SemaDecl.cpp revision 1bfe1c2129771c06fb58ae5e8c079ae30e138309
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 const ParenExpr* PE = cast<ParenExpr>(Init); 877 return CheckAddressConstantExpression(PE->getSubExpr()); 878 } 879 case Expr::StringLiteralClass: 880 case Expr::ObjCStringLiteralClass: 881 return false; 882 case Expr::CallExprClass: { 883 const CallExpr *CE = cast<CallExpr>(Init); 884 if (CE->isBuiltinConstantExpr(Context)) 885 return false; 886 Diag(Init->getExprLoc(), 887 diag::err_init_element_not_constant, Init->getSourceRange()); 888 return true; 889 } 890 case Expr::UnaryOperatorClass: { 891 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 892 893 // C99 6.6p9 894 if (Exp->getOpcode() == UnaryOperator::AddrOf) 895 return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); 896 897 if (Exp->getOpcode() == UnaryOperator::Extension) 898 return CheckAddressConstantExpression(Exp->getSubExpr()); 899 900 Diag(Init->getExprLoc(), 901 diag::err_init_element_not_constant, Init->getSourceRange()); 902 return true; 903 } 904 case Expr::BinaryOperatorClass: { 905 // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? 906 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 907 908 Expr *PExp = Exp->getLHS(); 909 Expr *IExp = Exp->getRHS(); 910 if (IExp->getType()->isPointerType()) 911 std::swap(PExp, IExp); 912 913 // FIXME: Should we pedwarn if IExp isn't an integer constant expression? 914 return CheckAddressConstantExpression(PExp) || 915 CheckArithmeticConstantExpression(IExp); 916 } 917 case Expr::ImplicitCastExprClass: 918 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 if (CE->isBuiltinConstantExpr(Context)) 1084 return false; 1085 Diag(Init->getExprLoc(), 1086 diag::err_init_element_not_constant, Init->getSourceRange()); 1087 return true; 1088 } 1089 case Expr::DeclRefExprClass: { 1090 const Decl *D = cast<DeclRefExpr>(Init)->getDecl(); 1091 if (isa<EnumConstantDecl>(D)) 1092 return false; 1093 Diag(Init->getExprLoc(), 1094 diag::err_init_element_not_constant, Init->getSourceRange()); 1095 return true; 1096 } 1097 case Expr::CompoundLiteralExprClass: 1098 // Allow "(vector type){2,4}"; normal C constraints don't allow this, 1099 // but vectors are allowed to be magic. 1100 if (Init->getType()->isVectorType()) 1101 return false; 1102 Diag(Init->getExprLoc(), 1103 diag::err_init_element_not_constant, Init->getSourceRange()); 1104 return true; 1105 case Expr::UnaryOperatorClass: { 1106 const UnaryOperator *Exp = cast<UnaryOperator>(Init); 1107 1108 switch (Exp->getOpcode()) { 1109 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. 1110 // See C99 6.6p3. 1111 default: 1112 Diag(Init->getExprLoc(), 1113 diag::err_init_element_not_constant, Init->getSourceRange()); 1114 return true; 1115 case UnaryOperator::SizeOf: 1116 case UnaryOperator::AlignOf: 1117 case UnaryOperator::OffsetOf: 1118 // sizeof(E) is a constantexpr if and only if E is not evaluted. 1119 // See C99 6.5.3.4p2 and 6.6p3. 1120 if (Exp->getSubExpr()->getType()->isConstantSizeType()) 1121 return false; 1122 Diag(Init->getExprLoc(), 1123 diag::err_init_element_not_constant, Init->getSourceRange()); 1124 return true; 1125 case UnaryOperator::Extension: 1126 case UnaryOperator::LNot: 1127 case UnaryOperator::Plus: 1128 case UnaryOperator::Minus: 1129 case UnaryOperator::Not: 1130 return CheckArithmeticConstantExpression(Exp->getSubExpr()); 1131 } 1132 } 1133 case Expr::SizeOfAlignOfTypeExprClass: { 1134 const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init); 1135 // Special check for void types, which are allowed as an extension 1136 if (Exp->getArgumentType()->isVoidType()) 1137 return false; 1138 // alignof always evaluates to a constant. 1139 // FIXME: is sizeof(int[3.0]) a constant expression? 1140 if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { 1141 Diag(Init->getExprLoc(), 1142 diag::err_init_element_not_constant, Init->getSourceRange()); 1143 return true; 1144 } 1145 return false; 1146 } 1147 case Expr::BinaryOperatorClass: { 1148 const BinaryOperator *Exp = cast<BinaryOperator>(Init); 1149 1150 if (Exp->getLHS()->getType()->isArithmeticType() && 1151 Exp->getRHS()->getType()->isArithmeticType()) { 1152 return CheckArithmeticConstantExpression(Exp->getLHS()) || 1153 CheckArithmeticConstantExpression(Exp->getRHS()); 1154 } 1155 1156 if (Exp->getLHS()->getType()->isPointerType() && 1157 Exp->getRHS()->getType()->isPointerType()) { 1158 const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); 1159 const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); 1160 1161 // Only allow a null (constant integer) base; we could 1162 // allow some additional cases if necessary, but this 1163 // is sufficient to cover offsetof-like constructs. 1164 if (!LHSBase && !RHSBase) { 1165 return CheckAddressConstantExpression(Exp->getLHS()) || 1166 CheckAddressConstantExpression(Exp->getRHS()); 1167 } 1168 } 1169 1170 Diag(Init->getExprLoc(), 1171 diag::err_init_element_not_constant, Init->getSourceRange()); 1172 return true; 1173 } 1174 case Expr::ImplicitCastExprClass: 1175 case Expr::ExplicitCastExprClass: { 1176 const Expr *SubExpr = cast<CastExpr>(Init)->getSubExpr(); 1177 if (SubExpr->getType()->isArithmeticType()) 1178 return CheckArithmeticConstantExpression(SubExpr); 1179 1180 if (SubExpr->getType()->isPointerType()) { 1181 const Expr* Base = FindExpressionBaseAddress(SubExpr); 1182 // If the pointer has a null base, this is an offsetof-like construct 1183 if (!Base) 1184 return CheckAddressConstantExpression(SubExpr); 1185 } 1186 1187 Diag(Init->getExprLoc(), 1188 diag::err_init_element_not_constant, Init->getSourceRange()); 1189 return true; 1190 } 1191 case Expr::ConditionalOperatorClass: { 1192 const ConditionalOperator *Exp = cast<ConditionalOperator>(Init); 1193 if (CheckArithmeticConstantExpression(Exp->getCond())) 1194 return true; 1195 if (Exp->getLHS() && 1196 CheckArithmeticConstantExpression(Exp->getLHS())) 1197 return true; 1198 return CheckArithmeticConstantExpression(Exp->getRHS()); 1199 } 1200 } 1201} 1202 1203bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 1204 Init = Init->IgnoreParens(); 1205 1206 // Look through CXXDefaultArgExprs; they have no meaning in this context. 1207 if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init)) 1208 return CheckForConstantInitializer(DAE->getExpr(), DclT); 1209 1210 if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init)) 1211 return CheckForConstantInitializer(e->getInitializer(), DclT); 1212 1213 if (Init->getType()->isReferenceType()) { 1214 // FIXME: Work out how the heck reference types work 1215 return false; 1216#if 0 1217 // A reference is constant if the address of the expression 1218 // is constant 1219 // We look through initlists here to simplify 1220 // CheckAddressConstantExpressionLValue. 