SemaDecl.cpp revision 33d34a6f7a65be1821ab31c7d08b8e9f36d8759c
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() && isDeclInScope(*I, TD->getDeclContext(), S)) { 90 // There is already a declaration with the same name in the same 91 // scope. It must be found before we find the new declaration, 92 // so swap the order on the shadowed declaration chain. 93 94 IdResolver.AddShadowedDecl(TD, *I); 95 return; 96 } 97 } 98 IdResolver.AddDecl(D); 99} 100 101void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { 102 if (S->decl_empty()) return; 103 assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); 104 105 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); 106 I != E; ++I) { 107 Decl *TmpD = static_cast<Decl*>(*I); 108 assert(TmpD && "This decl didn't get pushed??"); 109 110 if (isa<CXXFieldDecl>(TmpD)) continue; 111 112 assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?"); 113 ScopedDecl *D = cast<ScopedDecl>(TmpD); 114 115 IdentifierInfo *II = D->getIdentifier(); 116 if (!II) continue; 117 118 // We only want to remove the decls from the identifier decl chains for 119 // local scopes, when inside a function/method. 120 if (S->getFnParent() != 0) 121 IdResolver.RemoveDecl(D); 122 123 // Chain this decl to the containing DeclContext. 124 D->setNext(CurContext->getDeclChain()); 125 CurContext->setDeclChain(D); 126 } 127} 128 129/// getObjCInterfaceDecl - Look up a for a class declaration in the scope. 130/// return 0 if one not found. 131ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { 132 // The third "scope" argument is 0 since we aren't enabling lazy built-in 133 // creation from this context. 134 Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); 135 136 return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl); 137} 138 139/// LookupDecl - Look up the inner-most declaration in the specified 140/// namespace. 141Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, 142 Scope *S, bool enableLazyBuiltinCreation) { 143 if (II == 0) return 0; 144 unsigned NS = NSI; 145 if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) 146 NS |= Decl::IDNS_Tag; 147 148 // Scan up the scope chain looking for a decl that matches this identifier 149 // that is in the appropriate namespace. This search should not take long, as 150 // shadowing of names is uncommon, and deep shadowing is extremely uncommon. 151 for (IdentifierResolver::iterator 152 I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) 153 if ((*I)->getIdentifierNamespace() & NS) 154 return *I; 155 156 // If we didn't find a use of this identifier, and if the identifier 157 // corresponds to a compiler builtin, create the decl object for the builtin 158 // now, injecting it into translation unit scope, and return it. 159 if (NS & Decl::IDNS_Ordinary) { 160 if (enableLazyBuiltinCreation) { 161 // If this is a builtin on this (or all) targets, create the decl. 162 if (unsigned BuiltinID = II->getBuiltinID()) 163 return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); 164 } 165 if (getLangOptions().ObjC1) { 166 // @interface and @compatibility_alias introduce typedef-like names. 167 // Unlike typedef's, they can only be introduced at file-scope (and are 168 // therefore not scoped decls). They can, however, be shadowed by 169 // other names in IDNS_Ordinary. 170 ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); 171 if (IDI != ObjCInterfaceDecls.end()) 172 return IDI->second; 173 ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); 174 if (I != ObjCAliasDecls.end()) 175 return I->second->getClassInterface(); 176 } 177 } 178 return 0; 179} 180 181void Sema::InitBuiltinVaListType() { 182 if (!Context.getBuiltinVaListType().isNull()) 183 return; 184 185 IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); 186 Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); 187 TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl); 188 Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); 189} 190 191/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. 192/// lazily create a decl for it. 193ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, 194 Scope *S) { 195 Builtin::ID BID = (Builtin::ID)bid; 196 197 if (Context.BuiltinInfo.hasVAListUse(BID)) 198 InitBuiltinVaListType(); 199 200 QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); 201 FunctionDecl *New = FunctionDecl::Create(Context, 202 Context.getTranslationUnitDecl(), 203 SourceLocation(), II, R, 204 FunctionDecl::Extern, false, 0); 205 206 // Create Decl objects for each parameter, adding them to the 207 // FunctionDecl. 208 if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) { 209 llvm::SmallVector<ParmVarDecl*, 16> Params; 210 for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) 211 Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, 212 FT->getArgType(i), VarDecl::None, 0, 213 0)); 214 New->setParams(&Params[0], Params.size()); 215 } 216 217 218 219 // TUScope is the translation-unit scope to insert this function into. 220 PushOnScopeChains(New, TUScope); 221 return New; 222} 223 224/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name 225/// and scope as a previous declaration 'Old'. Figure out how to resolve this 226/// situation, merging decls or emitting diagnostics as appropriate. 227/// 228TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { 229 // Allow multiple definitions for ObjC built-in typedefs. 230 // FIXME: Verify the underlying types are equivalent! 231 if (getLangOptions().ObjC1) { 232 const IdentifierInfo *typeIdent = New->getIdentifier(); 233 if (typeIdent == Ident_id) { 234 Context.setObjCIdType(New); 235 return New; 236 } else if (typeIdent == Ident_Class) { 237 Context.setObjCClassType(New); 238 return New; 239 } else if (typeIdent == Ident_SEL) { 240 Context.setObjCSelType(New); 241 return New; 242 } else if (typeIdent == Ident_Protocol) { 243 Context.setObjCProtoType(New->getUnderlyingType()); 244 return New; 245 } 246 // Fall through - the typedef name was not a builtin type. 247 } 248 // Verify the old decl was also a typedef. 249 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD); 250 if (!Old) { 251 Diag(New->getLocation(), diag::err_redefinition_different_kind, 252 New->getName()); 253 Diag(OldD->getLocation(), diag::err_previous_definition); 254 return New; 255 } 256 257 // If the typedef types are not identical, reject them in all languages and 258 // with any extensions enabled. 259 if (Old->getUnderlyingType() != New->getUnderlyingType() && 260 Context.getCanonicalType(Old->getUnderlyingType()) != 261 Context.getCanonicalType(New->getUnderlyingType())) { 262 Diag(New->getLocation(), diag::err_redefinition_different_typedef, 263 New->getUnderlyingType().getAsString(), 264 Old->getUnderlyingType().getAsString()); 265 Diag(Old->getLocation(), diag::err_previous_definition); 266 return Old; 267 } 268 269 if (getLangOptions().Microsoft) return New; 270 271 // Redeclaration of a type is a constraint violation (6.7.2.3p1). 272 // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if 273 // *either* declaration is in a system header. The code below implements 274 // this adhoc compatibility rule. FIXME: The following code will not 275 // work properly when compiling ".i" files (containing preprocessed output). 276 if (PP.getDiagnostics().getSuppressSystemWarnings()) { 277 SourceManager &SrcMgr = Context.getSourceManager(); 278 if (SrcMgr.isInSystemHeader(Old->getLocation())) 279 return New; 280 if (SrcMgr.isInSystemHeader(New->getLocation())) 281 return New; 282 } 283 284 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 285 Diag(Old->getLocation(), diag::err_previous_definition); 286 return New; 287} 288 289/// DeclhasAttr - returns true if decl Declaration already has the target 290/// attribute. 291static bool DeclHasAttr(const Decl *decl, const Attr *target) { 292 for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) 293 if (attr->getKind() == target->getKind()) 294 return true; 295 296 return false; 297} 298 299/// MergeAttributes - append attributes from the Old decl to the New one. 300static void MergeAttributes(Decl *New, Decl *Old) { 301 Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp; 302 303 while (attr) { 304 tmp = attr; 305 attr = attr->getNext(); 306 307 if (!DeclHasAttr(New, tmp)) { 308 New->addAttr(tmp); 309 } else { 310 tmp->setNext(0); 311 delete(tmp); 312 } 313 } 314 315 Old->invalidateAttrs(); 316} 317 318/// MergeFunctionDecl - We just parsed a function 'New' from 319/// declarator D which has the same name and scope as a previous 320/// declaration 'Old'. Figure out how to resolve this situation, 321/// merging decls or emitting diagnostics as appropriate. 322/// Redeclaration will be set true if thisNew is a redeclaration OldD. 323FunctionDecl * 324Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { 325 Redeclaration = false; 326 // Verify the old decl was also a function. 327 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD); 328 if (!Old) { 329 Diag(New->getLocation(), diag::err_redefinition_different_kind, 330 New->getName()); 331 Diag(OldD->getLocation(), diag::err_previous_definition); 332 return New; 333 } 334 335 QualType OldQType = Context.getCanonicalType(Old->getType()); 336 QualType NewQType = Context.getCanonicalType(New->getType()); 337 338 // C++ [dcl.fct]p3: 339 // All declarations for a function shall agree exactly in both the 340 // return type and the parameter-type-list. 341 if (getLangOptions().CPlusPlus && OldQType == NewQType) { 342 MergeAttributes(New, Old); 343 Redeclaration = true; 344 return MergeCXXFunctionDecl(New, Old); 345 } 346 347 // C: Function types need to be compatible, not identical. This handles 348 // duplicate function decls like "void f(int); void f(enum X);" properly. 349 if (!getLangOptions().CPlusPlus && 350 Context.typesAreCompatible(OldQType, NewQType)) { 351 MergeAttributes(New, Old); 352 Redeclaration = true; 353 return New; 354 } 355 356 // A function that has already been declared has been redeclared or defined 357 // with a different type- show appropriate diagnostic 358 diag::kind PrevDiag; 359 if (Old->isThisDeclarationADefinition()) 360 PrevDiag = diag::err_previous_definition; 361 else if (Old->isImplicit()) 362 PrevDiag = diag::err_previous_implicit_declaration; 363 else 364 PrevDiag = diag::err_previous_declaration; 365 366 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 367 // TODO: This is totally simplistic. It should handle merging functions 368 // together etc, merging extern int X; int X; ... 369 Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); 370 Diag(Old->getLocation(), PrevDiag); 371 return New; 372} 373 374/// Predicate for C "tentative" external object definitions (C99 6.9.2). 375static bool isTentativeDefinition(VarDecl *VD) { 376 if (VD->isFileVarDecl()) 377 return (!VD->getInit() && 378 (VD->getStorageClass() == VarDecl::None || 379 VD->getStorageClass() == VarDecl::Static)); 380 return false; 381} 382 383/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors 384/// when dealing with C "tentative" external object definitions (C99 6.9.2). 