exp->getRHS()); 966 } 967 case Expr::AddrLabelExprClass: 968 return false; 969 } 970} 971 972static const Expr* FindExpressionBaseAddress(const Expr* E); 973 974static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 975 switch (E->getStmtClass()) { 976 default: 977 return E; 978 case Expr::ParenExprClass: { 979 const ParenExpr* PE = cast<ParenExpr>(E); 980 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 981 } 982 case Expr::MemberExprClass: { 983 const MemberExpr *M = cast<MemberExpr>(E); 984 if (M->isArrow()) 985 return FindExpressionBaseAddress(M->getBase()); 986 return FindExpressionBaseAddressLValue(M->getBase()); 987 } 988 case Expr::ArraySubscriptExprClass: { 989 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 990 return FindExpressionBaseAddress(ASE->getBase()); 991 } 992 case Expr::UnaryOperatorClass: { 993 const UnaryOperator *Exp = cast<UnaryOperator>(E); 994 995 if (Exp->getOpcode() == UnaryOperator::Deref) 996 return FindExpressionBaseAddress(Exp->getSubExpr()); 997 998 return E; 999 } 1000 } 1001} 1002 1003static const Expr* FindExpressionBaseAddress(const Expr* E) { 1004 switch (E->getStmtClass()) { 1005 default: 1006 return E; 1007 case Expr::ParenExprClass: { 1008 const ParenExpr* PE = cast<ParenExpr>(E); 1009 return FindExpressionBaseAddress(PE->getSubExpr()); 1010 } 1011 case Expr::UnaryOperatorClass: { 1012 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1013 1014 // C99 6.6p9 1015 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1016 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1017 1018 if (Exp->getOpcode() == UnaryOperator::Extension) 1019 return FindExpressionBaseAddress(Exp->getSubExpr()); 1020 1021 return E; 1022 } 1023 case Expr::BinaryOperatorClass: { 1024 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1025 1026 Expr *PExp = Exp->getLHS(); 1027 Expr *IExp = Exp->getRHS(); 1028 if (IExp->getType()->isPointerType()) 1029 std::swap(PExp, IExp); 1030 1031 return FindExpressionBaseAddress(PExp); 1032 } 1033 case Expr::ImplicitCastExprClass: { 1034 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1035 1036 // Check for implicit promotion 1037 if (SubExpr->getType()->isFunctionType() || 1038 SubExpr->getType()->isArrayType()) 1039 return FindExpressionBaseAddressLValue(SubExpr); 1040 1041 // Check for pointer->pointer cast 1042 if (SubExpr->getType()->isPointerType()) 1043 return FindExpressionBaseAddress(SubExpr); 1044 1045 // We assume that we have an arithmetic expression here; 1046 // if we don't, we'll figure it out later 1047 return 0; 1048 } 1049 case Expr::ExplicitCastExprClass: { 1050 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1051 1052 // Check for pointer->pointer cast 1053 if (SubExpr->getType()->isPointerType()) 1054 return FindExpressionBaseAddress(SubExpr); 1055 1056 // We assume that we have an arithmetic expression here; 1057 // if we don't, we'll figure it out later 1058 return 0; 1059 } 1060 } 1061} 1062 1063bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1064 switch (Init->getStmtClass()) { 1065 default: 1066 Diag(Init->getExprLoc(), 1067 diag::err_init_element_not_constant, Init->getSourceRange()); 1068 return true; 1069 case Expr::ParenExprClass: { 1070 const ParenExpr* PE = cast<ParenExpr>(Init); 1071 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1072 } 1073 case Expr::FloatingLiteralClass: 1074 case Expr::IntegerLiteralClass: 1075 case Expr::CharacterLiteralClass: 1076 case Expr::ImaginaryLiteralClass: 1077 case Expr::TypesCompatibleExprClass: 1078 case Expr::CXXBoolLiteralExprClass: 1079 return false; 1080 case Expr::CallExprClass: { 1081 const CallExpr *CE = cast<CallExpr>(Init); 1082 if (CE->isBuiltinConstantExpr()) 1083 return false; 1084 Diag(Init->getExprLoc(), 1085 diag::err_init_element_not_constant, Init->getSourceRange()); 1086 return true; 1087 } 1088 case Expr::DeclRefExprClass: { 1089 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1090 if (isa<EnumConstantDecl>(D)) 1091 return false; 1092 Diag(Init->getExprLoc(), 1093 diag::err_init_element_not_constant, Init->getSourceRange()); 1094 return true; 1095 } 1096 case Expr::CompoundLiteralExprClass: 1097 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1098 // but vectors are allowed to be magic. 1099 if (Init->getType()->isVectorType()) 1100 return false; 1101 Diag(Init->getExprLoc(), 1102 diag::err_init_element_not_constant, Init->getSourceRange()); 1103 return true; 1104 case Expr::UnaryOperatorClass: { 1105 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1106 1107 switch (Exp->getOpcode()) { 1108 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1109 // See C99 6.6p3. 1110 default: 1111 Diag(Init->getExprLoc(), 1112 diag::err_init_element_not_constant, Init->getSourceRange()); 1113 return true; 1114 case UnaryOperator::SizeOf: 1115 case UnaryOperator::AlignOf: 1116 case UnaryOperator::OffsetOf: 1117 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1118 // See C99 6.5.3.4p2 and 6.6p3. 1119 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1120 return false; 1121 Diag(Init->getExprLoc(), 1122 diag::err_init_element_not_constant, Init->getSourceRange()); 1123 return true; 1124 case UnaryOperator::Extension: 1125 case UnaryOperator::LNot: 1126 case UnaryOperator::Plus: 1127 case UnaryOperator::Minus: 1128 case UnaryOperator::Not: 1129 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1130 } 1131 } 1132 case Expr::SizeOfAlignOfTypeExprClass: { 1133 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1134 // Special check for void types, which are allowed as an extension 1135 if (Exp->getArgumentType()->isVoidType()) 1136 return false; 1137 // alignof always evaluates to a constant. 1138 // FIXME: is sizeof(int[3.0]) a constant expression? 1139 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1140 Diag(Init->getExprLoc(), 1141 diag::err_init_element_not_constant, Init->getSourceRange()); 1142 return true; 1143 } 1144 return false; 1145 } 1146 case Expr::BinaryOperatorClass: { 1147 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1148 1149 if (Exp->getLHS()->getType()->isArithmeticType() && 1150 Exp->getRHS()->getType()->isArithmeticType()) { 1151 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1152 CheckArithmeticConstantExpression(Exp->getRHS()); 1153 } 1154 1155 if (Exp->getLHS()->getType()->isPointerType() && 1156 Exp->getRHS()->getType()->isPointerType()) { 1157 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1158 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1159 1160 // Only allow a null (constant integer) base; we could 1161 // allow some additional cases if necessary, but this 1162 // is sufficient to cover offsetof-like constructs. 