1221 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1222 assert(Exp->getNumInits() > 0 && 1223 "Refernce initializer cannot be empty"); 1224 Init = Exp->getInit(0); 1225 } 1226 return CheckAddressConstantExpressionLValue(Init); 1227#endif 1228 } 1229 1230 if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) { 1231 unsigned numInits = Exp->getNumInits(); 1232 for (unsigned i = 0; i < numInits; i++) { 1233 // FIXME: Need to get the type of the declaration for C++, 1234 // because it could be a reference? 1235 if (CheckForConstantInitializer(Exp->getInit(i), 1236 Exp->getInit(i)->getType())) 1237 return true; 1238 } 1239 return false; 1240 } 1241 1242 if (Init->isNullPointerConstant(Context)) 1243 return false; 1244 if (Init->getType()->isArithmeticType()) { 1245 QualType InitTy = Context.getCanonicalType(Init->getType()) 1246 .getUnqualifiedType(); 1247 if (InitTy == Context.BoolTy) { 1248 // Special handling for pointers implicitly cast to bool; 1249 // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. 1250 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) { 1251 Expr* SubE = ICE->getSubExpr(); 1252 if (SubE->getType()->isPointerType() || 1253 SubE->getType()->isArrayType() || 1254 SubE->getType()->isFunctionType()) { 1255 return CheckAddressConstantExpression(Init); 1256 } 1257 } 1258 } else if (InitTy->isIntegralType()) { 1259 Expr* SubE = 0; 1260 if (CastExpr* CE = dyn_cast<CastExpr>(Init)) 1261 SubE = CE->getSubExpr(); 1262 // Special check for pointer cast to int; we allow as an extension 1263 // an address constant cast to an integer if the integer 1264 // is of an appropriate width (this sort of code is apparently used 1265 // in some places). 1266 // FIXME: Add pedwarn? 1267 // FIXME: Don't allow bitfields here! Need the FieldDecl for that. 1268 if (SubE && (SubE->getType()->isPointerType() || 1269 SubE->getType()->isArrayType() || 1270 SubE->getType()->isFunctionType())) { 1271 unsigned IntWidth = Context.getTypeSize(Init->getType()); 1272 unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); 1273 if (IntWidth >= PointerWidth) 1274 return CheckAddressConstantExpression(Init); 1275 } 1276 } 1277 1278 return CheckArithmeticConstantExpression(Init); 1279 } 1280 1281 if (Init->getType()->isPointerType()) 1282 return CheckAddressConstantExpression(Init); 1283 1284 // An array type at the top level that isn't an init-list must 1285 // be a string literal 1286 if (Init->getType()->isArrayType()) 1287 return false; 1288 1289 if (Init->getType()->isFunctionType()) 1290 return false; 1291 1292 // Allow block exprs at top level. 1293 if (Init->getType()->isBlockPointerType()) 1294 return false; 1295 1296 Diag(Init->getExprLoc(), diag::err_init_element_not_constant, 1297 Init->getSourceRange()); 1298 return true; 1299} 1300 1301void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { 1302 Decl *RealDecl = static_cast<Decl *>(dcl); 1303 Expr *Init = static_cast<Expr *>(init); 1304 assert(Init && "missing initializer"); 1305 1306 // If there is no declaration, there was an error parsing it. Just ignore 1307 // the initializer. 1308 if (RealDecl == 0) { 1309 delete Init; 1310 return; 1311 } 1312 1313 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 1314 if (!VDecl) { 1315 Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(), 1316 diag::err_illegal_initializer); 1317 RealDecl->setInvalidDecl(); 1318 return; 1319 } 1320 // Get the decls type and save a reference for later, since 1321 // CheckInitializerTypes may change it. 1322 QualType DclT = VDecl->getType(), SavT = DclT; 1323 if (VDecl->isBlockVarDecl()) { 1324 VarDecl::StorageClass SC = VDecl->getStorageClass(); 1325 if (SC == VarDecl::Extern) { // C99 6.7.8p5 1326 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 1327 VDecl->setInvalidDecl(); 1328 } else if (!VDecl->isInvalidDecl()) { 1329 if (CheckInitializerTypes(Init, DclT)) 1330 VDecl->setInvalidDecl(); 1331 1332 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1333 if (!getLangOptions().CPlusPlus) { 1334 if (SC == VarDecl::Static) // C99 6.7.8p4. 1335 CheckForConstantInitializer(Init, DclT); 1336 } 1337 } 1338 } else if (VDecl->isFileVarDecl()) { 1339 if (VDecl->getStorageClass() == VarDecl::Extern) 1340 Diag(VDecl->getLocation(), diag::warn_extern_init); 1341 if (!VDecl->isInvalidDecl()) 1342 if (CheckInitializerTypes(Init, DclT)) 1343 VDecl->setInvalidDecl(); 1344 1345 // C++ 3.6.2p2, allow dynamic initialization of static initializers. 1346 if (!getLangOptions().CPlusPlus) { 1347 // C99 6.7.8p4. All file scoped initializers need to be constant. 1348 CheckForConstantInitializer(Init, DclT); 1349 } 1350 } 1351 // If the type changed, it means we had an incomplete type that was 1352 // completed by the initializer. For example: 1353 // int ary[] = { 1, 3, 5 }; 1354 // "ary" transitions from a VariableArrayType to a ConstantArrayType. 1355 if (!VDecl->isInvalidDecl() && (DclT != SavT)) { 1356 VDecl->setType(DclT); 1357 Init->setType(DclT); 1358 } 1359 1360 // Attach the initializer to the decl. 1361 VDecl->setInit(Init); 1362 return; 1363} 1364 1365/// The declarators are chained together backwards, reverse the list. 1366Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { 1367 // Often we have single declarators, handle them quickly. 1368 Decl *GroupDecl = static_cast<Decl*>(group); 1369 if (GroupDecl == 0) 1370 return 0; 1371 1372 ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl); 1373 ScopedDecl *NewGroup = 0; 1374 if (Group->getNextDeclarator() == 0) 1375 NewGroup = Group; 1376 else { // reverse the list. 1377 while (Group) { 1378 ScopedDecl *Next = Group->getNextDeclarator(); 1379 Group->setNextDeclarator(NewGroup); 1380 NewGroup = Group; 1381 Group = Next; 1382 } 1383 } 1384 // Perform semantic analysis that depends on having fully processed both 1385 // the declarator and initializer. 1386 for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { 1387 VarDecl *IDecl = dyn_cast<VarDecl>(ID); 1388 if (!IDecl) 1389 continue; 1390 QualType T = IDecl->getType(); 1391 1392 // C99 6.7.5.2p2: If an identifier is declared to be an object with 1393 // static storage duration, it shall not have a variable length array. 1394 if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && 1395 IDecl->getStorageClass() == VarDecl::Static) { 1396 if (T->isVariableArrayType()) { 1397 Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); 1398 IDecl->setInvalidDecl(); 1399 } 1400 } 1401 // Block scope. C99 6.7p7: If an identifier for an object is declared with 1402 // no linkage (C99 6.2.2p6), the type for the object shall be complete... 