385void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { 386 bool VDIsTentative = isTentativeDefinition(VD); 387 bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); 388 389 for (IdentifierResolver::iterator 390 I = IdResolver.begin(VD->getIdentifier(), 391 VD->getDeclContext(), false/*LookInParentCtx*/), 392 E = IdResolver.end(); I != E; ++I) { 393 if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { 394 VarDecl *OldDecl = dyn_cast<VarDecl>(*I); 395 396 // Handle the following case: 397 // int a[10]; 398 // int a[]; - the code below makes sure we set the correct type. 399 // int a[11]; - this is an error, size isn't 10. 400 if (OldDecl && VDIsTentative && VDIsIncompleteArray && 401 OldDecl->getType()->isConstantArrayType()) 402 VD->setType(OldDecl->getType()); 403 404 // Check for "tentative" definitions. We can't accomplish this in 405 // MergeVarDecl since the initializer hasn't been attached. 406 if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) 407 continue; 408 409 // Handle __private_extern__ just like extern. 410 if (OldDecl->getStorageClass() != VarDecl::Extern && 411 OldDecl->getStorageClass() != VarDecl::PrivateExtern && 412 VD->getStorageClass() != VarDecl::Extern && 413 VD->getStorageClass() != VarDecl::PrivateExtern) { 414 Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); 415 Diag(OldDecl->getLocation(), diag::err_previous_definition); 416 } 417 } 418 } 419} 420 421/// MergeVarDecl - We just parsed a variable 'New' which has the same name 422/// and scope as a previous declaration 'Old'. Figure out how to resolve this 423/// situation, merging decls or emitting diagnostics as appropriate. 424/// 425/// Tentative definition rules (C99 6.9.2p2) are checked by 426/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative 427/// definitions here, since the initializer hasn't been attached. 428/// 429VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { 430 // Verify the old decl was also a variable. 431 VarDecl *Old = dyn_cast<VarDecl>(OldD); 432 if (!Old) { 433 Diag(New->getLocation(), diag::err_redefinition_different_kind, 434 New->getName()); 435 Diag(OldD->getLocation(), diag::err_previous_definition); 436 return New; 437 } 438 439 MergeAttributes(New, Old); 440 441 // Verify the types match. 442 QualType OldCType = Context.getCanonicalType(Old->getType()); 443 QualType NewCType = Context.getCanonicalType(New->getType()); 444 if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { 445 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 446 Diag(Old->getLocation(), diag::err_previous_definition); 447 return New; 448 } 449 // C99 6.2.2p4: Check if we have a static decl followed by a non-static. 450 if (New->getStorageClass() == VarDecl::Static && 451 (Old->getStorageClass() == VarDecl::None || 452 Old->getStorageClass() == VarDecl::Extern)) { 453 Diag(New->getLocation(), diag::err_static_non_static, New->getName()); 454 Diag(Old->getLocation(), diag::err_previous_definition); 455 return New; 456 } 457 // C99 6.2.2p4: Check if we have a non-static decl followed by a static. 458 if (New->getStorageClass() != VarDecl::Static && 459 Old->getStorageClass() == VarDecl::Static) { 460 Diag(New->getLocation(), diag::err_non_static_static, New->getName()); 461 Diag(Old->getLocation(), diag::err_previous_definition); 462 return New; 463 } 464 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. 465 if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { 466 Diag(New->getLocation(), diag::err_redefinition, New->getName()); 467 Diag(Old->getLocation(), diag::err_previous_definition); 468 } 469 return New; 470} 471 472/// CheckParmsForFunctionDef - Check that the parameters of the given 473/// function are appropriate for the definition of a function. This 474/// takes care of any checks that cannot be performed on the 475/// declaration itself, e.g., that the types of each of the function 476/// parameters are complete. 477bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 478 bool HasInvalidParm = false; 479 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 480 ParmVarDecl *Param = FD->getParamDecl(p); 481 482 // C99 6.7.5.3p4: the parameters in a parameter type list in a 483 // function declarator that is part of a function definition of 484 // that function shall not have incomplete type. 485 if (Param->getType()->isIncompleteType() && 486 !Param->isInvalidDecl()) { 487 Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, 488 Param->getType().getAsString()); 489 Param->setInvalidDecl(); 490 HasInvalidParm = true; 491 } 492 } 493 494 return HasInvalidParm; 495} 496 497/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with 498/// no declarator (e.g. "struct foo;") is parsed. 499Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { 500 // TODO: emit error on 'int;' or 'const enum foo;'. 501 // TODO: emit error on 'typedef int;' 502 // if (!DS.isMissingDeclaratorOk()) Diag(...); 503 504 return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep())); 505} 506 507bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { 508 // Get the type before calling CheckSingleAssignmentConstraints(), since 509 // it can promote the expression. 510 QualType InitType = Init->getType(); 511 512 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); 513 return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 514 InitType, Init, "initializing"); 515} 516 517bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { 518 const ArrayType *AT = Context.getAsArrayType(DeclT); 519 520 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 521 // C99 6.7.8p14. We have an array of character type with unknown size 522 // being initialized to a string literal. 523 llvm::APSInt ConstVal(32); 524 ConstVal = strLiteral->getByteLength() + 1; 525 // Return a new array type (C99 6.7.8p22). 526 DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, 527 ArrayType::Normal, 0); 528 } else { 529 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 530 // C99 6.7.8p14. We have an array of character type with known size. 531 // FIXME: Avoid truncation for 64-bit length strings. 532 if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) 533 Diag(strLiteral->getSourceRange().getBegin(), 534 diag::warn_initializer_string_for_char_array_too_long, 535 strLiteral->getSourceRange()); 536 } 537 // Set type from "char *" to "constant array of char". 538 strLiteral->setType(DeclT); 539 // For now, we always return false (meaning success). 540 return false; 541} 542 543StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { 544 const ArrayType *AT = Context.getAsArrayType(DeclType); 545 if (AT && AT->getElementType()->isCharType()) { 546 return dyn_cast<StringLiteral>(Init); 547 } 548 return 0; 549} 550 551bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { 552 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 553 // of unknown size ("[]") or an object type that is not a variable array type. 554 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 555 return Diag(VAT->getSizeExpr()->getLocStart(), 556 diag::err_variable_object_no_init, 557 VAT->getSizeExpr()->getSourceRange()); 558 559 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 560 if (!InitList) { 561 // FIXME: Handle wide strings 562 if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) 563 return CheckStringLiteralInit(strLiteral, DeclType); 564 565 // C99 6.7.8p16. 566 if (DeclType->isArrayType()) 567 return Diag(Init->getLocStart(), 568 diag::err_array_init_list_required, 569 Init->getSourceRange()); 570 571 return CheckSingleInitializer(Init, DeclType); 572 } 573 574 InitListChecker CheckInitList(this, InitList, DeclType); 575 return CheckInitList.HadError(); 576} 577 578Sema::DeclTy * 579Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { 580 ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl); 581 IdentifierInfo *II = D.getIdentifier(); 582 583 // All of these full declarators require an identifier. If it doesn't have 584 // one, the ParsedFreeStandingDeclSpec action should be used. 585 if (II == 0) { 586 Diag(D.getDeclSpec().getSourceRange().getBegin(), 587 diag::err_declarator_need_ident, 588 D.getDeclSpec().getSourceRange(), D.getSourceRange()); 589 return 0; 590 } 591 592 // The scope passed in may not be a decl scope. Zip up the scope tree until 593 // we find one that is. 594 while ((S->getFlags() & Scope::DeclScope) == 0) 595 S = S->getParent(); 596 597 // See if this is a redefinition of a variable in the same scope. 598 Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); 599 ScopedDecl *New; 600 bool InvalidDecl = false; 601 602 // In C++, the previous declaration we find might be a tag type 603 // (class or enum). In this case, the new declaration will hide the 604 // tag type. 605 if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) 606 PrevDecl = 0; 607 608 QualType R = GetTypeForDeclarator(D, S); 609 assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); 610 611 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 612 // Check that there are no default arguments (C++ only). 613 if (getLangOptions().CPlusPlus) 614 CheckExtraCXXDefaultArguments(D); 615 616 TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); 617 if (!NewTD) return 0; 618 619 // Handle attributes prior to checking for duplicates in MergeVarDecl 620 ProcessDeclAttributes(NewTD, D); 621 // Merge the decl with the existing one if appropriate. If the decl is 622 // in an outer scope, it isn't the same thing. 623 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)) { 624 NewTD = MergeTypeDefDecl(NewTD, PrevDecl); 625 if (NewTD == 0) return 0; 626 } 627 New = NewTD; 628 if (S->getFnParent() == 0) { 629 // C99 6.7.7p2: If a typedef name specifies a variably modified type 630 // then it shall have block scope. 631 if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { 632 // FIXME: Diagnostic needs to be fixed. 633 Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); 634 InvalidDecl = true; 635 } 636 } 637 } else if (R.getTypePtr()->isFunctionType()) { 638 FunctionDecl::StorageClass SC = FunctionDecl::None; 639 switch (D.getDeclSpec().getStorageClassSpec()) { 640 default: assert(0 && "Unknown storage class!"); 641 case DeclSpec::SCS_auto: 642 case DeclSpec::SCS_register: 643 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, 644 R.getAsString()); 645 InvalidDecl = true; 646 break; 647 case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; 648 case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; 649 case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; 650 case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; 651 } 652 653 bool isInline = D.getDeclSpec().isInlineSpecified(); 654 FunctionDecl *NewFD; 655 if (D.getContext() == Declarator::MemberContext) { 656 // This is a C++ method declaration. 657 NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 658 D.getIdentifierLoc(), II, R, 659 (SC == FunctionDecl::Static), isInline, 660 LastDeclarator); 661 } else { 662 NewFD = FunctionDecl::Create(Context, CurContext, 663 D.getIdentifierLoc(), 664 II, R, SC, isInline, LastDeclarator, 665 // FIXME: Move to DeclGroup... 