1163 if (!LHSBase && !RHSBase) { 1164 return CheckAddressConstantExpression(Exp->getLHS()) || 1165 CheckAddressConstantExpression(Exp->getRHS()); 1166 } 1167 } 1168 1169 Diag(Init->getExprLoc(), 1170 diag::err_init_element_not_constant, Init->getSourceRange()); 1171 return true; 1172 } 1173 case Expr::ImplicitCastExprClass: 1174 case Expr::ExplicitCastExprClass: { 1175 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1176 if (SubExpr->getType()->isArithmeticType()) 1177 return CheckArithmeticConstantExpression(SubExpr); 1178 1179 if (SubExpr->getType()->isPointerType()) { 1180 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1181 // If the pointer has a null base, this is an offsetof-like construct 1182 if (!Base) 1183 return CheckAddressConstantExpression(SubExpr); 1184 } 1185 1186 Diag(Init->getExprLoc(), 1187 diag::err_init_element_not_constant, Init->getSourceRange()); 1188 return true; 1189 } 1190 case Expr::ConditionalOperatorClass: { 1191 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1192 if (CheckArithmeticConstantExpression(Exp->getCond())) 1193 return true; 1194 if (Exp->getLHS() && 1195 CheckArithmeticConstantExpression(Exp->getLHS())) 1196 return true; 1197 return CheckArithmeticConstantExpression(Exp->getRHS()); 1198 } 1199 } 1200} 1201 1202bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1203 Init = Init->IgnoreParens(); 1204 1205 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1206 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1207 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1208 1209 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1210 return CheckForConstantInitializer(e->getInitializer(), DclT); 1211 1212 if (Init->getType()->isReferenceType()) { 1213 // FIXME: Work out how the heck reference types work 1214 return false; 1215#if 0 1216 // A reference is constant if the address of the expression 1217 // is constant 1218 // We look through initlists here to simplify 1219 // CheckAddressConstantExpressionLValue. 1220 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1221 assert(Exp->getNumInits() > 0 && 1222 "Refernce initializer cannot be empty"); 1223 Init = Exp->getInit(0); 1224 } 1225 return CheckAddressConstantExpressionLValue(Init); 1226#endif 1227 } 1228 1229 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1230 unsigned numInits = Exp->getNumInits(); 1231 for (unsigned i = 0; i < numInits; i++) { 1232 // FIXME: Need to get the type of the declaration for C++, 1233 // because it could be a reference? 1234 if (CheckForConstantInitializer(Exp->getInit(i), 1235 Exp->getInit(i)->getType())) 1236 return true; 1237 } 1238 return false; 1239 } 1240 1241 if (Init->isNullPointerConstant(Context)) 1242 return false; 1243 if (Init->getType()->isArithmeticType()) { 1244 QualType InitTy = Context.getCanonicalType(Init->getType()) 1245 .getUnqualifiedType(); 1246 if (InitTy == Context.BoolTy) { 1247 // Special handling for pointers implicitly cast to bool; 1248 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1249 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1250 Expr* SubE = ICE->getSubExpr(); 1251 if (SubE->getType()->isPointerType() || 1252 SubE->getType()->isArrayType() || 1253 SubE->getType()->isFunctionType()) { 1254 return CheckAddressConstantExpression(Init); 1255 } 1256 } 1257 } else if (InitTy->isIntegralType()) { 1258 Expr* SubE = 0; 1259 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1260 SubE = CE->getSubExpr(); 1261 // Special check for pointer cast to int; we allow as an extension 1262 // an address constant cast to an integer if the integer 1263 // is of an appropriate width (this sort of code is apparently used 1264 // in some places). 1265 // FIXME: Add pedwarn? 1266 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1267 if (SubE && (SubE->getType()->isPointerType() || 1268 SubE->getType()->isArrayType() || 1269 SubE->getType()->isFunctionType())) { 1270 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1271 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1272 if (IntWidth >= PointerWidth) 1273 return CheckAddressConstantExpression(Init); 1274 } 1275 } 1276 1277 return CheckArithmeticConstantExpression(Init); 1278 } 1279 1280 if (Init->getType()->isPointerType()) 1281 return CheckAddressConstantExpression(Init); 1282 1283 // An array type at the top level that isn't an init-list must 1284 // be a string literal 1285 if (Init->getType()->isArrayType()) 1286 return false; 1287 1288 if (Init->getType()->isFunctionType()) 1289 return false; 1290 1291 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1292 Init->getSourceRange()); 1293 return true; 1294} 1295 1296void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1297 Decl *RealDecl = static_cast<Decl *>(dcl); 1298 Expr *Init = static_cast<Expr *>(init); 1299 assert(Init && "missing initializer"); 1300 1301 // If there is no declaration, there was an error parsing it. Just ignore 1302 // the initializer. 1303 if (RealDecl == 0) { 1304 delete Init; 1305 return; 1306 } 1307 1308 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1309 if (!VDecl) { 1310 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1311 diag::err_illegal_initializer); 1312 RealDecl->setInvalidDecl(); 1313 return; 1314 } 1315 // Get the decls type and save a reference for later, since 1316 // CheckInitializerTypes may change it. 1317 QualType DclT = VDecl->getType(), SavT = DclT; 1318 if (VDecl->isBlockVarDecl()) { 1319 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1320 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1321 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1322 VDecl->setInvalidDecl(); 1323 } else if (!VDecl->isInvalidDecl()) { 1324 if (CheckInitializerTypes(Init, DclT)) 1325 VDecl->setInvalidDecl(); 1326 1327 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1328 if (!getLangOptions().CPlusPlus) { 1329 if (SC == VarDecl::Static) // C99 6.7.8p4. 1330 CheckForConstantInitializer(Init, DclT); 1331 } 1332 } 1333 } else if (VDecl->isFileVarDecl()) { 1334 if (VDecl->getStorageClass() == VarDecl::Extern) 1335 Diag(VDecl->getLocation(), diag::warn_extern_init); 1336 if (!VDecl->isInvalidDecl()) 1337 if (CheckInitializerTypes(Init, DclT)) 1338 VDecl->setInvalidDecl(); 1339 1340 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1341 if (!getLangOptions().CPlusPlus) { 1342 // C99 6.7.8p4. All file scoped initializers need to be constant. 1343 CheckForConstantInitializer(Init, DclT); 1344 } 1345 } 1346 // If the type changed, it means we had an incomplete type that was 1347 // completed by the initializer. For example: 1348 // int ary[] = { 1, 3, 5 }; 1349 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1350 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1351 VDecl->setType(DclT); 1352 Init->setType(DclT); 1353 } 1354 1355 // Attach the initializer to the decl. 1356 VDecl->setInit(Init); 1357 return; 1358} 1359 1360/// The declarators are chained together backwards, reverse the list. 1361Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1362 // Often we have single declarators, handle them quickly. 