1403 if (IDecl->isBlockVarDecl() && 1404 IDecl->getStorageClass() != VarDecl::Extern) { 1405 if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1406 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1407 T.getAsString()); 1408 IDecl->setInvalidDecl(); 1409 } 1410 } 1411 // File scope. C99 6.9.2p2: A declaration of an identifier for and 1412 // object that has file scope without an initializer, and without a 1413 // storage-class specifier or with the storage-class specifier "static", 1414 // constitutes a tentative definition. Note: A tentative definition with 1415 // external linkage is valid (C99 6.2.2p5). 1416 if (isTentativeDefinition(IDecl)) { 1417 if (T->isIncompleteArrayType()) { 1418 // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete 1419 // array to be completed. Don't issue a diagnostic. 1420 } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { 1421 // C99 6.9.2p3: If the declaration of an identifier for an object is 1422 // a tentative definition and has internal linkage (C99 6.2.2p3), the 1423 // declared type shall not be an incomplete type. 1424 Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, 1425 T.getAsString()); 1426 IDecl->setInvalidDecl(); 1427 } 1428 } 1429 if (IDecl->isFileVarDecl()) 1430 CheckForFileScopedRedefinitions(S, IDecl); 1431 } 1432 return NewGroup; 1433} 1434 1435/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 1436/// to introduce parameters into function prototype scope. 1437Sema::DeclTy * 1438Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 1439 const DeclSpec &DS = D.getDeclSpec(); 1440 1441 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 1442 VarDecl::StorageClass StorageClass = VarDecl::None; 1443 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 1444 StorageClass = VarDecl::Register; 1445 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 1446 Diag(DS.getStorageClassSpecLoc(), 1447 diag::err_invalid_storage_class_in_func_decl); 1448 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1449 } 1450 if (DS.isThreadSpecified()) { 1451 Diag(DS.getThreadSpecLoc(), 1452 diag::err_invalid_storage_class_in_func_decl); 1453 D.getMutableDeclSpec().ClearStorageClassSpecs(); 1454 } 1455 1456 // Check that there are no default arguments inside the type of this 1457 // parameter (C++ only). 1458 if (getLangOptions().CPlusPlus) 1459 CheckExtraCXXDefaultArguments(D); 1460 1461 // In this context, we *do not* check D.getInvalidType(). If the declarator 1462 // type was invalid, GetTypeForDeclarator() still returns a "valid" type, 1463 // though it will not reflect the user specified type. 1464 QualType parmDeclType = GetTypeForDeclarator(D, S); 1465 1466 assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); 1467 1468 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. 1469 // Can this happen for params? We already checked that they don't conflict 1470 // among each other. Here they can only shadow globals, which is ok. 1471 IdentifierInfo *II = D.getIdentifier(); 1472 if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { 1473 if (S->isDeclScope(PrevDecl)) { 1474 Diag(D.getIdentifierLoc(), diag::err_param_redefinition, 1475 dyn_cast<NamedDecl>(PrevDecl)->getName()); 1476 1477 // Recover by removing the name 1478 II = 0; 1479 D.SetIdentifier(0, D.getIdentifierLoc()); 1480 } 1481 } 1482 1483 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). 1484 // Doing the promotion here has a win and a loss. The win is the type for 1485 // both Decl's and DeclRefExpr's will match (a convenient invariant for the 1486 // code generator). The loss is the orginal type isn't preserved. For example: 1487 // 1488 // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" 1489 // int blockvardecl[5]; 1490 // sizeof(parmvardecl); // size == 4 1491 // sizeof(blockvardecl); // size == 20 1492 // } 1493 // 1494 // For expressions, all implicit conversions are captured using the 1495 // ImplicitCastExpr AST node (we have no such mechanism for Decl's). 1496 // 1497 // FIXME: If a source translation tool needs to see the original type, then 1498 // we need to consider storing both types (in ParmVarDecl)... 1499 // 1500 if (parmDeclType->isArrayType()) { 1501 // int x[restrict 4] -> int *restrict 1502 parmDeclType = Context.getArrayDecayedType(parmDeclType); 1503 } else if (parmDeclType->isFunctionType()) 1504 parmDeclType = Context.getPointerType(parmDeclType); 1505 1506 ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, 1507 D.getIdentifierLoc(), II, 1508 parmDeclType, StorageClass, 1509 0, 0); 1510 1511 if (D.getInvalidType()) 1512 New->setInvalidDecl(); 1513 1514 if (II) 1515 PushOnScopeChains(New, S); 1516 1517 ProcessDeclAttributes(New, D); 1518 return New; 1519 1520} 1521 1522Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { 1523 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 1524 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 1525 "Not a function declarator!"); 1526 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 1527 1528 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 1529 // for a K&R function. 1530 if (!FTI.hasPrototype) { 1531 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 1532 if (FTI.ArgInfo[i].Param == 0) { 1533 Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, 1534 FTI.ArgInfo[i].Ident->getName()); 1535 // Implicitly declare the argument as type 'int' for lack of a better 1536 // type. 1537 DeclSpec DS; 1538 const char* PrevSpec; // unused 1539 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, 1540 PrevSpec); 1541 Declarator ParamD(DS, Declarator::KNRTypeListContext); 1542 ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); 1543 FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); 1544 } 1545 } 1546 } else { 1547 // FIXME: Diagnose arguments without names in C. 1548 } 1549 1550 Scope *GlobalScope = FnBodyScope->getParent(); 1551 1552 // See if this is a redefinition. 1553 Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, 1554 GlobalScope); 1555 if (PrevDcl && isDeclInScope(PrevDcl, CurContext)) { 1556 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) { 1557 const FunctionDecl *Definition; 1558 if (FD->getBody(Definition)) { 1559 Diag(D.getIdentifierLoc(), diag::err_redefinition, 1560 D.getIdentifier()->getName()); 1561 Diag(Definition->getLocation(), diag::err_previous_definition); 1562 } 1563 } 1564 } 1565 1566 return ActOnStartOfFunctionDef(FnBodyScope, 1567 ActOnDeclarator(GlobalScope, D, 0)); 1568} 1569 1570Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { 1571 Decl *decl = static_cast<Decl*>(D); 1572 FunctionDecl *FD = cast<FunctionDecl>(decl); 1573 PushDeclContext(FD); 1574 1575 // Check the validity of our function parameters 1576 CheckParmsForFunctionDef(FD); 1577 1578 // Introduce our parameters into the function scope 1579 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 1580 ParmVarDecl *Param = FD->getParamDecl(p); 1581 // If this has an identifier, add it to the scope stack. 