SemaExprCXX.cpp revision 428c620478d513081399798db5550bf0c779f244
1//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===// 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 C++ expressions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/DeclSpec.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Lookup.h" 18#include "clang/Sema/ParsedTemplate.h" 19#include "clang/Sema/ScopeInfo.h" 20#include "clang/Sema/Scope.h" 21#include "clang/Sema/TemplateDeduction.h" 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/CharUnits.h" 24#include "clang/AST/CXXInheritance.h" 25#include "clang/AST/DeclObjC.h" 26#include "clang/AST/ExprCXX.h" 27#include "clang/AST/ExprObjC.h" 28#include "clang/AST/TypeLoc.h" 29#include "clang/Basic/PartialDiagnostic.h" 30#include "clang/Basic/TargetInfo.h" 31#include "clang/Lex/Preprocessor.h" 32#include "TypeLocBuilder.h" 33#include "llvm/ADT/APInt.h" 34#include "llvm/ADT/STLExtras.h" 35#include "llvm/Support/ErrorHandling.h" 36using namespace clang; 37using namespace sema; 38 39ParsedType Sema::getDestructorName(SourceLocation TildeLoc, 40 IdentifierInfo &II, 41 SourceLocation NameLoc, 42 Scope *S, CXXScopeSpec &SS, 43 ParsedType ObjectTypePtr, 44 bool EnteringContext) { 45 // Determine where to perform name lookup. 46 47 // FIXME: This area of the standard is very messy, and the current 48 // wording is rather unclear about which scopes we search for the 49 // destructor name; see core issues 399 and 555. Issue 399 in 50 // particular shows where the current description of destructor name 51 // lookup is completely out of line with existing practice, e.g., 52 // this appears to be ill-formed: 53 // 54 // namespace N { 55 // template <typename T> struct S { 56 // ~S(); 57 // }; 58 // } 59 // 60 // void f(N::S<int>* s) { 61 // s->N::S<int>::~S(); 62 // } 63 // 64 // See also PR6358 and PR6359. 65 // For this reason, we're currently only doing the C++03 version of this 66 // code; the C++0x version has to wait until we get a proper spec. 67 QualType SearchType; 68 DeclContext *LookupCtx = 0; 69 bool isDependent = false; 70 bool LookInScope = false; 71 72 // If we have an object type, it's because we are in a 73 // pseudo-destructor-expression or a member access expression, and 74 // we know what type we're looking for. 75 if (ObjectTypePtr) 76 SearchType = GetTypeFromParser(ObjectTypePtr); 77 78 if (SS.isSet()) { 79 NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 80 81 bool AlreadySearched = false; 82 bool LookAtPrefix = true; 83 // C++ [basic.lookup.qual]p6: 84 // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier, 85 // the type-names are looked up as types in the scope designated by the 86 // nested-name-specifier. In a qualified-id of the form: 87 // 88 // ::[opt] nested-name-specifier ~ class-name 89 // 90 // where the nested-name-specifier designates a namespace scope, and in 91 // a qualified-id of the form: 92 // 93 // ::opt nested-name-specifier class-name :: ~ class-name 94 // 95 // the class-names are looked up as types in the scope designated by 96 // the nested-name-specifier. 97 // 98 // Here, we check the first case (completely) and determine whether the 99 // code below is permitted to look at the prefix of the 100 // nested-name-specifier. 101 DeclContext *DC = computeDeclContext(SS, EnteringContext); 102 if (DC && DC->isFileContext()) { 103 AlreadySearched = true; 104 LookupCtx = DC; 105 isDependent = false; 106 } else if (DC && isa<CXXRecordDecl>(DC)) 107 LookAtPrefix = false; 108 109 // The second case from the C++03 rules quoted further above. 110 NestedNameSpecifier *Prefix = 0; 111 if (AlreadySearched) { 112 // Nothing left to do. 113 } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) { 114 CXXScopeSpec PrefixSS; 115 PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); 116 LookupCtx = computeDeclContext(PrefixSS, EnteringContext); 117 isDependent = isDependentScopeSpecifier(PrefixSS); 118 } else if (ObjectTypePtr) { 119 LookupCtx = computeDeclContext(SearchType); 120 isDependent = SearchType->isDependentType(); 121 } else { 122 LookupCtx = computeDeclContext(SS, EnteringContext); 123 isDependent = LookupCtx && LookupCtx->isDependentContext(); 124 } 125 126 LookInScope = false; 127 } else if (ObjectTypePtr) { 128 // C++ [basic.lookup.classref]p3: 129 // If the unqualified-id is ~type-name, the type-name is looked up 130 // in the context of the entire postfix-expression. If the type T 131 // of the object expression is of a class type C, the type-name is 132 // also looked up in the scope of class C. At least one of the 133 // lookups shall find a name that refers to (possibly 134 // cv-qualified) T. 135 LookupCtx = computeDeclContext(SearchType); 136 isDependent = SearchType->isDependentType(); 137 assert((isDependent || !SearchType->isIncompleteType()) && 138 "Caller should have completed object type"); 139 140 LookInScope = true; 141 } else { 142 // Perform lookup into the current scope (only). 143 LookInScope = true; 144 } 145 146 TypeDecl *NonMatchingTypeDecl = 0; 147 LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName); 148 for (unsigned Step = 0; Step != 2; ++Step) { 149 // Look for the name first in the computed lookup context (if we 150 // have one) and, if that fails to find a match, in the scope (if 151 // we're allowed to look there). 152 Found.clear(); 153 if (Step == 0 && LookupCtx) 154 LookupQualifiedName(Found, LookupCtx); 155 else if (Step == 1 && LookInScope && S) 156 LookupName(Found, S); 157 else 158 continue; 159 160 // FIXME: Should we be suppressing ambiguities here? 161 if (Found.isAmbiguous()) 162 return ParsedType(); 163 164 if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) { 165 QualType T = Context.getTypeDeclType(Type); 166 167 if (SearchType.isNull() || SearchType->isDependentType() || 168 Context.hasSameUnqualifiedType(T, SearchType)) { 169 // We found our type! 170 171 return ParsedType::make(T); 172 } 173 174 if (!SearchType.isNull()) 175 NonMatchingTypeDecl = Type; 176 } 177 178 // If the name that we found is a class template name, and it is 179 // the same name as the template name in the last part of the 180 // nested-name-specifier (if present) or the object type, then 181 // this is the destructor for that class. 182 // FIXME: This is a workaround until we get real drafting for core 183 // issue 399, for which there isn't even an obvious direction. 184 if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) { 185 QualType MemberOfType; 186 if (SS.isSet()) { 187 if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) { 188 // Figure out the type of the context, if it has one. 189 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) 190 MemberOfType = Context.getTypeDeclType(Record); 191 } 192 } 193 if (MemberOfType.isNull()) 194 MemberOfType = SearchType; 195 196 if (MemberOfType.isNull()) 197 continue; 198 199 // We're referring into a class template specialization. If the 200 // class template we found is the same as the template being 201 // specialized, we found what we are looking for. 202 if (const RecordType *Record = MemberOfType->getAs<RecordType>()) { 203 if (ClassTemplateSpecializationDecl *Spec 204 = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) { 205 if (Spec->getSpecializedTemplate()->getCanonicalDecl() == 206 Template->getCanonicalDecl()) 207 return ParsedType::make(MemberOfType); 208 } 209 210 continue; 211 } 212 213 // We're referring to an unresolved class template 214 // specialization. Determine whether we class template we found 215 // is the same as the template being specialized or, if we don't 216 // know which template is being specialized, that it at least 217 // has the same name. 218 if (const TemplateSpecializationType *SpecType 219 = MemberOfType->getAs<TemplateSpecializationType>()) { 220 TemplateName SpecName = SpecType->getTemplateName(); 221 222 // The class template we found is the same template being 223 // specialized. 224 if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) { 225 if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl()) 226 return ParsedType::make(MemberOfType); 227 228 continue; 229 } 230 231 // The class template we found has the same name as the 232 // (dependent) template name being specialized. 233 if (DependentTemplateName *DepTemplate 234 = SpecName.getAsDependentTemplateName()) { 235 if (DepTemplate->isIdentifier() && 236 DepTemplate->getIdentifier() == Template->getIdentifier()) 237 return ParsedType::make(MemberOfType); 238 239 continue; 240 } 241 } 242 } 243 } 244 245 if (isDependent) { 246 // We didn't find our type, but that's okay: it's dependent 247 // anyway. 248 249 // FIXME: What if we have no nested-name-specifier? 250 QualType T = CheckTypenameType(ETK_None, SourceLocation(), 251 SS.getWithLocInContext(Context), 252 II, NameLoc); 253 return ParsedType::make(T); 254 } 255 256 if (NonMatchingTypeDecl) { 257 QualType T = Context.getTypeDeclType(NonMatchingTypeDecl); 258 Diag(NameLoc, diag::err_destructor_expr_type_mismatch) 259 << T << SearchType; 260 Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here) 261 << T; 262 } else if (ObjectTypePtr) 263 Diag(NameLoc, diag::err_ident_in_dtor_not_a_type) 264 << &II; 265 else 266 Diag(NameLoc, diag::err_destructor_class_name); 267 268 return ParsedType(); 269} 270 271ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) { 272 if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType) 273 return ParsedType(); 274 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype 275 && "only get destructor types from declspecs"); 276 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 277 QualType SearchType = GetTypeFromParser(ObjectType); 278 if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) { 279 return ParsedType::make(T); 280 } 281 282 Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) 283 << T << SearchType; 284 return ParsedType(); 285} 286 287/// \brief Build a C++ typeid expression with a type operand. 288ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 289 SourceLocation TypeidLoc, 290 TypeSourceInfo *Operand, 291 SourceLocation RParenLoc) { 292 // C++ [expr.typeid]p4: 293 // The top-level cv-qualifiers of the lvalue expression or the type-id 294 // that is the operand of typeid are always ignored. 295 // If the type of the type-id is a class type or a reference to a class 296 // type, the class shall be completely-defined. 297 Qualifiers Quals; 298 QualType T 299 = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(), 300 Quals); 301 if (T->getAs<RecordType>() && 302 RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 303 return ExprError(); 304 305 return Owned(new (Context) CXXTypeidExpr(TypeInfoType.withConst(), 306 Operand, 307 SourceRange(TypeidLoc, RParenLoc))); 308} 309 310/// \brief Build a C++ typeid expression with an expression operand. 311ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 312 SourceLocation TypeidLoc, 313 Expr *E, 314 SourceLocation RParenLoc) { 315 if (E && !E->isTypeDependent()) { 316 if (E->getType()->isPlaceholderType()) { 317 ExprResult result = CheckPlaceholderExpr(E); 318 if (result.isInvalid()) return ExprError(); 319 E = result.take(); 320 } 321 322 QualType T = E->getType(); 323 if (const RecordType *RecordT = T->getAs<RecordType>()) { 324 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl()); 325 // C++ [expr.typeid]p3: 326 // [...] If the type of the expression is a class type, the class 327 // shall be completely-defined. 328 if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 329 return ExprError(); 330 331 // C++ [expr.typeid]p3: 332 // When typeid is applied to an expression other than an glvalue of a 333 // polymorphic class type [...] [the] expression is an unevaluated 334 // operand. [...] 335 if (RecordD->isPolymorphic() && E->Classify(Context).isGLValue()) { 336 // The subexpression is potentially evaluated; switch the context 337 // and recheck the subexpression. 338 ExprResult Result = TranformToPotentiallyEvaluated(E); 339 if (Result.isInvalid()) return ExprError(); 340 E = Result.take(); 341 342 // We require a vtable to query the type at run time. 343 MarkVTableUsed(TypeidLoc, RecordD); 344 } 345 } 346 347 // C++ [expr.typeid]p4: 348 // [...] If the type of the type-id is a reference to a possibly 349 // cv-qualified type, the result of the typeid expression refers to a 350 // std::type_info object representing the cv-unqualified referenced 351 // type. 352 Qualifiers Quals; 353 QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals); 354 if (!Context.hasSameType(T, UnqualT)) { 355 T = UnqualT; 356 E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).take(); 357 } 358 } 359 360 return Owned(new (Context) CXXTypeidExpr(TypeInfoType.withConst(), 361 E, 362 SourceRange(TypeidLoc, RParenLoc))); 363} 364 365/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression); 366ExprResult 367Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, 368 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 369 // Find the std::type_info type. 370 if (!getStdNamespace()) 371 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 372 373 if (!CXXTypeInfoDecl) { 374 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); 375 LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName); 376 LookupQualifiedName(R, getStdNamespace()); 377 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); 378 if (!CXXTypeInfoDecl) 379 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 380 } 381 382 QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl); 383 384 if (isType) { 385 // The operand is a type; handle it as such. 386 TypeSourceInfo *TInfo = 0; 387 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 388 &TInfo); 389 if (T.isNull()) 390 return ExprError(); 391 392 if (!TInfo) 393 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 394 395 return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc); 396 } 397 398 // The operand is an expression. 399 return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 400} 401 402/// Retrieve the UuidAttr associated with QT. 403static UuidAttr *GetUuidAttrOfType(QualType QT) { 404 // Optionally remove one level of pointer, reference or array indirection. 405 const Type *Ty = QT.getTypePtr();; 406 if (QT->isPointerType() || QT->isReferenceType()) 407 Ty = QT->getPointeeType().getTypePtr(); 408 else if (QT->isArrayType()) 409 Ty = cast<ArrayType>(QT)->getElementType().getTypePtr(); 410 411 // Loop all record redeclaration looking for an uuid attribute. 412 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); 413 for (CXXRecordDecl::redecl_iterator I = RD->redecls_begin(), 414 E = RD->redecls_end(); I != E; ++I) { 415 if (UuidAttr *Uuid = I->getAttr<UuidAttr>()) 416 return Uuid; 417 } 418 419 return 0; 420} 421 422/// \brief Build a Microsoft __uuidof expression with a type operand. 423ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 424 SourceLocation TypeidLoc, 425 TypeSourceInfo *Operand, 426 SourceLocation RParenLoc) { 427 if (!Operand->getType()->isDependentType()) { 428 if (!GetUuidAttrOfType(Operand->getType())) 429 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 430 } 431 432 // FIXME: add __uuidof semantic analysis for type operand. 433 return Owned(new (Context) CXXUuidofExpr(TypeInfoType.withConst(), 434 Operand, 435 SourceRange(TypeidLoc, RParenLoc))); 436} 437 438/// \brief Build a Microsoft __uuidof expression with an expression operand. 439ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 440 SourceLocation TypeidLoc, 441 Expr *E, 442 SourceLocation RParenLoc) { 443 if (!E->getType()->isDependentType()) { 444 if (!GetUuidAttrOfType(E->getType()) && 445 !E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 446 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 447 } 448 // FIXME: add __uuidof semantic analysis for type operand. 449 return Owned(new (Context) CXXUuidofExpr(TypeInfoType.withConst(), 450 E, 451 SourceRange(TypeidLoc, RParenLoc))); 452} 453 454/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); 455ExprResult 456Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, 457 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 458 // If MSVCGuidDecl has not been cached, do the lookup. 459 if (!MSVCGuidDecl) { 460 IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID"); 461 LookupResult R(*this, GuidII, SourceLocation(), LookupTagName); 462 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 463 MSVCGuidDecl = R.getAsSingle<RecordDecl>(); 464 if (!MSVCGuidDecl) 465 return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof)); 466 } 467 468 QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl); 469 470 if (isType) { 471 // The operand is a type; handle it as such. 472 TypeSourceInfo *TInfo = 0; 473 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 474 &TInfo); 475 if (T.isNull()) 476 return ExprError(); 477 478 if (!TInfo) 479 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 480 481 return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc); 482 } 483 484 // The operand is an expression. 485 return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 486} 487 488/// ActOnCXXBoolLiteral - Parse {true,false} literals. 489ExprResult 490Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { 491 assert((Kind == tok::kw_true || Kind == tok::kw_false) && 492 "Unknown C++ Boolean value!"); 493 return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true, 494 Context.BoolTy, OpLoc)); 495} 496 497/// ActOnCXXNullPtrLiteral - Parse 'nullptr'. 498ExprResult 499Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { 500 return Owned(new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc)); 501} 502 503/// ActOnCXXThrow - Parse throw expressions. 504ExprResult 505Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) { 506 bool IsThrownVarInScope = false; 507 if (Ex) { 508 // C++0x [class.copymove]p31: 509 // When certain criteria are met, an implementation is allowed to omit the 510 // copy/move construction of a class object [...] 511 // 512 // - in a throw-expression, when the operand is the name of a 513 // non-volatile automatic object (other than a function or catch- 514 // clause parameter) whose scope does not extend beyond the end of the 515 // innermost enclosing try-block (if there is one), the copy/move 516 // operation from the operand to the exception object (15.1) can be 517 // omitted by constructing the automatic object directly into the 518 // exception object 519 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens())) 520 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 521 if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) { 522 for( ; S; S = S->getParent()) { 523 if (S->isDeclScope(Var)) { 524 IsThrownVarInScope = true; 525 break; 526 } 527 528 if (S->getFlags() & 529 (Scope::FnScope | Scope::ClassScope | Scope::BlockScope | 530 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope | 531 Scope::TryScope)) 532 break; 533 } 534 } 535 } 536 } 537 538 return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope); 539} 540 541ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex, 542 bool IsThrownVarInScope) { 543 // Don't report an error if 'throw' is used in system headers. 544 if (!getLangOptions().CXXExceptions && 545 !getSourceManager().isInSystemHeader(OpLoc)) 546 Diag(OpLoc, diag::err_exceptions_disabled) << "throw"; 547 548 if (Ex && !Ex->isTypeDependent()) { 549 ExprResult ExRes = CheckCXXThrowOperand(OpLoc, Ex, IsThrownVarInScope); 550 if (ExRes.isInvalid()) 551 return ExprError(); 552 Ex = ExRes.take(); 553 } 554 555 return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc, 556 IsThrownVarInScope)); 557} 558 559/// CheckCXXThrowOperand - Validate the operand of a throw. 560ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E, 561 bool IsThrownVarInScope) { 562 // C++ [except.throw]p3: 563 // A throw-expression initializes a temporary object, called the exception 564 // object, the type of which is determined by removing any top-level 565 // cv-qualifiers from the static type of the operand of throw and adjusting 566 // the type from "array of T" or "function returning T" to "pointer to T" 567 // or "pointer to function returning T", [...] 568 if (E->getType().hasQualifiers()) 569 E = ImpCastExprToType(E, E->getType().getUnqualifiedType(), CK_NoOp, 570 E->getValueKind()).take(); 571 572 ExprResult Res = DefaultFunctionArrayConversion(E); 573 if (Res.isInvalid()) 574 return ExprError(); 575 E = Res.take(); 576 577 // If the type of the exception would be an incomplete type or a pointer 578 // to an incomplete type other than (cv) void the program is ill-formed. 579 QualType Ty = E->getType(); 580 bool isPointer = false; 581 if (const PointerType* Ptr = Ty->getAs<PointerType>()) { 582 Ty = Ptr->getPointeeType(); 583 isPointer = true; 584 } 585 if (!isPointer || !Ty->isVoidType()) { 586 if (RequireCompleteType(ThrowLoc, Ty, 587 PDiag(isPointer ? diag::err_throw_incomplete_ptr 588 : diag::err_throw_incomplete) 589 << E->getSourceRange())) 590 return ExprError(); 591 592 if (RequireNonAbstractType(ThrowLoc, E->getType(), 593 PDiag(diag::err_throw_abstract_type) 594 << E->getSourceRange())) 595 return ExprError(); 596 } 597 598 // Initialize the exception result. This implicitly weeds out 599 // abstract types or types with inaccessible copy constructors. 600 601 // C++0x [class.copymove]p31: 602 // When certain criteria are met, an implementation is allowed to omit the 603 // copy/move construction of a class object [...] 604 // 605 // - in a throw-expression, when the operand is the name of a 606 // non-volatile automatic object (other than a function or catch-clause 607 // parameter) whose scope does not extend beyond the end of the 608 // innermost enclosing try-block (if there is one), the copy/move 609 // operation from the operand to the exception object (15.1) can be 610 // omitted by constructing the automatic object directly into the 611 // exception object 612 const VarDecl *NRVOVariable = 0; 613 if (IsThrownVarInScope) 614 NRVOVariable = getCopyElisionCandidate(QualType(), E, false); 615 616 InitializedEntity Entity = 617 InitializedEntity::InitializeException(ThrowLoc, E->getType(), 618 /*NRVO=*/NRVOVariable != 0); 619 Res = PerformMoveOrCopyInitialization(Entity, NRVOVariable, 620 QualType(), E, 621 IsThrownVarInScope); 622 if (Res.isInvalid()) 623 return ExprError(); 624 E = Res.take(); 625 626 // If the exception has class type, we need additional handling. 627 const RecordType *RecordTy = Ty->getAs<RecordType>(); 628 if (!RecordTy) 629 return Owned(E); 630 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl()); 631 632 // If we are throwing a polymorphic class type or pointer thereof, 633 // exception handling will make use of the vtable. 634 MarkVTableUsed(ThrowLoc, RD); 635 636 // If a pointer is thrown, the referenced object will not be destroyed. 637 if (isPointer) 638 return Owned(E); 639 640 // If the class has a destructor, we must be able to call it. 641 if (RD->hasIrrelevantDestructor()) 642 return Owned(E); 643 644 CXXDestructorDecl *Destructor 645 = const_cast<CXXDestructorDecl*>(LookupDestructor(RD)); 646 if (!Destructor) 647 return Owned(E); 648 649 MarkFunctionReferenced(E->getExprLoc(), Destructor); 650 CheckDestructorAccess(E->getExprLoc(), Destructor, 651 PDiag(diag::err_access_dtor_exception) << Ty); 652 DiagnoseUseOfDecl(Destructor, E->getExprLoc()); 653 return Owned(E); 654} 655 656QualType Sema::getCurrentThisType() { 657 DeclContext *DC = getFunctionLevelDeclContext(); 658 QualType ThisTy; 659 if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) { 660 if (method && method->isInstance()) 661 ThisTy = method->getThisType(Context); 662 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 663 // C++0x [expr.prim]p4: 664 // Otherwise, if a member-declarator declares a non-static data member 665 // of a class X, the expression this is a prvalue of type "pointer to X" 666 // within the optional brace-or-equal-initializer. 