1363 Decl *GroupDecl = static_cast<Decl*>(group); 1364 if (GroupDecl == 0) 1365 return 0; 1366 1367 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1368 ScopedDecl *NewGroup = 0; 1369 if (Group->getNextDeclarator() == 0) 1370 NewGroup = Group; 1371 else { // reverse the list. 1372 while (Group) { 1373 ScopedDecl *Next = Group->getNextDeclarator(); 1374 Group->setNextDeclarator(NewGroup); 1375 NewGroup = Group; 1376 Group = Next; 1377 } 1378 } 1379 // Perform semantic analysis that depends on having fully processed both 1380 // the declarator and initializer. 1381 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1382 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1383 if (!IDecl) 1384 continue; 1385 QualType T = IDecl->getType(); 1386 1387 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1388 // static storage duration, it shall not have a variable length array. 1389 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1390 IDecl->getStorageClass() == VarDecl::Static) { 1391 if (T->isVariableArrayType()) { 1392 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1393 IDecl->setInvalidDecl(); 1394 } 1395 } 1396 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1397 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1398 if (IDecl->isBlockVarDecl() && 1399 IDecl->getStorageClass() != VarDecl::Extern) { 1400 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1401 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1402 T.getAsString()); 1403 IDecl->setInvalidDecl(); 1404 } 1405 } 1406 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1407 // object that has file scope without an initializer, and without a 1408 // storage-class specifier or with the storage-class specifier "static", 1409 // constitutes a tentative definition. Note: A tentative definition with 1410 // external linkage is valid (C99 6.2.2p5). 1411 if (isTentativeDefinition(IDecl)) { 1412 if (T->isIncompleteArrayType()) { 1413 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1414 // array to be completed. Don't issue a diagnostic. 1415 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1416 // C99 6.9.2p3: If the declaration of an identifier for an object is 1417 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1418 // declared type shall not be an incomplete type. 1419 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1420 T.getAsString()); 1421 IDecl->setInvalidDecl(); 1422 } 1423 } 1424 if (IDecl->isFileVarDecl()) 1425 CheckForFileScopedRedefinitions(S, IDecl); 1426 } 1427 return NewGroup; 1428} 1429 1430/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1431/// to introduce parameters into function prototype scope. 1432Sema::DeclTy * 1433Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1434 const DeclSpec &DS = D.getDeclSpec(); 1435 1436 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1437 VarDecl::StorageClass StorageClass = VarDecl::None; 1438 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1439 StorageClass = VarDecl::Register; 1440 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1441 Diag(DS.getStorageClassSpecLoc(), 1442 diag::err_invalid_storage_class_in_func_decl); 1443 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1444 } 1445 if (DS.isThreadSpecified()) { 1446 Diag(DS.getThreadSpecLoc(), 1447 diag::err_invalid_storage_class_in_func_decl); 1448 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1449 } 1450 1451 // Check that there are no default arguments inside the type of this 1452 // parameter (C++ only). 1453 if (getLangOptions().CPlusPlus) 1454 CheckExtraCXXDefaultArguments(D); 1455 1456 // In this context, we *do not* check D.getInvalidType(). If the declarator 1457 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1458 // though it will not reflect the user specified type. 1459 QualType parmDeclType = GetTypeForDeclarator(D, S); 1460 1461 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1462 1463 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1464 // Can this happen for params? We already checked that they don't conflict 1465 // among each other. Here they can only shadow globals, which is ok. 1466 IdentifierInfo *II = D.getIdentifier(); 1467 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1468 if (S->isDeclScope(PrevDecl)) { 1469 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1470 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1471 1472 // Recover by removing the name 1473 II = 0; 1474 D.SetIdentifier(0, D.getIdentifierLoc()); 1475 } 1476 } 1477 1478 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1479 // Doing the promotion here has a win and a loss. The win is the type for 1480 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1481 // code generator). The loss is the orginal type isn't preserved. For example: 1482 // 1483 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1484 // int blockvardecl[5]; 1485 // sizeof(parmvardecl); // size == 4 1486 // sizeof(blockvardecl); // size == 20 1487 // } 1488 // 1489 // For expressions, all implicit conversions are captured using the 1490 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1491 // 1492 // FIXME: If a source translation tool needs to see the original type, then 1493 // we need to consider storing both types (in ParmVarDecl)... 1494 // 1495 if (parmDeclType->isArrayType()) { 1496 // int x[restrict 4] -> int *restrict 1497 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1498 } else if (parmDeclType->isFunctionType()) 1499 parmDeclType = Context.getPointerType(parmDeclType); 1500 1501 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1502 D.getIdentifierLoc(), II, 1503 parmDeclType, StorageClass, 1504 0, 0); 1505 1506 if (D.getInvalidType()) 1507 New->setInvalidDecl(); 1508 1509 if (II) 1510 PushOnScopeChains(New, S); 1511 1512 ProcessDeclAttributes(New, D); 1513 return New; 1514 1515} 1516 1517Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1518 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1519 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1520 "Not a function declarator!"); 1521 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1522 1523 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1524 // for a K&R function. 1525 if (!FTI.hasPrototype) { 1526 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1527 if (FTI.ArgInfo[i].Param == 0) { 1528 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1529 FTI.ArgInfo[i].Ident->getName()); 1530 // Implicitly declare the argument as type 'int' for lack of a better 1531 // type. 1532 DeclSpec DS; 1533 const char* PrevSpec; // unused 1534 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1535 PrevSpec); 1536 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1537 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1538 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1539 } 1540 } 1541 } else { 1542 // FIXME: Diagnose arguments without names in C. 1543 } 1544 1545 Scope *GlobalScope = FnBodyScope->getParent(); 1546 1547 // See if this is a redefinition. 