1582 if (Param->getIdentifier()) 1583 PushOnScopeChains(Param, FnBodyScope); 1584 } 1585 1586 return FD; 1587} 1588 1589Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { 1590 Decl *dcl = static_cast<Decl *>(D); 1591 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) { 1592 FD->setBody((Stmt*)Body); 1593 assert(FD == getCurFunctionDecl() && "Function parsing confused"); 1594 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 1595 MD->setBody((Stmt*)Body); 1596 } else 1597 return 0; 1598 PopDeclContext(); 1599 // Verify and clean out per-function state. 1600 1601 // Check goto/label use. 1602 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 1603 I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { 1604 // Verify that we have no forward references left. If so, there was a goto 1605 // or address of a label taken, but no definition of it. Label fwd 1606 // definitions are indicated with a null substmt. 1607 if (I->second->getSubStmt() == 0) { 1608 LabelStmt *L = I->second; 1609 // Emit error. 1610 Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); 1611 1612 // At this point, we have gotos that use the bogus label. Stitch it into 1613 // the function body so that they aren't leaked and that the AST is well 1614 // formed. 1615 if (Body) { 1616 L->setSubStmt(new NullStmt(L->getIdentLoc())); 1617 cast<CompoundStmt>((Stmt*)Body)->push_back(L); 1618 } else { 1619 // The whole function wasn't parsed correctly, just delete this. 1620 delete L; 1621 } 1622 } 1623 } 1624 LabelMap.clear(); 1625 1626 return D; 1627} 1628 1629/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 1630/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 1631ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 1632 IdentifierInfo &II, Scope *S) { 1633 // Extension in C99. Legal in C90, but warn about it. 1634 if (getLangOptions().C99) 1635 Diag(Loc, diag::ext_implicit_function_decl, II.getName()); 1636 else 1637 Diag(Loc, diag::warn_implicit_function_decl, II.getName()); 1638 1639 // FIXME: handle stuff like: 1640 // void foo() { extern float X(); } 1641 // void bar() { X(); } <-- implicit decl for X in another scope. 1642 1643 // Set a Declarator for the implicit definition: int foo(); 1644 const char *Dummy; 1645 DeclSpec DS; 1646 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); 1647 Error = Error; // Silence warning. 1648 assert(!Error && "Error setting up implicit decl!"); 1649 Declarator D(DS, Declarator::BlockContext); 1650 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); 1651 D.SetIdentifier(&II, Loc); 1652 1653 // Insert this function into translation-unit scope. 1654 1655 DeclContext *PrevDC = CurContext; 1656 CurContext = Context.getTranslationUnitDecl(); 1657 1658 FunctionDecl *FD = 1659 dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0))); 1660 FD->setImplicit(); 1661 1662 CurContext = PrevDC; 1663 1664 return FD; 1665} 1666 1667 1668TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 1669 ScopedDecl *LastDeclarator) { 1670 assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); 1671 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 1672 1673 // Scope manipulation handled by caller. 1674 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, 1675 D.getIdentifierLoc(), 1676 D.getIdentifier(), 1677 T, LastDeclarator); 1678 if (D.getInvalidType()) 1679 NewTD->setInvalidDecl(); 1680 return NewTD; 1681} 1682 1683/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the 1684/// former case, Name will be non-null. In the later case, Name will be null. 1685/// TagType indicates what kind of tag this is. TK indicates whether this is a 1686/// reference/declaration/definition of a tag. 1687Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, 1688 SourceLocation KWLoc, IdentifierInfo *Name, 1689 SourceLocation NameLoc, AttributeList *Attr) { 1690 // If this is a use of an existing tag, it must have a name. 1691 assert((Name != 0 || TK == TK_Definition) && 1692 "Nameless record must be a definition!"); 1693 1694 TagDecl::TagKind Kind; 1695 switch (TagType) { 1696 default: assert(0 && "Unknown tag type!"); 1697 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 1698 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 1699 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 1700 case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; 1701 } 1702 1703 // Two code paths: a new one for structs/unions/classes where we create 1704 // separate decls for forward declarations, and an old (eventually to 1705 // be removed) code path for enums. 1706 if (Kind != TagDecl::TK_enum) 1707 return ActOnTagStruct(S, Kind, TK, KWLoc, Name, NameLoc, Attr); 1708 1709 // If this is a named struct, check to see if there was a previous forward 1710 // declaration or definition. 1711 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1712 ScopedDecl *PrevDecl = 1713 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S)); 1714 1715 if (PrevDecl) { 1716 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1717 "unexpected Decl type"); 1718 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1719 // If this is a use of a previous tag, or if the tag is already declared 1720 // in the same scope (so that the definition/declaration completes or 1721 // rementions the tag), reuse the decl. 1722 if (TK == TK_Reference || isDeclInScope(PrevDecl, CurContext, S)) { 1723 // Make sure that this wasn't declared as an enum and now used as a 1724 // struct or something similar. 1725 if (PrevTagDecl->getTagKind() != Kind) { 1726 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1727 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1728 // Recover by making this an anonymous redefinition. 1729 Name = 0; 1730 PrevDecl = 0; 1731 } else { 1732 // If this is a use or a forward declaration, we're good. 1733 if (TK != TK_Definition) 1734 return PrevDecl; 1735 1736 // Diagnose attempts to redefine a tag. 1737 if (PrevTagDecl->isDefinition()) { 1738 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1739 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1740 // If this is a redefinition, recover by making this struct be 1741 // anonymous, which will make any later references get the previous 1742 // definition. 1743 Name = 0; 1744 } else { 1745 // Okay, this is definition of a previously declared or referenced 1746 // tag. Move the location of the decl to be the definition site. 1747 PrevDecl->setLocation(NameLoc); 1748 return PrevDecl; 1749 } 1750 } 1751 } 1752 // If we get here, this is a definition of a new struct type in a nested 1753 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new 1754 // type. 1755 } else { 1756 // PrevDecl is a namespace. 1757 if (isDeclInScope(PrevDecl, CurContext, S)) { 1758 // The tag name clashes with a namespace name, issue an error and 1759 // recover by making this tag be anonymous. 