667 Scope *S = getScopeForContext(DC); 668 if (!S || S->getFlags() & Scope::ThisScope) 669 ThisTy = Context.getPointerType(Context.getRecordType(RD)); 670 } 671 672 return ThisTy; 673} 674 675void Sema::CheckCXXThisCapture(SourceLocation Loc, bool Explicit) { 676 // We don't need to capture this in an unevaluated context. 677 if (ExprEvalContexts.back().Context == Unevaluated && !Explicit) 678 return; 679 680 // Otherwise, check that we can capture 'this'. 681 unsigned NumClosures = 0; 682 for (unsigned idx = FunctionScopes.size() - 1; idx != 0; idx--) { 683 if (CapturingScopeInfo *CSI = 684 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) { 685 if (CSI->CXXThisCaptureIndex != 0) { 686 // 'this' is already being captured; there isn't anything more to do. 687 break; 688 } 689 690 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref || 691 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval || 692 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block || 693 Explicit) { 694 // This closure can capture 'this'; continue looking upwards. 695 NumClosures++; 696 Explicit = false; 697 continue; 698 } 699 // This context can't implicitly capture 'this'; fail out. 700 Diag(Loc, diag::err_this_capture) << Explicit; 701 return; 702 } 703 break; 704 } 705 706 // Mark that we're implicitly capturing 'this' in all the scopes we skipped. 707 // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated 708 // contexts. 709 for (unsigned idx = FunctionScopes.size() - 1; 710 NumClosures; --idx, --NumClosures) { 711 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]); 712 Expr *ThisExpr = 0; 713 QualType ThisTy = getCurrentThisType(); 714 if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) { 715 // For lambda expressions, build a field and an initializing expression. 716 CXXRecordDecl *Lambda = LSI->Lambda; 717 FieldDecl *Field 718 = FieldDecl::Create(Context, Lambda, Loc, Loc, 0, ThisTy, 719 Context.getTrivialTypeSourceInfo(ThisTy, Loc), 720 0, false, false); 721 Field->setImplicit(true); 722 Field->setAccess(AS_private); 723 Lambda->addDecl(Field); 724 ThisExpr = new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/true); 725 } 726 bool isNested = NumClosures > 1; 727 CSI->addThisCapture(isNested, Loc, ThisTy, ThisExpr); 728 } 729} 730 731ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { 732 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 733 /// is a non-lvalue expression whose value is the address of the object for 734 /// which the function is called. 735 736 QualType ThisTy = getCurrentThisType(); 737 if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use); 738 739 CheckCXXThisCapture(Loc); 740 return Owned(new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false)); 741} 742 743ExprResult 744Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, 745 SourceLocation LParenLoc, 746 MultiExprArg exprs, 747 SourceLocation RParenLoc) { 748 if (!TypeRep) 749 return ExprError(); 750 751 TypeSourceInfo *TInfo; 752 QualType Ty = GetTypeFromParser(TypeRep, &TInfo); 753 if (!TInfo) 754 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); 755 756 return BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc); 757} 758 759/// ActOnCXXTypeConstructExpr - Parse construction of a specified type. 760/// Can be interpreted either as function-style casting ("int(x)") 761/// or class type construction ("ClassType(x,y,z)") 762/// or creation of a value-initialized type ("int()"). 763ExprResult 764Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, 765 SourceLocation LParenLoc, 766 MultiExprArg exprs, 767 SourceLocation RParenLoc) { 768 QualType Ty = TInfo->getType(); 769 unsigned NumExprs = exprs.size(); 770 Expr **Exprs = (Expr**)exprs.get(); 771 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); 772 773 if (Ty->isDependentType() || 774 CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) { 775 exprs.release(); 776 777 return Owned(CXXUnresolvedConstructExpr::Create(Context, TInfo, 778 LParenLoc, 779 Exprs, NumExprs, 780 RParenLoc)); 781 } 782 783 bool ListInitialization = LParenLoc.isInvalid(); 784 assert((!ListInitialization || (NumExprs == 1 && isa<InitListExpr>(Exprs[0]))) 785 && "List initialization must have initializer list as expression."); 786 SourceRange FullRange = SourceRange(TyBeginLoc, 787 ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc); 788 789 if (Ty->isArrayType()) 790 return ExprError(Diag(TyBeginLoc, 791 diag::err_value_init_for_array_type) << FullRange); 792 if (!Ty->isVoidType() && 793 RequireCompleteType(TyBeginLoc, Ty, 794 PDiag(diag::err_invalid_incomplete_type_use) 795 << FullRange)) 796 return ExprError(); 797 798 if (RequireNonAbstractType(TyBeginLoc, Ty, 799 diag::err_allocation_of_abstract_type)) 800 return ExprError(); 801 802 803 // C++ [expr.type.conv]p1: 804 // If the expression list is a single expression, the type conversion 805 // expression is equivalent (in definedness, and if defined in meaning) to the 806 // corresponding cast expression. 807 if (NumExprs == 1 && !ListInitialization) { 808 Expr *Arg = Exprs[0]; 809 exprs.release(); 810 return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc); 811 } 812 813 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); 814 InitializationKind Kind 815 = NumExprs ? ListInitialization 816 ? InitializationKind::CreateDirectList(TyBeginLoc) 817 : InitializationKind::CreateDirect(TyBeginLoc, 818 LParenLoc, RParenLoc) 819 : InitializationKind::CreateValue(TyBeginLoc, 820 LParenLoc, RParenLoc); 821 InitializationSequence InitSeq(*this, Entity, Kind, Exprs, NumExprs); 822 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, move(exprs)); 823 824 if (!Result.isInvalid() && ListInitialization && 825 isa<InitListExpr>(Result.get())) { 826 // If the list-initialization doesn't involve a constructor call, we'll get 827 // the initializer-list (with corrected type) back, but that's not what we 828 // want, since it will be treated as an initializer list in further 829 // processing. Explicitly insert a cast here. 830 InitListExpr *List = cast<InitListExpr>(Result.take()); 831 Result = Owned(CXXFunctionalCastExpr::Create(Context, List->getType(), 832 Expr::getValueKindForType(TInfo->getType()), 833 TInfo, TyBeginLoc, CK_NoOp, 834 List, /*Path=*/0, RParenLoc)); 835 } 836 837 // FIXME: Improve AST representation? 838 return move(Result); 839} 840 841/// doesUsualArrayDeleteWantSize - Answers whether the usual 842/// operator delete[] for the given type has a size_t parameter. 843static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, 844 QualType allocType) { 845 const RecordType *record = 846 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>(); 847 if (!record) return false; 848 849 // Try to find an operator delete[] in class scope. 850 851 DeclarationName deleteName = 852 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); 853 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); 854 S.LookupQualifiedName(ops, record->getDecl()); 855 856 // We're just doing this for information. 857 ops.suppressDiagnostics(); 858 859 // Very likely: there's no operator delete[]. 860 if (ops.empty()) return false; 861 862 // If it's ambiguous, it should be illegal to call operator delete[] 863 // on this thing, so it doesn't matter if we allocate extra space or not. 864 if (ops.isAmbiguous()) return false; 865 866 LookupResult::Filter filter = ops.makeFilter(); 867 while (filter.hasNext()) { 868 NamedDecl *del = filter.next()->getUnderlyingDecl(); 869 870 // C++0x [basic.stc.dynamic.deallocation]p2: 871 // A template instance is never a usual deallocation function, 872 // regardless of its signature. 873 if (isa<FunctionTemplateDecl>(del)) { 874 filter.erase(); 875 continue; 876 } 877 878 // C++0x [basic.stc.dynamic.deallocation]p2: 879 // If class T does not declare [an operator delete[] with one 880 // parameter] but does declare a member deallocation function 881 // named operator delete[] with exactly two parameters, the 882 // second of which has type std::size_t, then this function 883 // is a usual deallocation function. 884 if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) { 885 filter.erase(); 886 continue; 887 } 888 } 889 filter.done(); 890 891 if (!ops.isSingleResult()) return false; 892 893 const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl()); 894 return (del->getNumParams() == 2); 895} 896 897/// \brief Parsed a C++ 'new' expression (C++ 5.3.4). 898 899/// E.g.: 900/// @code new (memory) int[size][4] @endcode 901/// or 902/// @code ::new Foo(23, "hello") @endcode 903/// 904/// \param StartLoc The first location of the expression. 905/// \param UseGlobal True if 'new' was prefixed with '::'. 906/// \param PlacementLParen Opening paren of the placement arguments. 907/// \param PlacementArgs Placement new arguments. 908/// \param PlacementRParen Closing paren of the placement arguments. 909/// \param TypeIdParens If the type is in parens, the source range. 910/// \param D The type to be allocated, as well as array dimensions. 911/// \param ConstructorLParen Opening paren of the constructor args, empty if 912/// initializer-list syntax is used. 913/// \param ConstructorArgs Constructor/initialization arguments. 914/// \param ConstructorRParen Closing paren of the constructor args. 915ExprResult 916Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 917 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 918 SourceLocation PlacementRParen, SourceRange TypeIdParens, 919 Declarator &D, Expr *Initializer) { 920 bool TypeContainsAuto = D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto; 921 922 Expr *ArraySize = 0; 923 // If the specified type is an array, unwrap it and save the expression. 924 if (D.getNumTypeObjects() > 0 && 925 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 926 DeclaratorChunk &Chunk = D.getTypeObject(0); 927 if (TypeContainsAuto) 928 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) 929 << D.getSourceRange()); 930 if (Chunk.Arr.hasStatic) 931 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 932 << D.getSourceRange()); 933 if (!Chunk.Arr.NumElts) 934 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 935 << D.getSourceRange()); 936 937 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 938 D.DropFirstTypeObject(); 939 } 940 941 // Every dimension shall be of constant size. 942 if (ArraySize) { 943 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { 944 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) 945 break; 946 947 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; 948 if (Expr *NumElts = (Expr *)Array.NumElts) { 949 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { 950 Array.NumElts = VerifyIntegerConstantExpression(NumElts, 0, 951 PDiag(diag::err_new_array_nonconst)).take(); 952 if (!Array.NumElts) 953 return ExprError(); 954 } 955 } 956 } 957 } 958 959 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/0); 960 QualType AllocType = TInfo->getType(); 961 if (D.isInvalidType()) 962 return ExprError(); 963 964 SourceRange DirectInitRange; 965 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) 966 DirectInitRange = List->getSourceRange(); 967 968 return BuildCXXNew(StartLoc, UseGlobal, 969 PlacementLParen, 970 move(PlacementArgs), 971 PlacementRParen, 972 TypeIdParens, 973 AllocType, 974 TInfo, 975 ArraySize, 976 DirectInitRange, 977 Initializer, 978 TypeContainsAuto); 979} 980 981static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, 982 Expr *Init) { 983 if (!Init) 984 return true; 985 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) 986 return PLE->getNumExprs() == 0; 987 if (isa<ImplicitValueInitExpr>(Init)) 988 return true; 989 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) 990 return !CCE->isListInitialization() && 991 CCE->getConstructor()->isDefaultConstructor(); 992 else if (Style == CXXNewExpr::ListInit) { 993 assert(isa<InitListExpr>(Init) && 994 "Shouldn't create list CXXConstructExprs for arrays."); 995 return true; 996 } 997 return false; 998} 999 1000ExprResult 1001Sema::BuildCXXNew(SourceLocation StartLoc, bool UseGlobal, 1002 SourceLocation PlacementLParen, 1003 MultiExprArg PlacementArgs, 1004 SourceLocation PlacementRParen, 1005 SourceRange TypeIdParens, 1006 QualType AllocType, 1007 TypeSourceInfo *AllocTypeInfo, 1008 Expr *ArraySize, 1009 SourceRange DirectInitRange, 1010 Expr *Initializer, 1011 bool TypeMayContainAuto) { 1012 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); 1013 1014 CXXNewExpr::InitializationStyle initStyle; 1015 if (DirectInitRange.isValid()) { 1016 assert(Initializer && "Have parens but no initializer."); 1017 initStyle = CXXNewExpr::CallInit; 1018 } else if (Initializer && isa<InitListExpr>(Initializer)) 1019 initStyle = CXXNewExpr::ListInit; 1020 else { 1021 // In template instantiation, the initializer could be a CXXDefaultArgExpr 1022 // unwrapped from a CXXConstructExpr that was implicitly built. There is no 1023 // particularly sane way we can handle this (especially since it can even 1024 // occur for array new), so we throw the initializer away and have it be 1025 // rebuilt. 1026 if (Initializer && isa<CXXDefaultArgExpr>(Initializer)) 1027 Initializer = 0; 1028 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) || 1029 isa<CXXConstructExpr>(Initializer)) && 1030 "Initializer expression that cannot have been implicitly created."); 1031 initStyle = CXXNewExpr::NoInit; 1032 } 1033 1034 Expr **Inits = &Initializer; 1035 unsigned NumInits = Initializer ? 1 : 0; 1036 if (initStyle == CXXNewExpr::CallInit) { 1037 if (ParenListExpr *List = dyn_cast<ParenListExpr>(Initializer)) { 1038 Inits = List->getExprs(); 1039 NumInits = List->getNumExprs(); 1040 } else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Initializer)){ 1041 if (!isa<CXXTemporaryObjectExpr>(CCE)) { 1042 // Can happen in template instantiation. Since this is just an implicit 1043 // construction, we just take it apart and rebuild it. 1044 Inits = CCE->getArgs(); 1045 NumInits = CCE->getNumArgs(); 1046 } 1047 } 1048 } 1049 1050 // C++0x [decl.spec.auto]p6. Deduce the type which 'auto' stands in for. 1051 if (TypeMayContainAuto && AllocType->getContainedAutoType()) { 1052 if (initStyle == CXXNewExpr::NoInit || NumInits == 0) 1053 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) 1054 << AllocType << TypeRange); 1055 if (initStyle == CXXNewExpr::ListInit) 1056 return ExprError(Diag(Inits[0]->getSourceRange().getBegin(), 1057 diag::err_auto_new_requires_parens) 1058 << AllocType << TypeRange); 1059 if (NumInits > 1) { 1060 Expr *FirstBad = Inits[1]; 1061 return ExprError(Diag(FirstBad->getSourceRange().getBegin(), 1062 diag::err_auto_new_ctor_multiple_expressions) 1063 << AllocType << TypeRange); 1064 } 1065 Expr *Deduce = Inits[0]; 1066 TypeSourceInfo *DeducedType = 0; 1067 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == 1068 DAR_Failed) 1069 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) 1070 << AllocType << Deduce->getType() 1071 << TypeRange << Deduce->getSourceRange()); 1072 if (!DeducedType) 1073 return ExprError(); 1074 1075 AllocTypeInfo = DeducedType; 1076 AllocType = AllocTypeInfo->getType(); 1077 } 1078 1079 // Per C++0x [expr.new]p5, the type being constructed may be a 1080 // typedef of an array type. 1081 if (!ArraySize) { 1082 if (const ConstantArrayType *Array 1083 = Context.getAsConstantArrayType(AllocType)) { 1084 ArraySize = IntegerLiteral::Create(Context, Array->getSize(), 1085 Context.getSizeType(), 1086 TypeRange.getEnd()); 1087 AllocType = Array->getElementType(); 1088 } 1089 } 1090 1091 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) 1092 return ExprError(); 1093 1094 if (initStyle == CXXNewExpr::ListInit && isStdInitializerList(AllocType, 0)) { 1095 Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(), 1096 diag::warn_dangling_std_initializer_list) 1097 << /*at end of FE*/0 << Inits[0]->getSourceRange(); 1098 } 1099 1100 // In ARC, infer 'retaining' for the allocated 1101 if (getLangOptions().ObjCAutoRefCount && 1102 AllocType.getObjCLifetime() == Qualifiers::OCL_None && 1103 AllocType->isObjCLifetimeType()) { 1104 AllocType = Context.getLifetimeQualifiedType(AllocType, 1105 AllocType->getObjCARCImplicitLifetime()); 1106 } 1107 1108 QualType ResultType = Context.getPointerType(AllocType); 1109 1110 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have 1111 // integral or enumeration type with a non-negative value." 1112 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped 1113 // enumeration type, or a class type for which a single non-explicit 1114 // conversion function to integral or unscoped enumeration type exists. 1115 if (ArraySize && !ArraySize->isTypeDependent()) { 1116 ExprResult ConvertedSize = ConvertToIntegralOrEnumerationType( 1117 StartLoc, ArraySize, 1118 PDiag(diag::err_array_size_not_integral) << getLangOptions().CPlusPlus0x, 1119 PDiag(diag::err_array_size_incomplete_type) 1120 << ArraySize->getSourceRange(), 1121 PDiag(diag::err_array_size_explicit_conversion), 1122 PDiag(diag::note_array_size_conversion), 1123 PDiag(diag::err_array_size_ambiguous_conversion), 1124 PDiag(diag::note_array_size_conversion), 1125 PDiag(getLangOptions().CPlusPlus0x ? 1126 diag::warn_cxx98_compat_array_size_conversion : 1127 diag::ext_array_size_conversion), 1128 /*AllowScopedEnumerations*/ false); 1129 if (ConvertedSize.isInvalid()) 1130 return ExprError(); 1131 1132 ArraySize = ConvertedSize.take(); 1133 QualType SizeType = ArraySize->getType(); 1134 if (!SizeType->isIntegralOrUnscopedEnumerationType()) 1135 return ExprError(); 1136 1137 // C++98 [expr.new]p7: 1138 // The expression in a direct-new-declarator shall have integral type 1139 // with a non-negative value. 1140 // 1141 // Let's see if this is a constant < 0. If so, we reject it out of 1142 // hand. Otherwise, if it's not a constant, we must have an unparenthesized 1143 // array type. 1144 // 1145 // Note: such a construct has well-defined semantics in C++11: it throws 1146 // std::bad_array_new_length. 1147 if (!ArraySize->isValueDependent()) { 1148 llvm::APSInt Value; 1149 // We've already performed any required implicit conversion to integer or 1150 // unscoped enumeration type. 1151 if (ArraySize->isIntegerConstantExpr(Value, Context)) { 1152 if (Value < llvm::APSInt( 1153 llvm::APInt::getNullValue(Value.getBitWidth()), 1154 Value.isUnsigned())) { 1155 if (getLangOptions().CPlusPlus0x) 1156 Diag(ArraySize->getSourceRange().getBegin(), 1157 diag::warn_typecheck_negative_array_new_size) 1158 << ArraySize->getSourceRange(); 1159 else 1160 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 1161 diag::err_typecheck_negative_array_size) 1162 << ArraySize->getSourceRange()); 1163 } else if (!AllocType->isDependentType()) { 1164 unsigned ActiveSizeBits = 1165 ConstantArrayType::getNumAddressingBits(Context, AllocType, Value); 1166 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) { 1167 if (getLangOptions().CPlusPlus0x) 1168 Diag(ArraySize->getSourceRange().getBegin(), 1169 diag::warn_array_new_too_large) 1170 << Value.toString(10) 1171 << ArraySize->getSourceRange(); 1172 else 1173 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 1174 diag::err_array_too_large) 1175 << Value.toString(10) 1176 << ArraySize->getSourceRange()); 1177 } 1178 } 1179 } else if (TypeIdParens.isValid()) { 1180 // Can't have dynamic array size when the type-id is in parentheses. 1181 Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst) 1182 << ArraySize->getSourceRange() 1183 << FixItHint::CreateRemoval(TypeIdParens.getBegin()) 1184 << FixItHint::CreateRemoval(TypeIdParens.getEnd()); 1185 1186 TypeIdParens = SourceRange(); 1187 } 1188 } 1189 1190 // ARC: warn about ABI issues. 1191 if (getLangOptions().ObjCAutoRefCount) { 1192 QualType BaseAllocType = Context.getBaseElementType(AllocType); 1193 if (BaseAllocType.hasStrongOrWeakObjCLifetime()) 1194 Diag(StartLoc, diag::warn_err_new_delete_object_array) 1195 << 0 << BaseAllocType; 1196 } 1197 1198 // Note that we do *not* convert the argument in any way. It can 1199 // be signed, larger than size_t, whatever. 1200 } 1201 1202 FunctionDecl *OperatorNew = 0; 1203 FunctionDecl *OperatorDelete = 0; 1204 Expr **PlaceArgs = (Expr**)PlacementArgs.get(); 1205 unsigned NumPlaceArgs = PlacementArgs.size(); 1206 1207 if (!AllocType->isDependentType() && 1208 !Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) && 1209 FindAllocationFunctions(StartLoc, 1210 SourceRange(PlacementLParen, PlacementRParen), 1211 UseGlobal, AllocType, ArraySize, PlaceArgs, 1212 NumPlaceArgs, OperatorNew, OperatorDelete)) 1213 return ExprError(); 1214 1215 // If this is an array allocation, compute whether the usual array 1216 // deallocation function for the type has a size_t parameter. 1217 bool UsualArrayDeleteWantsSize = false; 1218 if (ArraySize && !AllocType->isDependentType()) 1219 UsualArrayDeleteWantsSize 1220 = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); 1221 1222 SmallVector<Expr *, 8> AllPlaceArgs; 1223 if (OperatorNew) { 1224 // Add default arguments, if any. 1225 const FunctionProtoType *Proto = 1226 OperatorNew->getType()->getAs<FunctionProtoType>(); 1227 VariadicCallType CallType = 1228 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 1229 1230 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, 1231 Proto, 1, PlaceArgs, NumPlaceArgs, 1232 AllPlaceArgs, CallType)) 1233 return ExprError(); 1234 1235 NumPlaceArgs = AllPlaceArgs.size(); 1236 if (NumPlaceArgs > 0) 1237 PlaceArgs = &AllPlaceArgs[0]; 1238 1239 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, 1240 PlaceArgs, NumPlaceArgs); 1241 1242 // FIXME: Missing call to CheckFunctionCall or equivalent 1243 } 1244 1245 // Warn if the type is over-aligned and is being allocated by global operator 1246 // new. 1247 if (NumPlaceArgs == 0 && OperatorNew && 1248 (OperatorNew->isImplicit() || 1249 getSourceManager().isInSystemHeader(OperatorNew->getLocStart()))) { 1250 if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){ 1251 unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign(); 1252 if (Align > SuitableAlign) 1253 Diag(StartLoc, diag::warn_overaligned_type) 1254 << AllocType 1255 << unsigned(Align / Context.getCharWidth()) 1256 << unsigned(SuitableAlign / Context.getCharWidth()); 1257 } 1258 } 1259 1260 QualType InitType = AllocType; 1261 // Array 'new' can't have any initializers except empty parentheses. 1262 // Initializer lists are also allowed, in C++11. Rely on the parser for the 1263 // dialect distinction. 1264 if (ResultType->isArrayType() || ArraySize) { 1265 if (!isLegalArrayNewInitializer(initStyle, Initializer)) { 1266 SourceRange InitRange(Inits[0]->getLocStart(), 1267 Inits[NumInits - 1]->getLocEnd()); 1268 Diag(StartLoc, diag::err_new_array_init_args) << InitRange; 1269 return ExprError(); 1270 } 1271 if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) { 1272 // We do the initialization typechecking against the array type 1273 // corresponding to the number of initializers + 1 (to also check 1274 // default-initialization). 