1548 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1549 GlobalScope); 1550 if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) { 1551 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1552 const FunctionDecl *Definition; 1553 if (FD->getBody(Definition)) { 1554 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1555 D.getIdentifier()->getName()); 1556 Diag(Definition->getLocation(), diag::err_previous_definition); 1557 } 1558 } 1559 } 1560 1561 return ActOnStartOfFunctionDef(FnBodyScope, 1562 ActOnDeclarator(GlobalScope, D, 0)); 1563} 1564 1565Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1566 Decl *decl = static_cast<Decl*>(D); 1567 FunctionDecl *FD = cast<FunctionDecl>(decl); 1568 PushDeclContext(FD); 1569 1570 // Check the validity of our function parameters 1571 CheckParmsForFunctionDef(FD); 1572 1573 // Introduce our parameters into the function scope 1574 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1575 ParmVarDecl *Param = FD->getParamDecl(p); 1576 // If this has an identifier, add it to the scope stack. 1577 if (Param->getIdentifier()) 1578 PushOnScopeChains(Param, FnBodyScope); 1579 } 1580 1581 return FD; 1582} 1583 1584Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1585 Decl *dcl = static_cast<Decl *>(D); 1586 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1587 FD->setBody((Stmt*)Body); 1588 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1589 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1590 MD->setBody((Stmt*)Body); 1591 } else 1592 return 0; 1593 PopDeclContext(); 1594 // Verify and clean out per-function state. 1595 1596 // Check goto/label use. 1597 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1598 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1599 // Verify that we have no forward references left. If so, there was a goto 1600 // or address of a label taken, but no definition of it. Label fwd 1601 // definitions are indicated with a null substmt. 1602 if (I->second->getSubStmt() == 0) { 1603 LabelStmt *L = I->second; 1604 // Emit error. 1605 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1606 1607 // At this point, we have gotos that use the bogus label. Stitch it into 1608 // the function body so that they aren't leaked and that the AST is well 1609 // formed. 1610 if (Body) { 1611 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1612 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1613 } else { 1614 // The whole function wasn't parsed correctly, just delete this. 1615 delete L; 1616 } 1617 } 1618 } 1619 LabelMap.clear(); 1620 1621 return D; 1622} 1623 1624/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1625/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1626ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1627 IdentifierInfo &II, Scope *S) { 1628 // Extension in C99. Legal in C90, but warn about it. 1629 if (getLangOptions().C99) 1630 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1631 else 1632 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1633 1634 // FIXME: handle stuff like: 1635 // void foo() { extern float X(); } 1636 // void bar() { X(); } <-- implicit decl for X in another scope. 1637 1638 // Set a Declarator for the implicit definition: int foo(); 1639 const char *Dummy; 1640 DeclSpec DS; 1641 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1642 Error = Error; // Silence warning. 1643 assert(!Error && "Error setting up implicit decl!"); 1644 Declarator D(DS, Declarator::BlockContext); 1645 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1646 D.SetIdentifier(&II, Loc); 1647 1648 // Insert this function into translation-unit scope. 1649 1650 DeclContext *PrevDC = CurContext; 1651 CurContext = Context.getTranslationUnitDecl(); 1652 1653 FunctionDecl *FD = 1654 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1655 FD->setImplicit(); 1656 1657 CurContext = PrevDC; 1658 1659 return FD; 1660} 1661 1662 1663TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1664 ScopedDecl *LastDeclarator) { 1665 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1666 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1667 1668 // Scope manipulation handled by caller. 1669 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1670 D.getIdentifierLoc(), 1671 D.getIdentifier(), 1672 T, LastDeclarator); 1673 if (D.getInvalidType()) 1674 NewTD->setInvalidDecl(); 1675 return NewTD; 1676} 1677 1678/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1679/// former case, Name will be non-null. In the later case, Name will be null. 1680/// TagType indicates what kind of tag this is. TK indicates whether this is a 1681/// reference/declaration/definition of a tag. 1682Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1683 SourceLocation KWLoc, IdentifierInfo *Name, 1684 SourceLocation NameLoc, AttributeList *Attr) { 1685 // If this is a use of an existing tag, it must have a name. 1686 assert((Name != 0 || TK == TK_Definition) && 1687 "Nameless record must be a definition!"); 1688 1689 TagDecl::TagKind Kind; 1690 switch (TagType) { 1691 default: assert(0 && "Unknown tag type!"); 1692 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1693 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1694 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1695 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1696 } 1697 1698 // Two code paths: a new one for structs/unions/classes where we create 1699 // separate decls for forward declarations, and an old (eventually to 1700 // be removed) code path for enums. 1701 if (Kind != TagDecl::TK_enum) 1702 return ActOnTagStruct(S, Kind, TK, KWLoc, Name, NameLoc, Attr); 1703 1704 // If this is a named struct, check to see if there was a previous forward 1705 // declaration or definition. 1706 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1707 ScopedDecl *PrevDecl = 1708 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S)); 1709 1710 if (PrevDecl) { 1711 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1712 "unexpected Decl type"); 1713 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1714 // If this is a use of a previous tag, or if the tag is already declared 1715 // in the same scope (so that the definition/declaration completes or 1716 // rementions the tag), reuse the decl. 1717 if (TK == TK_Reference || 1718 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1719 // Make sure that this wasn't declared as an enum and now used as a 1720 // struct or something similar. 1721 if (PrevTagDecl->getTagKind() != Kind) { 1722 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1723 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1724 // Recover by making this an anonymous redefinition. 1725 Name = 0; 1726 PrevDecl = 0; 1727 } else { 1728 // If this is a use or a forward declaration, we're good. 1729 if (TK != TK_Definition) 1730 return PrevDecl; 1731 1732 // Diagnose attempts to redefine a tag. 1733 if (PrevTagDecl->isDefinition()) { 1734 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1735 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1736 // If this is a redefinition, recover by making this struct be 1737 // anonymous, which will make any later references get the previous 1738 // definition. 