1760 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1761 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1762 Name = 0; 1763 } 1764 } 1765 } 1766 1767 // If there is an identifier, use the location of the identifier as the 1768 // location of the decl, otherwise use the location of the struct/union 1769 // keyword. 1770 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1771 1772 // Otherwise, if this is the first time we've seen this tag, create the decl. 1773 TagDecl *New; 1774 if (Kind == TagDecl::TK_enum) { 1775 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1776 // enum X { A, B, C } D; D should chain to X. 1777 New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); 1778 // If this is an undefined enum, warn. 1779 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); 1780 } else { 1781 // struct/union/class 1782 1783 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1784 // struct X { int A; } D; D should chain to X. 1785 if (getLangOptions().CPlusPlus) 1786 // FIXME: Look for a way to use RecordDecl for simple structs. 1787 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name); 1788 else 1789 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name); 1790 } 1791 1792 // If this has an identifier, add it to the scope stack. 1793 if (Name) { 1794 // The scope passed in may not be a decl scope. Zip up the scope tree until 1795 // we find one that is. 1796 while ((S->getFlags() & Scope::DeclScope) == 0) 1797 S = S->getParent(); 1798 1799 // Add it to the decl chain. 1800 PushOnScopeChains(New, S); 1801 } 1802 1803 if (Attr) 1804 ProcessDeclAttributeList(New, Attr); 1805 return New; 1806} 1807 1808/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike 1809/// the logic for enums, we create separate decls for forward declarations. 1810/// This is called by ActOnTag, but eventually will replace its logic. 1811Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, 1812 SourceLocation KWLoc, IdentifierInfo *Name, 1813 SourceLocation NameLoc, AttributeList *Attr) { 1814 1815 // If this is a named struct, check to see if there was a previous forward 1816 // declaration or definition. 1817 // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. 1818 ScopedDecl *PrevDecl = 1819 dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S)); 1820 1821 if (PrevDecl) { 1822 assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) && 1823 "unexpected Decl type"); 1824 1825 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 1826 // If this is a use of a previous tag, or if the tag is already declared 1827 // in the same scope (so that the definition/declaration completes or 1828 // rementions the tag), reuse the decl. 1829 if (TK == TK_Reference || isDeclInScope(PrevDecl, CurContext, S)) { 1830 // Make sure that this wasn't declared as an enum and now used as a 1831 // struct or something similar. 1832 if (PrevTagDecl->getTagKind() != Kind) { 1833 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); 1834 Diag(PrevDecl->getLocation(), diag::err_previous_use); 1835 // Recover by making this an anonymous redefinition. 1836 Name = 0; 1837 PrevDecl = 0; 1838 } else { 1839 // If this is a use, return the original decl. 1840 1841 // FIXME: In the future, return a variant or some other clue 1842 // for the consumer of this Decl to know it doesn't own it. 1843 // For our current ASTs this shouldn't be a problem, but will 1844 // need to be changed with DeclGroups. 1845 if (TK == TK_Reference) 1846 return PrevDecl; 1847 1848 // The new decl is a definition? 1849 if (TK == TK_Definition) { 1850 // Diagnose attempts to redefine a tag. 1851 if (RecordDecl* DefRecord = 1852 cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) { 1853 Diag(NameLoc, diag::err_redefinition, Name->getName()); 1854 Diag(DefRecord->getLocation(), diag::err_previous_definition); 1855 // If this is a redefinition, recover by making this struct be 1856 // anonymous, which will make any later references get the previous 1857 // definition. 1858 Name = 0; 1859 PrevDecl = 0; 1860 } 1861 // Okay, this is definition of a previously declared or referenced 1862 // tag. We're going to create a new Decl. 1863 } 1864 } 1865 // If we get here we have (another) forward declaration. Just create 1866 // a new decl. 1867 } 1868 else { 1869 // If we get here, this is a definition of a new struct type in a nested 1870 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 1871 // new decl/type. We set PrevDecl to NULL so that the Records 1872 // have distinct types. 1873 PrevDecl = 0; 1874 } 1875 } else { 1876 // PrevDecl is a namespace. 1877 if (isDeclInScope(PrevDecl, CurContext, S)) { 1878 // The tag name clashes with a namespace name, issue an error and 1879 // recover by making this tag be anonymous. 1880 Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); 1881 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 1882 Name = 0; 1883 } 1884 } 1885 } 1886 1887 // If there is an identifier, use the location of the identifier as the 1888 // location of the decl, otherwise use the location of the struct/union 1889 // keyword. 1890 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 1891 1892 // Otherwise, if this is the first time we've seen this tag, create the decl. 1893 TagDecl *New; 1894 1895 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 1896 // struct X { int A; } D; D should chain to X. 1897 if (getLangOptions().CPlusPlus) 1898 // FIXME: Look for a way to use RecordDecl for simple structs. 1899 New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 1900 dyn_cast_or_null<CXXRecordDecl>(PrevDecl)); 1901 else 1902 New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 1903 dyn_cast_or_null<RecordDecl>(PrevDecl)); 1904 1905 // If this has an identifier, add it to the scope stack. 1906 if ((TK == TK_Definition || !PrevDecl) && Name) { 1907 // The scope passed in may not be a decl scope. Zip up the scope tree until 1908 // we find one that is. 1909 while ((S->getFlags() & Scope::DeclScope) == 0) 1910 S = S->getParent(); 1911 1912 // Add it to the decl chain. 1913 PushOnScopeChains(New, S); 1914 } 1915 1916 if (Attr) 1917 ProcessDeclAttributeList(New, Attr); 1918 1919 return New; 1920} 1921 1922 1923/// Collect the instance variables declared in an Objective-C object. Used in 1924/// the creation of structures from objects using the @defs directive. 1925static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, 1926 llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) { 1927 if (Class->getSuperClass()) 1928 CollectIvars(Class->getSuperClass(), Ctx, ivars); 1929 1930 // For each ivar, create a fresh ObjCAtDefsFieldDecl. 1931 for (ObjCInterfaceDecl::ivar_iterator 1932 I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { 1933 1934 ObjCIvarDecl* ID = *I; 1935 ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), 1936 ID->getIdentifier(), 1937 ID->getType(), 1938 ID->getBitWidth())); 1939 } 1940} 1941 1942/// Called whenever @defs(ClassName) is encountered in the source. Inserts the 1943/// instance variables of ClassName into Decls. 