1275 unsigned NumElements = ILE->getNumInits() + 1; 1276 InitType = Context.getConstantArrayType(AllocType, 1277 llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements), 1278 ArrayType::Normal, 0); 1279 } 1280 } 1281 1282 if (!AllocType->isDependentType() && 1283 !Expr::hasAnyTypeDependentArguments(Inits, NumInits)) { 1284 // C++11 [expr.new]p15: 1285 // A new-expression that creates an object of type T initializes that 1286 // object as follows: 1287 InitializationKind Kind 1288 // - If the new-initializer is omitted, the object is default- 1289 // initialized (8.5); if no initialization is performed, 1290 // the object has indeterminate value 1291 = initStyle == CXXNewExpr::NoInit 1292 ? InitializationKind::CreateDefault(TypeRange.getBegin()) 1293 // - Otherwise, the new-initializer is interpreted according to the 1294 // initialization rules of 8.5 for direct-initialization. 1295 : initStyle == CXXNewExpr::ListInit 1296 ? InitializationKind::CreateDirectList(TypeRange.getBegin()) 1297 : InitializationKind::CreateDirect(TypeRange.getBegin(), 1298 DirectInitRange.getBegin(), 1299 DirectInitRange.getEnd()); 1300 1301 InitializedEntity Entity 1302 = InitializedEntity::InitializeNew(StartLoc, InitType); 1303 InitializationSequence InitSeq(*this, Entity, Kind, Inits, NumInits); 1304 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, 1305 MultiExprArg(Inits, NumInits)); 1306 if (FullInit.isInvalid()) 1307 return ExprError(); 1308 1309 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because 1310 // we don't want the initialized object to be destructed. 1311 if (CXXBindTemporaryExpr *Binder = 1312 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get())) 1313 FullInit = Owned(Binder->getSubExpr()); 1314 1315 Initializer = FullInit.take(); 1316 } 1317 1318 // Mark the new and delete operators as referenced. 1319 if (OperatorNew) 1320 MarkFunctionReferenced(StartLoc, OperatorNew); 1321 if (OperatorDelete) 1322 MarkFunctionReferenced(StartLoc, OperatorDelete); 1323 1324 // C++0x [expr.new]p17: 1325 // If the new expression creates an array of objects of class type, 1326 // access and ambiguity control are done for the destructor. 1327 if (ArraySize && AllocType->isRecordType() && !AllocType->isDependentType()) { 1328 if (CXXDestructorDecl *dtor = LookupDestructor( 1329 cast<CXXRecordDecl>(AllocType->getAs<RecordType>()->getDecl()))) { 1330 MarkFunctionReferenced(StartLoc, dtor); 1331 CheckDestructorAccess(StartLoc, dtor, 1332 PDiag(diag::err_access_dtor) 1333 << Context.getBaseElementType(AllocType)); 1334 DiagnoseUseOfDecl(dtor, StartLoc); 1335 } 1336 } 1337 1338 PlacementArgs.release(); 1339 1340 return Owned(new (Context) CXXNewExpr(Context, UseGlobal, OperatorNew, 1341 OperatorDelete, 1342 UsualArrayDeleteWantsSize, 1343 PlaceArgs, NumPlaceArgs, TypeIdParens, 1344 ArraySize, initStyle, Initializer, 1345 ResultType, AllocTypeInfo, 1346 StartLoc, DirectInitRange)); 1347} 1348 1349/// \brief Checks that a type is suitable as the allocated type 1350/// in a new-expression. 1351bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, 1352 SourceRange R) { 1353 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 1354 // abstract class type or array thereof. 1355 if (AllocType->isFunctionType()) 1356 return Diag(Loc, diag::err_bad_new_type) 1357 << AllocType << 0 << R; 1358 else if (AllocType->isReferenceType()) 1359 return Diag(Loc, diag::err_bad_new_type) 1360 << AllocType << 1 << R; 1361 else if (!AllocType->isDependentType() && 1362 RequireCompleteType(Loc, AllocType, 1363 PDiag(diag::err_new_incomplete_type) 1364 << R)) 1365 return true; 1366 else if (RequireNonAbstractType(Loc, AllocType, 1367 diag::err_allocation_of_abstract_type)) 1368 return true; 1369 else if (AllocType->isVariablyModifiedType()) 1370 return Diag(Loc, diag::err_variably_modified_new_type) 1371 << AllocType; 1372 else if (unsigned AddressSpace = AllocType.getAddressSpace()) 1373 return Diag(Loc, diag::err_address_space_qualified_new) 1374 << AllocType.getUnqualifiedType() << AddressSpace; 1375 else if (getLangOptions().ObjCAutoRefCount) { 1376 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { 1377 QualType BaseAllocType = Context.getBaseElementType(AT); 1378 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && 1379 BaseAllocType->isObjCLifetimeType()) 1380 return Diag(Loc, diag::err_arc_new_array_without_ownership) 1381 << BaseAllocType; 1382 } 1383 } 1384 1385 return false; 1386} 1387 1388/// \brief Determine whether the given function is a non-placement 1389/// deallocation function. 1390static bool isNonPlacementDeallocationFunction(FunctionDecl *FD) { 1391 if (FD->isInvalidDecl()) 1392 return false; 1393 1394 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 1395 return Method->isUsualDeallocationFunction(); 1396 1397 return ((FD->getOverloadedOperator() == OO_Delete || 1398 FD->getOverloadedOperator() == OO_Array_Delete) && 1399 FD->getNumParams() == 1); 1400} 1401 1402/// FindAllocationFunctions - Finds the overloads of operator new and delete 1403/// that are appropriate for the allocation. 1404bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 1405 bool UseGlobal, QualType AllocType, 1406 bool IsArray, Expr **PlaceArgs, 1407 unsigned NumPlaceArgs, 1408 FunctionDecl *&OperatorNew, 1409 FunctionDecl *&OperatorDelete) { 1410 // --- Choosing an allocation function --- 1411 // C++ 5.3.4p8 - 14 & 18 1412 // 1) If UseGlobal is true, only look in the global scope. Else, also look 1413 // in the scope of the allocated class. 1414 // 2) If an array size is given, look for operator new[], else look for 1415 // operator new. 1416 // 3) The first argument is always size_t. Append the arguments from the 1417 // placement form. 1418 1419 SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs); 1420 // We don't care about the actual value of this argument. 1421 // FIXME: Should the Sema create the expression and embed it in the syntax 1422 // tree? Or should the consumer just recalculate the value? 1423 IntegerLiteral Size(Context, llvm::APInt::getNullValue( 1424 Context.getTargetInfo().getPointerWidth(0)), 1425 Context.getSizeType(), 1426 SourceLocation()); 1427 AllocArgs[0] = &Size; 1428 std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1); 1429 1430 // C++ [expr.new]p8: 1431 // If the allocated type is a non-array type, the allocation 1432 // function's name is operator new and the deallocation function's 1433 // name is operator delete. If the allocated type is an array 1434 // type, the allocation function's name is operator new[] and the 1435 // deallocation function's name is operator delete[]. 1436 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 1437 IsArray ? OO_Array_New : OO_New); 1438 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 1439 IsArray ? OO_Array_Delete : OO_Delete); 1440 1441 QualType AllocElemType = Context.getBaseElementType(AllocType); 1442 1443 if (AllocElemType->isRecordType() && !UseGlobal) { 1444 CXXRecordDecl *Record 1445 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1446 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 1447 AllocArgs.size(), Record, /*AllowMissing=*/true, 1448 OperatorNew)) 1449 return true; 1450 } 1451 if (!OperatorNew) { 1452 // Didn't find a member overload. Look for a global one. 1453 DeclareGlobalNewDelete(); 1454 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 1455 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 1456 AllocArgs.size(), TUDecl, /*AllowMissing=*/false, 1457 OperatorNew)) 1458 return true; 1459 } 1460 1461 // We don't need an operator delete if we're running under 1462 // -fno-exceptions. 1463 if (!getLangOptions().Exceptions) { 1464 OperatorDelete = 0; 1465 return false; 1466 } 1467 1468 // FindAllocationOverload can change the passed in arguments, so we need to 1469 // copy them back. 1470 if (NumPlaceArgs > 0) 1471 std::copy(&AllocArgs[1], AllocArgs.end(), PlaceArgs); 1472 1473 // C++ [expr.new]p19: 1474 // 1475 // If the new-expression begins with a unary :: operator, the 1476 // deallocation function's name is looked up in the global 1477 // scope. Otherwise, if the allocated type is a class type T or an 1478 // array thereof, the deallocation function's name is looked up in 1479 // the scope of T. If this lookup fails to find the name, or if 1480 // the allocated type is not a class type or array thereof, the 1481 // deallocation function's name is looked up in the global scope. 1482 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); 1483 if (AllocElemType->isRecordType() && !UseGlobal) { 1484 CXXRecordDecl *RD 1485 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1486 LookupQualifiedName(FoundDelete, RD); 1487 } 1488 if (FoundDelete.isAmbiguous()) 1489 return true; // FIXME: clean up expressions? 1490 1491 if (FoundDelete.empty()) { 1492 DeclareGlobalNewDelete(); 1493 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 1494 } 1495 1496 FoundDelete.suppressDiagnostics(); 1497 1498 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches; 1499 1500 // Whether we're looking for a placement operator delete is dictated 1501 // by whether we selected a placement operator new, not by whether 1502 // we had explicit placement arguments. This matters for things like 1503 // struct A { void *operator new(size_t, int = 0); ... }; 1504 // A *a = new A() 1505 bool isPlacementNew = (NumPlaceArgs > 0 || OperatorNew->param_size() != 1); 1506 1507 if (isPlacementNew) { 1508 // C++ [expr.new]p20: 1509 // A declaration of a placement deallocation function matches the 1510 // declaration of a placement allocation function if it has the 1511 // same number of parameters and, after parameter transformations 1512 // (8.3.5), all parameter types except the first are 1513 // identical. [...] 1514 // 1515 // To perform this comparison, we compute the function type that 1516 // the deallocation function should have, and use that type both 1517 // for template argument deduction and for comparison purposes. 1518 // 1519 // FIXME: this comparison should ignore CC and the like. 1520 QualType ExpectedFunctionType; 1521 { 1522 const FunctionProtoType *Proto 1523 = OperatorNew->getType()->getAs<FunctionProtoType>(); 1524 1525 SmallVector<QualType, 4> ArgTypes; 1526 ArgTypes.push_back(Context.VoidPtrTy); 1527 for (unsigned I = 1, N = Proto->getNumArgs(); I < N; ++I) 1528 ArgTypes.push_back(Proto->getArgType(I)); 1529 1530 FunctionProtoType::ExtProtoInfo EPI; 1531 EPI.Variadic = Proto->isVariadic(); 1532 1533 ExpectedFunctionType 1534 = Context.getFunctionType(Context.VoidTy, ArgTypes.data(), 1535 ArgTypes.size(), EPI); 1536 } 1537 1538 for (LookupResult::iterator D = FoundDelete.begin(), 1539 DEnd = FoundDelete.end(); 1540 D != DEnd; ++D) { 1541 FunctionDecl *Fn = 0; 1542 if (FunctionTemplateDecl *FnTmpl 1543 = dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) { 1544 // Perform template argument deduction to try to match the 1545 // expected function type. 1546 TemplateDeductionInfo Info(Context, StartLoc); 1547 if (DeduceTemplateArguments(FnTmpl, 0, ExpectedFunctionType, Fn, Info)) 1548 continue; 1549 } else 1550 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl()); 1551 1552 if (Context.hasSameType(Fn->getType(), ExpectedFunctionType)) 1553 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1554 } 1555 } else { 1556 // C++ [expr.new]p20: 1557 // [...] Any non-placement deallocation function matches a 1558 // non-placement allocation function. [...] 1559 for (LookupResult::iterator D = FoundDelete.begin(), 1560 DEnd = FoundDelete.end(); 1561 D != DEnd; ++D) { 1562 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl())) 1563 if (isNonPlacementDeallocationFunction(Fn)) 1564 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1565 } 1566 } 1567 1568 // C++ [expr.new]p20: 1569 // [...] If the lookup finds a single matching deallocation 1570 // function, that function will be called; otherwise, no 1571 // deallocation function will be called. 1572 if (Matches.size() == 1) { 1573 OperatorDelete = Matches[0].second; 1574 1575 // C++0x [expr.new]p20: 1576 // If the lookup finds the two-parameter form of a usual 1577 // deallocation function (3.7.4.2) and that function, considered 1578 // as a placement deallocation function, would have been 1579 // selected as a match for the allocation function, the program 1580 // is ill-formed. 1581 if (NumPlaceArgs && getLangOptions().CPlusPlus0x && 1582 isNonPlacementDeallocationFunction(OperatorDelete)) { 1583 Diag(StartLoc, diag::err_placement_new_non_placement_delete) 1584 << SourceRange(PlaceArgs[0]->getLocStart(), 1585 PlaceArgs[NumPlaceArgs - 1]->getLocEnd()); 1586 Diag(OperatorDelete->getLocation(), diag::note_previous_decl) 1587 << DeleteName; 1588 } else { 1589 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), 1590 Matches[0].first); 1591 } 1592 } 1593 1594 return false; 1595} 1596 1597/// FindAllocationOverload - Find an fitting overload for the allocation 1598/// function in the specified scope. 1599bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, 1600 DeclarationName Name, Expr** Args, 1601 unsigned NumArgs, DeclContext *Ctx, 1602 bool AllowMissing, FunctionDecl *&Operator, 1603 bool Diagnose) { 1604 LookupResult R(*this, Name, StartLoc, LookupOrdinaryName); 1605 LookupQualifiedName(R, Ctx); 1606 if (R.empty()) { 1607 if (AllowMissing || !Diagnose) 1608 return false; 1609 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1610 << Name << Range; 1611 } 1612 1613 if (R.isAmbiguous()) 1614 return true; 1615 1616 R.suppressDiagnostics(); 1617 1618 OverloadCandidateSet Candidates(StartLoc); 1619 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); 1620 Alloc != AllocEnd; ++Alloc) { 1621 // Even member operator new/delete are implicitly treated as 1622 // static, so don't use AddMemberCandidate. 1623 NamedDecl *D = (*Alloc)->getUnderlyingDecl(); 1624 1625 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { 1626 AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), 1627 /*ExplicitTemplateArgs=*/0, Args, NumArgs, 1628 Candidates, 1629 /*SuppressUserConversions=*/false); 1630 continue; 1631 } 1632 1633 FunctionDecl *Fn = cast<FunctionDecl>(D); 1634 AddOverloadCandidate(Fn, Alloc.getPair(), Args, NumArgs, Candidates, 1635 /*SuppressUserConversions=*/false); 1636 } 1637 1638 // Do the resolution. 1639 OverloadCandidateSet::iterator Best; 1640 switch (Candidates.BestViableFunction(*this, StartLoc, Best)) { 1641 case OR_Success: { 1642 // Got one! 1643 FunctionDecl *FnDecl = Best->Function; 1644 MarkFunctionReferenced(StartLoc, FnDecl); 1645 // The first argument is size_t, and the first parameter must be size_t, 1646 // too. This is checked on declaration and can be assumed. (It can't be 1647 // asserted on, though, since invalid decls are left in there.) 1648 // Watch out for variadic allocator function. 1649 unsigned NumArgsInFnDecl = FnDecl->getNumParams(); 1650 for (unsigned i = 0; (i < NumArgs && i < NumArgsInFnDecl); ++i) { 1651 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context, 1652 FnDecl->getParamDecl(i)); 1653 1654 if (!Diagnose && !CanPerformCopyInitialization(Entity, Owned(Args[i]))) 1655 return true; 1656 1657 ExprResult Result 1658 = PerformCopyInitialization(Entity, SourceLocation(), Owned(Args[i])); 1659 if (Result.isInvalid()) 1660 return true; 1661 1662 Args[i] = Result.takeAs<Expr>(); 1663 } 1664 Operator = FnDecl; 1665 CheckAllocationAccess(StartLoc, Range, R.getNamingClass(), Best->FoundDecl, 1666 Diagnose); 1667 return false; 1668 } 1669 1670 case OR_No_Viable_Function: 1671 if (Diagnose) { 1672 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1673 << Name << Range; 1674 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 1675 } 1676 return true; 1677 1678 case OR_Ambiguous: 1679 if (Diagnose) { 1680 Diag(StartLoc, diag::err_ovl_ambiguous_call) 1681 << Name << Range; 1682 Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 1683 } 1684 return true; 1685 1686 case OR_Deleted: { 1687 if (Diagnose) { 1688 Diag(StartLoc, diag::err_ovl_deleted_call) 1689 << Best->Function->isDeleted() 1690 << Name 1691 << getDeletedOrUnavailableSuffix(Best->Function) 1692 << Range; 1693 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 1694 } 1695 return true; 1696 } 1697 } 1698 llvm_unreachable("Unreachable, bad result from BestViableFunction"); 1699} 1700 1701 1702/// DeclareGlobalNewDelete - Declare the global forms of operator new and 1703/// delete. These are: 1704/// @code 1705/// // C++03: 1706/// void* operator new(std::size_t) throw(std::bad_alloc); 1707/// void* operator new[](std::size_t) throw(std::bad_alloc); 1708/// void operator delete(void *) throw(); 1709/// void operator delete[](void *) throw(); 1710/// // C++0x: 1711/// void* operator new(std::size_t); 1712/// void* operator new[](std::size_t); 1713/// void operator delete(void *); 1714/// void operator delete[](void *); 1715/// @endcode 1716/// C++0x operator delete is implicitly noexcept. 1717/// Note that the placement and nothrow forms of new are *not* implicitly 1718/// declared. Their use requires including \<new\>. 1719void Sema::DeclareGlobalNewDelete() { 1720 if (GlobalNewDeleteDeclared) 1721 return; 1722 1723 // C++ [basic.std.dynamic]p2: 1724 // [...] The following allocation and deallocation functions (18.4) are 1725 // implicitly declared in global scope in each translation unit of a 1726 // program 1727 // 1728 // C++03: 1729 // void* operator new(std::size_t) throw(std::bad_alloc); 1730 // void* operator new[](std::size_t) throw(std::bad_alloc); 1731 // void operator delete(void*) throw(); 1732 // void operator delete[](void*) throw(); 1733 // C++0x: 1734 // void* operator new(std::size_t); 1735 // void* operator new[](std::size_t); 1736 // void operator delete(void*); 1737 // void operator delete[](void*); 1738 // 1739 // These implicit declarations introduce only the function names operator 1740 // new, operator new[], operator delete, operator delete[]. 1741 // 1742 // Here, we need to refer to std::bad_alloc, so we will implicitly declare 1743 // "std" or "bad_alloc" as necessary to form the exception specification. 1744 // However, we do not make these implicit declarations visible to name 1745 // lookup. 1746 // Note that the C++0x versions of operator delete are deallocation functions, 1747 // and thus are implicitly noexcept. 1748 if (!StdBadAlloc && !getLangOptions().CPlusPlus0x) { 1749 // The "std::bad_alloc" class has not yet been declared, so build it 1750 // implicitly. 1751 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, 1752 getOrCreateStdNamespace(), 1753 SourceLocation(), SourceLocation(), 1754 &PP.getIdentifierTable().get("bad_alloc"), 1755 0); 1756 getStdBadAlloc()->setImplicit(true); 1757 } 1758 1759 GlobalNewDeleteDeclared = true; 1760 1761 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 1762 QualType SizeT = Context.getSizeType(); 1763 bool AssumeSaneOperatorNew = getLangOptions().AssumeSaneOperatorNew; 1764 1765 DeclareGlobalAllocationFunction( 1766 Context.DeclarationNames.getCXXOperatorName(OO_New), 1767 VoidPtr, SizeT, AssumeSaneOperatorNew); 1768 DeclareGlobalAllocationFunction( 1769 Context.DeclarationNames.getCXXOperatorName(OO_Array_New), 1770 VoidPtr, SizeT, AssumeSaneOperatorNew); 1771 DeclareGlobalAllocationFunction( 1772 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 1773 Context.VoidTy, VoidPtr); 1774 DeclareGlobalAllocationFunction( 1775 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 1776 Context.VoidTy, VoidPtr); 1777} 1778 1779/// DeclareGlobalAllocationFunction - Declares a single implicit global 1780/// allocation function if it doesn't already exist. 1781void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 1782 QualType Return, QualType Argument, 1783 bool AddMallocAttr) { 1784 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 1785 1786 // Check if this function is already declared. 1787 { 1788 DeclContext::lookup_iterator Alloc, AllocEnd; 1789 for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Name); 1790 Alloc != AllocEnd; ++Alloc) { 1791 // Only look at non-template functions, as it is the predefined, 1792 // non-templated allocation function we are trying to declare here. 1793 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) { 1794 QualType InitialParamType = 1795 Context.getCanonicalType( 1796 Func->getParamDecl(0)->getType().getUnqualifiedType()); 1797 // FIXME: Do we need to check for default arguments here? 1798 if (Func->getNumParams() == 1 && InitialParamType == Argument) { 1799 if(AddMallocAttr && !Func->hasAttr<MallocAttr>()) 1800 Func->addAttr(::new (Context) MallocAttr(SourceLocation(), Context)); 1801 return; 1802 } 1803 } 1804 } 1805 } 1806 1807 QualType BadAllocType; 1808 bool HasBadAllocExceptionSpec 1809 = (Name.getCXXOverloadedOperator() == OO_New || 1810 Name.getCXXOverloadedOperator() == OO_Array_New); 1811 if (HasBadAllocExceptionSpec && !getLangOptions().CPlusPlus0x) { 1812 assert(StdBadAlloc && "Must have std::bad_alloc declared"); 1813 BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); 1814 } 1815 1816 FunctionProtoType::ExtProtoInfo EPI; 1817 if (HasBadAllocExceptionSpec) { 1818 if (!getLangOptions().CPlusPlus0x) { 1819 EPI.ExceptionSpecType = EST_Dynamic; 1820 EPI.NumExceptions = 1; 1821 EPI.Exceptions = &BadAllocType; 1822 } 1823 } else { 1824 EPI.ExceptionSpecType = getLangOptions().CPlusPlus0x ? 1825 EST_BasicNoexcept : EST_DynamicNone; 1826 } 1827 1828 QualType FnType = Context.getFunctionType(Return, &Argument, 1, EPI); 1829 FunctionDecl *Alloc = 1830 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), 1831 SourceLocation(), Name, 1832 FnType, /*TInfo=*/0, SC_None, 1833 SC_None, false, true); 1834 Alloc->setImplicit(); 1835 1836 if (AddMallocAttr) 1837 Alloc->addAttr(::new (Context) MallocAttr(SourceLocation(), Context)); 1838 1839 ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(), 1840 SourceLocation(), 0, 1841 Argument, /*TInfo=*/0, 1842 SC_None, SC_None, 0); 1843 Alloc->setParams(Param); 1844 1845 // FIXME: Also add this declaration to the IdentifierResolver, but 1846 // make sure it is at the end of the chain to coincide with the 1847 // global scope. 1848 Context.getTranslationUnitDecl()->addDecl(Alloc); 1849} 1850 1851bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 1852 DeclarationName Name, 1853 FunctionDecl* &Operator, bool Diagnose) { 1854 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); 1855 // Try to find operator delete/operator delete[] in class scope. 1856 LookupQualifiedName(Found, RD); 1857 1858 if (Found.isAmbiguous()) 1859 return true; 1860 1861 Found.suppressDiagnostics(); 1862 1863 SmallVector<DeclAccessPair,4> Matches; 1864 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 1865 F != FEnd; ++F) { 1866 NamedDecl *ND = (*F)->getUnderlyingDecl(); 1867 1868 // Ignore template operator delete members from the check for a usual 1869 // deallocation function. 1870 if (isa<FunctionTemplateDecl>(ND)) 1871 continue; 1872 1873 if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction()) 1874 Matches.push_back(F.getPair()); 1875 } 1876 1877 // There's exactly one suitable operator; pick it. 1878 if (Matches.size() == 1) { 1879 Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl()); 1880 1881 if (Operator->isDeleted()) { 1882 if (Diagnose) { 1883 Diag(StartLoc, diag::err_deleted_function_use); 1884 Diag(Operator->getLocation(), diag::note_unavailable_here) << true; 1885 } 1886 return true; 1887 } 1888 1889 CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), 1890 Matches[0], Diagnose); 1891 return false; 1892 1893 // We found multiple suitable operators; complain about the ambiguity. 