1739 Name = 0; 1740 } else { 1741 // Okay, this is definition of a previously declared or referenced 1742 // tag. Move the location of the decl to be the definition site. 1743 PrevDecl->setLocation(NameLoc); 1744 return PrevDecl; 1745 } 1746 } 1747 } 1748 // If we get here, this is a definition of a new struct type in a nested 1749 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1750 // type. 1751 } else { 1752 // PrevDecl is a namespace. 1753 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1754 // The tag name clashes with a namespace name, issue an error and 1755 // recover by making this tag be anonymous. 1756 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1757 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1758 Name = 0; 1759 } 1760 } 1761 } 1762 1763 // If there is an identifier, use the location of the identifier as the 1764 // location of the decl, otherwise use the location of the struct/union 1765 // keyword. 1766 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1767 1768 // Otherwise, if this is the first time we've seen this tag, create the decl. 1769 TagDecl *New; 1770 if (Kind == TagDecl::TK_enum) { 1771 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1772 // enum X { A, B, C } D; D should chain to X. 1773 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1774 // If this is an undefined enum, warn. 1775 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1776 } else { 1777 // struct/union/class 1778 1779 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1780 // struct X { int A; } D; D should chain to X. 1781 if (getLangOptions().CPlusPlus) 1782 // FIXME: Look for a way to use RecordDecl for simple structs. 1783 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name); 1784 else 1785 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name); 1786 } 1787 1788 // If this has an identifier, add it to the scope stack. 1789 if (Name) { 1790 // The scope passed in may not be a decl scope. Zip up the scope tree until 1791 // we find one that is. 1792 while ((S->getFlags() & Scope::DeclScope) == 0) 1793 S = S->getParent(); 1794 1795 // Add it to the decl chain. 1796 PushOnScopeChains(New, S); 1797 } 1798 1799 if (Attr) 1800 ProcessDeclAttributeList(New, Attr); 1801 return New; 1802} 1803 1804/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 1805/// the logic for enums, we create separate decls for forward declarations. 1806/// This is called by ActOnTag, but eventually will replace its logic. 1807Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 1808 SourceLocation KWLoc, IdentifierInfo *Name, 1809 SourceLocation NameLoc, AttributeList *Attr) { 1810 1811 // If this is a named struct, check to see if there was a previous forward 1812 // declaration or definition. 1813 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1814 ScopedDecl *PrevDecl = 1815 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S)); 1816 1817 if (PrevDecl) { 1818 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1819 "unexpected Decl type"); 1820 1821 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1822 // If this is a use of a previous tag, or if the tag is already declared 1823 // in the same scope (so that the definition/declaration completes or 1824 // rementions the tag), reuse the decl. 1825 if (TK == TK_Reference || 1826 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1827 // Make sure that this wasn't declared as an enum and now used as a 1828 // struct or something similar. 1829 if (PrevTagDecl->getTagKind() != Kind) { 1830 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1831 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1832 // Recover by making this an anonymous redefinition. 1833 Name = 0; 1834 PrevDecl = 0; 1835 } else { 1836 // If this is a use, return the original decl. 1837 1838 // FIXME: In the future, return a variant or some other clue 1839 // for the consumer of this Decl to know it doesn't own it. 1840 // For our current ASTs this shouldn't be a problem, but will 1841 // need to be changed with DeclGroups. 1842 if (TK == TK_Reference) 1843 return PrevDecl; 1844 1845 // The new decl is a definition? 1846 if (TK == TK_Definition) { 1847 // Diagnose attempts to redefine a tag. 1848 if (RecordDecl* DefRecord = 1849 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 1850 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1851 Diag(DefRecord->getLocation(), diag::err_previous_definition); 1852 // If this is a redefinition, recover by making this struct be 1853 // anonymous, which will make any later references get the previous 1854 // definition. 1855 Name = 0; 1856 PrevDecl = 0; 1857 } 1858 // Okay, this is definition of a previously declared or referenced 1859 // tag. We're going to create a new Decl. 1860 } 1861 } 1862 // If we get here we have (another) forward declaration. Just create 1863 // a new decl. 1864 } 1865 else { 1866 // If we get here, this is a definition of a new struct type in a nested 1867 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 1868 // new decl/type. We set PrevDecl to NULL so that the Records 1869 // have distinct types. 1870 PrevDecl = 0; 1871 } 1872 } else { 1873 // PrevDecl is a namespace. 1874 if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 1875 // The tag name clashes with a namespace name, issue an error and 1876 // recover by making this tag be anonymous. 1877 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1878 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1879 Name = 0; 1880 } 1881 } 1882 } 1883 1884 // If there is an identifier, use the location of the identifier as the 1885 // location of the decl, otherwise use the location of the struct/union 1886 // keyword. 1887 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1888 1889 // Otherwise, if this is the first time we've seen this tag, create the decl. 1890 TagDecl *New; 1891 1892 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1893 // struct X { int A; } D; D should chain to X. 1894 if (getLangOptions().CPlusPlus) 1895 // FIXME: Look for a way to use RecordDecl for simple structs. 1896 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 1897 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 1898 else 1899 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 1900 dyn_cast_or_null<RecordDecl>(PrevDecl)); 1901 1902 // If this has an identifier, add it to the scope stack. 1903 if ((TK == TK_Definition || !PrevDecl) && Name) { 1904 // The scope passed in may not be a decl scope. Zip up the scope tree until 1905 // we find one that is. 1906 while ((S->getFlags() & Scope::DeclScope) == 0) 1907 S = S->getParent(); 1908 1909 // Add it to the decl chain. 1910 PushOnScopeChains(New, S); 1911 } 1912 1913 if (Attr) 1914 ProcessDeclAttributeList(New, Attr); 1915 1916 return New; 1917} 1918 1919 1920/// Collect the instance variables declared in an Objective-C object. Used in 1921/// the creation of structures from objects using the @defs directive. 