1944void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 1945 IdentifierInfo *ClassName, 1946 llvm::SmallVectorImpl<DeclTy*> &Decls) { 1947 // Check that ClassName is a valid class 1948 ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); 1949 if (!Class) { 1950 Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); 1951 return; 1952 } 1953 // Collect the instance variables 1954 CollectIvars(Class, Context, Decls); 1955} 1956 1957QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { 1958 // This method tries to turn a variable array into a constant 1959 // array even when the size isn't an ICE. This is necessary 1960 // for compatibility with code that depends on gcc's buggy 1961 // constant expression folding, like struct {char x[(int)(char*)2];} 1962 if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) { 1963 APValue Result; 1964 if (VLATy->getSizeExpr() && 1965 VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { 1966 llvm::APSInt &Res = Result.getInt(); 1967 if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) 1968 return Context.getConstantArrayType(VLATy->getElementType(), 1969 Res, ArrayType::Normal, 0); 1970 } 1971 } 1972 return QualType(); 1973} 1974 1975/// ActOnField - Each field of a struct/union/class is passed into this in order 1976/// to create a FieldDecl object for it. 1977Sema::DeclTy *Sema::ActOnField(Scope *S, 1978 SourceLocation DeclStart, 1979 Declarator &D, ExprTy *BitfieldWidth) { 1980 IdentifierInfo *II = D.getIdentifier(); 1981 Expr *BitWidth = (Expr*)BitfieldWidth; 1982 SourceLocation Loc = DeclStart; 1983 if (II) Loc = D.getIdentifierLoc(); 1984 1985 // FIXME: Unnamed fields can be handled in various different ways, for 1986 // example, unnamed unions inject all members into the struct namespace! 1987 1988 if (BitWidth) { 1989 // TODO: Validate. 1990 //printf("WARNING: BITFIELDS IGNORED!\n"); 1991 1992 // 6.7.2.1p3 1993 // 6.7.2.1p4 1994 1995 } else { 1996 // Not a bitfield. 1997 1998 // validate II. 1999 2000 } 2001 2002 QualType T = GetTypeForDeclarator(D, S); 2003 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2004 bool InvalidDecl = false; 2005 2006 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2007 // than a variably modified type. 2008 if (T->isVariablyModifiedType()) { 2009 QualType FixedTy = TryFixInvalidVariablyModifiedType(T); 2010 if (!FixedTy.isNull()) { 2011 Diag(Loc, diag::warn_illegal_constant_array_size, Loc); 2012 T = FixedTy; 2013 } else { 2014 // FIXME: This diagnostic needs work 2015 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2016 InvalidDecl = true; 2017 } 2018 } 2019 // FIXME: Chain fielddecls together. 2020 FieldDecl *NewFD; 2021 2022 if (getLangOptions().CPlusPlus) { 2023 // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. 2024 NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext), 2025 Loc, II, T, BitWidth); 2026 if (II) 2027 PushOnScopeChains(NewFD, S); 2028 } 2029 else 2030 NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); 2031 2032 ProcessDeclAttributes(NewFD, D); 2033 2034 if (D.getInvalidType() || InvalidDecl) 2035 NewFD->setInvalidDecl(); 2036 return NewFD; 2037} 2038 2039/// TranslateIvarVisibility - Translate visibility from a token ID to an 2040/// AST enum value. 2041static ObjCIvarDecl::AccessControl 2042TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 2043 switch (ivarVisibility) { 2044 case tok::objc_private: return ObjCIvarDecl::Private; 2045 case tok::objc_public: return ObjCIvarDecl::Public; 2046 case tok::objc_protected: return ObjCIvarDecl::Protected; 2047 case tok::objc_package: return ObjCIvarDecl::Package; 2048 default: assert(false && "Unknown visitibility kind"); 2049 } 2050} 2051 2052/// ActOnIvar - Each ivar field of an objective-c class is passed into this 2053/// in order to create an IvarDecl object for it. 2054Sema::DeclTy *Sema::ActOnIvar(Scope *S, 2055 SourceLocation DeclStart, 2056 Declarator &D, ExprTy *BitfieldWidth, 2057 tok::ObjCKeywordKind Visibility) { 2058 IdentifierInfo *II = D.getIdentifier(); 2059 Expr *BitWidth = (Expr*)BitfieldWidth; 2060 SourceLocation Loc = DeclStart; 2061 if (II) Loc = D.getIdentifierLoc(); 2062 2063 // FIXME: Unnamed fields can be handled in various different ways, for 2064 // example, unnamed unions inject all members into the struct namespace! 2065 2066 2067 if (BitWidth) { 2068 // TODO: Validate. 2069 //printf("WARNING: BITFIELDS IGNORED!\n"); 2070 2071 // 6.7.2.1p3 2072 // 6.7.2.1p4 2073 2074 } else { 2075 // Not a bitfield. 2076 2077 // validate II. 2078 2079 } 2080 2081 QualType T = GetTypeForDeclarator(D, S); 2082 assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); 2083 bool InvalidDecl = false; 2084 2085 // C99 6.7.2.1p8: A member of a structure or union may have any type other 2086 // than a variably modified type. 2087 if (T->isVariablyModifiedType()) { 2088 // FIXME: This diagnostic needs work 2089 Diag(Loc, diag::err_typecheck_illegal_vla, Loc); 2090 InvalidDecl = true; 2091 } 2092 2093 // Get the visibility (access control) for this ivar. 2094 ObjCIvarDecl::AccessControl ac = 2095 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 2096 : ObjCIvarDecl::None; 2097 2098 // Construct the decl. 2099 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, 2100 (Expr *)BitfieldWidth); 2101 2102 // Process attributes attached to the ivar. 2103 ProcessDeclAttributes(NewID, D); 2104 2105 if (D.getInvalidType() || InvalidDecl) 2106 NewID->setInvalidDecl(); 2107 2108 return NewID; 2109} 2110 2111void Sema::ActOnFields(Scope* S, 2112 SourceLocation RecLoc, DeclTy *RecDecl, 2113 DeclTy **Fields, unsigned NumFields, 2114 SourceLocation LBrac, SourceLocation RBrac, 2115 AttributeList *Attrs) { 2116 Decl *EnclosingDecl = static_cast<Decl*>(RecDecl); 2117 assert(EnclosingDecl && "missing record or interface decl"); 2118 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 2119 2120 if (Record) 2121 if (RecordDecl* DefRecord = Record->getDefinition(Context)) { 2122 // Diagnose code like: 2123 // struct S { struct S {} X; }; 2124 // We discover this when we complete the outer S. Reject and ignore the 2125 // outer S. 2126 Diag(DefRecord->getLocation(), diag::err_nested_redefinition, 2127 DefRecord->getKindName()); 2128 Diag(RecLoc, diag::err_previous_definition); 2129 Record->setInvalidDecl(); 2130 return; 2131 } 2132 2133 // Verify that all the fields are okay. 2134 unsigned NumNamedMembers = 0; 2135 llvm::SmallVector<FieldDecl*, 32> RecFields; 2136 llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs; 2137 2138 for (unsigned i = 0; i != NumFields; ++i) { 2139 2140 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i])); 2141 assert(FD && "missing field decl"); 2142 2143 // Remember all fields. 