1894 } else if (!Matches.empty()) { 1895 if (Diagnose) { 1896 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) 1897 << Name << RD; 1898 1899 for (SmallVectorImpl<DeclAccessPair>::iterator 1900 F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F) 1901 Diag((*F)->getUnderlyingDecl()->getLocation(), 1902 diag::note_member_declared_here) << Name; 1903 } 1904 return true; 1905 } 1906 1907 // We did find operator delete/operator delete[] declarations, but 1908 // none of them were suitable. 1909 if (!Found.empty()) { 1910 if (Diagnose) { 1911 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) 1912 << Name << RD; 1913 1914 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 1915 F != FEnd; ++F) 1916 Diag((*F)->getUnderlyingDecl()->getLocation(), 1917 diag::note_member_declared_here) << Name; 1918 } 1919 return true; 1920 } 1921 1922 // Look for a global declaration. 1923 DeclareGlobalNewDelete(); 1924 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 1925 1926 CXXNullPtrLiteralExpr Null(Context.VoidPtrTy, SourceLocation()); 1927 Expr* DeallocArgs[1]; 1928 DeallocArgs[0] = &Null; 1929 if (FindAllocationOverload(StartLoc, SourceRange(), Name, 1930 DeallocArgs, 1, TUDecl, !Diagnose, 1931 Operator, Diagnose)) 1932 return true; 1933 1934 assert(Operator && "Did not find a deallocation function!"); 1935 return false; 1936} 1937 1938/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 1939/// @code ::delete ptr; @endcode 1940/// or 1941/// @code delete [] ptr; @endcode 1942ExprResult 1943Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 1944 bool ArrayForm, Expr *ExE) { 1945 // C++ [expr.delete]p1: 1946 // The operand shall have a pointer type, or a class type having a single 1947 // conversion function to a pointer type. The result has type void. 1948 // 1949 // DR599 amends "pointer type" to "pointer to object type" in both cases. 1950 1951 ExprResult Ex = Owned(ExE); 1952 FunctionDecl *OperatorDelete = 0; 1953 bool ArrayFormAsWritten = ArrayForm; 1954 bool UsualArrayDeleteWantsSize = false; 1955 1956 if (!Ex.get()->isTypeDependent()) { 1957 QualType Type = Ex.get()->getType(); 1958 1959 if (const RecordType *Record = Type->getAs<RecordType>()) { 1960 if (RequireCompleteType(StartLoc, Type, 1961 PDiag(diag::err_delete_incomplete_class_type))) 1962 return ExprError(); 1963 1964 SmallVector<CXXConversionDecl*, 4> ObjectPtrConversions; 1965 1966 CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()); 1967 const UnresolvedSetImpl *Conversions = RD->getVisibleConversionFunctions(); 1968 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1969 E = Conversions->end(); I != E; ++I) { 1970 NamedDecl *D = I.getDecl(); 1971 if (isa<UsingShadowDecl>(D)) 1972 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1973 1974 // Skip over templated conversion functions; they aren't considered. 1975 if (isa<FunctionTemplateDecl>(D)) 1976 continue; 1977 1978 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 1979 1980 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 1981 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 1982 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) 1983 ObjectPtrConversions.push_back(Conv); 1984 } 1985 if (ObjectPtrConversions.size() == 1) { 1986 // We have a single conversion to a pointer-to-object type. Perform 1987 // that conversion. 1988 // TODO: don't redo the conversion calculation. 1989 ExprResult Res = 1990 PerformImplicitConversion(Ex.get(), 1991 ObjectPtrConversions.front()->getConversionType(), 1992 AA_Converting); 1993 if (Res.isUsable()) { 1994 Ex = move(Res); 1995 Type = Ex.get()->getType(); 1996 } 1997 } 1998 else if (ObjectPtrConversions.size() > 1) { 1999 Diag(StartLoc, diag::err_ambiguous_delete_operand) 2000 << Type << Ex.get()->getSourceRange(); 2001 for (unsigned i= 0; i < ObjectPtrConversions.size(); i++) 2002 NoteOverloadCandidate(ObjectPtrConversions[i]); 2003 return ExprError(); 2004 } 2005 } 2006 2007 if (!Type->isPointerType()) 2008 return ExprError(Diag(StartLoc, diag::err_delete_operand) 2009 << Type << Ex.get()->getSourceRange()); 2010 2011 QualType Pointee = Type->getAs<PointerType>()->getPointeeType(); 2012 QualType PointeeElem = Context.getBaseElementType(Pointee); 2013 2014 if (unsigned AddressSpace = Pointee.getAddressSpace()) 2015 return Diag(Ex.get()->getLocStart(), 2016 diag::err_address_space_qualified_delete) 2017 << Pointee.getUnqualifiedType() << AddressSpace; 2018 2019 CXXRecordDecl *PointeeRD = 0; 2020 if (Pointee->isVoidType() && !isSFINAEContext()) { 2021 // The C++ standard bans deleting a pointer to a non-object type, which 2022 // effectively bans deletion of "void*". However, most compilers support 2023 // this, so we treat it as a warning unless we're in a SFINAE context. 2024 Diag(StartLoc, diag::ext_delete_void_ptr_operand) 2025 << Type << Ex.get()->getSourceRange(); 2026 } else if (Pointee->isFunctionType() || Pointee->isVoidType()) { 2027 return ExprError(Diag(StartLoc, diag::err_delete_operand) 2028 << Type << Ex.get()->getSourceRange()); 2029 } else if (!Pointee->isDependentType()) { 2030 if (!RequireCompleteType(StartLoc, Pointee, 2031 PDiag(diag::warn_delete_incomplete) 2032 << Ex.get()->getSourceRange())) { 2033 if (const RecordType *RT = PointeeElem->getAs<RecordType>()) 2034 PointeeRD = cast<CXXRecordDecl>(RT->getDecl()); 2035 } 2036 } 2037 2038 // Perform lvalue-to-rvalue cast, if needed. 2039 Ex = DefaultLvalueConversion(Ex.take()); 2040 2041 // C++ [expr.delete]p2: 2042 // [Note: a pointer to a const type can be the operand of a 2043 // delete-expression; it is not necessary to cast away the constness 2044 // (5.2.11) of the pointer expression before it is used as the operand 2045 // of the delete-expression. ] 2046 if (!Context.hasSameType(Ex.get()->getType(), Context.VoidPtrTy)) 2047 Ex = Owned(ImplicitCastExpr::Create(Context, Context.VoidPtrTy, 2048 CK_BitCast, Ex.take(), 0, VK_RValue)); 2049 2050 if (Pointee->isArrayType() && !ArrayForm) { 2051 Diag(StartLoc, diag::warn_delete_array_type) 2052 << Type << Ex.get()->getSourceRange() 2053 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(StartLoc), "[]"); 2054 ArrayForm = true; 2055 } 2056 2057 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 2058 ArrayForm ? OO_Array_Delete : OO_Delete); 2059 2060 if (PointeeRD) { 2061 if (!UseGlobal && 2062 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, 2063 OperatorDelete)) 2064 return ExprError(); 2065 2066 // If we're allocating an array of records, check whether the 2067 // usual operator delete[] has a size_t parameter. 2068 if (ArrayForm) { 2069 // If the user specifically asked to use the global allocator, 2070 // we'll need to do the lookup into the class. 2071 if (UseGlobal) 2072 UsualArrayDeleteWantsSize = 2073 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); 2074 2075 // Otherwise, the usual operator delete[] should be the 2076 // function we just found. 2077 else if (isa<CXXMethodDecl>(OperatorDelete)) 2078 UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2); 2079 } 2080 2081 if (!PointeeRD->hasIrrelevantDestructor()) 2082 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2083 MarkFunctionReferenced(StartLoc, 2084 const_cast<CXXDestructorDecl*>(Dtor)); 2085 DiagnoseUseOfDecl(Dtor, StartLoc); 2086 } 2087 2088 // C++ [expr.delete]p3: 2089 // In the first alternative (delete object), if the static type of the 2090 // object to be deleted is different from its dynamic type, the static 2091 // type shall be a base class of the dynamic type of the object to be 2092 // deleted and the static type shall have a virtual destructor or the 2093 // behavior is undefined. 2094 // 2095 // Note: a final class cannot be derived from, no issue there 2096 if (PointeeRD->isPolymorphic() && !PointeeRD->hasAttr<FinalAttr>()) { 2097 CXXDestructorDecl *dtor = PointeeRD->getDestructor(); 2098 if (dtor && !dtor->isVirtual()) { 2099 if (PointeeRD->isAbstract()) { 2100 // If the class is abstract, we warn by default, because we're 2101 // sure the code has undefined behavior. 2102 Diag(StartLoc, diag::warn_delete_abstract_non_virtual_dtor) 2103 << PointeeElem; 2104 } else if (!ArrayForm) { 2105 // Otherwise, if this is not an array delete, it's a bit suspect, 2106 // but not necessarily wrong. 2107 Diag(StartLoc, diag::warn_delete_non_virtual_dtor) << PointeeElem; 2108 } 2109 } 2110 } 2111 2112 } else if (getLangOptions().ObjCAutoRefCount && 2113 PointeeElem->isObjCLifetimeType() && 2114 (PointeeElem.getObjCLifetime() == Qualifiers::OCL_Strong || 2115 PointeeElem.getObjCLifetime() == Qualifiers::OCL_Weak) && 2116 ArrayForm) { 2117 Diag(StartLoc, diag::warn_err_new_delete_object_array) 2118 << 1 << PointeeElem; 2119 } 2120 2121 if (!OperatorDelete) { 2122 // Look for a global declaration. 2123 DeclareGlobalNewDelete(); 2124 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 2125 Expr *Arg = Ex.get(); 2126 if (FindAllocationOverload(StartLoc, SourceRange(), DeleteName, 2127 &Arg, 1, TUDecl, /*AllowMissing=*/false, 2128 OperatorDelete)) 2129 return ExprError(); 2130 } 2131 2132 MarkFunctionReferenced(StartLoc, OperatorDelete); 2133 2134 // Check access and ambiguity of operator delete and destructor. 2135 if (PointeeRD) { 2136 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2137 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, 2138 PDiag(diag::err_access_dtor) << PointeeElem); 2139 } 2140 } 2141 2142 } 2143 2144 return Owned(new (Context) CXXDeleteExpr(Context.VoidTy, UseGlobal, ArrayForm, 2145 ArrayFormAsWritten, 2146 UsualArrayDeleteWantsSize, 2147 OperatorDelete, Ex.take(), StartLoc)); 2148} 2149 2150/// \brief Check the use of the given variable as a C++ condition in an if, 2151/// while, do-while, or switch statement. 2152ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, 2153 SourceLocation StmtLoc, 2154 bool ConvertToBoolean) { 2155 QualType T = ConditionVar->getType(); 2156 2157 // C++ [stmt.select]p2: 2158 // The declarator shall not specify a function or an array. 2159 if (T->isFunctionType()) 2160 return ExprError(Diag(ConditionVar->getLocation(), 2161 diag::err_invalid_use_of_function_type) 2162 << ConditionVar->getSourceRange()); 2163 else if (T->isArrayType()) 2164 return ExprError(Diag(ConditionVar->getLocation(), 2165 diag::err_invalid_use_of_array_type) 2166 << ConditionVar->getSourceRange()); 2167 2168 ExprResult Condition = 2169 Owned(DeclRefExpr::Create(Context, NestedNameSpecifierLoc(), 2170 SourceLocation(), 2171 ConditionVar, 2172 ConditionVar->getLocation(), 2173 ConditionVar->getType().getNonReferenceType(), 2174 VK_LValue)); 2175 2176 MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get())); 2177 2178 if (ConvertToBoolean) { 2179 Condition = CheckBooleanCondition(Condition.take(), StmtLoc); 2180 if (Condition.isInvalid()) 2181 return ExprError(); 2182 } 2183 2184 return move(Condition); 2185} 2186 2187/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 2188ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr) { 2189 // C++ 6.4p4: 2190 // The value of a condition that is an initialized declaration in a statement 2191 // other than a switch statement is the value of the declared variable 2192 // implicitly converted to type bool. If that conversion is ill-formed, the 2193 // program is ill-formed. 2194 // The value of a condition that is an expression is the value of the 2195 // expression, implicitly converted to bool. 2196 // 2197 return PerformContextuallyConvertToBool(CondExpr); 2198} 2199 2200/// Helper function to determine whether this is the (deprecated) C++ 2201/// conversion from a string literal to a pointer to non-const char or 2202/// non-const wchar_t (for narrow and wide string literals, 2203/// respectively). 2204bool 2205Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 2206 // Look inside the implicit cast, if it exists. 2207 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 2208 From = Cast->getSubExpr(); 2209 2210 // A string literal (2.13.4) that is not a wide string literal can 2211 // be converted to an rvalue of type "pointer to char"; a wide 2212 // string literal can be converted to an rvalue of type "pointer 2213 // to wchar_t" (C++ 4.2p2). 2214 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens())) 2215 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) 2216 if (const BuiltinType *ToPointeeType 2217 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) { 2218 // This conversion is considered only when there is an 2219 // explicit appropriate pointer target type (C++ 4.2p2). 2220 if (!ToPtrType->getPointeeType().hasQualifiers()) { 2221 switch (StrLit->getKind()) { 2222 case StringLiteral::UTF8: 2223 case StringLiteral::UTF16: 2224 case StringLiteral::UTF32: 2225 // We don't allow UTF literals to be implicitly converted 2226 break; 2227 case StringLiteral::Ascii: 2228 return (ToPointeeType->getKind() == BuiltinType::Char_U || 2229 ToPointeeType->getKind() == BuiltinType::Char_S); 2230 case StringLiteral::Wide: 2231 return ToPointeeType->isWideCharType(); 2232 } 2233 } 2234 } 2235 2236 return false; 2237} 2238 2239static ExprResult BuildCXXCastArgument(Sema &S, 2240 SourceLocation CastLoc, 2241 QualType Ty, 2242 CastKind Kind, 2243 CXXMethodDecl *Method, 2244 DeclAccessPair FoundDecl, 2245 bool HadMultipleCandidates, 2246 Expr *From) { 2247 switch (Kind) { 2248 default: llvm_unreachable("Unhandled cast kind!"); 2249 case CK_ConstructorConversion: { 2250 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method); 2251 ASTOwningVector<Expr*> ConstructorArgs(S); 2252 2253 if (S.CompleteConstructorCall(Constructor, 2254 MultiExprArg(&From, 1), 2255 CastLoc, ConstructorArgs)) 2256 return ExprError(); 2257 2258 S.CheckConstructorAccess(CastLoc, Constructor, Constructor->getAccess(), 2259 S.PDiag(diag::err_access_ctor)); 2260 2261 ExprResult Result 2262 = S.BuildCXXConstructExpr(CastLoc, Ty, cast<CXXConstructorDecl>(Method), 2263 move_arg(ConstructorArgs), 2264 HadMultipleCandidates, /*ZeroInit*/ false, 2265 CXXConstructExpr::CK_Complete, SourceRange()); 2266 if (Result.isInvalid()) 2267 return ExprError(); 2268 2269 return S.MaybeBindToTemporary(Result.takeAs<Expr>()); 2270 } 2271 2272 case CK_UserDefinedConversion: { 2273 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!"); 2274 2275 // Create an implicit call expr that calls it. 2276 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Method, 2277 HadMultipleCandidates); 2278 if (Result.isInvalid()) 2279 return ExprError(); 2280 // Record usage of conversion in an implicit cast. 2281 Result = S.Owned(ImplicitCastExpr::Create(S.Context, 2282 Result.get()->getType(), 2283 CK_UserDefinedConversion, 2284 Result.get(), 0, 2285 Result.get()->getValueKind())); 2286 2287 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ 0, FoundDecl); 2288 2289 return S.MaybeBindToTemporary(Result.get()); 2290 } 2291 } 2292} 2293 2294/// PerformImplicitConversion - Perform an implicit conversion of the 2295/// expression From to the type ToType using the pre-computed implicit 2296/// conversion sequence ICS. Returns the converted 2297/// expression. Action is the kind of conversion we're performing, 2298/// used in the error message. 2299ExprResult 2300Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2301 const ImplicitConversionSequence &ICS, 2302 AssignmentAction Action, 2303 CheckedConversionKind CCK) { 2304 switch (ICS.getKind()) { 2305 case ImplicitConversionSequence::StandardConversion: { 2306 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, 2307 Action, CCK); 2308 if (Res.isInvalid()) 2309 return ExprError(); 2310 From = Res.take(); 2311 break; 2312 } 2313 2314 case ImplicitConversionSequence::UserDefinedConversion: { 2315 2316 FunctionDecl *FD = ICS.UserDefined.ConversionFunction; 2317 CastKind CastKind; 2318 QualType BeforeToType; 2319 assert(FD && "FIXME: aggregate initialization from init list"); 2320 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) { 2321 CastKind = CK_UserDefinedConversion; 2322 2323 // If the user-defined conversion is specified by a conversion function, 2324 // the initial standard conversion sequence converts the source type to 2325 // the implicit object parameter of the conversion function. 2326 BeforeToType = Context.getTagDeclType(Conv->getParent()); 2327 } else { 2328 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD); 2329 CastKind = CK_ConstructorConversion; 2330 // Do no conversion if dealing with ... for the first conversion. 2331 if (!ICS.UserDefined.EllipsisConversion) { 2332 // If the user-defined conversion is specified by a constructor, the 2333 // initial standard conversion sequence converts the source type to the 2334 // type required by the argument of the constructor 2335 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); 2336 } 2337 } 2338 // Watch out for elipsis conversion. 2339 if (!ICS.UserDefined.EllipsisConversion) { 2340 ExprResult Res = 2341 PerformImplicitConversion(From, BeforeToType, 2342 ICS.UserDefined.Before, AA_Converting, 2343 CCK); 2344 if (Res.isInvalid()) 2345 return ExprError(); 2346 From = Res.take(); 2347 } 2348 2349 ExprResult CastArg 2350 = BuildCXXCastArgument(*this, 2351 From->getLocStart(), 2352 ToType.getNonReferenceType(), 2353 CastKind, cast<CXXMethodDecl>(FD), 2354 ICS.UserDefined.FoundConversionFunction, 2355 ICS.UserDefined.HadMultipleCandidates, 2356 From); 2357 2358 if (CastArg.isInvalid()) 2359 return ExprError(); 2360 2361 From = CastArg.take(); 2362 2363 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, 2364 AA_Converting, CCK); 2365 } 2366 2367 case ImplicitConversionSequence::AmbiguousConversion: 2368 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), 2369 PDiag(diag::err_typecheck_ambiguous_condition) 2370 << From->getSourceRange()); 2371 return ExprError(); 2372 2373 case ImplicitConversionSequence::EllipsisConversion: 2374 llvm_unreachable("Cannot perform an ellipsis conversion"); 2375 2376 case ImplicitConversionSequence::BadConversion: 2377 return ExprError(); 2378 } 2379 2380 // Everything went well. 2381 return Owned(From); 2382} 2383 2384/// PerformImplicitConversion - Perform an implicit conversion of the 2385/// expression From to the type ToType by following the standard 2386/// conversion sequence SCS. Returns the converted 2387/// expression. Flavor is the context in which we're performing this 2388/// conversion, for use in error messages. 2389ExprResult 2390Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2391 const StandardConversionSequence& SCS, 2392 AssignmentAction Action, 2393 CheckedConversionKind CCK) { 2394 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); 2395 2396 // Overall FIXME: we are recomputing too many types here and doing far too 2397 // much extra work. What this means is that we need to keep track of more 2398 // information that is computed when we try the implicit conversion initially, 2399 // so that we don't need to recompute anything here. 2400 QualType FromType = From->getType(); 2401 2402 if (SCS.CopyConstructor) { 2403 // FIXME: When can ToType be a reference type? 2404 assert(!ToType->isReferenceType()); 2405 if (SCS.Second == ICK_Derived_To_Base) { 2406 ASTOwningVector<Expr*> ConstructorArgs(*this); 2407 if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor), 2408 MultiExprArg(*this, &From, 1), 2409 /*FIXME:ConstructLoc*/SourceLocation(), 2410 ConstructorArgs)) 2411 return ExprError(); 2412 return BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(), 2413 ToType, SCS.CopyConstructor, 2414 move_arg(ConstructorArgs), 2415 /*HadMultipleCandidates*/ false, 2416 /*ZeroInit*/ false, 2417 CXXConstructExpr::CK_Complete, 2418 SourceRange()); 2419 } 2420 return BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(), 2421 ToType, SCS.CopyConstructor, 2422 MultiExprArg(*this, &From, 1), 2423 /*HadMultipleCandidates*/ false, 2424 /*ZeroInit*/ false, 2425 CXXConstructExpr::CK_Complete, 2426 SourceRange()); 2427 } 2428 2429 // Resolve overloaded function references. 2430 if (Context.hasSameType(FromType, Context.OverloadTy)) { 2431 DeclAccessPair Found; 2432 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, 2433 true, Found); 2434 if (!Fn) 2435 return ExprError(); 2436 2437 if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin())) 2438 return ExprError(); 2439 2440 From = FixOverloadedFunctionReference(From, Found, Fn); 2441 FromType = From->getType(); 2442 } 2443 2444 // Perform the first implicit conversion. 2445 switch (SCS.First) { 2446 case ICK_Identity: 2447 // Nothing to do. 2448 break; 2449 2450 case ICK_Lvalue_To_Rvalue: { 2451 assert(From->getObjectKind() != OK_ObjCProperty); 2452 FromType = FromType.getUnqualifiedType(); 2453 ExprResult FromRes = DefaultLvalueConversion(From); 2454 assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!"); 2455 From = FromRes.take(); 2456 break; 2457 } 2458 2459 case ICK_Array_To_Pointer: 2460 FromType = Context.getArrayDecayedType(FromType); 2461 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, 2462 VK_RValue, /*BasePath=*/0, CCK).take(); 2463 break; 2464 2465 case ICK_Function_To_Pointer: 2466 FromType = Context.getPointerType(FromType); 2467 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, 2468 VK_RValue, /*BasePath=*/0, CCK).take(); 2469 break; 2470 2471 default: 2472 llvm_unreachable("Improper first standard conversion"); 2473 } 2474 2475 // Perform the second implicit conversion 2476 switch (SCS.Second) { 2477 case ICK_Identity: 2478 // If both sides are functions (or pointers/references to them), there could 2479 // be incompatible exception declarations. 2480 if (CheckExceptionSpecCompatibility(From, ToType)) 2481 return ExprError(); 2482 // Nothing else to do. 2483 break; 2484 2485 case ICK_NoReturn_Adjustment: 2486 // If both sides are functions (or pointers/references to them), there could 2487 // be incompatible exception declarations. 2488 if (CheckExceptionSpecCompatibility(From, ToType)) 2489 return ExprError(); 2490 2491 From = ImpCastExprToType(From, ToType, CK_NoOp, 2492 VK_RValue, /*BasePath=*/0, CCK).take(); 2493 break; 2494 2495 case ICK_Integral_Promotion: 2496 case ICK_Integral_Conversion: 2497 From = ImpCastExprToType(From, ToType, CK_IntegralCast, 2498 VK_RValue, /*BasePath=*/0, CCK).take(); 2499 break; 2500 2501 case ICK_Floating_Promotion: 2502 case ICK_Floating_Conversion: 2503 From = ImpCastExprToType(From, ToType, CK_FloatingCast, 2504 VK_RValue, /*BasePath=*/0, CCK).take(); 2505 break; 2506 2507 case ICK_Complex_Promotion: 2508 case ICK_Complex_Conversion: { 2509 QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType(); 2510 QualType ToEl = ToType->getAs<ComplexType>()->getElementType(); 2511 CastKind CK; 2512 if (FromEl->isRealFloatingType()) { 2513 if (ToEl->isRealFloatingType()) 2514 CK = CK_FloatingComplexCast; 2515 else 2516 CK = CK_FloatingComplexToIntegralComplex; 2517 } else if (ToEl->isRealFloatingType()) { 2518 CK = CK_IntegralComplexToFloatingComplex; 2519 } else { 2520 CK = CK_IntegralComplexCast; 2521 } 2522 From = ImpCastExprToType(From, ToType, CK, 2523 VK_RValue, /*BasePath=*/0, CCK).take(); 2524 break; 2525 } 2526 2527 case ICK_Floating_Integral: 2528 if (ToType->isRealFloatingType()) 2529 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, 2530 VK_RValue, /*BasePath=*/0, CCK).take(); 2531 else 2532 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, 2533 VK_RValue, /*BasePath=*/0, CCK).take(); 2534 break; 2535 2536 case ICK_Compatible_Conversion: 2537 From = ImpCastExprToType(From, ToType, CK_NoOp, 2538 VK_RValue, /*BasePath=*/0, CCK).take(); 2539 break; 2540 2541 case ICK_Writeback_Conversion: 2542 case ICK_Pointer_Conversion: { 2543 if (SCS.IncompatibleObjC && Action != AA_Casting) { 2544 // Diagnose incompatible Objective-C conversions 2545 if (Action == AA_Initializing || Action == AA_Assigning) 2546 Diag(From->getSourceRange().getBegin(), 2547 diag::ext_typecheck_convert_incompatible_pointer) 2548 << ToType << From->getType() << Action 2549 << From->getSourceRange() << 0; 2550 else 2551 Diag(From->getSourceRange().getBegin(), 2552 diag::ext_typecheck_convert_incompatible_pointer) 2553 << From->getType() << ToType << Action 2554 << From->getSourceRange() << 0; 2555 2556 if (From->getType()->isObjCObjectPointerType() && 2557 ToType->isObjCObjectPointerType()) 2558 EmitRelatedResultTypeNote(From); 2559 } 2560 else if (getLangOptions().ObjCAutoRefCount && 2561 !CheckObjCARCUnavailableWeakConversion(ToType, 2562 From->getType())) { 2563 if (Action == AA_Initializing) 2564 Diag(From->getSourceRange().getBegin(), 2565 diag::err_arc_weak_unavailable_assign); 2566 else 2567 Diag(From->getSourceRange().getBegin(), 2568 diag::err_arc_convesion_of_weak_unavailable) 2569 << (Action == AA_Casting) << From->getType() << ToType 2570 << From->getSourceRange(); 2571 } 2572 2573 CastKind Kind = CK_Invalid; 2574 CXXCastPath BasePath; 2575 if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle)) 2576 return ExprError(); 2577 2578 // Make sure we extend blocks if necessary. 