666 D.getDeclSpec().getSourceRange().getBegin()); 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||isDeclInScope(PrevDecl, CurContext, S))) { 718 bool Redeclaration = false; 719 NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); 720 if (NewFD == 0) return 0; 721 if (Redeclaration) { 722 NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl)); 723 } 724 } 725 New = NewFD; 726 727 // In C++, check default arguments now that we have merged decls. 728 if (getLangOptions().CPlusPlus) 729 CheckCXXDefaultArguments(NewFD); 730 } else { 731 // Check that there are no default arguments (C++ only). 732 if (getLangOptions().CPlusPlus) 733 CheckExtraCXXDefaultArguments(D); 734 735 if (R.getTypePtr()->isObjCInterfaceType()) { 736 Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, 737 D.getIdentifier()->getName()); 738 InvalidDecl = true; 739 } 740 741 VarDecl *NewVD; 742 VarDecl::StorageClass SC; 743 switch (D.getDeclSpec().getStorageClassSpec()) { 744 default: assert(0 && "Unknown storage class!"); 745 case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; 746 case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; 747 case DeclSpec::SCS_static: SC = VarDecl::Static; break; 748 case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; 749 case DeclSpec::SCS_register: SC = VarDecl::Register; break; 750 case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; 751 } 752 if (D.getContext() == Declarator::MemberContext) { 753 assert(SC == VarDecl::Static && "Invalid storage class for member!"); 754 // This is a static data member for a C++ class. 755 NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 756 D.getIdentifierLoc(), II, 757 R, LastDeclarator); 758 } else { 759 bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); 760 if (S->getFnParent() == 0) { 761 // C99 6.9p2: The storage-class specifiers auto and register shall not 762 // appear in the declaration specifiers in an external declaration. 763 if (SC == VarDecl::Auto || SC == VarDecl::Register) { 764 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, 765 R.getAsString()); 766 InvalidDecl = true; 767 } 768 } 769 NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), 770 II, R, SC, LastDeclarator, 771 // FIXME: Move to DeclGroup... 772 D.getDeclSpec().getSourceRange().getBegin()); 773 NewVD->setThreadSpecified(ThreadSpecified); 774 } 775 // Handle attributes prior to checking for duplicates in MergeVarDecl 776 ProcessDeclAttributes(NewVD, D); 777 778 // Handle GNU asm-label extension (encoded as an attribute). 779 if (Expr *E = (Expr*) D.getAsmLabel()) { 780 // The parser guarantees this is a string. 781 StringLiteral *SE = cast<StringLiteral>(E); 782 NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), 783 SE->getByteLength()))); 784 } 785 786 // Emit an error if an address space was applied to decl with local storage. 787 // This includes arrays of objects with address space qualifiers, but not 788 // automatic variables that point to other address spaces. 789 // ISO/IEC TR 18037 S5.1.2 790 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { 791 Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); 792 InvalidDecl = true; 793 } 794 // Merge the decl with the existing one if appropriate. If the decl is 795 // in an outer scope, it isn't the same thing. 796 if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)) { 797 NewVD = MergeVarDecl(NewVD, PrevDecl); 798 if (NewVD == 0) return 0; 799 } 800 New = NewVD; 801 } 802 803 // If this has an identifier, add it to the scope stack. 804 if (II) 805 PushOnScopeChains(New, S); 806 // If any semantic error occurred, mark the decl as invalid. 807 if (D.getInvalidType() || InvalidDecl) 808 New->setInvalidDecl(); 809 810 return New; 811} 812 813bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { 814 switch (Init->getStmtClass()) { 815 default: 816 Diag(Init->getExprLoc(), 817 diag::err_init_element_not_constant, Init->getSourceRange()); 818 return true; 819 case Expr::ParenExprClass: { 820 const ParenExpr* PE = cast<ParenExpr>(Init); 821 return CheckAddressConstantExpressionLValue(PE->getSubExpr()); 822 } 823 case Expr::CompoundLiteralExprClass: 824 return cast<CompoundLiteralExpr>(Init)->isFileScope(); 825 case Expr::DeclRefExprClass: { 826 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 827 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 828 if (VD->hasGlobalStorage()) 829 return false; 830 Diag(Init->getExprLoc(), 831 diag::err_init_element_not_constant, Init->getSourceRange()); 832 return true; 833 } 834 if (isa<FunctionDecl>(D)) 835 return false; 836 Diag(Init->getExprLoc(), 837 diag::err_init_element_not_constant, Init->getSourceRange()); 838 return true; 839 } 840 case Expr::MemberExprClass: { 841 const MemberExpr *M = cast<MemberExpr>(Init); 842 if (M->isArrow()) 843 return CheckAddressConstantExpression(M->getBase()); 844 return CheckAddressConstantExpressionLValue(M->getBase()); 845 } 846 case Expr::ArraySubscriptExprClass: { 847 // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? 848 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init); 849 return CheckAddressConstantExpression(ASE->getBase()) || 850 CheckArithmeticConstantExpression(ASE->getIdx()); 851 } 852 case Expr::StringLiteralClass: 853 case Expr::PredefinedExprClass: 854 return false; 855 case Expr::UnaryOperatorClass: { 856 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 857 858 // C99 6.6p9 859 if (Exp->getOpcode() == UnaryOperator::Deref) 860 return CheckAddressConstantExpression(Exp->getSubExpr()); 861 862 Diag(Init->getExprLoc(), 863 diag::err_init_element_not_constant, Init->getSourceRange()); 864 return true; 865 } 866 } 867} 868 869bool Sema::CheckAddressConstantExpression(const Expr* Init) { 870 switch (Init->getStmtClass()) { 871 default: 872 Diag(Init->getExprLoc(), 873 diag::err_init_element_not_constant, Init->getSourceRange()); 874 return true; 875 case Expr::ParenExprClass: 876 return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr()); 877 case Expr::StringLiteralClass: 878 case Expr::ObjCStringLiteralClass: 879 return false; 880 case Expr::CallExprClass: 881 // __builtin___CFStringMakeConstantString is a valid constant l-value. 882 if (cast<CallExpr>(Init)->isBuiltinCall() == 883 Builtin::BI__builtin___CFStringMakeConstantString) 884 return false; 885 886 Diag(Init->getExprLoc(), 887 diag::err_init_element_not_constant, Init->getSourceRange()); 888 return true; 889 890 case Expr::UnaryOperatorClass: { 891 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 892 893 // C99 6.6p9 894 if (Exp->getOpcode() == UnaryOperator::AddrOf) 895 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 896 897 if (Exp->getOpcode() == UnaryOperator::Extension) 898 return CheckAddressConstantExpression(Exp->getSubExpr()); 899 900 Diag(Init->getExprLoc(), 901 diag::err_init_element_not_constant, Init->getSourceRange()); 902 return true; 903 } 904 case Expr::BinaryOperatorClass: { 905 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 906 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 907 908 Expr *PExp = Exp->getLHS(); 909 Expr *IExp = Exp->getRHS(); 910 if (IExp->getType()->isPointerType()) 911 std::swap(PExp, IExp); 912 913 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 914 return CheckAddressConstantExpression(PExp) || 915 CheckArithmeticConstantExpression(IExp); 916 } 917 case Expr::ImplicitCastExprClass: 918 case Expr::ExplicitCastExprClass: { 919 const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr(); 920 if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { 921 // Check for implicit promotion 922 if (SubExpr->getType()->isFunctionType() || 923 SubExpr->getType()->isArrayType()) 924 return CheckAddressConstantExpressionLValue(SubExpr); 925 } 926 927 // Check for pointer->pointer cast 928 if (SubExpr->getType()->isPointerType()) 929 return CheckAddressConstantExpression(SubExpr); 930 931 if (SubExpr->getType()->isIntegralType()) { 932 // Check for the special-case of a pointer->int->pointer cast; 933 // this isn't standard, but some code requires it. See 934 // PR2720 for an example. 935 if (const CastExpr* SubCast = dyn_cast<CastExpr>(SubExpr)) { 936 if (SubCast->getSubExpr()->getType()->isPointerType()) { 937 unsigned IntWidth = Context.getIntWidth(SubCast->getType()); 938 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 939 if (IntWidth >= PointerWidth) { 940 return CheckAddressConstantExpression(SubCast->getSubExpr()); 941 } 942 } 943 } 944 } 945 if (SubExpr->getType()->isArithmeticType()) { 946 return CheckArithmeticConstantExpression(SubExpr); 947 } 948 949 Diag(Init->getExprLoc(), 950 diag::err_init_element_not_constant, Init->getSourceRange()); 951 return true; 952 } 953 case Expr::ConditionalOperatorClass: { 954 // FIXME: Should we pedwarn here? 955 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 956 if (!Exp->getCond()->getType()->isArithmeticType()) { 957 Diag(Init->getExprLoc(), 958 diag::err_init_element_not_constant, Init->getSourceRange()); 959 return true; 960 } 961 if (CheckArithmeticConstantExpression(Exp->getCond())) 962 return true; 963 if (Exp->getLHS() && 964 CheckAddressConstantExpression(Exp->getLHS())) 965 return true; 966 return CheckAddressConstantExpression(Exp->getRHS()); 967 } 968 case Expr::AddrLabelExprClass: 969 return false; 970 } 971} 972 973static const Expr* FindExpressionBaseAddress(const Expr* E); 974 975static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { 976 switch (E->getStmtClass()) { 977 default: 978 return E; 979 case Expr::ParenExprClass: { 980 const ParenExpr* PE = cast<ParenExpr>(E); 981 return FindExpressionBaseAddressLValue(PE->getSubExpr()); 982 } 983 case Expr::MemberExprClass: { 984 const MemberExpr *M = cast<MemberExpr>(E); 985 if (M->isArrow()) 986 return FindExpressionBaseAddress(M->getBase()); 987 return FindExpressionBaseAddressLValue(M->getBase()); 988 } 989 case Expr::ArraySubscriptExprClass: { 990 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E); 991 return FindExpressionBaseAddress(ASE->getBase()); 992 } 993 case Expr::UnaryOperatorClass: { 994 const UnaryOperator *Exp = cast<UnaryOperator>(E); 995 996 if (Exp->getOpcode() == UnaryOperator::Deref) 997 return FindExpressionBaseAddress(Exp->getSubExpr()); 998 999 return E; 1000 } 1001 } 1002} 1003 1004static const Expr* FindExpressionBaseAddress(const Expr* E) { 1005 switch (E->getStmtClass()) { 1006 default: 1007 return E; 1008 case Expr::ParenExprClass: { 1009 const ParenExpr* PE = cast<ParenExpr>(E); 1010 return FindExpressionBaseAddress(PE->getSubExpr()); 1011 } 1012 case Expr::UnaryOperatorClass: { 1013 const UnaryOperator *Exp = cast<UnaryOperator>(E); 1014 1015 // C99 6.6p9 1016 if (Exp->getOpcode() == UnaryOperator::AddrOf) 1017 return FindExpressionBaseAddressLValue(Exp->getSubExpr()); 1018 1019 if (Exp->getOpcode() == UnaryOperator::Extension) 1020 return FindExpressionBaseAddress(Exp->getSubExpr()); 1021 1022 return E; 1023 } 1024 case Expr::BinaryOperatorClass: { 1025 const BinaryOperator *Exp = cast<BinaryOperator>(E); 1026 1027 Expr *PExp = Exp->getLHS(); 1028 Expr *IExp = Exp->getRHS(); 1029 if (IExp->getType()->isPointerType()) 1030 std::swap(PExp, IExp); 1031 1032 return FindExpressionBaseAddress(PExp); 1033 } 1034 case Expr::ImplicitCastExprClass: { 1035 const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr(); 1036 1037 // Check for implicit promotion 1038 if (SubExpr->getType()->isFunctionType() || 1039 SubExpr->getType()->isArrayType()) 1040 return FindExpressionBaseAddressLValue(SubExpr); 1041 1042 // Check for pointer->pointer cast 1043 if (SubExpr->getType()->isPointerType()) 1044 return FindExpressionBaseAddress(SubExpr); 1045 1046 // We assume that we have an arithmetic expression here; 1047 // if we don't, we'll figure it out later 1048 return 0; 1049 } 1050 case Expr::ExplicitCastExprClass: { 1051 const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1052 1053 // Check for pointer->pointer cast 1054 if (SubExpr->getType()->isPointerType()) 1055 return FindExpressionBaseAddress(SubExpr); 1056 1057 // We assume that we have an arithmetic expression here; 1058 // if we don't, we'll figure it out later 1059 return 0; 1060 } 1061 } 1062} 1063 1064bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { 1065 switch (Init->getStmtClass()) { 1066 default: 1067 Diag(Init->getExprLoc(), 1068 diag::err_init_element_not_constant, Init->getSourceRange()); 1069 return true; 1070 case Expr::ParenExprClass: { 1071 const ParenExpr* PE = cast<ParenExpr>(Init); 1072 return CheckArithmeticConstantExpression(PE->getSubExpr()); 1073 } 1074 case Expr::FloatingLiteralClass: 1075 case Expr::IntegerLiteralClass: 1076 case Expr::CharacterLiteralClass: 1077 case Expr::ImaginaryLiteralClass: 1078 case Expr::TypesCompatibleExprClass: 1079 case Expr::CXXBoolLiteralExprClass: 1080 return false; 1081 case Expr::CallExprClass: { 1082 const CallExpr *CE = cast<CallExpr>(Init); 1083 1084 // Allow any constant foldable calls to builtins. 1085 if (CE->isBuiltinCall() && CE->isEvaluatable(Context)) 1086 return false; 1087 1088 Diag(Init->getExprLoc(), 1089 diag::err_init_element_not_constant, Init->getSourceRange()); 1090 return true; 1091 } 1092 case Expr::DeclRefExprClass: { 1093 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1094 if (isa<EnumConstantDecl>(D)) 1095 return false; 1096 Diag(Init->getExprLoc(), 1097 diag::err_init_element_not_constant, Init->getSourceRange()); 1098 return true; 1099 } 1100 case Expr::CompoundLiteralExprClass: 1101 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1102 // but vectors are allowed to be magic. 1103 if (Init->getType()->isVectorType()) 1104 return false; 1105 Diag(Init->getExprLoc(), 1106 diag::err_init_element_not_constant, Init->getSourceRange()); 1107 return true; 1108 case Expr::UnaryOperatorClass: { 1109 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1110 1111 switch (Exp->getOpcode()) { 1112 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1113 // See C99 6.6p3. 1114 default: 1115 Diag(Init->getExprLoc(), 1116 diag::err_init_element_not_constant, Init->getSourceRange()); 1117 return true; 1118 case UnaryOperator::SizeOf: 1119 case UnaryOperator::AlignOf: 1120 case UnaryOperator::OffsetOf: 1121 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1122 // See C99 6.5.3.4p2 and 6.6p3. 1123 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1124 return false; 1125 Diag(Init->getExprLoc(), 1126 diag::err_init_element_not_constant, Init->getSourceRange()); 1127 return true; 1128 case UnaryOperator::Extension: 1129 case UnaryOperator::LNot: 1130 case UnaryOperator::Plus: 1131 case UnaryOperator::Minus: 1132 case UnaryOperator::Not: 1133 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1134 } 1135 } 1136 case Expr::SizeOfAlignOfTypeExprClass: { 1137 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1138 // Special check for void types, which are allowed as an extension 1139 if (Exp->getArgumentType()->isVoidType()) 1140 return false; 1141 // alignof always evaluates to a constant. 1142 // FIXME: is sizeof(int[3.0]) a constant expression? 1143 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1144 Diag(Init->getExprLoc(), 1145 diag::err_init_element_not_constant, Init->getSourceRange()); 1146 return true; 1147 } 1148 return false; 1149 } 1150 case Expr::BinaryOperatorClass: { 1151 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1152 1153 if (Exp->getLHS()->getType()->isArithmeticType() && 1154 Exp->getRHS()->getType()->isArithmeticType()) { 1155 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1156 CheckArithmeticConstantExpression(Exp->getRHS()); 1157 } 1158 1159 if (Exp->getLHS()->getType()->isPointerType() && 1160 Exp->getRHS()->getType()->isPointerType()) { 1161 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1162 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1163 1164 // Only allow a null (constant integer) base; we could 1165 // allow some additional cases if necessary, but this 1166 // is sufficient to cover offsetof-like constructs. 1167 if (!LHSBase && !RHSBase) { 1168 return CheckAddressConstantExpression(Exp->getLHS()) || 1169 CheckAddressConstantExpression(Exp->getRHS()); 1170 } 1171 } 1172 1173 Diag(Init->getExprLoc(), 1174 diag::err_init_element_not_constant, Init->getSourceRange()); 1175 return true; 1176 } 1177 case Expr::ImplicitCastExprClass: 1178 case Expr::ExplicitCastExprClass: { 1179 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1180 if (SubExpr->getType()->isArithmeticType()) 1181 return CheckArithmeticConstantExpression(SubExpr); 1182 1183 if (SubExpr->getType()->isPointerType()) { 1184 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1185 // If the pointer has a null base, this is an offsetof-like construct 1186 if (!Base) 1187 return CheckAddressConstantExpression(SubExpr); 1188 } 1189 1190 Diag(Init->getExprLoc(), 1191 diag::err_init_element_not_constant, Init->getSourceRange()); 1192 return true; 1193 } 1194 case Expr::ConditionalOperatorClass: { 1195 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1196 1197 // If GNU extensions are disabled, we require all operands to be arithmetic 1198 // constant expressions. 1199 if (getLangOptions().NoExtensions) { 1200 return CheckArithmeticConstantExpression(Exp->getCond()) || 1201 (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) || 1202 CheckArithmeticConstantExpression(Exp->getRHS()); 1203 } 1204 1205 // Otherwise, we have to emulate some of the behavior of fold here. 1206 // Basically GCC treats things like "4 ? 1 : somefunc()" as a constant 1207 // because it can constant fold things away. To retain compatibility with 1208 // GCC code, we see if we can fold the condition to a constant (which we 1209 // should always be able to do in theory). If so, we only require the 1210 // specified arm of the conditional to be a constant. This is a horrible 1211 // hack, but is require by real world code that uses __builtin_constant_p. 1212 APValue Val; 1213 if (!Exp->getCond()->tryEvaluate(Val, Context)) { 1214 // If the tryEvaluate couldn't fold it, CheckArithmeticConstantExpression 1215 // won't be able to either. Use it to emit the diagnostic though. 1216 bool Res = CheckArithmeticConstantExpression(Exp->getCond()); 1217 assert(Res && "tryEvaluate couldn't evaluate this constant?"); 1218 return Res; 1219 } 1220 1221 // Verify that the side following the condition is also a constant. 1222 const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS(); 1223 if (Val.getInt() == 0) 1224 std::swap(TrueSide, FalseSide); 1225 1226 if (TrueSide && CheckArithmeticConstantExpression(TrueSide)) 1227 return true; 1228 1229 // Okay, the evaluated side evaluates to a constant, so we accept this. 1230 // Check to see if the other side is obviously not a constant. If so, 1231 // emit a warning that this is a GNU extension. 1232 if (FalseSide && !FalseSide->isEvaluatable(Context)) 1233 Diag(Init->getExprLoc(), 1234 diag::ext_typecheck_expression_not_constant_but_accepted, 1235 FalseSide->getSourceRange()); 1236 return false; 1237 } 1238 } 1239} 1240 1241bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1242 Init = Init->IgnoreParens(); 1243 1244 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1245 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1246 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1247 1248 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1249 return CheckForConstantInitializer(e->getInitializer(), DclT); 1250 1251 if (Init->getType()->isReferenceType()) { 1252 // FIXME: Work out how the heck references work. 1253 return false; 1254 } 1255 1256 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1257 unsigned numInits = Exp->getNumInits(); 1258 for (unsigned i = 0; i < numInits; i++) { 1259 // FIXME: Need to get the type of the declaration for C++, 1260 // because it could be a reference? 1261 if (CheckForConstantInitializer(Exp->getInit(i), 1262 Exp->getInit(i)->getType())) 1263 return true; 1264 } 1265 return false; 1266 } 1267 1268 if (Init->isNullPointerConstant(Context)) 1269 return false; 1270 if (Init->getType()->isArithmeticType()) { 1271 QualType InitTy = Context.getCanonicalType(Init->getType()) 1272 .getUnqualifiedType(); 1273 if (InitTy == Context.BoolTy) { 1274 // Special handling for pointers implicitly cast to bool; 1275 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1276 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1277 Expr* SubE = ICE->getSubExpr(); 1278 if (SubE->getType()->isPointerType() || 1279 SubE->getType()->isArrayType() || 1280 SubE->getType()->isFunctionType()) { 1281 return CheckAddressConstantExpression(Init); 1282 } 1283 } 1284 } else if (InitTy->isIntegralType()) { 1285 Expr* SubE = 0; 1286 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1287 SubE = CE->getSubExpr(); 1288 // Special check for pointer cast to int; we allow as an extension 1289 // an address constant cast to an integer if the integer 1290 // is of an appropriate width (this sort of code is apparently used 1291 // in some places). 1292 // FIXME: Add pedwarn? 1293 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1294 if (SubE && (SubE->getType()->isPointerType() || 1295 SubE->getType()->isArrayType() || 1296 SubE->getType()->isFunctionType())) { 1297 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1298 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1299 if (IntWidth >= PointerWidth) 1300 return CheckAddressConstantExpression(Init); 1301 } 1302 } 1303 1304 return CheckArithmeticConstantExpression(Init); 1305 } 1306 1307 if (Init->getType()->isPointerType()) 1308 return CheckAddressConstantExpression(Init); 1309 1310 // An array type at the top level that isn't an init-list must 1311 // be a string literal 1312 if (Init->getType()->isArrayType()) 1313 return false; 1314 1315 if (Init->getType()->isFunctionType()) 1316 return false; 1317 1318 // Allow block exprs at top level. 