2144 RecFields.push_back(FD); 2145 2146 // Get the type for the field. 2147 Type *FDTy = FD->getType().getTypePtr(); 2148 2149 // C99 6.7.2.1p2 - A field may not be a function type. 2150 if (FDTy->isFunctionType()) { 2151 Diag(FD->getLocation(), diag::err_field_declared_as_function, 2152 FD->getName()); 2153 FD->setInvalidDecl(); 2154 EnclosingDecl->setInvalidDecl(); 2155 continue; 2156 } 2157 // C99 6.7.2.1p2 - A field may not be an incomplete type except... 2158 if (FDTy->isIncompleteType()) { 2159 if (!Record) { // Incomplete ivar type is always an error. 2160 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2161 FD->setInvalidDecl(); 2162 EnclosingDecl->setInvalidDecl(); 2163 continue; 2164 } 2165 if (i != NumFields-1 || // ... that the last member ... 2166 !Record->isStruct() || // ... of a structure ... 2167 !FDTy->isArrayType()) { //... may have incomplete array type. 2168 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); 2169 FD->setInvalidDecl(); 2170 EnclosingDecl->setInvalidDecl(); 2171 continue; 2172 } 2173 if (NumNamedMembers < 1) { //... must have more than named member ... 2174 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, 2175 FD->getName()); 2176 FD->setInvalidDecl(); 2177 EnclosingDecl->setInvalidDecl(); 2178 continue; 2179 } 2180 // Okay, we have a legal flexible array member at the end of the struct. 2181 if (Record) 2182 Record->setHasFlexibleArrayMember(true); 2183 } 2184 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the 2185 /// field of another structure or the element of an array. 2186 if (const RecordType *FDTTy = FDTy->getAsRecordType()) { 2187 if (FDTTy->getDecl()->hasFlexibleArrayMember()) { 2188 // If this is a member of a union, then entire union becomes "flexible". 2189 if (Record && Record->isUnion()) { 2190 Record->setHasFlexibleArrayMember(true); 2191 } else { 2192 // If this is a struct/class and this is not the last element, reject 2193 // it. Note that GCC supports variable sized arrays in the middle of 2194 // structures. 2195 if (i != NumFields-1) { 2196 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, 2197 FD->getName()); 2198 FD->setInvalidDecl(); 2199 EnclosingDecl->setInvalidDecl(); 2200 continue; 2201 } 2202 // We support flexible arrays at the end of structs in other structs 2203 // as an extension. 2204 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, 2205 FD->getName()); 2206 if (Record) 2207 Record->setHasFlexibleArrayMember(true); 2208 } 2209 } 2210 } 2211 /// A field cannot be an Objective-c object 2212 if (FDTy->isObjCInterfaceType()) { 2213 Diag(FD->getLocation(), diag::err_statically_allocated_object, 2214 FD->getName()); 2215 FD->setInvalidDecl(); 2216 EnclosingDecl->setInvalidDecl(); 2217 continue; 2218 } 2219 // Keep track of the number of named members. 2220 if (IdentifierInfo *II = FD->getIdentifier()) { 2221 // Detect duplicate member names. 2222 if (!FieldIDs.insert(II)) { 2223 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); 2224 // Find the previous decl. 2225 SourceLocation PrevLoc; 2226 for (unsigned i = 0, e = RecFields.size(); ; ++i) { 2227 assert(i != e && "Didn't find previous def!"); 2228 if (RecFields[i]->getIdentifier() == II) { 2229 PrevLoc = RecFields[i]->getLocation(); 2230 break; 2231 } 2232 } 2233 Diag(PrevLoc, diag::err_previous_definition); 2234 FD->setInvalidDecl(); 2235 EnclosingDecl->setInvalidDecl(); 2236 continue; 2237 } 2238 ++NumNamedMembers; 2239 } 2240 } 2241 2242 // Okay, we successfully defined 'Record'. 2243 if (Record) { 2244 Record->defineBody(Context, &RecFields[0], RecFields.size()); 2245 // If this is a C++ record, HandleTagDeclDefinition will be invoked in 2246 // Sema::ActOnFinishCXXClassDef. 2247 if (!isa<CXXRecordDecl>(Record)) 2248 Consumer.HandleTagDeclDefinition(Record); 2249 } else { 2250 ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]); 2251 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) 2252 ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); 2253 else if (ObjCImplementationDecl *IMPDecl = 2254 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 2255 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); 2256 IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); 2257 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 2258 } 2259 } 2260} 2261 2262Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, 2263 DeclTy *lastEnumConst, 2264 SourceLocation IdLoc, IdentifierInfo *Id, 2265 SourceLocation EqualLoc, ExprTy *val) { 2266 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl)); 2267 EnumConstantDecl *LastEnumConst = 2268 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst)); 2269 Expr *Val = static_cast<Expr*>(val); 2270 2271 // The scope passed in may not be a decl scope. Zip up the scope tree until 2272 // we find one that is. 2273 while ((S->getFlags() & Scope::DeclScope) == 0) 2274 S = S->getParent(); 2275 2276 // Verify that there isn't already something declared with this name in this 2277 // scope. 2278 if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { 2279 // When in C++, we may get a TagDecl with the same name; in this case the 2280 // enum constant will 'hide' the tag. 2281 assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) && 2282 "Received TagDecl when not in C++!"); 2283 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 2284 if (isa<EnumConstantDecl>(PrevDecl)) 2285 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); 2286 else 2287 Diag(IdLoc, diag::err_redefinition, Id->getName()); 2288 Diag(PrevDecl->getLocation(), diag::err_previous_definition); 2289 delete Val; 2290 return 0; 2291 } 2292 } 2293 2294 llvm::APSInt EnumVal(32); 2295 QualType EltTy; 2296 if (Val) { 2297 // Make sure to promote the operand type to int. 2298 UsualUnaryConversions(Val); 2299 2300 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 2301 SourceLocation ExpLoc; 2302 if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { 2303 Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, 2304 Id->getName()); 2305 delete Val; 2306 Val = 0; // Just forget about it. 2307 } else { 2308 EltTy = Val->getType(); 2309 } 2310 } 2311 2312 if (!Val) { 2313 if (LastEnumConst) { 2314 // Assign the last value + 1. 2315 EnumVal = LastEnumConst->getInitVal(); 2316 ++EnumVal; 2317 2318 // Check for overflow on increment. 2319 if (EnumVal < LastEnumConst->getInitVal()) 2320 Diag(IdLoc, diag::warn_enum_value_overflow); 2321 2322 EltTy = LastEnumConst->getType(); 2323 } else { 2324 // First value, set to zero. 2325 EltTy = Context.IntTy; 2326 EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy))); 2327 } 2328 } 2329 2330 EnumConstantDecl *New = 2331 EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, 2332 Val, EnumVal, 2333 LastEnumConst); 2334 2335 // Register this decl in the current scope stack. 