1922static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 1923 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1924 if (Class->getSuperClass()) 1925 CollectIvars(Class->getSuperClass(), Ctx, ivars); 1926 1927 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 1928 for (ObjCInterfaceDecl::ivar_iterator 1929 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 1930 1931 ObjCIvarDecl* ID = *I; 1932 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 1933 ID->getIdentifier(), 1934 ID->getType(), 1935 ID->getBitWidth())); 1936 } 1937} 1938 1939/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1940/// instance variables of ClassName into Decls. 1941void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1942 IdentifierInfo *ClassName, 1943 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1944 // Check that ClassName is a valid class 1945 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1946 if (!Class) { 1947 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1948 return; 1949 } 1950 // Collect the instance variables 1951 CollectIvars(Class, Context, Decls); 1952} 1953 1954QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1955 // This method tries to turn a variable array into a constant 1956 // array even when the size isn't an ICE. This is necessary 1957 // for compatibility with code that depends on gcc's buggy 1958 // constant expression folding, like struct {char x[(int)(char*)2];} 1959 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1960 APValue Result; 1961 if (VLATy->getSizeExpr() && 1962 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1963 llvm::APSInt &Res = Result.getInt(); 1964 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1965 return Context.getConstantArrayType(VLATy->getElementType(), 1966 Res, ArrayType::Normal, 0); 1967 } 1968 } 1969 return QualType(); 1970} 1971 1972/// ActOnField - Each field of a struct/union/class is passed into this in order 1973/// to create a FieldDecl object for it. 1974Sema::DeclTy *Sema::ActOnField(Scope *S, 1975 SourceLocation DeclStart, 1976 Declarator &D, ExprTy *BitfieldWidth) { 1977 IdentifierInfo *II = D.getIdentifier(); 1978 Expr *BitWidth = (Expr*)BitfieldWidth; 1979 SourceLocation Loc = DeclStart; 1980 if (II) Loc = D.getIdentifierLoc(); 1981 1982 // FIXME: Unnamed fields can be handled in various different ways, for 1983 // example, unnamed unions inject all members into the struct namespace! 1984 1985 if (BitWidth) { 1986 // TODO: Validate. 1987 //printf("WARNING: BITFIELDS IGNORED!\n"); 1988 1989 // 6.7.2.1p3 1990 // 6.7.2.1p4 1991 1992 } else { 1993 // Not a bitfield. 1994 1995 // validate II. 1996 1997 } 1998 1999 QualType T = GetTypeForDeclarator(D, S); 2000 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2001 bool InvalidDecl = false; 2002 2003 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2004 // than a variably modified type. 2005 if (T->isVariablyModifiedType()) { 2006 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 2007 if (!FixedTy.isNull()) { 2008 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 2009 T = FixedTy; 2010 } else { 2011 // FIXME: This diagnostic needs work 2012 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2013 InvalidDecl = true; 2014 } 2015 } 2016 // FIXME: Chain fielddecls together. 2017 FieldDecl *NewFD; 2018 2019 if (getLangOptions().CPlusPlus) { 2020 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2021 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2022 Loc, II, T, BitWidth); 2023 if (II) 2024 PushOnScopeChains(NewFD, S); 2025 } 2026 else 2027 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2028 2029 ProcessDeclAttributes(NewFD, D); 2030 2031 if (D.getInvalidType() || InvalidDecl) 2032 NewFD->setInvalidDecl(); 2033 return NewFD; 2034} 2035 2036/// TranslateIvarVisibility - Translate visibility from a token ID to an 2037/// AST enum value. 2038static ObjCIvarDecl::AccessControl 2039TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2040 switch (ivarVisibility) { 2041 case tok::objc_private: return ObjCIvarDecl::Private; 2042 case tok::objc_public: return ObjCIvarDecl::Public; 2043 case tok::objc_protected: return ObjCIvarDecl::Protected; 2044 case tok::objc_package: return ObjCIvarDecl::Package; 2045 default: assert(false && "Unknown visitibility kind"); 2046 } 2047} 2048 2049/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2050/// in order to create an IvarDecl object for it. 2051Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2052 SourceLocation DeclStart, 2053 Declarator &D, ExprTy *BitfieldWidth, 2054 tok::ObjCKeywordKind Visibility) { 2055 IdentifierInfo *II = D.getIdentifier(); 2056 Expr *BitWidth = (Expr*)BitfieldWidth; 2057 SourceLocation Loc = DeclStart; 2058 if (II) Loc = D.getIdentifierLoc(); 2059 2060 // FIXME: Unnamed fields can be handled in various different ways, for 2061 // example, unnamed unions inject all members into the struct namespace! 2062 2063 2064 if (BitWidth) { 2065 // TODO: Validate. 2066 //printf("WARNING: BITFIELDS IGNORED!\n"); 2067 2068 // 6.7.2.1p3 2069 // 6.7.2.1p4 2070 2071 } else { 2072 // Not a bitfield. 2073 2074 // validate II. 2075 2076 } 2077 2078 QualType T = GetTypeForDeclarator(D, S); 2079 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2080 bool InvalidDecl = false; 2081 2082 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2083 // than a variably modified type. 2084 if (T->isVariablyModifiedType()) { 2085 // FIXME: This diagnostic needs work 2086 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2087 InvalidDecl = true; 2088 } 2089 2090 // Get the visibility (access control) for this ivar. 2091 ObjCIvarDecl::AccessControl ac = 2092 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2093 : ObjCIvarDecl::None; 2094 2095 // Construct the decl. 2096 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2097 (Expr *)BitfieldWidth); 2098 2099 // Process attributes attached to the ivar. 2100 ProcessDeclAttributes(NewID, D); 2101 2102 if (D.getInvalidType() || InvalidDecl) 2103 NewID->setInvalidDecl(); 2104 2105 return NewID; 2106} 2107 2108void Sema::ActOnFields(Scope* S, 2109 SourceLocation RecLoc, DeclTy *RecDecl, 2110 DeclTy **Fields, unsigned NumFields, 2111 SourceLocation LBrac, SourceLocation RBrac) { 2112 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2113 assert(EnclosingDecl && "missing record or interface decl"); 2114 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2115 2116 if (Record) 2117 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2118 // Diagnose code like: 2119 // struct S { struct S {} X; }; 2120 // We discover this when we complete the outer S. Reject and ignore the 2121 // outer S. 2122 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2123 DefRecord->getKindName()); 2124 Diag(RecLoc, diag::err_previous_definition); 2125 Record->setInvalidDecl(); 2126 return; 2127 } 2128 2129 // Verify that all the fields are okay. 2130 unsigned NumNamedMembers = 0; 2131 llvm::SmallVector<FieldDecl*, 32> RecFields; 2132 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2133 2134 for (unsigned i = 0; i != NumFields; ++i) { 2135 2136 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2137 assert(FD && "missing field decl"); 2138 2139 // Remember all fields. 