1319 if (Init->getType()->isBlockPointerType()) 1320 return false; 1321 1322 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1323 Init->getSourceRange()); 1324 return true; 1325} 1326 1327void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1328 Decl *RealDecl = static_cast<Decl *>(dcl); 1329 Expr *Init = static_cast<Expr *>(init); 1330 assert(Init && "missing initializer"); 1331 1332 // If there is no declaration, there was an error parsing it. Just ignore 1333 // the initializer. 1334 if (RealDecl == 0) { 1335 delete Init; 1336 return; 1337 } 1338 1339 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1340 if (!VDecl) { 1341 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1342 diag::err_illegal_initializer); 1343 RealDecl->setInvalidDecl(); 1344 return; 1345 } 1346 // Get the decls type and save a reference for later, since 1347 // CheckInitializerTypes may change it. 1348 QualType DclT = VDecl->getType(), SavT = DclT; 1349 if (VDecl->isBlockVarDecl()) { 1350 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1351 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1352 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1353 VDecl->setInvalidDecl(); 1354 } else if (!VDecl->isInvalidDecl()) { 1355 if (CheckInitializerTypes(Init, DclT)) 1356 VDecl->setInvalidDecl(); 1357 1358 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1359 if (!getLangOptions().CPlusPlus) { 1360 if (SC == VarDecl::Static) // C99 6.7.8p4. 1361 CheckForConstantInitializer(Init, DclT); 1362 } 1363 } 1364 } else if (VDecl->isFileVarDecl()) { 1365 if (VDecl->getStorageClass() == VarDecl::Extern) 1366 Diag(VDecl->getLocation(), diag::warn_extern_init); 1367 if (!VDecl->isInvalidDecl()) 1368 if (CheckInitializerTypes(Init, DclT)) 1369 VDecl->setInvalidDecl(); 1370 1371 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1372 if (!getLangOptions().CPlusPlus) { 1373 // C99 6.7.8p4. All file scoped initializers need to be constant. 1374 CheckForConstantInitializer(Init, DclT); 1375 } 1376 } 1377 // If the type changed, it means we had an incomplete type that was 1378 // completed by the initializer. For example: 1379 // int ary[] = { 1, 3, 5 }; 1380 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1381 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1382 VDecl->setType(DclT); 1383 Init->setType(DclT); 1384 } 1385 1386 // Attach the initializer to the decl. 1387 VDecl->setInit(Init); 1388 return; 1389} 1390 1391/// The declarators are chained together backwards, reverse the list. 1392Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1393 // Often we have single declarators, handle them quickly. 1394 Decl *GroupDecl = static_cast<Decl*>(group); 1395 if (GroupDecl == 0) 1396 return 0; 1397 1398 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1399 ScopedDecl *NewGroup = 0; 1400 if (Group->getNextDeclarator() == 0) 1401 NewGroup = Group; 1402 else { // reverse the list. 1403 while (Group) { 1404 ScopedDecl *Next = Group->getNextDeclarator(); 1405 Group->setNextDeclarator(NewGroup); 1406 NewGroup = Group; 1407 Group = Next; 1408 } 1409 } 1410 // Perform semantic analysis that depends on having fully processed both 1411 // the declarator and initializer. 1412 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1413 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1414 if (!IDecl) 1415 continue; 1416 QualType T = IDecl->getType(); 1417 1418 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1419 // static storage duration, it shall not have a variable length array. 1420 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1421 IDecl->getStorageClass() == VarDecl::Static) { 1422 if (T->isVariableArrayType()) { 1423 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1424 IDecl->setInvalidDecl(); 1425 } 1426 } 1427 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1428 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1429 if (IDecl->isBlockVarDecl() && 1430 IDecl->getStorageClass() != VarDecl::Extern) { 1431 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1432 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1433 T.getAsString()); 1434 IDecl->setInvalidDecl(); 1435 } 1436 } 1437 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1438 // object that has file scope without an initializer, and without a 1439 // storage-class specifier or with the storage-class specifier "static", 1440 // constitutes a tentative definition. Note: A tentative definition with 1441 // external linkage is valid (C99 6.2.2p5). 1442 if (isTentativeDefinition(IDecl)) { 1443 if (T->isIncompleteArrayType()) { 1444 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1445 // array to be completed. Don't issue a diagnostic. 1446 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1447 // C99 6.9.2p3: If the declaration of an identifier for an object is 1448 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1449 // declared type shall not be an incomplete type. 1450 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1451 T.getAsString()); 1452 IDecl->setInvalidDecl(); 1453 } 1454 } 1455 if (IDecl->isFileVarDecl()) 1456 CheckForFileScopedRedefinitions(S, IDecl); 1457 } 1458 return NewGroup; 1459} 1460 1461/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1462/// to introduce parameters into function prototype scope. 1463Sema::DeclTy * 1464Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1465 const DeclSpec &DS = D.getDeclSpec(); 1466 1467 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1468 VarDecl::StorageClass StorageClass = VarDecl::None; 1469 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1470 StorageClass = VarDecl::Register; 1471 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1472 Diag(DS.getStorageClassSpecLoc(), 1473 diag::err_invalid_storage_class_in_func_decl); 1474 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1475 } 1476 if (DS.isThreadSpecified()) { 1477 Diag(DS.getThreadSpecLoc(), 1478 diag::err_invalid_storage_class_in_func_decl); 1479 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1480 } 1481 1482 // Check that there are no default arguments inside the type of this 1483 // parameter (C++ only). 1484 if (getLangOptions().CPlusPlus) 1485 CheckExtraCXXDefaultArguments(D); 1486 1487 // In this context, we *do not* check D.getInvalidType(). If the declarator 1488 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1489 // though it will not reflect the user specified type. 1490 QualType parmDeclType = GetTypeForDeclarator(D, S); 1491 1492 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1493 1494 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1495 // Can this happen for params? We already checked that they don't conflict 1496 // among each other. Here they can only shadow globals, which is ok. 1497 IdentifierInfo *II = D.getIdentifier(); 1498 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1499 if (S->isDeclScope(PrevDecl)) { 1500 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1501 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1502 1503 // Recover by removing the name 1504 II = 0; 1505 D.SetIdentifier(0, D.getIdentifierLoc()); 1506 } 1507 } 1508 1509 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1510 // Doing the promotion here has a win and a loss. The win is the type for 1511 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1512 // code generator). The loss is the orginal type isn't preserved. For example: 1513 // 1514 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1515 // int blockvardecl[5]; 1516 // sizeof(parmvardecl); // size == 4 1517 // sizeof(blockvardecl); // size == 20 1518 // } 1519 // 1520 // For expressions, all implicit conversions are captured using the 1521 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1522 // 1523 // FIXME: If a source translation tool needs to see the original type, then 1524 // we need to consider storing both types (in ParmVarDecl)... 1525 // 1526 if (parmDeclType->isArrayType()) { 1527 // int x[restrict 4] -> int *restrict 1528 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1529 } else if (parmDeclType->isFunctionType()) 1530 parmDeclType = Context.getPointerType(parmDeclType); 1531 1532 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1533 D.getIdentifierLoc(), II, 1534 parmDeclType, StorageClass, 1535 0, 0); 1536 1537 if (D.getInvalidType()) 1538 New->setInvalidDecl(); 1539 1540 if (II) 1541 PushOnScopeChains(New, S); 1542 1543 ProcessDeclAttributes(New, D); 1544 return New; 1545 1546} 1547 1548Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1549 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1550 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1551 "Not a function declarator!"); 1552 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1553 1554 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1555 // for a K&R function. 1556 if (!FTI.hasPrototype) { 1557 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1558 if (FTI.ArgInfo[i].Param == 0) { 1559 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1560 FTI.ArgInfo[i].Ident->getName()); 1561 // Implicitly declare the argument as type 'int' for lack of a better 1562 // type. 1563 DeclSpec DS; 1564 const char* PrevSpec; // unused 1565 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1566 PrevSpec); 1567 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1568 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1569 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1570 } 1571 } 1572 } else { 1573 // FIXME: Diagnose arguments without names in C. 1574 } 1575 1576 Scope *GlobalScope = FnBodyScope->getParent(); 1577 1578 // See if this is a redefinition. 1579 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1580 GlobalScope); 1581 if (PrevDcl && isDeclInScope(PrevDcl, CurContext)) { 1582 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1583 const FunctionDecl *Definition; 1584 if (FD->getBody(Definition)) { 1585 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1586 D.getIdentifier()->getName()); 1587 Diag(Definition->getLocation(), diag::err_previous_definition); 1588 } 1589 } 1590 } 1591 1592 return ActOnStartOfFunctionDef(FnBodyScope, 1593 ActOnDeclarator(GlobalScope, D, 0)); 1594} 1595 1596Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1597 Decl *decl = static_cast<Decl*>(D); 1598 FunctionDecl *FD = cast<FunctionDecl>(decl); 1599 PushDeclContext(FD); 1600 1601 // Check the validity of our function parameters 1602 CheckParmsForFunctionDef(FD); 1603 1604 // Introduce our parameters into the function scope 1605 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1606 ParmVarDecl *Param = FD->getParamDecl(p); 1607 // If this has an identifier, add it to the scope stack. 1608 if (Param->getIdentifier()) 1609 PushOnScopeChains(Param, FnBodyScope); 1610 } 1611 1612 return FD; 1613} 1614 1615Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1616 Decl *dcl = static_cast<Decl *>(D); 1617 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1618 FD->setBody((Stmt*)Body); 1619 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1620 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1621 MD->setBody((Stmt*)Body); 1622 } else 1623 return 0; 1624 PopDeclContext(); 1625 // Verify and clean out per-function state. 