2336 PushOnScopeChains(New, S); 2337 return New; 2338} 2339 2340// FIXME: For consistency with ActOnFields(), we should have the parser 2341// pass in the source location for the left/right braces. 2342void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, 2343 DeclTy **Elements, unsigned NumElements) { 2344 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX)); 2345 2346 if (Enum && Enum->isDefinition()) { 2347 // Diagnose code like: 2348 // enum e0 { 2349 // E0 = sizeof(enum e0 { E1 }) 2350 // }; 2351 Diag(Enum->getLocation(), diag::err_nested_redefinition, 2352 Enum->getName()); 2353 Diag(EnumLoc, diag::err_previous_definition); 2354 Enum->setInvalidDecl(); 2355 return; 2356 } 2357 // TODO: If the result value doesn't fit in an int, it must be a long or long 2358 // long value. ISO C does not support this, but GCC does as an extension, 2359 // emit a warning. 2360 unsigned IntWidth = Context.Target.getIntWidth(); 2361 2362 // Verify that all the values are okay, compute the size of the values, and 2363 // reverse the list. 2364 unsigned NumNegativeBits = 0; 2365 unsigned NumPositiveBits = 0; 2366 2367 // Keep track of whether all elements have type int. 2368 bool AllElementsInt = true; 2369 2370 EnumConstantDecl *EltList = 0; 2371 for (unsigned i = 0; i != NumElements; ++i) { 2372 EnumConstantDecl *ECD = 2373 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2374 if (!ECD) continue; // Already issued a diagnostic. 2375 2376 // If the enum value doesn't fit in an int, emit an extension warning. 2377 const llvm::APSInt &InitVal = ECD->getInitVal(); 2378 assert(InitVal.getBitWidth() >= IntWidth && 2379 "Should have promoted value to int"); 2380 if (InitVal.getBitWidth() > IntWidth) { 2381 llvm::APSInt V(InitVal); 2382 V.trunc(IntWidth); 2383 V.extend(InitVal.getBitWidth()); 2384 if (V != InitVal) 2385 Diag(ECD->getLocation(), diag::ext_enum_value_not_int, 2386 InitVal.toString(10)); 2387 } 2388 2389 // Keep track of the size of positive and negative values. 2390 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 2391 NumPositiveBits = std::max(NumPositiveBits, 2392 (unsigned)InitVal.getActiveBits()); 2393 else 2394 NumNegativeBits = std::max(NumNegativeBits, 2395 (unsigned)InitVal.getMinSignedBits()); 2396 2397 // Keep track of whether every enum element has type int (very commmon). 2398 if (AllElementsInt) 2399 AllElementsInt = ECD->getType() == Context.IntTy; 2400 2401 ECD->setNextDeclarator(EltList); 2402 EltList = ECD; 2403 } 2404 2405 // Figure out the type that should be used for this enum. 2406 // FIXME: Support attribute(packed) on enums and -fshort-enums. 2407 QualType BestType; 2408 unsigned BestWidth; 2409 2410 if (NumNegativeBits) { 2411 // If there is a negative value, figure out the smallest integer type (of 2412 // int/long/longlong) that fits. 2413 if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 2414 BestType = Context.IntTy; 2415 BestWidth = IntWidth; 2416 } else { 2417 BestWidth = Context.Target.getLongWidth(); 2418 2419 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) 2420 BestType = Context.LongTy; 2421 else { 2422 BestWidth = Context.Target.getLongLongWidth(); 2423 2424 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 2425 Diag(Enum->getLocation(), diag::warn_enum_too_large); 2426 BestType = Context.LongLongTy; 2427 } 2428 } 2429 } else { 2430 // If there is no negative value, figure out which of uint, ulong, ulonglong 2431 // fits. 2432 if (NumPositiveBits <= IntWidth) { 2433 BestType = Context.UnsignedIntTy; 2434 BestWidth = IntWidth; 2435 } else if (NumPositiveBits <= 2436 (BestWidth = Context.Target.getLongWidth())) { 2437 BestType = Context.UnsignedLongTy; 2438 } else { 2439 BestWidth = Context.Target.getLongLongWidth(); 2440 assert(NumPositiveBits <= BestWidth && 2441 "How could an initializer get larger than ULL?"); 2442 BestType = Context.UnsignedLongLongTy; 2443 } 2444 } 2445 2446 // Loop over all of the enumerator constants, changing their types to match 2447 // the type of the enum if needed. 2448 for (unsigned i = 0; i != NumElements; ++i) { 2449 EnumConstantDecl *ECD = 2450 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i])); 2451 if (!ECD) continue; // Already issued a diagnostic. 2452 2453 // Standard C says the enumerators have int type, but we allow, as an 2454 // extension, the enumerators to be larger than int size. If each 2455 // enumerator value fits in an int, type it as an int, otherwise type it the 2456 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 2457 // that X has type 'int', not 'unsigned'. 2458 if (ECD->getType() == Context.IntTy) { 2459 // Make sure the init value is signed. 2460 llvm::APSInt IV = ECD->getInitVal(); 2461 IV.setIsSigned(true); 2462 ECD->setInitVal(IV); 2463 continue; // Already int type. 2464 } 2465 2466 // Determine whether the value fits into an int. 2467 llvm::APSInt InitVal = ECD->getInitVal(); 2468 bool FitsInInt; 2469 if (InitVal.isUnsigned() || !InitVal.isNegative()) 2470 FitsInInt = InitVal.getActiveBits() < IntWidth; 2471 else 2472 FitsInInt = InitVal.getMinSignedBits() <= IntWidth; 2473 2474 // If it fits into an integer type, force it. Otherwise force it to match 2475 // the enum decl type. 2476 QualType NewTy; 2477 unsigned NewWidth; 2478 bool NewSign; 2479 if (FitsInInt) { 2480 NewTy = Context.IntTy; 2481 NewWidth = IntWidth; 2482 NewSign = true; 2483 } else if (ECD->getType() == BestType) { 2484 // Already the right type! 2485 continue; 2486 } else { 2487 NewTy = BestType; 2488 NewWidth = BestWidth; 2489 NewSign = BestType->isSignedIntegerType(); 2490 } 2491 2492 // Adjust the APSInt value. 2493 InitVal.extOrTrunc(NewWidth); 2494 InitVal.setIsSigned(NewSign); 2495 ECD->setInitVal(InitVal); 2496 2497 // Adjust the Expr initializer and type. 2498 ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); 2499 ECD->setType(NewTy); 2500 } 2501 2502 Enum->defineElements(EltList, BestType); 2503 Consumer.HandleTagDeclDefinition(Enum); 2504} 2505 2506Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, 2507 ExprTy *expr) { 2508 StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr); 2509 2510 return FileScopeAsmDecl::Create(Context, Loc, AsmString); 2511} 2512 2513Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, 2514 SourceLocation LBrace, 2515 SourceLocation RBrace, 2516 const char *Lang, 2517 unsigned StrSize, 2518 DeclTy *D) { 2519 LinkageSpecDecl::LanguageIDs Language; 2520 Decl *dcl = static_cast<Decl *>(D); 2521 if (strncmp(Lang, "\"C\"", StrSize) == 0) 2522 Language = LinkageSpecDecl::lang_c; 2523 else if (strncmp(Lang, "\"C++\"", StrSize) == 0) 2524 Language = LinkageSpecDecl::lang_cxx; 2525 else { 2526 Diag(Loc, diag::err_bad_language); 2527 return 0; 2528 } 2529 2530 // FIXME: Add all the various semantics of linkage specifications 2531 return LinkageSpecDecl::Create(Context, Loc, Language, dcl); 2532} 2533