2140 RecFields.push_back(FD); 2141 2142 // Get the type for the field. 2143 Type *FDTy = FD->getType().getTypePtr(); 2144 2145 // C99 6.7.2.1p2 - A field may not be a function type. 2146 if (FDTy->isFunctionType()) { 2147 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2148 FD->getName()); 2149 FD->setInvalidDecl(); 2150 EnclosingDecl->setInvalidDecl(); 2151 continue; 2152 } 2153 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2154 if (FDTy->isIncompleteType()) { 2155 if (!Record) { // Incomplete ivar type is always an error. 2156 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2157 FD->setInvalidDecl(); 2158 EnclosingDecl->setInvalidDecl(); 2159 continue; 2160 } 2161 if (i != NumFields-1 || // ... that the last member ... 2162 !Record->isStruct() || // ... of a structure ... 2163 !FDTy->isArrayType()) { //... may have incomplete array type. 2164 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2165 FD->setInvalidDecl(); 2166 EnclosingDecl->setInvalidDecl(); 2167 continue; 2168 } 2169 if (NumNamedMembers < 1) { //... must have more than named member ... 2170 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2171 FD->getName()); 2172 FD->setInvalidDecl(); 2173 EnclosingDecl->setInvalidDecl(); 2174 continue; 2175 } 2176 // Okay, we have a legal flexible array member at the end of the struct. 2177 if (Record) 2178 Record->setHasFlexibleArrayMember(true); 2179 } 2180 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2181 /// field of another structure or the element of an array. 2182 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2183 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2184 // If this is a member of a union, then entire union becomes "flexible". 2185 if (Record && Record->isUnion()) { 2186 Record->setHasFlexibleArrayMember(true); 2187 } else { 2188 // If this is a struct/class and this is not the last element, reject 2189 // it. Note that GCC supports variable sized arrays in the middle of 2190 // structures. 2191 if (i != NumFields-1) { 2192 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2193 FD->getName()); 2194 FD->setInvalidDecl(); 2195 EnclosingDecl->setInvalidDecl(); 2196 continue; 2197 } 2198 // We support flexible arrays at the end of structs in other structs 2199 // as an extension. 2200 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2201 FD->getName()); 2202 if (Record) 2203 Record->setHasFlexibleArrayMember(true); 2204 } 2205 } 2206 } 2207 /// A field cannot be an Objective-c object 2208 if (FDTy->isObjCInterfaceType()) { 2209 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2210 FD->getName()); 2211 FD->setInvalidDecl(); 2212 EnclosingDecl->setInvalidDecl(); 2213 continue; 2214 } 2215 // Keep track of the number of named members. 2216 if (IdentifierInfo *II = FD->getIdentifier()) { 2217 // Detect duplicate member names. 2218 if (!FieldIDs.insert(II)) { 2219 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2220 // Find the previous decl. 2221 SourceLocation PrevLoc; 2222 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2223 assert(i != e && "Didn't find previous def!"); 2224 if (RecFields[i]->getIdentifier() == II) { 2225 PrevLoc = RecFields[i]->getLocation(); 2226 break; 2227 } 2228 } 2229 Diag(PrevLoc, diag::err_previous_definition); 2230 FD->setInvalidDecl(); 2231 EnclosingDecl->setInvalidDecl(); 2232 continue; 2233 } 2234 ++NumNamedMembers; 2235 } 2236 } 2237 2238 // Okay, we successfully defined 'Record'. 2239 if (Record) { 2240 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2241 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2242 // Sema::ActOnFinishCXXClassDef. 2243 if (!isa<CXXRecordDecl>(Record)) 2244 Consumer.HandleTagDeclDefinition(Record); 2245 } else { 2246 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2247 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2248 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2249 else if (ObjCImplementationDecl *IMPDecl = 2250 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2251 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2252 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2253 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2254 } 2255 } 2256} 2257 2258Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2259 DeclTy *lastEnumConst, 2260 SourceLocation IdLoc, IdentifierInfo *Id, 2261 SourceLocation EqualLoc, ExprTy *val) { 2262 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2263 EnumConstantDecl *LastEnumConst = 2264 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2265 Expr *Val = static_cast<Expr*>(val); 2266 2267 // The scope passed in may not be a decl scope. Zip up the scope tree until 2268 // we find one that is. 2269 while ((S->getFlags() & Scope::DeclScope) == 0) 2270 S = S->getParent(); 2271 2272 // Verify that there isn't already something declared with this name in this 2273 // scope. 2274 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2275 // When in C++, we may get a TagDecl with the same name; in this case the 2276 // enum constant will 'hide' the tag. 2277 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2278 "Received TagDecl when not in C++!"); 2279 if (!isa<TagDecl>(PrevDecl) && 2280 IdResolver.isDeclInScope(PrevDecl, CurContext, S)) { 2281 if (isa<EnumConstantDecl>(PrevDecl)) 2282 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2283 else 2284 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2285 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2286 delete Val; 2287 return 0; 2288 } 2289 } 2290 2291 llvm::APSInt EnumVal(32); 2292 QualType EltTy; 2293 if (Val) { 2294 // Make sure to promote the operand type to int. 2295 UsualUnaryConversions(Val); 2296 2297 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2298 SourceLocation ExpLoc; 2299 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2300 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2301 Id->getName()); 2302 delete Val; 2303 Val = 0; // Just forget about it. 2304 } else { 2305 EltTy = Val->getType(); 2306 } 2307 } 2308 2309 if (!Val) { 2310 if (LastEnumConst) { 2311 // Assign the last value + 1. 2312 EnumVal = LastEnumConst->getInitVal(); 2313 ++EnumVal; 2314 2315 // Check for overflow on increment. 2316 if (EnumVal < LastEnumConst->getInitVal()) 2317 Diag(IdLoc, diag::warn_enum_value_overflow); 2318 2319 EltTy = LastEnumConst->getType(); 2320 } else { 2321 // First value, set to zero. 2322 EltTy = Context.IntTy; 2323 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2324 } 2325 } 2326 2327 EnumConstantDecl *New = 2328 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2329 Val, EnumVal, 2330 LastEnumConst); 2331 2332 // Register this decl in the current scope stack. 