2579 // FIXME: doing this here is really ugly. 2580 if (Kind == CK_BlockPointerToObjCPointerCast) { 2581 ExprResult E = From; 2582 (void) PrepareCastToObjCObjectPointer(E); 2583 From = E.take(); 2584 } 2585 2586 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 2587 .take(); 2588 break; 2589 } 2590 2591 case ICK_Pointer_Member: { 2592 CastKind Kind = CK_Invalid; 2593 CXXCastPath BasePath; 2594 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) 2595 return ExprError(); 2596 if (CheckExceptionSpecCompatibility(From, ToType)) 2597 return ExprError(); 2598 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 2599 .take(); 2600 break; 2601 } 2602 2603 case ICK_Boolean_Conversion: 2604 // Perform half-to-boolean conversion via float. 2605 if (From->getType()->isHalfType()) { 2606 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).take(); 2607 FromType = Context.FloatTy; 2608 } 2609 2610 From = ImpCastExprToType(From, Context.BoolTy, 2611 ScalarTypeToBooleanCastKind(FromType), 2612 VK_RValue, /*BasePath=*/0, CCK).take(); 2613 break; 2614 2615 case ICK_Derived_To_Base: { 2616 CXXCastPath BasePath; 2617 if (CheckDerivedToBaseConversion(From->getType(), 2618 ToType.getNonReferenceType(), 2619 From->getLocStart(), 2620 From->getSourceRange(), 2621 &BasePath, 2622 CStyle)) 2623 return ExprError(); 2624 2625 From = ImpCastExprToType(From, ToType.getNonReferenceType(), 2626 CK_DerivedToBase, From->getValueKind(), 2627 &BasePath, CCK).take(); 2628 break; 2629 } 2630 2631 case ICK_Vector_Conversion: 2632 From = ImpCastExprToType(From, ToType, CK_BitCast, 2633 VK_RValue, /*BasePath=*/0, CCK).take(); 2634 break; 2635 2636 case ICK_Vector_Splat: 2637 From = ImpCastExprToType(From, ToType, CK_VectorSplat, 2638 VK_RValue, /*BasePath=*/0, CCK).take(); 2639 break; 2640 2641 case ICK_Complex_Real: 2642 // Case 1. x -> _Complex y 2643 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) { 2644 QualType ElType = ToComplex->getElementType(); 2645 bool isFloatingComplex = ElType->isRealFloatingType(); 2646 2647 // x -> y 2648 if (Context.hasSameUnqualifiedType(ElType, From->getType())) { 2649 // do nothing 2650 } else if (From->getType()->isRealFloatingType()) { 2651 From = ImpCastExprToType(From, ElType, 2652 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).take(); 2653 } else { 2654 assert(From->getType()->isIntegerType()); 2655 From = ImpCastExprToType(From, ElType, 2656 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).take(); 2657 } 2658 // y -> _Complex y 2659 From = ImpCastExprToType(From, ToType, 2660 isFloatingComplex ? CK_FloatingRealToComplex 2661 : CK_IntegralRealToComplex).take(); 2662 2663 // Case 2. _Complex x -> y 2664 } else { 2665 const ComplexType *FromComplex = From->getType()->getAs<ComplexType>(); 2666 assert(FromComplex); 2667 2668 QualType ElType = FromComplex->getElementType(); 2669 bool isFloatingComplex = ElType->isRealFloatingType(); 2670 2671 // _Complex x -> x 2672 From = ImpCastExprToType(From, ElType, 2673 isFloatingComplex ? CK_FloatingComplexToReal 2674 : CK_IntegralComplexToReal, 2675 VK_RValue, /*BasePath=*/0, CCK).take(); 2676 2677 // x -> y 2678 if (Context.hasSameUnqualifiedType(ElType, ToType)) { 2679 // do nothing 2680 } else if (ToType->isRealFloatingType()) { 2681 From = ImpCastExprToType(From, ToType, 2682 isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating, 2683 VK_RValue, /*BasePath=*/0, CCK).take(); 2684 } else { 2685 assert(ToType->isIntegerType()); 2686 From = ImpCastExprToType(From, ToType, 2687 isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast, 2688 VK_RValue, /*BasePath=*/0, CCK).take(); 2689 } 2690 } 2691 break; 2692 2693 case ICK_Block_Pointer_Conversion: { 2694 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast, 2695 VK_RValue, /*BasePath=*/0, CCK).take(); 2696 break; 2697 } 2698 2699 case ICK_TransparentUnionConversion: { 2700 ExprResult FromRes = Owned(From); 2701 Sema::AssignConvertType ConvTy = 2702 CheckTransparentUnionArgumentConstraints(ToType, FromRes); 2703 if (FromRes.isInvalid()) 2704 return ExprError(); 2705 From = FromRes.take(); 2706 assert ((ConvTy == Sema::Compatible) && 2707 "Improper transparent union conversion"); 2708 (void)ConvTy; 2709 break; 2710 } 2711 2712 case ICK_Lvalue_To_Rvalue: 2713 case ICK_Array_To_Pointer: 2714 case ICK_Function_To_Pointer: 2715 case ICK_Qualification: 2716 case ICK_Num_Conversion_Kinds: 2717 llvm_unreachable("Improper second standard conversion"); 2718 } 2719 2720 switch (SCS.Third) { 2721 case ICK_Identity: 2722 // Nothing to do. 2723 break; 2724 2725 case ICK_Qualification: { 2726 // The qualification keeps the category of the inner expression, unless the 2727 // target type isn't a reference. 2728 ExprValueKind VK = ToType->isReferenceType() ? 2729 From->getValueKind() : VK_RValue; 2730 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), 2731 CK_NoOp, VK, /*BasePath=*/0, CCK).take(); 2732 2733 if (SCS.DeprecatedStringLiteralToCharPtr && 2734 !getLangOptions().WritableStrings) 2735 Diag(From->getLocStart(), diag::warn_deprecated_string_literal_conversion) 2736 << ToType.getNonReferenceType(); 2737 2738 break; 2739 } 2740 2741 default: 2742 llvm_unreachable("Improper third standard conversion"); 2743 } 2744 2745 return Owned(From); 2746} 2747 2748ExprResult Sema::ActOnUnaryTypeTrait(UnaryTypeTrait UTT, 2749 SourceLocation KWLoc, 2750 ParsedType Ty, 2751 SourceLocation RParen) { 2752 TypeSourceInfo *TSInfo; 2753 QualType T = GetTypeFromParser(Ty, &TSInfo); 2754 2755 if (!TSInfo) 2756 TSInfo = Context.getTrivialTypeSourceInfo(T); 2757 return BuildUnaryTypeTrait(UTT, KWLoc, TSInfo, RParen); 2758} 2759 2760/// \brief Check the completeness of a type in a unary type trait. 2761/// 2762/// If the particular type trait requires a complete type, tries to complete 2763/// it. If completing the type fails, a diagnostic is emitted and false 2764/// returned. If completing the type succeeds or no completion was required, 2765/// returns true. 2766static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, 2767 UnaryTypeTrait UTT, 2768 SourceLocation Loc, 2769 QualType ArgTy) { 2770 // C++0x [meta.unary.prop]p3: 2771 // For all of the class templates X declared in this Clause, instantiating 2772 // that template with a template argument that is a class template 2773 // specialization may result in the implicit instantiation of the template 2774 // argument if and only if the semantics of X require that the argument 2775 // must be a complete type. 2776 // We apply this rule to all the type trait expressions used to implement 2777 // these class templates. We also try to follow any GCC documented behavior 2778 // in these expressions to ensure portability of standard libraries. 2779 switch (UTT) { 2780 // is_complete_type somewhat obviously cannot require a complete type. 2781 case UTT_IsCompleteType: 2782 // Fall-through 2783 2784 // These traits are modeled on the type predicates in C++0x 2785 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as 2786 // requiring a complete type, as whether or not they return true cannot be 2787 // impacted by the completeness of the type. 2788 case UTT_IsVoid: 2789 case UTT_IsIntegral: 2790 case UTT_IsFloatingPoint: 2791 case UTT_IsArray: 2792 case UTT_IsPointer: 2793 case UTT_IsLvalueReference: 2794 case UTT_IsRvalueReference: 2795 case UTT_IsMemberFunctionPointer: 2796 case UTT_IsMemberObjectPointer: 2797 case UTT_IsEnum: 2798 case UTT_IsUnion: 2799 case UTT_IsClass: 2800 case UTT_IsFunction: 2801 case UTT_IsReference: 2802 case UTT_IsArithmetic: 2803 case UTT_IsFundamental: 2804 case UTT_IsObject: 2805 case UTT_IsScalar: 2806 case UTT_IsCompound: 2807 case UTT_IsMemberPointer: 2808 // Fall-through 2809 2810 // These traits are modeled on type predicates in C++0x [meta.unary.prop] 2811 // which requires some of its traits to have the complete type. However, 2812 // the completeness of the type cannot impact these traits' semantics, and 2813 // so they don't require it. This matches the comments on these traits in 2814 // Table 49. 2815 case UTT_IsConst: 2816 case UTT_IsVolatile: 2817 case UTT_IsSigned: 2818 case UTT_IsUnsigned: 2819 return true; 2820 2821 // C++0x [meta.unary.prop] Table 49 requires the following traits to be 2822 // applied to a complete type. 2823 case UTT_IsTrivial: 2824 case UTT_IsTriviallyCopyable: 2825 case UTT_IsStandardLayout: 2826 case UTT_IsPOD: 2827 case UTT_IsLiteral: 2828 case UTT_IsEmpty: 2829 case UTT_IsPolymorphic: 2830 case UTT_IsAbstract: 2831 // Fall-through 2832 2833 // These traits require a complete type. 2834 case UTT_IsFinal: 2835 2836 // These trait expressions are designed to help implement predicates in 2837 // [meta.unary.prop] despite not being named the same. They are specified 2838 // by both GCC and the Embarcadero C++ compiler, and require the complete 2839 // type due to the overarching C++0x type predicates being implemented 2840 // requiring the complete type. 2841 case UTT_HasNothrowAssign: 2842 case UTT_HasNothrowConstructor: 2843 case UTT_HasNothrowCopy: 2844 case UTT_HasTrivialAssign: 2845 case UTT_HasTrivialDefaultConstructor: 2846 case UTT_HasTrivialCopy: 2847 case UTT_HasTrivialDestructor: 2848 case UTT_HasVirtualDestructor: 2849 // Arrays of unknown bound are expressly allowed. 2850 QualType ElTy = ArgTy; 2851 if (ArgTy->isIncompleteArrayType()) 2852 ElTy = S.Context.getAsArrayType(ArgTy)->getElementType(); 2853 2854 // The void type is expressly allowed. 2855 if (ElTy->isVoidType()) 2856 return true; 2857 2858 return !S.RequireCompleteType( 2859 Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr); 2860 } 2861 llvm_unreachable("Type trait not handled by switch"); 2862} 2863 2864static bool EvaluateUnaryTypeTrait(Sema &Self, UnaryTypeTrait UTT, 2865 SourceLocation KeyLoc, QualType T) { 2866 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 2867 2868 ASTContext &C = Self.Context; 2869 switch(UTT) { 2870 // Type trait expressions corresponding to the primary type category 2871 // predicates in C++0x [meta.unary.cat]. 2872 case UTT_IsVoid: 2873 return T->isVoidType(); 2874 case UTT_IsIntegral: 2875 return T->isIntegralType(C); 2876 case UTT_IsFloatingPoint: 2877 return T->isFloatingType(); 2878 case UTT_IsArray: 2879 return T->isArrayType(); 2880 case UTT_IsPointer: 2881 return T->isPointerType(); 2882 case UTT_IsLvalueReference: 2883 return T->isLValueReferenceType(); 2884 case UTT_IsRvalueReference: 2885 return T->isRValueReferenceType(); 2886 case UTT_IsMemberFunctionPointer: 2887 return T->isMemberFunctionPointerType(); 2888 case UTT_IsMemberObjectPointer: 2889 return T->isMemberDataPointerType(); 2890 case UTT_IsEnum: 2891 return T->isEnumeralType(); 2892 case UTT_IsUnion: 2893 return T->isUnionType(); 2894 case UTT_IsClass: 2895 return T->isClassType() || T->isStructureType(); 2896 case UTT_IsFunction: 2897 return T->isFunctionType(); 2898 2899 // Type trait expressions which correspond to the convenient composition 2900 // predicates in C++0x [meta.unary.comp]. 2901 case UTT_IsReference: 2902 return T->isReferenceType(); 2903 case UTT_IsArithmetic: 2904 return T->isArithmeticType() && !T->isEnumeralType(); 2905 case UTT_IsFundamental: 2906 return T->isFundamentalType(); 2907 case UTT_IsObject: 2908 return T->isObjectType(); 2909 case UTT_IsScalar: 2910 // Note: semantic analysis depends on Objective-C lifetime types to be 2911 // considered scalar types. However, such types do not actually behave 2912 // like scalar types at run time (since they may require retain/release 2913 // operations), so we report them as non-scalar. 2914 if (T->isObjCLifetimeType()) { 2915 switch (T.getObjCLifetime()) { 2916 case Qualifiers::OCL_None: 2917 case Qualifiers::OCL_ExplicitNone: 2918 return true; 2919 2920 case Qualifiers::OCL_Strong: 2921 case Qualifiers::OCL_Weak: 2922 case Qualifiers::OCL_Autoreleasing: 2923 return false; 2924 } 2925 } 2926 2927 return T->isScalarType(); 2928 case UTT_IsCompound: 2929 return T->isCompoundType(); 2930 case UTT_IsMemberPointer: 2931 return T->isMemberPointerType(); 2932 2933 // Type trait expressions which correspond to the type property predicates 2934 // in C++0x [meta.unary.prop]. 2935 case UTT_IsConst: 2936 return T.isConstQualified(); 2937 case UTT_IsVolatile: 2938 return T.isVolatileQualified(); 2939 case UTT_IsTrivial: 2940 return T.isTrivialType(Self.Context); 2941 case UTT_IsTriviallyCopyable: 2942 return T.isTriviallyCopyableType(Self.Context); 2943 case UTT_IsStandardLayout: 2944 return T->isStandardLayoutType(); 2945 case UTT_IsPOD: 2946 return T.isPODType(Self.Context); 2947 case UTT_IsLiteral: 2948 return T->isLiteralType(); 2949 case UTT_IsEmpty: 2950 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2951 return !RD->isUnion() && RD->isEmpty(); 2952 return false; 2953 case UTT_IsPolymorphic: 2954 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2955 return RD->isPolymorphic(); 2956 return false; 2957 case UTT_IsAbstract: 2958 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2959 return RD->isAbstract(); 2960 return false; 2961 case UTT_IsFinal: 2962 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2963 return RD->hasAttr<FinalAttr>(); 2964 return false; 2965 case UTT_IsSigned: 2966 return T->isSignedIntegerType(); 2967 case UTT_IsUnsigned: 2968 return T->isUnsignedIntegerType(); 2969 2970 // Type trait expressions which query classes regarding their construction, 2971 // destruction, and copying. Rather than being based directly on the 2972 // related type predicates in the standard, they are specified by both 2973 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those 2974 // specifications. 2975 // 2976 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html 2977 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 2978 case UTT_HasTrivialDefaultConstructor: 2979 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 2980 // If __is_pod (type) is true then the trait is true, else if type is 2981 // a cv class or union type (or array thereof) with a trivial default 2982 // constructor ([class.ctor]) then the trait is true, else it is false. 2983 if (T.isPODType(Self.Context)) 2984 return true; 2985 if (const RecordType *RT = 2986 C.getBaseElementType(T)->getAs<RecordType>()) 2987 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialDefaultConstructor(); 2988 return false; 2989 case UTT_HasTrivialCopy: 2990 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 2991 // If __is_pod (type) is true or type is a reference type then 2992 // the trait is true, else if type is a cv class or union type 2993 // with a trivial copy constructor ([class.copy]) then the trait 2994 // is true, else it is false. 2995 if (T.isPODType(Self.Context) || T->isReferenceType()) 2996 return true; 2997 if (const RecordType *RT = T->getAs<RecordType>()) 2998 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialCopyConstructor(); 2999 return false; 3000 case UTT_HasTrivialAssign: 3001 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3002 // If type is const qualified or is a reference type then the 3003 // trait is false. Otherwise if __is_pod (type) is true then the 3004 // trait is true, else if type is a cv class or union type with 3005 // a trivial copy assignment ([class.copy]) then the trait is 3006 // true, else it is false. 3007 // Note: the const and reference restrictions are interesting, 3008 // given that const and reference members don't prevent a class 3009 // from having a trivial copy assignment operator (but do cause 3010 // errors if the copy assignment operator is actually used, q.v. 3011 // [class.copy]p12). 3012 3013 if (C.getBaseElementType(T).isConstQualified()) 3014 return false; 3015 if (T.isPODType(Self.Context)) 3016 return true; 3017 if (const RecordType *RT = T->getAs<RecordType>()) 3018 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialCopyAssignment(); 3019 return false; 3020 case UTT_HasTrivialDestructor: 3021 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3022 // If __is_pod (type) is true or type is a reference type 3023 // then the trait is true, else if type is a cv class or union 3024 // type (or array thereof) with a trivial destructor 3025 // ([class.dtor]) then the trait is true, else it is 3026 // false. 3027 if (T.isPODType(Self.Context) || T->isReferenceType()) 3028 return true; 3029 3030 // Objective-C++ ARC: autorelease types don't require destruction. 3031 if (T->isObjCLifetimeType() && 3032 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) 3033 return true; 3034 3035 if (const RecordType *RT = 3036 C.getBaseElementType(T)->getAs<RecordType>()) 3037 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialDestructor(); 3038 return false; 3039 // TODO: Propagate nothrowness for implicitly declared special members. 3040 case UTT_HasNothrowAssign: 3041 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3042 // If type is const qualified or is a reference type then the 3043 // trait is false. Otherwise if __has_trivial_assign (type) 3044 // is true then the trait is true, else if type is a cv class 3045 // or union type with copy assignment operators that are known 3046 // not to throw an exception then the trait is true, else it is 3047 // false. 3048 if (C.getBaseElementType(T).isConstQualified()) 3049 return false; 3050 if (T->isReferenceType()) 3051 return false; 3052 if (T.isPODType(Self.Context) || T->isObjCLifetimeType()) 3053 return true; 3054 if (const RecordType *RT = T->getAs<RecordType>()) { 3055 CXXRecordDecl* RD = cast<CXXRecordDecl>(RT->getDecl()); 3056 if (RD->hasTrivialCopyAssignment()) 3057 return true; 3058 3059 bool FoundAssign = false; 3060 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(OO_Equal); 3061 LookupResult Res(Self, DeclarationNameInfo(Name, KeyLoc), 3062 Sema::LookupOrdinaryName); 3063 if (Self.LookupQualifiedName(Res, RD)) { 3064 Res.suppressDiagnostics(); 3065 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); 3066 Op != OpEnd; ++Op) { 3067 if (isa<FunctionTemplateDecl>(*Op)) 3068 continue; 3069 3070 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op); 3071 if (Operator->isCopyAssignmentOperator()) { 3072 FoundAssign = true; 3073 const FunctionProtoType *CPT 3074 = Operator->getType()->getAs<FunctionProtoType>(); 3075 if (CPT->getExceptionSpecType() == EST_Delayed) 3076 return false; 3077 if (!CPT->isNothrow(Self.Context)) 3078 return false; 3079 } 3080 } 3081 } 3082 3083 return FoundAssign; 3084 } 3085 return false; 3086 case UTT_HasNothrowCopy: 3087 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3088 // If __has_trivial_copy (type) is true then the trait is true, else 3089 // if type is a cv class or union type with copy constructors that are 3090 // known not to throw an exception then the trait is true, else it is 3091 // false. 3092 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) 3093 return true; 3094 if (const RecordType *RT = T->getAs<RecordType>()) { 3095 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 3096 if (RD->hasTrivialCopyConstructor()) 3097 return true; 3098 3099 bool FoundConstructor = false; 3100 unsigned FoundTQs; 3101 DeclContext::lookup_const_iterator Con, ConEnd; 3102 for (llvm::tie(Con, ConEnd) = Self.LookupConstructors(RD); 3103 Con != ConEnd; ++Con) { 3104 // A template constructor is never a copy constructor. 3105 // FIXME: However, it may actually be selected at the actual overload 3106 // resolution point. 3107 if (isa<FunctionTemplateDecl>(*Con)) 3108 continue; 3109 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3110 if (Constructor->isCopyConstructor(FoundTQs)) { 3111 FoundConstructor = true; 3112 const FunctionProtoType *CPT 3113 = Constructor->getType()->getAs<FunctionProtoType>(); 3114 if (CPT->getExceptionSpecType() == EST_Delayed) 3115 return false; 3116 // FIXME: check whether evaluating default arguments can throw. 3117 // For now, we'll be conservative and assume that they can throw. 3118 if (!CPT->isNothrow(Self.Context) || CPT->getNumArgs() > 1) 3119 return false; 3120 } 3121 } 3122 3123 return FoundConstructor; 3124 } 3125 return false; 3126 case UTT_HasNothrowConstructor: 3127 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3128 // If __has_trivial_constructor (type) is true then the trait is 3129 // true, else if type is a cv class or union type (or array 3130 // thereof) with a default constructor that is known not to 3131 // throw an exception then the trait is true, else it is false. 3132 if (T.isPODType(C) || T->isObjCLifetimeType()) 3133 return true; 3134 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>()) { 3135 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 3136 if (RD->hasTrivialDefaultConstructor()) 3137 return true; 3138 3139 DeclContext::lookup_const_iterator Con, ConEnd; 3140 for (llvm::tie(Con, ConEnd) = Self.LookupConstructors(RD); 3141 Con != ConEnd; ++Con) { 3142 // FIXME: In C++0x, a constructor template can be a default constructor. 3143 if (isa<FunctionTemplateDecl>(*Con)) 3144 continue; 3145 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3146 if (Constructor->isDefaultConstructor()) { 3147 const FunctionProtoType *CPT 3148 = Constructor->getType()->getAs<FunctionProtoType>(); 3149 if (CPT->getExceptionSpecType() == EST_Delayed) 3150 return false; 3151 // TODO: check whether evaluating default arguments can throw. 3152 // For now, we'll be conservative and assume that they can throw. 3153 return CPT->isNothrow(Self.Context) && CPT->getNumArgs() == 0; 3154 } 3155 } 3156 } 3157 return false; 3158 case UTT_HasVirtualDestructor: 3159 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3160 // If type is a class type with a virtual destructor ([class.dtor]) 3161 // then the trait is true, else it is false. 