1626 1627 // Check goto/label use. 1628 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1629 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1630 // Verify that we have no forward references left. If so, there was a goto 1631 // or address of a label taken, but no definition of it. Label fwd 1632 // definitions are indicated with a null substmt. 1633 if (I->second->getSubStmt() == 0) { 1634 LabelStmt *L = I->second; 1635 // Emit error. 1636 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1637 1638 // At this point, we have gotos that use the bogus label. Stitch it into 1639 // the function body so that they aren't leaked and that the AST is well 1640 // formed. 1641 if (Body) { 1642 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1643 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1644 } else { 1645 // The whole function wasn't parsed correctly, just delete this. 1646 delete L; 1647 } 1648 } 1649 } 1650 LabelMap.clear(); 1651 1652 return D; 1653} 1654 1655/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1656/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1657ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1658 IdentifierInfo &II, Scope *S) { 1659 // Extension in C99. Legal in C90, but warn about it. 1660 if (getLangOptions().C99) 1661 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1662 else 1663 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1664 1665 // FIXME: handle stuff like: 1666 // void foo() { extern float X(); } 1667 // void bar() { X(); } <-- implicit decl for X in another scope. 1668 1669 // Set a Declarator for the implicit definition: int foo(); 1670 const char *Dummy; 1671 DeclSpec DS; 1672 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1673 Error = Error; // Silence warning. 1674 assert(!Error && "Error setting up implicit decl!"); 1675 Declarator D(DS, Declarator::BlockContext); 1676 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1677 D.SetIdentifier(&II, Loc); 1678 1679 // Insert this function into translation-unit scope. 1680 1681 DeclContext *PrevDC = CurContext; 1682 CurContext = Context.getTranslationUnitDecl(); 1683 1684 FunctionDecl *FD = 1685 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1686 FD->setImplicit(); 1687 1688 CurContext = PrevDC; 1689 1690 return FD; 1691} 1692 1693 1694TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1695 ScopedDecl *LastDeclarator) { 1696 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1697 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1698 1699 // Scope manipulation handled by caller. 1700 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1701 D.getIdentifierLoc(), 1702 D.getIdentifier(), 1703 T, LastDeclarator); 1704 if (D.getInvalidType()) 1705 NewTD->setInvalidDecl(); 1706 return NewTD; 1707} 1708 1709/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1710/// former case, Name will be non-null. In the later case, Name will be null. 1711/// TagType indicates what kind of tag this is. TK indicates whether this is a 1712/// reference/declaration/definition of a tag. 1713Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1714 SourceLocation KWLoc, IdentifierInfo *Name, 1715 SourceLocation NameLoc, AttributeList *Attr) { 1716 // If this is a use of an existing tag, it must have a name. 1717 assert((Name != 0 || TK == TK_Definition) && 1718 "Nameless record must be a definition!"); 1719 1720 TagDecl::TagKind Kind; 1721 switch (TagType) { 1722 default: assert(0 && "Unknown tag type!"); 1723 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1724 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1725 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1726 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1727 } 1728 1729 // Two code paths: a new one for structs/unions/classes where we create 1730 // separate decls for forward declarations, and an old (eventually to 1731 // be removed) code path for enums. 1732 if (Kind != TagDecl::TK_enum) 1733 return ActOnTagStruct(S, Kind, TK, KWLoc, Name, NameLoc, Attr); 1734 1735 // If this is a named struct, check to see if there was a previous forward 1736 // declaration or definition. 1737 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1738 ScopedDecl *PrevDecl = 1739 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S)); 1740 1741 if (PrevDecl) { 1742 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1743 "unexpected Decl type"); 1744 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1745 // If this is a use of a previous tag, or if the tag is already declared 1746 // in the same scope (so that the definition/declaration completes or 1747 // rementions the tag), reuse the decl. 1748 if (TK == TK_Reference || isDeclInScope(PrevDecl, CurContext, S)) { 1749 // Make sure that this wasn't declared as an enum and now used as a 1750 // struct or something similar. 1751 if (PrevTagDecl->getTagKind() != Kind) { 1752 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1753 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1754 // Recover by making this an anonymous redefinition. 1755 Name = 0; 1756 PrevDecl = 0; 1757 } else { 1758 // If this is a use or a forward declaration, we're good. 1759 if (TK != TK_Definition) 1760 return PrevDecl; 1761 1762 // Diagnose attempts to redefine a tag. 1763 if (PrevTagDecl->isDefinition()) { 1764 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1765 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1766 // If this is a redefinition, recover by making this struct be 1767 // anonymous, which will make any later references get the previous 1768 // definition. 1769 Name = 0; 1770 } else { 1771 // Okay, this is definition of a previously declared or referenced 1772 // tag. Move the location of the decl to be the definition site. 1773 PrevDecl->setLocation(NameLoc); 1774 return PrevDecl; 1775 } 1776 } 1777 } 1778 // If we get here, this is a definition of a new struct type in a nested 1779 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1780 // type. 1781 } else { 1782 // PrevDecl is a namespace. 1783 if (isDeclInScope(PrevDecl, CurContext, S)) { 1784 // The tag name clashes with a namespace name, issue an error and 1785 // recover by making this tag be anonymous. 1786 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1787 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1788 Name = 0; 1789 } 1790 } 1791 } 1792 1793 // If there is an identifier, use the location of the identifier as the 1794 // location of the decl, otherwise use the location of the struct/union 1795 // keyword. 1796 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1797 1798 // Otherwise, if this is the first time we've seen this tag, create the decl. 1799 TagDecl *New; 1800 if (Kind == TagDecl::TK_enum) { 1801 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1802 // enum X { A, B, C } D; D should chain to X. 1803 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1804 // If this is an undefined enum, warn. 1805 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1806 } else { 1807 // struct/union/class 1808 1809 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1810 // struct X { int A; } D; D should chain to X. 1811 if (getLangOptions().CPlusPlus) 1812 // FIXME: Look for a way to use RecordDecl for simple structs. 1813 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name); 1814 else 1815 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name); 1816 } 1817 1818 // If this has an identifier, add it to the scope stack. 1819 if (Name) { 1820 // The scope passed in may not be a decl scope. Zip up the scope tree until 1821 // we find one that is. 1822 while ((S->getFlags() & Scope::DeclScope) == 0) 1823 S = S->getParent(); 1824 1825 // Add it to the decl chain. 1826 PushOnScopeChains(New, S); 1827 } 1828 1829 if (Attr) 1830 ProcessDeclAttributeList(New, Attr); 1831 return New; 1832} 1833 1834/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 1835/// the logic for enums, we create separate decls for forward declarations. 1836/// This is called by ActOnTag, but eventually will replace its logic. 1837Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 1838 SourceLocation KWLoc, IdentifierInfo *Name, 1839 SourceLocation NameLoc, AttributeList *Attr) { 1840 1841 // If this is a named struct, check to see if there was a previous forward 1842 // declaration or definition. 1843 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1844 ScopedDecl *PrevDecl = 1845 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S)); 1846 1847 if (PrevDecl) { 1848 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1849 "unexpected Decl type"); 1850 1851 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1852 // If this is a use of a previous tag, or if the tag is already declared 1853 // in the same scope (so that the definition/declaration completes or 1854 // rementions the tag), reuse the decl. 1855 if (TK == TK_Reference || isDeclInScope(PrevDecl, CurContext, S)) { 1856 // Make sure that this wasn't declared as an enum and now used as a 1857 // struct or something similar. 1858 if (PrevTagDecl->getTagKind() != Kind) { 1859 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1860 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1861 // Recover by making this an anonymous redefinition. 1862 Name = 0; 1863 PrevDecl = 0; 1864 } else { 1865 // If this is a use, return the original decl. 1866 1867 // FIXME: In the future, return a variant or some other clue 1868 // for the consumer of this Decl to know it doesn't own it. 1869 // For our current ASTs this shouldn't be a problem, but will 1870 // need to be changed with DeclGroups. 1871 if (TK == TK_Reference) 1872 return PrevDecl; 1873 1874 // The new decl is a definition? 1875 if (TK == TK_Definition) { 1876 // Diagnose attempts to redefine a tag. 1877 if (RecordDecl* DefRecord = 1878 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 1879 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1880 Diag(DefRecord->getLocation(), diag::err_previous_definition); 1881 // If this is a redefinition, recover by making this struct be 1882 // anonymous, which will make any later references get the previous 1883 // definition. 1884 Name = 0; 1885 PrevDecl = 0; 1886 } 1887 // Okay, this is definition of a previously declared or referenced 1888 // tag. We're going to create a new Decl. 1889 } 1890 } 1891 // If we get here we have (another) forward declaration. Just create 1892 // a new decl. 1893 } 1894 else { 1895 // If we get here, this is a definition of a new struct type in a nested 1896 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 1897 // new decl/type. We set PrevDecl to NULL so that the Records 1898 // have distinct types. 1899 PrevDecl = 0; 1900 } 1901 } else { 1902 // PrevDecl is a namespace. 1903 if (isDeclInScope(PrevDecl, CurContext, S)) { 1904 // The tag name clashes with a namespace name, issue an error and 1905 // recover by making this tag be anonymous. 1906 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1907 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1908 Name = 0; 1909 } 1910 } 1911 } 1912 1913 // If there is an identifier, use the location of the identifier as the 1914 // location of the decl, otherwise use the location of the struct/union 1915 // keyword. 