2333 PushOnScopeChains(New, S); 2334 return New; 2335} 2336 2337// FIXME: For consistency with ActOnFields(), we should have the parser 2338// pass in the source location for the left/right braces. 2339void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2340 DeclTy **Elements, unsigned NumElements) { 2341 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2342 2343 if (Enum && Enum->isDefinition()) { 2344 // Diagnose code like: 2345 // enum e0 { 2346 // E0 = sizeof(enum e0 { E1 }) 2347 // }; 2348 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2349 Enum->getName()); 2350 Diag(EnumLoc, diag::err_previous_definition); 2351 Enum->setInvalidDecl(); 2352 return; 2353 } 2354 // TODO: If the result value doesn't fit in an int, it must be a long or long 2355 // long value. ISO C does not support this, but GCC does as an extension, 2356 // emit a warning. 2357 unsigned IntWidth = Context.Target.getIntWidth(); 2358 2359 // Verify that all the values are okay, compute the size of the values, and 2360 // reverse the list. 2361 unsigned NumNegativeBits = 0; 2362 unsigned NumPositiveBits = 0; 2363 2364 // Keep track of whether all elements have type int. 2365 bool AllElementsInt = true; 2366 2367 EnumConstantDecl *EltList = 0; 2368 for (unsigned i = 0; i != NumElements; ++i) { 2369 EnumConstantDecl *ECD = 2370 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2371 if (!ECD) continue; // Already issued a diagnostic. 2372 2373 // If the enum value doesn't fit in an int, emit an extension warning. 2374 const llvm::APSInt &InitVal = ECD->getInitVal(); 2375 assert(InitVal.getBitWidth() >= IntWidth && 2376 "Should have promoted value to int"); 2377 if (InitVal.getBitWidth() > IntWidth) { 2378 llvm::APSInt V(InitVal); 2379 V.trunc(IntWidth); 2380 V.extend(InitVal.getBitWidth()); 2381 if (V != InitVal) 2382 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2383 InitVal.toString(10)); 2384 } 2385 2386 // Keep track of the size of positive and negative values. 2387 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2388 NumPositiveBits = std::max(NumPositiveBits, 2389 (unsigned)InitVal.getActiveBits()); 2390 else 2391 NumNegativeBits = std::max(NumNegativeBits, 2392 (unsigned)InitVal.getMinSignedBits()); 2393 2394 // Keep track of whether every enum element has type int (very commmon). 2395 if (AllElementsInt) 2396 AllElementsInt = ECD->getType() == Context.IntTy; 2397 2398 ECD->setNextDeclarator(EltList); 2399 EltList = ECD; 2400 } 2401 2402 // Figure out the type that should be used for this enum. 2403 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2404 QualType BestType; 2405 unsigned BestWidth; 2406 2407 if (NumNegativeBits) { 2408 // If there is a negative value, figure out the smallest integer type (of 2409 // int/long/longlong) that fits. 2410 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2411 BestType = Context.IntTy; 2412 BestWidth = IntWidth; 2413 } else { 2414 BestWidth = Context.Target.getLongWidth(); 2415 2416 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2417 BestType = Context.LongTy; 2418 else { 2419 BestWidth = Context.Target.getLongLongWidth(); 2420 2421 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2422 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2423 BestType = Context.LongLongTy; 2424 } 2425 } 2426 } else { 2427 // If there is no negative value, figure out which of uint, ulong, ulonglong 2428 // fits. 2429 if (NumPositiveBits <= IntWidth) { 2430 BestType = Context.UnsignedIntTy; 2431 BestWidth = IntWidth; 2432 } else if (NumPositiveBits <= 2433 (BestWidth = Context.Target.getLongWidth())) { 2434 BestType = Context.UnsignedLongTy; 2435 } else { 2436 BestWidth = Context.Target.getLongLongWidth(); 2437 assert(NumPositiveBits <= BestWidth && 2438 "How could an initializer get larger than ULL?"); 2439 BestType = Context.UnsignedLongLongTy; 2440 } 2441 } 2442 2443 // Loop over all of the enumerator constants, changing their types to match 2444 // the type of the enum if needed. 2445 for (unsigned i = 0; i != NumElements; ++i) { 2446 EnumConstantDecl *ECD = 2447 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2448 if (!ECD) continue; // Already issued a diagnostic. 2449 2450 // Standard C says the enumerators have int type, but we allow, as an 2451 // extension, the enumerators to be larger than int size. If each 2452 // enumerator value fits in an int, type it as an int, otherwise type it the 2453 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2454 // that X has type 'int', not 'unsigned'. 2455 if (ECD->getType() == Context.IntTy) { 2456 // Make sure the init value is signed. 2457 llvm::APSInt IV = ECD->getInitVal(); 2458 IV.setIsSigned(true); 2459 ECD->setInitVal(IV); 2460 continue; // Already int type. 2461 } 2462 2463 // Determine whether the value fits into an int. 2464 llvm::APSInt InitVal = ECD->getInitVal(); 2465 bool FitsInInt; 2466 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2467 FitsInInt = InitVal.getActiveBits() < IntWidth; 2468 else 2469 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2470 2471 // If it fits into an integer type, force it. Otherwise force it to match 2472 // the enum decl type. 2473 QualType NewTy; 2474 unsigned NewWidth; 2475 bool NewSign; 2476 if (FitsInInt) { 2477 NewTy = Context.IntTy; 2478 NewWidth = IntWidth; 2479 NewSign = true; 2480 } else if (ECD->getType() == BestType) { 2481 // Already the right type! 2482 continue; 2483 } else { 2484 NewTy = BestType; 2485 NewWidth = BestWidth; 2486 NewSign = BestType->isSignedIntegerType(); 2487 } 2488 2489 // Adjust the APSInt value. 2490 InitVal.extOrTrunc(NewWidth); 2491 InitVal.setIsSigned(NewSign); 2492 ECD->setInitVal(InitVal); 2493 2494 // Adjust the Expr initializer and type. 2495 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2496 ECD->setType(NewTy); 2497 } 2498 2499 Enum->defineElements(EltList, BestType); 2500 Consumer.HandleTagDeclDefinition(Enum); 2501} 2502 2503Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2504 ExprTy *expr) { 2505 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2506 2507 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2508} 2509 2510Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2511 SourceLocation LBrace, 2512 SourceLocation RBrace, 2513 const char *Lang, 2514 unsigned StrSize, 2515 DeclTy *D) { 2516 LinkageSpecDecl::LanguageIDs Language; 2517 Decl *dcl = static_cast<Decl *>(D); 2518 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2519 Language = LinkageSpecDecl::lang_c; 2520 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2521 Language = LinkageSpecDecl::lang_cxx; 2522 else { 2523 Diag(Loc, diag::err_bad_language); 2524 return 0; 2525 } 2526 2527 // FIXME: Add all the various semantics of linkage specifications 2528 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2529} 2530