3162 if (const RecordType *Record = T->getAs<RecordType>()) { 3163 CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()); 3164 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) 3165 return Destructor->isVirtual(); 3166 } 3167 return false; 3168 3169 // These type trait expressions are modeled on the specifications for the 3170 // Embarcadero C++0x type trait functions: 3171 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 3172 case UTT_IsCompleteType: 3173 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): 3174 // Returns True if and only if T is a complete type at the point of the 3175 // function call. 3176 return !T->isIncompleteType(); 3177 } 3178 llvm_unreachable("Type trait not covered by switch"); 3179} 3180 3181ExprResult Sema::BuildUnaryTypeTrait(UnaryTypeTrait UTT, 3182 SourceLocation KWLoc, 3183 TypeSourceInfo *TSInfo, 3184 SourceLocation RParen) { 3185 QualType T = TSInfo->getType(); 3186 if (!CheckUnaryTypeTraitTypeCompleteness(*this, UTT, KWLoc, T)) 3187 return ExprError(); 3188 3189 bool Value = false; 3190 if (!T->isDependentType()) 3191 Value = EvaluateUnaryTypeTrait(*this, UTT, KWLoc, T); 3192 3193 return Owned(new (Context) UnaryTypeTraitExpr(KWLoc, UTT, TSInfo, Value, 3194 RParen, Context.BoolTy)); 3195} 3196 3197ExprResult Sema::ActOnBinaryTypeTrait(BinaryTypeTrait BTT, 3198 SourceLocation KWLoc, 3199 ParsedType LhsTy, 3200 ParsedType RhsTy, 3201 SourceLocation RParen) { 3202 TypeSourceInfo *LhsTSInfo; 3203 QualType LhsT = GetTypeFromParser(LhsTy, &LhsTSInfo); 3204 if (!LhsTSInfo) 3205 LhsTSInfo = Context.getTrivialTypeSourceInfo(LhsT); 3206 3207 TypeSourceInfo *RhsTSInfo; 3208 QualType RhsT = GetTypeFromParser(RhsTy, &RhsTSInfo); 3209 if (!RhsTSInfo) 3210 RhsTSInfo = Context.getTrivialTypeSourceInfo(RhsT); 3211 3212 return BuildBinaryTypeTrait(BTT, KWLoc, LhsTSInfo, RhsTSInfo, RParen); 3213} 3214 3215static bool EvaluateBinaryTypeTrait(Sema &Self, BinaryTypeTrait BTT, 3216 QualType LhsT, QualType RhsT, 3217 SourceLocation KeyLoc) { 3218 assert(!LhsT->isDependentType() && !RhsT->isDependentType() && 3219 "Cannot evaluate traits of dependent types"); 3220 3221 switch(BTT) { 3222 case BTT_IsBaseOf: { 3223 // C++0x [meta.rel]p2 3224 // Base is a base class of Derived without regard to cv-qualifiers or 3225 // Base and Derived are not unions and name the same class type without 3226 // regard to cv-qualifiers. 3227 3228 const RecordType *lhsRecord = LhsT->getAs<RecordType>(); 3229 if (!lhsRecord) return false; 3230 3231 const RecordType *rhsRecord = RhsT->getAs<RecordType>(); 3232 if (!rhsRecord) return false; 3233 3234 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) 3235 == (lhsRecord == rhsRecord)); 3236 3237 if (lhsRecord == rhsRecord) 3238 return !lhsRecord->getDecl()->isUnion(); 3239 3240 // C++0x [meta.rel]p2: 3241 // If Base and Derived are class types and are different types 3242 // (ignoring possible cv-qualifiers) then Derived shall be a 3243 // complete type. 3244 if (Self.RequireCompleteType(KeyLoc, RhsT, 3245 diag::err_incomplete_type_used_in_type_trait_expr)) 3246 return false; 3247 3248 return cast<CXXRecordDecl>(rhsRecord->getDecl()) 3249 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl())); 3250 } 3251 case BTT_IsSame: 3252 return Self.Context.hasSameType(LhsT, RhsT); 3253 case BTT_TypeCompatible: 3254 return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(), 3255 RhsT.getUnqualifiedType()); 3256 case BTT_IsConvertible: 3257 case BTT_IsConvertibleTo: { 3258 // C++0x [meta.rel]p4: 3259 // Given the following function prototype: 3260 // 3261 // template <class T> 3262 // typename add_rvalue_reference<T>::type create(); 3263 // 3264 // the predicate condition for a template specialization 3265 // is_convertible<From, To> shall be satisfied if and only if 3266 // the return expression in the following code would be 3267 // well-formed, including any implicit conversions to the return 3268 // type of the function: 3269 // 3270 // To test() { 3271 // return create<From>(); 3272 // } 3273 // 3274 // Access checking is performed as if in a context unrelated to To and 3275 // From. Only the validity of the immediate context of the expression 3276 // of the return-statement (including conversions to the return type) 3277 // is considered. 3278 // 3279 // We model the initialization as a copy-initialization of a temporary 3280 // of the appropriate type, which for this expression is identical to the 3281 // return statement (since NRVO doesn't apply). 3282 if (LhsT->isObjectType() || LhsT->isFunctionType()) 3283 LhsT = Self.Context.getRValueReferenceType(LhsT); 3284 3285 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); 3286 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 3287 Expr::getValueKindForType(LhsT)); 3288 Expr *FromPtr = &From; 3289 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, 3290 SourceLocation())); 3291 3292 // Perform the initialization in an unevaluated context within a SFINAE 3293 // trap at translation unit scope. 3294 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 3295 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 3296 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 3297 InitializationSequence Init(Self, To, Kind, &FromPtr, 1); 3298 if (Init.Failed()) 3299 return false; 3300 3301 ExprResult Result = Init.Perform(Self, To, Kind, MultiExprArg(&FromPtr, 1)); 3302 return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); 3303 } 3304 } 3305 llvm_unreachable("Unknown type trait or not implemented"); 3306} 3307 3308ExprResult Sema::BuildBinaryTypeTrait(BinaryTypeTrait BTT, 3309 SourceLocation KWLoc, 3310 TypeSourceInfo *LhsTSInfo, 3311 TypeSourceInfo *RhsTSInfo, 3312 SourceLocation RParen) { 3313 QualType LhsT = LhsTSInfo->getType(); 3314 QualType RhsT = RhsTSInfo->getType(); 3315 3316 if (BTT == BTT_TypeCompatible) { 3317 if (getLangOptions().CPlusPlus) { 3318 Diag(KWLoc, diag::err_types_compatible_p_in_cplusplus) 3319 << SourceRange(KWLoc, RParen); 3320 return ExprError(); 3321 } 3322 } 3323 3324 bool Value = false; 3325 if (!LhsT->isDependentType() && !RhsT->isDependentType()) 3326 Value = EvaluateBinaryTypeTrait(*this, BTT, LhsT, RhsT, KWLoc); 3327 3328 // Select trait result type. 3329 QualType ResultType; 3330 switch (BTT) { 3331 case BTT_IsBaseOf: ResultType = Context.BoolTy; break; 3332 case BTT_IsConvertible: ResultType = Context.BoolTy; break; 3333 case BTT_IsSame: ResultType = Context.BoolTy; break; 3334 case BTT_TypeCompatible: ResultType = Context.IntTy; break; 3335 case BTT_IsConvertibleTo: ResultType = Context.BoolTy; break; 3336 } 3337 3338 return Owned(new (Context) BinaryTypeTraitExpr(KWLoc, BTT, LhsTSInfo, 3339 RhsTSInfo, Value, RParen, 3340 ResultType)); 3341} 3342 3343ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, 3344 SourceLocation KWLoc, 3345 ParsedType Ty, 3346 Expr* DimExpr, 3347 SourceLocation RParen) { 3348 TypeSourceInfo *TSInfo; 3349 QualType T = GetTypeFromParser(Ty, &TSInfo); 3350 if (!TSInfo) 3351 TSInfo = Context.getTrivialTypeSourceInfo(T); 3352 3353 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); 3354} 3355 3356static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, 3357 QualType T, Expr *DimExpr, 3358 SourceLocation KeyLoc) { 3359 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 3360 3361 switch(ATT) { 3362 case ATT_ArrayRank: 3363 if (T->isArrayType()) { 3364 unsigned Dim = 0; 3365 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 3366 ++Dim; 3367 T = AT->getElementType(); 3368 } 3369 return Dim; 3370 } 3371 return 0; 3372 3373 case ATT_ArrayExtent: { 3374 llvm::APSInt Value; 3375 uint64_t Dim; 3376 if (Self.VerifyIntegerConstantExpression(DimExpr, &Value, 3377 Self.PDiag(diag::err_dimension_expr_not_constant_integer), 3378 false).isInvalid()) 3379 return 0; 3380 if (Value.isSigned() && Value.isNegative()) { 3381 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer), 3382 DimExpr->getSourceRange(); 3383 return 0; 3384 } 3385 Dim = Value.getLimitedValue(); 3386 3387 if (T->isArrayType()) { 3388 unsigned D = 0; 3389 bool Matched = false; 3390 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 3391 if (Dim == D) { 3392 Matched = true; 3393 break; 3394 } 3395 ++D; 3396 T = AT->getElementType(); 3397 } 3398 3399 if (Matched && T->isArrayType()) { 3400 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) 3401 return CAT->getSize().getLimitedValue(); 3402 } 3403 } 3404 return 0; 3405 } 3406 } 3407 llvm_unreachable("Unknown type trait or not implemented"); 3408} 3409 3410ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, 3411 SourceLocation KWLoc, 3412 TypeSourceInfo *TSInfo, 3413 Expr* DimExpr, 3414 SourceLocation RParen) { 3415 QualType T = TSInfo->getType(); 3416 3417 // FIXME: This should likely be tracked as an APInt to remove any host 3418 // assumptions about the width of size_t on the target. 3419 uint64_t Value = 0; 3420 if (!T->isDependentType()) 3421 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); 3422 3423 // While the specification for these traits from the Embarcadero C++ 3424 // compiler's documentation says the return type is 'unsigned int', Clang 3425 // returns 'size_t'. On Windows, the primary platform for the Embarcadero 3426 // compiler, there is no difference. On several other platforms this is an 3427 // important distinction. 3428 return Owned(new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, 3429 DimExpr, RParen, 3430 Context.getSizeType())); 3431} 3432 3433ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, 3434 SourceLocation KWLoc, 3435 Expr *Queried, 3436 SourceLocation RParen) { 3437 // If error parsing the expression, ignore. 3438 if (!Queried) 3439 return ExprError(); 3440 3441 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); 3442 3443 return move(Result); 3444} 3445 3446static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { 3447 switch (ET) { 3448 case ET_IsLValueExpr: return E->isLValue(); 3449 case ET_IsRValueExpr: return E->isRValue(); 3450 } 3451 llvm_unreachable("Expression trait not covered by switch"); 3452} 3453 3454ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, 3455 SourceLocation KWLoc, 3456 Expr *Queried, 3457 SourceLocation RParen) { 3458 if (Queried->isTypeDependent()) { 3459 // Delay type-checking for type-dependent expressions. 3460 } else if (Queried->getType()->isPlaceholderType()) { 3461 ExprResult PE = CheckPlaceholderExpr(Queried); 3462 if (PE.isInvalid()) return ExprError(); 3463 return BuildExpressionTrait(ET, KWLoc, PE.take(), RParen); 3464 } 3465 3466 bool Value = EvaluateExpressionTrait(ET, Queried); 3467 3468 return Owned(new (Context) ExpressionTraitExpr(KWLoc, ET, Queried, Value, 3469 RParen, Context.BoolTy)); 3470} 3471 3472QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, 3473 ExprValueKind &VK, 3474 SourceLocation Loc, 3475 bool isIndirect) { 3476 assert(!LHS.get()->getType()->isPlaceholderType() && 3477 !RHS.get()->getType()->isPlaceholderType() && 3478 "placeholders should have been weeded out by now"); 3479 3480 // The LHS undergoes lvalue conversions if this is ->*. 3481 if (isIndirect) { 3482 LHS = DefaultLvalueConversion(LHS.take()); 3483 if (LHS.isInvalid()) return QualType(); 3484 } 3485 3486 // The RHS always undergoes lvalue conversions. 3487 RHS = DefaultLvalueConversion(RHS.take()); 3488 if (RHS.isInvalid()) return QualType(); 3489 3490 const char *OpSpelling = isIndirect ? "->*" : ".*"; 3491 // C++ 5.5p2 3492 // The binary operator .* [p3: ->*] binds its second operand, which shall 3493 // be of type "pointer to member of T" (where T is a completely-defined 3494 // class type) [...] 3495 QualType RHSType = RHS.get()->getType(); 3496 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>(); 3497 if (!MemPtr) { 3498 Diag(Loc, diag::err_bad_memptr_rhs) 3499 << OpSpelling << RHSType << RHS.get()->getSourceRange(); 3500 return QualType(); 3501 } 3502 3503 QualType Class(MemPtr->getClass(), 0); 3504 3505 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the 3506 // member pointer points must be completely-defined. However, there is no 3507 // reason for this semantic distinction, and the rule is not enforced by 3508 // other compilers. Therefore, we do not check this property, as it is 3509 // likely to be considered a defect. 3510 3511 // C++ 5.5p2 3512 // [...] to its first operand, which shall be of class T or of a class of 3513 // which T is an unambiguous and accessible base class. [p3: a pointer to 3514 // such a class] 3515 QualType LHSType = LHS.get()->getType(); 3516 if (isIndirect) { 3517 if (const PointerType *Ptr = LHSType->getAs<PointerType>()) 3518 LHSType = Ptr->getPointeeType(); 3519 else { 3520 Diag(Loc, diag::err_bad_memptr_lhs) 3521 << OpSpelling << 1 << LHSType 3522 << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); 3523 return QualType(); 3524 } 3525 } 3526 3527 if (!Context.hasSameUnqualifiedType(Class, LHSType)) { 3528 // If we want to check the hierarchy, we need a complete type. 3529 if (RequireCompleteType(Loc, LHSType, PDiag(diag::err_bad_memptr_lhs) 3530 << OpSpelling << (int)isIndirect)) { 3531 return QualType(); 3532 } 3533 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 3534 /*DetectVirtual=*/false); 3535 // FIXME: Would it be useful to print full ambiguity paths, or is that 3536 // overkill? 3537 if (!IsDerivedFrom(LHSType, Class, Paths) || 3538 Paths.isAmbiguous(Context.getCanonicalType(Class))) { 3539 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 3540 << (int)isIndirect << LHS.get()->getType(); 3541 return QualType(); 3542 } 3543 // Cast LHS to type of use. 3544 QualType UseType = isIndirect ? Context.getPointerType(Class) : Class; 3545 ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind(); 3546 3547 CXXCastPath BasePath; 3548 BuildBasePathArray(Paths, BasePath); 3549 LHS = ImpCastExprToType(LHS.take(), UseType, CK_DerivedToBase, VK, 3550 &BasePath); 3551 } 3552 3553 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) { 3554 // Diagnose use of pointer-to-member type which when used as 3555 // the functional cast in a pointer-to-member expression. 3556 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; 3557 return QualType(); 3558 } 3559 3560 // C++ 5.5p2 3561 // The result is an object or a function of the type specified by the 3562 // second operand. 3563 // The cv qualifiers are the union of those in the pointer and the left side, 3564 // in accordance with 5.5p5 and 5.2.5. 3565 QualType Result = MemPtr->getPointeeType(); 3566 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); 3567 3568 // C++0x [expr.mptr.oper]p6: 3569 // In a .* expression whose object expression is an rvalue, the program is 3570 // ill-formed if the second operand is a pointer to member function with 3571 // ref-qualifier &. In a ->* expression or in a .* expression whose object 3572 // expression is an lvalue, the program is ill-formed if the second operand 3573 // is a pointer to member function with ref-qualifier &&. 3574 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) { 3575 switch (Proto->getRefQualifier()) { 3576 case RQ_None: 3577 // Do nothing 3578 break; 3579 3580 case RQ_LValue: 3581 if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) 3582 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 3583 << RHSType << 1 << LHS.get()->getSourceRange(); 3584 break; 3585 3586 case RQ_RValue: 3587 if (isIndirect || !LHS.get()->Classify(Context).isRValue()) 3588 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 3589 << RHSType << 0 << LHS.get()->getSourceRange(); 3590 break; 3591 } 3592 } 3593 3594 // C++ [expr.mptr.oper]p6: 3595 // The result of a .* expression whose second operand is a pointer 3596 // to a data member is of the same value category as its 3597 // first operand. The result of a .* expression whose second 3598 // operand is a pointer to a member function is a prvalue. The 3599 // result of an ->* expression is an lvalue if its second operand 3600 // is a pointer to data member and a prvalue otherwise. 3601 if (Result->isFunctionType()) { 3602 VK = VK_RValue; 3603 return Context.BoundMemberTy; 3604 } else if (isIndirect) { 3605 VK = VK_LValue; 3606 } else { 3607 VK = LHS.get()->getValueKind(); 3608 } 3609 3610 return Result; 3611} 3612 3613/// \brief Try to convert a type to another according to C++0x 5.16p3. 3614/// 3615/// This is part of the parameter validation for the ? operator. If either 3616/// value operand is a class type, the two operands are attempted to be 3617/// converted to each other. This function does the conversion in one direction. 3618/// It returns true if the program is ill-formed and has already been diagnosed 3619/// as such. 3620static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 3621 SourceLocation QuestionLoc, 3622 bool &HaveConversion, 3623 QualType &ToType) { 3624 HaveConversion = false; 3625 ToType = To->getType(); 3626 3627 InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(), 3628 SourceLocation()); 3629 // C++0x 5.16p3 3630 // The process for determining whether an operand expression E1 of type T1 3631 // can be converted to match an operand expression E2 of type T2 is defined 3632 // as follows: 3633 // -- If E2 is an lvalue: 3634 bool ToIsLvalue = To->isLValue(); 3635 if (ToIsLvalue) { 3636 // E1 can be converted to match E2 if E1 can be implicitly converted to 3637 // type "lvalue reference to T2", subject to the constraint that in the 3638 // conversion the reference must bind directly to E1. 3639 QualType T = Self.Context.getLValueReferenceType(ToType); 3640 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 3641 3642 InitializationSequence InitSeq(Self, Entity, Kind, &From, 1); 3643 if (InitSeq.isDirectReferenceBinding()) { 3644 ToType = T; 3645 HaveConversion = true; 3646 return false; 3647 } 3648 3649 if (InitSeq.isAmbiguous()) 3650 return InitSeq.Diagnose(Self, Entity, Kind, &From, 1); 3651 } 3652 3653 // -- If E2 is an rvalue, or if the conversion above cannot be done: 3654 // -- if E1 and E2 have class type, and the underlying class types are 3655 // the same or one is a base class of the other: 3656 QualType FTy = From->getType(); 3657 QualType TTy = To->getType(); 3658 const RecordType *FRec = FTy->getAs<RecordType>(); 3659 const RecordType *TRec = TTy->getAs<RecordType>(); 3660 bool FDerivedFromT = FRec && TRec && FRec != TRec && 3661 Self.IsDerivedFrom(FTy, TTy); 3662 if (FRec && TRec && 3663 (FRec == TRec || FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) { 3664 // E1 can be converted to match E2 if the class of T2 is the 3665 // same type as, or a base class of, the class of T1, and 3666 // [cv2 > cv1]. 3667 if (FRec == TRec || FDerivedFromT) { 3668 if (TTy.isAtLeastAsQualifiedAs(FTy)) { 3669 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 3670 InitializationSequence InitSeq(Self, Entity, Kind, &From, 1); 3671 if (InitSeq) { 3672 HaveConversion = true; 3673 return false; 3674 } 3675 3676 if (InitSeq.isAmbiguous()) 3677 return InitSeq.Diagnose(Self, Entity, Kind, &From, 1); 3678 } 3679 } 3680 3681 return false; 3682 } 3683 3684 // -- Otherwise: E1 can be converted to match E2 if E1 can be 3685 // implicitly converted to the type that expression E2 would have 3686 // if E2 were converted to an rvalue (or the type it has, if E2 is 3687 // an rvalue). 3688 // 3689 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not 3690 // to the array-to-pointer or function-to-pointer conversions. 3691 if (!TTy->getAs<TagType>()) 3692 TTy = TTy.getUnqualifiedType(); 3693 3694 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 3695 InitializationSequence InitSeq(Self, Entity, Kind, &From, 1); 3696 HaveConversion = !InitSeq.Failed(); 3697 ToType = TTy; 3698 if (InitSeq.isAmbiguous()) 3699 return InitSeq.Diagnose(Self, Entity, Kind, &From, 1); 3700 3701 return false; 3702} 3703 3704/// \brief Try to find a common type for two according to C++0x 5.16p5. 3705/// 3706/// This is part of the parameter validation for the ? operator. If either 3707/// value operand is a class type, overload resolution is used to find a 3708/// conversion to a common type. 3709static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, 3710 SourceLocation QuestionLoc) { 3711 Expr *Args[2] = { LHS.get(), RHS.get() }; 3712 OverloadCandidateSet CandidateSet(QuestionLoc); 3713 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, 2, 3714 CandidateSet); 3715 3716 OverloadCandidateSet::iterator Best; 3717 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { 3718 case OR_Success: { 3719 // We found a match. Perform the conversions on the arguments and move on. 3720 ExprResult LHSRes = 3721 Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0], 3722 Best->Conversions[0], Sema::AA_Converting); 3723 if (LHSRes.isInvalid()) 3724 break; 3725 LHS = move(LHSRes); 3726 3727 ExprResult RHSRes = 3728 Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1], 3729 Best->Conversions[1], Sema::AA_Converting); 3730 if (RHSRes.isInvalid()) 3731 break; 3732 RHS = move(RHSRes); 3733 if (Best->Function) 3734 Self.MarkFunctionReferenced(QuestionLoc, Best->Function); 3735 return false; 3736 } 3737 3738 case OR_No_Viable_Function: 3739 3740 // Emit a better diagnostic if one of the expressions is a null pointer 3741 // constant and the other is a pointer type. In this case, the user most 3742 // likely forgot to take the address of the other expression. 3743 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 3744 return true; 3745 3746 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 3747 << LHS.get()->getType() << RHS.get()->getType() 3748 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3749 return true; 3750 3751 case OR_Ambiguous: 3752 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) 3753 << LHS.get()->getType() << RHS.get()->getType() 3754 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3755 // FIXME: Print the possible common types by printing the return types of 3756 // the viable candidates. 3757 break; 3758 3759 case OR_Deleted: 3760 llvm_unreachable("Conditional operator has only built-in overloads"); 3761 } 3762 return true; 3763} 3764 3765/// \brief Perform an "extended" implicit conversion as returned by 3766/// TryClassUnification. 3767static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { 3768 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 3769 InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(), 3770 SourceLocation()); 3771 Expr *Arg = E.take(); 3772 InitializationSequence InitSeq(Self, Entity, Kind, &Arg, 1); 3773 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, MultiExprArg(&Arg, 1)); 3774 if (Result.isInvalid()) 3775 return true; 3776 3777 E = Result; 3778 return false; 3779} 3780 3781/// \brief Check the operands of ?: under C++ semantics. 3782/// 3783/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 3784/// extension. In this case, LHS == Cond. (But they're not aliases.) 3785QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, 3786 ExprValueKind &VK, ExprObjectKind &OK, 3787 SourceLocation QuestionLoc) { 3788 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ 3789 // interface pointers. 3790 3791 // C++0x 5.16p1 3792 // The first expression is contextually converted to bool. 3793 if (!Cond.get()->isTypeDependent()) { 3794 ExprResult CondRes = CheckCXXBooleanCondition(Cond.take()); 3795 if (CondRes.isInvalid()) 3796 return QualType(); 3797 Cond = move(CondRes); 3798 } 3799 3800 // Assume r-value. 3801 VK = VK_RValue; 3802 OK = OK_Ordinary; 3803 3804 // Either of the arguments dependent? 3805 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) 3806 return Context.DependentTy; 3807 3808 // C++0x 5.16p2 3809 // If either the second or the third operand has type (cv) void, ... 3810 QualType LTy = LHS.get()->getType(); 3811 QualType RTy = RHS.get()->getType(); 3812 bool LVoid = LTy->isVoidType(); 3813 bool RVoid = RTy->isVoidType(); 3814 if (LVoid || RVoid) { 3815 // ... then the [l2r] conversions are performed on the second and third 3816 // operands ... 