1916 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1917 1918 // Otherwise, if this is the first time we've seen this tag, create the decl. 1919 TagDecl *New; 1920 1921 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1922 // struct X { int A; } D; D should chain to X. 1923 if (getLangOptions().CPlusPlus) 1924 // FIXME: Look for a way to use RecordDecl for simple structs. 1925 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 1926 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 1927 else 1928 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 1929 dyn_cast_or_null<RecordDecl>(PrevDecl)); 1930 1931 // If this has an identifier, add it to the scope stack. 1932 if ((TK == TK_Definition || !PrevDecl) && Name) { 1933 // The scope passed in may not be a decl scope. Zip up the scope tree until 1934 // we find one that is. 1935 while ((S->getFlags() & Scope::DeclScope) == 0) 1936 S = S->getParent(); 1937 1938 // Add it to the decl chain. 1939 PushOnScopeChains(New, S); 1940 } 1941 1942 if (Attr) 1943 ProcessDeclAttributeList(New, Attr); 1944 1945 return New; 1946} 1947 1948 1949/// Collect the instance variables declared in an Objective-C object. Used in 1950/// the creation of structures from objects using the @defs directive. 1951static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 1952 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1953 if (Class->getSuperClass()) 1954 CollectIvars(Class->getSuperClass(), Ctx, ivars); 1955 1956 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 1957 for (ObjCInterfaceDecl::ivar_iterator 1958 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 1959 1960 ObjCIvarDecl* ID = *I; 1961 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 1962 ID->getIdentifier(), 1963 ID->getType(), 1964 ID->getBitWidth())); 1965 } 1966} 1967 1968/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1969/// instance variables of ClassName into Decls. 1970void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1971 IdentifierInfo *ClassName, 1972 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1973 // Check that ClassName is a valid class 1974 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1975 if (!Class) { 1976 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1977 return; 1978 } 1979 // Collect the instance variables 1980 CollectIvars(Class, Context, Decls); 1981} 1982 1983QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1984 // This method tries to turn a variable array into a constant 1985 // array even when the size isn't an ICE. This is necessary 1986 // for compatibility with code that depends on gcc's buggy 1987 // constant expression folding, like struct {char x[(int)(char*)2];} 1988 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1989 APValue Result; 1990 if (VLATy->getSizeExpr() && 1991 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1992 llvm::APSInt &Res = Result.getInt(); 1993 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1994 return Context.getConstantArrayType(VLATy->getElementType(), 1995 Res, ArrayType::Normal, 0); 1996 } 1997 } 1998 return QualType(); 1999} 2000 2001/// ActOnField - Each field of a struct/union/class is passed into this in order 2002/// to create a FieldDecl object for it. 2003Sema::DeclTy *Sema::ActOnField(Scope *S, 2004 SourceLocation DeclStart, 2005 Declarator &D, ExprTy *BitfieldWidth) { 2006 IdentifierInfo *II = D.getIdentifier(); 2007 Expr *BitWidth = (Expr*)BitfieldWidth; 2008 SourceLocation Loc = DeclStart; 2009 if (II) Loc = D.getIdentifierLoc(); 2010 2011 // FIXME: Unnamed fields can be handled in various different ways, for 2012 // example, unnamed unions inject all members into the struct namespace! 2013 2014 if (BitWidth) { 2015 // TODO: Validate. 2016 //printf("WARNING: BITFIELDS IGNORED!\n"); 2017 2018 // 6.7.2.1p3 2019 // 6.7.2.1p4 2020 2021 } else { 2022 // Not a bitfield. 2023 2024 // validate II. 2025 2026 } 2027 2028 QualType T = GetTypeForDeclarator(D, S); 2029 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2030 bool InvalidDecl = false; 2031 2032 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2033 // than a variably modified type. 2034 if (T->isVariablyModifiedType()) { 2035 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 2036 if (!FixedTy.isNull()) { 2037 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 2038 T = FixedTy; 2039 } else { 2040 // FIXME: This diagnostic needs work 2041 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2042 InvalidDecl = true; 2043 } 2044 } 2045 // FIXME: Chain fielddecls together. 2046 FieldDecl *NewFD; 2047 2048 if (getLangOptions().CPlusPlus) { 2049 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2050 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2051 Loc, II, T, BitWidth); 2052 if (II) 2053 PushOnScopeChains(NewFD, S); 2054 } 2055 else 2056 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2057 2058 ProcessDeclAttributes(NewFD, D); 2059 2060 if (D.getInvalidType() || InvalidDecl) 2061 NewFD->setInvalidDecl(); 2062 return NewFD; 2063} 2064 2065/// TranslateIvarVisibility - Translate visibility from a token ID to an 2066/// AST enum value. 2067static ObjCIvarDecl::AccessControl 2068TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2069 switch (ivarVisibility) { 2070 default: assert(0 && "Unknown visitibility kind"); 2071 case tok::objc_private: return ObjCIvarDecl::Private; 2072 case tok::objc_public: return ObjCIvarDecl::Public; 2073 case tok::objc_protected: return ObjCIvarDecl::Protected; 2074 case tok::objc_package: return ObjCIvarDecl::Package; 2075 } 2076} 2077 2078/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2079/// in order to create an IvarDecl object for it. 2080Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2081 SourceLocation DeclStart, 2082 Declarator &D, ExprTy *BitfieldWidth, 2083 tok::ObjCKeywordKind Visibility) { 2084 IdentifierInfo *II = D.getIdentifier(); 2085 Expr *BitWidth = (Expr*)BitfieldWidth; 2086 SourceLocation Loc = DeclStart; 2087 if (II) Loc = D.getIdentifierLoc(); 2088 2089 // FIXME: Unnamed fields can be handled in various different ways, for 2090 // example, unnamed unions inject all members into the struct namespace! 2091 2092 2093 if (BitWidth) { 2094 // TODO: Validate. 2095 //printf("WARNING: BITFIELDS IGNORED!\n"); 2096 2097 // 6.7.2.1p3 2098 // 6.7.2.1p4 2099 2100 } else { 2101 // Not a bitfield. 2102 2103 // validate II. 2104 2105 } 2106 2107 QualType T = GetTypeForDeclarator(D, S); 2108 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2109 bool InvalidDecl = false; 2110 2111 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2112 // than a variably modified type. 2113 if (T->isVariablyModifiedType()) { 2114 // FIXME: This diagnostic needs work 2115 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2116 InvalidDecl = true; 2117 } 2118 2119 // Get the visibility (access control) for this ivar. 2120 ObjCIvarDecl::AccessControl ac = 2121 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2122 : ObjCIvarDecl::None; 2123 2124 // Construct the decl. 2125 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2126 (Expr *)BitfieldWidth); 2127 2128 // Process attributes attached to the ivar. 2129 ProcessDeclAttributes(NewID, D); 2130 2131 if (D.getInvalidType() || InvalidDecl) 2132 NewID->setInvalidDecl(); 2133 2134 return NewID; 2135} 2136 2137void Sema::ActOnFields(Scope* S, 2138 SourceLocation RecLoc, DeclTy *RecDecl, 2139 DeclTy **Fields, unsigned NumFields, 2140 SourceLocation LBrac, SourceLocation RBrac, 2141 AttributeList *Attr) { 2142 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2143 assert(EnclosingDecl && "missing record or interface decl"); 2144 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2145 2146 if (Record) 2147 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2148 // Diagnose code like: 2149 // struct S { struct S {} X; }; 2150 // We discover this when we complete the outer S. Reject and ignore the 2151 // outer S. 2152 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2153 DefRecord->getKindName()); 2154 Diag(RecLoc, diag::err_previous_definition); 2155 Record->setInvalidDecl(); 2156 return; 2157 } 2158 2159 // Verify that all the fields are okay. 2160 unsigned NumNamedMembers = 0; 2161 llvm::SmallVector<FieldDecl*, 32> RecFields; 2162 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2163 2164 for (unsigned i = 0; i != NumFields; ++i) { 2165 2166 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2167 assert(FD && "missing field decl"); 2168 2169 // Remember all fields. 2170 RecFields.push_back(FD); 2171 2172 // Get the type for the field. 2173 Type *FDTy = FD->getType().getTypePtr(); 2174 2175 // C99 6.7.2.1p2 - A field may not be a function type. 2176 if (FDTy->isFunctionType()) { 2177 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2178 FD->getName()); 2179 FD->setInvalidDecl(); 2180 EnclosingDecl->setInvalidDecl(); 2181 continue; 2182 } 2183 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2184 if (FDTy->isIncompleteType()) { 2185 if (!Record) { // Incomplete ivar type is always an error. 2186 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2187 FD->setInvalidDecl(); 2188 EnclosingDecl->setInvalidDecl(); 2189 continue; 2190 } 2191 if (i != NumFields-1 || // ... that the last member ... 2192 !Record->isStruct() || // ... of a structure ... 2193 !FDTy->isArrayType()) { //... may have incomplete array type. 2194 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2195 FD->setInvalidDecl(); 2196 EnclosingDecl->setInvalidDecl(); 2197 continue; 2198 } 2199 if (NumNamedMembers < 1) { //... must have more than named member ... 2200 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2201 FD->getName()); 2202 FD->setInvalidDecl(); 2203 EnclosingDecl->setInvalidDecl(); 2204 continue; 2205 } 2206 // Okay, we have a legal flexible array member at the end of the struct. 2207 if (Record) 2208 Record->setHasFlexibleArrayMember(true); 2209 } 2210 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2211 /// field of another structure or the element of an array. 2212 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2213 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2214 // If this is a member of a union, then entire union becomes "flexible". 2215 if (Record && Record->isUnion()) { 2216 Record->setHasFlexibleArrayMember(true); 2217 } else { 2218 // If this is a struct/class and this is not the last element, reject 2219 // it. Note that GCC supports variable sized arrays in the middle of 2220 // structures. 2221 if (i != NumFields-1) { 2222 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2223 FD->getName()); 2224 FD->setInvalidDecl(); 2225 EnclosingDecl->setInvalidDecl(); 2226 continue; 2227 } 2228 // We support flexible arrays at the end of structs in other structs 2229 // as an extension. 