3817 LHS = DefaultFunctionArrayLvalueConversion(LHS.take()); 3818 RHS = DefaultFunctionArrayLvalueConversion(RHS.take()); 3819 if (LHS.isInvalid() || RHS.isInvalid()) 3820 return QualType(); 3821 LTy = LHS.get()->getType(); 3822 RTy = RHS.get()->getType(); 3823 3824 // ... and one of the following shall hold: 3825 // -- The second or the third operand (but not both) is a throw- 3826 // expression; the result is of the type of the other and is an rvalue. 3827 bool LThrow = isa<CXXThrowExpr>(LHS.get()); 3828 bool RThrow = isa<CXXThrowExpr>(RHS.get()); 3829 if (LThrow && !RThrow) 3830 return RTy; 3831 if (RThrow && !LThrow) 3832 return LTy; 3833 3834 // -- Both the second and third operands have type void; the result is of 3835 // type void and is an rvalue. 3836 if (LVoid && RVoid) 3837 return Context.VoidTy; 3838 3839 // Neither holds, error. 3840 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 3841 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 3842 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3843 return QualType(); 3844 } 3845 3846 // Neither is void. 3847 3848 // C++0x 5.16p3 3849 // Otherwise, if the second and third operand have different types, and 3850 // either has (cv) class type, and attempt is made to convert each of those 3851 // operands to the other. 3852 if (!Context.hasSameType(LTy, RTy) && 3853 (LTy->isRecordType() || RTy->isRecordType())) { 3854 ImplicitConversionSequence ICSLeftToRight, ICSRightToLeft; 3855 // These return true if a single direction is already ambiguous. 3856 QualType L2RType, R2LType; 3857 bool HaveL2R, HaveR2L; 3858 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) 3859 return QualType(); 3860 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) 3861 return QualType(); 3862 3863 // If both can be converted, [...] the program is ill-formed. 3864 if (HaveL2R && HaveR2L) { 3865 Diag(QuestionLoc, diag::err_conditional_ambiguous) 3866 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3867 return QualType(); 3868 } 3869 3870 // If exactly one conversion is possible, that conversion is applied to 3871 // the chosen operand and the converted operands are used in place of the 3872 // original operands for the remainder of this section. 3873 if (HaveL2R) { 3874 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) 3875 return QualType(); 3876 LTy = LHS.get()->getType(); 3877 } else if (HaveR2L) { 3878 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) 3879 return QualType(); 3880 RTy = RHS.get()->getType(); 3881 } 3882 } 3883 3884 // C++0x 5.16p4 3885 // If the second and third operands are glvalues of the same value 3886 // category and have the same type, the result is of that type and 3887 // value category and it is a bit-field if the second or the third 3888 // operand is a bit-field, or if both are bit-fields. 3889 // We only extend this to bitfields, not to the crazy other kinds of 3890 // l-values. 3891 bool Same = Context.hasSameType(LTy, RTy); 3892 if (Same && 3893 LHS.get()->isGLValue() && 3894 LHS.get()->getValueKind() == RHS.get()->getValueKind() && 3895 LHS.get()->isOrdinaryOrBitFieldObject() && 3896 RHS.get()->isOrdinaryOrBitFieldObject()) { 3897 VK = LHS.get()->getValueKind(); 3898 if (LHS.get()->getObjectKind() == OK_BitField || 3899 RHS.get()->getObjectKind() == OK_BitField) 3900 OK = OK_BitField; 3901 return LTy; 3902 } 3903 3904 // C++0x 5.16p5 3905 // Otherwise, the result is an rvalue. If the second and third operands 3906 // do not have the same type, and either has (cv) class type, ... 3907 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 3908 // ... overload resolution is used to determine the conversions (if any) 3909 // to be applied to the operands. If the overload resolution fails, the 3910 // program is ill-formed. 3911 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 3912 return QualType(); 3913 } 3914 3915 // C++0x 5.16p6 3916 // LValue-to-rvalue, array-to-pointer, and function-to-pointer standard 3917 // conversions are performed on the second and third operands. 3918 LHS = DefaultFunctionArrayLvalueConversion(LHS.take()); 3919 RHS = DefaultFunctionArrayLvalueConversion(RHS.take()); 3920 if (LHS.isInvalid() || RHS.isInvalid()) 3921 return QualType(); 3922 LTy = LHS.get()->getType(); 3923 RTy = RHS.get()->getType(); 3924 3925 // After those conversions, one of the following shall hold: 3926 // -- The second and third operands have the same type; the result 3927 // is of that type. If the operands have class type, the result 3928 // is a prvalue temporary of the result type, which is 3929 // copy-initialized from either the second operand or the third 3930 // operand depending on the value of the first operand. 3931 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { 3932 if (LTy->isRecordType()) { 3933 // The operands have class type. Make a temporary copy. 3934 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); 3935 ExprResult LHSCopy = PerformCopyInitialization(Entity, 3936 SourceLocation(), 3937 LHS); 3938 if (LHSCopy.isInvalid()) 3939 return QualType(); 3940 3941 ExprResult RHSCopy = PerformCopyInitialization(Entity, 3942 SourceLocation(), 3943 RHS); 3944 if (RHSCopy.isInvalid()) 3945 return QualType(); 3946 3947 LHS = LHSCopy; 3948 RHS = RHSCopy; 3949 } 3950 3951 return LTy; 3952 } 3953 3954 // Extension: conditional operator involving vector types. 3955 if (LTy->isVectorType() || RTy->isVectorType()) 3956 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false); 3957 3958 // -- The second and third operands have arithmetic or enumeration type; 3959 // the usual arithmetic conversions are performed to bring them to a 3960 // common type, and the result is of that type. 3961 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 3962 UsualArithmeticConversions(LHS, RHS); 3963 if (LHS.isInvalid() || RHS.isInvalid()) 3964 return QualType(); 3965 return LHS.get()->getType(); 3966 } 3967 3968 // -- The second and third operands have pointer type, or one has pointer 3969 // type and the other is a null pointer constant; pointer conversions 3970 // and qualification conversions are performed to bring them to their 3971 // composite pointer type. The result is of the composite pointer type. 3972 // -- The second and third operands have pointer to member type, or one has 3973 // pointer to member type and the other is a null pointer constant; 3974 // pointer to member conversions and qualification conversions are 3975 // performed to bring them to a common type, whose cv-qualification 3976 // shall match the cv-qualification of either the second or the third 3977 // operand. The result is of the common type. 3978 bool NonStandardCompositeType = false; 3979 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS, 3980 isSFINAEContext()? 0 : &NonStandardCompositeType); 3981 if (!Composite.isNull()) { 3982 if (NonStandardCompositeType) 3983 Diag(QuestionLoc, 3984 diag::ext_typecheck_cond_incompatible_operands_nonstandard) 3985 << LTy << RTy << Composite 3986 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3987 3988 return Composite; 3989 } 3990 3991 // Similarly, attempt to find composite type of two objective-c pointers. 3992 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); 3993 if (!Composite.isNull()) 3994 return Composite; 3995 3996 // Check if we are using a null with a non-pointer type. 3997 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 3998 return QualType(); 3999 4000 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4001 << LHS.get()->getType() << RHS.get()->getType() 4002 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4003 return QualType(); 4004} 4005 4006/// \brief Find a merged pointer type and convert the two expressions to it. 4007/// 4008/// This finds the composite pointer type (or member pointer type) for @p E1 4009/// and @p E2 according to C++0x 5.9p2. It converts both expressions to this 4010/// type and returns it. 4011/// It does not emit diagnostics. 4012/// 4013/// \param Loc The location of the operator requiring these two expressions to 4014/// be converted to the composite pointer type. 4015/// 4016/// If \p NonStandardCompositeType is non-NULL, then we are permitted to find 4017/// a non-standard (but still sane) composite type to which both expressions 4018/// can be converted. When such a type is chosen, \c *NonStandardCompositeType 4019/// will be set true. 4020QualType Sema::FindCompositePointerType(SourceLocation Loc, 4021 Expr *&E1, Expr *&E2, 4022 bool *NonStandardCompositeType) { 4023 if (NonStandardCompositeType) 4024 *NonStandardCompositeType = false; 4025 4026 assert(getLangOptions().CPlusPlus && "This function assumes C++"); 4027 QualType T1 = E1->getType(), T2 = E2->getType(); 4028 4029 if (!T1->isAnyPointerType() && !T1->isMemberPointerType() && 4030 !T2->isAnyPointerType() && !T2->isMemberPointerType()) 4031 return QualType(); 4032 4033 // C++0x 5.9p2 4034 // Pointer conversions and qualification conversions are performed on 4035 // pointer operands to bring them to their composite pointer type. If 4036 // one operand is a null pointer constant, the composite pointer type is 4037 // the type of the other operand. 4038 if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4039 if (T2->isMemberPointerType()) 4040 E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).take(); 4041 else 4042 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).take(); 4043 return T2; 4044 } 4045 if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4046 if (T1->isMemberPointerType()) 4047 E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).take(); 4048 else 4049 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).take(); 4050 return T1; 4051 } 4052 4053 // Now both have to be pointers or member pointers. 4054 if ((!T1->isPointerType() && !T1->isMemberPointerType()) || 4055 (!T2->isPointerType() && !T2->isMemberPointerType())) 4056 return QualType(); 4057 4058 // Otherwise, of one of the operands has type "pointer to cv1 void," then 4059 // the other has type "pointer to cv2 T" and the composite pointer type is 4060 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2. 4061 // Otherwise, the composite pointer type is a pointer type similar to the 4062 // type of one of the operands, with a cv-qualification signature that is 4063 // the union of the cv-qualification signatures of the operand types. 4064 // In practice, the first part here is redundant; it's subsumed by the second. 4065 // What we do here is, we build the two possible composite types, and try the 4066 // conversions in both directions. If only one works, or if the two composite 4067 // types are the same, we have succeeded. 4068 // FIXME: extended qualifiers? 4069 typedef SmallVector<unsigned, 4> QualifierVector; 4070 QualifierVector QualifierUnion; 4071 typedef SmallVector<std::pair<const Type *, const Type *>, 4> 4072 ContainingClassVector; 4073 ContainingClassVector MemberOfClass; 4074 QualType Composite1 = Context.getCanonicalType(T1), 4075 Composite2 = Context.getCanonicalType(T2); 4076 unsigned NeedConstBefore = 0; 4077 do { 4078 const PointerType *Ptr1, *Ptr2; 4079 if ((Ptr1 = Composite1->getAs<PointerType>()) && 4080 (Ptr2 = Composite2->getAs<PointerType>())) { 4081 Composite1 = Ptr1->getPointeeType(); 4082 Composite2 = Ptr2->getPointeeType(); 4083 4084 // If we're allowed to create a non-standard composite type, keep track 4085 // of where we need to fill in additional 'const' qualifiers. 4086 if (NonStandardCompositeType && 4087 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4088 NeedConstBefore = QualifierUnion.size(); 4089 4090 QualifierUnion.push_back( 4091 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4092 MemberOfClass.push_back(std::make_pair((const Type *)0, (const Type *)0)); 4093 continue; 4094 } 4095 4096 const MemberPointerType *MemPtr1, *MemPtr2; 4097 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) && 4098 (MemPtr2 = Composite2->getAs<MemberPointerType>())) { 4099 Composite1 = MemPtr1->getPointeeType(); 4100 Composite2 = MemPtr2->getPointeeType(); 4101 4102 // If we're allowed to create a non-standard composite type, keep track 4103 // of where we need to fill in additional 'const' qualifiers. 4104 if (NonStandardCompositeType && 4105 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4106 NeedConstBefore = QualifierUnion.size(); 4107 4108 QualifierUnion.push_back( 4109 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4110 MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(), 4111 MemPtr2->getClass())); 4112 continue; 4113 } 4114 4115 // FIXME: block pointer types? 4116 4117 // Cannot unwrap any more types. 4118 break; 4119 } while (true); 4120 4121 if (NeedConstBefore && NonStandardCompositeType) { 4122 // Extension: Add 'const' to qualifiers that come before the first qualifier 4123 // mismatch, so that our (non-standard!) composite type meets the 4124 // requirements of C++ [conv.qual]p4 bullet 3. 4125 for (unsigned I = 0; I != NeedConstBefore; ++I) { 4126 if ((QualifierUnion[I] & Qualifiers::Const) == 0) { 4127 QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const; 4128 *NonStandardCompositeType = true; 4129 } 4130 } 4131 } 4132 4133 // Rewrap the composites as pointers or member pointers with the union CVRs. 4134 ContainingClassVector::reverse_iterator MOC 4135 = MemberOfClass.rbegin(); 4136 for (QualifierVector::reverse_iterator 4137 I = QualifierUnion.rbegin(), 4138 E = QualifierUnion.rend(); 4139 I != E; (void)++I, ++MOC) { 4140 Qualifiers Quals = Qualifiers::fromCVRMask(*I); 4141 if (MOC->first && MOC->second) { 4142 // Rebuild member pointer type 4143 Composite1 = Context.getMemberPointerType( 4144 Context.getQualifiedType(Composite1, Quals), 4145 MOC->first); 4146 Composite2 = Context.getMemberPointerType( 4147 Context.getQualifiedType(Composite2, Quals), 4148 MOC->second); 4149 } else { 4150 // Rebuild pointer type 4151 Composite1 4152 = Context.getPointerType(Context.getQualifiedType(Composite1, Quals)); 4153 Composite2 4154 = Context.getPointerType(Context.getQualifiedType(Composite2, Quals)); 4155 } 4156 } 4157 4158 // Try to convert to the first composite pointer type. 4159 InitializedEntity Entity1 4160 = InitializedEntity::InitializeTemporary(Composite1); 4161 InitializationKind Kind 4162 = InitializationKind::CreateCopy(Loc, SourceLocation()); 4163 InitializationSequence E1ToC1(*this, Entity1, Kind, &E1, 1); 4164 InitializationSequence E2ToC1(*this, Entity1, Kind, &E2, 1); 4165 4166 if (E1ToC1 && E2ToC1) { 4167 // Conversion to Composite1 is viable. 4168 if (!Context.hasSameType(Composite1, Composite2)) { 4169 // Composite2 is a different type from Composite1. Check whether 4170 // Composite2 is also viable. 4171 InitializedEntity Entity2 4172 = InitializedEntity::InitializeTemporary(Composite2); 4173 InitializationSequence E1ToC2(*this, Entity2, Kind, &E1, 1); 4174 InitializationSequence E2ToC2(*this, Entity2, Kind, &E2, 1); 4175 if (E1ToC2 && E2ToC2) { 4176 // Both Composite1 and Composite2 are viable and are different; 4177 // this is an ambiguity. 4178 return QualType(); 4179 } 4180 } 4181 4182 // Convert E1 to Composite1 4183 ExprResult E1Result 4184 = E1ToC1.Perform(*this, Entity1, Kind, MultiExprArg(*this,&E1,1)); 4185 if (E1Result.isInvalid()) 4186 return QualType(); 4187 E1 = E1Result.takeAs<Expr>(); 4188 4189 // Convert E2 to Composite1 4190 ExprResult E2Result 4191 = E2ToC1.Perform(*this, Entity1, Kind, MultiExprArg(*this,&E2,1)); 4192 if (E2Result.isInvalid()) 4193 return QualType(); 4194 E2 = E2Result.takeAs<Expr>(); 4195 4196 return Composite1; 4197 } 4198 4199 // Check whether Composite2 is viable. 4200 InitializedEntity Entity2 4201 = InitializedEntity::InitializeTemporary(Composite2); 4202 InitializationSequence E1ToC2(*this, Entity2, Kind, &E1, 1); 4203 InitializationSequence E2ToC2(*this, Entity2, Kind, &E2, 1); 4204 if (!E1ToC2 || !E2ToC2) 4205 return QualType(); 4206 4207 // Convert E1 to Composite2 4208 ExprResult E1Result 4209 = E1ToC2.Perform(*this, Entity2, Kind, MultiExprArg(*this, &E1, 1)); 4210 if (E1Result.isInvalid()) 4211 return QualType(); 4212 E1 = E1Result.takeAs<Expr>(); 4213 4214 // Convert E2 to Composite2 4215 ExprResult E2Result 4216 = E2ToC2.Perform(*this, Entity2, Kind, MultiExprArg(*this, &E2, 1)); 4217 if (E2Result.isInvalid()) 4218 return QualType(); 4219 E2 = E2Result.takeAs<Expr>(); 4220 4221 return Composite2; 4222} 4223 4224ExprResult Sema::MaybeBindToTemporary(Expr *E) { 4225 if (!E) 4226 return ExprError(); 4227 4228 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?"); 4229 4230 // If the result is a glvalue, we shouldn't bind it. 4231 if (!E->isRValue()) 4232 return Owned(E); 4233 4234 // In ARC, calls that return a retainable type can return retained, 4235 // in which case we have to insert a consuming cast. 4236 if (getLangOptions().ObjCAutoRefCount && 4237 E->getType()->isObjCRetainableType()) { 4238 4239 bool ReturnsRetained; 4240 4241 // For actual calls, we compute this by examining the type of the 4242 // called value. 4243 if (CallExpr *Call = dyn_cast<CallExpr>(E)) { 4244 Expr *Callee = Call->getCallee()->IgnoreParens(); 4245 QualType T = Callee->getType(); 4246 4247 if (T == Context.BoundMemberTy) { 4248 // Handle pointer-to-members. 4249 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee)) 4250 T = BinOp->getRHS()->getType(); 4251 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee)) 4252 T = Mem->getMemberDecl()->getType(); 4253 } 4254 4255 if (const PointerType *Ptr = T->getAs<PointerType>()) 4256 T = Ptr->getPointeeType(); 4257 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>()) 4258 T = Ptr->getPointeeType(); 4259 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>()) 4260 T = MemPtr->getPointeeType(); 4261 4262 const FunctionType *FTy = T->getAs<FunctionType>(); 4263 assert(FTy && "call to value not of function type?"); 4264 ReturnsRetained = FTy->getExtInfo().getProducesResult(); 4265 4266 // ActOnStmtExpr arranges things so that StmtExprs of retainable 4267 // type always produce a +1 object. 4268 } else if (isa<StmtExpr>(E)) { 4269 ReturnsRetained = true; 4270 4271 // For message sends and property references, we try to find an 4272 // actual method. FIXME: we should infer retention by selector in 4273 // cases where we don't have an actual method. 4274 } else { 4275 ObjCMethodDecl *D = 0; 4276 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) { 4277 D = Send->getMethodDecl(); 4278 } 4279 4280 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>()); 4281 4282 // Don't do reclaims on performSelector calls; despite their 4283 // return type, the invoked method doesn't necessarily actually 4284 // return an object. 4285 if (!ReturnsRetained && 4286 D && D->getMethodFamily() == OMF_performSelector) 4287 return Owned(E); 4288 } 4289 4290 // Don't reclaim an object of Class type. 4291 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) 4292 return Owned(E); 4293 4294 ExprNeedsCleanups = true; 4295 4296 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject 4297 : CK_ARCReclaimReturnedObject); 4298 return Owned(ImplicitCastExpr::Create(Context, E->getType(), ck, E, 0, 4299 VK_RValue)); 4300 } 4301 4302 if (!getLangOptions().CPlusPlus) 4303 return Owned(E); 4304 4305 // Search for the base element type (cf. ASTContext::getBaseElementType) with 4306 // a fast path for the common case that the type is directly a RecordType. 4307 const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); 4308 const RecordType *RT = 0; 4309 while (!RT) { 4310 switch (T->getTypeClass()) { 4311 case Type::Record: 4312 RT = cast<RecordType>(T); 4313 break; 4314 case Type::ConstantArray: 4315 case Type::IncompleteArray: 4316 case Type::VariableArray: 4317 case Type::DependentSizedArray: 4318 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 4319 break; 4320 default: 4321 return Owned(E); 4322 } 4323 } 4324 4325 // That should be enough to guarantee that this type is complete, if we're 4326 // not processing a decltype expression. 4327 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 4328 if (RD->isInvalidDecl() || RD->isDependentContext()) 4329 return Owned(E); 4330 4331 bool IsDecltype = ExprEvalContexts.back().IsDecltype; 4332 CXXDestructorDecl *Destructor = IsDecltype ? 0 : LookupDestructor(RD); 4333 4334 if (Destructor) { 4335 MarkFunctionReferenced(E->getExprLoc(), Destructor); 4336 CheckDestructorAccess(E->getExprLoc(), Destructor, 4337 PDiag(diag::err_access_dtor_temp) 4338 << E->getType()); 4339 DiagnoseUseOfDecl(Destructor, E->getExprLoc()); 4340 4341 // If destructor is trivial, we can avoid the extra copy. 4342 if (Destructor->isTrivial()) 4343 return Owned(E); 4344 4345 // We need a cleanup, but we don't need to remember the temporary. 4346 ExprNeedsCleanups = true; 4347 } 4348 4349 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); 4350 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); 4351 4352 if (IsDecltype) 4353 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); 4354 4355 return Owned(Bind); 4356} 4357 4358ExprResult 4359Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { 4360 if (SubExpr.isInvalid()) 4361 return ExprError(); 4362 4363 return Owned(MaybeCreateExprWithCleanups(SubExpr.take())); 4364} 4365 4366Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { 4367 assert(SubExpr && "sub expression can't be null!"); 4368 4369 CleanupVarDeclMarking(); 4370 4371 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; 4372 assert(ExprCleanupObjects.size() >= FirstCleanup); 4373 assert(ExprNeedsCleanups || ExprCleanupObjects.size() == FirstCleanup); 4374 if (!ExprNeedsCleanups) 4375 return SubExpr; 4376 4377 ArrayRef<ExprWithCleanups::CleanupObject> Cleanups 4378 = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, 4379 ExprCleanupObjects.size() - FirstCleanup); 4380 4381 Expr *E = ExprWithCleanups::Create(Context, SubExpr, Cleanups); 4382 DiscardCleanupsInEvaluationContext(); 4383 4384 return E; 4385} 4386 4387Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { 4388 assert(SubStmt && "sub statement can't be null!"); 4389 4390 CleanupVarDeclMarking(); 4391 4392 if (!ExprNeedsCleanups) 4393 return SubStmt; 4394 4395 // FIXME: In order to attach the temporaries, wrap the statement into 4396 // a StmtExpr; currently this is only used for asm statements. 4397 // This is hacky, either create a new CXXStmtWithTemporaries statement or 4398 // a new AsmStmtWithTemporaries. 4399 CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, &SubStmt, 1, 4400 SourceLocation(), 4401 SourceLocation()); 4402 Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), 4403 SourceLocation()); 4404 return MaybeCreateExprWithCleanups(E); 4405} 4406 4407/// Process the expression contained within a decltype. For such expressions, 4408/// certain semantic checks on temporaries are delayed until this point, and 4409/// are omitted for the 'topmost' call in the decltype expression. If the 4410/// topmost call bound a temporary, strip that temporary off the expression. 4411ExprResult Sema::ActOnDecltypeExpression(Expr *E) { 4412 ExpressionEvaluationContextRecord &Rec = ExprEvalContexts.back(); 4413 assert(Rec.IsDecltype && "not in a decltype expression"); 4414 4415 // C++11 [expr.call]p11: 4416 // If a function call is a prvalue of object type, 4417 // -- if the function call is either 4418 // -- the operand of a decltype-specifier, or 4419 // -- the right operand of a comma operator that is the operand of a 4420 // decltype-specifier, 4421 // a temporary object is not introduced for the prvalue. 4422 4423 // Recursively rebuild ParenExprs and comma expressions to strip out the 4424 // outermost CXXBindTemporaryExpr, if any. 4425 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4426 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); 4427 if (SubExpr.isInvalid()) 4428 return ExprError(); 4429 if (SubExpr.get() == PE->getSubExpr()) 4430 return Owned(E); 4431 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.take()); 4432 } 4433 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 4434 if (BO->getOpcode() == BO_Comma) { 4435 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); 4436 if (RHS.isInvalid()) 4437 return ExprError(); 4438 if (RHS.get() == BO->getRHS()) 4439 return Owned(E); 4440 return Owned(new (Context) BinaryOperator(BO->getLHS(), RHS.take(), 4441 BO_Comma, BO->getType(), 4442 BO->getValueKind(), 4443 BO->getObjectKind(), 4444 BO->getOperatorLoc())); 4445 } 4446 } 4447 4448 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E); 4449 if (TopBind) 4450 E = TopBind->getSubExpr(); 4451 4452 // Disable the special decltype handling now. 4453 Rec.IsDecltype = false; 4454 4455 // Perform the semantic checks we delayed until this point. 4456 CallExpr *TopCall = dyn_cast<CallExpr>(E); 4457 for (unsigned I = 0, N = Rec.DelayedDecltypeCalls.size(); I != N; ++I) { 4458 CallExpr *Call = Rec.DelayedDecltypeCalls[I]; 4459 if (Call == TopCall) 4460 continue; 4461 4462 if (CheckCallReturnType(Call->getCallReturnType(), 4463 Call->getSourceRange().getBegin(), 4464 Call, Call->getDirectCallee())) 4465 return ExprError(); 4466 } 4467 4468 // Now all relevant types are complete, check the destructors are accessible 4469 // and non-deleted, and annotate them on the temporaries. 4470 for (unsigned I = 0, N = Rec.DelayedDecltypeBinds.size(); I != N; ++I) { 4471 CXXBindTemporaryExpr *Bind = Rec.DelayedDecltypeBinds[I]; 4472 if (Bind == TopBind) 4473 continue; 4474 4475 CXXTemporary *Temp = Bind->getTemporary(); 4476 4477 CXXRecordDecl *RD = 4478 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 4479 CXXDestructorDecl *Destructor = LookupDestructor(RD); 4480 Temp->setDestructor(Destructor); 4481 4482 MarkFunctionReferenced(E->getExprLoc(), Destructor); 4483 CheckDestructorAccess(E->getExprLoc(), Destructor, 4484 PDiag(diag::err_access_dtor_temp) 4485 << E->getType()); 4486 DiagnoseUseOfDecl(Destructor, E->getExprLoc()); 4487 4488 // We need a cleanup, but we don't need to remember the temporary. 4489 ExprNeedsCleanups = true; 4490 } 4491 4492 // Possibly strip off the top CXXBindTemporaryExpr. 4493 return Owned(E); 4494} 4495 4496ExprResult 4497Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, SourceLocation OpLoc, 4498 tok::TokenKind OpKind, ParsedType &ObjectType, 4499 bool &MayBePseudoDestructor) { 4500 // Since this might be a postfix expression, get rid of ParenListExprs. 4501 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 4502 if (Result.isInvalid()) return ExprError(); 4503 Base = Result.get(); 4504 4505 Result = CheckPlaceholderExpr(Base); 4506 if (Result.isInvalid()) return ExprError(); 4507 Base = Result.take(); 4508 4509 QualType BaseType = Base->getType(); 4510 MayBePseudoDestructor = false; 4511 if (BaseType->isDependentType()) { 4512 // If we have a pointer to a dependent type and are using the -> operator, 4513 // the object type is the type that the pointer points to. We might still 4514 // have enough information about that type to do something useful. 4515 if (OpKind == tok::arrow) 4516 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) 4517 BaseType = Ptr->getPointeeType(); 4518 4519 ObjectType = ParsedType::make(BaseType); 4520 MayBePseudoDestructor = true; 4521 return Owned(Base); 4522 } 4523 4524 // C++ [over.match.oper]p8: 4525 // [...] When operator->returns, the operator-> is applied to the value 4526 // returned, with the original second operand. 4527 if (OpKind == tok::arrow) { 4528 // The set of types we've considered so far. 4529 llvm::SmallPtrSet<CanQualType,8> CTypes; 4530 SmallVector<SourceLocation, 8> Locations; 4531 CTypes.insert(Context.getCanonicalType(BaseType)); 4532 4533 while (BaseType->isRecordType()) { 4534 Result = BuildOverloadedArrowExpr(S, Base, OpLoc); 4535 if (Result.isInvalid()) 4536 return ExprError(); 4537 Base = Result.get(); 4538 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base)) 4539 Locations.push_back(OpCall->getDirectCallee()->getLocation()); 4540 BaseType = Base->getType(); 4541 CanQualType CBaseType = Context.getCanonicalType(BaseType); 4542 if (!CTypes.insert(CBaseType)) { 4543 Diag(OpLoc, diag::err_operator_arrow_circular); 4544 for (unsigned i = 0; i < Locations.size(); i++) 4545 Diag(Locations[i], diag::note_declared_at); 4546 return ExprError(); 4547 } 4548 } 4549 4550 if (BaseType->isPointerType() || BaseType->isObjCObjectPointerType()) 4551 BaseType = BaseType->getPointeeType(); 4552 } 4553 4554 // Objective-C properties allow "." access on Objective-C pointer types, 4555 // so adjust the base type to the object type itself. 4556 if (BaseType->isObjCObjectPointerType()) 4557 BaseType = BaseType->getPointeeType(); 4558 4559 // C++ [basic.lookup.classref]p2: 4560 // [...] If the type of the object expression is of pointer to scalar 4561 // type, the unqualified-id is looked up in the context of the complete 4562 // postfix-expression. 4563 // 4564 // This also indicates that we could be parsing a pseudo-destructor-name. 4565 // Note that Objective-C class and object types can be pseudo-destructor 4566 // expressions or normal member (ivar or property) access expressions. 4567 if (BaseType->isObjCObjectOrInterfaceType()) { 4568 MayBePseudoDestructor = true; 4569 } else if (!BaseType->isRecordType()) { 4570 ObjectType = ParsedType(); 4571 MayBePseudoDestructor = true; 4572 return Owned(Base); 4573 } 4574 4575 // The object type must be complete (or dependent). 4576 if (!BaseType->isDependentType() && 4577 RequireCompleteType(OpLoc, BaseType, 4578 PDiag(diag::err_incomplete_member_access))) 4579 return ExprError(); 4580 4581 // C++ [basic.lookup.classref]p2: 4582 // If the id-expression in a class member access (5.2.5) is an 4583 // unqualified-id, and the type of the object expression is of a class 4584 // type C (or of pointer to a class type C), the unqualified-id is looked 4585 // up in the scope of class C. [...] 4586 ObjectType = ParsedType::make(BaseType); 4587 return move(Base); 4588} 4589 4590ExprResult Sema::DiagnoseDtorReference(SourceLocation NameLoc, 4591 Expr *MemExpr) { 4592 SourceLocation ExpectedLParenLoc = PP.getLocForEndOfToken(NameLoc); 4593 Diag(MemExpr->getLocStart(), diag::err_dtor_expr_without_call) 4594 << isa<CXXPseudoDestructorExpr>(MemExpr) 4595 << FixItHint::CreateInsertion(ExpectedLParenLoc, "()"); 4596 4597 return ActOnCallExpr(/*Scope*/ 0, 4598 MemExpr, 4599 /*LPLoc*/ ExpectedLParenLoc, 4600 MultiExprArg(), 4601 /*RPLoc*/ ExpectedLParenLoc); 4602} 4603 4604static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base, 4605 tok::TokenKind& OpKind, SourceLocation OpLoc) { 4606 if (Base->hasPlaceholderType()) { 4607 ExprResult result = S.CheckPlaceholderExpr(Base); 4608 if (result.isInvalid()) return true; 4609 Base = result.take(); 4610 } 4611 ObjectType = Base->getType(); 4612 4613 // C++ [expr.pseudo]p2: 4614 // The left-hand side of the dot operator shall be of scalar type. The 4615 // left-hand side of the arrow operator shall be of pointer to scalar type. 4616 // This scalar type is the object type. 4617 // Note that this is rather different from the normal handling for the 4618 // arrow operator. 4619 if (OpKind == tok::arrow) { 4620 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) { 4621 ObjectType = Ptr->getPointeeType(); 4622 } else if (!Base->isTypeDependent()) { 4623 // The user wrote "p->" when she probably meant "p."; fix it. 4624 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 4625 << ObjectType << true 4626 << FixItHint::CreateReplacement(OpLoc, "."); 4627 if (S.isSFINAEContext()) 4628 return true; 4629 4630 OpKind = tok::period; 4631 } 4632 } 4633 4634 return false; 4635} 4636 4637ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, 4638 SourceLocation OpLoc, 4639 tok::TokenKind OpKind, 4640 const CXXScopeSpec &SS, 4641 TypeSourceInfo *ScopeTypeInfo, 4642 SourceLocation CCLoc, 4643 SourceLocation TildeLoc, 4644 PseudoDestructorTypeStorage Destructed, 4645 bool HasTrailingLParen) { 4646 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); 4647 4648 QualType ObjectType; 4649 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 4650 return ExprError(); 4651 4652 if (!ObjectType->isDependentType() && !ObjectType->isScalarType()) { 4653 if (getLangOptions().MicrosoftMode && ObjectType->isVoidType()) 4654 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); 4655 else 4656 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) 4657 << ObjectType << Base->getSourceRange(); 4658 return ExprError(); 4659 } 4660 4661 // C++ [expr.pseudo]p2: 4662 // [...] The cv-unqualified versions of the object type and of the type 4663 // designated by the pseudo-destructor-name shall be the same type. 4664 if (DestructedTypeInfo) { 4665 QualType DestructedType = DestructedTypeInfo->getType(); 4666 SourceLocation DestructedTypeStart 4667 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); 4668 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { 4669 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { 4670 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) 4671 << ObjectType << DestructedType << Base->getSourceRange() 4672 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 4673 4674 // Recover by setting the destructed type to the object type. 4675 DestructedType = ObjectType; 4676 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 4677 DestructedTypeStart); 4678 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 4679 } else if (DestructedType.getObjCLifetime() != 4680 ObjectType.getObjCLifetime()) { 4681 4682 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { 4683 // Okay: just pretend that the user provided the correctly-qualified 4684 // type. 4685 } else { 4686 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) 4687 << ObjectType << DestructedType << Base->getSourceRange() 4688 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 4689 } 4690 4691 // Recover by setting the destructed type to the object type. 4692 DestructedType = ObjectType; 4693 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 4694 DestructedTypeStart); 4695 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 4696 } 4697 } 4698 } 4699 4700 // C++ [expr.pseudo]p2: 4701 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the 4702 // form 4703 // 4704 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name 4705 // 4706 // shall designate the same scalar type. 4707 if (ScopeTypeInfo) { 4708 QualType ScopeType = ScopeTypeInfo->getType(); 4709 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && 4710 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { 4711 4712 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), 4713 diag::err_pseudo_dtor_type_mismatch) 4714 << ObjectType << ScopeType << Base->getSourceRange() 4715 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); 4716 4717 ScopeType = QualType(); 4718 ScopeTypeInfo = 0; 4719 } 4720 } 4721 4722 Expr *Result 4723 = new (Context) CXXPseudoDestructorExpr(Context, Base, 4724 OpKind == tok::arrow, OpLoc, 4725 SS.getWithLocInContext(Context), 4726 ScopeTypeInfo, 4727 CCLoc, 4728 TildeLoc, 4729 Destructed); 4730 4731 if (HasTrailingLParen) 4732 return Owned(Result); 4733 4734 return DiagnoseDtorReference(Destructed.getLocation(), Result); 4735} 4736 4737ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 4738 SourceLocation OpLoc, 4739 tok::TokenKind OpKind, 4740 CXXScopeSpec &SS, 4741 UnqualifiedId &FirstTypeName, 4742 SourceLocation CCLoc, 4743 SourceLocation TildeLoc, 4744 UnqualifiedId &SecondTypeName, 4745 bool HasTrailingLParen) { 4746 assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 4747 FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) && 4748 "Invalid first type name in pseudo-destructor"); 4749 assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId || 4750 SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) && 4751 "Invalid second type name in pseudo-destructor"); 4752 4753 QualType ObjectType; 4754 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 4755 return ExprError(); 4756 4757 // Compute the object type that we should use for name lookup purposes. Only 4758 // record types and dependent types matter. 4759 ParsedType ObjectTypePtrForLookup; 4760 if (!SS.isSet()) { 4761 if (ObjectType->isRecordType()) 4762 ObjectTypePtrForLookup = ParsedType::make(ObjectType); 4763 else if (ObjectType->isDependentType()) 4764 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); 4765 } 4766 4767 // Convert the name of the type being destructed (following the ~) into a 4768 // type (with source-location information). 4769 QualType DestructedType; 4770 TypeSourceInfo *DestructedTypeInfo = 0; 4771 PseudoDestructorTypeStorage Destructed; 4772 if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) { 4773 ParsedType T = getTypeName(*SecondTypeName.Identifier, 4774 SecondTypeName.StartLocation, 4775 S, &SS, true, false, ObjectTypePtrForLookup); 4776 if (!T && 4777 ((SS.isSet() && !computeDeclContext(SS, false)) || 4778 (!SS.isSet() && ObjectType->isDependentType()))) { 4779 // The name of the type being destroyed is a dependent name, and we 4780 // couldn't find anything useful in scope. Just store the identifier and 4781 // it's location, and we'll perform (qualified) name lookup again at 4782 // template instantiation time. 4783 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, 4784 SecondTypeName.StartLocation); 4785 } else if (!T) { 4786 Diag(SecondTypeName.StartLocation, 4787 diag::err_pseudo_dtor_destructor_non_type) 4788 << SecondTypeName.Identifier << ObjectType; 4789 if (isSFINAEContext()) 4790 return ExprError(); 4791 4792 // Recover by assuming we had the right type all along. 4793 DestructedType = ObjectType; 4794 } else 4795 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); 4796 } else { 4797 // Resolve the template-id to a type. 4798 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; 4799 ASTTemplateArgsPtr TemplateArgsPtr(*this, 4800 TemplateId->getTemplateArgs(), 4801 TemplateId->NumArgs); 4802 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 4803 TemplateId->TemplateKWLoc, 4804 TemplateId->Template, 4805 TemplateId->TemplateNameLoc, 4806 TemplateId->LAngleLoc, 4807 TemplateArgsPtr, 4808 TemplateId->RAngleLoc); 4809 if (T.isInvalid() || !T.get()) { 4810 // Recover by assuming we had the right type all along. 4811 DestructedType = ObjectType; 4812 } else 4813 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); 4814 } 4815 4816 // If we've performed some kind of recovery, (re-)build the type source 4817 // information. 4818 if (!DestructedType.isNull()) { 4819 if (!DestructedTypeInfo) 4820 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, 4821 SecondTypeName.StartLocation); 4822 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 4823 } 4824 4825 // Convert the name of the scope type (the type prior to '::') into a type. 4826 TypeSourceInfo *ScopeTypeInfo = 0; 4827 QualType ScopeType; 4828 if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 4829 FirstTypeName.Identifier) { 4830 if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) { 4831 ParsedType T = getTypeName(*FirstTypeName.Identifier, 4832 FirstTypeName.StartLocation, 4833 S, &SS, true, false, ObjectTypePtrForLookup); 4834 if (!T) { 4835 Diag(FirstTypeName.StartLocation, 4836 diag::err_pseudo_dtor_destructor_non_type) 4837 << FirstTypeName.Identifier << ObjectType; 4838 4839 if (isSFINAEContext()) 4840 return ExprError(); 4841 4842 // Just drop this type. It's unnecessary anyway. 4843 ScopeType = QualType(); 4844 } else 4845 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); 4846 } else { 4847 // Resolve the template-id to a type. 4848 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; 4849 ASTTemplateArgsPtr TemplateArgsPtr(*this, 4850 TemplateId->getTemplateArgs(), 4851 TemplateId->NumArgs); 4852 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 4853 TemplateId->TemplateKWLoc, 4854 TemplateId->Template, 4855 TemplateId->TemplateNameLoc, 4856 TemplateId->LAngleLoc, 4857 TemplateArgsPtr, 4858 TemplateId->RAngleLoc); 4859 if (T.isInvalid() || !T.get()) { 4860 // Recover by dropping this type. 4861 ScopeType = QualType(); 4862 } else 4863 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); 4864 } 4865 } 4866 4867 if (!ScopeType.isNull() && !ScopeTypeInfo) 4868 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, 4869 FirstTypeName.StartLocation); 4870 4871 4872 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, 4873 ScopeTypeInfo, CCLoc, TildeLoc, 4874 Destructed, HasTrailingLParen); 4875} 4876 4877ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 4878 SourceLocation OpLoc, 4879 tok::TokenKind OpKind, 4880 SourceLocation TildeLoc, 4881 const DeclSpec& DS, 4882 bool HasTrailingLParen) { 4883 QualType ObjectType; 4884 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 4885 return ExprError(); 4886 4887 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 4888 4889 TypeLocBuilder TLB; 4890 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); 4891 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); 4892 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); 4893 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); 4894 4895 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), 4896 0, SourceLocation(), TildeLoc, 4897 Destructed, HasTrailingLParen); 4898} 4899 4900ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, 4901 CXXMethodDecl *Method, 4902 bool HadMultipleCandidates) { 4903 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/0, 4904 FoundDecl, Method); 4905 if (Exp.isInvalid()) 4906 return true; 4907 4908 MemberExpr *ME = 4909 new (Context) MemberExpr(Exp.take(), /*IsArrow=*/false, Method, 4910 SourceLocation(), Context.BoundMemberTy, 4911 VK_RValue, OK_Ordinary); 4912 if (HadMultipleCandidates) 4913 ME->setHadMultipleCandidates(true); 4914 4915 QualType ResultType = Method->getResultType(); 4916 ExprValueKind VK = Expr::getValueKindForType(ResultType); 4917 ResultType = ResultType.getNonLValueExprType(Context); 4918 4919 MarkFunctionReferenced(Exp.get()->getLocStart(), Method); 4920 CXXMemberCallExpr *CE = 4921 new (Context) CXXMemberCallExpr(Context, ME, 0, 0, ResultType, VK, 4922 Exp.get()->getLocEnd()); 4923 return CE; 4924} 4925 4926ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, 4927 SourceLocation RParen) { 4928 return Owned(new (Context) CXXNoexceptExpr(Context.BoolTy, Operand, 4929 Operand->CanThrow(Context), 4930 KeyLoc, RParen)); 4931} 4932 4933ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, 4934 Expr *Operand, SourceLocation RParen) { 4935 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); 4936} 4937 4938/// Perform the conversions required for an expression used in a 4939/// context that ignores the result. 4940ExprResult Sema::IgnoredValueConversions(Expr *E) { 4941 if (E->hasPlaceholderType()) { 4942 ExprResult result = CheckPlaceholderExpr(E); 4943 if (result.isInvalid()) return Owned(E); 4944 E = result.take(); 4945 } 4946 4947 // C99 6.3.2.1: 4948 // [Except in specific positions,] an lvalue that does not have 4949 // array type is converted to the value stored in the 4950 // designated object (and is no longer an lvalue). 4951 if (E->isRValue()) { 4952 // In C, function designators (i.e. expressions of function type) 4953 // are r-values, but we still want to do function-to-pointer decay 4954 // on them. This is both technically correct and convenient for 4955 // some clients. 4956 if (!getLangOptions().CPlusPlus && E->getType()->isFunctionType()) 4957 return DefaultFunctionArrayConversion(E); 4958 4959 return Owned(E); 4960 } 4961 4962 // Otherwise, this rule does not apply in C++, at least not for the moment. 4963 if (getLangOptions().CPlusPlus) return Owned(E); 4964 4965 // GCC seems to also exclude expressions of incomplete enum type. 4966 if (const EnumType *T = E->getType()->getAs<EnumType>()) { 4967 if (!T->getDecl()->isComplete()) { 4968 // FIXME: stupid workaround for a codegen bug! 4969 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).take(); 4970 return Owned(E); 4971 } 4972 } 4973 4974 ExprResult Res = DefaultFunctionArrayLvalueConversion(E); 4975 if (Res.isInvalid()) 4976 return Owned(E); 4977 E = Res.take(); 4978 4979 if (!E->getType()->isVoidType()) 4980 RequireCompleteType(E->getExprLoc(), E->getType(), 4981 diag::err_incomplete_type); 4982 return Owned(E); 4983} 4984 4985ExprResult Sema::ActOnFinishFullExpr(Expr *FE) { 4986 ExprResult FullExpr = Owned(FE); 4987 4988 if (!FullExpr.get()) 4989 return ExprError(); 4990 4991 if (DiagnoseUnexpandedParameterPack(FullExpr.get())) 4992 return ExprError(); 4993 4994 // Top-level message sends default to 'id' when we're in a debugger. 4995 if (getLangOptions().DebuggerCastResultToId && 4996 FullExpr.get()->getType() == Context.UnknownAnyTy && 4997 isa<ObjCMessageExpr>(FullExpr.get())) { 4998 FullExpr = forceUnknownAnyToType(FullExpr.take(), Context.getObjCIdType()); 4999 if (FullExpr.isInvalid()) 5000 return ExprError(); 5001 } 5002 5003 FullExpr = CheckPlaceholderExpr(FullExpr.take()); 5004 if (FullExpr.isInvalid()) 5005 return ExprError(); 5006 5007 FullExpr = IgnoredValueConversions(FullExpr.take()); 5008 if (FullExpr.isInvalid()) 5009 return ExprError(); 5010 5011 CheckImplicitConversions(FullExpr.get(), FullExpr.get()->getExprLoc()); 5012 return MaybeCreateExprWithCleanups(FullExpr); 5013} 5014 5015StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { 5016 if (!FullStmt) return StmtError(); 5017 5018 return MaybeCreateStmtWithCleanups(FullStmt); 5019} 5020 5021Sema::IfExistsResult 5022Sema::CheckMicrosoftIfExistsSymbol(Scope *S, 5023 CXXScopeSpec &SS, 5024 const DeclarationNameInfo &TargetNameInfo) { 5025 DeclarationName TargetName = TargetNameInfo.getName(); 5026 if (!TargetName) 5027 return IER_DoesNotExist; 5028 5029 // If the name itself is dependent, then the result is dependent. 5030 if (TargetName.isDependentName()) 5031 return IER_Dependent; 5032 5033 // Do the redeclaration lookup in the current scope. 5034 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, 5035 Sema::NotForRedeclaration); 5036 LookupParsedName(R, S, &SS); 5037 R.suppressDiagnostics(); 5038 5039 switch (R.getResultKind()) { 5040 case LookupResult::Found: 5041 case LookupResult::FoundOverloaded: 5042 case LookupResult::FoundUnresolvedValue: 5043 case LookupResult::Ambiguous: 5044 return IER_Exists; 5045 5046 case LookupResult::NotFound: 5047 return IER_DoesNotExist; 5048 5049 case LookupResult::NotFoundInCurrentInstantiation: 5050 return IER_Dependent; 5051 } 5052 5053 llvm_unreachable("Invalid LookupResult Kind!"); 5054} 5055 5056Sema::IfExistsResult 5057Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, 5058 bool IsIfExists, CXXScopeSpec &SS, 5059 UnqualifiedId &Name) { 5060 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); 5061 5062 // Check for unexpanded parameter packs. 5063 SmallVector<UnexpandedParameterPack, 4> Unexpanded; 5064 collectUnexpandedParameterPacks(SS, Unexpanded); 5065 collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded); 5066 if (!Unexpanded.empty()) { 5067 DiagnoseUnexpandedParameterPacks(KeywordLoc, 5068 IsIfExists? UPPC_IfExists 5069 : UPPC_IfNotExists, 5070 Unexpanded); 5071 return IER_Error; 5072 } 5073 5074 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); 5075} 5076