2230 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2231 FD->getName()); 2232 if (Record) 2233 Record->setHasFlexibleArrayMember(true); 2234 } 2235 } 2236 } 2237 /// A field cannot be an Objective-c object 2238 if (FDTy->isObjCInterfaceType()) { 2239 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2240 FD->getName()); 2241 FD->setInvalidDecl(); 2242 EnclosingDecl->setInvalidDecl(); 2243 continue; 2244 } 2245 // Keep track of the number of named members. 2246 if (IdentifierInfo *II = FD->getIdentifier()) { 2247 // Detect duplicate member names. 2248 if (!FieldIDs.insert(II)) { 2249 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2250 // Find the previous decl. 2251 SourceLocation PrevLoc; 2252 for (unsigned i = 0; ; ++i) { 2253 assert(i != RecFields.size() && "Didn't find previous def!"); 2254 if (RecFields[i]->getIdentifier() == II) { 2255 PrevLoc = RecFields[i]->getLocation(); 2256 break; 2257 } 2258 } 2259 Diag(PrevLoc, diag::err_previous_definition); 2260 FD->setInvalidDecl(); 2261 EnclosingDecl->setInvalidDecl(); 2262 continue; 2263 } 2264 ++NumNamedMembers; 2265 } 2266 } 2267 2268 // Okay, we successfully defined 'Record'. 2269 if (Record) { 2270 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2271 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2272 // Sema::ActOnFinishCXXClassDef. 2273 if (!isa<CXXRecordDecl>(Record)) 2274 Consumer.HandleTagDeclDefinition(Record); 2275 } else { 2276 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2277 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2278 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2279 else if (ObjCImplementationDecl *IMPDecl = 2280 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2281 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2282 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2283 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2284 } 2285 } 2286 2287 if (Attr) 2288 ProcessDeclAttributeList(Record, Attr); 2289} 2290 2291Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2292 DeclTy *lastEnumConst, 2293 SourceLocation IdLoc, IdentifierInfo *Id, 2294 SourceLocation EqualLoc, ExprTy *val) { 2295 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2296 EnumConstantDecl *LastEnumConst = 2297 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2298 Expr *Val = static_cast<Expr*>(val); 2299 2300 // The scope passed in may not be a decl scope. Zip up the scope tree until 2301 // we find one that is. 2302 while ((S->getFlags() & Scope::DeclScope) == 0) 2303 S = S->getParent(); 2304 2305 // Verify that there isn't already something declared with this name in this 2306 // scope. 2307 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2308 // When in C++, we may get a TagDecl with the same name; in this case the 2309 // enum constant will 'hide' the tag. 2310 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2311 "Received TagDecl when not in C++!"); 2312 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2313 if (isa<EnumConstantDecl>(PrevDecl)) 2314 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2315 else 2316 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2317 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2318 delete Val; 2319 return 0; 2320 } 2321 } 2322 2323 llvm::APSInt EnumVal(32); 2324 QualType EltTy; 2325 if (Val) { 2326 // Make sure to promote the operand type to int. 2327 UsualUnaryConversions(Val); 2328 2329 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2330 SourceLocation ExpLoc; 2331 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2332 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2333 Id->getName()); 2334 delete Val; 2335 Val = 0; // Just forget about it. 2336 } else { 2337 EltTy = Val->getType(); 2338 } 2339 } 2340 2341 if (!Val) { 2342 if (LastEnumConst) { 2343 // Assign the last value + 1. 2344 EnumVal = LastEnumConst->getInitVal(); 2345 ++EnumVal; 2346 2347 // Check for overflow on increment. 2348 if (EnumVal < LastEnumConst->getInitVal()) 2349 Diag(IdLoc, diag::warn_enum_value_overflow); 2350 2351 EltTy = LastEnumConst->getType(); 2352 } else { 2353 // First value, set to zero. 2354 EltTy = Context.IntTy; 2355 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2356 } 2357 } 2358 2359 EnumConstantDecl *New = 2360 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2361 Val, EnumVal, 2362 LastEnumConst); 2363 2364 // Register this decl in the current scope stack. 2365 PushOnScopeChains(New, S); 2366 return New; 2367} 2368 2369// FIXME: For consistency with ActOnFields(), we should have the parser 2370// pass in the source location for the left/right braces. 2371void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2372 DeclTy **Elements, unsigned NumElements) { 2373 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2374 2375 if (Enum && Enum->isDefinition()) { 2376 // Diagnose code like: 2377 // enum e0 { 2378 // E0 = sizeof(enum e0 { E1 }) 2379 // }; 2380 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2381 Enum->getName()); 2382 Diag(EnumLoc, diag::err_previous_definition); 2383 Enum->setInvalidDecl(); 2384 return; 2385 } 2386 // TODO: If the result value doesn't fit in an int, it must be a long or long 2387 // long value. ISO C does not support this, but GCC does as an extension, 2388 // emit a warning. 2389 unsigned IntWidth = Context.Target.getIntWidth(); 2390 2391 // Verify that all the values are okay, compute the size of the values, and 2392 // reverse the list. 2393 unsigned NumNegativeBits = 0; 2394 unsigned NumPositiveBits = 0; 2395 2396 // Keep track of whether all elements have type int. 2397 bool AllElementsInt = true; 2398 2399 EnumConstantDecl *EltList = 0; 2400 for (unsigned i = 0; i != NumElements; ++i) { 2401 EnumConstantDecl *ECD = 2402 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2403 if (!ECD) continue; // Already issued a diagnostic. 2404 2405 // If the enum value doesn't fit in an int, emit an extension warning. 2406 const llvm::APSInt &InitVal = ECD->getInitVal(); 2407 assert(InitVal.getBitWidth() >= IntWidth && 2408 "Should have promoted value to int"); 2409 if (InitVal.getBitWidth() > IntWidth) { 2410 llvm::APSInt V(InitVal); 2411 V.trunc(IntWidth); 2412 V.extend(InitVal.getBitWidth()); 2413 if (V != InitVal) 2414 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2415 InitVal.toString(10)); 2416 } 2417 2418 // Keep track of the size of positive and negative values. 2419 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2420 NumPositiveBits = std::max(NumPositiveBits, 2421 (unsigned)InitVal.getActiveBits()); 2422 else 2423 NumNegativeBits = std::max(NumNegativeBits, 2424 (unsigned)InitVal.getMinSignedBits()); 2425 2426 // Keep track of whether every enum element has type int (very commmon). 2427 if (AllElementsInt) 2428 AllElementsInt = ECD->getType() == Context.IntTy; 2429 2430 ECD->setNextDeclarator(EltList); 2431 EltList = ECD; 2432 } 2433 2434 // Figure out the type that should be used for this enum. 2435 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2436 QualType BestType; 2437 unsigned BestWidth; 2438 2439 if (NumNegativeBits) { 2440 // If there is a negative value, figure out the smallest integer type (of 2441 // int/long/longlong) that fits. 2442 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2443 BestType = Context.IntTy; 2444 BestWidth = IntWidth; 2445 } else { 2446 BestWidth = Context.Target.getLongWidth(); 2447 2448 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2449 BestType = Context.LongTy; 2450 else { 2451 BestWidth = Context.Target.getLongLongWidth(); 2452 2453 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2454 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2455 BestType = Context.LongLongTy; 2456 } 2457 } 2458 } else { 2459 // If there is no negative value, figure out which of uint, ulong, ulonglong 2460 // fits. 2461 if (NumPositiveBits <= IntWidth) { 2462 BestType = Context.UnsignedIntTy; 2463 BestWidth = IntWidth; 2464 } else if (NumPositiveBits <= 2465 (BestWidth = Context.Target.getLongWidth())) { 2466 BestType = Context.UnsignedLongTy; 2467 } else { 2468 BestWidth = Context.Target.getLongLongWidth(); 2469 assert(NumPositiveBits <= BestWidth && 2470 "How could an initializer get larger than ULL?"); 2471 BestType = Context.UnsignedLongLongTy; 2472 } 2473 } 2474 2475 // Loop over all of the enumerator constants, changing their types to match 2476 // the type of the enum if needed. 2477 for (unsigned i = 0; i != NumElements; ++i) { 2478 EnumConstantDecl *ECD = 2479 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2480 if (!ECD) continue; // Already issued a diagnostic. 2481 2482 // Standard C says the enumerators have int type, but we allow, as an 2483 // extension, the enumerators to be larger than int size. If each 2484 // enumerator value fits in an int, type it as an int, otherwise type it the 2485 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2486 // that X has type 'int', not 'unsigned'. 2487 if (ECD->getType() == Context.IntTy) { 2488 // Make sure the init value is signed. 2489 llvm::APSInt IV = ECD->getInitVal(); 2490 IV.setIsSigned(true); 2491 ECD->setInitVal(IV); 2492 continue; // Already int type. 2493 } 2494 2495 // Determine whether the value fits into an int. 2496 llvm::APSInt InitVal = ECD->getInitVal(); 2497 bool FitsInInt; 2498 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2499 FitsInInt = InitVal.getActiveBits() < IntWidth; 2500 else 2501 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2502 2503 // If it fits into an integer type, force it. Otherwise force it to match 2504 // the enum decl type. 2505 QualType NewTy; 2506 unsigned NewWidth; 2507 bool NewSign; 2508 if (FitsInInt) { 2509 NewTy = Context.IntTy; 2510 NewWidth = IntWidth; 2511 NewSign = true; 2512 } else if (ECD->getType() == BestType) { 2513 // Already the right type! 2514 continue; 2515 } else { 2516 NewTy = BestType; 2517 NewWidth = BestWidth; 2518 NewSign = BestType->isSignedIntegerType(); 2519 } 2520 2521 // Adjust the APSInt value. 2522 InitVal.extOrTrunc(NewWidth); 2523 InitVal.setIsSigned(NewSign); 2524 ECD->setInitVal(InitVal); 2525 2526 // Adjust the Expr initializer and type. 2527 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2528 ECD->setType(NewTy); 2529 } 2530 2531 Enum->defineElements(EltList, BestType); 2532 Consumer.HandleTagDeclDefinition(Enum); 2533} 2534 2535Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2536 ExprTy *expr) { 2537 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2538 2539 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2540} 2541 2542Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2543 SourceLocation LBrace, 2544 SourceLocation RBrace, 2545 const char *Lang, 2546 unsigned StrSize, 2547 DeclTy *D) { 2548 LinkageSpecDecl::LanguageIDs Language; 2549 Decl *dcl = static_cast<Decl *>(D); 2550 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2551 Language = LinkageSpecDecl::lang_c; 2552 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2553 Language = LinkageSpecDecl::lang_cxx; 2554 else { 2555 Diag(Loc, diag::err_bad_language); 2556 return 0; 2557 } 2558 2559 // FIXME: Add all the various semantics of linkage specifications 2560 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2561} 2562